Resist material and pattern forming method

Abstract

The invention relates to a resist material and a pattern forming method. The present invention addresses the problem of providing: a resist material having high sensitivity regardless of the positive type or the negative type and improved LWR and CDU; and a pattern forming method using the resist material. [Solution] A resist material which contains a quenching agent that contains a sulfonium salt of one or more compounds selected from the group consisting of N-carbonyl trifluoromethoxybenzenesulfonamide, N-carbonyl difluoromethoxybenzenesulfonamide, trifluoromethoxybenzenesulfonimide, and difluoromethoxybenzenesulfonimide, and which is characterized in that the quenching agent contains a sulfonium salt of one or more compounds selected from the group consisting of N-carbonyl trifluoromethoxybenzenesulfonamide, N-carbonyl difluoromethoxybenzenesulfonamide, N-carbonyl difluoromethoxybenzenesulfonamide, N-carbonyl difluoromethoxybenzenesulfonamide and difluoromethoxybenzenesulfonimide.

Description

Technical Field

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

[0002] With the high integration and high speed of LSI, the miniaturization of pattern rules is also progressing rapidly. This is due to the popularization of 5G high-speed communication and artificial intelligence (AI), and the need for high-performance devices to handle them. As for the most advanced miniaturization technology, mass production of 5nm node devices using extreme ultraviolet (EUV) lithography with a wavelength of 13.5nm is already underway. In addition, discussions on the use of EUV lithography are also underway in the next-generation 3nm node and the next-generation 2nm node devices.

[0003] As the miniaturization progresses, the blurring of the image due to the diffusion of acid has also become a problem. In order to ensure the resolution of fine patterns below 45nm in size, it is not only known that the dissolution contrast has been improved, but also that the control of acid diffusion is important (Non-Patent Document 1). However, chemically amplified resist materials increase sensitivity and contrast due to the diffusion of acid, so if the post-exposure baking (PEB) temperature is lowered or the time is shortened to suppress the acid diffusion to the limit, the sensitivity and contrast will be significantly reduced.

[0004] The triangular trade-off relationship between sensitivity, resolution, and edge roughness (LWR) is shown. In order to improve the resolution, it is necessary to suppress the diffusion of acid, but if the acid diffusion distance is shortened, the sensitivity will decrease.

[0005] It is effective to add an acid generator that generates bulky acid to inhibit acid diffusion. Therefore, it is proposed to contain repeating units from an onium salt having a polymerizable unsaturated bond in the polymer. In this case, the polymer also functions as an acid generator (polymer-bonded acid generator). In Patent Document 1, it is proposed to have a sulfonium salt or iodonium salt having a polymerizable unsaturated bond that generates a specific sulfonic acid. In Patent Document 2, it is proposed to have a sulfonium salt in which a sulfonic acid is directly bonded to the main chain.

[0006] The acid-labile group used in the (meth)acrylate polymer used in the ArF resist material undergoes a deprotection reaction by using a photoacid generator that generates a sulfonic acid substituted with a fluorine atom at the α position, while an acid generator that generates a sulfonic acid or carboxylic acid that is not substituted with a fluorine atom at the α position does not undergo a deprotection reaction. If a sulfonium salt or iodonium salt that generates a sulfonic acid substituted with a fluorine atom at the α position is mixed with a sulfonium salt or iodonium salt that generates a sulfonic acid substituted with a fluorine atom at the α position, the sulfonium salt or iodonium salt that generates a sulfonic acid substituted with a fluorine atom at the α position will cause ion exchange with the sulfonic acid substituted with a fluorine atom at the α position. The sulfonic acid substituted with a fluorine atom at the α position generated by light will return to the sulfonium salt or iodonium salt by ion exchange, so the sulfonium salt or iodonium salt of the sulfonic acid or carboxylic acid that is not substituted with a fluorine atom at the α position will function as a quencher. A resist material using a sulfonium salt or iodonium salt that generates a carboxylic acid as a quencher has been proposed (Patent Document 3).

[0007] Sulfonamide has an acidity close to that of carboxylic acid, and its sulfonium salt functions as a quencher. Sulfonium salt-type quenchers that generate sulfonamide have been proposed (Patent Documents 4 to 6).

[0008] It has been pointed out that the dimensional uniformity of the resist pattern is reduced due to the aggregation of the quencher. It is expected that the dimensional uniformity of the pattern after development can be improved by preventing the aggregation of the quencher in the resist film and making the distribution uniform.

[0009] Perfluoroalkyl compounds (PFAS) have been criticized for their health effects, and there are moves to limit the manufacture and sale of PFAS in European REACH. In the field of semiconductor lithography, many compounds containing PFAS are currently used. For example, materials containing PFAS are used in surfactants, acid generators, quenchers, etc.

[0010] Prior art literature

[0011] Patent Literature

[0012] [Patent Document 1] Japanese Patent Application Publication No. 2006-045311

[0013] [Patent Document 2] Japanese Patent Application Publication No. 2006-178317

[0014] [Patent Document 3] Japanese Patent Application Publication No. 2007-114431

[0015] [Patent Document 4] Japanese Patent Application Publication No. 2012-108447

[0016] [Patent Document 5] Japanese Patent Application Publication No. 2010-365435

[0017] [Patent Document 6] Japanese Patent Application Publication No. 2013-145256

[0018] Non-patent literature

[0019] [Non-patent document 1] SPIE Vol.6520 65203L-1 (2007) Summary of the invention

[0020] [Problems to be solved by the invention]

[0021] It is desired to develop a quencher that can improve the LWR of a line pattern, the size uniformity (CDU) of a hole pattern, and the sensitivity in a resist material. Therefore, it is necessary to further reduce the blurring of an image caused by diffusion.

[0022] The present invention is made in view of the above situation, and an object of the present invention is to provide a resist material having high sensitivity regardless of positive or negative type and improved LWR and CDU, and a pattern forming method using the resist material.

[0023] [Methods to solve the problem]

[0024] The present inventors have conducted in-depth studies to achieve the above-mentioned purpose, and as a result, have found that sulfonium salts of one or more compounds selected from N-carbonyltrifluoromethoxybenzenesulfonamide, N-carbonyldifluoromethoxybenzenesulfonamide, trifluoromethoxybenzenesulfonimide and difluoromethoxybenzenesulfonimide are quenchers for inhibiting acid diffusion. The excellent acid diffusion inhibition effect and the effect of preventing the quencher from agglomerating due to electron repulsion of the bulky groups of trifluoromethoxy and difluoromethoxy groups can be used to obtain a resist material with improved LWR and CDU, excellent resolution, and a wide range of process latitude, thereby completing the present invention.

[0025] That is, the present invention provides the following resist material and pattern forming method.

[0026] 1. A resist material comprising:

[0027] The quencher comprises sulfonium salts of one or more compounds selected from the group consisting of N-carbonyltrifluoromethoxybenzenesulfonamide, N-carbonyldifluoromethoxybenzenesulfonamide, trifluoromethoxybenzenesulfonimide, and difluoromethoxybenzenesulfonimide.

[0028] 2. The resist material according to 1., wherein the sulfonium salt is represented by the following formula (1).

[0029] [Chemistry 1]

[0030]

[0031] In the formula, m is an integer of 1 to 5, and n is an integer of 0 to 4. However, 1≤m+n≤5.

[0032] X 1It is -C(=O)- or -S(=O)2-.

[0033] R 1 It is trifluoromethyl or difluoromethyl.

[0034] R 2 It is a saturated hydrocarbon group having 1 to 6 carbon atoms, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a hydroxyl group, a carboxyl group, a cyano group, a nitro group or a halogen atom.

[0035] R 3 It is a hydrocarbon group having 1 to 26 carbon atoms, and the hydrocarbon group may contain at least one selected from the group consisting of an oxygen atom, a sulfur atom, a nitrogen atom and a halogen atom.

[0036] R 4 ~R 6 are each independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. 4 and R 5 They may also bond to each other and to the sulfur atom to which they are bonded to form a ring.

[0037] 3. The resist material as in 1. further comprises a base polymer.

[0038] 4. The resist material according to 3., wherein the base polymer contains a repeating unit represented by the following formula (a1) or a repeating unit represented by the following formula (a2).

[0039] [Chemistry 2]

[0040]

[0041] In the formula, R A are each independently a hydrogen atom or a methyl group.

[0042] Y 1 It is a single bond, a phenylene group or a naphthylene group, or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, an ether bond, and a lactone ring.

[0043] Y 2 It is a single bond or an ester bond.

[0044] Y 3 It is a single bond, an ether bond or an ester bond.

[0045] R 11 and R 12 are each independently an acid-labile group.

[0046] R 13 It is a fluorine atom, a trifluoromethyl group, a cyano group or a saturated hydrocarbon group having 1 to 6 carbon atoms.

[0047] R 14It is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and a part of the -CH2- group of the alkanediyl group may be substituted with an ether bond or an ester bond.

[0048] a is 1 or 2. b is an integer from 0 to 4. However, 1≤a+b≤5.

[0049] 5. The resist material as described in 4., which is a chemically amplified positive resist material.

[0050] 6. The resist material according to 3., wherein the base polymer does not contain an acid-labile group.

[0051] 7. The resist material as described in 6., which is a chemically amplified negative resist material.

[0052] 8. The resist material according to any one of 3. to 7., wherein the base polymer contains at least one selected from the group consisting of a repeating unit represented by the following formula (f1), a repeating unit represented by the following formula (f2), and a repeating unit represented by the following formula (f3).

[0053] [Chemistry 3]

[0054]

[0055] In the formula, R A are each independently a hydrogen atom or a methyl group.

[0056] Z 1 is a single bond, an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these groups, or -OZ 11 -、-C(=O)-OZ 11 -or-C(=O)-NH-Z 11 -.Z 11 It is an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these groups, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group.

[0057] Z 2 It is a single bond or an ester bond.

[0058] Z 3 is a single bond, -Z 31 -C(=O)-O-, -Z 31 -O- or -Z 31 -OC(=O)-. Z 31 It is a alkylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining these groups, and may contain a carbonyl group, an ester bond, an ether bond, an iodine atom, or a bromine atom.

[0059] Z 4It is methylene, 2,2,2-trifluoro-1,1-ethanediyl or carbonyl.

[0060] Z 5 is a single bond, methylene, ethylene, phenylene, fluorinated phenylene, phenylene substituted with trifluoromethyl, -OZ 51 -、-C(=O)-OZ 51 -or-C(=O)-NH-Z 51 -.Z 51 It is an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group or a phenylene group substituted with a trifluoromethyl group, and may contain a carbonyl group, an ester bond, an ether bond, a halogen atom or a hydroxyl group.

[0061] R 21 ~R 28 are each independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. 23 and R 24 or R 26 and R 27 They may also bond to each other and to the sulfur atom to which they are bonded to form a ring.

[0062] M - It is a non-nucleophilic relative ion.

[0063] 9. The resist material according to any one of 1. to 8., further comprising an acid generator that generates a strong acid.

[0064] 10. The resist material according to 9., wherein the acid generator generates sulfonic acid, imidic acid or methylated acid.

[0065] 11. The resist material according to any one of 1. to 10., further comprising an organic solvent.

[0066] 12. The resist material according to any one of 1. to 11., further comprising a surfactant.

[0067] 13. A pattern forming method comprising the following steps:

[0068] Using the resist material as described in any one of 1. to 12., forming a resist film on a substrate,

[0069] exposing the resist film to high energy radiation, and

[0070] The exposed resist film is developed using a developer.

[0071] 14. The pattern forming method according to 13., wherein the high-energy ray is KrF excimer laser, ArF excimer laser, electron beam (EB) or EUV with a wavelength of 3 to 15 nm.

[0072] [Effects of the Invention]

[0073] The above-mentioned one or more sulfonium salts selected from N-carbonyl trifluoromethoxybenzenesulfonamide, N-carbonyl difluoromethoxybenzenesulfonamide, trifluoromethoxybenzenesulfonimide, and difluoromethoxybenzenesulfonimide are quenchers that inhibit acid diffusion. This can achieve low acid diffusion characteristics and improve LWR and CDU. This can construct a resist material with low LWR and improved CDU. DETAILED DESCRIPTION

[0074] [Resist material]

[0075] The resist material of the present invention contains a quencher comprising a sulfonium salt of one or more compounds selected from N-carbonyltrifluoromethoxybenzenesulfonamide, N-carbonyldifluoromethoxybenzenesulfonamide, trifluoromethoxybenzenesulfonimide and difluoromethoxybenzenesulfonimide (hereinafter also referred to as sulfonium salt A).

[0076] [Quencher]

[0077] The sulfonium salt A is preferably represented by the following formula (1).

[0078] [Chemistry 4]

[0079]

[0080] In formula (1), m is an integer of 1 to 5, and n is an integer of 0 to 4. However, 1≤m+n≤5.

[0081] In formula (1), X 1 It is -C(=O)- or -S(=O)2-.

[0082] In formula (1), R 1 It is trifluoromethyl or difluoromethyl.

[0083] In formula (1), R 2 It is a saturated hydrocarbon group having 1 to 6 carbon atoms, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a hydroxyl group, a carboxyl group, a cyano group, a nitro group or a halogen atom.

[0084] R 2 The saturated hydrocarbon group having 1 to 6 carbon atoms and the saturated hydrocarbon group of the saturated hydrocarbon group oxy group having 1 to 6 carbon atoms may be straight chain, branched or cyclic. Specific examples thereof include: alkyl groups having 1 to 6 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, neopentyl and n-hexyl; cyclic saturated hydrocarbon groups having 3 to 6 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl; and groups obtained by combining them. 2 Specific examples of the halogen atom represented by include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like.

[0085] In formula (1), R 3 is a hydrocarbon group having 1 to 26 carbon atoms. 3 The hydrocarbon group having 1 to 26 carbon atoms represented by 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, hexadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl; cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclopropylmethyl, cyclopropylethyl, cyclopropylpropyl, 4-methylcyclohexyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylpropyl, norbornyl, norbornylmethyl, norbornylethyl, norbornylpropyl, adamantyl, adamantylmethyl, adamantylethyl, adamantylpropyl, and noradamantyl; vinyl, propenyl, Alkenyl groups having 2 to 20 carbon atoms, such as butenyl and hexenyl; alkynyl groups having 2 to 20 carbon atoms, such as ethynyl, propynyl and butynyl; cyclic unsaturated aliphatic hydrocarbon groups having 3 to 20 carbon atoms, such as cyclohexenyl and norbornyl; phenyl, tolyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl, methyl naphthyl, ethyl naphthyl, n-propyl naphthyl, isopropyl Aryl groups having 6 to 20 carbon atoms, such as naphthyl, n-butylnaphthyl, isobutylnaphthyl, sec-butylnaphthyl, tert-butylnaphthyl, anthracenyl, phenanthrenyl, phenalenyl, pyrenyl, dihydroindenyl, indenyl, tetrahydronaphthyl, dihydroacenaphthyl, acenaphthyl, fluorenyl, etc.; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, phenethyl, phenpropyl, naphthylmethyl, naphthylethyl, naphthylpropyl, etc.; groups obtained by combining them, etc.

[0086] Again, R 3 The hydrocarbon group represented by may also contain at least one selected from oxygen atoms, sulfur atoms, nitrogen atoms and halogen atoms. That is, part or all of its hydrogen atoms may be substituted by hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, amino groups, carboxyl groups, etc., and part of its -CH2- may be substituted by carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, amide bonds, carbamate bonds, urea bonds, etc. The anions of the sulfonium salt A may be listed as follows, but are not limited thereto.

[0087] [Chemistry 5]

[0088]

[0089] [Chemistry 6]

[0090]

[0091] [Chemistry 7]

[0092]

[0093] [Chemistry 8]

[0094]

[0095] [Chemistry 9]

[0096]

[0097] [Chemistry 10]

[0098]

[0099] [Chemistry 11]

[0100]

[0101] [Chemistry 12]

[0102]

[0103] [Chemistry 13]

[0104]

[0105] [Chemistry 14]

[0106]

[0107] [Chemistry 15]

[0108]

[0109] [Chemistry 16]

[0110]

[0111] [Chemistry 17]

[0112]

[0113] [Chemistry 18]

[0114]

[0115] [Chemistry 19]

[0116]

[0117] [Chemistry 20]

[0118]

[0119] [Chemistry 21]

[0120]

[0121] [Chemistry 22]

[0122]

[0123] [Chemistry 23]

[0124]

[0125] [Chemistry 24]

[0126]

[0127] [Chemistry 25]

[0128]

[0129] [Chemistry 26]

[0130]

[0131] [Chemistry 27]

[0132]

[0133] The synthesis method of the anion of the sulfonium salt A can be cited as the method described in paragraph

[0083] of Japanese Patent Application Laid-Open No. 2018-130534. That is, the halide salt and ammonium salt can be obtained by the reaction of trifluoromethoxybenzenesulfonamide or difluoromethoxybenzenesulfonamide with carboxylic acid chloride. In addition, the carboxylic acid chloride can be converted into sulfonyl chloride and obtained by the same reaction.

[0134] In formula (1), R 4 ~R 6 Each is independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom.

[0135] R 4 ~R 6 Examples of the halogen atom represented by include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0136] R 4 ~R 6The hydrocarbon group having 1 to 20 carbon atoms represented by may be saturated or unsaturated, and may be straight-chain, 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, eicosyl, etc.; cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl, etc.; ethenyl, propenyl, butenyl, hexenyl Alkenyl groups having 2 to 20 carbon atoms, such as ethynyl, propynyl, butynyl, etc.; alkynyl groups having 2 to 20 carbon atoms, such as ethynyl, propynyl, butynyl, etc.; cyclic unsaturated aliphatic hydrocarbon groups having 3 to 20 carbon atoms, such as cyclohexenyl and norbornyl, etc.; aryl groups having 6 to 20 carbon atoms, such as phenyl, tolyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, sec-butylnaphthyl, tert-butylnaphthyl, etc.; aralkyl groups having 7 to 20 carbon atoms, such as benzyl and phenethyl, and groups derived from combinations thereof.

[0137] Furthermore, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and part of the -CH2- of the aforementioned hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, it may contain a hydroxyl 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 bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, and the like.

[0138] Again, R 4 and R 5 They may also be bonded to each other and to form a ring together with the sulfur atom to which they are bonded. In this case, the aforementioned ring is preferably a structure shown below.

[0139] [Chemistry 28]

[0140]

[0141] In the formula, the dotted line is and R 6 of atomic bonds.

[0142] Examples of the cation of the sulfonium salt A include, but are not limited to, the following.

[0143] [Chemistry 29]

[0144]

[0145] [Chemistry 30]

[0146]

[0147] [Chemistry 31]

[0148]

[0149] [Chemistry 32]

[0150]

[0151] [Chemistry 33]

[0152]

[0153] [Chemistry 34]

[0154]

[0155] [Chemistry 35]

[0156]

[0157] [Chemistry 36]

[0158]

[0159] [Chemistry 37]

[0160]

[0161] [Chemistry 38]

[0162]

[0163] [Chemistry 39]

[0164]

[0165] [Chemistry 40]

[0166]

[0167] [Chemistry 41]

[0168]

[0169] [Chemistry 42]

[0170]

[0171] [Chemistry 43]

[0172]

[0173] [Chemistry 44]

[0174]

[0175] [Chemistry 45]

[0176]

[0177] [Chemistry 46]

[0178]

[0179] [Chemistry 47]

[0180]

[0181] [Chemistry 48]

[0182]

[0183] [Chemistry 49]

[0184]

[0185] [Chemistry 50]

[0186]

[0187] [Chemistry 51]

[0188]

[0189] [Chemistry 52]

[0190]

[0191] [Chemistry 53]

[0192]

[0193] [Chemistry 54]

[0194]

[0195] [Chemistry 55]

[0196]

[0197] [Chemistry 56]

[0198]

[0199] [Chemistry 57]

[0200]

[0201] The sulfonium salt A can be synthesized by, for example, ion-exchanging a hydrochloride or carbonate having a sulfonium cation with a protonic acid or ammonium salt having an anion.

[0202] In the resist material of the present invention, the content of the sulfonium salt A is preferably 0.001 to 50 parts by mass, more preferably 0.01 to 40 parts by mass, based on 100 parts by mass of the base polymer described below. The sulfonium salt A may be used alone or in combination of two or more.

[0203] [Base polymer]

[0204] The resist material of the present invention may also contain a base polymer. In the case of a positive resist material, the base polymer contains a repeating unit containing an acid-labile group. The repeating unit containing an acid-labile group is preferably a repeating unit represented by the following formula (a1) (hereinafter also referred to as repeating unit a1) or a repeating unit represented by the following formula (a2) (hereinafter also referred to as repeating unit a2).

[0205] [Chemistry 58]

[0206]

[0207] In formula (a1) and (a2), R A are independently a hydrogen atom or a methyl group. 1 Y is a single bond, a phenylene group or a naphthylene group, or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, an ether bond, and a lactone ring. 2 is a single bond or an ester bond. 3 is a single bond, an ether bond or an ester bond. 11 and R 12 are independently acid-labile groups. 13 R is a fluorine atom, a trifluoromethyl group, a cyano group or a saturated hydrocarbon group having 1 to 6 carbon atoms. 14 It is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and a part of -CH2- in the alkanediyl group may be substituted with an ether bond or an ester bond. a is 1 or 2. b is an integer from 0 to 4. However, 1≤a+b≤5.

[0208] The monomers providing the repeating unit a1 include, but are not limited to, the following. A and R 11 Same as above.

[0209] [Chemistry 59]

[0210]

[0211] The monomers providing the repeating unit a2 may be exemplified by the following, but are not limited thereto. A and R 12 Same as above.

[0212] [Chemistry 60]

[0213]

[0214] R 11 and R 12 Examples of the acid-labile group represented by include those described in JP-A-2013-80033 and JP-A-2013-83821.

[0215] Representative examples of the acid-labile group include those represented by the following formulae (AL-1) to (AL-3).

[0216] [Chemistry 61]

[0217]

[0218] In the formula, the dotted lines are atomic bonds.

[0219] In formula (AL-1) and (AL-2), R L1 and R L2 Each of the above hydrocarbon groups is independently a hydrocarbon group having 1 to 40 carbon atoms, and may contain heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and fluorine atoms. The above hydrocarbon group may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. The above hydrocarbon group is preferably a saturated hydrocarbon group having 1 to 40 carbon atoms, and more preferably a saturated hydrocarbon group having 1 to 20 carbon atoms.

[0220] In the formula (AL-1), c is an integer of 0-10, preferably an integer of 1-5.

[0221] In formula (AL-2), R L3 and R L4 Each of them is independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and may contain heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and fluorine atoms. The hydrocarbon group may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. The hydrocarbon group is preferably a saturated hydrocarbon group having 1 to 20 carbon atoms. L2 , R L3 and R L4 Any two of them may be bonded to each other and together with the carbon atom to which they are bonded or with the carbon atom and oxygen atom form a ring having 3 to 20 carbon atoms. The aforementioned ring is preferably a ring having 4 to 16 carbon atoms, and is particularly preferably an alicyclic ring.

[0222] In formula (AL-3), R L5 , R L6 and R L7 Each of them is independently a hydrocarbon group having 1 to 20 carbon atoms, and may contain heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and fluorine atoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. The aforementioned hydrocarbon group is preferably a saturated hydrocarbon group having 1 to 20 carbon atoms. L5 , R L6 and RL7 Any two of them may be bonded to each other and together with the carbon atoms to which they are bonded form a ring having 3 to 20 carbon atoms. The aforementioned ring is preferably a ring having 4 to 16 carbon atoms, and is particularly preferably an alicyclic ring.

[0223] The aforementioned base polymer may also contain a repeating unit b containing a phenolic hydroxyl group as an adhesive group. The monomers providing the repeating unit b may be listed below, but are not limited thereto. In the following formula, R A Same as above.

[0224] [Chemistry 62]

[0225]

[0226] [Chemistry 63]

[0227]

[0228] [Chemistry 64]

[0229]

[0230] The base polymer may also contain a repeating unit c having a hydroxyl group other than a phenolic hydroxyl group, a lactone ring, a sultone ring, an ether bond, an ester bond, a sulfonate bond, a carbonyl group, a sulfonyl group, a cyano group or a carboxyl group as another adhesive group. The monomers providing the repeating unit c may be listed below, but are not limited thereto. In the following formula, R A Same as above.

[0231] [Chemistry 65]

[0232]

[0233] [Chemistry 66]

[0234]

[0235] [Chemistry 67]

[0236]

[0237] [Chemistry 68]

[0238]

[0239] [Chemistry 69]

[0240]

[0241] [Chemistry 70]

[0242]

[0243] [Chemistry 71]

[0244]

[0245] [Chemistry 72]

[0246]

[0247] [Chemistry 73]

[0248]

[0249] The base polymer may further contain a repeating unit d derived from indene, benzofuran, benzothiophene, acenaphthene, chromone, coumarin, norbornadiene or a derivative thereof. Examples of the monomer providing the repeating unit d include the following, but are not limited thereto.

[0250] [Chemistry 74]

[0251]

[0252] The aforementioned base polymer may contain a repeating unit e derived from styrene, vinylnaphthalene, vinylanthracene, vinylpyrene, methylenedihydroindane, vinylpyridine or vinylcarbazole.

[0253] The base polymer may also contain a repeating unit f derived from an onium salt containing a polymerizable unsaturated bond. Desirable repeating units f include: a repeating unit represented by the following formula (f1) (hereinafter also referred to as repeating unit f1), a repeating unit represented by the following formula (f2) (hereinafter also referred to as repeating unit f2), and a repeating unit represented by the following formula (f3) (hereinafter also referred to as repeating unit f3). In addition, the repeating units f1 to f3 may be used alone or in combination of two or more.

[0254] [Chemistry 75]

[0255]

[0256] In formulas (f1) to (f3), R A are each independently a hydrogen atom or a methyl group. 1 is a single bond, an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these groups, or -OZ 11 -、-C(=O)-OZ 11 -or-C(=O)-NH-Z 11 -.Z 11 It is an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these groups, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. 2 is a single bond or an ester bond. 3 is a single bond, -Z 31 -C(=O)-O-, -Z31 -O- or -Z 31 -OC(=O)-. Z 31 It is a alkylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining them, and may contain a carbonyl group, an ester bond, an ether bond, an iodine atom, or a bromine atom. 4 Z is methylene, 2,2,2-trifluoro-1,1-ethanediyl or carbonyl. 5 is a single bond, methylene, ethylene, phenylene, fluorinated phenylene, phenylene substituted with trifluoromethyl, -OZ 51 -、-C(=O)-OZ 51 -or-C(=O)-NH-Z 51 -.Z 51 It is an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group or a phenylene group substituted with a trifluoromethyl group, and may contain a carbonyl group, an ester bond, an ether bond, a halogen atom or a hydroxyl group.

[0257] In formulas (f1) to (f3), R 21 ~R 28 Each is independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include those exemplified as R in the description of formula (1): 4 ~R 6 The same examples are given for the hydrocarbon groups represented by . A part or all of the hydrogen atoms of the aforementioned hydrocarbon groups may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and a part of the carbon atoms of these groups may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms, and as a result, hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sultone rings, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl groups, and the like may be contained. In addition, R 23 and R 24 or R 26 and R 27 They may also be bonded to each other and form a ring together with the sulfur atom to which they are bonded. In this case, the ring may be exemplified as R in the description of formula (1): 4 and R 5 The same example is true of the ring that can be formed by bonding with the sulfur atom to which they are bonded.

[0258] In formula (f1), M -It is a non-nucleophilic counter ion. Examples of the non-nucleophilic counter ions include halide ions such as chloride ion and bromide ion; fluoroalkyl sulfonate ions such as trifluoromethanesulfonate ion, 1,1,1-trifluoroethanesulfonate ion and nonafluorobutanesulfonate ion; aryl sulfonate ions such as toluenesulfonate ion, benzenesulfonate ion, 4-fluorobenzenesulfonate ion and 1,2,3,4,5-pentafluorobenzenesulfonate ion; alkyl sulfonate ions such as methanesulfonate ion and butanesulfonate ion; imide ions such as bis(trifluoromethylsulfonyl)imide ion, bis(perfluoroethylsulfonyl)imide ion and bis(perfluorobutylsulfonyl)imide ion; and methylated ions such as tris(trifluoromethylsulfonyl)methylated ion and tris(perfluoroethylsulfonyl)methylated ion.

[0259] Other examples of the non-nucleophilic counter ion include: a sulfonate ion represented by the following formula (f1-1) in which the α-position is substituted with a fluorine atom, a sulfonate ion represented by the following formula (f1-2) in which the α-position is substituted with a fluorine atom and the β-position is substituted with a trifluoromethyl group, and the like.

[0260] [Chemistry 76]

[0261]

[0262] In formula (f1-1), R 31 is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group may also contain an ether bond, an ester bond, a carbonyl group, a lactone ring or a fluorine atom. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be straight-chain, branched or cyclic. Specific examples thereof include and are illustrated as R in the formula (2A') described below. fa1 The same examples are given for the hydrocarbon groups represented.

[0263] In formula (f1-2), R 32 is a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or a hydrocarbon carbonyl group having 2 to 20 carbon atoms, and the hydrocarbon group and the hydrocarbon carbonyl group may also contain an ether bond, an ester bond, a carbonyl group, or a lactone ring. The hydrocarbon group portion of the aforementioned hydrocarbon group and the hydrocarbon carbonyl group may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Specific examples thereof include and are illustrated as R in the formula (2A') described later. fa1 The same examples are given for the hydrocarbon groups represented.

[0264] The cation of the monomer providing the repeating unit f1 may be exemplified by the following, but is not limited thereto. A Same as above.

[0265] [Chemistry 77]

[0266]

[0267] Specific examples of the cation of the monomer providing the repeating unit f2 or f3 include the same examples as those exemplified as the cation of the sulfonium salt A.

[0268] The anions of the monomers providing the repeating unit f2 may be exemplified by the following, but are not limited thereto. A Same as above.

[0269] [Chemistry 78]

[0270]

[0271] [Chemistry 79]

[0272]

[0273] [Chemistry 80]

[0274]

[0275] [Chemistry 81]

[0276]

[0277] [Chemistry 82]

[0278]

[0279] [Chemistry 83]

[0280]

[0281] [Chemistry 84]

[0282]

[0283] [Chemistry 85]

[0284]

[0285] [Chemistry 86]

[0286]

[0287] [Chemistry 87]

[0288]

[0289] [Chemistry 88]

[0290]

[0291] [Chemistry 89]

[0292]

[0293] [Chemistry 90]

[0294]

[0295] [Chemistry 91]

[0296]

[0297] The anion of the monomer providing the repeating unit f3 may be exemplified by the following, but is not limited thereto. A Same as above.

[0298] [Chemistry 92]

[0299]

[0300] [Chemistry 93]

[0301]

[0302] Repeating units f1 to f3 function as an acid generator. By bonding the acid generator to the polymer main chain, the acid diffusion can be reduced and the reduction in resolution caused by blurring of the acid diffusion can be prevented. In addition, the acid generator can be evenly dispersed to improve LWR and CDU. In addition, when a base polymer containing repeating units f is used, the blending of the additive acid generator described later can be omitted.

[0303] In the above-mentioned base polymer, the content ratio of the repeating units a1, a2, b, c, d, e, f1, f2 and f3 is preferably 0≤a1≤0.9, 0≤a2≤0.9, 0≤a1+a2≤0.9, 0≤b≤0.9, 0≤c≤0.9, 0≤d≤0.5, 0≤e≤0.5, 0≤f1≤0.5, 0≤f2≤0.5, 0≤f3≤0.5, 0≤f1+f2+f3≤0.5, and 0≤a1≤0.8, 0≤a2≤0.8, 0≤a1+a2≤0.8, 0≤b≤0.9 ≤0.8, 0≤c≤0.8, 0≤d≤0.4, 0≤e≤0.4, 0≤f1≤0.4, 0≤f2≤0.4, 0≤f3≤0.4, 0≤f1+f2+f3≤0.4 is more preferred, and 0≤a1≤0.7, 0≤a2≤0.7, 0≤a1+a2≤0.7, 0≤b≤0.7, 0≤c≤0.7, 0≤d≤0.3, 0≤e≤0.3, 0≤f1≤0.3, 0≤f2≤0.3, 0≤f3≤0.3, 0≤f1+f2+f3≤0.3 is even more preferred. However, a1+a2+b+c+d+f1+f2+f3+e=1.0.

[0304] When synthesizing the aforementioned base polymer, for example, the monomers providing the aforementioned repeating units are placed in an organic solvent, a radical polymerization initiator is added, and the mixture is heated to carry out polymerization.

[0305] Examples of organic solvents used in the polymerization include toluene, benzene, tetrahydrofuran (THF), diethyl ether, dioxane, etc. Examples of polymerization initiators include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2-azobis(2-methylpropionic acid) dimethyl ester, benzoyl peroxide, lauroyl peroxide, etc. The polymerization temperature is preferably 50 to 80°C. The reaction time is preferably 2 to 100 hours, more preferably 5 to 20 hours.

[0306] When copolymerizing hydroxyl-containing monomers, the hydroxyl groups may be replaced with acetal groups such as ethoxyethoxy groups which are easily deprotected by acid during polymerization, and then deprotected using weak acid and water after polymerization. Alternatively, the hydroxyl groups may be replaced with acetyl groups, formyl groups, trimethylacetyl groups, etc., and then alkaline hydrolysis may be performed after polymerization.

[0307] When copolymerizing hydroxystyrene and hydroxyvinylnaphthalene, acetoxystyrene and acetoxyvinylnaphthalene may be used instead of hydroxystyrene and hydroxyvinylnaphthalene, and after polymerization, the acetoxy group may be deprotected by alkaline hydrolysis to obtain hydroxystyrene and hydroxyvinylnaphthalene.

[0308] The base used in the alkaline hydrolysis may be 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.

[0309] The polystyrene-equivalent weight average molecular weight (Mw) of the base polymer measured by gel permeation chromatography (GPC) using THF as a solvent is preferably 1,000 to 500,000, more preferably 2,000 to 30,000. When Mw is within the above range, the heat resistance and solubility in an alkaline developer of the resist film are good.

[0310] In addition, when the molecular weight distribution (Mw / Mn) of the base polymer is wide, there will be low molecular weight and high molecular weight polymers, so there is a concern that foreign matter may be observed on the pattern after exposure, and the shape of the pattern may deteriorate. As the pattern rules become finer, the influence of Mw and Mw / Mn is also likely to become greater. Therefore, in order to obtain a resist material that can be ideally used in a fine pattern size, the Mw / Mn of the base polymer is preferably 1.0 to 2.0, and a narrow distribution of 1.0 to 1.5 is particularly preferred.

[0311] In order to obtain a narrowly dispersed polymer, not only conventional radical polymerization but also living radical polymerization can be used. Examples of living radical polymerization include living radical polymerization using nitroxide radicals (Nitroxide-Mediated Radical Polymerization: NMP), atom transfer radical polymerization (Atom Transfer Radical Polymerization: ATRP), and reversible addition-fragmentation chain transfer (Reversible Addition-Fragmentation Chain Transfer: RAFT) polymerization.

[0312] The base polymer may contain two or more polymers having different composition ratios, Mw, and Mw / Mn.

[0313] [Acid generator]

[0314] The resist material of the present invention may also contain an acid generator (hereinafter also referred to as an additive acid generator) that generates a strong acid. The so-called strong acid herein refers to a compound having an acidity sufficient to cause a deprotection reaction of an acid-labile group of a base polymer in the case of a chemically amplified positive resist material, and a compound having an acidity sufficient to cause an acid-induced polarity change reaction or a crosslinking reaction in the case of a chemically amplified negative resist material. By containing such an acid generator, the sulfonium salt A can function as a quencher, and the resist material of the present invention can function as a chemically amplified positive resist material or a chemically amplified negative resist material.

[0315] The acid generator may include, for example, a compound that is sensitive to active light or radiation and generates an acid (photoacid generator). If the photoacid generator is a compound that generates an acid due to high-energy radiation, it may be any compound, but it is preferably one that generates sulfonic acid, imidic acid, or methylated acid. Ideal photoacid generators include sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, oxime-O-sulfonate acid generators, and the like. Specific examples of the photoacid generator include the examples described in paragraphs

[0122] to

[0142] of Japanese Patent Application Publication No. 2008-111103.

[0316] 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 preferably used.

[0317] [Chemistry 94]

[0318]

[0319] In formula (2-1) and (2-2), R 101 ~R 105Each is independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include those exemplified as R in the description of formula (1): 4 ~R 6 The same examples are given for hydrocarbon groups represented by 101 and R 102 They may also be bonded to each other and form a ring together with the sulfur atom to which they are bonded. In this case, the ring may be exemplified as R in the description of formula (1): 4 and R 5 The same example is true of the ring that can be formed by bonding with the sulfur atom to which they are bonded.

[0320] Examples of the cation of the sulfonium salt represented by the formula (2-1) include the same examples as those exemplified as the cation of the sulfonium salt A.

[0321] Examples of the cation of the iodonium salt represented by the formula (2-2) include the following, but are not limited thereto.

[0322] [Chemistry 95]

[0323]

[0324] [Chemistry 96]

[0325]

[0326] In formula (2-1) and (2-2), Xa - is an anion selected from the following formulae (2A) to (2D).

[0327] [Chemistry 97]

[0328]

[0329] In formula (2A), R fa is a fluorine atom or a hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom. The hydrocarbon group may be saturated or unsaturated, and may be straight chain, branched, or cyclic. Specific examples thereof include and are exemplified as R in the formula (2A') described below. fa1 The same examples are given for the hydrocarbon groups represented.

[0330] The anion represented by the formula (2A) is preferably represented by the following formula (2A').

[0331] [Chemistry 98]

[0332]

[0333] In formula (2A'), R HF R is a hydrogen atom or a trifluoromethyl group, and is preferably a trifluoromethyl group.fa1 It is a hydrocarbon group having 1 to 38 carbon atoms which may contain a hetero atom. The hetero atom is preferably an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom, etc., and is more preferably an oxygen atom. The hydrocarbon group is particularly preferably one having 6 to 30 carbon atoms from the viewpoint of obtaining a high resolution in fine pattern formation.

[0334] R fa1 The hydrocarbon group represented by 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 methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecyl, and eicosyl; cyclic saturated hydrocarbon groups having 3 to 38 carbon atoms, such as cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norbornyl, norbornylmethyl, tricyclodecanyl, tetracyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl; unsaturated aliphatic hydrocarbon groups having 2 to 38 carbon atoms, such as allyl and 3-cyclohexenyl; aryl groups having 6 to 38 carbon atoms, such as phenyl, 1-naphthyl, and 2-naphthyl; aralkyl groups having 7 to 38 carbon atoms, such as benzyl and diphenylmethyl; groups obtained by combining these, and the like.

[0335] Furthermore, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and part of the -CH2- of the aforementioned hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, a hydroxyl 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 bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. Examples of the hydrocarbon group containing a hetero atom include a tetrahydrofuranyl group, a methoxymethyl group, an ethoxymethyl group, a methylthiomethyl group, an acetamidomethyl group, a trifluoroethyl group, a (2-methoxyethoxy)methyl group, an acetoxymethyl group, a 2-carboxy-1-cyclohexyl group, a 2-oxopropyl group, a 4-oxo-1-adamantyl group, and a 3-oxocyclohexyl group.

[0336] For details on the synthesis of sulfonium salts containing anions represented by formula (2A'), see Japanese Patent Publication No. 2007-145797, Japanese Patent Publication No. 2008-106045, Japanese Patent Publication No. 2009-7327, Japanese Patent Publication No. 2009-258695, etc. Also, sulfonium salts described in Japanese Patent Publication No. 2010-215608, Japanese Patent Publication No. 2012-41320, Japanese Patent Publication No. 2012-106986, Japanese Patent Publication No. 2012-153644, etc. can also be preferably used.

[0337] Examples of the anion represented by formula (2A) include the same examples as those exemplified as the anion represented by formula (1A) in JP-A-2018-197853.

[0338] In formula (2B), R fb1 and R fb2 Each is independently a fluorine atom or a hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include: fa1 The same examples are given for hydrocarbon groups. fb1 and R fb2 It is preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. fb1 With R fb2 They can also bond to each other and to the groups to which they are bonded (-CF2-SO2-N - -SO2-CF2-) together to form a ring, at this time, R fb1 With R fb2 The groups obtained by bonding to each other are preferably fluorinated ethylene groups or fluorinated propylene groups.

[0339] In formula (2C), R fc1 , R fc2 and R fc3 Each is independently a fluorine atom or a hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include: fa1 The same examples are given for hydrocarbon groups. fc1 , R fc2 and R fc3 It is preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. fc1 With R fc2 They can also bond to each other and to the groups to which they are bonded (-CF2-SO2-C - -SO2-CF2-) together to form a ring, at this time, R fc1 With R fc2 The groups obtained by bonding to each other are preferably fluorinated ethylene groups or fluorinated propylene groups.

[0340] In formula (2D), R fd is a hydrocarbon group having 1 to 40 carbon atoms which may contain a heteroatom. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include and are illustrated as R in formula (2A'): fa1 The same examples are given for the hydrocarbon groups represented.

[0341] For details on the synthesis of the sulfonium salt of the anion represented by the formula (2D), see Japanese Patent Application Laid-Open Nos. 2010-215608 and 2014-133723.

[0342] Examples of the anion represented by formula (2D) include the same examples as those exemplified as the anion represented by formula (1D) in JP-A-2018-197853.

[0343] In addition, the photoacid generator containing the anion represented by formula (2D) has no fluorine atom at the α position of the sulfonic group, but has two trifluoromethyl groups at the β position, and thus has acidity sufficient to cut off the acid-labile group in the base polymer. Therefore, it can be used as a photoacid generator.

[0344] As the photoacid generator, a photoacid generator represented by the following formula (3) can also be preferably used.

[0345] [Chemistry 99]

[0346]

[0347] In formula (3), R 201 and R 202 Each of R is independently a halogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may contain a hetero atom. 203 is a alkylene group having 1 to 30 carbon atoms which may contain a hetero atom. 201 , R 202 and R 203 Any two of them may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. In this case, the ring may be exemplified as R in the description of formula (1): 4 and R 5 The same example is true of the ring that can be formed by bonding with the sulfur atom to which they are bonded.

[0348] R 201 and R 202 The hydrocarbon group represented by may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Specific examples thereof include: alkyl groups having 1 to 30 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, oxanorbornyl, tricyclo[5.2.1.0 2,6] cyclic saturated hydrocarbon groups having 3 to 30 carbon atoms, such as decyl and adamantyl; aryl groups having 6 to 30 carbon atoms, such as phenyl, tolyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, sec-butylnaphthyl, tert-butylnaphthyl and anthracenyl; groups derived from combinations thereof, etc. Furthermore, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and part of the -CH2- of the aforementioned hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, it may contain a hydroxyl 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 bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, and the like.

[0349] R 203 The alkylene group represented by may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Specific examples thereof include methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexadecane-1,16-diyl, heptane-1,17-diyl, and heptadecane-1,1 7-diyl and the like; alkanediyl groups having 1 to 30 carbon atoms, such as cyclopentanediyl, cyclohexanediyl, norbornanediyl and adamantanediyl; cyclic saturated alkylene groups having 3 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 derived from combinations thereof. Furthermore, part or all of the hydrogen atoms of the aforementioned alkylene group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and part of the -CH2- of the aforementioned alkylene group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, a hydroxyl 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 bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. may be contained. The aforementioned hetero atom is preferably an oxygen atom.

[0350] In formula (3), L Ais a single bond, an ether bond or an alkylene group having 1 to 20 carbon atoms which may contain a hetero atom. The alkylene group may be saturated or unsaturated and may be linear, branched or cyclic. Specific examples thereof include and are shown as R 203 The same examples are given for the alkylene groups represented by .

[0351] In formula (3), X A , X B , X C and X D are independently a hydrogen atom, a fluorine atom or a trifluoromethyl group. A , X B , X C and X D At least one of them is a fluorine atom or a trifluoromethyl group.

[0352] In formula (3), k is an integer from 0 to 3.

[0353] The photoacid generator represented by the formula (3) is preferably represented by the following formula (3').

[0354] [Chemical 100]

[0355]

[0356] In formula (3'), L A Same as above. X e R is a hydrogen atom or a trifluoromethyl group, and is preferably a trifluoromethyl group. 301 , R 302 and R 303 Each is independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include and are exemplified as R in formula (2A'): fa1 The same examples apply to the hydrocarbon groups represented by .x and y are each independently an integer of 0-5, and z is an integer of 0-4.

[0357] Examples of the photo-acid generator represented by formula (3) include the same examples as those exemplified as the photo-acid generator represented by formula (2) in JP-A-2017-026980.

[0358] Among the above-mentioned photoacid generators, those containing anions represented by formula (2A') or (2D) are particularly preferred because they have low acid diffusion and excellent solubility in solvents. Also, those represented by formula (3') are particularly preferred because they have extremely low acid diffusion.

[0359] The photoacid generator may be a sulfonium salt or iodonium salt containing an anion having an aromatic ring substituted with an iodine atom or a bromine atom. Examples of such salts include those represented by the following formula (4-1) or (4-2).

[0360] [Chemistry 101]

[0361]

[0362] In formula (4-1) and (4-2), p is an integer satisfying 1≤p≤3. q and r are integers satisfying 1≤q≤5, 0≤r≤3 and 1≤q+r≤5. q is preferably an integer satisfying 1≤q≤3, more preferably 2 or 3. r is preferably an integer satisfying 0≤r≤2.

[0363] In formula (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 as or different from each other.

[0364] In formula (4-1) and (4-2), L 1 It is a saturated alkylene group having 1 to 6 carbon atoms which may contain a single bond, an ether bond or an ester bond. The saturated alkylene group may be linear, branched or cyclic.

[0365] In formula (4-1) and (4-2), L 2 When p is 1, it is a single bond or a divalent linking group having 1 to 20 carbon atoms. When p is 2 or 3, it is a (p+1)-valent linking group having 1 to 20 carbon atoms. The linking group may contain an oxygen atom, a sulfur atom or a nitrogen atom.

[0366] In formula (4-1) and (4-2), R 401 is a hydroxyl group, a carboxyl group, a fluorine atom, a chlorine atom, a bromine atom or an amino group, or a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon oxy group having 1 to 20 carbon atoms, a hydrocarbon carbonyl group having 2 to 20 carbon atoms, a hydrocarbon oxycarbonyl group having 2 to 20 carbon atoms, a hydrocarbon carbonyloxy group having 2 to 20 carbon atoms or a hydrocarbon sulfonyloxy group having 1 to 20 carbon atoms which may contain a fluorine atom, a chlorine atom, a bromine atom, a hydroxyl group, an amino group or an ether bond, or -N(R 401A )(R 401B )、-N(R 401C )-C(=O)-R 401D or -N(R 401C )-C(=O)-OR 401D . R 401A and R 401B R is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. 401C R is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms, and may contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyl oxy group having 2 to 6 carbon atoms. 401DIt is an aliphatic hydrocarbon 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 also contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyloxy group having 2 to 6 carbon atoms. The aforementioned aliphatic hydrocarbon group may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. The aforementioned hydrocarbon group, hydrocarbon oxy group, hydrocarbon oxycarbonyl group, hydrocarbon carbonyl group, hydrocarbon carbonyloxy group, and hydrocarbon sulfonyloxy group may be straight-chain, branched, or cyclic. When p and / or r are 2 or more, each R 401 They can be the same or different.

[0367] Among them, R 401 Preferably, it is hydroxyl, -N(R 401C )-C(=O)-R 401D 、-N(R 401C )-C(=O)-OR 401D , fluorine atom, chlorine atom, bromine atom, methyl group, methoxy group and the like.

[0368] In formula (4-1) and (4-2), Rf 1 ~Rf 4 are independently a hydrogen atom, a fluorine atom or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group. 1 With Rf 2 They can also combine to form a carbonyl group. 3 and Rf 4 Fluorine atoms are particularly preferred.

[0369] In formula (4-1) and (4-2), R 402 ~R 406 Each is independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include those exemplified in the description of formula (1) as R 4 ~R 6 The same examples are given for the hydrocarbon groups represented by . In addition, part or all of the hydrogen atoms of the aforementioned hydrocarbon groups may be substituted by hydroxyl groups, carboxyl groups, halogen atoms, cyano groups, nitro groups, mercapto groups, sultone rings, sulfone groups or groups containing sulfonium salts, and part of the -CH2- of the aforementioned hydrocarbon groups may be substituted by ether bonds, ester bonds, carbonyl groups, amide bonds, carbonate bonds or sulfonate bonds. In addition, R 402 and R 403 They may also be bonded to each other and form a ring together with the sulfur atom to which they are bonded. In this case, the ring may be exemplified as R in the description of formula (1): 4 and R 5 The same example is true of the rings that can be formed by bonding to each other and to the sulfur atoms to which they are bonded.

[0370] Examples of the cation of the sulfonium salt represented by formula (4-1) include the same examples as those exemplified as the cation of the sulfonium salt represented by formula (1). Examples of the cation of the iodonium salt represented by formula (4-2) include the same examples as those exemplified as the cation of the iodonium salt represented by formula (2-2).

[0371] The anion of the onium salt represented by formula (4-1) or (4-2) may be exemplified by the following, but is not limited thereto. BI Same as above.

[0372] [Chemistry 102]

[0373]

[0374] [Chemistry 103]

[0375]

[0376] [Chemistry 104]

[0377]

[0378] [Chemistry 105]

[0379]

[0380] [Chemistry 106]

[0381]

[0382] [Chemistry 107]

[0383]

[0384] [Chemistry 108]

[0385]

[0386] [Chemistry 109]

[0387]

[0388] [Chemistry 110]

[0389]

[0390] [Chemistry 111]

[0391]

[0392] [Chemistry 112]

[0393]

[0394] [Chemistry 113]

[0395]

[0396] [Chemistry 114]

[0397]

[0398] [Chemistry 115]

[0399]

[0400] [Chemistry 116]

[0401]

[0402] [Chemistry 117]

[0403]

[0404] [Chemistry 118]

[0405]

[0406] [Chemistry 119]

[0407]

[0408] [Chemistry 120]

[0409]

[0410] [Chemistry 121]

[0411]

[0412] [Chemistry 122]

[0413]

[0414] [Chemistry 123]

[0415]

[0416] [Chemistry 124]

[0417]

[0418] When the resist material of the present invention contains an additive acid generator, its content is preferably 0.1 to 50 parts by mass, more preferably 1 to 40 parts by mass, relative to 100 parts by mass of the base polymer. In the resist material of the present invention, the base polymer can function as a chemically amplified resist material by containing any one of the repeating units f1 to f3 and / or containing an additive acid generator.

[0419] [Organic solvents]

[0420] 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 above-mentioned components and the components described below. Examples of the organic solvent include ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentyl ketone, and 2-heptanone described in paragraphs

[0144] to

[0145] of JP-A-2008-111103; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and diacetone alcohol; ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene 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.

[0421] In the resist material 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, based on 100 parts by mass of the base polymer. The organic solvent may be used alone or in combination of two or more.

[0422] [Other ingredients]

[0423] The resist material of the present invention may contain, in addition to the above-mentioned components, a surfactant, a dissolution inhibitor, a crosslinking agent, a quencher other than the sulfonium salt A (hereinafter referred to as other quenchers), a water repellency improving agent, acetylene alcohols, and the like.

[0424] The surfactants include the examples described in paragraphs

[0165] to

[0166] of Japanese Patent Application Laid-Open No. 2008-111103. By adding a surfactant, the coating properties of the resist material can be further improved or controlled. When the resist material of the present invention contains the surfactant, the content thereof is preferably 0.0001 to 10 parts by mass relative to 100 parts by mass of the base polymer. The surfactants may be used alone or in combination of two or more.

[0425] When the resist material of the present invention is positive type, by mixing a dissolution inhibitor, the difference in dissolution rate between the exposed part and the unexposed part can be further enlarged, and the resolution can be further improved. The above-mentioned dissolution inhibitor can be listed as follows: a compound having a molecular weight of preferably 100 to 1000 and more preferably 150 to 800, and a compound containing two or more phenolic hydroxyl groups in the molecule, wherein the hydrogen atom of the phenolic hydroxyl group is replaced by an acid-labile group at a ratio of 0 to 100 mol% as a whole, or a compound containing a carboxyl group in the molecule, wherein the hydrogen atom of the carboxyl group is replaced by an acid-labile group at an average ratio of 50 to 100 mol% as a whole. Specifically, it can be listed as follows: a compound in which the hydrogen atom of the hydroxyl group or the carboxyl group of bisphenol A, trisphenol, phenolphthalein, cresol novolac resin, naphthalenecarboxylic acid, adamantanecarboxylic acid, bile acid is replaced by an acid-labile group, etc., for example, described in paragraphs

[0155] to

[0178] of Japanese Patent Publication No. 2008-122932.

[0426] When the resist material of the present invention is positive type and 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.

[0427] On the other hand, when the resist material of the present invention is negative, a negative pattern can be obtained by adding a crosslinking agent to reduce the dissolution rate of the exposed part. The crosslinking agent can be listed as: epoxy compounds substituted with at least one group selected from hydroxymethyl, alkoxymethyl and acyloxymethyl, melamine compounds, guanamine compounds, glycoluril compounds or urea compounds, isocyanate compounds, azide compounds, compounds containing double bonds such as alkenyloxy groups, etc. They can be used in the form of additives or introduced into the side chains of polymers as pendant groups. In addition, hydroxyl-containing compounds can also be used as crosslinking agents.

[0428] Examples of the epoxy compound include tris(2,3-epoxypropyl)isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and triethylolethane triglycidyl ether.

[0429] Examples of the melamine compound include hexamethylolmelamine, hexamethoxymethylmelamine, a compound in which 1 to 6 methylol groups in hexamethylolmelamine are methoxymethylated, or a mixture thereof, hexamethoxyethylmelamine, hexaacyloxymethylmelamine, a compound in which 1 to 6 methylol groups in hexamethylolmelamine are acyloxymethylated, or a mixture thereof.

[0430] Examples of the guanamine compound include tetramethylolguanamine, tetramethoxymethylguanamine, compounds in which 1 to 4 hydroxymethyl groups of tetramethylolguanamine are methoxymethylated, or mixtures thereof, tetramethoxyethylguanamine, tetraacyloxyguanamine, compounds in which 1 to 4 hydroxymethyl groups of tetramethylolguanamine are acyloxymethylated, or mixtures thereof.

[0431] Examples of the glycoluril compound include tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, compounds in which 1 to 4 hydroxymethyl groups in tetramethylol glycoluril are methoxymethylated, or mixtures thereof, compounds in which 1 to 4 hydroxymethyl groups in tetramethylol glycoluril are acyloxymethylated, or mixtures thereof, etc. Examples of the urea compound include tetramethylol urea, tetramethoxymethyl urea, compounds in which 1 to 4 hydroxymethyl groups in tetramethylol urea are methoxymethylated, or mixtures thereof, and tetramethoxyethyl urea, etc.

[0432] Examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0433] Examples of the azide compound include 1,1′-biphenyl-4,4′-bisazide, 4,4′-methylenebisazide, and 4,4′-oxybisazide.

[0434] Examples of the alkenyloxy group-containing compound include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, and trimethylolpropane trivinyl ether.

[0435] When the resist material of the present invention is negative type and contains the crosslinking agent, the content thereof is preferably 0.1 to 50 parts by mass, more preferably 1 to 40 parts by mass, relative to 100 parts by mass of the base polymer. The crosslinking agent may be used alone or in combination of two or more.

[0436] The aforementioned other quenchers may include known basic compounds. Known basic compounds may include: primary, secondary or tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having carboxyl groups, nitrogen-containing compounds having sulfonyl groups, nitrogen-containing compounds having hydroxyl groups, nitrogen-containing compounds having hydroxyphenyl groups, alcoholic nitrogen-containing compounds, amides, imides, carbamates, etc. In particular, primary, secondary and tertiary amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Publication No. 2008-111103 are preferred, and amine compounds having hydroxyl groups, ether bonds, ester bonds, lactone rings, cyano groups, sulfonate bonds, or compounds having carbamate groups described in Japanese Patent Publication No. 3790649 are particularly preferred. By adding such basic compounds, for example, the diffusion rate of the acid in the resist film can be further suppressed or the shape can be corrected.

[0437] In addition, other quenchers include onium salts such as sulfonium salts, iodonium salts, and ammonium salts of sulfonic acids and carboxylic acids that are not fluorinated at the α-position as described in Japanese Patent Application Laid-Open No. 2008-158339. Sulfonic acids, imidic acids, or methylated acids that are fluorinated at the α-position are necessary to deprotect the acid-labile group of the carboxylate, and the sulfonic acids or carboxylic acids that are not fluorinated at the α-position are released by salt exchange with the onium salts that are not fluorinated at the α-position. Sulfonic acids and carboxylic acids that are not fluorinated at the α-position do not cause deprotection reactions, and thus function as quenchers.

[0438] Other quenchers include polymer quenchers described in Japanese Patent Application Publication No. 2008-239918. The polymer quenchers improve the rectangularity of the resist pattern by being aligned on the resist film surface. The polymer quenchers also have the effect of preventing film loss and doming of the pattern when using a protective film for immersion exposure.

[0439] When the resist material of the present invention contains other quenchers, the content thereof is preferably 0 to 5 parts by mass, more preferably 0 to 4 parts by mass, based on 100 parts by mass of the base polymer. Other quenchers may be used alone or in combination of two or more.

[0440] The aforementioned water repellency improver is a material that improves the water repellency of the surface of the resist film and can be used in immersion lithography without using a top coat. The aforementioned water repellency improver is preferably a polymer containing a fluorinated alkyl group, a polymer containing a 1,1,1,3,3,3-hexafluoro-2-propanol residue of a specific structure, etc., and the examples illustrated in Japanese Patent Publication No. 2007-297590 and Japanese Patent Publication No. 2008-111103 are more preferred. The aforementioned water repellency improver must be dissolved in an alkaline developer or an organic solvent developer. The aforementioned specific water repellency improver having a 1,1,1,3,3,3-hexafluoro-2-propanol residue has good solubility in a developer. As for the water repellency improver, a polymer containing a repeating unit containing an amino group or an amine salt has a high effect of preventing the evaporation of the acid during PEB and preventing the poor opening of the hole pattern after development. When the resist material of the present invention contains the water repellency improver, its content is preferably 0 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, based on 100 parts by mass of the base polymer. The water repellency improver may be used alone or in combination of two or more.

[0441] Examples of the acetylene alcohols include those described in paragraphs

[0179] to

[0182] of Japanese Patent Application Laid-Open No. 2008-122932. When the resist material of the present invention contains the acetylene alcohols, the content thereof is preferably 0 to 5 parts by mass relative to 100 parts by mass of the base polymer. The acetylene alcohols may be used alone or in combination of two or more.

[0442] [Pattern Formation Method]

[0443] When the resist material of the present invention is used in the manufacture of various integrated circuits, known photolithography techniques can be used. For example, as for the pattern forming method, a method comprising the following steps can be cited:

[0444] Using the aforementioned resist material to form a resist film on a substrate,

[0445] exposing the resist film to high energy radiation, and

[0446] The exposed resist film is developed using a developer.

[0447] First, the resist material of the present invention is applied to a substrate (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflection film, etc.) for integrated circuit manufacturing or a substrate (Cr, CrO, CrON, MoSi2, SiO2, etc.) for mask circuit manufacturing using a coating film thickness of 0.01 to 2 μm. The resist material is then pre-baked at 60 to 150° C., 10 seconds to 30 minutes, and preferably at 80 to 120° C., 30 seconds to 20 minutes on a hot plate to form a resist film.

[0448] Then, the resist film is exposed using high-energy radiation. Examples of the high-energy radiation include ultraviolet rays, far ultraviolet rays, EB, EUV with a wavelength of 3 to 15 nm, X-rays, soft X-rays, excimer lasers, gamma rays, synchrotron radiation, etc. When ultraviolet rays, far ultraviolet rays, EUV, X-rays, soft X-rays, excimer lasers, gamma rays, synchrotron radiation, etc. are used as the high-energy radiation, the exposure is preferably about 1 to 200 mJ / cm directly or using a mask for forming a desired pattern. 2 More preferably, it is about 10 to 100 mJ / cm 2 When using EB, the exposure dose is preferably about 0.1 to 300 μC / cm 2 More preferably, it is about 0.5 to 200 μC / cm 2 The resist material of the present invention is particularly suitable for fine patterning by KrF excimer laser, ArF excimer laser, EB, EUV, X-ray, soft X-ray, gamma ray, synchrotron radiation among high-energy rays, and is particularly suitable for fine patterning by EB or EUV.

[0449] After the exposure, PEB may be performed on a hot plate or in an oven, preferably at 30 to 150° C. for 10 seconds to 30 minutes, more preferably at 50 to 120° C. for 30 seconds to 20 minutes, but it is not necessary to perform PEB.

[0450] After exposure or PEB, the resist film is exposed for 3 seconds to 3 minutes and preferably for 5 seconds to 2 minutes by a common method such as dipping, puddle, spraying, etc., and developed using a developer of an alkaline aqueous solution of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, etc., preferably 0.1 to 10% by mass and ideally 2 to 5% by mass, to form a desired pattern. In the case of a positive resist material, the portion irradiated with light will dissolve in the developer, while the portion not exposed will not dissolve, and a desired positive pattern will be formed on the substrate. In the case of a negative resist material, the portion irradiated with light will not dissolve in the developer, while the portion not exposed will dissolve, as opposed to the positive resist material.

[0451] A negative pattern can also be obtained by using a positive resist material containing a base polymer containing an acid-labile group and developing with an organic solvent. The developer used in this case can be exemplified by 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, amyl acetate, butyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl valerate, methyl pentenoate, methyl crotonate, crotonyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl valerate, methyl pentenoate, methyl croton ... ethyl acetate, methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl 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.

[0452] At the end of the development, rinsing is performed. The rinsing solution is preferably a solvent that is miscible with the developer and does not dissolve the resist film. Such solvents can preferably be 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.

[0453] Examples of the alcohol having 3 to 10 carbon atoms include n-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, tert-pentanol, neopentyl alcohol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, 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.

[0454] 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.

[0455] Examples of the aforementioned 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 aforementioned alkenes having 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, cyclooctene, etc. Examples of the aforementioned alkynes having 6 to 12 carbon atoms include hexyne, heptyne, octyne, etc.

[0456] Examples of the aromatic solvent include toluene, xylene, ethylbenzene, cumene, tert-butylbenzene, and mesitylene.

[0457] By performing rinsing, the occurrence of collapse and defects in the resist pattern can be reduced. In addition, rinsing is not essential, and by not performing rinsing, the amount of solvent used can be reduced.

[0458] The hole pattern and groove pattern after development can also be shrunk by heat flow, RELACS technology or DSA technology. A shrinking agent is coated on the hole pattern, and the diffusion of the acid catalyst from the resist film during baking will cause cross-linking of the shrinking agent on the surface of the resist film, and the shrinking agent will adhere to the side wall of the hole pattern. The baking temperature should be 70-180°C, preferably 80-170°C, and the baking time should be 10-300 seconds to remove the excess shrinking agent and shrink the hole pattern.

[0459] Example

[0460] Hereinafter, the present invention will be specifically described with reference to synthesis examples, examples and comparative examples, but the present invention is not limited to the following examples.

[0461] The structures of quenchers Q-1 to Q-20 used in the resist material are shown below.

[0462] [Chemistry 125]

[0463]

[0464] [Chemistry 126]

[0465]

[0466] [Chemistry 127]

[0467]

[0468] [Synthesis Example] Synthesis of base polymers (polymers P-1 to P-6)

[0469] The monomers were combined and copolymerized in THF as a solvent, and then placed in methanol. The precipitated solid was washed with hexane, separated and dried to obtain base polymers (polymers P-1 to P-6) with the following compositions. 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC (solvent: THF, standard: polystyrene).

[0470] [Chemistry 128]

[0471]

[0472] [Chemistry 129]

[0473]

[0474] [Chemistry 130]

[0475]

[0476] [Examples 1 to 25, Comparative Examples 1 to 4] Preparation and Evaluation of Resist Materials

[0477] (1) Preparation of resist materials

[0478] The solutions prepared by dissolving the components in the compositions shown in Tables 1 and 2 were filtered through a 0.2 μm filter to obtain resist materials. The resist materials of Examples 1 to 24 and Comparative Examples 1 to 3 were positive-type, and the resist materials of Example 25 and Comparative Example 4 were negative-type.

[0479] In Tables 1 and 2, the components are as follows.

[0480] Organic solvent: PGMEA (propylene glycol monomethyl ether acetate)

[0481] DAA (Diacetone Alcohol)

[0482] EL(ethyl lactate)

[0483] Acid generator: PAG-1, PAG-2

[0484] [Chemistry 131]

[0485]

[0486] ·Mixed quencher: BQ-1~BQ-4

[0487] [Chemistry 132]

[0488]

[0489] Comparative quenchers: cQ-1 to cQ-3

[0490] [Chemistry 133]

[0491]

[0492] (2) EUV lithography evaluation

[0493] Each resist material shown in Tables 1 and 2 was spin-coated on a Si substrate on which a silicon-containing spin-coating hard mask SHB-A940 (containing 43% by mass of silicon) manufactured by Shin-Etsu Chemical Co., Ltd. was formed with a film thickness of 20 nm, and pre-baked at 100° C. for 60 seconds using a hot plate to obtain a resist film with a film thickness of 60 nm. Then, the resist film was exposed using an EUV scanning exposure machine NXE3400 manufactured by ASML (NA 0.33, σ 0.9 / 0.6, quadrupole illumination, mask with a hole pattern having a size of 44 nm pitch on the wafer, +20% bias), and PEB was performed for 60 seconds on a hot plate at the temperature described in Tables 1 and 2, and then developed for 30 seconds using a 2.38% by mass TMAH aqueous solution, and a hole pattern having a size of 22 nm was obtained in Examples 1 to 24 and Comparative Examples 1 to 3, and a dot pattern having a size of 22 nm was obtained in Example 25 and Comparative Example 4.

[0494] Using a length measurement SEM (CG6300) manufactured by Hitachi High-Tech Co., Ltd., the exposure amount when the hole or dot size is formed at 22 nm was measured and this was defined as sensitivity. In addition, the size of 50 holes or dots at this time was measured, and the value (3σ) three times the standard deviation (σ) obtained from the result was defined as CDU. The results are summarized in Tables 1 and 2.

[0495] [Table 1]

[0496]

[0497]

[0498] [Table 2]

[0499]

[0500]

[0501] From the results shown in Tables 1 and 2, it can be seen that the resist material of the present invention containing the sulfonium salt of one or more compounds selected from N-carbonyltrifluoromethoxybenzenesulfonamide, N-carbonyldifluoromethoxybenzenesulfonamide, trifluoromethoxybenzenesulfonimide and difluoromethoxybenzenesulfonimide has high sensitivity and improved CDU. In the case of the sulfonium salt of the known type sulfonamide and sulfonimide of the comparative example, the acid diffusion control ability is low, and although it is highly sensitive, the CDU is poor.

Claims

1. A resist material comprising: The quencher comprises sulfonium salts of one or more compounds selected from the group consisting of N-carbonyltrifluoromethoxybenzenesulfonamide, N-carbonyldifluoromethoxybenzenesulfonamide, trifluoromethoxybenzenesulfonimide, and difluoromethoxybenzenesulfonimide.

2. The resist material according to claim 1, wherein The sulfonium salt is represented by the following formula (1): In the formula, m is an integer from 1 to 5, and n is an integer from 0 to 4; however, 1≤m+n≤5; X 1 is -C(=O)- or -S(=O)2-; R 1 is trifluoromethyl or difluoromethyl; R 2 is a saturated hydrocarbon group having 1 to 6 carbon atoms, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a hydroxyl group, a carboxyl group, a cyano group, a nitro group or a halogen atom; R 3 A hydrocarbon group having 1 to 26 carbon atoms, and the hydrocarbon group may contain at least one selected from an oxygen atom, a sulfur atom, a nitrogen atom and a halogen atom; R 4 ~R 6 are independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom; and R 4 and R 5 They may also bond to each other and to the sulfur atom to which they are bonded to form a ring. The resist material according to claim 1 , further comprising a base polymer.

4. The resist material according to claim 3, wherein The base polymer contains a repeating unit represented by the following formula (a1) or a repeating unit represented by the following formula (a2); In the formula, R A are each independently a hydrogen atom or a methyl group; Y 1 is a single bond, a phenylene group or a naphthylene group, or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, an ether bond, and a lactone ring; Y 2 is a single bond or an ester bond; Y 3 is a single bond, an ether bond or an ester bond; R 11 and R 12 are each independently an acid-labile group; R 13 is a fluorine atom, a trifluoromethyl group, a cyano group or a saturated hydrocarbon group having 1 to 6 carbon atoms; R 14 It is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and a portion of the -CH2- of the alkanediyl group may be substituted by an ether bond or an ester bond; a is 1 or 2; b is an integer from 0 to 4; however, 1≤a+b≤5. The resist material according to claim 4 , which is a chemically amplified positive resist material.

6. The resist material according to claim 3, wherein The base polymer does not contain acid-labile groups. The resist material according to claim 6 , which is a chemically amplified negative resist material.

8. The positive resist material according to claim 3, wherein The base polymer contains at least one selected from the group consisting of a repeating unit represented by the following formula (f1), a repeating unit represented by the following formula (f2), and a repeating unit represented by the following formula (f3); In the formula, R A are each independently a hydrogen atom or a methyl group; Z 1 is a single bond, an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these groups, or -OZ 11 -、-C(=O)-OZ 11 -or-C(=O)-NH-Z 11 -;Z 11 It is an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining them, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group; Z 2 is a single bond or an ester bond; Z 3 is a single bond, -Z 31 -C(=O)-O-, -Z 31 -O- or -Z 31 -OC(=O)-; Z 31 A alkylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining these groups, and may contain a carbonyl group, an ester bond, an ether bond, an iodine atom, or a bromine atom; Z 4 is methylene, 2,2,2-trifluoro-1,1-ethanediyl or carbonyl; Z 5 is a single bond, methylene, ethylene, phenylene, fluorinated phenylene, phenylene substituted with trifluoromethyl, -OZ 51 -、-C(=O)-OZ 51 -or-C(=O)-NH-Z 51 -;Z 51 It is an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group or a phenylene group substituted with a trifluoromethyl group, and may also contain a carbonyl group, an ester bond, an ether bond, a halogen atom or a hydroxyl group; R 21 ~R 28 are independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom; and R 23 and R 24 or R 26 and R 27 They can also bond to each other and to the sulfur atoms to which they are bonded to form a ring; M - It is a non-nucleophilic relative ion.

9. The resist material according to claim 1, further comprising an acid generator that generates a strong acid.

10. The resist material according to claim 9, wherein The acid generator is one that generates sulfonic acid, imidic acid or methylated acid. The resist material according to claim 1 , further comprising an organic solvent.

12. The resist material according to claim 1, further comprising a surfactant.

13. A pattern forming method comprising the following steps: forming a resist film on a substrate using the resist material according to any one of claims 1 to 12, exposing the resist film to high energy radiation, and The exposed resist film is developed using a developer.

14. The pattern forming method according to claim 13, wherein: The high-energy ray is KrF excimer laser, ArF excimer laser, electron beam or extreme ultraviolet ray with a wavelength of 3 to 15 nm.

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