Radiation-sensitive resin composition, method for forming resist pattern and compound

Abstract

A radiation-sensitive resin composition includes a resin having a partial structure represented by formula (1). R.sup.1 and R.sup.2 each independently represent a substituted or unsubstituted chain aliphatic hydrocarbon group having 1 to 6 carbon atoms or a substituted or unsubstituted alicyclic hydrocarbon group having 3 to 6 carbon atoms, or R.sup.1 and R.sup.2 are bonded to each other to form a part of a 3- to 6-membered cyclic structure together with the carbon atom to which R.sup.1 and R.sup.2 are bonded; R.sup.3 represents a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms and containing a fluorine atom. No fluorine atom is bonded to carbon atoms located at ?-, ?- and ?-positions of the carbon atom to which R.sup.1 and R.sup.2 are bonded; and No fluorine atom is bonded to carbon atoms located at ?- and ?-positions of the carbon atom to which R.sup.3 is bonded. ##STR00001##

Claims

1. A radiation-sensitive resin composition comprising: a resin having a partial structure represented by formula (1); a radiation-sensitive acid generator; and a solvent; ##STR00069## wherein, in the formula (1), R.sup.1 and R.sup.2 each independently represent a substituted or unsubstituted chain aliphatic hydrocarbon group having 1 to 6 carbon atoms or a substituted or unsubstituted alicyclic hydrocarbon group having 3 to 6 carbon atoms, or R.sup.1 and R.sup.2 are bonded to each other to form a part of a 3- to 6-membered cyclic structure together with the carbon atom to which R.sup.1 and R.sup.2 are bonded; R.sup.3 represents a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms and comprising an alicyclic ring, wherein the alicyclic ring comprises CF.sub.2 group, and the carbon atom of the CF.sub.2 group is a ring atom of the alicyclic ring; provided that in R.sup.1 and R.sup.2, no fluorine atom is bonded to carbon atoms located at ?-, ?- and ?-positions of the carbon atom to which R.sup.1 and R.sup.2 are bonded; in R.sup.3, no fluorine atom is bonded to carbon atoms located at ?- and ?-positions of the carbon atom to which R.sup.3 is bonded; and * represents a bond.

2. The radiation-sensitive resin composition according to claim 1, wherein the partial structure represented by the formula (1) is a partial structure represented by formula (1-1-1), a partial structure represented by formula (1-1-2), a partial structure represented by formula (1-1-3), or a partial structure represented by formula (1-1-4): ##STR00070## wherein, in the formulae (1-1-1), (1-1-2), (1-1-3), and (1-1-4), R.sup.1 and R.sup.2 have the same meanings as those in the formula (1); R.sup.f101 and R.sup.f102 are each a fluorine atom, and R.sup.f103 to R.sup.f119 each independently represent a fluorine atom, a fluorinated alkyl group having 1 to 3 carbon atoms, a hydrogen atom, or an alkyl group having 1 to 3 carbon atoms; provided that at least one of R.sup.f103CR.sup.f104 and R.sup.f105CR.sup.f106, at least one of R.sup.f107CR.sup.f108, R.sup.f109CR.sup.f110 and R.sup.f111CR.sup.f112, and at least one of R.sup.f113CR.sup.f114, R.sup.f115CR.sup.f116 and R.sup.f118CR.sup.f119 are CF.sub.2 group; and * represents a bond.

3. The radiation-sensitive resin composition according to claim 1, wherein the partial structure represented by the formula (1) is a partial structure represented by formula (1-2-1), a partial structure represented by formula (1-2-2), or a partial structure represented by formula (1-2-3): ##STR00071## wherein, in the formulae (1-2-1), (1-2-2), and (1-2-3), R.sup.1 and R.sup.2 have the same meanings as those in the formula (1); R.sup.f201 and R.sup.f202 are each a fluorine atom, and R.sup.f203 to R.sup.f217 each independently represent a fluorine atom, a fluorinated alkyl group having 1 to 3 carbon atoms, a hydrogen atom, or an alkyl group having 1 to 3 carbon atoms; provided at least one of R.sup.f204CR.sup.f205 and R.sup.f207CR.sup.f208, and at least one of R.sup.f210CR.sup.f211, R.sup.f213CR.sup.f214 and R.sup.f216CR.sup.f217 are CF.sub.2 group; and * represents a bond.

4. The radiation-sensitive resin composition according to claim 1, wherein a content of a structural unit having the partial structure represented by the formula (1) in the resin is 5 mol % or more and 40 mol % or less.

5. A method for forming a resist pattern, comprising: forming a resist film from the radiation-sensitive resin composition according to claim 1; exposing the resist film; and developing the exposed resist film.

6. The method for forming a resist pattern according to claim 5, wherein the exposure is performed with use of ArF excimer laser light or extreme ultraviolet light.

7. The method for forming a resist pattern according to claim 5, wherein the partial structure represented by the formula (1) is a partial structure represented by formula (1-1-1), a partial structure represented by formula (1-1-2), a partial structure represented by formula (1-1-3), or a partial structure represented by formula (1-1-4): ##STR00072## wherein, in the formulae (1-1-1), (1-1-2), (1-1-3), and (1-1-4), R.sup.1 and R.sup.2 have the same meanings as those in the formula (1); R.sup.f101 and R.sup.f102 are each a fluorine atom, and R.sup.f103 to R.sup.f119 each independently represent a fluorine atom, a fluorinated alkyl group having 1 to 3 carbon atoms, a hydrogen atom, or an alkyl group having 1 to 3 carbon atoms; provided that at least one of R.sup.f103CR.sup.f104 and R.sup.f105CR.sup.f106, at least one of R.sup.f107CR.sup.f108, R.sup.f109CR.sup.f110 and R.sup.f111CR.sup.f112, and at least one of R.sup.f113CR.sup.f114, R.sup.f115CR.sup.f116 and R.sup.f118CR.sup.f119 are CF.sub.2; and * represents a bond.

8. The method for forming a resist pattern according to claim 5, wherein the partial structure represented by the formula (1) is a partial structure represented by formula (1-2-1), a partial structure represented by formula (1-2-2), or a partial structure represented by formula (1-2-3): ##STR00073## wherein, in the formulae (1-2-1), (1-2-2), and (1-2-3), R.sup.1 and R.sup.2 have the same meanings as those in the formula (1); R.sup.f201 and R.sup.f202 are each a fluorine atom, and R.sup.f203 to R.sup.f217 each independently represent a fluorine atom, a fluorinated alkyl group having 1 to 3 carbon atoms, a hydrogen atom, or an alkyl group having 1 to 3 carbon atoms; provided at least one of R.sup.f204CR.sup.f205 and R.sup.f207CR.sup.f208, and at least one of R.sup.f210CR.sup.f211, R.sup.f213CR.sup.f214 and R.sup.f216CR.sup.f217 are CF.sub.2; and * represents a bond.

9. The method for forming a resist pattern according to claim 5, wherein a content of a structural unit having the partial structure represented by the formula (1) in the resin is 5 mol % or more and 40 mol % or less.

10. The method for forming a resist pattern according to claim 5, wherein the resin comprises a first structural unit, and the partial structure represented by the formula (1) is introduced as a side chain structure of the first structural unit.

11. The method for forming a resist pattern according to claim 10, wherein the resin further comprises a second structural unit which comprises an acid-dissociable group.

12. The method for forming a resist pattern according to claim 10, wherein the resin further comprises a third structural unit which comprises a group comprising at least one structure selected from the group consisting of a lactone structure, a cyclic carbonate structure, and a sultone structure.

13. The radiation-sensitive resin composition according to claim 1, wherein the resin comprises a first structural unit, and the partial structure represented by the formula (1) is introduced as a side chain structure of the first structural unit.

14. The radiation-sensitive resin composition according to claim 13, wherein the resin further comprises a second structural unit which comprises an acid-dissociable group.

15. The radiation-sensitive resin composition according to claim 14, wherein a content of the second structural unit is 10 to 70 mol % relative to total structural units in the resin.

16. The radiation-sensitive resin composition according to claim 13, wherein the resin further comprises a third structural unit which comprises a group comprising at least one structure selected from the group consisting of a lactone structure, a cyclic carbonate structure, and a sultone structure.

17. The radiation-sensitive resin composition according to claim 16, wherein a content of the third structural unit is 20 to 70 mol % relative to total structural units in the resin.

18. A compound represented by formula (I): ##STR00074## wherein, in the formula (I), R.sup.x is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; R.sup.1 and R.sup.2 each independently represent a substituted or unsubstituted chain aliphatic hydrocarbon group having 1 to 6 carbon atoms or a substituted or unsubstituted alicyclic hydrocarbon group having 3 to 6 carbon atoms, or R.sup.1 and R.sup.2 are bonded to each other to form a part of a 3- to 6-membered cyclic structure together with the carbon atom to which R.sup.1 and R.sup.2 are bonded; R.sup.3 represents a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms and comprising an alicyclic ring, wherein the alicyclic ring comprises CF.sub.2 group, and the carbon atom of the CF.sub.2 group is a ring atom of the alicyclic ring; provided that in R.sup.1 and R.sup.2, no fluorine atom is bonded to carbon atoms located at ?-, ?- and ?-positions of the carbon atom to which R.sup.1 and R.sup.2 are bonded; and in R.sup.3, no fluorine atom is bonded to carbon atoms located at ?- and ?-positions of the carbon atom to which R.sup.3 is bonded.

19. A compound represented by formula (i): ##STR00075## wherein, in the formula (i), R.sup.1 and R.sup.2 each independently represent a substituted or unsubstituted chain aliphatic hydrocarbon group having 1 to 6 carbon atoms or a substituted or unsubstituted alicyclic hydrocarbon group having 3 to 6 carbon atoms, or R.sup.1 and R.sup.2 are bonded to each other to form a part of a 3- to 6-membered cyclic structure together with the carbon atom to which R.sup.1 and R.sup.2 are bonded; R.sup.3 represents a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms and comprising an alicyclic ring, wherein the alicyclic ring comprises CF.sub.2 group, and the carbon atom of the CF.sub.2 group is a ring atom of the alicyclic ring; provided that in R.sup.1 and R.sup.2, no fluorine atom is bonded to carbon atoms located at ?-, ?- and ?-positions of the carbon atom to which R.sup.1 and R.sup.2 are bonded; and in R.sup.3, no fluorine atom is bonded to carbon atoms located at ?- and ?-positions of the carbon atom to which R.sup.3 is bonded.

Description

EXAMPLES

(1) Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. Methods for measuring various physical property values will be described below.

(2) [Measurement of Weight Average Molecular Weight (Mw), Number Average Molecular Weight (Mn) and Dispersity (Mw/Mn)]

(3) The Mw and Mn of the resin were measured by Gel Permeation Chromatography (GPC) with GPC columns manufactured by Tosoh Corporation (two G2000HXLs, one G3000HXL, and one G4000HXL) under the analysis condition as described below, and the dispersity (Mw/Mn) was calculated by the measurement results of Mw and Mn: flow rate: 1.0 mL/min; eluting solvent: tetrahydrofuran; column temperature: 40? C.; and reference material: monodisperse polystyrene.

(4) [.sup.1H-NMR Analysis and .sup.13C-NMR Analysis]

(5) Measurement was performed with use of JNM-Delta 400 manufactured by JEOL Ltd.

(6) <Synthesis of Resin>

(7) Among the monomers used in the synthesis of the resins in Examples, the structure of the monomer having the partial structure represented by the above formula (1) (that is, the compound (I)) will be shown below. In the following Synthesis Examples, unless otherwise specified, parts by mass means a value assuming that the total mass of the used monomers is 100 parts by mass, and mol % means a value assuming that the total mole number of the used monomers is 100 mol %. The present invention is not limited to the following structural units.

(8) ##STR00057## ##STR00058##

(9) Among the monomers used in the synthesis of the resins in Examples and Comparative Examples, the structures of monomers other than the monomer having the partial structure represented by the above formula (1) will be shown.

(10) ##STR00059## ##STR00060## ##STR00061##
<Method for Synthesizing Monomer Having Partial Structure Represented by Above Formula (1) (Compound (I))>

(11) The monomer (M-1) having a partial structure represented by the above formula (1) was synthesized by the following procedure. Monomers (M-2) to (M-14) were also synthesized in the same manner as in the method for synthesizing the monomer (M-1).

Synthesis Example 1: Synthesis of Monomer (M-1)

(12) ##STR00062##

(13) 4,4 Difluorocyclohexane-1-carboxylic acid (40.22 g (0.245 mol)) was weighed in a 1-L recovery flask, and dissolved in a mixed solution of tetrahydrofuran (245 mL) and dimethylformamide (1 mL). After the solution was cooled to 0? 37.32 g (0.294 mol) of oxalyl dichloride was added dropwise to the solution at a rate not exceeding 10? C., followed by stirring at room temperature for 0.5 hours after the completion of the dropwise addition. Then, the solution was cooled to 0? C., and methanol (10 mL) was then added dropwise to the solution, followed by stirring at room temperature for 1 hour after completion of the dropwise addition. After the completion of the reaction, the resulting solution was quenched with a saturated aqueous sodium bicarbonate solution, extracted with ethyl acetate, concentrated under reduced pressure, and purified by column chromatography to obtain 39.2 g of methyl 4,4-difluorocyclohexane-1-carboxylate (yield: 90%).

(14) ##STR00063##

(15) Methyl 4,4-difluorocyclohexane-1-carboxylate (39.2 g (0.22 mol)) was weighed in a 2-L recovery flask, and dissolved in tetrahydrofuran (70 mL). The solution was cooled to 0? C., and then 480 mL of a tetrahydrofuran solution (1.0 M) of ethyl magnesium chloride was added dropwise thereto. After the completion of the reaction, the resulting solution was quenched with a saturated aqueous ammonium chloride solution, extracted with ethyl acetate, concentrated under reduced pressure, and purified by column chromatography to obtain 35.2 g of 3-(4,4-difluorocyclohexyl)pentane-3-ol (yield: 78%).

(16) ##STR00064##

(17) 3-(4,4-Difluorocyclohexyl)pentane-3-ol (35.21 g (0.171 mol)), triethylamine (25.91 g (0.256 mol)), and 1,4-diazabicyclo[2.2.2]octane (5.74 g (0.051 mol)) were weighed in a 500-mL recovery flask, and dissolved in 170 mL of acetonitrile. The solution was cooled to 0? C., and then 26.76 g (0.256 mol) of methacryloyl chloride was added dropwise thereto. After the completion of the dropwise addition, the solution was stirred at room temperature for 24 hours. After the completion of the reaction, the resulting solution was quenched with a saturated aqueous ammonium chloride solution, extracted with ethyl acetate, and concentrated under reduced pressure. The resulting residue was purified by column chromatography to obtain 11.41 g of a monomer (M-1) (yield: 71%).

(18) <Method for Synthesizing Resin>

Synthesis Example 1: Synthesis of Resin (P-1)

(19) The compound (M-1), a compound (M-16), a compound (M-22), and a compound (M-29) as monomers were dissolved in 2-butanone (200 parts by mass with respect to the total amount of monomers) at a molar ratio of 20/30/35/10. Azobisisobutyronitrile (AIBN) (2 mol %) as an initiator was added thereto to prepare a monomer solution. 2-butanone (100 parts by mass) was placed in a reaction vessel, and the reaction vessel was purged with nitrogen gas for 30 minutes. The temperature in the reaction vessel was set at 80? C., and the monomer solution was added dropwise to the reaction vessel under stirring for 3 hours. The polymerization reaction was performed for 6 hours with the start of the dropwise addition as the start time of the polymerization reaction. After the completion of the polymerization reaction, the polymerization solution was cooled with water to 30? C. or lower. The cooled polymerization solution was charged into methanol (2,000 parts by mass), and a precipitated white powder was separated by filtration. The filtered white powder was washed twice with methanol (400 parts by mass), then filtered and dried at 60? C. for 15 hours to obtain a white powdery resin (P-1) in a good yield. The Mw of the resulting resin (P-1) was 9,700, and the Mw/Mn was 1.35. As a result of .sup.13C-NMR analysis, the content rate of the structural unit derived from the compound (M-1): the structural unit derived from the compound (M-16): the structural unit derived from the compound (M-22): the structural unit derived from the compound (M-29) was 18:30:37:15 (mol %).

[Synthesis Examples 2 to 17, 24, 29, and 30] (Synthesis of Resins (P-2) to (P-17), (P-24), (P-29), and (P-30))

(20) Resins (P-2) to (P-17), (P-24), (P-29), and (P-30) each containing a predetermined amount of monomer shown in Table 1 were obtained in the same manner as in Synthesis Example 1. The Mw and Mw/Mn of each of the resulting resins, and the content rate of the structural unit derived from each of the monomers in each of the resins are shown together in Table 1.

Synthesis Example 18: Synthesis of Resin (P-18)

(21) The compound (M-1), the compound (M-16), and a compound (M-32) as monomers were dissolved in l-methoxy-2-propanol (200 parts by mass with respect to the total amount of monomers) at a molar ratio of 20/35/45. Next, 4 mol % of azobisisobutyronitrile as an initiator was added into the total of the monomers to prepare a monomer solution. Meanwhile, 1-methoxy-2-propanol (100 parts by mass with respect to the total amount of monomers) was added into an empty reaction vessel, and heated to 85? C. while being stirred. Next, the monomer solution prepared above was added dropwise thereto over 3 hours, followed by further heating at 85? C. for 3 hours to perform a polymerization reaction for a total of 6 hours. After the completion of the polymerization reaction, the polymerization solution was cooled to room temperature. The cooled polymerization solution was charged into hexane (500 parts by mass with respect to the polymerization solution), and a precipitated white powder was separated by filtration. The white powder separated by filtration was washed twice with 100 parts by mass of hexane relative to the polymerization solution, then separated by filtration, and dissolved in l-methoxy-2-propanol (300 parts by mass). Next, methanol (500 parts by mass), triethylamine (50 parts by mass), and ultrapure water (10 parts by mass) were added to the resulting solution, and a hydrolysis reaction was performed at 70? C. for 6 hours under stirring. After the completion of the reaction, the remaining solvent was distilled off, and the resulting solid was dissolved in acetone (100 parts by mass). The resulting solution was added dropwise into 500 parts by mass of water to permit the coagulation of the resin. The resulting solid was separated by filtration. The solid was dried at 50? C. for 12 hours to synthesize a white powdery resin (P-18). The Mw of the resulting resin (P-18) was 6,800, and the Mw/Mn was 1.59. As a result of .sup.13C-NMR analysis, the content rate of the structural unit derived from the compound (M-1): the structural unit derived from the compound (M-16): the structural unit derived from the compound (M-32) was 18:35:47 (mol %).

Synthesis Examples 19 to 23, 25 to 28, and 31 and 32

(Synthesis of Resins (P-19) to (P-23), (P-25) to (P-28), and (P-31) and (P-32))

(22) Resins (P-19) to (P-23), (P-25) to (P-28), and (P-31) and (P-32) each containing a predetermined amount of monomer shown in Table 1 were obtained in the same manner as in Synthesis Example 18. The Mw and Mw/Mn of each of the resulting resins, and the content rate of the structural unit derived from each of the monomers in each of the resins are shown together in Table 1.

(23) TABLE-US-00001 TABLE 1 Content Rate of Each Structural Unit in Polymer (mol %) Blending Amount of Compound Corresponding to Each Structural Unit (mol %) Compar- Physical Structural Structural Structural Structural Structural Comparative Struc- Struc- Struc- Struc- Struc- ative Property Unit (A) Unit (B) Unit (C) Unit (D) Unit (E) Structural Unit tural tural tural tural tural Struc- Value Blending Blending Blending Blending Blending Blending Unit Unit Unit Unit Unit tural Mw/ Resin Type Amount Type Amount Type Amount Type Amount Type Amount Type Amount (A) (B) (C) (D) (E) Unit Mw Mn Synthesis P-1 M-1 20 M-16 30 M-22 35 M-29 10 18 30 37 15 9700 1.35 Example 1 Synthesis P-2 M-2 25 M-21 20 M-23 55 26 17 57 9400 1.44 Example 2 Synthesis P-3 M-3 15 M-16 40 M-24 45 11 40 49 10900 1.42 Example 3 Synthesis P-4 M-4 35 M-20 25 M-26 40 31 25 44 9600 1.48 Example 4 Synthesis P-5 M-5 10 M-18 50 M-27 40 6 51 43 9800 1.45 Example 5 Synthesis P-6 M-6 25 M-16 25 M-25 50 23 23 54 9800 1.47 Example 6 Synthesis P-7 M-7 15 M-19 50 M-22 35 14 46 40 8700 1.46 Example 7 Synthesis P-8 M-8 5 M-17 40 M-28 45 M-30 10 5 37 48 11 8500 1.44 Example 8 Synthesis P-9 M-9 20 M-16 35 M-28 45 18 32 49 8700 1.39 E,ample 9 Synthesis P-10 M-10 10 M-18 40 M-26 50 9 37 54 8900 1.51 Example 10 Synthesis P-11 M-11 20 M-16 45 M-23 35 18 41 40 8800 1.61 Example 11 Synthesis P-12 M-12 15 M-19 35 M-24 50 14 32 54 8200 1.44 Example 12 Synthesis P-13 M-13 20 M-16 50 M-27 30 18 46 36 10500 1.56 Example 13 Synthesis P-14 M-14 30 M-18 35 M-23 35 28 32 40 9800 1.60 Example 14 Synthesis P-15 M-1 20 M-16 30 M-22 35 M-29 10 18 30 37 15 11200 1.41 Example 15 Synthesis P-16 M-1 20 M-16 30 M-22 35 M-29 10 19 31 37 15 13300 1.44 Example 16 Synthesis P-17 M-1 20 M-16 30 M-22 35 M-29 10 18 30 36 16 15400 1.50 Example 17 Synthesis P-18 M-1 20 M-16 35 M-32 45 18 35 47 6800 1.59 Example 18 Synthesis P-19 M-12 25 M-16 20 M-33 55 23 19 58 6900 1.68 Example 19 Synthesis P-20 M-13 20 M-17 20 M-34 60 18 19 63 7000 1.43 Example 20 Synthesis P-21 M-1 10 M-16 45 M-35 45 9 42 49 6500 1.49 Example 21 Synthesis P-22 M-2 30 M-31 15 M-36 55 28 14 58 6700 1.33 Example 22 Synthesis P-23 M-1 40 M-16 10 M-30 15 M-32 35 37 11 15 37 6700 1.56 Example 23 Synthesis P-24 M-8 15 M-31 25 M-22 60 14 63 23 6700 1.55 Example 24 Synthesis P-25 M-1 20 M-16 35 M-32 45 19 34 47 8300 1.66 Example 25 Synthesis P-26 M-1 20 M-16 35 M-32 45 18 35 47 10100 1.77 Example 26 Synthesis P-27 M-1 20 M-16 35 M-32 45 18 34 48 12400 1.81 Example 27 Synthesis P-28 M-1 20 M-16 35 M-32 45 18 35 47 14600 1.82 Example 28 Synthesis P-29 M-16 30 M-22 35 M-29 10 28 38 13 6500 1.41 Example 29 M-18 20 21 Synthesis P-30 M-21 20 M-23 55 M-39 25 18 54 28 6400 1.38 Example 30 Synthesis P-31 M-18 10 M-35 45 9 48 6700 1.34 Example 31 M-16 45 43 Synthesis P-32 M-31 15 M-36 55 M-39 30 15 58 27 6300 1.31 Example 32

Synthesis of High Fluorine-Containing Resin

Synthesis Example 33: Synthesis of High Fluorine-Containing Resin (E-1)

(24) Compounds (M-26) and (M-37) as monomers were dissolved in 2-butanone (200 parts by mass) at a molar ratio of 30/70. AIBN (5 mol % with respect to the total monomers) as an initiator was added thereto to prepare a monomer solution. 2-butanone (100 parts by mass) was placed in a reaction vessel, and the reaction vessel was purged with nitrogen gas for 30 minutes. The temperature in the reaction vessel was set at 80? C., and the monomer solution was added dropwise thereto under stirring for 3 hours. The polymerization reaction was performed for 6 hours with the start of the dropwise addition as the start time of the polymerization reaction. After the completion of the polymerization reaction, the polymerization solution was cooled with water to 30? C. or lower. The solvent was replaced with acetonitrile (400 parts by mass). Hexane (100 parts by mass) was then added and stirred, and an acetonitrile layer was collected. The collection was repeated three times in total. By replacing the solvent with propylene glycol monomethyl ether acetate, a solution of a high fluorine-containing resin (E-1) was obtained in a good yield.

Synthesis Example 34: Synthesis of High Fluorine-Containing Resin (E-2)

(25) A high fluorine-containing resin (E-2) containing a predetermined amount of monomer shown in Table 2 was obtained in the same manner as in Synthesis Example 33. The Mw and Mw/Mn of each of the resulting high fluorine-containing resins, and the content rate of the structural unit derived from each of the monomers in each of the high fluorine-containing resins are shown together in Table 2. The compound (M-26), the compound (M-37), the compound (M-16), and the compound (M-38) respectively provide a structural unit (C), a structural unit (F), a structural unit (B), and a structural unit (D).

(26) TABLE-US-00002 TABLE 2 High Content Rate of Fluorine- Blending Amount of Compound (mol %) Structural Unit Physical Containing Blending Blending Derived from Each Property Value Resin Type Amount Type Amount Compound (mol %) Mw Mw/Mn Synthesis E-1 M-26 30 M-37 70 M-26/M-37 = 31/69 5600 1.69 Example 33 Synthesis E-2 M-16 50 M-38 50 M-16/M-38 = 46/54 6700 1.78 Example 34
<Preparation of Radiation-Sensitive Resin Composition>

(27) The following compounds were used as a radiation-sensitive acid generator, an acid diffusion inhibitor, and a solvent constituting a radiation-sensitive resin composition.

(28) [Radiation-Sensitive Acid Generator]

(29) C-1 to C-9: Compounds represented by the following formulae (C-1) to (C-9)

(30) ##STR00065## ##STR00066## ##STR00067##
[Acid Diffusion Inhibitor]

(31) D-1 to D-6: Compounds represented by the following formulae (D-1) to (D-6)

(32) ##STR00068##
[Solvent]

(33) F-1 to F-4: solvents represented by the following F-1 to F-4

(34) F-1: propylene glycol monomethyl ether acetate

(35) F-2: cyclohexanone

(36) F-3: ?-butyrolactone

(37) F-4: propylene glycol monomethyl ether

(38) [Preparation of Radiation-Sensitive Resin Composition for ArF Exposure]

Example 1

(39) (P-1) (100 parts by mass) as a resin, (C-4) (15.0 parts by mass) as a radiation-sensitive acid generator, (D-5) (2.5 parts by mass) as an acid diffusion inhibitor, (E-1) (7 parts by mass) as a high fluorine-containing resin, (F-1) (2,240 parts by mass) as a solvent, (F-2) (960 parts by mass), and (F-3) (30 parts by mass) were mixed, and the mixture was filtered through a 0.2 ?m membrane filter to prepare a radiation-sensitive resin composition (J-1).

Example 2 to 17 and Comparative Example 1 and 2

(40) Radiation-sensitive resin compositions (J-2) to (J-17) and (CJ-1) and (CJ-2) were prepared in the same manner as in Example 1 except that components of types and contents shown in the following Table 3 were used.

(41) TABLE-US-00003 TABLE 3 Base Resin Radiation- Acid Diffusion High Fluorine- Radiation- Con- Sensitive Controlling Containing Sensitive tent Acid Generator Agent Resin Resin (Parts Content Content Content Solvent Compo- by (Parts by (Parts by (Parts by Content sition Type Mass) Type Mass) Type Mass) Type Mass) Type (Parts by Mass) Example 1 J-1 P-1 100 C-4 15.0 D-5 2.5 E-1 7 F-1/F-2/F-3 2,240/960/30 Example 2 J-2 P-2 100 C-7 11.3 D-1 3.0 E-1 7 F-1/F-2/F-3 2,240/960/30 Example 3 J-3 P-3 100 C-2 10.5 D-6 3.3 E-1 7 F-1/F-2/F-3 2,240/960/30 Example 4 J-4 P-4 100 C-4 15.5 D-1 2.5 E-1 7 F-1/F-2/F-3 2,240/960/30 Example 5 J-5 P-5 100 C-3 11.1 D-2 2.6 E-1 7 F-1/F-2/F-3 2,240/960/30 Example 6 J-6 P-6 100 C-1 15.4 D-2 4.0 E-1 7 F-1/F-2/F-3 2,240/960/30 Example 7 J-7 P-7 100 C-9 13.2 D-5 3.1 E-1 7 F-1/F-2/F-3 2,240/960/30 Example 8 J-8 P-8 100 C-8 17.6 D-1 1.5 E-1 7 F-1/F-2/F-3 2,240/960/30 Example 9 J-9 P-9 100 C-7 13.2 D-3 3.2 E-1 7 F-1/F-2/F-3 2,240/960/30 Example 10 J-10 P-10 100 C-9 11.9 D-3 2.5 E-1 7 F-1/F-2/F-3 2,240/960/30 Example 11 J-11 P-11 100 C-6 14.2 D-3 2.0 E-1 7 F-1/F-2/F-3 2,240/960/30 Example 12 J-12 P-12 100 C-5 17.1 D-4 3.1 E-1 7 F-1/F-2/F-3 2,240/960/30 Example 13 J-13 P-13 100 C-3 14.6 D-4 1.9 E-1 7 F-1/F-2/F-3 2,240/960/30 Example 14 J-14 P-14 100 C-6 9.9 D-1 2.0 E-1 7 F-1/F-2/F-3 2,240/960/30 Example 15 J-15 P-15 100 C-4 15.0 D-S 2.5 E-1 7 F-1/F-2/F-3 2,240/960/30 Example 16 J-16 P-16 100 C-4 15.0 D-3 2.5 E-1 7 F-1/F-2/F-3 2,240/960/30 Example 17 J-17 P-17 100 C-4 15.0 D-5 2.5 E-1 7 F-1/F-2/F-3 2,240/960/30 Comparative CJ-1 P-29 100 C-4 15.0 D-5 2.5 E-1 7 F-1/F-2/F-3 2,240/960/30 Example 1 Comparative CJ-2 P-30 100 C-7 11.3 D-1 3.0 E-1 7 F-1/F-2/F-3 2,240/960/30 Example 2
<Formation of Resist Pattern (1)> (ArF Exposure, Alkali Development)

(42) Onto the surface of a 12-inch silicon wafer, an underlayer antireflection film forming composition (ARC66 manufactured by Brewer Science Incorporated) was applied with use of a spin coater (CLEAN TRACK ACT12 manufactured by Tokyo Electron Limited). The wafer was then heated at 205? C. for 60 seconds to form an underlayer antireflection film having a film thickness of 105 nm. Each radiation-sensitive resin composition for ArF exposure was applied onto the underlayer antireflection film with use of the spin coater, followed by performing PAB at 120? C. for 50 seconds. Thereafter, cooling was performed at 23? C. for 30 seconds to form a resist film having an average thickness of 90 nm. Next, the coating film was exposed through a mask pattern for forming a resist pattern having a space of 44 nm and a pitch of 102 nm with an ArF excimer laser immersion exposure apparatus (TWINSCAN XT-1900i manufactured by ASML) in optical conditions of NA=1.35 and Annular (?=0.8/0.6). After exposing, PEB was performed at 90? C. for 60 seconds. Thereafter, paddle development was performed at 23? C. for 10 seconds using a 2.38 wt % aqueous TMAH solution, and spin drying was performed at 2,000 rpm for 15 seconds with shaking off, to form a resist pattern having a space of 45 nm.

(43) <Evaluation>

(44) The sensitivity, CDU, LWR, watermark defects, and residue defects of each of the radiation-sensitive resin compositions were evaluated by measuring each of the formed resist patterns according to the following method. A scanning electron microscope (CG-5000 manufactured by Hitachi High-Tech Corporation) was used for measuring the length of the resist pattern.

(45) [Sensitivity]

(46) An exposure dose at which a 40-nm line-and-space pattern was formed in the aforementioned resist pattern formation using each of the radiation-sensitive resin compositions for ArF exposure was defined as an optimum exposure dose Eop, and this optimum exposure dose was adopted as sensitivity (mJ/cm.sup.2). The sensitivity was evaluated to be good in a case of being mJ/cm.sup.2 or less, and poor in a case of exceeding 25 mJ/cm.sup.2.

(47) [CDU Performance]

(48) A resist pattern was formed by adjusting a mask size so as to form a pattern having a hole of 45 nm and a pitch of 110 nm by irradiation with the exposure dose Eop obtained above. The formed resist pattern was observed from above the pattern with use of the scanning electron microscope. The hole diameter was measured at 16 points within a square of 500 nm, and the measurement values were averaged to determine the average value. The average value was measured at five hundred of optional points. The 1 sigma value was calculated from the distribution of the measurement values, and defined as CDU performance (nm). The smaller the value of the CDU performance is, the smaller the variation in the hole diameter over long period is, which is better. The CDU performance can be evaluated to be good in a case of being 6.0 nm or less, and poor in a case of exceeding 6.0 nm.

(49) [LWR Performance]

(50) A resist pattern was formed by adjusting a mask size so as to form a pattern having a space of 45 nm and a pitch of 800 nm by irradiation with the exposure dose Eop obtained above. The formed resist pattern was observed from above the pattern with use of the scanning electron microscope. The variation in the line width was measured at a total of 500 points. The 3 sigma value was obtained from the distribution of the measurement values, and the 3 sigma value was defined as LWR performance (nm). The smaller the value of the LWR performance is, the smaller the wobble of the line is, which is better. The LWR performance can be evaluated to be good in a case of being 5.8 nm or less, and poor in a case of exceeding 5.8 nm.

(51) [Watermark Defects, Residue Defects]

(52) Watermark defects and residue defects in each resist pattern formed in the evaluation of the CDU and LWR performances were evaluated. The substrate on which the resist pattern had been formed was subjected to a defect test with use of a defect testing apparatus (KLA2810 manufactured by KLA-Tencor Corporation), and observed with use of a scanning electron microscope (RS6000 manufactured by Hitachi High-Tech Corporation), so as to evaluate the watermark defects and the residue defects according to the following evaluation criteria.

(53) [Evaluation Criteria of Watermark Defects]

(54) Good: the number of watermark defects was 0 per one wafer

(55) Average: the number of watermark defects was 1 or more and less than 3 per one wafer

(56) Poor: the number of watermark defects was 3 or more per one wafer

(57) [Evaluation Criteria of Residue Defects]

(58) Good: the number of residue defects was less than 100 per one wafer

(59) Poor: the number of residue defects was 100 or more per one wafer

(60) [Evaluation of Receding Contact Angle of Water]

(61) The receding contact angle (dRCA) of water on the surface of the film formed with use of each of the radiation-sensitive resin compositions for ArF exposure was evaluated. A 8-inch silicon wafer was spin-coated with the radiation-sensitive resin composition for ArF exposure, followed by performing PB at 90? C. for 60 seconds on a hot plate, to form an upper layer film having a film thickness of 30 nm. Thereafter, a receding contact angle was rapidly measured by the following procedure in an environment of room temperature of 23? C., a humidity of 45%, and an ordinary pressure with use of a contact angle meter (DSA-10 manufactured by KRUS). First, the wafer stage position of the contact angle meter was adjusted, and the wafer was set on the adjusted stage. Next, water was injected into a needle, and the position of the needle was finely adjusted to an initial position where a water droplet could be formed on the set wafer. Thereafter, water was discharged from the needle, and a water droplet of 25 ?L was formed on the wafer. Then, the needle was temporarily drawn out from the water droplet, and the needle was pulled down at the initial position again and placed in the water droplet. Subsequently, the water droplet was sucked with the needle for 90 seconds at a speed of 10 ?L/min and, at the same time, the contact angle was measured once per second for a total of 90 times. Among these, an average value of the contact angles for 20 seconds from the time point at which the measured value of the contact angle was stabilized was calculated, so as to determine the receding contact angle (unit: degree (?)).

(62) The evaluation results of the sensitivity, CDU performance, LWR performance, defect-suppression performance, and receding contact angle of water will be shown below.

(63) TABLE-US-00004 TABLE 4 Reced- Radiation- ing Sensitive Sensi- Con- Resi- Resin tivity tact due Compo- (mJ/ CDU LWR Angle WM De- sition cm.sup.2) (nm) (nm) (?) Defects tects Example 1 J-1 24.3 5.80 5.39 80.2 Good Good Example 2 J-2 22.2 5.95 5.53 79.8 Good Good Example 3 J-3 23.1 5.46 5.08 80.7 Good Good Example 4 J-4 22.5 5.89 5.48 80.4 Good Good Example 5 J-5 23.7 5.61 5.22 79.1 Good Good Example 6 J-6 24.0 5.76 5.36 79.5 Good Good Example 7 J-7 24.3 5.55 5.16 80.9 Good Good Example 8 J-8 22.1 5.90 5.49 81.5 Good Good Example 9 J-9 23.2 5.70 5.30 81.0 Good Good Example 10 J-10 22.7 5.62 5.23 82.0 Good Good Example 11 J-11 23.7 5.61 5.22 80.1 Good Good Example 12 J-12 24.6 5.45 5.07 80.8 Good Good Example 13 J-13 24.0 5.45 5.07 81.5 Good Good Example 14 J-14 22.4 5.88 5.47 81.2 Good Good Example 15 J-15 23.0 5.55 5.16 79.8 Good Good Example 16 J-16 23.5 5.37 4.99 80.1 Good Good Example 17 J-17 23.0 5.53 5.14 80.5 Good Good Compar- CJ-1 24.5 6.70 6.23 75.4 Poor Aver- ative age Example 1 Compar- CJ-2 23.5 6.88 6.40 81.1 Good Poor ative Example 2

(64) As is apparent from the results in Table 4 above, the radiation-sensitive resin compositions in Examples had good CDU performance, LWR performance, and defect-suppression performance.

(65) [Preparation of Radiation-Sensitive Resin Composition for Extreme Ultraviolet (EUV) Exposure]

Example 18

(66) (P-18) (100 parts by mass) as a resin, (C-4) (25.8 parts by mass) as a radiation-sensitive acid generator, (D-2) (8.1 parts by mass) as an acid diffusion inhibitor, (E-2) (7 parts by mass) as a high fluorine-containing resin, and (F-1) (4,280 parts by mass) and (F-4) (1,830 parts by mass) as solvents were mixed, and the resulting mixture was filtered through a membrane filter having a pore size of 0.2 ?m to prepare a radiation-sensitive resin composition (J-18).

Example 19 to 28 and Comparative Example 3 and 4

(67) Radiation-sensitive resin compositions (J-19) to (J-28) and (CJ-3) and (CJ-4) were prepared in the same manner as in Example 18 except that components of types and contents shown in the following Table 5 were used.

(68) TABLE-US-00005 TABLE 5 Base Resin Radiation- High Fluorine- Radiation- Con- Sensitive Acid Diffusion Containing Sensitive tent Acid Generator Inhibitor Resin Resin (Parts Content Content Content Solvent Compo- by (Parts by (Parts by (Parts by Content sition Type Mass) Type Mass) Type Mass) Type Mass) Type (Parts by Mass) Example 18 J-18 P-18 100 C-4 25.8 D-2 8.1 E-2 7 F-1/F-4 4,280/1,830 Example 19 J-19 P-19 100 C-5 28.1 D-2 8.1 E-2 7 F-1/F-4 4,280/1,830 Example 20 J-20 P-20 100 C-9 22.1 D-2 8.1 E-2 7 F-1/F-4 4,280/1,830 Example 21 J-21 P-21 100 C-7 25.6 D-3 9.2 E-2 7 F-1/F-4 4,280/1,830 Example 22 J-22 P-22 100 C-3 19.1 D-2 8.1 E-2 7 F-1/F-4 4,280/1,830 Example 23 J-23 P-23 100 C-4 25.8 D-3 9.2 E-2 7 F-1/F-4 4,280/1,830 Example 24 J-24 P-24 100 C-10 22.4 D-3 9.2 E-2 7 F-1/F-4 4,280/1,830 Example 25 J-25 P-25 100 C-5 28.1 D-2 8.1 E-2 7 F-1/F-4 4,280/1,830 Example 26 J-26 P-26 100 C-5 28.1 D-2 8.1 E-2 7 F-1/F-4 4,280/1,830 Example 27 J-27 P-27 100 C-5 28.1 D-2 8.1 E-2 7 F-1/F-4 4,280/1,830 Example 28 J-28 P-28 100 C-5 28.1 D-2 8.1 E-2 7 F-1/F-4 4,280/1,830 Comparative CJ-3 P-31 100 C-7 25.6 D-3 9.2 E-2 7 F-1/F-4 4,280/1,830 Example 3 Comparative CJ-4 P-32 100 C-3 19.1 D-2 8.1 E-2 7 F-1/F-4 4,280/1,830 Example 4
<Formation of Resist Pattern Using Radiation-Sensitive Resin Composition for EUV Exposure>

(69) Onto the surface of a 12-inch silicon wafer, an underlayer antireflection film forming composition (ARC66 manufactured by Brewer Science Incorporated) was applied with use of a spin coater (CLEAN TRACK ACT12 manufactured by Tokyo Electron Limited). The wafer was then heated at 205? C. for 60 seconds to form an underlayer antireflection film having an average film thickness of 105 nm. The radiation-sensitive resin composition for EUV exposure prepared above was applied onto the underlayer antireflection film with use of the spin coater, followed by performing PB at 130? C. for 60 seconds. Thereafter, cooling was performed at 23? C. for 30 seconds to form a resist film having an average thickness of 55 nm. Next, the resist film was exposed by an EUV exposure apparatus (NXE3300, manufactured by ASML) with NA of 0.33 under a lighting condition of Conventional s=0.89 and with a mask of imecDEFECT32FFR02. After exposing, PEB was performed at 120? C. for 60 seconds. Thereafter, the resist film was developed with an alkali with use of a 2.38% by mass aqueous TMAH solution as an alkaline developer solution, followed by washing with water and further drying to form a positive resist pattern (32-nm line-and-space pattern).

(70) <Evaluation>

(71) The resist patterns formed using the radiation-sensitive resin compositions for EUV exposure were evaluated on sensitivity, CDU performance, and LWR performance according to the following methods. The results are shown in Table 6 below. A scanning electron microscope (CG-5000 manufactured by Hitachi High-Tech Corporation) was used for measuring the length of the resist pattern.

(72) [Sensitivity]

(73) An exposure dose at which a 32-nm line-and-space pattern was formed in the aforementioned resist pattern formation using the radiation-sensitive resin composition for EUV exposure was defined as an optimum exposure dose Eop, and this optimum exposure dose was defined as sensitivity (mJ/cm.sup.2). The sensitivity was evaluated to be good in a case of being 35 mJ/cm.sup.2 or less, and poor in a case of exceeding 35 mJ/cm.sup.2.

(74) [CDU Performance]

(75) A resist pattern was formed by adjusting a mask size so as to form a pattern having a hole of 35 nm and a pitch of 90 nm by irradiation with the exposure dose Eop obtained above. The formed resist pattern was observed from above the pattern with use of the scanning electron microscope. The hole diameter was measured at 16 points within a square of 500 nm, and the measurement values were averaged to determine the average value. The average value was measured at five hundred of optional points. The 1 sigma value was calculated from the distribution of the measurement values, and defined as CDU performance (nm). The smaller the value of the CDU performance is, the smaller the variation in the hole diameter over long period is, which is better. The CDU performance was evaluated to be good in a case of being 2.0 nm or less, and poor in a case of exceeding 2.0 nm.

(76) [LWR Performance]

(77) A resist pattern was formed by adjusting a mask size so as to form a 32-nm line-and-space pattern by irradiation with the optimum exposure dose Eop obtained in the evaluation of the sensitivity. The formed resist pattern was observed from above the pattern with use of the scanning electron microscope. The variation in the line width was measured at a total of 500 points. The 3 sigma value was obtained from the distribution of the measurement values, and defined as LWR performance (nm). The smaller the value of the LWR is, the smaller the wobble of the line is, which is better. The LWR performance was evaluated to be good in a case of being 2.5 nm or less, and poor in a case of exceeding 2.5 nm.

(78) The evaluation results of the sensitivity, LWR performance, and CDU performance are shown in Table 6 below.

(79) TABLE-US-00006 TABLE 6 Radiation- Sensitive Resin Sensitivity CDU LWR Composition (mJ/cm.sup.2) (nm) (nm) Example 18 J-18 33.6 1.81 2.26 Example 19 J-19 33.2 1.89 2.36 Example 20 J-20 33.8 1.85 2.31 Example 21 J-21 34.5 1.79 2.23 Example 22 J-22 32.0 1.91 2.38 Example 23 J-23 31.4 1.94 2.42 Example 24 J-24 34.0 1.83 2.28 Example 25 J-25 33.5 1.80 2.24 Example 26 J-26 33.0 1.73 2.22 Example 27 J-27 34.0 1.78 2.16 Example 28 J-28 32.5 1.80 2.24 Comparative CJ-3 37.4 2.33 3.11 Example 3 Comparative CJ-4 36.8 2.44 3.21 Example 4

(80) As is apparent from the results in Table 6 above, the radiation-sensitive resin compositions in Examples had good sensitivity, CDU performance, and LWR performance.

(81) According to the radiation-sensitive resin composition and the method for forming a resist pattern of the embodiments of the present invention, a resist pattern having small CDU and LWR and few defects such as watermark can be formed. Therefore, these can be suitably used for a machining process and the like of a semiconductor device in which micronization is expected to progress more and more in the future.

(82) Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.