Acid generator, resist composition, method for producing resist pattern, and salt

Abstract

To provide a resist composition, a resin and the like which allow a resist pattern having good line edge roughness to be produced.SOLUTION: There are provided: an acid generator containing a salt represented by formula (I-A2); a resist composition; and the like. [In the formula, Lb2 represents a single bond or a substituted / unsubstituted hydrocarbon group, and -CH2- contained in the group may be substituted with -O-, -S-, -CO- or -SO2-; Rb1 represents a halogen atom or an alkyl group, and -CH2- contained in the group may be substituted with -O- or -CO-; nb3 represents an integer of 0-4; R3 represents a halogen atom, a haloalkyl group or a substituted / unsubstituted hydrocarbon group, and -CH2- contained in the haloalkyl group and the hydrocarbon group may be substituted with -O-, -CO-, -S- or -SO2-; m3 represents an integer of 0-4; nb4 represents an integer of 1-5, provided that 1≤nb4+nb3≤5 is satisfied; and Z represents an organic cation.]SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a salt for an acid generator used in semiconductor microfabrication, an acid generator containing the salt, a resist composition, and a method for producing a resist pattern.

Background Art

[0002] Patent Document 1 describes a salt represented by the following formula and a composition containing the salt as an acid generator. TIFF2025100419000001.tif3665

[0003] Patent Document 2 describes a salt represented by the following formula. TIFF2025100419000002.tif2947

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention provides a salt capable of producing a resist pattern with better line edge roughness (LER) than a resist pattern formed from the above resist composition.

Means for Solving the Problems

[0006] The present invention includes the following inventions. [1] An acid generator containing a salt represented by formula (I-A2). TIFF2025100419000003.tif28133[In formula (I-A2), L b2represents a divalent hydrocarbon group having 1 to 24 carbon atoms which may have a single bond or a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. R b1 represents a halogen atom or an alkyl group having 1 to 6 carbon atoms, and -CH2- contained in the alkyl group may be replaced by -O- or -CO-. nb3 represents any integer from 0 to 4. When nb3 is 2 or more, a plurality of R b1 may be the same as or different from each other. R 3 represents a halogen atom, a haloalkyl group having 1 to 12 carbon atoms or a hydrocarbon group having 1 to 18 carbon atoms. The hydrocarbon group may have a substituent, and -CH2- contained in the haloalkyl group and the hydrocarbon group may be replaced by -O- or -CO-, -S-, -SO2-. m3 represents any integer from 0 to 4. When m3 is 2 or more, a plurality of R 3 may be the same as or different from each other. nb4 represents any integer from 1 to 5. When nb4 is 2 or more, the groups within a plurality of parentheses may be the same as or different from each other. However, 1 ≤ nb4 + nb3 ≤ 5 is satisfied. Z + represents an organic cation. The acid generator according to [1], wherein nb4 is 1. A resist composition containing the acid generator according to [1] or [2]. [4] contains a resin containing a structural unit having an acid-labile group, The resist composition according to [3], wherein the structural unit having an acid-labile group contains at least one selected from the group consisting of a structural unit represented by formula (a1-0), a structural unit represented by formula (a1-1), a structural unit represented by formula (a1-2), a structural unit represented by formula (a1-4), a structural unit represented by formula (a1-5) and a structural unit represented by formula (a1-6). TIFF2025100419000004.tif44145 [In formula (a1-0), formula (a1-1) and formula (a1-2), L a01 、L a1 and L a2 each independently represents -O- or *-O-(CH2) k1 -CO-O-, k1 represents any integer from 1 to 7, and * represents the bonding site with -CO-. R a01 、R a4 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 formed by combining these. The alkyl group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group may have a halogen atom. 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, and the alkyl group, the alkenyl group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group may have a halogen atom. m1’ represents any integer from 0 to 14. n1 represents any integer from 0 to 10. n1’ represents any integer from 0 to 3.] TIFF2025100419000005.tif31118[In formula (a1-4), R a1 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a17represents a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, 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 a11 represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and -CH2- contained in the alkanediyl group may be replaced by -O-, -CO- or -NR a18 -. R a18 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X a1 represents a single bond or a carbonyl group. R a34 and R a35 each independently represent 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 a divalent hydrocarbon group having 2 to 20 carbon atoms together with the -C-O- to which they are bonded, and -CH2- contained in the hydrocarbon group and the divalent hydrocarbon group may be replaced by -O- or -S-. na1 represents any integer from 1 to 5. When na1 is 2 or more, the groups in the plurality of parentheses may be the same as or different from each other. na11 represents any integer from 0 to 4. When na11 is 2 or more, the plurality of R a17 may be the same as or different from each other. mc represents any integer from 0 to 2.] TIFF2025100419000006.tif4558[In formula (a1-5), R a8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom. Z a1 represents a single bond or *-(CH2) h3 -CO-L54 represents -, h3 represents any integer from 1 to 4, and * represents the bonding site with L 51 and the bonding site with L is represented. L 51 L 52 L 53 and L 54 each independently represents -O- or -S-. s1 represents any integer from 1 to 3. s1’ represents any integer from 0 to 3. TIFF2025100419000007.tif3479 [In formula (a1-6), R a61 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a62 R a63 and R a64 each independently represents an alkyl group having 1 to 6 carbon atoms or a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, or R a62 and R a63 are bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded. X a61 represents a single bond, -CO-O-*, or -CO-NR a65 -*, where * represents the bond with Ar, and R a65 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X a62 represents a single bond, *-O-L a61 - or *-CO-O-L a62 -, where * represents the bond with Ar, and L a61 and L a62 each independently represents an alkanediyl group having 1 to 4 carbon atoms. Ar represents an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent. [5] The resist composition according to [3] or [4], comprising a resin containing a structural unit represented by formula (a2-A). TIFF2025100419000008.tif30128 [In formula (a2-A), R a2represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a27 represents a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, 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 a21 represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and -CH2- contained in the alkanediyl group may be replaced by -O-, -CO-, or -NR a28 -. R a28 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X a2 represents a single bond or a carbonyl group. nA2 represents any integer from 1 to 5, and when nA2 is 2 or more, the groups in a plurality of parentheses may be the same as or different from each other. na21 represents any integer from 0 to 4, and when na21 is 2 or more, a plurality of R a27 may be the same as or different from each other. mc represents any integer from 0 to 2. [6] A step of applying the resist composition according to any one of [3] to [5] on a substrate, (2) A step of drying the applied resist composition to form a composition layer, (3) A step of exposing the composition layer, (4) A step of heating the exposed composition layer, and (5) A step of developing the heated composition layer, A method for producing a resist pattern including the above steps. [7] The salt represented by the above formula (I-A2). [8] The salt according to [7] wherein nb1 is 1. [Advantages of the Invention]

[0007] By using the resist composition of the present invention, a resist pattern can be manufactured with good line edge roughness (LER).

Mode for Carrying Out the Invention

[0008] In this specification, the “(meth)acrylic monomer” means “at least one of an acrylic monomer and a methacrylic monomer”. Expressions such as “(meth)acrylate” and “(meth)acrylic acid” also represent the same meaning. Among the groups described in this specification, those that can take both a linear structure and a branched structure may be either of them. When -CH2- contained in a hydrocarbon group or the like is replaced by -O-, -S-, -CO- or -SO2-, the same examples are applied to each group, and the number of carbon atoms before replacement is defined as the number of carbon atoms of the hydrocarbon group or the like. The “combined group” means a group formed by bonding two or more of the exemplified groups, and the valences of those groups may be appropriately changed depending on the bonding form. “Derived from” or “derived” refers to the fact that the polymerizable C═C bond contained in the molecule becomes a -C-C- group (single bond) by polymerization. When stereoisomers exist, all stereoisomers are included. The “acid-labile group” means a group having a leaving group, and when contacted with an acid (for example, trifluoromethanesulfonic acid or the like), the leaving group leaves to form a hydrophilic group (for example, a hydroxy group or a carboxy group). The base-labile group means a group that, as described later, forms a carboxy group or a hydroxy group when contacted with a base (for example, trimethylamine, tetramethylammonium hydroxide or the like). In this specification, the “solid content of the resist composition” means the total of the components excluding the solvent (E) described later from the total amount of the resist composition.

[0009] <Salt represented by formula (I-A2)> The present invention relates to a salt represented by formula (I-A2) (hereinafter sometimes referred to as “salt (I-A2)”). Among salts (I-A2), the side having a negative charge may be referred to as “anion (I)”, and the side having a positive charge may be referred to as “cation (I)”.

[0010] [Anion (I)] In formula (I-A2), L b2 As the divalent hydrocarbon group of, a group obtained by removing nb4 hydrogen atoms from a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a group combining two or more of these groups and bonding to one or more benzene rings can be mentioned. As the chain hydrocarbon group, a group obtained by removing nb1 hydrogen atoms from an alkyl group or an alkenyl group can be mentioned. The alkyl group may be linear or branched, and specifically, a methane group, an ethane group, a propane group, an iso-propyl group, an n-butyl group, a sec-butyl group, an iso-butyl group, a tert-butyl group, a heptyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decane group, an undecane group, a dodecane group, a tridecane group, a tetradecane group, a pentadecane, a heptadecane group, etc. can be mentioned. As the alkenyl group, an ethenyl group, a propenyl group, an isopropenyl group, a butenyl group, an isobutenyl group, a tert-butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an octenyl group, an isooctenyl group, a nonenyl group can be mentioned. The number of carbon atoms of the chain hydrocarbon group is preferably 1 to 20, more preferably 1 to 16, and even more preferably 1 to 10. As the alicyclic hydrocarbon group, a group obtained by removing nb1 hydrogen atoms from a monocyclic or polycyclic cycloalkyl group can be mentioned. As the monocyclic cycloalkyl group, a cyclobutyl group, a cyclopentane group, a cyclohexane group, a cyclopentyl group, a cyclooctyl group, etc. can be mentioned. Examples of the polycyclic cycloalkyl group include a cycloalkyl group having a crosslinked structure, a cycloalkyl group in which two or more rings are condensed, or a cycloalkyl group in which two rings are spiro-bonded. Examples of the cycloalkyl group having a crosslinked structure include a norbornane group and an adamantane group. Examples of the cycloalkyl group in which two or more rings are condensed include a bicyclo[4.4.0]decane group and a steroid group (steroid skeleton). Examples of the ring in which two rings are spiro-bonded include a spirocycloalkyl group in which one cycloalkyl group selected from the group consisting of a cyclopentyl group, a cyclohexyl group, a norbornane group, and an adamantyl group is spiro-bonded to a cycloalkyl group having 5 to 8 carbon atoms. In addition, a double bond may be formed between two carbon atoms contained in the alicyclic hydrocarbon group. More specifically, examples of the alicyclic hydrocarbon group represented by the following formula can be given. TIFF2025100419000009.tif28158 When the alicyclic hydrocarbon group is a monocyclic cycloalkyl group, the number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 18, more preferably 3 to 12, and even more preferably 3 to 8. When the alicyclic hydrocarbon group is a polycyclic cycloalkyl group, the number of carbon atoms in the alicyclic hydrocarbon group is preferably 7 to 18. Examples of the aromatic hydrocarbon group include an aryl group from which nb1 hydrogen atoms have been removed. Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a fluorene group. The number of carbon atoms in the aromatic hydrocarbon group is preferably 5 to 18, more preferably 5 to 14, and even more preferably 5 to 10. L b2 When -CH2- contained in the hydrocarbon group of L is replaced by -O-, -CO-, -S-, or -SO2-, the number of carbon atoms before replacement is defined as the number of carbon atoms in the hydrocarbon group. L b2Among the hydrocarbon groups, examples of the group in which -CH2- contained in the chain hydrocarbon group is replaced by -O-, -CO-, -S- or -SO2- include a hydroxy group (a group in which -CH2- contained in the methyl group is replaced by -O-), a thiol group (a group in which -CH2- contained in the methyl group is replaced by -S-), a sulfonyl group (a group in which -CH2- contained in the methylene group is replaced by -SO2-), a carboxy group (a group in which -CH2-CH2- contained in the ethyl group is replaced by -O-CO-), a carbonyl group (a group in which -CH2- contained in the methylene group is replaced by -CO-), an oxy group (a group in which -CH2- contained in the methylene group is replaced by -O-), an alkoxy group (a group in which -CH2- at any position contained in the alkyl group is replaced by -O-), an alkoxycarbonyl group (a group in which -CH2-CH2- at any position contained in the alkyl group is replaced by -O-CO-), an alkylcarbonyl group (a group in which -CH2- at any position contained in the alkyl group is replaced by -CO-), an alkylthio group (a group in which -CH2- at any position contained in the alkyl group is replaced by -S-), an alkylsulfonyl group (a group in which -CH2- at any position contained in the alkyl group is replaced by -SO2-), an alkylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in the alkyl group is replaced by -CO-O-), an alkoxycarbonyloxy group (a group in which -CH2-CH2-CH2- at any position contained in the alkyl group is replaced by -OCO-O-), an alkanedioxy group (a group in which -CH2- at any position contained in the alkanedioyl group is replaced by -O-), an alkanedioxycarbonyl group (a group in which -CH2-CH2- at any position contained in the alkanedioyl group is replaced by -O-CO-), an alkanedioylcarbonyl group (a group in which -CH2- at any position contained in the alkanedioyl group is replaced by -CO-), an alkanedioylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in the alkanedioyl group is replaced by -CO-O-), an alkanedioylsulfonyl group (a group in which -CH2- at any position contained in the alkanedioyl group is replaced by -SO2-), an alkanedioylthio group (a group in which -CH2- at any position contained in the alkanedioyl group is-S- replaced group), etc. Examples of the alkoxy group include alkoxy groups having 1 to 23 carbon atoms, such as methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group and the like. The number of carbon atoms of the alkoxy group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 23 carbon atoms, such as methoxycarbonyl group, ethoxycarbonyl group, butoxycarbonyl group and the like. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 24 carbon atoms, such as acetyl group, propionyl group and butyryl group and the like. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 23 carbon atoms, such as acetyloxy group, propionyloxy group, butyryloxy group and the like. Examples of the alkoxycarbonyloxy group include alkoxycarbonyloxy groups having 2 to 23 carbon atoms, such as butoxycarbonyloxy group and the like. The number of carbon atoms of the alkoxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyloxy group and the alkoxycarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3, respectively. Examples of the alkylthio group include alkylthio groups having 1 to 23 carbon atoms, such as methylthio group, ethylthio group, propylthio group, butylthio group and the like. The number of carbon atoms of the alkylthio group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkylsulfonyl group include alkylsulfonyl groups having 1 to 23 carbon atoms, such as methylsulfonyl group, ethylsulfonyl group, propylsulfonyl group and the like. The number of carbon atoms of the alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 23 carbon atoms, such as acetyloxy group, propionyloxy group, butyryloxy group and the like. The number of carbon atoms of the alkylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. Examples of the alkanedioxy group include alkanedioxy groups having 1 to 23 carbon atoms, such as methyleneoxy group, ethyleneoxy group, propanediyl-oxy group, butanediyl-oxy group, pentanediyl-oxy group and the like. The number of carbon atoms of the alkanedioxy group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediyl-oxycarbonyl group include alkanediyl-oxycarbonyl groups having 2 to 23 carbon atoms, such as a methylene-oxycarbonyl group, an ethylene-oxycarbonyl group, a propanediyl-oxycarbonyl group, and a butanediyl-oxycarbonyl group. Examples of the alkanediyl-carbonyl group include alkanediyl-carbonyl groups having 2 to 24 carbon atoms, such as a methylene-carbonyl group, an ethylene-carbonyl group, a propanediyl-carbonyl group, a butanediyl-carbonyl group, and a pentanediyl-carbonyl group. Examples of the alkanediyl-carbonyloxy group include alkanediyl-carbonyloxy groups having 2 to 23 carbon atoms, such as a methylene-carbonyloxy group, an ethylene-carbonyloxy group, a propanediyl-carbonyloxy group, and a butanediyl-carbonyloxy group. The number of carbon atoms of the alkanediyl-oxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkanediyl-carbonyl group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkanediyl-carbonyloxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. Examples of the alkanediyl-thio group include alkanediyl-thio groups having 1 to 23 carbon atoms, such as a methylene-thio group, an ethylene-thio group, and a propanediyl-thio group. The number of carbon atoms of the alkanediyl-thio group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediyl-sulfonyl group include alkanediyl-sulfonyl groups having 1 to 23 carbon atoms, such as a methylene-sulfonyl group, an ethylene-sulfonyl group, and a propylene-sulfonyl group. The number of carbon atoms of the alkanediyl-sulfonyl group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. L b2Among the hydrocarbon groups, examples of the group in which -CH2- contained in the alicyclic hydrocarbon group is replaced by -O-, -CO-, -S- or -SO2- include cyclic ethers, cyclic ketones, cyclic esters (lactones), cyclic thioethers, cyclic acetals, cyclic sultones, and the like. Specifically, alicyclic hydrocarbon groups represented by the following formulas can be mentioned. The bonding position of the alicyclic hydrocarbon group mentioned in the following formulas can be any position. TIFF2025100419000010.tif46146L b2 Among the hydrocarbon groups, -CH2- contained in the aromatic hydrocarbon group may be replaced by -O- or -S-. Examples of the group in which -CH2- is replaced by -O- or -S- include a furan ring and a thiophene ring, respectively. Examples of the group in which -CH2- contained in the group combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2- also include the following groups, etc. The bonding site can be any position. TIFF2025100419000011.tif26164Examples of the group combining two or more of a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group include the group combining the above chain hydrocarbon group and the above alicyclic hydrocarbon group, the group combining the above chain hydrocarbon group and the above aromatic hydrocarbon group, the group combining the above alicyclic hydrocarbon group and the above aromatic hydrocarbon group, and the group combining the above chain hydrocarbon group, the above alicyclic hydrocarbon group and the above aromatic hydrocarbon group. The group combining the above alicyclic hydrocarbon group and the above aromatic hydrocarbon group may be a condensed ring. L b2 Examples of the substituent that the hydrocarbon group may have include a halogen atom, a cyano group, and a nitro group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like. L b2 When is a group combining an alicyclic hydrocarbon group or an aromatic hydrocarbon group and a chain hydrocarbon group, substantially, the chain hydrocarbon group may be regarded as a substituent that the alicyclic hydrocarbon group or the aromatic hydrocarbon group has. Also, L b2The -CH2- of the chain hydrocarbon group contained in the hydrocarbon group is replaced by -O-, -CO-, -S- or -SO2- to form L b2 The hydrocarbon group of b2 can substantially have substituents such as a hydroxy group, a carboxyl group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, a thiol group, a sulfonyl group, etc. L b2 The bonding position of L is at the o-position, m-position or p-position relative to the bonding position of SO3 on the benzene ring - and may be o-position, m-position or p-position substitution.

[0011] R 3 Examples of the halogen atom of R include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. R 3 The haloalkyl group having 1 to 12 carbon atoms of R represents an alkyl group having 1 to 12 carbon atoms with a halogen atom, and examples thereof include a fluoroalkyl group having 1 to 12 carbon atoms, a chloroalkyl group having 1 to 12 carbon atoms, a bromoalkyl group having 1 to 12 carbon atoms, and an iodoalkyl group having 1 to 12 carbon atoms. Examples of the haloalkyl group include a perfluoroalkyl group having 1 to 12 carbon atoms (such as a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, a nonafluorobutyl group, etc.), a 2,2,2-trifluoroethyl group, a 3,3,3-trifluoropropyl group, a 4,4,4-trifluorobutyl group, and a 3,3,4,4,4-pentafluorobutyl group, a chloromethyl group, a bromomethyl group, an iodomethyl group, etc. The number of carbon atoms of the haloalkyl group is preferably 1 to 9, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. R 3 Examples of the hydrocarbon group having 1 to 18 carbon atoms of R include chain hydrocarbon groups such as an alkyl group and an alkanediyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these. The alkyl group is a straight-chain or branched alkyl group, and examples thereof 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, 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, and the like. Examples of the alkanediyl group 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, and branched alkanediyl groups such as 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. The terminal of the branched alkanediyl group may be a methyl group. The number of carbon atoms of the chain hydrocarbon group is preferably 1 to 12, more preferably 1 to 9, still more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3. The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and examples thereof include the groups represented below. The bonding site can be at any position. TIFF2025100419000012.tif46168Specifically, examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group and the like. Examples of the polycyclic alicyclic hydrocarbon group include cycloalkyl groups such as decahydronaphthyl group, adamantyl group, norbornyl group, spirocyclohexane-1,2'-cyclopentane, spiroadamantane-2,3'-cyclopentane group and the like, spiro rings having a norbornyl group or an adamantyl group and a cycloalkyl group bonded thereto by spiro, respectively. The number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 18, more preferably 3 to 16, and even more preferably 3 to 12. Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, biphenyl group, anthryl group, phenanthryl group, binaphthyl group and the like. The number of carbon atoms of the aromatic hydrocarbon group is preferably 6 to 18, more preferably 6 to 14, and even more preferably 6 to 10.

[0012] Examples of the group formed by combination include a group formed by combining an aromatic hydrocarbon group and a chain hydrocarbon group (for example, aromatic hydrocarbon group - alkanediyl group - *, alkyl group - aromatic hydrocarbon group - *, -CH2- contained in the alkanediyl group and the alkyl group may be replaced by -O-, -CO-, -S- or -SO2-), a group formed by combining an alicyclic hydrocarbon group and a chain hydrocarbon group (for example, alicyclic hydrocarbon group - alkanediyl group - *, alkyl group - alicyclic hydrocarbon group - *, -CH2- contained in the alkanediyl group and the alkyl group may be replaced by -O-, -CO-, -S- or -SO2-), a group formed by combining an aromatic hydrocarbon group and an alicyclic hydrocarbon group (for example, aromatic hydrocarbon group - alicyclic hydrocarbon group - *, alicyclic hydrocarbon group - aromatic hydrocarbon group - *). * represents a bonding site. Examples of the aromatic hydrocarbon group - alkanediyl group - * include aralkyl groups such as benzyl group and phenethyl group. Examples of the alkyl group - aromatic hydrocarbon group - * include tolyl group, xylyl group, cumenyl group and the like. Examples of the alicyclic hydrocarbon group-alkanediyl group-* include cycloalkylalkyl groups such as cyclohexylmethyl group, cyclohexylethyl group, 1-(adamantan-1-yl)methyl group, 1-(adamantan-1-yl)-1-methylethyl group, and the like. Examples of the alkyl group-alicyclic hydrocarbon group-* include cycloalkyl groups having an alkyl group such as methylcyclohexyl group, dimethylcyclohexyl group, 2-alkyladamantan-2-yl group, and the like. Examples of the aromatic hydrocarbon group-alicyclic hydrocarbon group-* include phenylcyclohexyl group and the like. Examples of the alicyclic hydrocarbon group-aromatic hydrocarbon group-* include cyclohexylphenyl group and the like. In the combination, two or more alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and chain hydrocarbon groups may be combined respectively. Also, any of these groups may be bonded to the benzene ring.

[0013] R 3 When -CH2- contained in the haloalkyl group or hydrocarbon group represented by R is replaced by -O-, -CO-, -S-, or -SO2-, the number of carbon atoms before replacement is taken as the total number of carbon atoms of the haloalkyl group or the hydrocarbon group. Also, the number may be one or two or more. Examples of groups in which -CH2- contained in a haloalkyl group and a hydrocarbon group is replaced by -O-, -S-, -SO2- or -CO- include a hydroxy group (a group in which -CH2- contained in a methyl group is replaced by -O-), a thiol group (a group in which -CH2- contained in a methyl group is replaced by -S-), a carboxy group (a group in which -CH2-CH2- contained in an ethyl group is replaced by -O-CO-), an alkoxy group (a group in which -CH2- at any position contained in an alkyl group is replaced by -O-), an alkoxycarbonyl group (a group in which -CH2-CH2- at any position contained in an alkyl group is replaced by -O-CO-), an alkylcarbonyl group (a group in which -CH2- at any position contained in an alkyl group is replaced by -CO-), an alkylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in an alkyl group is replaced by -CO-O-), an alkylthio group (a group in which -CH2- at any position contained in an alkyl group is replaced by -S-), an alkylsulfonyl group (a group in which -CH2- at any position contained in an alkyl group is replaced by -SO2-), an oxy group (a group in which -CH2- contained in a methylene group is replaced by -O-), a carbonyl group (a group in which -CH2- contained in a methylene group is replaced by -CO-), a thio group (a group in which -CH2- contained in a methylene group is replaced by -S-), a sulfonyl group (a group in which -CH2- contained in a methylene group is replaced by -SO2-), an alkanedioxy group (a group in which -CH2- at any position contained in an alkanediyl group is replaced by -O-), an alkanedioxycarbonyl group (a group in which -CH2-CH2- at any position contained in an alkanediyl group is replaced by -O-CO-), an alkanediylcarbonyl group (a group in which -CH2- at any position contained in an alkanediyl group is replaced by -CO-), an alkanediylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in an alkanediyl group is replaced by -CO-O-), an alkanediylthio group (a group in which -CH2- at any position contained in an alkanediyl group is replaced by -S-), an alkanediylsulfonyl group (a group in which -CH2- at any position contained in an alkanediyl group is replaced by -SO2-), a cycloalkoxy group, a cycloalkylalkoxy group,An alkoxycarbonyloxy group, an aromatic hydrocarbon group-carbonyl-oxy group, an aromatic hydrocarbon group-carbonyl group, an aromatic hydrocarbon group-oxy group, a haloalkoxy group (a group in which any -CH2- in a haloalkyl group is replaced by -O-), a haloalkoxycarbonyl group (a group in which any -CH2-CH2- in a haloalkyl group is replaced by -O-CO-), a haloalkylcarbonyl group (a group in which any -CH2- in a haloalkyl group is replaced by -CO-), a haloalkylcarbonyloxy group (a group in which any -CH2-CH2- in a haloalkyl group is replaced by -CO-O-), a group formed by combining two or more of these groups, etc. may be mentioned. Examples of these substituted groups are the same as those described above., Examples of the cycloalkoxy group include cycloalkoxy groups having 3 to 18 carbon atoms, such as a cyclohexyloxy group. Examples of the cycloalkylalkoxy group include cycloalkylalkoxy groups having 4 to 17 carbon atoms, such as a cyclohexylmethoxy group. Examples of the alkoxycarbonyloxy group include alkoxycarbonyloxy groups having 2 to 18 carbon atoms, such as a butoxycarbonyloxy group. Examples of the aromatic hydrocarbon group-carbonyl-oxy group include aromatic hydrocarbon group-carbonyl-oxy groups having 7 to 17 carbon atoms, such as a benzoyloxy group. Examples of the aromatic hydrocarbon group-carbonyl group include aromatic hydrocarbon group-carbonyl groups having 7 to 18 carbon atoms, such as a benzoyl group. Examples of the aromatic hydrocarbon group-oxy group include aromatic hydrocarbon group-oxy groups having 6 to 18 carbon atoms, such as a phenyloxy group., Examples of the haloalkoxy group, the haloalkoxycarbonyl group, the haloalkylcarbonyl group, and the haloalkylcarbonyloxy group include haloalkoxy groups having 1 to 12 carbon atoms, haloalkoxycarbonyl groups having 2 to 12 carbon atoms, haloalkylcarbonyl groups having 2 to 12 carbon atoms, and haloalkylcarbonyloxy groups having 2 to 12 carbon atoms. For example, groups in which one or more hydrogen atoms of the groups exemplified above are replaced by halogen atoms may be mentioned.,

[0014] In addition, examples of the group in which -CH2- contained in the alicyclic hydrocarbon group is replaced by -O-, -S-, or -CO- include the groups represented below. The bonding site can be at any position. Examples of the group in which -CH2- contained in the group combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group is replaced by -O-, -S-, -CO-, or -SO2- also include the following groups. The bonding site can be at any position. TIFF2025100419000014.tif26164

[0015] R 3 Examples of the substituent that the hydrocarbon group of R may have include a halogen atom and a cyano group. R 3 When R is a group combining an alicyclic hydrocarbon group or an aromatic hydrocarbon group and an alkyl group, the alkyl group can be a substituent of the alicyclic hydrocarbon group or the aromatic hydrocarbon group. Examples of the halogen atom include the same groups as those described above. Also, when -CH2- contained in the alkyl group contained in R 3 is replaced by -O-, -CO-, -S-, or -SO2-, R 3 can substantially have substituents such as a hydroxy group, a carboxyl group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, a thiol group, a sulfonyl group, etc. The hydrocarbon group may have one substituent or a plurality of substituents. R 3 is preferably a halogen atom, an alkyl group having 1 to 4 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), or a haloalkyl group having 1 to 4 carbon atoms, and more preferably an iodine atom, a fluorine atom, a hydroxy group, or a fluorinated alkyl group having 1 to 4 carbon atoms. m3 is preferably any integer represented by 0 to 4, and more preferably 0. R 3When it is 1 or more, the bonding site to the benzene ring is L b2 It may be any of the o-position, m-position, and p-position with respect to L

[0016] R 3 In the benzene ring to which R can be bonded, the bonding position of the carboxy group is L b2 It may be o-position, m-position, or p-position substitution with respect to the bonding position of L, and among them, o-position substitution is preferable

[0017] L b2 preferably represents an alkanediyl group having 1 to 12 carbon atoms, and -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-. More preferably, *-CO-O-L b41 -(L b41 is a single bond or a chain hydrocarbon group having 1 to 6 carbon atoms, and -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-. * represents SO3 - represents the bonding site with the phenyl group to which SO3 is bonded. L b41 is preferably a single bond or a chain hydrocarbon group having 1 to 3 carbon atoms.

[0018] In formula (I-A2), nb4 is preferably any integer from 1 to 4, more preferably any integer from 1 to 3, and even more preferably 1 or 2. When nb4 is 1 or 2, the bonding position of -L b2 - is preferably the following structure which is m-position substitution of the benzene ring with respect to the bonding position of SO3 - TIFF2025100419000015.tif30133[In the above formula, the symbols represent the same meanings as in formula (I-A2).] In formula (I-A2), when n4b is 2 or more, a plurality of L b2 and R 3 preferably represent the same group as each other

[0019] R b1 ​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, and hexyl group. The number of carbon atoms of the alkyl group is preferably 1 to 4, more preferably 1 to 3. R b1 Examples of the halogen atom of b1 include fluorine atom, chlorine atom, bromine atom, iodine atom and the like. R b1 Each R is preferably independently a halogen atom or an alkyl group having 1 to 4 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), more preferably a fluorine atom, an iodine atom or an alkyl group having 1 to 3 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methoxy group or a methyl group. nb3 is any integer from 0 to 4, preferably any integer from 0 to 3, more preferably any integer from 0 to 2. In one embodiment, nb3 is preferably 0. In another embodiment, nb3 is preferably 1 or 2. When nb3 is 1, R b1 is preferably a halogen atom, and R b1 is more preferably a fluorine atom or an iodine atom. When nb3 is 2, one of R b1 is preferably a halogen atom and the other is preferably a halogen atom or an alkyl group having 1 to 4 carbon atoms, and one of R b1 is more preferably a fluorine atom or an iodine atom and the other is preferably a fluorine atom, an iodine atom or an alkyl group having 1 to 3 carbon atoms.

[0020] Examples of the anion (I-A2) include, for example, the following anions. Among them, the anions represented by formula (I-A2-1) to formula (I-A2-30) are preferred, and the anions represented by formula (I-A2-1) to formula (I-A2-11), formula (I-A2-16) to formula (I-A2-26) are more preferred. TIFF2025100419000016.tif253150

[0021] Cation (I) Z in formula (I) + Examples of the organic cation of + 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. Specifically, cations represented by any of formula (b2-1) to formula (b2-5) (hereinafter, may be referred to as "cation (b2-1)" etc. according to the formula number) are included. TIFF2025100419000017.tif83159[In formula (b2-1) to formula (b2-5), R b4 ~R b6 each independently represents a linear 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. The hydrogen atom contained in the linear 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. The 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. The 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 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and -CH2- contained in the ring may be replaced with -O-, -S-, or -CO-. R b7 and R b8Each independently represents a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. m2 and n2 each independently represent any integer from 0 to 5. When m2 is 2 or more, a plurality of R b7 may be the same or different, and when n2 is 2 or more, a plurality of R b8 may be the same or different. R b9 and R b10 each independently represent 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 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and -CH2- contained in the ring may be replaced by -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, and 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 -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 and R b21 ~R b2 each independently represent a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. Rb13 and R b14 and R b21 and R b22 and may be combined with each other to form a ring containing a sulfur atom together with the benzene ring to which they are attached, and the -CH2- contained in the ring may be replaced by -O-, -S- or -CO-. R b27 ~R b29 each independently represents a hydrogen atom or a group containing an acid-labile group. L b31 and L b41 ~L b43 represents a sulfur atom or an oxygen atom. o2, p2, s2, and t2 each independently represent an integer from 0 to 5. q2 and r2 each independently represent an integer from 0 to 4. u2 represents 0 or 1. When o2 is 2 or more, the plurality of R b13 are the same or different, and when p2 is 2 or more, the plurality of R b14 are the same or different, and when q2 is 2 or more, the plurality of R b15 are the same or different, and when r2 is 2 or more, the plurality of R b16 are the same or different, and when s2 is 2 or more, the plurality of R b17 are the same or different, and when t2 is 2 or more, the plurality of R b18 are the same or different. u3 represents an integer from 1 to 3 and satisfies 1 ≦ u3 + q23 ≦ 5. u4 and u5 each independently represent an integer from 0 to 3 and satisfy 0 ≦ u4 + o21 ≦ 5 and 0 ≦ u5 + p22 ≦ 5. When u3, u4, and u5 are each 2 or more, the groups in parentheses are each the same or different. o21, p22, q23, r24, t25, and s26 each independently represent an integer from 0 to 4. When o21, p22, q23, r24, t25, and s26 are each 2 or more, the plurality of R b21 ~R b26 are each the same or different.] When u2 is 0, at least one of o2, p2, q2, and r2 is 1 or more, and it is preferable that at least one of R b13 ~R b16 is a halogen atom. When u2 is 1, at least one of o2, p2, s2, t2, q2, and r2 is 1 or more, and it is preferable that at least one of R b13 ~R b18 is a halogen atom. Furthermore, when u2 is 0, r2 is preferably 1 or more, and more preferably 1. Also, when u2 is 0 and r2 is 1 or more, it is preferable that R b16 is a halogen atom.

[0022] The aliphatic hydrocarbon group represents a chain hydrocarbon group and an alicyclic hydrocarbon group. Examples of the chain hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, and 2-ethylhexyl group. In particular, the chain hydrocarbon group of R b9 ~R b12 is preferably C1-C12. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups. TIFF2025100419000018.tif11157In particular, the alicyclic hydrocarbon group of R b9 ~R b12 is preferably C3-C18, more preferably C4-C12.

[0023] 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 methylnorbornil 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 of the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less. The alkyl fluoride group represents an alkyl group having 1 to 12 carbon atoms and having 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 of the alkyl fluoride group is preferably 1 to 9, more preferably 1 to 6, and even more preferably 1 to 4.

[0024] Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a biphenyl group, a naphthyl group, a phenanthryl group, etc. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and examples of the aromatic hydrocarbon group having a chain hydrocarbon group (a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a p-ethylphenyl group, a p-tert-butylphenyl group, a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, etc.) and the aromatic hydrocarbon group having an alicyclic hydrocarbon group (a p-cyclohexylphenyl group, a p-adamantylphenyl group, etc.) etc. are mentioned. In addition, when the aromatic hydrocarbon group has a chain hydrocarbon group or an alicyclic hydrocarbon group, a chain hydrocarbon group having 1 to 18 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms are preferable. Examples of the aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group include a p-methoxyphenyl group, etc. 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, a naphthylethyl group, etc.

[0025] 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, a dodecyloxy group, and the like. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, a butyryl group, and the like. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like. 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, a 2-ethylhexylcarbonyloxy group, and the like.

[0026] R b4 and R b5 The ring formed by R and R bonding to each other together with the sulfur atom to which they are bonded may be any of a monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. Examples of this ring include rings having 3 to 18 carbon atoms, preferably rings having 4 to 18 carbon atoms. Further, examples of the ring containing a sulfur atom include 3-membered to 12-membered rings, preferably 3-membered to 7-membered rings. For example, the following rings can be mentioned. * represents a bonding site. TIFF2025100419000019.tif24142

[0027] R b9 and R b10 The ring formed by R and R together may be any of a monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. Examples of this ring include 3-membered to 12-membered rings, preferably 3-membered to 7-membered rings. For example, a thiolan-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, a 1,4-oxathian-4-ium ring, and the like can be mentioned. R b11 and R b12The ring formed by combining them may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring includes 3-membered rings to 12-membered rings, preferably 3-membered rings to 7-membered rings. Examples include oxocycloheptane ring, oxocyclohexane ring, oxonorbornane ring, oxoadamantane ring, etc. R b27 ~R b29 Examples of the group containing an acid-labile group of ~R c30 include -R c30 or -L c10 -CO-O-R c30 represented by (L c10 represents an alkanediyl group having 1 to 6 carbon atoms, and R c30 represents an acid-labile group.). etc. are mentioned. R b27 ~R b29 Examples of the acid-labile group of ~R include, for example, the above-mentioned group (1) or group (2).

[0028] Among cations (b2-1) to cations (b2-5), preferably, it is cation (b2-1). Examples of cation (b2-1) include the following cations. TIFF2025100419000020.tif149164 Examples of cation (b2-2) include the following cations. TIFF2025100419000021.tif18150 Examples of cation (b2-3) include the following cations. TIFF2025100419000022.tif26140 Examples of cation (b2-4) include the following cations. TIFF2025100419000023.tif123164 Examples of cation (b2-5) include the following cations. TIFF2025100419000024.tif115157

[0029] Specific examples of salt (I-A2) include salts obtained by arbitrarily combining the above-mentioned cations and anions. Specific examples of salt (I-A2) are shown in the following table. In the following table, each symbol represents the symbol attached to the structure representing the above-mentioned anion or cation, and "~" indicates that each of the salt (I-A2) and the anion (I) corresponds. For example, the salt (I-1) is a salt composed of the anion represented by the formula (I-A2-1) and the cation represented by the formula (b2-c-1), the salt (I-2) is a salt composed of the anion represented by the formula (I-A2-2) and the cation represented by the formula (b2-c-1), and the salt (I-16) is a salt composed of the anion represented by the formula (I-A2-1) and the cation represented by the formula (b2-c-10). TIFF2025100419000025.tif27103 [Table 1] TIFF2025100419000027.tif229159

[0030] Among them, the salt (I-A2) is preferably a salt obtained by combining an anion represented by any of the formulas (I-A2-1) to (I-A2-11), (I-A2-16) to (I-A2-26) and a cation represented by any of the formulas (b2-c-1) to (b2-c-79).

[0031] <Method for producing salt (I-A2)>[[]] In the salt represented by the formula (I-A2), L b2 is *-CO-O-L b2’ - The salt represented by the formula (I1-A2) can be produced, for example, by reacting the salt represented by the formula (I1-A2-a) with carbonyldiimidazole in a solvent, and then further reacting with the salt represented by the formula (I1-A2-b) and treating with an acid. TIFF2025100419000028.tif66152 (wherein all symbols have the same meanings as described above. L b2’ represents a group obtained by removing -CO-O- from L b2 .) Examples of the solvent in this reaction include chloroform and acetonitrile. Examples of the acid in this reaction include oxalic acid, hydrochloric acid, acetic acid, etc. The reaction temperature is generally 5°C to 80°C, and the reaction time is generally 0.5 hour to 24 hours. The salts represented by formula (I1-A2-a) include salts represented by the following formula, etc., can be easily obtained from the market, and can also be easily produced by known production methods. TIFF2025100419000029.tif137164

[0032] The salts represented by formula (I1-A2-b) include, for example, compounds represented by the following, etc., can be easily obtained from the market, and can also be easily produced by known production methods. TIFF2025100419000030.tif50153

[0033] In the salts represented by formula (I-A2), L b2 is *-O-CO-L b2’’ The salts (- represented by formula (I2-A2)) can be produced, for example, by reacting the salts represented by formula (I2-A2-b) with carbonyldiimidazole in a solvent, then further reacting with the salts represented by formula (I2-A2-a), and treating with an acid. TIFF2025100419000031.tif63155(In the formula, all symbols have the same meanings as described above. L b2’’ represents a group obtained by removing -O-CO- from L b2 .) Examples of the solvent in this reaction include chloroform, acetonitrile, etc. Examples of the acid in this reaction include oxalic acid, hydrochloric acid, acetic acid, etc. The reaction temperature is generally 5°C to 80°C, and the reaction time is generally 0.5 hour to 24 hours. The salts represented by formula (I2-A2-a) include salts represented by the following formula, etc., can be easily obtained from the market, and can also be easily produced by known production methods. TIFF2025100419000032.tif143164

[0034] The salts represented by the formula (I2-A2-b) include, for example, the compounds represented below, can be easily obtained from the market, and can also be easily produced by known production methods. TIFF2025100419000033.tif24117

[0035] <Acid generator> In addition to the salt (I-A2), the acid generator of the present invention may contain a known compound (hereinafter sometimes referred to as "compound (B)") that acts as an acid generator in the resist field. However, compound (B) does not contain salt (I-A2). Compound (B) may be used alone or in combination of two or more.

[0036] Either a nonionic compound or an ionic compound may be used for compound (B). Examples of nonionic compounds include sulfonate esters (e.g., 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxy ketone, diazonaphthoquinone 4-sulfonate), sulfones (e.g., disulfone, ketosulfone, sulfonyldiazomethane), etc. Representative examples of ionic compounds include onium salts containing an onium cation (e.g., diazonium salt, phosphonium salt, sulfonium salt, iodonium salt). Examples of anions of onium salts include sulfonic acid anion, sulfonylimide anion, sulfonylmethide anion, and carboxylic acid anion. Compound (B) may be one of the structural units constituting the resin contained in the resist composition of the present invention, such as structural unit (a7).

[0037] As the compound (B), compounds that generate an acid upon irradiation, 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. Patent No. 3,779,778, U.S. Patent No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712, etc., can be used. Further, compounds produced by known methods may also be used. The compound (B) may be an acid generator having an acid-labile group. For example, the compound or resin that serves as the acid generator may contain a partial structure that becomes an acid-labile group, and the acid-labile group preferably contains the above-described group (1) or group (2). When the resist composition of the present invention has a compound having an acid-labile group, a resin containing a structural unit having an acid-labile group may not be included.

[0038] A preferred form of the compound (B) includes a salt represented by formula (B1) (hereinafter sometimes referred to as "acid generator (B1)"). TIFF2025100419000034.tif1395[In formula (B1), L b1 represents a single bond or an (nb1 + 1)-valent hydrocarbon group which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. L b2 represents a single bond or a divalent hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. Y b1 represents a methyl group which may have a substituent or a cyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-. nb1 represents any integer from 1 to 6. When nb1 is 2 or more, the groups within the plurality of parentheses may be the same as or different from each other. ZI+ represents an organic cation. L b1 As the (nb1 + 1)-valent hydrocarbon group of L, a group obtained by removing nb1 hydrogen atoms from a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a group combining two or more of these groups is mentioned. b2 And a group that binds to L. The number of carbon atoms of the hydrocarbon group is preferably from 1 to 48, more preferably from 1 to 42, still more preferably from 1 to 36, even more preferably from 1 to 30, still even more preferably from 1 to 24. As the chain hydrocarbon group, a group obtained by removing nb1 hydrogen atoms from an alkyl group or an alkenyl group is mentioned. The alkyl group may be linear or branched. Specifically, methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, sec-butyl group, iso-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, heptadecyl group, etc. are mentioned. As the alkenyl group, ethenyl group, propenyl group, isopropenyl group, butenyl group, isobutenyl group, tert-butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, isooctenyl group, nonenyl group are mentioned. The number of carbon atoms of the chain hydrocarbon group is preferably from 1 to 36, more preferably from 1 to 24, still more preferably from 1 to 20, even more preferably from 1 to 18, still even more preferably from 1 to 12, and still even more preferably from 1 to 10. As the alicyclic hydrocarbon group, a group obtained by removing nb1 hydrogen atoms from a monocyclic or polycyclic cycloalkyl group is mentioned. As the monocyclic cycloalkyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, etc. are mentioned. Examples of the polycyclic cycloalkyl group include a cycloalkyl group having a crosslinked structure, a cycloalkyl group in which two or more rings are condensed, or a cycloalkyl group in which two rings are spiro-bonded. Examples of the cycloalkyl group having a crosslinked structure include a norbornyl group and an adamantyl group. Examples of the cycloalkyl group in which two or more rings are condensed include a bicyclo[4,4,0]decane group and a steroid group (steroid skeleton). Examples of the cycloalkyl group in which two rings are spiro-bonded include a spirocyclic cycloalkyl group in which one cycloalkyl group selected from the group consisting of a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group is spiro-bonded to a cycloalkyl group having 5 to 8 carbon atoms. Further, a double bond may be formed between two carbon atoms included in the alicyclic hydrocarbon group. More specifically, examples of the alicyclic hydrocarbon group include those represented by the following formula. TIFF2025100419000035.tif26168 When the alicyclic hydrocarbon group is a monocyclic cycloalkyl group, the number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 24, more preferably 3 to 20, still more preferably 3 to 18, even more preferably 3 to 12, even more preferably 3 to 10, and even more preferably 3 to 8. When the alicyclic hydrocarbon group is a polycyclic cycloalkyl group, the number of carbon atoms in the alicyclic hydrocarbon group is preferably 6 to 24, more preferably 6 to 20, still more preferably 6 to 18, even more preferably 6 to 12, and even more preferably 7 to 12. Examples of the aromatic hydrocarbon group include a group in which nb1 hydrogen atoms of an aryl group are removed. Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a fluorenyl group. More specifically, examples of the aromatic hydrocarbon group include those represented by the following formula. As for the carbon number of the aromatic hydrocarbon group, it is preferably 4 to 24, more preferably 4 to 20, still more preferably 4 to 18, even more preferably 5 to 14, still even more preferably 5 to 10, and even more preferably 6 to 10. L b1 When -CH2- contained in the hydrocarbon group is replaced by -O-, -CO-, -S- or -SO2-, the carbon number before replacement shall be taken as the carbon number of the hydrocarbon group. L b1Among the hydrocarbon groups, examples of the group in which -CH2- contained in the chain hydrocarbon group is replaced by -O-, -CO-, -S- or -SO2- include a hydroxy group (a group in which -CH2- contained in the methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- contained in the ethyl group is replaced by -O-CO-), a carbonyl group (a group in which -CH2- contained in the methylene group is replaced by -CO-), an oxy group (a group in which -CH2- contained in the methylene group is replaced by -O-), an alkoxy group (a group in which -CH2- at any position contained in the alkyl group is replaced by -O-), an alkoxycarbonyl group (a group in which -CH2-CH2- at any position contained in the alkyl group is replaced by -O-CO-), an alkylcarbonyl group (a group in which -CH2- at any position contained in the alkyl group is replaced by -CO-), an alkylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in the alkyl group is replaced by -CO-O-), an alkoxycarbonyloxy group (a group in which -CH2-CH2-CH2- at any position contained in the alkyl group is replaced by -O-CO-O-), an alkanedioxy group (a group in which -CH2- at any position contained in the alkanedioyl group is replaced by -O-), an alkanedioxycarbonyl group (a group in which -CH2-CH2- at any position contained in the alkanedioyl group is replaced by -O-CO-), an alkanedioylcarbonyl group (a group in which -CH2- at any position contained in the alkanedioyl group is replaced by -CO-), an alkanedioylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in the alkanedioyl group is replaced by -CO-O-), and the like. Examples of these replaced groups include the same as those described above within the range allowed by the upper limit of the number of carbon atoms. L b1Among the hydrocarbon groups, examples of the group in which -CH2- contained in the alicyclic hydrocarbon group is replaced by -O-, -CO-, -S- or -SO2- include groups containing structures such as cyclic ethers, cyclic ketones, cyclic esters (lactones), cyclic thioethers, cyclic acetals, cyclic sulfonic acid esters (sultones), and the like. Specifically, alicyclic hydrocarbon groups represented by the following formulas can be mentioned. The bonding position of the alicyclic hydrocarbon group mentioned in the following formulas can be any position. TIFF2025100419000037.tif48165L b1 Among the hydrocarbon groups, -CH2- contained in the aromatic hydrocarbon group may be replaced by -O- or -S-. Examples of the group in which -CH2- is replaced by -O- or -S- include groups derived from a furan ring or a thiophene ring, respectively. Specifically, aromatic hydrocarbon groups represented by the following formulas can be mentioned. TIFF2025100419000038.tif1324L b1 Among the hydrocarbon groups, -CH2- contained in the aromatic hydrocarbon group may be replaced by -O- or -S-. Examples of the group in which -CH2- is replaced by -O- or -S- include a furan ring or a thiophene ring, respectively. Examples of the group in which -CH2- contained in a group combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2- include the same groups as those exemplified in this specification within the range where the upper limit of the number of carbon atoms permits. Examples of the group combining two or more of a chain hydrocarbon group, an alicyclic hydrocarbon group and an aromatic hydrocarbon group include a group combining the above chain hydrocarbon group and the above alicyclic hydrocarbon group, a group combining the above chain hydrocarbon group and the above aromatic hydrocarbon group, a group combining the above alicyclic hydrocarbon group and the above aromatic hydrocarbon group, and a group combining the above chain hydrocarbon group, the above alicyclic hydrocarbon group and the above aromatic hydrocarbon group. The above combined groups can be mentioned. The group combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group may be a condensed ring. L b2Examples of the divalent hydrocarbon group include a group in which one hydrogen atom is removed from a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, a divalent aromatic hydrocarbon group, or a group formed by combining two or more of these groups, and is a group that binds to Y b1 Examples of the divalent chain hydrocarbon group, divalent alicyclic hydrocarbon group, divalent aromatic hydrocarbon group, and divalent group formed by combining two or more of these groups of L L b2 b1 include a group in which one hydrogen atom is removed from the chain hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and group formed by combining two or more of these groups exemplified by L b1 L b1 and L b2 Examples of the substituent that the hydrocarbon group of L L b1 and L b2 may have include a halogen atom, a cyano group, and a nitro group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. b1 and L b2 When L b1 and L b2 are a group formed by combining an alicyclic hydrocarbon group or an aromatic hydrocarbon group with a chain hydrocarbon group, the chain hydrocarbon group may be substantially regarded as a substituent that the alicyclic hydrocarbon group or the aromatic hydrocarbon group has. Further, when -CH2- of the chain hydrocarbon group contained in the hydrocarbon group of L L b1 and L b2 is replaced by -O-, -CO-, -S-, or -SO2-, the hydrocarbon group of L Y b1 Examples of the cyclic hydrocarbon group of Y Y b1 include an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group. b1Examples thereof include the same as the alicyclic hydrocarbon group and aromatic hydrocarbon group exemplified above, and when having no substituent, they may be monovalent alicyclic hydrocarbon groups and aromatic hydrocarbon groups. Y b1 Examples of the substituent that the methyl group of Y may have include a halogen atom, a cyano group, a hydroxy group, and a nitro group. b1 Examples of the substituent that the cyclic hydrocarbon group of Y may have include a halogen atom, a cyano group, a nitro group, or a hydrocarbon group having 1 to 18 carbon atoms which may have a halogen atom, a cyano group, and a nitro group (wherein -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-). b1 In the hydrocarbon group that the cyclic hydrocarbon group of Y may have, the number of carbon atoms b1 is not included in the number of hydrocarbon groups of the cyclic hydrocarbon group of Y. Y b1 Examples of the hydrocarbon group having 1 to 18 carbon atoms that the cyclic hydrocarbon group of Y may have as a substituent include a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group combining these groups. Examples of the chain hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and a group combining two or more of these groups include, within the range allowed by the upper limit of the number of carbon atoms, b1 the same groups as the chain hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and a group combining two or more of these groups exemplified by L. Also, b1 Examples of the group in which -CH2- contained in the hydrocarbon group having 1 to 18 carbon atoms that the cyclic hydrocarbon group of Y may have as a substituent is replaced by -O-, -S-, -CO- or -SO2- include, within the range allowed by the upper limit of the number of carbon atoms, b1 the same groups as the groups exemplified by the group in which -CH2- contained in the hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2-. Also, b1 Examples of the hydrocarbon group having 1 to 18 carbon atoms that the cyclic hydrocarbon group of Y may have as a substituent may constitute a protecting group or a leaving group (an acid-labile group or a base-labile group) generally used in the art. The anion of the salt represented by formula (B1) is preferably an anion represented by the following formula (B1-A1) or an anion represented by formula (B1-A2). TIFF2025100419000039.tif30124[In formula (B1-A1), L b2 and Y b1 have the same meanings as in formula (I-A). Q b1 、Q b2 、Q b3 and Q b4 each independently represents a hydrogen atom, a fluorine atom, a C1-C6 perfluoroalkyl group or a C1-C6 alkyl group. z1 represents any integer from 0 to 6. When z1 is 2 or more, the groups in the plurality of parentheses may be the same as or different from each other. X 1 represents -O-CO-, -CO-O-, -O-CO-O- or -O-. L b3 represents a single bond or an (nb2 + 1)-valent hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. nb2 represents any integer from 1 to 3. When nb2 is 2 or more, the groups in the plurality of parentheses may be the same as or different from each other.] Q b1 、Q b2 、Q b3 and Q b4 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 and the like. Q b1 、Q b2 、Q b3 and Q b4 Examples of the perfluoroalkyl group 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 and the like. Q b1 and Q b2 is preferably included in at least one of Q b1 and Q b2 with a fluorine atom or a perfluoroalkyl group, more preferably a fluorine atom or a perfluoroalkyl group, still more preferably a fluorine atom or a trifluoromethyl group, and even more preferably both fluorine atoms. Q b3 and Q b4 are each independently preferably a hydrogen atom, a fluorine atom or a perfluoroalkyl group having 1 to 3 carbon atoms, and Q b3 is preferably a hydrogen atom, a fluorine atom or a perfluoroalkyl group having 1 to 3 carbon atoms, and Q b4 is preferably a hydrogen atom or a fluorine atom. z1 is preferably any integer from 0 to 3, more preferably 0, 1 or 2. X 1 is preferably -O-CO- or -CO-O-.

[0039] L b3 As the hydrocarbon group in, within the range allowed by the upper limit of the number of carbon atoms, the L of formula (I-A) b1 is exemplified by the same hydrocarbon groups as those exemplified for In formula (B1-A1), L b3is a single bond, an optionally substituted chain hydrocarbon group having 1 to 12 carbon atoms (wherein -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-), an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms (wherein -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-), an optionally substituted aromatic hydrocarbon group having 6 to 10 carbon atoms (wherein -CH2- contained in the aromatic hydrocarbon group may be replaced by -O- or -S-), or a group formed by combining two or more of these groups, and is preferably a single bond, a chain hydrocarbon group having 1 to 6 carbon atoms or a group represented by the following formula (Lb3-1). When -CH2- contained in the chain hydrocarbon group is replaced by -O- or -CO-, the number thereof is preferably 1 to 4, and preferably one -CH2-CH2- contained in the chain hydrocarbon group is replaced by -O-CO- or -CO-O-, or one -CH2-CH2-CH2- contained in the chain hydrocarbon group is replaced by -O-CO-O-. JPEG2025100419000040.jpg1582[In the formula (Lb3-1), nb2 represents the same meaning as in the formula (I-A1). L b31 represents a single bond or a chain hydrocarbon group having 1 to 12 carbon atoms, -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-, and the chain hydrocarbon group may have a substituent. W b3 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms, -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-, -CH2- contained in the aromatic hydrocarbon group may be replaced by -O- or -S-, and the alicyclic hydrocarbon group and the aromatic hydrocarbon group may have a substituent. * and ** represent bonding sites, and * represents the bonding site with X 1 and is represented by.] In the formula (Lb3-1), L b31 's chain hydrocarbon group, as long as the upper limit of the number of carbon atoms permits, L b1Examples thereof include the same groups as the chain hydrocarbon groups exemplified above. In formula (Lb3-1), W b3 The alicyclic hydrocarbon group and the aromatic hydrocarbon group of, as long as the upper limit of the number of carbon atoms permits, are the same groups as the alicyclic hydrocarbon groups and the aromatic hydrocarbon groups exemplified by L b1 Examples thereof include the same groups as the alicyclic hydrocarbon groups and the aromatic hydrocarbon groups exemplified above. In formula (Lb3-1), L b31 The substituents that the chain hydrocarbon group of may have and W b3 The substituents that the alicyclic hydrocarbon group and the aromatic hydrocarbon group of may have are the same groups as the substituents exemplified as the substituents that the hydrocarbon group of L b1 may have. L b31 is preferably a single bond or an alkanediyl group having 1 to 6 carbon atoms (the -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-). Among them, as the alicyclic hydrocarbon group and the aromatic hydrocarbon group of W b3 the following alicyclic hydrocarbon groups and aromatic hydrocarbon groups are preferred. In the alicyclic hydrocarbon groups and aromatic hydrocarbon groups represented below, * and ** represent bonding sites, * represents the bonding site with X 1 or L b31 and ** represents a hydrogen atom, a substituent or the bonding site with L b2 and at least one ** represents the bonding site with L b2 In addition, in the alicyclic hydrocarbon groups represented below, the -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. When the -CH2- contained in the alicyclic hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2-, it preferably forms an ether ring, an ester ring (lactone), a carbonate ester ring, a sulfonic acid ester ring ( sultone) or an acetal ring. TIFF2025100419000041.tif37165 In formula (B1-A1), L b2is a single bond or a chain hydrocarbon group having 1 to 12 carbon atoms (the -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-), preferably a single bond, -O-, -O-CO-, -CO-O-, -O-CO-O- or *-L b21 -X 2 -L b22 -**(L b21 and L b22 either one of which represents a chain hydrocarbon group having 1 to 6 carbon atoms, and the other represents a single bond or a chain hydrocarbon group having 1 to 6 carbon atoms. X 2 represents -O-, -CO-O-, -O-CO- or -O-CO-O-. * and ** represent bonding sites, and ** represents the bonding site with Y b1 However, L b21 X 2 and L b22 The total number of carbon atoms of is 12 or less. ) is more preferable. In formula (B1-A1), Y b1 is preferably a cyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent (the -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -CO-, -S- or -SO2-), more preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (the -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -CO-, -S- or -SO2-) or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, and still more preferably an alicyclic hydrocarbon group having 3 to 16 carbon atoms which may have a substituent (the -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -CO-, -S- or -SO2-) or an aromatic hydrocarbon group having 6 to 10 carbon atoms which may have a substituent. Specifically, it is preferably a group represented by the following formula (Y1) to formula (Y36). In formula (Y1) to formula (Y36), R Yb represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms among the substituents that the cyclic hydrocarbon group of Y b1 may have, R Yc represents a hydrogen atom or a substituent that the cyclic hydrocarbon group of Y b1 may have, and * represents L b2represents a binding site with. The alicyclic hydrocarbon group and aromatic hydrocarbon group represented by the following formula are not particularly shown in the following formula, but may have other substituents that the cyclic hydrocarbon group of Y b1 may have. TIFF2025100419000042.tif94164

[0040] As the anion represented by the formula (B1-A1), anions represented by the formulas (B1-A1-1) to (B1-A1-85) [hereinafter, may be referred to as "anion (B1-A1-1)" etc. according to the formula number] are preferable, and anions represented by any of the formulas (B1-A1-1) to (B1-A1-4), formula (B1-A1-9), formula (B1-A1-10), formulas (B1-A1-24) to (B1-A1-33), formulas (B1-A1-36) to (B1-A1-40), and formulas (B1-A1-47) to (B1-A1-85) are more preferable. TIFF2025100419000043.tif234160

[0041] TIFF2025100419000044.tif249152

[0042] TIFF2025100419000045.tif254163

[0043] In the formulas (B1-A1-1) to (B1-A1-85), R i2 ~R i7 are, independently of each other, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. R i8 is, for example, an aliphatic 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. L A41 is a single bond or an alkanediyl group having 1 to 4 carbon atoms. Q b1 and Q b2 represent the same meaning as described above. Specific examples of the anion in the salt represented by formula (B1-A1) include the anions described in JP-A-2010-204646.

[0044] Preferred anions in the salt represented by formula (B1-A1) include the anions represented by formula (B1a-1) to formula (B1a-70), respectively. TIFF2025100419000046.tif185163

[0045] TIFF2025100419000047.tif252166

[0046] TIFF2025100419000048.tif70166

[0047] Among them, anions represented by any of formula (B1a-1) to formula (B1a-3), formula (B1a-7) to formula (B1a-19), and formula (B1a-22) to formula (B1a-70) are preferred.

[0048] The anion represented by formula (B1-A2) is represented by the following formula. TIFF2025100419000049.tif24100[In formula (B1-A2), L b2 and Y b1 have the same meanings as in formula (B1). R b1 represents a halogen atom or an alkyl group having 1 to 6 carbon atoms, and -CH2- contained in the alkyl group may be replaced by -O- or -CO-. nb4 represents any integer from 1 to 5. When nb4 is 2 or more, a plurality of -L b2 -Y b12 may be the same as or different from each other. nb3 represents any integer from 0 to 4. When nb3 is 2 or more, a plurality of R b1 may be the same as or different from each other. However, 1 ≦ nb4 + nb3 ≦ 5 is satisfied.]

[0049] In formula (B1-A2), L b2 Examples of the hydrocarbon group and Y b1 of the cyclic hydrocarbon group are, within the range permitted by the upper limit of the number of carbon atoms, the examples of the hydrocarbon group of L b2 in formula (B1) and the examples of the cyclic hydrocarbon group of Y b1 which are the same as those. L b2 For the hydrocarbon group of L b1 the methyl group of Y b2 and the substituents which the cyclic hydrocarbon group may have, the same examples as those of the hydrocarbon group of L b1 in formula (B1), the methyl group of Y and the substituents which the cyclic hydrocarbon group may have can be mentioned. In formula (B1-A2), L b2 is preferably a chain hydrocarbon group having 1 to 12 carbon atoms (in the chain hydrocarbon group, -CH2- contained therein may be replaced by -O- or -CO-), more preferably, *-CO-O-L b41 -(L b41 is a single bond or a chain hydrocarbon group having 1 to 6 carbon atoms, and -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-. * represents the bonding site with the benzene ring to which SO3 - is bonded. L b41 is preferably a single bond or a chain hydrocarbon group having 1 to 3 carbon atoms.). More preferably, it is *-CO-O-. Y b1 is preferably a cyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent (in the cyclic hydrocarbon group, -CH2- contained therein may be replaced by -O-, -CO-, -S- or -SO2-), more preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (in the alicyclic hydrocarbon group, -CH2- contained therein may be replaced by -O-, -CO-, -S- or -SO2-) or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent. Y b1 or L b1It is more preferable that it is an alicyclic hydrocarbon group or an aromatic hydrocarbon group exemplified above. Specifically, it is preferably a group represented by the above-described formulas (Y1) to (Y36), and more preferably a group represented by the above-described formulas (Y1) to (Y19).

[0050] In formula (B1-A2), n4b is preferably any integer from 1 to 4, more preferably any integer from 1 to 3, still more preferably 1 or 2, and even more preferably 2. When n4b is 1 or 2, -L b2 -Y b1 is preferably bonded at the m-position substitution of the benzene ring with respect to the bonding position of SO3 - to have the following structure. TIFF2025100419000050.tif25101[In the above formula, L b2 , Y b1 , R b1 , and nb3 represent the same meanings as in formula (B1-A2).] When nb4 is 2 or more, the plurality of L b2 and Y b1 are preferably the same group as each other.

[0051] Examples of the alkyl group having 1 to 6 carbon atoms for R b1 include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, and hexyl group. The number of carbon atoms of the alkyl group is preferably 1 to 4, and more preferably 1 to 3. Examples of the halogen atom for R b1 include fluorine atom, chlorine atom, bromine atom, and iodine atom. Examples of the group in which -CH2- contained in the alkyl group is replaced by -O- or -CO- include hydroxy group, carboxy group, alkoxy group, alkoxycarbonyl group, alkylcarbonyl group, alkylcarbonyloxy group, oxy group, and carbonyl group. These replaced groups include those similar to the groups exemplified in the present specification within the range where the upper limit of the number of carbon atoms allows. For R b1is each independently preferably a halogen atom or an alkyl group having 1 to 4 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), more preferably a fluorine atom, an iodine atom or an alkyl group having 1 to 3 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methoxy group or a methyl group. nb3 is any integer from 0 to 4 (that is, nb3 - 1 represents any integer from 0 to 3), preferably any integer from 0 to 3, and more preferably any integer from 0 to 2. In one embodiment, nb3 is preferably 0. In another embodiment, nb3 is preferably 1 or 2. When nb3 is 1, R b1 is preferably a halogen atom, and R b1 is more preferably a fluorine atom or an iodine atom. When n3b is 2, one of R b1 is preferably a halogen atom and the other is preferably a halogen atom or an alkyl group having 1 to 4 carbon atoms, and one of R b1 is more preferably a fluorine atom or an iodine atom and the other is more preferably a fluorine atom, an iodine atom or an alkyl group having 1 to 3 carbon atoms.

[0052] Examples of the anion (B1 - A2) include the following anions. Among them, the anions represented by formula (B2a - 1) to formula (B2a - 20) are preferred, and the anions represented by formula (B2a - 1) to formula (B2a - 11), formula (B2a - 16) to formula (B2a - 20) are more preferred. Some of the following anions have some R b1 omitted and may contain substituents not shown. TIFF2025100419000051.tif94161

[0053] In another form of the acid generator (B), an anion in which the anion represented by the formula (B1) is replaced with a sulfonimide anion, a sulfonylmethide anion, or a carboxylic acid anion is also preferably used as the acid generator (B). As the sulfonylimide anion or sulfonylmethide anion, it is preferably a sulfonylimide anion or sulfonylmethide anion represented by the formula (B1-A3) (hereinafter, may be referred to as "anion (B1-A3)"). TIFF2025100419000052.tif1189[In the formula (B1-A3), A 1 represents a nitrogen atom or a carbon atom. L b2 ’ represents a single bond or a hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced with -O-, -S-, -CO- or -SO2-. Y b1 ’ represents a methyl group which may have a substituent or a cyclic hydrocarbon group having 3 to 24 carbon atoms, and -CH2- contained in the cyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or -SO2-. nb5 represents 2 or 3. When A 1 is a nitrogen atom, nb5 is 2, and when A 1 is a carbon atom, nb5 is 3. A plurality of -L b2 ’-Y b1 ’ may be the same as or different from each other, and a plurality of R b2 may be the same as or different from each other, and two -SO2-L b2 ’-Y b1 ’ may combine together to form a ring.] In the formula (B1-A3), L b2’ and Y b1’ are exemplified by the same groups as L b2 and Y b1 in the formula (B1-A1). In the formula (B1-A3), L b2’ is a single bond, *-L b23 -X 2 -, or *-L b23 -X2 -W 2 -X 3 -(L b23 represents an alkanediyl group having 1 to 6 carbon atoms which may have a fluorine atom, and X 2 and X 3 each independently represent -O-, -CO-O-, -O-CO-, -O-CO-O- or -O-, and W 2 represents an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and the -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O- or -CO-, and * represents the bonding site with SO2.) is preferable. In formula (B1-A3), Y b1’ is preferably a trifluoromethyl group, an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent or a phenyl group which may have a substituent, and more preferably a trifluoromethyl group or a group represented by formula (Y1) to formula (Y36) in formula (B1-A1). nb5 is preferably 2 or 3, and nb6 is preferably 0 or 1. In formula (B1-A3), when SO2-L b2 ’-R b2 ’ combine to form a ring, for example, the anion represented by formula (B1-A3’) can be mentioned. TIFF2025100419000053.tif21122[In formula (B1-A3’), A, Y b1 L b2 nb5 represent the same meaning as in formula (B1-A3). W b4 represents a disulfonylimide ring or a disulfonylmethide ring having 3 to 12 carbon atoms which may have a fluorine atom.] W b4 The disulfonylimide ring or the disulfonylmethide ring of W

[0054] Examples of the anion represented by formula (B1-A3) include the following. Among them, the anions represented by formula (B3a-1) and formula (B3a-2) are preferable. TIFF2025100419000054.tif189164

[0055] Examples of the carboxylic acid anion include the following. TIFF2025100419000055.tif41155

[0056] ZI + Examples of the organic cation of [ZI] 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. Specifically, examples include cations represented by any of the above cations (b2-1) to (b2-5).

[0057] The salt (B1) is a combination of the above anion and the above organic cation, and these can be arbitrarily combined. Preferred examples of the salt (B1) include any anion represented by any of formula (B1a-1) to formula (B1a-3), formula (B1a-7) to formula (B1a-19), formula (B1a-22) to formula (B1a-70), formula (B2a-1) to formula (B2a-11), formula (B2a-16) to formula (B2a-20), formula (B3a-1) to formula (B3a-3), or formula (B3a-11) to formula (B3a-14), and a combination with cation (b2-1), cation (b2-2), cation (b2-3), cation (b2-4), or cation (b2-5).

[0058] As the compound (B), those represented by formula (B1-1) to formula (B1-105), formula (B2-1) to formula (B2-20), and formula (B3-1) to formula (B3-28) are preferably mentioned. Among them, those containing an arylsulfonium cation are preferred, and those represented by formula (B1-1) to formula (B1-3), formula (B1-5) to formula (B1-7), formula (B1-11) to formula (B1-14), formula (B1-20) to formula (B1-26), formula (B1-29), formula (B1-31) to formula (B1-105), formula (B2-1) to formula (B2-20), and formula (B3-1) to formula (B3-28) are particularly preferred. TIFF2025100419000056.tif248168

[0059] TIFF2025100419000057.tif243160

[0060] TIFF2025100419000058.tif250163

[0061] TIFF2025100419000059.tif254160

[0062] TIFF2025100419000060.tif249162

[0063] TIFF2025100419000061.tif250151

[0064] TIFF2025100419000062.tif187159

[0065] When the acid generator contains the salt (I-A2) and the compound (B), the ratio of the content of the salt (I-A2) to the compound (B) (mass ratio; salt (I-A2): compound (B)) is usually 1:99 to 99:1, preferably 2:98 to 98:2, more preferably 5:95 to 95:5, still more preferably 10:90 to 90:10, and particularly preferably 15:85 to 85:15. It is below the parts by weight.

[0066] <Resist composition> The resist composition of the present invention contains an acid generator containing a salt (I-A2). The resist composition of the present invention may further contain a resin. Examples of the resin include a resin containing a structural unit having an acid-labile group (hereinafter sometimes referred to as "resin (A)") and / or a resin other than resin (A). Here, the "acid-labile group" means a group having a leaving group, and when contacted with an acid, the leaving group leaves and the constitutional unit is converted into a constitutional unit having a hydrophilic group (for example, a hydroxy group or a carboxy group). The resist composition of the present invention preferably contains a quencher (hereinafter sometimes referred to as "quencher (C)") such as a salt that generates an acid having a lower acidity than the acid generated from the acid generator, and preferably contains a solvent (hereinafter sometimes referred to as "solvent (E)").

[0067] <Acid generator> In the resist composition of the present invention, the total content of the acid generator is preferably 0.1% by mass or more and 99.9% by mass or less, more preferably 1% by mass or more and 45% by mass or less, still more preferably 1% by mass or more and 40% by mass or less, and even more preferably 3% by mass or more and 40% by mass or less, based on the solid content of the resist composition. When containing the resin (A) described later, the total content of the acid generator is preferably 1 part by mass or more and 45 parts by mass or less, more preferably 1 part by mass or more and 40 parts by mass or less, still more preferably 3 parts by mass or more and 40 parts by mass or less, based on 100 parts by mass of the resin (A) described later.

[0068] <Resin (A)> Resin (A) contains a structural unit having an acid-labile group (hereinafter sometimes referred to as "structural unit (a1)"). Resin (A) preferably further contains a structural unit other than structural unit (a1). Examples of the structural unit other than structural unit (a1) include a structural unit having no acid-labile group (hereinafter sometimes referred to as "structural unit (s)"), a structural unit other than structural unit (a1) and structural unit (s) (for example, a structural unit having a halogen atom described later (hereinafter sometimes referred to as "structural unit (a4)"), a structural unit having a non-leaving hydrocarbon group described later (hereinafter sometimes referred to as "structural unit (a5)"), and a structural unit derived from other monomers known in the art, etc.).

[0069] 〈Structural unit (a1)〉 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 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)). TIFF2025100419000063.tif2298[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 these, or R a1 and R a2 are bonded to each other to form an alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded, and the alkyl group, the alkenyl group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group may have a halogen atom. ma and na each independently represent 0 or 1, and at least one of ma and na represents 1. * represents a bonding site.] TIFF2025100419000064.tif2278[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 a heterocyclic group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded and X. The -CH2- contained in the hydrocarbon group and the heterocyclic group may be replaced by -O- or -S-, and the hydrocarbon group and the heterocyclic group may have a halogen atom. X represents an oxygen atom or a sulfur atom. na’ represents 0 or 1. * represents a bonding site.]

[0070] R a1 、R a2 and R a3 Examples of the alkyl group in R R a1 、R a2 and R a3 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 and the like. R a1 、R a2 and R a3 Examples of the alicyclic hydrocarbon group in R a1 、R a2 and R a3 The alicyclic hydrocarbon group of R TIFF2025100419000065.tif10159R a1 、R a2 and R a3Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, and phenanthryl group. Examples of the combined group include groups formed by combining the above-mentioned alkyl group and alicyclic hydrocarbon group (for example, alkyl cycloalkyl groups or cycloalkyl alkyl groups such as methylcyclohexyl group, dimethylcyclohexyl group, methyl norbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornylethyl group, etc.), aralkyl groups such as benzyl group, aromatic hydrocarbon groups having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon groups having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl groups such as phenylcyclohexyl group, etc. Preferably, ma is 0 and na is 1. R a1 and R a2 When they are bonded to each other to form an alicyclic hydrocarbon group, examples of -C(R a1 )(R a2 )(R a3 ) include the following groups. The alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * represents a bond to -O-. TIFF2025100419000066.tif29138

[0071] R a1’ 、R a2’ and R a3’ Examples of the hydrocarbon group in R 、R a1 、R a2 and R a3 include alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these. R a2’ and R a3’When they are bonded to each other to form a heterocyclic ring together with the carbon atom to which they are bonded and X, -C(R a1’ )(R a2’ )-X-R a3’ includes the following groups. * represents a bond. TIFF2025100419000067.tif19124R a1 R a2 R a3 R a1 R a2’ R a3’ The halogen atom that R R a1’ and R a2’ may have includes a fluorine atom, a chlorine atom, a bromine atom or an iodine atom. na' is preferably 0.

[0072] Examples of the group (1) include the following groups. In formula (1), a group in which R a1 R a2 and R a3 are alkyl groups, ma = 0, and na = 1. As such a group, a tert-butoxycarbonyl group is preferable. In formula (1), a group in which R a1 R a2 together with the carbon atom to which they are bonded form an adamantyl group, R a3 is an alkyl group, ma = 0, and na = 1. In formula (1), a group in which R a1 and R a2 are each independently an alkyl group, R a3 is an adamantyl group, ma = 0, and na = 1. Specific examples of the group (1) include the following groups. * represents a bond. TIFF2025100419000068.tif149163

[0073] Specific examples of the group (2) include the following groups. * represents a bond. TIFF2025100419000069.tif55153

[0074] 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. Among the (meth)acrylic monomers having an acid-labile group, those having an alicyclic hydrocarbon group with 5 to 20 carbon atoms are preferable. If 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 the resist composition, the resolution of the resist pattern can be improved.

[0075] As the structural unit derived from the (meth)acrylic monomer having group (1), 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)) can be mentioned. Preferably, it is at least one structural unit selected from the group consisting of structural unit (a1-0), structural unit (a1-1), and structural unit (a1-2), more preferably at least one or two structural units selected from the group consisting of structural unit (a1-1) and structural unit (a1-2). These may be used alone or in combination of two or more. TIFF2025100419000070.tif44144[In formula (a1-0), formula (a1-1), and formula (a1-2), all symbols have the same meanings as described above.]

[0076] R a01 、R a4 and R a5 The halogen atoms in are fluorine atom, chlorine atom, bromine atom, or iodine atom. R a01 、R a4 and R a5Examples of the alkyl group which may have a halogen atom in the above formula 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, a perfluorohexyl group, a chloromethyl group, a bromomethyl group, and an iodomethyl group. 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. The alkyl group is preferably a methyl group or an ethyl group, and more preferably a methyl group. R a01 , R a4 and R a5 is preferably a hydrogen atom or a methyl group, and 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 a04 The 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 Ra7 The alkyl group in a7 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 still more preferably an ethyl group, an isopropyl group or a t-butyl group. R a6 and R a7 The alkenyl group in a7 is preferably an alkenyl group having 2 to 6 carbon atoms, more preferably an ethenyl group, a propenyl group, an isopropenyl group or a butenyl group. R a02 R a03 R a04 R a6 and R a7 The number of carbon atoms of the alicyclic hydrocarbon group of a7 is preferably 5 to 12, more preferably 5 to 10. R a02 R a03 R a04 R a6 and R a7 The number of carbon atoms of the aromatic hydrocarbon group of a7 is preferably 6 to 12, more preferably 6 to 10. For the group formed by combining an alkyl group and an alicyclic hydrocarbon group, it is preferable that the total number of carbon atoms of these alkyl group and alicyclic hydrocarbon group is 18 or less. For the group formed by combining an alkyl group and an aromatic hydrocarbon group, it is preferable that the total number of carbon atoms of these alkyl group and aromatic hydrocarbon group is 18 or less. R a02 and R a03 R and R are preferably an alkyl group having 1 to 6 carbon atoms which may have a halogen atom or an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a halogen atom, more preferably a methyl group, an ethyl group, a phenyl group or a naphthyl group which may have a halogen atom. R a04 R is preferably an alkyl group having 1 to 6 carbon atoms which may have a halogen atom or an alicyclic hydrocarbon group having 5 to 12 carbon atoms which may have a halogen atom, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group which may have a halogen atom. R a6 and R a7is preferably an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, an alkenyl group having 2 to 6 carbon atoms which may have a halogen atom, or an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a halogen atom, 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 which may have a halogen atom, and still more preferably an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group or a phenyl group which may have a halogen atom. m1’ is preferably any integer from 0 to 3, more preferably 0 or 1. n1 is preferably any integer from 0 to 3, more preferably 0 or 1. n1’ is preferably 0 or 1.

[0077] Examples of the structural unit (a1-0) include structural units represented by any of formula (a1-0-1) to formula (a1-0-24) and structural units in which the methyl group corresponding to R in the structural unit (a1-0) a01 is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group. Structural units represented by any of formula (a1-0-1) to formula (a1-0-10), formula (a1-0-13), formula (a1-0-14), formula (a1-0-19) to formula (a1-0-24) are preferred. TIFF2025100419000071.tif119160

[0078] Examples of the structural unit (a1-1) include structural units derived from the monomers described in JP-A-2010-204646. Among them, structural units represented by any of formula (a1-1-1) to formula (a1-1-7) and structural units in which the methyl group corresponding to R in the structural unit (a1-1) a4 is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group are preferred, and structural units represented by any of formula (a1-1-1) to formula (a1-1-4) are more preferred. TIFF2025100419000072.tif35170

[0079] Examples of the structural unit (a1-2) include a structural unit represented by any one of formulae (a1-2-1) to (a1-2-20) and a structural unit in which the methyl group corresponding to R in the structural unit (a1-2) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group. A structural unit represented by any one of formula (a1-2-2), formula (a1-2-5), formula (a1-2-6), and formulae (a1-2-10) to (a1-2-20) is preferable. a5 Examples of the structural unit (a1-2) include a structural unit represented by any one of formulae (a1-2-1) to (a1-2-20) and a structural unit in which the methyl group corresponding to R in the structural unit (a1-2) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group. A structural unit represented by any one of formula (a1-2-2), formula (a1-2-5), formula (a1-2-6), and formulae (a1-2-10) to (a1-2-20) is preferable. TIFF2025100419000073.tif91163

[0080] When the resin (A) contains the structural unit (a1-0) and / or the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more, still more preferably 25 mol% or more, even more preferably 30 mol% or more, and still even more preferably 40 mol% or more, based on all the structural units of the resin (A). Also, it is 95 mol% or less, preferably 90 mol% or less, more preferably 85 mol% or less, still more preferably 70 mol% or less, and even more preferably 65 mol% or less. Specifically, it is 10 to 95 mol%, preferably 15 to 90 mol%, more preferably 20 to 85 mol%, still more preferably 25 to 70 mol%, and even more preferably 30 to 70 mol%. When the resin (A) contains the structural unit (a1-0), its content is 5 mol% or more, preferably 10 mol% or more, more preferably 15 mol% or more, still more preferably 20 mol% or more, even more preferably 25 mol% or more, even still more preferably 30 mol% or more, and even more preferably 35 mol% or more, based on all the structural units of the resin (A). Also, it is 80 mol% or less, preferably 75 mol% or less, more preferably 70 mol% or less, still more preferably 65 mol% or less, even more preferably 60 mol% or less. Specifically, it is 5 to 80 mol%, preferably 5 to 75 mol%, and more preferably 10 to 70 mol%. When the resin (A) contains the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more, still more preferably 25 mol% or more, even more preferably 30 mol% or more, even still more preferably 40 mol% or more, and even more preferably 50 mol% or more, based on all the structural units of the resin (A). Also, it is 95 mol% or less, preferably 90 mol% or less, more preferably 85 mol% or less, still more preferably 80 mol% or less, even more preferably 75 mol% or less, even still more preferably 70 mol% or less, and even more preferably 65 mol% or less. Specifically, it is 10 to 90 mol%, preferably 15 to 85 mol%, more preferably 15 to 80 mol%, still more preferably 20 to 80 mol%, even more preferably 20 to 75 mol%, and even still more preferably 20 to 70 mol%.

[0081] Examples of the structural unit having the group (2) in the structural unit (a1) include the structural unit represented by the formula (a1-4) (hereinafter sometimes referred to as "structural unit (a1-4)"). TIFF2025100419000074.tif31118[In the formula (a1-4), all the symbols have the same meanings as described above.]

[0082] R a1 and R a17 Examples of the halogen atom and the alkyl group which may have a halogen atom in R include R of formula (a1-0) to formula (a1-2). a01 R a4 and R a5 are the same as those exemplified by R R a1 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 a17 Examples of the alkoxy group in R 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 a17 Examples of the alkoxyalkyl group in R 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 a17 Examples of the alkoxyalkoxy group in R 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, more preferably a methoxyethoxy group or an ethoxyethoxy group. R a17 Examples of the alkylcarbonyl group in R include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, more preferably an acetyl group. R a17Examples of the alkylcarbonyloxy group 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 a17 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 ethoxy methoxy group, and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group. na12 is preferably 0, 1, or 2, more preferably 0 or 1, and even more preferably 0.

[0083] A a11 Examples of the alkanediyl group of A include branched alkanediyl groups such as 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, a 2-methylbutane-1,4-diyl group, a heptane-1,6-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, and a decane-1,10-diyl group. The number of carbon atoms of the alkanediyl group is preferably 1 to 6, more preferably 1 to 4, even more preferably 1 to 3, and even more preferably 1 or 2. Among them, A a11 is preferably a methylene group or an ethylene group. R a18 Examples of the alkyl group of R include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a tert-butyl group. A a11 When -CH2- contained in the alkanediyl group of A is replaced by -O-, -CO-, or -NR a18 , the number of carbon atoms before replacement is defined as the number of carbon atoms of the hydrocarbon group. A a11 Examples of the group in which -CH2- contained in the alkanediyl group of A is replaced by -O- or -CO- include a hydroxy group, a carboxy group, a carbonyl group, an oxy group, an amino group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylamino group, a peptide group, an alkanediyl-oxy group, an alkanediyl-oxycarbonyl group, an alkanediylcarbonyl group, an alkanediylcarbonyl-oxy group, an alkanediylsulfonyl group, an alkanediylthio group, an alkanediylamino group, and the like. As long as the upper limit of the number of carbon atoms is allowed, the replaced groups include those similar to those exemplified herein. Examples of the alkylamino group include alkylamino groups having 1 to 11 carbon atoms, such as a methylamino group, an ethylamino group, a propylamino group, a butylamino group, a pentylamino group, a hexylamino group, and an octylamino group. Examples of the alkanediylamino group include alkanediylthio groups having 1 to 11 carbon atoms, such as a methyleneamino group, an ethyleneamino group, and a propyleneamino group. The number of carbon atoms of the alkanediylamino group is preferably 1 to 8, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. For example, A a11 Examples of the group in which -CH2- contained in the alkanediyl group of A is replaced by -O-, -CO- or -NR a28 include *-O-, *-CO-O-, *-O-CO-, *-CO-O-A a12 -CO-O-, *-O-CO-A a12 -O-, *-O-A a12 -CO-O-, *-CO-O-A a12 -O-CO-, *-O-CO-A a12 -O-CO-, *-CO-NR a18 -. Among them, *-CO-O-, *-CO-O-A a12 -CO-O- or *-O-A a12 -CO-O-, *-CO-NR a18 - are preferred. Here, A a12 represents an alkanediyl group having 1 to 8 carbon atoms, and * represents Ra1 represents a bonding site bonded to a carbon atom to which it is bonded. A a12 The alkandiyl group of may be the same alkandiyl group as A within the range allowed by the upper limit of the number of carbon atoms. a11 Examples thereof include the same alkandiyl group as A. A a11 is a single bond, *-CO-O- or *-CO-O-A a12 -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. na1 is preferably 1, 2, 3 or 4, more preferably 1, 2 or 3, and even more preferably 1 or 2. na11 is preferably 0, 1, 2 or 3, more preferably 0, 1 or 2, and even more preferably 0 or 1. mc is preferably 0 or 1.

[0084] 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 combining these. 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, an octyl group, etc. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, etc. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bonding site). etc. TIFF2025100419000075.tif10151 Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, a phenanthryl group, etc. Examples of the combined group include a group formed by combining the above-described alkyl group and alicyclic hydrocarbon group (e.g., an alkylcycloalkyl group or cycloalkylalkyl group such as methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornil group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornylethyl group, etc.), an aralkyl group such as benzyl group, an aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), an aryl-cycloalkyl group such as phenylcyclohexyl group, etc. In particular, R a36 Examples of R 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. R a35 and R a36 Examples of the divalent hydrocarbon group having 2 to 20 carbon atoms formed by R and R bonding to each other together with the -C-O- to which they are bonded include the following groups. * represents a bonding site, and one of them is the bonding site with R a34 TIFF2025100419000076.tif15105

[0085] 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 of 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. R a36 ​The alkyl group and alicyclic hydrocarbon group in [compound name] are preferably unsubstituted. R a36 The aromatic hydrocarbon group in [compound name] preferably has an aromatic ring having an aryloxy group with 6 to 10 carbon atoms.

[0086] -OC(R a34 )(R a35 )-O-R a36 in the structural unit (a1-4) eliminates upon contact with an acid (e.g., p-toluenesulfonic acid) to form a hydroxy group or a carboxy group. -X a1 -OC(R a34 )(R a35 )-O-R a36 In the case of a benzene ring, it may be bonded to any of the o-position, m-position, or p-position with respect to the bonding position of A a11 . Among them, at least one is preferably bonded to the o-position or p-position, and more preferably bonded to the p-position. In the case of a naphthalene ring, when the bonding position of A a11 is at the 1-position, it may be bonded to any of the 2nd to 8th positions, and when the bonding position of A a11 is at the 2nd position, it may be bonded to any of the 1st and 3rd to 8th positions. Among them, when the bonding position of A a11 is at the 1st position, at least one is preferably bonded to the 3rd to 6th positions, and more preferably bonded to the 3rd or 4th position. When the bonding position of A a11 is at the 2nd position, it is preferably bonded to the 4th to 7th positions, and more preferably bonded to the 5th or 6th position. .

[0087] Examples of the structural unit (a1-4) include structural units derived from the monomers described in JP-A-2010-204646. Preferably, structural units represented by formula (a1-4-1) to formula (a1-4-42) and structural units in which the hydrogen atom corresponding to R a1 in the structural unit (a1-4) is replaced by a halogen atom, a haloalkyl group, or an alkyl group are mentioned, and more preferably, structural units represented by formula (a1-4-1) to formula (a1-4-5), formula (a1-4-10), formula (a1-4-13), and formula (a1-4-14) are mentioned. TIFF2025100419000077.tif228165

[0088] When the resin (A) contains the structural unit (a1-4), its content is preferably 10 to 95 mol%, more preferably 15 to 90 mol%, still more preferably 20 to 85 mol%, still more preferably 20 to 70 mol%, and particularly preferably 20 to 60 mol% based on the total of all the structural units of the resin (A).

[0089] Examples of the structural unit derived from the (meth)acrylic monomer having the group (2) also include the structural unit represented by the formula (a1-5) (hereinafter sometimes referred to as "structural unit (a1-5)"). TIFF2025100419000078.tif4558[In the formula (a1-5), all the symbols have the same meanings as described above.]

[0090] R a8 Examples of the halogen atom and the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in R a01 are the same as those exemplified by the like of R in the formula (a1-0). In the 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 them, it is preferable that one is -O- and the other is -S-. s1 is preferably 1. s1' is preferably any integer from 0 to 2. Z a1 is preferably a single bond or *-CH2-CO-O-. Examples of the structural unit (a1-5) include structural units derived from monomers described in JP-A-2010-61117. Among them, structural units represented by formula (a1-5-1) to formula (a1-5-4) are preferable, and a structural unit represented by formula (a1-5-1) or formula (a1-5-2) is more preferable. When the resin (A) contains the structural unit (a1-5), the content thereof is 1 mol% or more, preferably 2 mol% or more, more preferably 3 mol% or more, still more preferably 5 mol% or more, even more preferably 10 mol% or more, still even more preferably 20 mol% or more, and even more preferably 25 mol% or more, based on all the structural units of the resin (A). Further, it is 80 mol% or less, preferably 70 mol% or less, more preferably 60 mol% or less, still more preferably 50 mol% or less, even more preferably 45 mol% or less, still even more preferably 40 mol% or less, and even more preferably 30 mol% or less. Specifically, 1 to 50 mol% is preferable, 3 to 45 mol% is more preferable, 5 to 40 mol% is still more preferable, and 5 to 30 mol% is even more preferable.

[0091] Examples of the structural unit having the group (1) in the structural unit (a1) include a structural unit represented by formula (a1-6) (hereinafter sometimes referred to as "structural unit (a1-6)"). TIFF2025100419000080.tif3479[In formula (a1-6), all the symbols have the same meanings as described above.]

[0092] For the halogen atom and the alkyl group which may have a halogen atom in R of formula (a1-6), the same ones as exemplified for the halogen atom and the alkyl group which may have a halogen atom in R of formula (a1-0) etc. can be mentioned. a61 For the halogen atom and the alkyl group which may have a halogen atom in R of formula (a1-6), the same ones as exemplified for the halogen atom and the alkyl group which may have a halogen atom in R of formula (a1-0) etc. can be mentioned. a01 The same ones as exemplified for the halogen atom and the alkyl group which may have a halogen atom in R of formula (a1-0) etc. can be mentioned. R a61 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group. R a62 、Ra63 , R a64 and R a65 Examples of the alkyl group in R, R, and R include a methyl group, an ethyl group, a propyl group, a butyl group, a heptyl group, a hexyl group, and the like. R a62 , R a63 and R a64 Examples of the cyclic hydrocarbon group in R, R, and R include an alicyclic hydrocarbon group and an aromatic hydrocarbon group. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and the like. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the like. The number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 16, more preferably 3 to 12. Examples of the aromatic hydrocarbon group include a phenylene group, a naphthylene group, and the like. Examples of the substituent that the cyclic hydrocarbon group may have include 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. R a62 and R a63 The ring formed by R and R bonding to each other preferably has 3 to 12 carbon atoms. Examples of the ring include an adamantane ring, a cyclohexane ring, and the like. Specifically, when R and R bond to each other to form a ring, examples of -C(R)(R)(R) include the following groups. * represents the bonding site with an oxygen atom. The number of carbon atoms of the ring is preferably 3 to 16, more preferably 3 to 12. a62 and R a63 (R a62 )(R a63 )(R a64 ) include the following groups. * represents the bonding site with an oxygen atom. The number of carbon atoms of the ring is preferably 3 to 16, more preferably 3 to 12. TIFF2025100419000081.tif33108X a61is preferably a single bond or -CO-O-*, more preferably a single bond. X a62 is preferably a single bond or *-O-L a61 -, more preferably a single bond. L a61 and L a62 Examples of the alkanediyl group in L and L 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, and the like. L a61 and L a62 are preferably a methylene group or an ethylene group.

[0093] Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms in Ar include a phenylene group, a 1-naphthylene group, a 2-naphthylene group, a 1-anthrylene group, a 9-anthrylene group, a biphenylene group, a 1-phenanthrylene group, and a 2-phenanthrylene group. Examples of the substituent that the aromatic hydrocarbon group may have include 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. The halogen atom and the alkyl group having 1 to 6 carbon atoms which may have a halogen atom are the same as those exemplified by R a61 and the like. 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, 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. Examples of the alkoxy group 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. Examples of the alkoxyalkyl group 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. Examples of the alkoxyalkoxy group 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, more preferably a methoxyethoxy group or an ethoxyethoxy group. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, more preferably an acetyl group. Examples of the alkylcarbonyloxy group 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, more preferably an acetyloxy group. Examples of the substituent include 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 preferred are 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. Even more preferred are a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group. Ar is preferably a phenylene group which may have a substituent, more preferably a phenylene group which may have a hydroxy group.

[0094] Examples of the structural unit (a1-6) include structural units represented by Formula (a1-6-1) to Formula (a1-6-44), etc. Structural units represented by Formula (a1-6-1) to Formula (a1-6-9) are preferred, and structural units represented by Formula (a1-6-1), Formula (a1-6-2), Formula (a1-6-4), Formula (a1-6-5), Formula (a1-6-7) or Formula (a1-6-8) are more preferred, and structural units represented by Formula (a1-6-1) or Formula (a1-6-2) are even more preferred. In the following structural units, the hydrogen atom corresponding to R a61 replaced by a methyl group or the like, and the structural unit in which the methyl group corresponding to R a61 is replaced by a hydrogen atom or the like are also included as the structural unit (a1-6). TIFF2025100419000082.tif227164 In the structural units represented by Formula (a1-6-1) to Formula (a1-6-9), Formula (a1-6-16) to Formula (a1-6-21), Formula (a1-6-28) to Formula (a1-6-30), and Formula (a1-6-37) to Formula (a1-6-43), the hydrogen atom corresponding to R a61 replaced by a methyl group, a halogen atom or a haloalkyl group, etc., and in the structural units represented by Formula (a1-6-10) to Formula (a1-6-15), Formula (a1-6-22) to Formula (a1-6-27), and Formula (a1-6-31) to Formula (a1-6-36), the structural unit in which the methyl group corresponding to R a61 is replaced by a hydrogen atom, a halogen atom or a haloalkyl group, etc. are also included as the structural unit (a1-6).

[0095] When the resin (A) contains the structural unit (a1-6), its content is 3 mol% or more, preferably 5 mol% or more, more preferably 7 mol% or more, still more preferably 10 mol% or more, based on all the structural units of the resin (A). Also, it is 80 mol% or less, preferably 75 mol% or less, more preferably 70 mol% or less, still more preferably 65 mol% or less, and even more preferably 60 mol% or less. Specifically, it is preferably 3 to 80 mol%, more preferably 5 to 75 mol%, still more preferably 7 to 70 mol%, still even more preferably 7 to 65 mol%, and particularly preferably 10 to 60 mol%.

[0096] Moreover, examples of the structural unit (a1) also include the following structural units. TIFF2025100419000083.tif33167

[0097] When the resin (A) etc. contain the structural units represented by the formulas (a1-7-1) to (a1-7-7), its content is 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more, still more preferably 25 mol% or more, even more preferably 30 mol% or more, still even more preferably 40 mol% or more, and still more preferably 50 mol% or more, based on all the structural units of the resin (A) etc. Also, it is 95 mol% or less, preferably 90 mol% or less, more preferably 85 mol% or less, still more preferably 80 mol% or less, even more preferably 75 mol% or less, still even more preferably 70 mol% or less, and still more preferably 60 mol% or less. Specifically, it is preferably 10 to 95 mol%, more preferably 15 to 90 mol%, still more preferably 20 to 85 mol%, still even more preferably 20 to 70 mol%, and particularly preferably 20 to 60 mol%.

[0098] Moreover, examples of the structural unit (a1) also include the following structural units. When resin (A) etc. contains structural units represented by formulas (a1-8-1) to (a1-8-3), the content is 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more, still more preferably 25 mol% or more, even more preferably 30 mol% or more, still even more preferably 40 mol% or more, and even more preferably 50 mol% or more, based on all the structural units of resin (A) etc. Also, 95 mol% or less is mentioned, preferably 90 mol% or less, more preferably 85 mol% or less, still more preferably 80 mol% or less, even more preferably 75 mol% or less, still even more preferably 70 mol% or less, and even more preferably 60 mol% or less. Specifically, 10 to 60 mol% is preferable, 15 to 55 mol% is more preferable, 20 to 50 mol% is still more preferable, 20 to 45 mol% is even more preferable, and 20 to 40 mol% is particularly preferable.

[0099] 〈Structural unit(s)〉 The structural unit(s) is derived from a monomer having no acid-labile group (hereinafter sometimes referred to as "monomer(s)"). As the monomer that leads to the structural unit(s), a monomer having no acid-labile group known in the resist field can be used. As the structural unit(s), it is preferable to have a hydroxy group, a carboxy group or a lactone ring. If a resin containing a structural unit having a hydroxy group or a carboxy group and having no acid-labile group (hereinafter sometimes referred to as "structural unit (a2)") and / or a structural unit having a lactone ring and having no acid-labile group (hereinafter sometimes referred to as "structural unit (a3)") is used in the resist composition of the present invention, the resolution of the resist pattern and the adhesion to the substrate can be improved.

[0100] 〈Structural unit (a2)〉 The structural unit (a2) is a structural unit represented by formula (a2) and has an alcoholic hydroxy, a phenolic hydroxy group or a phenolic carboxy group. TIFF2025100419000085.tif4094[In formula (a2), R a2 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. A a21 represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and -CH2- contained in the alkanediyl group may be replaced by -O-, -CO-, or -NR a28 -. R a28 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. L a21 represents a single bond or a hydrocarbon group having 1 to 28 carbon atoms, the hydrocarbon group may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -CO-, -S-, or -SO2-. L a22 represents a single bond or an alkanediyl group having 1 to 12 carbon atoms which may have a fluorine atom, and -CH2- contained in the alkanediyl may be replaced by -O- or -CO-. na2 represents any integer from 1 to 4. When na2 is 2 or more, a plurality of L a22 may be the same as or different from each other.]

[0101] R a2 Examples of the halogen atom in R include a fluorine atom, a chlorine atom, and a bromine atom. R a2 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in R 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, a perfluorohexyl group, a chloromethyl group, a bromomethyl group, and an iodomethyl group. R a2 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 still more preferably a hydrogen atom or a methyl group.

[0102] A a21 Examples of the alkanediyl group of A include linear alkanediyl groups such as 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, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, etc., and branched alkanediyl groups such as butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, heptane-1,6-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, etc. A a21 is preferably a methylene group or an ethylene group. The number of carbon atoms of the alkanediyl group is preferably 1 to 6, more preferably 1 to 4, still more preferably 1 to 3, and even more preferably 1 or 2. R a28 Examples of the alkyl group of R include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, tert-butyl group. A a21 When -CH2- contained in the alkanediyl group of A is replaced by -O-, -CO- or -NR a28 , the number of carbon atoms before replacement is taken as the number of carbon atoms of the hydrocarbon group. A a21As the group in which -CH2- contained in the alkanediyl group is replaced by -O- or -CO-, there are a hydroxy group (the group in which -CH2- contained in the methyl group is replaced by -O-), a carboxy group (the group in which -CH2-CH2- contained in the ethyl group is replaced by -O-CO-), a carbonyl group (the group in which -CH2- contained in the methylene group is replaced by -CO-), an oxy group (the group in which -CH2- contained in the methylene group is replaced by -O-), an amino group (the group in which -CH2- contained in the alkanediyl group is replaced by -NR a28 -), an alkoxy group (the group in which any -CH2- contained in the alkyl group is replaced by -O-), an alkoxycarbonyl group (the group in which any -CH2-CH2- contained in the alkyl group is replaced by -O-CO-), an alkylcarbonyl group (the group in which any -CH2- contained in the alkyl group is replaced by -CO-), an alkylamino group (the group in which -CH2- contained in the alkyl group is replaced by -NR a28 -), a peptide group (the group in which -CH2-CH2- contained in the ethylene group is replaced by -CO-NR a28 -), an alkanediylamino group (the group in which any -CH2- contained in the alkanediyl group is replaced by -NR a28 -), etc. These replaced groups include those similar to the ones exemplified in this specification as long as the upper limit of the number of carbon atoms permits. For example, as the group in which -CH2- contained in the alkanediyl group of A a21 is replaced by -O-, -CO- or -NR a28 , there are *-O-, *-CO-O-, *-O-CO-, *-CO-O-A a22 -CO-O-, *-O-CO-A a22 -O-, *-O-A a22 -CO-O-, *-CO-O-A a22 -O-CO-, *-O-CO-A a22 -O-CO-, *-CO-NR a28 -. Among them, *-CO-O-, *-CO-O-A a22 -CO-O- or *-O-A a22 -CO-O-, *-CO-NR a28- is preferred. Here, A a22 represents an alkanediyl group having 1 to 8 carbon atoms, and * represents a bonding site bonded to the carbon atom to which R a2 is bonded. The alkanediyl group of A a22 may be the same alkanediyl group as A a21 within the range allowed by the upper limit of the number of carbon atoms. A a21 is preferably a single bond, *-CO-O- or *-CO-O-A a22 -CO-O-, more preferably a single bond, *-CO-O- or *-CO-O-CH2-CO-O-, and even more preferably a single bond or *-CO-O-.

[0103] The hydrocarbon group in L a21 is a (na2 + 1)-valent hydrocarbon group, and examples include chain hydrocarbon groups, alicyclic hydrocarbon groups of monocyclic or polycyclic (including spiro rings, condensed rings, bridged rings, etc.), and cyclic hydrocarbon groups such as aromatic hydrocarbon groups. A group formed by combining two or more of these groups (for example, a hydrocarbon group formed from an alicyclic hydrocarbon group or an aromatic hydrocarbon group and a chain hydrocarbon group) may also be used. The chain hydrocarbon group of L a21 includes divalent to pentavalent chain hydrocarbon groups such as alkanediyl groups, alkanetriyl groups, alkanetetrayl groups, and alkanepentayl groups. As the alkanediyl group of L a21 , for example, the same alkanediyl group as A a21 can be mentioned. As the alkanetriyl group of L a21 , examples include methanetriyl group, ethanetriyl group, propanetriyl group, butanetriyl group, pentanetriyl group, hexanetriyl group, heptanetriyl group, octanetriyl group, nonanetriyl group, decanetriyl group, undecanetriyl group, dodecanetriyl group, tridecanetriyl group, tetradecanetriyl group, pentadecanetriyl group, hexadecanetriyl group, and heptadecanetriyl group. Examples of the alkanetetrayl group include a methanetetrayl group, an ethanetetrayl group, a propanetetrayl group, a butanetetrayl group, a pentanetetrayl group, a hexanetetrayl group, a heptanetetrayl group, an octanetetrayl group, a nonanetetrayl group, a decanetetrayl group, an undecanetetrayl group, a dodecanetetrayl group, a tridecanetetrayl group, a tetradecanetetrayl group, a pentadecanetetrayl group, a hexadecanetetrayl group, and a heptadecanetetrayl group. Examples of the alkanepentayl group include a methanepentayl group, an ethanepentayl group, a propanepentayl group, a butanepentayl group, a pentanepentayl group, and a hexanepentayl group. Examples also include a group in which one or more hydrogen atoms of the above-described group are replaced with a bonding site. L a21 The number of carbon atoms in the chain hydrocarbon group of L is preferably 1 to 18, more preferably 1 to 12, still more preferably 1 to 10, even more preferably 1 to 9, still even more preferably 1 to 8, still more preferably 1 to 6, still even more preferably 1 to 5, and particularly preferably 1 to 4. L a21 Examples of the monocyclic and polycyclic divalent alicyclic hydrocarbon groups in L include the following alicyclic hydrocarbon groups, etc. The bonding site can be at any position. TIFF2025100419000086.tif46168For example, monocyclic alicyclic hydrocarbon groups such as a cyclobutane-1,3-diyl group, a cyclopentane-1,3-diyl group, a cyclohexane-1,4-diyl group, a cyclooctane-1,5-diyl group, a cyclopropanetriyl group, a cyclobutanetriyl group, a cyclopentanetriyl group, a cyclohexanetriyl group, a cycloheptanetriyl group, a cyclooctanetriyl group, a cyclodecanetriyl group, a cyclopropanetetrayl group, a cyclobutanetetrayl group, a cyclopentanetetrayl group, a cyclohexanetetrayl group, a cycloheptanetetrayl group, a cyclooctanetetrayl group, and a cyclodecanetetrayl group, and Examples of the polycyclic alicyclic hydrocarbon group include norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, decahydronaphthalenediyl group, bicyclo[3.3.0]octanediy group, norbornanetril group, adamantanetril group, decahydronaphthalenetril group, bicyclo[3.3.0]octanetril group, norbornanetetrayl group, adamantanetetrayl group, decahydronaphthalenetetrayl group, bicyclo[3.3.0]octanetetrayl group, and the like. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 20, more preferably 3 to 18, still more preferably 3 to 16, and even more preferably 3 to 12. L a21 Examples of the divalent aromatic hydrocarbon group in L include aromatic hydrocarbon groups such as phenylene group, naphthylene group, anthrylene group, biphenylene group, phenanthrylene group, benzenetriyl group, naphthalenetriyl group, anthracenetriyl group, biphenylenetriyl group, phenanthrenetriyl group, benzenetetrayl group, naphthalenetetrayl group, anthracenetetrayl group, biphenylenetetrayl group, phenanthrenetetrayl group, and the like. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 20, more preferably 6 to 18, still more preferably 6 to 14, and even more preferably 6 to 10. Examples of the trivalent to pentavalent alicyclic hydrocarbon group and aromatic hydrocarbon group include groups formed by removing 1 to 3 hydrogen atoms from the above-described divalent groups to form bonds. Examples of the group formed by combining two or more types include a group formed by combining an alicyclic hydrocarbon group and a chain hydrocarbon group, a group formed by combining an aromatic hydrocarbon group and a chain hydrocarbon group, a group formed by combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group, a group formed by combining an alicyclic hydrocarbon group, a chain hydrocarbon group, and an aromatic hydrocarbon group, and the like. In the combination, two or more types of alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and chain hydrocarbon groups may be combined respectively. Also, any group may be bonded to A a21 and L a22 and may be bonded. La21 As the alkanediyl group of, it may be replaced by -O- or -CO-, and L a21 When the alkanediyl group of is replaced by -O- or -CO-, for example, *-L a23 -X a21 -(L a23 represents an alkanediyl group having 1 to 8 carbon atoms, and X a21 represents -O-, -O-CO-, -CO-O- or -O-CO-O-, and * represents the bonding site with X a2 .) is preferably the case. Examples of the trivalent to pentavalent alicyclic hydrocarbon group and aromatic hydrocarbon group include groups formed by removing 1 to 3 hydrogen atoms from the above-described divalent group to form a bond. Examples of groups in which -CH2- contained in a hydrocarbon group is replaced by -O-, -S-, -SO2- or -CO- include a hydroxy group (a group in which -CH2- contained in a methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- contained in an ethyl group is replaced by -O-CO-), a thiol group (a group in which -CH2- contained in a methyl group is replaced by -S-), an alkoxy group (a group in which -CH2- at any position contained in an alkyl group is replaced by -O-), an alkylthio group (a group in which -CH2- at any position contained in an alkyl group is replaced by -S-), an alkoxycarbonyl group (a group in which -CH2-CH2- at any position contained in an alkyl group is replaced by -O-CO-), an alkylsulfonyl group (a group in which -CH2- at any position contained in an alkyl group is replaced by -SO2-), an alkylcarbonyl group (a group in which -CH2- at any position contained in an alkyl group is replaced by -CO-), an alkylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in an alkyl group is replaced by -CO-O-), an oxy group (a group in which -CH2- contained in a methylene group is replaced by -O-), a carbonyl group (a group in which -CH2- contained in a methylene group is replaced by -CO-), a thio group (a group in which -CH2- contained in a methylene group is replaced by -S-), a sulfonyl group (a group in which -CH2- contained in a methylene group is replaced by -SO2-), an alkanedioxy group (a group in which -CH2- at any position contained in an alkanediyl group is replaced by -O-), an alkanedioxycarbonyl group (a group in which -CH2-CH2- at any position contained in an alkanediyl group is replaced by -O-CO-), an alkanediylcarbonyl group (a group in which -CH2- at any position contained in an alkanediyl group is replaced by -CO-), an alkanediylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in an alkanediyl group is replaced by -CO-O-), an alkanediylsulfonyl group (a group in which -CH2- at any position contained in an alkanediyl group is replaced by -SO2-), an alkanediylthio group (a group in which -CH2- at any position contained in an alkanediyl group is replaced by -S-), a cycloalkoxy group, a cycloalkylalkoxy group, an alkoxycarbonyloxy group,Examples include an aromatic hydrocarbon group-carbonyl oxy group, an aromatic hydrocarbon group-carbonyl group, an aromatic hydrocarbon group-oxy group, and a group formed by combining two or more of these groups. Also included are groups in which one or more hydrogen atoms of these groups are replaced by a bonding site, etc. Examples of the alkoxy group include alkoxy groups having 1 to 27 carbon atoms, such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, and the like. The number of carbon atoms of the alkoxy group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkylthio group include alkylthio groups having 1 to 27 carbon atoms, such as a methylthio group, an ethylthio group, a propylthio group, a butylthio group, and the like. The number of carbon atoms of the alkylthio group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 27 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, a butoxycarbonyl group, and the like. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 28 carbon atoms, such as an acetyl group, a propionyl group, and a butyryl group. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 27 carbon atoms, such as an acetyloxy group, a propionyloxy group, a butyryloxy group, and the like. The number of carbon atoms of the alkoxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. Examples of the alkylsulfonyl group include alkylsulfonyl groups having 1 to 27 carbon atoms, such as methylsulfonyl group, ethylsulfonyl group, propylsulfonyl group and the like. The number of carbon atoms of the alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediyl-oxy group include alkanediyl-oxy groups having 1 to 27 carbon atoms, such as methyleneoxy group, ethyleneoxy group, propanediyl-oxy group, butanediyl-oxy group, pentanediyl-oxy group and the like. The number of carbon atoms of the alkanediyl-oxy group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediyl-oxycarbonyl group include alkanediyl-oxycarbonyl groups having 2 to 27 carbon atoms, such as methyleneoxycarbonyl group, ethyleneoxycarbonyl group, propanediyl-oxycarbonyl group, butanediyl-oxycarbonyl group and the like. Examples of the alkanediylcarbonyl group include alkanediylcarbonyl groups having 2 to 28 carbon atoms, such as methylenecarbonyl group, ethylenecarbonyl group, propanediylcarbonyl group, butanediylcarbonyl group, pentanediylcarbonyl group and the like. Examples of the alkanediylcarbonyl-oxy group include alkanediylcarbonyl-oxy groups having 2 to 27 carbon atoms, such as methylenecarbonyl-oxy group, ethylenecarbonyl-oxy group, propanediylcarbonyl-oxy group, butanediylcarbonyl-oxy group and the like. The number of carbon atoms of the alkanediyl-oxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkanediylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkanediylcarbonyl-oxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. Examples of the alkanediylthio group include alkanediylthio groups having 1 to 27 carbon atoms, such as a methylene thio group, an ethylene thio group, and a propanediylthio group. The number of carbon atoms of the alkanediylthio group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediylsulfonyl group include alkanediylsulfonyl groups having 1 to 27 carbon atoms, such as a methylene sulfonyl group, an ethylene sulfonyl group, and a propylene sulfonyl group. The number of carbon atoms of the alkanediylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3.

[0104] Examples of the cycloalkoxy group include cycloalkoxy groups having 3 to 27 carbon atoms, such as a cyclohexyloxy group. Examples of the cycloalkylalkoxy group include cycloalkylalkoxy groups having 4 to 27 carbon atoms, such as a cyclohexylmethoxy group. Examples of the alkoxycarbonyloxy group include alkoxycarbonyloxy groups having 2 to 26 carbon atoms, such as a butoxycarbonyloxy group. Examples of the aromatic hydrocarbon group-carbonyl oxy group include aromatic hydrocarbon group-carbonyl oxy groups having 7 to 27 carbon atoms, such as a benzoyloxy group. Examples of the aromatic hydrocarbon group-carbonyl group include aromatic hydrocarbon group-carbonyl groups having 7 to 27 carbon atoms, such as a benzoyl group. Examples of the aromatic hydrocarbon group-oxy group include aromatic hydrocarbon group-oxy groups having 6 to 27 carbon atoms, such as a phenyloxy group.

[0105] Examples of the group in which -CH2- contained in the alicyclic hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2- include the following groups. Among the groups represented below, groups in which -O- is replaced by -S- and -CO- is replaced by -SO2- are also included. The bonding site can be at any position. Among the groups in which -CH2- contained in the base combined with 47,168 TIFF2025100419000087.tif is replaced by -O-, -S-, -CO- or -SO2-, the following groups and the like can be mentioned. The bonding site can be at any position. TIFF2025100419000088.tif 26,164 L a21 The hydrocarbon group in may have one or more substituents. Examples of the substituent include a halogen atom, a haloalkyl group having 1 to 6 carbon atoms, or an alkyl group having 1 to 12 carbon atoms (the -CH2- contained in the haloalkyl group and the alkyl group may be replaced by -O-, -CO-, -S- or -SO2-). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like. L a21 By having a halogen atom as a substituent, the hydrocarbon group in can substantially have a substituent such as a haloalkyl group. Examples of the haloalkyl group include a chloromethyl group, a bromomethyl group, a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a perfluorobutyl group, etc. A haloalkyl group having 1 to 4 carbon atoms is preferred, and a haloalkyl group having 1 to 3 carbon atoms is more preferred. L a21 Since the hydrocarbon group of contains a branched structure, L a21 can substantially have a substituent such as an alkyl group. 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, 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 and a dodecyl group. The number of carbon atoms of the alkyl group is preferably 1 to 10, more preferably 1 to 8, still more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3. L a21 Due to the group in which -CH2- contained in the hydrocarbon group of is replaced by -O-, -CO-, -S- or -SO2-, L a21can substantially have substituents such as a hydroxy group, a carboxy group, a thiol group, a sulfonyl group, an alkoxy group, an alkoxyalkyl group, an alkoxyalkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, an alkoxycarbonyloxy group, etc. L a21 As the substituents that the hydrocarbon group in a21 may have, a halogen atom, a haloalkyl group having 1 to 4 carbon atoms or an alkyl group having 1 to 6 carbon atoms (in the alkyl group, -CH2- may be replaced by -O- or -CO-) is preferable, a fluorine atom, an iodine atom, a haloalkyl group having 1 to 3 carbon atoms or an alkyl group having 1 to 4 carbon atoms (in the alkyl group, -CH2- may be replaced by -O- or -CO-) is more preferable, and a fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, a hydroxy group or a methoxy group is even more preferable. L a21is a group formed by combining a single bond, an optionally substituted chain hydrocarbon group having 1 to 12 carbon atoms (provided that -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-), an optionally substituted cyclic hydrocarbon group having 3 to 20 carbon atoms (provided that -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-), or an optionally substituted chain hydrocarbon group having 1 to 8 carbon atoms and an optionally substituted cyclic hydrocarbon group having 3 to 20 carbon atoms (provided that -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-, and -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-). It is preferably a group formed by combining an optionally substituted chain hydrocarbon group having 1 to 10 carbon atoms (provided that -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-), an optionally substituted cyclic hydrocarbon group having 3 to 18 carbon atoms (provided that -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-), or an optionally substituted chain hydrocarbon group having 1 to 6 carbon atoms and an optionally substituted cyclic hydrocarbon group having 3 to 18 carbon atoms (provided that -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-, and -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-).

[0106] L a22Examples of the C1-C12 alkanediyl group include linear alkanediyl groups such as 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, dodecane-1,12-diyl group, etc., and ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-dimethylpropane-1,3-diyl group, pentane-2,4-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, etc. The number of carbon atoms of the alkanediyl group is preferably 1-10, more preferably 1-8, still more preferably 1-6, and even more preferably 1-4. L a22 The fluorine atom(s) that L has may be one or two or more. na2 is preferably any integer from 1 to 3, and more preferably 1 or 2. L a21 Examples of the structural unit (a2) when L is a single bond or a chain hydrocarbon group include, for example, the following structural units. Among the following groups, the structural units in which the methyl group corresponding to R a2 is replaced by a hydrogen atom or the like are also preferred structural units of the structural unit (a2) in the same manner as the following structural units. TIFF2025100419000089.tif67164

[0107] When producing a resist pattern from the resist composition of the present invention, when using a high-energy ray such as a KrF excimer laser (248 nm), an electron beam, or EUV (extreme ultraviolet light) as an exposure light source, as the structural unit (a2), a structural unit (a2) having a phenolic hydroxy group is preferable, and it is more preferable to use the structural unit (a2-A) described later. Further, when using an ArF excimer laser (193 nm) or the like, as the structural unit (a2), a structural unit (a2) having an alcoholic hydroxy group is preferable, and it is more preferable to use the structural unit (a2-1) described later. The structural unit (a2) may contain one kind alone or two or more kinds.

[0108] Examples of the structural unit having a phenolic hydroxy group in the structural unit (a2) include a structural unit represented by the formula (a2-A) (hereinafter sometimes referred to as "structural unit (a2-A)"). TIFF2025100419000090.tif30128[In the formula (a2-A), all symbols represent the same meaning as described above.]

[0109] R a2 and A a21 are each a group similar to those exemplified in the formula (a2). R a27 Examples of the halogen atom of R include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom. R a27Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, chloromethyl group, bromomethyl group, iodomethyl group. The number of carbon atoms of the alkyl group is preferably 1 to 4, more preferably 1 to 3, still more preferably methyl group or ethyl group, and even more preferably methyl group. R a27 Examples of the alkoxy group of R a27 include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, sec-butoxy group, tert-butoxy group. The number of carbon atoms of the alkoxy group is preferably 1 to 4, more preferably 1 to 3, still more preferably methoxy group or ethoxy group, and even more preferably methoxy group. R a27 Examples of the alkoxyalkyl group of R a27 include methoxymethyl group, ethoxyethyl group, propoxymethyl group, isopropoxymethyl group, butoxymethyl group, sec-butoxymethyl group, tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably methoxymethyl group or ethoxyethyl group, and still more preferably methoxymethyl group. R a27 Examples of the alkoxyalkoxy group of R a27 include methoxymethoxy group, methoxyethoxy group, ethoxymethoxy group, ethoxyethoxy group, propoxymethoxy group, isopropoxymethoxy group, butoxymethoxy group, sec-butoxymethoxy group, tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably methoxyethoxy group or ethoxyethoxy group. R a27Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group. R a27 Examples of the alkylcarbonyloxy group 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 a27 is preferably a halogen atom, a hydroxy group, a hydroxy group, a carboxy 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 ethoxy methoxy group, and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group. nA2 is preferably 1, 2, 3, or 4, more preferably 1, 2, or 3, and even more preferably 1 or 2. na21 is preferably 0, 1, 2, or 3, more preferably 0, 1, or 2, and even more preferably 0 or 1. mc is preferably 0 or 1. -X a2 -OH, in the case of a benzene ring, may be bonded to any of the o-position, m-position, or p-position with respect to the bonding position of A a21 . Among them, at least one is preferably bonded to the m-position or p-position, and more preferably bonded to the m-position. In the case of a naphthalene ring, when the bonding position of A a21 is at the 1-position, it may be bonded to any of the 2nd to 8th positions, and when the bonding position of A a21 is at the 2nd position, it may be bonded to any of the 1st and 3rd to 8th positions. Among them, when the bonding position of A a21 is at the 1st position, at least one is preferably bonded to the 3rd to 6th positions, and more preferably bonded to the 3rd or 4th position. When the bonding position of A a21 is at the 2nd position, it is preferably bonded to the 4th to 7th positions, and more preferably bonded to the 5th or 6th position.

[0110] Examples of the structural unit (a2-A) include structural units derived from monomers described in JP-A-2010-204634 and JP-A-2012-12577. Examples of the structural unit (a2-A) include structural units represented by Formula (a2-2-1) to Formula (a2-2-32), Formula (a2-3-1) to Formula (a2-3-24), and structural units in which the methyl group corresponding to R in the structural unit (a2-A) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group. a2 Examples thereof include structural units in which the methyl group corresponding to R in the structural unit (a2-A) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group. TIFF2025100419000091.tif107170

[0111] When the resin (A) contains the structural unit (a2-A), the content of the structural unit (a2-A) is preferably 5 mol% or more, more preferably 10 mol% or more, still more preferably 15 mol% or more, and even more preferably 20 mol% or more, based on all the structural units. Also, it is preferably 80 mol% or less, more preferably 70 mol% or less, still more preferably 65 mol% or less. Specifically, it is preferably 5 to 80 mol%, more preferably 10 to 70 mol%, still more preferably 15 to 65 mol%, and even more preferably 20 to 65 mol%. The structural unit (a2-A) is a compound that induces the structural unit (a2-A) (for example, -CH2-C(-R a2 )- of the structural unit (a2-A) is CH2=C(-R of the double bond before cleavage a2) in the state of a compound (a2-A'), etc.) can be incorporated into the resin (A) by polymerization. Further, for example, after polymerization using the structural unit (a1-4), it can be incorporated into the resin (A) by treatment with an acid such as p-toluenesulfonic acid. Also, after polymerization using acetoxystyrene or the like, the structural unit (a2-A) can be incorporated into the resin (A) by treatment with an alkali such as tetramethylammonium hydroxide.

[0112] In the structural unit (a2), when L a21 is a cyclic hydrocarbon group, examples of the structural unit having an alcoholic hydroxy group include the structural unit represented by the formula (a2-B) (hereinafter sometimes referred to as "structural unit (a2-B)"), the structural unit represented by the formula (a2-C) (hereinafter sometimes referred to as "structural unit (a2-C)"), and the structural unit represented by the formula (a2-D) (hereinafter sometimes referred to as "structural unit (a2-D)"). TIFF2025100419000093.tif45100 [In the formula (a2-B) and the formula (a2-C), R a2 represents the same meaning as in the formula (a2). R a27 represents the same meaning as in the formula (a2-A). L a25 is -O- or *-O-(CH2) k2 -CO-O- represents, and k2 represents an integer of 1 to 7. * represents the bonding position with -CO-. X a2 represents a single bond or -CO-. R a25 and R a26 each independently represents a hydrogen atom, a methyl group, or a hydroxy group. nB2 represents an integer of 1 to 5. When nB2 is 2 or more, a plurality of X a2 may be the same as or different from each other. nB22 represents an integer of 0 to 8. When nB22 is 2 or more, a plurality of R a27 may be the same as or different from each other. nC22 represents any integer from 0 to 10. When nC22 is 2 or more, a plurality of Rs a27 may be the same as or different from each other.] L a25 is preferably -O-, -O-(CH2) f1 -CO-O- (wherein f1 represents any integer from 1 to 4), and more preferably -O-. R a2 is preferably a methyl group. X a2 is preferably a single bond. R a25 is preferably a hydrogen atom. R a26 is preferably a hydrogen atom or a hydroxy group. R a27 is preferably a halogen atom, a hydroxy group, a carboxy group, an optionally halogenated C1-4 alkyl group, a C1-4 alkoxy group or a C2-8 alkoxyalkoxy group, 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 ethoxy methoxy group, and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group or an ethoxyethoxy group. nB2 is preferably 1, 2, 3 or 4, more preferably 1, 2 or 3, and even more preferably 1 or 2. nB22 is preferably any integer from 0 to 3, more preferably 0, 1 or 2, and even more preferably 0 or 1. nC22 is preferably any integer from 0 to 6, more preferably any integer from 0 to 3, and even more preferably 0 or 1.

[0113] Examples of the structural unit (a2-B) and the structural unit (a2-C) include structural units derived from the monomers described in JP-A-2010-204646, the following structural units, and Rs in the following structural units a2Examples of structural units include those in which the methyl group or hydrogen atom corresponding thereto is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group. Among these, structural units represented by any of formula (a2-B-1) to formula (a2-B-5) and formula (a2-C-1) to formula (a2-C-9) are preferred. When the resin (A) contains the structural unit (a2-B) or the formula (a2-C), the content thereof is 1 mol% or more, preferably 2 mol% or more, based on all the structural units of the resin (A). Further, it is 45 mol% or less, preferably 40 mol% or less, more preferably 35 mol% or less, still more preferably 20 mol% or less, and even more preferably 10 mol% or less. Specifically, it is 1 to 45 mol%, preferably 1 to 40 mol%, more preferably 1 to 35 mol%, still more preferably 1 to 20 mol% or 2 to 20 mol%, and even more preferably 1 to 10 mol% or 2 to 10 mol%.

[0114] TIFF2025100419000095.tif51106[In formula (a2-D), R a2 and A a21 each represent the same meaning as in formula (a2). R a27 represents the same meaning as in formula (a2-A). R a21 and R a22 each independently represent a fluoroalkyl group having 1 to 4 carbon atoms. L a24 represents a single bond or an alkanediyl group having 1 to 3 carbon atoms, and the alkanediyl group may be substituted with a fluorine atom. nD2 represents any integer from 1 to 5. When nD2 is 2 or more, the plural parentheses may be the same as or different from each other. nD22 represents any integer from 0 to 4. When nD22 is 2 or more, the plural R a27 may be the same as or different from each other. However, 1 ≦ nD2 + nD22 ≦ 5.] R a21and R a22 Examples of the alkyl fluoride group of a22 include a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a 3,3,3-trifluoropropyl group, a 4,4,4-trifluorobutyl group, etc., each independently. R a21 and R a22 As a22 , a trifluoromethyl group is preferred. L a24 Examples of the alkanediyl group of a24 include a methylene group, an ethane-1,1-diyl group, a propane-1,1-diyl group, a propane-2,2-diyl group, etc. L a24 As a24 , a single bond or a methylene group is preferred. R a27 R is preferably a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 4 carbon atoms which may have a halogen atom, 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 ethoxyethoxy group, and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group or an ethoxyethoxy group. nD2 is preferably 1, 2, 3 or 4, more preferably 1, 2 or 3, even more preferably 1 or 2, and even more preferably 1. Also, preferably, nD2 is 1 and the group in parentheses is bonded to the para position. nD22 is preferably any integer from 0 to 3, more preferably any integer from 0 to 2, even more preferably 0 or 1, and even more preferably 0.

[0115] As the structural unit (a2-D), a structural unit represented by the following formula (a2-D1) (hereinafter, may be referred to as "structural unit (a2-D1)") is more preferred. TIFF2025100419000096.tif51107[In formula (a2-D1), R a2 、A a21 、R a27, na2 and na21 represent the same meaning as formula (a2-D). In formula (a2-D1), R a2 is preferably a hydrogen atom or a methyl group. A a21 is preferably a single bond.

[0116] Examples of the structural unit (a2-D) include the structural units described below. TIFF2025100419000097.tif62167

[0117] In the structural units represented by formula (a2-D-1) to formula (a2-D-8), the hydrogen atom corresponding to R a2 replaced by a methyl group or the like, and in the structural units represented by formula (a2-D-9) to formula (a2-D-16), the methyl group corresponding to R a2 replaced by a hydrogen atom or the like can also be cited as specific examples of the structural unit (a2-D). Among them, the structural units represented by formula (a2-D-1) to formula (a2-D-8) are preferred, the structural units represented by formula (a2-D-1) to formula (a2-D-4) are more preferred, and the structural unit represented by formula (a2-D-1) is even more preferred.

[0118] When the resin (A) contains the structural unit (a2-D), its content is preferably 3 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more based on all the structural units of the resin (A). Also, it is preferably 80 mol% or less, more preferably 75 mol% or less, even more preferably 70 mol% or less, and still more preferably 65 mol% or less. Specifically, it is preferably 3 to 80 mol%, more preferably 5 to 75 mol%, even more preferably 10 to 70 mol%, and still more preferably 10 to 65 mol%.

[0119] 〈Structural unit (a3)〉 The lactone ring possessed by 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 may be a condensed ring of a monocyclic lactone ring and another ring. Preferably, a γ-butyrolactone ring, an adamantanlactone ring, or a bridged ring containing a γ-butyrolactone ring structure (for example, a structural unit represented by the following formula (a3-2)) can be mentioned.

[0120] The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), the formula (a3-3), or the formula (a3-4). These may be contained alone or in combination of two or more. TIFF2025100419000098.tif51164[In the formula (a3-1), the formula (a3-2), the formula (a3-3), and the formula (a3-4), L a4 、L a5 and L a6 each independently represents a group represented by -O- or *-O-(CH2) k3 -CO-O- (where k3 represents an integer from 1 to 7). L a7 represents -O-, *-O-L a8 -O-, *-O-L a8 -CO-O-, *-O-L a8 -CO-O-L a9 -CO-O- or *-O-L a8 -O-CO-L a9 -O-. L a8 and L a9 each independently represents an alkanediyl group having 1 to 6 carbon atoms. * represents the bonding site with the carbonyl group. R a18 、R a19 、R a20 and R a24 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. 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 any integer from 0 to 5. q1 represents any integer from 0 to 3. r1 represents any integer from 0 to 3. w1 represents any integer from 0 to 8. When p1, q1, r1, and / or w1 is 2 or more, a plurality of R a21 、R a22 、R a23 and / or R a25 may be the same as or different from each other.

[0121] R a21 、R a22 、R a23 and R a25 Examples of the aliphatic hydrocarbon group in R a18 、R a19 、R a20 and R a24 include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, and tert-butyl group. a01 Examples of the halogen atom and the alkyl group which may have a halogen atom in L a8 and L a9 include the same ones as those exemplified by R of formula (a1-0) L a4 ~L a6 each independently is preferably -O- or, *-O-(CH2) k3In -CO-O-, a group in which k3 is any integer from 1 to 4, more preferably -O- and, *-O-CH2-CO-O-, even more preferably an oxygen atom. L a7 is preferably -O- or *-O-L a8 -CO-O-, more preferably -O-, -O-CH2-CO-O- or -O-C2H4-CO-O-. R a18 , R a19 , R a20 and R a24 are 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, even more preferably a hydrogen atom or a methyl group. R a21 is preferably a methyl group. R a22 , R a23 and R a25 are each independently preferably a carboxy group, a cyano group or a methyl group. p1, q1 and r1 are each independently preferably any integer from 0 to 2, more preferably 0 or 1. w1 is preferably any integer from 0 to 2, more preferably 0 or 1. In particular, formula (a3-4) is preferably formula (a3-4)’. TIFF2025100419000099.tif4051 (wherein R a24 , L a7 represent the same meaning as above.)

[0122] Examples of the structural unit (a3) include structural units derived from the monomers described in JP-A-2010-204646, JP-A-2000-122294, and JP-A-2012-41274. Examples of the structural unit (a3) include structural units represented by any of formula (a3-1-1), formula (a3-1-2), formula (a3-2-1), formula (a3-2-2), formula (a3-3-1), formula (a3-3-2), and formula (a3-4-1) to formula (a3-4-12), and in the said structural units, R in formula (a3-1) to formula (a3-4) a18 , R a19 , R a20 and R a24 are preferably structural units in which the methyl groups corresponding to are replaced by hydrogen atoms. When the resin (A) contains the structural unit (a3), the total content thereof is 1 mol% or more, preferably 3 mol% or more, more preferably 5 mol% or more, still more preferably 10 mol% or more, based on all the structural units of the resin (A). Also, it is 70 mol% or less, preferably 65 mol% or less, more preferably 60 mol% or less, still more preferably 50 mol% or less, even more preferably 40 mol% or less, still even more preferably 30 mol% or less, still more preferably 25 mol% or less, and still even more preferably 20 mol% or less. Specifically, it is 1 to 70 mol%, preferably 1 to 65 mol%, more preferably 1 to 60 mol%, and still more preferably 3 to 60 mol%. In addition, the content rate 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 mol% or more, more preferably 3 mol% or more, still more preferably 5 mol% or more, and even more preferably 10 mol% or more, respectively, based on all the structural units of the resin (A). Further, it is preferably 60 mol% or less, more preferably 55 mol% or less, still more preferably 50 mol% or less, even more preferably 40 mol% or less, still even more preferably 30 mol% or less, even more preferably 25 mol% or less, and even more preferably 20 mol% or less. Specifically, 1 to 60 mol% is preferable, 3 to 50 mol% is more preferable, and 5 to 50 mol% is still more preferable.

[0123] 〈Structural unit (a4)〉 The structural unit represented by the formula (a4) is shown below. TIFF2025100419000101.tif2770[In the formula (a4), R 41 represents a hydrogen atom or a methyl group. R 42 represents an aliphatic hydrocarbon group having a halogen atom with 1 to 48 carbon atoms, and -CH2- contained in the aliphatic hydrocarbon group may be replaced by -O- or -CO-.

[0124] R 42 The aliphatic hydrocarbon group represented by includes a linear or branched chain hydrocarbon group, a monocyclic or polycyclic alicyclic hydrocarbon group, and a group formed by combining these. Examples of the chain hydrocarbon group include linear alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, heptadecyl group, and octadecyl group, and branched alkyl groups such as isopropyl group and isobutyl group. Examples of the monocyclic or polycyclic alicyclic hydrocarbon group include monocyclic alicyclic hydrocarbon groups that are monocyclic cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; and polycyclic alicyclic hydrocarbon groups that are polycyclic cycloalkyl groups such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* represents a bonding site). Examples of the group formed by the combination of TIFF2025100419000102.tif10146 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, -alkanediyl group-alicyclic hydrocarbon group-alkyl group, and the like. Examples of the alkanediyl group 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, and a hexane-1,6-diyl group; and branched alkanediyl groups such as a propane-1,2-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a 1-methylbutane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. The terminal of the branched alkanediyl group may be a methyl group. R 42 Examples of the halogen atom included in the aliphatic hydrocarbon group contained in 42 include a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. R 42 Examples of the group in which -CH2- of the aliphatic hydrocarbon group contained in 42 is replaced by -O- or -CO- include a hydroxy group, a carboxy group, a carbonyl group, an oxy group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, an alkanediyl-oxy group, an alkanediyl-oxycarbonyl group, an alkanediylcarbonyl group, an alkanediylcarbonyloxy group, a cycloalkoxy group, a cycloalkylalkoxy group, and a group formed by combining two or more of these groups. These replaced groups include those similar to the groups exemplified in this specification as long as the upper limit of the number of carbon atoms permits.

[0125] As the structural unit (a4), R 42 is preferably an aliphatic hydrocarbon group having a fluorine atom, and R 42 Examples of the structural unit (a4) in which is an aliphatic hydrocarbon group having a fluorine atom include a structural unit represented by the formula (a4-1) (hereinafter, may be referred to as "structural unit (a4-1)"), a structural unit represented by the formula (a4-2) (hereinafter, may be referred to as "structural unit (a4-2)"), a structural unit represented by the formula (a4-3) (hereinafter, may be referred to as "structural unit (a4-3)"), and a structural unit represented by the formula (a4-A) (hereinafter, may be referred to as "structural unit (a4-A)"). The structural unit represented by the formula (a4-1) is the structural unit shown below. TIFF2025100419000103.tif3092[In the formula (a4-1), R 41 represents a hydrogen atom or a methyl group. L 41 represents a single bond or an alkanediyl group having 1 to 4 carbon atoms. L 42f represents an alkanediyl group having 1 to 8 carbon atoms having a fluorine atom or a cycloalkanediyl group having 3 to 12 carbon atoms having a fluorine atom. R 42f represents a hydrogen atom or a fluorine atom.]

[0126] L 41 Examples of the alkanediyl group in 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. The terminal of the branched alkanediyl group may be a methyl group. L 42fExamples of the alkanediyl group having a fluorine atom in [compound name] include linear alkanediyl groups having a fluorine atom such as a methylene group having a fluorine atom, an ethylene group having a fluorine atom, a propane-1,3-diyl group having a fluorine atom, a butane-1,4-diyl group having a fluorine atom, a pentane-1,5-diyl group having a fluorine atom, a hexane-1,6-diyl group having a fluorine atom, a heptane-1,7-diyl group having a fluorine atom, and an octane-1,8-diyl group having a fluorine atom; branched alkanediyl groups having a fluorine atom such as an ethane-1,1-diyl group having a fluorine atom, a propane-1,1-diyl group having a fluorine atom, a propane-1,2-diyl group having a fluorine atom, a propane-2,2-diyl group having a fluorine atom, a pentane-2,4-diyl group having a fluorine atom, a 2-methylpropane-1,3-diyl group having a fluorine atom, a 2-methylpropane-1,2-diyl group having a fluorine atom, a pentane-1,4-diyl group having a fluorine atom, and a 2-methylbutane-1,4-diyl group having a fluorine atom. The terminal of the branched alkanediyl group may be a methyl group which may have a fluorine atom. L 42f Examples of the cycloalkanediyl group having a fluorine atom in [compound name] include monocyclic cycloalkanediyl groups having a fluorine atom such as a cyclobutane-1,3-diyl group having a fluorine atom, a cyclopentane-1,3-diyl group having a fluorine atom, a cyclohexane-1,4-diyl group having a fluorine atom, a cyclohexene-3,6-diyl group having a fluorine atom, and a cyclooctane-1,5-diyl group having a fluorine atom, and polycyclic cycloalkanediyl groups having a fluorine atom such as a norbornane-1,4-diyl group having a fluorine atom, a norbornane-2,5-diyl group having a fluorine atom, a 5-norbornene-2,3-diyl group having a fluorine atom, an adamantane-1,5-diyl group having a fluorine atom, and an adamantane-2,6-diyl group having a fluorine atom. L 42f The number of fluorine atoms in the alkanediyl group and cycloalkanediyl group having a fluorine atom in [compound name] may be 1 or more, and is preferably 2 or more. L42f The alkandiyl group and the cycloalkandiyl group having a fluorine atom in are preferably a perfluoroalkandiyl group and a perfluorocycloalkandiyl group, respectively.

[0127] L 42f Examples of the perfluoroalkandiyl group in include a difluoromethylene group, a perfluoroethylene group, a perfluoroethylfluoromethylene 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, a perfluorohexane-1,6-diyl group, a perfluorohexane-2,2-diyl group, a perfluorohexane-3,3-diyl group, a perfluoroheptane-1,7-diyl group, a perfluoroheptane-2,2-diyl group, a perfluoroheptane-3,4-diyl group, a perfluoroheptane-4,4-diyl group, a perfluorooctane-1,8-diyl group, a perfluorooctane-2,2-diyl group, a perfluorooctane-3,3-diyl group, a perfluorooctane-4,4-diyl group, and the like. L 42f Examples of the perfluorocycloalkandiyl group in include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, a perfluoroadamantanediyl group, and the like.

[0128] L 41 is preferably a single bond or an alkandiyl group having 1 to 3 carbon atoms, more preferably a single bond, a methylene group or an ethylene group, and still more preferably a single bond or a methylene group. L 42fis preferably a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms, more preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, and still more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

[0129] Examples of the structural unit (a4-1) include the structural units shown below and the structural units in the structural unit (a4-1) in the following structural units where the methyl group corresponding to R 41 is replaced by a hydrogen atom. The structural unit represented by the formula (a4-2) is the structural unit shown below. TIFF2025100419000105.tif33101 [In the formula (a4-2), R 41 represents a hydrogen atom or a methyl group. L 43f represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a fluorine atom, and -CH2- contained in the aliphatic hydrocarbon group may be replaced by -O- or -CO-. R 43f represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a fluorine atom, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. However, at least one of L 43f and R 43f has a fluorine atom, and the upper limit of the total number of carbon atoms of L 43f and R 43f is 21.

[0130] Examples of the aliphatic hydrocarbon group in L 43f and R 43f include linear or branched chain hydrocarbon groups, monocyclic or polycyclic alicyclic hydrocarbon groups, and groups formed by combining these. Examples of the aliphatic hydrocarbon group in L 43f and R 43f are, as long as the upper limit of the total number of carbon atoms of L 43f and R 43f allows, R in the formula (a4)42 Examples of the aliphatic hydrocarbon group of 42 include the same groups as the exemplified aliphatic hydrocarbon groups.

[0131] L 43f As the aliphatic hydrocarbon group of 43f , an alkanediyl group having 1 to 6 carbon atoms or a group represented by the formula (L43f-1) is preferable. TIFF2025100419000106.tif14120 [In the formula (L43f-1), s represents 0 or 1. L 45f and L 46f each independently represent a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a fluorine atom. L 47f represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a fluorine atom. X 46f and X 47f each independently represent -O-, -CO-, -CO-O- or -O-CO-. However, the total number of carbon atoms of L 45f L 46f L 47f X 46f and X 47f is 7 or less. * and ** are bonding sites, and ** is the bonding site with -O-CO-R 43f .

[0132] Examples of the divalent aliphatic hydrocarbon group represented by L 45f L 46f and L 47f in the group represented by the formula (L43f-1) include linear or branched alkanediyl groups, monocyclic or polycyclic divalent alicyclic hydrocarbon groups, and divalent aliphatic hydrocarbon groups formed by combining an alkanediyl group and a divalent alicyclic hydrocarbon group. Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group and the like can be mentioned. s is preferably 0.

[0133] Examples of the group represented by formula (L43f-1) include the following groups. In the following examples, * and ** each represent a bonding site, and ** is -O-CO-R 43f and is the bonding site with -O-CO-R. TIFF2025100419000107.tif47140

[0134] R 43f is preferably an aliphatic hydrocarbon group having a fluorine atom. In this case, examples of the structural unit represented by formula (a4-2) include the structural units represented by formula (a4-2A) or (formula a4-2B). TIFF2025100419000108.tif41157[In formula (a4-2A) and formula (a4-2B), R 41 and L 43f represent the same as those in formula (a4-2). R 43fA represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms and having a fluorine atom. A 43f represents a divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms that may have a fluorine atom, and -CH2- contained in the aliphatic hydrocarbon group may be replaced by -O- or -CO-. X 43 represents **-O-CO- or **-CO-O-, and ** represents the bonding site with A 43f and represents the bonding site with A. R 43fB represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms that may have a fluorine atom. However, in formula (a4-2A), the total number of carbon atoms of L 43f and R 43fA is 21 or less, and in formula (a4-2B), the total number of carbon atoms of L 43f , A 43f , X 43 and R 43fB is 21 or less, and at least one of A 43f and R 43fB has at least one fluorine atom. R 43fA The aliphatic hydrocarbon group of R, as long as the upper limit of the number of carbon atoms permits, is the same aliphatic hydrocarbon group as the aliphatic hydrocarbon group exemplified by R 42 above. R 43fA is preferably an alkyl group having 1 to 13 carbon atoms and having fluorine atoms, a cycloalkyl group having 3 to 12 carbon atoms and having fluorine atoms, or a group combining them, *-(CF2) n43f -R 42’ (* represents the bonding site with the carbonyl group. n43f represents any integer from 1 to 6. R 42’ represents a hydrogen atom or a fluorine atom.) or a perfluorocycloalkyl group having 3 to 12 carbon atoms is more preferable. A 43f and the aliphatic hydrocarbon group of R, as long as the upper limit of the number of carbon atoms permits, is the same aliphatic hydrocarbon group as the aliphatic hydrocarbon group exemplified by R 43fB in formula (a4). 42 above. A 43f is preferably a divalent chain hydrocarbon group which may have fluorine atoms, a divalent alicyclic hydrocarbon group, or a group combining them, more preferably a divalent chain hydrocarbon group having fluorine atoms, and even more preferably a fluorinated alkanediyl group having 1 to 6 carbon atoms. R 43fBThe aliphatic hydrocarbon group which may have a fluorine atom is preferably a chain hydrocarbon group, an alicyclic hydrocarbon group or a combination thereof which may have a fluorine atom, more preferably an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms or a combination thereof which may have a fluorine atom, and still more preferably 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, a perfluorohexyl group, a heptyl group, a perfluoroheptyl group, an octyl group, a perfluorooctyl group and other alkyl fluoride groups, 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, a perfluoroadamantylmethyl group and the like.

[0135] In formula (a4-2B), *-A f43 -X 43 -R f43B An example of the structure that the group represented by can take is the following structure (* is the bonding site with the carbonyl group). TIFF2025100419000109.tif15170

[0136] Examples of the structural unit represented by formula (a4-2A) include the following structural units and the structural units in which the methyl group corresponding to R in the structural unit represented by formula (a4-2A) below is replaced by a hydrogen atom. 41 are mentioned. TIFF2025100419000110.tif99167

[0137] Examples of the structural unit represented by formula (a4-2B) include the following structural units and structural units in which the methyl group corresponding to R in the following structural units is replaced by a hydrogen atom. 41 Examples include structural units in which the methyl group corresponding to R in the following structural units is replaced by a hydrogen atom. TIFF2025100419000111.tif111163

[0138] Examples of the structural unit (a4) also include the structural unit represented by formula (a4-3). TIFF2025100419000112.tif3689 [In formula (a4-3), R 41 represents a hydrogen atom or a methyl group. L 44f represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a fluorine atom, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. R 44f represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a fluorine atom, and -CH2- contained in the aliphatic hydrocarbon group may be replaced by -O- or -CO-. However, at least one of 44f L 44f and 44f R 44f has a fluorine atom, and the upper limit of the total carbon number of

[0139] L 44f and 44f R 44f and 44f R 44f and 44f R 42 in formula (a4) includes linear or branched chain aliphatic hydrocarbon groups, monocyclic or polycyclic alicyclic hydrocarbon groups, and groups formed by combining these, etc. Examples of the aliphatic hydrocarbon groups in L 44fis preferably an alkanediyl group having 1 to 14 carbon atoms (wherein -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-), and -(CH2) j1 -, -(CH2) j2 -O-(CH2) j3 - or -(CH2) j4 -CO-O-(CH2) j5 - (where j1 to j5 each independently represent an integer of 1 to 6). More preferably, it is an alkanediyl group having 1 to 4 carbon atoms (where one -CH2- contained in the alkanediyl group may be replaced by -O-, and one -CH2-CH2- contained in the alkanediyl group may be replaced by -CO-O- or -O-CO-). R 44f is preferably an aliphatic hydrocarbon group having 1 to 10 carbon atoms having a fluorine atom, more preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom, an alicyclic hydrocarbon group having 3 to 10 carbon atoms having a fluorine atom, or a group combining them, still more preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom, and even more preferably an alkyl group having 1 to 6 carbon atoms having a fluorine atom.

[0140] Examples of the structural unit represented by the formula (a4-3) include structural units represented by the following structural units and the following formulas, in which the methyl group corresponding to R in the structural unit (a4-3) is replaced by a hydrogen atom. 41 TIFF2025100419000113.tif86170

[0141] Examples of the structural unit (a4) also include a structural unit represented by the formula (a4-A). TIFF2025100419000114.tif3686 [In the formula (a4-A), all symbols represent the same meaning as described above.]

[0142] R 1 ​The alkyl group having 1 to 6 carbon atoms in [substance] includes 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, a pentyl group, and a hexyl group. R 1 Examples of the halogen atom in [substance] include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R 1 Examples of the alkyl group having 1 to 6 carbon atoms and having a halogen atom in [substance] 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, a trichloromethyl group, a dichloromethyl group, a triiodomethyl group, a diiodomethyl group, a tribromomethyl group, and a dibromomethyl group. R 1 R is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, still more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group.

[0143] L 1 Examples of the aliphatic hydrocarbon group in [substance] include a chain hydrocarbon group, a monocyclic or polycyclic (including a spiro ring, a condensed ring, a bridged ring, etc.) alicyclic hydrocarbon group, and a group formed by combining two or more of these groups (for example, a hydrocarbon group formed from an alicyclic hydrocarbon group and a chain hydrocarbon group) may also be used. Examples of the chain hydrocarbon group include a divalent to pentavalent chain hydrocarbon group such as an alkanediyl group, an alkanetriyl group, an alkanetetrayl group, and an alkanpentayl group. Examples of the alkanediyl group include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-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, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, and heptadecane-1,17-diyl group, and branched alkanediyl groups such as ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, and 2-methylbutane-1,4-diyl group. Examples also include groups in which one or more hydrogen atoms of the above-described groups are replaced with a bonding site. The number of carbon atoms in the chain hydrocarbon group is preferably 1 to 18, more preferably 1 to 12, still more preferably 1 to 10, even more preferably 1 to 9, still even more preferably 1 to 8, still more preferably 1 to 6, still even more preferably 1 to 5, and particularly preferably 1 to 4.

[0144] Examples of the monocyclic or polycyclic alicyclic hydrocarbon group include the following alicyclic hydrocarbon groups. The bonding site can be at any position. TIFF2025100419000115.tif45164 For example, alicyclic hydrocarbon groups such as cycloalkanediyl groups. Specifically, monocyclic alicyclic hydrocarbon groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, and cyclooctane-1,5-diyl group, and Examples of the polycyclic alicyclic hydrocarbon group include a spiro ring having a cycloalkanediyl group such as a norbornane-1,4-diyl group, a norbornane-2,5-diyl group, an adamantane-1,5-diyl group, an adamantane-2,6-diyl group, a decahydronaphthalenediyl group, a bicyclo[3.3.0]octanediyl group, a spirocyclohexane-1,2'-cyclopentane-diyl group, a spiroadamantane-2,3'-cyclopentane-diyl group, etc., a norbornyl group or an adamantyl group, and a cycloalkanediyl group spiro-bonded thereto respectively. The number of carbon atoms of the alicyclic hydrocarbon group is preferably from 3 to 20, more preferably from 3 to 18, still more preferably from 3 to 16, and even more preferably from 3 to 12.

[0145] Examples of the group formed by combining two or more of them include a group formed by combining an alicyclic hydrocarbon group and a chain hydrocarbon group. In the combination, two or more alicyclic hydrocarbon groups and two or more chain hydrocarbon groups may be combined respectively. Also, any of the groups may be bonded to X 11 . Examples of the group formed by combining an alicyclic hydrocarbon group and a chain hydrocarbon group include a group in which an alicyclic hydrocarbon group is bonded to a chain hydrocarbon group (e.g., *-chain hydrocarbon group-alicyclic hydrocarbon group-), a group in which a chain hydrocarbon group is bonded to an alicyclic hydrocarbon group (e.g., *-alicyclic hydrocarbon group-chain hydrocarbon group-), a group in which an alicyclic hydrocarbon group and a chain hydrocarbon group are bonded to a chain hydrocarbon group (e.g., *-chain hydrocarbon group-alicyclic hydrocarbon group-chain hydrocarbon group-), a group in which a chain hydrocarbon group and an alicyclic hydrocarbon group are bonded to an alicyclic hydrocarbon group (e.g., *-alicyclic hydrocarbon group-chain hydrocarbon group-alicyclic hydrocarbon group-), a group in which an alicyclic hydrocarbon group, a chain hydrocarbon group, and an alicyclic hydrocarbon group are bonded to a chain hydrocarbon group (e.g., *-chain hydrocarbon group-alicyclic hydrocarbon group-chain hydrocarbon group-alicyclic hydrocarbon group-), a group in which a chain hydrocarbon group, an alicyclic hydrocarbon group, and a chain hydrocarbon group are bonded to an alicyclic hydrocarbon group (e.g., *-alicyclic hydrocarbon group-chain hydrocarbon group-alicyclic hydrocarbon group-chain hydrocarbon group-), etc. * represents the bonding site to X 11 .

[0146] L 1 In the aliphatic hydrocarbon group having 1 to 28 carbon atoms in L, -CH2- may be replaced by -O-, -S-, -SO2- or -CO-. L 1 When -CH2- contained in the aliphatic hydrocarbon group having 1 to 28 carbon atoms in L is replaced by -O-, -S-, -SO2- or -CO-, the number of carbon atoms before replacement is defined as the number of carbon atoms of the aliphatic hydrocarbon group. Examples of the group in which -CH2- contained in the aliphatic hydrocarbon group is replaced by -O-, -S-, -SO2- or -CO- include a hydroxy group, a carboxy group, a thiol group, an alkoxy group, an alkylthio group, an alkoxycarbonyl group, an alkylsulfonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, an alkoxycarbonyloxy group, an oxy group, a carbonyl group, a thio group, a sulfonyl group, an alkanedioxy group, an alkanedioxycarbonyl group, an alkanediylcarbonyl group, an alkanediylcarbonyloxy group, an alkanediylsulfonyl group, an alkanediylthio group, a cycloalkoxy group, a cycloalkylalkoxy group, an alkoxycarbonyloxy group, a group formed by combining two or more of these groups, and the like. These replaced groups include those similar to the groups exemplified in this specification within the range where the upper limit of the number of carbon atoms permits. Also included are groups in which one or more hydrogen atoms of the above-described groups are replaced by a bonding site, and the like. Examples of the group in which -CH2- contained in the alicyclic hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2- include those similar to the groups exemplified in this specification within the range where the upper limit of the number of carbon atoms permits.

[0147] L 1 The aliphatic hydrocarbon group in may have one or more substituents. Examples of the substituent include a halogen atom, a haloalkyl group having 1 to 4 carbon atoms, an alkyl 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 (in the alkyl group or the alicyclic hydrocarbon group, -CH2- may be replaced by -O- or -CO-). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. The haloalkyl group having 1 to 4 carbon atoms includes a fluoroalkyl group having 1 to 4 carbon atoms, a chloroalkyl group having 1 to 4 carbon atoms, a bromoalkyl group having 1 to 4 carbon atoms, an iodoalkyl group having 1 to 4 carbon atoms, etc. Examples of the haloalkyl group include a perfluoroalkyl group having 1 to 4 carbon atoms (such as a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, a nonafluorobutyl group, etc.), a 2,2,2-trifluoroethyl group, a 3,3,3-trifluoropropyl group, a 4,4,4-trifluorobutyl group, a 3,3,4,4,4-pentafluorobutyl group, a chloromethyl group, a bromomethyl group, an iodomethyl group, etc. The number of carbon atoms of the haloalkyl group is preferably 1 to 3, more preferably 1 or 2. Examples of the alkyl group having 1 to 12 carbon atoms 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 nonyl group, a decyl group, an undecyl group, a dodecyl group, etc. The number of carbon atoms of the alkyl group is preferably 1 to 9, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. When -CH2- contained in the alkyl group is replaced by -O- or -CO-, the total number of carbon atoms before replacement is defined as the total number of carbon atoms of the alkyl group. Examples of the replaced group include a hydroxy group, a carboxy group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, an alkoxycarbonyloxy group, etc. L 1Examples of the substituent that the aliphatic hydrocarbon group in [compound name] may have include a halogen atom, a haloalkyl group having 1 to 3 carbon atoms, an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms (wherein -CH2- contained in the alkyl group or the alicyclic hydrocarbon group may be replaced by -O- or -CO-). A fluorine atom, an iodine atom, a perfluoroalkyl group having 1 to 3 carbon atoms, or an alkyl group having 1 to 4 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-) is more preferable. A fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, a hydroxy group, or a methoxy group is even more preferable. L 1 is R 3When not forming an alkyl fluoride group and an alicyclic hydrocarbon group, it is preferably a linear hydrocarbon group having 1 to 12 carbon atoms which may have a substituent (wherein -CH2- contained in the linear hydrocarbon group may be replaced by -O- or -CO-), an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (wherein -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O- or -CO-), or a group formed by combining a linear hydrocarbon group having 1 to 6 carbon atoms which may have a substituent and an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (wherein -CH2- contained in the linear hydrocarbon group may be replaced by -O- or -CO-, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O- or -CO-). More preferably, it is a linear hydrocarbon group having 1 to 8 carbon atoms which may have a substituent (wherein -CH2- contained in the linear hydrocarbon group may be replaced by -O- or -CO-), an alicyclic hydrocarbon group having 3 to 12 carbon atoms which may have a substituent, or a group formed by combining a linear hydrocarbon group having 1 to 6 carbon atoms which may have a substituent and an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (wherein -CH2- contained in the linear hydrocarbon group may be replaced by -O- or -CO-). Even more preferably, it is a linear hydrocarbon group having 1 to 8 carbon atoms which may have a substituent (wherein -CH2- contained in the linear hydrocarbon group may be replaced by -O- or -CO-), an alicyclic hydrocarbon group having 5 to 12 carbon atoms which may have a substituent, a group formed by combining a linear hydrocarbon group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 5 to 12 carbon atoms which may have a substituent (wherein -CH2- contained in the linear hydrocarbon group may be replaced by -O- or -CO-), or a group formed by combining an alicyclic hydrocarbon group having 5 to 12 carbon atoms, a linear hydrocarbon group having 1 to 6 carbon atoms, and an alicyclic hydrocarbon group having 5 to 12 carbon atoms which may have a substituent (wherein -CH2- contained in the linear hydrocarbon group may be replaced by -O- or -CO-).

[0148] R 2Examples of the C1-C8 fluoroalkyl group in [reference] include difluoromethyl group, trifluoromethyl group, 1,1-difluoroethyl group, 2,2-difluoroethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1-(trifluoromethyl)-1,2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis(trifluoro)methyl-2,2,2-trifluoroethyl group, 2-(perfluoropropyl)ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5-decafluoropentyl group, 1,1-bis(trifluoromethyl)-2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2-(perfluorobutyl)ethyl group, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluorohexyl group, perfluoropentylmethyl group, perfluorohexyl group, perfluoroheptyl group, and perfluorooctyl group. The carbon number of the fluoroalkyl group is preferably 1-6, more preferably 1-5, still more preferably 1-4, and even more preferably 1-3. R 3 The C1-C6 fluoroalkyl group in [reference] includes, as long as the upper limit of the carbon number allows, the C1-C6 fluoroalkyl groups exemplified in the examples of the fluoroalkyl group of R 2 Similarly included are the C1-C6 fluoroalkyl groups exemplified in the examples of the fluoroalkyl group of R R 2 is preferably a C1-C6 fluoroalkyl group, more preferably a C1-C3 fluoroalkyl group, still more preferably a trifluoromethyl group, a perfluoroethyl group or a perfluoropropyl group, and even more preferably a trifluoromethyl group when R 3 is a C1-C6 fluoroalkyl group. R2 When R 3 is a hydrogen atom, it is preferably an alkyl fluoride group having 1 to 6 carbon atoms, more preferably an alkyl fluoride group having 1 to 5 carbon atoms, and still more preferably an alkyl fluoride group having 3 to 5 carbon atoms. R 3 is L 1 and combines to form an alicyclic hydrocarbon group having 3 to 6 carbon atoms, R 3 is L 1 Examples of the group formed by the combination with L 2 include, for example, groups represented by the following formulas. Among the following formulas, * and ** represent bonding sites, and the two ** represent, one represents the bonding site with a hydroxy group, and the other represents the bonding site with R 1A is L 1 is a part of the hydrocarbon group of L TIFF2025100419000116.tif22138R 3 is preferably a hydrogen atom or an alkyl fluoride group having 1 to 3 carbon atoms. mi is preferably any integer from 1 to 3, more preferably 1 or 2, and still more preferably 1.

[0149] Examples of the structural unit (a4-A) include the following structural units and the like. In the following structural units, structural units in which the methyl group corresponding to R 1 is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or an alkyl group other than a methyl group, and structural units in which the hydrogen atom corresponding to R 1 is replaced with a halogen atom, a haloalkyl group or an alkyl group can also be cited as specific examples of the structural unit (a4-A). TIFF2025100419000117.tif192167

[0150] When the resin (A) etc. has the structural unit (a4), its content is preferably 1 to 97 mol%, more preferably 2 to 95 mol%, and still more preferably 3 to 90 mol% with respect to all the structural units of the resin (A) etc.

[0151] <Structural unit (a5)> Examples of the non-detachable hydrocarbon group possessed by the structural unit (a5) include groups having a linear, branched or cyclic hydrocarbon group. Among them, the structural unit (a5) preferably has a group having an alicyclic hydrocarbon group. Examples of the structural unit (a5) include a structural unit represented by the formula (a5-1). TIFF2025100419000118.tif3971[In the 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 the hydrogen atoms contained in the alicyclic hydrocarbon group may be substituted with aliphatic hydrocarbon groups 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 by -O- or -CO-.]

[0152] R 52 The alicyclic hydrocarbon group in R may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group and a norbornyl group. Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms include 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, an octyl group, and a 2-ethylhexyl group. Examples of the alicyclic hydrocarbon group having a substituent include a 3-methyladamantyl group. R 52 is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, more preferably an adamantyl group, a norbornyl group or a cyclohexyl group. L 55Examples of the divalent saturated hydrocarbon group include a divalent chain saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, preferably a divalent chain saturated hydrocarbon group. Examples of the divalent chain saturated hydrocarbon group include alkane diyl groups such as a methylene group, an ethylene group, a propane diyl group, a butane diyl group, and a pentane diyl group. The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkane diyl groups such as a cyclopentane diyl group and a cyclohexane diyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantane diyl group and a norbornane diyl group.

[0153] L 55 Examples of the group in which -CH2- contained in the divalent saturated hydrocarbon group represented by L is replaced by -O- or -CO- include the groups represented by formula (L1-1) to formula (L1-4). In the following formulas, * and ** each represent a bonding site, and * represents a bonding site with an oxygen atom. TIFF2025100419000119.tif18165[In formula (L1-1), X x1 represents *-O-CO- or *-CO-O- (* represents a bonding site with L x1 .). 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, the total number of carbon atoms of L x1 and L x2 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, the total number of carbon atoms of L x3 and L x4 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 represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms. However, the total number of carbon atoms of L x5 , L x6 and L x7 is 15 or less. In formula (L1-4), L x8 and L x9 each represent 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, the total number of carbon atoms of L x8 , L x9 and W x1 is 15 or less.]

[0154] 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 x6 is 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.

[0155] Examples of the group represented by the formula (L1-1) include the following divalent groups. TIFF2025100419000120.tif36147 Examples of the group represented by the formula (L1-2) include the following divalent groups. TIFF2025100419000121.tif23130 Examples of the group represented by the formula (L1-3) include the following divalent groups. TIFF2025100419000122.tif16147 Examples of the group represented by the formula (L1-4) include the following divalent groups. TIFF2025100419000123.tif13168L 55 is preferably a single bond or a group represented by the formula (L1-1).

[0156] Examples of the structural unit (a5-1) include the following structural units and the structural units in the following structural units where the methyl group corresponding to R in the structural unit (a5-1) is replaced by a hydrogen atom. 51 are mentioned. TIFF2025100419000124.tif104151 When the resin (A) contains the structural unit (a5), its content is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, and still more preferably 3 to 15 mol% based on all the structural units of the resin (A).

[0157] 〈Structural unit (a6)〉 The structural unit (a6) is a structural unit having a -SO2- group, and preferably has a -SO2- group in the side chain. The structural unit having a -SO2- group may have a linear structure having a -SO2- group, a branched structure having a -SO2- group, or a cyclic structure (monocyclic and polycyclic structures) having a -SO2- group. Preferably, it is a structural unit having a cyclic structure having a -SO2- group, and more preferably, it is a structural unit having a cyclic structure (sultone ring) containing -SO2-O-.

[0158] Examples of the sultone ring include the following formula (T 1 -1), formula (T 1 -2), formula (T 1 -3) and formula (T 1 -4). The bonding site can be at any position. The sultone ring may be monocyclic, but is preferably polycyclic. The polycyclic sultone ring means a bridged ring containing -SO2-O- as an atomic group constituting the ring, and examples include the rings represented by formula (T 1 -1) and formula (T 1 -2). The sultone ring may further contain a heteroatom in addition to -SO2-O- as an atomic group constituting the ring, like the ring represented by formula (T 1 -2). Examples of the heteroatom include an oxygen atom, a sulfur atom or a nitrogen atom, and preferably an oxygen atom. TIFF2025100419000125.tif2977

[0159] The sultone ring may have a substituent, and examples of the substituent include a halogen atom or an alkyl group having 1 to 12 carbon atoms which may have 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, etc.

[0160] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. 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, 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 hydroxyalkyl group such as 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. Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, and a naphthylethyl group. Examples of the alkoxycarbonyl group include a group in which an alkoxy group such as a methoxycarbonyl group and an ethoxycarbonyl group is bonded to a carbonyl group, preferably an alkoxycarbonyl group having 6 or less carbon atoms, and more preferably a methoxycarbonyl group. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. From the viewpoint that the production of the monomer leading to the structural unit (a6) is easy, a sultone ring having no substituent is preferred.

[0161] As the sultone ring, a ring represented by the following formula (T1') is preferred. TIFF2025100419000126.tif2666[In the 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 any integer from 0 to 9. When ma is 2 or more, a plurality of R 41 may be the same or different. The bonding site is at an arbitrary position.] X 11 is preferably an oxygen atom or a methylene group, more preferably a methylene group. R 41 is the same as those of the substituents of 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. ma is preferably 0 or 1, more preferably 0.

[0162] Examples of the ring represented by the formula (T1') include the following rings. The bonding site is at an arbitrary position. Among them, those in which the bonding site is at the 1-position or the 3-position are preferred. TIFF2025100419000127.tif44147

[0163] The structural unit having a -SO2- group preferably further has a group derived from a polymerizable group. Examples of the polymerizable group include a vinyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an acryloylamino group, a methacryloylamino group, an acryloylthio group, a methacryloylthio group and the like. Among them, the monomer leading to the structural unit (a6) is preferably a monomer having an ethylenically unsaturated bond, more preferably a (meth)acrylic monomer.

[0164] The structural unit (a6) is preferably a structural unit represented by the formula (a6-0). TIFF2025100419000128.tif4077[In the formula (a6-0), R x represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom. A xx represents an oxygen atom, -N(R c )- or a sulfur atom. A x 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 by -O-, -CO- or -N(R d ). X 11 represents an oxygen atom, a sulfur atom or a methylene group. R 41 has the same meaning as described above. ma represents any integer from 0 to 9. When ma is 2 or more, a plurality of R 41 may be the same or different. R c and R d each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.]

[0165] Examples of the halogen atom of R x include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Examples of the alkyl group of R x include, for example, 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, etc., preferably an alkyl group having 1 to 4 carbon atoms, 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 still more preferably a hydrogen atom or a methyl group. A x Examples of the divalent saturated hydrocarbon group of A include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and a combination of two or more of these groups may also be used. Specifically, linear alkanediyl groups such as 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 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, 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 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; monocyclic divalent alicyclic saturated hydrocarbon groups which are cycloalkanediyl groups such as a cyclobutane-1,3-diyl group, a cyclopentane-1,3-diyl group, a cyclohexane-1,4-diyl group, and a cyclooctane-1,5-diyl group; Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include a norbornane-1,4-diyl group, a norbornane-2,5-diyl group, an adamantane-1,5-diyl group, an adamantane-2,6-diyl group, and the like. A x The bonding position to the sultone ring of x can be any position, but the position at the 1-position is preferred.

[0166] Examples of the structural unit (a6-0) include the following structural units. TIFF2025100419000129.tif93150

[0167] Among them, the 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 the structural units represented by formula (a6-1), formula (a6-2), formula (a6-7) and (a6-8) are more preferred. When the resin (A) has the structural unit (a6), its content is preferably 1 to 50 mol%, more preferably 2 to 40 mol%, and still more preferably 3 to 30 mol% based on all the structural units of the resin (A).

[0168] <Structural unit (a7)> The resin (A) etc. may further contain a structural unit that decomposes upon exposure to generate an acid (hereinafter sometimes referred to as "structural unit (a7)"). Specific examples of the structural unit (a7) include the structural units described in JP-A-2016-79235, and it is preferably a structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain or a structural unit having a sulfonio group and an organic anion in the side chain.

[0169] The structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain is preferably a structural unit represented by formula (a7-A). TIFF2025100419000130.tif26123[In formula (a7-A), R a7represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. X a71 represents a single bond, *-O-, *-CO-O-, *-O-CO-O-**, *-CO-NR a71 -**, *-NR a71 -CO-O-**, *-O-CO-NR a71 -** or *-Ax-Ph-Ay-**. R a71 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Ph represents a phenylene group which may have a substituent. Ax and Ay each independently represent one type of bond species selected from the group consisting of a single bond, an ether bond, a thioether bond, an ester bond, an amide bond, and a carbonate ester bond. * and ** represent bonding sites, and * represents the bonding site with the carbon atom to which R a7 is bonded. L a71 and L a72 each independently represent a hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO-, or -SO2-. X a72 represents ***-CO-O-, ***-O-CO-, ***-O-CO-O-, ***-O-, and *** represents the bonding site with L a71 . RA - represents a sulfonate anion or a carboxylate anion. ZA + represents an organic cation.

[0170] R a7 Examples of the alkyl group having 1 to 6 carbon atoms in R 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, a pentyl group, and a hexyl group. R a7 Examples of the halogen atom in R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Ra7 Examples of the alkyl group having 1 to 6 carbon atoms and a halogen atom include trifluoromethyl group, difluoromethyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, perfluorohexyl group, trichloromethyl group, dichloromethyl group, triiodomethyl group, diiodomethyl group, tribromomethyl group, dibromomethyl group, and the like. R a7 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, still more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group.

[0171] X a71 When it is a group represented by *-Ax-Ph-Ay-**, it is preferably a linking group represented by the following formula (X10). TIFF2025100419000131.tif3351[In the formula (X10), Ax represents the bonding type that binds to the carbon atom to which R a7 is bonded, and represents one or more bonding types selected from the group consisting of a single bond, an ether bond, a thioether bond, an ester bond, a carbonate ester bond, and an amide bond. Ay represents the bonding type that binds to L a71 and represents one or more bonding types selected from the group consisting of a single bond, an ether bond, a thioether bond, an ester bond, a carbonate ester bond, and an amide bond. Rx represents a halogen atom, a hydroxy group, a fluorinated alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. mx represents any integer from 0 to 4. When mx is an integer of 2 or more, the plurality of Rx may be the same as or different from each other. When either Ax or Ay is a single bond, the other is preferably at least one selected from the group consisting of an ether bond, a thioether bond, an ester bond, a carbonate ester bond, and an amide bond. When either Ax or Ay is an amide bond, the bond represented by -CO-NR a71 - is preferred. The bonding position of Ay in the phenylene group is preferably the m-position or the p-position with respect to the bonding position of Ax, and more preferably the p-position. Among others, Rx is preferably a fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, or an ethyl group. mx is preferably 0, 1, or 2. X a71 As, for example, a single bond, the following formula (X 10 -1) to formula (X 10 -10) represent groups. * represents the bonding site with the carbon atom to which -R a7 is bonded. ** represents the bonding site with L a71 . X 20 represents -O- or -NR a71 -. TIFF2025100419000132.tif43163 Formula (X 10 -1) to formula (X 10 -10) specific examples of the groups represented by are as follows. TIFF2025100419000133.tif78162 Among others, X 10 is preferably a single bond or a group represented by formula (X 10 -1’) and formula (X 10 -3’) to formula (X 10 -10’), more preferably a single bond or a group represented by formula (X 10 -1’), formula (X 10 -4’), formula (X 10 -5’), formula (X 10 -6’) and formula (X 10 -10’), still more preferably a single bond, a group represented by formula (X 10 -1’), a group represented by formula (X 10 -5’) or formula (X10 It is more preferable that it is a group represented by -6’).

[0172] L a71 As the hydrocarbon group of L, one hydrogen atom is removed from a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a group combining two or more of these groups, and X a71 and X a72 and the group bonded to X a72 As the hydrocarbon group of L, one hydrogen atom is removed from a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a group combining two or more of these groups, and X a72 and RA - and the group bonded to RA L a71 and L a72 Examples of the chain hydrocarbon group of L and L include a group obtained by removing one hydrogen atom from an alkyl group or an alkenyl group. The alkyl group may be linear or branched, and specifically includes a methane group, an ethane group, a propane group, an iso-propyl group, an n-butyl group, a sec-butyl group, an iso-butyl group, a tert-butyl group, a heptyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decane group, an undecane group, a dodecane group, a tridecane group, a tetradecane group, a pentadecane group, a heptadecane group, etc. Examples of the alkenyl group include an ethenyl group, a propenyl group, an isopropenyl group, a butenyl group, an isobutenyl group, a tert-butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an octenyl group, an isooctenyl group, a nonenyl group. The number of carbon atoms of the chain hydrocarbon group is preferably 1 to 36, more preferably 1 to 20, and even more preferably 1 to 10. L a71 and L a72 Examples of the alicyclic hydrocarbon group of L and L include a group obtained by removing one hydrogen atom from a monocyclic or polycyclic cycloalkyl group. Examples of the monocyclic cycloalkyl group include a cyclobutyl group, a cyclopentane group, a cyclohexane group, a cyclopentyl group, a cyclooctyl group, etc. L a71 and L a72Examples of the polycyclic cycloalkyl group include a cycloalkyl group having a crosslinked structure, a cycloalkyl group in which two or more rings are condensed, or a cycloalkyl group in which two rings are spiro-bonded. Examples of the cycloalkyl group having a crosslinked structure include a norbornane group and an adamantane group. Examples of the cycloalkyl group in which two or more rings are condensed include a bicyclo[4.4.0]decane group and a steroid group (steroid skeleton). Examples of the ring in which two rings are spiro-bonded include a spirocyclic cycloalkyl group in which one cycloalkyl group selected from the group consisting of a cyclopentyl group, a cyclohexyl group, a norbornane group, and an adamantyl group is spiro-bonded to a cycloalkyl group having 5 to 8 carbon atoms. Also, a double bond may be formed between two carbon atoms included in the alicyclic hydrocarbon group. More specifically, examples of the alicyclic hydrocarbon group represented by the following formula can be given. TIFF2025100419000134.tif28158 When the alicyclic hydrocarbon group is a monocyclic cycloalkyl group, the number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 12, more preferably 3 to 8. When the alicyclic hydrocarbon group is a polycyclic cycloalkyl group, the number of carbon atoms of the alicyclic hydrocarbon group is preferably 7 to 12. L a71 and L a72 Examples of the aromatic hydrocarbon group of L and L include an aryl group from which one hydrogen atom has been removed. Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a fluorene group. The number of carbon atoms of the aromatic hydrocarbon group is preferably 5 to 14, more preferably 5 to 10. L a71 and L a72 When -CH2- contained in the hydrocarbon group of L and L is replaced by -O-, -CO-, -S- or -SO2-, the number of carbon atoms before replacement is defined as the number of carbon atoms of the hydrocarbon group. L a71 and L a72Among the hydrocarbon groups, examples of the group in which -CH2- contained in the chain hydrocarbon group is replaced by -O-, -CO-, -S- or -SO2- include a hydroxy group, a carboxy group, a thiol group, a carbonyl group, an oxy group, a thio group, a sulfonyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, an alkanedioxy group, an alkanedioxycarbonyl group, an alkanediylcarbonyl group, an alkanediylcarbonyloxy group and the like. These replaced groups include the same groups as those exemplified in the present specification within the range where the upper limit of the number of carbon atoms permits. L a71 and L a72 Among the hydrocarbon groups, examples of the group in which -CH2- contained in the alicyclic hydrocarbon group and the group combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group is replaced by -O-, -CO-, -S- or -SO2- include the same groups as those exemplified in the present specification within the range where the upper limit of the number of carbon atoms permits. L a71 and L a72 Among the hydrocarbon groups, -CH2- contained in the aromatic hydrocarbon group may be replaced by -O- or -S-. Examples of the group in which -CH2- is replaced by -O- or -S- include a furan ring and a thiophene ring, respectively. L a71 and L a72 Examples of the group combining two or more of the chain hydrocarbon group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group include the group combining the above chain hydrocarbon group and the above alicyclic hydrocarbon group, the group combining the above chain hydrocarbon group and the above aromatic hydrocarbon group, the group combining the above alicyclic hydrocarbon group and the above aromatic hydrocarbon group, and the group combining the above chain hydrocarbon group, the above alicyclic hydrocarbon group and the above aromatic hydrocarbon group. The above combined groups are included. The group combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group may be a condensed ring. L a71 and L a72 Examples of the substituent that the hydrocarbon group may have include a halogen atom, a cyano group and a nitro group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like. L a71 and L a72 When the group is a group in which an alicyclic hydrocarbon group or an aromatic hydrocarbon group is combined with a chain hydrocarbon group, the chain hydrocarbon group may be substantially regarded as a substituent possessed by the alicyclic hydrocarbon group or the aromatic hydrocarbon group. Also, L b1‘ and L b2‘ When the -CH2- of the chain hydrocarbon group contained in the hydrocarbon group of is replaced by -O-, -CO-, -S- or -SO2-, L b1‘ and L b2‘ The hydrocarbon group of may substantially have substituents such as a hydroxy group, a carboxyl group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, a thiol group, a sulfonyl group and the like.

[0173] ZA in formula (a7-A) + is the same as the cation Z1 in the salt represented by formula (B1) described later + and the like can be mentioned. Examples of the structural unit represented by formula (a7-A) include, for example, the following structural units, R a7 Structural units in which a group corresponding to the methyl group of is replaced by a hydrogen atom, a halogen atom (for example, a fluorine atom) or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (for example, a trifluoromethyl group, etc.) and the structural units described in International Publication No. 2012 / 050015. ZA + represents an organic cation. TIFF2025100419000135.tif244163

[0174] TIFF2025100419000136.tif131157

[0175] The structural unit having a sulfonio group and an organic anion in the side chain is preferably a structural unit represented by formula (a7-B). TIFF2025100419000137.tif27105[In formula (a7-B), R a7represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. 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 which may have a substituent. R II2 and R II3 each independently represent a hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, and R II2 and R II3 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. A - represents an organic anion. R a7 Examples of the halogen atom and the alkyl group which may have a halogen atom of R include the same halogen atom and the alkyl group which may have a halogen atom as those in formula (a7-A). R II1 Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by include a phenylene group and a naphthylene group. R II2 and R II3 Examples of the hydrocarbon group represented by include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these. Examples of the alkyl group, the alicyclic hydrocarbon group, the aromatic hydrocarbon group, and the group formed by combining these are the same as those described above. A II1 Examples of the divalent linking group represented by 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-. Examples of the divalent saturated hydrocarbon group include a linear or branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and combinations thereof. Specifically, linear alkanediyl groups such as 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, dodecane-1,12-diyl group; branched alkanediyl groups such as butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group; cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group; divalent polycyclic alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. can be mentioned. Examples of those in which -CH2- contained in the saturated hydrocarbon group is replaced by -O-, -S- or -CO- include divalent groups represented by formula (X1) to formula (X53). However, the number of carbon atoms before -CH2- contained in the saturated hydrocarbon group is replaced by -O-, -S- or -CO- is 17 or less respectively. In the following formula, * and ** represent bonding sites, and * represents the bonding site with R II2 and represents the bonding site with R. JPEG2025100419000138.jpg123161[wherein, 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.]

[0176] Examples of the structural unit containing the cation in formula (a7-B) include the structural unit represented below and a group corresponding to the methyl group of R a7 wherein the group corresponding to the methyl group of R is replaced with a hydrogen atom, a halogen atom (e.g., fluorine atom), or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (e.g., trifluoromethyl group), etc. JPEG2025100419000139.jpg72163

[0177] A - Examples of the organic anion represented by A include sulfonate anion, sulfonylimide anion, and sulfonylmethide anion. A - The organic anion represented by A is preferably a sulfonate anion, more preferably an anion contained in the salt represented by the above formula (B1). Examples of the sulfonylimide anion, sulfonylmethide anion, and carboxylate anion are the same as those exemplified as the anion of compound (B).

[0178] Examples of the structural unit represented by formula (a7-B) include the structural unit represented below. TIFF2025100419000140.tif96157

[0179] When the resin (A) contains the structural unit (a7), the structural unit (a7) may be contained alone or in combination of two or more. The content rate of the total structural unit (a7) is preferably 1 to 30 mol% with respect to all the structural units of the resin (A), more preferably 2 to 25 mol%, and still more preferably 3 to 20 mol%.

[0180] The resin (A) is preferably a resin composed of the structural unit (a1) and the structural unit (s). The structural unit (a1) is preferably at least one selected from the group consisting of the structural unit represented by the formula (a1-0), the structural unit represented by the formula (a1-1), the structural unit represented by the formula (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group), the structural unit represented by the formula (a1-4), the structural unit represented by the formula (a1-5), and the structural unit represented by the formula (a1-6). More preferably, it is at least one selected from the group consisting of the structural unit (a1-0), the structural unit (a1-1), and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group), still more preferably at least two kinds, and still more preferably, the structural unit (a1-1) and / or the structural unit (a1-2). 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 represented by the formula (a2-A) or the structural unit represented by the formula (a2-1). The structural unit (a3) is preferably at least one selected from the group consisting of the structural unit represented by the formula (a3-1), the structural unit represented by the formula (a3-2), and the structural unit represented by the formula (a3-4).

[0181] Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and can be produced by a known polymerization method (for example, radical polymerization method) using the monomers that lead to these structural units. The content of each structural unit of the resin (A) can be adjusted by the amount of the monomers 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, still more preferably 3,000 or more), and 50,000 or less (more preferably 30,000 or less, still more preferably 15,000 or less). In this specification, the weight average molecular weight is the value determined by gel permeation chromatography under the conditions described in the examples.

[0182] <Resins other than resin (A)> The resist composition of the present invention may be used in combination with a resin other than the resin (A). Examples of the resin other than the resin (A) include, for example, a resin containing the structural unit (a4) or the structural unit (a5) (hereinafter sometimes referred to as resin (X)). Among them, examples of the resin (X) include a resin composed only of the structural unit (a4) and a resin composed of the structural unit (a4) and the structural unit (a5) (hereinafter, the resin composed only of the structural unit (a4) and the resin composed of the structural unit (a4) and the structural unit (a5) may be collectively referred to as resin (X)). Examples of the structural unit that the resin (X) may further have include the structural unit (a2), the structural unit (a3), and a structural unit derived from other known monomers. When the resin (X) contains the structural unit (a4), in the resin (X), the content of the structural unit (a4) is 20 mol% or more, preferably 30 mol% or more, more preferably 40 mol% or more, and still more preferably 45 mol% or more, based on the total of all the structural units of the resin (X). Also, it is 100 mol% or less, preferably 80 mol% or less, more preferably 70 mol% or less, still more preferably 60 mol% or less, and even more preferably 55 mol% or less. Specifically, it is 20 to 100 mol%, preferably 20 to 80 mol%, more preferably 30 to 70 mol%, still more preferably 40 to 60 mol%, and even more preferably 45 to 55 mol%. When the resin (X) contains the structural unit (a5), the content of the structural unit (a5) is 20 mol% or more, preferably 30 mol% or more, more preferably 40 mol% or more, and still more preferably 45 mol% or more, based on the total of all the structural units of the resin (X). Also, it is 100 mol% or less, preferably 80 mol% or less, more preferably 70 mol% or less, still more preferably 60 mol% or less, and even more preferably 55 mol% or less. Specifically, it is 20 to 100 mol%, preferably 20 to 80 mol%, more preferably 30 to 70 mol%, still more preferably 40 to 60 mol%, and even more preferably 45 to 55 mol%. Further, when the resin (X) contains the structural unit (a4) and the structural unit (a5), the total content of the structural unit (a4) and the structural unit (a5) is 40 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more, and still more preferably 80 mol% or more, based on the total of all the structural units of the resin (X). Also, it is 100 mol% or less. Specifically, it is 40 to 100 mol%, preferably 60 to 100 mol%, more preferably 70 to 100 mol%, and still more preferably 80 to 100 mol%. Among them, the resin (X) is preferably a resin composed only of the structural unit (a4) and / or the structural unit (a5). In this case, the ratio of the structural unit (a4): the structural unit (a5) is 0:100 to 100:0, preferably 10:90 to 90:10, and more preferably 30:70 to 70:30 or 40:60 to 60:40. Each structural unit constituting the resin (X) may be used alone or in combination of two or more, and can be produced by a known polymerization method (for example, radical polymerization method) using the monomers that induce these structural units. The content of each structural unit of the resin (X) can be adjusted by the amount of monomers used in the polymerization. The weight average molecular weight of the resin (X) is preferably 6,000 or more (more preferably 7,000 or more) and 80,000 or less (more preferably 60,000 or less), but may contain oligomers having a weight average molecular weight smaller than this. The measuring means for the weight average molecular weight of the resin (X) is the same as that of the resin (A).

[0183] When the resist composition of the present invention contains the resin (X), its content is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, still more preferably 1 to 40 parts by mass, even more preferably 1 to 30 parts by mass, and particularly preferably 1 to 8 parts by mass with respect to 100 parts by mass of the resin (A).

[0184] The content of the resin (A) in the resist composition is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 99% by mass or less with respect to the solid content of the resist composition. When containing a resin other than the resin (A), the total content of the resin (A) and the resin other than the resin (A) is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 99% by mass or less with respect to the solid content of the resist composition. The solid content of the resist composition and the content of the resin with respect thereto can be measured by known analytical means such as liquid chromatography or gas chromatography.

[0185] <Solvent (E)> The content of the solvent (E) in the resist composition is usually 90% by mass or more and 99.9% by mass or less, preferably 92% by mass or more and 99% by mass or less, more preferably 94% by mass or more and 99% by mass or less. 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 type of the solvent (E) may be used alone, or two or more types may be used.

[0186] <Quencher (C)> Examples of the quencher (C) include basic nitrogen-containing organic compounds and salts that generate an acid having a lower acidity than the acid generated from the acid generator (salt (I-A2) or compound (B)). When the resist composition contains the quencher (C), 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 8% by mass, and even more preferably about 0.1 to 7% by mass based on the solid content of the resist composition. Examples of the basic nitrogen-containing organic compound include amines and ammonium salts. Examples of the amines include aliphatic amines and aromatic amines. Examples of the aliphatic amines include primary amines, secondary amines, and tertiary amines.

[0187] Examples of the amine 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, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, 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, 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'-dipyridylsulfide, 4,4'-dipyridyldisulfide, 2,2'-dipyridylamine, 2,2'-dipicolylamine, bipyridine and the like. Preferably, diisopropylaniline is mentioned, and more preferably 2,6-diisopropylaniline is mentioned.

[0188] Examples of the ammonium salt include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3-(trifluoromethyl)phenyltrimethylammonium hydroxide, tetra-n-butylammonium salicylate, choline, and the like.

[0189] The acidity of a salt that generates an acid with a lower acidity than the acid generated from the acid generator is indicated by the acid dissociation constant (pKa). A salt that generates an acid with a lower acidity than the acid generated from the acid generator is a salt having an acid dissociation constant of the acid generated from the salt usually of -3 < pKa, preferably -1 < pKa < 7, and more preferably 0 < pKa < 5. Examples of the salt that generates an acid with a lower acidity than the acid generated from the acid generator include salts represented by the following formula, salts represented by formula (D) described in JP-A-2015-147926 (hereinafter sometimes referred to as "weak acid inner salt (D)"), and salts described in JP-A-2012-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-39502, and JP-A-2011-191745. The salt that generates an acid with a lower acidity than the acid generated from the acid generator is preferably a salt that generates a carboxylic acid with a lower acidity than the acid generated from the acid generator (a salt having a carboxylic acid anion), more preferably a weak acid inner salt (D), and even more preferably a diphenyliodonium salt containing a phenyl group substituted with a carboxylic acid anion among the weak acid inner salts (D). JPEG2025100419000141.jpg99157

[0190] The weak acid inner salt (D) is preferably a diphenyliodonium salt having an iodonium cation to which two phenyl groups are bonded and a carboxylic acid anion substituted for at least one of the two phenyl groups bonded to the iodonium cation, and specifically includes salts represented by the following formula.

[0191] TIFF2025100419000142.tif1775 [In formula (D), R D1 and R D2 each independently represents a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, an acyloxy group having 2 to 7 carbon atoms, an alkoxycarbonyl group having 2 to 7 carbon atoms, a nitro group or a halogen atom. m' and n' each independently represent any integer from 0 to 4. When m' is 2 or more, a plurality of R D1 may be the same or different, and when n' is 2 or more, a plurality of R D2 may be the same or different.] R D1 and R D2 Examples of the hydrocarbon group include a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these. Examples of the chain hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, nonyl group, etc. The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and may be either saturated or unsaturated. Examples include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclononyl group, cyclododecyl group, etc., norbornyl group, adamantyl group, etc. Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, 1-naphthyl group, 2-naphthyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-propylphenyl group, 4-isopropylphenyl group, 4-butylphenyl group, 4-t-butylphenyl group, 4-hexylphenyl group, 4-cyclohexylphenyl group, anthryl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl, etc. Groups formed by combining these include alkyl-cycloalkyl groups, cycloalkyl-alkyl groups, aralkyl groups (e.g., phenylmethyl group, 1-phenylethyl group, 2-phenylethyl group, 1-phenyl-1-propyl group, 1-phenyl-2-propyl group, 2-phenyl-2-propyl group, 3-phenyl-1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, 6-phenyl-1-hexyl group, etc.), and the like. Examples of the alkoxy group include a methoxy group, an ethoxy group, and the like. Examples of the acyl group include an acetyl group, a propanoyl group, a benzoyl group, a cyclohexanecarbonyl group, and the like. Examples of the acyloxy group include groups in which an oxy group (-O-) is bonded to the above acyl group, and the like. Examples of the alkoxycarbonyl group include groups in which a carbonyl group (-CO-) is bonded to the above alkoxy group, and the like. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and the like. R D1 and R D2 are each independently preferably an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a nitro group, or a halogen atom. m' and n' are each independently preferably any integer from 0 to 2, more preferably 0. When m' is 2 or more, the plurality of R D1 may be the same or different, and when n' is 2 or more, the plurality of R D2 may be the same or different.

[0192] More specifically, the following salts are included. TIFF2025100419000143.tif72165

[0193] 〈Other components〉 The resist composition of the present invention may contain, if necessary, components other than the above-described components (hereinafter sometimes 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, dyes, etc. can be used.

[0194] 〈Preparation of Resist Composition〉 The resist composition of the present invention can be prepared by mixing salt (I-A2), and, if necessary, compound (B), resin (A), resins other than resin (A), solvent (E), quencher (C) and other components (F). The mixing order is arbitrary and is not particularly limited. The temperature during mixing can be appropriately selected from 10 to 40°C according to the type of resin, etc. and the solubility of the resin, etc. in the solvent (E). The mixing time can be appropriately selected from 0.5 to 24 hours according to the mixing temperature. Note that the mixing means is also not particularly limited, and stirring and mixing, etc. can be used. After mixing the respective components, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

[0195] 〈Method for Manufacturing Resist Pattern〉 The method for manufacturing a resist pattern of the present invention (1) A step of applying the resist composition of the present invention onto a substrate, (2) A step of drying the applied composition to form a composition layer, (3) A step of exposing the composition layer, (4) A step of heating the exposed composition layer, and (5) A step of developing the heated composition layer. To apply the resist composition onto a substrate, it can be performed by a commonly used apparatus such as a spin coater. Examples of the substrate include inorganic substrates such as silicon wafers and organic substrates having a resist film or the like formed on the surface. Before applying the resist composition, the substrate may be cleaned, or an antireflection film or the like may be formed on the substrate. By drying the coated composition, the solvent is removed to form a composition layer. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-bake), or by using a decompression device. The heating temperature is preferably 50 to 200 °C, and the heating time is preferably 10 to 180 seconds. Also, the pressure during vacuum drying is preferably about 1 to 1.0×10 5 Pa. The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. As the exposure light source, those that emit laser light in the ultraviolet region such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F2 excimer laser (wavelength 157 nm), those that convert laser light from a solid laser light source (such as YAG or semiconductor laser) into harmonic laser light in the far ultraviolet region or vacuum ultraviolet region and emit it, those that irradiate electron beams, extreme ultraviolet light (EUV), etc., various ones can be used. In this specification, irradiating these radiations may be collectively referred to as "exposure". During exposure, usually, exposure is performed through a mask corresponding to the required pattern. When the exposure light source is an electron beam, exposure may be performed by direct drawing without using a mask. The exposed composition layer is heat-treated (so-called post-exposure bake) to promote the deprotection reaction in the acid-labile group. The heating temperature is usually about 50 to 200 °C, preferably about 70 to 150 °C. Chemical treatment (silylation) may be performed to adjust the hydrophilicity or hydrophobicity of the resin on the surface side of the composition after heating. Also, before development, the steps of coating, drying, exposing, and heating the resist composition may be repeated on the exposed composition layer. The heated composition layer is usually developed using a developing solution with a developing device. Examples of the developing method include dip method, paddle method, spray method, dynamic dispense method, etc. The developing temperature is preferably, for example, 5 to 60 °C, and the developing time is preferably, for example, 5 to 300 seconds. By selecting the type of developing solution as follows, a positive resist pattern or a negative resist pattern can be manufactured. When producing a positive resist pattern 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. For example, aqueous solutions of tetramethylammonium hydroxide, (2-hydroxyethyl)trimethylammonium hydroxide (commonly known as choline), etc. may be mentioned. The alkaline developer may contain a surfactant. After development, it is preferable to wash the resist pattern with ultrapure water and then remove the water remaining on the substrate and the pattern. When producing a negative resist pattern 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 the organic solvent contained in the organic developer 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; aromatic hydrocarbon solvents such as anisole, etc. In the organic developer, the content of the organic solvent 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 them, as the organic developer, a developer containing butyl acetate and / or 2-heptanone is preferable. In the organic developer, the total content of butyl acetate and 2-heptanone 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. Also, the organic developer may contain a small amount of water. During development, the development may be stopped by substituting with a solvent of a different type from the organic developer. It is preferable to wash the developed resist pattern with a rinse solution. The rinse solution is not particularly limited 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 washing, it is preferable to remove the rinse solution remaining on the substrate and the pattern.

[0196] <Usage> 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, particularly a resist composition for electron beam (EB) exposure or a resist composition for EUV exposure, and is useful for semiconductor microfabrication.

Examples

[0197] The present invention will be described more specifically with reference to examples. In the examples, “%” and “parts” representing content or usage amount are based on mass unless otherwise specified. The weight average molecular weight is a value determined by gel permeation chromatography. The analysis conditions for gel permeation chromatography are as follows. Column: TSKgel Multipore HXL-M x 3 + guard column (manufactured by Tosoh Corporation) Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min Detector: RI detector Column temperature: 40 °C Injection volume: 100 μl Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation) The structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC is Agilent 1100 type, MASS is Agilent LC / MSD type). In the following examples, the value of this molecular ion peak is indicated by “MASS”.

[0198] Example 1: Synthesis of the salt represented by formula (I-7) 4.37 parts of the salt represented by TIFF2025100419000144 (I-7-d), 1.28 parts of dimethylaminopyridine, 1.06 parts of triethylamine and 40 parts of acetonitrile were mixed and stirred at 23 °C for 30 minutes. Then, 1.48 parts of the compound represented by formula (I-1-b) and 80 parts of chloroform were added, and the mixture was stirred at 50 °C for 5 hours and further stirred at 23 °C for 2 hours. To the resulting reaction mixture, 25 parts of 1N hydrochloric acid was added and stirred at 23 °C for 30 minutes, and the organic layer was obtained by liquid separation. To the recovered organic layer, 30 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes, and the organic layer was obtained by liquid separation. This washing operation with water was carried out 3 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and after stirring at 23 °C for 30 minutes, the supernatant was removed and concentrated to obtain 4.08 parts of the salt represented by formula (I-7). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 321.0

[0199] Example 2: Synthesis of the salt represented by formula (I-10) 2.32 parts of the salt represented by TIFF2025100419000145.tif54157 (I-10-d) and 50 parts of chloroform were mixed and stirred at 23°C for 30 minutes. Then, 0.81 part of the compound represented by the formula (I-1-e) was added. After raising the temperature to 50°C, the mixture was stirred at 50°C for 2 hours. To the obtained reaction mixture, 2.26 parts of the salt represented by the formula (I-10-c) were added, and the mixture was stirred at 50°C for 3 hours. After cooling the obtained reaction mixture to 23°C, 25 parts of ion-exchanged water were added and the mixture was stirred at 23°C for 30 minutes. Then, the layers were separated and the organic layer was taken out. To the obtained organic layer, 25 parts of 1N hydrochloric acid were added and the mixture was stirred at 23°C for 30 minutes. The layers were separated to obtain an organic layer. To the obtained organic layer, 25 parts of ion-exchanged water were added and the mixture was stirred at 23°C for 30 minutes. Then, the layers were separated and the organic layer was taken out. This water washing operation was repeated 3 times. The obtained organic layer was concentrated. To the concentrated residue, 30 parts of tert-butyl methyl ether were added and the mixture was stirred at 23°C for 30 minutes. Then, the supernatant was removed and the residue was concentrated to obtain 3.32 parts of the salt represented by the formula (I-10). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 513.1

[0200] Example 3: Synthesis of the salt represented by the formula (I-22) 5.09 parts of the salt represented by TIFF2025100419000146.tif36157 (I-22-d), 1.28 parts of dimethylaminopyridine, 1.06 parts of triethylamine and 40 parts of acetonitrile were mixed and stirred at 23 °C for 30 minutes. Then, 1.48 parts of the compound represented by formula (I-1-b) and 80 parts of chloroform were added, and the mixture was stirred at 50 °C for 5 hours and further stirred at 23 °C for 2 hours. To the resulting reaction mixture, 25 parts of 1N hydrochloric acid was added and stirred at 23 °C for 30 minutes, and the organic layer was obtained by liquid separation. To the recovered organic layer, 30 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes, and the organic layer was obtained by liquid separation. This washing operation with water was carried out 3 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and after stirring at 23 °C for 30 minutes, the supernatant was removed and concentrated to obtain 5.54 parts of the salt represented by formula (I-22). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 393.0

[0201] Example 4: Synthesis of the salt represented by formula (I-25) 2.68 parts of the salt represented by TIFF2025100419000147.tif66155 (I-25-d) and 50 parts of chloroform were mixed and stirred at 23°C for 30 minutes. Then, 0.81 part of the compound represented by the formula (I-1-e) was added. After raising the temperature to 50°C, the mixture was stirred at 50°C for 2 hours. To the resulting reaction mixture, 2.26 parts of the salt represented by the formula (I-10-c) were added, and the mixture was stirred at 50°C for 3 hours. After cooling the resulting reaction mixture to 23°C, 25 parts of ion-exchanged water were added and the mixture was stirred at 23°C for 30 minutes. Then, liquid separation was performed to extract the organic layer. To the obtained organic layer, 25 parts of 1N hydrochloric acid were added and the mixture was stirred at 23°C for 30 minutes, and an organic layer was obtained by liquid separation. To the obtained organic layer, 25 parts of ion-exchanged water were added and the mixture was stirred at 23°C for 30 minutes. Then, liquid separation was performed to extract the organic layer. This water washing operation was repeated 3 times. The obtained organic layer was concentrated. To the concentrated residue, 30 parts of tert-butyl methyl ether were added and the mixture was stirred at 23°C for 30 minutes. Then, the supernatant was removed and concentrated to obtain 3.68 parts of the salt represented by the formula (I-25). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 585.1

[0202] Example 5: Synthesis of the salt represented by the formula (I-26) 2.33 parts of the salt represented by formula (I-26-c) and 50 parts of chloroform were mixed and stirred at 23 °C for 30 minutes. Then, 0.81 part of the compound represented by formula (I-1-e) was added. After raising the temperature to 50 °C, the mixture was stirred at 50 °C for 2 hours. To the resulting reaction mixture, 2.54 parts of the salt represented by formula (I-22-d) was added, and the mixture was stirred at 50 °C for 3 hours. After cooling the resulting reaction mixture to 23 °C, 25 parts of ion-exchanged water was added and the mixture was stirred at 23 °C for 30 minutes. Then, the layers were separated and the organic layer was taken out. To the obtained organic layer, 25 parts of 1N hydrochloric acid was added and the mixture was stirred at 23 °C for 30 minutes. The layers were separated to obtain an organic layer. To the obtained organic layer, 25 parts of ion-exchanged water was added and the mixture was stirred at 23 °C for 30 minutes. Then, the layers were separated and the organic layer was taken out. This water washing operation was repeated 3 times. The obtained organic layer was concentrated. To the concentrated residue, 30 parts of tert-butyl methyl ether was added and the mixture was stirred at 23 °C for 30 minutes. Then, the supernatant was removed and the residue was concentrated to obtain 3.55 parts of the salt represented by formula (I-26). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 571.1

[0203] Example 6: Synthesis of the salt represented by formula (I-791) 2.33 parts of the salt represented by formula (I-26-c) and 50 parts of chloroform were mixed and stirred at 23 °C for 30 minutes. Then, 0.81 part of the compound represented by formula (I-1-e) was added. After heating to 50 °C, the mixture was stirred at 50 °C for 2 hours. To the resulting reaction mixture, 3.85 parts of the compound represented by formula (I-791-d) was added and stirred at 50 °C for 3 hours. After cooling the resulting reaction mixture to 23 °C, 25 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes. Then, the layers were separated and the organic layer was taken out. To the obtained organic layer, 25 parts of 1N hydrochloric acid was added and stirred at 23 °C for 30 minutes, and the organic layer was obtained by separating the layers. To the obtained organic layer, 25 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes. Then, the layers were separated and the organic layer was taken out. This water-washing operation was repeated 3 times. The obtained organic layer was concentrated. To the concentrated residue, 30 parts of tert-butyl methyl ether was added and stirred at 23 °C for 30 minutes. Then, the supernatant was removed and concentrated to obtain 5.02 parts of the salt represented by formula (I-791). MASS(ESI(+)Spectrum):M + 525.0 MASS(ESI(-)Spectrum):M - 571.1

[0204] Example 7: Synthesis of the salt represented by formula (I-1211) 2.33 parts of the salt represented by the formula (I-26-c) and 50 parts of chloroform were mixed and stirred at 23 °C for 30 minutes. Then, 0.81 part of the compound represented by the formula (I-1-e) was added. After raising the temperature to 50 °C, the mixture was stirred at 50 °C for 2 hours. To the resulting reaction mixture, 3.35 parts of the compound represented by the formula (I-1211-d) was added and stirred at 50 °C for 3 hours. After cooling the resulting reaction mixture to 23 °C, 25 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes. Then, the layers were separated and the organic layer was taken out. To the obtained organic layer, 25 parts of 1N hydrochloric acid was added and stirred at 23 °C for 30 minutes, and the organic layer was obtained by separating the layers. To the obtained organic layer, 25 parts of ion-exchanged water was added and stirred at 23 °C for 30 minutes. Then, the layers were separated and the organic layer was taken out. This water washing operation was repeated 3 times. The obtained organic layer was concentrated. To the concentrated residue, 30 parts of tert-butyl methyl ether was added and stirred at 23 °C for 30 minutes. Then, the supernatant was removed and concentrated to obtain 4.42 parts of the salt represented by the formula (I-1211). MASS(ESI(+)Spectrum):M + 425.0 MASS(ESI(-)Spectrum):M - 571.1

[0205] Synthesis Example 1: Synthesis of the salt represented by the formula (IX-2) 2.99 parts of the salt represented by formula (IX-2-a), 2.24 parts of the salt represented by formula (IX-2-b), and 50 parts of acetonitrile were mixed and stirred at 23 °C for 30 minutes. To the resulting mixture, 10 parts of a 5% aqueous oxalic acid solution was added and stirred at 23 °C for 30 minutes, and then further stirred at 23 °C for 3 hours. To the resulting reaction product, 100 parts of chloroform and 50 parts of ion-exchanged water were added, stirred at 23 °C for 30 minutes, and then separated to extract the organic layer. To the recovered organic layer, 30 parts of ion-exchanged water was added, stirred at 23 °C for 30 minutes, and then separated to extract the organic layer. This water washing operation was repeated 5 times. After concentrating the obtained organic layer, 30 parts of tert-butyl methyl ether was added to the concentrated residue, stirred at 23 °C for 30 minutes, and then the supernatant was removed and concentrated to obtain 3.59 parts of the salt represented by formula (IX-2). MASS(ESI(+)Spectrum):M+ 263.1 MASS(ESI(-)Spectrum):M- 201.0

[0206] The compounds (monomers) used in the synthesis of resin (A) are shown below. Hereinafter, these compounds are referred to as "monomer (a1-2-6)" etc. according to their formula numbers. TIFF2025100419000152.tif3850

[0207] Synthesis Example 2 [Synthesis of Resin A1] As monomers, monomer (a1-4-2) and monomer (a1-2-6) were used and mixed so that the molar ratio [monomer (a1-4-2): monomer (a1-2-6)] was 38:62. Further, 1.5 times the mass of methyl isobutyl ketone with respect to the total mass of all monomers was mixed into this monomer mixture. Azobisisobutyronitrile was added to the resulting mixture as an initiator so as to be 7 mol% with respect to the total number of moles of all monomers, and polymerization was carried out by heating this at 85 °C for about 5 hours. Thereafter, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, and after stirring for 6 hours, liquid separation was performed. The obtained organic layer was poured into a large amount of n-heptane to precipitate the resin, and the resin was obtained by filtration and recovery, whereby resin A1 (copolymer) having a weight average molecular weight of about 5.4×10 3 was obtained with a yield of 88%. This resin A1 has the following structural units. TIFF2025100419000153.tif2679

[0208] <Preparation of resist composition> As shown in Table 2, the following respective components were mixed, and the resulting mixture was filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

Table 2

[0209] <Resin> A1: Resin A1 <Salt (I-A2)> I-7: Salt represented by formula (I-7) I-10: Salt represented by formula (I-10) I-22: Salt represented by formula (I-22) I-25: Salt represented by formula (I-25) I-26: Salt represented by formula (I-26) I-791: Salt represented by formula (I-791) I-1211: Salt represented by formula (I-1211) <Acid generator> IX-1: Salt represented by formula (IX-1) TIFF2025100419000155.tif5972<Quencher (C)> C1: Synthesized by the method described in JP-A-2011-39502 TIFF2025100419000156.tif4370<Solvent> 400 parts of propylene glycol monomethyl ether acetate 100 parts of propylene glycol monomethyl ether 5 parts of γ-butyrolactone

[0210] (Electron beam exposure evaluation of the 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 2 for 60 seconds to form a composition layer. Using an electron beam lithography machine ["ELS-F125 125 keV" manufactured by Elionix, Inc.], the exposure dose was gradually changed, and direct drawing was performed on the composition layer formed on the wafer so as to obtain a line and space pattern (pitch 60 nm / line width 30 nm) after development. After exposure, post-exposure baking was performed on a hot plate at the temperature shown in the "PEB" column of Table 2 for 60 seconds. Next, the composition layer on this silicon wafer was paddle-developed with a 2.38 mass% aqueous solution of tetramethylammonium hydroxide for 60 seconds to obtain a resist pattern. The obtained resist pattern (line and space pattern) was observed with a scanning electron microscope, and the exposure dose at which the line width and space width of the line and space pattern with a pitch of 60 nm became 1:1 was defined as the effective sensitivity.

[0211] Line edge roughness evaluation (LER): The fluctuation width of the unevenness on the side wall surface of the resist pattern manufactured with the effective sensitivity was measured with a scanning electron microscope to determine the line edge roughness. The results are shown in Table 3. [Table 3] Compared with Comparative Compositions 1 and 2, the fluctuation width of the unevenness on the side wall surface of the resist pattern in Compositions 1 to 7 was small, and the line edge roughness evaluation was good.

Industrial Applicability

[0212] Since the resist composition containing the salt of the present invention can obtain a resist pattern having good line edge roughness (LER), it is suitable for semiconductor microfabrication and is extremely useful industrially.

Claims

1. An acid generator containing a salt represented by formula (I-A2). [In formula (I-A2), L b2 represents a divalent hydrocarbon group having 1 to 24 carbon atoms which may have a single bond or a substituent, and -CH 2 - in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO 2 -. R b1 represents a halogen atom or an alkyl group having 1 to 6 carbon atoms, and the -CH 2 - contained in the alkyl group may be replaced by -O- or -CO-. nb3 represents any integer from 0 to 4, and when nb3 is 2 or more, the plurality of Rs b1 may be the same as or different from each other. R ３ represents a halogen atom, a haloalkyl group having 1 to 12 carbon atoms, or a hydrocarbon group having 1 to 18 carbon atoms. The hydrocarbon group may have a substituent, and the -CH 2 - may be replaced by -O-, -CO-, -S-, -SO ２ -. m3 represents any integer from 0 to 4, and when m3 is 2 or more, the plurality of Rs ３ may be the same as or different from each other. nb4 represents an integer of any one of 1 to 5. When nb4 is 2 or more, the groups in a plurality of parentheses may be the same as or different from each other. However, 1 ≦ nb4 + nb3 ≦ 5 is satisfied. Z ＋ represents an organic cation.]

2. The acid generator according to claim 1, wherein nb4 is 1.

3. A resist composition containing the acid generator according to claim 1 or 2.

4. Including a resin containing a structural unit having an acid-labile group, The resist composition according to claim 3, wherein the structural unit having an acid-labile group includes at least one selected from the group consisting of a structural unit represented by formula (a1-0), a structural unit represented by formula (a1-1), a structural unit represented by formula (a1-2), a structural unit represented by formula (a1-4), a structural unit represented by formula (a1-5), and a structural unit represented by formula (a1-6). [In formula (a1-0), formula (a1-1), and formula (a1-2), L a01 , L ａ１ and L ａ２ each independently represents -O- or *-O-(CH ２ ), ｋ１ -CO-O-, k1 represents any integer from 1 to 7, and * represents the bonding site with -CO-. R a01 , R ａ４ 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. The alkyl group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group may have a halogen atom. 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, and the alkyl group, the alkenyl group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group may have a halogen atom. m1' represents an integer of any one of 0 to 14. n1 represents an integer of any one of 0 to 10. n1' represents an integer of any one of 0 to 3. ] [In formula (a1-4), R ａ１ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R ａ１７ represents a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, 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 ａ１１ represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and -CH ２ - in the alkanediyl group may be replaced by -O-, -CO- or -NR ａ１８ -. R ａ１８ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X ａ１ represents a single bond or a carbonyl group. R a34 and R a35 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and 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 a divalent hydrocarbon group having 2 to 20 carbon atoms together with the -C-O- to which they are bonded, and the -CH 2 - contained in the hydrocarbon group and the divalent hydrocarbon group may be replaced by -O- or -S-. na1 represents an integer of any one of 1 to 5. When na1 is 2 or more, the groups in a plurality of parentheses may be the same as or different from each other. na11 represents any integer from 0 to 4, and when na11 is 2 or more, a plurality of Rs ａ１７ may be the same as or different from each other. mc represents an integer of any one of 0 to 2. ] [In formula (a1-5), R a8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom. Z a1 represents a single bond or *-(CH 2 ) h3 -CO-L 54 -, h3 represents an integer from 1 to 4, and * represents the bonding site with 51 L. L 51 , L 52 , L 53 , and L 54 each independently represents -O- or -S-. s1 represents an integer of any one of 1 to 3. s1' represents an integer of any one of 0 to 3. ] [In formula (a1-6), R a61 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a6２ 、 R a63 and R a6４ each independently represents an alkyl group having 1 to 6 carbon atoms or a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, or R a6２ and R a63 are bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded. X a61 represents a single bond, -CO-O-*, or -CO-NR a65 -*, where * represents a bond to Ar, and R a65 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X a62 represents a single bond, *-O-L a61 -, or *-CO-O-L a62 -, where * represents a bond to Ar, and L a61 and L a62 each independently represent an alkanediyl group having 1 to 4 carbon atoms. Ar represents an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms. ]

5. The resist composition according to claim 3, including a resin containing a structural unit represented by formula (a2-A). [In formula (a2-A), R ａ２ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R ａ２７ represents a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, 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 ａ２１ represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and -CH ２ - in the alkanediyl group may be replaced by -O-, -CO- or -NR ａ２８ -. R ａ２８ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X ａ２ represents a single bond or a carbonyl group. nA2 represents an integer of any one of 1 to 5. When nA2 is 2 or more, the groups in a plurality of parentheses may be the same as or different from each other. na21 represents any integer from 0 to 4, and when na21 is 2 or more, a plurality of Rs ａ２７ may be the same as or different from each other. mc represents an integer of any one of 0 to 2. ]

6. (1) A step of applying the resist composition according to claim 3 onto a substrate, (2) A step of drying the applied resist composition to form a composition layer, (3) A step of exposing the composition layer, (4) A step of heating the exposed composition layer, and (5) A step of developing the heated composition layer, A method for manufacturing a resist pattern, including these steps.

7. A salt represented by formula (I-A2). [In formula (I-A2), L b2 represents a divalent hydrocarbon group having 1 to 24 carbon atoms which may have a single bond or a substituent, and -CH 2 - in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO 2 -. R b1 represents a halogen atom or an alkyl group having 1 to 6 carbon atoms, and -CH 2 - contained in the alkyl group may be replaced by -O- or -CO-. nb3 represents any integer from 0 to 4, and when nb3 is 2 or more, the plurality of Rs b1 may be the same as or different from each other. R ３ represents a halogen atom, a haloalkyl group having 1 to 12 carbon atoms or a hydrocarbon group having 1 to 18 carbon atoms, the hydrocarbon group may have a substituent, and -CH contained in the haloalkyl group and the hydrocarbon group 2 - is -O- or -CO-, -S-, -SO ２ - may be replaced with. m3 represents any integer from 0 to 4, and when m3 is 2 or more, the plurality of Rs ３ may be the same as or different from each other. nb4 represents any integer from 1 to 5. When nb4 is 2 or more, the groups within the plurality of parentheses may be the same as or different from each other. However, 1 ≦ nb4 + nb3 ≦ 5 is satisfied. Z ＋ represents an organic cation. **Claim 8** The salt according to claim 7, wherein nb1 is 1.

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