Compound, resin, resist composition, and method for producing resist pattern

Abstract

To provide a compound capable of producing a resist pattern having good CD uniformity (CDU), a resin, and a resist composition containing the same.SOLUTION: The compound represented by formula (I), the resin, and the resist composition are provided. [In the formula, R1 represents a C1-6 alkyl group optionally having a halogen atom, H or a halogen atom; R2 represents a C1-6 alkyl group or a C1-3 alkoxy group; R3 represents a fluorine atom, a C1-6 fluorinated alkyl group or a C1-12 alkyl group, provided that -CH2- contained in the fluorinated alkyl group and the alkyl group may be substituted with -O- or -CO-; and m3 represents an integer of 0-4.]SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a compound, a resin containing a structural unit derived from said compound, a resist composition containing said resin, and a method for producing a resist pattern using said resist composition. [Background technology]

[0002] Patent Document 1 describes resist compositions containing resins that include structural units derived from the following compounds: TIFF0007788806000001.tif3032 Patent Document 2 describes a resist composition containing a resin that includes a structural unit derived from the following compound. TIFF0007788806000002.tif3031 Patent Document 3 describes a resist composition containing a resin that includes a structural unit derived from the following compound. TIFF0007788806000003.tif3084 [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-193539 [Patent Document 2] Japanese Patent Application Publication No. 2019-006991 [Patent Document 3] Japanese Patent Application Publication No. 2019-038998 Summary of the Invention [Problem to be solved by the invention]

[0004] Resist compositions using resins containing structural units derived from the above compounds have not always been able to achieve satisfactory CD uniformity (CDU). [Means for solving the problem]

[0005] The present invention includes the following inventions. [1] A compound represented by formula (I): TIFF0007788806000004.tif4750[In formula (I), R 1 represents an alkyl group having 1 to 6 carbon atoms which may have one or more halogen atoms, a hydrogen atom, or a halogen atom. R 2 represents an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 3 carbon atoms. R 3 represents a fluorine atom, an iodine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, or an alkyl group having 1 to 12 carbon atoms, and —CH2— contained in the fluorinated alkyl group or the alkyl group may be replaced with —O— or —CO—. m3 represents an integer of 0 to 4, and when m3 is 2 or more, a plurality of R 3 may be the same or different from each other.] [2] R 2 The compound according to [1], wherein [3] m3 is 1 or more and at least one R 3 The compound according to [1] or [2], wherein the bonding position of is m-position relative to the bonding position of -CO-O-CH2- in the benzene ring. [4] A resin containing a structural unit derived from the compound according to any one of [1] to [3]. [5] The resin according to [4], further comprising a structural unit having an acid labile group other than the structural unit derived from the compound represented by formula (I). [6] A resist composition containing the resin according to [4] or [5] and an acid generator. [7] The resist composition according to [6], wherein the acid generator contains a salt represented by formula (B1). TIFF0007788806000005.tif2855[In formula (B1), Q b1 and Q b2 each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. L b1represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, wherein -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O- or -CO-, and wherein a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted by a fluorine atom or a hydroxy group. Y represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 24 carbon atoms, and one -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -SO2-, or -CO-. Z + represents an organic cation. [8] The resist composition according to [6] or [7], further comprising a salt that generates an acid that is weaker in acidity than the acid generated from the acid generator. [9] (1) A step of applying the resist composition according to any one of [6] to [8] onto a substrate; (2) drying the applied composition to form a composition layer; (3) exposing the composition layer to light; (4) heating the composition layer after exposure; and (5) A method for producing a resist pattern, comprising the step of developing the composition layer after heating. [Effects of the Invention]

[0006] By using a resist composition that uses a resin that includes a structural unit derived from the compound of the present invention, it is possible to produce a resist pattern that has excellent CD uniformity (CDU). DETAILED DESCRIPTION OF THE INVENTION

[0007] In this specification, "(meth)acrylic monomer" means "at least one of an acrylic monomer and a methacrylic monomer." The terms "(meth)acrylate" and "(meth)acrylic acid" have the same meaning. Regarding groups described in this specification, those that can have both a linear structure and a branched structure may have either. The term "combined group" refers to a group in which two or more of the exemplified groups are bonded, and the valence of these groups may be changed appropriately depending on the bonding form. "Derived from" or "derived from" refers to a polymerizable C=C bond contained in the molecule becoming a -CC- group by polymerization. When stereoisomers exist, all stereoisomers are included.

[0008] [Compound represented by formula (I)] The compound of the present invention relates to a compound represented by formula (I) (hereinafter, sometimes referred to as "compound (I)"). TIFF0007788806000006.tif4750 [In formula (I), all symbols have the same meanings as defined above.]

[0009] In formula (I), R 1 Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group, and are preferably alkyl groups having 1 to 4 carbon atoms, and more preferably a methyl group or an ethyl group. R 1 Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R 1 Examples of the alkyl group having a halogen atom include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a perchloromethyl group, a perbromomethyl group, and a periodomethyl group. R 1 is preferably a hydrogen atom or a methyl group.

[0010] R 2 Examples of the alkyl group having 1 to 6 carbon atoms include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, etc. The number of carbon atoms in the alkyl group is preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 or 2. R 2 Examples of the alkoxy group having 1 to 3 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, etc. The alkoxy group preferably has 1 or 2 carbon atoms, and more preferably 1 carbon atom. R 2 is preferably a methoxy group or an ethoxy group, more preferably a methoxy group. R 3 Examples of the alkyl group having 1 to 12 carbon atoms include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, octyl group, nonyl group, etc. The number of carbon atoms in the alkyl group is preferably 1 to 9, more preferably 1 to 6, and even more preferably 1 to 4. R 3 When —CH2— contained in the alkyl group in the formula (I) is replaced with —O— or —CO—, the number of carbon atoms before the replacement is counted as the total number of carbon atoms in the alkyl group. R 3Examples of the group in which -CH2- in the alkyl group is replaced with -O- or -CO- include a hydroxy group (a group in which -CH2- in a methyl group is replaced with -O-), a carboxy group (a group in which -CH2-CH2- in an ethyl group is replaced with -O-CO-), an alkoxy group (a group in which -CH2- at any position in the alkyl group is replaced with -O-), an alkoxycarbonyl group (a group in which -CH2-CH2- at any position in the alkyl group is replaced with -O-CO-), an alkylcarbonyl group (a group in which -CH2- at any position in the alkyl group is replaced with -CO-), an alkylcarbonyloxy group (a group in which -CH2-CH2- at any position in the alkyl group is replaced with -CO-O-), and a group in which two or more of these groups are combined. R 3 Examples of the fluorinated alkyl group having 1 to 6 carbon atoms include a trifluoromethyl group, a difluoromethyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a perfluorohexyl group, etc. The number of carbon atoms in the fluorinated alkyl group is preferably 1 to 4, and more preferably 1 to 3. R 3 In the above formula, when —CH2— contained in the fluorinated alkyl group is replaced with —O— or —CO—, the number of carbon atoms before the replacement is counted as the total number of carbon atoms in the alkyl group. R 3Examples of groups in which -CH2- in the fluorinated alkyl group is replaced with -O- or -CO- include fluorinated alkoxy groups (groups in which -CH2- at any position in the fluorinated alkyl group is replaced with -O-), fluorinated alkoxycarbonyl groups (groups in which -CH2-CH2- at any position in the fluorinated alkyl group is replaced with -O-CO-), fluorinated alkylcarbonyl groups (groups in which -CH2- at any position in the fluorinated alkyl group is replaced with -CO-), fluorinated alkylcarbonyloxy groups (groups in which -CH2-CH2- at any position in the fluorinated alkyl group is replaced with -CO-O-), and groups in which two or more of these groups are combined. Examples of the alkoxy group include alkoxy groups having 1 to 11 carbon atoms, such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a nonyloxy group, a decyloxy group, and an undecyloxy group. The alkoxycarbonyl group includes an alkoxycarbonyl group having 2 to 11 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, and a butoxycarbonyl group. The alkylcarbonyl group includes alkylcarbonyl groups having 2 to 12 carbon atoms, such as an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyloxy group includes alkylcarbonyloxy groups having 2 to 11 carbon atoms, such as a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, and a butylcarbonyloxy group. Examples of the fluorinated alkoxy group, fluorinated alkoxycarbonyl group, fluorinated alkylcarbonyl group, and fluorinated alkylcarbonyloxy group include fluorinated alkoxy groups having 1 to 5 carbon atoms, fluorinated alkoxycarbonyl groups having 2 to 5 carbon atoms, fluorinated alkylcarbonyl groups having 2 to 6 carbon atoms, and fluorinated alkylcarbonyloxy groups having 2 to 5 carbon atoms, and include, for example, groups in which one or more hydrogen atoms of the above-exemplified groups have been replaced with fluorine atoms. R 3is preferably a fluorine atom, an iodine atom, a fluorinated alkyl group having 1 to 4 carbon atoms, or an alkyl group having 1 to 8 carbon atoms (-CH2- contained in the fluorinated alkyl group and the alkyl group may be replaced by -O- or -CO-), more preferably a fluorine atom, an iodine atom, a trifluoromethyl group, or an alkoxy group having 1 to 6 carbon atoms, and even more preferably a fluorine atom, an iodine atom, a trifluoromethyl group, or an alkoxy group having 1 to 3 carbon atoms. m3 is preferably an integer of 0 to 2, more preferably 1 or 2. When m3 is 1 or more, at least one R 3 is preferably at the m-position relative to the bonding position of -CO-O-CH2- in the benzene ring.

[0011] Examples of Compound (I) include the following compounds: TIFF0007788806000007.tif188144

[0012] In the compounds represented by formulas (I-1) to (I-14), R 1 Specific examples of compound (I) include compounds in which the methyl group corresponding to the formula (I) is replaced with a hydrogen atom. Of these, the compounds represented by formulas (I-1) to (I-5) and (I-11) to (I-14) are preferred.

[0013] <Method for producing compound (I)> Compound (I) can be obtained by reacting a compound represented by formula (Ia) with a compound represented by formula (Ib) in a solvent in the presence of a base catalyst. TIFF0007788806000008.tif49126 (wherein all symbols have the same meanings as defined above.)

[0014] Examples of the base include pyridine, dimethylaminopyridine, and triethylamine. Examples of the solvent include methyl isobutyl ketone, tetrahydrofuran, chloroform, and acetonitrile. The reaction temperature is usually 0° C. to 80° C., and the reaction time is usually 0.5 to 24 hours. Examples of the compound represented by formula (Ia) include compounds represented by the following formula, which are readily available on the market. TIFF0007788806000009.tif1747 Examples of the compound represented by formula (Ib) include compounds represented by the following formula, which are readily available on the market and can also be easily produced by known production methods. TIFF0007788806000010.tif60151

[0015] 〔resin〕 The resin of the present invention is a resin (hereinafter sometimes referred to as "resin (A)") containing a structural unit derived from compound (I) (hereinafter sometimes referred to as "structural unit (I)"). Resin (A) may be a homopolymer of structural unit (I), a copolymer consisting of only structural unit (I), or a polymer containing one or more structural units other than structural unit (I). Examples of structural units other than structural unit (I) include structural units having an acid labile group other than structural unit (I) (hereinafter sometimes referred to as "structural unit (a1)"), structural units having a halogen atom other than structural units having an acid labile group (hereinafter sometimes referred to as "structural unit (a4)"), structural units not having an acid labile group (hereinafter sometimes referred to as "structural unit (s)"), and structural units having a non-leaving hydrocarbon group (hereinafter sometimes referred to as "structural unit (a5)"). Here, the acid labile group refers to a group that has a leaving group and that is released upon contact with acid to form a hydrophilic group (e.g., a hydroxy group or a carboxy group). The content of the structural unit (I) is usually 1 to 90 mol %, preferably 1 to 80 mol %, more preferably 3 to 50 mol %, and even more preferably 3 to 30 mol %, based on all monomers in the resin (A). When the resin (A) contains structural units represented by formula (a4) and / or (a5) described below (hereinafter, sometimes referred to as "resin (AX)"), the content of the structural unit (I) in the resin (AX) of the present invention is preferably 1 to 75 mol %, more preferably 1 to 70 mol %, even more preferably 3 to 65 mol %, and particularly preferably 3 to 60 mol %, based on the sum of all structural units in the resin (AX) of the present invention.

[0016] <Structural unit (a1)> The structural unit (a1) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as "monomer (a1)"). The acid labile group contained in the resin (A) is preferably a group represented by formula (1) (hereinafter also referred to as group (1)) and / or a group represented by formula (2) (hereinafter also referred to as group (2)). TIFF0007788806000011.tif2397 [In formula (1), R a1 , R a2 and R a3 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining any of these; or R a1 and R a2 are bonded to each other to form, together with the carbon atoms to which they are bonded, an alicyclic hydrocarbon group having 3 to 20 carbon atoms. ma and na each independently represent 0 or 1, and at least one of ma and na represents 1. * represents a bond.] TIFF0007788806000012.tif2379 [In formula (2), R a1’ and R a2’ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms; R a3’ represents a hydrocarbon group having 1 to 20 carbon atoms, or R a2’ and R a3’ are bonded to each other to form, together with the carbon atom to which they are bonded and X, a heterocyclic group having 3 to 20 carbon atoms, and -CH2- contained in the hydrocarbon group and the heterocyclic group may be replaced with -O- or -S-. X represents an oxygen atom or a sulfur atom. na' represents 0 or 1. * represents a bond.]

[0017] R a1 , R a2 and R a3 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. R a1 , R a2 and R a3 Examples of the alkenyl group in the formula (I) include ethenyl, propenyl, isopropenyl, butenyl, isobutenyl, tert-butenyl, pentenyl, hexenyl, heptenyl, octenyl, isooctenyl, and nonenyl groups. R a1 , R a2 and R a3 The alicyclic hydrocarbon group in may be either monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Examples of polycyclic alicyclic hydrocarbon groups include decahydronaphthyl, adamantyl, and norbornyl groups, as well as the following groups (where * represents a bond): a1 , R a2 and R a3 The alicyclic hydrocarbon group preferably has 3 to 16 carbon atoms. TIFF0007788806000013.tif9159R a1 , R a2 and R a3 Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. Examples of the combined group include a group combining the above-mentioned alkyl group with an alicyclic hydrocarbon group (for example, an alkylcycloalkyl group or a cycloalkylalkyl group), an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (e.g., a p-methylphenyl group, a p-tert-butylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, etc.), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (e.g., a p-cyclohexylphenyl group, a p-adamantylphenyl group, etc.), and an aryl-cycloalkyl group such as a phenylcyclohexyl group. Preferably, ma is 0 and na is 1. R a1 and R a2 -C(R a1 )(R a2 )(R a3 ) includes the following groups. The alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * represents a bond to -O-. TIFF0007788806000014.tif31135

[0018] R a1’ , R a2’ and R a3’ Examples of the hydrocarbon group in include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups. The alkyl group and the alicyclic hydrocarbon group are represented by R a1 , R a2 and R a3 Examples of the groups include the same as those listed in the above. Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. Examples of the combined group include a group combining the above-mentioned alkyl group with an alicyclic hydrocarbon group (for example, an alkylcycloalkyl group or a cycloalkylalkyl group), an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (e.g., a p-methylphenyl group, a p-tert-butylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, etc.), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (e.g., a p-cyclohexylphenyl group, a p-adamantylphenyl group), and an aryl-cycloalkyl group such as a phenylcyclohexyl group. R a2’ and R a3’ When they are bonded to each other to form a heterocycle together with the carbon atoms to which they are attached and X, -C(R a1’ )(R a2’ )-XR a3’ Examples of the group include the following: * represents a bond. TIFF0007788806000015.tif21142R a1’ and R a2’ At least one of these is preferably a hydrogen atom. na' is preferably 0.

[0019] Examples of the group (1) include the following groups. In formula (1), R a1 , R a2 and R a3 is an alkyl group, ma=0, and na=1. The group is preferably a tert-butoxycarbonyl group. In formula (1), R a1 , R a2 together with the carbon atom to which they are attached form an adamantyl group, and R a3 is an alkyl group, ma=0, and na=1. In formula (1), R a1 and R a2 are each independently an alkyl group, and R a3 is an adamantyl group, ma=0, and na=1. Specific examples of the group (1) include the following: * represents a bond. TIFF0007788806000016.tif170163

[0020] Specific examples of group (2) include the following groups: * represents a bond. TIFF0007788806000017.tif68162

[0021] The monomer (a1) is preferably a monomer having an acid labile group and an ethylenically unsaturated bond, more preferably a (meth)acrylic monomer having an acid labile group. Of the (meth)acrylic monomers having an acid labile group, preferred are those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms. When a resin (A) having a structural unit derived from a monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used in a resist composition, the resolution of the resist pattern can be improved.

[0022] Examples of structural units derived from a (meth)acrylic monomer having group (1) include a structural unit represented by formula (a1-0) (hereinafter, sometimes referred to as structural unit (a1-0)), a structural unit represented by formula (a1-1) (hereinafter, sometimes referred to as structural unit (a1-1)), or a structural unit represented by formula (a1-2) (hereinafter, sometimes referred to as structural unit (a1-2)). Preferably, at least one structural unit selected from the group consisting of structural unit (a1-1) and structural unit (a1-2) is used. These may be used alone or in combination of two or more. TIFF0007788806000018.tif46153 [In formula (a1-0), formula (a1-1) and formula (a1-2), L a01 , L a1 and L a2 are each independently -O- or * -O-(CH2) k1 represents —CO—O—, k1 represents an integer of 1 to 7, and * represents a bond to —CO—. R a01 , Ra4 and R a5 each independently represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a02 , R a03 and R a04 each independently represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these. R a6 and R a7 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these. m1 represents an integer of 0 to 14. n1 represents an integer of 0 to 10. n1' represents an integer of 0 to 3.

[0023] R a01 , R a4 and R a5 is preferably a hydrogen atom or a methyl group, more preferably a methyl group. L a01 , L a1 and L a2 is preferably an oxygen atom or —O—(CH2) k01 It is —CO—O— (wherein k01 is preferably an integer of any one of 1 to 4, more preferably 1), and more preferably an oxygen atom. R a02 , R a03 , R a04 , R a6 and R a7 The alkyl group, alkenyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group and combinations thereof in the formula (1) include R a1 , R a2 and R a3 Examples of the groups include the same groups as those listed in the above. R a02 , R a03 , and R a04The alkyl group in the formula (I) is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. R a6 and R a7 The alkyl group in the formula (I) is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group, or a t-butyl group, and even more preferably an ethyl group, an isopropyl group, or a t-butyl group. R a6 and R a7 The alkenyl group in the formula (I) is preferably an alkenyl group having 2 to 6 carbon atoms, and more preferably an ethenyl group, a propenyl group, an isopropenyl group, or a butenyl group. R a02 , R a03 and R a04 The alicyclic hydrocarbon group preferably has 5 to 12 carbon atoms, and more preferably 5 to 10 carbon atoms. R a02 , R a03 , R a04 , R a6 and R a7 The aromatic hydrocarbon group preferably has 6 to 12 carbon atoms, and more preferably 6 to 10 carbon atoms. In the group in which an alkyl group and an alicyclic hydrocarbon group are combined, the total number of carbon atoms in the combination of the alkyl group and the alicyclic hydrocarbon group is preferably 18 or less. In the group in which an alkyl group and an aromatic hydrocarbon group are combined, the total number of carbon atoms in the combination of the alkyl group and the aromatic hydrocarbon group is preferably 18 or less. R a02 and R a03 is preferably an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a phenyl group or a naphthyl group. R a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. R a6 and R a7is preferably an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an aromatic hydrocarbon group having 6 to 12 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group, a phenyl group, or a naphthyl group, and even more preferably an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group, or a phenyl group. m1 is preferably an integer of 0 to 3, and more preferably 0 or 1. n1 is preferably an integer of 0 to 3, and more preferably 0 or 1. n1' is preferably 0 or 1.

[0024] Examples of the structural unit (a1-0) include structural units represented by any one of formulas (a1-0-1) to (a1-0-18) and R a01 and structural units in which the methyl group corresponding to the formula (a1-0-1) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group, and structural units represented by any of formulas (a1-0-1) to (a1-0-10), (a1-0-13) and (a1-0-14) are preferred. TIFF0007788806000019.tif99168

[0025] Examples of the structural unit (a1-1) include structural units derived from monomers described in JP-A-2010-204646. Among these, structural units represented by any one of formulas (a1-1-1) to (a1-1-7) and R in the structural unit (a1-1) are preferred. a4 A structural unit in which the methyl group corresponding to the formula (a1-1-1) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group is preferred, and a structural unit represented by any one of formulas (a1-1-1) to (a1-1-4) is more preferred. TIFF0007788806000020.tif39167

[0026] The structural unit (a1-2) includes a structural unit represented by any one of formulas (a1-2-1) to (a1-2-14) and R a5and structural units in which the methyl group corresponding to the formula (a1-2-1) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group, and structural units represented by any of formulas (a1-2-2), (a1-2-5), (a1-2-6), and (a1-2-10) to (a1-2-14) are preferred. TIFF0007788806000021.tif67163

[0027] When the resin (A) contains the structural unit (a1-0), the content thereof is usually 5 to 60 mol %, preferably 5 to 50 mol %, and more preferably 10 to 40 mol %, based on all structural units in the resin (A). When the resin (A) contains the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is usually 10 to 95 mol %, preferably 15 to 90 mol %, more preferably 15 to 85 mol %, even more preferably 20 to 80 mol %, and still more preferably 25 to 75 mol %, based on all structural units in the resin (A).

[0028] An example of the structural unit (a1) having the group (2) is a structural unit represented by formula (a1-4) (hereinafter, sometimes referred to as "structural unit (a1-4)"). TIFF0007788806000022.tif3854[In formula (a1-4), R a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a33 represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A a30 is a single bond or * -X a31 -(A a32 -X a32 ) nc- represents -R a32 represents the bonding site with the carbon atom to which it is bonded. A a32 represents an alkanediyl group having 1 to 6 carbon atoms. X a31 and X a32 each independently represents -O-, -CO-O- or -O-CO-. nc represents 0 or 1. la represents an integer of 0 to 4. When la is 2 or more, a plurality of R a33 may be the same or different from each other. R a34 and R a35 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms; R a36 represents a hydrocarbon group having 1 to 20 carbon atoms, or R a35 and R a36 are bonded to each other to form, together with the -CO- to which they are bonded, a divalent hydrocarbon group having 2 to 20 carbon atoms, and the hydrocarbon group and the -CH2- contained in the divalent hydrocarbon group may be replaced with -O- or -S-.]

[0029] R a32 and R a33 Examples of the halogen atom in the formula include a fluorine atom, a chlorine atom, and a bromine atom. R a32 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in the formula (I) include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, a hexyl group, and a perfluorohexyl group. R a32is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group. R a33 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. R a33 Examples of the alkoxy group in include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, and a hexyloxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group. R a33 Examples of the alkoxyalkyl group in the formula (I) include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and even more preferably a methoxymethyl group. R a33 Examples of the alkoxyalkoxy group in include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, and more preferably a methoxyethyl group or an ethoxyethyl group. R a33 Examples of the alkylcarbonyl group in the formula (I) include an acetyl group, a propionyl group, a butyryl group, etc. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group. R a33Examples of the alkylcarbonyloxy group in the formula (I) include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group. R a33 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group, and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group.

[0030] *-X a31 -(A a32 -X a32 ) nc -Examples include *-O-, *-CO-O-, *-O-CO-, *-CO-OA a32 -CO-O-, *-O-CO-A a32 -O-, *-OA a32 -CO-O-, *-CO-OA a32 -O-CO-, *-O-CO-A a32 -O-CO-, and *-CO-O- and *-CO-OA are particularly mentioned. a32 -CO-O- or *-OA a32 -CO-O- is preferred.

[0031] Examples of the alkanediyl group include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. A a32 is preferably a methylene group or an ethylene group.

[0032] A a30is a single bond, *-CO-O- or *-CO-OA a32 -CO-O- is preferred, a single bond, *-CO-O- or *-CO-O-CH2-CO-O- is more preferred, and a single bond or *-CO-O- is even more preferred.

[0033] la is preferably 0, 1 or 2, more preferably 0 or 1, and even more preferably 0. R a34 , R a35 and R a36 Examples of the hydrocarbon group in include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group in which these groups are combined. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Examples of polycyclic alicyclic hydrocarbon groups include decahydronaphthyl, adamantyl, and norbornyl groups, as well as the following groups (* indicates a bonding site): TIFF0007788806000023.tif10151 Examples of aromatic hydrocarbon groups include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. Examples of the combined group include a group combining the above-mentioned alkyl group and alicyclic hydrocarbon group (for example, a cycloalkylalkyl group), an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (such as a p-methylphenyl group, a p-tert-butylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a 2,6-diethylphenyl group, or a 2-methyl-6-ethylphenyl group), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (such as a p-cyclohexylphenyl group or a p-adamantylphenyl group), and an aryl-cycloalkyl group such as a phenylcyclohexyl group. a36Examples of the group include an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these.

[0034] R a34 is preferably a hydrogen atom. R a35 is preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a methyl group or an ethyl group. R a36 The hydrocarbon group in R is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these, and more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. a36 The alkyl group and alicyclic hydrocarbon group in R are preferably unsubstituted. a36 The aromatic hydrocarbon group in is preferably an aromatic ring having an aryloxy group having 6 to 10 carbon atoms.

[0035] -OC(R a34 )(R a35 )-OR a36 is eliminated on contact with an acid (e.g., p-toluenesulfonic acid) to form a hydroxy group. -OC(R a34 )(R a35 )-OR a36 is preferably bonded to the o- or p-position of the benzene ring, more preferably to the p-position.

[0036] Examples of the structural unit (a1-4) include structural units derived from monomers described in JP-A-2010-204646. Preferably, the structural units represented by formulas (a1-4-1) to (a1-4-18) and R in the structural unit (a1-4) are a32and more preferably, the structural units represented by formulas (a1-4-1) to (a1-4-5), (a1-4-10), (a1-4-13), and (a1-4-14), respectively. TIFF0007788806000024.tif99165 When the resin (A) has the structural unit (a1-4), the content thereof is preferably 5 to 60 mol %, more preferably 5 to 50 mol %, and even more preferably 10 to 40 mol %, based on the total of all structural units in the resin (A).

[0037] Examples of the structural unit derived from a (meth)acrylic monomer having the group (2) include a structural unit represented by formula (a1-5) (hereinafter, sometimes referred to as "structural unit (a1-5)"). TIFF0007788806000025.tif4354 formula (a1-5), R a8 represents an alkyl group having 1 to 6 carbon atoms which may have one or more halogen atoms, a hydrogen atom, or a halogen atom. Z a1 is a single bond or -(CH2) h3 -CO-L 54 -, h3 represents an integer of 1 to 4, * represents L 51 Represents a bond with . L 51 , L 52 , L 53 and L 54 each independently represents -O- or -S-. s1 represents an integer of 1 to 3. s1' represents an integer of 0 to 3.

[0038] Examples of halogen atoms include fluorine atoms and chlorine atoms, with fluorine atoms being preferred. Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a fluoromethyl group, and a trifluoromethyl group. In formula (a1-5), R a8 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group. L 51 is preferably an oxygen atom. L 52 and L 53 Among these, it is preferred that one is —O— and the other is —S—. s1 is preferably 1. s1' is preferably an integer of 0 to 2. Z a1 is preferably a single bond or —CH2—CO—O—.

[0039] Examples of the structural unit (a1-5) include structural units derived from monomers described in JP-A-2010-61117. Among these, the structural units represented by formulas (a1-5-1) to (a1-5-4) are preferred, and the structural unit represented by formula (a1-5-1) or (a1-5-2) is more preferred. TIFF0007788806000026.tif34138 When the resin (A) has the structural unit (a1-5), the content thereof is preferably 1 to 50 mol %, more preferably 3 to 45 mol %, even more preferably 5 to 40 mol %, and even more preferably 5 to 30 mol %, based on the total structural units of the resin (A).

[0040] Further, examples of the structural unit (a1) include the following structural units. When the resin (A) contains the above structural unit, the content thereof is preferably 5 to 60 mol %, more preferably 5 to 50 mol %, and even more preferably 10 to 40 mol %, based on the total structural units of the resin (A).

[0041] <Structural unit(s)> The structural unit (s) is derived from a monomer (hereinafter sometimes referred to as "monomer (s)") that does not have an acid labile group. As the monomer from which the structural unit (s) is derived, a monomer that does not have an acid labile group known in the resist field can be used. The structural unit (s) preferably has a hydroxy group or a lactone ring. By using a resin having a structural unit that has a hydroxy group but no acid labile group (hereinafter sometimes referred to as "structural unit (a2)") and / or a structural unit that has a lactone ring but no acid labile group (hereinafter sometimes referred to as "structural unit (a3)") in the resist composition of the present invention, the resolution of the resist pattern and adhesion to the substrate can be improved.

[0042] <Structural unit (a2)> The hydroxy group contained in the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group. When producing a resist pattern from the resist composition of the present invention, if a high-energy ray such as a KrF excimer laser (248 nm), an electron beam, or EUV (extreme ultraviolet) is used as an exposure light source, the structural unit (a2) preferably has a phenolic hydroxy group, and more preferably the structural unit (a2-A) described below. Furthermore, if an ArF excimer laser (193 nm) or the like is used, the structural unit (a2) preferably has an alcoholic hydroxy group, and more preferably the structural unit (a2-1) described below. The structural unit (a2) may contain one type alone or two or more types.

[0043] In the structural unit (a2), the structural unit having a phenolic hydroxy group includes a structural unit represented by formula (a2-A) (hereinafter, sometimes referred to as "structural unit (a2-A)"). TIFF0007788806000028.tif4753[In formula (a2-A), R a50 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a51represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A a50 is a single bond or *-X a51 -(A a52 -X a52 ) nb - represents -R a50 represents the bond to the carbon atom to which it is bonded. A a52 represents an alkanediyl group having 1 to 6 carbon atoms. X a51 and X a52 each independently represents -O-, -CO-O- or -O-CO-. nb represents 0 or 1. mb represents an integer of 0 to 4. When mb is an integer of 2 or more, a plurality of R a51 may be the same or different from each other.]

[0044] R a50 and R a51 Examples of the halogen atom in the formula include a fluorine atom, a chlorine atom, and a bromine atom. R a50 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in the formula (I) include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, a hexyl group, and a perfluorohexyl group. R a50is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group. R a51 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. R a51 Examples of the alkoxy group in include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, and a tert-butoxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group. R a51 Examples of the alkoxyalkyl group in the formula (I) include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and even more preferably a methoxymethyl group. R a51 Examples of the alkoxyalkoxy group in include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, and more preferably a methoxyethoxy group or an ethoxyethoxy group. R a51 Examples of the alkylcarbonyl group in the formula (I) include an acetyl group, a propionyl group, a butyryl group, etc. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group. R a51Examples of the alkylcarbonyloxy group in the formula (I) include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group. R a51 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group, and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group.

[0045] *-X a51 -(A a52 -X a52 ) nb -Examples include *-O-, *-CO-O-, *-O-CO-, *-CO-OA a52 -CO-O-, *-O-CO-A a52 -O-, *-OA a52 -CO-O-, *-CO-OA a52 -O-CO-, *-O-CO-A a52 -O-CO-, and *-CO-O- and *-CO-OA are particularly mentioned. a52 -CO-O- or *-OA a52 -CO-O- is preferred. Examples of the alkanediyl group include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. A a52 is preferably a methylene group or an ethylene group. A a50 is a single bond, *-CO-O- or *-CO-OA a52-CO-O- is preferred, a single bond, *-CO-O- or *-CO-O-CH2-CO-O- is more preferred, and a single bond or *-CO-O- is even more preferred. mb is preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 0. The hydroxy group is preferably bonded to the ortho- or para-position of the benzene ring, more preferably to the para-position.

[0046] Examples of the structural unit (a2-A) include structural units derived from monomers described in JP-A Nos. 2010-204634 and 2012-12577. The structural unit (a2-A) includes structural units represented by formulas (a2-2-1) to (a2-2-16) and R in the structural unit (a2-A) in the structural units represented by formulas (a2-2-1) to (a2-2-16). a50 The structural unit (a2-A) includes a structural unit represented by formula (a2-2-1), a structural unit represented by formula (a2-2-3), a structural unit represented by formula (a2-2-6), a structural unit represented by formula (a2-2-8), a structural unit represented by formula (a2-2-12) to (a2-2-14), and a structural unit represented by formula (a2-2-1), a structural unit represented by formula (a2-2-3), a structural unit represented by formula (a2-2-6), a structural unit represented by formula (a2-2-8), a structural unit represented by formula (a2-2-12) to (a2-2-14), and a structural unit represented by formula (a2-2-1), a structural unit represented by formula (a2-2-3), a structural unit represented by formula (a2-2-6), a structural unit represented by formula (a2-2-8), a structural unit represented by formula (a2-2-12) to (a2-2-14), a50 In the structural unit represented by formula (a2-2-3), the structural unit represented by formula (a2-2-8), the structural unit represented by formula (a2-2-12) to formula (a2-2-14), and the structural unit represented by formula (a2-2-3), the structural unit represented by formula (a2-2-8), and the structural unit represented by formula (a2-2-12) to formula (a2-2-14), R in the structural unit (a2-A) a50In the structural unit represented by formula (a2-2-8), R in the structural unit (a2-A) is more preferably a structural unit represented by formula (a2-2-8) in which a methyl group corresponding to the structural unit represented by formula (a2-2-8) is replaced with a hydrogen atom. a50 More preferably, the structural unit is a structural unit in which a methyl group corresponding to the following formula is replaced with a hydrogen atom: TIFF0007788806000029.tif64168 When the structural unit (a2-A) is contained in the resin (A), the content of the structural unit (a2-A) is preferably 5 to 80 mol %, more preferably 10 to 70 mol %, even more preferably 15 to 65 mol %, and still more preferably 15 to 50 mol %, based on all structural units. The structural unit (a2-A) can be incorporated into the resin (A) by, for example, polymerizing the structural unit (a1-4) and then treating with an acid such as p-toluenesulfonic acid. Alternatively, the structural unit (a2-A) can be incorporated into the resin (A) by polymerizing the structural unit (a1-4) and then treating with an alkali such as tetramethylammonium hydroxide.

[0047] An example of the structural unit (a2) having an alcoholic hydroxy group is a structural unit represented by formula (a2-1) (hereinafter, sometimes referred to as "structural unit (a2-1)"). TIFF0007788806000030.tif4362 formula (a2-1), L a3 is -O- or * -O-(CH2) k2 represents -CO-O-, k2 represents an integer of 1 to 7. * represents a bond to —CO—. R a14 represents a hydrogen atom or a methyl group. R a15 and R a16 each independently represents a hydrogen atom, a methyl group, or a hydroxy group. o1 represents an integer between 0 and 10.

[0048] In equation (a2-1), La3 is preferably -O-, -O-(CH2) f1 It is —CO—O— (wherein f1 represents an integer of 1 to 4), and more preferably —O—. R a14 is preferably a methyl group. R a15 is preferably a hydrogen atom. R a16 is preferably a hydrogen atom or a hydroxy group. o1 is preferably an integer of 0 to 3, and more preferably 0 or 1.

[0049] Examples of the structural unit (a2-1) include structural units derived from monomers described in JP 2010-204646 A. A structural unit represented by any one of formulas (a2-1-1) to (a2-1-6) is preferred, a structural unit represented by any one of formulas (a2-1-1) to (a2-1-4) is more preferred, and a structural unit represented by formula (a2-1-1) or formula (a2-1-3) is even more preferred. TIFF0007788806000031.tif50140 When the resin (A) contains the structural unit (a2-1), the content thereof is usually 1 to 45 mol %, preferably 1 to 40 mol %, more preferably 1 to 35 mol %, even more preferably 2 to 20 mol %, and still more preferably 2 to 10 mol %, based on all structural units of the resin (A).

[0050] <Structural unit (a3)> The lactone ring contained in the structural unit (a3) ​​may be a monocyclic ring such as a β-propiolactone ring, a γ-butyrolactone ring, or a δ-valerolactone ring, or a condensed ring of a monocyclic lactone ring with another ring. Preferred examples include a γ-butyrolactone ring, an adamantane lactone ring, or a bridged ring containing a γ-butyrolactone ring structure (for example, a structural unit represented by the following formula (a3-2)).

[0051] The structural unit (a3) ​​is preferably a structural unit represented by formula (a3-1), formula (a3-2), formula (a3-3), or formula (a3-4). One of these may be contained alone, or two or more may be contained. TIFF0007788806000032.tif52164 [In formula (a3-1), formula (a3-2), formula (a3-3) and formula (a3-4), L a4 , L a5 and L a6 are each independently -O- or -O-(CH2) k3 It represents a group represented by —CO—O— (k3 represents an integer of 1 to 7). L a7 -O-, *-OL a8 -O-, *-OL a8 -CO-O-, *-OL a8 -CO-OL a9 -CO-O- or *-OL a8 -O-CO-L a9 Represents -O-. L a8 and L a9 each independently represents an alkanediyl group having 1 to 6 carbon atoms. * indicates the bonding site with the carbonyl group. R a18 , R a19 and R a20 each independently represents a hydrogen atom or a methyl group. R a24 represents an alkyl group having 1 to 6 carbon atoms which may have one or more halogen atoms, a hydrogen atom, or a halogen atom. X a3 represents -CH2- or an oxygen atom. R a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms. R a22 , R a23 and R a25 each independently represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms. p1 represents an integer of 0 to 5. q1 represents an integer of 0 to 3. r1 represents an integer of 0 to 3. w1 represents an integer of 0 to 8. When p1, q1, r1 and / or w1 are 2 or more, multiple R a21 , R a22 , R a23 and / or R a25 may be the same as or different from each other.

[0052] R a21 , R a22 , R a23 and R a25 Examples of the aliphatic hydrocarbon group in include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, and a tert-butyl group. R a24 Examples of the halogen atom in the formula include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R a24 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group, and preferably an alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group or an ethyl group. R a24 Examples of the alkyl group having a halogen atom in the formula (I) include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group. L a8 and L a9Examples of the alkanediyl group in the formula (I) include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group.

[0053] In formulas (a3-1) to (a3-3), L a4 ~L a6 are each independently preferably -O- or -O-(CH2) k3 In -CO-O-, k3 is a group in which k3 is any integer of 1 to 4, more preferably -O- and *-O-CH2-CO-O-, and even more preferably an oxygen atom. R a18 ~R a21 is preferably a methyl group. R a22 and R a23 are each independently preferably a carboxy group, a cyano group, or a methyl group. p1, q1 and r1 each independently represent an integer of preferably 0 to 2, and more preferably 0 or 1.

[0054] In formula (a3-4), R a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group. R a25 is preferably a carboxy group, a cyano group or a methyl group. L a7 is preferably -O- or *-OL a8 It is —CO—O—, and more preferably —O—, —O—CH 2 —CO—O— or —O—C 2 H 4 —CO—O—. w1 is preferably an integer of 0 to 2, and more preferably 0 or 1. In particular, the formula (a3-4) is preferably the formula (a3-4)'. TIFF0007788806000033.tif4154 (in the formula, R a24 , L a7 has the same meaning as above.)

[0055] Examples of the structural unit (a3) ​​include structural units derived from monomers described in JP 2010-204646 A, JP 2000-122294 A, and JP 2012-41274 A. Examples of the structural unit (a3) ​​include structural units represented by any of formulas (a3-1-1), (a3-1-2), (a3-2-1), (a3-2-2), (a3-3-1), (a3-3-2), and (a3-4-1) to (a3-4-12), and in the structural units, R in formulas (a3-1) to (a3-4) a18 , R a19 , R a20 and R a24 A structural unit in which a methyl group corresponding to the following is replaced with a hydrogen atom is preferred.

[0056] TIFF0007788806000034.tif117165When the resin (A) contains the structural unit (a3), the total content thereof is usually 1 to 70 mol%, preferably 1 to 65 mol%, and more preferably 1 to 60 mol%, based on all structural units of the resin (A). Furthermore, the content of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3), or the structural unit (a3-4) is preferably 1 to 60 mol %, more preferably 1 to 50 mol %, and even more preferably 1 to 50 mol %, based on the total structural units of the resin (A).

[0057] <Structural unit (a4)> Examples of the structural unit (a4) include the following structural units. TIFF0007788806000035.tif3070[In formula (a4), R 41 represents a hydrogen atom or a methyl group. R 42represents a saturated hydrocarbon group having 1 to 24 carbon atoms and containing a fluorine atom, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-.] R 42 Examples of the saturated hydrocarbon group represented by the formula (I) include chain hydrocarbon groups, monocyclic or polycyclic alicyclic hydrocarbon groups, and groups formed by combining these groups.

[0058] Examples of the chain hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group. Examples of the monocyclic or polycyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; and polycyclic alicyclic hydrocarbon groups such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bond): TIFF0007788806000036.tif11158 Examples of groups formed by combination include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic hydrocarbon groups, such as -alkanediyl group-alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, and -alkanediyl group-alicyclic hydrocarbon group-alkyl group.

[0059] The structural unit (a4) includes at least one structural unit selected from the group consisting of formula (a4-0), formula (a4-1), formula (a4-2), formula (a4-3) and formula (a4-4). TIFF0007788806000037.tif4155[In formula (a4-0), R 5a represents a hydrogen atom or a methyl group. L 4a represents a single bond or an alkanediyl group having 1 to 4 carbon atoms. L 3arepresents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms. R 6a represents a hydrogen atom or a fluorine atom.

[0060] L 4a Examples of the alkanediyl group in the formula (I) include linear alkanediyl groups such as a methylene group, an ethylene group, a propane-1,3-diyl group, and a butane-1,4-diyl group, and branched alkanediyl groups such as an ethane-1,1-diyl group, a propane-1,2-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, and a 2-methylpropane-1,2-diyl group.

[0061] L 3a Examples of the perfluoroalkanediyl group in the formula (I) include a difluoromethylene group, a perfluoroethylene group, a perfluoropropane-1,1-diyl group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, a perfluoropropane-2,2-diyl group, a perfluorobutane-1,4-diyl group, a perfluorobutane-2,2-diyl group, a perfluorobutane-1,2-diyl group, a perfluoropentane-1,5-diyl group, a perfluoropentane-2,2-diyl group, a perfluoropentane-3 ,3-diyl group, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane-1,7-diyl group, perfluoroheptane-2,2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane-2,2-diyl group, perfluorooctane-3,3-diyl group, and perfluorooctane-4,4-diyl group. L 3a Examples of the perfluorocycloalkanediyl group in the formula (I) include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, and a perfluoroadamantanediyl group.

[0062] L 4a is preferably a single bond, a methylene group, or an ethylene group, and more preferably a single bond or a methylene group. L 3a is preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, and more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

[0063] The structural unit (a4-0) includes the structural units shown below and R in the structural unit (a4-0) in the structural units shown below. 5a The structural unit in which a methyl group corresponding to the above is replaced with a hydrogen atom is an example. TIFF0007788806000038.tif98165

[0064] TIFF0007788806000039.tif4975[In formula (a4-1), R a41 represents a hydrogen atom or a methyl group. R a42 represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-. A a41 represents an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a group represented by formula (a-g1), a41 and R a42 At least one of the groups has a halogen atom (preferably a fluorine atom) as a substituent. TIFF0007788806000040.tif1384 [In formula (a-g1), s represents 0 or 1. A a42 and A a44 each independently represents a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. A a43 represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. X a41 and X a42each independently represents -O-, -CO-, -CO-O- or -O-CO-. However, A a42 , A a43 , A a44 , X a41 and X a42 The total number of carbon atoms is 7 or less. * is a bond, and the * on the right is -O-CO-R a42 It is a combination with .]

[0065] R a42 Examples of the saturated hydrocarbon group in include a chain saturated hydrocarbon group, a monocyclic or polycyclic alicyclic saturated hydrocarbon group, and groups formed by combining these groups.

[0066] Examples of the chain saturated hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group. Examples of the monocyclic or polycyclic alicyclic saturated hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; and polycyclic alicyclic saturated hydrocarbon groups such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bond): TIFF0007788806000041.tif11158 Examples of groups formed by this combination include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more saturated alicyclic hydrocarbon groups, such as -alkanediyl group-saturated alicyclic hydrocarbon group, -saturated alicyclic hydrocarbon group-alkyl group, and -alkanediyl group-saturated alicyclic hydrocarbon group-alkyl group.

[0067] R a42 Examples of the substituent that may be possessed by include at least one selected from a halogen atom and a group represented by formula (a-g3): Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferred. TIFF0007788806000042.tif752[In formula (a-g3), X a43 represents an oxygen atom, a carbonyl group, *-O-CO- or *-CO-O-. A a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. * denotes R a42 represents a bond with .] However, R a42 -X a43 -A a45 In R a42 If A does not have a halogen atom, a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms and at least one halogen atom.

[0068] A a45 Examples of the aliphatic hydrocarbon group in the formula (I) include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group; Monocyclic alicyclic hydrocarbon groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups; and Examples include polycyclic and alicyclic hydrocarbon groups such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bond): TIFF0007788806000043.tif11158 Examples of groups formed by combination include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic hydrocarbon groups, such as -alkanediyl group-alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, and -alkanediyl group-alicyclic hydrocarbon group-alkyl group.

[0069] R a42 is preferably a saturated hydrocarbon group which may have a halogen atom, and more preferably a saturated hydrocarbon group having an alkyl group having a halogen atom and / or a group represented by formula (a-g3). R a42 When is a saturated hydrocarbon group having a halogen atom, it is preferably a saturated hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, still more preferably a perfluoroalkyl group having 1 to 6 carbon atoms, and particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Examples of perfluoroalkyl groups include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, and a perfluorooctyl group. Examples of perfluorocycloalkyl groups include a perfluorocyclohexyl group. R a42 is a saturated hydrocarbon group having a group represented by formula (a-g3), the number of carbon atoms contained in the group represented by formula (a-g3) is a42 The total number of carbon atoms is preferably 15 or less, more preferably 12 or less. When the group represented by formula (a-g3) is contained as a substituent, the number thereof is preferably 1.

[0070] R a42 is a saturated hydrocarbon group having a group represented by formula (a-g3), R a42 is more preferably a group represented by formula (a-g2). TIFF0007788806000044.tif874[In formula (a-g2), A a46 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. X a44 represents **-O-CO- or **-CO-O- (** represents A a46 represents a bond with . ). A a47 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. However, A a46 , A a47 and X a44 The total number of carbon atoms in A is 18 or less. a46 and A a47At least one of the groups has at least one halogen atom. * indicates a bond to the carbonyl group.

[0071] A a46 The saturated hydrocarbon group preferably has 1 to 6 carbon atoms, and more preferably 1 to 3 carbon atoms. A a47 The aliphatic hydrocarbon group preferably has 4 to 15 carbon atoms, more preferably 5 to 12 carbon atoms, and A a47 is more preferably a cyclohexyl group or an adamantyl group.

[0072] A preferred structure of the group represented by formula (a-g2) is the following structure (* represents a bond to the carbonyl group): TIFF0007788806000045.tif13170

[0073] A a41 Examples of the alkanediyl group in the formula (I) include linear alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, and hexane-1,6-diyl; and branched alkanediyl groups such as propane-1,2-diyl, butane-1,3-diyl, 2-methylpropane-1,2-diyl, 1-methylbutane-1,4-diyl, and 2-methylbutane-1,4-diyl. A a41 Examples of the substituent in the alkanediyl group represented by the formula (I) include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms. A a41 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 2 to 4 carbon atoms, and even more preferably an ethylene group.

[0074] A in the group represented by formula (a-g1) a42 , A a43 and A a44Examples of the divalent saturated hydrocarbon group represented by include a linear or branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic hydrocarbon group, and a group formed by combining an alkanediyl group with a divalent alicyclic hydrocarbon group. Specific examples include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a 1-methylpropane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, and a 2-methylpropane-1,2-diyl group. A a42 , A a43 and A a44 Examples of the substituent of the divalent saturated hydrocarbon group represented by the formula include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms. Preferably, s is 0.

[0075] In the group represented by formula (a-g1), X a42 In the following examples, * and ** each represent a bond, and ** represents -O-CO-R a42 It is a combination of. TIFF0007788806000046.tif49153

[0076] The structural unit represented by formula (a4-1) includes the structural units shown below and R in the structural unit represented by formula (a4-1) in the structural units shown below. a41 The structural unit in which a methyl group corresponding to the above is replaced with a hydrogen atom is an example. TIFF0007788806000047.tif100142

[0077] TIFF0007788806000048.tif122140

[0078] The structural unit represented by formula (a4-1) is preferably a structural unit represented by formula (a4-2). TIFF0007788806000049.tif3658[In formula (a4-2), R f5represents a hydrogen atom or a methyl group. L 44 represents an alkanediyl group having 1 to 6 carbon atoms, and -CH2- contained in the alkanediyl group may be replaced with -O- or -CO-. R f6 represents a saturated hydrocarbon group having 1 to 20 carbon atoms and containing a fluorine atom. However, L 44 and R f6 The maximum total carbon number is 21.]

[0079] L 44 The alkanediyl group of A a41 Examples of the groups include the same groups as those exemplified in R f6 The saturated hydrocarbon group of R a42 Examples of the groups include the same groups as those exemplified in L 44 The alkanediyl group in the formula (I) is preferably an alkanediyl group having 2 to 4 carbon atoms, more preferably an ethylene group.

[0080] Examples of the structural unit represented by formula (a4-2) include structural units represented by formulas (a4-1-1) to (a4-1-11). f5 The structural unit represented by formula (a4-2) also includes a structural unit in which a methyl group corresponding to the following is replaced with a hydrogen atom:

[0081] TIFF0007788806000050.tif5771[In formula (a4-3), R f7 represents a hydrogen atom or a methyl group. L 5 represents an alkanediyl group having 1 to 6 carbon atoms. A f13 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms which may contain a fluorine atom. X f12 represents *-O-CO- or *-CO-O- (* represents A f13 Represents a bond with . A f14represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may contain a fluorine atom. However, A f13 and A f14 At least one of L has a fluorine atom, 5 , A f13 and A f14 The total number of carbon atoms in a molecule is limited to 20.

[0082] L 5 The alkanediyl group in a41 Examples of the alkanediyl group include the same groups as those exemplified as the alkanediyl group.

[0083] A f13 The divalent saturated hydrocarbon group optionally having a fluorine atom in the formula (I) is preferably a divalent chain saturated hydrocarbon group optionally having a fluorine atom and a divalent alicyclic saturated hydrocarbon group optionally having a fluorine atom, and more preferably a perfluoroalkanediyl group. Examples of the divalent chain hydrocarbon group which may have a fluorine atom include alkanediyl groups such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group, and a pentanediyl group; and perfluoroalkanediyl groups such as a difluoromethylene group, a perfluoroethylene group, a perfluoropropanediyl group, a perfluorobutanediyl group, and a perfluoropentanediyl group. The divalent alicyclic hydrocarbon group optionally having a fluorine atom may be either monocyclic or polycyclic. Examples of the monocyclic group include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the polycyclic group include an adamantanediyl group, a norbornanediyl group, and a perfluoroadamantanediyl group.

[0084] A f14 The saturated hydrocarbon group and the saturated hydrocarbon group which may have a fluorine atom are R a42Among these, a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, Preferred are fluorinated alkyl groups such as a hexyl group, a perfluorohexyl group, a heptyl group, a perfluoroheptyl group, an octyl group, and a perfluorooctyl group, a cyclopropylmethyl group, a cyclopropyl group, a cyclobutylmethyl group, a cyclopentyl group, a cyclohexyl group, a perfluorocyclohexyl group, an adamantyl group, an adamantylmethyl group, an adamantyldimethyl group, a norbornyl group, a norbornylmethyl group, a perfluoroadamantyl group, and a perfluoroadamantylmethyl group.

[0085] In formula (a4-3), L 5 is preferably an ethylene group. A f13 The divalent saturated hydrocarbon group is preferably a group containing a divalent chain hydrocarbon group having 1 to 6 carbon atoms and a divalent alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a divalent chain hydrocarbon group having 2 to 3 carbon atoms. A f14 The saturated hydrocarbon group is preferably a group containing a chain hydrocarbon group having 3 to 12 carbon atoms and an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a group containing a chain hydrocarbon group having 3 to 10 carbon atoms and an alicyclic hydrocarbon group having 3 to 10 carbon atoms. f14 is preferably a group containing an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, or an adamantyl group.

[0086] Examples of the structural unit represented by formula (a4-3) include structural units represented by formulas (a4-1'-1) to (a4-1'-11).f7 The structural unit represented by formula (a4-3) also includes a structural unit in which a methyl group corresponding to the following is replaced with a hydrogen atom:

[0087] The structural unit (a4) also includes a structural unit represented by formula (a4-4). TIFF0007788806000051.tif4670[In formula (a4-4), R f21 represents a hydrogen atom or a methyl group. A f21 is -(CH2) j1 -, -(CH2) j2 -O-(CH2) j3 -or-(CH2) j4 -CO-O-(CH2) j5 - represents. j1 to j5 each independently represent an integer of 1 to 6. R f22 represents a saturated hydrocarbon group having 1 to 10 carbon atoms and containing a fluorine atom.] R f22 The saturated hydrocarbon group of R a42 Examples of saturated hydrocarbon groups include the same as those represented by R f22 is preferably an alkyl group having 1 to 10 carbon atoms and containing a fluorine atom or an alicyclic hydrocarbon group having 1 to 10 carbon atoms and containing a fluorine atom, more preferably an alkyl group having 1 to 10 carbon atoms and containing a fluorine atom, and even more preferably an alkyl group having 1 to 6 carbon atoms and containing a fluorine atom. In formula (a4-4), A f21 As -(CH2) j1 - is preferred, an ethylene group or a methylene group is more preferred, and a methylene group is even more preferred.

[0088] Examples of the structural unit represented by formula (a4-4) include the following structural units and structural units represented by the following formulas: f21 The structural unit in which a methyl group corresponding to the above is replaced with a hydrogen atom is an example. When the resin (A) has the structural unit (a4), the content thereof is preferably 1 to 20 mol %, more preferably 2 to 15 mol %, and even more preferably 3 to 10 mol %, based on all structural units in the resin (A).

[0089] <Structural unit (a5)> The non-leaving hydrocarbon group contained in the structural unit (a5) may be a group containing a linear, branched, or cyclic hydrocarbon group, and among these, the structural unit (a5) is preferably a group containing an alicyclic hydrocarbon group. Examples of the structural unit (a5) include a structural unit represented by formula (a5-1). TIFF0007788806000053.tif3972[In formula (a5-1), R 51 represents a hydrogen atom or a methyl group. R 52 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms. L 55 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-.]

[0090] R 52 The alicyclic hydrocarbon group in may be either monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. Examples of polycyclic alicyclic hydrocarbon groups include adamantyl and norbornyl. Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, and 2-ethylhexyl. Examples of the alicyclic hydrocarbon group having a substituent include a 3-methyladamantyl group. R52 is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and more preferably an adamantyl group, a norbornyl group, or a cyclohexyl group.

[0091] L 55 The divalent saturated hydrocarbon group in the formula (I) includes a divalent saturated chain hydrocarbon group and a divalent saturated alicyclic hydrocarbon group, and is preferably a divalent saturated chain hydrocarbon group. Examples of the divalent chain saturated hydrocarbon group include a methylene group, an ethylene group, and an alkanediyl group such as a propanediyl group, a butanediyl group, and a pentanediyl group. The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkanediyl groups such as cyclopentanediyl and cyclohexanediyl. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include adamantanediyl and norbornanediyl.

[0092] L 55 Examples of the divalent saturated hydrocarbon group represented by formula (L1-1) in which one -CH2- is replaced with -O- or -CO- include groups represented by formula (L1-1) to formula (L1-4). In the following formulae, * and ** represent bonding sites, and * represents a bond to an oxygen atom. TIFF0007788806000054.tif18165 formula (L1-1), X x1 represents *-O-CO- or *-CO-O- (* represents L x1 represents a bond with . ). L x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. L x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. However, L x1 and L x2 The total number of carbon atoms is 16 or less. In formula (L1-2), L x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms. L x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. However, L x3 and L x4 The total number of carbon atoms is 17 or less. In formula (L1-3), L x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. L x6 and L x7 each independently represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms. However, L x5 , L x6 and L x7 The total number of carbon atoms is 15 or less. In formula (L1-4), L x8 and L x9 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms. W x1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms. However, L x8 , L x9 and W x1 The total number of carbon atoms is 15 or less.

[0093] L x1 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x2 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond. L x3 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x5 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x6is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x8 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group. L x9 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group. W x1 is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, more preferably a cyclohexanediyl group or an adamantanediyl group.

[0094] Examples of the group represented by formula (L1-1) include the divalent groups shown below. TIFF0007788806000055.tif53135

[0095] Examples of the group represented by formula (L1-2) include the divalent groups shown below. TIFF0007788806000056.tif24131

[0096] Examples of the group represented by formula (L1-3) include the divalent groups shown below. TIFF0007788806000057.tif15146

[0097] Examples of the group represented by formula (L1-4) include the divalent groups shown below. TIFF0007788806000058.tif26116L 55 is preferably a single bond or a group represented by formula (L1-1).

[0098] The structural unit (a5-1) includes the structural units shown below and R in the structural unit (a5-1) in the structural units shown below. 51The structural unit in which a methyl group corresponding to the above is replaced with a hydrogen atom is an example. When the resin (A) has the structural unit (a5), the content thereof is preferably from 1 to 30 mol %, more preferably from 2 to 20 mol %, and even more preferably from 3 to 15 mol %, based on all structural units in the resin (A). <Structural unit (a6)> The structural unit (a6) is a structural unit having an -SO2- group, and preferably has an -SO2- group in a side chain. The structural unit having an -SO2- group may have a linear structure having an -SO2- group, a branched structure having an -SO2- group, or a cyclic structure (monocyclic or polycyclic structure) having an -SO2- group. A structural unit having a cyclic structure having an -SO2- group is preferred, and a structural unit having a cyclic structure containing an -SO2-O- group (sultone ring) is more preferred.

[0099] The sultone ring may be a ring having the following formula (T 1 -1), formula (T 1 -2), formula (T 1 -3) and the formula (T 1 The bonding site can be any position. The sultone ring may be monocyclic, but is preferably polycyclic. A polycyclic sultone ring refers to a bridged ring containing -SO2-O- as an atomic group constituting the ring, and is represented by the formula (T 1 -1) and the formula (T 1 The sultone ring is represented by the formula (T 1 As in the ring represented by formula (2), the atomic group constituting the ring may further contain a heteroatom in addition to —SO—O—. Examples of the heteroatom include an oxygen atom, a sulfur atom, and a nitrogen atom, and an oxygen atom is preferred. TIFF0007788806000060.tif3187

[0100] The sultone ring may have a substituent, and examples of the substituent include an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms, and an alkylcarbonyl group having 2 to 4 carbon atoms.

[0101] Halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, and a decyl group, and preferably an alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group. Examples of the alkyl group having a halogen atom include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group, and preferably a trifluoromethyl group. Examples of the alkyl group having a hydroxy group include a hydroxymethyl group and a 2-hydroxyethyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group. Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-tert-butylphenyl group, a p-adamantylphenyl group, a tolyl group, a xylyl group, a cumyl group, a mesityl group, a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group. Aralkyl groups include benzyl, phenethyl, phenylpropyl, naphthylmethyl and naphthylethyl groups. Examples of the alkoxycarbonyl group include groups in which an alkoxy group, such as a methoxycarbonyl group or an ethoxycarbonyl group, is bonded to a carbonyl group, and preferably includes an alkoxycarbonyl group having 6 or less carbon atoms, more preferably a methoxycarbonyl group. Alkylcarbonyl groups include acetyl, propionyl and butyryl groups.

[0102] From the viewpoint of ease of production of the monomer from which the structural unit (a6) is derived, a sultone ring having no substituent is preferred. The sultone ring is preferably a ring represented by the following formula (T1'). TIFF0007788806000061.tif3172[In formula (T1'), X 11 represents an oxygen atom, a sulfur atom or a methylene group. R 41 represents an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms, or an alkylcarbonyl group having 2 to 4 carbon atoms. ma represents an integer of 0 to 9. When ma is 2 or more, multiple R 41 may be the same or different. The binding site is at any position.] X 11 is preferably an oxygen atom or a methylene group, more preferably a methylene group. R 41 Examples of the substituent include the same as the substituent on the sultone ring, and an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group is preferred.

[0103] The sultone ring is more preferably a ring represented by formula (T1). TIFF0007788806000062.tif3149[In formula (T1), R 8represents an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms, or an alkylcarbonyl group having 2 to 4 carbon atoms. m represents an integer of 0 to 9. When m is 2 or more, a plurality of R 8 may be the same or different. The binding site is at any position.]

[0104] R 8 is R 41 The same can be mentioned. ma in formula (T1′) and m in formula (T1) are preferably 0 or 1, and more preferably 0.

[0105] Examples of the ring represented by formula (T1') and the ring represented by formula (T1) include the following rings: The binding site is at any position. TIFF0007788806000063.tif57165

[0106] The structural unit having a sultone ring preferably has the following group: In the following group, * represents a bonding site. TIFF0007788806000064.tif51165

[0107] The structural unit having an -SO2- group preferably further has a group derived from a polymerizable group, such as a vinyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an acryloylamino group, a methacryloylamino group, an acryloylthio group, or a methacryloylthio group. Among these, the monomer from which the structural unit (a6) is derived is preferably a monomer having an ethylenically unsaturated bond, and more preferably a (meth)acrylic monomer.

[0108] The structural unit (a6) is preferably a structural unit represented by formula (Ix). TIFF0007788806000065.tif4956[In formula (Ix), R x represents an alkyl group having 1 to 6 carbon atoms which may have one or more halogen atoms, a hydrogen atom, or a halogen atom. A xx is an oxygen atom, -N(R c )- or a sulfur atom. A x represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group is -O-, -CO- or -N(R d )- may be replaced. X 11 represents an oxygen atom, a sulfur atom or a methylene group. R 41 represents an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms, or an alkylcarbonyl group having 2 to 4 carbon atoms. ma represents an integer of 0 to 9. When ma is 2 or more, multiple R 41 may be the same or different. R c and R d each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0109] R x Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R x Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group, and are preferably alkyl groups having 1 to 4 carbon atoms, and more preferably a methyl group or an ethyl group. R xExamples of the alkyl group having a halogen atom include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group. R x is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group.

[0110] A x Examples of the divalent saturated hydrocarbon group include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and may be a combination of two or more of these groups. Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group linear alkanediyl groups such as a dodecane-1,12-diyl group, a tridecane-1,13-diyl group, a tetradecane-1,14-diyl group, a pentadecane-1,15-diyl group, a hexadecane-1,16-diyl group, a heptadecane-1,17-diyl group, an ethane-1,1-diyl group, a propane-1,1-diyl group, and a propane-2,2-diyl group; branched alkanediyl groups such as butane-1,3-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, and 2-methylbutane-1,4-diyl; monocyclic divalent alicyclic saturated hydrocarbon groups such as cycloalkanediyl groups, such as cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, and cyclooctane-1,5-diyl; Examples include polycyclic divalent alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group.

[0111] R 41 , X 11 and ma may be the same as those in formula (T1'). Examples of the sultone ring include those mentioned above, and among these, those having a specific bonding position are preferred.

[0112] Examples of the structural unit (a6) include the following structural units. TIFF0007788806000066.tif104168

[0113] Of these, structural units represented by formula (a6-1), formula (a6-2), formula (a6-6), formula (a6-7), formula (a6-8), and formula (a6-12) are preferred, and structural units represented by formula (a6-1), formula (a6-2), formula (a6-7), and formula (a6-8) are more preferred. When the resin (A) has the structural unit (a6), the content thereof is preferably from 1 to 50 mol %, more preferably from 2 to 40 mol %, and even more preferably from 3 to 30 mol %, based on all structural units in the resin (A).

[0114] <Structural unit (II)> The resin (A) may further contain a structural unit that decomposes upon exposure to generate an acid (hereinafter, sometimes referred to as "structural unit (II)"). Specific examples of the structural unit (II) include the structural units described in JP-A-2016-79235, and the structural unit (II) is preferably a structural unit having a sulfonate group or carboxylate group and an organic cation in a side chain, or a structural unit having a sulfonio group and an organic anion in a side chain.

[0115] The structural unit having a sulfonate group or a carboxylate group in the side chain is preferably a structural unit represented by formula (II-2-A'). TIFF0007788806000067.tif36104[In formula (II-2-A'), X III3 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, wherein one -CH2- contained in the saturated hydrocarbon group may be replaced by -O-, -S-, or -CO-, and a hydrogen atom contained in the saturated hydrocarbon group may be replaced by a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, or a hydroxy group. A x1 represents an alkanediyl group having 1 to 8 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. RA - represents a sulfonate group or a carboxylate group. R III3 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. ZA + represents an organic cation.

[0116] R III3 Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R III3 The alkyl group having 1 to 6 carbon atoms which may have a halogen atom and is represented by the formula: a8 Examples of the alkyl group include the same alkyl groups having 1 to 6 carbon atoms which may have a halogen atom and which are represented by the following formula: A x1 Examples of the alkanediyl group having 1 to 8 carbon atoms represented by the formula (I) include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, an ethane-1,1-diyl group, a propane-1,1-diyl group, a propane-1,2-diyl group, a propane-2,2-diyl group, a pentane-2,4-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. A X1Examples of the perfluoroalkyl group having 1 to 6 carbon atoms which may be substituted include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. X III3 Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by the formula (I) include a linear or branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and these may be used in combination. Specific examples thereof include linear alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, propane-1,2-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, and dodecane-1,12-diyl; butane-1,3-diyl, 2-methylpropane-1,3-diyl, and 2-methylpropane-1,3-diyl; Examples include branched alkanediyl groups such as pentane-1,2-diyl, pentane-1,4-diyl, and 2-methylbutane-1,4-diyl; cycloalkanediyl groups such as cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, and cyclooctane-1,5-diyl; and divalent polycyclic alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl, norbornane-2,5-diyl, adamantane-1,5-diyl, and adamantane-2,6-diyl. Examples of saturated hydrocarbon groups in which -CH2- is replaced with -O-, -S-, or -CO- include divalent groups represented by formulae (X1) to (X53). However, the number of carbon atoms before the -CH2- in the saturated hydrocarbon group is replaced with -O-, -S-, or -CO- is 17 or less. In the following formulae, * and ** represent bonding sites, and * represents A x1 Represents a bond with . TIFF0007788806000068.tif145161

[0117] X 3 represents a divalent saturated hydrocarbon group having 1 to 16 carbon atoms. X 4 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. X 5 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms. X 6 represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms. X 7 represents a trivalent saturated hydrocarbon group having 1 to 14 carbon atoms. X 8 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.

[0118] ZA in formula (II-2-A') + represents the cation Z in the salt represented by the formula (B1) described below. + The same can be mentioned.

[0119] The structural unit represented by formula (II-2-A') is preferably a structural unit represented by formula (II-2-A). TIFF0007788806000069.tif38109 [In formula (II-2-A), R III3 , X III3 and ZA + has the same meaning as above. z2A represents an integer of 0 to 6. R III2 and R III4 each independently represents a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms; when z2A is 2 or more, a plurality of R III2 and R III4 may be the same as or different from each other. Q a and Q b each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.] R III2 , R III4 , Q a and Q bAs the perfluoroalkyl group having 1 to 6 carbon atoms represented by the formula (I), the following Q b1 Examples include the same perfluoroalkyl groups having 1 to 6 carbon atoms as those represented by the following formula:

[0120] The structural unit represented by formula (II-2-A) is preferably a structural unit represented by formula (II-2-A-1). TIFF0007788806000070.tif5578 [In formula (II-2-A-1), R III2 , R III3 , R III4 , Q a , Q b and ZA + has the same meaning as above. R III5 represents a saturated hydrocarbon group having 1 to 12 carbon atoms. z2A1 represents an integer of 0 to 6. X I2 represents a divalent saturated hydrocarbon group having 1 to 11 carbon atoms, wherein -CH2- contained in the saturated hydrocarbon group may be replaced by -O-, -S-, or -CO-, and wherein a hydrogen atom contained in the saturated hydrocarbon group may be substituted by a halogen atom or a hydroxy group. R III5 Examples of the saturated hydrocarbon group having 1 to 12 carbon atoms represented by the formula (I) include linear or branched alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group. X I2 As the divalent saturated hydrocarbon group represented by X III3 Examples of the divalent saturated hydrocarbon group include those similar to those represented by the following formula:

[0121] As the structural unit represented by formula (II-2-A-1), a structural unit represented by formula (II-2-A-2) is more preferred. TIFF0007788806000071.tif5288 [In formula (II-2-A-2), R III3 , RIII5 and ZA + has the same meaning as above. mA and nA each independently represent 1 or 2.]

[0122] Examples of the structural unit represented by formula (II-2-A') include the following structural units, R III3 Examples of such a structural unit include a structural unit in which the group corresponding to the methyl group in the formula (1) is replaced with a hydrogen atom, a halogen atom (e.g., a fluorine atom), or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (e.g., a trifluoromethyl group), and the structural units described in WO 2012 / 050015. + represents an organic cation. TIFF0007788806000072.tif86163

[0123] The structural unit having a sulfonio group and an organic anion on the side chain is preferably a structural unit represented by formula (II-1-1). TIFF0007788806000073.tif3791 [In formula (II-1-1), A II1 represents a single bond or a divalent linking group. R II1 represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms. R II2 and R II3 each independently represents a hydrocarbon group having 1 to 18 carbon atoms; R II2 and R II3 may be bonded to each other to form a ring together with the sulfur atom to which they are attached. R II4 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. A - represents an organic anion. R II1 Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by the formula include a phenylene group and a naphthylene group. R II2 and R II3Examples of the hydrocarbon group represented by the formula (I) include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups. R II4 Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R II4 The alkyl group having 1 to 6 carbon atoms which may have a halogen atom and is represented by the formula: a8 Examples of the alkyl group include the same alkyl groups having 1 to 6 carbon atoms which may have a halogen atom and which are represented by the following formula: A II1 Examples of the divalent linking group represented by the formula (I) include a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O-, -S- or -CO-. III3 Examples include the same divalent saturated hydrocarbon groups having 1 to 18 carbon atoms as those represented by the following formula:

[0124] The structural unit containing a cation in formula (II-1-1) includes the structural unit represented by the following formula and R II4 and structural units in which a group corresponding to the methyl group in the above formula (I) is replaced with a hydrogen atom, a fluorine atom, a trifluoromethyl group, or the like. TIFF0007788806000074.tif84130

[0125] A - Examples of the organic anion represented by the formula (A) include a sulfonate anion, a sulfonylimide anion, a sulfonylmethide anion, and a carboxylate anion. - The organic anion represented by the formula (B1) is preferably a sulfonate anion, and the sulfonate anion is more preferably an anion contained in a salt represented by the formula (B1) described below. A - Examples of the sulfonylimide anion represented by the formula (I) include the following. TIFF0007788806000075.tif33136 Examples of sulfonylmethide anions include the following: TIFF0007788806000076.tif29123Carboxylate anions include the following: TIFF0007788806000077.tif51153

[0126] Examples of the structural unit represented by formula (II-1-1) include structural units represented by the following formulas. TIFF0007788806000078.tif88149 When the structural unit (II) is contained in the resin (A), the content of the structural unit (II) is preferably 1 to 20 mol %, more preferably 2 to 15 mol %, and even more preferably 3 to 10 mol %, based on the total structural units of the resin (A).

[0127] The resin (A) may have structural units other than the above-mentioned structural units, and examples of such structural units include structural units well known in the art.

[0128] Resin (A) is preferably a resin consisting of structural units (I) and (a1), a resin consisting of structural units (I) and (s), a resin consisting of structural units (I), (a1), and (s), a resin consisting of structural units (I), (a1), (s), and (a4) and / or (a5), a resin consisting only of structural units (I), or a resin consisting only of structural units (I) and (a4), and more preferably a resin consisting of structural units (I), (a1), and (s), a resin consisting of structural units (I), (a4), and (a5), a resin consisting only of structural units (I), (a4), and (a1).

[0129] The structural unit (a1) is preferably at least one selected from the group consisting of the structural unit (a1-0), the structural unit (a1-0X), the structural unit (a1-1), and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group), and more preferably at least two selected from the group consisting of the structural unit (a1-0), the structural unit (a1-0X), the structural unit (a1-1), and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group). The structural unit (s) is preferably at least one selected from the group consisting of the structural unit (a2) and the structural unit (a3). The structural unit (a2) is preferably the structural unit (a2-A) or the structural unit (a2-1). The structural unit (a3) ​​is preferably at least one selected from the group consisting of the structural unit represented by formula (a3-1), the structural unit represented by formula (a3-2), and the structural unit represented by formula (a3-4).

[0130] The structural units constituting the resin (A) may be used singly or in combination of two or more, and can be produced by a known polymerization method (e.g., radical polymerization) using monomers that lead to these structural units. The content of each structural unit in the resin (A) can be adjusted by the amount of monomer used in the polymerization. The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, even more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less, even more preferably 15,000 or less). In this specification, the weight average molecular weight is a value determined by gel permeation chromatography, which can be measured under the analytical conditions described in the Examples.

[0131] [Resist Composition] The resist composition of the present invention preferably contains a resin (A) and an acid generator known in the resist field (hereinafter sometimes referred to as "acid generator (B)"). The resist composition of the present invention may further contain a resin other than the resin (A). The resist composition of the present invention preferably contains a quencher such as a salt that generates an acid with a weaker acidity than the acid generated from the acid generator (hereinafter may be referred to as "quencher (C)"), and preferably contains a solvent (hereinafter may be referred to as "solvent (E)").

[0132] <Resins other than Resin (A)> The resist composition of the present invention may contain a resin other than resin (A). A resin other than resin (A) is a resin that does not contain structural unit (I). Examples of such a resin include a resin that has a structural unit having an acid labile group but does not contain structural unit (I) (hereinafter, may be referred to as "resin (A2)"), a resin consisting only of structural unit (a4), and a resin consisting of structural unit (a4) and structural unit (a5) (hereinafter, a resin consisting only of structural unit (a4) and a resin consisting of structural unit (a4) and structural unit (a5) may be collectively referred to as resin (X)). In the resin (X), the content of the structural unit (a4) is preferably 30 mol % or more, more preferably 40 mol % or more, and even more preferably 45 mol % or more, based on the total of all structural units in the resin (X). The structural units constituting the resin (X) may be used singly or in combination of two or more, and can be produced by a known polymerization method (e.g., radical polymerization) using monomers that derive these structural units. The content of each structural unit in the resin (X) can be adjusted by the amount of monomer used in the polymerization. The weight average molecular weights of resin (A2) and resin (X) are each independently preferably 6,000 or more (more preferably 7,000 or more) and 80,000 or less (more preferably 60,000 or less). The means for measuring the weight average molecular weights of resin (A2) and resin (X) are the same as those for resin (A). When the resist composition of the present invention contains resin (A2), the content thereof is typically 1 to 2500 parts by mass (more preferably 10 to 1000 parts by mass) per 100 parts by mass of resin (A). Furthermore, when the resist composition contains resin (X), the content thereof is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, even more preferably 1 to 40 parts by mass, still more preferably 1 to 30 parts by mass, and particularly preferably 1 to 8 parts by mass, relative to 100 parts by mass of resin (A).

[0133] The content of resin (A) in the resist composition is preferably 80 to 99 mass% based on the solid content of the resist composition, and more preferably 90 to 99 mass%. Furthermore, when a resin other than resin (A) is contained, the total content of resin (A) and the resin other than resin (A) based on the solid content of the resist composition is preferably 80 to 99 mass% based on the solid content of the resist composition, and more preferably 90 to 99 mass%. The solid content of the resist composition and the resin content relative to the solid content can be measured using known analytical methods such as liquid chromatography or gas chromatography.

[0134] <Acid generator (B)> The acid generator (B) may be either nonionic or ionic. Nonionic acid generators include sulfonate esters (e.g., 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate), sulfones (e.g., disulfone, ketosulfone, sulfonyldiazomethane), etc. Ionic acid generators include onium salts containing onium cations (e.g., diazonium salts, phosphonium salts, sulfonium salts, iodonium salts). Anions of onium salts include sulfonate anions, sulfonylimide anions, sulfonylmethide anions, etc. The acid generator (B) may be a compound that generates an acid when exposed to radiation, as described in JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853, JP-A-63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. No. 3,849,137, German Patent No. 3,914,407, or European Patent No. 126,712. Compounds produced by known methods may also be used. Two or more types of acid generator (B) may be used in combination.

[0135] The acid generator (B) is preferably a fluorine-containing acid generator, and more preferably a salt represented by formula (B1) (hereinafter sometimes referred to as "acid generator (B1)"). TIFF0007788806000079.tif2958[In formula (B1), Q b1 and Q b2 each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. L b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, wherein -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O- or -CO-, and wherein a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted by a fluorine atom or a hydroxy group. Y represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 24 carbon atoms, and one -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -SO2-, or -CO-. Z + represents an organic cation.

[0136] Q b1 and Q b2Examples of the perfluoroalkyl group represented by the formula (I) include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. Q b1 and Q b2 and are each independently preferably a fluorine atom or a trifluoromethyl group, and more preferably both are fluorine atoms.

[0137] L b1 Examples of the divalent saturated hydrocarbon group in include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and may also be a group formed by combining two or more of these groups. Specific examples include linear alkanediyl groups such as a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, a decane-1,10-diyl group, an undecane-1,11-diyl group, a dodecane-1,12-diyl group, a tridecane-1,13-diyl group, a tetradecane-1,14-diyl group, a pentadecane-1,15-diyl group, a hexadecane-1,16-diyl group, and a heptadecane-1,17-diyl group; branched alkanediyl groups such as ethane-1,1-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-2,2-diyl, pentane-2,4-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, and 2-methylbutane-1,4-diyl; monocyclic divalent alicyclic saturated hydrocarbon groups such as cycloalkanediyl groups, such as cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, and cyclooctane-1,5-diyl; Examples include polycyclic divalent alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group.

[0138] L b1 Examples of the divalent saturated hydrocarbon group represented by the formula (b1-1) in which one -CH2- is replaced with -O- or -CO- include groups represented by any of formulas (b1-1) to (b1-3). In the groups represented by formulas (b1-1) to (b1-3) and specific examples thereof, groups represented by formulas (b1-4) to (b1-11), * and ** represent bonding sites, and * represents a bond to -Y.

[0139] TIFF0007788806000080.tif23105[In formula (b1-1), L b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the saturated hydrocarbon group may be substituted with -O- or -CO-. However, L b2 and L b3 The total number of carbon atoms is 22 or less. In formula (b1-2), L b4 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the saturated hydrocarbon group may be substituted with -O- or -CO-. However, L b4 and L b5The total number of carbon atoms is 22 or less. In formula (b1-3), L b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. L b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the saturated hydrocarbon group may be substituted with -O- or -CO-. However, L b6 and L b7 The total number of carbon atoms is 23 or less.

[0140] In the groups represented by formulae (b1-1) to (b1-3), when -CH2- contained in the saturated hydrocarbon group is replaced with -O- or -CO-, the number of carbon atoms before replacement is defined as the number of carbon atoms of the saturated hydrocarbon group. As the divalent saturated hydrocarbon group, L b1 Examples of the divalent saturated hydrocarbon group include the same as the divalent saturated hydrocarbon group.

[0141] L b2 is preferably a single bond. L b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms. L b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom. L b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b6 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b7is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the divalent saturated hydrocarbon group may be substituted with -O- or -CO-.

[0142] L b1 As the divalent saturated hydrocarbon group represented by the formula (b1-1) or (b1-3), in which one --CH.sub.2-- contained in the group is replaced by --O-- or --CO--, a group represented by the formula (b1-1) or (b1-3) is preferred. Examples of the group represented by formula (b1-1) include groups represented by formulas (b1-4) to (b1-8). TIFF0007788806000081.tif48120[In formula (b1-4), L b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. In formula (b1-5), L b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-. L b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b9 and L b10 The total number of carbon atoms is 20 or less. In formula (b1-6), L b11 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b11 and L b12 The total number of carbon atoms is 21 or less. In formula (b1-7), L b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms. L b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-. L b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b13 ~L b15 The total number of carbon atoms is 19 or less. In formula (b1-8), L b16 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-. L b17 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms. L b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b16 ~L b18 The total number of carbon atoms is 19 or less.

[0143] L b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms. L b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b10 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b12is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. L b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms. L b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b16 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. L b17 is preferably a divalent saturated hydrocarbon group having 1 to 6 carbon atoms. L b18 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.

[0144] Examples of the group represented by formula (b1-3) include groups represented by formulas (b1-9) to (b1-11). TIFF0007788806000082.tif23140[In formula (b1-9), L b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxy group, or an alkylcarbonyloxy group. -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group. However, L b19 and L b20 The total number of carbon atoms is 23 or less. In formula (b1-10), L b21represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b22 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b23 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxy group, or an alkylcarbonyloxy group. -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group. However, L b21 , L b22 and L b23 The total number of carbon atoms is 21 or less. In formula (b1-11), L b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b26 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxy group, or an alkylcarbonyloxy group. -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group. However, L b24 , L b25 and L b26 The total number of carbon atoms is 21 or less.

[0145] In addition, in the groups represented by formulae (b1-9) to (b1-11), when a hydrogen atom contained in the saturated hydrocarbon group is substituted with an alkylcarbonyloxy group, the number of carbon atoms before substitution is defined as the number of carbon atoms in the saturated hydrocarbon group. Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group, and an adamantylcarbonyloxy group.

[0146] Examples of the group represented by formula (b1-4) include the following. TIFF0007788806000083.tif16154

[0147] Examples of the group represented by formula (b1-5) include the following. TIFF0007788806000084.tif68152

[0148] Examples of the group represented by formula (b1-6) include the following. TIFF0007788806000085.tif29150

[0149] Examples of the group represented by formula (b1-7) include the following. TIFF0007788806000086.tif57146

[0150] Examples of the group represented by formula (b1-8) include the following. TIFF0007788806000087.tif23150

[0151] Examples of the group represented by formula (b1-2) include the following. TIFF0007788806000088.tif31161

[0152] Examples of the group represented by formula (b1-9) include the following. TIFF0007788806000089.tif44137

[0153] Examples of the group represented by formula (b1-10) include the following. TIFF0007788806000090.tif92165

[0154] Examples of the group represented by formula (b1-11) include the following. TIFF0007788806000091.tif84164

[0155] Examples of the alicyclic hydrocarbon group represented by Y include groups represented by formulae (Y1) to (Y11) and (Y36) to (Y38). When one -CH2- in the alicyclic hydrocarbon group represented by Y is replaced with -O-, -SO2- or -CO-, the number may be 1 or 2 or more. Examples of such groups include groups represented by formulae (Y12) to (Y35) and formulae (Y39) to (Y43).

[0156] The alicyclic hydrocarbon group represented by TIFF0007788806000092.tif83167Y is preferably a group represented by any one of formulas (Y1) to (Y20), (Y26), (Y27), (Y30), (Y31), and (Y39) to (Y43), and more preferably a group represented by formula (Y11), (Y15), (Y16), (Y20), or (Y43). Preferred are groups represented by formula (Y11), formula (Y15), formula (Y20), formula (Y26), formula (Y27), formula (Y30), formula (Y31), formula (Y39), formula (Y40), formula (Y42), or formula (Y43), and more preferred are groups represented by formula (Y11), formula (Y15), formula (Y20), formula (Y26), formula (Y27), formula (Y30), formula (Y31), formula (Y39), formula (Y40), formula (Y42), or formula (Y43). When the alicyclic hydrocarbon group represented by Y is a spiro ring having an oxygen atom such as those of formulae (Y28) to (Y35), (Y39), (Y40), (Y42), and (Y43), the alkanediyl group between the two oxygen atoms preferably has one or more fluorine atoms. Furthermore, among the alkanediyl groups contained in the ketal structure, it is preferred that the methylene group adjacent to the oxygen atom is not substituted with a fluorine atom.

[0157] The substituent of the methyl group represented by Y is a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, a glycidyloxy group, -(CH2)ja -CO-OR b1 group or -(CH2) ja -O-CO-R b1 group (in the formula, R b1 represents an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these, wherein -CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -SO2-, or -CO-, and a hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group, or the aromatic hydrocarbon group may be replaced by a hydroxy group or a fluorine atom. ja represents an integer of 0 to 4. Substituents of the alicyclic hydrocarbon group represented by Y include a halogen atom, a hydroxy group, an alkyl group having 1 to 16 carbon atoms which may be substituted with a hydroxy group (-CH2- contained in the alkyl group may be replaced with -O- or -CO-), an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, a glycidyloxy group, -(CH2) ja -CO-OR b1 group or -(CH2) ja -O-CO-R b1 group (in the formula, R b1 represents an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these, wherein -CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -SO2-, or -CO-, and a hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group, or the aromatic hydrocarbon group may be replaced by a hydroxy group or a fluorine atom. ja represents an integer of 0 to 4.

[0158] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a norbornyl group, and an adamantyl group. The alicyclic hydrocarbon group may have a chain hydrocarbon group, such as a methylcyclohexyl group or a dimethylcyclohexyl group. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 12, and more preferably 3 to 10. Examples of aromatic hydrocarbon groups include aryl groups such as phenyl, naphthyl, anthryl, biphenyl, and phenanthryl. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and aromatic hydrocarbon groups having a chain hydrocarbon group of 1 to 18 carbon atoms (such as tolyl, xylyl, cumenyl, mesityl, p-methylphenyl, p-ethylphenyl, p-tert-butylphenyl, 2,6-diethylphenyl, and 2-methyl-6-ethylphenyl) and aromatic hydrocarbon groups having an alicyclic hydrocarbon group of 3 to 18 carbon atoms (such as p-adamantylphenyl and p-cyclohexylphenyl) are preferred. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 14, and more preferably 6 to 10. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, etc. The number of carbon atoms in the alkyl group is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 4. Examples of the alkyl group substituted with a hydroxy group include hydroxyalkyl groups such as a hydroxymethyl group and a hydroxyethyl group. Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, and a naphthylethyl group. Examples of groups in which -CH2- in an alkyl group is replaced by -O-, -SO2-, -CO-, etc. include an alkoxy group, an alkylsulfonyl group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, or a combination thereof. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group. The number of carbon atoms in the alkoxy group is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 4. Examples of the alkylsulfonyl group include a methylsulfonyl group, an ethylsulfonyl group, a propylsulfonyl group, etc. The alkylsulfonyl group preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 4 carbon atoms. Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, a butoxycarbonyl group, etc. The alkoxycarbonyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and even more preferably 2 to 4 carbon atoms. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and even more preferably 2 to 4 carbon atoms. Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, etc. The alkylcarbonyloxy group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and even more preferably 2 to 4 carbon atoms. Examples of the combined group include a group combining an alkoxy group and an alkyl group, a group combining an alkoxy group and an alkoxy group, a group combining an alkoxy group and an alkylcarbonyl group, and a group combining an alkoxy group and an alkylcarbonyloxy group. Examples of the group combining an alkoxy group and an alkyl group include alkoxyalkyl groups such as a methoxymethyl group, a methoxyethyl group, an ethoxyethyl group, an ethoxymethyl group, etc. The number of carbon atoms in the alkoxyalkyl group is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 to 4. Examples of a group formed by combining an alkoxy group with another alkoxy group include alkoxyalkoxy groups such as a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, etc. The number of carbon atoms in the alkoxyalkoxy group is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 to 4. Examples of the group combining an alkoxy group and an alkylcarbonyl group include alkoxyalkylcarbonyl groups such as a methoxyacetyl group, a methoxypropionyl group, an ethoxyacetyl group, an ethoxypropionyl group, etc. The number of carbon atoms in the alkoxyalkylcarbonyl group is preferably 3 to 13, more preferably 3 to 7, and even more preferably 3 to 5. Examples of the group combining an alkoxy group and an alkylcarbonyloxy group include alkoxyalkylcarbonyloxy groups such as a methoxyacetyloxy group, a methoxypropionyloxy group, an ethoxyacetyloxy group, an ethoxypropionyloxy group, etc. The number of carbon atoms in the alkoxyalkylcarbonyloxy group is preferably 3 to 13, more preferably 3 to 7, and even more preferably 3 to 5. Examples of the group in which one -CH2- in the alicyclic hydrocarbon group is replaced by -O-, -SO2-, -CO- or the like include groups represented by formulae (Y12) to (Y35) and formulae (Y39) to (Y43).

[0159] Examples of Y include the following: TIFF0007788806000093.tif103165

[0160] TIFF0007788806000094.tif66163

[0161] Y is preferably an alicyclic hydrocarbon group of 3 to 24 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon group of 3 to 20 carbon atoms which may have a substituent, even more preferably an alicyclic hydrocarbon group of 3 to 18 carbon atoms which may have a substituent, and even more preferably an adamantyl group which may have a substituent, wherein -CH2- constituting the alicyclic hydrocarbon group or the adamantyl group may be replaced by -CO-, -SO2- or -CO-. Specifically, Y is preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group or a group represented by formula (Y42) or formula (Y100) to formula (Y114).

[0162] The anion in the salt represented by formula (B1) is preferably an anion represented by formula (B1-A-1) to formula (B1-A-59) (hereinafter, sometimes referred to as "anion (B1-A-1)" depending on the formula number).), and more preferably an anion represented by any of formula (B1-A-1) to formula (B1-A-4), formula (B1-A-9), formula (B1-A-10), formula (B1-A-24) to formula (B1-A-33), formula (B1-A-36) to formula (B1-A-40), and formula (B1-A-47) to formula (B1-A-59). TIFF0007788806000095.tif87159

[0163] TIFF0007788806000096.tif117158

[0164] TIFF0007788806000097.tif125157

[0165] TIFF0007788806000098.tif129140

[0166] TIFF0007788806000099.tif111158

[0167] TIFF0007788806000100.tif67139 Here R i2 ~R i7are each independently, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. i8 is, for example, a chain hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a group formed by combining these, more preferably a methyl group, an ethyl group, a cyclohexyl group, or an adamantyl group. A41 is a single bond or an alkanediyl group having 1 to 4 carbon atoms. b1 and Q b2 has the same meaning as above. Specific examples of the anion in the salt represented by formula (B1) include the anions described in JP-A-2010-204646.

[0168] Preferable anions in the salt represented by formula (B1) include anions represented by formulas (B1a-1) to (B1a-38). TIFF0007788806000101.tif89152

[0169] TIFF0007788806000102.tif93139

[0170] TIFF0007788806000103.tif142156

[0171] TIFF0007788806000104.tif63150

[0172] Among these, anions represented by any one of formulas (B1a-1) to (B1a-3), (B1a-7) to (B1a-16), (B1a-18), (B1a-19), and (B1a-22) to (B1a-38) are preferred.

[0173] Z +Examples of the organic cation include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, organic sulfonium cations and organic iodonium cations are preferred, and arylsulfonium cations are more preferred. Specific examples include cations represented by any of formulas (b2-1) to (b2-4) (hereinafter, sometimes referred to as "cation (b2-1)" depending on the formula number).

[0174] TIFF0007788806000105.tif46167In equations (b2-1) to (b2-4), R b4 ~R b6 each independently represent a chain hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms, a hydrogen atom contained in the chain hydrocarbon group may be substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, or a glycidyloxy group, and a hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. R b4 and R b5 and may be bonded to each other to form a ring together with the sulfur atom to which they are attached, and -CH2- contained in the ring may be replaced with -O-, -S- or -CO-. R b7 and R b8 each independently represents a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. m2 and n2 each independently represent an integer of 0 to 5; When m2 is 2 or more, multiple R b7may be the same or different, and when n2 is 2 or more, multiple R b8 may be the same or different. R b9 and R b10 each independently represents a chain hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms. R b9 and R b10 and may be bonded to each other to form a ring together with the sulfur atom to which they are attached, and -CH2- contained in the ring may be replaced with -O-, -S- or -CO-. R b11 represents a hydrogen atom, a chain hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. R b12 represents a chain hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and a hydrogen atom contained in the chain hydrocarbon group may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a hydrogen atom contained in the aromatic hydrocarbon group may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms. R b11 and R b12 may be bonded to each other to form a ring including the -CH-CO- to which they are bonded, and -CH2- contained in the ring may be replaced by -O-, -S- or -CO-. R b13 ~R b18 each independently represents a halogen atom, a hydroxy group, a fluorinated alkyl group having 1 to 12 carbon atoms, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. L b31 represents a sulfur atom or an oxygen atom. o2, p2, s2, and t2 each independently represent an integer of 0 to 5. q2 and r2 each independently represent an integer of 0 to 4; u2 represents 0 or 1. When o2 is 2 or more, multiple R b13are the same or different, and when p2 is 2 or more, multiple R b14 are the same or different, and when q2 is 2 or more, multiple R b15 are the same or different, and when r2 is 2 or more, multiple R b16 are the same or different, and when s2 is 2 or more, multiple R b17 are the same or different, and when t2 is 2 or more, multiple R b18 are the same or different. When u2 is 0, any one of o2, p2, q2, and r2 is 1 or more, and R b13 ~R b16 At least one of o2, p2, s2, t2, q2 and r2 is preferably a halogen atom, and when u2 is 1, any one of o2, p2, s2, t2, q2 and r2 is 1 or more, and R b13 ~R b18 At least one of these is preferably a halogen atom. The aliphatic hydrocarbon group refers to a chain hydrocarbon group and an alicyclic hydrocarbon group. Examples of the chain hydrocarbon group include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, and 2-ethylhexyl. In particular, R b9 ~R b12 The chain hydrocarbon group preferably has 1 to 12 carbon atoms. The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and cyclodecyl. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl, adamantyl, and norbornyl groups, as well as the following groups: TIFF0007788806000106.tif11158 In particular, R b9 ~R b12 The alicyclic hydrocarbon group preferably has 3 to 18 carbon atoms, and more preferably has 4 to 12 carbon atoms. Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-methyladamantan-2-yl group, a 2-ethyladamantan-2-yl group, a 2-isopropyladamantan-2-yl group, a methylnorbornyl group, an isobornyl group, etc. In the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group, the total number of carbon atoms in the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less. The fluorinated alkyl group refers to an alkyl group having 1 to 12 carbon atoms and a fluorine atom, and examples thereof include a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a perfluorobutyl group, etc. The number of carbon atoms in the fluorinated alkyl group is preferably 1 to 9, more preferably 1 to 6, and even more preferably 1 to 4.

[0175] Examples of aromatic hydrocarbon groups include aryl groups such as phenyl, biphenyl, naphthyl, and phenanthryl. The aromatic hydrocarbon group may contain a chain hydrocarbon group or an alicyclic hydrocarbon group, and examples include aromatic hydrocarbon groups having a chain hydrocarbon group of 1 to 18 carbon atoms (such as tolyl, xylyl, cumenyl, mesityl, p-ethylphenyl, p-tert-butylphenyl, 2,6-diethylphenyl, and 2-methyl-6-ethylphenyl) and aromatic hydrocarbon groups having an alicyclic hydrocarbon group of 3 to 18 carbon atoms (such as p-cyclohexylphenyl and p-adamantylphenyl). When the aromatic hydrocarbon group contains a chain hydrocarbon group or an alicyclic hydrocarbon group, chain hydrocarbon groups having 1 to 18 carbon atoms and alicyclic hydrocarbon groups having 3 to 18 carbon atoms are preferred. Examples of aromatic hydrocarbon groups in which hydrogen atoms are substituted with alkoxy groups include p-methoxyphenyl groups. Examples of the chain hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include aralkyl groups such as a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, an isopropylcarbonyloxy group, a butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group. R b4 and R b5 and bond to each other together with the sulfur atom to which they are bonded to form a ring which may be monocyclic, polycyclic, aromatic, non-aromatic, saturated, or unsaturated. This ring may be a ring having 3 to 18 carbon atoms, preferably a ring having 4 to 18 carbon atoms. The ring containing a sulfur atom may be a 3- to 12-membered ring, preferably a 3- to 7-membered ring, for example, the following rings. * represents a bonding site. TIFF0007788806000107.tif23144R b9 and R b10 The ring formed by these together may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring may be a 3- to 12-membered ring, preferably a 3- to 7-membered ring. Examples thereof include a thiolan-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring. R b11 and R b12The ring formed by combining these may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. Examples of this ring include a 3- to 12-membered ring, and preferably a 3- to 7-membered ring. Examples include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

[0176] Among the cations (b2-1) to (b2-4), the cation (b2-1) is preferred. Examples of the cation (b2-1) include the following cations. TIFF0007788806000108.tif79161

[0177] TIFF0007788806000109.tif110165

[0178] Examples of the cation (b2-2) include the following cations. TIFF0007788806000110.tif18150

[0179] Examples of the cation (b2-3) include the following cations. TIFF0007788806000111.tif26140

[0180] Examples of the cation (b2-4) include the following cations. TIFF0007788806000112.tif127165

[0181] The acid generator (B) is a combination of the above-mentioned anions and the above-mentioned organic cations, which can be combined arbitrarily. Preferred examples of the acid generator (B) include a combination of an anion represented by any of formulas (B1a-1) to (B1a-3), (B1a-7) to (B1a-16), (B1a-18), (B1a-19), and (B1a-22) to (B1a-38) with a cation (b2-1), a cation (b2-3), or a cation (b2-4).

[0182] The acid generator (B) is preferably one represented by formulas (B1-1) to (B1-56), of which those containing an arylsulfonium cation are preferred, and those represented by formulas (B1-1) to (B1-3), (B1-5) to (B1-7), (B1-11) to (B1-14), (B1-20) to (B1-26), (B1-29), and (B1-31) to (B1-56) are particularly preferred. JPEG0007788806000113.jpg98162

[0183] TIFF0007788806000114.tif152165

[0184] TIFF0007788806000115.tif92158

[0185] TIFF0007788806000116.tif143161

[0186] TIFF0007788806000117.tif99130

[0187] TIFF0007788806000118.tif92158

[0188] In the resist composition of the present invention, the content of the acid generator is preferably from 1 to 45 parts by mass, more preferably from 1 to 40 parts by mass, and even more preferably from 3 to 35 parts by mass, per 100 parts by mass of the resin (A). The resist composition of the present invention may contain one type of acid generator (B) alone, or may contain multiple types.

[0189] <Solvent (E)> The content of the solvent (E) in the resist composition is usually from 90 to 99.9% by mass, preferably from 92 to 99% by mass, and more preferably from 94 to 99% by mass. The content of the solvent (E) can be measured by known analytical means such as liquid chromatography or gas chromatography. Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate, and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; esters such as ethyl lactate, butyl acetate, amyl acetate, and ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone, and cyclohexanone; cyclic esters such as γ-butyrolactone; and the like. One kind of the solvent (E) may be used alone, or two or more kinds may be used.

[0190] <Quencher (C)> Examples of the quencher (C) include salts that generate an acid having a lower acidity than the acid generated from the acid generator (B), and basic nitrogen-containing organic compounds. The content of the quencher (C) is preferably about 0.01 to 15% by mass, more preferably about 0.01 to 10% by mass, still more preferably about 0.1 to 5% by mass, and still more preferably about 0.1 to 3% by mass, based on the solid content of the resist composition.

[0191] <Salt that generates an acid having a lower acidity than the acid generated from the acid generator> The acidity of the salt that generates an acid having a lower acidity than the acid generated from the acid generator (B) is represented by the acid dissociation constant (pKa). The salt that generates an acid having a lower acidity than the acid generated from the acid generator (B) is usually a salt having an acid dissociation constant of the acid generated from the salt of -3 < pKa, preferably a salt of -1 < pKa < 7, and more preferably a salt of 0 < pKa < 5. Examples of salts that generate an acid that is weaker in acidity than the acid generated from acid generator (B) include salts represented by the following formula, salts represented by formula (D) described in JP 2015-147926 A (hereinafter sometimes referred to as "weak acid inner salt (D)"), and salts described in JP 2012-229206 A, JP 2012-6908 A, JP 2012-72109 A, JP 2011-39502 A, and JP 2011-191745 A. Salts that generate an acid that is weaker in acidity than the acid generated from acid generator (B) are preferably salts (salts having a carboxylic acid anion) that generate a carboxylic acid that is weaker in acidity than the acid generated from acid generator (B), and more preferably weak acid inner salt (D). TIFF0007788806000119.tif94163

[0192] Examples of the weak acid inner salt (D) include the following salts. TIFF0007788806000120.tif72165

[0193] The basic nitrogen-containing organic compound includes amines and ammonium salts. The amines include aliphatic amines and aromatic amines. The aliphatic amines include primary amines, secondary amines, and tertiary amines. Amines include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N,N-dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, Amine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine amine, dicyclohexylmethylamine, tris[2-(2-methoxyethoxy)ethyl]amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 2,2'-methylenebisaniline, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-di(2-pyridyl)ethane Examples of the amines include 1,2-di(4-pyridyl)ethane, 1,2-di(2-pyridyl)ethene, 1,2-di(4-pyridyl)ethene, 1,3-di(4-pyridyl)propane, 1,2-di(4-pyridyloxy)ethane, di(2-pyridyl)ketone, 4,4'-dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipicolylamine, and bipyridine. Preferred are aromatic amines such as diisopropylaniline, and more preferred is 2,6-diisopropylaniline. Examples of ammonium salts include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3-(trifluoromethyl)phenyltrimethylammonium hydroxide, tetra-n-butylammonium salicylate, and choline.

[0194] <Other ingredients> The resist composition of the present invention may optionally contain components other than those described above (hereinafter, these may be referred to as "other components (F)"). There are no particular limitations on the other components (F), and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, and dyes, can be used.

[0195] <Preparation of Resist Composition> The resist composition of the present invention can be prepared by mixing the resin (A) of the present invention, the acid generator (B), a salt that generates an acid weaker in acidity than the acid generated by the acid generator, and, if necessary, the resin (A2), the resin (X), the quencher (C), the solvent (E), and other components (F). The order of mixing is arbitrary and is not particularly limited. The temperature during mixing can be selected from 10 to 40°C, depending on the type of resin, the solubility of the resin in the solvent (E), and other factors. The mixing time can be selected from 0.5 to 24 hours, depending on the mixing temperature. The mixing method is also not particularly limited, and stirring and mixing can be used. After mixing the components, it is preferable to filter the mixture using a filter with a pore size of about 0.003 to 0.2 μm.

[0196] <Method for producing a resist pattern> The method for producing a resist pattern of the present invention comprises the steps of: (1) applying the resist composition of the present invention onto a substrate; (2) drying the applied composition to form a composition layer; (3) exposing the composition layer to light; (4) heating the composition layer after exposure; and (5) A step of developing the composition layer after heating is included.

[0197] The resist composition can be applied to a substrate using a commonly used device such as a spin coater. Examples of the substrate include inorganic substrates such as silicon wafers, and already formed resist films. Before applying the resist composition, the substrate may be cleaned, and an anti-reflective film or the like may be formed on the substrate. The composition after coating is dried to remove the solvent and form a composition layer. Drying is carried out, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking), or by using a vacuum device. The heating temperature is preferably 50 to 200°C, and the heating time is preferably 10 to 180 seconds. The pressure during vacuum drying is preferably 1 to 1.0 x 10 5 It is preferable that the pressure is about Pa. The resulting composition layer is typically exposed using an exposure machine. The exposure machine may be an immersion exposure machine. Various exposure light sources can be used, including those that emit ultraviolet laser light such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), and F2 excimer laser (wavelength 157 nm); those that convert the wavelength of laser light from a solid-state laser source (such as a YAG or semiconductor laser) to emit harmonic laser light in the far ultraviolet or vacuum ultraviolet range; and those that irradiate with electron beams or extreme ultraviolet light (EUV). In this specification, irradiation with these types of radiation may be collectively referred to as "exposure." During exposure, exposure is typically performed through a mask corresponding to the desired pattern. When the exposure light source is an electron beam, exposure may be performed by direct writing without using a mask. The composition layer after exposure is subjected to a heat treatment (so-called post-exposure bake) to promote the deprotection reaction of the acid labile groups. The heating temperature is usually about 50 to 200°C, preferably about 70 to 150°C. A chemical treatment (silylation) may be performed to adjust the hydrophilicity or hydrophobicity of the resin on the surface side of the heated composition. Furthermore, before development, the steps of applying a resist composition, drying, exposing, and heating may be repeated on the composition layer after exposure. The heated composition layer is usually developed using a developer in a developing device. Development methods include dipping, puddling, spraying, and dynamic dispensing. The development temperature is preferably, for example, 5 to 60°C, and the development time is preferably, for example, 5 to 300 seconds. By selecting the type of developer as follows, a positive resist pattern or a negative resist pattern can be produced. When a positive resist pattern is produced from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be any of various alkaline aqueous solutions used in this field. Examples include aqueous solutions of tetramethylammonium hydroxide and (2-hydroxyethyl)trimethylammonium hydroxide (commonly known as choline). The alkaline developer may also contain a surfactant. After development, the resist pattern is preferably washed with ultrapure water, and then water remaining on the substrate and pattern is removed. When a negative resist pattern is produced from the resist composition of the present invention, a developer containing an organic solvent (hereinafter sometimes referred to as an "organic developer") is used as the developer. Examples of organic solvents contained in organic developers include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycol ether solvents such as propylene glycol monomethyl ether; amide solvents such as N,N-dimethylacetamide; and aromatic hydrocarbon solvents such as anisole. The content of the organic solvent in the organic developer is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and even more preferably substantially only the organic solvent. Among these, the organic developer is preferably a developer containing butyl acetate and / or 2-heptanone. The total content of butyl acetate and 2-heptanone in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and even more preferably substantially only butyl acetate and / or 2-heptanone. The organic developer may contain a surfactant and a small amount of water. During development, development may be stopped by replacing the organic developer with a different type of solvent. The developed resist pattern is preferably washed with a rinse solution. There are no particular limitations on the rinse solution as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, preferably an alcohol solvent or an ester solvent. After cleaning, it is preferable to remove the rinse liquid remaining on the substrate and the pattern.

[0198] <Application> The resist composition of the present invention is suitable as a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, and is more suitable as a resist composition for electron beam (EB) exposure or a resist composition for EUV exposure, and is useful for semiconductor microfabrication. [Example]

[0199] The present invention will be explained in more detail with reference to examples. In the examples, "%" and "parts" representing the content or amount used are by mass unless otherwise specified. The weight average molecular weight is a value determined by gel permeation chromatography under the following conditions. Device: HLC-8120GPC model (Tosoh Corporation) Column: TSKgel Multipore H XL -M x 3 + guard column (Tosoh) Eluent: tetrahydrofuran Flow rate: 1.0mL / min Detector: RI detector Column temperature: 40℃ Injection volume: 100μl Molecular weight standard: Standard polystyrene (Tosoh Corporation) The structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC: Agilent 1100, MASS: Agilent LC / MSD). In the following examples, the value of this molecular ion peak is indicated by "MASS."

[0200] Example 1: Synthesis of compound represented by formula (I-1) TIFF0007788806000121.tif4597 1.21 parts of the compound represented by formula (I-1-a), 1.53 parts of pyridine, 0.43 parts of dimethylaminopyridine, and 30 parts of methyl isobutyl ketone were mixed and stirred at 23°C for 30 minutes, then cooled to 5°C. 1.63 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution and stirred at 23°C for 18 hours. 100 parts of n-heptane and 50 parts of a 10% aqueous potassium carbonate solution were added to the resulting reaction mixture, and the mixture was stirred at 23°C for 30 minutes, followed by separation to isolate the organic layer. 50 parts of ion-exchanged water was added to the resulting organic layer, and the mixture was stirred at 23°C for 30 minutes, followed by separation to isolate the organic layer. This water washing procedure was repeated five times. 50 parts of a 5% aqueous oxalic acid solution was added to the recovered organic layer, and the mixture was stirred at 23°C for 30 minutes, followed by separation to isolate the organic layer. 50 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23°C for 30 minutes, followed by separation to separate the organic layer. This water washing procedure was repeated five times. The obtained organic layer was concentrated, and the concentrated mixture was separated using a column (silica gel 60N (spherical, neutral) 100-210 µm; manufactured by Kanto Chemical Co., Inc., developing solvent: n-heptane / ethyl acetate = 5 / 1) to obtain 1.12 parts of the compound represented by formula (I-1). MASS (mass spectrometry):207.1[M+H] +

[0201] Example 2: Synthesis of compound represented by formula (I-4) 1.37 parts of the compound represented by formula (I-4-a), 1.53 parts of pyridine, 0.43 parts of dimethylaminopyridine, and 30 parts of methyl isobutyl ketone were mixed and stirred at 23°C for 30 minutes, then cooled to 5°C. 1.63 parts of the compound represented by formula (I-1-b) were added to the resulting mixture and stirred at 23°C for 18 hours. 100 parts of n-heptane and 50 parts of a 10% aqueous potassium carbonate solution were added to the resulting reaction mixture, and the mixture was stirred at 23°C for 30 minutes, followed by separation to isolate the organic layer. 50 parts of ion-exchanged water was added to the resulting organic layer, and the mixture was stirred at 23°C for 30 minutes, followed by separation to isolate the organic layer. This water washing procedure was repeated five times. 50 parts of a 5% aqueous oxalic acid solution was added to the recovered organic layer, and the mixture was stirred at 23°C for 30 minutes, followed by separation to isolate the organic layer. 50 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23°C for 30 minutes, followed by separation to separate the organic layer. This water washing procedure was repeated five times. The obtained organic layer was concentrated, and the concentrated mixture was separated using a column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Inc., developing solvent: n-heptane / ethyl acetate = 5 / 1) to obtain 1.08 parts of the compound represented by formula (I-4). MASS (mass spectrometry):225.1[M+H] +

[0202] Example 3: Synthesis of compound represented by formula (I-5) 1.53 parts of the compound represented by formula (I-5-a), 1.53 parts of pyridine, 0.43 parts of dimethylaminopyridine, and 30 parts of methyl isobutyl ketone were mixed and stirred at 23°C for 30 minutes, then cooled to 5°C. 1.63 parts of the compound represented by formula (I-1-b) were added to the resulting mixture and stirred at 23°C for 18 hours. 100 parts of n-heptane and 50 parts of a 10% aqueous potassium carbonate solution were added to the resulting reaction mixture, and the mixture was stirred at 23°C for 30 minutes. The organic layer was separated and the organic layer was isolated. 50 parts of ion-exchanged water was added to the resulting organic layer and stirred at 23°C for 30 minutes. The organic layer was then separated and the organic layer was isolated. This water washing procedure was repeated five times. 50 parts of a 5% aqueous oxalic acid solution was added to the recovered organic layer, and the mixture was stirred at 23°C for 30 minutes. The organic layer was then separated and the organic layer was isolated. 50 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23°C for 30 minutes, followed by separation to separate the organic layer. This water washing procedure was repeated five times. The obtained organic layer was concentrated, and the concentrated mixture was separated using a column (silica gel 60N (spherical, neutral) 100-210 µm; manufactured by Kanto Chemical Co., Inc., developing solvent: n-heptane / ethyl acetate = 5 / 1) to obtain 1.19 parts of the compound represented by formula (I-5). MASS (mass spectrometry):243.1[M+H] +

[0203] Example 4: Synthesis of compound represented by formula (I-11) 2.32 parts of the compound represented by formula (I-11-a), 1.53 parts of pyridine, 0.43 parts of dimethylaminopyridine, and 30 parts of methyl isobutyl ketone were mixed and stirred at 23°C for 30 minutes, then cooled to 5°C. 1.63 parts of the compound represented by formula (I-1-b) were added to the resulting mixture and stirred at 23°C for 18 hours. 100 parts of n-heptane and 50 parts of a 10% aqueous potassium carbonate solution were added to the resulting reaction mixture, and the mixture was stirred at 23°C for 30 minutes, followed by separation to isolate the organic layer. 50 parts of ion-exchanged water was added to the resulting organic layer, and the mixture was stirred at 23°C for 30 minutes, followed by separation to isolate the organic layer. This water washing procedure was repeated five times. 50 parts of a 5% aqueous oxalic acid solution was added to the recovered organic layer, and the mixture was stirred at 23°C for 30 minutes, followed by separation to isolate the organic layer. 50 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23°C for 30 minutes, followed by separation to separate the organic layer. This water washing procedure was repeated five times. The obtained organic layer was concentrated, and the concentrated mixture was separated using a column (silica gel 60N (spherical, neutral) 100-210 μm; manufactured by Kanto Chemical Co., Inc., developing solvent: n-heptane / ethyl acetate = 5 / 1) to obtain 2.18 parts of the compound represented by formula (I-11). MASS (mass spectrometry):333.0[M+H] +

[0204] Example 5: Synthesis of compound represented by formula (I-13) 1.81 parts of the compound represented by formula (I-13-a), 1.53 parts of pyridine, 0.43 parts of dimethylaminopyridine, and 30 parts of methyl isobutyl ketone were mixed and stirred at 23°C for 30 minutes, then cooled to 5°C. 1.63 parts of the compound represented by formula (I-1-b) were added to the resulting mixture and stirred at 23°C for 18 hours. 100 parts of n-heptane and 50 parts of a 10% aqueous potassium carbonate solution were added to the resulting reaction mixture, and the mixture was stirred at 23°C for 30 minutes, followed by separation to isolate the organic layer. 50 parts of ion-exchanged water was added to the resulting organic layer, and the mixture was stirred at 23°C for 30 minutes, followed by separation to isolate the organic layer. This water washing procedure was repeated five times. 50 parts of a 5% aqueous oxalic acid solution was added to the recovered organic layer, and the mixture was stirred at 23°C for 30 minutes, followed by separation to isolate the organic layer. 50 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23°C for 30 minutes, followed by separation to separate the organic layer. This water washing procedure was repeated five times. The obtained organic layer was concentrated, and the concentrated mixture was separated using a column (silica gel 60N (spherical, neutral) 100-210 μm; Kanto Chemical Co., Inc., developing solvent: n-heptane / ethyl acetate = 5 / 1) to obtain 1.59 parts of the compound represented by formula (I-13). MASS (mass spectrometry):275.1[M+H] +

[0205] Resin synthesis The compounds (monomers) used in the synthesis of the resin are shown below. TIFF0007788806000126.tif93157Hereinafter, these compounds will be referred to as "monomer (a1-1-3)" etc. according to their formula numbers.

[0206] Example 6 [Synthesis of Resin A1] The monomers used were acetoxystyrene, monomer (I-1), monomer (a1-1-3), and monomer (a1-2-6). They were mixed in a molar ratio of 28:10:32:30 [acetoxystyrene:monomer (I-1):monomer (a1-1-3):monomer (a1-2-6)]. This monomer mixture was then mixed with methyl isobutyl ketone in an amount 1.5 times the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the resulting mixture at 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and the mixture was heated at 73°C for approximately 5 hours. A 25% aqueous solution of tetramethylammonium hydroxide was then added to the polymerization reaction mixture, which was stirred for 12 hours and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate a resin. The resin was then filtered and recovered, yielding a polymer with a weight-average molecular weight of approximately 5.3 x 10. 3 Resin A1 having the following structural units was obtained in a yield of 68%. TIFF0007788806000127.tif36135

[0207] Example 7 [Synthesis of Resin A2] The monomers used were acetoxystyrene, monomer (I-4), monomer (a1-1-3), and monomer (a1-2-6). They were mixed in a molar ratio of 28:10:32:30 [acetoxystyrene:monomer (I-4):monomer (a1-1-3):monomer (a1-2-6)]. This monomer mixture was then mixed with methyl isobutyl ketone in an amount 1.5 times the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the resulting mixture at 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and the mixture was heated at 73°C for approximately 5 hours. A 25% aqueous solution of tetramethylammonium hydroxide was then added to the polymerization reaction mixture, which was stirred for 12 hours and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate a resin. This was then filtered and recovered, yielding a polymer with a weight-average molecular weight of approximately 5.4 x 10. 3Resin A2 having the following structural units was obtained in a yield of 65%. TIFF0007788806000128.tif36135

[0208] Example 8 [Synthesis of Resin A3] The monomers used were acetoxystyrene, monomer (I-5), monomer (a1-1-3), and monomer (a1-2-6). They were mixed in a molar ratio of 28:10:32:30 [acetoxystyrene:monomer (I-5):monomer (a1-1-3):monomer (a1-2-6)]. This monomer mixture was then mixed with methyl isobutyl ketone in an amount 1.5 times the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the resulting mixture at 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and the mixture was heated at 73°C for approximately 5 hours. A 25% aqueous solution of tetramethylammonium hydroxide was then added to the polymerization reaction mixture, which was stirred for 12 hours and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate a resin. This was then filtered and recovered, yielding a polymer with a weight-average molecular weight of approximately 5.6 x 10. 3 Resin A3 having the following structural units was obtained in a yield of 63%. TIFF0007788806000129.tif36135

[0209] Example 9 [Synthesis of Resin A4] The monomers used were acetoxystyrene, monomer (I-11), monomer (a1-1-3), and monomer (a1-2-6). They were mixed in a molar ratio of 28:10:32:30 [acetoxystyrene:monomer (I-11):monomer (a1-1-3):monomer (a1-2-6)]. This monomer mixture was then mixed with methyl isobutyl ketone in an amount 1.5 times the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the resulting mixture at 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and the mixture was heated at 73°C for approximately 5 hours. A 25% aqueous solution of tetramethylammonium hydroxide was then added to the polymerization reaction mixture, which was stirred for 12 hours and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate a resin. This was then filtered and recovered, yielding a polymer with a weight-average molecular weight of approximately 5.1 x 10. 3 Resin A4 having the following structural units was obtained in a yield of 60%. TIFF0007788806000130.tif36135

[0210] Example 10 [Synthesis of Resin A5] The monomers used were acetoxystyrene, monomer (I-13), monomer (a1-1-3), and monomer (a1-2-6). They were mixed in a molar ratio of 28:10:32:30 [acetoxystyrene:monomer (I-13):monomer (a1-1-3):monomer (a1-2-6)]. This monomer mixture was then mixed with methyl isobutyl ketone in an amount 1.5 times the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the resulting mixture at 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and the mixture was heated at 73°C for approximately 5 hours. A 25% aqueous solution of tetramethylammonium hydroxide was then added to the polymerization reaction mixture, which was stirred for 12 hours and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate a resin. This was then filtered and recovered, yielding a polymer with a weight-average molecular weight of approximately 5.5 x 10. 3Resin A5 having the following structural units was obtained in a yield of 69%. TIFF0007788806000131.tif36135

[0211] Example 11 [Synthesis of Resin A6] Monomers (a1-1-3), (a1-2-6), (I-1), (a2-1-3), (a3-4-2), and acetoxystyrene were mixed in a molar ratio of 15:30:10:3:15:27 (monomer (a1-1-3):monomer (a1-2-6):monomer (I-1):monomer (a2-1-3):monomer (a3-4-2):acetoxystyrene). Methyl isobutyl ketone was added to the monomer mixture in an amount of 1.5 times the total weight of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in amounts of 1.2 mol% and 3.6 mol%, respectively, relative to the total monomer amount. The mixture was heated at 73°C for approximately 5 hours. Then, to the polymerization reaction solution, 2.0 times the mass of the total amount of all monomers was added an aqueous solution of p-toluenesulfonic acid (2.5 wt%), and the mixture was stirred for 12 hours, followed by separation. The recovered organic layer was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and recovered, resulting in a resin with a weight-average molecular weight of approximately 5.7 × 10 3 Resin A6 having the following structural units was obtained in a yield of 64%. TIFF0007788806000132.tif37163

[0212] Example 12 [Synthesis of Resin A7] Monomers (a1-1-3), (a1-2-6), (I-4), (a2-1-3), (a3-4-2), and acetoxystyrene were mixed in a molar ratio of 15:30:10:3:15:27 (monomer (a1-1-3):monomer (a1-2-6):monomer (I-4):monomer (a2-1-3):monomer (a3-4-2):acetoxystyrene). 1.5 times the total mass of all monomers was mixed with methyl isobutyl ketone. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators at 1.2 mol% and 3.6 mol%, respectively, and the mixture was heated at 73°C for approximately 5 hours. Then, to the polymerization reaction solution, 2.0 times the mass of the total mass of all monomers was added an aqueous solution of p-toluenesulfonic acid (2.5 wt%), and after stirring for 12 hours, the layers were separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and recovered, resulting in a resin with a weight-average molecular weight of approximately 5.3 × 10 3 Resin A7 having the following structural units was obtained in a yield of 62%. TIFF0007788806000133.tif37163

[0213] Example 13 [Synthesis of Resin A8] Monomers (a1-1-3), (a1-2-6), (I-11), (a2-1-3), (a3-4-2), and acetoxystyrene were mixed in a molar ratio of 15:30:10:3:15:27 (monomer (a1-1-3):monomer (a1-2-6):monomer (I-11):monomer (a2-1-3):monomer (a3-4-2):acetoxystyrene). 1.5 times the total mass of all monomers was mixed with methyl isobutyl ketone. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators at 1.2 mol% and 3.6 mol%, respectively, and the mixture was heated at 73°C for approximately 5 hours. Then, to the polymerization reaction solution, 2.0 times the mass of the total amount of all monomers was added an aqueous solution of p-toluenesulfonic acid (2.5 wt%), and the mixture was stirred for 12 hours, followed by separation. The recovered organic layer was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and recovered to give a resin with a weight-average molecular weight of approximately 5.2 × 10 3 Resin A8 having the following structural units was obtained in a yield of 60%. TIFF0007788806000134.tif37163

[0214] Example 14 [Synthesis of Resin A9] Monomers (a1-1-3), (a1-2-6), (I-13), (a2-1-3), (a3-4-2), and acetoxystyrene were mixed in a molar ratio of 15:30:10:3:15:27 (monomer (a1-1-3):monomer (a1-2-6):monomer (I-13):monomer (a2-1-3):monomer (a3-4-2):acetoxystyrene). 1.5 times the total mass of all monomers was mixed with methyl isobutyl ketone. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators at 1.2 mol% and 3.6 mol%, respectively, and the mixture was heated at 73°C for approximately 5 hours. Then, to the polymerization reaction solution, 2.0 times the mass of the total amount of all monomers was added an aqueous solution of p-toluenesulfonic acid (2.5 wt%), and the mixture was stirred for 12 hours, followed by separation. The recovered organic layer was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and recovered, resulting in a resin with a weight-average molecular weight of approximately 5.5 × 10 3 Resin A9 having the following structural units was obtained in a yield of 70%. TIFF0007788806000135.tif37163

[0215] Synthesis Example 1 [Synthesis of Resin AX1] The monomers used were acetoxystyrene, monomer (IX-1), monomer (a1-1-3), and monomer (a1-2-6). They were mixed in a molar ratio of 28:10:32:30 [acetoxystyrene:monomer (IX-1):monomer (a1-1-3):monomer (a1-2-6)]. This monomer mixture was then mixed with methyl isobutyl ketone in an amount 1.5 times the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the resulting mixture at 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and the mixture was heated at 73°C for approximately 5 hours. A 25% aqueous solution of tetramethylammonium hydroxide was then added to the polymerization reaction mixture, which was stirred for 12 hours and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate a resin. The resin was then filtered and recovered, yielding a polymer with a weight-average molecular weight of approximately 5.5 x 10. 3 Resin AX1 having the following structural units was obtained in a yield of 58%. TIFF0007788806000136.tif36138

[0216] Synthesis Example 2 [Synthesis of Resin AX2] The monomers used were acetoxystyrene, monomer (IX-2), monomer (a1-1-3), and monomer (a1-2-6). They were mixed in a molar ratio of 28:10:32:30 [acetoxystyrene:monomer (IX-2):monomer (a1-1-3):monomer (a1-2-6)]. This monomer mixture was then mixed with methyl isobutyl ketone in an amount 1.5 times the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the resulting mixture at 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and the mixture was heated at 73°C for approximately 5 hours. A 25% aqueous solution of tetramethylammonium hydroxide was then added to the polymerization reaction mixture, which was stirred for 12 hours and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate a resin. The resin was then filtered and recovered, yielding a polymer with a weight-average molecular weight of approximately 5.3 x 10. 3Resin AX2 having the following structural units was obtained in a yield of 61%. TIFF0007788806000137.tif36138

[0217] Synthesis Example 3 [Synthesis of Resin AX3] The monomers used were acetoxystyrene, monomer (IX-3), monomer (a1-1-3), and monomer (a1-2-6). They were mixed in a molar ratio of 28:10:32:30 [acetoxystyrene:monomer (IX-3):monomer (a1-1-3):monomer (a1-2-6)]. This monomer mixture was then mixed with methyl isobutyl ketone in an amount 1.5 times the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the resulting mixture at 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and the mixture was heated at 73°C for approximately 5 hours. A 25% aqueous solution of tetramethylammonium hydroxide was then added to the polymerization reaction mixture, which was stirred for 12 hours and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate a resin. The resin was then filtered and recovered, yielding a polymer with a weight-average molecular weight of approximately 5.5 x 10. 3 Resin AX3 having the following structural units was obtained in a yield of 65%. TIFF0007788806000138.tif47138

[0218] Synthesis Example 4 [Synthesis of Resin AX4] The monomers used were acetoxystyrene, monomer (IX-4), monomer (a1-1-3), and monomer (a1-2-6). They were mixed in a molar ratio of 28:10:32:30 [acetoxystyrene:monomer (IX-4):monomer (a1-1-3):monomer (a1-2-6)]. This monomer mixture was then mixed with methyl isobutyl ketone in an amount 1.5 times the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the resulting mixture at 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and the mixture was heated at 73°C for approximately 5 hours. A 25% aqueous solution of tetramethylammonium hydroxide was then added to the polymerization reaction mixture, which was stirred for 12 hours and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate a resin. The resin was then filtered and recovered, yielding a polymer with a weight-average molecular weight of approximately 5.6 x 10. 3 Resin AX4 having the following structural units was obtained in a yield of 67%. TIFF0007788806000139.tif34138

[0219] <Preparation of Resist Composition> The components shown in Table 1 were mixed and dissolved to obtain a mixture, which was then filtered through a fluororesin filter with a pore size of 0.2 μm to prepare a resist composition. [Table 1]

[0220] <Resin> A1 to A9, AX1 to AX4: Resin A1 to Resin A9, Resin AX1 to Resin AX4 <Acid generator (B)> B1-43: Salt represented by formula (B1-43) (synthesized according to the examples in JP 2016-47815 A) TIFF0007788806000141.tif3787<Quencher (C)> (Salts that generate acids that are weaker in acidity than the acid generated by acid generators) Synthesized by the method described in JP-A-2011-39502 TIFF0007788806000142.tif3546 <solvent> 400 parts of propylene glycol monomethyl ether acetate 150 parts of propylene glycol monomethyl ether 5 parts of γ-butyrolactone

[0221] (Electron beam exposure evaluation of resist composition) A 6-inch silicon wafer was treated on a direct hot plate with hexamethyldisilazane at 90°C for 60 seconds. The resist composition was spin-coated onto this silicon wafer so that the film thickness of the composition layer was 0.04 μm. Then, it was prebaked on a direct hot plate at the temperature shown in the "PB" column of Table 1 for 60 seconds to form a composition layer. A contact hole pattern (hole pitch 40 nm / hole diameter 17 nm) was directly drawn on the composition layer formed on the wafer using an electron beam lithography machine ["ELS-F125 125 keV" manufactured by Elionix, Inc.] while changing the exposure dose stepwise.<000​​​​​​​​​​​​​​​​ Compared with Comparative Compositions 1 to 4, the standard deviations in Compositions 1 to 9 were small, and the CD uniformity (CDU) evaluation was good.

[0223] (Electron Beam Exposure Evaluation of Resist Composition: Organic Solvent Development) A 6-inch silicon wafer was treated on a direct hot plate with hexamethyldisilazane at 90 °C for 60 seconds. The resist composition was spin-coated on this silicon wafer so that the film thickness of the composition layer was 0.04 μm. Then, it was pre-baked on a direct hot plate at the temperature shown in the "PB" column of Table 1 for 60 seconds to form a composition layer. A contact hole pattern (hole pitch 40 nm / hole diameter 17 nm) was directly drawn on the composition layer formed on the wafer using an electron beam lithography machine ["ELS-F125 125 keV" manufactured by Elionix, Inc.] while changing the exposure dose stepwise. After exposure, post-exposure baking was performed on a hot plate at the temperature shown in the "PEB" column of Table 1 for 60 seconds. Next, the composition layer on this silicon wafer was developed at 23 °C for 20 seconds by the dynamic dispense method using butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as the developer to obtain a resist pattern.

[0224] In the resist pattern obtained after development, the exposure dose at which the formed hole diameter became 17 nm was defined as the effective sensitivity.

[0225] [[ID=?]] <CD Uniformity (CDU) Evaluation> At the effective sensitivity, the hole diameter of the pattern formed with a hole diameter of 17 nm was measured 24 times for each hole, and the average value was taken as the average hole diameter of one hole. The standard deviation was obtained using, as the population, the average hole diameters of 400 patterns formed with a hole diameter of 17 nm within the same wafer. The results are shown in Table 3. The numerical values in the table indicate the standard deviation (nm).

Table 3

[0226] A resist composition containing a resin having a structural unit derived from the compound of the present invention can provide a resist pattern with excellent CD uniformity (CDU), and is therefore suitable for semiconductor microfabrication and extremely useful industrially.

Claims

1. A compound represented by formula (I): [In formula (I), R １ represents an alkyl group having 1 to 6 carbon atoms which may have one or more halogen atoms, a hydrogen atom, or a halogen atom. R ２ represents an alkoxy group having 1 to 3 carbon atoms. R ３ represents a fluorine atom, an iodine atom, or a fluorinated alkyl group having 1 to 6 carbon atoms. m3 represents an integer of 1 to 4, and when m3 is 2 or more, a plurality of R ３ may be the same or different.]

2. R ２ The compound according to claim 1, wherein is a methoxy group.

3. At least one R ３ The bonding position of is -CO-O-CH ２ The compound according to claim 1 or 2, which is in the m-position relative to the bonding position of -.

4. A resin comprising a structural unit derived from the compound according to any one of claims 1 to 3.

5. The resin according to claim 4, further comprising a structural unit having an acid labile group other than the structural unit derived from the compound represented by formula (I).

6. A resist composition comprising the resin according to claim 4 or 5 and an acid generator.

7. 7. The resist composition according to claim 6, wherein the acid generator comprises a salt represented by formula (B1). [In formula (B1), Q ｂ１ and Q ｂ２ each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. L ｂ１ represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ２ The - may be replaced by -O- or -CO-, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted by a fluorine atom or a hydroxy group. Y represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 24 carbon atoms, and —CH ２ - is -O-, -SO ２ It may be replaced by - or -CO-. Z ＋ represents an organic cation.

8. 8. The resist composition according to claim 6, further comprising a salt that generates an acid that is weaker in acidity than the acid generated from the acid generator.

9. (1) a step of applying the resist composition according to any one of claims 6 to 8 onto a substrate; (2) a step of drying the applied composition to form a composition layer; (3) exposing the composition layer to light; (4) a step of heating the composition layer after exposure; and (5) developing the composition layer after heating; A method for producing a resist pattern comprising:

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