RESIST COMPOSITION, RESIST PATTERN FORMING METHOD, COMPOUND AND ACID DIFFUSION CONTROL AGENT

Abstract

A resist composition including a base material component whose solubility in a developing solution is changed by an action of an acid and a compound represented by General Formula (d0). In Formula (d0), Rf represents a fluorinated hydrocarbon group; V.sup.0 represents a hydrocarbon group which may have a substituent or a single bond; Y.sup.0 represents a divalent linking group having an oxygen atom; I represents an iodine atom; x represents an integer of 1 to 4, y represents an integer of 1 to 4; 2x+y5 is satisfied; a total number of fluorine atoms contained in x pieces of Rf's is 5 or more; M.sup.m+ represents a sulfonium cation or an iodonium cation; and m represents an integer of 1 or greater.

##STR00001##

Claims

1. A resist composition which generates an acid upon light exposure and whose solubility in a developing solution is changed by an action of the acid, the resist composition comprising: a base material component (A) whose solubility in a developing solution is changed by the action of the acid; and a compound (D0) represented by General Formula (d0), ##STR00149## wherein Rf represents a fluorinated hydrocarbon group, V.sup.0 represents a hydrocarbon group which may have a substituent or a single bond, Y.sup.0 represents a divalent linking group having an oxygen atom, I represents an iodine atom, x represents an integer of 1 to 4, y represents an integer of 1 to 4, 2x+y5 is satisfied, a total number of fluorine atoms contained in x pieces of Rf's is 5 or more, a benzene ring in the formula may have a substituent other than a group represented by (RfV.sup.0Y.sup.0) and the iodine atom, M.sup.m+ represents a sulfonium cation or an iodonium cation, and m represents an integer of 1 or greater.

2. The resist composition according to claim 1, wherein in Formula (d0), the total number of fluorine atoms contained in x pieces of Rf's is 5 or more and 11 or less.

3. The resist composition according to claim 1, wherein in Formula (d0), y represents an integer of 1 to 3.

4. The resist composition according to claim 3, wherein in Formula (d0), Rf represents a chain-like fluorinated hydrocarbon group.

5. A resist pattern formation method comprising: forming a resist film on a support using the resist composition according to claim 1; exposing the resist film to light; and developing the resist film exposed to light to form a resist pattern.

6. The resist pattern formation method according to claim 5, wherein exposing the resist film to light comprises exposing the resist film to an extreme ultraviolet (EUV) ray or an electron beam (EB).

7. A compound which is represented by General Formula (d0), ##STR00150## wherein Rf represents a fluorinated hydrocarbon group, V.sup.0 represents a hydrocarbon group which may have a substituent or a single bond, Y.sup.0 represents a divalent linking group having an oxygen atom, I represents an iodine atom, x represents an integer of 1 to 4, y represents an integer of 1 to 4, 2x+y5 is satisfied, a total number of fluorine atoms contained in x pieces of Rf's is 5 or more, a benzene ring in the formula may have a substituent other than a group represented by (RfV.sup.0Y.sup.0) and the iodine atom, M.sup.m+ represents a sulfonium cation or an iodonium cation, and m represents an integer of 1 or greater.

8. An acid diffusion control agent comprising the compound according to claim 7.

Description

DESCRIPTION OF EMBODIMENTS

[0022] In the present specification and the scope of the present claims, the term aliphatic is a relative concept used with respect to aromatic and defines a group, a compound, or the like that has no aromaticity.

[0023] The term alkyl group includes a linear, branched, or cyclic monovalent saturated hydrocarbon group unless otherwise specified. The same applies to the alkyl group in an alkoxy group.

[0024] The term alkylene group includes a linear, branched, or cyclic divalent saturated hydrocarbon group unless otherwise specified.

[0025] Examples of halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0026] The term constitutional unit indicates a monomer unit constituting a polymer compound (a resin, a polymer, or a copolymer).

[0027] The expression may have a substituent includes both a case where a hydrogen atom (H) is substituted with a monovalent group and a case where a methylene (CH.sub.2) group is substituted with a divalent group.

[0028] The term light exposure is a general concept for irradiation with radiation.

[0029] The term acid decomposable group indicates a group having acid decomposability in which at least a part of a bond in the structure of the acid decomposable group can be cleaved by the action of an acid.

[0030] Examples of the acid decomposable group whose polarity is increased by the action of an acid include groups which are decomposed by the action of an acid to generate a polar group.

[0031] Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, and a sulfo group (SO.sub.3H).

[0032] More specific examples of the acid decomposable group include a group in which the above-described polar group has been protected by an acid dissociable group (such as a group in which a hydrogen atom of the OH-containing polar group has been protected by an acid dissociable group).

[0033] Here, the term acid dissociable group indicates both a group (i) having an acid dissociation property in which a bond between the acid dissociable group and an atom adjacent to the acid dissociable group can be cleaved by the action of an acid and a group (ii) in which some bonds are cleaved by the action of an acid, a decarboxylation reaction occurs, and thus the bond between the acid dissociable group and the atom adjacent to the acid dissociable group can be cleaved.

[0034] It is necessary that the acid dissociable group that constitutes the acid decomposable group is a group which exhibits a lower polarity than that of the polar group generated by the dissociation of the acid dissociable group. Thus, in a case where the acid dissociable group is dissociated by the action of an acid, a polar group exhibiting a higher polarity than that of the acid dissociable group is generated so that the polarity is increased. As a result, the polarity of the entire base material component increases. Due to the increase in the polarity, the solubility in a developing solution is relatively changed such that the solubility is increased in a case where the developing solution is an alkali developing solution and the solubility is decreased in a case where the developing solution is an organic developing solution.

[0035] The term base material component denotes an organic compound having a film-forming ability. Organic compounds used as the base material component are classified into non-polymers and polymers. As the non-polymers, typically non-polymers having a molecular weight of 500 or greater and less than 4000 (hereinafter, referred to as low-molecular-weight compounds) are used. Hereinafter, the term resin, polymer compound, or polymer indicates a polymer having a molecular weight of 1000 or greater. As the molecular weight of the polymer, the weight-average molecular weight in terms of polystyrene according to gel permeation chromatography (GPC) is used.

[0036] The expression constitutional unit to be derived denotes a constitutional unit formed by cleavage of a multiple bond between carbon atoms, for example, an ethylenic double bond.

[0037] In acrylic acid ester, the hydrogen atom bonded to the carbon atom at the -position may be substituted with a substituent. The substituent (R.sup.x) that substitutes the hydrogen atom bonded to the carbon atom at the -position is an atom other than the hydrogen atom or a group. Further, itaconic acid diester in which the substituent (R.sup.x) has been substituted with a substituent having an ester bond or -hydroxyacryl ester in which the substituent (R.sup.x) has been substituted with a hydroxyalkyl group or a group obtained by modifying a hydroxyl group thereof can be described as acrylic acid ester. Further, the carbon atom at the -position of acrylic acid ester indicates the carbon atom to which the carbonyl group of acrylic acid is bonded, unless otherwise specified.

[0038] Hereinafter, acrylic acid ester in which the hydrogen atom bonded to the carbon atom at the -position has been substituted with a substituent is also referred to as -substituted acrylic acid ester.

[0039] The concept derivative includes those obtained by substituting a hydrogen atom at the -position of a target compound with another substituent such as an alkyl group or a halogenated alkyl group, and derivatives thereof. Examples of the derivatives thereof include those obtained by substituting a hydrogen atom of a hydroxyl group of a target compound, in which the hydrogen atom at the -position may be substituted with a substituent, with an organic group, and those obtained by bonding a substituent other than a hydroxyl group to a target compound in which the hydrogen atom at the -position may be substituted with a substituent. Further, the -position denotes the first carbon atom adjacent to a functional group unless otherwise specified.

[0040] Examples of the substituent that substitutes a hydrogen atom at the -position of hydroxystyrene include the same groups as those for Ray, such as an alkyl group and a halogenated alkyl group.

[0041] In the present specification and the scope of the present claims, asymmetric carbons may be present and enantiomers or diastereomers may be present depending on the structures of the chemical formulae. In this case, these isomers are represented by one chemical formula. These isomers may be used alone or in the form of a mixture.

(Resist Composition)

[0042] The resist composition according to the first aspect of the present invention is a resist composition that generates an acid upon light exposure and whose solubility in a developing solution is changed by the action of the acid.

[0043] According to one embodiment, such a resist composition contains a base material component (A) (hereinafter, also referred to as component (A)) whose solubility in a developing solution is changed by the action of the acid, and a base component (hereinafter, also referred to as component (D)) that traps an acid generated upon light exposure (that is, controls the diffusion of the acid). In the resist composition according to the present embodiment, a compound (D0) represented by General Formula (d0) is used as the component (D).

[0044] In the resist composition according to the present embodiment, the component (A) may generate an acid upon light exposure, or a blended component that is blended separately from the component (A) may generate an acid upon light exposure.

[0045] Specifically, the resist composition according to the present embodiment may (1) further contain an acid generator component (B) (hereinafter, referred to as component (B)) that generates an acid upon light exposure; (2) have a component (A) that generates an acid upon light exposure; and (3) have a component (A) that generates an acid upon light exposure and further contains component (B).

[0046] That is, in the cases of (2) and (3) described above, the component (A) is base material component which generates an acid upon light exposure and whose solubility in a developing solution is changed by the action of the acid. In a case where the component (A) is a base material component which generates an acid upon light exposure and whose solubility in a developing solution is changed by the action of the acid, it is preferable that the component (A1) described below is a resin which generates an acid upon light exposure and whose solubility in a developing solution is changed by the action of the acid. As such a resin, a polymer compound having a constitutional unit that generates an acid upon light exposure can be used. As the constitutional unit that generates an acid upon light exposure, those which have been known can be used.

[0047] Among the examples, it is preferable that the resist composition according to the present embodiment corresponds to the case (1). That is, it is preferable that the resist composition according to the present embodiment contains the component (A), the compound (D0), and the component (B).

[0048] In a case where a resist film is formed using the resist composition according to the present embodiment and the formed resist film is subjected to selective exposure, for example, an acid is generated from the component (B) at exposed portions of the resist film, and the solubility of the component (A) in a developing solution is changed by the action of the acid, whereas the solubility of the component (A) in a developing solution is not changed at unexposed portions of the resist film, and thus a difference in solubility in the developing solution occurs between the exposed portions and the unexposed portions of the resist film. Therefore, in a case where the resist film is developed, the exposed portion of the resist film is dissolved and removed to form a positive-tone resist pattern in a case where the resist composition is of a positive-tone, whereas the unexposed portion of the resist film is dissolved and removed to form a negative-tone resist pattern in a case where the resist composition is of a negative tone.

[0049] The resist composition of the present embodiment may be a positive-tone resist composition or a negative-tone resist composition. Further, in the formation of a resist pattern, the resist composition according to the present embodiment may be applied to an alkali developing process using an alkali developing solution in the developing treatment, or a solvent developing process using a developing solution containing an organic solvent (organic developing solution) in the developing treatment.

[0050] In the resist composition according to the present embodiment, it is preferable that the component (A) has a resin component (A1) whose solubility in a developing solution is changed by the action of an acid (hereinafter, also referred to as component (A1)). Since the polarity of the base material component before and after the light exposure is changed by using the component (A1), a satisfactory development contrast can be obtained not only in an alkali developing process but also in a solvent developing process.

[0051] As the component (A), at least one of other polymer compounds or low-molecular-weight compounds may be used in combination with the component (A1).

[0052] In the resist composition according to the present embodiment, the component (A) may be used alone or in combination of two or more kinds thereof.

In Regard to Component (A1)

[0053] The component (A1) is a resin component whose solubility in a developing solution is changed by the action of an acid.

[0054] As the component (A1), those having a constitutional unit (a1) containing an acid decomposable group whose polarity is increased by the action of an acid are preferable. Further, the component (A1) may have other constitutional units as necessary in addition to the constitutional unit (a1).

[0055] Examples of the other constitutional units include a constitutional unit (a10) represented by General Formula (a10-1), a constitutional unit (a2) containing a lactone-containing cyclic group, and a constitutional unit (a8) derived from a compound represented by General Formula (a8-1).

In Regard to Constitutional Unit (a1):

[0056] The constitutional unit (a1) is a constitutional unit that contains an acid decomposable group whose polarity is increased due to the action of an acid.

[0057] Examples of the acid decomposable group include a group in which a polar group is protected by an acid dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected by an acid dissociable group).

[0058] Examples of the acid dissociable group are the same as those which have been suggested as the acid dissociable groups of the base resin for a chemically amplified resist composition.

[0059] Specific examples of the acid dissociable group of the base resin suggested for a chemically amplified resist composition include acetal type acid dissociable group, tertiary alkyl ester type acid dissociable group, tertiary alkyloxycarbonyl acid dissociable group, and secondary alkyl ester type acid dissociable group described below.

Acetal Type Acid Dissociable Group:

[0060] Examples of the acid dissociable group that protects a carboxy group or a hydroxyl group in the polar groups include an acid dissociable group represented by General Formula (a1-r-1) (hereinafter, also referred to as acetal type acid dissociable group).

##STR00004##

[0061] [In the formula, Ra.sup.1 and Ra.sup.2 represent a hydrogen atom or an alkyl group. Ra.sup.3 represents a hydrocarbon group, and Ra.sup.3 may be bonded to any of Ra.sup.1 and Ra.sup.2 to form a ring.]

[0062] In Formula (a1-r-1), it is preferable that at least one of Ra.sup.1 and Ra.sup.2 represents a hydrogen atom and more preferable that both Ra.sup.1 and Ra.sup.2 represent a hydrogen atom.

[0063] In a case where Ra.sup.1 or Ra.sup.2 represents an alkyl group, examples of the alkyl group include the same alkyl groups described as the substituent which may be bonded to the carbon atom at the -position in the description on -substituted acrylic acid ester. Among these, an alkyl group having 1 to 5 carbon atoms is preferable. Specific preferred examples thereof include linear or branched alkyl groups. More specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. Among these, a methyl group or an ethyl group is more preferable, and a methyl group is particularly preferable.

[0064] In Formula (a1-r-1), examples of the hydrocarbon group as Ra.sup.3 include a linear or branched alkyl group and a cyclic hydrocarbon group.

[0065] The linear alkyl group has preferably 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and still more preferably 1 or 2 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

[0066] The branched alkyl group has preferably 3 to 10 carbon atoms and more preferably 3 to 5 carbon atoms. Specific examples thereof include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group. Among these, an isopropyl group is preferable.

[0067] In a case where Ra.sup.3 represents a cyclic hydrocarbon group, the hydrocarbon group may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group and may be a polycyclic group or a monocyclic group.

[0068] The alicyclic hydrocarbon group which is a monocyclic group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane has preferably 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane.

[0069] The alicyclic hydrocarbon group which is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane. The polycycloalkane preferably has 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0070] In a case where the cyclic hydrocarbon group as Ra.sup.3 becomes an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.

[0071] The aromatic ring is not particularly limited as long as the aromatic ring is a cyclic conjugated system having (4n+2) electrons and may be monocyclic or polycyclic. The aromatic ring has preferably 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms.

[0072] Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocyclic rings in which some carbon atoms constituting the above-described aromatic hydrocarbon rings have been substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocyclic rings include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring.

[0073] Specific examples of the aromatic hydrocarbon group as Ra.sup.3 include a group in which one hydrogen atom has been removed from the above-described aromatic hydrocarbon ring or aromatic heterocyclic ring (such as an aryl group or a heteroaryl group); a group in which one hydrogen atom has been removed from an aromatic compound having two or more aromatic rings (such as biphenyl or fluorene); and a group in which one hydrogen atom of the above-described aromatic hydrocarbon ring or aromatic heterocyclic ring has been substituted with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms in the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocyclic ring is preferably in a range of 1 to 4, more preferably 1 or 2, and particularly preferably 1.

[0074] The cyclic hydrocarbon group as Ra.sup.3 may have a substituent. Examples of the substituent include R.sup.P1, R.sup.P2OR.sup.P1, R.sup.P2COR.sup.P1, R.sup.P2COOR.sup.P1, R.sup.P2OCOR.sup.P1, R.sup.P2OH, R.sup.P2CN, and R.sup.P2COOH (hereinafter, these substituents will also be collectively referred to as Ra.sup.x5).

[0075] Here, R.sup.P1 represents a chain-like monovalent saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Further, R.sup.P2 represents a single bond, a chain-like divalent saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. Some or all hydrogen atoms in the chain-like saturated hydrocarbon group, the aliphatic cyclic saturated hydrocarbon group, and the aromatic hydrocarbon group as R.sup.P1 and R.sup.P2 may be substituted with fluorine atoms. The aliphatic cyclic hydrocarbon group may have one or more of one kind of substituents or one or more of each of plural kinds of the substituents.

[0076] Examples of the chain-like monovalent saturated hydrocarbon group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group.

[0077] Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include a monocyclic aliphatic saturated hydrocarbon group such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, or a cyclododecyl group; and a polycyclic aliphatic saturated hydrocarbon group such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7] decanyl group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group, or an adamantyl group.

[0078] Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include a group formed by removing one hydrogen atom from an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, or phenanthrene.

[0079] In a case where Ra.sup.3 is bonded to any of Ra.sup.1 and Ra.sup.2 to form a ring, the cyclic group is preferably a 4- to 7-membered ring and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

Tertiary Alkyl Ester Type Acid Dissociable Group:

[0080] Examples of the acid dissociable group that protects a carboxy group among the polar groups include an acid dissociable group represented by General Formula (a1-r-2).

[0081] Among examples of the acid dissociable group represented by Formula (a1-r-2), hereinafter, a group formed of an alkyl group will also be referred to as tertiary alkyl ester type acid dissociable group for convenience.

##STR00005##

[0082] [In the formula, Ra.sup.4 to Ra.sup.6 each represent a hydrocarbon group, and Ra.sup.5 and Ra.sup.6 may be bonded to each other to form a ring.]

[0083] Examples of the hydrocarbon group as Ra.sup.4 include a linear or branched alkyl group, a chain-like or cyclic alkenyl group, a chain-like alkynyl group, and a cyclic hydrocarbon group.

[0084] Examples of the linear or branched alkyl group and the cyclic hydrocarbon group (an alicyclic hydrocarbon group which is a monocyclic group, an alicyclic hydrocarbon group which is a polycyclic group, or an aromatic hydrocarbon group) as Ra.sup.4 include the same groups as those for Ra.sup.3.

[0085] As the chain-like or cyclic alkenyl group as Ra.sup.4, an alkenyl group having 2 to carbon atoms is preferable.

[0086] Examples of the hydrocarbon group as Ra.sup.5 or Ra.sup.6 include the same groups as those for Ra.sup.3.

[0087] In a case where Ra.sup.5 and Ra.sup.6 are bonded to each other to form a ring, suitable examples thereof include a group represented by General Formula (a1-r2-1), a group represented by General Formula (a1-r2-2), and a group represented by General Formula (a1-r2-3).

[0088] Meanwhile, in a case where Ra.sup.4 to Ra.sup.6 represent an independent hydrocarbon group without being bonded to each other, suitable examples thereof include a group represented by General Formula (a1-r2-4).

##STR00006##

[0089] [In Formula (a1-r2-1), Ra.sup.10 represents a linear or branched alkyl group having 1 to 12 carbon atoms, in which a part thereof may be substituted with a halogen atom or a heteroatom-containing group. Ra.sup.11 represents a group that forms an aliphatic cyclic group with the carbon atom to which Ra.sup.10 has been bonded. In Formula (a1-r2-2), Ya represents a carbon atom. Xa represents a group that forms a cyclic hydrocarbon group with Ya. Some or all hydrogen atoms in this cyclic hydrocarbon group may be substituted. Ra.sup.101 to Ra.sup.103 each independently represent a hydrogen atom, a chain-like monovalent saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all hydrogen atoms in the chain-like saturated hydrocarbon group and the aliphatic cyclic saturated hydrocarbon group may be substituted. Two or more of Ra.sup.101 to Ra.sup.103 may be bonded to each other to form a cyclic structure. In Formula (a1-r2-3). Yaa represents a carbon atom. Xaa represents a group that forms an aliphatic cyclic group with Yaa. Ra.sup.104 represents an aromatic hydrocarbon group which may have a substituent. In Formula (a1-r2-4), Ra.sup.12 and Ra.sup.13 each independently represent a chain-like monovalent saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all hydrogen atoms contained in the chain-like saturated hydrocarbon group may be substituted. Ra.sup.14 represents a hydrocarbon group which may have a substituent. * represents a bonding site (the same applies hereinafter).]

[0090] In Formula (a1-r2-1), Ra.sup.10 represents a linear or branched alkyl group having 1 to 12 carbon atoms, in which a part thereof may be substituted with a halogen atom or a heteroatom-containing group.

[0091] The linear alkyl group as Ra.sup.10 has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms.

[0092] Examples of the branched alkyl group as Ra.sup.10 include the same groups as those for Ra.sup.3 described above.

[0093] The alkyl group in Ra.sup.10 may be partially substituted with a halogen atom or a heteroatom-containing group. For example, some hydrogen atoms constituting the alkyl group may be substituted with a halogen atom or a heteroatom-containing group. Further, some carbon atoms (methylene group or the like) constituting the alkyl group may be substituted with a heteroatom-containing group.

[0094] Examples of the heteroatoms here include an oxygen atom, a nitrogen atom, and a sulfur atom. Examples of the heteroatom-containing group include (O), C(O)O, OC(O), C(O), OC(O)O, C(O)NH, NH, S, S(O).sub.2, and S(O).sub.2O.

[0095] In Formula (a1-r2-1), preferred examples of Ra.sup.11 (an aliphatic cyclic group that is formed together with a carbon atom to which Ra.sup.10 is bonded) include the groups described as the alicyclic hydrocarbon group (alicyclic hydrocarbon group) which is a monocyclic group or a polycyclic group as Ra.sup.3 in Formula (a1-r-1). Among these, it is preferably a monocyclic alicyclic hydrocarbon group, and specifically, it is more preferably a cyclopentyl group or a cyclohexyl group.

[0096] In Formula (a1-r2-2), examples of the cyclic hydrocarbon group that is formed by Xa together with Ya include a group in which one or more hydrogen atoms have been further removed from the cyclic monovalent hydrocarbon group (alicyclic hydrocarbon group) as Ra.sup.3 in Formula (a1-r-1).

[0097] The cyclic hydrocarbon group that is formed by Xa together with Ya may have a substituent. Examples of the substituent include those which are the same as the substituents which may be included in the cyclic hydrocarbon group as Ra.sup.3.

[0098] In Formula (a1-r2-2), examples of the chain-like monovalent saturated hydrocarbon group having 1 to 10 carbon atoms as Ra.sup.101 to Ra.sup.103 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a decyl group.

[0099] Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms as Ra.sup.101 to Ra.sup.103 include a monocyclic aliphatic saturated hydrocarbon group such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, or a cyclododecyl group; and a polycyclic aliphatic saturated hydrocarbon group such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7] decanyl group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group, or an adamantyl group.

[0100] From the viewpoint of ease of synthesis, Ra.sup.101 to Ra.sup.103 represent preferably a hydrogen atom or a chain-like monovalent saturated hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrogen atom, a methyl group, or an ethyl group, and particularly preferably a hydrogen atom.

[0101] Examples of the substituent included in the chain-like saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group represented by Ra.sup.101 to Ra.sup.103 are the same groups as those for Ra.sup.x5.

[0102] Examples of the group having a carbon-carbon double bond generated by two or more of Ra.sup.101 to Ra.sup.103 being bonded to each other to form a cyclic structure include a cyclopentenyl group, a cyclohexenyl group, a methylcyclopentenyl group, a methylcyclohexenyl group, a cyclopentylidenethenyl group, and a cyclohexylidenethenyl group. Among these, from the viewpoint of ease of synthesis, a cyclopentenyl group, a cyclohexenyl group, or a cyclopentylidenethenyl group is preferable.

[0103] In Formula (a1-r2-3), as the aliphatic cyclic group that is formed by Xaa together with Yaa, the group described as the alicyclic hydrocarbon group which is a monocyclic group or a polycyclic group as Ra.sup.3 in Formula (a1-r-1) is preferable.

[0104] In Formula (a1-r2-3), examples of the aromatic hydrocarbon group as Ra.sup.104 include a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. Among the examples, Ra.sup.104 represents preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene, or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from benzene or naphthalene, and most preferably a group in which one or more hydrogen atoms have been removed from benzene.

[0105] Examples of the substituent which may be included in Ra.sup.104 in Formula (a1-r2-3) include a methyl group, an ethyl group, a propyl group, a hydroxyl group, a carboxyl group, a halogen atom, an alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group), and an alkyloxycarbonyl group.

[0106] In Formula (a1-r2-4). Ra.sup.12 and Ra.sup.13 each independently represent a chain-like monovalent saturated hydrocarbon group having 1 to 10 carbon atoms. Examples of the chain-like monovalent saturated hydrocarbon group having 1 to 10 carbon atoms as Ra.sup.12 and Ra.sup.13 include the same one as the chain-like monovalent saturated hydrocarbon group having 1 to 10 carbon atoms as Ra.sup.101 to Ra.sup.103 as described above. Some or all hydrogen atoms contained in the chain-like saturated hydrocarbon group may be substituted.

[0107] Ra.sup.12 and Ra.sup.13 represent preferably an alkyl group having 1 to 5 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, still more preferably a methyl group or an ethyl group, and particularly preferably a methyl group.

[0108] In a case where the chain-like saturated hydrocarbon group represented by Ra.sup.12 and Ra.sup.13 is substituted, examples of the substituent include the same groups as those for Ra.sup.x5 described above.

[0109] In Formula (a1-r2-4), Ra.sup.14 represents a hydrocarbon group which may have a substituent. Examples of the hydrocarbon group as Ra.sup.14 include a linear or branched alkyl group and a cyclic hydrocarbon group.

[0110] The linear alkyl group as Ra.sup.14 has preferably 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and still more preferably 1 or 2 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

[0111] The branched alkyl group as Ra 14 has preferably 3 to 10 carbon atoms and more preferably 3 to 5 carbon atoms. Specific examples thereof include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, and a 2,2-dimethylbutyl group. Among these, an isopropyl group is preferable.

[0112] In a case where Ra 4 represents a cyclic hydrocarbon group, the hydrocarbon group may be an alicyclic hydrocarbon group or an aromatic hydrocarbon group and may be a polycyclic group or a monocyclic group.

[0113] The alicyclic hydrocarbon group which is a monocyclic group is preferably a group in which one hydrogen atom has been removed from a monocycloalkane. The monocycloalkane has preferably 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane.

[0114] The alicyclic hydrocarbon group which is a polycyclic group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane. The polycycloalkane preferably has 7 to 12 carbon atoms, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0115] Examples of the aromatic hydrocarbon group as Ra.sup.14 include the same groups as those for the aromatic hydrocarbon group as Ra.sup.104. Among these, Ra.sup.14 represents preferably a group in which one or more hydrogen atoms have been removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, anthracene, or phenanthrene, still more preferably a group in which one or more hydrogen atoms have been removed from benzene, naphthalene, or anthracene, particularly preferably a group in which one or more hydrogen atoms have been removed from naphthalene or anthracene, and most preferably a group in which one or more hydrogen atoms have been removed from naphthalene.

[0116] Examples of the substituent which may be included in Ra.sup.14 include the same groups as those for the substituent which may be included in Ra.sup.104.

[0117] In a case where Ra.sup.14 in Formula (a1-r2-4) represents a naphthyl group, the position bonded to the tertiary carbon atom in Formula (a1-r2-4) may be any of the 1-position or the 2-position of the naphthyl group.

[0118] In a case where Ra.sup.14 in Formula (a1-r2-4) represents an anthryl group, the position bonded to the tertiary carbon atom in Formula (a1-r2-4) may be any of the 1-position, the 2-position, or the 9-position of the anthryl group.

[0119] Specific examples of the group represented by Formula (a1-r2-1) are shown below.

##STR00007## ##STR00008## ##STR00009## ##STR00010## ##STR00011##

[0120] Specific examples of the group represented by Formula (a1-r2-2) are shown below.

##STR00012## ##STR00013## ##STR00014## ##STR00015##

[0121] Specific examples of the group represented by Formula (a1-r2-3) are shown below.

##STR00016## ##STR00017##

[0122] Specific examples of the group represented by Formula (a1-12-4) are shown below.

##STR00018## ##STR00019## ##STR00020##

Tertiary Alkyloxycarbonyl Acid Dissociable Group:

[0123] Examples of the acid dissociable group that protects a hydroxyl group among the polar groups include an acid dissociable group (hereinafter, also referred to as tertiary alkyloxycarbonyl acid dissociable group for convenience) represented by General Formula (a1-r-3).

##STR00021##

[0124] [In the formula, Ra.sup.7 to Ra.sup.9 each represent an alkyl group.]

[0125] In Formula (a1-r-3), Ra.sup.7 to Ra.sup.9 each represent preferably an alkyl group having 1 to 5 carbon atoms and more preferably an alkyl group having 1 to 3 carbon atoms.

[0126] Further, the total number of carbon atoms in each alkyl group is preferably in a range of 3 to 7, more preferably in a range of 3 to 5, and most preferably 3 or 4.

Secondary Alkyl Ester Type Acid Dissociable Group:

[0127] Examples of the acid dissociable group that protects a carboxy group among the polar groups include an acid dissociable group represented by General Formula (a1-r-4).

##STR00022##

[0128] [In the formula, Ra.sup.10 represents a hydrocarbon group. Ra.sup.11a and Ra.sup.11b each independently represent a hydrogen atom, a halogen atom, or an alkyl group, Ra.sup.12 represents a hydrogen atom or a hydrocarbon group. Ra.sup.10 and Ra.sup.11a or Ra.sup.11b may be bonded to each other to form a ring. Ra.sup.11a or Ra.sup.11b and Ra.sup.12 may be bonded to each other to form a ring.]

[0129] Examples of the hydrocarbon group as Ra.sup.10 or Ra.sup.12 in the formula include the same groups as those for Ra.sup.3.

[0130] Examples of the alkyl group as Ra.sup.11a and Ra.sup.11b in the formula include the same groups as those for the alkyl group as Ra.sup.1.

[0131] In the formula, the hydrocarbon group as Ra.sup.10 or Ra.sup.12 and the alkyl group as Ra.sup.11a and Ra.sup.11b may have a substituent. Examples of this substituent include Ra.sup.x5 described above.

[0132] Ra.sup.10 and Ra.sup.11a or Ra.sup.11b may be bonded to each other to form a ring. The ring may be a polycyclic ring or a monocyclic ring, and may be an alicyclic ring or an aromatic ring.

[0133] The alicyclic ring and the aromatic ring may have a heteroatom.

[0134] Among the examples described above, as the ring formed by Ra.sup.10 and Ra.sup.11a or Ra.sup.11b being bonded to each other, monocycloalkene, a ring in which some carbon atoms of monocycloalkene are substituted with heteroatoms (such as an oxygen atom and a sulfur atom), or monocycloalkadiene is preferable, cycloalkene having 3 to 6 carbon atoms is preferable, and cyclopentene or cyclohexene is preferable.

[0135] The ring formed by Ra.sup.10 and Ra.sup.11a or Ra.sup.11b being bonded to each other may be a condensed ring. Specific examples of the condensed ring include indane.

[0136] The ring formed by Ra.sup.10 and Ra.sup.11a or Ra.sup.11b being bonded to each other may have a substituent. Examples of this substituent include Ra.sup.x5 described above.

[0137] Ra.sup.11a or Ra.sup.11b and Ra.sup.12 may be bonded to each other to form a ring, and examples of the ring include the same rings as those formed by Ra.sup.10 and Ra.sup.11a or Ra.sup.11b being bonded to each other.

[0138] Specific examples of the group represented by Formula (a1-r-4) are shown below.

##STR00023##

[0139] Examples of the constitutional unit (a1) include a constitutional unit derived from acrylic acid ester in which the hydrogen atom bonded to the carbon atom at the -position may be substituted with a substituent; a constitutional unit derived from acrylamide; a constitutional unit in which at least some hydrogen atoms in a hydroxyl group of a constitutional unit derived from hydroxystyrene or a hydroxystyrene derivative are protected by a substituent containing the acid decomposable group; and a constitutional unit in which at least some hydrogen atoms in C(O)OH of a constitutional unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative are protected by a substituent containing the acid decomposable group.

[0140] Among the examples, as the constitutional unit (a1), a constitutional unit derived from acrylic acid ester in which the hydrogen atom bonded to the carbon atom at the -position may be substituted with a substituent is preferable.

[0141] Specific preferred examples of such a constitutional unit (a1) include a constitutional unit represented by General Formula (a1-1), (a1-2), or (a1-3).

##STR00024##

[0142] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. V.sup.a1 represents a divalent hydrocarbon group which may contain an ether bond. n.sub.a1 represents an integer of 0 to 2. Ra.sup.1 represents an acid dissociable group represented by General Formula (a1-r-1), (a1-r-2), or (a1-r-4). Wa.sup.1 represents an (n.sub.a2+1)-valent hydrocarbon group. n.sub.a2 represents an integer of 1 to 3. Ra.sup.2 represents an acid dissociable group represented by General Formula (a1-r-1) or (a1-r-3). Ya.sup.001 represents a single bond or a divalent linking group. Ya.sup.01 represents a single bond or a divalent linking group. Rax.sup.01 represents an acid dissociable group represented by General Formula (a1-r-1), (a1-r-2), or (a1-r-4). q represents an integer of 0 to 3. n represents an integer of 1 or more. Here, nq2+4 is satisfied.]

[0143] In Formulae (a1-1) to (a1-3), as the alkyl group having 1 to 5 carbon atoms as R, a linear or branched alkyl group having 1 to 5 carbon atoms is preferable, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all hydrogen atoms in the alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. As the halogen atom, a fluorine atom is particularly preferable.

[0144] R represents preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and most preferably a hydrogen atom or a methyl group from the viewpoint of the industrial availability.

[0145] In Formula (a1-1), the divalent hydrocarbon group as Va.sup.1 may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

[0146] The aliphatic hydrocarbon group as the divalent hydrocarbon group represented by Va.sup.1 may be saturated or unsaturated. In general, it is preferable that the aliphatic hydrocarbon group is saturated.

[0147] More specific examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group having a ring in the structure thereof.

[0148] The linear aliphatic hydrocarbon group has preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.

[0149] As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specific examples thereof include a methylene group [CH.sub.2], an ethylene group [(CH.sub.2).sub.2], a trimethylene group [(CH.sub.2).sub.3], a tetramethylene group [(CH.sub.2).sub.4], and a pentamethylene group [(CH.sub.2).sub.5].

[0150] The branched aliphatic hydrocarbon group has preferably 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms.

[0151] As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable. Specifically, alkylalkylene groups, for example, alkylmethylene groups such as CH(CH.sub.3), CH(CH.sub.2CH.sub.3), C(CH.sub.3).sub.2, C(CH.sub.3)(CH.sub.2CH.sub.3), C(CH.sub.3)(CH.sub.2CH.sub.2CH.sub.3), and C(CH.sub.2CH.sub.3).sub.2; alkylethylene groups such as CH(CH.sub.3)CH.sub.2, CH(CH.sub.3)CH(CH.sub.3), C(CH.sub.3).sub.2CH.sub.2, CH(CH.sub.2CH.sub.3)CH.sub.2, and C(CH.sub.2CH.sub.3).sub.2CH.sub.2; alkyltrimethylene groups such as CH(CH.sub.3)CH.sub.2CH.sub.2, and CH.sub.2CH(CH.sub.3)CH.sub.2; and alkyltetramethylene groups such as CH(CH.sub.3)CH.sub.2CH.sub.2CH.sub.2 and CH.sub.2CH(CH.sub.3)CH.sub.2CH.sub.2 are exemplary examples. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

[0152] Examples of the aliphatic hydrocarbon group having a ring in the structure thereof include an alicyclic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), a group in which the alicyclic hydrocarbon group is bonded to the terminal of the linear or branched aliphatic hydrocarbon group, and a group in which the alicyclic hydrocarbon group is interposed in the middle of the linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same groups as those for the linear aliphatic hydrocarbon group or the branched aliphatic hydrocarbon group.

[0153] The alicyclic hydrocarbon group has preferably 3 to 20 carbon atoms and more preferably 3 to 12 carbon atoms.

[0154] The alicyclic hydrocarbon group may be monocyclic or polycyclic. As the monocyclic alicyclic hydrocarbon group, a group in which two hydrogen atoms have been removed from a monocycloalkane is preferable. The monocycloalkane has preferably 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon group, a group in which two hydrogen atoms have been removed from a polycycloalkane is preferable. As the polycycloalkane, a group having 7 to 12 carbon atoms is preferable. Specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0155] The aromatic hydrocarbon group as the divalent hydrocarbon group represented by Va.sup.1 is a hydrocarbon group having an aromatic ring.

[0156] The aromatic hydrocarbon group has preferably 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 12 carbon atoms. Here, the number of carbon atoms in a substituent is not included in the number of carbon atoms.

[0157] Specific examples of the aromatic ring contained in the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and aromatic heterocyclic rings in which some carbon atoms constituting the above-described aromatic hydrocarbon rings have been substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocyclic rings include an oxygen atom, a sulfur atom, and a nitrogen atom.

[0158] Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms have been removed from the above-described aromatic hydrocarbon ring (an arylene group); and a group in which one hydrogen atom of a group (an aryl group) formed by removing one hydrogen atom from the aromatic hydrocarbon ring has been substituted with an alkylene group (for example, a group formed by further removing one more hydrogen atom from an aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The alkylene group (alkyl chain in the arylalkyl group) has preferably 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.

[0159] In Formula (a1-1), Ra.sup.1 represents preferably an acid dissociable group represented by General Formula (a1-r-2) or (a1-r-4) and, among these, more preferably a group represented by General Formula (a1-r2-1) or an acid dissociable group represented by General Formula (a1-r-4).

[0160] In Formula (a1-2), the (n.sub.a2+1)-valent hydrocarbon group as Wa.sup.1 may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group indicates a hydrocarbon group that has no aromaticity and may be saturated or unsaturated. In general, it is preferable that the aliphatic hydrocarbon group is saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group having a ring in the structure thereof, and a group obtained by combining the linear or branched aliphatic hydrocarbon group and the aliphatic hydrocarbon group having a ring in the structure thereof.

[0161] The valency of n.sub.a2+1 is preferably divalent, trivalent, or tetravalent and more preferably divalent or trivalent.

[0162] In Formula (a1-2), it is preferable that Ra.sup.2 represents an acid dissociable group represented by General Formula (a1-r-1).

[0163] In Formula (a1-3), the divalent linking group as Ya.sup.001 is not particularly limited, and suitable examples thereof include a divalent hydrocarbon group which may have a substituent and a divalent linking group having a heteroatom.

[0164] Among these, it is preferable that Ya.sup.001 represents an ester bond [C(O)O or OC(O)], an ether bond (O), a linear or branched alkylene group, an aromatic hydrocarbon group, a combination thereof, or a single bond. The alkylene group has preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms.

[0165] Among these, Ya.sup.001 represents more preferably a combination of an ester bond [C(O)O or OC(O)] and a linear alkylene group, or a single bond and still more preferably a single bond.

[0166] In Formula (a1-3), the divalent linking group as Ya.sup.01 is not particularly limited, and suitable examples thereof include a divalent hydrocarbon group which may have a substituent and a divalent linking group having a heteroatom.

[0167] Among these, it is preferable that Ya.sup.01 represents an ester bond [C(O)O or OC(O)], an ether bond (O), a linear or branched alkylene group, an aromatic hydrocarbon group, a combination thereof, or a single bond. Among these, Ya.sup.01 is more preferably a combination of an ester bond [C(O)O or OC(O)] and a linear alkylene group, or a single bond, and still more preferably a single bond.

[0168] In Formula (a1-3), Rax.sup.01 represents preferably an acid dissociable group represented by General Formula (a1-r-2) or (a1-r-4) and, among these, more preferably an acid dissociable group represented by General Formula (a1-r-2) and still more preferably a group represented by General Formula (a1-r2-1).

[0169] In Formula (a1-3), q represents an integer of 0 to 3. A benzene structure is formed in a case where q represents 0, a naphthalene structure is formed in a case where q represents 1, an anthracene structure is formed in a case where q represents 2, and a tetracene structure is formed in a case where q represents 3.

[0170] In Formula (a1-3), n represents an integer of 1 or greater, preferably an integer of 1 to 5, more preferably an integer of 1 to 3, and still more preferably an integer of 1 or 2.

[0171] In Formula (a1-3), nq2+4 is satisfied. For example, in a case where q represents 1 and thus a naphthalene structure is formed, all six hydrogen atoms of the naphthalene may be substituted with hydroxy groups. In addition, the substitution positions of Ya.sup.001, the -Ya.sup.01-C(O)ORa.sup.01 group, and the hydroxy group in the naphthalene are not particularly limited.

[0172] Specific examples of the constitutional unit (a1) are shown below.

[0173] In the formulae shown below, R.sup. represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

##STR00025## ##STR00026## ##STR00027## ##STR00028## ##STR00029## ##STR00030## ##STR00031## ##STR00032## ##STR00033## ##STR00034## ##STR00035## ##STR00036## ##STR00037## ##STR00038## ##STR00039## ##STR00040## ##STR00041##

##STR00042## ##STR00043##

[0174] The constitutional unit (a1) included in the component (A1) may be used alone or two or more kinds thereof.

[0175] As the constitutional unit (a1), from the viewpoint that lithography characteristics due to electron beams or EUV are likely to be further enhanced, a constitutional unit represented by Formula (a1-1) or a constitutional unit represented by Formula (a1-3) is more preferable.

[0176] In a case where the component (A1) has the constitutional unit (a1), the proportion of the constitutional unit (a1) in the component (A1) is preferably in a range of 20% to 80% by mole, more preferably in a range of 25% to 75% by mole, still more preferably in a range of 30% to 70% by mole, and particularly preferably in a range of 40% to 60% by mole with respect to the total amount (100% by mole) of all constitutional units constituting the component (A1).

[0177] In a case where the proportion of the constitutional unit (a1) is set to be greater than or equal to the lower values of the above-described preferable ranges, lithography characteristics such as sensitivity, rectangularity of a pattern shape, and roughness reduction are improved. Further, in a case where the proportion of the constitutional unit (a1) is less than or equal to the upper limits of the above-described preferable ranges, the constitutional unit (a1) and other constitutional units can be balanced, and various lithography characteristics are enhanced.

In Regard to Constitutional Unit (a10):

[0178] The constitutional unit (a10) is a constitutional unit represented by General Formula (a10-1) (here, a constitutional unit corresponding to the constitutional unit (a1) is excluded).

##STR00044##

[0179] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya.sup.x1 represents a single bond or a divalent linking group. Wa.sup.x1 represents an aromatic hydrocarbon group which may have a substituent. n.sub.ax1 represents an integer of 1 or greater.]

[0180] In the Formula (a10-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.

[0181] R represents preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and from the viewpoint of industrial availability, more preferably a hydrogen atom, a methyl group, or trifluoromethyl group, still more preferably a hydrogen atom or a methyl group, and particularly preferably a hydrogen atom.

[0182] In Formula (a10-1), Ya.sup.x1 represents a single bond or a divalent linking group. In the chemical formula, the divalent linking group as Ya.sup.x1 is not particularly limited, and suitable examples thereof include a divalent hydrocarbon group which may have a substituent and a divalent linking group having a heteroatom.

[0183] Ya.sup.x1 represents preferably a single bond, an ester bond [C(O)O or OC(O)], an ether bond (O), a linear or branched alkylene group, or a combination thereof and more preferably a single bond or an ester bond [C(O)O or OC(O)].

[0184] In Formula (a10-1), Wa.sup.x1 represents an aromatic hydrocarbon group which may have a substituent.

[0185] Examples of the aromatic hydrocarbon group as Wa.sup.x1 include a group obtained by removing (n.sub.ax1+1) hydrogen atoms from an aromatic ring which may have a substituent. The aromatic ring is not particularly limited as long as the aromatic ring is a cyclic conjugated system having (4n+2) electrons. The aromatic ring has preferably 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and an aromatic heterocyclic ring obtained by substituting some carbon atoms constituting the above-described aromatic hydrocarbon ring with a heteroatom. Examples of the heteroatom in the aromatic heterocyclic rings include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring.

[0186] Examples of the aromatic hydrocarbon group as Wa.sup.x1 also include a group obtained by removing (n.sub.ax1+1) hydrogen atoms from an aromatic compound including an aromatic ring (for example, biphenyl or fluorene) which may have two or more substituents.

[0187] Among these, Wa.sup.x1 represents preferably a group in which (n.sub.ax1+1) hydrogen atoms have been removed from benzene, naphthalene, anthracene, or biphenyl, more preferably a group in which (n.sub.ax1+1) hydrogen atoms have been removed from benzene or naphthalene, and still more preferably a group in which (n.sub.ax1+1) hydrogen atoms have been removed from benzene.

[0188] The aromatic hydrocarbon group as Wa.sup.x1 may or may not have a substituent. Examples of substituents include an alkyl group, an alkoxy group, a halogen atom, and a halogenated alkyl group. Examples of the alkyl group, the alkoxy group, the halogen atom, and the halogenated alkyl group as the substituent include the same groups as those for the substituent of the cyclic alicyclic hydrocarbon group as Ya.sup.x1. The substituent is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, still more preferably an ethyl group or a methyl group, and particularly preferably a methyl group. It is preferable that the aromatic hydrocarbon group as Wa.sup.x1 has no substituent.

[0189] In Formula (a10-1), n.sub.ax1 represents an integer of 1 or greater, preferably an integer of 1 to 10, more preferably an integer of 1 to 5, still more preferably 1, 2, or 3, and particularly preferably 1 or 2.

[0190] Specific examples of the constitutional unit (a10) represented by Formula (a10-1) are described below.

[0191] In the formulae shown below, Ra represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

##STR00045## ##STR00046## ##STR00047## ##STR00048## ##STR00049##

[0192] The constitutional unit (a10) included in the component (A1) may be used alone or two or more kinds thereof.

[0193] In a case where the component (A1) has the constitutional unit (a10), the proportion of the constitutional unit (a10) in the component (A1) is preferably in a range of 20% to 80% by mole, more preferably in a range of 25% to 75% by mole, still more preferably in a range of 30% to 70% by mole, and particularly preferably in a range of 40% to 60% by mole with respect to the total amount (100% by mole) of all constitutional units constituting the component (A1).

[0194] In a case where the proportion of the constitutional unit (a10) is set to be greater than or equal to the above-described lower limits, the sensitivity is likely to be enhanced. Meanwhile, in a case where the proportion thereof is set to be less than or equal to the upper limits, the constitutional unit (a10) and other constitutional units are likely to be balanced.

In Regard to Constitutional Unit (a2):

[0195] The component (A1) may further have a constitutional unit (a2) (here, a constitutional unit corresponding to the constitutional unit (a1) is excluded) containing a lactone-containing cyclic group.

[0196] In a case where the component (A1) is used to form a resist film, the lactone-containing cyclic group of the constitutional unit (a2) is effective for increasing the adhesiveness of the resist film to the substrate. Further, in a case where the component (A1) contains the constitutional unit (a2), the lithography characteristics and the like are enhanced, for example, due to the effects of appropriately adjusting the acid diffusion length, increasing the adhesiveness of the resist film to the substrate, appropriately adjusting the solubility during the development, and the like.

[0197] The term lactone-containing cyclic group indicates a cyclic group that has a ring (lactone ring) containing OC(O) in the ring skeleton. In a case where the lactone ring is counted as the first ring and the group contains only the lactone ring, the group is referred to as a monocyclic group. Further, in a case where the group has other ring structures, the group is referred to as a polycyclic group regardless of the structures. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.

[0198] The lactone-containing cyclic group in the constitutional unit (a2) is not particularly limited, and an optional constitutional unit can be used. Specific examples thereof include groups each represented by General Formulae (a2-r-1) to (a2-r-7).

##STR00050##

[0199] [In the formulae, Ra.sup.21's each independently represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, COOR, OC(O)R, a hydroxyalkyl group, or a cyano group, R represents a hydrogen atom, an alkyl group, or a lactone-containing cyclic group, A represents an alkylene group having 1 to 5 carbon atoms which may have an oxygen atom (O) or a sulfur atom (S), an oxygen atom, or a sulfur atom, n represents an integer of 0 to 2, and m represents 0 or 1. * represents a bonding site (the same applies hereinafter).]

[0200] In General Formulae (a2-r-1) to (a2-r-7), it is preferable that the alkyl group as Ra.sup.21 is an alkyl group having 1 to 6 carbon atoms. Further, it is preferable that the alkyl group is linear or branched. Specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a hexyl group. Among these, a methyl group or ethyl group is preferable, and a methyl group is particularly preferable.

[0201] It is preferable that the alkoxy group as Ra.sup.21 is an alkoxy group having 1 to 6 carbon atoms. Further, it is preferable that the alkoxy group is linear or branched. Specific examples of the alkoxy groups include a group formed by linking the above-described alkyl group described as the alkyl group represented by Ra.sup.21 to an oxygen atom (O).

[0202] As the halogen atom as Ra.sup.21, a fluorine atom is preferable.

[0203] Examples of the halogenated alkyl group as Ra.sup.21 include groups in which some or all hydrogen atoms in the alkyl group as Ra.sup.21 have been substituted with the halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

[0204] In COOR and OC(O)R as Ra.sup.21, each R represents a hydrogen atom, an alkyl group, or a lactone-containing cyclic group.

[0205] The alkyl group as R may be linear, branched, or cyclic and has preferably 1 to 15 carbon atoms.

[0206] In a case where R represents a linear or branched alkyl group, an alkyl group having 1 to 10 carbon atoms is preferable, an alkyl group having 1 to 5 carbon atoms is more preferable, and a methyl group or an ethyl group is particularly preferable.

[0207] In a case where R represents a cyclic alkyl group, the number of carbon atoms thereof is preferably in a range of 3 to 15, more preferably in a range of 4 to 12, and most preferably in a range of 5 to 10. Specific examples thereof include groups in which one or more hydrogen atoms have been removed from a monocycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; and groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as bicycloalkane, tricycloalkane, or tetracycloalkane. More specific examples thereof include groups in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; and groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane.

[0208] Examples of the lactone-containing cyclic group as R include the same groups as those for the groups each represented by General Formulae (a2-r-1) to (a2-r-7).

[0209] As the hydroxyalkyl group as Ra.sup.21, a hydroxyalkyl group having 1 to 6 carbon atoms is preferable, and specific examples thereof include a group in which at least one hydrogen atom in the alkyl group as Ra.sup.21 has been substituted with a hydroxyl group.

[0210] Among the examples, it is preferable that each Ra.sup.21 independently represent a hydrogen atom or a cyano group.

[0211] In General Formulae (a2-r-2), (a2-r-3) and (a2-r-5), as the alkylene group having 1 to 5 carbon atoms as A, a linear or branched alkylene group is preferable, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group. Specific examples of the alkylene groups that contain an oxygen atom or a sulfur atom include a group obtained by interposing O or S in the terminal of the alkylene group or between the carbon atoms of the alkylene group, and examples thereof include OCH.sub.2, CH.sub.2OCH.sub.2, SCH.sub.2, and CH.sub.2SCH.sub.2. A represents preferably an alkylene group having 1 to 5 carbon atoms or O, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

[0212] Specific examples of the groups each represented by General Formulae (a2-r-1) to (a2-r-7) are shown below.

##STR00051## ##STR00052## ##STR00053## ##STR00054## ##STR00055## ##STR00056##

[0213] As the constitutional unit (a2), a constitutional unit derived from acrylic acid ester in which the hydrogen atom bonded to the carbon atom at the -position may be substituted with a substituent is preferable.

[0214] It is preferable that such a constitutional unit (a2) is a constitutional unit represented by General Formula (a2-1).

##STR00057##

[0215] [In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya.sup.21 represents a single bond or a divalent linking group. La.sup.21 represents O, COO, CON(R), OCO, CONHCO, or CONHCS, and R represents a hydrogen atom or a methyl group. In a case where La.sup.21 represents O, Ya.sup.21 does not represent CO. Ra.sup.21 represents a lactone-containing cyclic group.]

[0216] In Formula (a2-1), R has the same definition as described above. R represents preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms and particularly preferably a hydrogen atom or a methyl group from the viewpoint of the industrial availability.

[0217] In Formula (a2-1), the divalent linking group as Ya.sup.21 is not particularly limited, and suitable examples thereof include a divalent hydrocarbon group which may have a substituent and a divalent linking group having a heteroatom.

[0218] It is preferable that Ya.sup.21 represents a single bond, an ester bond [C(O)O], an ether bond (O), a linear or branched alkylene group, or a combination thereof.

[0219] In Formula (a2-1), it is preferable that Ya.sup.21 represents a single bond and La.sup.21 represents COO or OCO.

[0220] In Formula (a2-1), Ra.sup.21 represents a lactone-containing cyclic group.

[0221] Suitable examples of the lactone-containing cyclic group as Ra.sup.21 include groups each represented by General Formulae (a2-r-1) to (a2-r-7).

[0222] The constitutional unit (a2) included in the component (A1) may be used alone or two or more kinds thereof.

[0223] In a case where the component (A1) has the constitutional unit (a2), the proportion of the constitutional unit (a2) is preferably 20% by mole or less, more preferably in a range of 1% to 20% by mole, still more preferably in a range of 1% to 15% by mole, and particularly preferably in a range of 1% to 10% by mole with respect to the total amount (100% by mole) of all constitutional units constituting the component (A1).

[0224] In a case where the proportion of the constitutional unit (a2) is set to be greater than or equal to the above-described preferable lower limits, the effect to be obtained by allowing the component (A1) to have the constitutional unit (a2) is sufficiently obtained by the above-described effects. Further, in a case where the proportion thereof is set to be less than or equal to the upper limits of the above-described preferable ranges, the constitutional unit (a2) and other constitutional units can be balanced, and various lithography characteristics are enhanced.

In Regard to Constitutional Unit (a8):

[0225] The constitutional unit (a8) is a constitutional unit derived from a compound represented by General Formula (a8-1).

##STR00058##

[0226] [In the formula, W.sup.2 represents a polymerizable group-containing group. Ya.sup.x2 represents a single bond or an (n.sub.ax2+1)-valent linking group. Ya.sup.x2 and W.sup.2 may form a condensed ring. R.sup.1 represents a fluorinated alkyl group having 1 to 12 carbon atoms. R.sup.2 represents an organic group having 1 to 12 carbon atoms, which may have a fluorine atom, or a hydrogen atom. R.sup.2 and Ya.sup.x2 may be bonded to each other to form a ring structure by being bonded to each other. n.sub.ax2 represents an integer of 1 to 3.]

[0227] The term polymerizable group in the polymerizable group-containing group as W.sup.2 is a group that enables a compound having the polymerizable group to be polymerized by radical polymerization or the like, and refers to a group containing multiple bonds between carbon atoms, such as an ethylenic double bond.

[0228] The polymerizable group-containing group may be a group formed of only a polymerizable group or a group formed of a polymerizable group and a group other than the polymerizable group. Examples of the group other than the polymerizable group include a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a heteroatom.

[0229] Suitable examples of the polymerizable group-containing group include a group represented by a chemical formula: C(R.sup.X11)(R.sup.X12)C(R.sup.X13)-Ya.sup.x0-.

[0230] In the chemical formula, R.sup.X11, R.sup.X12, and R.sup.X13 each represent a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Ya.sup.x0 represents a single bond or a divalent linking group.

[0231] Examples of the condensed ring formed by Ya.sup.x2 and W.sup.2 include a condensed ring formed by a polymerizable group of the W.sup.2 moiety and by Ya.sup.x2 and a condensed ring formed by a group other than the polymerizable group of the W.sup.2 moiety and by Ya.sup.x2.

[0232] The condensed ring formed by Ya.sup.x2 and W.sup.2 may have a substituent.

[0233] Specific examples of the constitutional unit (a8) are shown below.

[0234] In the following formulae, R.sup. represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

##STR00059## ##STR00060##

[0235] The constitutional unit (a8) contained in the component (A1) may be used alone or two or more kinds thereof.

[0236] In a case where the component (A1) has the constitutional unit (a8), the proportion of the constitutional unit (a8) is preferably 20% by mole or less and more preferably in a range of 0% to 10% by mole with respect to the total amount (100% by mole) of all constitutional units constituting the component (A1).

[0237] The component (A1) contained in the resist composition may be used alone or in combination of two or more kinds thereof.

[0238] In the resist composition of the present embodiment, preferred examples of the component (A1) include a polymer compound having a repeating structure of the constitutional unit (a1). Among the examples, particularly suitable examples of the component (A1) include a polymer compound having a repeating structure of the constitutional unit (a1) and the constitutional unit (a10).

[0239] More specifically, preferred examples of the component (A1) include a polymer compound having a repeating structure of a constitutional unit represented by Formula (a1-1) and the constitutional unit (a10), and a polymer compound having a repeating structure of a constitutional unit represented by Formula (a1-3) and the constitutional unit (a10). Among these, from the viewpoint of high sensitivity, a polymer compound having a repeating structure of a constitutional unit represented by Formula (a1-3) and the constitutional unit (a10) is more preferable.

[0240] The proportion of the constitutional unit (a1) in the polymer compound having a repeating structure of the constitutional unit (a1) and the constitutional unit (a10) is preferably in a range of 20% to 80% by mole, more preferably in a range of 25% to 75% by mole, still more preferably in a range of 30% to 70% by mole, and particularly preferably in a range of 40% to 60% by mole with respect to the total amount (100% by mole) of all constitutional units constituting the polymer compound.

[0241] In addition, the proportion of the constitutional unit (a10) in the polymer compound is preferably in a range of 20% to 80% by mole, more preferably in a range of 25% to 75% by mole, still more preferably in a range of 30% to 70% by mole, and particularly preferably in a range of 40% to 60% by mole with respect to the total amount (100% by mole) of all constitutional units constituting the polymer compound.

[0242] Such a component (A1) can be produced by dissolving a monomer, from which each constitutional unit is derived, in a polymerization solvent and adding a radical polymerization initiator such as azobisisobutylonitrile (AIBN) or dimethyl azobisisobutyrate (for example, V-601) to the solution so that the polymerization is carried out.

[0243] Alternatively, the component (A1) can be produced by dissolving, in a polymerization solvent, a monomer from which the constitutional unit (a1) is derived and, as necessary, a monomer from which a constitutional unit (for example, the constitutional unit (a10)) other than the constitutional unit (a1) is derived, adding thereto a radical polymerization initiator as described above to carry out polymerization, and then carrying out a deprotection reaction.

[0244] Further, a C(CF.sub.3).sub.2OH group may be introduced into the terminal of the component (A1) during the polymerization using a chain transfer agent such as HSCH.sub.2CH.sub.2CH.sub.2C(CF.sub.3).sub.2OH in combination. As described above, a copolymer into which a hydroxyalkyl group, formed by substitution of some hydrogen atoms in the alkyl group with fluorine atoms, has been introduced is effective for reducing development defects and reducing line edge roughness (LER: uneven irregularities of a line side wall).

[0245] The weight-average molecular weight (Mw) (in terms of polystyrene according to gel permeation chromatography (GPC)) of the component (A1) is not particularly limited, but is preferably in a range of 1000 to 40000, more preferably in a range of 2000 to 20000, and still more preferably in a range of 3000 to 10000.

[0246] In a case where the Mw of the component (A1) is less than or equal to the upper limits of the above-described preferable ranges, the resist composition exhibits a satisfactory solubility in a resist solvent for a resist enough to be used as a resist. On the contrary, in a case where the Mw of the component (A1) is greater than or equal to the lower limits of the above-described preferable ranges, the dry etching resistance and the cross-sectional shape of the resist pattern are satisfactory.

[0247] Further, the dispersity (Mw/Mn) of the component (A1) is not particularly limited, but is preferably in a range of 1.0 to 4.0, more preferably in a range of 1.0 to 3.0, and particularly preferably in a range of 1.0 to 2.0. Further, Mn represents the number average molecular weight.

In Regard to Component (A2)

[0248] In the resist composition of the present embodiment, a base material component (hereinafter, also referred to as component (A2)) which does not correspond to the component (A1) and whose solubility in a developing solution is changed due to the action of an acid may be used in combination as the component (A).

[0249] The component (A2) is not particularly limited and may be optionally selected from a plurality of components of the related art which have been known as base material components for a chemically amplified resist composition and used.

[0250] As the component (A2), a polymer compound or a low-molecular-weight compound may be used alone or in combination of two or more kinds thereof.

[0251] The proportion of the component (A1) in the component (A) is preferably 25% by mass or greater, more preferably 50% by mass or greater, and still more preferably 75% by mass or greater, and may be 100% by mass with respect to the total mass of the component (A). In a case where the proportion thereof is 25% by mass or greater, a resist pattern having various excellent lithography characteristics such as high sensitivity, resolution, and roughness reduction is likely to be formed.

[0252] In the resist composition of the present embodiment, the content of the component (A) may be adjusted according to the thickness and the like of the resist film intended to be formed.

[0253] In the present embodiment, the component (D) includes a compound (D0) represented by General Formula (d0) (hereinafter, also referred to as component (D0)).

[0254] The component (D0) is a component that can act as a quencher (acid diffusion control agent) which traps the acid generated in the resist composition upon light exposure.

In Regard to Component (D0)

[0255] The component (D0) is a compound represented by General Formula (d0).

##STR00061##

[0256] [In the formula, Rf represents a fluorinated hydrocarbon group. V.sup.0 represents a hydrocarbon group which may have a substituent or a single bond. Y.sup.0 represents a divalent linking group having an oxygen atom. I represents an iodine atom. x represents an integer of 1 to 4, y represents an integer of 1 to 4, and 2x+y5 is satisfied. A total number of fluorine atoms contained in x pieces of Rf's is 5 or more. A benzene ring in the formula may have a substituent other than a group represented by (RfV.sup.0Y.sup.0) and the iodine atom. M.sup.m+ represents a sulfonium cation or an iodonium cation. m represents an integer of 1 or greater.]

[0257] In Formula (d0), examples of the fluorinated hydrocarbon group as Rf include a monovalent hydrocarbon group having a fluorine atom. The monovalent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

Aliphatic Hydrocarbon Group as Rf

[0258] The aliphatic hydrocarbon group may be saturated or unsaturated but is preferably saturated. Examples of the aliphatic hydrocarbon group include a chain-like aliphatic hydrocarbon group (linear or branched aliphatic hydrocarbon group) and an aliphatic hydrocarbon group having a ring in the structure.

Linear or Branched Aliphatic Hydrocarbon Group

[0259] The linear aliphatic hydrocarbon group has preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkyl group is preferable, and specific examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group.

[0260] The branched aliphatic hydrocarbon group has preferably 3 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and particularly preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkyl group is preferable, and specific examples thereof include an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group.

[0261] The linear or branched aliphatic hydrocarbon group has at least one fluorine atom as a substituent. In the linear or branched aliphatic hydrocarbon group, it is preferable that 25% or greater of hydrogen atoms in the aliphatic hydrocarbon group are fluorinated, more preferable that 50% or greater of hydrogen atoms in the aliphatic hydrocarbon group are fluorinated, and still more preferable that 60% or greater of hydrogen atoms in the aliphatic hydrocarbon group are fluorinated. In a case where the proportion of hydrogen atoms to be fluorinated is greater than or equal to the upper limits of the above-described preferable ranges, the sensitivity and the hydrophobicity of the resist film are improved.

[0262] The linear or branched aliphatic hydrocarbon group may have a substituent other than a fluorine atom. Examples of the substituent other than a fluorine atom include a hydroxyl group and a halogen atom other than a fluorine atom.

Aliphatic Hydrocarbon Group Containing Ring in Structure Thereof

[0263] Examples of the aliphatic hydrocarbon group having a ring in the structure thereof include a cyclic aliphatic hydrocarbon group which may have a substituent having a heteroatom (excluding a fluorine atom) in the ring structure thereof (a group in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), a group in which the cyclic aliphatic hydrocarbon group is bonded to a terminal of a linear or branched aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. As the linear or branched aliphatic hydrocarbon group, the same groups as those described above are exemplary examples.

[0264] The cyclic aliphatic hydrocarbon group has preferably 3 to 20 carbon atoms and more preferably 3 to 12 carbon atoms.

[0265] The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group in which one hydrogen atom has been removed from a monocycloalkane is preferable. The monocycloalkane has preferably 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon group, a group in which one hydrogen atom has been removed from a polycycloalkane is preferable. As the polycycloalkane, a group having 7 to 12 carbon atoms is preferable, and specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

[0266] The cyclic aliphatic hydrocarbon group has at least one fluorine atom as a substituent. In the cyclic aliphatic hydrocarbon group, it is preferable that 25% or greater of hydrogen atoms in the cyclic hydrocarbon group are fluorinated, more preferable that 50% or greater of hydrogen atoms in the cyclic hydrocarbon group are fluorinated, and still more preferable that 60% or greater of hydrogen atoms in the cyclic hydrocarbon group are fluorinated.

[0267] The cyclic aliphatic hydrocarbon group may have a substituent other than a fluorine atom. Examples of the substituent other than a fluorine atom include a hydroxyl group, a halogen atom other than fluorine, an alkyl group, an alkoxy group, and a carbonyl group.

[0268] As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group is more preferable.

[0269] As the alkoxy group as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group is more preferable, and a methoxy group or an ethoxy group is still more preferable.

[0270] Examples of the halogenated alkyl group as the substituent include groups in which some or all hydrogen atoms in the above-described alkyl groups are substituted with the above-described halogen atoms.

[0271] In the cyclic aliphatic hydrocarbon group, some carbon atoms constituting the ring structure thereof may be substituted with a substituent having a heteroatom. As the substituent having a heteroatom, O, C(O)O, S, S(O).sub.2, or S(O).sub.2O is preferable.

Aromatic Hydrocarbon Group as Rf

[0272] The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.

[0273] The aromatic ring is not particularly limited as long as the aromatic ring is a cyclic conjugated system having (4n+2) electrons and may be monocyclic or polycyclic. The aromatic ring has preferably 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. Here, the number of carbon atoms in a substituent is not included in the number of carbon atoms.

[0274] Specific examples of the aromatic ring include an aromatic hydrocarbon ring such as benzene, naphthalene, anthracene, or phenanthrene, and an aromatic heterocyclic ring in which some carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms (excluding a fluorine atom). Examples of the heteroatom in the aromatic heterocyclic rings include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring.

[0275] Specific examples of the aromatic hydrocarbon group include a group (an aryl group or a heteroaryl group) obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring, a group obtained by removing one hydrogen atom from an aromatic compound (for example, biphenyl or fluorene) having two or more aromatic rings, and a group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group) in which one hydrogen atom in the aromatic hydrocarbon ring or aromatic heterocyclic ring is substituted with an alkylene group. The number of carbon atoms in the alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocyclic ring is preferably in a range of 1 to 4, more preferably 1 or 2, and particularly preferably 1.

[0276] The aromatic hydrocarbon group has at least one fluorine atom as a substituent. In the aromatic hydrocarbon group, it is preferable that 25% or greater of hydrogen atoms in the aromatic hydrocarbon group are fluorinated, more preferable that 50% or greater of hydrogen atoms in the aromatic hydrocarbon group are fluorinated, and still more preferable that 60% or greater of hydrogen atoms in the aromatic hydrocarbon group are fluorinated.

[0277] The aromatic hydrocarbon group may have a substituent other than a fluorine atom. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom other than a fluorine atom, and a hydroxyl group.

[0278] As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group is more preferable.

[0279] Examples of the alkoxy group as the substituent include those described as the substituent that substitutes the hydrogen atom of the cyclic aliphatic hydrocarbon group.

[0280] From the viewpoint of easily controlling the distribution of the component (D0) in the resist film (uneven distribution on the surface of the resist film), Rf represents preferably an aliphatic hydrocarbon group having a fluorine atom, more preferably a chain-like fluorinated hydrocarbon group, and still more preferably a linear fluorinated alkyl group. The linear fluorinated alkyl group has preferably 1 to 6 carbon atoms, more preferably 1 to 5 carbon atoms, and still more preferably 1 to 3 carbon atoms.

[0281] In Formula (d0), x represents an integer of 1 to 4, preferably an integer of 1 to 3, more preferably 1 or 2, and particularly preferably 1.

[0282] Here, in Formula (d0), the total number of fluorine atoms contained in x pieces of Rf's is 5 or more and preferably 5 or more and 11 or less, and may be 6 or more, 10 or less, and 9 or less, and is particularly preferably 7.

[0283] In a case where the total number of fluorine atoms is in the above-described preferable ranges, lithography characteristics such as rectangularity of a pattern shape and roughness reduction are enhanced in the resist pattern formation.

[0284] In a case where x represents 2 or greater, the total number of fluorine atoms contained in Rf denotes the number obtained by adding all the fluorine atoms contained in 2 or more Rf's.

[0285] In Formula (d0), the hydrocarbon group as V.sup.0 is preferably an aliphatic hydrocarbon group, and examples thereof include a divalent saturated hydrocarbon group. Examples of this divalent saturated hydrocarbon group include an alkylene group, and the divalent saturated hydrocarbon group may be a linear alkylene group or a branched alkylene group and preferably a linear alkylene group. The divalent saturated hydrocarbon group is preferably an alkylene group having 1 to 10 carbon atoms and more preferably an alkylene group having 1 to 5 carbon atoms, and some methylene groups constituting the alkylene group as V.sup.0 may be substituted with divalent aliphatic cyclic groups having 5 to 10 carbon atoms. Examples of the aliphatic cyclic group include a cyclohexylene group, a 1,5-adamantylene group, and a 2,6-adamantylene group.

[0286] Examples of the substituent which may be contained in the hydrocarbon group as V.sup.0 include a halogen atom other than a fluorine atom, a carbonyl group, and a hydroxyl group.

[0287] It is preferable that V.sup.0 represents an alkylene group or a single bond.

[0288] In Formula (d0), examples of the divalent linking group having an oxygen atom as Y.sup.0 include non-hydrocarbon-based oxygen atom-containing linking groups such as an oxygen atom (ether bond: O), an ester bond (C(O)O), an oxycarbonyl group (OC(O)), an amide bond (C(O)NH), a carbonyl group (C(O)), and a carbonate bond (OC(O)O); and a combination of the non-hydrocarbon-based oxygen atom-containing linking group and a divalent hydrocarbon group which may have a substituent. Further, a sulfonyl group (SO.sub.2) may be further linked to the combination. Here, examples of the divalent hydrocarbon group which may have a substituent include the same groups as those for the hydrocarbon group which may have a substituent as V.sup.0 described above.

[0289] It is preferable that Y.sup.0 represents an oxygen atom (ether bond:O), an ester bond (C(O)O or OC(O)), or an amide bond (C(O)NH or NHC(O)).

[0290] In Formula (d0), y represents an integer of 1 to 4, and from the viewpoint of achieving high sensitivity, it is preferable that the number of iodine atoms is large. Alternatively, from the viewpoint of synthesis and achieving high sensitivity, y represents preferably an integer of 1 to 3 and more preferably 1 or 2.

[0291] Specific preferred examples of the anion moiety of the component (D0) are shown below.

[0292] Specific examples of the anion moiety in a case where y in Formula (d0) represents 1 include anions each represented by Chemical Formulae (d0-an-101) to (d0-an-125).

[0293] Specific examples of the anion moiety in a case where y in Formula (d0) represents 2 include anions each represented by Chemical Formulae (d0-an-201) to (do-an-267).

[0294] Specific examples of the anion moiety in a case where y in Formula (d0) represents 3 include anions each represented by Chemical Formulae (d0-an-301) to (d0-an-320).

##STR00062## ##STR00063## ##STR00064## ##STR00065## ##STR00066## ##STR00067## ##STR00068## ##STR00069## ##STR00070## ##STR00071## ##STR00072## ##STR00073## ##STR00074##

##STR00075## ##STR00076## ##STR00077## ##STR00078## ##STR00079##

[0295] As the anion moiety of the component (D0), at least one selected from the group consisting of anions each represented by Chemical Formulae (d0-an-101) to (d0-an-125), Chemical Formulae (d0-an-201) to (d0-an-267), and Chemical Formulae (d0-an-301) to (d0-an-320) is preferable.

[0296] In Formula (d0), M.sup.m+ represents a sulfonium cation or an iodonium cation. m represents an integer of 1 or greater.

[0297] Preferred examples of the cation moiety ((M.sup.m+).sub.1/m) include onium cations each represented by General Formulae (ca-1) to (ca-3).

##STR00080##

[0298] [In the formulae, R.sup.201 to R.sup.207 each independently represent an aryl group, an alkyl group, or an alkenyl group, each of which may have a substituent. R.sup.201 to R.sup.203, and R.sup.206 and R.sup.207 may be bonded to each other to form a ring together with the sulfur atoms in the formulae. R.sup.208 and R.sup.209 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R.sup.210 represents an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a SO.sub.2-containing cyclic group which may have a substituent. L.sup.201 represents C(O) or C(O)O.]

[0299] In General Formulae (ca-1) to (ca-3), examples of the aryl group as R.sup.201 to R.sup.207 include an unsubstituted aryl group having 6 to 20 carbon atoms, where a phenyl group or a naphthyl group is preferable.

[0300] The alkyl group as R.sup.201 to R.sup.207 is preferably a chain-like or cyclic alkyl group which has 1 to 30 carbon atoms.

[0301] The alkenyl group as R.sup.201 to R.sup.207 preferably has 2 to 10 carbon atoms.

[0302] Examples of the substituent which may be contained in R.sup.201 to R.sup.207 and R.sup.210 include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and groups each represented by General Formulae (ca-r-1) to (ca-r-7).

##STR00081##

[0303] [In the formulae, R.sup.201's each independently represents a hydrogen atom, a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent.]

Cyclic Group which May have Substituent:

[0304] The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group indicates a hydrocarbon group that has no aromaticity. Further, the aliphatic hydrocarbon group may be saturated or unsaturated. In general, it is preferable that the aliphatic hydrocarbon group is saturated.

[0305] The aromatic hydrocarbon group as R.sup.201 is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group has preferably 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. Here, the number of carbon atoms in a substituent is not included in the number of carbon atoms.

[0306] Specific examples of the aromatic ring contained in the aromatic hydrocarbon group as R.sup.201 include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heterocyclic ring in which some carbon atoms constituting any of these aromatic rings have been substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocyclic rings include an oxygen atom, a sulfur atom, and a nitrogen atom.

[0307] Specific examples of the aromatic hydrocarbon group as R.sup.201 include a group in which one hydrogen atom has been removed from the aromatic ring (an aryl group such as a phenyl group or a naphthyl group), and a group in which one hydrogen atom in the aromatic ring has been substituted with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, 1-naphthylethyl group, or a 2-naphthylethyl group). The alkylene group (alkyl chain in the arylalkyl group) has preferably 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.

[0308] Examples of the cyclic aliphatic hydrocarbon group as R.sup.201 include an aliphatic hydrocarbon group having a ring in the structure thereof.

[0309] Examples of the aliphatic hydrocarbon group having a ring in the structure thereof include an alicyclic hydrocarbon group (group in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), a group in which the alicyclic hydrocarbon group is bonded to the terminal of a linear or branched aliphatic hydrocarbon group, and a group in which the alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group.

[0310] The alicyclic hydrocarbon group has preferably 3 to 20 carbon atoms and more preferably 3 to 12 carbon atoms.

[0311] The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group in which one or more hydrogen atoms have been removed from a monocycloalkane is preferable. The monocycloalkane has preferably 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon group, a group in which one or more hydrogen atoms have been removed from a polycycloalkane is preferable, and the number of carbon atoms of the polycycloalkane is preferably in a range of 7 to 30. Among these, a polycycloalkane having a crosslinked ring-based polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane; and a polycycloalkane having a condensed ring-based polycyclic skeleton such as a cyclic group having a steroid skeleton are preferable as the polycycloalkane.

[0312] Among these examples, as the cyclic aliphatic hydrocarbon group as R.sup.201, a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane is preferable, a group in which one hydrogen atom has been removed from a polycycloalkane is more preferable, an adamantyl group or a norbornyl group is particularly preferable, and an adamantyl group is most preferable.

[0313] The linear or branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group has preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms.

[0314] As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specific examples thereof include a methylene group [CH.sub.2], an ethylene group [(CH.sub.2).sub.2], a trimethylene group [(CH.sub.2).sub.3], a tetramethylene group [(CH.sub.2).sub.4], and a pentamethylene group [(CH.sub.2).sub.5].

[0315] As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable. Specifically, alkylalkylene groups, for example, alkylmethylene groups such as CH(CH.sub.3), CH(CH.sub.2CH.sub.3), C(CH.sub.3).sub.2, C(CH.sub.3)(CH.sub.2CH.sub.3), C(CH.sub.3)(CH.sub.2CH.sub.2CH.sub.3), and C(CH.sub.2CH.sub.3).sub.2; alkylethylene groups such as CH(CH.sub.3)CH.sub.2, CH(CH.sub.3)CH(CH.sub.3), C(CH.sub.3).sub.2CH.sub.2, CH(CH.sub.2CH.sub.3)CH.sub.2, and C(CH.sub.2CH.sub.3).sub.2CH.sub.2; alkyltrimethylene groups such as CH(CH.sub.3)CH.sub.2CH.sub.2, and CH.sub.2CH(CH.sub.3)CH.sub.2; and alkyltetramethylene groups such as CH(CH.sub.3)CH.sub.2CH.sub.2CH.sub.2 and CH.sub.2CH(CH.sub.3)CH.sub.2CH.sub.2 are exemplary examples. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

[0316] Further, the cyclic hydrocarbon group as R.sup.201 may have a heteroatom such as a heterocyclic ring. Examples thereof include a lactone-containing cyclic group, an SO.sub.2 containing cyclic group, and another heterocyclic group represented by any of Chemical Formulae (r-hr-1) to (r-hr-16).

##STR00082##

[0317] Examples of the substituent for the cyclic group as R.sup.201 include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group.

[0318] As the alkyl group as the substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group is most preferable.

[0319] As the alkoxy group as the substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group is more preferable, and a methoxy group or an ethoxy group is most preferable.

[0320] As the halogen atom as a substituent, a fluorine atom is preferable.

[0321] Example of the above-described halogenated alkyl group as the substituent includes a group in which some or all hydrogen atoms in an alkyl group having 1 to 5 carbon atoms such as a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group have been substituted with the above-described halogen atoms.

[0322] The carbonyl group as the substituent is a group that substitutes a methylene group (CH.sub.2) constituting the cyclic hydrocarbon group.

Chain-Like Alkyl Group which May have Substituent:

[0323] The chain-like alkyl group as R.sup.201 may be linear or branched.

[0324] The linear alkyl group has preferably 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms.

[0325] The branched alkyl group has preferably 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specific examples thereof include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

Chain-Like Alkenyl Group which May have Substituent:

[0326] The chain-like alkenyl group as R.sup.201 may be linear or branched, and has preferably 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, still more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butenyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group. Among the examples, as the chain-like alkenyl group, a linear alkenyl group is preferable, a vinyl group or a propenyl group is more preferable, and a vinyl group is particularly preferable.

[0327] Examples of the substituent for the chain-like alkyl group or alkenyl group as R.sup.201 include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and a cyclic group as R.sup.201.

[0328] Examples of the cyclic group which may have a substituent, the chain-like alkyl group which may have a substituent, and the chain-like alkenyl group which may have a substituent as R.sup.201 include the same groups as those for the acid dissociable group represented by Formula (a1-r-2) which are the exemplary examples of the cyclic group which may have a substituent and the chain-like alkyl group which may have a substituent, in addition to those described above.

[0329] Among the examples, R.sup.201 represents preferably a cyclic group which may have a substituent and more preferably a cyclic hydrocarbon group which may have a substituent. More specific preferred examples include a group obtained by removing one or more hydrogen atoms from a phenyl group, a naphthyl group, or a polycycloalkane, a lactone-containing cyclic group, and a SO.sub.2-containing cyclic group.

[0330] In General Formulae (ca-1) to (ca-3), in a case where R.sup.201 to R.sup.203 and R.sup.206 and R.sup.207 are bonded to each other to form a ring with a sulfur atom in the formula, these groups may be bonded to each other via a heteroatom such as a sulfur atom, an oxygen atom, or a nitrogen atom, or a functional group such as a carbonyl group, SO, SO.sub.2, SO.sub.3, COO, CONH, or N(R.sub.N) (here, R.sub.N represents an alkyl group having 1 to 5 carbon atoms). As a ring to be formed, a ring containing the sulfur atom in the formula in the ring skeleton thereof is preferably a 3- to 10-membered ring and particularly preferably a 5- to 7-membered ring containing the sulfur atom. Specific examples of the ring to be formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

[0331] R.sup.208 and R.sup.209 each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms and preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. In a case where R.sup.208 and R.sup.209 each represent an alkyl group, R.sup.208 and R.sup.209 may be bonded to each other to form a ring.

[0332] R.sup.210 represents an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a SO.sub.2-containing cyclic group which may have a substituent.

[0333] Examples of the aryl group as R.sup.210 include an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group or a naphthyl group is preferable.

[0334] As the alkyl group represented by R.sup.210, a chain-like or cyclic alkyl group having 1 to 30 carbon atoms is preferable.

[0335] It is preferable that the alkenyl group as R.sup.210 has 2 to 10 carbon atoms. The SO.sub.2-containing cyclic group which may have a substituent, as R.sup.210, is preferably SO.sub.2-containing polycyclic group.

[0336] Specific examples of the suitable cation represented by Formula (ca-1) include cations each represented by the following chemical formulae.

##STR00083## ##STR00084## ##STR00085## ##STR00086## ##STR00087## ##STR00088##

[0337] [In the formulae, g1, g2, and g3 represent a repeating number, g1 represents an integer of 1 to 5, g2 represents an integer of 0 to 20, and g3 represents an integer of 0 to 20.]

##STR00089## ##STR00090## ##STR00091## ##STR00092##

[0338] [In the formulae, R.sup.201 represents a hydrogen atom or a substituent, and examples of the substituent include the same groups as those for the substituents which may be included in R.sup.201 to R.sup.207 and R.sup.210 to R.sup.212.]

##STR00093## ##STR00094## ##STR00095##

[0339] Specific examples of suitable cations represented by Formula (ca-2) include a diphenyliodonium cation and a bis(4-tert-butylphenyl) iodonium cation.

[0340] Specific examples of suitable cations represented by Formula (ca-3) include cations each represented by Formulae (ca-3-1) to (ca-3-6).

##STR00096##

[0341] As the cation moiety ((M.sup.m+).sub.1/m), at least one selected from the group consisting of cations each represented by General Formulae (ca-1) to (ca-3) is preferable, and at least one selected from the group consisting of cations each represented by General Formulae (ca-1) and (ca-2) is more preferable. Among these, a cation represented by General Formula (ca-1) is still more preferable.

[0342] In particular, from the viewpoint of achieving high sensitivity, the suitable cation represented by Formula (ca-1) preferably has, as a substituent, an electron-withdrawing group such as a fluorine atom, a fluorinated alkyl group, or a sulfonyl group and is, for example, particularly preferably a cation selected from the group consisting of cations each represented by Chemical Formulae (ca-1-44) and (ca-1-71) to (ca-1-84).

[0343] Alternatively, the cation moiety ((M.sup.m+).sub.1/m) is preferably an m-valent sulfonium cation having a fluorine atom, from the viewpoint of achieving high sensitivity. This cation moiety ((M.sup.m+).sub.1/m) is preferably a cation represented by Formula (ca-1-1).

##STR00097##

[0344] [In the formula, Rf.sup.201 to Rf.sup.203 each independently represent an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. Rf.sup.201 to Rf.sup.203 may be bonded to each other to form a ring together with the sulfur atoms in the formula. Here, at least one of Rf.sup.201 to Rf.sup.203 contains at least one fluorine atom.]

[0345] Rf.sup.201 to Rf.sup.203 in Formula (ca-1-1) are each have the same as that for R.sup.201 to R.sup.203 in Formula (ca-1). Here, at least one of Rf.sup.201 to Rf.sup.203 contains at least one fluorine atom. The cation represented by Formula (ca-1-1) preferably contains three or more fluorine atoms. Any one of Rf.sup.201 to Rf.sup.203 may have three or more fluorine atoms, or the total number of fluorine atoms in Rf.sup.201 to Rf.sup.203 may be three or more.

[0346] Specific examples of the component (D0) are shown below but are not limited thereto.

##STR00098## ##STR00099## ##STR00100## ##STR00101## ##STR00102##

[0347] In the resist composition according to the present embodiment, the component (D0) may be used alone or in combination of two or more kinds thereof.

[0348] As the component (D0), at least one selected from the group consisting of compounds each represented by Chemical Formulae (D0-1) to (D0-19) is preferable.

[0349] The content of the component (D0) in the resist composition according to the present embodiment is preferably in a range of 0.5 to 25 parts by mass, more preferably in a range of 1 to 20 parts by mass, still more preferably in a range of 3 to 15 parts by mass, and particularly preferably in a range of 5 to 10 parts by mass with respect to 100 parts by mass of the component (A).

[0350] In a case where the content of the component (D0) is greater than or equal to the lower limits of the above-described preferable ranges, the lithography characteristics such as the rectangularity of the pattern shape and roughness reduction in the formation of a resist pattern are improved. Meanwhile, in a case where the content thereof is less than or equal to the upper limits of the above-described preferable ranges, the sensitivity can be maintained more satisfactorily.

[0351] The component (D) in the resist composition according to the present embodiment may contain a base component other than the above-described component (D0).

[0352] Examples of the base component other than component (D0) include a photodecomposable base (D1) having acid diffusion controllability (hereinafter, referred to as component (D1)) which is lost by decomposition upon light exposure and a nitrogen-containing organic compound (D2) (hereinafter, referred to as component (D2)) which does not correspond to the component (D1). Among these, a photodecomposable base (component (D1)) is preferable from the viewpoint that all the characteristics of high sensitivity, roughness reduction, and the pattern shape (rectangularity) are likely to be enhanced. The compound described as the component (D1) below may be used as the acid generator component (component (B)) depending on the combination with other compounds.

In Regard to Component (D1)

[0353] In a case where a resist composition containing the component (D1) is obtained, the contrast between an exposed portion and an unexposed portion of the resist film can be further improved in a case of forming a resist pattern.

[0354] The component (D1) is not particularly limited as long as the component is decomposed upon light exposure and loses an acid diffusion controllability, and one or more compounds selected from the group consisting of a compound represented by General Formula (d1-1) (hereinafter, referred to as component (d1-1)), a compound represented by General Formula (d1-2) (hereinafter, referred to as component (d1-2)), and a compound represented by General Formula (d1-3) (hereinafter, referred to as component (d1-3)) are preferable.

[0355] Since the components (d1-1) to (d1-3) are decomposed and lose the acid diffusion controllability (basicity), the components (d1-1) to (d1-3) do not act as a quencher at the exposed portion of the resist film, but act as a quencher at the unexposed portion of the resist film.

##STR00103##

[0356] [In the formulae, Rd.sup.1 to Rd.sup.4 represent a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent. Here, the carbon atom adjacent to the S atom as Rd.sup.2 in Formula (d1-2) has no fluorine atom bonded thereto. Yd represents a single bond or a divalent linking group. m represents an integer of 1 or greater, and M.sup.m+'s each independently represents an m-valent organic cation.]

{Component (d1-1)}

Anion Moiety

[0357] In Formula (d1-1), Rd.sup.1 represents a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent, and examples of each of the cyclic groups include the same groups as those for R.sup.201.

[0358] Among these, it is preferable that the group as Rd.sup.1 represents an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain-like alkyl group which may have a substituent.

[0359] Suitable examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, and a polycyclic structure having a bicyclooctane skeleton (for example, a polycyclic structure formed of a bicyclooctane skeleton and a ring structure other than the bicyclooctane skeleton).

[0360] As the aliphatic cyclic group, a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane is more preferable.

[0361] It is preferable that the chain-like alkyl group has 1 to 10 carbon atoms, and specific examples thereof include a linear alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, or a decyl group; and a branched alkyl group such as a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, or a 4-methylpentyl group.

[0362] Examples of the substituent which may be contained in the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain-like alkyl group as Rd.sup.1 include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, a lactone-containing cyclic group represented by any of General Formulae (a2-r-1) to (a2-r-7), an ether bond, an ester bond, and a combination thereof.

[0363] In a case where the chain-like alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the fluorinated alkyl group has preferably 1 to 11 carbon atoms, more preferably 1 to 8 carbon atoms, and still more preferably 1 to 4 carbon atoms. The fluorinated alkyl group may have an atom other than a fluorine atom. Examples of the atom other than a fluorine atom include an oxygen atom, a sulfur atom, and a nitrogen atom.

[0364] In a case where an ether bond or an ester bond is contained as the substituent, the substituent may be bonded through an alkylene group, and the substituent in this case is preferably linking groups each represented by General Formulae (y-al-1) to (y-al-8) described below.

[0365] Further, in a case where the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain-like alkyl group as Rd.sup.1 has a linking group represented by any of General Formulae (y-al-1) to (y-al-8) as a substituent, in General Formulae (y-al-1) to (y-al-8), the group that is bonded to a carbon atom constituting the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain-like alkyl group as Rd.sup.1 in Formula (d1-1) is V.sup.101 in General Formulae (y-al-1) to (y-al-8).

##STR00104##

[0366] [In the formula, V.sup.101 represents an alkylene group having 1 to 5 carbon atoms or a single bond. V.sup.102 represents a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.]

[0367] As the divalent saturated hydrocarbon group as V.sup.102, an alkylene group having 1 to 30 carbon atoms is preferable, an alkylene group having 1 to 10 carbon atoms is more preferable, and an alkylene group having 1 to 5 carbon atoms is still more preferable.

[0368] The alkylene group as V.sup.101 and V.sup.102 may be a linear alkylene group or a branched alkylene group, and a linear alkylene group is preferable.

[0369] Specific examples of the alkylene group as V.sup.101 and V.sup.102 include a methylene group [CH.sub.2]; an alkylmethylene group such as CH(CH.sub.3), CH(CH.sub.2CH.sub.3), C(CH.sub.3).sub.2, C(CH.sub.3)(CH.sub.2CH.sub.3), C(CH.sub.3)(CH.sub.2CH.sub.2CH.sub.3), or C(CH.sub.2CH.sub.3).sub.2; an ethylene group [CH.sub.2CH.sub.2]; an alkylethylene group such as CH(CH.sub.3)CH.sub.2, CH(CH.sub.3)CH(CH.sub.3), C(CH.sub.3).sub.2CH.sub.2, or CH(CH.sub.2CH.sub.3)CH.sub.2; a trimethylene group (n-propylene group) [CH.sub.2CH.sub.2CH.sub.2]; an alkyltrimethylene group such as CH(CH.sub.3)CH.sub.2CH.sub.2 or CH.sub.2CH(CH.sub.3)CH.sub.2; a tetramethylene group [CH.sub.2CH.sub.2CH.sub.2CH.sub.2]; an alkyltetramethylene group such as CH(CH.sub.3)CH.sub.2CH.sub.2CH.sub.2 or CH.sub.2CH(CH.sub.3)CH.sub.2CH.sub.2; and a pentamethylene group [CH.sub.2CH.sub.2CH.sub.2CH.sub.2CH.sub.2].

[0370] Further, a part of methylene groups in the alkylene group as V.sup.101 and V.sup.102 may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is preferably a cyclohexylene group, a 1,5-adamantylene group, or a 2,6-adamantylene group.

[0371] Specific preferred examples of the anion moiety in the component (d1-1) are described below.

##STR00105## ##STR00106##

Cation Moiety

[0372] In Formula (d1-1), M.sup.m+ represents an m-valent organic cation.

[0373] Suitable examples of the organic cation as M.sup.m+ include the same cations as those for the cations each represented by General Formulae (ca-1) to (ca-3). Among these, a cation represented by General Formula (ca-1) is more preferable, and cations each represented by Formulae (ca-1-1) to (ca-1-84) are still more preferable.

[0374] The component (d1-1) may be used alone or in combination of two or more kinds thereof.

{Component (d1-2)}

Anion Moiety

[0375] In Formula (d1-2), Rd.sup.2 represents a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent, and examples thereof include the same groups as those for R.sup.201.

[0376] Here, the carbon atom adjacent to the S atom in Rd.sup.2 has no fluorine atom bonded thereto (the carbon atom is not substituted with fluorine). As a result, the anion of the component (d1-2) becomes an appropriately weak acid anion, thereby improving the quenching ability of the component (D).

[0377] It is preferable that Rd.sup.2 represents a chain-like alkyl group which may have a substituent or an aliphatic cyclic group which may have a substituent. The chain-like alkyl group has preferably 1 to 10 carbon atoms and more preferably 3 to 10 carbon atoms. As the aliphatic cyclic group, a group in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like (a group which may have a substituent); and a group in which one or more hydrogen atoms have been removed from camphor or the like are more preferable.

[0378] The hydrocarbon group as Rd.sup.2 may have a substituent, and examples of the substituent include the same substituents as those that the hydrocarbon group (an aromatic hydrocarbon group, an aliphatic cyclic group, or a chain-like alkyl group) as Rd.sup.1 in Formula (d1-1) may have.

[0379] Specific preferred examples of the anion moiety in the component (d1-2) are described below.

##STR00107##

Cation Moiety

[0380] In Formula (d1-2), M.sup.m+ represents an m-valent organic cation and has the same definition as that for M.sup.m+ in Formula (d1-1).

[0381] The component (d1-2) may be used alone or in combination of two or more kinds thereof.

{Component (d1-3)}

Anion Moiety

[0382] In Formula (d1-3), Rd.sup.3 represents a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent, and examples thereof include the same groups as those for R.sup.201. Among these, a cyclic group having a fluorine atom, a chain-like alkyl group, or a chain-like alkenyl group is preferable. Among these, a fluorinated alkyl group is preferable, and the same groups as those for the fluorinated alkyl group represented by Rd.sup.1 are more preferable.

[0383] In Formula (d1-3), Rd.sup.4 represents a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent, and examples thereof include the same groups as those for R.sup.201.

[0384] Among these, an alkyl group which may have a substituent, an alkoxy group which may have a substituent, an alkenyl group which may have a substituent, or a cyclic group which may have a substituent is preferable.

[0385] It is preferable that the alkyl group as Rd.sup.4 is a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. Some hydrogen atoms in the alkyl group as Rd.sup.4 may be substituted with a hydroxyl group, a cyano group, or the like.

[0386] It is preferable that the alkoxy group as Rd.sup.4 is an alkoxy group having 1 to 5 carbon atoms, and specific examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group. Among these, a methoxy group and an ethoxy group are preferable.

[0387] Examples of the alkenyl group as Rd.sup.4 include the same groups as those for the alkenyl group as R.sup.201. Among these, a vinyl group, a propenyl group (an allyl group), a 1-methylpropenyl group, and a 2-methylpropenyl group are preferable. These groups may further contain an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms as a substituent.

[0388] Examples of the cyclic group as Rd.sup.4 include the same groups as those for the cyclic group as R.sup.201. Among these, an alicyclic group in which one or more hydrogen atoms have been removed from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane or an aromatic group such as a phenyl group or a naphthyl group is preferable. In a case where Rd.sup.4 represents an alicyclic group, the resist composition is satisfactorily dissolved in an organic solvent so that the lithography characteristics are enhanced. Further, in a case where Rd.sup.4 represents an aromatic group, the resist composition has excellent light absorption efficiency in lithography using EUV or the like as an exposure light source, and thus the sensitivity and lithography characteristics are enhanced.

[0389] In Formula (d1-3), Yd.sup.1 represents a single bond or a divalent linking group.

[0390] The divalent linking group as Yd.sup.1 is not particularly limited, and examples thereof include a divalent hydrocarbon group (an aliphatic hydrocarbon group or an aromatic hydrocarbon group) which may have a substituent and a divalent linking group having a heteroatom.

[0391] It is preferable that Yd.sup.1 represents a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination of these. As the alkylene group, a linear or branched alkylene group is more preferable, and a methylene group or an ethylene group is still more preferable.

[0392] Specific preferred examples of the anion moiety in the component (d1-3) are described below.

##STR00108## ##STR00109##

Cation Moiety

[0393] In Formula (d1-3), M.sup.m+ represents an m-valent organic cation and has the same definition as that for M.sup.m+ in Formula (d1-1).

[0394] The component (d1-3) may be used alone or in combination of two or more kinds thereof.

[0395] As the component (D1), only any one of the above-described components (d1-1) to (d1-3) or a combination of two or more kinds thereof may be used.

[0396] In a case where the resist composition contains the component (D1), the content of the component (D1) in the resist composition is preferably in a range of 0.5 to 20 parts by mass, more preferably in a range of 1 to 15 parts by mass, and still more preferably in a range of 2 to 8 parts by mass with respect to 100 parts by mass of the component (A).

[0397] In a case where the content of the component (D1) is greater than or equal to the lower limits of the above-described preferable ranges, particularly satisfactory lithography characteristics and a particularly satisfactory resist pattern shape are likely to be obtained. On the contrary, in a case where the content is less than or equal to the upper limits of the above-described ranges, the sensitivity can be satisfactorily maintained and the throughput is also excellent.

Method of Producing Component (D1):

[0398] The methods of producing the component (d1-1) and the component (d1-2) are not particularly limited, and these components can be produced by known methods.

[0399] Further, the method of producing the component (d1-3) is not particularly limited, and the component is produced by the same method as disclosed in United States Patent Application, Publication No. 2012-0149916.

In Regard to Component (D2)

[0400] The component (D) may contain a nitrogen-containing organic compound component (hereinafter, referred to as component (D2)) which does not correspond to the above-described component (D0) or component (D1).

[0401] The component (D2) is not particularly limited as long as the component acts as an acid diffusion control agent and does not correspond to the component (D0) or the component (D1), and any known compound may be used. Among the examples, an aliphatic amine is preferable, and particularly a secondary aliphatic amine and a tertiary aliphatic amine are more preferable.

[0402] The aliphatic amine is an amine containing one or more aliphatic groups, and the number of carbon atoms in the aliphatic group is preferably in a range of 1 to 12.

[0403] Examples of these aliphatic amines include amines in which at least one hydrogen atom of ammonia NH.sub.3 has been substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms (alkylamines or alkylalcoholamines), and cyclic amines.

[0404] Specific examples of the alkylamines and the alkylalcoholamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkylalcoholamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, a trialkylamine having 6 to 30 carbon atoms is still more preferable, and tri-n-pentylamine or tri-n-octylamine is particularly preferable.

[0405] Examples of the cyclic amine include a heterocyclic compound having a nitrogen atom as a heteroatom. The heterocyclic compound may be a monocyclic compound (aliphatic monocyclic amine) or a polycyclic compound (aliphatic polycyclic amine).

[0406] Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.

[0407] It is preferable that the aliphatic polycyclic amine has 6 to 10 carbon atoms, and specific examples thereof include 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

[0408] Examples of other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris {2-(2-methoxyethoxy)ethyl}amine, tris {2-(2-methoxyethoxymethoxy)ethyl}amine, tris {2-(1-methoxyethoxy)ethyl}amine, tris {2-(1-ethoxyethoxy)ethyl}amine, tris {2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy) ethoxy}ethyl]amine, and triethanolamine triacetate. Among these, triethanolamine triacetate is preferable.

[0409] As the component (D2), an aromatic amine may be used.

[0410] Examples of aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole, and derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine, and 2,6-di-tert-butylpyridine.

[0411] The component (D2) may be used alone or in combination of two or more kinds thereof.

[0412] In a case where the resist composition contains the component (D2), the content of the component (D2) in the resist composition is typically in a range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the component (A). In a case where the content thereof is set to be in the above-described range, the resist pattern shape, the post-exposure temporal stability, and the like are improved.

[0413] The content of the component (D0) in the total component (D) contained in the resist composition according to the present embodiment is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass or more, and the component (D) may be formed of only the component (D0).

[0414] The resist composition according to the present embodiment may further contain other components in addition to the component (A) and the component (D) described above. Examples of the other components include a component (B), a component (E), a component (F), and a component(S), which are described below.

<<Component (B): Acid Generator Component>>

[0415] It is preferable that the resist composition of the present embodiment further contains an acid generator component (B) (here, the compound (D0) is excluded) that generates an acid upon light exposure.

[0416] The component (B) is not particularly limited, and those which have been suggested so far as an acid generator for a chemically amplified resist composition in the related art can be used.

[0417] Examples of the acid generator include various acid generators, for example, onium salt-based acid generators such as iodonium salts and sulfonium salts; oxime sulfonate-based acid generators; diazomethane-based acid generators such as bisalkyl or bisaryl sulfonyl diazomethanes and poly(bis-sulfonyl)diazomethanes; nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators.

[0418] Examples of the onium salt-based acid generators include a compound represented by General Formula (b-1) (hereinafter, also referred to as component (b-1)), a compound represented by General Formula (b-2) (hereinafter, also referred to as component (b-2)), and a compound represented by General Formula (b-3) (hereinafter, also referred to as component (b-3)).

##STR00110##

[0419] [In the formulae, R.sup.101 and R.sup.104 to R.sup.108 each independently represent a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent. R.sup.104 and R.sup.105 may be bonded to each other to form a ring structure. R.sup.102 represents a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. Y.sup.101 represents a divalent linking group having an oxygen atom or a single bond. V.sup.101 to V.sup.103 each independently represent a single bond, an alkylene group, or a fluorinated alkylene group. Here, both Y.sup.101 and V.sup.101 do not form a single bond. L.sup.101 and L.sup.102 each independently represent a single bond or an oxygen atom. L.sup.103 to L.sup.105 each independently represent a single bond, CO, or SO.sub.2. m represents an integer of 1 or greater, and Mm.sup.+ represents an m-valent onium cation.]

{Anion Moiety}

Anions in Component (b-1)

[0420] In Formula (b-1), R.sup.101 represents a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent.

Cyclic Group which May have Substituent:

[0421] The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group indicates a hydrocarbon group that has no aromaticity. In addition, it is preferable that the aliphatic hydrocarbon group is saturated.

[0422] The aromatic hydrocarbon group as R.sup.101 is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group has preferably 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. Here, the number of carbon atoms in a substituent is not included in the number of carbon atoms.

[0423] Specific examples of the aromatic ring of the aromatic hydrocarbon group as R.sup.101 include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heterocyclic ring in which some carbon atoms constituting any of these aromatic rings have been substituted with heteroatoms. Examples of the heteroatom in the aromatic heterocyclic rings include an oxygen atom, a sulfur atom, and a nitrogen atom.

[0424] Specific examples of the aromatic hydrocarbon group as R.sup.101 include a group obtained by removing one hydrogen atom from the aromatic ring (an aryl group such as a phenyl group or a naphthyl group) and a group in which one hydrogen atom of the aromatic ring is substituted with an alkylene group (for example, a benzyl group, a phenethyl group, or a 1-naphthylmethyl group). The alkylene group (alkyl chain in the arylalkyl group) has preferably 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably 1 carbon atom.

[0425] Examples of the cyclic aliphatic hydrocarbon group as R.sup.101 include an aliphatic hydrocarbon group having a ring in the structure thereof.

[0426] Examples of the aliphatic hydrocarbon group having a ring in the structure thereof include an alicyclic hydrocarbon group (group in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), a group in which the alicyclic hydrocarbon group is bonded to the terminal of a linear or branched aliphatic hydrocarbon group, and a group in which the alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group.

[0427] The alicyclic hydrocarbon group has preferably 3 to 20 carbon atoms and more preferably 3 to 12 carbon atoms.

[0428] The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group in which one or more hydrogen atoms have been removed from a monocycloalkane is preferable. The monocycloalkane has preferably 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon group, a group in which one or more hydrogen atoms have been removed from a polycycloalkane is preferable, and the number of carbon atoms of the polycycloalkane is preferably in a range of 7 to 30. Among these, a polycycloalkane having a crosslinked ring-based polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane; and a polycycloalkane having a condensed ring-based polycyclic skeleton such as a cyclic group having a steroid skeleton are preferable as the polycycloalkane.

[0429] Among these examples, as the cyclic aliphatic hydrocarbon group as R.sup.101, a group in which one or more hydrogen atoms have been removed from a monocycloalkane or a polycycloalkane is preferable, a group in which one hydrogen atom has been removed from a polycycloalkane is more preferable, an adamantyl group or a norbornyl group is still more preferable, and an adamantyl group is particularly preferable.

[0430] The linear aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group has preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specific examples thereof include a methylene group [CH.sub.2], an ethylene group [(CH.sub.2).sub.2], a trimethylene group [(CH.sub.2).sub.3], a tetramethylene group [(CH.sub.2).sub.4], and a pentamethylene group [(CH.sub.2).sub.5].

[0431] The branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group has preferably 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable. Specifically, alkylalkylene groups, for example, alkylmethylene groups such as CH(CH.sub.3), CH(CH.sub.2CH.sub.3), C(CH.sub.3).sub.2, C(CH.sub.3) (CH.sub.2CH.sub.3), C(CH.sub.3)(CH.sub.2CH.sub.2CH.sub.3), and C(CH.sub.2CH.sub.3).sub.2; alkylethylene groups such as CH(CH.sub.3)CH.sub.2, CH(CH.sub.3)CH(CH.sub.3), C(CH.sub.3).sub.2CH.sub.2, CH(CH.sub.2CH.sub.3)CH.sub.2, and C(CH.sub.2CH.sub.3).sub.2CH.sub.2; alkyltrimethylene groups such as CH(CH.sub.3)CH.sub.2CH.sub.2, and CH.sub.2CH(CH.sub.3)CH.sub.2; and alkyltetramethylene groups such as CH(CH.sub.3)CH.sub.2CH.sub.2CH.sub.2 and CH.sub.2CH(CH.sub.3)CH.sub.2CH.sub.2 are exemplary examples. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

[0432] Further, the cyclic hydrocarbon group as R.sup.101 may have a heteroatom such as a heterocyclic ring. Specific examples thereof include lactone-containing cyclic groups each represented by General Formulae (a2-r-1) to (a2-r-7), SO.sub.2-containing cyclic groups each represented by General Formulae (b5-r-1) to (b5-r-4), and other heterocyclic groups each represented by Chemical Formulae (r-hr-1) to (r-hr-16). In the formulae, * represents a bonding site with respect to Y.sup.101 in Formula (b-1).

##STR00111##

[0433] [In the formulae, Rb.sup.51's each independently represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, COOR, OC(O)R, a hydroxyalkyl group, or a cyano group; R represents a hydrogen atom, an alkyl group, a lactone-containing cyclic group, or an SO.sub.2-containing cyclic group; B represents an oxygen atom, a sulfur atom, or an alkylene group having 1 to 5 carbon atoms, which may have an oxygen atom or a sulfur atom; and n represents an integer of 0 to 2. * represents a bonding site.]

[0434] In General Formulae (b5-r-1) and (b5-r-2), B represents an alkylene group having 1 to 5 carbon atoms which may have an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom.

B represents preferably an alkylene group having 1 to 5 carbon atoms or O, more preferably an alkylene group having 1 to 5 carbon atoms, and still more preferably a methylene group.

[0435] In General Formulae (b5-r-1) to (b5-r-4), Rb.sup.51's each independently represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, COOR, OC(O)R, a hydroxyalkyl group, or a cyano group, and among the examples, it is preferable that Rb.sup.51's each independently represent a hydrogen atom or a cyano group.

[0436] Specific examples of the groups each represented by General Formulae (b5-r-1) to (b5-r-4) are shown below. In the formulae shown below, Ac represents an acetyl group.

##STR00112## ##STR00113## ##STR00114## ##STR00115## ##STR00116##

[0437] Examples of the substituent for the cyclic group as R.sup.101 include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group.

[0438] An alkyl group having 1 to 5 carbon atoms is preferable as the alkyl group serving as a substituent.

[0439] An alkoxy group having 1 to 5 carbon atoms is preferable as the alkoxy group serving as the substituent.

[0440] A fluorine atom, a bromine atom, or an iodine atom is preferable as the halogen atom serving as a substituent.

[0441] Example of the above-described halogenated alkyl group as the substituent includes a group in which some or all hydrogen atoms in an alkyl group having 1 to 5 carbon atoms such as a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group are substituted with the above-described halogen atoms.

[0442] The carbonyl group as the substituent is a group that substitutes a methylene group (CH.sub.2) constituting the cyclic hydrocarbon group.

[0443] The cyclic hydrocarbon group as R.sup.101 may be a condensed cyclic group containing a condensed ring in which an aliphatic hydrocarbon ring and an aromatic ring are condensed. Examples of the condensed ring include those obtained by condensing one or more aromatic rings with a polycycloalkane having a crosslinked ring-based polycyclic skeleton. Specific examples of the crosslinked ring-based polycycloalkane include a bicycloalkane such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. As the condensed cyclic group, a group having a condensed ring in which two or three aromatic rings are condensed with a bicycloalkane is preferable, and a group having a condensed ring in which two or three aromatic rings are condensed with bicyclo[2.2.2]octane is more preferable. Specific examples of the condensed cyclic group as R.sup.101 include those represented by Formulae (r-br-1) and (r-br-2). In the formulae, * represents a bonding site with respect to Y.sup.101 in Formula (b-1).

##STR00117##

[0444] Examples of the substituent that the condensed cyclic group as R.sup.101 may have include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an aromatic hydrocarbon group, and an alicyclic hydrocarbon group.

[0445] Examples of the alkyl group, the alkoxy group, the halogen atom, and the halogenated alkyl group as the substituent of the condensed cyclic group include the same groups as those for the substituent of the cyclic group as R.sup.101.

[0446] Examples of the aromatic hydrocarbon group as the substituent of the condensed cyclic group include a group in which one hydrogen atom has been removed from the aromatic ring (an aryl group such as a phenyl group or a naphthyl group), a group in which one hydrogen atom in the aromatic ring has been substituted with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, 1-naphthylethyl group, or a 2-naphthylethyl group), and a heterocyclic group represented by any of Formulae (r-hr-1) to (r-hr-6).

[0447] Examples of the alicyclic hydrocarbon group as the substituent of the condensed cyclic group include a group in which one hydrogen atom has been removed from a monocycloalkane such as cyclopentane or cyclohexane, a group in which one hydrogen atom has been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane, a lactone-containing cyclic group represented by any of General Formulae (a2-r-1) to (a2-r-7), a SO.sub.2-containing cyclic group represented by any of General Formulae (b5-r-1) to (b5-r-4), and a heterocyclic group represented by any of Formulae (r-hr-7) to (r-hr-16).

Chain-Like Alkyl Group which May have Substituent:

[0448] The chain-like alkyl group as R.sup.101 may be linear or branched.

[0449] The number of carbon atoms in the linear alkyl group is preferably in a range of 1 to 20, more preferably in a range of 1 to 15, and most preferably in a range of 1 to 10.

[0450] The branched alkyl group has preferably 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specific examples thereof include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

Chain-Like Alkenyl Group which May have Substituent:

[0451] The chain-like alkenyl group as R.sup.101 may be linear or branched, and the number of carbon atoms thereof is preferably in a range of 2 to 10, more preferably in a range of 2 to 5, still more preferably in a range of 2 to 4, and particularly preferably 3. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butenyl group. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group.

[0452] Among the examples, as the chain-like alkenyl group, a linear alkenyl group is preferable, a vinyl group or a propenyl group is more preferable, and a vinyl group is particularly preferable.

[0453] Examples of the substituent for the chain-like alkyl group or alkenyl group as R.sup.101 include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and a cyclic group as R.sup.101.

[0454] In Formula (b-1), Y.sup.101 represents a single bond or a divalent linking group having an oxygen atom.

[0455] In a case where Y.sup.101 represents a divalent linking group having an oxygen atom, Y.sup.101 may have an atom other than the oxygen atom. Examples of atoms other than an oxygen atom include a carbon atom, a hydrogen atom, a sulfur atom, and a nitrogen atom.

[0456] Examples of the divalent linking group having an oxygen atom include linking groups each represented by General Formulae (y-al-1) to (y-al-8).

[0457] In Formula (b-1), V.sup.101 represents a single bond, an alkylene group, or a fluorinated alkylene group. It is preferable that the alkylene group and the fluorinated alkylene group as V.sup.101 have 1 to 4 carbon atoms. Among these, it is preferable that V.sup.101 represents a single bond or a linear fluorinated alkylene group having 1 to 4 carbon atoms.

[0458] In Formula (b-1), R.sup.102 represents a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. R.sup.102 represents preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms and more preferably a fluorine atom.

[0459] In a case where Y.sup.101 represents a single bond, specific examples of the anion moiety represented by Formula (b-1) include a fluorinated alkylsulfonate anion such as a trifluoromethanesulfonate anion or a perfluorobutanesulfonate anion. Further, in a case where Y.sup.101 represents a divalent linking group having an oxygen atom, specific examples thereof include an anion represented by any of Formulae (an-1) to (an-3).

##STR00118##

[0460] [In the formulae, R.sup.101 represents an aliphatic cyclic group which may have a substituent, a monovalent heterocyclic group represented by any of Chemical Formulae (r-hr-1) to (r-hr-6), a condensed cyclic group represented by Formula (r-br-1) or (r-br-2), a chain-like alkyl group which may have a substituent, or an aromatic cyclic group which may have a substituent. R.sup.102 represents an aliphatic cyclic group which may have a substituent, a condensed cyclic group represented by Formula (r-br-1) or (r-br-2), a lactone-containing cyclic group represented by any of General Formulae (a2-r-1) and (a2-r-3) to (a2-r-7), or a SO.sub.2-containing cyclic group represented by any of General Formulae (b5-r-1) to (b5-r-4). R.sup.103 represents an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain-like alkenyl group which may have a substituent. V.sup.101 represents a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. R.sup.102 represents a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Each v independently represents an integer of 0 to 3, each q independently represents an integer of 0 to 20, and n represents 0 or 1.]

[0461] As the aliphatic cyclic group as R.sup.101, R.sup.102, and R.sup.103 which may have a substituent, the same groups as those for the cyclic aliphatic hydrocarbon group as R.sup.101 in Formula (b-1) are preferable. Examples of the substituent include the same groups as those for the substituent which may substitute the cyclic aliphatic hydrocarbon group as R.sup.101 in Formula (b-1).

[0462] As the aromatic cyclic group which may have a substituent as R.sup.101 and R.sup.103, the groups described as the aromatic hydrocarbon group in the cyclic hydrocarbon group as R.sup.101 in Formula (b-1) are preferable. Examples of the substituent include the same substituents as those which may substitute the aromatic hydrocarbon group as R.sup.101 in Formula (b-1).

[0463] As the chain-like alkyl group as R.sup.101 which may have a substituent, the same groups as those for the chain-like alkyl group as R.sup.101 in Formula (b-1) are preferable.

[0464] As the chain-like alkenyl group as R.sup.103 which may have a substituent, the same groups as those for the chain-like alkenyl group as R.sup.101 in Formula (b-1) are preferable.

[0465] The alkylene group and the fluorinated alkylene group as V.sup.101 have preferably 1 to 3 carbon atoms and more preferably 1 or 2 carbon atoms. Specific examples of V.sup.101 include CH.sub.2, (CH.sub.2).sub.2, CFH, CH.sub.2CFH, and CH(CF.sub.3).

[0466] As the anion moiety represented by Formula (b-1), an anion moiety represented by Formula (an-1) is preferable. Among these, R.sup.101 in (an-1) represents preferably an aromatic cyclic group which may have a substituent and more preferably a phenyl group which may have a substituent. Examples of the substituent include a hydroxy group, an alkyl group, and a halogen atom. Among these, a hydroxy group or a halogen atom is preferable. As the halogen atom, a bromine atom or an iodine atom is preferable, and an iodine atom is more preferable.

Anions in Component (b-2)

[0467] In Formula (b-2), R.sup.104 and R.sup.105 each independently represent a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent, and examples thereof include the same groups as those for R.sup.101 in Formula (b-1). Here, R.sup.104 and R.sup.105 may be bonded to each other to form a ring.

[0468] R.sup.104 and R.sup.105 represent preferably a chain-like alkyl group which may have a substituent and more preferably a linear or branched alkyl group or a linear or branched fluorinated alkyl group.

[0469] The chain-like alkyl group has preferably 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and still more preferably 1 to 3 carbon atoms. It is preferable that the number of carbon atoms in the chain-like alkyl group as R.sup.104 and R.sup.105 decreases within the range of the number of carbon atoms because the solubility in a solvent for a resist is also satisfactory. Further, in the chain-like alkyl group as R.sup.104 and R.sup.105, it is preferable that the number of hydrogen atoms substituted with fluorine atoms is as large as possible because the acid strength increases and the transparency to high energy light with a wavelength of 250 nm or less or electron beams is improved. The proportion of fluorine atoms in the chain-like alkyl group, that is, the fluorination ratio is preferably in a range of 70% to 100% and more preferably in a range of 90% to 100%, and it is most preferable that the chain-like alkyl group is a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms.

[0470] In Formula (b-2), V.sup.102 and V.sup.103 each independently represent a single bond, an alkylene group, or a fluorinated alkylene group, and examples of each of the groups include the same groups as those for V.sup.101 in Formula (b-1).

[0471] In Formula (b-2), L.sup.101 and L.sup.102 each independently represent a single bond or an oxygen atom.

Anions in Component (b-3)

[0472] In Formula (b-3), R.sup.106 to R.sup.108 each independently represent a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent, and examples thereof include those for R.sup.101 in Formula (b-1).

[0473] In Formula (b-3), L.sup.103 to L.sup.105 each independently represent a single bond, CO, or SO.sub.2.

[0474] Among the examples, as the anion moiety of the component (B), an anion in the component (b-1) is preferable.

{Cation Moiety}

[0475] In Formulae (b-1), (b-2), and (b-3), M.sup.m+ represents an m-valent onium cation. Among them, a sulfonium cation and an iodonium cation are preferable.

[0476] m represents an integer of 1 or greater.

[0477] Preferred examples of the cation moiety ((M.sup.m+).sub.1/m) include the same cations as those for the onium cations each represented by General Formulae (ca-1) to (ca-3). Among these, a cation represented by General Formula (ca-1) is more preferable, and cations each represented by Formulae (ca-1-1) to (ca-1-84) are still more preferable.

[0478] In particular, from the viewpoint of achieving high sensitivity, the suitable cation represented by Formula (ca-1) preferably has, as a substituent, an electron-withdrawing group such as a fluorine atom, a fluorinated alkyl group, or a sulfonyl group and is, for example, particularly preferably a cation selected from the group consisting of cations each represented by Chemical Formulae (ca-1-44) and (ca-1-71) to (ca-1-84).

[0479] Alternatively, the cation moiety ((M.sup.m+).sub.1/m) is preferably an m-valent sulfonium cation having a fluorine atom from the viewpoint of achieving high sensitivity. As the cation moiety ((M.sup.m+).sub.1/m), a cation represented by Formula (ca-1-1) is preferable.

[0480] In the resist composition according to the present embodiment, the component (B) may be used alone or in combination of two or more kinds thereof.

[0481] In a case where the resist composition contains the component (B), the content of the component (B) in the resist composition is preferably less than 50 parts by mass, more preferably in a range of 5 to 40 parts by mass, and still more preferably in a range of 10 to 30 parts by mass, with respect to 100 parts by mass of the component (A).

[0482] In a case where the content of the component (B) is set to be in the above-described preferable ranges, pattern formation can be sufficiently carried out. Further, it is preferable that each component of the resist composition is dissolved in an organic solvent from the viewpoint that a uniform solution is easily obtained and the storage stability of the resist composition is enhanced.

<<Component (E): At Least One Compound Selected from Group Consisting of Organic Carboxylic Acid, Phosphorus Oxo Acid, and Derivatives Thereof>>

[0483] For the purpose of preventing deterioration in sensitivity and improving the resist pattern shape, the post-exposure temporal stability, and the like, the resist composition according to the present embodiment may contain, as an optional component, at least one compound (E) (hereinafter referred to as component (E)) selected from the group consisting of an organic carboxylic acid, and a phosphorus oxo acid and a derivative thereof.

[0484] Specific examples of the organic carboxylic acid include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid. Among these, salicylic acid is preferable.

[0485] Examples of the phosphorus oxo acid include phosphoric acid, phosphonic acid, and phosphinic acid. Among these, phosphonic acid is particularly preferable.

[0486] Examples of the phosphorus oxo acid derivative include an ester obtained by substituting a hydrogen atom in the above-described oxo acid with a hydrocarbon group. Examples of the hydrocarbon group include an alkyl group having 1 to 5 carbon atoms and an aryl group having 6 to 15 carbon atoms.

[0487] Examples of the phosphoric acid derivatives include phosphoric acid esters such as phosphoric acid di-n-butyl ester and phosphoric acid diphenyl ester.

[0488] Examples of the phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.

[0489] Examples of the phosphinic acid derivatives include phosphinic acid ester and phenylphosphinic acid.

[0490] In the resist composition of the present embodiment, the component (E) may be used alone or in combination of two or more kinds thereof.

[0491] In a case where the resist composition contains the component (E), the content of the component (E) is preferably in a range of 0.01 to 5 parts by mass and more preferably in a range of 0.05 to 3 parts by mass with respect to 100 parts by mass of the component (A). In a case where the content thereof is in the above-described range, the sensitivity, lithography characteristics, and the like are improved.

<<Component (F): Fluorine Additive Component>>

[0492] The resist composition according to the present embodiment may further contain a fluorine additive component (hereinafter, referred to as component (F)) as a hydrophobic resin. The component (F) is used to impart water repellency to the resist film and used as a resin different from the component (A), whereby the lithography characteristics can be improved.

[0493] As the component (F), for example, the fluorine-containing polymer compounds described in Japanese Unexamined Patent Application, First Publication Nos. 2010-002870, 2010-032994, 2010-277043, 2011-13569, and 2011-128226 can be used.

[0494] Specific examples of the component (F) include a polymer having a constitutional unit (f1) represented by General Formula (f1-1). As the polymer, a polymer (homopolymer) formed of only the constitutional unit (f1) represented by Formula (f1-1); a copolymer of the constitutional unit (f1) and the constitutional unit (a1); or a copolymer of the constitutional unit (f1), a constitutional unit derived from acrylic acid or methacrylic acid, and the constitutional unit (a1) is preferable, and a copolymer of the constitutional unit (f1) and the constitutional unit (a1) is more preferable. Here, as the constitutional unit (a1) copolymerized with the constitutional unit (f1), a constitutional unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate or a constitutional unit derived from 1-methyl-1-adamantyl (meth)acrylate is preferable, and a constitutional unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate is more preferable.

##STR00119##

[0495] [In the formula, R has the same definition as described above, Rf.sup.102 and Rf.sup.103 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Rf.sup.102 and Rf.sup.103 may be the same as or different from each other. nf.sup.1 represents an integer of 0 to 5, and Rf.sup.101 represents an organic group having a fluorine atom.]

[0496] In Formula (f1-1), R bonded to the carbon atom at the -position has the same definition as described above. It is preferable that R represents a hydrogen atom or a methyl group.

[0497] In Formula (f1-1), a fluorine atom is preferable as the halogen atom as Rf.sup.102 and Rf.sup.103. Examples of the alkyl group having 1 to 5 carbon atoms as Rf.sup.102 and Rf.sup.103 include the same groups as those for the alkyl group having 1 to 5 carbon atoms as R. Among the examples, a methyl group or an ethyl group is preferable. Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms for Rf.sup.102 and Rf.sup.103 include groups in which some or all hydrogen atoms of an alkyl group having 1 to 5 carbon atoms have been substituted with halogen atoms. Among these, a fluorine atom is preferable as the halogen atom. Among these, Rf.sup.102 and Rf.sup.103 represent preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group, and still more preferably a hydrogen atom.

[0498] In Formula (f1-1), nf.sup.1 represents an integer of 0 to 5, preferably an integer of 0 to 3, and more preferably 1 or 2.

[0499] In Formula (f1-1), Rf.sup.101 represents an organic group having a fluorine atom and preferably a hydrocarbon group having a fluorine atom.

[0500] The hydrocarbon group having a fluorine atom may be linear, branched, or cyclic, and the number of carbon atoms thereof is preferably in a range of 1 to 20, more preferably in a range of 1 to 15, and particularly preferably in a range of 1 to 10.

[0501] In the hydrocarbon group having a fluorine atom, preferably 25% or greater of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or greater thereof are fluorinated, and particularly preferably 60% or greater thereof are fluorinated from the viewpoint of increasing the hydrophobicity of the resist film during immersion exposure.

[0502] Among examples, Rf.sup.101 represents more preferably a fluorinated hydrocarbon group having 1 to 6 carbon atoms and particularly preferably a trifluoromethyl group, CH.sub.2CF.sub.3, CH.sub.2CF.sub.2CF.sub.3, CH(CF.sub.3).sub.2, CH.sub.2CH.sub.2CF.sub.3, or CH.sub.2CH.sub.2CF.sub.2CF.sub.2CF.sub.2CF.sub.3.

[0503] The weight-average molecular weight (Mw) (in terms of polystyrene according to gel permeation chromatography) of the component (F) is preferably in a range of 1000 to 50000, more preferably in a range of 5000 to 40000, and most preferably in a range of 10000 to 30000. In a case where the weight-average molecular weight thereof is less than or equal to the upper limits of the above-described ranges, the resist composition exhibits a satisfactory solubility in a solvent for a resist enough to be used as a resist. Meanwhile, in a case where the weight-average molecular weight thereof is greater than or equal to the lower limits of the above-described ranges, water repellency of the resist film is satisfactory.

[0504] Further, the dispersity (Mw/Mn) of the component (F) is preferably in a range of 1.0 to 5.0, more preferably in a range of 1.0 to 3.0, and most preferably in a range of 1.0 to 2.5.

[0505] In the resist composition according to the present embodiment, the component (F) may be used alone or in combination of two or more kinds thereof.

[0506] In a case where the resist composition contains the component (F), the content of the component (F) is preferably in a range of 0.5 to 10 parts by mass and more preferably in a range of 1 to 10 parts by mass with respect to 100 parts by mass of the component (A).

<<Component(S): Organic Solvent Component>>

[0507] The resist composition of the present embodiment can be produced by dissolving the resist materials in an organic solvent component (hereinafter, referred to as component(S)).

[0508] The component(S) may be any organic solvent which can dissolve each component to be used to obtain a uniform solution, and an optional organic solvent can be appropriately selected from those which have been known as solvents of a chemically amplified resist composition and then used in the related art.

[0509] In the resist composition of the present embodiment, the component(S) may be used alone or in the form of a mixed solvent of two or more kinds thereof. Among these, PGMEA, PGME, -butyrolactone, EL, or cyclohexanone is preferable.

[0510] Further, a mixed solvent obtained by mixing PGMEA with a polar solvent is also preferable as the component(S). The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility or the like between PGMEA and the polar solvent.

[0511] Further, a mixed solvent of -butyrolactone and at least one selected from PGMEA and EL is also preferable as the component(S). In this case, as the mixing ratio, the mass ratio between the former and the latter is preferably in a range of 70:30 to 95:5.

[0512] The amount of the component(S) to be used is not particularly limited and is appropriately set to have a concentration which enables coating a substrate or the like depending on the thickness of the coated film. The component(S) is typically used in an amount such that the solid content concentration of the resist composition is set to be in a range of 0.1% to 20% by mass and preferably in a range of 0.2% to 15% by mass.

[0513] As desired, miscible additives such as additive resins, dissolution inhibitors, plasticizers, stabilizers, colorants, halation prevention agents, and dyes for improving the performance of the resist film can be added to the resist composition of the present embodiment, as appropriate.

[0514] After the resist material is dissolved in the component(S), impurities and the like may be removed from the resist composition of the present embodiment using a porous polyimide film, a porous polyamideimide film, or the like. For example, the resist composition may be filtered using a filter formed of a porous polyimide film, a filter formed of a porous polyamideimide film, a filter formed of a porous polyimide film and a porous polyamideimide film, or the like. Examples of the porous polyimide film and the porous polyamideimide film include those described in Japanese Unexamined Patent Application, First Publication No. 2016-155121.

[0515] The resist composition of the present embodiment described above contains a specific component (D0) represented by General Formula (do). The component (D0) generates a carboxylic acid upon light exposure and can act as a quencher (acid diffusion control agent) in an unexposed portion of the resist film. In the component (D0), an iodine atom (I) and a fluorinated hydrocarbon group (Rf) are bonded to a benzene ring of the anion moiety via a linking group. The iodine atom (I) has high hydrophobicity and large absorption of EUV having a wavelength of 13.5 nm.

[0516] In the present embodiment, since the anion moiety of the component (D0) has an iodine atom (I), the hydrophobicity of the unexposed portion of the resist film is increased, and the dissolution contrast is easily obtained. In addition, since the anion moiety of the component (D0) has an iodine atom (I), the absorption increases with respect to light exposure.

[0517] However, the amount of light reaching the bottom portion of the resist film (the interface with the substrate) is likely to be reduced. That is, the amount of the acid to be generated in the resist film is relatively small at the bottom portion of the resist film and relatively large at the upper portion of the resist film.

[0518] In the present embodiment, since the anion moiety of the component (D0) contains a fluorinated hydrocarbon group (Rf) having a total of 5 or more fluorine atoms, the component (D0) is likely to be unevenly distributed in the upper portion of the resist film. In this manner, a difference in the amount of each acid generated upon light exposure is reduced at the bottom portion and the upper portion of the resist film.

[0519] According to the resist composition of the present embodiment, it is assumed that both high sensitivity and roughness reduction can be achieved and a pattern having a satisfactory shape with high rectangularity can be formed, due to the synergistic action described above.

(Method for Forming Resist Pattern)

[0520] A resist pattern formation method according to the second aspect according to the present invention is a method including a step of forming a resist film on a support using the resist composition according to the first aspect of the present invention described above, a step of exposing the resist film to light, and a step of developing the resist film exposed to light to form a resist pattern.

[0521] According to the embodiment of the resist pattern formation method, a resist pattern formation method by performing processes as described below is an exemplary example.

[0522] First, a support is coated with the resist composition of the present embodiment using a spinner or the like, and a bake (post apply bake (PAB)) treatment is performed, for example, under a temperature condition of 80 C. to 150 C. for 40 to 120 seconds and preferably 60 to 90 seconds to form a resist film.

[0523] Following the selective exposure carried out on the resist film by, for example, exposure through a mask (mask pattern) having a predetermined pattern formed on the mask by using an exposure apparatus such as an electron beam lithography apparatus or an ArF exposure apparatus, or direct irradiation of the resist film for drawing or the like with an electron beam without using a mask pattern, a bake treatment (post-exposure bake (PEB)) is carried out, for example, under a temperature condition in a range of 80 C. to 150 C. for 40 to 120 seconds and preferably 60 to 90 seconds.

[0524] Next, the resist film is subjected to a developing treatment. The developing treatment is conducted using an alkali developing solution in a case of an alkali developing process and using a developing solution containing an organic solvent (organic developing solution) in a case of a solvent developing process.

[0525] After the developing treatment, it is preferable to conduct a rinse treatment. As the rinse treatment, water rinsing using pure water is preferable in a case of the alkali developing process, and rinsing using a rinse solution containing an organic solvent is preferable in a case of the solvent developing process.

[0526] In a case of the solvent developing process, after the developing treatment or the rinse treatment, the developing solution or the rinse solution attached onto the pattern may be removed by a treatment using a supercritical fluid.

[0527] After the developing treatment or the rinse treatment, drying is conducted. A bake treatment (post bake) may be conducted after the developing treatment in some cases.

[0528] The support is not particularly limited and a known support of the related art can be used, and examples thereof include a substrate for an electronic component and a substrate on which a predetermined wiring pattern has been formed. Specific examples thereof include a metal substrate such as a silicon wafer, copper, chromium, iron, or aluminum; and a glass substrate. As the materials of the wiring pattern, for example, copper, aluminum, nickel, or gold can be used.

[0529] The wavelength to be used for light exposure is not particularly limited and the exposure can be conducted using radiation such as an ArF excimer laser, a KrF excimer laser, an F.sub.2 excimer laser, extreme ultraviolet (EUV) rays, vacuum ultraviolet rays (VUV), electron beams (EB), X-rays, and soft X-rays.

[0530] The resist pattern formation method of the present embodiment is particularly useful in a case where the step of exposing the resist film to light includes an operation of exposing the resist film to extreme ultraviolet (EUV) rays or electron beams (EB).

[0531] The method of exposing the resist film to light may be general exposure (dry exposure) conducted in air or an inert gas such as nitrogen, or liquid immersion lithography.

[0532] The liquid immersion lithography is an exposure method in which the region between the resist film and the lens at the lowermost position of the exposure apparatus is filled with a solvent (liquid immersion medium) in advance that has a refractive index greater than the refractive index of air, and the exposure (immersion exposure) is conducted in this state.

[0533] As the liquid immersion medium, a solvent having a refractive index greater than the refractive index of air but less than the refractive index of the resist film to be exposed is preferable, and examples thereof include water, a fluorine-based inert liquid, a silicon-based solvent, and a hydrocarbon-based solvent.

[0534] As the liquid immersion medium, water is preferably used.

[0535] As the alkali developing solution used for the developing treatment in the alkali developing process, a 0.1 to 10 mass % tetramethylammonium hydroxide (TMAH) aqueous solution is an exemplary example.

[0536] The organic solvent contained in the organic developing solution used for the developing treatment in the solvent developing process may be any solvent that is capable of dissolving the component (A) (the component (A) before light exposure) and can be appropriately selected from known organic solvents. Specific examples thereof include a polar solvent such as a ketone-based solvent, an ester-based solvent, an alcohol-based solvent, a nitrile-based solvent, an amide-based solvent, and an ether-based solvent, and a hydrocarbon-based solvent.

[0537] Examples of the ester-based solvent include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butyl butanoate, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, and butyl propionate.

[0538] Examples of the nitrile-based solvent include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

[0539] Known additives can be blended into the organic developing solution as necessary. Examples of the additive include a surfactant. The surfactant is not particularly limited, and for example, an ionic or non-ionic fluorine-based and/or silicon-based surfactant can be used.

[0540] The developing treatment can be performed according to a known developing method, and examples thereof include a method of immersing a support in a developing solution for a certain time (a dip method), a method of raising a developing solution on the surface of a support using the surface tension and maintaining the state for a certain time (a puddle method), a method of spraying a developing solution to the surface of a support (spray method), and a method of continuously ejecting a developing solution onto a support rotating at a certain rate while scanning a developing solution ejection nozzle at a certain rate (dynamic dispense method).

[0541] As the organic solvent contained in the rinse solution used for the rinse treatment after the developing treatment in the solvent developing process, for example, a solvent that is unlikely to dissolve a resist pattern can be appropriately selected from the organic solvents described as the organic solvent used in the organic developing solution and then used. Typically, at least one solvent selected from a hydrocarbon-based solvent, a ketone-based solvent, an ester-based solvent, an alcohol-based solvent, an amide-based solvent, and an ether-based solvent is used.

[0542] These organic solvents may be used alone or in combination of two or more kinds thereof. Further, an organic solvent other than the above-described solvents and water may be mixed and used.

[0543] The rinse treatment carried out using a rinse solution (washing treatment) can be performed according to a known rinse method. Examples of the method of performing the rinse treatment include a method of continuously ejecting a rinse solution onto a support rotating at a certain rate (rotary coating method), a method of immersing a support in a rinse solution for a certain time (dip method), and a method of spraying a rinse solution to the surface of a support (spray method).

[0544] According to the resist pattern formation method of the present embodiment described above, since the above-described resist composition is used, high sensitivity can be achieved in a case of forming a resist pattern, and a decrease in film thickness during development can be suppressed.

[0545] Various materials that are used in the resist composition according to the above-described embodiment and the resist pattern formation method according to the above-described embodiment (for example, a resist solvent, a developing solution, a rinse solution, a composition for forming an antireflection film, and a composition for forming a top coat) preferably do not contain impurities such as a metal, a metal salt containing halogen, an acid, an alkali, and a component containing a sulfur atom or phosphorus atom.

[0546] Here, examples of the impurities containing metal atoms include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, and salts thereof. The content of the impurities contained in these materials is preferably 200 ppb or less, more preferably 1 ppb or less, still more preferably 100 parts per trillion (ppt) or less, particularly preferably 10 ppt or less, and most preferably substantially zero (less than or equal to the detection limit of the measuring device).

(Compound)

[0547] The compound according to a third aspect of the present invention is a compound represented by General Formula (d0).

##STR00120##

[0548] [In the formula, Rf represents a fluorinated hydrocarbon group. V.sup.0 represents a hydrocarbon group which may have a substituent or a single bond. Y.sup.0 represents a divalent linking group having an oxygen atom. I represents an iodine atom. x represents an integer of 1 to 4, y represents an integer of 1 to 4, and 2x+y5 is satisfied. A total number of fluorine atoms contained in x pieces of Rf's is 5 or more. A benzene ring in the formula may have a substituent other than a group represented by (RfV.sup.0Y.sup.0) and the iodine atom. M.sup.m+ represents a sulfonium cation or an iodonium cation. m represents an integer of 1 or greater.]

[0549] The compound represented by General Formula (do) is the same as the component (D0) in the resist composition according to the first aspect of the present invention described above.

[0550] The compound of the present embodiment is preferably a compound in which the total number of fluorine atoms contained in x pieces of Rf's in Formula (d0) is 5 or more and 11 or less.

[0551] Alternatively, the compound of the present embodiment is preferably a compound in which y in Formula (d0) represents an integer of 1 to 3.

[0552] Alternatively, the compound of the present embodiment is preferably a compound in which Rf in Formula (d) represents a chain-like fluorinated hydrocarbon group.

[Method of Producing Compound Represented by General Formula (d0)]

[0553] The component (D0) can be produced by a known production method.

[0554] As an embodiment of the method of producing the component (D0), a production method for each compound in a case where Y.sup.0 in General Formula (d0) represents O (ether bond) and a case where Y.sup.0 in General Formula (d0) represents C(O)O (ester bond) is described below.

First Step:

[0555] First, a compound (ca0) represented by General Formula (ca0) is used as a starting raw material, and the compound (ca0) reacts with a tertiary alcohol to obtain a first intermediate (a0) represented by General Formula (a0).

##STR00121##

[0556] [In the formula, I is an iodine atom. x represents an integer of 1 to 4, y represents an integer of 1 to 4, and 2x+y5 is satisfied. The benzene ring in the formula may have a substituent other than a hydroxy group and an iodine atom. R$ represents a tertiary alkyl group.]

[0557] In the first step, the number of bonds and the bonding positions of the hydroxy group and the number of bonds and the bonding positions of the iodine atom of the compound (ca0) as a starting raw material are appropriately selected according to the target compound (component (D0)).

[0558] As the tertiary alcohol (R.sup.SOH), tert-butyl alcohol, 1-methylcyclopentanol, and the like can be used.

[0559] In the reaction between the compound (ca0) and the tertiary alcohol, a condensing agent is appropriately selected and used. Examples of the condensing agent include dicyclohexylcarbodiimide, diisopropylcarbodiimide (DIC), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride, and carbonyldiimidazole (CDI).

[0560] The organic solvent in a case where the compound (ca) reacts with a tertiary alcohol may be an organic solvent which can dissolve the compound (ca0), does not react with the compound (ca0), and has satisfactory compatibility with a tertiary alcohol, and examples thereof include dichloromethane, dichloroethane, chloroform, tetrahydrofuran, N,N-dimethylformamide, acetonitrile, propionitrile, N,N-dimethylacetamide, and dimethyl sulfoxide.

[0561] In the first step, the reaction temperature is, for example, in a range of 40 C. to 80 C., and the reaction time is, for example, 1 hour or longer and 10 hours or shorter.

Second Step:

[0562] Next, in a case where the target component (D0) is a component in which Y.sup.0 in General Formula (d0) represents O (ether bond), the first intermediate (a0) reacts with the following raw material compound (cb0-1) to obtain the following second intermediate (b0-1) (second-1 step).

[0563] Alternatively, in a case where the target component (D0) is a component in which Y.sup.0 in General Formula (d0) represents C(O)O (ester bond), the first intermediate (a0) reacts with the following raw material compound (cb0-2) to obtain the following second intermediate (b0-2) (second-2 step).

Second-1 Step:

[0564] In the second-1 step, the first intermediate (a0) reacts with a bromo-containing reagent (cb0-1) represented by General Formula (cb0-1) in the presence of a base to obtain a second intermediate (b0-1) represented by General Formula (b0-1).

##STR00122##

[0565] [In the formula, I is an iodine atom. x represents an integer of 1 to 4, y represents an integer of 1 to 4, and 2x+y5 is satisfied. The benzene ring in the formula may have a substituent other than a hydroxy group and an iodine atom. R.sup.S represents a tertiary alkyl group. Rf represents a fluorinated hydrocarbon group. V.sup.0 represents a hydrocarbon group which may have a substituent or a single bond. Br represents a bromine atom.]

[0566] In the second-1 step, the number of fluorine atoms, the structure of the hydrocarbon group, and the like of the bromo-containing reagent (cb0-1) are appropriately selected in a range of 5 or more depending on the target compound (component (D0)).

[0567] Specific examples of the base include sodium hydride, K.sub.2CO.sub.3, Cs.sub.2CO.sub.3, lithium diisopropylamide (LDA), triethylamine, and 4-dimethylaminopyridine.

[0568] The organic solvent in a case where the first intermediate (a0) reacts with the bromo-containing reagent (cb0-1) may be an organic solvent that can dissolve the first intermediate (a0) and the bromo-containing reagent (cb0-1) and does not react with the first intermediate (a0) and the bromo-containing reagent (cb0-1), and examples thereof include dichloromethane, dichloroethane, chloroform, tetrahydrofuran, N,N-dimethylformamide, acetonitrile, propionitrile, N,N-dimethylacetamide, and dimethyl sulfoxide.

[0569] In the second-1 step, the reaction temperature is, for example, in a range of 0 C. to 50 C., and the reaction time is, for example, 1 hour or longer and 24 hours or shorter.

Second-2 Step:

[0570] In the second-2 step, the first intermediate (a0) reacts with a carboxylic acid raw material (cb0-2) represented by General Formula (cb0-2) in the presence of a base to obtain a second intermediate (b0-2) represented by General Formula (b0-2).

##STR00123##

[0571] [In the formula, I is an iodine atom. x represents an integer of 1 to 4, y represents an integer of 1 to 4, and 2x+y5 is satisfied. The benzene ring in the formula may have a substituent other than a hydroxy group and an iodine atom. R$ represents a tertiary alkyl group.

[0572] Rf represents a fluorinated hydrocarbon group. V.sup.0 represents a hydrocarbon group which may have a substituent or a single bond.]

[0573] In the second-2 step, the number of fluorine atoms, the structure of the hydrocarbon group, and the like of the carboxylic acid raw material (cb0-2) are appropriately selected in a range of 5 or more depending on the target compound (component (D0)).

[0574] Specific examples of the base include sodium hydride, K.sub.2CO.sub.3, Cs.sub.2CO.sub.3, lithium diisopropylamide (LDA), triethylamine, and 4-dimethylaminopyridine.

[0575] In the reaction between the compound (ca0) and the tertiary alcohol, a condensing agent is appropriately selected and used. Examples of the condensing agent include dicyclohexylcarbodiimide, diisopropylcarbodiimide (DIC), 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride, and carbonyldiimidazole (CDI).

[0576] The organic solvent in a case where the first intermediate (a0) reacts with the carboxylic acid raw material (cb0-2) may be an organic solvent which can dissolve the first intermediate (a0) and the carboxylic acid raw material (cb0-2) and does not react with the first intermediate (a0) and the carboxylic acid raw material (cb0-2), and examples thereof include dichloromethane, dichloroethane, chloroform, tetrahydrofuran, N,N-dimethylformamide, acetonitrile, propionitrile, N,N-dimethylacetamide, and dimethyl sulfoxide.

[0577] In the second-2 step, the reaction temperature is, for example, in a range of 0 C. to 50 C., and the reaction time is, for example, 1 hour or longer and 24 hours or shorter.

Third Step:

[0578] Next, the second intermediate (b0-1) or the second intermediate (b0-2) is hydrolyzed to obtain a precursor (D0pre).

[0579] In the following reaction formulae, a case of hydrolyzing the second intermediate (b0-1) will be described.

##STR00124##

[0580] [In the formula, I is an iodine atom. x represents an integer of 1 to 4, y represents an integer of 1 to 4, and 2x+y5 is satisfied. The benzene ring in the formula may have a substituent other than a hydroxy group and an iodine atom. R.sup.S represents a tertiary alkyl group.

[0581] Rf represents a fluorinated hydrocarbon group. V.sup.0 represents a hydrocarbon group which may have a substituent or a single bond.]

[0582] In the hydrolysis of the second intermediate (b0-1) and the second intermediate (b0-2), an acid can be used as a catalyst. As this acid, for example, trifluoroacetic acid, methanesulfonic acid, or the like can be used.

[0583] The organic solvent in a case of hydrolyzing the second intermediate (b0-1) and the second intermediate (b0-2) may be an organic solvent that can dissolve as the second intermediate and the acid catalyst and does not react with the second intermediate and the acid catalyst, and examples thereof include dichloromethane, dichloroethane, chloroform, tetrahydrofuran, N,N-dimethylformamide, acetonitrile, propionitrile, N,N-dimethylacetamide, and dimethyl sulfoxide.

[0584] In the third step, the reaction temperature is, for example, in a range of 10 C. to 60 C., and the reaction time is, for example, 1 hour or longer and 24 hours or shorter.

Fourth Step:

[0585] Next, a target compound represented by General Formula (d0) is obtained by carrying out a salt exchange reaction between the precursor (D0pre) and a compound (S-1) represented by General Formula (S-1).

##STR00125##

[0586] [In the formula, 1 is an iodine atom. x represents an integer of 1 to 4, y represents an integer of 1 to 4, and 2x+y5 is satisfied. The benzene ring in the formula may have a substituent other than a hydroxy group and an iodine atom. R.sup.S represents a tertiary alkyl group. Rf represents a fluorinated hydrocarbon group. V.sup.0 represents a hydrocarbon group which may have a substituent or a single bond. Z represents a counter anion. M.sup.m+ represents a sulfonium cation or an iodonium cation. m represents an integer of 1 or greater.]

[0587] In the formula, examples of the counter anion as Z.sup. include ions that can be an acid having a lower acidity than that of a precursor represented by General Formula (D0pre), and specific examples thereof include a halogen ion such as a bromine ion or a chloride ion; and BF.sub.4.sup., AsF.sub.6.sup., SbF.sub.6.sup., PF.sub.6.sup., and ClO.sub.4.sup.. Among these, Z represents preferably a halogen ion and more preferably a bromine ion.

[0588] In the formulae, M.sup.m+ and m each have the same definition as that for M.sup.m+ and m in General Formula (d0).

[0589] In the fourth step, a base may be used for the salt exchange reaction between the precursor (D0pre) and the compound (S-1). Examples of the base include tetramethylammonium hydroxide (TMAH), sodium hydride, K.sub.2CO.sub.3, Cs.sub.2CO.sub.3, lithium diisopropylamide (LDA), triethylamine, and 4-dimethylaminopyridine.

[0590] The solvent in a case of carrying out the salt exchange reaction between the precursor (D0pre) and the compound (S-1) may be an organic solvent or a mixed solvent of an organic solvent and water. Examples of the organic solvent include a ketone-based solvent such as cyclohexanone, methyl ethyl ketone, diethyl ketone, or methyl isobutyl ketone, an ether-based solvent such as diethyl ether, t-butyl methyl ether, or diisopropyl ether, a halogen-based solvent such as tetrahydrofuran, 1,3-dioxolane, dichloromethane, or 1,2-dichloroethane, an ester-based solvent such as ethyl acetate or propylene glycol monomethyl ether acetate, propionitrile, and a mixed solvent thereof.

[0591] In the fourth step, the reaction temperature is, for example, in a range of 0 C. to 50 C., and the reaction time is, for example, 10 minutes or longer and 5 hours or shorter.

[0592] After the salt exchange reaction is completed, the compound in the reaction solution may be isolated and purified. A known method in the related art can be used for isolation and purification, and for example, concentration, solvent extraction, distillation, crystallization, recrystallization, or chromatography can be appropriately combined and used.

[0593] The structure of the compound obtained as described above can be identified by general organic analysis methods such as .sup.1H-nuclear magnetic resonance (NMR) spectroscopy, .sup.13C-NMR spectroscopy, .sup.19F-NMR spectroscopy, infrared (IR) absorption spectroscopy, mass spectrometry (MS), elemental analysis, and X-ray crystal diffraction.

[0594] As raw materials, reagents, and the like used in each step, commercially available products may be used, or synthesized products may be used.

[0595] In the above-described method of producing the component (D0), the method of producing each compound in a case where Y.sup.0 in General Formula (d0) represents O (ether bond) and in a case where Y.sup.0 in General Formula (d0) represents C(O)O (ester bond) has been described, and for example, in the method of producing a compound in a case where Y.sup.0 in General Formula (d0) represents C(O)NH (amide bond), amino-iodobenzoic acid may be used as a starting raw material instead of the compound (ca0). For example, OH in General Formula (ca0) may be changed to NH.sub.2.

[0596] The compound according to the third aspect of the present invention described above is a compound useful as a base component in the resist composition according to the first aspect of the present invention described above.

(Acid Diffusion Control Agent)

[0597] An acid diffusion control agent according to a fourth aspect of the present invention contains the compound according to the third aspect described above.

[0598] Such an acid diffusion control agent is useful as an acid diffusion control agent for a chemically amplified resist composition.

[0599] Since the compound according to the third aspect described above has a carboxylate anion in the anion moiety, an acid with relatively weak acid strength as compared with a fluorinated alkylsulfonate anion or the like contained in an anion moiety of an acid generator that is typically used in a chemically amplified resist composition is generated upon light exposure.

[0600] In a case where such an acid diffusion control agent is used in the chemically amplified resist composition, the lithography characteristics such as the pattern shape (rectangularity) and roughness reduction are further improved in the resist pattern formation. Particularly in the resist pattern formation using EB or an EUV light source, the lithography characteristics such as the sensitivity, the pattern shape (rectangularity), and the roughness reduction are further improved by using such an acid diffusion control agent.

EXAMPLES

[0601] Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

[0602] In present Examples, a compound represented by Chemical Formula (X-1-1) is denoted by a compound (X-1-1), and compounds represented by other chemical formulae are also denoted in the same manner.

(Production Example 1-1)

[0603] A three-neck flask having a volume of 300 mL was charged with 1,1-carbonyldiimidazole (CDI) (4.60 g, 28.4 mmol) and tetrahydrofuran (THF) (20 g), a solution obtained by dissolving 6-iodosalicylic acid (ca1) (6.7 g, 25.5 mmol) as a starting raw material in THF (20 g) was added dropwise thereto over 30 minutes, and the solution was allowed to react for 1 hour. Thereafter, tert-butyl alcohol (2.7 g, 30.6 mmol) was added to the solution, and the solution was allowed to react at 65 C. for 3 hours. After the solution was cooled, ultrapure water (250 g) and methyl tert-butyl ether (MTBE) (150 g) were added thereto, the solution was stirred for 30 minutes, and the aqueous layer was removed. Thereafter, the organic layer was washed with ultrapure water (100 g) three times, the organic layer was concentrated using a rotary evaporator, the obtained crude product was dissolved again in THF (20 g), the solution was added dropwise to methanol (150 g), and the precipitated solid was filtered. The obtained residue was dried under reduced pressure, thereby obtaining a first intermediate (a1) (6.1 g, yield: 75.0%).

##STR00126##

(Production Examples 1-2 to 1-7)

[0604] 6-lodosalicylic acid (ca1) (6.7 g, 25.5 mmol) serving as a starting raw material was changed to each of the following starting raw materials (ca2) to (ca8) at the equimolar ratio, thereby obtaining first intermediates (a2) to (a8) in the same manner as in (Production Example 1-1) described above.

##STR00127##

[0605] The obtained first intermediates (a1) to (a8) are shown below.

##STR00128##

Production (1) of Second Intermediate

Production Example 2-1-1

[0606] A three-neck flask having a volume of 300 mL was charged with the first intermediate (a1) (6.1 g, 19.0 mmol), potassium carbonate (2.8 g, 20.3 mmol), and N,N-dimethylformamide (DMF) (50 g), 3-bromo 1,1,1,2,2 pentafluoropropane (cb1) as a bromo-containing reagent was added dropwise thereto over 30 minutes, and the mixture was allowed to react for 6 hours. After the reaction, ultrapure water (100 g) and MTBE (100 g) were added thereto, the mixture was stirred for 30 minutes, and the aqueous layer was removed. Thereafter, the organic layer was washed with ultrapure water (100 g) three times, and the organic layer was concentrated using a rotary evaporator, thereby obtaining a second intermediate (b1) (7.0 g, yield: 80.0%).

##STR00129##

Production Example 2-1-2 to Production Example Feb. 1, 2011

[0607] The first intermediates (a2) to (a4) and (a6) to (a8), and the following bromo-containing reagents (cb1) to (cb6) were allowed to react with each other in the following combinations in the same manner as in (Production Example 2-1-1) described above, thereby obtaining second intermediates (b2) to (b5), (b8), (b10), and (b12) to (b15).

[0608] Second intermediate (b1): combination of first intermediate (a1) and bromo-containing reagent (cb1)

[0609] Second intermediate (b2): combination of first intermediate (a2) and bromo-containing reagent (cb6)

[0610] Second intermediate (b3): combination of first intermediate (a2) and bromo-containing reagent (cb3)

[0611] Second intermediate (b4): combination of first intermediate (a3) and bromo-containing reagent (cb1)

[0612] Second intermediate (b5): combination of first intermediate (a4) and bromo-containing reagent (cb1)

[0613] Second intermediate (b8): combination of first intermediate (a4) and bromo-containing reagent (cb4)

[0614] Second intermediate (b10): combination of first intermediate (a6) and bromo-containing reagent (cb5)

[0615] Second intermediate (b12): combination of first intermediate (a7) and bromo-containing reagent (cb1)

[0616] Second intermediate (b13): combination of first intermediate (a8) and bromo-containing reagent (cb2)

[0617] Second intermediate (b14): combination of first intermediate (a8) and bromo-containing reagent (cb6)

[0618] Second intermediate (b15): combination of first intermediate (a8) and bromo-containing reagent (cb3)

##STR00130##

[0619] The obtained second intermediates (b2) to (b5), (b8), (b10), and (b12) to (b15) are shown below.

##STR00131## ##STR00132##

Production of Second Intermediate (2)

Production Example 2-2-1

[0620] A three-neck flask having a volume of 200 mL was charged with 3,5-bis(trifluoromethyl)benzoic acid (cb7) (5.4 g, 20.9 mmol) as a carboxylic acid raw material, dichloromethane (150 g), diisopropylcarbodiimide (2.8 g, 22.2 mmol), and dimethylaminopyridine (0.045 g, 0.4 mmol), and the mixture was stirred at room temperature for 30 minutes. Thereafter, the first intermediate (a4) (8.5 g, 19.0 mmol) was put thereinto, and the mixture was stirred at room temperature for 6 hours. The reaction solution was filtered, and the filtrate was concentrated using a rotary evaporator. The concentrate was dissolved in acetonitrile (30 g) and subsequently added dropwise into MTBE (180 g), and the precipitated solid was filtered. The residue was dissolved again in THF (20 g), the solution was added dropwise to methanol (150 g), and the precipitated solid was filtered. After repeating this operation twice, the residue was dried under reduced pressure, thereby obtaining a second intermediate (b6) (10.7 g, yield: 82.1%).

##STR00133##

Production Example 2-2-2 to Production Example 2-2-4

[0621] The first intermediates (a5) and (a6) and the following carboxylic acid raw materials (cb7) to (cb9) were allowed to react with each other in the following combinations in the same manner as in (Production Example 2-2-1) described above, thereby obtaining second intermediates (b7), (b9), and (b11).

[0622] Second intermediate (b6): combination of first intermediate (a4) and carboxylic acid raw material (cb7)

[0623] Second intermediate (b7): combination of first intermediate (a5) and carboxylic acid raw material (cb7)

[0624] Second intermediate (b9): combination of first intermediate (a6) and carboxylic acid raw material (cb8)

[0625] Second intermediate (b11): combination of first intermediate (a6) and carboxylic acid raw material (cb9)

##STR00134##

[0626] The obtained second intermediates (b6), (b7), (b9), and (b11) are shown below.

##STR00135##

Production of Precursor (D0pre)

Production Example 3-1

[0627] A three-neck flask having a volume of 200 mL was charged with the second intermediate (b1) (6.5 g, 14.3 mmol), dichloromethane (100 g), and trifluoroacetic acid (TFA) (16.3 g, 143 mmol), and the mixture was stirred at 30 C. for 8 hours. After the reaction, ultrapure water (100 g) and MTBE (100 g) were added thereto, the mixture was stirred for 30 minutes, and the aqueous layer was removed. Thereafter, the organic layer was washed with ultrapure water (100 g) three times, and the organic layer was concentrated using a rotary evaporator, thereby obtaining a precursor (D0pre-1) (5.3 g, yield: 93.5%).

##STR00136##

Production Examples 3-2 to 3-15

[0628] The second intermediates (b2) to (b15) and trifluoroacetic acid were allowed to react with each other in the same manner as in (Production Example 3-1) described above, thereby obtaining precursors (D0pre-2) to (D0pre-15).

[0629] The obtained precursors (D0pre-1) to (D0pre-15) are shown below.

##STR00137## ##STR00138## ##STR00139##

Production of Compound (D0)

Production Example 4-1

[0630] The precursor (D0pre-1) (5.0 g, 12.6 mmol) and a compound (S-1-1) for salt exchange (4.7 g, 13.7 mmol) were dissolved in dichloromethane (100 g), a 5% tetramethylammonium hydroxide (TMAH) aqueous solution (25 g) was added thereto, and the solution was allowed to react at room temperature for 30 minutes. After completion of the reaction, the aqueous phase was removed, and the organic phase was washed with ultrapure water (20 g) 5 times. The organic phase was concentrated and dried using a rotary evaporator, thereby obtaining a target compound (D0-1) (7.9 g, yield: 95.2%).

##STR00140##

Production Examples 4-2 to 4-19

[0631] The precursors (D0pre-2) to (D0pre-15) and the following compounds (S-1-1) to (S-1-5) for salt exchange were allowed to react with each other in the following combinations in the same manner as in (Production Example 4-1) described above, thereby obtaining target compounds (D0-2) to (D0-19).

##STR00141##

[0632] Compound (D0-1): combination of precursor (D0pre-1) and compound (S-1-1) for salt exchange

[0633] Compound (D0-2): combination of precursor (D0pre-2) and compound (S-1-1) for salt exchange

[0634] Compound (D0-3): combination of precursor (D0pre-3) and compound (S-1-1) for salt exchange

[0635] Compound (D0-4): combination of precursor (D0pre-4) and compound (S-1-1) for salt exchange

[0636] Compound (D0-5): combination of precursor (D0pre-5) and compound (S-1-1) for salt exchange

[0637] Compound (D0-6): combination of precursor (D0pre-6) and compound (S-1-1) for salt exchange

[0638] Compound (D0-7): combination of precursor (D0pre-7) and compound (S-1-1) for salt exchange

[0639] Compound (D0-8): combination of precursor (D0pre-8) and compound (S-1-1) for salt exchange

[0640] Compound (D0-9): combination of precursor (D0pre-9) and compound (S-1-1) for salt exchange

[0641] Compound (D0-10): combination of precursor (D0pre-10) and compound (S-1-1) for salt exchange

[0642] Compound (D0-11): combination of precursor (D0pre-11) and compound (S-1-1) for salt exchange

[0643] Compound (D0-12): combination of precursor (D0pre-12) and compound (S-1-1) for salt exchange

[0644] Compound (D0-13): combination of precursor (D0pre-13) and compound (S-1-1) for salt exchange

[0645] Compound (D0-14): combination of precursor (D0pre-14) and compound (S-1-1) for salt exchange Compound (D0-15): combination of precursor (D0pre-15) and compound (S-1-1) for salt exchange

[0646] Compound (D0-16): combination of precursor (D0pre-8) and compound (S-1-2) for salt exchange

[0647] Compound (D0-17): combination of precursor (D0pre-8) and compound (S-1-4) for salt exchange

[0648] Compound (D0-18): combination of precursor (D0pre-8) and compound (S-1-3) for salt exchange

[0649] Compound (D0-19): combination of precursor (D0pre-14) and compound (S-1-5) for salt exchange

[0650] The obtained compounds (D0-1) to (D0-19) are shown below.

##STR00142## ##STR00143## ##STR00144## ##STR00145##

[0651] Further, the structures of the above-described compounds (D0-1) to (D0-19) were identified from the analysis results of the .sup.1H-NMR measurement shown below.

Structure of Compound (D0-1)

[0652] .sup.1H-NMR (DMSO, 400 MHz): (ppm)=7.74-7.90 (m, ArH, 15H), 7.56 (d, J-ArH, 1H), 7.18 (d, IArH, 1H), 6.89 (d, IArH, 1H), 4.51-4.68 (m, CH2, 2H)

Structure of Compound (D0-2)

[0653] .sup.1H-NMR (DMSO, 400 MHz): (ppm)=7.74-7.90 (m, ArH, 15H), 7.57 (d, IArH, 1H), 6.84 (d, IArH, 1H), 6.73 (d, IArH, 1H), 4.59 (s, CH2, 2H)

Structure of Compound (D0-3)

[0654] .sup.1H-NMR (DMSO, 400 MHz): (ppm)=7.74-7.90 (m, ArH, 15H), 7.57 (d, IArH, 1H), 6.84 (d, IArH, 1H), 6.73 (d, IArH, 1H), 4.51-4.68 (m, CH2, 2H)

Structure of Compound (D0-4)

[0655] .sup.1H-NMR (DMSO, 400 MHz): (ppm)=7.74-7.90 (m, ArH, IArH, 16H), 6.94 (d, IArH, 1H), 4.51-4.68 (m, CH2, 4H)

Structure of Compound (D0-5)

[0656] .sup.1H-NMR (DMSO, 400 MHz): (ppm)=7.99 (d, IArH, 1H), 7.74-7.90 (m, ArH, IArH, 16H), 4.51-4.68 (m, CH2, 2H)

Structure of Compound (D0-6)

[0657] .sup.1H-NMR (DMSO, 400 MHz): (ppm)=8.39 (d, ArH, 2H), 8.01 (d, ArH, 1H), 7.99 (d, IArH, 1H), 7.74-7.90 (m, ArH, IArH, 16H)

Structure of Compound (D0-7)

[0658] .sup.1H-NMR (DMSO, 400 MHz): (ppm)=9.48 (s, NH, 1H), 8.39 (d, ArH, 2H), 8.01 (d, ArH. 1H), 7.99 (d, IArH, 1H), 7.74-7.90 (m, ArH, IArH, 16H)

Structure of Compound (D0-8)

[0659] .sup.1H-NMR (DMSO, 400 MHz): (ppm)=7.99 (d, IArH, 1H), 7.74-7.90 (m, ArH, IArH, 16H), 4.05-4.25 (m, CH2, 2H), 2.63-2.73 (m, CH2, 2H)

Structure of Compound (D0-9)

[0660] .sup.1H-NMR (DMSO, 400 MHz): (ppm)=7.74-7.90 (m, ArH, IArH, 17H)

Structure of Compound (D0-10)

[0661] .sup.1H-NMR (DMSO, 400 MHz): (ppm)=7.74-7.90 (m, ArH, IArH, 17H), 4.05-4.25 (m, CH2, 2H), 2.63-2.73 (m, CH2, 2H)

Structure of Compound (D0-11)

[0662] .sup.1H-NMR (DMSO, 400 MHz): (ppm)=8.41 (d, ArH, 2H), 7.74-7.90 (m, ArH, IArH, 17H)

Structure of Compound (D0-12)

[0663] .sup.1H-NMR (DMSO, 400 MHz): (ppm)=7.74-7.90 (m, ArH, IArH, 16H), 4.51-4.68 (m, CH2, 4H)

Structure of Compound (D0-13)

[0664] .sup.1H-NMR (DMSO, 400 MHz): (ppm)=8.12 (d, IArH, 1H), 7.74-7.90 (m, ArH, 15H), 4.05-4.25 (m, CH2, 2H), 2.63-2.73 (m, CH2, 2H)

Structure of Compound (D0-14)

[0665] .sup.1H-NMR (DMSO, 400 MHz): (ppm)=8.12 (d, IArH, 1H), 7.74-7.90 (m, ArH, 15H), 4.59 (s, CH2, 2H)

Structure of Compound (D0-15)

[0666] .sup.1H-NMR (DMSO, 400 MHz): (ppm)=8.12 (d, IArH, 1H), 7.74-7.90 (m, ArH, 15), 4.51-4.68 (m, CH2, 2H)

Structure of Compound (D0-16)

[0667] .sup.1H-NMR (DMSO, 400 MHz): (ppm)=7.70-8.22 (m, ArH, IArH, 16H), 4.05-4.25 (m, CH2, 2H), 3.30-3.45 (m, SO2CH, 1H), 2.63-2.73 (m, CH2, 2H), 1.09-1.90 (m, Cyclohexyl, 10H)

Structure of Compound (D0-17)

[0668] .sup.1H-NMR (DMSO, 400 MHz): (ppm)=8.50 (d, ArH, 2H), 8.37 (d, ArH, 2H), 7.99 (d, IArH, 1H), 7.93 (t, ArH, 2H), 7.84 (d, IArH, 1H), 7.55-7.75 (m, ArH, 7H), 4.05-4.25 (m, CH2, 2H), 2.63-2.73 (m, CH2, 2H)

Structure of Compound (D0-18)

[0669] .sup.1H-NMR (DMSO, 400 MHz): (ppm)=7.77-7.99 (m, ArH, IArH, 13H), 4.05-4.25 (m, CH2, 2H), 2.63-2.73 (m, CH2, 2H)

Structure of Compound (D0-19)

[0670] .sup.1H-NMR (DMSO, 400 MHz): (ppm)=8.12 (d, IArH, 1H), 7.92-7.94 (m, ArH, 4H), 7.43-7.46 (m, ArH, 2H), 7.27-7.31 (m, ArH, 4H), 4.59 (s, CH2, 2H)

Preparation of Resist Composition

Examples 1 to 26 and Comparative Examples 1 to 4

[0671] Each of the components listed in Tables 1 to 3 was mixed and dissolved to prepare a resist composition of each example.

TABLE-US-00001 TABLE 1 Component Component Component Component (A) (B) (D) (S) Example 1 (A)-1 (B)-1 (D)-1 (S)-1 [100] [20.0] [6.2] [8000] Example 2 (A)-1 (B)-1 (D)-2 (S)-1 [100] [20.0] [6.6] [8000] Example 3 (A)-1 (B)-1 (D)-3 (S)-1 [100] [20.0] [6.7] [8000] Example 4 (A)-1 (B)-1 (D)-4 (S)-1 [100] [20.0] [6.7] [8000] Example 5 (A)-1 (B)-1 (D)-5 (S)-1 [100] [20.0] [7.4] [8000] Example 6 (A)-1 (B)-1 (D)-6 (S)-1 [100] [20.0] [8.4] [8000] Example 7 (A)-1 (B)-1 (D)-7 (S)-1 [100] [20.0] [8.4] [8000] Example 8 (A)-1 (B)-1 (D)-8 (S)-1 [100] [20.0] [8.0] [8000] Example 9 (A)-1 (B)-1 (D)-9 (S)-1 [100] [20.0] [8.0] [8000] Example 10 (A)-1 (B)-1 (D)-10 (S)-1 [100] [20.0] [8.9] [8000] Example 11 (A)-1 (B)-1 (D)-11 (S)-1 [100] [20.0] [9.0] [8000] Example 12 (A)-1 (B)-1 (D)-12 (S)-1 [100] [20.0] [8.8] [8000] Example 13 (A)-1 (B)-1 (D)-13 (S)-1 [100] [20.0] [8.7] [8000] Example 14 (A)-1 (B)-1 (D)-14 (S)-1 [100] [20.0] [9.0] [8000] Example 15 (A)-1 (B)-1 (D)-15 (S)-1 [100] [20.0] [9.0] [8000] Example 16 (A)-1 (B)-1 (D)-16 (S)-1 [100] [20.0] [9.3] [8000] Example 17 (A)-1 (B)-1 (D)-17 (S)-1 [100] [20.0] [7.9] [8000] Example 18 (A)-1 (B)-1 (D)-18 (S)-1 [100] [20.0] [8.6] [8000] Example 19 (A)-1 (B)-1 (D)-19 (S)-1 [100] [20.0] [9.2] [8000]

TABLE-US-00002 TABLE 2 Component Component Component Component (A) (B) (D) (S) Example 20 (A)-1 (B)-2 (D)-1 (S)-1 [100] [17.8] [6.2] [8000] Example 21 (A)-1 (B)-2 (D)-8 (S)-1 [100] [17.8] [8.0] [8000] Example 22 (A)-1 (B)-2 (D)-18 (S)-1 [100] [17.8] [8.6] [8000] Example 23 (A)-2 (B)-1 (D)-1 (S)-1 [100] [20.0] [6.2] [8000] Example 24 (A)-2 (B)-1 (D)-18 (S)-1 [100] [20.0] [8.6] [8000] Example 25 (A)-3 (B)-1 (D)-18 (S)-1 [100] [20.0] [8.6] [8000] Example 26 (A)-3 (B)-2 (D)-18 (S)-1 [100] [17.8] [8.6] [8000]

TABLE-US-00003 TABLE 3 Component Component Component Component (A) (B) (D) (S) Comparative (A)-1 (B)-1 (D)-21 (S)-1 Example 1 [100] [20.0] [5.0] [8000] Comparative (A)-1 (B)-1 (D)-22 (S)-1 Example 2 [100] [20.0] [5.8] [8000] Comparative (A)-1 (B)-1 (D)-23 (S)-1 Example 3 [100] [20.0] [9.1] [8000] Comparative (A)-1 (B)-1 (D)-24 (S)-1 Example 4 [100] [20.0] [3.9] [8000]

[0672] In Tables 1 to 3, each abbreviation has the following meaning. The numerical values in the brackets are blending amounts (parts by mass).

[0673] (A)-1: polymer compound represented by Chemical Formula (A1-1) The weight-average molecular weight (Mw) of the polymer compound (A1-1) in terms of standard polystyrene determined by GPC measurement was 5800, and the polydispersity (Mw/Mn) thereof was 1.54. The copolymerization compositional ratio (the ratio (molar ratio) of each constitutional unit in the structural formula) determined by .sup.13C-NMR was l/m=50/50.

[0674] (A)-2: polymer compound represented by Chemical Formula (A1-2) The weight-average molecular weight (Mw) of the polymer compound (A1-2) in terms of standard polystyrene determined by GPC measurement was 6000, and the polydispersity (Mw/Mn) thereof was 1.55. The copolymerization compositional ratio (the ratio (molar ratio) of each constitutional unit in the structural formula) determined by .sup.13C-NMR was l/m=50/50.

[0675] (A)-3: polymer compound represented by Chemical Formula (A1-3) The weight-average molecular weight (Mw) of the polymer compound (A1-3) in terms of standard polystyrene determined by GPC measurement was 5900, and the polydispersity (Mw/Mn) thereof was 1.54. The copolymerization compositional ratio (the ratio (molar ratio) of each constitutional unit in the structural formula) determined by .sup.13C-NMR was l/m=50/50.

##STR00146##

[0676] (B)-1: acid generator formed of compound (B1-1) shown below

[0677] (B)-2: acid generator formed of compound (B1-2) shown below

##STR00147##

[0678] (D)-1 to (D)-19: compounds (D0-1) to (D0-19) shown above

[0679] (D)-21: acid diffusion control agent formed of compound (D1-1) shown below

[0680] (D)-22: acid diffusion control agent formed of compound (D1-2) shown below

[0681] (D)-23: acid diffusion control agent formed of compound (D1-3) shown below

[0682] (D)-24: acid diffusion control agent formed of compound (D1-4) shown below

##STR00148##

[0683] (S)-1: mixed solvent of propylene glycol monomethyl ether acetate/propylene glycol monomethyl ether at mass ratio of 60/40

[0684] The resist composition of each example was applied onto an 8-inch silicon substrate which had been subjected to a hexamethyldisilazane (HMDS) treatment using a spinner, the coated film was subjected to a pre-bake (PAB) treatment on a hot plate at a temperature of 110 C. for 60 seconds so that the coated film was dried to form a resist film having a film thickness of 50 nm.

[0685] Next, drawing (exposure) was carried out on the resist film by using an electron beam lithography apparatus JEOL-JBX-9300FS (manufactured by JEOL Ltd.), with the target size being set to a 1:1 line-and-space pattern (hereinafter, referred to as an LS pattern) of a line width of 50 nm, at an acceleration voltage of 100 kV.

[0686] Thereafter, a post exposure bake (PEB) treatment was performed on the resist film at 110 C. for 60 seconds.

[0687] Subsequently, alkali development was performed at 23 C. for 60 seconds using a 2.38 mass % tetramethylammonium hydroxide (TMAH) aqueous solution NMD-3 (trade name, manufactured by TOKYO OHKA KOGYO CO., LTD.). Thereafter, water rinsing was performed for 15 seconds using pure water.

[0688] As a result, a 1:1 LS pattern having a line width of 50 nm was formed.

[Evaluation of Sensitivity]

[0689] An optimum exposure amount Eop (C/cm.sup.2) at which the LS pattern with a target size was formed according to the method in the section of <Resist pattern formation> was determined. The results thereof are listed in the columns of Eop (C/cm.sup.2) in Tables 4 to 6.

[Evaluation of Line Width Roughness (LWR)]

[0690] 3, which is a measure indicating LWR, was determined for the LS pattern formed by <Resist pattern formation> described above.

[0691] Here, 3 denotes the triple value (3) (unit: nm) of the standard deviation () determined from measurement results obtained by measuring 400 sites of line positions in the longitudinal direction of the line with a scanning electron microscope (trade name: S-9380, manufactured by Hitachi High-Tech Corporation, acceleration voltage of 800 V). The results are listed in the columns of LWR (nm) in Tables 4 to 6.

[0692] In a case where the value of the 3 is small, this indicates that the roughness of a line side wall is small and an LS pattern with a uniform width is obtained.

[Evaluation of Pattern Shape]

[0693] In the <Resist pattern formation>, the cross-sectional shape of the line in each of the obtained LS patterns was observed with a scanning electron microscope (trade name: SU8000, manufactured by Hitachi High-Tech Corporation, acceleration voltage of 300 V). In the observation of the cross-sectional shape of the line, the shape was observed at any 20 points of the line pattern.

[0694] A line width (Lt) in an upper portion of the line and a line width (Lm) in an intermediate portion of the line were measured in the height direction of the LS pattern, and the ratio (Lt/Lm) thereof was determined from the average value of 20 measured values of each of Lt and Lm. The rectangularity of the cross-sectional shape of the line denotes that the rectangularity is more satisfactory (that is, the rectangularity is high) as the value of Lt/Lm is close to 1.

[0695] In regard to the pattern shape, the rectangularity of the cross-sectional shape of the line was evaluated according to the following evaluation criteria using the ratio (Lt/Lm) as an index.

[0696] The evaluation was performed such that a case where 0.95(Lt/Lm)1.05 was satisfied was evaluated as A: particularly satisfactory; a case where 0.90(Lt/Lm)<0.95 or 1.05<(Lt/Lm)1.10 was satisfied was evaluated as B: satisfactory; and a case where (Lt/Lm)<0.90 or 1.10< (Lt/Lm) was satisfied was evaluated as C: defective.

[0697] As the evaluation of the pattern shape, the values of Lt/Lm and the evaluation results of rectangularity are listed in Tables 4 to 6.

TABLE-US-00004 TABLE 4 PAB PEB Eop LWR Pattern shape ( C.) ( C.) (C/cm.sup.2) (nm) Lt/Lm Rectangularity Example 1 110 110 106 5.2 0.93 B Example 2 110 110 105 5.2 0.91 B Example 3 110 110 105 5.4 0.98 A Example 4 110 110 104 5.4 1.07 B Example 5 110 110 98 5.2 0.93 B Example 6 110 110 98 5.4 0.94 B Example 7 110 110 100 5.4 0.94 B Example 8 110 110 97 5.1 0.98 A Example 9 110 110 97 5.2 0.98 A Example 10 110 110 97 5.4 1.10 B Example 11 110 110 97 5.5 1.06 B Example 12 110 110 98 5.5 1.10 B Example 13 110 110 92 5.6 0.93 B Example 14 110 110 92 5.7 0.91 B Example 15 110 110 92 5.6 0.98 A Example 16 110 110 98 5.2 0.98 A Example 17 110 110 98 5.2 0.98 A Example 18 110 110 96 5.1 0.98 A Example 19 110 110 92 5.7 0.91 B

TABLE-US-00005 TABLE 5 PAB PEB Eop LWR Pattern shape ( C.) ( C.) (C/cm.sup.2) (nm) Lt/Lm Rectangularity Example 20 110 110 107 5.3 0.93 B Example 21 110 110 99 5.2 0.98 A Example 22 110 110 98 5.1 0.98 A Example 23 110 110 107 5.3 0.93 B Example 24 110 110 96 5.1 0.98 A Example 25 110 110 96 5.0 0.98 A Example 26 110 110 98 5.0 0.98 A

TABLE-US-00006 TABLE 6 PAB PEB Eop LWR Pattern shape ( C.) ( C.) (C/cm.sup.2) (nm) Lt/Lm Rectangularity Comparative 110 110 115 6.1 0.93 B Example 1 Comparative 110 110 109 5.8 0.85 C Example 2 Comparative 110 110 92 6.0 0.88 C Example 3 Comparative 110 110 142 5.9 0.85 C Example 4

[0698] As shown in the results listed in Tables 4 to 6, based on the comparison between Examples 1 to 26 and Comparative Examples 1 to 4, it can be confirmed that the resist compositions of Examples 1 to 26, to which the present invention was applied, achieved both high sensitivity and roughness reduction and were capable of forming a pattern having a satisfactory shape with high rectangularity.

[0699] Hereinbefore, preferred examples of the present invention have been described, but the present invention is not limited to these examples. Additions, omissions, substitutions, and other modifications can be made without departing from the scope of the present invention. The present invention is not limited by the description above, but is limited only by the appended claims.

RESIST COMPOSITION, RESIST PATTERN FORMING METHOD, COMPOUND AND ACID DIFFUSION CONTROL AGENT

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Abstract

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