RESIST COMPOSITION, LAMINATE, AND PATTERNING PROCESS

Abstract

A resist composition including a hypervalent iodine compound represented by formula (1), a carboxy group-containing compound, and a solvent. In formula (1), n represents an integer of 0 to 4 when m is 0, an integer of 0 to 6 when m is 1, and an integer of 0 to 8 when m is 2; R.sup.1, R.sup.2, and R.sup.3 represent a halogen atom or a hydrocarbyl group having 1 to 10 carbon atoms; R.sup.4 represents a halogen atom or a hydrocarbyl group having 1 to 40 carbon atoms; R.sup.5 represents a carbonyl group or a hydrocarbylene group having 1 to 10 carbon atom; and I and R.sup.5 are bonded to adjacent carbon atoms of aromatic ring. This can provide: a resist composition that exhibits excellent sensitivity and resolution in photolithography using a high-energy beam, particularly in electron beam (EB) lithography and EUV lithography; and a patterning process using resist composition.

##STR00001##

Claims

1. A resist composition comprising a hypervalent iodine compound represented by the following formula (1), a carboxy group-containing compound, and a solvent, ##STR00271## wherein m represents an integer of 0 to 2; n represents an integer of 0 to 4 when m is 0, an integer of 0 to 6 when m is 1, and an integer of 0 to 8 when m is 2; R.sup.1, R.sup.2, and R.sup.3 represent each independently a halogen atom or a hydrocarbyl group having 1 to 10 carbon atoms and optionally having a heteroatom, and R.sup.1, R.sup.2, and R.sup.3 may be bonded to each other to form a ring; R.sup.4 represents a halogen atom or a hydrocarbyl group having 1 to 40 carbon atoms and optionally having a heteroatom, R.sup.4s may be identical to or different from each other when n is 2 or greater, and a plurality of R.sup.4s may be bonded to each other to form a ring together with the carbon atoms of the aromatic ring bonded thereto; R.sup.5 represents a carbonyl group or a hydrocarbylene group having 1 to 10 carbon atoms and optionally having a heteroatom; and *1 and *2 represent an attachment point to a carbon atom of the aromatic ring in the formula, and *1 and *2 are bonded to adjacent carbon atoms of the aromatic ring.

2. The resist composition according to claim 1, wherein the carboxy group-containing compound is one or both of a polymer having a repeating unit represented by the following formula (2) and a compound represented by the following formula (3), ##STR00272## wherein R.sup.A represents a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group; X.sup.A represents a single bond, a phenylene group, a naphthylene group, or *C(O)OX.sup.A1, X.sup.A1 represents a saturated hydrocarbylene group, a phenylene group, or a naphthylene group, each having 1 to 10 carbon atoms, the saturated hydrocarbylene group may have a hydroxy group, an ether bond, an ester bond, or a lactone ring, and * represents an attachment point to a carbon atom of the main chain; p represents 1, 2, 3, or 4; R.sup.31 represents a p-valent hydrocarbon group having 1 to 40 carbon atoms or a p-valent heterocyclic group having 2 to 40 carbon atoms, and when p is 2, R.sup.31 may be an ether bond, a carbonyl group, an azo group, a thioether bond, a carbonate bond, a carbamate bond, a sulfinyl group, or a sulfonyl group; part or all of the hydrogen atoms of the p-valent hydrocarbon group or p-valent heterocyclic group may be substituted with a group having a heteroatom, and part of the CH.sub.2 of the p-valent hydrocarbon group may be substituted with a group having a heteroatom; R.sup.32 is a single bond or a hydrocarbylene group having 1 to 20 carbon atoms, and part or all of the hydrogen atoms of the hydrocarbylene group may be substituted with a group having a heteroatom, or part of the CH.sub.2 of the hydrocarbylene group may be substituted with a group having a heteroatom; and when p is 2, 3, or 4, R.sup.32s may be identical to or different from each other.

3. The resist composition according to claim 1, further comprising at least one kind of hypervalent iodine compounds represented by the following formula (4) or (5), ##STR00273## wherein m1 and m2 represent integers from 0 to 2; n1 represents an integer from 0 to 4 when m1 is 0, an integer from 0 to 6 when m1 is 1, and an integer from 0 to 8 when m1 is 2; when m2 is 0, n2 represents an integer from 1 to 3, n3 represents an integer from 0 to 5, and 1(n2+n3)6 is satisfied, when m2 is 1, n2 represents an integer from 1 to 3, and n3 represents an integer from 0 to 7, and 1(n2+n3)8 is satisfied, and when m2 is 2, n2 represents an integer from 1 to 3, and n3 represents an integer from 0 to 9, and 1(n2+n3)10 is satisfied; R.sup.41 represents a halogen atom or a hydrocarbyl group having 1 to 10 carbon atoms and optionally having a heteroatom; R.sup.42 represents a halogen atom or a hydrocarbyl group having 1 to 40 carbon atoms and optionally having a heteroatom, R.sup.42s may be identical to or different from each other when n1 is 2 to 6, and a plurality of R.sup.42s may be bonded to each other to form a ring together with the carbon atoms of the aromatic ring bonded thereto; R.sup.43 is a carbonyl group or a hydrocarbylene group having 1 to 10 carbon atoms and optionally having a heteroatom; *3 and *4 represent an attachment point to a carbon atom of the aromatic ring in the formula, and *3 and *4 must be bonded to adjacent carbon atoms of the aromatic ring; R.sup.51 and R.sup.52 represent each independently a halogen atom or a hydrocarbyl group having 1 to 10 carbon atoms and optionally having a heteroatom, R.sup.51 and R.sup.52 may be bonded to each other to form a ring together with the carbon atoms bonded thereto and with an atom between the carbon atoms, and when n2 is 2 to 3, R.sup.51 and R.sup.52 may be identical to or different from each other; R.sup.53 represents a halogen atom or a hydrocarbyl group having 1 to 40 carbon atoms and optionally having a heteroatom, R.sup.53s may be identical to or different from each other when n3 is 2 to 9, and a plurality of R.sup.53s may be bonded to each other to form a ring together with the carbon atoms of the aromatic ring bonded thereto.

4. The resist composition according to claim 2, further comprising at least one kind of hypervalent iodine compounds represented by the following formula (4) or (5), ##STR00274## wherein m1 and m2 represent integers from 0 to 2; n1 represents an integer from 0 to 4 when m1 is 0, an integer from 0 to 6 when m1 is 1, and an integer from 0 to 8 when m1 is 2; when m2 is 0, n2 represents an integer from 1 to 3, n3 represents an integer from 0 to 5, and 1(n2+n3)6 is satisfied, when m2 is 1, n2 represents an integer from 1 to 3, and n3 represents an integer from 0 to 7, and 1(n2+n3)8 is satisfied, and when m2 is 2, n2 represents an integer from 1 to 3, and n3 represents an integer from 0 to 9, and 1(n2+n3)10 is satisfied; R.sup.41 represents a halogen atom or a hydrocarbyl group having 1 to 10 carbon atoms and optionally having a heteroatom; R.sup.42 represents a halogen atom or a hydrocarbyl group having 1 to 40 carbon atoms and optionally having a heteroatom, R.sup.42s may be identical to or different from each other when n1 is 2 to 6, and a plurality of R.sup.42s may be bonded to each other to form a ring together with the carbon atoms of the aromatic ring bonded thereto; R.sup.43 is a carbonyl group or a hydrocarbylene group having 1 to 10 carbon atoms and optionally having a heteroatom; *3 and *4 represent an attachment point to a carbon atom of the aromatic ring in the formula, and *3 and *4 must be bonded to adjacent carbon atoms of the aromatic ring; R.sup.51 and R.sup.52 represent each independently a halogen atom or a hydrocarbyl group having 1 to 10 carbon atoms and optionally having a heteroatom, R.sup.51 and R.sup.52 may be bonded to each other to form a ring together with the carbon atoms bonded thereto and with an atom between the carbon atoms, and when n2 is 2 to 3, R.sup.51 and R.sup.52 may be identical to or different from each other; R.sup.53 represents a halogen atom or a hydrocarbyl group having 1 to 40 carbon atoms and optionally having a heteroatom, R.sup.53s may be identical to or different from each other when n3 is 2 to 9, and a plurality of R.sup.53s may be bonded to each other to form a ring together with the carbon atoms of the aromatic ring bonded thereto.

5. A laminate comprising a substrate and a resist film which is a film made of the resist composition formed on the substrate according to claim 1.

6. A laminate comprising a substrate and a resist film which is a film made of the resist composition formed on the substrate according to claim 2.

7. A laminate comprising a substrate and a resist film which is a film made of the resist composition formed on the substrate according to claim 3.

8. The laminate according to claim 5, further comprising a resist underlayer film between the substrate and the resist film.

9. The laminate according to claim 6, further comprising a resist underlayer film between the substrate and the resist film.

10. The laminate according to claim 5, wherein the resist film contains a product of a ligand exchange reaction between the hypervalent iodine compound and the carboxy group-containing compound.

11. The laminate according to claim 6, wherein the resist film contains a product of a ligand exchange reaction between the hypervalent iodine compound and the carboxy group-containing compound.

12. A patterning process comprising steps of: forming a resist film on a substrate or on a resist underlayer film of a substrate having a resist underlayer film laminated thereon, using the resist composition according to claim 1; exposing the resist film by a high-energy beam; and developing the exposed resist film by using a developer.

13. A patterning process comprising steps of: forming a resist film on a substrate or on a resist underlayer film of a substrate having a resist underlayer film laminated thereon, using the resist composition according to claim 2; exposing the resist film by a high-energy beam; and developing the exposed resist film by using a developer.

14. A patterning process comprising steps of: forming a resist film on a substrate or on a resist underlayer film of a substrate having a resist underlayer film laminated thereon, using the resist composition according to claim 3; exposing the resist film by a high-energy beam; and developing the exposed resist film by using a developer.

15. The patterning process according to claim 12, wherein an i-line, a KrF excimer laser beam, an ArF excimer laser beam, an electron beam, or an extreme ultraviolet ray is used as the high-energy beam.

16. The patterning process according to claim 13, wherein an i-line, a KrF excimer laser beam, an ArF excimer laser beam, an electron beam, or an extreme ultraviolet ray is used as the high-energy beam.

17. The patterning process according to claim 12, wherein the developer used is one that dissolves exposed areas and does not dissolve unexposed areas.

18. The patterning process according to claim 15, wherein the developer used is one that dissolves exposed areas and does not dissolve unexposed areas.

19. The patterning process according to claim 12, wherein the developer used is one that dissolves unexposed areas and does not dissolve exposed areas.

20. The patterning process according to claim 15, wherein the developer used is one that dissolves unexposed areas and does not dissolve exposed areas.

Description

EXAMPLE

[0123] Hereinafter, the present invention will be specifically described with reference to Synthesis Example, Examples, and Comparative Examples. However, the present invention is not limited thereto.

[1] Hypervalent Iodine(V) Compounds

[0124] The hypervalent iodine compounds used in the examples are represented by the following formulae I-1 and I-2.

##STR00262##

[0125] The hypervalent iodine compound represented by the formula I-1 was synthesized with reference to Heterocycles, 2021, 103, 694. The hypervalent iodine compound represented by the formula I-2 was synthesized with reference to J. Am. Chem. Soc., 1991, 113, 7277.

[2] Synthesis of Polymers

[0126] The monomers a-1 to a-3, b-1 to b-3, c-1, and c-2 used in the synthesis of polymers are as follows.

##STR00263## ##STR00264##

[Synthesis Example 2-1] Synthesis of Polymer P-1

[0127] Monomer a-1 (56 g), monomer b-1 (105 g), 5.4 g of V-601 (FUJIFILM Wako Pure Chemical Industries, Ltd.), and 180 g of MEK were placed in a flask under a nitrogen atmosphere to prepare a monomer-polymerization initiator solution. 55 g of MEK was placed in another flask under a nitrogen atmosphere and heated to 80 C. with stirring, and then the monomer-polymerization initiator solution was added thereto dropwise over 4 hours. After completion of the dropwise addition, the stirring was continued for 2 hours while maintaining the temperature of the polymerization solution at 80 C., and then the polymerization solution was cooled to room temperature. The obtained polymerization solution was added dropwise to 4000 g of vigorously stirred hexane, and the precipitated polymer was separated by filtration. The obtained polymer was further washed twice with 1200 g of hexane and then dried in a vacuum at 50 C. for 20 hours to obtain polymer P-1 in a form of a white powder (yield: 155 g, 96%). The Mw of polymer P-1 was 7700, and Mw/Mn was 1.82. The Mw was value measured by GPC using THF as a solvent in terms of standard polystyrene.

##STR00265##

[Synthesis Examples 2-2 to 2-10] Synthesis of Polymers P-2 to P-10

[0128] The polymers shown in Table 1 below were synthesized in the same manner as in Synthesis Example 1, except that the types and blending ratios of the respective monomers were changed.

TABLE-US-00001 TABLE 1 Introduction Introduction ratio ratio Polymer Unit 1 (mol %) Unit 2 (mol %) Mw Mw/Mn Synthesis P-1 a-1 65 b-1 35 7700 1.82 Example 1 Synthesis P-2 a-1 50 b-2 50 8400 1.84 Example 2 Synthesis P-3 a-1 60 b-3 40 8100 1.79 Example 3 Synthesis P-4 a-2 65 b-1 35 8300 1.83 Example 4 Synthesis P-5 a-2 50 b-2 50 8300 1.83 Example 5 Synthesis P-6 a-2 60 b-3 40 8200 1.82 Example 6 Synthesis P-7 a-3 65 b-1 35 8000 1.80 Example 7 Synthesis P-8 a-3 50 b-2 50 8600 1.84 Example 8 Synthesis P-9 a-3 60 b-3 40 7900 1.81 Example 9 Synthesis P-10 c-1 60 c-2 40 9800 1.82 Example 10

[3] Preparation of Resist Compositions

Examples 1-1 to 1-22 and Comparative Examples 1-1 to 1-4

[0129] Resist compositions (R-01 to R-22) and comparative resist compositions (CR-01 to CR-02) were prepared by dissolving the hypervalent iodine compound, other hypervalent iodine compounds, and polymers in a solvent containing 0.01 mass % of a surfactant (PF-636, manufactured by OMNOVA Solutions Inc.) according to the compositions shown in Table 2 below, and filtering the resulting solution through a 0.2 m Teflon (registered trademark) filter. Comparative resist compositions (CR-03 to CR-04) were prepared by dissolving the polymer, photoacid generator, and sensitivity modifier in a solvent containing 0.01 mass % of a surfactant (PF-636, manufactured by OMNOVA Solutions Inc.) according to the compositions shown in Table 3 below, and filtering the resulting solution through a 0.2 m Teflon (registered trademark) filter.

TABLE-US-00002 TABLE 2 Other Carboxy Hypervalent hypervalent group- iodine iodine containing compound compound compound Solvent 1 Solvent 2 Resist (parts by (parts by (parts by (parts by (parts by composition mass) mass) mass) mass) mass) Example 1-1 R-01 I-1 P-1 PGMEA AcOH (10) (17.5) (800) (200) Example 1-2 R-02 I-2 P-1 PGMEA AcOH (10) (13.6) (800) (200) Example 1-3 R-03 I-1 P-2 PGMEA AcOH (10) (21.8) (800) (200) Example 1-4 R-04 I-1 P-3 PGMEA AcOH (10) (15.2) (800) (200) Example 1-5 R-05 I-1 P-4 PGMEA AcOH (10) (24.3) (800) (200) Example 1-6 R-06 I-1 P-5 PGMEA AcOH (10) (34.4) (800) (200) Example 1-7 R-07 I-1 P-6 PGMEA AcOH (10) (27.8) (800) (200) Example 1-8 R-08 I-1 P-7 PGMEA AcOH (10) (21.9) (800) (200) Example 1-9 R-09 I-1 P-8 PGMEA AcOH (10) (26.2) (800) (200) Example 1-10 R-10 I-1 P-9 PGMEA AcOH (10) (19.6) (800) (200) Example 1-11 R-11 I-1 P-1 HBM AcOH (10) (17.5) (800) (200) Example 1-12 R-12 I-1 P-1 PGMEA PA (10) (17.5) (800) (200) Example 1-13 R-13 I-1 P-1 PGMEA AcOH (5) (17.5) (800) (200) Example 1-14 R-14 I-1 O-1 P-1 PGMEA AcOH (5) (2.5) (17.5) (800) (200) Example 1-15 R-15 I-1 (5) P-1 PGMEA AcOH I-2 (5) (17.5) (800) (200) Example1-16 R-16 I-1 m-1 PGMEA AcOH (10) (8.5) (800) (200) Example 1-17 R-17 I-1 m-2 PGMEA AcOH (10) (4.1) (800) (200) Example 1-18 R-18 I-1 m-3 PGMEA AcOH (10) (8.4) (800) (200) Example 1-19 R-19 I-1 m-4 PGMEA AcOH (10) (7.6) (800) (200) Example 1-20 R-20 I-1 m-5 PGMEA AcOH (10) (11.6) (800) (200) Example 1-21 R-21 I-1 m-6 PGMEA AcOH (10) (8.9) (800) (200) Example 1-22 R-22 I-2 m-6 PGMEA AcOH (10) (6.9) (800) (200) Comparative CR-01 O-1 P-1 PGMEA AcOH Example 1-1 (10) (15) (800) (200) Comparative CR-02 O-1 m-1 PGMEA AcOH Example 1-2 (10) (7.5) (800) (200)

TABLE-US-00003 TABLE 3 Photo-acid Sensitivity Polymer generator modifier Solvent 1 Solvent 2 Resist (parts by (parts by (parts by (parts by (parts by composition mass) mass) mass) mass) mass) Comparative CR-03 P-10 PAG-1 Q-1 PGMEA GBL Example 1-3 (80) (19) (6) (1890) (210) Comparative CR-04 P-10 PAG-1 I-1 PGMEA GBL(210) Example 1-4 (80) (19) (5) (1890)

[0130] In Tables 2 and 3, hypervalent iodine compound 0-1, carboxy group-containing compounds m-1 to m-6, photoacid generator PAG-1, sensitivity modifier Q-1, and solvents are as follows.

##STR00266## ##STR00267##

[0131] Solvent: PGMEA (Propylene Glycol Monomethyl Ether Acetate) [0132] AcOH (Acetic Acid) [0133] HBM (2-Hydroxyisobutyrate Methyl) [0134] PA (Propionic Acid) [0135] GBL (Gamma-Butyrolactone)

[4] Evaluation of EUV Lithography (Line-and-Space Pattern, Positive Development)

Examples 2-1 to 2-22 and Comparative Examples 2-1 to 2-4

[0136] One of resist composition (R-01 to R-22 and CR-01 to CR-04) was spin-coated onto a Si substrate on which a silicon-containing spin-on hard mask SHB-A940 (silicon content: 43 mass %) manufactured by Shin-Etsu Chemical Co., Ltd. had been formed with a thickness of 20 nm, and pre-baking (PAB) was performed on a hot plate at the temperature shown in Table 4 for 60 seconds to prepare a resist film with a thickness of 40 nm. Using an EUV scanner NXE3400 (NA 0.33, a 0.9, 90-degree dipole illumination) manufactured by ASML Holding N.V., a 36 nm line and space (LS) 1:1 pattern was exposed, and then PEB was performed on a hot plate at the temperature shown in Table 4 for 60 seconds, followed by development for 30 seconds using a developer shown in Table 4 to form an LS pattern with a space width of 18 nm and a pitch of 36 nm.

[0137] The resulting resist patterns were evaluated as follows, and the results are shown in Table 4.

[Evaluation of Sensitivity]

[0138] The LS patterns were observed with a CD-SEM CG-6300 manufactured by Hitachi High-Technologies Corporation, and the optimum exposure dose E.sub.op(mJ/cm.sup.2) at which the LS pattern with a space width of 18 nm and a pitch of 36 nm could be obtained was determined and defined as the sensitivity.

[Evaluation of LWR]

[0139] The dimensions of the LS pattern obtained by the irradiation at the optimum exposure dose was measured at ten positions in the longitudinal direction of the space width with CD-SEM CG-6300 manufactured by Hitachi High-Technologies Corporation. Based on this result, the triple value (3) of the standard deviation () was determined as LWR. The smaller this value, the smaller the roughness and the more uniform the line width of the obtained pattern.

[Evaluation of Limit Resolution]

[0140] The limit line width (nm) that can be resolved when forming a pattern by gradually increasing an exposure dose from the optimum exposure dose at which the LS pattern is formed was determined with CD-SEM CG-6300 manufactured by Hitachi High-Technologies Corporation, and was defined as the limit resolution (nm). The smaller this value, the more excellent the limit resolution and the finer the pattern that can be formed.

TABLE-US-00004 TABLE 4 Limit Resist PAB/PEB Eop LWR resolution composition ( C.) Developer (mJ/cm.sup.2) (nm) (nm) Example 2-1 R-01 130/90 nBA 27 2.5 9 Example 2-2 R-02 130/90 nBA 28 3.0 10 Example 2-3 R-03 130/90 nBA 28 2.9 10 Example 2-4 R-04 130/90 nBA 30 2.8 9 Example 2-5 R-05 130/90 nBA 32 2.5 9 Example 2-6 R-06 130/90 nBA 33 2.7 11 Example 2-7 R-07 130/90 nBA 32 2.8 12 Example 2-8 R-08 130/90 nBA 33 2.6 12 Example 2-9 R-09 130/90 nBA 28 2.5 12 Example 2-10 R-10 130/90 nBA 30 2.7 10 Example 2-11 R-11 130/90 nBA 26 2.4 12 Example 2-12 R-12 130/90 nBA 25 2.4 9 Example 2-13 R-13 130/90 CHA 20 2.4 9 Example 2-14 R-14 130/90 nBA 24 2.2 8 Example 2-15 R-15 130/90 nBA 27 2.3 9 Example 2-16 R-16 130/90 nBA 28 2.7 9 Example 2-17 R-17 130/90 nBA 25 2.6 10 Example 2-18 R-18 130/90 nBA 29 2.8 10 Example 2-19 R-19 130/90 nBA 26 2.6 11 Example 2-20 R-20 130/90 nBA 26 2.5 9 Example 2-21 R-21 130/90 nBA 25 2.9 9 Example 2-22 R-22 130/90 nBA 27 2.2 11 Comparative CR-01 130/90 nBA 39 3.6 14 Example 2-1 Comparative CR-02 130/90 nBA 40 3.8 16 Example 2-2 Comparative CR-03 105/90 TMAH 80 4.5 18 Example 2-3 Comparative CR-04 105/90 TMAH 85 4.8 18 Example 2-4

[0141] Developer: nBA (butyl acetate) [0142] CHA (cyclohexyl acetate) [0143] TMAH (2.38 mass % aqueous solution of tetramethylammonium hydroxide)

[5] Evaluation of EUV Lithography (Line-and-Space Pattern, Negative Development)

Examples 3-1 to 3-22 and Comparative Examples 3-1 to 3-4

[0144] One of resist composition (R-01 to R-22 and CR-01 to CR-04) was spin-coated onto a Si substrate on which a silicon-containing spin-on hard mask SHB-A940 (silicon content: 43 mass %) manufactured by Shin-Etsu Chemical Co., Ltd. had been formed with a thickness of 20 nm, and pre-baking (PAB) was performed on a hot plate at the temperature shown in Table 5 for 60 seconds to prepare a resist film with a thickness of 40 nm. Using an EUV scanner NXE3400 (NA 0.33, a 0.9, 90-degree dipole illumination) manufactured by ASML Holding N.V., a 36 nm line and space (LS) 1:1 pattern was exposed, and then PEB was performed on a hot plate at the temperature shown in Table 5 for 60 seconds, followed by development for 30 seconds using a developer shown in Table 5 to form an LS pattern with a space width of 18 nm and a pitch of 36 nm.

[0145] The resulting resist patterns were evaluated as follows, and the results are shown in Table 5.

[Evaluation of Sensitivity]

[0146] The LS patterns were observed with a CD-SEM CG-6300 manufactured by Hitachi High-Technologies Corporation, and the optimum exposure dose E.sub.op (mJ/cm.sup.2) at which the LS pattern with a space width of 18 nm and a pitch of 36 nm could be obtained was determined and defined as the sensitivity.

[Evaluation of LWR]

[0147] The dimensions of the LS pattern obtained by the irradiation at the optimum exposure dose was measured at ten positions in the longitudinal direction of the space width with CD-SEM CG-6300 manufactured by Hitachi High-Technologies Corporation. Based on this result, the triple value (3) of the standard deviation () was determined as LWR. The smaller this value, the smaller the roughness and the more uniform the line width of the obtained pattern.

[Evaluation of Limit Resolution]

[0148] The limit line width (nm) that can be resolved when forming a pattern by gradually increasing an exposure dose from the optimum exposure dose at which the LS pattern is formed was determined with CD-SEM CG-6300 manufactured by Hitachi High-Technologies Corporation, and was defined as the limit resolution (nm). The smaller this value, the more excellent the limit resolution and the finer the pattern that can be formed.

TABLE-US-00005 TABLE 5 Limit Resist PAB/PEB Eop LWR resolution composition ( C.) Developer (mJ/cm.sup.2) (nm) (nm) Example 3-1 R-01 130/90 TMAH 29 3.0 10 Example 3-2 R-02 130/90 TMAH 30 3.4 11 Example 3-3 R-03 130/90 TMAH 30 3.4 10 Example 3-4 R-04 130/90 TMAH 31 3.3 10 Example 3-5 R-05 130/90 TMAH 32 2.9 10 Example 3-6 R-06 130/90 TMAH 33 3.1 12 Example 3-7 R-07 130/90 TMAH 32 3.2 13 Example 3-8 R-08 130/90 TMAH 33 3.2 12 Example 3-9 R-09 130/90 TMAH 30 3.0 13 Example 3-10 R-10 130/90 TMAH 30 3.1 11 Example 3-11 R-11 130/90 TMAH 28 2.9 13 Example 3-12 R-12 130/90 TMAH 27 2.9 9 Example 3-13 R-13 130/90 TMAH 22 2.9 10 Example 3-14 R-14 130/90 TMAH 26 2.8 9 Example 3-15 R-15 130/90 TMAH 29 2.7 11 Example 3-16 R-16 130/90 TMAH 30 3.2 10 Example 3-17 R-17 130/90 TMAH 27 3.1 11 Example 3-18 R-18 130/90 TMAH 31 3.3 11 Example 3-19 R-19 130/90 TMAH 28 3.1 12 Example 3-20 R-20 130/90 TMAH 26 3.0 10 Example 3-21 R-21 130/90 TMAH 27 3.4 10 Example 3-22 R-22 130/90 TMAH 29 2.7 11 Comparative CR-01 130/90 TMAH 40 4.1 16 Example 3-1 Comparative CR-02 130/90 TMAH 41 4.2 17 Example 3-2 Comparative CR-03 105/90 nBA 83 4.6 18 Example 3-3 Comparative CR-04 105/90 nBA 86 4.9 18 Example 3-4

[0149] The results shown in Tables 4 and 5 demonstrate that the inventive resist composition is excellent in sensitivity, LWR, and resolution in both positive tone and negative tone development when forming a line and space pattern by EUV exposure.

[6] Evaluation of EUV Lithography (Contact Hole Pattern)

Examples 4-1 to 4-22 and Comparative Examples 4-1 to 4-4

[0150] One of resist composition (R-01 to R-22 and CR-01 to CR-04) was spin-coated onto a Si substrate on which a silicon-containing spin-on hard mask SHB-A940 (silicon content: 43 mass %) manufactured by Shin-Etsu Chemical Co., Ltd. had been formed with a thickness of 20 nm, and pre-baking (PAB) was performed on a hot plate at the temperature shown in Table 6 for 60 seconds to prepare a resist film with a thickness of 50 nm. Next, using an EUV scanner NXE3400 (NA 0.33, 0.9/0.6, quadrupole illumination, with a mask having a hole pattern with a pitch of 64 nm and +20% bias, in terms of on-wafer size) manufactured by ASML Holding N.V., the resist film was exposed and baked (PEB) on a hot plate at the temperature shown in Table 6 for 60 seconds, followed by development for 30 seconds using a developer shown in Table 6 to form a hole pattern with a dimension of 32 nm.

[0151] The resulting resist patterns were evaluated as follows, and the results are shown in Table 6.

[Evaluation of Sensitivity]

[0152] The hole patterns were observed with a CD-SEM CG-6300 manufactured by Hitachi High-Technologies Corporation, and the optimum exposure dose E.sub.op(mJ/cm.sup.2) at which the hole pattern with a dimension of 32 nm could be obtained was determined.

[Evaluation of CD Uniformity (CDU)]

[0153] Dimensions of 50 hole patterns obtained by the irradiation at the optimum exposure dose were measured, and a tripled value (3) of a standard variation () calculated from the results was defined as CDU. The smaller this value, the more uniform the hole diameter that can be obtained.

[Evaluation of Limit Resolution]

[0154] The limit hole diameter (nm) that can be resolved when forming a hole pattern by gradually decreasing an exposure dose from the optimum exposure dose at which the hole pattern is formed was determined with CD-SEM CG-6300 manufactured by Hitachi High-Technologies Corporation, and was defined as the limit resolution (nm). The smaller this value, the more excellent the limit resolution and the finer the hole pattern that can be formed.

TABLE-US-00006 TABLE 6 Limit Resist PAB/PEB Eop CDU resolution composition ( C.) Developer (mJ/cm.sup.2) (nm) (nm) Example 4-1 R-01 130/90 nBA 17 2.0 19 Example 4-2 R-02 130/90 nBA 18 2.3 20 Example 4-3 R-03 130/90 nBA 18 2.2 20 Example 4-4 R-04 130/90 nBA 20 2.3 19 Example 4-5 R-05 130/90 nBA 22 2.0 19 Example 4-6 R-06 130/90 nBA 21 2.2 21 Example 4-7 R-07 130/90 nBA 22 2.3 22 Example 4-8 R-08 130/90 nBA 22 2.1 22 Example 4-9 R-09 130/90 nBA 18 2.0 22 Example 4-10 R-10 130/90 nBA 20 2.2 20 Example 4-11 R-11 130/90 nBA 16 1.9 22 Example 4-12 R-12 130/90 nBA 15 1.9 19 Example 4-13 R-13 130/90 CHA 13 1.9 19 Example 4-14 R-14 130/90 nBA 14 1.7 18 Example 4-15 R-15 130/90 nBA 17 1.8 19 Example 4-16 R-16 130/90 nBA 18 2.2 19 Example 4-17 R-17 130/90 nBA 15 2.1 20 Example 4-18 R-18 130/90 nBA 19 2.2 20 Example 4-19 R-19 130/90 nBA 16 2.1 21 Example 4-20 R-20 130/90 nBA 16 2.0 19 Example 4-21 R-21 130/90 nBA 15 2.1 19 Example 4-22 R-22 130/90 nBA 17 1.7 21 Comparative CR-01 130/90 nBA 25 2.7 26 Example 4-1 Comparative CR-02 130/90 nBA 26 2.9 28 Example 4-2 Comparative CR-03 105/90 TMAH 42 3.8 32 Example 4-3 Comparative CR-04 105/90 TMAH 40 4.0 32 Example 4-4

[0155] The results shown in Table 6 demonstrate that the inventive resist composition is excellent in sensitivity, CDU, and resolution when forming a contact hole pattern by EUV exposure.

[0156] The present description includes the following embodiments.

[1]: A resist composition comprising a hypervalent iodine compound represented by the following formula (1), a carboxy group-containing compound, and a solvent,

##STR00268##

wherein m represents an integer of 0 to 2; n represents an integer of 0 to 4 when m is 0, an integer of 0 to 6 when m is 1, and an integer of 0 to 8 when m is 2; R.sup.1, R.sup.2, and R.sup.3 represent each independently a halogen atom or a hydrocarbyl group having 1 to 10 carbon atoms and optionally having a heteroatom, and R.sup.1, R.sup.2, and R.sup.3 may be bonded to each other to form a ring; R.sup.4 represents a halogen atom or a hydrocarbyl group having 1 to 40 carbon atoms and optionally having a heteroatom, R.sup.4s may be identical to or different from each other when n is 2 or greater, and a plurality of R.sup.4s may be bonded to each other to form a ring together with the carbon atoms of the aromatic ring bonded thereto; R.sup.5 represents a carbonyl group or a hydrocarbylene group having 1 to 10 carbon atoms and optionally having a heteroatom; and *1 and *2 represent an attachment point to a carbon atom of the aromatic ring in the formula, and *1 and *2 are bonded to adjacent carbon atoms of the aromatic ring.
[2]: The resist composition of the above [1], wherein the carboxy group-containing compound is one or both of a polymer having a repeating unit represented by the following formula (2) and a compound represented by the following formula (3),

##STR00269##

wherein R.sup.A represents a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group; X.sup.A represents a single bond, a phenylene group, a naphthylene group, or *C(O)OX.sup.A1, X.sup.A1 represents a saturated hydrocarbylene group, a phenylene group, or a naphthylene group, each having 1 to 10 carbon atoms, the saturated hydrocarbylene group may have a hydroxy group, an ether bond, an ester bond, or a lactone ring, and * represents an attachment point to a carbon atom of the main chain; p represents 1, 2, 3, or 4; R.sup.31 represents a p-valent hydrocarbon group having 1 to 40 carbon atoms or a p-valent heterocyclic group having 2 to 40 carbon atoms, and when p is 2, R.sup.31 may be an ether bond, a carbonyl group, an azo group, a thioether bond, a carbonate bond, a carbamate bond, a sulfinyl group, or a sulfonyl group; part or all of the hydrogen atoms of the p-valent hydrocarbon group or p-valent heterocyclic group may be substituted with a group having a heteroatom, and part of the CH.sub.2 of the p-valent hydrocarbon group may be substituted with a group having a heteroatom; R.sup.32 is a single bond or a hydrocarbylene group having 1 to 20 carbon atoms, and part or all of the hydrogen atoms of the hydrocarbylene group may be substituted with a group having a heteroatom, or part of the CH.sub.2 of the hydrocarbylene group may be substituted with a group having a heteroatom; and when p is 2, 3, or 4, R.sup.32s may be identical to or different from each other.
[3]: The resist composition of the above [1] or [2], further comprising at least one kind of hypervalent iodine compounds represented by the following formula (4) or (5),

##STR00270##

wherein m1 and m2 represent integers from 0 to 2; n1 represents an integer from 0 to 4 when m1 is 0, an integer from 0 to 6 when m1 is 1, and an integer from 0 to 8 when m1 is 2; when m2 is 0, n2 represents an integer from 1 to 3, n3 represents an integer from 0 to 5, and 1(n2+n3)6 is satisfied, when m2 is 1, n2 represents an integer from 1 to 3, and n3 represents an integer from 0 to 7, and 1(n2+n3)8 is satisfied, and when m2 is 2, n2 represents an integer from 1 to 3, and n3 represents an integer from 0 to 9, and 1(n2+n3)10 is satisfied; R.sup.41 represents a halogen atom or a hydrocarbyl group having 1 to 10 carbon atoms and optionally having a heteroatom; R.sup.42 represents a halogen atom or a hydrocarbyl group having 1 to 40 carbon atoms and optionally having a heteroatom, R.sup.42s may be identical to or different from each other when n1 is 2 to 6, and a plurality of R.sup.42s may be bonded to each other to form a ring together with the carbon atoms of the aromatic ring bonded thereto; R.sup.43 is a carbonyl group or a hydrocarbylene group having 1 to 10 carbon atoms and optionally having a heteroatom; *3 and *4 represent an attachment point to a carbon atom of the aromatic ring in the formula, and *3 and *4 must be bonded to adjacent carbon atoms of the aromatic ring; R.sup.51 and R.sup.52 represent each independently a halogen atom or a hydrocarbyl group having 1 to 10 carbon atoms and optionally having a heteroatom, R.sup.51 and R.sup.52 may be bonded to each other to form a ring together with the carbon atoms bonded thereto and with an atom between the carbon atoms, and when n2 is 2 to 3, R.sup.51 and R.sup.52 may be identical to or different from each other; R.sup.53 represents a halogen atom or a hydrocarbyl group having 1 to 40 carbon atoms and optionally having a heteroatom, R.sup.53s may be identical to or different from each other when n3 is 2 to 9, and a plurality of R.sup.53s may be bonded to each other to form a ring together with the carbon atoms of the aromatic ring bonded thereto.
[4]: A laminate comprising a substrate and a resist film which is a film made of the resist composition formed on the substrate of any one of the above [1] to [3].
[5]: The laminate of the above [4], further comprising a resist underlayer film between the substrate and the resist film.
[6]: The laminate of the above [4] or [5], wherein the resist film contains a product of a ligand exchange reaction between the hypervalent iodine compound and the carboxy group-containing compound.
[7]: A patterning process comprising steps of: forming a resist film on a substrate or on a resist underlayer film of a substrate having a resist underlayer film laminated thereon, using the resist composition of any one of the above [1] to [3]; exposing the resist film by a high-energy beam; and developing the exposed resist film by using a developer.
[8]: The patterning process of the above [7], wherein an i-line, a KrF excimer laser beam, an ArF excimer laser beam, an electron beam, or an extreme ultraviolet ray is used as the high-energy beam.
[9]: The patterning process of the above [7] or [8], wherein the developer used is one that dissolves exposed areas and does not dissolve unexposed areas.
[10]: The patterning process of the above [7] or [8], wherein the developer used is one that dissolves unexposed areas and does not dissolve exposed areas.

[0157] It should be noted that the present invention is not limited to the above-described embodiments. The embodiments are just examples, and any examples that have substantially the same feature and demonstrate the same functions and effects as those in the technical concept disclosed in claims of the present invention are included in the technical scope of the present invention.