Method for producing metatungstate compound, metatungstate compound for resists, and resist material

Abstract

The present invention provides: a method for selectively producing a metatungstate compound which contains five onium cations or onium dications by performing a salt exchange reaction of a metatungstate in an acidic solution that has a pH of less than 3; a novel metatungstate compound for resists, the metatungstate compound being produced by the production method; and a resist material which contains the metatungstate compound for resists.

Description

[Rule 26 Supplement 21.08.2024] Method for producing metatungstate compound, metatungstate compound for resist, and resist material

[0001] The present invention relates to a method for producing a metatungstate compound, a metatungstate compound for a resist, and a resist material.

[0002] Ammonium metatungstate is widely used in the production of tungsten metal, steel alloys, flame-retardant fabrics, and petrochemical catalysts.

[0003] In recent years, resist-related compositions containing metatungstate have been reported. For example, Patent Document 1 discloses a resist underlayer film-forming composition containing metatungstate (alkali metal salt, ammonium salt, etc.) and polysiloxane, etc. Furthermore, Patent Document 2 discloses a composition containing ammonium metatungstate and silane or polysiloxane, which is applied to a resist pattern to reverse the pattern by utilizing the difference in etching rate.

[0004] U.S. Patent No. 9,725,618 U.S. Patent No. 10,558,119

[0005] The present invention aims to provide a method for selectively producing a metatungstate compound in which a predetermined number of cation moieties of metatungstate are substituted with a predetermined number of counter cations, and also provides a novel metatungstate compound for resist and a novel resist material containing such a metatungstate compound for resist.

[0006] As a result of intensive research aimed at solving the above problems, the present inventors discovered that a metatungstate compound containing five onium cations or five onium dications can be selectively produced by carrying out a salt exchange reaction of metatungstate in an acidic solution having a pH of less than 3, thereby completing the present invention.

[0007] That is, the present invention relates to the following inventions: <1> A method for producing a metatungstate compound represented by general formula (I-1) or (I-2), comprising a step of salt exchange in an acidic solution having a pH of less than 3. (A ＋ ) ５ ・[H ３ W １２ O ４０ ] ５－ (I-1) (A' ２＋ ) ５ ・([H ３ W １２ O ４０ ] ５－ ) ２ (I-2) [In formulas (I-1) and (I-2), A ＋ A' each independently represents an onium cation; ２＋ each independently represents an onium dication.] <2> The method for producing a metatungstate compound according to <1>, wherein the onium cation is one or more selected from the group consisting of an organic sulfonium cation, an organic iodonium cation, and an organic ammonium cation. <3> The method for producing a metatungstate compound according to <1>, wherein the acidic solution having a pH of less than 3 contains an inorganic acid, an organic acid having a carboxy group, or an organic acid having a sulfo group. <4> The method for producing a metatungstate compound according to <1>, wherein the salt exchange is between a metatungstate represented by general formula (II) and an onium salt represented by general formula (III-1) or (III-2). (B ＋ ) ６ ・[H ２ W １２ O ４０ ] ６－ (II) A ＋ ・X － (III-1) A' ２＋ ・(X － ) ２ (III-2) [In formula (II), B ＋ are each independently H ＋, a metal ion, or an ammonium ion; ＋ represents an onium cation; ２＋ represents an onium dication; X － represents a monovalent counter anion.] <5> The monovalent counter anion is Br － , Cl － , I － ,Br ３－ , O.H. － , HSO ４ － , C.F. ３ SO ３ － , C ２ F ５ SO ３ － , C ３ F ７ SO ３ － , C ４ F ９ SO ３ － , p-CH ３ (C ６ H ４ ) SO ３ － , ClSO ３ － , ClO ４ － , NO ３ － , (C ６ F ５ ) ４ B － , B.F. ４ － , P.F. ６ － , SbF ６ － , AlCl ４ － , BiF ６ － , AsF ６ － , (CF ３ SO ２ ) ２ N － or (FSO ２ ) ２ N －<6> A metatungstate compound for resist represented by general formula (I-1) or (I-2): (A ＋ ) ５ ・[H ３ W １２ O ４０ ] ５－ (I-1) (A' ２＋ ) ５ ・([H ３ W １２ O ４０ ] ５－ ) ２ (I-2) [In formulas (I-1) and (I-2), A ＋ A' each independently represents an onium cation; ２＋ each independently represents an onium dication.] <7> A resist material comprising the metatungstate for resists according to <6>. <8> The resist material according to <7>, further comprising a solvent. <9> The resist material according to <7> or <8>, which is a resist material for electron or EUV radiation. <10> A patterned structure formed using the resist material according to <7> or <8>.

[0008] According to the present invention, a metatungstate compound containing five onium cations or onium dications can be selectively produced. Furthermore, the metatungstate compound has improved actinic ray and / or radiation sensitivity and can be suitably used as a metatungstate compound for resists. Furthermore, since the metatungstate compound selectively produced by the production method of the present invention has a certain degree of uniformity, when incorporated into a resist material, a novel resist material can be provided that exhibits minimal change in pattern dimension (CD: critical dimension).

[0009] Preferred embodiments of the present invention will be described in detail below, but the present invention is not limited to the following embodiments.

[0010] As used herein, the term "halogen atom" refers to a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

[0011] In this specification, for example, "C １－６ " and other terms refer to the number of carbon atoms in the core group.

[0012] As used herein, "C １－１８ The term "hydrocarbylene group" refers to a divalent hydrocarbon group generated by removing two hydrogen atoms from a hydrocarbon having 1 to 18 carbon atoms. The hydrocarbylene group may be linear or branched, or may be partially or entirely cyclic. The hydrocarbylene group includes alkylene groups, arylene groups, etc. Also, "C １－１８ The divalent carbon atom at any position of the "hydrocarbylene group" may be -O-, -S-, -C(=O)-, -COO-, -OCO-, -CONH-, -NHCO-, -NH(C=O)O-, -S-, -SO-, or -SO ２ - may be substituted (however, adjacent divalent carbon atoms may not be substituted at the same time). １－１８ The "hydrocarbylene group" is not particularly limited, and examples thereof include "C" such as methylene group, ethylene group, n-propylene group, i-propylene group, cyclopentadiyl group, cyclohexanediyl group, oxyethane-1,1-diyl group, oxyethane-1,2-diyl group, oxypropane-1,3-diyl group, oxypropane-1,2-diyl group, 2-methylpropane-1,3-diyl group, and oxyethyleneoxyethane-1,1-diyl group. １－１８ alkylene group"; 1,4-phenylene group, 1,3-phenylene group, 1,2-phenylene group, 1,4-naphthylene group, 1,5-naphthylene group, 1,8-naphthylene group, 4,4'-biphenylene group, anthracenediyl group, phenanthrenediyl group, naphthacenediyl group, pyrenediyl group, perylenediyl group, chrysenediyl group, etc. ６－１８ arylene group" and the like.

[0013] As used herein, "C １－１８ The term "alkyl group" means a linear or branched alkyl group having 1 to 18 carbon atoms. １－１８The divalent carbon atom at any position excluding the terminal contained in the "alkyl group" is -O-, -C(=O)-, -C(=O)O-, -OCO-, -CONH-, -NHCO-, -NH(C=O)O-, -S-, or -SO ２ However, adjacent divalent carbon atoms may not be replaced at the same time. １－１８ The "alkyl group" is not particularly limited, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a sec-butyl group, a t-butyl group, an n-pentyl group, an i-pentyl group, a sec-pentyl group, a t-pentyl group, a neopentyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 1,1-dimethylpropyl group, a 1,2-dimethylpropyl group, an n-hexyl group, an i-hexyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, a 1 , 1-dimethylbutyl group, 1,2-dimethylbutyl group, 2,2-dimethylbutyl group, 1,3-dimethylbutyl group, 2,3-dimethylbutyl group, 3,3-dimethylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1,1,2-trimethylpropyl group, 1,2,2-trimethylpropyl group, 1-ethyl-1-methylpropyl group, 1-ethyl-2-methylpropyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, n-undecyl group, n-dodecyl group, and the like. １－１８ The alkyl group may have a divalent carbon atom at any position excluding the terminal, and the divalent carbon atom may be -O-, -C(=O)-, -C(=O)O-, -OCO-, -CONH-, -NHCO-, -NH(C=O)O-, -S-, or -SO ２ The group substituted with - is not particularly limited, and examples thereof include a 2-methoxyethoxymethyl group, an ethoxycarbonylmethyl group, and the like.

[0014] As used herein, "C １－１８ The term "haloalkyl group" refers to "C １－１８ "C" means a group in which one or more hydrogen atoms of an "alkyl group" are substituted with halogen atoms. １－１８The "haloalkyl group" is not particularly limited, and examples thereof include a dichloromethyl group, a trifluoromethyl group, a 2,2-difluoroethyl group, a 2,2,2-trifluoroethyl group, a pentafluoroethyl group, and a 3,3,3-trifluoropropyl group.

[0015] As used herein, "C ２－１８ The term "alkenyl group" refers to a group having two or more carbon atoms. １－１８ "C" means an alkenyl group having one or more double bonds, and includes alkadienyl groups, alkatrienyl groups, etc. ２－１８ The "alkenyl group" is not particularly limited, and examples thereof include a vinyl group (ethenyl group), an allyl group (2-propenyl group), a 1-propenyl group, an isopropenyl group (1-methylvinyl group), a 1-butenyl group, a 2-butenyl group, a 3-butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an octenyl group, a nonenyl group, a decenyl group, an undecenyl group, and a dodecenyl group.

[0016] As used herein, "C ２－１８ The term "alkynyl group" refers to a group having two or more carbon atoms. １－１８ "C" means an alkynyl group having one or more triple bonds in the "alkyl group." ２－１８ The "alkynyl group" is not particularly limited, and examples thereof include an ethynyl group, a 1-propynyl group, a 2-propynyl group, a pentynyl group, a hexynyl group, a heptynyl group, an octynyl group, a nonynyl group, a decynyl group, an undecynyl group, and a dodecynyl group.

[0017] As used herein, "C ３－１８ The term "alicyclic group" refers to a hydrocarbon group having, in whole or in part, a monocyclic or polycyclic structure having 3 to 18 carbon atoms. Alicyclic groups also include cycloalkyl groups, cycloalkenyl groups, cycloalkynyl groups, monocycloalkyl groups, polycycloalkyl groups, etc. ３－１８ A divalent carbon atom at any position excluding the terminals contained in the "alicyclic group" may be -O-, -C(=O)-, -C(=O)O-, -OCO-, -CONH-, -NHCO-, -NH(C=O)O-, -S-, or SO ２- may be substituted (however, adjacent divalent carbon atoms may not be substituted at the same time). ３－１８ The "cycloalkyl group" is not particularly limited, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a 1-i-propylcyclopentan-1-yl group, a cyclohexyl group, a t-butylcyclohexyl group, a tricyclodecanyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, a 2-methyladamantan-2-yl group, a 2-i-propyladamantan-2-yl group, a bornyl group, a norbornyl group, a fenchyl group, a pinanyl group, an adamantyl group, a tricyclodecyl group, a tetracyclododecyl group, a cyclopropylmethyl group, a cyclobutylmethyl group, a cyclopentylmethyl group, a cyclohexylmethyl group, a bornylmethyl group, a norbornylmethyl group, an adamantylmethyl group, a 1-methylcyclopentyloxycarbonylmethyl group, a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group.

[0018] As used herein, the term "3- to 18-membered non-aromatic heterocyclic group" refers to a 3- to 18-membered non-aromatic heterocyclic group containing one or more heteroatoms selected from the group consisting of nitrogen atoms, oxygen atoms, and sulfur atoms, and may be a monocyclic, polycyclic, or fused ring, and may be saturated or partially unsaturated. The "3- to 18-membered non-aromatic heterocyclic group" is not particularly limited, and examples thereof include an aziridinyl group, an azetidyl group, a pyrrolidinyl group, a pyrrolyl group, a piperidinyl group, a piperazinyl group, a morpholinyl group, a thiomorpholinyl group, a tetrahydrofuryl group, a tetrahydropyranyl group, an oxetanyl group, a tetrahydrofuryl group, a tetrahydropyranyl group, an imidazolinyl group, an oxazolinyl group, a 2,5-diazabicyclo[2.2.1]heptyl group, a 2,5-diazabicyclo[2.2.2]octyl group, a 3,8-diazabicyclo[3.2.1]octyl group, a 1,4-diazabicyclo[4.3.0]nonyl group, a 1-azaadamantyl group, and a 2-azaadamantyl group.

[0019] As used herein, "C ２－１８The term "aryl group" means an aromatic hydrocarbon cyclic group having 6 to 18 carbon atoms or an aromatic heterocyclic group having 2 to 10 carbon atoms. In the case of an aromatic heterocyclic group, a ring is formed by a carbon atom having 2 to 10 carbon atoms and one or more heteroatoms selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom, and each may be a monocyclic ring, a polycyclic ring, or a fused ring. ２－１８ The "aryl group" is not particularly limited, and examples thereof include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, an azulenyl group, a pentalenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a phenanthrenyl group, an anthracenyl group, and the like.

[0020] As used herein, "C ７－１８ The term "aralkyl group" refers to "C １－１２ The substitutable portion of the "C alkyl group" is ２－１２ "C" means a group substituted with an "aryl group." ７－１８ The "aralkyl group" is not particularly limited, and examples thereof include a benzyl group, a phenethyl group, a 3-phenylpropyl group, a 4-phenylbutyl group, a 1-naphthylmethyl group, and a 2-naphthylmethyl group.

[0021] As used herein, "C １－１８ The term "hydrocarbyl group" refers to a monovalent group formed by removing one hydrogen atom from a hydrocarbon having 1 to 18 carbon atoms. Hydrocarbyl groups include alkyl groups, alkenyl groups, alkynyl groups, alicyclic groups, aryl groups, aralkyl groups, and the like. １－１８ A divalent carbon atom at any position excluding the terminal contained in the "hydrocarbyl group" may be -O-, -C(=O)-, -C(=O)O-, -OCO-, -CONH-, -NHCO-, -NH(C=O)O-, -S-, or -SO ２ - (however, adjacent divalent carbon atoms cannot be replaced at the same time). １－１８ The term "C" used in the definition of "hydrocarbyloxy group" and the like is used in the definition of "C" １－１８ The same applies to "hydrocarbyl group" and the like. １－１８ The "hydrocarbyl group" is not particularly limited, and examples thereof include "C １－１８alkyl group," "C ２－１８ alkenyl group," "C ２－１８ alkynyl group," "C ３－１８ Alicyclic group”, “C ２－１８ aryl group," "C ７－１８ aralkyl groups, etc.

[0022] As used herein, "C １－１８ The term "hydrocarbyloxy group" refers to a group consisting of "C １－１８ "C" means a group in which an oxygen atom (-O-) is bonded to a "hydrocarbyl group." １－１８ The "hydrocarbyloxy group" is not particularly limited, and examples thereof include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, an i-butoxy group, a sec-butoxy group, a t-butoxy group, an n-pentoxy group, an i-pentoxy group, a sec-pentoxy group, an n-hexoxy group, an i-hexoxy group, a 1,1-dimethylpropyloxy group, a 1,2-dimethylpropyloxy group, a 2,2-dimethylpropyloxy group, a 1-methyl- "C" groups such as 2-ethylpropyloxy group, 1-ethyl-2-methylpropyloxy group, 1,1,2-trimethylpropyloxy group, 1,2,2-trimethylpropyloxy group, 1,1-dimethylbutyloxy group, 1,2-dimethylbutyloxy group, 2,2-dimethylbutyloxy group, 2,3-dimethylbutyloxy group, 1,3-dimethylbutyloxy group, 2-ethylbutyloxy group, 2-methylpentyloxy group, and 3-methylpentyloxy group １－１８ alkoxy group"; cyclopropyloxy group, cyclobutyloxy group, cyclopentyloxy group, cyclohexyloxy group, cycloheptyloxy group, cyclooctyloxy group, 1-methylcyclopentyloxycarbonylmethoxy group, 1-ethylcyclohexyloxycarbonylmethoxy group, 1-methyladamantyloxycarbonylmethoxy group, etc. ３－１８ alicyclic oxy group"; phenyloxy group, 1-naphthyloxy group, 2-naphthyloxy group, azulenyloxy group, pentalenyloxy group, heptalenyloxy group, indacenyloxy group, acenaphthyloxy group, phenanthrenyloxy group, anthracenyloxy group, etc. ６－１８ aryloxy group."１－１８ The "hydrocarbyloxy group" includes "C １－１８ It is preferred that a divalent carbon atom at any position except the terminal contained in the "hydrocarbyl group" is replaced with -O-, -C(=O)-, and / or -C(=O)O-. １－１８ A "hydrocarbyloxycarbonylalkyloxy group" is more preferred, and from the viewpoint of solubility, it is even more preferred that the carbon bonded to the oxygen atom of the hydrocarbyloxy is a tertiary carbon. Specific examples of the hydrocarbyloxy include optionally substituted ethylcyclopentyloxy, methyladamantyloxy, ethyladamantyloxy, t-butyloxy, and the like.

[0023] As used herein, "C １－１８ The term "hydrocarbyl carbonyl group" refers to a group consisting of "C １－１８ It means a group in which a carbonyl group (—C(═O)—) is bonded to a “hydrocarbyl group.” １－１８ The "hydrocarbyl carbonyl group" is not particularly limited, and examples thereof include "C" such as an acetyl group, a propionyl group, an isopropionyl group, a butyryl group, an isobutyryl group, a valeryl group, an isovaleryl group, a pentanoyl group, a 3-methylbutanoyl group, a pivaloyl group, a hexanoyl group, and a heptanoyl group. １－１８ alkylcarbonyl group"; cyclopropylcarbonyl group, cyclobutylcarbonyl group, cyclopentylcarbonyl group, 2-methylcyclopentylcarbonyl group, 3-methylcyclopentylcarbonyl group, cyclohexylcarbonyl group, 2-methylcyclohexylcarbonyl group, 3-methylcyclohexylcarbonyl group, 4-methylcyclohexylcarbonyl group, adamantylcarbonyl group, etc. ３－１８ alicyclic carbonyl group"; "C" such as benzoyl group, 1-naphthoyl group, 2-naphthoyl group, etc. ６－１８ arylcarbonyl group" and the like.

[0024] As used herein, "C １－１８ The term "hydrocarbylcarbonyloxy group" refers to a group consisting of "C １－１８ "C" means a group in which an oxygen atom (-O-) is bonded to a "hydrocarbyl carbonyl group." １－１８The "hydrocarbylcarbonyloxy group" is not particularly limited, and examples thereof include "C" such as a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, an isobutylcarbonyloxy group, a t-butylcarbonyloxy group, an n-pentylcarbonyloxy group, an isopentylcarbonyloxy group, and a hexylcarbonyloxy group. １－１８ alkylcarbonyloxy group"; cyclopropylcarbonyloxy group, cyclobutylcarbonyloxy group, cyclopentylcarbonyloxy group, cyclohexylcarbonyloxy group, etc. ３－１８ alicyclic carbonyloxy group"; "C" such as a phenylcarbonyloxy group, a naphthylcarbonyloxy group, an acenaphthylcarbonyloxy group, a phenanthrenylcarbonyloxy group, an anthracenylcarbonyloxy group, etc. ６－１８ arylcarbonyloxy group" and the like.

[0025] As used herein, "C １－１８ The term "hydrocarbyloxycarbonyl group" refers to a group consisting of "C １－１８ It means a group in which a carbonyl group (—C(═O)—) is bonded to a “hydrocarbyloxy group.” １－１８ The "hydrocarbyloxycarbonyl group" is not particularly limited, and examples thereof include "C" such as a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, an i-propoxycarbonyl group, an n-butoxycarbonyl group, an i-butoxycarbonyl group, a sec-butoxycarbonyl group, a t-butoxycarbonyl group, an n-pentoxycarbonyl group, and a neopentyloxycarbonyl group. １－１８ alkoxycarbonyl group"; "C" such as a cyclopropyloxycarbonyl group, a cyclobutyloxycarbonyl group, a cyclopentyloxycarbonyl group, a cyclohexyloxycarbonyl group, a 2-methylcyclopentyloxycarbonyl group, a 3-methylcyclopentyloxycarbonyl group, a 2-methylcyclohexyloxycarbonyl group, a 3-methylcyclohexyloxycarbonyl group, and a 4-methylcyclohexyloxycarbonyl group; ３－１８alicyclic oxycarbonyl group"; "C" such as a phenoxycarbonyl group, a naphthoxycarbonyl group, an acenaphthyloxycarbonyl group, a phenanthrenyloxycarbonyl group, an anthracenyloxycarbonyl group, etc. ６－１８ aryloxycarbonyl group" and the like.

[0026] As used herein, "C １－１８ The term "hydrocarbyloxycarbonyloxy group" refers to a group consisting of "C １－１８ "C" means a group in which an oxygen atom (-O-) is bonded to a "hydrocarbyloxycarbonyl group." １－１８ The "hydrocarbyloxycarbonyloxy group" is not particularly limited, and examples thereof include "C" such as a methoxycarbonyloxy group, an ethoxycarbonyloxy group, an n-propyloxycarbonyloxy group, an i-propyloxycarbonyloxy group, an n-butoxycarbonyloxy group, an i-butoxycarbonyloxy group, a sec-butoxycarbonyloxy group, a t-butoxycarbonyloxy group, an n-pentyloxycarbonyloxy group, an i-pentyloxycarbonyloxy group, and an n-hexyloxycarbonyloxy group. １－１８ alkoxycarbonyloxy group"; "C" such as cyclopropyloxycarbonyloxy group, cyclobutyloxycarbonyloxy group, cyclopentyloxycarbonyloxy group, cyclohexyloxycarbonyloxy group, etc. ３－１８ alicyclic oxycarbonyloxy group"; "C" such as a phenoxycarbonyloxy group, a naphthoxycarbonyloxy group, an acenaphthyloxycarbonyloxy group, a phenanthrenyloxycarbonyloxy group, an anthracenyloxycarbonyloxy group, etc. ６－１８ aryloxycarbonyloxy group" and the like.

[0027] As used herein, "C １－１８ The term "hydrocarbylamino group" refers to a group consisting of one "C １－１８ "C" means a group bonded to an amino group. １－１８The "hydrocarbylamino group" is not particularly limited, and examples thereof include a "C hydrocarbylamino group" such as a methylamino group, an ethylamino group, an n-propylamino group, an i-propylamino group, an n-butylamino group, an i-butylamino group, a sec-butylamino group, a t-butylamino group, an n-pentylamino group, an i-pentylamino group, a neopentylamino group, and an n-hexylamino group. １－１８ alkylamino group"; cyclopropylamino group, cyclobutylamino group, cyclopentylamino group, 2-methylcyclopentylamino group, 3-methylcyclopentylamino group, cyclohexylamino group, 2-methylcyclohexylamino group, 3-methylcyclohexylamino group, 4-methylcyclohexylamino group, etc. ３－１８ alicyclic amino group"; phenylamino group, 1-naphthylamino group, 2-naphthylamino group, etc. ６－１８ arylamino group" and the like.

[0028] As used herein, "diC １－１８ The term "hydrocarbylamino group" refers to two identical or different "C １－１８ "DiC" means a group in which a "hydrocarbyl group" is bonded to an amino group. １－１８ The "hydrocarbylamino group" is not particularly limited, and examples thereof include a dimethylamino group, a diethylamino group, a di-n-propylamino group, a diisopropylamino group, a di-n-butylamino group, a diisobutylamino group, a di-t-butylamino group, a di-n-pentylamino group, a di-n-hexylamino group, an N-ethyl-N-methylamino group, an N-methyl-N-n-propylamino group, an N-isopropyl-N-methylamino group, an N-n-butyl-N-methylamino group, an N N-isobutyl-N-methylamino group, N-t-butyl-N-methylamino group, N-methyl-N-n-pentylamino group, N-n-hexyl-N-methylamino group, N-ethyl-N-n-propylamino group, N-ethyl-N-isopropylamino group, N-n-butyl-N-ethylamino group, N-ethyl-N-isobutylamino group, N-t-butyl-N-ethylamino group, N-ethyl-N-n-pentylamino group, N-ethyl-N-n-hexylamino group, and other "di-C １－１８alkylamino group"; "di-C" such as dicyclopropylamino group, dicyclobutylamino group, dicyclopentylamino group, dicyclohexylamino group, etc. ３－１８ alicyclic amino group"; "di-C" such as diphenylamino group, phenylnaphthylamino group, etc. ６－１８ "N-C arylamino group" such as N-methylcyclopentanamino group, N-methylcyclohexylamino group, etc. １－１８ Alkyl-N—C ３－１８ cycloalkylamino group"; "N-C cycloalkylamino group" such as N-methyl-2-phenylethylamino group, N-ethyl-N-(4-methylphenyl)amino group, etc. １－１８ Alkyl-N—C ６－１８ arylamino group" and the like.

[0029] As used herein, "C １－１８ The term "hydrocarbylaminocarbonyl group" refers to a group consisting of "C １－１８ It means a group in which a carbonyl group (—C(═O)—) is bonded to a “hydrocarbylamino group.” １－１８ The "hydrocarbylaminocarbonyl group" is not particularly limited, and examples thereof include "C" such as a methylaminocarbonyl group, an ethylaminocarbonyl group, an n-propylaminocarbonyl group, an i-propylaminocarbonyl group, an n-butylaminocarbonyl group, a sec-butylaminocarbonyl group, a t-butylaminocarbonyl group, an n-pentylaminocarbonyl group, a 2-pentylaminocarbonyl group, a neopentylaminocarbonyl group, a 4-methyl-2-pentylaminocarbonyl group, an n-hexylaminocarbonyl group, and a 3-methyl-n-pentylaminocarbonyl group. １－１８ alkylaminocarbonyl group"; cyclopropylaminocarbonyl group, cyclobutylaminocarbonyl group, cyclopentylaminocarbonyl group, cyclohexylaminocarbonyl group, 2-methylcyclopentylaminocarbonyl group, 3-methylcyclopentylaminocarbonyl group, 2-methylcyclohexylaminocarbonyl group, 3-methylcyclohexylaminocarbonyl group, 4-methylcyclohexylaminocarbonyl group, etc. ３－１８ alicyclic aminocarbonyl group"; phenylaminocarbonyl group, 1-naphthylaminocarbonyl group, 2-naphthylaminocarbonyl group, etc.６－１８ arylaminocarbonyl group.

[0030] As used herein, "diC １－１８ The term "hydrocarbylaminocarbonyl group" refers to a "diC １－１８ "DiC" refers to a group in which a carbonyl group (-C(=O)-) is bonded to a "hydrocarbylamino group." １－１８ The "hydrocarbylaminocarbonyl group" is not particularly limited, and examples thereof include a dimethylaminocarbonyl group, a diethylaminocarbonyl group, a di-n-propylaminocarbonyl group, a diisopropylaminocarbonyl group, a di-n-butylaminocarbonyl group, a diisobutylaminocarbonyl group, a di-t-butylaminocarbonyl group, a di-n-pentylaminocarbonyl group, a di-n-hexylaminocarbonyl group, an N-ethyl-N-methylaminocarbonyl group, an N-methyl-N-n-propylaminocarbonyl group, an N-isopropyl-N-methylaminocarbonyl group, an N-n-butyl-N-methylaminocarbonyl group, an "DiC" groups such as a carboxyl group, an N-isobutyl-N-methylaminocarbonyl group, an N-t-butyl-N-methylaminocarbonyl group, an N-methyl-N-n-pentylaminocarbonyl group, an N-n-hexyl-N-methylaminocarbonyl group, an N-ethyl-N-n-propylaminocarbonyl group, an N-ethyl-N-isopropylaminocarbonyl group, an N-n-butyl-N-ethylaminocarbonyl group, an N-ethyl-N-isobutylaminocarbonyl group, an N-t-butyl-N-ethylaminocarbonyl group, an N-ethyl-N-n-pentylaminocarbonyl group, and an N-ethyl-N-n-hexylaminocarbonyl group. １－１８ alkylamino group"; "di-C" such as dicyclopropylaminocarbonyl group, dicyclobutylaminocarbonyl group, dicyclopentylaminocarbonyl group, dicyclohexylaminocarbonyl group, etc. ３－１８ alicyclic aminocarbonyl group"; "di-C" such as diphenylaminocarbonyl group, phenylnaphthylaminocarbonyl group, etc. ６－１８ arylaminocarbonyl group" and the like.

[0031] As used herein, "C １－１８ The term "hydrocarbylcarbonylamino group" refers to a group consisting of "C １－１８"C" means a group in which an amino group is bonded to a "hydrocarbyl carbonyl group." １－１８ The "hydrocarbylcarbonylamino group" is not particularly limited, and examples thereof include "C" such as methylcarbonylamino group, ethylcarbonylamino group, n-propylcarbonylamino group, i-propylcarbonylamino group, n-butylcarbonylamino group, i-butylcarbonylamino group, sec-butylcarbonylamino group, t-butylcarbonylamino group, n-pentylcarbonylamino group, i-pentylcarbonylamino group, and n-hexylcarbonylamino group. １－１８ alkylcarbonylamino group"; cyclopropylcarbonylamino group, cyclobutylcarbonylamino group, cyclopentylcarbonylamino group, cyclohexylcarbonylamino group, etc. ３－１８ alicyclic carbonylamino group"; "C" such as phenylcarbonylamino group, naphthylcarbonylamino group, acenaphthylcarbonylamino group, phenanthrenylcarbonylamino group, anthracenylcarbonylamino group, etc. ６－１８ arylcarbonylamino group" and the like.

[0032] As used herein, "C １－１８ The term "hydrocarbylaminocarbonyloxy group" refers to a group consisting of "C １－１８ "C" means a group in which an oxygen atom (-O-) is bonded to a "hydrocarbylaminocarbonyl group." １－１８ The "hydrocarbylaminocarbonyloxy group" is not particularly limited, and examples thereof include "C" such as a methylaminocarbonyloxy group, an ethylaminocarbonyloxy group, and an n-propylaminocarbonyloxy group. １－１８ alkylaminocarbonyloxy group"; cyclopropylaminocarbonyloxy group, cyclohexylaminocarbonyloxy group, etc. ３－１８ alicyclic aminocarbonyloxy group"; phenylaminocarbonyloxy group, 1-naphthylaminocarbonyloxy group, etc. ６－１８ arylaminocarbonyloxy group" and the like.

[0033] As used herein, "diC １－１８ The term "hydrocarbylaminocarbonyloxy group" refers to a "diC １－１８"DiC" means a group in which an oxygen atom (—O—) is bonded to a "hydrocarbylaminocarbonyl group." １－１８ The "hydrocarbylaminocarbonyloxy group" is not particularly limited, and examples thereof include "diC" such as dimethylaminocarbonyloxy group, diethylaminocarbonyloxy group, and di-n-propylaminocarbonyloxy group. １－１８ alkylaminocarbonyloxy group, etc.

[0034] As used herein, "C １－１８ The term "hydrocarbylaminocarbonylamino group" refers to a group consisting of "C １－１８ "C" means a group bonded to an amino group. １－１８ The "hydrocarbylaminocarbonylamino group" is not particularly limited, and examples thereof include "C" such as methylaminocarbonylamino group, ethylaminocarbonyloxy group, and n-propylaminocarbonylamino group. １－１８ alkylaminocarbonylamino group"; cyclopropylaminocarbonylamino group, cyclohexylaminocarbonylamino group, etc. ３－１８ alicyclic aminocarbonylamino group"; phenylaminocarbonylamino group, 1-naphthylaminocarbonylamino group, etc. ６－１８ arylaminocarbonylamino group" and the like.

[0035] As used herein, "diC １－１８ The term "hydrocarbylaminocarbonylamino group" refers to a "diC １－１８ "Hydrocarbylaminocarbonyl group" means a group bonded to an amino group. １－１８ The "hydrocarbylaminocarbonylamino group" is not particularly limited, and examples thereof include "diC" such as dimethylaminocarbonylamino group, diethylaminocarbonylamino group, and di-n-propylaminocarbonylamino group. １－１８ alkylaminocarbonylamino group, etc.

[0036] As used herein, "C １－１８ The term "hydrocarbyloxycarbonylamino group" refers to a group consisting of "C １－１８"C" means a group in which a "hydrocarbyloxycarbonyl group" is bonded to an amino group. １－１８ The "hydrocarbyloxycarbonylamino group" is not particularly limited, and examples thereof include "C" such as a methoxycarbonylamino group, an ethoxycarbonylamino group, an n-propoxycarbonylamino group, an i-propoxycarbonylamino group, an n-butoxycarbonylamino group, and a t-butoxycarbonylamino group. １－１８ alkoxycarbonylamino group"; cyclopropyloxycarbonylamino group, cyclohexyloxycarbonylamino group, etc. ３－１８ alicyclic oxycarbonylamino group"; phenyloxycarbonylamino group, 1-naphthyloxycarbonylamino group, etc. ６－１８ aryloxycarbonylamino group" and the like.

[0037] As used herein, "C １－１８ The term "hydrocarbylthio group" refers to a group consisting of "C １－１８ "C" means a group in which a sulfur atom (-S-) is bonded to a "hydrocarbyl group." １－１８ The "hydrocarbylthio group" is not particularly limited, and examples thereof include a "C methylthio group, an ethylthio group, an n-propylthio group, an i-propylthio group, an n-butylthio group, an i-butylthio group, a t-butylthio group, an n-pentylthio group, an n-hexylthio group, etc. １－１８ alkylthio group"; cyclopropylthio group, cyclobutylthio group, cyclopentylthio group, cyclohexylthio group, 2-methylcyclopentylthio group, 3-methylcyclopentylthio group, 2-methylcyclohexylthio group, 3-methylcyclohexylthio group, 4-methylcyclohexylthio group, etc. ３－１８ alicyclic thio group"; "C" such as a phenylthio group, a 1-naphthylthio group, a 2-naphthylthio group, an acenaphthylthio group, a phenanthrenylthio group, an anthracenylthio group, etc. ６－１８ arylthio group" and the like.

[0038] As used herein, "C １－１８ The term "hydrocarbylsulfinyl group" refers to a group consisting of "C １－１８ "C" means a group in which a sulfinyl group (-S(=O)-) is bonded to a "hydrocarbyl group."１－１８ The "hydrocarbylsulfinyl group" is not particularly limited, and examples thereof include "C" such as methylsulfinyl group, ethylsulfinyl group, n-propylsulfinyl group, i-propylsulfinyl group, n-butylsulfinyl group, t-butylsulfinyl group, pentylsulfinyl group, and hexylsulfinyl group. １－１８ alkylsulfinyl group"; cyclopropylsulfinyl group, cyclobutylsulfinyl group, cyclopentylsulfinyl group, cyclohexylsulfinyl group, 2-methylcyclopentylsulfinyl group, 3-methylcyclopentylsulfinyl group, 2-methylcyclohexylsulfinyl group, 3-methylcyclohexylsulfinyl group, 4-methylcyclohexylsulfinyl group, etc. ３－１８ alicyclic sulfinyl group"; "C" such as a phenylsulfinyl group, a naphthylsulfinyl group, an acenaphthylsulfinyl group, a phenanthrenylsulfinyl group, an anthracenylsulfinyl group, etc. ６－１８ arylsulfinyl group" and the like.

[0039] As used herein, "C １－１８ The term "hydrocarbylsulfonyl group" refers to a group consisting of "C １－１８ The hydrocarbyl group may be a sulfonyl group (-SO ２ -) is bonded to the group. １－１８ The "hydrocarbylsulfonyl group" is not particularly limited, and examples thereof include "C" such as a methylsulfonyl group, an ethylsulfonyl group, an n-propylsulfonyl group, an i-propylsulfonyl group, an n-butylsulfonyl group, a t-butylsulfonyl group, and a pentylsulfonyl group. １－１８ alkylsulfonyl group"; "C" such as cyclopropylsulfonyl group, cyclobutylsulfonyl group, cyclopentylsulfonyl group, cyclohexylsulfonyl group, 2-methylcyclopentylsulfonyl group, 3-methylcyclopentylsulfonyl group, 2-methylcyclohexylsulfonyl group, 3-methylcyclohexylsulfonyl group, and 4-methylcyclohexyl group; ３－１８ alicyclic sulfonyl group"; "C" such as a phenylsulfonyl group, a naphthylsulfonyl group, an acenaphthylsulfonyl group, a phenanthrenylsulfonyl group, an anthracenylsulfonyl group, etc. ６－１８arylsulfonyl group" and the like.

[0040] As used herein, the term "acid-dissociable group" refers to a group that substitutes a hydrogen atom of a carboxy group or a hydroxy group (including a phenolic hydroxyl group), and that dissociates under the action of an acid. The "acid-dissociable group" is not particularly limited, and examples thereof include a t-butyl group, a t-amyl group, a 1,1-dimethylpropyl group, a 1-methyl-1-cyclopentyl group, a 1-ethyl-1-cyclopentyl group, a 1-methyl-1-cyclohexyl group, a 1-ethyl-1-cyclohexyl group, a 2-methyl-2-adamantyl group, a 2-ethyl-2-adamantyl group, a 1-(1-methoxy-2-methylpropan-2-yl)cyclopentyl group, and a 1-(1-ethoxy-2-methylpropan-2-yl)cyclopentyl group.

[0041] In this specification, the term "optionally having a substituent" is not particularly limited as long as it is chemically permissible and has the effect of the present invention. Examples of the "substituent" include (1) a halogen atom, (2) a hydroxy group, (3) a thiol group, (4) a nitro group, (5) a cyano group, (6) a carboxy group, (7) an amino group, (8) a sulfo group, (9) a group in which a hydrogen atom of a carboxy group or a hydroxy group is substituted with an acid-dissociable group, or (10) a C group in which at least a part of the hydrogen atoms may be substituted with the above (1) to (9). １－８ Hydrocarbyl group, C １－８ Hydrocarbyloxy group, C １－８ Hydrocarbyl carbonyl group, C １－８ Hydrocarbylcarbonyloxy group, C １－８ Hydrocarbyloxycarbonyl group, C １－８ Hydrocarbyloxycarbonyloxy group, C １－８ Hydrocarbylamino group, diC １－８ Hydrocarbylamino group, C １－８ Hydrocarbylaminocarbonyl group, diC １－８ Hydrocarbylaminocarbonyl group, C １－８ Hydrocarbylcarbonylamino group, C １－８ Hydrocarbylaminocarbonyloxy group, diC １－８ Hydrocarbylaminocarbonyloxy group, C１－８ Hydrocarbylaminocarbonylamino group, diC １－８ Hydrocarbylaminocarbonylamino group, C １－８ Hydrocarbyloxycarbonylamino group, C １－８ Hydrocarbylthio group, C １－８ Hydrocarbylsulfinyl group, C １－８ A hydrocarbylsulfonyl group, in which a divalent carbon atom at any position except the terminal of the substituent is -O-, -C(=O)-, -C(=O)O-, -OCO-, -CONH-, -NHCO-, -NH(C=O)O-, -S-, or -SO ２ - may be substituted (provided that adjacent divalent carbon atoms are not substituted at the same time), etc.

[0042] [1. Method for Producing Metatungstate Compound] A method for producing a metatungstate compound according to one embodiment of the present invention is a method for producing a metatungstate compound represented by the following general formula (I-1) or (I-2) (hereinafter also referred to as "metatungstate compound (I-1)" or "metatungstate compound (I-2)"), and includes a step of salt exchange in an acidic solution of less than pH 3. ＋ ) ５ ・[H ３ W １２ O ４０ ] ５－ (I-1) (A' ２＋ ) ５ ・([H ３ W １２ O ４０ ] ５－ ) ２ (I-2) [In formulas (I-1) and (I-2), A ＋ A' each independently represents an onium cation; ２＋ Each independently represents an onium dication.] In addition, [H ３ W １２ O ４０ ] ５－ This statement includes cases where protons are contained within the Keggin shell and cases where protons are contained outside the Keggin shell (H ＋ )・[H ２ W１２ O ４０ ] ６－ ) are also included in both cases.

[0043] [1-1. Salt Exchange Step] By carrying out salt exchange between a metatungstate represented by the following general formula (II) (hereinafter also referred to as "metatungstate (II)") and an onium salt represented by the following general formula (III-1) or (III-2) (hereinafter also referred to as "onium salt (III-1)" or "onium salt (III-2)") in an acidic solution having a pH of less than 3, it is possible to selectively produce a metatungstate compound represented by the general formula (I-1) or (I-2). (B ＋ ) ６ ・[H ２ W １２ O ４０ ] ６－ (II) [In formula (II), B ＋ are each independently H ＋ , a metal ion, or an ammonium ion.] A ＋ ・X － (III-1) A' ２＋ ・(X － ) ２ (III-2) [In formulas (III-1) and (III-2), A ＋ represents an onium cation; ２＋ represents an onium dication; X － represents a monovalent counter anion.

[0044] [1-1-1. Metatungstate (II)] The metatungstate (II) used in this embodiment is not particularly limited, and any known or commonly used metatungstate may be used. ＋ ) ６ ・[H ２ W １２ O ４０ ] ６－ (II) Metatungstic acid is a type of isopolyoxotungstic acid, which is an anionic metal oxide cluster, and is ２ W １２ O ４０ ] ６－In addition, in the general formula (II), B ＋ are each independently H ＋ , a metal ion, or an ammonium ion, and metatungstate (II) may contain one or more of these counter cations.

[0045] B ＋ From the viewpoint of promoting the salt exchange reaction, ＋ , Li ＋ , Na ＋ , K. ＋ , Rb ＋ , Cs ＋ , Be ２＋ , Mg ２＋ , Ca ２＋ , Sr ２＋ , Ba ２＋ , Co ３＋ , Bi ３＋ , Zr ４＋ , Hf ４＋ , Bi ５＋ , N.H. ４＋ or a combination thereof, and H ＋ , Na ＋ , K. ＋ , Mg ２＋ , Ca ２＋ , N.H. ４＋ or a combination thereof is more preferable, ＋ , Na ＋ , K. ＋ , N.H. ４＋ Or a combination of these is more preferable.

[0046] Examples of commercially available metatungstate (II) include ammonium metatungstate hydrate manufactured by Merck; ammonium metatungstate manufactured by Nippon Inorganic Chemical Industry Co., Ltd.; and the like.

[0047] [1-1-2. Onium Salt (III-1) or (III-2)] The onium salt (III-1) or (III-2) used in this embodiment is not particularly limited, and any known or commonly used salt may be used. ＋ represents an onium cation, and X, which is the anion moiety of the onium salt (III-1),－ represents a monovalent counter anion. A', which is the cation moiety of the onium salt (III-2), ２＋ represents an onium dication, and X, which is the anion moiety of the onium salt (III-2), － represents a monovalent counter anion. ＋ ・X － (III-1) A' ２＋ ・(X － ) ２ (III-2)

[0048] [1-1-2-1. Cation moiety of onium salt (III-1) or (III-2)] A ＋ or A' ２＋ From the viewpoint of improving actinic ray sensitivity and / or radiation sensitivity, the onium cation or onium dication is preferably an onium cation or onium dication having at least one unsaturated bond which may have a substituent, and the unsaturated bond may be, for example, a carbon-carbon double bond or a carbon-carbon triple bond, with a carbon-carbon double bond being more preferred, and a benzene ring being even more preferred. Examples of the onium cation include an organic sulfonium cation, an organic iodonium cation, and an organic quaternary ammonium cation. Examples of the onium dication include an organic sulfonium dication, an organic iodonium dication, and an organic ammonium dication.

[0049] [1-1-2-1-1. Organic sulfonium cation or organic sulfonium dication] The organic sulfonium cation is not particularly limited, and known and commonly used ones can be used. Examples of the organic sulfonium cation include organic sulfonium cations represented by formula (IV).

[0050]

[0051] In formula (IV), R １Ａ , R １Ｂ and R １Ｃ are each independently C １－１８represents a hydrocarbyl group, a 3- to 18-membered non-aromatic heterocyclic group, or a 5- to 18-membered aromatic heterocyclic group, １Ａ , R １Ｂ and R １Ｃ The divalent carbon atom at any position excluding the terminal may be -O-, -C(=O)-, -C(=O)O-, -OCO-, -CONH-, -NHCO-, -NH(C=O)O-, -S- or -SO ２ - (provided that adjacent divalent carbon atoms are not simultaneously replaced); １Ａ , R １Ｂ and R １Ｃ The hydrogen atoms contained in the group may be, for example, (a) a halogen atom, (b) a haloalkyl group, (c) a hydroxy group, (d) a thiol group, (e) a nitro group, (f) a cyano group, (g) a carboxy group, (h) an amino group, (i) a sulfo group, or (j) a C group in which at least a part of the hydrogen atoms may be substituted with any of the above (a) to (i). １－１８ Hydrocarbyl group, C １－１８ Hydrocarbyloxy group, C １－１８ Hydrocarbyl carbonyl group, C １－１８ Hydrocarbylcarbonyloxy group, C １－１８ Hydrocarbyloxycarbonyl group, C １－１８ a hydrocarbyloxycarbonyloxy group, or C １－１８ A hydrocarbylthio group in which a divalent carbon atom at any position except the terminal of these substituents is -O-, -C(=O)-, -C(=O)O-, -OCO-, -CONH-, -NHCO-, -NH(C=O)O-, -S-, or -SO ２ - (provided that adjacent divalent carbon atoms are not simultaneously replaced); １Ａ , R １Ｂ and R １Ｃ Any two of these are directly connected to each other by a single bond, or are divalent linking groups -O-, -S-, -C(=O)-, -S(=O)-, -S(=O) ２ -, -C(=O)O-, or C １－３ They may be linked via an alkylene group to form a ring together with the sulfur atom in formula (IV).

[0052] R in formula (IV) １Ａ , R １Ｂ and R １Ｃ Each of the C groups independently has a substituent. ６－１８ It is preferably an aryl group. ６－１８ The substituent of the aryl group may be a halogen atom, a haloalkyl group, a hydroxy group, a nitro group, a cyano group, a C １－１２ A hydrocarbylthio group is preferred, a halogen atom, C １－４ A haloalkyl group or a nitro group is more preferred.

[0053] The organic sulfonium dication is not particularly limited, and any known or commonly used organic sulfonium dication can be used. Examples of the organic sulfonium dication include organic sulfonium dications represented by formula (V):

[0054] In formula (V), R ２Ａ , R ２Ｂ , R ２Ｃ and R ２Ｄ each independently represents a C １－１８ represents a hydrocarbyl group, a 3- to 18-membered non-aromatic heterocyclic group, or a 5- to 18-membered aromatic heterocyclic group, ２Ａ , R ２Ｂ , R ２Ｃ and R ２Ｄ The divalent carbon atom at any position excluding the terminal may be -O-, -C(=O)-, -C(=O)O-, -OCO-, -CONH-, -NHCO-, -NH(C=O)O-, -S- or -SO ２ - may be substituted (provided that adjacent divalent carbon atoms are not substituted at the same time); K ２Ａ , K. ２Ｂ and L each independently represent C which may have a substituent. １－１８ represents a hydrocarbylene group, ２Ａ , K. ２Ｂ and a divalent carbon atom at any position of L is -O-, -C(=O)-, -C(=O)O-, -OCO-, -CONH-, -NHCO-, -S- or SO ２- (provided that adjacent divalent carbon atoms are not simultaneously replaced); ２Ａ , R ２Ｂ , R ２Ｃ , R ２Ｄ , K. ２Ａ , K. ２Ｂ and the hydrogen atoms contained in L are, for example, (a) halogen atoms, (b) haloalkyl groups, (c) hydroxy groups, (d) thiol groups, (e) nitro groups, (f) cyano groups, (g) carboxy groups, (h) amino groups, (i) sulfo groups, or (j) C groups in which at least a part of the hydrogen atoms may be substituted with the above (a) to (i). １－１８ Hydrocarbyl group, C １－１８ Hydrocarbyloxy group, C １－１８ Hydrocarbyl carbonyl group, C １－１８ Hydrocarbylcarbonyloxy group, C １－１８ Hydrocarbyloxycarbonyl group, C １－１８ a hydrocarbyloxycarbonyloxy group, or C １－１８ A hydrocarbylthio group in which a divalent carbon atom at any position except the terminal of these substituents is -O-, -C(=O)-, -C(=O)O-, -OCO-, -CONH-, -NHCO-, -NH(C=O)O-, -S-, or -SO ２ - may be substituted (provided that adjacent divalent carbon atoms are not substituted at the same time); R ２Ａ , R ２Ｂ and K. ２Ａ and / or R ２Ｃ , R ２Ｄ and K. ２Ｂ Any two of these are directly connected to each other by a single bond, or are connected to each other by a divalent linking group -O-, -S-, -C(=O)-, -S(=O)-, -S(=O) ２ -, -C(=O)O-, or C １－３ They may be linked via an alkylene group to form a ring together with the sulfur atom in formula (V).

[0055] Specific examples of the organic sulfonium cation or organic sulfonium dication include dibutyl(pentyl)sulfonium cation, triethylsulfonium cation, (2-carboxyethyl)dimethylsulfonium cation, trimethylsulfonium cation, dimethylphenacylsulfonium cation, 1-(4-hydroxynaphthalen-1-yl)hexahydrothiopyrylium cation, dimethylphenylsulfonium cation, triphenylsulfonium cation, tris(4-methylphenyl)sulfonium cation, 4-methoxyphenyldiphenylsulfonium cation, 4-iodophenyldiphenylsulfonium cation, tris(4-fluorophenyl)sulfonium cation, 1-phenylhexahydrothiopyrylium cation, (ethane-1,2-diylbisoxy)bis(4,1-phenylene)bis(diphenylsulfonium) dication, (thiodi-4,1-phenylene)bis(diphenylsulfonium) dication, di(naphthalene- 1-yl)(phenyl)sulfonium cation, phenylbis(2-(trifluoromethyl)phenyl)sulfonium cation, mesitylbis(2-(trifluoromethyl)phenyl)sulfonium cation, bis(3,5-difluorophenyl)(phenyl)sulfonium cation, tris(3,5-difluorophenyl)sulfonium cation, (4-(dodecanoyloxy-3,5-dimethylphenyl))diphenylsulfonium cation, diphenyl(3-(trifluoromethoxy)phenyl)sulfonium cation, (4-(1-adamantylcarbonyloxy)phenyl)diphenylsulfonium cation, (4-phenylthiophenyl)diphenylsulfonium cation, 5-phenyl-5H-thianthren-5-ium cation, 5-(2,5-dimethylphenyl)thianthren-5-ium cation, 5-phenyl-5H-dibenzo[b,d]thiophen-5-ium cation, 5-(3-(trifluoromethyl)phenyl)-5H-dibenzo[b,Examples of the thiophene-5-ium cation include 1-(4-(t-butyl)phenyl)-1H-benzo[b]thiophen-1-ium cation, methyldiphenylsulfonium cation, (2-bromoethyl)diphenylsulfonium cation, (3-chloropropyl)diphenylsulfonium cation, benzyl(4-hydroxyphenyl)methylsulfonium cation, (4-hydroxyphenyl)methyl(2-methylbenzyl)sulfonium cation, 4-hydroxyphenyldimethylsulfonium cation, diphenyl(methyl)sulfonium cation, diphenyl(4-(phenylthio)phenyl)sulfonium cation, (2-bromoethyl)diphenylsulfonium cation, dimesityl(trifluoromethyl)sulfonium cation, and tri-p-tolyl sulfonium cation.

[0056] [1-1-2-1-2. Organic iodonium cation] The organic iodonium cation is not particularly limited, and known and commonly used ones can be used. Examples of the organic iodonium cation include the organic iodonium cation represented by formula (VI):

[0057]

[0058] In formula (VI), R ３Ａ and R ３Ｂ are each independently C １－１８ represents a hydrocarbyl group, a 3- to 18-membered non-aromatic heterocyclic group, or a 5- to 18-membered aromatic heterocyclic group, ３Ａ and R ３Ｂ The divalent carbon atom at any position excluding the terminal may be -O-, -C(=O)-, -C(=O)O-, -OCO-, -CONH-, -NHCO-, -NH(C=O)O-, -S- or -SO ２ - (provided that adjacent divalent carbon atoms are not simultaneously replaced); ３Ａ and R ３ＢThe hydrogen atoms contained in the group may be, for example, (a) a halogen atom, (b) a haloalkyl group, (c) a hydroxy group, (d) a thiol group, (e) a nitro group, (f) a cyano group, (g) a carboxy group, (h) an amino group, (i) a sulfo group, or (j) a C group in which at least a part of the hydrogen atoms may be substituted with any of the above (a) to (i). １－１８ Hydrocarbyl group, C １－１８ Hydrocarbyloxy group, C １－１８ Hydrocarbyl carbonyl group, C １－１８ Hydrocarbylcarbonyloxy group, C １－１８ a hydrocarbyloxycarbonyl group, or C １－１８ A hydrocarbyloxycarbonyloxy group in which a divalent carbon atom at any position except the terminal of these substituents is -O-, -C(=O)-, -C(=O)O-, -OCO-, -CONH-, -NHCO-, -NH(C=O)O-, -S-, or -SO ２ - (provided that adjacent divalent carbon atoms are not simultaneously replaced); ３Ａ and R ３Ｂ are directly connected to each other by a single bond, or are connected to each other by a divalent linking group -O-, -S-, -C(=O)-, -S(=O)-, -S(=O) ２ -, -C(=O)O-, or C １－３ They may be linked via an alkylene group to form a ring together with the iodine atom in formula (VI).

[0059] R in formula (VI) ３Ａ and R ３Ｂ Each of the C groups independently has a substituent. ６－１８ It is preferably an aryl group. ６－１８ The substituent of the aryl group may be a halogen atom, a haloalkyl group, a hydroxy group, a nitro group, a cyano group, a C １－１２ Hydrocarbyl group, C １－１２ Hydrocarbyloxy group, C １－１２ Hydrocarbyl carbonyl group, C １－１２ Hydrocarbylcarbonyloxy group, C １－１２ a hydrocarbyloxycarbonyl group, or C １－１２A hydrocarbyloxycarbonyloxy group is preferred, and a halogen atom, C １－４ Haloalkyl group, nitro group, C １－８ Hydrocarbyl group, C １－８ It is preferably a hydrocarbyloxy group.

[0060] Specific examples of the organic iodonium cation include ethynyl(phenyl)iodonium cation, bis(pyridine)iodonium cation, bis(2,4,6-trimethylpyridine)iodonium cation, diphenyliodonium cation, bis(4-(t-butyl)phenyl)iodonium cation, (2-carboxyphenyl)(phenyl)iodonium cation, (4-nitrophenyl)(phenyl)iodonium cation, (3-(trifluoromethyl)phenyl)(2,4,6-trimethylphenyl)iodonium cation, bis(4-fluorophenyl)iodonium cation, (4-(bromomethyl)phenyl)(2,4,6-trimethoxyphenyl)iodonium cation, 4-biphenylyl(2,4,6-trimethoxyphenyl)iodonium cation, bis(2,4,6-trimethylphenyl)iodonium cation, 4-isopropyl-4'-methyldiphenyliodonium cation, Examples of iodonium cation include (4-(trifluoromethyl)phenyl)(2,4,6-trimethylphenyl)iodonium cation, ((4-trifluoromethyl)phenyl)(2,4,6-trimethoxyphenyl)iodonium cation, (5-fluoro-2-nitrophenyl)(2,4,6-trimethoxyphenyl)iodonium cation, (3-bromophenyl)(mesityl)iodonium cation, bis(4-bromophenyl)iodonium cation, (3,5-dichlorophenyl)(2,4,6-trimethoxyphenyl)iodonium cation, (4-methylphenyl)(2,4,6-trimethylphenyl)iodonium cation, (3-methylphenyl)(2,4,6-trimethylphenyl)iodonium cation, (2-methylphenyl)(2,4,6-trimethylphenyl)iodonium cation, and phenyl(2,4,6-trimethoxyphenyl)iodonium cation.

[0061] [1-1-2-1-3. Organic quaternary ammonium cation] The organic quaternary ammonium cation is not particularly limited, and any known or commonly used organic quaternary ammonium cation can be used. Examples of the organic quaternary ammonium cation include the organic quaternary ammonium cation represented by formula (VII).

[0062]

[0063] In formula (VII), R ４Ａ , R ４Ｂ , R ４Ｃ and R ４Ｄ are each independently C １－１８ Alkyl group, C １－１８ Alkynyl group, C １－１８ represents an alicyclic group, a 3- to 18-membered non-aromatic heterocyclic group, or a 5- to 18-membered aromatic heterocyclic group, ４Ａ , R ４Ｂ , R ４Ｃ and R ４Ｄ The divalent carbon atom at any position excluding the terminal may be -O-, -C(=O)-, -C(=O)O-, -OCO-, -CONH-, -NHCO-, -NH(C=O)O-, -S- or -SO ２ - (provided that adjacent divalent carbon atoms are not simultaneously replaced); ４Ａ , R ４Ｂ , R ４Ｃ and R ４Ｄ The hydrogen atoms contained in the group may be, for example, (a) a halogen atom, (b) a haloalkyl group, (c) a hydroxy group, (d) a thiol group, (e) a nitro group, (f) a cyano group, (g) a carboxy group, (h) an amino group, (i) a sulfo group, or (j) a C group in which at least a part of the hydrogen atoms may be substituted with any of the above (a) to (i). １－１８ Hydrocarbyl group, C １－１８ Hydrocarbyloxy group, C １－１８ Hydrocarbyl carbonyl group, C １－１８ Hydrocarbylcarbonyloxy group, C １－１８ Hydrocarbyloxycarbonyl group, C １－１８ a hydrocarbyloxycarbonyloxy group, or C １－１８In a hydrocarbylthio group, the divalent carbon atom at any position except at the terminal of these substituents is -O-, -C(=O)-, -C(=O)O-, -OCO-, -CONH-, -NHCO-, -NH(C=O)O-, -S-, or -SO ２ - (provided that adjacent divalent carbon atoms are not simultaneously replaced); ４Ａ , R ４Ｂ , R ４Ｃ and R ４Ｄ Any two of these are directly connected to each other by a single bond, or are divalent linking groups -O-, -S-, -C(=O)-, -S(=O)-, -S(=O) ２ -, -C(=O)O-, or C １－３ They may be linked via an alkylene group to form a ring together with the nitrogen atom in formula (VII).

[0064] R in formula (VII) ４Ａ , R ４Ｂ , R ４Ｃ and R ４Ｄ Each of the C groups independently has a substituent. 1－１８ Preferably it is a hydrocarbyl group, C １－１２ Alkyl group, C １－１２ Alkynyl group, C １－１２ An alicyclic group is more preferred.

[0065] Specific examples of the organic quaternary ammonium cation include tetramethylammonium cation, tetraethylammonium cation, tetrapropylammonium cation, tetrabutylammonium cation, tetraheptylammonium cation, trimethylethylammonium cation, dimethyldiethylammonium cation, dimethylethylpropylammonium cation, methylethylpropylbutylammonium cation, trimethylphenylammonium cation, triethylhexylammonium cation, triethylcyclohexylammonium cation, and dodecyltrimethylammonium cation.

[0066] [1-1-2-2. Anion part of onium salt (III-1) or (III-2)] X, which is the anion part of onium salt (III-1) or (III-2), － represents a monovalent counter anion. ＋ ・X － (III-1) A' ２＋ ・(X － ) ２ (III-2)

[0067] X － The anion is not particularly limited, and examples thereof include inorganic anions and organic anions. Examples of the inorganic anion or organic anion include F － , Cl － ,Br － , I － Halide ions such as; hydroxide ions; HSO ４ － , C.F. ３ SO ３ － , C ２ F ５ SO ３ － , C ３ F ７ SO ３ － , C ４ F ９ SO ３ － , p-CH ３ (C ６ H ４ ) SO ３ － , ClSO ３ － sulfonate ions such as perchlorate ions; nitrate ions; (C ６ F ５ ) ４ B － , B.F. ４ － borate ions such as PF ６ － , (PF ５ OH) － , ((CF ３ CF ２ ) ３ PF ３ )－ Fluorophosphate ions such as (CF ３ SO ２ ) ２ N － , (FSO ２ ) ２ N － Imide ions such as SbF ６ － antimonate ions such as AsF ６ － arsenate ions such as AlCl ４ － ;BiF ６ － Examples include:

[0068] X － From the viewpoint of promoting the salt exchange reaction, Br － , Cl － , I － ,Br ３－ , O.H. － , HSO ４ － , C.F. ３ SO ３ － , C ２ F ５ SO ３ － , C ３ F ７ SO ３ － , C ４ F ９ SO ３ － , p-CH ３ (C ６ H ４ ) SO ３ － , ClSO ３ － , ClO ４ － , NO ３ － , (C ６ F ５ ) ４ B － , B.F. ４ － , P.F. ６ － , SbF ６ － , AlCl４ － , BiF ６ － , AsF ６ － , (CF ３ SO ２ ) ２ N － , (FSO ２ ) ２ N － Preferably, Br － , Cl － , I － , O.H. － , C.F. ３ SO ３ － , C ４ F ９ SO ３ － , B.F. ４ － , P.F. ６ － , SbF ６ － , (CF ３ SO ２ ) ２ N － , (FSO ２ ) ２ N － More preferably, Br － , Cl － , C.F. ３ SO ３ － , B.F. ４ － , P.F. ６ － , SbF ６ － , (CF ３ SO ２ ) ２ N － , (FSO ２ ) ２ N － It is more preferable that:

[0069] [1-1-2-3. Specific examples of onium salt (III-1) or (III-2)] Commercially available onium salts (III-1) or (III-2) include, for example, diphenyl-4-methylphenylsulfonium trifluoromethanesulfonate, diphenyl-2,4,6-trimethylphenylsulfonium p-toluenesulfonate, diphenyl(4-methoxyphenyl)sulfonium trifluoromethanesulfonate, 4-methylphenyldiphenylsulfonium nonafluorobutanesulfonate, tris(4-methylphenyl)sulfonium nonafluorobutanesulfonate, tributylmethylammonium bis(trifluoromethanesulfonyl)imide, methyltrioctylammonium bis(trifluoromethanesulfonyl)imide, tetrabutylammonium bromide, tetrabutylammonium hexafluorophosphate, N-ethyl-N-(2-methoxyethyl)-N,N-dimethylammonium bis(trifluoromethanesulfonyl)imide, and benzyl(4-hydroxyphenyl)methylsulfonium hexafluorophosphate, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. diphenyl(methyl)sulfonium tetrafluoroborate, trimethylsulfonium bromide, 4-hydroxyphenyldimethylsulfonium methylsulfate, (2-bromoethyl)diphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium bromide, trimethylsulfonium hydroxide, triphenylsulfonium nonafluoro-1-butanesulfonate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, diphenyl(4-(phenylthio)phenyl)sulfonium hexafluoroantimonate, diphenyl(4-(phenylthio)phenyl)sulfonium hexafluorophosphate, (3-chloropropyl)diphenylsulfonium tetrafluoroborate, (2-carboxyethyl)dimethylsulfonium chloride, (2-carboxyethyl)dimethylsulfonium bromide, tri-p-tolylsulfonium trifluoromethanesulfonate, (difluoromethyl)bis(2,(5-dimethylphenyl)sulfonium tetrafluoroborate, (4-hydroxyphenyl)methyl(2-methylbenzyl)sulfonium hexafluoroantimonate, tributylsulfonium iodide, (thiodi-4,1-phenylene)bis(diphenylsulfonium)bis(hexafluorophosphate), 4-isopropyl-4'-methyldiphenyliodonium tetrakis(pentafluorophenyl)borate, (4-(bromomethyl)phenyl)(2,4,6-trimethoxyphenyl)iodonium p-toluenesulfonate, 4-biphenylyl(2,4,6-trimethoxyphenyl)iodonium iodonium trifluoromethanesulfonate, bis(4-t-butylphenyl)iodonium hexafluorophosphate, bis(2,4,6-trimethylphenyl)iodonium trifluoromethanesulfonate, bis(2,4,6-trimethylpyridine)iodonium hexafluorophosphate, bis(4-fluorophenyl)iodonium trifluoromethanesulfonate, ethynyl(phenyl)iodonium tetrafluoroborate, (4-(trifluoromethyl)phenyl)(2,4,6-trimethoxyphenyl)iodonium p-toluenesulfonate, (4-(trifluoromethyl)phenyl)(2,4,(6-trimethylphenyl)iodonium trifluoromethanesulfonate, diphenyliodonium chloride, diphenyliodonium bromide, diphenyliodonium hexafluorophosphate, diphenyliodonium trifluoromethanesulfonate, benzyltrimethylammonium chloride, benzyldimethyltetradecylammonium chloride, benzyldodecyldimethylammonium chloride, tetrabutylammonium chloride, tetraamylammonium chloride, benzoylcholine chloride, benzyltributylammonium chloride, tetrabutylammonium bromide, tetrahexylammonium bromide, tetraheptylammonium bromide, tetra-n-octylammonium bromide, 1-butyl-1-methylpiperidinium bromide, 1-methyl-1-propylpiperidinium bromide, benzoylcholine bromide, benzyltriethylammonium bromide, benzyltributylammonium bromide, trimethylphenylammonium bromide, 3-(trifluoromethyl)phenyltrimethylammonium bromide, 4-ethyl-4- Examples of suitable ammonium iodides include methylmorpholinium bromide, 3-(trifluoromethyl)phenyltrimethylammonium iodide, acetylcholine iodide, acetylthiocholine iodide, benzoylcholine iodide, benzoylthiocholine iodide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, benzyltrimethylammonium hydroxide, benzyltriethylammonium hydroxide, 3-(trifluoromethyl)phenyltrimethylammonium hydroxide, tetrabutylammonium tetrafluoroborate, tetrabutylammonium hexafluorophosphate, amyltriethylammonium bis(trifluoromethanesulfonyl)imide, 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide, 1-butyl-1-methylpiperidinium bis(trifluoromethanesulfonyl)imide, methyltri-n-octylammonium hydrogen sulfate, diethyl(methyl)propylammonium bis(fluorosulfonyl)imide, and 1-ethyl-1-methylpyrrolidinium tetrafluoroborate.

[0070] [1-1-3. Acidic Solution] By carrying out salt exchange between metatungstate (II) and onium salt (III-1) or (III-2) in an acidic solution, it is possible to selectively produce a metatungstate compound represented by general formula (I-1) or (I-2). The pH of the acidic solution is preferably less than 3, more preferably 2.7 or less, even more preferably 2.6 or less, particularly preferably 2.5 or less, and may be about 3 or less.

[0071] The type of acid contained in the acidic solution is not particularly limited, and examples thereof include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, sulfamic acid, and phosphoric acid; organic acids having a carboxy group such as tartaric acid, oxalic acid, formic acid, acetic acid, propionic acid, malic acid, lactic acid, citric acid, succinic acid, maleic acid, fumaric acid, glycolic acid, trifluoroacetic acid, and trichloroacetic acid; and organic acids having a sulfo group such as methanesulfonic acid, ethanesulfonic acid, sulfosuccinic acid, methanesulfonic acid, and paratoluenesulfonic acid. The above acids may be used alone or in combination of two or more. Although the acid varies depending on the solvent used, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, formic acid, oxalic acid, trichloroacetic acid, methanesulfonic acid, and meta- or paratoluenesulfonic acid are preferred, and hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, and formic acid are more preferred.

[0072] As a reaction pathway and mechanism by which the metatungstate compound (I-1) or (I-2) can be selectively produced by carrying out a salt exchange reaction in an acidic solution, it is speculated that metatungstate (II) reacts with [H ３ W １２ O ４０ ] ５－ It is thought that the sigma-based ... exists in the form of a sigma-based sigma.

[0073] [1-2. Other Steps] The method for producing a metatungstate compound according to this embodiment may include other steps, such as common operations performed by a person skilled in the art to isolate and purify the target compound after the salt exchange reaction. The other steps are not particularly limited, and examples include quenching the reaction, salting out by adding a poor solvent, filtration, separation by liquid-liquid extraction, and purification by chromatography, recrystallization, etc.

[0074] [1-3. Number of onium cations or onium dications contained in metatungstate compound (I-1) or (I-2)] The method for producing a metatungstate compound according to this embodiment makes it possible to selectively produce a metatungstate compound (I-1) or (I-2) containing five onium cations or five onium dications. The number of onium cations contained in the metatungstate compound can be determined, for example, by XRF analysis or XPS analysis.

[0075] When the onium cation contained in the metatungstate compound is an organic sulfonium cation or an organic sulfonium dication, the molar ratio of S to W in the metatungstate compound can be determined, for example, by XRF analysis, a calibration curve method, or SQX analysis using the fundamental parameter (FP) method. Furthermore, the molar ratio of S to W in the metatungstate compound can be determined by XPS analysis, by determining the atomic percentage of each element based on the peak areas of S2p and W4f.

[0076] Furthermore, when the onium cation contained in the metatungstate compound is an organic iodonium cation, the molar ratio of I to W in the metatungstate compound can be determined, for example, by XRF analysis, a calibration curve method, or SQX analysis using the fundamental parameter (FP) method. Furthermore, the molar ratio of I to W in the metatungstate compound can be determined by XPS analysis, by determining the atomic % of each element based on the peak areas of I3d and W4f.

[0077] Furthermore, when the onium cation contained in the metatungstate compound is an organic ammonium cation, the molar ratio of N to W in the metatungstate compound can be determined, for example, by XRF analysis, a calibration curve method, or SQX analysis using the fundamental parameter (FP) method. Furthermore, the molar ratio of N to W in the metatungstate compound can be determined by XPS analysis, by determining the atomic % of each element based on the peak areas of N1s and W4f.

[0078] [2. Metatungstate Compound for Resist] A hexavalent anion, metatungstate ([H ２ W １０ O ４０ ] ６－ ), it has been difficult to selectively produce a metatungstate compound containing five onium cations or onium dications represented by general formula (I-1) or (I-2). That is, when produced by a conventional method, a mixture of metatungstate compounds containing 4 to 6 onium cations or onium dications is obtained, and it has not been possible to selectively produce a metatungstate compound containing five onium cations or onium dications. In contrast, the method for producing a metatungstate compound according to this embodiment makes it possible to selectively produce the metatungstate compound (I-1) or (I-2) containing five onium cations or onium dications. Furthermore, the metatungstate compound (I-1) or (I-2) has improved actinic ray and / or radiation sensitivity due to the onium cations or onium dications, and also has uniformity, making it suitable as a metatungstate compound for resists.

[0079] 3. Resist Material The resist material according to this embodiment contains a metatungstate compound (I-1) or (I-2). The resist material may also contain an organic solvent.

[0080] [3-1. Organic Solvent] The organic solvent used in this embodiment is not particularly limited, and any known or commonly used organic solvent can be used. The organic solvent is preferably an organic solvent that can uniformly dissolve or disperse the metatungstate compound (I-1) or (I-2).

[0081] Examples of organic solvents include polar solvents such as alcohol-based solvents, ether-based solvents, ketone-based solvents, amide-based solvents, ester-based solvents, nitrile-based solvents, and aprotic polar solvents, and examples of nonpolar solvents include hydrocarbon-based solvents. These organic solvents may be used alone or in combination of two or more.

[0082] Specific examples of polar solvents include: alcohol-based solvents such as methanol, ethanol, isopropyl alcohol (IPA), 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 4-methyl-2-pentanol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, and propylene glycol monomethyl ether (PGME); ether-based solvents such as diethyl ether, dipropyl ether, dibutyl ether, diisoamyl ether, tetrahydrofuran, anisole, propylene glycol monoethyl ether, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether; ketone-based solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, 2-heptanone, acetophenone, propylene carbonate, and furfural; Amide-based solvents such as N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylpyrrolidone, 1-ethyl-2-pyrrolidone, and 1-butyl-2-pyrrolidone; ester-based solvents such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and propylene glycol monomethyl ether acetate (PGMEA); nitrile-based solvents such as acetonitrile, propionitrile, and benzonitrile; aprotic polar solvents such as γ-butyrolactone, δ-valerolactone, γ-lactam, δ-lactam, dimethyl sulfoxide (DMSO), sulfolane, 1,3-dimethyl-2-imidazolidinone, and tetramethylurea; and nonpolar solvents such as hydrocarbon solvents such as n-pentane, n-hexane, toluene, and xylene. The above organic solvents may be used alone or in combination of two or more.

[0083] The organic solvent contained in the resist material according to this embodiment is preferably a polar solvent in terms of coatability, and more preferably an amide solvent, an ester solvent, an alcohol solvent, or a ketone solvent in terms of solubility. The amide solvent is preferably at least one selected from the group consisting of N,N-dimethylformamide, N,N-diethylformamide, acetamide, and N-methylpyrrolidone. Furthermore, the ester solvent or alcohol solvent preferably has an ester bond and / or a hydroxyl group in terms of solubility, and among the above, at least one selected from the group consisting of propylene glycol monomethyl ether, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, methyl pyruvate, ethyl pyruvate, and propylene glycol monomethyl ether acetate is preferred.

[0084] When the organic solvent contains both an amide solvent and an ester solvent, the blending ratio (mass ratio) of the amide solvent to the ester solvent is preferably 1:99 to 40:60, and more preferably 5:95 to 20:80.

[0085] The amount of organic solvent in the resist material is not particularly limited and can be set appropriately depending on the method for applying the resist material to a substrate, the thickness of the applied film, etc. The amount of organic solvent in the resist material is preferably such that the solids concentration of the resist material is 0.01 to 20 mass%, more preferably 0.1 to 15 mass%, and even more preferably 0.2 to 10 mass%.

[0086] [3-2. Others] The resist material according to this embodiment may further contain, as desired, miscible additives, such as additional resins for improving the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents, dyes, etc. Preferably, the resist material according to this embodiment does not contain an epoxy resin. It is also preferable that the resist material does not contain hydrogen peroxide.

[0087] 4. Pattern Forming Method The pattern forming method according to this embodiment includes the steps of applying a resist material to a substrate, exposing the resist film formed by the application step, and developing the exposed resist film.

[0088] [4-1. Coating Step] The pattern forming method according to this embodiment includes a step of coating a substrate with a resist material.

[0089] <Substrate> The substrate used in this embodiment is not particularly limited, and known and commonly used substrates can be used. For example, a substrate for electronic components or a substrate on which a predetermined wiring pattern is formed may be used. The material of the substrate is not particularly limited, and examples thereof include silicon wafers, metal substrates such as copper, chromium, iron, and aluminum, and inorganic substrates such as glass, titanium oxide, and silicon dioxide. The size, shape, and the like of the substrate are not particularly limited, and the surface of the substrate may be smooth, curved, or uneven, or may be a flake-shaped substrate.

[0090] The surface of the substrate may be subjected to a surface treatment as necessary. In the case of a substrate having hydroxyl groups on its surface layer, the surface of the substrate is treated with a silane coupling agent capable of reacting with the hydroxyl groups, thereby changing the surface layer of the substrate from hydrophilic to hydrophobic, thereby improving the adhesion between the substrate and the metal compound-containing film. Examples of the silane coupling agent include hexamethyldisilazane (HMDS).

[0091] <Coating Method> The method for coating the resist material on the substrate is not particularly limited, and any known or commonly used method can be used. Examples of dry coating methods include CVD (chemical vapor deposition) methods such as thermal CVD, plasma CVD, and photo-CVD; and PVD (physical vapor deposition) methods such as vacuum deposition, plasma-assisted deposition, sputtering, and ion plating. Examples of wet coating methods include spin coating, bar coating, roll coating, flow coating, dip coating, spray coating, inkjet printing, and screen printing.

[0092] As a method for applying the resist material according to this embodiment to a substrate, a wet method such as spin coating or screen printing is preferably used, and spin coating is more preferable, from the viewpoint of forming a uniform film thickness, etc. After forming the coating film, a backside rinse, an edge bead removal step, etc. may be performed to remove the edge bead.

[0093] The method for drying the resist film formed by applying a resist material to a substrate is not particularly limited, and can be performed using, for example, a heating device such as a hot plate (post-applied bake (PAB)), a pressure reducing device, or the like. The baking conditions are not particularly limited, and can be set appropriately depending on the type of resist film, application, etc. The baking temperature is preferably 80 to 300°C, more preferably 150 to 250°C, and even more preferably 170 to 230°C. The baking time is preferably 10 to 300 seconds, more preferably 20 to 180 seconds, and even more preferably 30 to 120 seconds.

[0094] The thickness of the resist film after drying is not particularly limited, but is preferably 0.5 to 100 nm, more preferably 1 to 75 nm, and even more preferably 1 to 60 nm.

[0095] [4-2. Exposure Step] The pattern formation method according to this embodiment includes a step of exposing the resist film formed in the above-described coating step.

[0096] As an exposure apparatus in the exposure step of the resist film, for example, an ArF exposure apparatus, an electron beam lithography apparatus, an EUV exposure apparatus, etc. Furthermore, in the exposure step, exposure may be performed through a mask (mask pattern) on which a predetermined pattern is formed, or selective exposure may be performed by lithography using direct irradiation with an electron beam without using a mask pattern.

[0097] The wavelength used for exposure is not particularly limited, and examples thereof include ArF excimer laser (wavelength 193 nm), KrF excimer laser (248 nm), F ２Radiation such as excimer laser (wavelength 157 nm), EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, or soft X-ray may also be used.

[0098] The exposure dose on the resist film is 1 to 200 mJ / cm in the case of an ArF excimer laser or a KrF excimer laser. ２ is preferably 20 to 60 mJ / cm ２ In the case of extreme ultraviolet rays, the exposure dose is, for example, 500 mJ / cm ２ or less, and 0.1 to 200 mJ / cm ２ is preferably 3 to 100 mJ / cm ２ More preferably, it is 5 to 50 mJ / cm ２ In the case of an electron beam, it is more preferable that the concentration is 3 μC / cm at 50 kV. ２ ~2mC / cm ２ It is preferable to expose with a dose of 10 μC / cm ２ ~1.5mC / cm ２ It is more preferable to expose at a dose of 1000 ppm.

[0099] After the resist film is exposed to light, it may or may not be baked (post-exposure bake (PEB)). The baking conditions are not particularly limited and can be set appropriately depending on the type of resist film, its intended use, etc. The baking temperature is preferably 80 to 300°C, more preferably 150 to 250°C, and even more preferably 170 to 230°C, using a heating device such as a hot plate. The baking time is preferably 10 to 300 seconds, more preferably 20 to 180 seconds, and even more preferably 30 to 120 seconds.

[0100] [4-3. Development Step] The pattern formation method according to this embodiment includes a step of developing the exposed resist film. In the development step, a pattern can be formed by developing the exposed resist film with a developer. A negative pattern formation process is one in which the exposed region remains as a pattern after development, while a positive pattern formation process is one in which the exposed region is removed after development. Whether a positive or negative pattern is formed can be appropriately selected depending on the resist material or the developer. After the development, the resist film may be washed with a rinse solution and then dried, and in some cases, a baking treatment may be further performed.

[0101] <Developer> Examples of the developer used in this embodiment include developers containing one or more polar solvents such as ketone-based solvents, ester-based solvents, alcohol-based solvents, nitrile-based solvents, amide-based solvents, and ether-based solvents, and organic solvents such as hydrocarbon-based solvents.

[0102] Specific examples of organic solvents include: ketone-based solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, 2-heptanone, acetophenone, propylene carbonate, and furfural; ester-based solvents such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and propylene glycol monomethyl ether acetate (PGMEA); alcohol-based solvents such as methanol, ethanol, isopropyl alcohol (IPA), 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 4-methyl-2-pentanol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, and propylene glycol monomethyl ether (PGME); and nitrile-based solvents such as acetonitrile, propionitrile, and benzonitrile. Examples of the solvent include amide-based solvents such as N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylpyrrolidone, 1-ethyl-2-pyrrolidone, and 1-butyl-2-pyrrolidone; ether-based solvents such as diethyl ether, dipropyl ether, dibutyl ether, diisoamyl ether, tetrahydrofuran, anisole, propylene glycol monoethyl ether, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether; and hydrocarbon-based solvents such as n-pentane, n-hexane, toluene, and xylene. These may be used alone or in combination of two or more.

[0103] Among these, the organic solvent used in the developer is preferably a polar solvent, and preferably contains an amide solvent, an alcohol solvent, or an ester solvent, and more preferably contains an amide solvent or an ester solvent and an alcohol solvent. The amide solvent is preferably at least one selected from the group consisting of N,N-dimethylformamide, N,N-diethylformamide, acetamide, and N-methylpyrrolidone. The ester solvent is preferably at least one selected from the group consisting of methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and propylene glycol monomethyl ether acetate. The alcohol solvent is preferably at least one selected from the group consisting of ethanol, isopropyl alcohol (IPA), 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 4-methyl-2-pentanol, benzyl alcohol, and 4-methylbenzyl alcohol.

[0104] When the developer contains both an amide solvent or an ester solvent and an alcohol solvent, the blending ratio (weight ratio) of the amide solvent or the ester solvent to the alcohol solvent is preferably 5:95 to 95:5, and more preferably 10:90 to 90:10.

[0105] The method for developing the exposed resist film using the developer is not particularly limited, and any known or commonly used method can be used. Examples of the method for developing using the developer include a method of immersing a substrate having an exposed resist film in the developer for a certain period of time (dip method), a method of spraying the developer onto the surface of the exposed resist film (spray method), and a method of discharging the developer at a constant speed from a discharge nozzle toward the surface of the exposed resist film on a substrate rotating at a constant speed (dynamic dispense method).

[0106] <Rinse liquid> After development with the developer, a step of washing with a rinse liquid may be included. The rinse liquid is not particularly limited, and any known or commonly used liquid may be used. As the rinse liquid, an organic solvent contained in the developer that does not easily dissolve the resist pattern may be appropriately selected and used.

[0107] The rinse liquid is not particularly limited, and may be, for example, at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents. Among these, it is preferable to use at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, and amide solvents as the rinse liquid, it is more preferable to use at least one solvent selected from the group consisting of alcohol solvents and ester solvents, and it is even more preferable to use at least one alcohol solvent.

[0108] The alcohol-based solvent used in the rinse solution is preferably a monohydric alcohol having 2 to 8 carbon atoms, and the monohydric alcohol may be linear, branched, or cyclic. Specific examples of the monohydric alcohol include ethanol, isopropyl alcohol (IPA), butanol, 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and benzyl alcohol. These organic solvents may be used alone or in combination of two or more.

[0109] The rinse solution may further contain an organic solvent other than the above or water in addition to the organic solvent described above. When water is contained in the rinse solution, the content of water is preferably 30 mass % or less, more preferably 10 mass % or less, further preferably 5 mass % or less, and particularly preferably 3 mass % or less, based on the total amount of the rinse solution.

[0110] The method for cleaning the resist pattern with the rinse liquid is not particularly limited, and any known or commonly used method can be used. Examples of the cleaning method using the rinse liquid include a method of immersing the resist pattern in the rinse liquid for a certain period of time (dip method), a method of spraying the rinse liquid onto the surface of the resist pattern (spray method), and a method of discharging the rinse liquid at a constant speed from a discharge nozzle toward the surface of the resist pattern that is rotating at a constant speed (dynamic dispense method).

[0111] 5. Patterned Structure The patterned structure according to this embodiment can be obtained by forming a pattern of the resist material on a substrate using the pattern formation method described above.

[0112] The average thickness of part or all of the patterned structure according to this embodiment is not particularly limited and can be set appropriately depending on the intended use, etc. The patterned structure preferably has portions with an average thickness of 10 to 100 nm, more preferably 15 to 75 nm, and even more preferably 20 to 60 nm.

[0113] The pitch of part or all of the patterned structure according to this embodiment is not particularly limited and can be set appropriately depending on the purpose of use, etc. In the patterned structure, it is preferable to have a part with a pitch of 100 nm or less, more preferably a part with a pitch of 50 nm or less, and even more preferably a part with a pitch of 20 nm or less. By patterning the resist material according to this embodiment using the above-mentioned pattern formation method, it is possible to create parts with pitches of 50 nm, 20 nm, or 15 nm in part or all of the patterned structure.

[0114] [6. Resist Material for Electron Beam or EUV] The resist material according to this embodiment has good sensitivity to electron beam and EUV light sources, and can therefore be suitably used as a resist material compatible with these exposure light sources.

[0115] EXAMPLES The present invention will be specifically explained below by showing examples, but the present invention is not limited to these examples.

[0116] [1. Synthesis of Metatungstate Compound] <Synthesis Example 1> Ammonium metatungstate (manufactured by Nippon Inorganic Chemical Industry Co., Ltd.: ammonium metatungstate hydrate ((NH ４ ) ６ [H ２ W １２ O ４０ ]・xH ２ To 16.67 g of bis(2-trifluoromethylphenyl)phenylsulfonium chloride, 10 g of water and 10 g of a 1 mol / L aqueous hydrochloric acid solution were added, and the mixture was stirred at room temperature for 60 minutes. An aqueous solution prepared by dissolving 13.47 g of bis(2-trifluoromethylphenyl)phenylsulfonium chloride in 200 g of pure water was then added to the reaction mixture, and the mixture was stirred at room temperature for 30 minutes. The reaction mixture was filtered, and the resulting powder was dried under reduced pressure at room temperature for 18 hours. The dried powder was dissolved in 100 g of dimethylformamide, and then 335 g of methanol was added. The mixture was crystallized at room temperature to obtain the target compound shown below. １ H-NMR (400MHz, DMSO-D6): δ (ppm) = 6.77 (s, 0.60H), 7.65-8.35 (m, 13H). １８３ W-NMR (20.84 MHz, DMSO-D6): δ (ppm) = -87.59 (s, 12 W). ESI-MS: POSITIVE m / z 399.1 ([C ２０ H １３ F ６ S] ＋ ) NEGATIVE m / z 712.3 (median) ([H ４ W １２ O ４０ ] ４－ )

[0117] <Synthesis Examples 2 to 8 and Comparative Synthesis Examples 1 and 2> In Synthesis Examples 2 to 8 and Comparative Synthesis Examples 1 and 2, metatungstate compounds were synthesized in a manner similar to that of Synthesis Example 1, except that the type, concentration, and amount of acid, the amount of water, the type and amount of onium salt, and the amount of pure water were changed as shown in Table 1 below. １ H-NMR, １８３ W-NMR and ESI-MS are shown respectively. １ H-NMR (400MHz, DMSO-D6): δ (ppm) = 5.97 (s, 0.33H), 7.65-8.35 (m, 13H). １８３ W-NMR (20.84 MHz, DMSO-D6): δ (ppm) = -100.13 (s, 12 W). ESI-MS: POSITIVE m / z 399.1 ([C ２０ H １３ F ６ S] ＋ ) NEGATIVE m / z 712.3 (median) ([H ４ W １２ O ４０ ] ４－ )

[0118] The onium salts (1) and (2) listed in Table 1 are as follows: Onium salt (1): bis(2-trifluoromethylphenyl)phenylsulfonium chloride Onium salt (2): bis(4-tert-butylphenyl)iodonium sulfonate (MeOH solution)

[0119] In the above Synthesis Examples 1 to 8 and Comparative Synthesis Examples 1 and 2, the production ratio of the metatungstate compound containing five onium cations to the metatungstate compound containing six onium cations was: １ The peak in the vicinity of 6.77 ppm in H-NMR ([H ３ W １２ O ４０ ] ５－ The integral value of the peak ([H ２ W １２ O４０ ] ６－ The results are shown in the "Ratio" section of Table 1.

[0120]

[0121] Table 1 shows that metatungstate compounds containing five onium cations can be selectively obtained in Synthesis Examples 1 to 8, which used acidic solutions with a pH of less than 3. Furthermore, no metatungstate compounds containing six onium cations were obtained in Synthesis Examples 1 to 7.

[0122] In contrast, in Comparative Synthesis Example 1, in which no acidic solution was used, metatungstate compounds containing six onium cations were selectively obtained, and metatungstate compounds containing five onium cations were also obtained. Furthermore, even when an acidic solution was used, as in Comparative Synthesis Example 2, when the pH was greater than 3, a mixture was obtained in which metatungstate compounds containing five onium cations and metatungstate compounds containing six onium cations were mixed, with the metatungstate compound containing six onium cations being contained in greater amounts.

[0123] [2. Preparation of Resist Materials] The metatungstate compounds obtained in Synthesis Examples 1 to 8 and Comparative Synthesis Examples 1 and 2 above were mixed with dimethylformamide and ethyl lactate as organic solvents in the amounts shown in Table 2 to prepare resist materials R-1 to R-10.

[0124]

[0125] [3. Formation of LS Pattern] Resist materials R-1 to R-10 were applied to a silicon wafer substrate using a spinner, and then post-applied bake (PAB) treatment was performed on a hot plate at a temperature of 200°C for 60 seconds, followed by drying to produce resist films M-1 to M-9 with a thickness of 50 nm. The thickness of the formed resist films was measured using a film thickness measurement device ("M-2000D" manufactured by J.A. Woollam Co.).

[0126] The resist films M-1 to M-10 were exposed through a mask using an EUV exposure machine, with the exposure dose being changed stepwise. After PEB treatment at 180°C for 60 seconds, development was carried out at 23°C using a developer (DMF (10 parts by mass), IPA (90 parts by mass)) for 60 seconds, and rinsing was carried out with IPA for 60 seconds to produce a negative 1:1 LS pattern with a line width of 50 nm. The optimal exposure dose Eop (mJ / cm) at which an LS pattern of the target size was formed was ２ ) was measured, and the resist films M-1 to M-6 were found to have a density of 100 mJ / cm ２ and the resist film M-9 was 115 mJ / cm ２ and the resist film M-10 was 110 mJ / cm ２ For each of the resist films M-1 to M-10, a 1:1 LS pattern with a line width of 50 nm was fabricated in the same manner as above, using the optimum exposure dose determined above. Note that for the resist films M-7 and M-8, the optimum exposure dose was not confirmed, but it was 100 mJ / cm ２ was used as the optimum exposure dose.

[0127] <Temporal Stability: CD Change Rate> The fabricated LS pattern was observed from above the LS pattern using a scanning electron microscope (product name: S-9380) manufactured by Hitachi High-Technologies Corporation, and the line width (nm) was measured. The ratio of the change in pattern dimension (CD) of the line width of the fabricated LS pattern to that of the mask pattern (CD change rate) was determined, and the temporal stability of the resist bottle was evaluated according to the following criteria. The results are shown in Table 3. CD change rate = (|Line width of LS pattern - Mask pattern|) / (Mask pattern) x 100 ○: CD change rate is 5.0% or less △: CD change rate is more than 5.0% and less than 7.5% ×: CD change rate is more than 7.5%

[0128]

[0129] As can be seen from Table 3, the resist films M-9 and M-10, which were made using resist materials R-9 and R-10, which were mixtures of a metatungstate compound containing five onium cations and a metatungstate compound containing six onium cations, and which contained a larger amount of the metatungstate compound containing six onium cations, had large CD change rates of 12.0% and 8.0%, respectively.

[0130] In contrast, resist films R-1 to R-7, which were made using resist materials R-1 to R-7 containing a metatungstate compound containing five onium cations but no metatungstate compound containing six onium cations, had CD change rates of less than 5.0%. Resist film M-8, which was made using resist material R-8, a mixture of a metatungstate compound containing five onium cations and a metatungstate compound containing six onium cations, and which contained a higher proportion of the metatungstate compound containing five onium cations, had a CD change rate of 6.0%, a better result than resist films R-9 and R-10.

[0131] From the above, it can be seen that resist materials containing metatungstate compounds synthesized by a method of selectively synthesizing a metatungstate compound containing five onium cations, such as in Synthesis Examples 1 to 8, provide excellent resist films.

Claims

1. A method for producing a metatungstate compound represented by general formula (I-1) or (I-2), comprising a step of salt exchange in an acidic solution having a pH of less than 3. ＋ ) ５ ・[H ３ W １２ O ４０ ] ５－ (I-1) (A' ２＋ ) ５ ・([H ３ W １２ O ４０ ] ５－ ) ２ (I-2) [In the formulas (I-1) and (I-2), A ＋ A' each independently represents an onium cation; ２＋ each independently represents an onium dication.

2. The method for producing a metatungstate compound according to claim 1, wherein the onium cation is one or more selected from the group consisting of organic sulfonium cations, organic iodonium cations, and organic ammonium cations.

3. The method for producing a metatungstate compound according to claim 1, wherein the acidic solution having a pH of less than 3 contains an inorganic acid, an organic acid having a carboxy group, or an organic acid having a sulfo group.

4. The method for producing a metatungstate compound according to claim 1, wherein the salt exchange is between a metatungstate represented by general formula (II) and an onium salt represented by general formula (III-1) or (III-2). (B ＋ ) ６ ・[H ２ W １２ O ４０ ] ６－ (II) A ＋ X － (III-1) A' ２＋ ・(X － ) ２ (III-2) [In formula (II), B ＋ are each independently H ＋ , a metal ion, or an ammonium ion; ＋ represents an onium cation; ２＋ represents an onium dication; X － represents a monovalent counter anion.

5. A metatungstate compound for resist represented by the general formula (I-1) or (I-2). ＋ ) ５ ・[H ３ W １２ O ４０ ] ５－ (I-1) (A' ２＋ ) ５ ・([H ３ W １２ O ４０ ] ５－ ) ２ (I-2) [In the formulas (I-1) and (I-2), A ＋ A' each independently represents an onium cation; ２＋ each independently represents an onium dication.

6. A resist material comprising the metatungstate for resist according to claim 5.

7. The resist material of claim 6, further comprising a solvent.

8. The resist material according to claim 6 or 7, which is a resist material for electrons or EUV.

9. A pattern structure formed by using the resist material according to claim 6 or 7.

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