Resist composition and patterning process

Abstract

To provide a resist material having high sensitivity, high resolution, small LWR (line width roughness), good CDU (critical dimension uniformity) and a good pattern profile after exposure, and a pattern forming method.SOLUTION: In one aspect, the invention provides a resist composition comprising a base polymer comprising recurring units having the formula (a) and recurring units having a salt structure of sulfonium cation and sulfonate anion of specific structure, and an organic solvent.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resist material and a pattern forming method. [Background technology]

[0002] As LSIs become more highly integrated and faster, pattern rules are becoming increasingly miniaturized. This is due to the increasing popularity of 5G high-speed communications and artificial intelligence (AI), which require high-performance devices to process these. The most advanced miniaturization technology is extreme ultraviolet (EUV) lithography with a wavelength of 13.5 nm, which is currently used to mass-produce 5 nm node devices. Furthermore, the use of EUV lithography is being considered for next-generation 3 nm node devices and the next-generation 2 nm node devices.

[0003] As miniaturization progresses, image blurring due to acid diffusion has become a problem. To ensure resolution in fine patterns with processing dimensions of 45 nm and below, it has been suggested that controlling acid diffusion is important, in addition to improving dissolution contrast, as has been proposed previously (Non-Patent Document 1). However, because chemically amplified resist materials increase sensitivity and contrast through acid diffusion, attempts to minimize acid diffusion by lowering the post-exposure bake (PEB) temperature or shortening the time result in a significant decrease in sensitivity and contrast.

[0004] The triangle trade-off relationship between sensitivity, resolution, and line width roughness (LWR) of the line pattern is shown. To improve the resolution, it is necessary to suppress acid diffusion, but as the acid diffusion distance becomes shorter, the sensitivity decreases.

[0005] It is effective to suppress acid diffusion by adding an acid generator that generates bulky acid. Therefore, it has been proposed to incorporate repeating units derived from onium salts having polymerizable unsaturated bonds into a polymer. In this case, the polymer also functions as an acid generator (polymer-bound acid generator). Patent Document 1 proposes sulfonium salts and iodonium salts having polymerizable unsaturated bonds that generate specific sulfonic acids. Patent Document 2 proposes sulfonium salts in which sulfonic acids are directly linked to the main chain.

[0006] To suppress acid diffusion, resist materials have been proposed that use a base polymer containing a repeating unit derived from a sulfonium salt of a weak acid having a polymerizable group and a pKa of -0.8 or higher as a polymer-bound quencher (Patent Documents 3 to 5). Patent Document 3 lists carboxylic acids, sulfonamides, phenols, hexafluoroalcohols, etc. as weak acids. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-045311 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-178317 [Patent Document 3] International Publication No. 2019 / 167737 [Patent Document 4] International Publication No. 2022 / 264845 [Patent Document 5] Japanese Patent Publication No. 2022-115072 [Non-patent literature]

[0008] [Non-Patent Document 1] SPIE Vol. 6520 65203L-1 (2007) Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a resist material and a pattern formation method which have higher sensitivity and higher resolution than conventional resist materials, a small LWR, good dimensional uniformity (CDU), and a good pattern shape after exposure. [Means for solving the problem]

[0010] The present inventors have conducted extensive research to obtain resists with the high resolution, small LWR, and good CDU required in recent years, and as a result have found that it is necessary to minimize the acid diffusion distance and to achieve a uniform acid concentration within the resist film in exposed areas, and that an effective way to achieve this is to use a base polymer that contains a repeating unit composed of a carboxylic acid anion and an organic cation having an iodine atom and a specific functional group bonded to the polymer main chain, and a repeating unit composed of a sulfonate anion and a sulfonium cation bonded to the polymer main chain.

[0011] Furthermore, the present inventors have found that by introducing a repeating unit in which the hydrogen atom of a carboxyl group or a phenolic hydroxyl group is substituted with an acid labile group in order to improve the dissolution contrast, it is possible to obtain a resist material that has high sensitivity, a significantly high alkali dissolution rate contrast before and after exposure, high sensitivity, a high effect of suppressing acid diffusion, high resolution, a good pattern shape after exposure, a small LWR, and good CDU, and is particularly suitable as a material for forming fine patterns in VLSI manufacturing or photomasks, and have completed the present invention.

[0012] That is, the present invention provides the following resist material and pattern forming method. 1. A resist material comprising a base polymer containing a repeating unit represented by the following formula (a) and a repeating unit represented by the following formula (b), and an organic solvent: [ka] (In the formula, p is 0 or 1. m1 and m2 each independently is 0 or 1. When p is 0, n1 is 1, 2, 3, or 4. When p is 1, n1 and n2 are each independently 0, 1, 2, 3, or 4, and n1+n2≧1. When p is 0, n3 is 1. When p is 1, n3 and n4 are each independently 0 or 1, but n3+n4=1. When p is 0, n5 is 1, 2, 3, or 4. When p is 1, n5 and n6 are each independently 0, 1, 2, 3, or 4, and n5+n6≧1. R A is a hydrogen atom or a methyl group. X 1 is a single bond or -C(=O)-OX 11 -X 11 is an alkanediyl group having 1 to 6 carbon atoms. X 2 is a single bond or an alkanediyl group having 1 to 6 carbon atoms. L 1 is a linking group having 1 to 12 carbon atoms and containing at least one bond selected from a single bond, an ester bond, and an ether bond, and the linking group may contain a heteroatom-containing group other than an ester bond or an ether bond. L 2 and L 3 are each independently a single bond, an ether bond, or an ester bond. R 1 and R 2 are each independently a hydroxy group, a saturated hydrocarbyloxy group having 1 to 12 carbon atoms, or an organic group having 1 to 12 carbon atoms and a hydroxy group or a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, and may contain at least one bond selected from an ester bond and an ether bond. 1 may be the same or different. When n6 is 2 or more, each R 2 may be the same as or different from each other. M + is a monovalent organic cation. [ka] (In the formula, R Aare each independently a hydrogen atom or a methyl group. Y 1 is a single bond or an ester bond. Y 2 -Y 21 -C(=O)-O- or -Y 21 -O-. Y 21 represents a hydrocarbylene group having 1 to 12 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and these groups may contain a carbonyl group, an ester bond, an ether bond, a lactone ring, a fluorine atom, a bromine atom, or an iodine atom. Y 3 is a single bond, a methylene group, or an ethylene group. Rf 1 ~Rf 4 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, provided that at least one is a fluorine atom. R 11 , R 12 and R 13 are each independently a halogen atom or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. 11 and R 12 may be bonded to each other to form a ring together with the sulfur atom to which they are attached. 2.L 1 Resist material 1, where the bond is a single bond. 3.X 1 The resist material of 1 or 2, wherein is a single bond. 4.M + is represented by the following formula (M-1), (M-2) or (M-3): [ka] (In the formula, R M1 ~R M9 are each independently a halogen atom or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. M1 and R M2may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and R M6 ~R M9 Any two of may be bonded to each other to form a ring together with the nitrogen atom to which they are attached. 5.R 1 is a hydroxy group or a saturated hydrocarbyloxy group having 1 to 12 carbon atoms. 6. The resist material of any one of 1 to 5, wherein the base polymer further comprises at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (c1) and a repeating unit represented by the following formula (c2): [ka] (In the formula, R A are each independently a hydrogen atom or a methyl group. Z 1 is a linking group having 1 to 12 carbon atoms and containing at least one selected from a single bond, a phenylene group, a naphthylene group, an ester bond, an ether bond, and a lactone ring. Z 2 is a single bond, an ester bond or an amide bond. Z 3 is a single bond, an ether bond or an ester bond. R 21 and R 22 is an acid labile group. R 23 is a fluorine atom, a trifluoromethyl group, a cyano group or a saturated hydrocarbyl group having 1 to 6 carbon atoms. R 24 is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and some of the -CH2- groups in the alkanediyl group may be substituted with ether bonds or ester bonds. a is 1 or 2. b is 0, 1, 2, 3, or 4. 7. The resist material of any one of 1 to 6, wherein the base polymer further contains a repeating unit d containing an adhesive group selected from a hydroxy group, a carboxy group, a lactone ring, a carbonate bond, a thiocarbonate bond, a carbonyl group, a cyclic acetal group, an ether bond, an ester bond, a sulfonate ester bond, a cyano group, an amide bond, -OC(=O)-S-, and -OC(=O)-NH-. 8. The resist material of any one of 1 to 7, further comprising one or more additives selected from the group consisting of an acid generator, a quencher, and a surfactant. 9. The resist material of 8, wherein the additive is a quencher. 10. The resist material according to 9, wherein the quencher is represented by the following formula (1): [ka] (In the formula, R q1 is a hydrocarbyl group having 1 to 30 carbon atoms which may contain a heteroatom. + is a monovalent organic cation. 11. A pattern forming method comprising the steps of forming a resist film on a substrate using a resist material according to any one of 1 to 10, exposing the resist film to high-energy rays, and developing the exposed resist film using a developer. 12. The pattern formation method according to 11, wherein the high-energy beam is i-line, KrF excimer laser light, ArF excimer laser light, electron beam (EB), or EUV having a wavelength of 3 to 15 nm. [Effects of the Invention]

[0013] According to the present invention, it is possible to construct a resist material that has higher sensitivity and higher resolution than conventional resist materials, has a small LWR, is excellent in CDU, and produces a good pattern shape after exposure. DETAILED DESCRIPTION OF THE INVENTION

[0014] [Resist materials] The resist material of the present invention comprises a base polymer including a repeating unit a, which is bonded to the polymer main chain and comprises a carboxylate anion and an organic cation having an iodine atom and a specific functional group, and a repeating unit b, which is bonded to the polymer main chain and comprises a sulfonate anion and a sulfonium cation.

[0015] [Base polymer] The repeating unit a is represented by the following formula (a). [ka]

[0016] In formula (a), p is 0 or 1. m1 and m2 each independently is 0 or 1.

[0017] In formula (a), when p is 0, n1 is 1, 2, 3, or 4, preferably 1 or 2. When p is 1, n1 and n2 are each independently 0, 1, 2, 3, or 4, and n1+n2≧1, but preferably n1+n2 is 1 or 2. When p is 0, n3 is 1. When p is 1, n3 and n4 are each independently 0 or 1, and n3+n4=1. When p is 0, n5 is 1, 2, 3, or 4. When p is 1, n5 and n6 are each independently 0, 1, 2, 3, or 4, and n5+n6≧1.

[0018] In formula (a), R A is a hydrogen atom or a methyl group, preferably a hydrogen atom.

[0019] In formula (a), X 1 is a single bond or -C(=O)-OX 11 -X 11 is an alkanediyl group having 1 to 6 carbon atoms. Specific examples of the alkanediyl group include a methanediyl group, an ethane-1,1-diyl group, an ethane-1,2-diyl group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-1,6-diyl group. X 1is preferably a single bond. 1 When is a single bond, a resist film having excellent etching resistance can be formed.

[0020] In formula (a), X 2 is a single bond or an alkanediyl group having 1 to 6 carbon atoms. Specific examples of the alkanediyl group include 11 Examples of the alkanediyl group represented by the following formula include the same as those exemplified above.

[0021] In formula (a), L 1 is a linking group having 1 to 12 carbon atoms and containing at least one bond selected from a single bond, an ester bond, and an ether bond, and the linking group may contain a heteroatom-containing group other than an ester bond or an ether bond. 1 is preferably a single bond. 1 When is a single bond, a resist film having excellent heat resistance and etching resistance can be formed.

[0022] Also, X 1 and L 1 When both are single bonds, the mobility of the side chain can be suppressed when the repeating unit a is incorporated into a polymer, which is expected to reduce image blur due to material diffusion.

[0023] In formula (a), L 2 and L 3 are each independently a single bond, an ether bond, or an ester bond.

[0024] In formula (a), R 1 and R 2are each independently a hydroxy group, a saturated hydrocarbyloxy group having 1 to 12 carbon atoms, or an organic group having 1 to 12 carbon atoms and a hydroxy group or a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, and may contain at least one bond selected from an ester bond and an ether bond. Specific examples of the saturated hydrocarbyloxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a hexyloxy group, an octyloxy group, and a dodecyloxy group. Specific examples of the organic group having 1 to 12 carbon atoms include -OC(=O)-R x , -O-CH2-CH2-OR x , -C(=O)-OR x R x Examples of R include a hydroxyphenyl group and a methoxyphenyl group. 1 and R 2 is preferably a hydroxy group or a saturated hydrocarbyloxy group having 1 to 12 carbon atoms. 1 and R 2 When n5 is a hydroxy group or a saturated hydrocarbyloxy group having 1 to 12 carbon atoms, the acid diffusion control ability can be improved, and a low LWR and a good CDU can be achieved. 1 may be the same or different. When n6 is 2 or more, each R 2 may be the same as or different from each other.

[0025] Specific examples of the anion of the monomer that gives the repeating unit a include, but are not limited to, the following: A is the same as above. [ka]

[0026] [ka]

[0027] [ka]

[0028] [ka]

[0029] [ka]

[0030] [ka]

[0031] [ka]

[0032] In formula (a), M + is a monovalent organic cation. The organic cation is preferably a sulfonium cation represented by the following formula (M-1), an iodonium cation represented by the following formula (M-2), or an ammonium cation represented by the following formula (M-3). [ka]

[0033] In formula (a), R M1 ~R M9 are each independently a halogen atom or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom.

[0034] R M1 ~R M9 Specific examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0035] R M1 ~R M9The hydrocarbyl group having 1 to 20 carbon atoms represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecyl, octadecyl, nonadecyl, and icosyl groups; cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl groups; alkenyl groups having 2 to 20 carbon atoms, such as vinyl, propenyl, butenyl, and hexenyl groups; and ethynyl groups. alkynyl groups having 2 to 20 carbon atoms such as a propynyl group or a butynyl group; cyclic unsaturated aliphatic hydrocarbyl groups having 3 to 20 carbon atoms such as a cyclohexenyl group or a norbornenyl group; aryl groups having 6 to 20 carbon atoms such as a phenyl group, a methylphenyl group, an ethylphenyl group, an n-propylphenyl group, an isopropylphenyl group, an n-butylphenyl group, an isobutylphenyl group, a sec-butylphenyl group, a tert-butylphenyl group, a naphthyl group, a methylnaphthyl group, an ethylnaphthyl group, an n-propylnaphthyl group, an isopropylnaphthyl group, an n-butylnaphthyl group, an isobutylnaphthyl group, a sec-butylnaphthyl group or a tert-butylnaphthyl group; aralkyl groups having 7 to 20 carbon atoms such as a benzyl group or a phenethyl group; and groups obtained by combining these.

[0036] Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and some of the -CH- groups of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, the hydrocarbyl group may contain a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a mercapto group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, or the like.

[0037] Also, R M1 and R M2 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. In this case, specific examples of the ring structure include those represented by the following formulas: [ka]

[0038] Furthermore, R M6 ~R M9 Any two of may be bonded to each other to form a ring together with the nitrogen atom to which they are attached.

[0039] The cation of the repeating unit a is preferably a sulfonium cation represented by formula (M-1).

[0040] Specific examples of the cation of the repeating unit a include, but are not limited to, the following: [ka]

[0041] [ka]

[0042] [ka]

[0043]

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[0044]

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[0045]

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[0064] The repeating unit b is represented by the following formula (b). [ka]

[0065] In formula (b), in the formula, R A are each independently a hydrogen atom or a methyl group.

[0066] In formula (b), Y 1 is a single bond or an ester bond.

[0067] In formula (b), Y 2 -Y 21 -C(=O)-O- or -Y 21 -O-. Y 21 represents a hydrocarbylene group having 1 to 12 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and these groups may contain a carbonyl group, an ester bond, an ether bond, a lactone ring, a fluorine atom, a bromine atom, or an iodine atom.

[0068] In formula (b), Y 3 is a single bond, a methylene group, or an ethylene group.

[0069] In formula (b), Rf 1 ~Rf 4 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, provided that at least one is a fluorine atom.

[0070] In formula (b), R 11 , R 12 and R 13 are each independently a halogen atom or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples of the halogen atom and hydrocarbyl group include RM1 ~R M9 Specific examples of the halogen atom and hydrocarbyl group represented by R include those exemplified above. 11 and R 12 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. In this case, the ring is the same as that described for R M1 and R M2 Examples of the ring that can be formed by bonding these together with the sulfur atom to which they are bonded are the same as those exemplified above.

[0071] Specific examples of the anion of the monomer that gives the repeating unit b include, but are not limited to, those shown below. A is the same as above. [ka]

[0072] TIFF2026004979000042.tif56148

[0073] [ka]

[0074] [ka]

[0075] [ka]

[0076] [ka]

[0077] [ka]

[0078] [ka]

[0079] [ka]

[0080] [ka]

[0081] [ka]

[0082] [ka]

[0083] [ka]

[0084] Specific examples of the cation of the repeating unit b include the same sulfonium cations as those exemplified as the cation of the repeating unit a.

[0085] Repeating unit b functions as an acid generator. By linking the acid generator to the polymer main chain, acid diffusion is reduced, preventing a decrease in resolution due to blurring of the acid diffusion. Furthermore, the uniform dispersion of the acid generator improves LWR.

[0086] In this patent, the polymerization rate of the monomer that provides the repeating unit a that functions as a quencher is comparable to the polymerization rate of the monomer that provides the repeating unit b that functions as an acid generator having a double bond represented by general formula (b), so that the repeating units a and b are uniformly present in the polymer. This improves the LWR after development. Furthermore, the presence of iodine atoms in the anion moieties of both of these repeating units increases the number of absorbed photons and improves the film uniformity, thereby improving contrast and LWR.

[0087] In order to enhance dissolution contrast, the base polymer may contain at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (c1) in which the hydrogen atom of the carboxyl group is substituted with an acid labile group (hereinafter also referred to as repeating unit c1), and a repeating unit represented by the following formula (c2) in which the hydrogen atom of the phenolic hydroxyl group is substituted with an acid labile group (hereinafter also referred to as repeating unit c2). [ka]

[0088] In formulas (c1) and (c2), R A are each independently a hydrogen atom or a methyl group. 1 Z is a single bond, a phenylene group, a naphthylene group, or a linking group having 1 to 12 carbon atoms and containing at least one bond selected from an ester bond, an ether bond, and a lactone ring. 2 is a single bond, an ester bond or an amide bond. 3 is a single bond, an ether bond, or an ester bond. 21 and R 22 is an acid labile group. 23 R is a fluorine atom, a trifluoromethyl group, a cyano group, or a saturated hydrocarbyl group having 1 to 6 carbon atoms. 24 represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, and some of the -CH2- groups in the alkanediyl group may be substituted with ether bonds or ester bonds. a is 1 or 2. b is 0, 1, 2, 3, or 4.

[0089] Examples of monomers that provide the repeating unit c1 include, but are not limited to, those shown below. A and R 11 is the same as above. [ka]

[0090] [ka]

[0091] Examples of monomers that provide the repeating unit c2 include, but are not limited to, those shown below. A and R 12 is the same as above. [ka]

[0092] R 11 or R 12 The acid labile group represented by the formula (AL-1) may be selected from a variety of groups, and examples thereof include those represented by the following formulae (AL-1) to (AL-3). [ka] (In the formula, the dashed lines represent bonds.)

[0093] In formula (AL-1), c is an integer of 0 to 6. L1 is a tertiary hydrocarbyl group having 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms, a trihydrocarbylsilyl group in which each hydrocarbyl group is a saturated hydrocarbyl group having 1 to 6 carbon atoms, a carbonyl group, or a saturated hydrocarbyl group having 4 to 20 carbon atoms containing an ether bond or an ester bond, or a group represented by formula (AL-3). The tertiary hydrocarbyl group means a group obtained by eliminating a hydrogen atom from a tertiary carbon atom of a hydrocarbon.

[0094] R L1 The tertiary hydrocarbyl group represented by the formula (I) may be saturated or unsaturated, and may be branched or cyclic. Specific examples thereof include a tert-butyl group, a tert-pentyl group, a 1,1-diethylpropyl group, a 1-ethylcyclopentyl group, a 1-butylcyclopentyl group, a 1-ethylcyclohexyl group, a 1-butylcyclohexyl group, a 1-ethyl-2-cyclopentenyl group, a 1-ethyl-2-cyclohexenyl group, and a 2-methyl-2-adamantyl group. Examples of the trihydrocarbylsilyl group include a trimethylsilyl group, a triethylsilyl group, and a dimethyl-tert-butylsilyl group. The saturated hydrocarbyl group containing a carbonyl group, an ether bond, or an ester bond may be linear, branched, or cyclic, but is preferably cyclic. Specific examples thereof include a 3-oxocyclohexyl group, a 4-methyl-2-oxooxan-4-yl group, a 5-methyl-2-oxoxolan-5-yl group, a 2-tetrahydropyranyl group, and a 2-tetrahydrofuranyl group.

[0095] Examples of the acid labile group represented by formula (AL-1) include a tert-butoxycarbonyl group, a tert-butoxycarbonylmethyl group, a tert-pentyloxycarbonyl group, a tert-pentyloxycarbonylmethyl group, a 1,1-diethylpropyloxycarbonyl group, a 1,1-diethylpropyloxycarbonylmethyl group, a 1-ethylcyclopentyloxycarbonyl group, a 1-ethylcyclopentyloxycarbonylmethyl group, a 1-ethyl-2-cyclopentenyloxycarbonyl group, a 1-ethyl-2-cyclopentenyloxycarbonylmethyl group, a 1-ethoxyethoxycarbonylmethyl group, a 2-tetrahydropyranyloxycarbonylmethyl group, and a 2-tetrahydrofuranyloxycarbonylmethyl group.

[0096] Further, examples of the acid labile group represented by formula (AL-1) include groups represented by the following formulae (AL-1)-1 to (AL-1)-10. [ka] (In the formula, the dashed lines represent bonds.)

[0097] In formulae (AL-1)-1 to (AL-1)-10, c is the same as defined above. L8 are each independently a saturated hydrocarbyl group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. L9 is a hydrogen atom or a saturated hydrocarbyl group having 1 to 10 carbon atoms. L10 is a saturated hydrocarbyl group having 2 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. The saturated hydrocarbyl group may be linear, branched, or cyclic.

[0098] In formula (AL-2), R L2 and R L3 are each independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 18 carbon atoms, preferably 1 to 10. The saturated hydrocarbyl group may be linear, branched, or cyclic, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a cyclopentyl group, a cyclohexyl group, a 2-ethylhexyl group, and an n-octyl group.

[0099] In formula (AL-2), R L4 is a hydrocarbyl group having 1 to 18 carbon atoms, preferably 1 to 10, which may contain a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Examples of the hydrocarbyl group include saturated hydrocarbyl groups having 1 to 18 carbon atoms, and some of the hydrogen atoms may be substituted with hydroxy groups, alkoxy groups, oxo groups, amino groups, alkylamino groups, etc. Examples of such substituted saturated hydrocarbyl groups include those shown below. [ka] (In the formula, the dashed lines represent bonds.)

[0100] R L2 and R L3and R L2 and R L4 and, or R L3 and R L4 may be bonded to each other to form a ring together with the carbon atom to which they are bonded, or together with the carbon atom and oxygen atom, and in this case, R L2 and R L3 , R L2 and R L4 , or R L3 and R L4 are each independently an alkanediyl group having 1 to 18 carbon atoms, preferably 1 to 10. The ring obtained by combining these groups preferably has 3 to 10 carbon atoms, more preferably 4 to 10 carbon atoms.

[0101] Among the acid labile groups represented by formula (AL-2), linear or branched ones include, but are not limited to, those represented by the following formulae (AL-2)-1 to (AL-2)-69, in which the dashed lines represent bonds. [ka]

[0102] [ka]

[0103] [ka]

[0104] [ka]

[0105] Among the acid labile groups represented by formula (AL-2), examples of cyclic groups include a tetrahydrofuran-2-yl group, a 2-methyltetrahydrofuran-2-yl group, a tetrahydropyran-2-yl group, and a 2-methyltetrahydropyran-2-yl group.

[0106] Further, examples of the acid labile group include groups represented by the following formula (AL-2a) or (AL-2b): The base polymer may be inter- or intramolecularly crosslinked by the acid labile group. [ka] (In the formula, the dashed lines represent bonds.)

[0107] In formula (AL-2a) or (AL-2b), R L11 and R L12 are each independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 8 carbon atoms. The saturated hydrocarbyl group may be linear, branched, or cyclic. L11 and R L12 may be bonded to each other to form a ring together with the carbon atoms to which they are attached, in which case R L11 and R L12 are each independently an alkanediyl group having 1 to 8 carbon atoms. L13 are each independently a saturated hydrocarbylene group having 1 to 10 carbon atoms. The saturated hydrocarbylene group may be linear, branched, or cyclic. d and e are each independently an integer of 0 to 10, preferably an integer of 0 to 5, and f is an integer of 1 to 7, preferably an integer of 1 to 3.

[0108] In formula (AL-2a) or (AL-2b), L A is an (f+1)-valent aliphatic saturated hydrocarbon group having 1 to 50 carbon atoms, an (f+1)-valent alicyclic saturated hydrocarbon group having 3 to 50 carbon atoms, an (f+1)-valent aromatic hydrocarbon group having 6 to 50 carbon atoms, or an (f+1)-valent heterocyclic group having 3 to 50 carbon atoms. In addition, some of the -CH2- in these groups may be substituted with a group containing a hetero atom, and some of the hydrogen atoms in these groups may be substituted with a hydroxy group, a carboxy group, an acyl group, or a fluorine atom. A As L, saturated hydrocarbon groups such as saturated hydrocarbylene groups having 1 to 20 carbon atoms, trivalent saturated hydrocarbon groups, and tetravalent saturated hydrocarbon groups, and arylene groups having 6 to 30 carbon atoms are preferred. The saturated hydrocarbon groups may be linear, branched, or cyclic.

[0109] Examples of the crosslinked acetal group represented by formula (AL-2a) or (AL-2b) include groups represented by the following formulae (AL-2)-70 to (AL-2)-77. [ka] (In the formula, the dashed lines represent bonds.)

[0110] In formula (AL-3), R L5 , R L6 and R L7 are each independently a hydrocarbyl group having 1 to 20 carbon atoms, which may contain heteroatoms such as oxygen, sulfur, nitrogen, or fluorine atoms. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms, cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, cyclic unsaturated hydrocarbyl groups having 3 to 20 carbon atoms, and aryl groups having 6 to 10 carbon atoms. In addition, R L5 and R L6 and R L5 and R L7 and, or R L6 and R L7 may be bonded to each other to form an alicyclic ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded.

[0111] Examples of the group represented by formula (AL-3) include a tert-butyl group, a 1,1-diethylpropyl group, a 1-ethylnorbornyl group, a 1-methylcyclopentyl group, a 1-ethylcyclopentyl group, a 1-isopropylcyclopentyl group, a 1-methylcyclohexyl group, a 2-(2-methyl)adamantyl group, a 2-(2-ethyl)adamantyl group, and a tert-pentyl group.

[0112] Further, examples of the group represented by formula (AL-3) include groups represented by the following formulae (AL-3)-1 to (AL-3)-19. [ka] (In the formula, the dashed lines represent bonds.)

[0113] In formulas (AL-3)-1 to (AL-3)-19, R L14 are each independently a hydrogen atom, a saturated hydrocarbyl group having 1 to 8 carbon atoms, or an aryl group having 6 to 20 carbon atoms. L15 and R L17 are each independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 20 carbon atoms. L16 is an aryl group having 6 to 20 carbon atoms. The saturated hydrocarbyl group may be linear, branched, or cyclic. The aryl group is preferably a phenyl group. R F is a fluorine atom or a trifluoromethyl group, and g is an integer of 1 to 5.

[0114] Further examples of the acid labile group include groups represented by the following formula (AL-3)-20 or (AL-3)-21: The acid labile group may cause intramolecular or intermolecular crosslinking of the polymer. [ka] (In the formula, the dashed lines represent bonds.)

[0115] In formulas (AL-3)-20 and (AL-3)-21, R L14 is the same as above. R L18 is a (h+1)-valent saturated hydrocarbylene group having 1 to 20 carbon atoms or a (h+1)-valent arylene group having 6 to 20 carbon atoms, and may contain a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. The saturated hydrocarbylene group may be linear, branched, or cyclic. h is an integer of 1 to 3.

[0116] Examples of the monomer that provides the repeating unit containing the acid labile group represented by formula (AL-3) include (meth)acrylate esters containing the exo structure represented by formula (AL-3)-22 below. [ka]

[0117] In formula (AL-3)-22, R A is the same as above. R Lc1 R is a saturated hydrocarbyl group having 1 to 8 carbon atoms or an optionally substituted aryl group having 6 to 20 carbon atoms. The saturated hydrocarbyl group may be linear, branched, or cyclic. Lc2 ~R Lc11 are each independently a hydrogen atom or a hydrocarbyl group having 1 to 15 carbon atoms which may contain a heteroatom. Examples of the heteroatom include an oxygen atom. Examples of the hydrocarbyl group include an alkyl group having 1 to 15 carbon atoms and an aryl group having 6 to 15 carbon atoms. R Lc2 and R Lc3 and R Lc4 and R Lc6 and R Lc4 and R Lc7 and R Lc5 and R Lc7 and R Lc5 and R Lc11 and R Lc6 and R Lc10 and R Lc8 and R Lc9 and, or R Lc9 and R Lc10 may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and in this case, the group participating in the bond is a hydrocarbylene group having 1 to 15 carbon atoms which may contain a heteroatom. Lc2 and R Lc11 and R Lc8 and R Lc11 and, or R Lc4 and R Lc6 The term "a" means that adjacent carbon atoms may bond to each other without any intervening bond to form a double bond. This formula also represents an enantiomer.

[0118] Here, examples of the monomer represented by formula (AL-3)-22 include those described in JP-A-2000-327633. Specific examples include, but are not limited to, the following. In the following formula, R A is the same as above. [ka]

[0119] Examples of monomers that provide repeating units containing an acid labile group represented by formula (AL-3) include (meth)acrylic acid esters containing a furandiyl group, a tetrahydrofurandiyl group, or an oxanorbornanediyl group represented by formula (AL-3)-23 below. [ka]

[0120] In formula (AL-3)-23, R A is the same as above. R Lc12 and R Lc13 are each independently a hydrogen atom or a hydrocarbyl group having 1 to 10 carbon atoms. Lc12 and R Lc13 may be bonded to each other to form an alicyclic ring together with the carbon atoms to which they are attached. Lc14 is a furandiyl group, a tetrahydrofurandiyl group, or an oxanorbornanediyl group. Lc15 is a hydrocarbyl group having 1 to 10 carbon atoms which may contain a hydrogen atom or a heteroatom. The hydrocarbyl group may be linear, branched, or cyclic. Specific examples thereof include saturated hydrocarbyl groups having 1 to 10 carbon atoms.

[0121] Examples of the monomer represented by formula (AL-3)-23 include, but are not limited to, the following: A is the same as above, Ac is an acetyl group, and Me is a methyl group. [ka]

[0122] [ka]

[0123] The base polymer may further contain a repeating unit d containing an adhesive group selected from a hydroxy group, a carboxy group, a lactone ring, a carbonate bond, a thiocarbonate bond, a carbonyl group, a cyclic acetal group, an ether bond, an ester bond, a sulfonate ester bond, a cyano group, an amide bond, -OC(=O)-S-, and -OC(=O)-NH-.

[0124] Examples of monomers that provide the repeating unit d include, but are not limited to, those shown below. A is the same as above. [ka]

[0125] [ka]

[0126] [ka]

[0127] [ka]

[0128] [ka]

[0129] [ka]

[0130] [ka]

[0131] [ka]

[0132] [ka]

[0133] [ka]

[0134] The base polymer may further contain a repeating unit e that does not contain an amino group but contains an iodine atom. Examples of monomers that provide the repeating unit e include, but are not limited to, the following. In the following formula, R A is the same as above. [ka]

[0135] [ka]

[0136] The base polymer may contain a repeating unit f other than the repeating units described above. Examples of the repeating unit f include those derived from styrene, vinylnaphthalene, indene, acenaphthylene, coumarin, and coumarone.

[0137] In the base polymer, the content ratios of repeating units a1, a2, b1, b2, c, d1, d2, d3, e, and f are preferably 0 ≦ a1 < 1.0, 0 ≦ a2 < 1.0, 0 < a1 + a2 < 1.0, 0 ≦ b1 ≦ 0.5, 0 ≦ b2 ≦ 0.5, 0 < b1 + b2 ≦ 0.9, 0 ≦ c ≦ 0.9, 0 ≦ d1 ≦ 0.5, 0 ≦ d2 ≦ 0.5, 0 ≦ d3 ≦ 0.5, 0 ≦ d1 + d2 + d3 ≦ 0.5, 0 ≦ e ≦ 0.5, and 0 ≦ f ≦ 0.5; more preferably 0.001 ≦ a1 ≦ 0.8, 0.001 ≦ a2 ≦ 0.8, 0.001 ≦ a1 + a2 ≦ 0.8, 0 ≦ b1 ≦ 0.8, 0 ≦ b2 ≦ 0.8, 0.1 ≦ b1 + b2 ≦ 0.8, 0 ≦ c ≦ 0.8, 0 ≦ d1 ≦ 0.4, 0 ≦ d2 ≦ 0.4, 0 ≦ d3 ≦ 0.4, 0 ≦ d1 + d2 + d3 ≦ 0.4, 0 ≦ e ≦ 0.4, and 0 ≦ f ≦ 0.4; and still more preferably 0.005 ≦ a1 ≦ 0.7, 0.005 ≦ a2 ≦ 0.7, 0.005 ≦ a1 + a2 ≦ 0.7, 0 ≦ b1 ≦ 0.7, 0 ≦ b2 ≦ 0.7, ≦ b1 + b2 ≦ 0.7, 0 ≦ c ≦ 0.7, 0 ≦ d1 ≦ 0.3, 0 ≦ d2 ≦ 0.3, 0 ≦ d3 ≦ 0.3, 0 ≦ d1 + d2 + d3 ≦ 0.3, 0 ≦ e ≦ 0.3, and 0 ≦ f ≦ 0.3. However, a1 + a2 + b1 + b2 + c + d1 + d2 + d3 + e + f = 1.0.

[0138] To synthesize the base polymer, for example, monomers that provide the aforementioned repeating units may be heated in an organic solvent with a radical polymerization initiator added thereto to perform polymerization.

[0139] Examples of the organic solvent used during polymerization include toluene, benzene, tetrahydrofuran (THF), diethyl ether, dioxane, propylene glycol monomethyl ether, γ-butyrolactone, and mixed solvents thereof. Examples of the polymerization initiator include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl 2,2-azobis(2-methylpropionate), benzoyl peroxide, lauroyl peroxide, and the like. The temperature during polymerization is preferably 50 to 80°C. The reaction time is preferably 2 to 100 hours, more preferably 5 to 20 hours.

[0140] When a monomer containing a hydroxy group is copolymerized, the hydroxy group may be substituted with an acetal group that is easily deprotected by an acid, such as an ethoxyethoxy group, during polymerization, and then deprotected with a weak acid and water after polymerization. Alternatively, the hydroxy group may be substituted with an acetyl group, a formyl group, a pivaloyl group, or the like, and then subjected to alkaline hydrolysis after polymerization.

[0141] When copolymerizing hydroxystyrene or hydroxyvinylnaphthalene, acetoxystyrene or acetoxyvinylnaphthalene may be used instead of hydroxystyrene or hydroxyvinylnaphthalene, and after polymerization, the acetoxy group may be deprotected by the alkaline hydrolysis to give hydroxystyrene or hydroxyvinylnaphthalene.

[0142] The base that can be used in alkaline hydrolysis includes aqueous ammonia, triethylamine, etc. The reaction temperature is preferably −20 to 100° C., more preferably 0 to 60° C. The reaction time is preferably 0.2 to 100 hours, more preferably 0.5 to 20 hours.

[0143] The base polymer preferably has a weight average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography (GPC) using THF as a solvent of 1,000 to 500,000, more preferably 2,000 to 30,000. When the Mw is within this range, the resist film has good heat resistance and solubility in an alkaline developer.

[0144] If the base polymer has a broad molecular weight distribution (Mw / Mn), the presence of low-molecular-weight and high-molecular-weight polymers may result in the appearance of foreign matter on the pattern after exposure, or the pattern shape may be deteriorated. As the pattern rule becomes finer, the effects of Mw and Mw / Mn tend to become greater. Therefore, in order to obtain a resist material that is suitable for use with fine pattern dimensions, it is preferable that the Mw / Mn of the base polymer has a narrow distribution of 1.0 to 2.0, particularly 1.0 to 1.7.

[0145] The base polymer may comprise two or more polymers with different composition ratios, Mw, or Mw / Mn. Alternatively, a polymer containing repeating units a and b may be blended with a polymer containing repeating unit b but not repeating unit a.

[0146] [Quencher] The resist material of the present invention may contain a quencher (hereinafter also referred to as an additive-type quencher). Examples of the quencher include conventional basic compounds. Specific examples of conventional basic compounds include primary, secondary, and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxy group, nitrogen-containing compounds having a sulfonyl group, nitrogen-containing compounds having a hydroxy group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amides, imides, and carbamates. In particular, the primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

[0164] of JP 2008-111103 A are preferred, including amine compounds having a hydroxy group, an ether bond, an ester bond, a lactone ring, a cyano group, or a sulfonate ester bond, and compounds having a carbamate bond described in Japanese Patent No. 3790649 A. By adding such a basic compound, for example, it is possible to further suppress the diffusion rate of the acid in the resist film and correct the shape.

[0147] Further, examples of the additive-type quencher include onium salts such as sulfonium salts, iodonium salts, and ammonium salts of sulfonic acids or carboxylic acids not fluorinated at the α-position, as described in JP-A-2008-158339. Sulfonic acids, imide acids, or methide acids fluorinated at the α-position are necessary for deprotecting the acid labile group of a carboxylic acid ester, and the sulfonic acids or carboxylic acids not fluorinated at the α-position are released by salt exchange with onium salts not fluorinated at the α-position. Sulfonic acids and carboxylic acids not fluorinated at the α-position do not undergo deprotection reactions and therefore function as quenchers.

[0148] Another example of the additive-type quencher is an onium salt of a carboxylic acid fluorinated at the α-position, as described in Japanese Patent No. 5904180. α-Fluorocarboxylic acids have lower acidity than sulfonic acids and therefore have high quenching ability, making it possible to form patterns with good roughness and resolution.

[0149] Other examples of the additive quencher include the polymer quencher described in JP 2008-239918 A. This quencher enhances the rectangularity of the resist pattern by orienting on the surface of the resist film. The polymer quencher also has the effect of preventing pattern film loss and rounding of the pattern top when a protective film for immersion lithography is applied.

[0150] The additive type quencher is preferably one represented by the following formula (1). [ka]

[0151] In formula (1), R q1 is a hydrocarbyl group having 1 to 30 carbon atoms which may contain a heteroatom.

[0152] R q1The hydrocarbyl group having 1 to 40 carbon atoms represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 40 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl groups; cyclic saturated hydrocarbyl groups having 3 to 40 carbon atoms, such as cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, tricyclo[5.2.1.02,6]decyl, adamantyl, and adamantylmethyl groups; vinyl, allyl, propenyl, butenyl, and hexenyl groups. Examples of such alkyl groups include alkenyl groups having 2 to 40 carbon atoms, such as an alkyl group; cyclic unsaturated aliphatic hydrocarbyl groups having 3 to 40 carbon atoms, such as a cyclohexenyl group; aryl groups having 6 to 40 carbon atoms, such as a phenyl group, a naphthyl group, an alkylphenyl group (e.g., a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, a 4-ethylphenyl group, a 4-tert-butylphenyl group, a 4-n-butylphenyl group), a di- or trialkylphenyl group (e.g., a 2,4-dimethylphenyl group, a 2,4,6-triisopropylphenyl group), an alkylnaphthyl group (e.g., a methylnaphthyl group, an ethylnaphthyl group), and a dialkylnaphthyl group (e.g., a dimethylnaphthyl group, a diethylnaphthyl group); and aralkyl groups having 7 to 40 carbon atoms, such as a benzyl group, a 1-phenylethyl group, and a 2-phenylethyl group.

[0153] In addition, some or all of the hydrogen atoms of the hydrocarbyl group may be replaced by oxygen atoms, sulfur atoms, nitrogen atoms, or the like. The hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and a portion of the -CH2- in the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom, resulting in the hydrocarbyl group containing a hydroxy group, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. Specific examples of hydrocarbyl groups containing heteroatoms include fluorinated alkyl groups such as trifluoromethyl, trifluoroethyl, 2,2,2-trifluoro-1-methyl-1-hydroxyethyl, and 2,2,2-trifluoro-1-(trifluoromethyl)-1-hydroxyethyl; fluorinated aryl groups such as pentafluorophenyl and 4-trifluoromethylphenyl; heteroaryl groups such as thienyl; 4-hydroxyphenyl, 4-methoxyphenyl, 3-methoxyphenyl, 2-methoxyphenyl, 4-ethoxyphenyl, and the like. alkoxyphenyl groups such as a phenyl group, a 4-tert-butoxyphenyl group, and a 3-tert-butoxyphenyl group; alkoxynaphthyl groups such as a methoxynaphthyl group, an ethoxynaphthyl group, an n-propoxynaphthyl group, and an n-butoxynaphthyl group; dialkoxynaphthyl groups such as a dimethoxynaphthyl group and a diethoxynaphthyl group; and aryloxoalkyl groups such as a 2-aryl-2-oxoethyl group, a 2-(1-naphthyl)-2-oxoethyl group, and a 2-(2-naphthyl)-2-oxoethyl group.

[0154] R q1 is preferably a hydrocarbyl group having 6 to 12 carbon atoms. q1 is preferably substituted with a halogen atom, more preferably with an iodine atom.

[0155] Specific examples of the anion of the quencher represented by formula (1) include, but are not limited to, those shown below. [ka]

[0156]

change

[0157]

change

[0158]

change

[0159]

change

[0160]

change

[0161]

change

[0162]

change

[0163]

change

[0164]

change

[0165]

change

[0166] In equation (1), Mq +is a monovalent organic cation. The organic cation is preferably a sulfonium cation represented by the above-mentioned formula (M-1), an iodonium cation represented by the formula (M-2), or an ammonium cation represented by the formula (M-3). Specific examples of the organic cation include the same as those exemplified as the cation of the repeating unit a.

[0167] In the resist material of the present invention, the content of the additive-type quencher is preferably 0 to 10 parts by mass, more preferably 0 to 7 parts by mass, relative to 100 parts by mass of the base polymer. The quencher may be used alone or in combination of two or more types.

[0168] [Acid generator] The resist material of the present invention may contain an acid generator that generates a strong acid (hereinafter also referred to as an additive-type acid generator). The strong acid here refers to a compound that has sufficient acidity to initiate a deprotection reaction of the acid labile groups in the base polymer.

[0169] Examples of the acid generator include compounds (photoacid generators) that generate acid in response to actinic rays or radiation. The photoacid generator may be any compound that generates an acid upon exposure to high-energy rays, but is preferably one that generates a sulfonic acid, an imide acid, or a methide acid. Suitable photoacid generators include sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, and oxime-O-sulfonate-type acid generators. Specific examples of photoacid generators include those described in paragraphs

[0122] to

[0142] of JP 2008-111103 A.

[0170] Furthermore, as the photoacid generator, a sulfonium salt represented by the following formula (2-1) or an iodonium salt represented by the following formula (2-2) can also be suitably used. [ka]

[0171] In formulas (2-1) and (2-2), R 101 ~R 105 are each independently a halogen atom or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples of the halogen atom and hydrocarbyl group include R M1 ~R M9 Specific examples of the halogen atom and hydrocarbyl group represented by R include those exemplified above. 101 , R 102 and R 103 Any two of these may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. In this case, the ring is the same as R M1 and R M2 Examples of the ring that can be formed by bonding these together with the sulfur atom to which they are bonded are the same as those exemplified above.

[0172] Specific examples of the cation of the sulfonium salt represented by formula (2-1) include the same sulfonium cations as those exemplified as the cation of the repeating unit a. Specific examples of the cation of the iodonium salt represented by formula (2-2) include the same iodonium cations as those exemplified as the cation of the repeating unit a.

[0173] In formulas (2-1) and (2-2), Xa - is an anion selected from the following formulae (2A) to (2D). [ka]

[0174] In formula (2A), R fa is a hydrocarbyl group having 1 to 40 carbon atoms which may contain a fluorine atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R in formula (2A') described below. fa1Examples of the hydrocarbyl group represented by the formula (I) include the same as those exemplified above.

[0175] The anion represented by formula (2A) is preferably one represented by the following formula (2A'). [ka]

[0176] In formula (2A'), R HF is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. fa1 is a hydrocarbyl group having 1 to 38 carbon atoms which may contain a heteroatom. The heteroatom is preferably an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom, or the like, and more preferably an oxygen atom. In order to obtain high resolution in the formation of a fine pattern, the hydrocarbyl group is particularly preferably one having 6 to 30 carbon atoms.

[0177] R fa1 The hydrocarbyl group represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 38 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, a nonyl group, an undecyl group, a tridecyl group, a pentadecyl group, a heptadecyl group, and an icosyl group; a cyclopentyl group, a cyclohexyl group, a 1-adamantyl group, a 2-adamantyl group, a 1-adamantylmethyl group, and a norbornyl group. cyclic saturated hydrocarbyl groups having 3 to 38 carbon atoms such as a norbornylmethyl group, a tricyclodecanyl group, a tetracyclododecanyl group, a tetracyclododecanylmethyl group, or a dicyclohexylmethyl group; unsaturated aliphatic hydrocarbyl groups having 2 to 38 carbon atoms such as an allyl group or a 3-cyclohexenyl group; aryl groups having 6 to 38 carbon atoms such as a phenyl group, a 1-naphthyl group, or a 2-naphthyl group; aralkyl groups having 7 to 38 carbon atoms such as a benzyl group or a diphenylmethyl group; and groups obtained by combining these.

[0178] Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and some of the -CH- groups of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, the hydrocarbyl group may contain a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. Examples of hydrocarbyl groups containing hetero atoms include tetrahydrofuryl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetamidomethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, and 3-oxocyclohexyl groups.

[0179] Synthesis of sulfonium salts containing anions represented by formula (2A') is described in detail in JP-A Nos. 2007-145797, 2008-106045, 2009-7327, and 2009-258695. Sulfonium salts described in JP-A Nos. 2010-215608, 2012-41320, 2012-106986, and 2012-153644 are also suitable.

[0180] Examples of the anion represented by formula (2A) include the same anions as those exemplified as the anion represented by formula (1A) in JP 2018-197853 A.

[0181] In formula (2B), R fb1 and R fb2are each independently a hydrocarbyl group having 1 to 40 carbon atoms which may contain a fluorine atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R in formula (2A'). fa1 Examples of the hydrocarbyl group represented by R include the same as those exemplified above. fb1 and R fb2 is preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. fb1 and R fb2 means that the groups to which they are bonded (-CF2-SO2-N - -SO2-CF2-) together to form a ring, in which case, R fb1 and R fb2 The group obtained by bonding together is preferably a fluorinated ethylene group or a fluorinated propylene group.

[0182] In formula (2C), R fc1 , R fc2 and R fc3 are each independently a hydrocarbyl group having 1 to 40 carbon atoms which may contain a fluorine atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R in formula (2A'). fa1 Examples of the hydrocarbyl group represented by R include the same as those exemplified above. fc1 , R fc2 and R fc3 is preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. fc1 and R fc2 are groups that are bonded together and bonded to each other (-CF2-SO2-C - -SO2-CF2-) together to form a ring, in which case, R fc1 and R fc2 The group obtained by bonding together is preferably a fluorinated ethylene group or a fluorinated propylene group.

[0183] In formula (2D), R fdis a hydrocarbyl group having 1 to 40 carbon atoms which may contain a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R in formula (2A'). fa1 Examples of the hydrocarbyl group represented by the formula (I) include the same as those exemplified above.

[0184] The synthesis of sulfonium salts containing anions represented by formula (2D) is described in detail in JP-A-2010-215608 and JP-A-2014-133723.

[0185] Examples of the anion represented by formula (2D) include the same anions as those exemplified as the anion represented by formula (1D) in JP 2018-197853 A.

[0186] Although the photoacid generator containing the anion represented by formula (2D) does not have a fluorine atom at the α-position of the sulfo group, it has two trifluoromethyl groups at the β-position, and therefore has sufficient acidity to cleave the acid labile groups in the base polymer, making it suitable for use as a photoacid generator.

[0187] As the photoacid generator, a compound represented by the following formula (3) can also be suitably used. [ka]

[0188] In formula (3), R 201 and R 202 R are each independently a halogen atom or a hydrocarbyl group having 1 to 30 carbon atoms which may contain a heteroatom. 203 is a hydrocarbylene group having 1 to 30 carbon atoms which may contain a heteroatom. 201 , R 202 and R 203 Any two of these may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. In this case, the ring is the same as R M1and R M2 Examples of the ring that can be formed by bonding these together with the sulfur atom to which they are bonded are the same as those exemplified above.

[0189] R 201 and R 202 The hydrocarbyl group represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 30 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, an n-hexyl group, an n-octyl group, a 2-ethylhexyl group, an n-nonyl group, and an n-decyl group; a cyclopentyl group, a cyclohexyl group, a cyclopentylmethyl group, a cyclopentylethyl group, a cyclopentylbutyl group, a cyclohexylmethyl group, a cyclohexylethyl group, a cyclohexylbutyl group, a norbornyl group, an oxanorbornyl group, and a tricyclo[5.2.1.0] 2,6cyclic saturated hydrocarbyl groups having 3 to 30 carbon atoms such as a phenyl group, a methylphenyl group, an ethylphenyl group, an n-propylphenyl group, an isopropylphenyl group, an n-butylphenyl group, an isobutylphenyl group, a sec-butylphenyl group, a tert-butylphenyl group, a naphthyl group, a methylnaphthyl group, an ethylnaphthyl group, an n-propylnaphthyl group, an isopropylnaphthyl group, an n-butylnaphthyl group, an isobutylnaphthyl group, a sec-butylnaphthyl group, a tert-butylnaphthyl group, an anthracenyl group, and the like; and groups obtained by combining these. Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and some of the -CH- groups of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, the hydrocarbyl group may contain a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc.

[0190] R 203The hydrocarbylene group represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkanediyl groups having 1 to 30 carbon atoms, such as methanediyl group, ethane-1,1-diyl group, ethane-1,2-diyl group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, and heptadecane-1,17-diyl group; cyclopentanediyl group, cyclohexene-1,18-diyl group, and the like. Examples of the alkylene groups include cyclic saturated hydrocarbylene groups having 3 to 30 carbon atoms, such as xanediyl, norbornanediyl, and adamantanediyl; arylene groups having 6 to 30 carbon atoms, such as phenylene, methylphenylene, ethylphenylene, n-propylphenylene, isopropylphenylene, n-butylphenylene, isobutylphenylene, sec-butylphenylene, tert-butylphenylene, naphthylene, methylnaphthylene, ethylnaphthylene, n-propylnaphthylene, isopropylnaphthylene, n-butylnaphthylene, isobutylnaphthylene, sec-butylnaphthylene, and tert-butylnaphthylene; and groups obtained by combining these groups. In addition, some or all of the hydrogen atoms of the hydrocarbylene group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and some of the -CH- groups of the hydrocarbylene group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom, resulting in the hydrocarbylene group containing a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. As the heteroatom, an oxygen atom is preferred.

[0191] In formula (3), LA is a single bond, an ether bond, or a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. The hydrocarbylene group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R 203 Examples of the hydrocarbylene group represented by the formula (I) include the same as those exemplified above.

[0192] In formula (3), X A , X B , X C and X D are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, provided that X A , X B , X C and X D At least one of the groups is a fluorine atom or a trifluoromethyl group.

[0193] In formula (3), k is 0, 1, 2 or 3.

[0194] The photoacid generator represented by formula (3) is preferably one represented by the following formula (3'). [ka]

[0195] In formula (3'), L A is the same as above. X E is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. 301 , R 302 and R 303 are each independently a hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R in formula (2A'). fa1 Examples of the hydrocarbyl group include the same as those exemplified above. Each of x and y is independently an integer of 0 to 5, and z is an integer of 0 to 4.

[0196] Examples of the photoacid generator represented by formula (3) include the same compounds as those exemplified as the photoacid generator represented by formula (2) in JP-A-2017-026980.

[0197] Among the photoacid generators, those containing an anion represented by formula (2A') or (2D) are particularly preferred because of their small acid diffusion and excellent solubility in solvents. Also, those represented by formula (3') are particularly preferred because of their extremely small acid diffusion.

[0198] The photoacid generator may also be a sulfonium salt or iodonium salt containing an anion having an aromatic ring substituted with an iodine atom or a bromine atom, such as those represented by the following formula (4-1) or (4-2): [ka]

[0199] In formulas (4-1) and (4-2), p is 1, 2, or 3. q is 1, 2, 3, 4, or 5. r is 0, 1, 2, or 3, provided that 1≦q+r≦5. q is preferably 1, 2, or 3, and more preferably 2 or 3. r is preferably 0, 1, or 2.

[0200] In formulas (4-1) and (4-2), X BI is an iodine atom or a bromine atom, and when p and / or q is 2 or more, they may be the same or different.

[0201] In formulas (4-1) and (4-2), L 1 is a single bond, an ether bond, an ester bond, or a saturated hydrocarbylene group having 1 to 6 carbon atoms which may contain an ether bond or an ester bond. The saturated hydrocarbylene group may be linear, branched, or cyclic.

[0202] In formulas (4-1) and (4-2), L 2represents a single bond or a divalent linking group having 1 to 20 carbon atoms when p is 1, and represents a (p+1)-valent linking group having 1 to 20 carbon atoms when p is 2 or 3, and the linking group may contain an oxygen atom, a sulfur atom, or a nitrogen atom.

[0203] In formulas (4-1) and (4-2), R 401 is a hydroxy group, a carboxy group, a fluorine atom, a chlorine atom, a bromine atom or an amino group, or a hydrocarbyl group having 1 to 20 carbon atoms, a hydrocarbyloxy group having 1 to 20 carbon atoms, a hydrocarbylcarbonyl group having 2 to 20 carbon atoms, a hydrocarbyloxycarbonyl group having 2 to 20 carbon atoms, a hydrocarbylcarbonyloxy group having 2 to 20 carbon atoms or a hydrocarbylsulfonyloxy group having 1 to 20 carbon atoms which may contain a fluorine atom, a chlorine atom, a bromine atom, a hydroxy group, an amino group or an ether bond, or 401A )(R 401B ), -N(R 401C )-C(=O)-R 401D or -N(R 401C )-C(=O)-OR 401D R 401A and R 401B are each independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. 401C is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms, and may contain a halogen atom, a hydroxy group, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms. 401Dis an aliphatic hydrocarbyl group having 1 to 16 carbon atoms, an aryl group having 6 to 14 carbon atoms, or an aralkyl group having 7 to 15 carbon atoms, and may contain a halogen atom, a hydroxy group, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms. The aliphatic hydrocarbyl group may be saturated or unsaturated and may be linear, branched, or cyclic. The hydrocarbyl group, hydrocarbyloxy group, hydrocarbyloxycarbonyl group, hydrocarbylcarbonyl group, hydrocarbylcarbonyloxy group, and hydrocarbylsulfonyloxy group may be linear, branched, or cyclic. When p and / or r is 2 or more, each R 401 may be the same or different from each other.

[0204] Of these, R 401 Examples of the hydroxyl group include -N(R 401C )-C(=O)-R 401D , -N(R 401C )-C(=O)-OR 401D fluorine atom, chlorine atom, bromine atom, methyl group, methoxy group, etc. are preferred.

[0205] In formulas (4-1) and (4-2), Rf 1 ~Rf 4 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, and at least one of them is a fluorine atom or a trifluoromethyl group. 1 and Rf 2 may combine to form a carbonyl group. 3 and Rf 4 are preferably both fluorine atoms.

[0206] In formulas (4-1) and (4-2), R 402 ~R 406are each independently a halogen atom or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples of the halogen atom and hydrocarbyl group include R M1 ~R M9 Examples of the hydrocarbyl group include the same as those exemplified above. In addition, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a hydroxy group, a carboxy group, a halogen atom, a cyano group, a nitro group, a mercapto group, a sultone group, a sulfo group, or a sulfonium salt-containing group, and some of the -CH2- groups of the hydrocarbyl group may be substituted with an ether bond, an ester bond, a carbonyl group, an amide bond, a carbonate bond, or a sulfonate ester bond. 402 and R 403 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. In this case, the ring is the same as that described for R in the explanation of formulas (M-1) to (M-3). M1 and R M2 Examples of the ring that can be formed by bonding these together with the sulfur atom to which they are bonded are the same as those exemplified above.

[0207] Specific examples of the cation of the sulfonium salt represented by formula (4-1) include the same sulfonium cations as those exemplified as the cation of the repeating unit a. Specific examples of the cation of the iodonium salt represented by formula (4-2) include the same iodonium cations as those exemplified as the cation of the repeating unit a.

[0208] Examples of the anion of the onium salt represented by formula (4-1) or (4-2) include, but are not limited to, the following: BI is the same as above. [ka]

[0209]

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[0210]

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[0211]

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[0212]

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[0213]

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[0216]

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[0217]

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[0218]

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[0219]

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[0220]

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[0222]

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[0223]

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[0231] In the resist material of the present invention, the content of the additive acid generator is preferably 0.1 to 50 parts by mass, and more preferably 1 to 40 parts by mass, per 100 parts by mass of the base polymer. By including the repeating unit b in the base polymer and / or by including the additive acid generator, the resist material of the present invention can function as a chemically amplified resist material.

[0232] [Organic solvents] The resist material of the present invention may contain an organic solvent. The organic solvent is not particularly limited as long as it can dissolve the components described above and the components described below. Specific examples of the organic solvent include ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentyl ketone, and 2-heptanone, as described in paragraphs

[0144] and

[0145] of JP-A No. 2008-111103; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and diacetone alcohol; propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, and ethylene glycol monomethyl ether. ethers such as propylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol mono-tert-butyl ether acetate; and lactones such as γ-butyrolactone.

[0233] In the resist composition of the present invention, the content of the organic solvent is preferably 100 to 10,000 parts by mass, more preferably 200 to 8,000 parts by mass, per 100 parts by mass of the base polymer. The organic solvents may be used singly or in combination of two or more.

[0234] [Other ingredients] The resist material of the present invention may contain, in addition to the above-mentioned components, a surfactant, a dissolution inhibitor, a water repellency improver, an acetylene alcohol, and the like.

[0235] Examples of the surfactant include those described in paragraphs

[0165] and

[0166] of JP 2008-111103 A. Adding a surfactant can further improve or control the coatability of the resist material. When the resist material of the present invention contains the surfactant, the content thereof is preferably 0.0001 to 10 parts by mass per 100 parts by mass of the base polymer. The surfactant may be used alone or in combination of two or more types.

[0236] The incorporation of a dissolution inhibitor into the resist composition of the present invention can further increase the difference in dissolution rate between exposed and unexposed areas, thereby further improving resolution. Examples of dissolution inhibitors include compounds having a molecular weight of preferably 100 to 1,000, more preferably 150 to 800, containing two or more phenolic hydroxy groups in the molecule, in which the hydrogen atoms of the phenolic hydroxy groups have been substituted with acid-labile groups at a ratio of 0 to 100 mol % overall, and compounds containing carboxy groups in the molecule, in which the hydrogen atoms of the carboxy groups have been substituted with acid-labile groups at an average ratio of 50 to 100 mol % overall. Specific examples include compounds in which the hydrogen atoms of the hydroxyl groups or carboxyl groups of bisphenol A, trisphenol, phenolphthalein, cresol novolak, naphthalenecarboxylic acid, adamantanecarboxylic acid, and cholic acid have been substituted with acid-labile groups. These compounds are described, for example, in paragraphs

[0155] to

[0178] of JP 2008-122932 A.

[0237] When the resist composition of the present invention contains the dissolution inhibitor, the content thereof is preferably 0 to 50 parts by mass, more preferably 5 to 40 parts by mass, relative to 100 parts by mass of the base polymer. The dissolution inhibitor may be used alone or in combination of two or more.

[0238] The water repellency improver improves the water repellency of the resist film surface and can be used in immersion lithography without a topcoat. Preferred examples of the water repellency improver include polymers containing fluorinated alkyl groups and polymers containing a specific 1,1,1,3,3,3-hexafluoro-2-propanol residue structure, with those exemplified in JP-A Nos. 2007-297590 and 2008-111103 being more preferred. The water repellency improver must be soluble in an alkaline developer or an organic solvent developer. The water repellency improver having the specific 1,1,1,3,3,3-hexafluoro-2-propanol residue described above has good solubility in the developer. As a water repellency improver, polymers containing repeating units containing an amino group or an amine salt are highly effective in preventing the evaporation of acid during PEB and preventing poor opening of the hole pattern after development. When the resist composition of the present invention contains a water repellency improver, the content thereof is preferably 0 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, relative to 100 parts by mass of the base polymer. The water repellency improver may be used alone or in combination of two or more.

[0239] Examples of the acetylene alcohols include those described in paragraphs

[0179] to

[0182] of JP 2008-122932 A. When the resist material of the present invention contains an acetylene alcohol, the content thereof is preferably 0 to 5 parts by mass per 100 parts by mass of the base polymer. The acetylene alcohols may be used alone or in combination of two or more.

[0240] [Pattern formation method] When the resist material of the present invention is used in the manufacture of various integrated circuits, known lithography techniques can be applied. For example, a pattern formation method can include a method comprising the steps of forming a resist film on a substrate using the resist material, exposing the resist film to high-energy radiation, and developing the exposed resist film using a developer.

[0241] First, the resist material of the present invention is applied to a substrate for integrated circuit manufacturing (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflective coating, etc.) or a substrate for mask circuit manufacturing (Cr, CrO, CrON, MoSi2, SiO2, etc.) by an appropriate coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, doctor coating, etc., to a coating thickness of 0.01 to 2 μm. This is then prebaked on a hot plate, preferably at 60 to 150°C for 10 seconds to 30 minutes, more preferably at 80 to 120°C for 30 seconds to 20 minutes, to form a resist film.

[0242] Next, the resist film is exposed to high-energy radiation. Examples of the high-energy radiation include ultraviolet radiation, far ultraviolet radiation, EB, EUV radiation with a wavelength of 3 to 15 nm, X-rays, soft X-rays, excimer laser light, gamma rays, and synchrotron radiation. When ultraviolet radiation, far ultraviolet radiation, EUV radiation, X-rays, soft X-rays, excimer laser light, gamma rays, and synchrotron radiation are used as the high-energy radiation, the exposure dose is preferably 1 to 200 mJ / cm, either directly or using a mask for forming a desired pattern. 2 approximately, more preferably 10 to 100 mJ / cm 2 When EB is used as the high energy beam, the exposure dose is preferably 0.1 to 100 μC / cm 2 approximately, more preferably 0.5 to 50 μC / cm 2The resist material of the present invention is particularly suitable for fine patterning using high-energy rays, such as i-rays with a wavelength of 365 nm, KrF excimer laser light, ArF excimer laser light, EB, EUV, X-rays, soft X-rays, γ-rays, and synchrotron radiation, and is particularly suitable for fine patterning using EB or EUV.

[0243] After the exposure, PEB may be performed on a hot plate or in an oven, preferably at 50 to 150° C. for 10 seconds to 30 minutes, more preferably at 60 to 120° C. for 30 seconds to 20 minutes.

[0244] After exposure or PEB, the exposed resist film is developed using a developer, preferably an aqueous alkaline solution of 0.1 to 10 mass %, more preferably 2 to 5 mass %, of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide (TBAH), or the like, for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, by a conventional method such as dipping, puddling, or spraying. The irradiated portions dissolve in the developer, while the unexposed portions do not, forming the desired positive pattern on the substrate.

[0245] A negative pattern can also be obtained by organic solvent development using a resist material containing a base polymer containing an acid labile group. The developer used in this case includes 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methylacetophenone, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, butenyl acetate, isopentyl acetate, propyl formate, butyl formate, isobutyl formate, pentyl formate, isopentyl formate, methyl valerate, methyl pentenoate, methyl crotonate, ethyl crotonate, Examples of the organic solvent include methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, pentyl lactate, isopentyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, 2-phenylethyl acetate, etc. These organic solvents may be used alone or in combination of two or more.

[0246] After the development is completed, the resist film is rinsed. A preferred rinse solution is a solvent that is miscible with the developer but does not dissolve the resist film. Preferred examples of such solvents include alcohols having 3 to 10 carbon atoms, ether compounds having 8 to 12 carbon atoms, alkanes, alkenes, alkynes, and aromatic solvents having 6 to 12 carbon atoms.

[0247] Examples of the alcohol having 3 to 10 carbon atoms include n-propyl alcohol, isopropyl alcohol, 1-butyl alcohol, 2-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, tert-pentyl alcohol, neopentyl alcohol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, Examples of such an alcohol include 2,3-dimethyl-2-butanol, 3,3-dimethyl-1-butanol, 3,3-dimethyl-2-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, cyclohexanol, and 1-octanol.

[0248] Examples of the ether compound having 8 to 12 carbon atoms include di-n-butyl ether, diisobutyl ether, di-sec-butyl ether, di-n-pentyl ether, diisopentyl ether, di-sec-pentyl ether, di-tert-pentyl ether, and di-n-hexyl ether.

[0249] Examples of the alkanes having 6 to 12 carbon atoms include hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, cyclononane, etc. Examples of the alkenes having 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, cyclooctene, etc. Examples of the alkynes having 6 to 12 carbon atoms include hexyne, heptine, octyne, etc.

[0250] Examples of the aromatic solvent include toluene, xylene, ethylbenzene, isopropylbenzene, tert-butylbenzene, and mesitylene.

[0251] Rinsing can reduce the occurrence of resist pattern collapse and defects. Rinsing is not always necessary, and not performing rinsing can reduce the amount of solvent used.

[0252] The developed hole or trench pattern can also be shrunk using thermal flow, RELACS, or DSA. A shrink agent is applied to the hole pattern, and the diffusion of an acid catalyst from the resist film during baking causes crosslinking of the shrink agent on the surface of the resist film, resulting in adhesion of the shrink agent to the sidewalls of the hole pattern. The baking temperature is preferably 70 to 180°C, more preferably 80 to 170°C, and the baking time is preferably 10 to 300 seconds. Excess shrink agent is removed, and the hole pattern is shrunk. [Example]

[0253] The present invention will be specifically explained below by showing synthesis examples, examples and comparative examples, but the present invention is not limited to the following examples.

[0254] [1] Polymer synthesis The monomers PM-1 to PM-6, QM-1 to QM-4, and ALG-1 to ALG-4 used in the synthesis of the polymers are as follows: The Mw of the polymers is a polystyrene-equivalent value measured by GPC using THF as a solvent. [ka]

[0255] [ka]

[0256] [ka]

[0257] [ka]

[0258] [Synthesis Example 1] Synthesis of Polymer P-1 A 2L flask was charged with 2.5g of monomer QM-1, 9.1g of monomer ALG-1, 3.4g of 3-hydroxystyrene, 8.0g of monomer PM-4, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and the reaction was carried out for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-1. The composition of polymer P-1 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0259] [Synthesis Example 2] Synthesis of Polymer P-2 A 2L flask was charged with 2.5g of Monomer QM-2, 9.1g of Monomer ALG-1, 3.4g of 3-hydroxystyrene, 8.0g of Monomer PM-4, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and the reaction was carried out for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain Polymer P-2. The composition of Polymer P-2 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0260] [Synthesis Example 3] Synthesis of Polymer P-3 A 2L flask was charged with 2.8g of Monomer QM-3, 9.0g of Monomer ALG-1, 3.4g of 3-hydroxystyrene, 8.0g of Monomer PM-4, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After warming to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and the reaction was carried out for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain Polymer P-3. The composition of Polymer P-3 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0261] [Synthesis Example 4] Synthesis of Polymer P-4 A 2L flask was charged with 3.8g of Monomer QM-4, 9.1g of Monomer ALG-1, 3.4g of 3-hydroxystyrene, 8.0g of Monomer PM-4, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After warming to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and the reaction was carried out for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain Polymer P-4. The composition of Polymer P-4 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0262] [Synthesis Example 5] Synthesis of Polymer P-5 A 2L flask was charged with 2.5g of Monomer QM-1, 6.9g of Monomer ALG-2, 3.4g of 3-hydroxystyrene, 6.0g of Monomer PM-1, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After warming to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and the reaction was carried out for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain Polymer P-5. The composition of Polymer P-5 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0263] [Synthesis Example 6] Synthesis of Polymer P-6 A 2L flask was charged with 2.5g of monomer QM-1, 6.9g of monomer ALG-2, 3.4g of 3-hydroxystyrene, 6.6g of monomer PM-2, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and the reaction was carried out for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-6. The composition of polymer P-6 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0264] [Synthesis Example 7] Synthesis of Polymer P-7 A 2L flask was charged with 2.5g of Monomer QM-1, 6.9g of Monomer ALG-2, 3.4g of 3-hydroxystyrene, 6.9g of Monomer PM-3, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and the reaction was carried out for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain Polymer P-7. The composition of Polymer P-7 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0265] [Synthesis Example 8] Synthesis of Polymer P-8 A 2L flask was charged with 2.5g of Monomer QM-1, 7.4g of Monomer ALG-3, 3.4g of 3-hydroxystyrene, 5.7g of Monomer PM-5, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After warming to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and the reaction was carried out for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain Polymer P-8. The composition of Polymer P-8 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0266] [Synthesis Example 9] Synthesis of Polymer P-9 A 2L flask was charged with 2.5g of Monomer QM-1, 7.4g of Monomer ALG-3, 2.9g of 3-hydroxystyrene, 8.1g of Monomer PM-6, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After warming to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and the reaction was carried out for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain Polymer P-9. The composition of Polymer P-9 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0267] [Synthesis Example 10] Synthesis of Polymer P-10 A 2L flask was charged with 2.5g of monomer QM-1, 7.1g of monomer ALG-4, 3.5g of 3-hydroxystyrene, 8.2g of monomer PM-3, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After heating to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and the reaction was carried out for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The resulting white solid was dried under reduced pressure at 60°C to obtain polymer P-10. The composition of polymer P-10 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0268] [Synthesis Example 11] Synthesis of Polymer P-11 A 2L flask was charged with 2.5g of monomer QM-1, 7.1g of monomer ALG-4, 3.5g of 3-hydroxystyrene, 9.6g of monomer PM-4, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After warming to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and the reaction was carried out for 15 hours. This reaction solution was added to 1L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer P-11. The composition of polymer P-11 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0269] [Comparative Synthesis Example 1] Synthesis of Comparative Polymer CP-1 Comparative polymer CP-1 was obtained in the same manner as in Synthesis Example 3, except that monomer QM-3 was not used. The composition of comparative polymer CP-1 was 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0270] [Comparative Synthesis Example 2] Synthesis of Comparative Polymer CP-2 A 2-liter flask was charged with 2.4 g of comparative monomer 1, 6.9 g of monomer ALG-2, 3.4 g of 3-hydroxystyrene, 6.0 g of monomer PM-1, and 40 g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After warming to room temperature, 1.2 g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and the reaction was carried out for 15 hours. This reaction solution was added to 1 liter of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain comparative polymer CP-2. The composition of comparative polymer CP-2 was as follows:13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0271] [Comparative Synthesis Example 3] Synthesis of Comparative Polymer CP-3 A 2-liter flask was charged with 2.2 g of comparative monomer 2, 6.9 g of monomer ALG-2, 3.4 g of 3-hydroxystyrene, 6.0 g of monomer PM-1, and 40 g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassing under reduced pressure and nitrogen blowing were repeated three times. After warming to room temperature, 1.2 g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C and the reaction was carried out for 15 hours. This reaction solution was added to 1 liter of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain comparative polymer CP-3. The composition of comparative polymer CP-3 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0272] [Comparative Synthesis Example 4] Synthesis of Comparative Polymer CP-4 Comparative polymer CP-4 was obtained in the same manner as in Synthesis Example 2-5, except that monomer PM-1 and monomer QM-1 were not used. The composition of comparative polymer CP-4 was: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0273] [Examples 1 to 15, Comparative Examples 1 to 4] Preparation and Evaluation of Resist Materials (1) Preparation of resist material A resist material was prepared by dissolving each component according to the composition shown in Table 1 in a solvent containing 50 ppm of Omnova surfactant PolyFox PF-636. The solution was then filtered through a 0.2 μm filter.

[0274] In Table 1, the components are as follows: Organic solvent: PGMEA (propylene glycol monomethyl ether acetate) DAA (diacetone alcohol) EL (Ethyl lactate)

[0275] Acid generator: PAG-1 Quencher: Q-1~Q-3 [ka]

[0276] (2) EUV lithography evaluation Each resist material shown in Tables 1 and 2 was spin-coated onto a Si substrate with a 20 nm thick silicon-containing spin-on hard mask SHB-A940 (43 wt % silicon), and pre-baked at 105 °C for 60 seconds using a hot plate to produce a 50 nm thick resist film. The resist film was exposed to light using an ASML EUV scanner NXE3400 (NA 0.33, σ 0.9 / 0.6, quadruple pole illumination, wafer dimensions 46 nm pitch, +20% bias hole pattern mask), and then subjected to PEB on a hot plate at the temperatures shown in Tables 1 and 2 for 60 seconds. Development was then performed for 30 seconds in a 2.38 wt % TMAH aqueous solution to obtain a 23 nm hole pattern. The exposure dose when each hole dimension was 23 nm was measured and used as the sensitivity. The dimensions of 50 holes were measured using a Hitachi High-Technologies Corporation critical dimension SEM (CG6300), and the CDU was calculated by multiplying the standard deviation (σ) by three (3σ). The results are shown in Tables 1 and 2.

[0277] [Table 1]

[0278] [Table 2]

[0279] The results shown in Tables 1 and 2 demonstrate that resist materials using base polymers containing repeating units each composed of a carboxylic acid anion and an organic cation having an iodine atom and a specific functional group bonded to the polymer main chain of the present invention, and repeating units each composed of a sulfonate anion and a sulfonium cation, have sufficient sensitivity and excellent dimensional uniformity.

Claims

1. A resist material comprising a base polymer containing a repeating unit represented by the following formula (a) and a repeating unit represented by the following formula (b), and an organic solvent. 【Chemistry 1】 (In the formula, p is 0 or 1. m1 and m2 each independently is 0 or 1. When p is 0, n1 is 1, 2, 3, or 4. When p is 1, n1 and n2 are each independently 0, 1, 2, 3, or 4, and n1 + n2 ≧ 1. When p is 0, n3 is 1. When p is 1, n3 and n4 are each independently 0 or 1, but n3 + n4 = 1. When p is 0, n5 is 1, 2, 3, or 4. When p is 1, n5 and n6 are each independently 0, 1, 2, 3, or 4, and n5 + n6 ≧ 1. R A is a hydrogen atom or a methyl group. X 1 is a single bond or -C(=O)-O-X 11 - is. X 11 is an alkanediyl group having 1 to 6 carbon atoms. X 2 is a single bond or an alkanediyl group having 1 to 6 carbon atoms. L 1 is a linking group having 1 to 12 carbon atoms and containing at least one bond selected from a single bond, an ester bond, and an ether bond, and the linking group may contain a heteroatom-containing group other than an ester bond or an ether bond. L 2 and L 3 are each independently a single bond, an ether bond, or an ester bond. R 1 and R 2 are each independently a hydroxy group, a saturated hydrocarbyloxy group having 1 to 12 carbon atoms, or an organic group having 1 to 12 carbon atoms and a hydroxy group or a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, and may contain at least one bond selected from an ester bond and an ether bond. 1 may be the same as or different from each other. When n6 is 2 or more, each R 2 may be the same as or different from each other. M + is a monovalent organic cation. 【Chemistry 2】 (In the formula, R A are each independently a hydrogen atom or a methyl group. Y 1 is a single bond or an ester bond. Y 2 is -Y 21 -C(=O)-O- or -Y 21 -O-. 21 represents a hydrocarbylene group having 1 to 12 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and these groups may contain a carbonyl group, an ester bond, an ether bond, a lactone ring, a fluorine atom, a bromine atom, or an iodine atom. Y 3 is a single bond, a methylene group, or an ethylene group. Rf 1 ~Rf 4 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, provided that at least one is a fluorine atom. R 11 , R 12 and R 13 are each independently a halogen atom or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. 11 and R 12 may be bonded to each other to form a ring together with the sulfur atom to which they are attached.)

2. L 1 2. The resist material according to claim 1, wherein is a single bond.

3. X 1 2. The resist material according to claim 1, wherein is a single bond.

4. M + The resist material according to claim 1, wherein M is represented by the following formula (M-1), (M-2) or (M-3): 【Transformation 3】 (In the formula, R M1 ~R M9 are each independently a halogen atom or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. M1 and R M2 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and R M6 ~R M9 Any two of may be bonded to each other to form a ring together with the nitrogen atom to which they are attached.

5. R 1 The resist material according to claim 1, wherein is a hydroxy group or a saturated hydrocarbyloxy group having 1 to 12 carbon atoms.

6. The resist material according to claim 1, wherein the base polymer further comprises at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (c1) and a repeating unit represented by the following formula (c2): 【Chemistry 4】 (In the formula, R A are each independently a hydrogen atom or a methyl group. Z 1 is a linking group having 1 to 12 carbon atoms and containing at least one selected from a single bond, a phenylene group, a naphthylene group, an ester bond, an ether bond, and a lactone ring. Z 2 is a single bond, an ester bond or an amide bond. Z 3 is a single bond, an ether bond or an ester bond. R 21 and R 22 is an acid labile group. R 23 is a fluorine atom, a trifluoromethyl group, a cyano group or a saturated hydrocarbyl group having 1 to 6 carbon atoms. R 24 is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and —CH 2 A portion of the - may be substituted with an ether bond or an ester bond. a is 1 or 2. b is 0, 1, 2, 3, or 4.

7. The resist material according to claim 1, wherein the base polymer further comprises a repeating unit d containing an adhesive group selected from a hydroxy group, a carboxy group, a lactone ring, a carbonate bond, a thiocarbonate bond, a carbonyl group, a cyclic acetal group, an ether bond, an ester bond, a sulfonate ester bond, a cyano group, an amide bond, —O—C(═O)—S—, and —O—C(═O)—NH—.

8. 2. The resist material according to claim 1, further comprising at least one additive selected from the group consisting of an acid generator, a quencher, and a surfactant.

9. 9. The resist material according to claim 8, wherein the additive is a quencher.

10. 10. The resist material according to claim 9, wherein the quencher is represented by the following formula (1): 【Transformation 5】 (In the formula, R q1 is a hydrocarbyl group having 1 to 30 carbon atoms which may contain a heteroatom. + is a monovalent organic cation.

11. A pattern forming method comprising the steps of: forming a resist film on a substrate using the resist material according to any one of claims 1 to 10; exposing the resist film to high-energy rays; and developing the exposed resist film using a developer.

12. 12. The pattern forming method according to claim 11, wherein the high-energy beam is i-ray, KrF excimer laser light, ArF excimer laser light, electron beam, or extreme ultraviolet light having a wavelength of 3 to 15 nm.

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