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 which can be either a positive type or a negative type, has high sensitivity, and has improved LWR and CDU; and a pattern forming method using the same. [Solution] A resist material containing an acid generator containing an onium salt represented by formula (1). # imgabs0 #

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 progressing rapidly. The popularization of 5G high-speed communication and artificial intelligence (AI) is in progress, and high-performance devices are needed 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 underway. Furthermore, the use of EUV lithography is also being explored in the next-generation 3nm node and the next-generation 2nm node devices, and IMEC in Belgium has announced the development of 1nm and 0.7nm devices.

[0003] As patterns become finer, the edge roughness (LWR) of line patterns and the dimensional uniformity (CDU) of hole patterns and dot patterns are considered to be problems. Some people criticize the uneven distribution and aggregation of base polymers and acid generators, and the influence of acid diffusion. In addition, as the thin film of the resist film becomes thinner, the LWR and CDU tend to increase. As the miniaturization progresses, the deterioration of LWR and CDU due to thin filming becomes a serious problem.

[0004] In EUV resist materials, high sensitivity, high resolution, and low LWR need to be achieved simultaneously. If the acid diffusion distance is shortened, LWR and CDU will increase, but sensitivity will decrease. For example, by lowering the post-exposure bake (PEB) temperature, LWR and CDU will increase, but sensitivity will decrease. Even if the amount of quencher added is increased, LWR and CDU will increase, but sensitivity will decrease. The trade-off between sensitivity and LWR needs to be broken.

[0005] Some people have proposed resist materials that add onium salts with anions containing iodine atoms or bromine atoms as acid generators (Patent Documents 1 to 5). By having iodine atoms with high EUV absorption and bromine atoms with high ionization efficiency, the efficiency of decomposition of the acid generator during exposure is improved, and the sensitivity is improved. The amount of photons absorbed increases, and the physical contrast can be improved.

[0006] Perfluoroalkyl compounds (PFAS) have been criticized for their health effects, and there are measures to set restrictions on the manufacture and sale of PFAS compounds in European REACH. In semiconductor lithography, many compounds containing PFAS are currently used. For example, materials containing PFAS are used in surfactants, acid generators, etc.

[0007] Prior art literature

[0008] Patent Literature

[0009] [Patent Document 1] Japanese Patent Application Publication No. 2018-159744

[0010] [Patent Document 2] Japanese Patent Application Publication No. 2018-5224

[0011] [Patent Document 3] Japanese Patent Application Publication No. 2018-25789

[0012] [Patent Document 4] Japanese Patent Application Publication No. 2019-003175

[0013] [Patent Document 5] Japanese Patent Application Publication No. 2023-021084 Summary of the invention

[0014] [Problems to be solved by the invention]

[0015] There is a need for development of a resist material that has higher sensitivity than conventional resist materials and can improve the LWR of a line pattern and the CDU of a hole pattern.

[0016] In view of the above situation, the present invention aims to provide a resist material which can be positive or negative, has high sensitivity, and has improved LWR and CDU, and a pattern forming method using the same.

[0017] [Methods to solve the problem]

[0018] The inventors of the present application have made repeated and diligent studies to achieve the above-mentioned purpose and have found that by using a sulfonium salt or iodonium salt containing an aromatic sulfonate anion having an aromatic group substituted with a bromine atom or an iodine atom as an acid generator, a resist material having high sensitivity, improved LWR and CDU, high contrast, excellent resolution, and a wide operating margin can be obtained, thereby completing the present invention.

[0019] That is, the present invention provides the following resist material and pattern forming method.

[0020] 1. A resist material comprising an acid generator containing an onium salt represented by the following formula (1),

[0021] [Chemistry 1]

[0022]

[0023] In the formula, m is an integer of 1 to 5, n is an integer of 0 to 4, but 1≤m+n≤5, p is an integer of 1 to 3, when Ar is a (q+2)-valent group derived from benzene, q is an integer of 1 to 4, when Ar is a (q+2)-valent group derived from naphthalene, q is an integer of 1 to 6,

[0024] X BI is a bromine atom or an iodine atom,

[0025] Ar is a (q+2)-valent group derived from benzene or naphthalene,

[0026] X 1 and X 2 is a single bond, an ether bond, an ester bond, a sulfonate bond, an amide bond, a carbamate bond, a urea bond, a carbonate bond, or an alkane diyl group having 1 to 6 carbon atoms, wherein the alkane diyl group may also contain at least one selected from an ether bond and an ester bond, but p=1, X BI When X is an iodine atom and Ar is a (q+2)-valent group derived from benzene, 1 Not *-C(=O)-O-; p=1, X BI is an iodine atom, X 1 and R 2 When X is a single bond and Ar is a (q+2)-valent group derived from benzene, 2 Not *-C(=O)-O-; p=1, X 2 and R 2 When X is a single bond and Ar is a (q+2)-valent group derived from benzene, 1 Not -OC(=O)-** and carbonate bond; p=1, X 1 When X is a single bond and Ar is a (q+2)-valent group derived from benzene, 2 It is not -OC(=O)-** and carbonate bond, * represents an atomic bond with the benzene ring in the formula, ** represents an atomic bond with Ar,

[0027] R 1 is a hydroxyl group, a carboxyl group, a fluorine atom, a chlorine atom, an amino group, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbonoxy group having 1 to 20 carbon atoms, a hydrocarbonoxycarbonyl group having 2 to 20 carbon atoms, a hydrocarboncarbonyloxy group having 2 to 20 carbon atoms, -N(R 1A )-C(=O)-R 1B 、-N(R 1A )-C(=O)-OR 1B or -N(R 1A )-S(=O)2-R 1B The hydrocarbon group, hydrocarbonoxy group, hydrocarbonoxycarbonyl group and hydrocarboncarbonyloxy group may also contain at least one selected from fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, hydroxyl groups, amino groups, ester bonds and ether bonds, R 1A is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms, the saturated hydrocarbon group 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, R 1B is an aliphatic hydrocarbon group having 1 to 16 carbon atoms or an aryl group having 6 to 12 carbon atoms, and may contain a halogen atom, a hydroxyl group, a saturated hydrocarbonoxy group having 1 to 6 carbon atoms, a saturated hydrocarboncarbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarboncarbonyloxy group having 2 to 6 carbon atoms,

[0028] R 2 is a single bond or a (p+1)-valent hydrocarbon group having 1 to 28 carbon atoms, and the hydrocarbon group may contain at least one atom selected from an oxygen atom, a nitrogen atom, a sulfur atom and a halogen atom,

[0029] R 3 is a fluorine atom, a trifluoromethoxy group, a nitro group, a saturated hydrocarbon group having 1 to 12 carbon atoms, or an aryl group having 6 to 10 carbon atoms,

[0030] M + It is a sulfonium cation or an iodonium cation.

[0031] 2. The resist material as in 1., wherein X 1 and X 2 is a group other than a single bond, and R 2 It is a group other than a single bond.

[0032] 3. The resist material as in 1. or 2., further comprising a base polymer.

[0033] 4. The resist material according to 3., wherein the base polymer comprises a repeating unit represented by the following formula (a1) or (a2),

[0034] [Chemistry 2]

[0035]

[0036] In the formula, R A are each independently a hydrogen atom or a methyl group,

[0037] 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,

[0038] Y 2 is a single bond or an ester bond,

[0039] Y 3 is a single bond, an ether bond or an ester bond,

[0040] R 11 and R 12 are each independently an acid-labile group,

[0041] R 13 is a saturated hydrocarbon group having 1 to 4 carbon atoms, a halogen atom, a saturated hydrocarbon carbonyl group having 2 to 5 carbon atoms, a cyano group, or a saturated hydrocarbon oxycarbonyl group having 2 to 5 carbon atoms,

[0042] R 14 is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the alkanediyl group may also contain an ether bond or an ester bond,

[0043] A is an integer from 0 to 4.

[0044] 5. The resist material as in 4. is a chemically amplified positive resist material.

[0045] 6. The resist material according to 3., wherein the base polymer does not contain an acid-labile group.

[0046] 7. The resist material as in 6. is a chemically amplified negative resist material.

[0047] 8. The resist material according to any one of 1. to 7., further comprising an organic solvent.

[0048] 9. The resist material according to any one of 1. to 8., further comprising a quencher.

[0049] 10. The resist material according to any one of 1. to 9., further comprising a surfactant.

[0050] 11. A pattern forming method comprising the following steps:

[0051] A resist film is formed on a substrate using the resist material according to any one of 1. to 10., the resist film is exposed to high-energy rays, and the exposed resist film is developed using a developer.

[0052] 12. The pattern forming method according to 11., wherein the high energy ray is ArF excimer laser with a wavelength of 193 nm, KrF excimer laser with a wavelength of 248 nm, electron beam (EB) or EUV with a wavelength of 3 to 15 nm.

[0053] [Effects of the Invention]

[0054] The resist film containing a sulfonium salt or iodonium salt containing an aromatic sulfonate anion having an aromatic group substituted with a bromine atom or an iodine atom as an acid generator has the characteristics of large absorption of EUV light and inhibiting acid diffusion. This can prevent the reduction of resolution due to blurring of acid diffusion, and can improve LWR and CDU. This makes it possible to construct a resist material with high sensitivity and improved LWR and CDU. DETAILED DESCRIPTION

[0055] [Resist material]

[0056] The resist material of the present invention comprises an acid generator containing a sulfonium salt or an iodonium salt containing an aromatic sulfonic acid anion having an aromatic group substituted with a bromine atom or an iodine atom. The absorption of iodine atoms, the ionization of bromine atoms and the barrier of aromatic acids make the salt have high contrast and low acid diffusion. This can improve LWR and CDU.

[0057] The effect of improving LWR and CDU obtained by the acid generator used in the present invention is effective in both positive and negative pattern formation by alkaline aqueous solution development and negative pattern formation by organic solvent development.

[0058] [Acid generator]

[0059] The acid generator used in the present invention comprises a sulfonium salt or iodonium salt containing an arylsulfonic acid anion represented by the following formula (1) having an aromatic group substituted with a bromine atom or an iodine atom.

[0060] [Chemistry 3]

[0061]

[0062] In formula (1), m is an integer of 1 to 5, and n is an integer of 0 to 4. However, 1≤m+n≤5. P is an integer of 1 to 3. When Ar is a (q+2)-valent group derived from benzene, q is an integer of 1 to 4, and when Ar is a (q+2)-valent group derived from naphthalene, q is an integer of 1 to 6.

[0063] In formula (1), X BI is a bromine atom or an iodine atom. When m is 2 or more, each X BI They can be the same or different.

[0064] In formula (1), Ar is a (q+2)-valent group derived from benzene or naphthalene. Specifically, it is a group obtained by removing (q+2) hydrogen atoms from benzene or naphthalene.

[0065] In formula (1), X 1 and X 2 is a single bond, an ether bond, an ester bond, a sulfonate bond, an amide bond, a carbamate bond, a urea bond, a carbonate bond, or an alkane diyl group having 1 to 6 carbon atoms, and the alkane diyl group may also contain at least one selected from an ether bond and an ester bond. However, p=1, X BI When X is an iodine atom and Ar is a (q+2)-valent group derived from benzene, 1 Not *-C(=O)-O-; p=1, X BI is an iodine atom, X 1 and R 2 When X is a single bond and Ar is a (q+2)-valent group derived from benzene, 2 Not *-C(=O)-O-; p=1, X 2 and R 2 When X is a single bond and Ar is a (q+2)-valent group derived from benzene, 1 Not -OC(=O)-** and carbonate bond; p=1, X 1 When X is a single bond and Ar is a (q+2)-valent group derived from benzene, 2It is not -OC(=O)-** and carbonate bond, * represents an atomic bond with the benzene ring in the formula, and ** represents an atomic bond with Ar. 1 and X 2 As for the group, it is preferably a group other than a single bond, and an ether bond, an ester bond, an amide bond, a carbamate bond, a urea bond, a carbonate bond, etc. are more preferred.

[0066] In formula (1), R 1 is a hydroxyl group, a carboxyl group, a fluorine atom, a chlorine atom, an amino group, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbonoxy group having 1 to 20 carbon atoms, a hydrocarbonoxycarbonyl group having 2 to 20 carbon atoms, a hydrocarboncarbonyloxy group having 2 to 20 carbon atoms, -N(R 1A )-C(=O)-R 1B 、-N(R 1A )-C(=O)-OR 1B or -N(R 1A )-S(=O)2-R 1B The hydrocarbon group, hydrocarbonoxy group, hydrocarbonoxycarbonyl group and hydrocarboncarbonyloxy group may also contain at least one selected from fluorine atom, chlorine atom, bromine atom, iodine atom, hydroxyl group, amino group, ester bond and ether bond. 1A R is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms, and the saturated hydrocarbon group 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. 1B is an aliphatic hydrocarbon group having 1 to 16 carbon atoms or an aryl group having 6 to 12 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. When n and / or p is 2 or more, each R 1 They can be the same or different.

[0067] R 1The hydrocarbon groups represented by and the hydrocarbon moieties of the hydrocarbonoxy, hydrocarbonoxycarbonyl and hydrocarboncarbonyloxy groups 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, dodecanyl, tridecyl, tetradecyl, pentadecyl, heptadecanyl, octadecyl, nonadecanyl and eicosyl; cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl and adamantyl; alkenyl groups having 2 to 20 carbon atoms, such as vinyl, propenyl, butenyl and hexenyl; Alkynyl groups having 2 to 20 carbon atoms, such as ethynyl, propynyl, and butynyl; cyclic unsaturated aliphatic hydrocarbon groups having 3 to 20 carbon atoms, such as cyclohexenyl and norbornenyl; aryl groups having 6 to 20 carbon atoms, such as phenyl, methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, sec-butylnaphthyl, and tert-butylnaphthyl; aralkyl groups having 7 to 20 carbon atoms, such as benzyl and phenethyl; and groups obtained by combining these.

[0068] In formula (1), R 2 It is a single bond or a (p+1)-valent hydrocarbon group having 1 to 28 carbon atoms, and the hydrocarbon group may also contain at least one selected from an oxygen atom, a nitrogen atom, a sulfur atom and a halogen atom. The aforementioned hydrocarbon group is a group obtained by separating (p+1) hydrogen atoms from a hydrocarbon having 1 to 28 carbon atoms. The aforementioned hydrocarbon may be saturated or unsaturated, and may be straight chain, branched or cyclic. Specific examples thereof include alkanes having 1 to 28 carbon atoms, such as methane, ethane, propane, butane, 2-methylpropane, pentane, 2-methylbutane, hexane, heptane, octane, nonane, decane, undecane, and dodecane; cyclic saturated hydrocarbons having 3 to 28 carbon atoms, such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, norbornane, and adamantane; olefins having 2 to 28 carbon atoms, such as ethylene, propylene, 1-butene, 2-butene, and 2-methylpropylene; cyclic unsaturated hydrocarbons having 3 to 28 carbon atoms, such as cyclohexene and norbornene; aromatic hydrocarbons having 6 to 28 carbon atoms, such as benzene, naphthalene, toluene, xylene, and anthracene; and compounds in which a part or all of their hydrogen atoms are substituted with hydrocarbon groups. 2 As for the group, it is preferably a group other than a single bond, and more preferably a group derived from an alkane, a cyclic saturated hydrocarbon which may contain an oxygen atom, or an aromatic hydrocarbon.

[0069] In formula (1), R 3 , is a fluorine atom, a trifluoromethoxy group, a nitro group, a saturated hydrocarbon group having 1 to 12 carbon atoms, or an aryl group having 6 to 10 carbon atoms. When q is 2 or more, each R 3 They can be the same or different.

[0070] Specific examples of the anion of the salt represented by formula (1) include those shown below, but are not limited to these.

[0071] [Chemistry 4]

[0072]

[0073] [Chemistry 5]

[0074]

[0075] [Chemistry 6]

[0076]

[0077] [Chemistry 7]

[0078]

[0079] [Chemistry 8]

[0080]

[0081] [Chemistry 9]

[0082]

[0083] [Chemistry 10]

[0084]

[0085] [Chemistry 11]

[0086]

[0087] [Chemistry 12]

[0088]

[0089] [Chemistry 13]

[0090]

[0091] [Chemistry 14]

[0092]

[0093] [Chemistry 15]

[0094]

[0095] [Chemistry 16]

[0096]

[0097] [Chemistry 17]

[0098]

[0099] [Chemistry 18]

[0100]

[0101] [Chemistry 19]

[0102]

[0103] [Chemistry 20]

[0104]

[0105] [Chemistry 21]

[0106]

[0107] [Chemistry 22]

[0108]

[0109] [Chemistry 23]

[0110]

[0111] [Chemistry 24]

[0112]

[0113] [Chemistry 25]

[0114]

[0115] [Chemistry 26]

[0116]

[0117] [Chemistry 27]

[0118]

[0119] [Chemistry 28]

[0120]

[0121] [Chemistry 29]

[0122]

[0123] [Chemistry 30]

[0124]

[0125] [Chemistry 31]

[0126]

[0127] [Chemistry 32]

[0128]

[0129] [Chemistry 33]

[0130]

[0131] [Chemistry 34]

[0132]

[0133] [Chemistry 35]

[0134]

[0135] [Chemistry 36]

[0136]

[0137] [Chemistry 37]

[0138]

[0139] [Chemistry 38]

[0140]

[0141] [Chemistry 39]

[0142]

[0143] [Chemistry 40]

[0144]

[0145] In formula (1), M + It is a sulfonium cation or an iodonium cation. The sulfonium cation is preferably represented by the following formula (2), and the iodonium cation is preferably represented by the following formula (3).

[0146] [Chemistry 41]

[0147]

[0148] In formula (2) and (3), R 4 ~R 8 Each is independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom.

[0149] Just R 4 ~R 8 Specific examples of the halogen atom represented by include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like.

[0150] R 4 ~R 8 The 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, dodecanyl, tridecyl, tetradecyl, pentadecyl, heptadecanyl, octadecyl, nonadecanyl, and eicosyl; cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; alkenyl groups having 2 to 20 carbon atoms, such as vinyl, propenyl, butenyl, and hexenyl; Alkynyl groups having 2 to 20 carbon atoms, such as ethynyl, propynyl, and butynyl; cyclic unsaturated aliphatic hydrocarbon groups having 3 to 20 carbon atoms, such as cyclohexenyl and norbornenyl; aryl groups having 6 to 20 carbon atoms, such as phenyl, methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, sec-butylnaphthyl, and tert-butylnaphthyl; aralkyl groups having 7 to 20 carbon atoms, such as benzyl and phenethyl; and groups obtained by combining these.

[0151] 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, resulting in 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.

[0152] Again, R 4 and R5 may be bonded to each other and form a ring together with the sulfur atom to which they are bonded. In this case, the ring is preferably a structure shown below.

[0153] [Chemistry 42]

[0154]

[0155] In the formula, the dotted lines represent atomic bonds.

[0156] Just M + Specific examples of the sulfonium cation represented by include those shown below, but are not limited to these.

[0157] [Chemistry 43]

[0158]

[0159] [Chemistry 44]

[0160]

[0161] [Chemistry 45]

[0162]

[0163] [Chemistry 46]

[0164]

[0165] [Chemistry 47]

[0166]

[0167] [Chemistry 48]

[0168]

[0169] [Chemistry 49]

[0170]

[0171] [Chemistry 50]

[0172]

[0173] [Chemistry 51]

[0174]

[0175] [Chemistry 52]

[0176]

[0177] [Chemistry 53]

[0178]

[0179] [Chemistry 54]

[0180]

[0181] [Chemistry 55]

[0182]

[0183] [Chemistry 56]

[0184]

[0185] [Chemistry 57]

[0186]

[0187] [Chemistry 58]

[0188]

[0189] [Chemistry 59]

[0190]

[0191] [Chemistry 60]

[0192]

[0193] [Chemistry 61]

[0194]

[0195] [Chemistry 62]

[0196]

[0197] [Chemistry 63]

[0198]

[0199] [Chemistry 64]

[0200]

[0201] [Chemistry 65]

[0202]

[0203] [Chemistry 66]

[0204]

[0205] [Chemistry 67]

[0206]

[0207] [Chemistry 68]

[0208]

[0209] [Chemistry 69]

[0210]

[0211] [Chemistry 70]

[0212]

[0213] [Chemistry 71]

[0214]

[0215] [Chemistry 72]

[0216]

[0217] [Chemistry 73]

[0218]

[0219] [Chemistry 74]

[0220]

[0221] [Chemistry 75]

[0222]

[0223] [Chemistry 76]

[0224]

[0225] [Chemistry 77]

[0226]

[0227] [Chemistry 78]

[0228]

[0229] Just M + Specific examples of the iodonium cation represented by include those shown below, but are not limited to these.

[0230] [Chemistry 79]

[0231]

[0232] [Chemistry 80]

[0233]

[0234] The synthesis method of the sulfonium salt and iodonium salt represented by formula (1) includes, for example, a method of salt-exchanging a sulfonium salt or iodonium salt containing a halogenated anion with an ammonium salt containing a sulfonic acid anion having an aromatic group substituted with a bromine atom or an iodine atom.

[0235] In the resist material of the present invention, the content of the sulfonium salt or iodonium salt represented by formula (1) is preferably 0.01 to 1000 parts by mass, more preferably 0.05 to 500 parts by mass, based on 100 parts by mass of the base polymer described below, from the viewpoint of sensitivity and acid diffusion inhibition effect.

[0236] [Base polymer]

[0237] The base polymer contained in the resist material of the present invention, when being a positive resist material, contains a repeating unit containing an acid-labile group. The repeating unit containing an acid-labile group is preferably a repeating unit represented by the following formula (a1) (hereinafter also referred to as repeating unit a1) or a repeating unit represented by formula (a2) (hereinafter also referred to as repeating unit a2).

[0238] [Chemistry 81]

[0239]

[0240] In formula (a1) and (a2), R A Each is independently a hydrogen atom or a methyl group. 1 Y is a single bond, a phenylene group or a naphthylene group, or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, an ether bond and a lactone ring. 2 is a single bond or an ester bond. 3 is a single bond, an ether bond or an ester bond. 11 and R 12 Each is independently an acid-labile group. 13 R is a saturated hydrocarbon group having 1 to 4 carbon atoms, a halogen atom, a saturated hydrocarbon carbonyl group having 2 to 5 carbon atoms, a cyano group, or a saturated hydrocarbon oxycarbonyl group having 2 to 5 carbon atoms. 14 is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the alkanediyl group may contain an ether bond or an ester bond. a is an integer of 0 to 4.

[0241] Specific examples of the monomer providing the repeating unit a1 include the following, but are not limited thereto. A and R 11 Same as above.

[0242] [Chemistry 82]

[0243]

[0244] [Chemistry 83]

[0245]

[0246] Specific examples of monomers providing repeating unit a2 include the following, but are not limited thereto. A and R 12 Same as above.

[0247] [Chemistry 84]

[0248]

[0249] For R in repeating units a1 and a2 11 and R 12Examples of the acid-labile group represented by include those described in JP-A-2013-80033 and JP-A-2013-83821.

[0250] Typically, specific examples of the acid-labile group include those represented by any one of the following formulae (AL-1) to (AL-3).

[0251] [Chemistry 85]

[0252]

[0253] In the formula, the dotted lines represent atomic bonds.

[0254] In formula (AL-1) and (AL-2), R L1 and R L2 Each is independently a hydrocarbon group having 1 to 40 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 linear, branched, or cyclic. As for the aforementioned hydrocarbon group, a saturated hydrocarbon group having 1 to 40 carbon atoms is preferred, and a saturated hydrocarbon group having 1 to 20 carbon atoms is more preferred.

[0255] In formula (AL-1), b is an integer of 0-10, preferably an integer of 1-5.

[0256] In formula (AL-2), R L3 and R L4 Each independently represents a hydrogen atom or 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 linear, branched, or cyclic. As for the aforementioned hydrocarbon group, it is preferably a saturated hydrocarbon group having 1 to 20 carbon atoms. In addition, R L2 , R L3 and R L4 Any two of them are bonded to each other and together with the carbon atom or the carbon atom and oxygen atom to which they are bonded form a ring having 3 to 20 carbon atoms. The aforementioned ring is preferably a ring having 4 to 16 carbon atoms, and an alicyclic ring is particularly preferred.

[0257] In formula (AL-3), R L5 , R L6 and R L7 Each 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 linear, branched, or cyclic. As for the aforementioned hydrocarbon group, it is preferably a saturated hydrocarbon group having 1 to 20 carbon atoms. In addition, R L5 , R L6 and R L7Any two of them are bonded to each other and together with the carbon atoms to which they are bonded form a ring having 3 to 20 carbon atoms. The aforementioned ring is preferably a ring having 4 to 16 carbon atoms, and an alicyclic ring is particularly preferred.

[0258] The base polymer may also include a repeating unit b containing a phenolic hydroxyl group as an adhesive group. Specific examples of monomers providing the repeating unit b include the following, but are not limited to these. A Same as above.

[0259] [Chemistry 86]

[0260]

[0261] The base polymer may also contain a repeating unit c containing a hydroxyl group other than a phenolic hydroxyl group, a lactone ring, a sultone ring, an ether bond, an ester bond, a sulfonate bond, a carbonyl group, a sulfonyl group, a cyano group or a carboxyl group as another adhesive group. Specific examples of monomers providing the repeating unit c include the following, but are not limited to these. In the following formula, R A Same as above.

[0262] [Chemistry 87]

[0263]

[0264] [Chemistry 88]

[0265]

[0266] [Chemistry 89]

[0267]

[0268] [Chemistry 90]

[0269]

[0270] [Chemistry 91]

[0271]

[0272] [Chemistry 92]

[0273]

[0274] [Chemistry 93]

[0275]

[0276] [Chemistry 94]

[0277]

[0278] The base polymer may also include a repeating unit d derived from indene, benzofuran, benzothiophene, acenaphthylene, chromone, coumarin, norbornadiene or a derivative thereof. Specific examples of the monomer providing the repeating unit d include the following, but are not limited thereto.

[0279] [Chemistry 95]

[0280]

[0281] The aforementioned base polymer may also include a repeating unit e derived from styrene, vinylnaphthalene, vinylanthracene, vinylpyrene, methylenedihydroindane, vinylpyridine or vinylcarbazole.

[0282] The base polymer may also contain repeating units f derived from an onium salt containing a polymerizable unsaturated bond. Japanese Patent Application Laid-Open No. 2005-84365 proposes sulfonium salts and iodonium salts of polymerizable olefins produced from specific sulfonic acids. Japanese Patent Application Laid-Open No. 2006-178317 proposes sulfonium salts in which sulfonic acid is directly bonded to the main chain.

[0283] As specific examples of preferred repeating units f, repeating units represented by the following formula (f1) (hereinafter also referred to as repeating units f1), repeating units represented by the following formula (f2) (hereinafter also referred to as repeating units f2), and repeating units represented by the following formula (f3) (hereinafter also referred to as repeating units f3). Furthermore, repeating units f1 to f3 may be used alone or in combination of two or more.

[0284] [Chemistry 96]

[0285]

[0286] In formulas (f1) to (f3), R A Each is 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 them, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. 2 It 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 31It 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 is methylene, 2,2,2-trifluoro-1,1-ethanediyl or carbonyl. 5 is a single bond, methylene, vinyl, 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.

[0287] In formulas (f1) to (f3), R 21 ~R 28 Each is independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. Specific examples of the halogen atom include fluorine atom, chlorine atom, bromine atom, iodine atom, etc. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include the same R as in the description of formulas (2) and (3). 4 ~R 8 The same as those exemplified for the hydrocarbon group represented by . In addition, 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 also 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. 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, specific examples of the aforementioned ring include the same R as in the description of formula (2). 4 and R 5 The same as those exemplified above are those which can be formed together with the sulfur atom to which they are bonded and with each other to form a ring.

[0288] In formula (f1), M -It is a non-nucleophilic counter ion. Specific examples of the non-nucleophilic counter ion include halogen ions such as chloride ion and bromide ion, fluoroalkanesulfonate 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, methide ions such as tris(trifluoromethylsulfonyl)methide ion and tris(perfluoroethylsulfonyl)methide ion.

[0289] Specific examples of the aforementioned non-nucleophilic relative ions include: sulfonate ions represented by the following formula (f1-1) in which the α-position is substituted with a fluorine atom, sulfonate ions represented by the following formula (f1-2) in which the α-position is substituted with a fluorine atom and the β-position is substituted with a trifluoromethyl group, etc.

[0290] [Chemistry 97]

[0291]

[0292]

[0293] In formula (f1-1), R 31 It is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. The hydrocarbon group may contain at least one selected from an ether bond, an ester bond, a carbonyl group, a lactone ring and a fluorine atom.

[0294] In formula (f1-2), R 32 It 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 may contain at least one selected from the group consisting of an ether bond, an ester bond, a carbonyl group, and a lactone ring.

[0295] R 31 or R 32 The hydrocarbon moiety of the hydrocarbon group and hydrocarbon carbonyl group represented by may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Specific examples thereof include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecanyl, and eicosyl; cyclic saturated hydrocarbon groups such as cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norbornyl, norbornylmethyl, tricyclodecanyl, tetracyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl; alkenyl groups such as allyl; cyclic unsaturated hydrocarbon groups such as 3-cyclohexenyl; aryl groups such as phenyl, 1-naphthyl, and 2-naphthyl; and aralkyl groups such as benzyl and diphenylmethyl.

[0296] Furthermore, part or all of the hydrogen atoms of these groups may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and part of the carbon atoms of these groups may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms, and as a result, hydroxyl groups, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate groups, lactone rings, sultone rings, carboxylic anhydrides, and haloalkyl groups may be included. Specific examples of heteroatom-containing hydrocarbon groups include tetrahydrofuranyl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetamidomethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, and 3-oxocyclohexyl.

[0297] Specific examples of the cation of the monomer providing the repeating unit f1 include those shown below, but are not limited to these. A Same as above.

[0298] [Chemistry 98]

[0299]

[0300] Specific examples of the cation of the monomer providing the repeating unit f2 or f3 include the same as M in the description of formula (1). + The sulfonium cations represented are the same as those exemplified above.

[0301] Specific examples of monomers providing repeating unit f2 include those shown below, but are not limited to these. A Same as above.

[0302] [Chemistry 99]

[0303]

[0304] [Chemical 100]

[0305]

[0306] [Chemistry 101]

[0307]

[0308] [Chemistry 102]

[0309]

[0310] [Chemistry 103]

[0311]

[0312] [Chemistry 104]

[0313]

[0314] [Chemistry 105]

[0315]

[0316] [Chemistry 106]

[0317]

[0318] [Chemistry 107]

[0319]

[0320] [Chemistry 108]

[0321]

[0322] [Chemistry 109]

[0323]

[0324] [Chemistry 110]

[0325]

[0326] [Chemistry 111]

[0327]

[0328] Specific examples of monomers providing repeating unit f3 include those shown below, but are not limited to these. A Same as above.

[0329] [Chemistry 112]

[0330]

[0331] Repeating units f1 to f3 function as acid generators. By bonding the acid generator to the polymer main chain, the acid diffusion is reduced, and the resolution loss caused by the blurring of the acid diffusion can be prevented. In addition, the acid generator can be used to evenly disperse LWR and CDU, which can improve the quality.

[0332] In the base polymer for a positive resist material, the repeating unit a1 or a2 containing an acid-labile group is necessary. In this case, the content ratios of the repeating units a1, a2, b, c, d, e, and f are preferably 0 ≤ a1 < 1.0, 0 ≤ a2 < 1.0, 0 < a1 + a2 < 1.0, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.9, 0 ≤ d ≤ 0.8, 0 ≤ e ≤ 0.8, and 0 ≤ f ≤ 0.5, more preferably 0 ≤ a1 ≤ 0.9, 0 ≤ a2 ≤ 0.9, 0.1 ≤ a1 + a2 ≤ 0.9, 0 ≤ b ≤ 0.8, 0 ≤ c ≤ 0.8, 0 ≤ d ≤ 0.7, 0 ≤ e ≤ 0.7, and 0 ≤ f ≤ 0.4, still more preferably 0 ≤ a1 ≤ 0.8, 0 ≤ a2 ≤ 0.8, 0.1 ≤ a1 + a2 ≤ 0.8, 0 ≤ b ≤ 0.75, 0 ≤ c ≤ 0.75, 0 ≤ d ≤ 0.6, 0 ≤ e ≤ 0.6, and 0 ≤ f ≤ 0.3. Further, when the repeating unit f is at least one selected from the repeating units f1 to f3, then f = f1 + f2 + f3. Also, a1 + a2 + b + c + d + e + f = 1.0.

[0333] On the other hand, in the base polymer for a negative resist material, an acid-labile group is not necessary. For such a base polymer, those containing the repeating unit b and, depending on need, further containing the repeating units c, d, e, and / or f can be mentioned. The content ratios of these repeating units are preferably 0 < b ≤ 1.0, 0 ≤ c ≤ 0.9, 0 ≤ d ≤ 0.8, 0 ≤ e ≤ 0.8, and 0 ≤ f ≤ 0.5, more preferably 0.2 ≤ b ≤ 1.0, 0 ≤ c ≤ 0.8, 0 ≤ d ≤ 0.7, 0 ≤ e ≤ 0.7, and 0 ≤ f ≤ 0.4, still more preferably 0.3 ≤ b ≤ 1.0, 0 ≤ c ≤ 0.75, 0 ≤ d ≤ 0.6, 0 ≤ e ≤ 0.6, and 0 ≤ f ≤ 0.3. Further, when the repeating unit f is at least one selected from the repeating units f1 to f3, then f = f1 + f2 + f3. Also, b + c + d + e + f = 1.0.

[0334] To synthesize the aforementioned base polymer, for example, the monomers providing the aforementioned repeating units can be polymerized by adding a radical polymerization initiator and heating in an organic solvent.

[0335] Specific examples of the organic solvent used in the polymerization include toluene, benzene, tetrahydrofuran (THF), diethyl ether, dioxane, etc. Specific examples of the polymerization initiator include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl 2,2-azobis(2-methylpropionate), benzoyl peroxide, lauroyl peroxide, etc. The temperature during the polymerization is preferably 50 to 80 °C. The reaction time is preferably 2 to 100 hours, more preferably 5 to 20 hours.

[0336] 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 the polymerization, and then deprotected using weak acid and water after the polymerization. Alternatively, the hydroxyl groups may be replaced with acetyl groups, formyl groups, pivaloyl groups, etc., and then hydrolyzed with alkali after the polymerization.

[0337] When copolymerizing hydroxystyrene and hydroxyvinylnaphthalene, acetoxystyrene and acetoxyvinylnaphthalene may be used instead of hydroxystyrene and hydroxyvinylnaphthalene, and the acetoxy group may be deprotected by the aforementioned alkaline hydrolysis after polymerization to obtain hydroxystyrene and hydroxyvinylnaphthalene.

[0338] As the base for alkaline hydrolysis, aqueous ammonia, triethylamine, etc. can be used. 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.

[0339] 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 of the resist film in an alkaline developer are good.

[0340] Furthermore, when the molecular weight distribution (Mw / Mn) in the base polymer is wide, there are low molecular weight and high molecular weight polymers, so there is a concern that foreign matter may be observed on the pattern after exposure, or the shape of the pattern may deteriorate. As the pattern rules become finer, the influence of Mw and Mw / Mn tends to become greater. Therefore, in order to obtain a resist material that can be ideally used in a fine pattern size, the Mw / Mn of the base polymer is preferably 1.0 to 2.0, and a narrow distribution of 1.0 to 1.5 is particularly preferred.

[0341] The base polymer may include two or more polymers having different composition ratios, Mw, and Mw / Mn.

[0342] [Organic solvents]

[0343] The resist material of the present invention may also contain an organic solvent. The aforementioned organic solvent is not particularly limited as long as it can dissolve the aforementioned components and the components described below. Specific examples of the aforementioned organic solvent include ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentanone, and 2-heptanone described in paragraphs

[0144] to

[0145] of Japanese Patent Publication No. 2008-111103; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and diacetone alcohol; propylene glycol monool Ethers such as methyl 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 monotert-butyl ether acetate; lactones such as γ-butyrolactone, etc.

[0344] In the resist material of the present invention, the content of the organic solvent is preferably 100 to 10,000 parts by mass, more preferably 200 to 8,000 parts by mass, based on 100 parts by mass of the base polymer. The organic solvent may be used alone or in combination of two or more.

[0345] [Quencher]

[0346] The resist material of the present invention may also contain a quencher. The quencher is a compound that can prevent the acid generated from the acid generator in the resist material from diffusing to the unexposed area by trapping the acid.

[0347] As for the above-mentioned quencher, known basic compounds can be cited. As specific examples of known basic compounds, primary, secondary, and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds with carboxyl groups, nitrogen-containing compounds with sulfonyl groups, nitrogen-containing compounds with hydroxyl groups, nitrogen-containing compounds with hydroxyphenyl groups, alcoholic nitrogen-containing compounds, amides, imides, and carbamates can be cited. In particular, the primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

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

[0348] In addition, as for the above-mentioned quencher, there can be mentioned onium salts such as sulfonium salts, iodonium salts, and ammonium salts of sulfonic acids, carboxylic acids, or fluorinated alkoxy compounds that are not fluorinated at the α-position as described in Japanese Patent Application Laid-Open No. 2008-158339. Sulfonic acids, imidic acids, or methide acids that are fluorinated at the α-position are necessary for deprotecting the acid-labile group of the carboxylate, and the sulfonic acids, carboxylic acids, or fluorinated alcohols that are not fluorinated at the α-position are released by exchanging with the salt of the above-mentioned onium salt. Sulfonic acids, carboxylic acids, and fluorinated alcohols that are not fluorinated at the α-position do not cause a deprotection reaction, and thus they function as quenchers.

[0349] Specific examples of such quenchers include compounds represented by the following formula (4) (onium salt of sulfonic acid not fluorinated at the α-position), compounds represented by the following formula (5) (onium salt of carboxylic acid), and compounds represented by the following formula (6) (onium salt of alkoxy compound).

[0350] [Chemistry 113]

[0351]

[0352] In formula (4), R 101 It is a hydrocarbon group having 1 to 40 carbon atoms which may contain a hydrogen atom or a heteroatom, but excludes a group in which the hydrogen atom bonded to the carbon atom at the α-position of the sulfonic acid group is substituted by a fluorine atom or a fluoroalkyl group.

[0353] R 101 The hydrocarbon group having 1 to 40 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 40 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, tricyclo[5.2.1.0 2,6 ] Cyclic saturated hydrocarbon groups having 3 to 40 carbon atoms, such as decyl, adamantyl, and adamantylmethyl; alkenyl groups having 2 to 40 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated aliphatic hydrocarbon groups having 3 to 40 carbon atoms, such as cyclohexenyl; aryl groups having 6 to 40 carbon atoms, such as phenyl, naphthyl, alkylphenyl (2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-ethylphenyl, 4-tert-butylphenyl, 4-n-butylphenyl, etc.), di- or trialkylphenyl (2,4-dimethylphenyl, 2,4,6-triisopropylphenyl, etc.), alkylnaphthyl (methylnaphthyl, ethylnaphthyl, etc.), dialkylnaphthyl (dimethylnaphthyl, diethylnaphthyl, etc.); aralkyl groups having 7 to 40 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl, etc.

[0354] 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, resulting in a hydroxyl group, a cyano 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. Specific examples of the hydrocarbon group containing a heteroatom include heteroaryl groups such as thienyl; alkoxyphenyl groups such as 4-hydroxyphenyl, 4-methoxyphenyl, 3-methoxyphenyl, 2-methoxyphenyl, 4-ethoxyphenyl, 4-tert-butoxyphenyl, and 3-tert-butoxyphenyl; alkoxynaphthyl groups such as methoxynaphthyl, ethoxynaphthyl, n-propoxynaphthyl, and n-butoxynaphthyl; dialkoxynaphthyl groups such as dimethoxynaphthyl and diethoxynaphthyl; aryloxyalkyl groups such as 2-aryl-2-oxoethyl groups such as 2-phenyl-2-oxoethyl, 2-(1-naphthyl)-2-oxoethyl, and 2-(2-naphthyl)-2-oxoethyl; and the like.

[0355] In formula (5), R 102 is a hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom. 102 Specific examples of the hydrocarbon group represented by include 101 Other specific examples include fluorinated alkyl groups such as trifluoromethyl, trifluoroethyl, 2,2,2-trifluoro-1-methyl-1-hydroxyethyl, and 2,2,2-trifluoro-1-(trifluoromethyl)-1-hydroxyethyl; and fluorinated aryl groups such as pentafluorophenyl and 4-trifluoromethylphenyl.

[0356] In formula (6), R 103 It is a saturated hydrocarbon group having 1 to 8 carbon atoms and having at least 3 fluorine atoms or an aryl group having 6 to 10 carbon atoms and having at least 3 fluorine atoms, and may also contain a nitro group.

[0357] In formulas (4), (5) and (6), Mq + is an onium cation. As for the onium cation, it is preferably a sulfonium cation, an iodonium cation or an ammonium cation, and more preferably a sulfonium cation. As specific examples of the sulfonium cation, there can be cited the same M as in the description of formula (1): + The sulfonium cations represented are the same as those exemplified above.

[0358] As the quencher, a sulfonium salt of a carboxylic acid containing an iodinated benzene ring represented by the following formula (7) can also be preferably used.

[0359] [Chemistry 114]

[0360]

[0361] In formula (7), x is an integer of 1 to 5. y is an integer of 0 to 3. z is an integer of 1 to 3.

[0362] In formula (7), R 111 is a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an amino group, a nitro group, a cyano group, or a saturated hydrocarbon group having 1 to 6 carbon atoms, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyloxy group having 2 to 6 carbon atoms, or a saturated hydrocarbon sulfonyloxy group having 1 to 4 carbon atoms, which may be partially or entirely substituted with halogen atoms, or -N(R 111A )-C(=O)-R 111B or -N(R 111A )-C(=O)-OR 111B . R 111A is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. 111B is a saturated hydrocarbon group having 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbon group having 2 to 8 carbon atoms. 111 They can be the same or different.

[0363] In formula (7), L 1 It is a single bond or a (z+1)-valent linking group having 1 to 20 carbon atoms, and may also include at least one selected from an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, a carbonate bond, a halogen atom, a hydroxyl group, and a carboxyl group. The aforementioned saturated hydrocarbon group, saturated hydrocarbon oxy group, saturated hydrocarbon carbonyloxy group, and saturated hydrocarbon sulfonyloxy group may be straight-chain, branched, or cyclic.

[0364] In formula (7), R 112 , R 113 and R 114 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 the same R as in the description of formulas (2) and (3). 4 ~R 8 The hydrocarbon groups represented are the same as those exemplified above.

[0365] Specific examples of the compound represented by formula (7) include those described in JP-A-2017-219836 and JP-A-2021-91666.

[0366] As another example of the quencher, there is a polymer quencher described in Japanese Patent Application Publication No. 2008-239918. This improves the rectangularity of the resist pattern by aligning the resist film surface. The polymer quencher also has the effect of preventing film loss and doming of the pattern when used as a protective film for immersion exposure.

[0367] Furthermore, betaine-type sulfonium salts described in Japanese Patent No. 6848776 and Japanese Patent Unexamined Publication No. 2020-37544, methylated acids not containing fluorine atoms described in Japanese Patent Unexamined Publication No. 2020-55797, sulfonium salts of sulfonic acid amides described in Japanese Patent No. 5807552, sulfonium salts of sulfonic acid amides containing iodine atoms described in Japanese Patent Unexamined Publication No. 2019-211751, phenol, halogens, and acid generators that generate carbonic acid can also be used as quenchers.

[0368] When the resist material of the present invention contains the 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 quencher may be used alone or in combination of two or more.

[0369] [Other ingredients]

[0370] In addition to the above components, an acid generator other than the salt represented by formula (1) (hereinafter referred to as other acid generator), a surfactant, a dissolution inhibitor, a crosslinking agent, a water repellency enhancer, acetylene alcohols, etc. may be contained.

[0371] As for the aforementioned other acid generators, compounds (photoacid generators) that generate acid by induction of active light or radiation can be listed. As for the composition of the photoacid generator, as long as it is a compound that generates acid due to high-energy ray irradiation, any one is fine, preferably an acid generator that generates sulfonic acid, imidic acid or methide acid. As for the specific examples of preferred photoacid generators, sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, oxime-O-sulfonate acid generators, etc. can be listed. As for the specific examples of the aforementioned acid generators, paragraphs

[0122] to

[0142] of Japanese Patent Publication No. 2008-111103, Japanese Patent Publication No. 2018-5224, and Japanese Patent Publication No. 2018-25789 can be listed. When the resist material of the present invention contains other acid generators, the content thereof is preferably 0 to 200 parts by mass, more preferably 0.1 to 100 parts by mass, based on 100 parts by mass of the base polymer.

[0372] As specific examples of the above-mentioned surfactant, those described in paragraphs

[0165] to

[0166] of Japanese Patent Publication No. 2008-111103 can be cited. By adding a surfactant, the coating property of the resist material can be further improved or controlled. When the resist material of the present invention contains a surfactant, its content is preferably 0.0001 to 10 parts by mass relative to 100 parts by mass of the base polymer. The above-mentioned surfactant can be used alone or in combination of two or more.

[0373] When the resist material of the present invention is positive, by mixing a dissolution inhibitor, the difference in dissolution rate between the exposed part and the unexposed part can be further increased, and the resolution can be further improved. As for the specific examples of the above-mentioned dissolution inhibitor, the molecular weight is preferably 100 to 1000, and more preferably 150 to 800, and examples include compounds containing two or more phenolic hydroxyl groups in the molecule, the hydrogen atoms of the phenolic hydroxyl groups of which are replaced by acid-labile groups at a ratio of 0 to 100 mol% as a whole, or compounds containing carboxyl groups in the molecule, the hydrogen atoms of the carboxyl groups of which are replaced by acid-labile groups at an average ratio of 50 to 100 mol% as a whole. Specifically, examples include compounds in which the hydrogen atoms of the hydroxyl groups and carboxyl groups of bisphenol A, trisphenol, phenolphthalein, cresol novolac, naphthalenecarboxylic acid, adamantanecarboxylic acid, and bile acid are replaced by acid-labile groups, for example, as described in paragraphs

[0155] to

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

[0374] When the resist material of the present invention is positive type and contains the dissolution inhibitor, its content is preferably 0 to 50 parts by mass, more preferably 5 to 40 parts by mass, relative to 100 parts by mass of the base polymer. The dissolution inhibitor may be used alone or in combination of two or more.

[0375] On the other hand, when the resist material of the present invention is negative, a negative pattern can be obtained by adding a crosslinking agent to reduce the dissolution rate of the exposure portion. As specific examples of the aforementioned crosslinking agent, epoxy compounds, melamine compounds, guanamine compounds, glycoluril compounds or urea compounds, isocyanate compounds, azide compounds, compounds containing double bonds of alkenyloxy groups, etc., which are substituted by at least one group selected from hydroxymethyl, alkoxymethyl and acyloxymethyl, can be listed. These can be used as additives and can also be introduced into polymer side chains in the form of pendant groups. In addition, hydroxyl-containing compounds can also be used as crosslinking agents.

[0376] Specific examples of the epoxy compound include tris(2,3-epoxypropyl)isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and triethylolethane triglycidyl ether.

[0377] Specific examples of the melamine compound include hexamethylolmelamine, hexamethoxymethylmelamine, a compound in which 1 to 6 hydroxymethyl groups of hexamethylolmelamine are methoxymethylated, or a mixture thereof, hexamethoxyethylmelamine, hexaacyloxymethylmelamine, a compound in which 1 to 6 hydroxymethyl groups of hexamethylolmelamine are acyloxymethylated, or a mixture thereof, and the like.

[0378] Specific examples of the guanamine compounds include tetrakishydroxymethylguanamine, tetrakismethoxymethylguanamine, compounds in which 1 to 4 hydroxymethyl groups of tetrakishydroxymethylguanamine are methoxymethylated, or mixtures thereof, tetrakismethoxyethylguanamine, tetrakisacyloxyguanamine, compounds in which 1 to 4 hydroxymethyl groups of tetrakishydroxymethylguanamine are acyloxymethylated, or mixtures thereof, and the like.

[0379] Specific examples of the glycoluril compound include tetrakishydroxymethyl glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, compounds in which 1 to 4 hydroxymethyl groups of tetrakishydroxymethyl glycoluril are methoxymethylated, or mixtures thereof, compounds in which 1 to 4 hydroxymethyl groups of tetrakishydroxymethyl glycoluril are acyloxymethylated, or mixtures thereof, etc. Specific examples of the urea compound include tetrakishydroxymethyl urea, tetramethoxymethyl urea, compounds in which 1 to 4 hydroxymethyl groups of tetrakishydroxymethyl urea are methoxymethylated, or mixtures thereof, and tetramethoxyethyl urea.

[0380] Specific examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate and the like.

[0381] Specific examples of the azide compound include 1,1′-biphenyl-4,4′-bisazide, 4,4′-methylenebisazide, and 4,4′-oxybisazide.

[0382] Specific examples of the alkenyloxy group-containing compound include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propylene glycol divinyl ether, 1,4-butylene glycol divinyl ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, and trimethylolpropane trivinyl ether.

[0383] When the resist material of the present invention is negative type and contains the crosslinking agent, the content thereof is preferably 0.1 to 50 parts by mass, more preferably 1 to 40 parts by mass, relative to 100 parts by mass of the base polymer. The crosslinking agent may be used alone or in combination of two or more.

[0384] The aforementioned water repellency enhancer is a device that enhances the water repellency of the surface of the resist film and can be used in immersion lithography without using a surface coating. As for the aforementioned water repellency enhancer, it 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, or the like, as exemplified by Japanese Patent Publication No. 2007-297590 and Japanese Patent Publication No. 2008-111103. The aforementioned water repellency enhancer must be dissolved in an alkaline developer or an organic solvent developer. The water repellency enhancer having the aforementioned specific 1,1,1,3,3,3-hexafluoro-2-propanol residue has good solubility in the developer. As for the water repellency enhancer, a polymer containing repeating units containing an amino group or an ammonium salt has a high effect of preventing the evaporation of the acid in the PEB and preventing the poor opening of the hole pattern after development. When the resist material of the present invention contains the water repellency enhancer, the content thereof is preferably 0 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, relative to 100 parts by mass of the base polymer. The water repellency enhancer may be used alone or in combination of two or more.

[0385] Specific examples of the acetylene alcohols include those described in paragraphs

[0179] to

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

[0386] [Pattern Formation Method]

[0387] 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: using the resist material to form a resist film on a substrate, exposing the resist film to high-energy rays, and developing the exposed resist film using a developer.

[0388] 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 by a suitable coating method such as spin coating, roller coating, flow coating, dip coating, spray coating, scraping coating, etc. to make the coating film thickness 0.01 to 2 μm. It is preferably pre-baked at 60 to 150° C., 10 seconds to 30 minutes, more preferably at 80 to 120° C., 30 seconds to 20 minutes on a hot plate to form a resist film.

[0389] Then, the resist film is exposed using high-energy radiation. Specific 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 amount is preferably about 1 to 200 mJ / cm directly or using a mask for forming a target pattern. 2 , more preferably about 10 to 100 mJ / cm 2 When EB is used as high energy ray, the exposure amount is preferably about 0.1 to 300 μC / cm 2 , preferably about 0.5 to 200 μC / cm 2 The resist material of the present invention is particularly suitable for fine patterning by KrF excimer laser, ArF excimer laser, EB, EUV, X-ray, soft X-ray, gamma ray, synchrotron radiation among high-energy rays, and is particularly suitable for fine patterning by EB or EUV.

[0390] After the exposure, PEB may be performed on a hot plate or in an oven, preferably at 30 to 150° C. for 10 seconds to 30 minutes, more preferably at 50 to 120° C. for 30 seconds to 20 minutes, or it may not be performed.

[0391] After exposure or PEB, the exposed resist film is developed for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, using a developer of an alkaline aqueous solution of 0.1 to 10% by mass, preferably 2 to 5% by mass, such as tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, etc., by using a common method such as a dip method, a puddle method, or a spray method to form a target pattern. In the case of a positive resist material, the portion irradiated with light will dissolve in the developer, while the unexposed portion will not dissolve, and a target positive pattern will be formed on the substrate. In the case of a negative resist material, in contrast to the case of a positive resist material, the portion irradiated with light will not dissolve in the developer, while the unexposed portion will dissolve.

[0392] A positive resist material containing a base polymer containing an acid-labile group may also be used, and a negative pattern may be obtained by developing with an organic solvent. Specific examples of the developer used at this time include 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 croton ... Ethyl beanate, 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.

[0393] When the development is finished, rinsing is performed. The rinsing liquid is preferably a solvent that is miscible with the developer and does not dissolve the resist film. As such a solvent, 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 are preferably used.

[0394] Specific 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, 1-octanol, etc.

[0395] Specific examples of the ether compound having 8 to 12 carbon atoms include di-n-butyl ether, diisobutyl ether, di-sec-butyl ether, di-n-amyl ether, diisoamyl ether, di-sec-amyl ether, di-tert-amyl ether, and di-n-hexyl ether.

[0396] Specific 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. Specific examples of the aforementioned alkenes having 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, cyclooctene, etc. Specific examples of the aforementioned alkynes having 6 to 12 carbon atoms include hexyne, heptyne, octyne, etc.

[0397] Specific examples of the aromatic solvent include toluene, xylene, ethylbenzene, cumene, tert-butylbenzene, mesitylene, and the like.

[0398] By performing rinsing, the collapse of the resist pattern and the generation of defects can be reduced. In addition, rinsing is not necessarily necessary, and the amount of solvent used can be reduced by not performing rinsing.

[0399] The developed hole pattern and groove pattern 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 causes the shrinking agent to crosslink on the surface of the resist film, and the shrinking agent will adhere to the side wall of the hole pattern. The baking temperature is preferably 70-180°C, more preferably 80-170°C, and the baking time is preferably 10-300 seconds to remove the excess shrinking agent and shrink the hole pattern.

[0400] Example

[0401] 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.

[0402] The structures of the acid generators PAG-1 to PAG-26 of sulfonium salt or iodonium salt used in the resist material are shown below.

[0403] [Chemistry 115]

[0404]

[0405] [Chemistry 116]

[0406]

[0407] [Chemistry 117]

[0408]

[0409] [Chemistry 118]

[0410]

[0411] [Chemistry 119]

[0412]

[0413] [Chemistry 120]

[0414]

[0415] [Chemistry 121]

[0416]

[0417] [Synthesis Example] Synthesis of base polymers (polymers P-1 to P-4)

[0418] The monomers were combined, copolymerized in THF as a solvent, added to methanol, and the precipitated solid was washed with hexane, separated, and dried to obtain base polymers (polymers P-1 to P-4) with the following compositions. 1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC (solvent: THF, standard: polystyrene).

[0419] [Chemistry 122]

[0420]

[0421] [Examples 1 to 29, Comparative Examples 1 to 3] Preparation and Evaluation of Resist Materials

[0422] (1) Preparation of resist materials

[0423] Solutions in which the components were dissolved in the compositions shown in Tables 1 to 3 were filtered using a 0.2 μm filter membrane to prepare a resist material.

[0424] In Tables 1 to 3, the components are as follows.

[0425] Organic solvent: PGMEA (propylene glycol monomethyl ether acetate)

[0426] EL(ethyl lactate)

[0427] DAA (Diacetone Alcohol)

[0428] PGME(propylene glycol monomethyl ether)

[0429] Comparative Acid Generators: cPAG-1, cPAG-2

[0430] [Chemistry 123]

[0431]

[0432] Quencher: Q-1, Q-2

[0433] [Chemistry 124]

[0434]

[0435] (2) EUV lithography evaluation

[0436] Each resist material shown in Tables 1 to 3 was spin-coated on a Si substrate formed with a 20 nm thick silicon-containing spin-coated hard mask SHB-A940 (silicon content: 43 mass%) manufactured by Shin-Etsu Chemical Co., Ltd., and pre-baked at 105° C. for 60 seconds using a hot plate to prepare a resist film with a thickness of 50 nm. The resist film was exposed using an EUV scanner NXE3400 manufactured by ASML (NA 0.33, σ 0.9 / 0.6, quadrupole illumination, mask of a hole pattern with a pitch of 40 nm and +20% deviation on the wafer), and PEB was performed for 60 seconds on a hot plate at the temperature described in Tables 1 to 3, and developed for 30 seconds with a 2.38 mass % TMAH aqueous solution. Examples 1 to 28 and Comparative Examples 1 and 2 formed a hole pattern with a size of 20 nm, and Example 29 and Comparative Example 3 formed a dot pattern with a size of 20 nm.

[0437] The exposure amount when the hole or dot size was 20 nm was measured using Hitachi Advanced Technology Co., Ltd.'s length measurement SEM (CG6300), and this was used as the sensitivity. The size of 50 holes or dots at this time was measured, and the value (3σ) three times the standard deviation (σ) calculated from the result was obtained and used as CDU. The results are shown in Tables 1 to 3.

[0438] [Table 1]

[0439]

[0440] [Table 2]

[0441]

[0442] [Table 3]

[0443]

[0444] From the results shown in Tables 1 to 3, it is understood that the resist material of the present invention comprising a sulfonium salt or iodonium salt containing an arylsulfonic acid anion having an aromatic group substituted with an iodine atom or a bromine atom as an acid generator has high sensitivity and good CDU.

Claims

1. A resist material comprising an acid generator containing an onium salt represented by the following formula (1), In the formula, m is an integer of 1 to 5, n is an integer of 0 to 4, but 1≤m+n≤5, p is an integer of 1 to 3, when Ar is a (q+2)-valent group derived from benzene, q is an integer of 1 to 4, when Ar is a (q+2)-valent group derived from naphthalene, q is an integer of 1 to 6, X BI is a bromine atom or an iodine atom, Ar is a (q+2)-valent group derived from benzene or naphthalene, X 1 and X 2 is a single bond, an ether bond, an ester bond, a sulfonate bond, an amide bond, a carbamate bond, a urea bond, a carbonate bond, or an alkane diyl group having 1 to 6 carbon atoms, wherein the alkane diyl group may also contain at least one selected from an ether bond and an ester bond, but p=1, X BI When X is an iodine atom and Ar is a (q+2)-valent group derived from benzene, 1 Not *-C(=O)-O-; p=1, X BI is an iodine atom, X 1 and R 2 When X is a single bond and Ar is a (q+2)-valent group derived from benzene, 2 Not *-C(=O)-O-; p=1, X 2 and R 2 When X is a single bond and Ar is a (q+2)-valent group derived from benzene, 1 Not -OC(=O)-** and carbonate bond; p=1, X 1 When X is a single bond and Ar is a (q+2)-valent group derived from benzene, 2 It is not -OC(=O)-** and carbonate bond, * represents an atomic bond with the benzene ring in the formula, ** represents an atomic bond with Ar, R 1 is a hydroxyl group, a carboxyl group, a fluorine atom, a chlorine atom, an amino group, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbonoxy group having 1 to 20 carbon atoms, a hydrocarbonoxycarbonyl group having 2 to 20 carbon atoms, a hydrocarboncarbonyloxy group having 2 to 20 carbon atoms, -N(R 1A )-C(=O)-R 1B 、-N(R 1A )-C(=O)-OR 1B or -N(R 1A )-S(=O)2-R 1B The hydrocarbon group, hydrocarbonoxy group, hydrocarbonoxycarbonyl group and hydrocarboncarbonyloxy group may also contain at least one selected from fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, hydroxyl groups, amino groups, ester bonds and ether bonds, R 1A is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms, the saturated hydrocarbon group 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, R 1B is an aliphatic hydrocarbon group having 1 to 16 carbon atoms or an aryl group having 6 to 12 carbon atoms, and may contain a halogen atom, a hydroxyl group, a saturated hydrocarbonoxy group having 1 to 6 carbon atoms, a saturated hydrocarboncarbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarboncarbonyloxy group having 2 to 6 carbon atoms, R 2 is a single bond or a (p+1)-valent hydrocarbon group having 1 to 28 carbon atoms, and the hydrocarbon group may contain at least one atom selected from an oxygen atom, a nitrogen atom, a sulfur atom and a halogen atom, R 3 is a fluorine atom, a trifluoromethoxy group, a nitro group, a saturated hydrocarbon group having 1 to 12 carbon atoms, or an aryl group having 6 to 10 carbon atoms, M + It is a sulfonium cation or an iodonium cation.

2. The resist material according to claim 1, wherein X 1 and X 2 is a group other than a single bond, and R 2 It is a group other than a single bond. The resist material according to claim 1 , further comprising a base polymer.

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

6. The resist material according to claim 3, wherein The base polymer contains no acid labile groups.

7. The resist material according to claim 6, which is a chemically amplified negative resist material. The resist material according to claim 1 , further comprising an organic solvent.

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

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

12. The pattern forming method according to claim 11, wherein: The high-energy radiation is ArF excimer laser with a wavelength of 193 nm, KrF excimer laser with a wavelength of 248 nm, electron beam, or extreme ultraviolet radiation with a wavelength of 3 to 15 nm.

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