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 to both positive and negative types and improved LWR and CDU; and a pattern forming method using the same. [Solution] The resist material contains a dionium salt containing an onium cation and a divalent anion having a benzene oxide anion structure substituted with an iodine atom and an aryl sulfonic acid anion structure bonded to an aromatic ring of the benzene oxide anion structure.

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 LSIs, the miniaturization of pattern rules has been rapidly progressing. The high-speed communication of 5G and the popularization of artificial intelligence (AI) are in progress, and high-performance devices for processing them are required. In the case of the most advanced miniaturization technology, mass production of devices at the 5nm node and 3nm node by extreme ultraviolet (EUV) lithography with a wavelength of 13.5nm is in progress. Furthermore, in the next-generation 2nm node devices and the next-next-generation nodes, discussions using EUV lithography are also underway, and IMEC in Belgium has announced the development of devices.

[0003] With the progress of miniaturization, image blur caused by acid diffusion has become a problem. In order to ensure the resolution in fine patterns with a processing size of 45nm or less, it has been proposed that in addition to the improvement of the dissolution contrast that has been proposed so far, the control of acid diffusion is also important (Non-Patent Document 1). However, in chemically amplified resist materials, since the sensitivity and contrast are increased by the diffusion of acid, if the post-exposure bake (PEB) temperature is lowered or the time is shortened to suppress acid diffusion to the limit, the sensitivity and contrast will decrease significantly.

[0004] In EUV resist materials, it is necessary to simultaneously achieve high sensitivity, high resolution, and low line width roughness (LWR). If the acid diffusion distance is shortened, the LWR and dimensional uniformity (CDU) will be improved, but the sensitivity will be lowered. For example, by lowering the PEB temperature, the LWR and CDU will be improved, but the sensitivity will be lowered. Even if the amount of quencher added is increased, still the LWR and CDU are improved, but the sensitivity is lowered. It is necessary to break the trade-off relationship between sensitivity and LWR.

[0005] Resist materials in which an onium salt containing an anion having an iodine atom or a bromine atom is added as an acid generator have been proposed (Patent Documents 1 to 4). Since it has an iodine atom with a large EUV absorption and a bromine atom with a high ionization efficiency, the efficiency of decomposition of the acid generator during exposure is increased, and the sensitivity is increased. The amount of photon absorption increases, and the physical contrast can be improved.

[0006] EUV light with a wavelength of 13.5 nm has a shorter wavelength by more than one order of magnitude compared to ArF excimer laser with a wavelength of 193 nm, so it has higher energy and is greatly affected by the deviation of the number of photons (Non-Patent Document 2). Therefore, it has been pointed out that LWR may deteriorate (Non-Patent Document 3). In addition, it has also been pointed out that with the progress of miniaturization, the influence of LWR deterioration caused by the deviation of resist components (polymer, PAG, quencher) (Resist Stochastics) (Non-Patent Document 4).

[0007] There has been proposed a resist material containing a polymer in which an acid generator (PAG) and a quencher (PDQ) are bonded (Patent Document 5). By integrating the polymer, PAG, and quencher, the deviation of these is suppressed, and LWR and CDU are improved. Furthermore, there has also been proposed a resist material containing an additive in which PAG and a quencher are bonded (Patent Documents 6 and 7).

[0008] The impact of perfluoroalkyl compounds (PFAS) on health has been pointed out, and there are measures to restrict the manufacture and sale of PFAS compounds in REACH in Europe. Currently, many compounds containing PFAS are used in semiconductor lithography. For example, materials containing it are used in surfactants, acid generators, etc.

[0009] Prior Art Documents

[0010] Patent Documents

[0011] [Patent Document 1] Japanese Unexamined Patent Application Publication No. 2018-159744

[0012] [Patent Document 2] Japanese Unexamined Patent Application Publication No. 2018-5224

[0013] [Patent Document 3] Japanese Unexamined Patent Application Publication No. 2018-25789

[0014] [Patent Document 4] Japanese Unexamined Patent Application Publication No. 2019-3175

[0015] [Patent Document 5] Japanese Unexamined Patent Application Publication No. 2022-115072

[0016] [Patent Document 6] Japanese Unexamined Patent Application Publication No. 2015-24989

[0017] [Patent Document 7] International Publication No. 2020 / 158313

[0018] Non-Patent Documents

[0019] [Non-Patent Document 1] SPIE Vol.6520 65203L-1(2007)

[0020] [Non-patent document 2] SPIE Vol. 3331 535 (1998)

[0021] [Non-patent document 3] SPIE Vol.7273 727343-1 (2009)

[0022] [Non-patent document 4] SPIE Vol.9776 97760V-1 (2016) Summary of the invention

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

[0024] It is necessary to develop a resist material that has higher sensitivity than known resist materials and can improve the LWR of a line pattern and the CDU of a hole pattern.

[0025] The present invention is made in view of the above situation, and an object of the present invention is to provide a resist material having high sensitivity in both positive and negative modes and improved LWR and CDU, and a pattern forming method using the same.

[0026] [Methods to solve the problem]

[0027] The inventors of the present application have repeatedly conducted in-depth studies to achieve the above-mentioned purpose, and as a result, they have found that by using a divalent anion containing a phenoxide anion structure substituted with an iodine atom and an arylsulfonic acid anion structure bonded to an aromatic ring of the phenoxide anion structure, and a dichonium salt of an onium cation as an acid generator and quencher, the acid generator is directly excited by exposure to radiation without being affected by the diffusion of secondary electrons, thereby obtaining a highly sensitive resist material with improved LWR and CDU, high contrast, excellent resolution, and high process latitude, and the present invention has been completed.

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

[0029] 1. A resist material comprising:

[0030] A bis-onium salt contains a divalent anion having a phenoxide anion structure substituted with an iodine atom and an arylsulfonic acid anion structure bonded to an aromatic ring of the phenoxide anion structure, and an onium cation.

[0031] 2. The resist material according to 1., wherein the bis-onium salt is represented by the following formula (1):

[0032] [Chemistry 1]

[0033]

[0034] In the formula, m is an integer of 1 to 4, n is an integer of 0 to 3, but 1≤m+n≤4, p is an integer of 0 to 10,

[0035] X 1 and X 2 each independently represents a single bond, an ether bond, an ester bond, a sulfonate bond, a carbonate bond or a carbamate bond,

[0036] R 1 is a hydrocarbon group having 1 to 10 carbon atoms, a halogen atom other than an iodine atom, a nitro group or a cyano group, and the hydrocarbon group may also have at least one selected from halogen atoms, oxygen atoms, sulfur atoms and nitrogen atoms,

[0037] R 2 is a single bond or a C1-C40 alkylene group, and the alkylene group may also contain at least one selected from oxygen atoms, nitrogen atoms, sulfur atoms and halogen atoms,

[0038] R 3 is a halogen atom, a trifluoromethyl group, a trifluoromethoxy group, a cyano group, a nitro group, a hydroxyl group, a carboxyl group, an amino group, a C1-C20 hydrocarbon group, a C1-C20 hydrocarbon oxy group, a C2-C20 hydrocarbon oxycarbonyl group, a C2-C20 hydrocarbon carbonyloxy group, a C1-C20 hydrocarbon sulfonyloxy group, -N(R 3A )-C(=O)-R 3B , -N(R 3A )-C(=O)-O-R 3B or -N(R 3A )-S(=O)2-R 3B , and the hydrocarbon group, hydrocarbon oxy group, hydrocarbon oxycarbonyl group, hydrocarbon carbonyloxy group, hydrocarbon sulfonyloxy group may also contain at least one selected from fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, hydroxyl groups, amino groups, ester bonds, ether bonds, carbamate bonds, urea bonds, carbonate bonds, amide bonds, sulfonic acid bonds, carbonyl groups, thioether groups and sulfonyl groups, R 3A is a hydrogen atom or a C1-C6 saturated hydrocarbon group, and the saturated hydrocarbon group may also contain a halogen atom, a hydroxyl group, a C1-C6 saturated hydrocarbon oxy group, a C2-C6 saturated hydrocarbon carbonyl group or a C2-C6 saturated hydrocarbon carbonyloxy group, R 3B is a C1-C16 aliphatic hydrocarbon group or a C6-C12 aryl group, and may also contain a halogen atom, a hydroxyl group, a C1-C6 saturated hydrocarbon oxy group, a C2-C6 saturated hydrocarbon carbonyl group or a C2-C6 saturated hydrocarbon carbonyloxy group,

[0039] Ar is a (p + 2)-valent aromatic hydrocarbon group having 6 to 16 carbon atoms,

[0040] M + is a sulfonium cation or an iodonium cation.

[0041] 3. The resist material according to 1. or 2., further comprising a base polymer.

[0042] 4. The resist material according to 3., wherein the base polymer contains repeating units represented by the following formula (a1) or (a2),

[0043] [Chemical formula 2]

[0044]

[0045] wherein, R A are each independently a hydrogen atom or a methyl group,

[0046] Y 1 is a single bond, a phenylene group, a naphthylene group, or a linking group having 1 to 12 carbon atoms containing at least one selected from an ester bond, an ether bond, and a lactone ring, and the phenylene group, naphthylene group, and linking group may also have at least one selected from a hydroxyl group, a saturated hydrocarbon group oxy group having 1 to 8 carbon atoms, and a saturated hydrocarbon group carbonyl oxy group having 2 to 8 carbon atoms,

[0047] Y 2 is a single bond or an ester bond,

[0048] Y 3 is a single bond, an ether bond, or an ester bond,

[0049] R 11 and R 12 are each independently an acid-labile group,

[0050] R 13 is a saturated hydrocarbon group having 1 to 4 carbon atoms, a halogen atom, a saturated hydrocarbon group carbonyl having 2 to 5 carbon atoms, a cyano group, or a saturated hydrocarbon group oxycarbonyl having 2 to 5 carbon atoms,

[0051] R 14 is a single bond or an alkylene group having 1 to 6 carbon atoms, and the alkylene group may also contain an ether bond or an ester bond,

[0052] a is an integer from 0 to 4.

[0053] 5. The resist material according to 4. is a chemically amplified positive resist material.

[0054] 6. The resist material according to 3., wherein the base polymer does not contain an acid-labile group.

[0055] 7. The resist material according to 6. is a chemically amplified negative resist material.

[0056] 8. The resist material according to any one of 1. to 7. further contains an organic solvent.

[0057] 9. The resist material according to any one of 1. to 8. further contains a quencher.

[0058] 10. The resist material according to any one of 1. to 9. further contains an acid generator.

[0059] 11. The resist material according to any one of 1. to 10. further comprises a surfactant.

[0060] 12. A pattern forming method comprising the following steps:

[0061] Using the resist material according to any one of 1. to 11. to form a resist film on a substrate, exposing the resist film using high-energy rays, and developing the exposed resist film using a developer.

[0062] 13. The pattern forming method according to 12., wherein the high-energy rays are an ArF excimer laser with a wavelength of 193 nm, a KrF excimer laser with a wavelength of 248 nm, an electron beam, or extreme ultraviolet rays with a wavelength of 3 to 15 nm.

[0063] [Effects of the Invention]

[0064] A resist film containing a bis-onium salt having a divalent anion containing a phenoxide anion structure substituted with an iodine atom and an arylsulfonic acid anion structure bonded to the aromatic ring of the phenoxide anion structure and an onium cation has a large absorption of EUV light, is directly excited during exposure, and has a characteristic of suppressing acid diffusion. Thereby, a decrease in resolution caused by secondary electrons and blurring of acid diffusion can be prevented. In the aforementioned bis-onium salt, since the acid generator of the onium salt that generates sulfonic acid is bonded to the quencher of the onium salt generated by iodinated phenol and the acid generator and the quencher are often arranged in a form at a certain distance, the aforementioned resist stochastics is improved, and thereby LWR and CDU can be improved. By having an iodine atom on the quencher side, the absorption on the quencher side is higher and the decomposition efficiency on the quencher side is higher than that on the acid generator side. Thereby, a resist material with high sensitivity and improved LWR and CDU can be constructed. Detailed Description of the Invention

[0065] [Resist Material]

[0066] The resist material of the present invention comprises: a bis-onium salt containing a divalent anion containing a phenoxide anion structure substituted with an iodine atom and an arylsulfonic acid anion structure bonded to the aromatic ring of the phenoxide anion structure, and an onium cation. The aforementioned bis-onium salt is an acid generator-cum-quencher having the functions of both an acid generator and a quencher. The light absorption obtained by the iodine atom, the high reactivity of the arylsulfonic acid, and the acid diffusion control obtained by the quencher being present nearby complement each other, resulting in small acid diffusion and uniform diffusion distance. Thereby, LWR and CDU can be improved.

[0067] The improvement effects of the LWR and CDU achieved by the bis-oxonium salts used in the present invention are effective for positive pattern formation, negative pattern formation in alkaline aqueous solution development, and negative pattern formation in organic solvent development.

[0068] [Bis-oxonium salt]

[0069] Regarding the aforementioned bis-oxonium salt, it is preferably represented by the following formula (1).

[0070] [Chemical formula 3]

[0071]

[0072] In formula (1), m is an integer from 1 to 4. n is an integer from 0 to 3. However, 1 ≤ m + n ≤ 4. p is an integer from 0 to 10.

[0073] In formula (1), X 1 and X 2 are each independently a single bond, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, or a carbamate bond. Among these, for X 1 , it is preferably a single bond, an ether bond, an ester bond, or a sulfonate bond, and for X 2 , it is preferably a single bond, an ether bond, or an ester bond.

[0074] In formula (1), R 1 is a hydrocarbon group having 1 to 10 carbon atoms, a halogen atom other than an iodine atom, a nitro group, or a cyano group, and the hydrocarbon group may also have at least one selected from halogen atoms, oxygen atoms, sulfur atoms, and nitrogen atoms.

[0075] Regarding specific examples of the halogen atom represented by R 1 , fluorine atom, chlorine atom, bromine atom, etc. can be cited. The hydrocarbon group represented by R 1 can be saturated or unsaturated, and can be linear, branched, or cyclic. Regarding specific examples thereof, alkyl groups having 1 to 10 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, and n-decyl can be cited; cycloalkyl saturated hydrocarbon groups having 3 to 10 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; alkenyl groups having 2 to 10 carbon atoms such as vinyl, propenyl, butenyl, and hexenyl; alkynyl groups having 2 to 10 carbon atoms such as ethynyl, propynyl, and butynyl; cycloalkenyl unsaturated aliphatic hydrocarbon groups having 3 to 10 carbon atoms such as cyclohexenyl and norbornenyl; aryl groups having 6 to 10 carbon atoms such as phenyl, methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, and naphthyl; aralkyl groups having 7 to 10 carbon atoms such as benzyl and phenethyl; groups obtained by combining these, etc.

[0076] In formula (1), R1 is a single bond or an alkylene group having 1 to 40 carbon atoms, which may also contain at least one selected from an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.

[0077] R 2 The alkylene group represented may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, 1-methylethane-1,2-diyl, 1-ethylethane-1,2-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-1,3-diyl, 2-methylpropane-1,1-diyl, butane-1,3-diyl, butane-1,4-diyl, butane-2,3-diyl, 1,1-dimethylpropane-1,3-diyl, 2,2-dimethylpropane-1,3-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, heptadecane-1,17-diyl, octadecane-1,18-diyl, nonadecane-1,19-diyl, eicosane-1,20-diyl and other alkylene groups having 1 to 40 carbon atoms; cyclopentanediyl, cyclohexanediyl, bicyclo[2.2.2]octanediyl, norbornanediyl, adamantanediyl and other cyclic saturated alkylene groups having 3 to 40 carbon atoms; ethylenediyl, propylenediyl, butylenediyl and other alkylene groups having 2 to 40 carbon atoms; acetylenediyl, propynediyl, butynediyl and other alkynylene groups having 2 to 40 carbon atoms; cyclohexenediyl, bicyclo[2.2.2]octenediyl, norbornenediyl and other cyclic unsaturated aliphatic alkylene groups having 3 to 40 carbon atoms; phenylene, methylphenylene, ethylphenylene, n-propylphenylene, isopropylphenylene, n-butylphenylene, isobutylphenylene, sec-butylphenylene, tert-butylphenylene, naphthylene, methylnaphthylene, ethylnaphthylene, 9,10-dihydro-9,10-ethylanthracenediyl and other arylene groups having 6 to 40 carbon atoms; groups obtained by combining these, etc.

[0078] In formula (1), R 3 is a halogen atom, trifluoromethyl, trifluoromethoxy, cyano, nitro, hydroxy, carboxy, amino, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon oxy group having 1 to 20 carbon atoms, a hydrocarbon oxycarbonyl group having 2 to 20 carbon atoms, a hydrocarbon carbonyloxy group having 2 to 20 carbon atoms, a hydrocarbon sulfonyloxy group having 1 to 20 carbon atoms, -N(R 3A )-C(=O)-R 3B 、-N(R 3A )-C(=O)-O-R 3B or -N(R3A )-S(=O)2-R 3B , the alkyl group, alkyloxy group, alkyloxycarbonyl group, alkylcarbonyloxy group, or alkylsulfonyloxy group may also contain at least one selected from a fluorine atom, chlorine atom, bromine atom, iodine atom, hydroxyl group, amino group, ester bond, ether bond, urethane bond, urea bond, carbonate bond, amide bond, sulfonic acid bond, carbonyl group, thioether group, and sulfonyl group. R 3A is a hydrogen atom or a saturated alkyl group having 1 to 6 carbon atoms, and the saturated alkyl group may also contain a halogen atom, hydroxyl group, saturated alkyloxy group having 1 to 6 carbon atoms, saturated alkylcarbonyl group having 2 to 6 carbon atoms, or saturated alkylcarbonyloxy group having 2 to 6 carbon atoms. R 3B 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, hydroxyl group, saturated alkyloxy group having 1 to 6 carbon atoms, saturated alkylcarbonyl group having 2 to 6 carbon atoms, or saturated alkylcarbonyloxy group having 2 to 6 carbon atoms.

[0079] R 3 The alkyl group represented by R, and the alkyl moieties of the alkyloxy group, alkyloxycarbonyl group, alkylcarbonyloxy group, and alkylsulfonyloxy group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl; cycloalkyl 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.

[0080] In formula (1), Ar is a (p + 2)-valent aromatic hydrocarbon group having 6 to 16 carbon atoms. Specific examples of the aromatic hydrocarbon group include groups obtained by removing (p + 2) hydrogen atoms from aromatic hydrocarbons such as benzene, naphthalene, anthracene, and pyrene.

[0081] Specific examples of the anion of the bis-onium salt include those shown below, but are not limited thereto.

[0082] [Chemical formula 4]

[0083]

[0084] [Chemical Formula 5]

[0085]

[0086] [Chemical Formula 6]

[0087]

[0088] [Chemical Formula 7]

[0089]

[0090] [Chemical Formula 8]

[0091]

[0092] [Chemical Formula 9]

[0093]

[0094] [Chemical Formula 10]

[0095]

[0096] [Chemical Formula 11]

[0097]

[0098] [Chemical Formula 12]

[0099]

[0100] [Chemical Formula 13]

[0101]

[0102] [Chemical Formula 14]

[0103]

[0104] [Chemical Formula 15]

[0105]

[0106] [Chemical Formula 16]

[0107]

[0108] [Chemical Formula 17]

[0109]

[0110] [Chemical Formula 18]

[0111]

[0112] [Chemical formula 19]

[0113]

[0114] [Chemical formula 20]

[0115]

[0116] [Chemical formula 21]

[0117]

[0118] [Chemical formula 22]

[0119]

[0120] [Chemical formula 23]

[0121]

[0122] [Chemical formula 24]

[0123]

[0124] [Chemical formula 25]

[0125]

[0126] [Chemical formula 26]

[0127]

[0128] [Chemical formula 27]

[0129]

[0130] [Chemical formula 28]

[0131]

[0132] [Chemical formula 29]

[0133]

[0134] [Chemical formula 30]

[0135]

[0136] [Chemical formula 31]

[0137]

[0138] [Chemical formula 32]

[0139]

[0140] [Chemical Formula 33]

[0141]

[0142] [Chemical Formula 34]

[0143]

[0144] [Chemical Formula 35]

[0145]

[0146] [Chemical Formula 36]

[0147]

[0148] [Chemical Formula 37]

[0149]

[0150] [Chemical Formula 38]

[0151]

[0152] [Chemical Formula 39]

[0153]

[0154] [Chemical Formula 40]

[0155]

[0156] [Chemical Formula 41]

[0157]

[0158] [Chemical Formula 42]

[0159]

[0160] In formula (1), M + is a sulfonium cation or an iodonium cation. Two M + , one may be a sulfonium cation and the other may be an iodonium cation, or both may be sulfonium cations, or both may be iodonium cations. Two M + When both are sulfonium cations, these may be the same as or different from each other. Also, when both of the two M + are iodonium cations, these may be the same as or different from each other.

[0161] Regarding the aforementioned sulfonium cation, it is preferably represented by the following formula (2), and regarding the aforementioned iodonium cation, it is preferably represented by the following formula (3).

[0162] [Chemical Formula 43]

[0163]

[0164] In Formulas (2) and (3), R 4 ~R 8 are each independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may also contain a heteroatom.

[0165] Specific examples of the halogen atom represented by R 4 ~R 8 include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc.

[0166] The hydrocarbon group having 1 to 20 carbon atoms represented by R 4 ~R 8 may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms such as a methyl group, an ethyl group, a n-propyl group, an isopropyl group, a n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a n-pentyl group, a n-hexyl group, a n-octyl group, a n-nonyl group, a n-decyl group, a undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a heptadecyl group, an octadecyl group, a nonadecyl group, a icosyl group; cycloalkyl saturated hydrocarbon groups having 3 to 20 carbon atoms such as a cyclopropyl group, a cyclopentyl group, a cyclohexyl group, a cyclopropylmethyl group, a 4-methylcyclohexyl group, a cyclohexylmethyl group, a norbornyl group, an adamantyl group; alkenyl groups having 2 to 20 carbon atoms such as a vinyl group, an allyl group, a butenyl group, a hexenyl group; alkynyl groups having 2 to 20 carbon atoms such as an ethynyl group, a propynyl group, a butynyl group; cyclo unsaturated aliphatic hydrocarbon groups having 3 to 20 carbon atoms such as a cyclohexenyl group, a norbornenyl group; aryl groups having 6 to 20 carbon atoms such as a phenyl group, a methylphenyl group, an ethylphenyl group, a n-propylphenyl group, an isopropylphenyl group, a n-butylphenyl group, an isobutylphenyl group, a sec-butylphenyl group, a tert-butylphenyl group, a naphthyl group, a methylnaphthyl group, an ethylnaphthyl group, a n-propylnaphthyl group, an isopropylnaphthyl group, a n-butylnaphthyl group, an isobutylnaphthyl group, a sec-butylnaphthyl group, a tert-butylnaphthyl group; aralkyl groups having 7 to 20 carbon atoms such as a benzyl group, a phenethyl group; groups obtained by combining these, etc.

[0167] Furthermore, a part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, a halogen atom, etc., and a part of -CH2- of the aforementioned hydrocarbon group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, etc., and as a result, it may also include 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 pentafluoromercapto 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)-O-C(=O)-), a haloalkyl group, etc.

[0168] Furthermore, R 4 and R 5 may also bond to each other and form a ring together with the sulfur atom to which they are bonded. In this case, the aforementioned ring preferably has the following structure.

[0169] [Chemical formula 44]

[0170]

[0171] In the formula, the dashed line represents an atomic bond.

[0172] Regarding specific examples of the sulfonium cation represented by M + the following can be cited, but are not limited to these.

[0173] [Chemical formula 45]

[0174]

[0175] [Chemical formula 46]

[0176]

[0177] [Chemical formula 47]

[0178]

[0179] [Chemical formula 48]

[0180]

[0181] [Chemical formula 49]

[0182]

[0183] [Chemical formula 50]

[0184]

[0185] [Chemical formula 51]

[0186]

[0187] [Chemical formula 52]

[0188]

[0189] [Chemical formula 53]

[0190]

[0191] [Chemical formula 54]

[0192]

[0193] [Chemical formula 55]

[0194]

[0195] [Chemical formula 56]

[0196]

[0197] [Chemical Formula 57]

[0198]

[0199] [Chemical Formula 58]

[0200]

[0201] [Chemical Formula 59]

[0202]

[0203] [Chemical Formula 60]

[0204]

[0205] [Chemical Formula 61]

[0206]

[0207] [Chemical Formula 62]

[0208]

[0209] [Chemical Formula 63]

[0210]

[0211] [Chemical Formula 64]

[0212]

[0213] [Chemical Formula 65]

[0214]

[0215] [Chemical Formula 66]

[0216]

[0217] [Chemical Formula 67]

[0218]

[0219] [Chemical Formula 68]

[0220]

[0221] [Chemical Formula 69]

[0222]

[0223] [Chemical Formula 70]

[0224]

[0225] [Chemical formula 71]

[0226]

[0227] [Chemical formula 72]

[0228]

[0229] [Chemical formula 73]

[0230]

[0231] [Chemical formula 74]

[0232]

[0233] [Chemical formula 75]

[0234]

[0235] [Chemical formula 76]

[0236]

[0237] [Chemical formula 77]

[0238]

[0239] [Chemical formula 78]

[0240]

[0241] [Chemical formula 79]

[0242]

[0243] Regarding M + Regarding specific examples of the sulfonium cation represented by + , the following can be cited, but are not limited thereto.

[0244] [Chemical formula 80]

[0245]

[0246] [Chemical formula 81]

[0247]

[0248] Regarding the method for synthesizing the aforementioned dicationic salt, for example, a method of salt exchange between a sulfonium salt or a sulfoxonium salt containing a halide anion and a diammonium salt containing a divalent anion having a phenoxide anion structure substituted with an iodine atom and an arylsulfonate anion structure bonded to the aromatic ring of the phenoxide anion structure can be cited.

[0249] In the resist material of the present invention, the content of the aforementioned bis-oxonium salt 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, considering the viewpoints of sensitivity and acid diffusion inhibition effect.

[0250] [Base polymer]

[0251] When the base polymer contained in the resist material of the present invention is a positive resist material, it contains repeating units having acid-labile groups. Regarding the repeating units having acid-labile groups, they are preferably repeating units represented by the following formula (a1) (hereinafter, also referred to as repeating unit a1) or repeating units represented by formula (a2) (hereinafter, also referred to as repeating unit a2).

[0252] [Chemical formula 82]

[0253]

[0254] In formulas (a1) and (a2), R A are each independently a hydrogen atom or a methyl group. Y 1 is a single bond, a phenylene group, a naphthylene group, or a linking group having 1 to 12 carbon atoms containing at least one selected from an ester bond, an ether bond, and a lactone ring, and the phenylene group, naphthylene group, and linking group may also have at least one selected from a hydroxyl group, a saturated hydrocarbon group oxy group having 1 to 8 carbon atoms, and a saturated hydrocarbon group carbonyl oxy group having 2 to 8 carbon atoms. 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 group carbonyl having 2 to 5 carbon atoms, a cyano group, or a saturated hydrocarbon group oxycarbonyl having 2 to 5 carbon atoms. R 14 is a single bond or an alkylene group having 1 to 6 carbon atoms, and the alkylene group may also contain an ether bond or an ester bond. a is an integer from 0 to 4.

[0255] Regarding specific examples of the monomer providing repeating unit a1, the following can be cited, but are not limited to these. And, in the following formulas, R A and R 11 are the same as those described above.

[0256] [Chemical formula 83]

[0257]

[0258] [Chemical formula 84]

[0259]

[0260] [Chemical formula 85]

[0261]

[0262] As specific examples of the monomer that provides the repeating unit a2, those shown below can be cited, but are not limited thereto. Further, in the following formula, R A and R 12 are the same as described above.

[0263] [Chemical formula 86]

[0264]

[0265] Regarding the acid-labile groups represented by R 11 and R 12 in the repeating units a1 and a2, for example, those described in JP-A-2013-80033 and JP-A-2013-83821 can be cited.

[0266] Typically, as specific examples of the foregoing acid-labile groups, those represented by any of the following formulas (AL-1) to (AL-3) can be cited.

[0267] [Chemical formula 87]

[0268]

[0269] In the formula, the dashed line represents an atomic bond.

[0270] In formulas (AL-1) and (AL-2), R L1 and R L2 are each independently a hydrocarbon group having 1 to 40 carbon atoms, and may also contain heteroatoms such as an oxygen atom, a sulfur atom, a nitrogen atom, and a fluorine atom. The foregoing hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Regarding the foregoing hydrocarbon group, a saturated hydrocarbon group having 1 to 40 carbon atoms is preferably used, and a saturated hydrocarbon group having 1 to 20 carbon atoms is more preferably used.

[0271] In formula (AL-1), b is an integer of 0 to 10, and an integer of 1 to 5 is preferably used.

[0272] In formula (AL-2), R L3 and R L4 are each independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and may also contain heteroatoms such as an oxygen atom, a sulfur atom, a nitrogen atom, and a fluorine atom. The foregoing hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Regarding the foregoing hydrocarbon group, a saturated hydrocarbon group having 1 to 20 carbon atoms is preferably used. Further, R L2 , R L3 and R L4Any two of them can also be bonded to each other and together with these bonded carbon atoms or carbon atoms and oxygen atoms form a ring having 3 to 20 carbon atoms. For the aforementioned ring, a ring having 4 to 16 carbon atoms is preferably used, and an alicyclic ring is particularly preferably used.

[0273] In formula (AL-3), R L5 , R L6 and R L7 are each independently a hydrocarbon group having 1 to 20 carbon atoms, and may also contain heteroatoms such as an oxygen atom, a sulfur atom, a nitrogen atom, and a fluorine atom. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. For the aforementioned hydrocarbon group, a saturated hydrocarbon group having 1 to 20 carbon atoms is preferably used. Also, any two of R L5 , R L6 and R L7 can also be bonded to each other and together with these bonded carbon atoms form a ring having 3 to 20 carbon atoms. For the aforementioned ring, a ring having 4 to 16 carbon atoms is preferably used, and an alicyclic ring is particularly preferably used.

[0274] The aforementioned base polymer may also contain a repeating unit b containing a phenolic hydroxyl group as an adhesion group. Specific examples of the monomer that provides the repeating unit b include those shown below, but are not limited to these. Also, in the following formula, R A is the same as the aforementioned one.

[0275] [Chemical formula 88]

[0276]

[0277] The aforementioned 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 adhesion group. Specific examples of the monomer that provides the repeating unit c include those shown below, but are not limited to these. Also, in the following formula, R A is the same as the aforementioned one.

[0278] [Chemical formula 89]

[0279]

[0280] [Chemical formula 90]

[0281]

[0282] [Chemical formula 91]

[0283]

[0284] [Chemical formula 92]

[0285]

[0286] [Chemical Formula 93]

[0287]

[0288] [Chemical Formula 94]

[0289]

[0290] [Chemical Formula 95]

[0291]

[0292] [Chemical Formula 96]

[0293]

[0294] The aforementioned base polymer may also contain repeating unit d derived from indene, benzofuran, benzothiophene, acenaphthylene, chromone, coumarin, norbornadiene or derivatives thereof. Specific examples of the monomer that provides repeating unit d include those shown below, but are not limited thereto.

[0295] [Chemical Formula 97]

[0296]

[0297] The aforementioned base polymer may also contain repeating unit e derived from styrene, vinylnaphthalene, vinylanthracene, vinylpyrene, methyleneindane, vinylpyridine or vinylcarbazole.

[0298] The aforementioned base polymer may also contain repeating unit f derived from an onium salt having a polymerizable unsaturated bond. Specific examples of preferred repeating unit f include the repeating unit represented by the following formula (f1) (hereinafter, also referred to as repeating unit f1), the repeating unit represented by the following formula (f2) (hereinafter, also referred to as repeating unit f2), the repeating unit represented by the following formula (f3) (hereinafter, also referred to as repeating unit f3), the repeating unit represented by the following formula (f4) (hereinafter, also referred to as repeating unit f4), and the repeating unit represented by the following formula (f5) (hereinafter, also referred to as repeating unit f5). Further, for repeating units f1 to f5, one kind may be used alone, or two or more kinds may be used in combination.

[0299] [Chemical Formula 98]

[0300]

[0301] In formulas (f1) to (f5), R A is each independently a hydrogen atom or a methyl group.

[0302] In formulas (f1) to (f3), Z 1is a single bond, an aliphatic alkylene group with 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group with 7 to 18 carbon atoms obtained by combining these, or -O-Z 11 -, -C(=O)-O-Z 11 -, or -C(=O)-NH-Z 11 -. Z 11 is an aliphatic alkylene group with 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group with 7 to 18 carbon atoms obtained by combining these, 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 -O-C(=O)-. Z 31 is an aliphatic alkylene group with 1 to 12 carbon atoms, a phenylene group, or a group with 7 to 18 carbon atoms obtained by combining these, and may also contain a carbonyl group, an ester bond, an ether bond, an iodine atom, or a bromine atom. Z 4 is a methylene group, a 2,2,2-trifluoro-1,1-ethanediyl group, or a carbonyl group. Z 5 is a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, -O-Z 51 -, -C(=O)-O-Z 51 -, or -C(=O)-NH-Z 51 -. Z 51 is an aliphatic alkylene group with 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, or a phenylene group substituted with a trifluoromethyl group, and may also contain a carbonyl group, an ester bond, an ether bond, a halogen atom, or a hydroxyl group. And, Z 1 , Z 11 , Z 31 and Z 51 The aliphatic alkylene group represented by may be saturated or unsaturated, and may be linear, branched, or cyclic.

[0303] In formulas (f4) and (f5), Z 6 is a single bond, a phenylene group, a naphthalene ring, an ester bond, or an amide bond.

[0304] In formula (f4), Z 7A is a single bond or a divalent organic group with 1 to 24 carbon atoms, and may also have at least 1 kind selected from a halogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom.

[0305] Z 7AThe divalent organic group represented can be saturated or unsaturated, and can be linear, branched or cyclic. Specific examples thereof include C1-C24 alkylene groups in which part or all of the hydrogen atoms are substituted with iodine atoms or bromine atoms. Specific examples of the C1-C24 alkylene groups include methane diyl, 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, heptadecane-1,17-diyl, octadecane-1,18-diyl, nonadecane-1,19-diyl, eicosane-1,20-diyl and other alkane diyls; cyclopentane diyl, methylcyclopentane diyl, dimethylcyclopentane diyl, trimethylcyclopentane diyl, tetramethylcyclopentane diyl, cyclohexane diyl, methylcyclohexane diyl, dimethylcyclohexane diyl, trimethylcyclohexane diyl, tetramethylcyclohexane diyl, norbornane diyl, adamantane diyl and other cyclic saturated alkylene groups; phenylene, methylphenylene, ethylphenylene, n-propylphenylene, isopropylphenylene, n-butylphenylene, isobutylphenylene, sec-butylphenylene, tert-butylphenylene, naphthylene, methylnaphthylene, ethylnaphthylene, n-propylnaphthylene, isopropylnaphthylene, n-butylnaphthylene, isobutylnaphthylene, sec-butylnaphthylene, tert-butylnaphthylene, biphenyl diyl, methylbiphenyl diyl, dimethylbiphenyl diyl and other arylene groups; groups obtained by combining these, etc. Also, Z 7A Part or all of the hydrogen atoms of can also be substituted with a group containing at least one selected from oxygen atoms, nitrogen atoms and sulfur atoms, and Z 7A Part of the -CH2- of can also be substituted with a group containing at least one selected from oxygen atoms, nitrogen atoms and sulfur atoms, and as a result, it can also contain hydroxyl groups, ester bonds, ether bonds, amide bonds, urethane bonds, urea bonds, etc.

[0306] In formula (f5), Z 7B is a monovalent organic group having 1 to 10 carbon atoms and can also have at least one selected from halogen atoms, oxygen atoms, nitrogen atoms and sulfur atoms.

[0307] Z 7BThe monovalent organic group represented can be saturated or unsaturated, and can be linear, branched or cyclic. Specific examples thereof include hydrocarbon groups having 1 to 10 carbon atoms in which part or all of the hydrogen atoms are substituted by iodine atoms or bromine atoms. Specific examples of the hydrocarbon groups having 1 to 10 carbon atoms include alkyl groups having 1 to 10 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, sec-pentyl, 3-pentyl, tert-pentyl, neopentyl, n-hexyl, n-octyl, n-nonyl, n-decyl; cycloalkyl saturated hydrocarbon groups having 3 to 10 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, norbornyl, cyclopropylmethyl, cyclopropylethyl, cyclobutylmethyl, cyclobutylethyl, cyclopentylmethyl, cyclopentylethyl, cyclohexylmethyl, cyclohexylethyl, methylcyclopropyl, methylcyclobutyl, methylcyclopentyl, methylcyclohexyl, ethylcyclopropyl, ethylcyclobutyl, ethylcyclopentyl, ethylcyclohexyl; alkenyl groups having 2 to 10 carbon atoms such as vinyl, 1-propenyl, 2-propenyl, butenyl, pentenyl, hexenyl, heptenyl, nonenyl, decenyl; alkynyl groups having 2 to 10 carbon atoms such as ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl, octynyl, nonynyl, decynyl; cyclic unsaturated aliphatic hydrocarbon groups having 3 to 10 carbon atoms such as cyclopentenyl, cyclohexenyl, methylcyclopentenyl, methylcyclohexenyl, ethylcyclopentenyl, ethylcyclohexenyl, norbornenyl; aryl groups having 6 to 10 carbon atoms such as phenyl, methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl; aralkyl groups having 7 to 10 carbon atoms such as benzyl, phenethyl, phenylpropyl, phenylbutyl; groups obtained by combining these, etc. Also, Z 7B Part or all of the hydrogen atoms of can also be substituted by a group containing at least one selected from an oxygen atom, a nitrogen atom and a sulfur atom, and Z 7B Part of the -CH2- of can also be substituted by a group containing at least one selected from an oxygen atom, a nitrogen atom and a sulfur atom, and as a result, it can also contain a hydroxyl group, an ester bond, an ether bond, an amide bond, a urethane bond, a urea bond, etc.

[0308] In formulas (f4) and (f5), Z 8 is a single bond, an ether bond, an ester bond, a thioether bond or an alkylene group having 1 to 6 carbon atoms.

[0309] In formula (f5), Z 9 is a trivalent organic group having 1 to 12 carbon atoms and can also have at least one selected from an oxygen atom, a nitrogen atom and a sulfur atom. Z 9The trivalent organic group represented can be saturated or unsaturated, and can be linear, branched or cyclic. Specific examples thereof include groups obtained by removing one hydrogen atom from an alkylene group having 1 to 12 carbon atoms. Specific examples of the alkylene group having 1 to 12 carbon atoms include those having 1 to 12 carbon atoms among the alkylene groups having 1 to 24 carbon atoms described above. Also, Z 9 A part or all of the hydrogen atoms thereof may also be substituted with a group containing at least one selected from an oxygen atom, a nitrogen atom and a sulfur atom, and Z 9 A part of the -CH2- thereof may also be substituted with a group containing at least one selected from an oxygen atom, a nitrogen atom and a sulfur atom, and as a result, it may also contain a hydroxyl group, an ester bond, an ether bond, an amide bond, a urethane bond, a urea bond, etc.

[0310] In formulas (f1) to (f5), R 21 ~R 25 are each independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may also contain a heteroatom. Specific examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. The hydrocarbon group can be saturated or unsaturated, and can be linear, branched or cyclic. Specific examples thereof include those the same as those exemplified for the hydrocarbon group represented by R 4 ~R 8 in the descriptions of formulas (2) and (3). Also, a part or all of the hydrogen atoms of the hydrocarbon group may also be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, a halogen atom, etc., and a part of the -CH2- of the hydrocarbon group may also be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, etc., 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)-O-C(=O)-), a haloalkyl group, etc. Furthermore, R 23 and R 24 may also be bonded to each other and form a ring together with the sulfur atom to which they are bonded. At this time, specific examples of the ring include those the same as those exemplified for the ring formed by bonding R 4 and R 5 to each other and forming a ring together with the sulfur atom to which they are bonded in the description of formula (2).

[0311] In formulas (f4) and (f5), R 26 are each independently a saturated hydrocarbon group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, a fluorine atom, an iodine atom, a trifluoromethoxy group, a difluoromethoxy group, a cyano group or a nitro group.

[0312] In formulas (f4) and (f5), the cyclic R is a (j + 2)-valent aromatic hydrocarbon group having 6 to 10 carbon atoms. Specific examples of the (j + 2)-valent aromatic hydrocarbon group include groups obtained by removing (j + 2) hydrogen atoms from aromatic hydrocarbons such as benzene and naphthalene.

[0313] In formulas (f4) and (f5), each j independently is an integer from 0 to 5.

[0314] In formula (f1), M - is a non-nucleophilic counter ion. Specific 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, methylide ions such as tris(trifluoromethylsulfonyl)methylide ion and tris(perfluoroethylsulfonyl)methylide ion.

[0315] Specific examples of the non-nucleophilic counter ion further include sulfonate ions having a fluorine atom substituted at the α-position represented by the following formula (f1-1), sulfonate ions having a fluorine atom substituted at the α-position and a trifluoromethyl group substituted at the β-position represented by the following formula (f1-2), etc.

[0316] [Chemical formula 99]

[0317] R 31 -CF2-SO3 - (f1-1)

[0318]

[0319] In formula (f1-1), R 31 is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and the hydrocarbon group may also contain at least one selected from an ether bond, an ester bond, a carbonyl group, a lactone ring, and a fluorine atom. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include the same ones as those exemplified for the hydrocarbon group represented by R f a 1 in formula (1A') described later.

[0320] In formula (f1-2), R 32is a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms or a hydrocarbon group carbonyl having 2 to 30 carbon atoms, and the hydrocarbon group and the hydrocarbon group carbonyl may also contain at least one selected from an ether bond, an ester bond, a carbonyl group, and a lactone ring. The hydrocarbon moiety of the aforementioned hydrocarbon group and hydrocarbon group carbonyl may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include those exemplified by the hydrocarbon group represented by R f a 1 shown later in formula (1A').

[0321] Specific examples of the cation of the monomer providing the repeating unit f1 include those shown below, but are not limited thereto. In the following formula, R A is the same as the aforementioned one.

[0322] [Chemical formula 100]

[0323]

[0324] Specific examples of the cations of the repeating units f2 to f5 include those exemplified by the cations of the onium salts represented by formula (1).

[0325] Specific examples of the anion of the monomer providing the repeating unit f2 include those shown below, but are not limited thereto. In the following formula, R A is the same as the aforementioned one.

[0326] [Chemical formula 101]

[0327]

[0328] [Chemical formula 102]

[0329]

[0330] [Chemical formula 103]

[0331]

[0332] [Chemical formula 104]

[0333]

[0334] [Chemical formula 105]

[0335]

[0336] [Chemical formula 106]

[0337]

[0338] [Chemical formula 107]

[0339]

[0340] [Chemistry 108]

[0341]

[0342] [Chemistry 109]

[0343]

[0344] [Chemistry 110]

[0345]

[0346] [Chemistry 111]

[0347]

[0348] [Chemistry 112]

[0349]

[0350] [Chemistry 113]

[0351]

[0352] [Chemistry 114]

[0353]

[0354] [Chemistry 115]

[0355]

[0356] Specific examples of the anion of the monomer providing the repeating unit f3 include those shown below, but are not limited to these. A Same as above.

[0357] [Chemistry 116]

[0358]

[0359] Specific examples of anions of monomers providing repeating units f4 or f5 include those shown below, but are not limited thereto. A and X BI Same as above.

[0360] [Chemistry 117]

[0361]

[0362] [Chemistry 118]

[0363]

[0364] [Chemistry 119]

[0365]

[0366] [Chemical Formula 120]

[0367]

[0368] [Chemical Formula 121]

[0369]

[0370] [Chemical Formula 122]

[0371]

[0372] [Chemical Formula 123]

[0373]

[0374] [Chemical Formula 124]

[0375]

[0376] [Chemical Formula 125]

[0377]

[0378] [Chemical Formula 126]

[0379]

[0380] [Chemical Formula 127]

[0381]

[0382] [Chemical Formula 128]

[0383]

[0384] [Chemical Formula 129]

[0385]

[0386] [Chemical Formula 130]

[0387]

[0388] [Chemical Formula 131]

[0389]

[0390] [Chemical Formula 132]

[0391]

[0392] [Chemical Formula 133]

[0393]

[0394] [Chemical formula 134]

[0395]

[0396] [Chemical formula 135]

[0397]

[0398] [Chemical formula 136]

[0399]

[0400] [Chemical formula 137]

[0401]

[0402] [Chemical formula 138]

[0403]

[0404] [Chemical formula 139]

[0405]

[0406] [Chemical formula 140]

[0407]

[0408] [Chemical formula 141]

[0409]

[0410] The repeating units f1 to f5 function as an acid generator. By bonding the acid generator to the polymer backbone, acid diffusion can be reduced, preventing a decrease in resolution caused by the blur of acid diffusion. Also, by uniformly dispersing the acid generator, LWR and CDU are improved.

[0411] 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. Also, when the repeating unit f is at least one selected from the repeating units f1 to f5, f = f1 + f2 + f3 + f4 + f5. Further, a1 + a2 + b + c + d + e + f = 1.0.

[0412] On the other hand, for the base polymer for a negative resist material, an acid-labile group is not necessarily required. For such a base polymer, those containing the repeating unit b and, depending on the 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. Also, when the repeating unit f is at least one selected from the repeating units f1 to f5, f = f1 + f2 + f3 + f4 + f5. Further, b + c + d + e + f = 1.0.

[0413] Regarding the method for synthesizing the aforementioned base polymer, for example, a method of adding a radical polymerization initiator and heating the aforementioned monomers providing the repeating units in an organic solvent for polymerization can be mentioned.

[0414] 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.

[0415] When copolymerizing a hydroxyl-containing monomer, the hydroxyl group can be substituted with an acetal group that is easily deprotected by an acid, such as ethoxyethoxy, prior to polymerization, and deprotected with a weak acid and water after polymerization. Alternatively, it can be substituted with an acetyl group, a formyl group, a pivaloyl group, etc. prior to polymerization, and subjected to base hydrolysis after polymerization.

[0416] When copolymerizing hydroxystyrene and hydroxyvinylnaphthalene, hydroxystyrene and hydroxyvinylnaphthalene can also be replaced with acetoxystyrene and acetoxyvinylnaphthalene, and after polymerization, the acetoxy group can be deprotected by the aforementioned base hydrolysis to become hydroxystyrene and hydroxyvinylnaphthalene.

[0417] As for the base in base hydrolysis, ammonia water, triethylamine, etc. can be used. Also, the reaction temperature should preferably be -20 to 100 °C, more preferably 0 to 60 °C. The reaction time should preferably be 0.2 to 100 hours, more preferably 0.5 to 20 hours.

[0418] The polystyrene-equivalent weight-average molecular weight (Mw) of the aforementioned base polymer determined by gel permeation chromatography (GPC) using THF as a solvent should preferably be 1000 to 500000, more preferably 2000 to 30000. If Mw is within the aforementioned range, the heat resistance and solubility in an alkaline developer of the resist film are good.

[0419] Moreover, when the molecular weight distribution (Mw / Mn) in the aforementioned base polymer is broad, since there will be low molecular weight and high molecular weight polymers, after exposure, there is a concern that foreign substances will be seen in the pattern or the shape of the pattern will deteriorate. As the pattern rule is miniaturized, the influence of Mw and Mw / Mn tends to become larger. Therefore, in order to obtain a resist material suitable for a fine pattern size, the Mw / Mn of the aforementioned base polymer is 1.0 to 2.0, particularly preferably a narrow dispersion of 1.0 to 1.5.

[0420] The aforementioned base polymer can also contain two or more polymers with different composition ratios, Mw, and Mw / Mn.

[0421] [Organic solvent]

[0422] 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 later. Specific examples of the aforementioned organic solvent include ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentanone, 2-heptanone, etc. 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, diacetone alcohol, etc.; ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, etc.; 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, propylene glycol monoter-butyl ether acetate, etc.; lactones such as γ-butyrolactone, etc.

[0423] In the resist material of the present invention, the content of the aforementioned organic solvent is preferably 100 to 10,000 parts by mass, more preferably 200 to 8,000 parts by mass, relative to 100 parts by mass of the base polymer. The aforementioned organic solvent may be used alone or in combination of two or more.

[0424] [Quencher]

[0425] The resist material of the present invention may also contain a quencher. And, the so-called quencher means a compound that can prevent the diffusion to the unexposed portion by capturing the acid generated by the acid generator in the resist material.

[0426] Regarding the aforementioned quencher, known types of basic compounds can be cited. Specific examples of the known types of basic compounds include primary, secondary, and tertiary aliphatic amines, hybrid amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxyl group, nitrogen-containing compounds having a sulfonyl group, nitrogen-containing compounds having a hydroxyl group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amides, imides, urethanes, etc. In particular, the primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

[0164] of JP-A-2008-111103, especially amine compounds having a hydroxyl group, an ether bond, an ester bond, a lactone ring, a cyano group, a sulfonate bond, or the compounds having a urethane bond described in Japanese Patent No. 3790649, etc. are 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.

[0427] Further, examples of the aforementioned quenching agent include sulfonium salts, oxonium salts, ammonium salts, etc. of sulfonic acids, carboxylic acids or fluorinated alkoxides 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 when deprotecting acid-labile groups of carboxylic esters, and by performing salt exchange with the aforementioned onium salts, sulfonic acids, carboxylic acids or fluorinated alcohols that are not fluorinated at the α-position are released. Sulfonic acids, carboxylic acids and fluorinated alcohols that are not fluorinated at the α-position do not undergo deprotection reactions, and thus function as quenching agents.

[0428] Specific examples of such a quenching agent include, for example, the compound represented by the following formula (4) (onium salt of sulfonic acid not fluorinated at the α-position), the compound represented by the following formula (5) (onium salt of carboxylic acid), and the compound represented by the following formula (6) (onium salt of alkoxide).

[0429] [Chemical Formula 142]

[0430]

[0431] In formula (4), R 101 is a hydrogen atom or a hydrocarbon group having 1 to 40 carbon atoms that may also contain heteroatoms, provided that the hydrogen atom bonded to the α-carbon atom of the sulfonic acid group is excluded from being substituted with a fluorine atom or a fluoroalkyl group.

[0432] R 101 The hydrocarbon group having 1 to 40 carbon atoms represented may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include alkyl groups having 1 to 40 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl; cycloalkyl groups having 3 to 40 carbon atoms such as cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, tricyclo[5.2.1.0 2,6 decyl, adamantyl, adamantylmethyl; alkenyl groups having 2 to 40 carbon atoms such as vinyl, allyl, propenyl, butenyl, hexenyl; cycloaliphatic unsaturated 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 tri-alkylphenyl (2,4-dimethylphenyl, 2,4,6-triisopropylphenyl, etc.), alkylnaphthyl (methylnaphthyl, ethylnaphthyl, etc.), di-alkylnaphthyl (dimethylnaphthyl, diethylnaphthyl, etc.); and aralkyl groups having 7 to 40 carbon atoms such as benzyl, 1-phenylethyl, 2-phenylethyl.

[0433] Further, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may also be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. Part of the -CH2- of the aforementioned hydrocarbon group may also be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may also contain hydroxyl groups, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate ester bonds, carbonate ester bonds, lactone rings, sultone rings, carboxylic anhydrides (-C(=O)-O-C(=O)-), haloalkyl groups, etc. Specific examples of the hydrocarbon group containing heteroatoms include heteroaryl groups such as thienyl; alkoxyphenyl groups such as 4-hydroxyphenyl, 4-methoxyphenyl, 3-methoxyphenyl, 2-methoxyphenyl, 4-ethoxyphenyl, 4-tert-butoxyphenyl, 3-tert-butoxyphenyl; alkoxynaphthyl groups such as methoxynaphthyl, ethoxynaphthyl, n-propoxynaphthyl, n-butoxynaphthyl; dialkoxynaphthyl groups such as dimethoxynaphthyl, diethoxynaphthyl; aryl oxoalkyl groups such as 2-aryl-2-oxoethyl groups such as 2-phenyl-2-oxoethyl, 2-(1-naphthyl)-2-oxoethyl, 2-(2-naphthyl)-2-oxoethyl, etc.

[0434] In formula (5), R 102 is a hydrocarbon group having 1 to 40 carbon atoms which may also contain heteroatoms. Specific examples of the hydrocarbon group represented by R 102 include those same as the examples shown for the hydrocarbon group represented by R 101 . Further, as other specific examples, fluoroalkyl groups such as trifluoromethyl, trifluoroethyl, 2,2,2-trifluoro-1-methyl-1-hydroxyethyl, 2,2,2-trifluoro-1-(trifluoromethyl)-1-hydroxyethyl; fluoroaryl groups such as pentafluorophenyl, 4-trifluoromethylphenyl, etc. may also be mentioned.

[0435] In formula (6), R 103 is a saturated hydrocarbon group having 1 to 8 carbon atoms having at least 3 fluorine atoms or an aryl group having 6 to 10 carbon atoms having at least 3 fluorine atoms, and may also contain a nitro group.

[0436] In formulas (4), (5) and (6), Mq + is an onium cation. Regarding the aforementioned onium cation, it is preferably a sulfonium cation, an iodonium cation or an ammonium cation, more preferably a sulfonium cation. Specific examples of the aforementioned sulfonium cation include those same as the examples shown for the sulfonium cation represented by M + in the description of formula (1).

[0437] Regarding the quencher, a sulfonium salt of a benzenoid carboxylic acid represented by the following formula (7) can also be preferably used.

[0438] [Chemical formula 143]

[0439]

[0440] In formula (7), x is an integer from 1 to 5. Y is an integer from 0 to 3. Z is an integer from 1 to 3.

[0441] 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 group oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon group carbonyl oxy group having 2 to 6 carbon atoms or a saturated hydrocarbon group sulfonyl oxy group having 1 to 4 carbon atoms, or -N(R 111A )-C(=O)-R 111B or -N(R 111A )-C(=O)-O-R 111B . R 111A is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. R 111B is a saturated hydrocarbon group having 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbon group having 2 to 8 carbon atoms. When y and / or z is 2 or more, each R 111 may be the same as or different from each other.

[0442] In formula (7), L 1 is a single bond or a (z + 1)-valent linking group having 1 to 20 carbon atoms, and may also contain 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 group oxy group, saturated hydrocarbon group carbonyl oxy group, and saturated hydrocarbon group sulfonyl oxy group may be linear, branched, or cyclic.

[0443] In formula (7), R 112 , R 113 and R 114 are each independently a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms which may also contain a hetero atom. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include those exemplified for the hydrocarbon groups represented by R 4 to R 8 in the descriptions of formulas (2) and (3).

[0444] Specific examples of the compound represented by formula (7) include those described in JP-A-2017-219836 and JP-A-2021-91666.

[0445] Examples other than the aforementioned quencher include the polymeric quencher described in JP-A-2008-239918. This improves the rectangularity of the resist pattern by aligning the surface of the resist film. The polymeric quencher also has the effect of preventing pattern film loss and pattern doming when using a protective film for immersion exposure.

[0446] Furthermore, sulfonium salts of betaine type described in Japanese Patent Publication No. 6848776 and Japanese Unexamined Patent Application Publication No. 2020-37544, fluoride atom-free methylated acids described in Japanese Unexamined Patent Application Publication No. 2020-55797, sulfonium salts of sulfonamides described in Japanese Patent Publication No. 5807552, sulfonium salts of sulfonamides containing iodine atoms described in Japanese Unexamined Patent Application Publication No. 2019-211751, and acid generators that generate phenol, halogen, and carbonic acid can be used as quenchers.

[0447] When the resist material of the present invention contains the aforementioned quencher, its content 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 aforementioned quencher can be used alone or in combination of two or more.

[0448] [Other Components]

[0449] In addition to the aforementioned components, it may also contain acid generators other than the salts represented by formula (1) (hereinafter referred to as other acid generators), surfactants, anti-dissolvents, crosslinking agents, water repellency improvers, acetylene alcohols, etc.

[0450] Regarding the aforementioned other acid generators, compounds that generate acid upon irradiation with actinic light or radiation (photoacid generators) can be cited. Regarding the components of the photoacid generator, there is no problem as long as it is a compound that generates acid upon irradiation with high-energy rays, and acid generators that generate sulfonic acid, imidic acid, or methylated acid are preferred. Specific examples of preferred acid generators include sulfonium salts, iodonium salts, sulfonyl diazomethane, N-sulfonyloxyimide, oxime-O-sulfonate type acid generators, etc. Regarding the specific examples of the aforementioned acid generators, those described in paragraphs

[0122] to

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

[0451] Regarding specific examples of the aforementioned surfactants, those described in paragraphs

[0165] to

[0166] of Japanese Unexamined Patent Application Publication No. 2008-111103 can be cited. By adding a surfactant, the coatability 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 aforementioned surfactant can be used alone or in combination of two or more.

[0452] In the case where the resist material of the present invention is positive type, by blending an anti-dissolving agent, the difference in dissolution rate between the exposed portion and the unexposed portion can be further increased, and the resolution can be further improved. As specific examples of the aforementioned anti-dissolving agent, compounds having a molecular weight preferably of 100 to 1000, more preferably 150 to 800, and containing two or more phenolic hydroxyl groups in the molecule, and in which the hydrogen atoms of the phenolic hydroxyl groups are substituted by acid-labile groups in a proportion of 0 to 100 mol% as a whole, or compounds containing a carboxyl group in the molecule, and in which the hydrogen atoms of the carboxyl group are substituted by acid-labile groups in an average proportion of 50 to 100 mol% as a whole can be mentioned. Specifically, bisphenol A, triphenol, phenolphthalein, cresol novolak, naphthyl carboxylic acid, adamantyl carboxylic acid, compounds in which the hydrogen atoms of the hydroxyl group and carboxyl group of cholic acid are substituted by acid-labile groups, etc. can be mentioned. For example, they are described in paragraphs

[0155] to

[0178] of Japanese Patent Laid-Open No. 2008-122932.

[0453] When the resist material of the present invention is positive type and contains the aforementioned anti-dissolving agent, 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 aforementioned anti-dissolving agent can be used alone or in combination of two or more.

[0454] On the other hand, in the case where the resist material of the present invention is negative type, by adding a crosslinking agent, the dissolution rate of the exposed portion can be reduced, and thereby a negative pattern can be obtained. As specific examples of the aforementioned crosslinking agent, epoxy compounds substituted by at least one group selected from hydroxymethyl, alkoxymethyl, and acyloxymethyl, melamine compounds, guanamine compounds, glycoluril compounds or urea compounds, isocyanate compounds, azide compounds, compounds containing double bonds such as vinyloxy groups, etc. can be mentioned. These can be used as additives or introduced as pendant groups on the polymer side chain. Also, compounds containing hydroxyl groups can be used as crosslinking agents.

[0455] As specific examples of the aforementioned epoxy compounds, tris(2,3-epoxypropyl)isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, triethylolethane triglycidyl ether, etc. can be mentioned.

[0456] As specific examples of the aforementioned melamine compounds, hexahydroxymethylmelamine, hexamethoxymethylmelamine, compounds in which 1 to 6 of the hydroxymethyl groups in hexahydroxymethylmelamine are methoxymethylated or mixtures thereof, hexamethoxyethylmelamine, hexacyloxymethylmelamine, compounds in which 1 to 6 of the hydroxymethyl groups in hexahydroxymethylmelamine are acyloxymethylated or mixtures thereof, etc. can be mentioned.

[0457] In terms of the specific examples of the guanylamine compounds, examples thereof include tetramethylol guanylamine, tetramethoxymethyl guanylamine, compounds or mixtures thereof in which 1 to 4 hydroxymethyl groups in tetramethylol guanylamine are methoxymethylated, tetramethoxyethyl guanylamine, tetraacyloxy guanylamine, compounds or mixtures thereof in which 1 to 4 hydroxymethyl groups in tetramethylol guanylamine are acyloxymethylated, and the like.

[0458] In terms of the specific examples of the glycoluril compounds, examples thereof include tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, compounds or mixtures thereof in which 1 to 4 of the hydroxymethyl groups in tetramethylol glycoluril are methoxymethylated, compounds or mixtures thereof in which 1 to 4 of the hydroxymethyl groups in tetramethylol glycoluril are acyloxymethylated, and the like. In terms of the specific examples of the urea compounds, examples thereof include tetramethylol urea, tetramethoxymethyl urea, compounds or mixtures thereof in which 1 to 4 hydroxymethyl groups in tetramethylol urea are methoxymethylated, tetramethoxyethyl urea, and the like.

[0459] In terms of the specific examples of the isocyanate compounds, examples thereof include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, and the like.

[0460] In terms of the specific examples of the azide compounds, examples thereof include 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylenebisazide, 4,4'-oxybisazide, and the like.

[0461] In terms of the specific examples of the compounds containing vinyloxy groups, examples thereof include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,4-butanediol divinyl ether, butanediol 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, trimethylolpropane trivinyl ether, and the like.

[0462] When the resist material of the present invention is a negative type and contains the aforementioned crosslinking agent, its content is preferably 0.1 to 50 parts by mass, more preferably 1 to 40 parts by mass, relative to 100 parts by mass of the base polymer. The aforementioned crosslinking agent can be used alone or in combination of two or more.

[0463] The aforementioned water repellency improver is one that improves the water repellency of the surface of the resist film and can be used in immersion lithography without using a surface coating. Regarding the aforementioned water repellency improver, a polymer containing a fluorinated alkyl group, a polymer containing a 1,1,1,3,3,3 - hexafluoro - 2 - propanol residue with a specific structure, etc. are preferred, and those exemplified in Japanese Patent Application Laid - Open No. 2007 - 297590, Japanese Patent Application Laid - Open No. 2008 - 111103, etc. are preferred. The aforementioned water repellency improver needs to be soluble in an alkaline developer and an organic solvent developer. The aforementioned water repellency improver having a specific 1,1,1,3,3,3 - hexafluoro - 2 - propanol residue has good solubility in the developer. Regarding the water repellency improver, a polymer containing repeating units of amino group and ammonium salt can prevent the evaporation of acid in PEB, so it has a high effect of preventing the opening defect of the hole pattern after development. When the resist material of the present invention contains the aforementioned water repellency improver, its content 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 aforementioned water repellency improver can be used alone or in combination of two or more kinds.

[0464] Regarding specific examples of the aforementioned acetylene alcohols, those described in paragraphs

[0179] to

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

[0465] [Pattern formation method]

[0466] When the resist material of the present invention is used in the manufacture of various integrated circuits, known lithography techniques can be adopted. For example, regarding the pattern formation method, a method including the following steps can be cited: forming a resist film on a substrate using the aforementioned resist material, exposing the aforementioned resist film using high - energy rays, and developing the exposed resist film using a developer.

[0467] First, the resist material of the present invention is coated on a substrate for integrated circuit manufacture (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti - reflection film, etc.) or a substrate for mask circuit manufacture (Cr, CrO, CrON, MoSi2, SiO2, etc.) by an appropriate coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, doctor blade coating, etc. so that the coating film thickness becomes 0.01 to 2 μm. It is pre - baked on a hot plate, preferably at 60 to 150 °C for 10 seconds to 30 minutes, more preferably at 80 to 120 °C for 30 seconds to 20 minutes, to form a resist film.

[0468] Then, a high-energy ray is used to expose the aforementioned resist film. Specific examples of the aforementioned high-energy ray include ultraviolet rays, far ultraviolet rays, EB, EUV with a wavelength of 3 to 15 nm, X-rays, soft X-rays, excimer lasers, γ-rays, synchrotron radiation, etc. When using ultraviolet rays, far ultraviolet rays, EUV, X-rays, soft X-rays, excimer lasers, γ-rays, synchrotron radiation, etc. as the aforementioned high-energy ray, irradiation is performed directly or using a mask for forming a target pattern, and the exposure dose is made about 1 to 200 mJ / cm 2 Preferably, more preferably about 10 to 100 mJ / cm 2 . When using EB as the high-energy ray, the exposure dose is preferably about 0.1 to 300 μC / cm 2 , more preferably about 0.5 to 200 μC / cm 2 and drawing is performed directly or using a mask for forming a target pattern. Moreover, the resist material of the present invention is particularly suitable for fine patterning by KrF excimer laser, ArF excimer laser, EB, EUV, X-rays, soft X-rays, γ-rays, synchrotron radiation in high-energy rays, and particularly suitable for fine patterning by EB or EUV.

[0469] After exposure, PEB may also 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, and it may not be performed either.

[0470] After exposure or after PEB, a developer of an alkaline aqueous solution such as 0.1 to 10% by mass, preferably 2 to 5% by mass of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, etc. is used, and the exposed resist film is developed by a conventional method such as a dip method, puddle method, spray method, etc. for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, to form a target pattern. In the case of a positive resist material, the irradiated part is dissolved in the developer, and the unexposed part is not dissolved, and a target positive pattern is formed on the substrate. In the case of a negative resist material, contrary to the case of the positive resist material, the irradiated part is made insoluble in the developer, and the unexposed part is dissolved.

[0471] Positive resist materials using a base polymer containing an acid-labile group can also obtain a negative pattern by developing with an organic solvent. Specific examples of the developing solution 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, butenyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl valerate, methyl pentenoate, methyl crotonate, ethyl crotonate, 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, phenethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, 2-phenylethyl acetate, etc. These organic solvents can be used alone or in combination of two or more.

[0472] At the end of development, rinsing is performed. As the rinsing liquid, a solvent that is miscible with the developing solution and does not dissolve the resist film is preferred. For 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.

[0473] Specific examples of the alcohols 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, neopentanol, 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.

[0474] Specific examples of the ether compounds 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, di-n-hexyl ether, etc.

[0475] For the specific examples of the alkanes having 6 to 12 carbon atoms, hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, cyclononane, etc. can be mentioned. For the specific examples of the alkenes having 6 to 12 carbon atoms, hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, cyclooctene, etc. can be mentioned. For the specific examples of the alkynes having 6 to 12 carbon atoms, hexyne, heptyne, octyne, etc. can be mentioned.

[0476] For the specific examples of the aromatic solvents, toluene, xylene, ethylbenzene, isopropylbenzene, tert-butylbenzene, mesitylene, etc. can be mentioned.

[0477] By performing rinsing, the collapse of the resist pattern and the generation of defects can be reduced. Also, rinsing is not necessary, and the amount of solvent used can be reduced by not performing rinsing.

[0478] The developed hole pattern and groove pattern can also be shrunk using heat flow, RELACS technology, or DSA technology. When a shrinkage agent is coated on the hole pattern, crosslinking of the shrinkage agent occurs on the surface of the resist film due to the diffusion of the acid catalyst from the resist film during baking, and the shrinkage agent adheres to the sidewalls of the hole pattern. The baking temperature should be 70 to 180 °C, more preferably 80 to 170 °C, and the baking time should be 10 to 300 seconds to remove the excess shrinkage agent and shrink the hole pattern.

[0479] Examples

[0480] Hereinafter, synthesis examples, examples, and comparative examples are illustrated to specifically describe the present invention, but the present invention is not limited to the following examples.

[0481] The structures of the bis-onium salts PAG-PDQ-1 to PAG-PDQ-11 used as an acid generator and quencher in the resist material are shown below.

[0482] [Chemical formula 144]

[0483]

[0484] [Chemical formula 145]

[0485]

[0486] [Chemical formula 146]

[0487]

[0488] [Chemical formula 147]

[0489]

[0490] [Chemical Formula 148]

[0491]

[0492] [Synthesis Example] Synthesis of Base Polymers (Polymers P-1 to P-5)

[0493] The monomers were combined and copolymerized in THF as a solvent, and then added to methanol. The precipitated solid was washed with hexane, separated, and dried to obtain the base polymers (Polymers P-1 to P-5) having the following compositions. The compositions of the obtained base polymers were confirmed by 1 1H-NMR, and Mw and Mw / Mn were confirmed by GPC (solvent: THF, standard: polystyrene).

[0494] [Chemical Formula 149]

[0495]

[0496] [Examples 1 to 18, Comparative Examples 1 to 3] Preparation and Evaluation of Resist Materials

[0497] (1) Preparation of Resist Materials

[0498] A solution prepared by dissolving each component with the composition shown in Table 1 was filtered through a 0.2-μm filter to prepare a resist material.

[0499] In Table 1, each component is as follows.

[0500] Organic solvent: PGMEA (propylene glycol monomethyl ether acetate), EL (ethyl lactate)

[0501] DAA (diacetone alcohol)

[0502] Comparative acid generator and quencher: cPAG-PDQ-1

[0503] [Chemical Formula 150]

[0504]

[0505] Comparative acid generator: cPAG-1

[0506] [Chemical Formula 151]

[0507]

[0508] Mixed acid generators: bPAG-1, bPAG-2

[0509] [Chemical Formula 152]

[0510]

[0511] Hybrid quencher: bPDQ-1

[0512] [Chemical 153]

[0513]

[0514] Comparative quencher: cPDQ-1

[0515] [Chemical 154]

[0516]

[0517] (2) EUV Lithography Evaluation

[0518] Each resist material shown in Table 1 was spin-coated on a Si substrate on which a spin-on hard mask SHB-A940 (silicon content: 43 mass%) manufactured by Shin-Etsu Chemical Co., Ltd. was formed with a film thickness of 20 nm, prebaked at 105 °C for 60 seconds using a hot plate to obtain a resist film with a film thickness of 40 nm. The aforementioned resist film was exposed using an EUV scanning exposure machine NXE3400 (NA 0.33, σ 0.9 / 0.7, dipole illumination) manufactured by ASML, PEB was performed at the temperature shown in Table 1 for 60 seconds on a hot plate, and development was performed for 30 seconds with a 2.38 mass% TMAH aqueous solution to form lines and spaces with a pitch of 32 nm and a line width of 16 nm. Examples 1 to 17 and Comparative Examples 1 and 2 are positive resist materials, and Examples 18 and Comparative Example 3 are negative resist materials.

[0519] Using a length measurement SEM (CG6300) manufactured by Hitachi High-Technologies Corporation, the exposure dose for forming a line pattern with a size of 16 nm ± 1.6 nm was obtained, and the LWR of the line pattern in this exposure dose was measured. The results are shown in Table 1.

[0520] [Table 1]

[0521]

[0522]

[0523] From the results shown in Table 1, it can be seen that the resist material of the present invention containing a dicationic salt having a divalent anion containing a phenoxide anion structure substituted with an iodine atom and an arylsulfonic acid anion structure bonded to the aromatic ring of the phenoxide anion structure and an onium cation is highly sensitive and has good LWR.

Claims

1. A resist material comprising: A bis - onium salt containing a divalent anion having a phenoxide anion structure substituted with an iodine atom and an arylsulfonic acid anion structure bonded to the aromatic ring of the phenoxide anion structure, and an onium cation.

2. The resist material according to claim 1, wherein The bis - onium salt is represented by the following formula (1), wherein m is an integer from 1 to 4, n is an integer from 0 to 3, provided that 1 ≤ m + n ≤ 4, p is an integer from 0 to 10, X 1 and X 2 each independently represents a single bond, an ether bond, an ester bond, a sulfonate bond, a carbonate bond or a carbamate bond, R 1 is a hydrocarbon group having 1 to 10 carbon atoms, a halogen atom other than an iodine atom, a nitro group or a cyano group, and the hydrocarbon group may also have at least one selected from halogen atoms, oxygen atoms, sulfur atoms and nitrogen atoms, R 2 is a single bond or a C1-C40 alkylene group, which may also contain at least one selected from the group consisting of an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom. R 3 is a halogen atom, trifluoromethyl, trifluoromethoxy, cyano, nitro, hydroxy, carboxy, amino, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbon oxy group having 1 to 20 carbon atoms, a hydrocarbon oxycarbonyl group having 2 to 20 carbon atoms, a hydrocarbon carbonyloxy group having 2 to 20 carbon atoms, a hydrocarbon sulfonyloxy group having 1 to 20 carbon atoms, -N(R 3A )-C(=O)-R 3B , -N(R 3A )-C(=O)-O-R 3B or -N(R 3A )-S(=O)2-R 3B , and the hydrocarbon group, hydrocarbon oxy group, hydrocarbon oxycarbonyl group, hydrocarbon carbonyloxy group, and hydrocarbon sulfonyloxy group may also contain at least one selected from a fluorine atom, chlorine atom, bromine atom, iodine atom, hydroxy, amino, ester bond, ether bond, urethane bond, urea bond, carbonate bond, amide bond, sulfonic acid bond, carbonyl, thioether group, and sulfonyl group; R 3A 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, hydroxy, 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 3B 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, hydroxy, 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. Ar is a (p + 2) - valent aromatic hydrocarbon group having 6 to 16 carbon atoms, M + is a sulfonium cation or an iodonium cation.

3. 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 each independently represents a hydrogen atom or a methyl group, Y 1 is a single bond, a phenylene group, a naphthylene group, or a linking group having 1 to 12 carbon atoms containing at least one selected from an ester bond, an ether bond, and a lactone ring, and the phenylene group, naphthylene group, and linking group may also have at least one selected from a hydroxyl group, a saturated hydrocarbon group oxy group having 1 to 8 carbon atoms, and a saturated hydrocarbon group carbonyl oxy group having 2 to 8 carbon atoms. 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 each independently represents an acid-labile group, R 13 is a saturated hydrocarbon group having 1 to 4 carbon atoms, a halogen atom, a saturated hydrocarbon group carbonyl having 2 to 5 carbon atoms, a cyano group or a saturated hydrocarbon group oxycarbonyl having 2 to 5 carbon atoms, R 14 is a single bond or an alkylene group having 1 to 6 carbon atoms, and the alkylene group may also contain an ether bond or an ester bond. a is an integer from 0 to 4.

5. The resist material according to claim 4 is a chemically amplified positive - type resist material.

6. The resist material according to claim 3, wherein, The base polymer does not contain acid - labile groups.

7. The resist material according to claim 6 is a chemically amplified negative - type resist material.

8. 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 an acid generator.

11. 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 with high - energy rays, and developing the exposed resist film with a developer.

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

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