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 and improved LWR and CDU; and a pattern forming method using the resist material. [Solution] A resist material containing: a base polymer having a trifluoromethoxybenzenesulfonamide anion, a difluoromethoxybenzenesulfonamide anion, a trifluoromethoxybenzenesulfonimide anion, or a sulfonium salt structure in which a difluoromethoxybenzenesulfonimide anion is bonded to a main chain;

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 of 3nm node and the next generation of 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 resolution, acid diffusion must be suppressed, 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 for 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 be restored to a 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] In order to suppress acid diffusion, resist materials containing a polymer-bonded quencher using a polymer having a sulfonium salt structure of a weak acid with a pKa of -0.8 or higher as a base polymer have been proposed (Patent Documents 7 to 9). In Patent Document 7, examples of weak acids include carboxylic acid, sulfonamide, phenol, hexafluoroalcohol, and the like.

[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 this structure 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] [Patent Document 7] International Publication No. 2019 / 167737

[0019] [Patent Document 8] International Publication No. 2022 / 264845

[0020] [Patent Document 9] Japanese Patent Application Publication No. 2022-115072

[0021] Non-patent literature

[0022] [Non-patent document 1] SPIE Vol.6520 65203L-1 (2007) Summary of the invention

[0023] [Problems to be solved by the invention]

[0024] 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.

[0025] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a resist material having high sensitivity and improved LWR and CDU, particularly among positive resist materials, and a pattern forming method using the resist material.

[0026] [Methods to solve the problem]

[0027] The present inventors have conducted intensive studies to achieve the above-mentioned object, and have found that a base polymer having a sulfonium salt structure in which a trifluoromethoxybenzenesulfonamide anion, a difluoromethoxybenzenesulfonamide anion, a trifluoromethoxybenzenesulfonimide anion or a difluoromethoxybenzenesulfonimide anion is bonded to the main chain also functions as a quencher for inhibiting acid diffusion, and that a resist material having improved LWR and CDU, excellent resolution and a wide range of process latitude can be obtained by utilizing the excellent acid diffusion inhibition effect and the effect of preventing the quencher from agglomerating due to electron repulsion of the bulky trifluoromethoxy and difluoromethoxy groups, thereby completing the present invention.

[0028] That is, the present invention provides the following resist material and pattern forming method.

[0029] 1. A resist material comprising:

[0030] The base polymer has a sulfonium salt structure in which a trifluoromethoxybenzenesulfonamide anion, a difluoromethoxybenzenesulfonamide anion, a trifluoromethoxybenzenesulfonimide anion or a difluoromethoxybenzenesulfonimide anion is bonded to the main chain.

[0031] 2. The resist material according to 1., wherein the base polymer comprises a repeating unit a represented by the following formula (a).

[0032] [Chemistry 1]

[0033]

[0034] 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.

[0035] R A A hydrogen atom or a methyl group.

[0036] X 1 It is a single bond, an ester bond, or an amide bond.

[0037] X 2 It is a single bond, a carbonyl group, a sulfonyl group or an ester bond.

[0038] R 1 It is trifluoromethyl or difluoromethyl.

[0039] R 2 It is a hydrogen atom, 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 nitro group, a cyano group or a halogen atom.

[0040] R 3 It is a single bond or a hydrocarbylene group having 1 to 16 carbon atoms, and the hydrocarbylene group may contain at least one selected from an oxygen atom and a halogen atom.

[0041] 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.

[0042] 3. The resist material according to 1. or 2., wherein the base polymer further comprises a repeating unit b in which a hydrogen atom of a carboxyl group or a phenolic hydroxyl group is substituted with an acid-labile group.

[0043] 4. The resist material according to 3., wherein the repeating unit b is at least one selected from the group consisting of a repeating unit b1 represented by the following formula (b1) and a repeating unit b2 represented by the following formula (b2).

[0044] [Chemistry 2]

[0045]

[0046] In the formula, R A are each independently a hydrogen atom or a methyl group.

[0047] 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.

[0048] Y 2 It is a single bond, an ester bond or an amide bond.

[0049] Y 3 It is a single bond, an ether bond or an ester bond.

[0050] R 11 and R 12 It is an acid-labile group.

[0051] R 13 It is a fluorine atom, a trifluoromethyl group, a cyano group or a saturated hydrocarbon group having 1 to 6 carbon atoms.

[0052] R 14 It 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.

[0053] a is 1 or 2. b is an integer from 0 to 4. However, 1≤a+b≤5.

[0054] 5. An anti-etching material as described in any one of 1. to 4., wherein the base polymer further contains a repeating unit c having an adhesive group selected from a hydroxyl group, a carboxyl group, a lactone ring, a carbonate bond, a thiocarbonate bond, a carbonyl group, a cyclic acetal group, an ether bond, an ester bond, a sulfonate bond, a cyano group, an amide bond, -OC(=O)-S- and -OC(=O)-NH-.

[0055] 6. The resist material according to any one of 1. to 5., wherein the base polymer further contains at least one selected from the group consisting of a repeating unit represented by the following formula (d1), a repeating unit represented by the following formula (d2), and a repeating unit represented by the following formula (d3).

[0056] [Chemistry 3]

[0057]

[0058] In the formula, R A are each independently a hydrogen atom or a methyl group.

[0059] 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 11It 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.

[0060] Z 2 It is a single bond or an ester bond.

[0061] Z 3 is a single bond, -Z 31 -C(=O)-O-, -Z 31 -O- or -Z 31 -OC(=O)-. Z 31 It is an aliphatic 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.

[0062] Z 4 It is methylene, 2,2,2-trifluoro-1,1-ethanediyl or carbonyl.

[0063] 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 hydroxyl group or a halogen atom.

[0064] 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.

[0065] M - It is a non-nucleophilic relative ion.

[0066] 7. The resist material according to 6., wherein Z 3 A group containing at least one iodine atom.

[0067] 8. The resist material according to any one of 1. to 7., further comprising an acid generator.

[0068] 9. The resist material according to any one of 1. to 8., further comprising an organic solvent.

[0069] 10. The resist material according to any one of 1. to 9., further comprising a quencher.

[0070] 11. The resist material according to any one of 1. to 10., further comprising a surfactant.

[0071] 12. A pattern forming method comprising the following steps:

[0072] Using the resist material as described in any one of 1. to 11. to form a resist film on a substrate,

[0073] exposing the resist film to high energy radiation, and

[0074] The exposed resist film is developed using a developer.

[0075] 13. The pattern forming method according to 12., wherein the high-energy ray is i-ray, KrF excimer laser, ArF excimer laser, electron beam (EB) or EUV with a wavelength of 3 to 15 nm.

[0076] [Effects of the Invention]

[0077] The aforementioned base polymer having a sulfonium salt structure in which trifluoromethoxybenzenesulfonamide anion, difluoromethoxybenzenesulfonamide anion, trifluoromethoxybenzenesulfonimide anion or difluoromethoxybenzenesulfonimide anion is bonded to the main chain also functions as a quencher that inhibits acid diffusion. This can achieve low acid diffusion characteristics and improve LWR and CDU. That is, using the aforementioned base polymer, a resist material with low LWR and improved CDU can be constructed. DETAILED DESCRIPTION

[0078] [Resist material]

[0079] The resist material of the present invention contains a base polymer having a sulfonium salt structure in which a trifluoromethoxybenzenesulfonamide anion, a difluoromethoxybenzenesulfonamide anion, a trifluoromethoxybenzenesulfonimide anion or a difluoromethoxybenzenesulfonimide anion is bonded to the main chain.

[0080] [Base polymer]

[0081] The base polymer preferably comprises a repeating unit a represented by the following formula (a).

[0082] [Chemistry 4]

[0083]

[0084] In formula (a), m is an integer of 1 to 5, and n is an integer of 0 to 4. However, 1≤m+n≤5.

[0085] In formula (a), R AA hydrogen atom or a methyl group.

[0086] In formula (a), X 1 It is a single bond, an ester bond, or an amide bond.

[0087] In formula (a), X 2 It is a single bond, a carbonyl group, a sulfonyl group or an ester bond.

[0088] In formula (a), R 1 It is trifluoromethyl or difluoromethyl.

[0089] In formula (a), R 2 It is a hydrogen atom, 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 nitro group, a cyano group or a halogen atom.

[0090] 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 these. 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.

[0091] In formula (a), R 3 It is a single bond or an alkylene group having 1 to 16 carbon atoms. The aforementioned alkylene group may be saturated or unsaturated, and may be any of a straight chain, a branched shape, or a cyclic shape. 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, etc. an alkylene group having 1 to 16 carbon atoms; a cyclic saturated alkylene group having 3 to 16 carbon atoms, such as cyclopentanediyl, cyclohexanediyl, norbornanediyl and adamantanediyl; an arylene group having 6 to 16 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.

[0092] Again, R 3 The alkylene group represented by may also contain at least one selected from oxygen 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, etc., and part of its -CH2- may be substituted by carbonyl groups, ether bonds, ester bonds, carbonate bonds, etc.

[0093] Examples of the anion of the monomer providing the repeating unit a include those shown below, but are not limited thereto.

[0094] [Chemistry 5]

[0095]

[0096] [Chemistry 6]

[0097]

[0098] [Chemistry 7]

[0099]

[0100] [Chemistry 8]

[0101]

[0102] [Chemistry 9]

[0103]

[0104] [Chemistry 10]

[0105]

[0106] [Chemistry 11]

[0107]

[0108] [Chemistry 12]

[0109]

[0110] [Chemistry 13]

[0111]

[0112] [Chemistry 14]

[0113]

[0114] [Chemistry 15]

[0115]

[0116] [Chemistry 16]

[0117]

[0118] [Chemistry 17]

[0119]

[0120] [Chemistry 18]

[0121]

[0122] [Chemistry 19]

[0123]

[0124] [Chemistry 20]

[0125]

[0126] [Chemistry 21]

[0127]

[0128] [Chemistry 22]

[0129]

[0130] [Chemistry 23]

[0131]

[0132] [Chemistry 24]

[0133]

[0134] [Chemistry 25]

[0135]

[0136] [Chemistry 26]

[0137]

[0138] In formula (a), 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.

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] [Chemistry 27]

[0144]

[0145] In the formula, the dotted line is and R 6 of atomic bonds.

[0146] Examples of the cation of the repeating unit a include, but are not limited to, the following.

[0147] [Chemistry 28]

[0148]

[0149] [Chemistry 29]

[0150]

[0151] [Chemistry 30]

[0152]

[0153] [Chemistry 31]

[0154]

[0155] [Chemistry 32]

[0156]

[0157] [Chemistry 33]

[0158]

[0159] [Chemistry 34]

[0160]

[0161] [Chemistry 35]

[0162]

[0163] [Chemistry 36]

[0164]

[0165] [Chemistry 37]

[0166]

[0167] [Chemistry 38]

[0168]

[0169] [Chemistry 39]

[0170]

[0171] [Chemistry 40]

[0172]

[0173] [Chemistry 41]

[0174]

[0175] [Chemistry 42]

[0176]

[0177] [Chemistry 43]

[0178]

[0179] [Chemistry 44]

[0180]

[0181] [Chemistry 45]

[0182]

[0183] [Chemistry 46]

[0184]

[0185] [Chemistry 47]

[0186]

[0187] [Chemistry 48]

[0188]

[0189] [Chemistry 49]

[0190]

[0191] [Chemistry 50]

[0192]

[0193] [Chemistry 51]

[0194]

[0195] [Chemistry 52]

[0196]

[0197] [Chemistry 53]

[0198]

[0199] [Chemistry 54]

[0200]

[0201] [Chemistry 55]

[0202]

[0203] [Chemistry 56]

[0204]

[0205] The monomer providing the repeating unit a can be synthesized, for example, by ion-exchanging a hydrochloride or carbonate having a sulfonium cation with trifluoromethoxybenzenesulfonamide, difluoromethoxybenzenesulfonamide, trifluoromethoxybenzenesulfonimide or difluoromethoxybenzenesulfonimide or their ammonium salts having a polymerizable group. Alternatively, the repeating unit a can be formed by polymerizing a polymer using trifluoromethoxybenzenesulfonamide, difluoromethoxybenzenesulfonamide, trifluoromethoxybenzenesulfonimide or difluoromethoxybenzenesulfonimide or their ammonium salts, and then ion-exchanging with a hydrochloride or carbonate having a sulfonium cation.

[0206] The repeating unit a may be used alone or in combination of two or more.

[0207] The base polymer may contain repeating units in which the hydrogen atoms of the carboxyl groups are replaced by acid-labile groups (hereinafter referred to as repeating units b1) and / or repeating units in which the hydrogen atoms of the phenolic hydroxyl groups are replaced by acid-labile groups (hereinafter referred to as repeating units b2) in order to improve the solubility contrast.

[0208] Examples of the repeating units b1 and b2 include those represented by the following formulae (b1) and (b2), respectively.

[0209] [Chemistry 57]

[0210]

[0211] In formula (b1) and (b2), 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, an ester bond or an amide bond. 3 is a single bond, an ether bond or an ester bond. 11 and R 12 R is an acid-labile group. 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.

[0212] The monomers providing the repeating unit b1 include, but are not limited to, the following. A and R 11 Same as above.

[0213] [Chemistry 58]

[0214]

[0215] [Chemistry 59]

[0216]

[0217] The monomers providing the repeating unit b2 may be exemplified by the following, but are not limited thereto. A and R 12 Same as above.

[0218] [Chemistry 60]

[0219]

[0220] R 11 or R 12 There are various options for the acid-labile group represented by , and examples thereof include those represented by the following formulae (AL-1) to (AL-3).

[0221] [Chemistry 61]

[0222]

[0223] In formula (AL-1), c is an integer of 0 to 6. L1 A tertiary hydrocarbon group having 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms, a trihydrocarbylsilyl group in which each hydrocarbon group is a saturated hydrocarbon group having 1 to 6 carbon atoms, a saturated hydrocarbon group having 4 to 20 carbon atoms containing a carbonyl group, an ether bond or an ester bond, or a group represented by the formula (AL-3). In addition, the tertiary hydrocarbon group means a group obtained by detaching a hydrogen atom from a tertiary carbon atom of a hydrocarbon.

[0224] R L1 The tertiary hydrocarbon group represented by may be saturated or unsaturated, branched or cyclic. Specific examples thereof include: tert-butyl, tert-amyl, 1,1-diethylpropyl, 1-ethylcyclopentyl, 1-butylcyclopentyl, 1-ethylcyclohexyl, 1-butylcyclohexyl, 1-ethyl-2-cyclopentenyl, 1-ethyl-2-cyclohexenyl, 2-methyl-2-adamantyl, etc. The aforementioned trialkylsilyl group may include: trimethylsilyl, triethylsilyl, dimethyl-tert-butylsilyl, etc. The aforementioned saturated hydrocarbon group containing a carbonyl group, an ether bond or an ester bond may be straight-chain, branched or cyclic, preferably cyclic, and specific examples thereof include: 3-oxocyclohexyl, 4-methyl-2-oxooxacyclohexane-4-yl, 5-methyl-2-oxooxacyclopentane-5-yl, 2-tetrahydropyranyl, 2-tetrahydrofuranyl, etc.

[0225] Examples of the acid-labile group represented by formula (AL-1) include tert-butoxycarbonyl, tert-butoxycarbonylmethyl, tert-pentyloxycarbonyl, tert-pentyloxycarbonylmethyl, 1,1-diethylpropoxycarbonyl, 1,1-diethylpropoxycarbonylmethyl, 1-ethylcyclopentyloxycarbonyl, 1-ethylcyclopentyloxycarbonylmethyl, 1-ethyl-2-cyclopentenyloxycarbonyl, 1-ethyl-2-cyclopentenyloxycarbonylmethyl, 1-ethoxyethoxycarbonylmethyl, 2-tetrahydropyranyloxycarbonylmethyl, and 2-tetrahydrofuranyloxycarbonylmethyl.

[0226] Examples of the acid-labile group represented by the formula (AL-1) include groups represented by the following formulae (AL-1)-1 to (AL-1)-10.

[0227] [Chemistry 62]

[0228]

[0229] In the formula, the dotted lines are atomic bonds.

[0230] In the formulas (AL-1)-1 to (AL-1)-10, c is the same as described above. L8 R is independently a saturated hydrocarbon group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. L9 R is a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms. L10 It is a saturated hydrocarbon group having 2 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. The saturated hydrocarbon group may be linear, branched or cyclic.

[0231] In formula (AL-2), R L2 and R L3 Each of them is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. The saturated hydrocarbon group may be linear, branched or cyclic, and specific examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclopentyl, cyclohexyl, 2-ethylhexyl and n-octyl.

[0232] In formula (AL-2), R L4 It is a hydrocarbon group having 1 to 18 carbon atoms and preferably 1 to 10 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be any of linear, branched, and cyclic. The aforementioned hydrocarbon group may include saturated hydrocarbon groups having 1 to 18 carbon atoms, and some of their hydrogen atoms may be substituted by hydroxyl, alkoxy, oxo, amino, alkylamino, etc. Such substituted saturated hydrocarbon groups may include those shown below.

[0233] [Chemistry 63]

[0234]

[0235] In the formula, the dotted lines are atomic bonds.

[0236] R L2 With R L3 , R L2 With R L4 , or R L3 With R L4 They can also bond to each other and to the carbon atoms to which they are bonded or to the carbon atoms and oxygen atoms to form a ring. In this case, R L2 and R L3 , R L2 and R L4 , or R L3 and R L4 Each independently represents an alkanediyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. The carbon number of the ring formed by these groups is preferably 3 to 10, more preferably 4 to 10 carbon atoms.

[0237] Among the acid-labile groups represented by formula (AL-2), linear or branched ones include those represented by the following formulae (AL-2)-1 to (AL-2)-69, but are not limited thereto. In the following formulae, the dotted lines represent atomic bonds.

[0238] [Chemistry 64]

[0239]

[0240] [Chemistry 65]

[0241]

[0242] [Chemistry 66]

[0243]

[0244] [Chemistry 67]

[0245]

[0246] Among the acid-labile groups represented by the formula (AL-2), cyclic ones include tetrahydrofuran-2-yl, 2-methyltetrahydrofuran-2-yl, tetrahydropyran-2-yl, and 2-methyltetrahydropyran-2-yl.

[0247] Examples of the acid-labile group include groups represented by the following formula (AL-2a) or (AL-2b): The base polymer may be crosslinked intermolecularly or intramolecularly via the acid-labile group.

[0248] [Chemistry 68]

[0249]

[0250] In the formula, the dotted lines are atomic bonds.

[0251] In formula (AL-2a) or (AL-2b), R L11 and R L12 are each independently a hydrogen atom or a saturated hydrocarbon group having 1 to 8 carbon atoms. The saturated hydrocarbon group may be linear, branched or cyclic. L11 With R L12 They can also bond to each other and to the carbon atoms to which they are bonded to form a ring. In this case, R L11 and R L12 Each R is independently an alkanediyl group having 1 to 8 carbon atoms. L13 Each of d and e is independently an integer of 0 to 10, preferably an integer of 0 to 5, and f is an integer of 1 to 7, preferably an integer of 1 to 3.

[0252] In formula (AL-2a) or (AL-2b), L A It is an aliphatic saturated hydrocarbon group with a valence of (f+1) and having 1 to 50 carbon atoms, an alicyclic saturated hydrocarbon group with a valence of (f+1) and having 3 to 50 carbon atoms, an aromatic hydrocarbon group with a valence of (f+1) and having 6 to 50 carbon atoms, or a heterocyclic group with a valence of (f+1) and having 3 to 50 carbon atoms. In addition, a part of -CH2- in these groups may be substituted by a heteroatom-containing group, and a part of hydrogen atoms bonded to carbon atoms in these groups may be substituted by hydroxyl groups, carboxyl groups, acyl groups or fluorine atoms. A Preferred are saturated hydrocarbon groups such as saturated hydrocarbon groups having 1 to 20 carbon atoms, trivalent saturated hydrocarbon groups, tetravalent saturated hydrocarbon groups, and arylene groups having 6 to 30 carbon atoms. The saturated hydrocarbon groups may be linear, branched, or cyclic. B It is -C(=O)-O-, -NH-C(=O)-O- or -NH-C(=O)-NH-.

[0253] Examples of the cross-linked acetal group represented by the formula (AL-2a) or (AL-2b) include groups represented by the following formulae (AL-2)-70 to (AL-2)-77.

[0254] [Chemistry 69]

[0255]

[0256] In the formula, the dotted lines are atomic bonds.

[0257] In formula (AL-3), R L5 , R L6 and R L7Each is independently a hydrocarbon group having 1 to 20 carbon atoms, and may also 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. Specific examples thereof include: alkyl groups having 1 to 20 carbon atoms, cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, cyclic unsaturated hydrocarbon groups having 3 to 20 carbon atoms, and aryl groups having 6 to 10 carbon atoms. In addition, R L5 With R L6 , R L5 With R L7 , or R L6 With R L7 They may also bond to each other and to form an alicyclic ring having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded.

[0258] Examples of the group represented by formula (AL-3) include tert-butyl, 1,1-diethylpropyl, 1-ethylnorbornyl, 1-methylcyclopentyl, 1-ethylcyclopentyl, 1-isopropylcyclopentyl, 1-methylcyclohexyl, 2-(2-methyl)adamantyl, 2-(2-ethyl)adamantyl, and tert-pentyl.

[0259] Furthermore, examples of the group represented by the formula (AL-3) include groups represented by the following formulae (AL-3)-1 to (AL-3)-19.

[0260] [Chemistry 70]

[0261]

[0262] In the formula, the dotted lines are atomic bonds.

[0263] In formula (AL-3)-1~(AL-3)-19, R L14 R is independently a saturated hydrocarbon group having 1 to 8 carbon atoms or an aryl group having 6 to 20 carbon atoms. L15 and R L17 R is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 20 carbon atoms. L16 is an aryl group having 6 to 20 carbon atoms. The saturated hydrocarbon group may be linear, branched or cyclic. The aryl group is preferably a phenyl group. F is a fluorine atom or a trifluoromethyl group. g is an integer of 1-5.

[0264] In addition, examples of the acid-labile group include groups represented by the following formula (AL-3)-20 or (AL-3)-21. The polymer may be cross-linked intramolecularly or intermolecularly via the acid-labile group.

[0265] [Chemistry 71]

[0266]

[0267] In the formula, the dotted lines are atomic bonds.

[0268] In formula (AL-3)-20 and (AL-3)-21, R L14 Same as above. L18 It is a saturated alkylene group with a valence of (h+1) and a carbon number of 1 to 20 or an arylene group with a valence of (h+1) and a carbon number of 6 to 20, and may contain heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. The saturated alkylene group may be linear, branched, or cyclic. h is an integer of 1 to 3.

[0269] Examples of the monomer providing a repeating unit containing an acid-labile group represented by the formula (AL-3) include (meth)acrylates having an exo-stereoisomer structure represented by the following formula (AL-3)-22.

[0270] [Chemistry 72]

[0271]

[0272] In formula (AL-3)-22, R A Same as above. Lc1 It is a saturated hydrocarbon group having 1 to 8 carbon atoms or an aryl group having 6 to 20 carbon atoms which may be substituted. The saturated hydrocarbon group may be linear, branched or cyclic. Lc2 ~R Lc11 Each of them is independently a hydrogen atom or a hydrocarbon group having 1 to 15 carbon atoms which may contain a hetero atom. Examples of the hetero atom include an oxygen atom. Examples of the hydrocarbon group include an alkyl group having 1 to 15 carbon atoms and an aryl group having 6 to 15 carbon atoms. Lc2 With R Lc3 , R Lc4 With R Lc6 , R Lc4 With R Lc7 , R Lc5 With R Lc7 , R Lc5 With R Lc11 , R Lc6 With R Lc10 , R Lc8 With R Lc9 , or R Lc9 With R Lc10 They may also bond to each other and form a ring together with the carbon atoms to which they are bonded. In this case, the group involved in the bond is an alkylene group having 1 to 15 carbon atoms and may also contain heteroatoms. Lc2 With R Lc11 , R Lc8 With R Lc11 , or R Lc4 With R Lc6 Those bonded to adjacent carbon atoms may be bonded to each other without any atoms in between to form a double bond. In addition, mirror image is also represented by this formula.

[0273] Here, the monomer represented by formula (AL-3)-22 may be listed in Japanese Patent Application Publication No. 2000-327633. Specifically, the following monomers may be listed, but are not limited thereto. A Same as above.

[0274] [Chemistry 73]

[0275]

[0276] Examples of the monomer providing a repeating unit containing an acid-labile group represented by the formula (AL-3) include (meth)acrylates containing a furandiyl group, a tetrahydrofurandiyl group or an oxanorbornanediyl group represented by the following formula (AL-3)-23.

[0277] [Chemistry 74]

[0278]

[0279] In formula (AL-3)-23, R A Same as above. Lc12 and R Lc13 R are each independently a hydrocarbon group having 1 to 10 carbon atoms. Lc12 With R Lc13 They can also bond to each other and to the carbon atoms to which they are bonded to form aliphatic rings. Lc14 R is furandiyl, tetrahydrofurandiyl or oxanorbornanediyl. Lc15 It is a hydrocarbon group having 1 to 10 carbon atoms which may contain a hydrogen atom or a hetero atom. The hydrocarbon group may be linear, branched or cyclic. Specific examples thereof include saturated hydrocarbon groups having 1 to 10 carbon atoms.

[0280] The monomers represented by formula (AL-3)-23 include, but are not limited to, the following. A As mentioned above, Ac is acetyl and Me is methyl.

[0281] [Chemistry 75]

[0282]

[0283] [Chemistry 76]

[0284]

[0285] The aforementioned base polymer may further contain a repeating unit c having an adhesive group selected from a hydroxyl group, a carboxyl group, a lactone ring, a carbonate bond, a thiocarbonate bond, a carbonyl group, a cyclic acetal group, an ether bond, an ester bond, a sulfonate bond, a cyano group, an amide bond, -OC(=O)-S- and -OC(=O)-NH-.

[0286] The monomers providing the repeating unit c include, but are not limited to, the following. A Same as above.

[0287] [Chemistry 77]

[0288]

[0289] [Chemistry 78]

[0290]

[0291] [Chemistry 79]

[0292]

[0293] [Chemistry 80]

[0294]

[0295] [Chemistry 81]

[0296]

[0297] [Chemistry 82]

[0298]

[0299] [Chemistry 83]

[0300]

[0301] [Chemistry 84]

[0302]

[0303] [Chemistry 85]

[0304]

[0305] [Chemistry 86]

[0306]

[0307] The above-mentioned base polymer may also contain at least one selected from the repeating unit represented by the following formula (d1) (hereinafter also referred to as repeating unit d1), the repeating unit represented by the following formula (d2) (hereinafter also referred to as repeating unit d2) and the repeating unit represented by the following formula (d3) (hereinafter also referred to as repeating unit d3).

[0308] [Chemistry 87]

[0309]

[0310] In formulas (d1) to (d3), 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-, -Z 31 -O- or -Z 31 -OC(=O)-. Z 31 It is an aliphatic 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 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 hydroxyl group, or a halogen atom. 1 , Z 11 , Z 31 and Z 51 The aliphatic hydrocarbylene group represented by may be saturated or unsaturated, and may be linear, branched, or cyclic.

[0311] In formulas (d1) to (d3), R 21 ~R 28 Each is independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom. Examples of the halogen atom include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc. The hydrocarbon group may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Specific examples thereof include those exemplified as R in the description of formula (a): 4 ~R 6 The same examples are given for the hydrocarbon groups represented.

[0312] Furthermore, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and part of the -CH2- of the aforementioned hydrocarbon group 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, etc. 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 (a). 4 and R 5 The same example is true of the rings that can be formed when they are bonded to the sulfur atoms to which they are bonded.

[0313] In formula (d1), M - It is a non-nucleophilic counter ion. Examples of the non-nucleophilic counter ion include halide ions such as chloride ion and bromide ion, fluoroalkylsulfonate ions such as trifluoromethanesulfonate ion, 1,1,1-trifluoroethanesulfonate ion and nonafluorobutanesulfonate ion, arylsulfonate ions such as toluenesulfonate ion, benzenesulfonate ion, 4-fluorobenzenesulfonate ion and 1,2,3,4,5-pentafluorobenzenesulfonate ion, alkylsulfonate 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 methide ions such as tris(trifluoromethylsulfonyl)methide ion and tris(perfluoroethylsulfonyl)methide ion.

[0314] The non-nucleophilic counter ion further includes a sulfonate ion represented by the following formula (d1-1) in which the α-position is substituted with a fluorine atom, and a sulfonate ion represented by the following formula (d1-2) in which the α-position is substituted with a fluorine atom and the β-position is substituted with a trifluoromethyl group.

[0315] [Chemistry 88]

[0316]

[0317] In formula (d1-1), 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 those exemplified below as R in formula (1A'): fa1 The same examples are given for the hydrocarbon groups represented.

[0318] In formula (d1-2), R 32 is a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or a hydrocarbon carbonyl group having 2 to 30 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 straight chain, branched, or cyclic. Specific examples thereof include those exemplified below as R in formula (1A'): fa1 The same examples are given for the hydrocarbon groups represented.

[0319] The cation of the monomer providing the repeating unit d1 may be exemplified by the following, but is not limited thereto. A and M - Same as above.

[0320] [Chemistry 89]

[0321]

[0322] Specific examples of the sulfonium cation in the repeating units d2 and d3 include the same examples as those exemplified as the sulfonium cation in the repeating unit a.

[0323] The anion of the monomer providing the repeating unit d2 may be exemplified by the following, but is not limited thereto. A Same as above.

[0324] [Chemistry 90]

[0325]

[0326] [Chemistry 91]

[0327]

[0328] [Chemistry 92]

[0329]

[0330] [Chemistry 93]

[0331]

[0332] [Chemistry 94]

[0333]

[0334] [Chemistry 95]

[0335]

[0336] [Chemistry 96]

[0337]

[0338] [Chemistry 97]

[0339]

[0340] [Chemistry 98]

[0341]

[0342] [Chemistry 99]

[0343]

[0344] [Chemical 100]

[0345]

[0346] [Chemistry 101]

[0347]

[0348] [Chemistry 102]

[0349]

[0350] The anion of the monomer providing the repeating unit d3 may be exemplified by the following, but is not limited thereto. A Same as above.

[0351] [Chemistry 103]

[0352]

[0353] Repeating units d1 to d3 function as acid generators. By bonding the acid generator to the polymer main chain, the acid diffusion can be reduced, and the reduction in resolution caused by the blurring of the acid diffusion can be prevented. In addition, the acid generator improves LWR and CDU by being evenly dispersed. In addition, when a base polymer containing repeating units d1 to d3 (i.e., a polymer-bonded acid generator) is used, the blending of the additive acid generator described later can be omitted.

[0354] By including the repeating unit a having the function of a quencher and the repeating units d1 to d3 having the function of an acid generator in the same polymer, all functions are contained in one polymer. In this case, when the materials added to the resist material are only organic solvents and surfactants in addition to the polymer, there is an advantage of high productivity because it is a simple material composition.

[0355] The polymerization rate of the monomer providing the repeating unit a and the polymerization rates of the monomers providing the repeating units d1 to d3 are of the same degree. Therefore, the quencher and the acid generator will be uniformly present in the polymer, thereby improving LWR and CDU. When the anion of the acid generator has an iodine atom, due to the improvement in the contrast during acid generation caused by the increase in the number of photons absorbed, LWR and CDU will be further improved.

[0356] The aforementioned base polymer may further contain a repeating unit e that does not contain an amino group but contains an iodine atom. Examples of the monomer providing the repeating unit e include, but are not limited to, those shown below. In addition, in the following formula, R A is the same as the above.

[0357] [Chemical formula 104]

[0358]

[0359] [Chemical formula 105]

[0360]

[0361] The aforementioned base polymer may also contain a repeating unit f other than the aforementioned repeating units. Examples of the repeating unit f include those derived from styrene, vinylnaphthalene, indene, acenaphthene, coumarin, coumarone, etc.

[0362] In the aforementioned base polymer, the content ratios of the repeating units a, b1, b2, c, d1, d2, d3, e, and f should be 0 < a < 1.0, 0 ≤ b1 ≤ 0.9, 0 ≤ b2 ≤ 0.9, 0 < b1 + b2 ≤ 0.9, 0 ≤ c ≤ 0.9, 0 ≤ d1 ≤ 0.5, 0 ≤ d2 ≤ 0.5, 0 ≤ d3 ≤ 0.5, 0 ≤ d1 + d2 + d3 ≤ 0.5, 0 ≤ e ≤ 0.5, and 0 ≤ f ≤ 0.5. It is better to be 0.001 ≤ a ≤ 0.8, 0 ≤ b1 ≤ 0.8, 0 ≤ b2 ≤ 0.8, 0.1 ≤ b1 + b2 ≤ 0.8, 0 ≤ c ≤ 0.8, 0 ≤ d1 ≤ 0.4, 0 ≤ d2 ≤ 0.4, 0 ≤ d3 ≤ 0.4, 0 ≤ d1 + d2 + d3 ≤ 0.4, 0 ≤ e ≤ 0.4, and 0 ≤ f ≤ 0.4. It is even better to be 0.005 ≤ a ≤ 0.7, 0 ≤ b1 ≤ 0.7, 0 ≤ b2 ≤ 0.7, 0.1 ≤ b1 + b2 ≤ 0.7, 0 ≤ c ≤ 0.7, 0 ≤ d1 ≤ 0.3, 0 ≤ d2 ≤ 0.3, 0 ≤ d3 ≤ 0.3, 0 ≤ d1 + d2 + d3 ≤ 0.3, 0 ≤ e ≤ 0.3, and 0 ≤ f ≤ 0.3. However, a + b1 + b2 + c + d1 + d2 + d3 + e + f = 1.0.

[0363] When synthesizing the aforementioned base polymer, for example, the monomers providing the aforementioned repeating units can be added with a radical polymerization initiator in an organic solvent and heated to carry out polymerization.

[0364] Examples of organic solvents used in the polymerization include toluene, benzene, tetrahydrofuran (THF), diethyl ether, dioxane, propylene glycol monomethyl ether, γ-butyrolactone, and mixed solvents thereof. 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, and the like. The polymerization temperature is preferably 50 to 80°C. The reaction time is preferably 2 to 100 hours, more preferably 5 to 20 hours.

[0365] 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.

[0366] 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.

[0367] 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.

[0368] 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 1000 to 500000, more preferably 2000 to 30000. When Mw is within the above range, the heat resistance and solubility in an alkaline developer of the resist film are good.

[0369] In addition, when the molecular weight distribution (Mw / Mn) of the base polymer is relatively broad, there are concerns that foreign matter may be observed on the pattern after exposure, the shape of the pattern may deteriorate, etc., due to the presence of low molecular weight and high molecular weight polymers. 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 suitable for fine pattern sizes, 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.

[0370] 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.

[0371] The base polymer may contain two or more polymers having different composition ratios, Mw, and Mw / Mn. In addition, a polymer containing repeating unit a and a polymer not containing repeating unit a may be mixed.

[0372] [Acid generator]

[0373] The resist material of the present invention may contain an acid generator that generates a strong acid (hereinafter also referred to as an additive acid generator). The 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.

[0374] 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.

[0375] Furthermore, as the photoacid generator, a sulfonium salt represented by the following formula (1-1) or an iodonium salt represented by the following formula (1-2) can also be preferably used.

[0376] [Chemistry 106]

[0377]

[0378] In formula (1-1) and (1-2), R 101 ~R 105 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 (a) as R 4 ~R 6The 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 (a): 4 and R 5 The same example is true of the rings that can be formed when they are bonded to the sulfur atoms to which they are bonded.

[0379] Examples of the cation of the sulfonium salt represented by the formula (1-1) include the same examples as those exemplified as the cation of the repeating unit a.

[0380] Examples of the cation of the iodonium salt represented by the formula (1-2) include the following, but are not limited thereto.

[0381] [Chemistry 107]

[0382]

[0383] [Chemistry 108]

[0384]

[0385] In formula (1-1) and (1-2), Xa - is an anion selected from the following formulae (1A) to (1D).

[0386] [Chemistry 109]

[0387]

[0388] In formula (1A), 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 linear, branched, or cyclic. Specific examples thereof include those exemplified below as R in formula (1A'): fa1 The same examples are given for the hydrocarbon groups represented.

[0389] The anion represented by the formula (1A) is preferably represented by the following formula (1A').

[0390] [Chemistry 110]

[0391]

[0392] In formula (1A'), 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 high resolution in fine pattern formation.

[0393] 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.

[0394] 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.

[0395] For details on the synthesis of sulfonium salts containing anions represented by formula (1A'), 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.

[0396] Examples of the anion represented by formula (1A) include the same examples as those exemplified as the anion represented by formula (1A) in JP-A-2018-197853.

[0397] In formula (1B), R fb1 and Rfb2 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.

[0398] In formula (1C), 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.

[0399] In formula (1D), 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: fa1 The same examples are given for the hydrocarbon groups represented.

[0400] The synthesis of the sulfonium salt of the anion represented by the formula (1D) is detailed in Japanese Unexamined Patent Publication Nos. 2010-215608 and 2014-133723.

[0401] Examples of the anion represented by the formula (1D) include the same examples as those exemplified as the anion represented by the formula (1D) in JP-A-2018-197853.

[0402] In addition, the photoacid generator containing the anion represented by formula (1D) 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.

[0403] As the photoacid generator, a photoacid generator represented by the following formula (2) can also be preferably used.

[0404] [Chemistry 111]

[0405]

[0406] In formula (2), 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 aforementioned ring may be exemplified as R in the description of formula (a): 4 and R 5 The same example is true of the rings that can be formed when they are bonded to the sulfur atoms to which they are bonded.

[0407] 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, isobutyl, 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, 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.

[0408] 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.

[0409] In formula (2), L Cis 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 .

[0410] In formula (2), 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.

[0411] In formula (2), k is an integer from 0 to 3.

[0412] The photoacid generator represented by the formula (2) is preferably represented by the following formula (2').

[0413] [Chemistry 112]

[0414]

[0415] In formula (2'), L C 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 shown as R in formula (1A'): 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.

[0416] Examples of the photo-acid generator represented by formula (2) include the same examples as those exemplified as the photo-acid generator represented by formula (2) in JP-A-2017-026980.

[0417] Among the above-mentioned photoacid generators, those containing anions represented by formula (1A') or (1D) are particularly preferred because they have low acid diffusion and excellent solubility in solvents. Those represented by formula (2') are particularly preferred because they have extremely low acid diffusion.

[0418] 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 (3-1) or (3-2).

[0419] [Chemistry 113]

[0420]

[0421] In formula (3-1) and (3-2), 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.

[0422] In formula (3-1) and (3-2), 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.

[0423] In formula (3-1) and (3-2), 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.

[0424] In formula (3-1) and (3-2), 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.

[0425] In formula (3-1) and (3-2), 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.

[0426] 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.

[0427] In formula (3-1) and (3-2), 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.

[0428] In formula (3-1) and (3-2), 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 (a) 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 groups, sulfonyl groups or groups containing sulfonium salts, and part of -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 (a): 4 and R 5 The same example is true of the rings that can be formed when they are bonded to the sulfur atoms to which they are bonded.

[0429] Specific examples of the cation of the sulfonium salt represented by formula (3-1) include the same examples as those exemplified as the cation of the repeating unit a. Specific examples of the cation of the iodonium salt represented by formula (3-2) include the same examples as those exemplified as the cation of the iodonium salt represented by formula (1-2).

[0430] The anion of the onium salt represented by formula (3-1) or (3-2) may be exemplified by the following, but is not limited thereto. BI Same as above.

[0431] [Chemistry 114]

[0432]

[0433] [Chemistry 115]

[0434]

[0435] [Chemistry 116]

[0436]

[0437] [Chemistry 117]

[0438]

[0439] [Chemistry 118]

[0440]

[0441] [Chemistry 119]

[0442]

[0443] [Chemistry 120]

[0444]

[0445] [Chemistry 121]

[0446]

[0447] [Chemistry 122]

[0448]

[0449] [Chemistry 123]

[0450]

[0451] [Chemistry 124]

[0452]

[0453] [Chemistry 125]

[0454]

[0455] [Chemistry 126]

[0456]

[0457] [Chemistry 127]

[0458]

[0459] [Chemistry 128]

[0460]

[0461] [Chemistry 129]

[0462]

[0463] [Chemistry 130]

[0464]

[0465] [Chemistry 131]

[0466]

[0467] [Chemistry 132]

[0468]

[0469] [Chemistry 133]

[0470]

[0471] [Chemistry 134]

[0472]

[0473] [Chemistry 135]

[0474]

[0475] [Chemistry 136]

[0476]

[0477] The photoacid generator may be a sulfonium salt or iodonium salt containing a sulfonic acid anion having an iodine atom as described in Japanese Patent Application Laid-Open No. 2018-159744.

[0478] When the resist material of the present invention contains an additive acid generator, its content is preferably 0.1 to 50 parts by mass, and more preferably 1 to 40 parts by mass, relative to 100 parts by mass of the base polymer. The aforementioned additive acid generator may be used alone or in combination of two or more. The aforementioned base polymer contains repeating units d1 to d3 and / or contains an additive acid generator, and the resist material of the present invention can function as a chemically amplified resist material.

[0479] [Organic solvents]

[0480] 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.

[0481] 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.

[0482] [Other ingredients]

[0483] The resist material of the present invention may contain, in addition to the above-mentioned components, a surfactant, a dissolution inhibitor, a quencher, a water repellency improver, acetylene alcohols, and the like.

[0484] 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.

[0485] By blending a dissolution inhibitor into the resist material of the present invention, the difference in dissolution rate between the exposed part and the unexposed part can be further increased, and the resolution can be further improved. The dissolution inhibitor may be a compound having a molecular weight of preferably 100 to 1,000 and more preferably 150 to 800, wherein the hydrogen atom of the phenolic hydroxyl group in the compound containing two or more phenolic hydroxyl groups in the molecule is replaced by an acid-labile group at a ratio of 0 to 100 mol % overall, or a compound containing a carboxyl group in the compound containing a carboxyl group in the molecule is replaced by an acid-labile group at an average ratio of 50 to 100 mol % overall. Specifically, the compounds may be bisphenol A, trisphenol, phenolphthalein, cresol novolac resin, naphthalenecarboxylic acid, adamantanecarboxylic acid, and bile acid hydroxyl group, carboxyl group hydrogen atom replaced by an acid-labile group, etc., such as those described in paragraphs

[0155] to

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

[0486] When the resist material of the present invention contains the dissolution inhibitor, the content thereof is preferably 0 to 50 parts by mass, more preferably 5 to 40 parts by mass, based on 100 parts by mass of the base polymer. The dissolution inhibitor may be used alone or in combination of two or more.

[0487] The resist material of the present invention may also be blended with a quencher (hereinafter referred to as an additive quencher). Examples of the additive quencher include known basic compounds. Examples of known basic compounds include primary, secondary, and 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, and carbamates. In particular, the primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Application Laid-Open No. 2008-111103 are preferred, and amine compounds having a hydroxyl group, an ether bond, an ester bond, a lactone ring, a cyano group, or a sulfonate bond, or compounds having a carbamate group described in Japanese Patent No. 3790649 are particularly preferred. By adding such a basic compound, for example, the diffusion rate of the acid in the resist film can be further suppressed or the shape can be corrected.

[0488] In addition, examples of the additive quencher 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 carboxylic acid esters, 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.

[0489] The aforementioned additive quencher may further include a polymer quencher described in Japanese Patent Application Publication No. 2008-239918. The polymer quencher improves the rectangularity of the resist after patterning by being oriented on the resist surface after coating. The polymer quencher also has the function of preventing film loss and doming of the pattern when using a protective film for immersion exposure.

[0490] When the resist material of the present invention contains the additive quencher, the content thereof is preferably 0 to 5 parts by mass, more preferably 0 to 4 parts by mass, relative to 100 parts by mass of the base polymer. The additive quencher may be used alone or in combination of two or more.

[0491] The aforementioned water repellency improver is a polymer 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 by 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 to prevent the poor opening of the hole pattern after development. The water repellency improver can be used alone or in combination of two or more. 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.

[0492] The aforementioned 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 acetylene alcohols, the content thereof is preferably 0 to 5 parts by mass relative to 100 parts by mass of the base polymer. The aforementioned acetylene alcohols may be used alone or in combination of two or more.

[0493] [Pattern Formation Method]

[0494] 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:

[0495] Using the aforementioned resist material to form a resist film on a substrate,

[0496] exposing the resist film to high energy radiation, and

[0497] The exposed resist film is developed using a developer.

[0498] 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.

[0499] 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 EB is used as the high energy ray, the exposure dose is preferably about 0.1 to 100 μC / cm 2 More preferably, it is about 0.5 to 50 μC / cm 2 The resist material of the present invention is particularly suitable for fine patterning by i-rays with a wavelength of 365 nm among high-energy rays, KrF excimer lasers, ArF excimer lasers, EB, EUV, X-rays, soft X-rays, gamma rays, and synchrotron radiation, and is particularly suitable for fine patterning by EB or EUV.

[0500] After the exposure, PEB may be performed on a hot plate preferably at 50 to 150° C. for 10 seconds to 30 minutes, more preferably at 60 to 120° C. for 30 seconds to 20 minutes.

[0501] After exposure or PEB, an alkaline aqueous solution of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide (TBAH), etc., preferably in an amount of 0.1 to 10% by mass and more preferably 2 to 5% by mass, is used to develop the exposed resist film by a common method such as a dip method, a puddle method, or a spray method for 3 seconds to 3 minutes and preferably 5 seconds to 2 minutes, thereby dissolving the light-irradiated portion in the developer and not dissolving the unexposed portion, thereby forming a desired positive pattern on the substrate.

[0502] It is also possible to use a resist material containing a base polymer containing an acid-labile group and develop with an organic solvent to obtain a negative pattern. 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.

[0503] When the development is finished, 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.

[0504] 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.

[0505] 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.

[0506] 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.

[0507] Examples of the aromatic solvent include toluene, xylene, ethylbenzene, cumene, tert-butylbenzene, and mesitylene.

[0508] 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.

[0509] 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.

[0510] [Example]

[0511] 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.

[0512] The structures of the quencher monomers QM-1 to QM-12 and RQM-1 to RQM-2 used in the resist material are shown below.

[0513] [Chemistry 137]

[0514]

[0515] [Chemistry 138]

[0516]

[0517] [Chemistry 139]

[0518]

[0519] [Synthesis of polymer]

[0520] The monomers PM-1 to PM-6 and the monomer ALG-1 used for the synthesis of the polymer are as follows: The Mw of the polymer is a polystyrene-equivalent value measured by GPC using THF as a solvent.

[0521] [Chemistry 140]

[0522]

[0523] [Chemistry 141]

[0524]

[0525] [Synthesis Example 1] Synthesis of Polymer P-1

[0526] In a 2L flask, add 3.1g of QM-1, 8.4g of 1-methyl-1-cyclopentyl methacrylate, 5.4g of 4-hydroxystyrene, and 40g of THF as a solvent. Cool the reaction container to -70°C under a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing three times. After warming to room temperature, add 1.2g of AIBN as a polymerization initiator, raise the temperature to 60°C, and react for 15 hours. Add the reaction solution to 1L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60°C to obtain polymer P-1. The composition of polymer P-1 is utilized 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0527] [Chemistry 142]

[0528]

[0529] [Synthesis Example 2] Synthesis of Polymer P-2

[0530] In a 2L flask, add 3.4g of QM-2, 7.3g of 1-methyl-1-cyclohexyl methacrylate, 4.8g of 4-hydroxystyrene, 11.0g of PAG monomer 2, and 40g of THF as a solvent. Cool the reaction container to -70°C under a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing 3 times. After heating to room temperature, add 1.2g of AIBN as a polymerization initiator, raise the temperature to 60°C, and react for 15 hours. Add the reaction solution to 1L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60°C to obtain polymer P-2. The composition of polymer P-2 is obtained by 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0531] [Chemistry 143]

[0532]

[0533] [Synthesis Example 3] Synthesis of Polymer P-3

[0534] In a 2L flask, add 3.2g of QM-3, 8.4g of 1-methyl-1-cyclopentyl methacrylate, 3.6g of 4-hydroxystyrene, 11.9g of PAG monomer 1, and 40g of THF as a solvent. Cool the reaction container to -70°C under a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing 3 times. After warming to room temperature, add 1.2g of AIBN as a polymerization initiator, raise the temperature to 60°C, and react for 15 hours. Add the reaction solution to 1L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60°C to obtain polymer P-3. The composition of polymer P-3 is utilized 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0535] [Chemistry 144]

[0536]

[0537] [Synthesis Example 4] Synthesis of Polymer P-4

[0538] In a 2L flask, add 4.4g of QM-4, 8.4g of 1-methyl-1-cyclopentyl methacrylate, 3.6g of 3-hydroxystyrene, 11.0g of PAG monomer 2, and 40g of THF as a solvent. Cool the reaction container to -70°C under a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing three times. After heating to room temperature, add 1.2g of AIBN as a polymerization initiator, raise the temperature to 60°C, and react for 15 hours. Add the reaction solution to 1L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60°C to obtain polymer P-4. The composition of polymer P-4 is obtained by 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0539] [Chemistry 145]

[0540]

[0541] [Synthesis Example 5] Synthesis of Polymer P-5

[0542] In a 2L flask, add 3.8g of QM-5, 8.4g of 1-methyl-1-cyclopentyl methacrylate, 4.2g of 4-hydroxystyrene, 8.5g of PAG monomer 3, and 40g of THF as a solvent. Cool the reaction container to -70°C under a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing 3 times. After heating to room temperature, add 1.2g of AIBN as a polymerization initiator, raise the temperature to 60°C, and react for 15 hours. Add the reaction solution to 1L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60°C to obtain polymer P-5. The composition of polymer P-5 is utilized 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0543] [Chemistry 146]

[0544]

[0545] [Synthesis Example 6] Synthesis of Polymer P-6

[0546] In a 2L flask, add 3.7g of QM-6, 8.9g of ALG-1, 5.4g of 4-hydroxystyrene, 410.2g of PAG monomer, and 40g of THF as a solvent. Cool the reaction container to -70°C under a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing 3 times. After warming to room temperature, add 1.2g of AIBN as a polymerization initiator, raise the temperature to 60°C, and react for 15 hours. Add the reaction solution to 1L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60°C to obtain polymer P-6. The composition of polymer P-6 is obtained by 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0547] [Chemistry 147]

[0548]

[0549] [Synthesis Example 7] Synthesis of Polymer P-7

[0550] In a 2L flask, add 3.7g of QM-7, 8.4g of 1-methyl-1-cyclopentyl methacrylate, 4.8g of 4-hydroxystyrene, 55.5g of PAG monomer, and 40g of THF as a solvent. Cool the reaction container to -70°C under a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing 3 times. After heating to room temperature, add 1.2g of AIBN as a polymerization initiator, raise the temperature to 60°C, and react for 15 hours. Add the reaction solution to 1L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60°C to obtain polymer P-7. The composition of polymer P-7 is obtained by 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0551] [Chemistry 148]

[0552]

[0553] [Synthesis Example 8] Synthesis of Polymer P-8

[0554] In a 2L flask, add 4.3g of QM-8, 8.9g of ALG-1, 5.4g of 4-hydroxystyrene, 49.7g of PAG monomer, and 40g of THF as a solvent. Cool the reaction container to -70°C under a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing three times. After warming to room temperature, add 1.2g of AIBN as a polymerization initiator, raise the temperature to 60°C, and react for 15 hours. Add the reaction solution to 1L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60°C to obtain polymer P-8. The composition of polymer P-8 is obtained by 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0555] [Chemistry 149]

[0556]

[0557] [Synthesis Example 9] Synthesis of Polymer P-9

[0558] In a 2L flask, add 4.9g of QM-9, 8.4g of 1-methyl-1-cyclopentyl methacrylate, 4.2g of 4-hydroxystyrene, 9.4g of PAG monomer 6, and 40g of THF as a solvent. Cool the reaction container to -70°C under a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing three times. After warming to room temperature, add 1.2g of AIBN as a polymerization initiator, raise the temperature to 60°C, and react for 15 hours. Add the reaction solution to 1L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60°C to obtain polymer P-9. The composition of polymer P-9 is obtained by 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0559] [Chemistry 150]

[0560]

[0561] [Synthesis Example 10] Synthesis of Polymer P-10

[0562] In a 2L flask, add 3.7g of QM-10, 8.4g of 1-methyl-1-cyclopentyl methacrylate, 4.2g of 4-hydroxystyrene, 9.4g of PAG monomer 6, and 40g of THF as a solvent. Cool the reaction container to -70°C under a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing three times. After warming to room temperature, add 1.2g of AIBN as a polymerization initiator, raise the temperature to 60°C, and react for 15 hours. Add the reaction solution to 1L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60°C to obtain polymer P-10. The composition of polymer P-10 is obtained by 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0563] [Chemistry 151]

[0564]

[0565] [Synthesis Example 11] Synthesis of Polymer P-11

[0566] In a 2L flask, add 3.3g of QM-11, 8.4g of 1-methyl-1-cyclopentyl methacrylate, 4.2g of 3-hydroxystyrene, 9.4g of PAG monomer 6, and 40g of THF as a solvent. Cool the reaction container to -70°C under a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing 3 times. After heating to room temperature, add 1.2g of AIBN as a polymerization initiator, raise the temperature to 60°C, and react for 15 hours. Add the reaction solution to 1L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60°C to obtain polymer P-11. The composition of polymer P-11 is utilized 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0567] [Chemistry 152]

[0568]

[0569] [Synthesis Example 12] Synthesis of Polymer P-12

[0570] In a 2L flask, add 3.3g of QM-12, 8.4g of 1-methyl-1-cyclopentyl methacrylate, 4.2g of 3-hydroxystyrene, 9.4g of PAG monomer 6, and 40g of THF as a solvent. Cool the reaction container to -70°C under a nitrogen environment, and repeat the reduced pressure degassing and nitrogen blowing three times. After heating to room temperature, add 1.2g of AIBN as a polymerization initiator, raise the temperature to 60°C, and react for 15 hours. Add the reaction solution to 1L of isopropanol, and filter the precipitated white solid. The obtained white solid is dried under reduced pressure at 60°C to obtain polymer P-12. The composition of polymer P-12 is obtained by 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0571] [Chemistry 153]

[0572]

[0573] [Comparative Synthesis Example 1] Synthesis of Comparative Polymer cP-1

[0574] A comparative polymer cP-1 was obtained in the same manner as in Synthesis Example 1 except that RQM-1 was used instead of QM-1. 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0575] [Chemistry 154]

[0576]

[0577] [Comparative Synthesis Example 2] Synthesis of Comparative Polymer cP-2

[0578] A comparative polymer cP-2 was obtained in the same manner as in Synthesis Example 1 except that RQM-2 was used instead of QM-1. 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0579] [Chemistry 155]

[0580]

[0581] [Comparative Synthesis Example 3] Synthesis of Comparative Polymer cP-3

[0582] A comparative polymer cP-3 was obtained in the same manner as in Synthesis Example 1 except that QM-1 was not used. The composition of the comparative polymer cP-3 was 13 C-NMR and 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC.

[0583] [Chemistry 156]

[0584]

[0585] [Examples 1 to 13, Comparative Examples 1 to 3] Preparation and Evaluation of Resist Materials

[0586] (1) Preparation of resist materials

[0587] A solution prepared by dissolving the components shown in Tables 1 and 2 in a solvent containing 50 ppm of OMNOVA surfactant PolyFox PF-636 was filtered through a 0.2 μm filter to prepare a resist material.

[0588] In Tables 1 and 2, the components are as follows.

[0589] Organic solvent: PGMEA (propylene glycol monomethyl ether acetate)

[0590] DAA (Diacetone Alcohol)

[0591] EL(ethyl lactate)

[0592] Acid generator: PAG-1

[0593] [Chemistry 157]

[0594]

[0595] Quencher: PDQ-1

[0596] [Chemistry 158]

[0597]

[0598] (2) EUV lithography evaluation

[0599] Each resist material shown in Tables 1 and 2 was spin-coated on a Si substrate on which a silicon-containing spin-coated hard mask SHB-A940 (containing 43% by mass of silicon) was formed with a film thickness of 20 nm, and pre-baked at 105° C. for 60 seconds using a hot plate to obtain a resist film with a film thickness of 50 nm. This was exposed using an EUV scanning exposure machine NXE3400 manufactured by ASML (NA 0.33, σ 0.9 / 0.6, quadrupole illumination, a mask with a hole pattern having a size of 46 nm pitch and +20% offset on the wafer), and PEB was performed on a hot plate at the temperature described in Tables 1 and 2 for 60 seconds, and then developed with a 2.38% by mass TMAH aqueous solution for 30 seconds to obtain a hole pattern having a size of 23 nm.

[0600] The exposure amount when the hole size is formed at 23nm is measured and defined as sensitivity. In addition, the size of 50 holes is measured using a length measurement SEM (CG6300) manufactured by Hitachi, Ltd., and the 3-fold value (3σ) of the standard deviation (σ) obtained from the result is calculated and defined as CDU. The results are combined and recorded in Tables 1 and 2.

[0601] [Table 1]

[0602]

[0603]

[0604] [Table 2]

[0605]

[0606] The results shown in Tables 1 and 2 show that the resist material of the present invention containing a base polymer having a sulfonium salt structure in which trifluoromethoxybenzenesulfonamide anion, difluoromethoxybenzenesulfonamide anion, trifluoromethoxybenzenesulfonimide anion or difluoromethoxybenzenesulfonimide anion is bonded to the main chain has high sensitivity and improved CDU.

Claims

1. A resist material comprising: The base polymer has a sulfonium salt structure in which a trifluoromethoxybenzenesulfonamide anion, a difluoromethoxybenzenesulfonamide anion, a trifluoromethoxybenzenesulfonimide anion or a difluoromethoxybenzenesulfonimide anion is bonded to the main chain.

2. The resist material according to claim 1, wherein The base polymer contains a repeating unit a represented by the following formula (a); 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; R A is a hydrogen atom or a methyl group; X 1 It is a single bond, an ester bond, or an amide bond; X 2 is a single bond, a carbonyl group, a sulfonyl group or an ester bond; R 1 is trifluoromethyl or difluoromethyl; R 2 is a hydrogen atom, 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 nitro group, a cyano group or a halogen atom; R 3 is a single bond or a hydrocarbylene group having 1 to 16 carbon atoms, and the hydrocarbylene group may contain at least one selected from an oxygen 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.

3. The resist material according to claim 1, wherein The base polymer further contains a repeating unit b in which the hydrogen atom of the carboxyl group or the phenolic hydroxyl group is substituted with an acid-labile group.

4. The resist material according to claim 3, wherein The repeating unit b is at least one selected from the repeating unit b1 represented by the following formula (b1) and the repeating unit b2 represented by the following formula (b2); 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, an ester bond or an amide bond; Y 3 is a single bond, an ether bond or an ester bond; R 11 and R 12 It is 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.

5. The resist material according to claim 1, wherein The base polymer further contains a repeating unit c having an adhesive group selected from a hydroxyl group, a carboxyl group, a lactone ring, a carbonate bond, a thiocarbonate bond, a carbonyl group, a cyclic acetal group, an ether bond, an ester bond, a sulfonate bond, a cyano group, an amide bond, -OC(=O)-S- and -OC(=O)-NH-.

6. The resist material according to claim 1, wherein The base polymer further contains at least one selected from the group consisting of a repeating unit represented by the following formula (d1), a repeating unit represented by the following formula (d2), and a repeating unit represented by the following formula (d3); In the formula, R A are 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 An aliphatic 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 also 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 hydroxyl group or a halogen atom; 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.

7. The resist material according to claim 6, wherein Z 3 A group containing at least one iodine atom. The resist material according to claim 1 , further comprising an acid generator.

9. The resist material according to claim 1, further comprising an organic solvent.

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

12. 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 11, exposing the resist film to high energy radiation, and The exposed resist film is developed using a developer.

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

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