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

Abstract

To provide a resist composition and the like which allow a resist pattern having good CD uniformity to be produced.SOLUTION: An acid generator contains a salt represented by formula (I). [In the formula, Lb1 represents a single bond or an optionally substituted hydrocarbon group, and -CH2- contained in the hydrocarbon group may be substituted with -O-, -S-, -CO- or -SO2-; Lb2 represents a single bond or an optionally substituted hydrocarbon group, and -CH2- contained in the hydrocarbon group may be substituted with -O-, -S-, -CO- or -SO2-; R3 represents a halogen atom, a C1-12 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; nb1 represents an integer of 1-6; and Z+ and Z'+ each represent 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. TIFF2025100439000001.tif3081

[0003] Patent Document 2 describes a salt represented by the following formula and a composition containing the salt as an acid generator. TIFF2025100439000002.tif2881

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 CD uniformity (CDU) 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). TIFF2025100439000003.tif19123[In formula (I), L b1represents a (nb1 + 1)-valent hydrocarbon group 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-. L b2 represents 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 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, and when m3 is 2 or more, a plurality of R 3 may be the same as or different from each other. nb1 represents any integer from 1 to 6. When nb1 is 2 or more, the groups in a plurality of parentheses may be the same as or different from each other. Z + and Z’ + each independently represents an organic cation. The acid generator according to [1], wherein the anion of the salt represented by the formula (I) is an anion represented by the formula (I-A1) or an anion represented by the formula (I-A2). TIFF2025100439000004.tif22144 [In the formula (I-A1), Q b1 Q b2 Q b3 and Q b4 each independently represents a hydrogen atom, a fluorine atom, a perfluoroalkyl group having 1 to 6 carbon atoms or an alkyl group having 1 to 6 carbon atoms. z1 represents any integer from 0 to 6. X 1 represents -O-CO-, -CO-O-, -O-CO-O- or -O-. L b3represents a single bond or a hydrocarbon group with (nb2 + 1) carbon atoms 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-. L b2 represents a single bond or a divalent hydrocarbon group with 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-. R 3 represents a halogen atom, a haloalkyl group with 1 to 12 carbon atoms or a hydrocarbon group with 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. nb2 represents any integer from 1 to 3. When nb2 is 2 or more, the groups within a plurality of parentheses may be the same as or different from each other. Z’ + represents an organic cation. TIFF2025100439000005.tif30130[In formula (I-A2), L b2 represents a single bond or a divalent hydrocarbon group with 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-. R b1 represents a halogen atom or an alkyl group with 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 3represents 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-, -CO-, -S-, or -SO2-. m3 represents any integer from 0 to 4. When m3 is 2 or more, a 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 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. The acid generator according to [1] or [2], wherein nb1 is 1. A resist composition containing the acid generator according to [1] or [2]. containing a resin containing a structural unit having an acid-labile group, The resist composition according to [4], 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). TIFF2025100439000006.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 a03and 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. TIFF2025100439000007.tif32119[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 -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 a35each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R a36 represents a hydrocarbon group having 1 to 20 carbon atoms, or R a35 and R a36 are bonded to each other to form, together with the -C-O- to which they are bonded, a divalent hydrocarbon group having 2 to 20 carbon atoms, and the -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 within 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.] TIFF2025100439000008.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-L 54 -, h3 represents any integer from 1 to 4, and * represents the bonding site with L 51 . 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.] TIFF2025100439000009.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 a64Each 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 aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent.] The resist composition according to [4] or [5], comprising a resin containing a structural unit represented by formula (a2-A). TIFF2025100439000010.tif30128[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 -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 an integer from 1 to 5, and when nA2 is 2 or more, the groups within the plurality of parentheses may be the same as or different from each other. na21 represents an integer from 0 to 4, and when na21 is 2 or more, the plurality of Rs a27 may be the same as or different from each other. mc represents an integer from 0 to 2. [7] A step of applying the resist composition according to any one of [4] to [6] 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 manufacturing a resist pattern including the above steps. [8] The salt represented by the above formula (I). [9] The salt according to [8], wherein the anion of the salt represented by formula (I) is the anion represented by the above formula (I-A1) or the anion represented by the above formula (I-A2).

[10] The salt according to [8] or [9], 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 CD uniformity (CDU). [Embodiments for Carrying Out the Invention]

[0008] In this specification, the term "(meth)acrylic monomer" means "at least one of acrylic monomers and methacrylic monomers". Expressions such as "(meth)acrylate" and "(meth)acrylic acid" also represent the same meaning. For groups described in this specification that can have both a linear structure and a branched structure, either one is acceptable. When -CH2- contained in a hydrocarbon group or the like is replaced by -O-, -S-, -CO- or -SO2-, the same examples are applicable 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 term "combined group" means a group formed by bonding two or more of the exemplified groups, and the valences of these groups may be appropriately changed depending on the bonding form. The terms "derived from" or "derived" refer 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 term "acid-labile group" means a group having a leaving group, and when contacted with an acid (e.g., trifluoromethanesulfonic acid, etc.), the leaving group detaches to form a hydrophilic group (e.g., hydroxy group or carboxy group). As will be described later, the base-labile group means a group that detaches to form a carboxy group or a hydroxy group when contacted with a base (e.g., trimethylamine, tetramethylammonium hydroxide, etc.). 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)> The present invention relates to a salt represented by formula (I) (hereinafter sometimes referred to as "salt (I)"). Among salts (I), 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), L b1 As the (nb1 + 1)-valent hydrocarbon group of, from a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining two or more of these groups, nb1 hydrogen atoms are removed, and one or more Lb2 Examples of the group that binds to... The number of carbon atoms in the hydrocarbon group is preferably 1 to 48, more preferably 1 to 42, still more preferably 1 to 36, even more preferably 1 to 30, and even still more preferably 1 to 24. Examples of the chain hydrocarbon group include a group obtained by removing nb1 hydrogen atoms from an alkyl group or an alkenyl group. The alkyl group may be linear or branched, and specifically includes methyl group, ethyl group, 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, decanyl group, undecanyl group, dodecanyl group, tridecanyl group, tetradecanyl group, pentadecanyl group, heptadecanyl group, etc. Examples of the alkenyl group include 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. The number of carbon atoms in the chain hydrocarbon group is preferably 1 to 36, more preferably 1 to 20, and still more preferably 1 to 10. Examples of the alicyclic hydrocarbon group include a group obtained by removing nb1 hydrogen atoms from a monocyclic or polycyclic cycloalkyl group. Examples of the monocyclic cycloalkyl group include cyclobutyl group, cyclopentane group, cyclohexane group, cyclopentyl group, cyclooctyl group, etc. 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]decanyl 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 norbornyl 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 include those represented by the following formula. TIFF2025100439000011.tif28160 When the alicyclic hydrocarbon group is a monocyclic cycloalkyl group, the number of carbon atoms in 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 in the alicyclic hydrocarbon group is preferably 7 to 12. 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 14, more preferably 5 to 10. L b1 When -CH2- included 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 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 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- substituted 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 26 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, propanedioxy group, butanedioxy group, pentanedioxy 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 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 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. TIFF2025100439000012.tif47147L 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 and 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- also include the following groups, etc. The bonding site can be any position. TIFF2025100439000013.tif26164Examples 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 b2 Examples of the divalent hydrocarbon group include a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, a divalent aromatic hydrocarbon group, and a group obtained by removing one hydrogen atom from a combination of two or more of these groups and bonding to a benzene ring. L b2 The divalent chain hydrocarbon group, the divalent alicyclic hydrocarbon group, the divalent aromatic hydrocarbon group, and the divalent group obtained by combining two or more of these groups are each, within the range allowed by the number of carbon atoms, L b1Examples thereof include a group in which one hydrogen atom has been removed from a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining two or more of these groups. L b1 and L b2 Examples of the substituent that the hydrocarbon group of 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 b1 and L b2 When and 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 the -CH2- of the chain hydrocarbon group contained in the hydrocarbon group of and is replaced with -O-, -CO-, -S- or -SO2-, the hydrocarbon group of and 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. b1 and L b2 the -CH2- of the chain hydrocarbon group contained in the hydrocarbon group of and is replaced with -O-, -CO-, -S- or -SO2-, the hydrocarbon group of and b1 and L b2 the hydrocarbon group of and 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. In formula (I), L b1 is preferably a single bond when nb1 is 1, and when nb1 is 2 or more, is preferably a (nb1 + 1)-valent hydrocarbon group (the -CH2- contained in the hydrocarbon group may have a substituent that may be replaced with -O-, -S-, -CO- or -SO2-).

[0011] R 3 Examples of the halogen atom of include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like. R 3The C1-C12 haloalkyl group represents an alkyl group having 1 to 12 carbon atoms and a halogen atom, and examples thereof include a C1-C12 fluoroalkyl group, a C1-C12 chloroalkyl group, a C1-C12 bromoalkyl group, and a C1-C12 iodoalkyl group. Examples of the haloalkyl group include a C1-C12 perfluoroalkyl group (such as a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, and a nonafluorobutyl group), 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, and an iodomethyl group. 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 C1-C18 hydrocarbon group of 3 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, and a dodecyl group. 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 Examples of the branched alkanediyl group include 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, a 2-methylbutane-1,4-diyl group, etc. The terminal of the branched alkanediyl group may be a methyl group. The number of carbon atoms in 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 include the groups represented below. The bonding site can be at any position. TIFF2025100439000014.tif46168Specifically, examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and a cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include cycloalkyl groups such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, a spirocyclohexane-1,2’-cyclopentane, and a spiroadamantane-2,3’-cyclopentane group, and spiro rings having a cycloalkyl group bonded spiro to each of a norbornyl group or an adamantyl group. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 18, more preferably 3 to 16, and still more preferably 3 to 12. Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, a biphenyl group, an anthryl group, a phenanthryl group, and a binaphthyl group. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 18, more preferably 6 to 14, and still more preferably 6 to 10.

[0012] Examples of the group formed by combination include a group combining an aromatic hydrocarbon group and a chain hydrocarbon group (for example, aromatic hydrocarbon group - alkane diyl group - *, alkyl group - aromatic hydrocarbon group - *, and -CH2- contained in the alkane diyl group and the alkyl group may be replaced by -O-, -CO-, -S- or -SO2-), a group combining an alicyclic hydrocarbon group and a chain hydrocarbon group (for example, alicyclic hydrocarbon group - alkane diyl group - *, alkyl group - alicyclic hydrocarbon group - *, and -CH2- contained in the alkane diyl group and the alkyl group may be replaced by -O-, -CO-, -S- or -SO2-), and a group 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 - alkane diyl 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 - alkane diyl group - * include cycloalkylalkyl groups such as cyclohexylmethyl group, cyclohexylethyl group, 1-(adamantan-1-yl)methyl group, 1-(adamantan-1-yl)-1-methylethyl 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 group may be bonded to the benzene ring.

[0013] R 3When -CH2- contained in the haloalkyl group or hydrocarbon group represented by is replaced by -O-, -CO-, -S- or -SO2-, the number of carbon atoms before replacement shall be 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 or 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- at any position in the haloalkyl group is replaced by -O-), a haloalkoxycarbonyl group (a group in which any -CH2-CH2- at any position in the haloalkyl group is replaced by -O-CO-), a haloalkylcarbonyl group (a group in which any -CH2- at any position in the haloalkyl group is replaced by -CO-), a haloalkylcarbonyloxy group (a group in which any -CH2-CH2- at any position in the haloalkyl group is replaced by -CO-O-), a group formed by combining two or more of these groups, etc. may be mentioned. These substituted groups include those similar to 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 with -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 with -O-, -S-, -CO- or -SO2- also include the following groups. The bonding site can be at any position. TIFF2025100439000016.tif26164

[0015] R 3 Examples of the substituent that the hydrocarbon group of 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 with -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 and the like. 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 with -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 may be any of the ortho, meta, and para positions with respect to b2 .

[0016] The anion of the salt represented by formula (I) is preferably an anion represented by the following formula (I-A1) or an anion represented by formula (I-A2). TIFF2025100439000017.tif22144 [In formula (I-A1), all symbols have the same meanings as described above.] Q b1 、Q b2 、Q b3 and Q b4 Examples of the alkyl group represented by Q b1 , Q b2 , Q b3 and Q b4 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. Q b1 、Q b2 、Q b3 and Q b4 Examples of the C1-C6 perfluoroalkyl group represented by Q b1 , Q b2 , Q b3 and Q b4 include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. Q b1 and Q b2 are preferably included in at least one of Q b1 and Q b2 a fluorine atom or a perfluoroalkyl group, more preferably a fluorine atom or a perfluoroalkyl group, even more preferably a fluorine atom or a trifluoromethyl group, and even more preferably both are fluorine atoms. Q b3 and Q b4 are each independently preferably a hydrogen atom, a fluorine atom or a C1-C3 perfluoroalkyl group, Q b3 is preferably a hydrogen atom, a fluorine atom or a C1-C3 perfluoroalkyl group, and Q b4 is preferably a hydrogen atom or a fluorine atom.​​​​​​​​ z1 is preferably from 0 to 3, more preferably 0, 1 or 2. X 1 is preferably -O-CO- or -CO-O-.

[0017] L b3 As the hydrocarbon group in L, within the range allowed by the upper limit of the number of carbon atoms, the same hydrocarbon groups as exemplified for L in formula (I) b1 can be mentioned. In formula (I-A1), L b3 is 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 alicyclic hydrocarbon group may be replaced by -O- or -S-), and groups combined from two or more of these groups are preferred, and a chain hydrocarbon group having 1 to 6 carbon atoms or a group represented by the following formula (Lb3-1) is more preferred. When the chain hydrocarbon group is replaced by -O- or -CO-, the number of -CH2- contained in the chain hydrocarbon group replaced by -O- or -CO- is preferably 1 to 4, and it is preferred that one -CH2-CH2- contained in the chain hydrocarbon group is replaced by -O-CO- or -CO-O-, or -CH2-CH2-CH2- contained in the chain hydrocarbon group is replaced by -O-CO-O-. TIFF2025100439000018.tif1581 [In formula (Lb3-1), nb2 has the same meaning as in formula (I-A1). L b31 is a single bond or a chain hydrocarbon group having 1 to 12 carbon atoms, and -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-, and it may have a substituent. W b3represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. The -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. The -CH2- contained in the aromatic hydrocarbon group may be replaced by -O- or -S-. The alicyclic hydrocarbon group may have a substituent. * and ** represent bonding sites, and * represents the bonding site with X 1 and represents the bonding site with.] In formula (Lb3-1), L b31 The chain hydrocarbon group of may be the same as the chain hydrocarbon group exemplified by L b1 as long as it has an upper limit of the number of carbon atoms, and the chain hydrocarbon group exemplified by the chain hydrocarbon group exemplified by. In formula (Lb3-1), W b3 The alicyclic hydrocarbon group and the aromatic hydrocarbon group of may be the alicyclic hydrocarbon group and the aromatic hydrocarbon group exemplified by L b1 as long as the upper limit of the number of carbon atoms permits. In formula (Lb3-1), the substituent that the chain hydrocarbon group of L b31 may have and the substituent that the alicyclic hydrocarbon group and the aromatic hydrocarbon group of W b1 may have are the same 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, the alicyclic hydrocarbon group and the aromatic hydrocarbon group of W b1 are preferably the alicyclic hydrocarbon group and the aromatic hydrocarbon group represented below. In the alicyclic hydrocarbon group and the aromatic hydrocarbon group represented below, * and ** represent bonding sites, and * represents the bonding site with X 1 or L b31 and represents the bonding site with, and ** represents a hydrogen atom, a substituent or the bonding site with L b2 and at least one ** is L b2represents a binding site. Further, in the alicyclic hydrocarbon group represented below, -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. When -CH2- contained in the alicyclic hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2-, it is preferable that an ether ring, an ester ring (lactone), a carbonate ring, a sultone ring or an acetal ring is formed. TIFF2025100439000019.tif36168 In formula (I-A1), L b2 is preferably a single bond or an alkanediyl group having 1 to 12 carbon atoms (wherein -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-), 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 them represents an alkanediyl group having at least 1 to 6 carbon atoms, the other represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, X 2 represents -O-, -CO-O-, -O-CO- or -O-CO-O-, * and ** represent binding sites, and ** represents a binding site with the benzene ring. However, the total number of carbon atoms of L b21 , X 2 and L b22 is preferably 12 or less. In formula (B1-A1), L b2 is preferably a single bond or an alkanediyl group having 1 to 12 carbon atoms (wherein -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-), 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 them represents an alkanediyl group having at least 1 to 6 carbon atoms, the other represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, X 2represents -O-, -CO-O-, -O-CO- or -O-CO-O-, * and ** represent bonding sites, and ** represents the bonding site with the benzene ring. However, L b21 , X 2 and L b22 preferably have a total carbon number of 12 or less.

[0018] Examples of the anion in the salt represented by formula (I) include anions represented by formula (I-A1-1) to formula (I-A1-40). Among them, an anion represented by any of formula (I-A1-1) to formula (I-A1-11), formula (I-A1-16) to formula (I-A1-24), and formula (I-A1-31) to formula (I-A1-40) is preferred. TIFF2025100439000020.tif238157

[0019] TIFF2025100439000021.tif253162

[0020] The anion represented by formula (I-A2) is represented by the following formula. TIFF2025100439000022.tif30130 [In formula (I-A2), all symbols have the same meanings as described above.]

[0021] In formula (I-A2), examples of the hydrocarbon group of L b2 are the same as the examples of the hydrocarbon group of L b2 in formula (I) within the range allowed by the upper limit of the carbon number. Examples of the substituents that the hydrocarbon group of L b2 may have are also the same as the examples of the substituents that the hydrocarbon group of L b2 in formula (I) may have. 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 b41is 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-, and * is SO3 - represents the bonding site with the phenyl group to which - is bonded. L b41 is preferably a single bond or a chain hydrocarbon group having 1 to 3 carbon atoms.

[0022] 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 the m-position substitution of the benzene ring with respect to the bonding position of SO3 - TIFF2025100439000023.tif32136 [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.

[0023] R b1 Examples of the alkyl group having 1 to 6 carbon atoms for R 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. R b1 Examples of the halogen atom for R include fluorine atom, chlorine atom, bromine atom, and iodine atom. R b1 is 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 an integer of any one of 0 to 4, preferably an integer of any one of 0 to 3, and more preferably an integer of any one of 0 to 2. In one embodiment, nb3 is preferably 0. In another embodiment, it is preferable that nb3 is 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. 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. R 3 The bonding position of the carboxylate anion in the benzene ring to which it can bond may be o-position, m-position or p-position substitution with respect to the bonding position of L b2 , and among them, o-position substitution is preferable.

[0024] Examples of the anion (I-A2) include the following anions. Among them, the anions represented by formula (I-A2-1) to formula (I-A2-30) are preferable, 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 preferable. TIFF2025100439000024.tif232164

[0025] 〔Cation (I)〕 Z in formula (I) + and Z’ +Examples of the organic cation include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, organic sulfonium cations and organic iodonium cations are preferred, and arylsulfonium cations are more preferred. 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. TIFF2025100439000025.tif82159[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, and 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, and 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, and 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 b8 each 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 an integer of 0 to 5. When m2 is 2 or more, a plurality of R b7may be the same or different, and when n2 is 2 or more, a plurality of Rs b8 may be the same or different. R b9 and R b10 each independently represents a chain hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms. R b9 and R b10 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and the -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 the hydrogen atom contained in the chain hydrocarbon group may be substituted by an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group may be substituted by 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 the -CH2- contained in the ring may be replaced by -O-, -S- or -CO-. R b13 ~R b18 and R b21 ~R b2 each 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. R b13 and R b14 and R b21 and R b22 may be bonded to each other to form a ring containing a sulfur atom together with the benzene ring to which they are bonded, and the -CH2- contained in the ring may be replaced by -O-, -S- or -CO-. Rb27 ~R b29 each independently represents a group containing a hydrogen atom or 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 any integer from 0 to 5. q2 and r2 each independently represent any 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; when p2 is 2 or more, the plurality of R b14 are the same or different; when q2 is 2 or more, the plurality of R b15 are the same or different; when r2 is 2 or more, the plurality of R b16 are the same or different; when s2 is 2 or more, the plurality of R b17 are the same or different; when t2 is 2 or more, the plurality of R b18 are the same or different. u3 represents any integer from 1 to 3 and satisfies 1 ≦ u3 + q23 ≦ 5. u4 and u5 each independently represent any 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 any 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, any one of o2, p2, q2, and r2 is 1 or more, and at least one of R b13 ~R b16 is preferably a halogen atom; when u2 is 1, any one of o2, p2, s2, t2, q2, and r2 is 1 or more, and R b13 ~R b18It is preferable that at least one of them 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, R b16 is preferably a halogen atom.

[0026] 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 a chain hydrocarbon group having 1 to 12 carbon atoms. 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. TIFF2025100439000026.tif11157 In particular, the alicyclic hydrocarbon group of R b9 ~R b12 is preferably a group having 3 to 18 carbon atoms, and more preferably 4 to 12 carbon atoms.

[0027] Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include methylcyclohexyl group, dimethylcyclohexyl group, 2-methyladamantan-2-yl group, 2-ethyladamantan-2-yl group, 2-isopropyladamantan-2-yl group, methylnorbornyl group, isobornyl group, and the like. 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.

[0028] The alkyl fluoride group represents an alkyl group having 1 to 12 carbon atoms with a fluorine atom, and examples include fluoromethyl group, difluoromethyl group, trifluoromethyl group, perfluorobutyl, etc. The number of carbon atoms of the alkyl fluoride group is preferably 1 to 9, more preferably 1 to 6, and still more preferably 1 to 4.

[0029] Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, biphenyl group, naphthyl group, 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 (such as tolyl group, xylyl group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.) and the aromatic hydrocarbon group having an alicyclic hydrocarbon group (such as p-cyclohexylphenyl group, p-adamantylphenyl group, etc.) can be 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 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 benzyl group, phenethyl group, phenylpropyl group, trityl group, naphthylmethyl group, naphthylethyl group, etc.

[0030] Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group, dodecyloxy group, etc. Examples of the alkylcarbonyl group include acetyl group, propionyl group, butyryl group, etc. Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom, iodine atom, etc. Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, an isopropylcarbonyloxy group, a butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group.

[0031] R b4 and R b5 The ring formed by R and R being bonded to each other together with the sulfur atom to which they are bonded may be any of 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, and examples thereof include the following rings. * represents a bonding site. TIFF2025100439000027.tif24142

[0032] R b9 and R b10 The ring formed by R and R together may be any of 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. Examples thereof include a thiolan-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring. R b11 and R b12 The ring formed by R and R together may be any of 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. Examples thereof include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring. R b27 ~R b29 Examples of the group containing an acid-labile group of R~R include -R c30 , -CO-O-R c30 or -L c10-CO-O-R c30 The group (L c10 represents an alkanediyl group having 1 to 6 carbon atoms, and R c30 represents an acid-labile group.) and the like can be mentioned. R b27 ~R b29 Examples of the acid-labile groups of R

[0033] Among the cations (b2-1) to (b2-5), preferably, it is the cation (b2-1). Examples of the cation (b2-1) include the following cations. TIFF2025100439000028.tif149164 Examples of the cation (b2-2) include the following cations. TIFF2025100439000029.tif18150 Examples of the cation (b2-3) include the following cations. TIFF2025100439000030.tif26140 Examples of the cation (b2-4) include the following cations. TIFF2025100439000031.tif123163 Examples of the cation (b2-5) include the following cations. TIFF2025100439000032.tif115158

[0034] Specific examples of the salt (I) include salts obtained by arbitrarily combining the above-mentioned cations and anions. Specific examples of the salt (I) 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) and the anion (I) corresponds. For example, the salt (I-1) is a salt composed of the anion represented by the formula (I-A1-1) 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-A1-2) and the cation represented by the formula (b2-c-1), and the salt (I-31) is a salt composed of the anion represented by the formula (I-A1-1) and the cation represented by the formula (b2-c-10). TIFF2025100439000033.tif3889

Table 1

[0035] Among them, the salt (I) is preferably a salt formed by combining an anion represented by any of the formulas (I-A1-1) to (I-A1-11), (I-A1-16) to (I-A1-24), (I-A1-31) to (I-A1-40), (I-A2-1) to (I-A2-11), and (I-A2-16) to (I-A2-26) with a cation represented by any of the formulas (b2-c-1) to (b2-c-79).

[0036] <Method for Producing Salt (I)> The salt (I) can be produced, for example, by reacting a salt represented by the formula (I-a) with silver oxide in a solvent and then further reacting with a salt represented by the formula (I-b). TIFF2025100439000038.tif22155 (In the formula, all symbols have the same meanings as described above.) Examples of the acid catalyst in this reaction include trifluoroacetic acid. Examples of the solvent in this reaction include chloroform, acetonitrile, and methanol. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours. Examples of the salt represented by the formula (I-a) include salts represented by the following formula, and they can also be easily produced by known production methods. TIFF2025100439000039.tif199159

[0037] TIFF2025100439000040.tif238161

[0038] TIFF2025100439000041.tif225161

[0039] The salt represented by formula (I-b) includes, for example, salts represented below and can be easily obtained from the market. TIFF2025100439000042.tif41165

[0040] <Acid generator> In addition to salt (I), 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 other than salt (I). Compound (B) may be used alone or in combination of two or more. Either a nonionic compound or an ionic compound may be used as 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, etc. 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).

[0041] 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 becomes an 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.

[0042] A preferred form of the compound (B) includes a salt represented by the formula (B1) (hereinafter sometimes referred to as "acid generator (B1)"). However, salt (I) is excluded. TIFF2025100439000043.tif1396[In the formula (B1), L b1 represents a single bond or an (nb1 + 1)-valent hydrocarbon group that 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 that 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 that may have a substituent or a cyclic hydrocarbon group having 3 to 24 carbon atoms that 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 in 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, nb1 hydrogen atoms are 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 the group that binds to L b2 is mentioned. The number of carbon atoms of the hydrocarbon group is preferably 1 to 48, more preferably 1 to 42, further preferably 1 to 36, still more preferably 1 to 30, and even more preferably 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 1 to 36, more preferably 1 to 24, further preferably 1 to 20, still more preferably 1 to 18, even more preferably 1 to 12, and still 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 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]decanyl group and a steroid group (steroid skeleton). Examples of the cycloalkyl group 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 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. TIFF2025100439000044.tif26168 When the alicyclic hydrocarbon group is a monocyclic cycloalkyl group, the number of carbon atoms of 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 of 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 obtained by removing nb1 hydrogen atoms from an aryl group. 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 number of carbon atoms in the aromatic hydrocarbon group in TIFF2025100439000045.tif1085, it is preferably 4 to 24, more preferably 4 to 20, still more preferably 4 to 18, even more preferably 5 to 14, even still more preferably 5 to 10, and even more preferably 6 to 10. L b1 When -CH2- contained in the hydrocarbon group of b1 is replaced by -O-, -CO-, -S- or -SO2-, the number of carbon atoms before replacement shall be taken as the number of carbon atoms of the hydrocarbon group. L b1 When -CH2- contained in the hydrocarbon group of b1 is replaced by -O-, -CO-, -S- or -SO2-, the number of carbon atoms before replacement shall be taken as the number of carbon atoms 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 alkanediyl-oxy group (a group in which -CH2- at any position contained in the alkanediyl group is replaced by -O-), an alkanediyl-oxycarbonyl group (a group in which -CH2-CH2- at any position contained in the alkanediyl group is replaced by -O-CO-), an alkanediyl-carbonyl group (a group in which -CH2- at any position contained in the alkanediyl group is replaced by -CO-), an alkanediyl-carbonyl-oxy group (a group in which -CH2-CH2- at any position contained in the alkanediyl 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. TIFF2025100439000046.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. TIFF2025100439000047.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 those similar to the groups 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 obtained by removing one hydrogen atom from a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, a divalent aromatic hydrocarbon group, and a group formed by combining two or more of these groups, and bonding 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 obtained by removing one hydrogen atom from the chain hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and a 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. The alicyclic hydrocarbon group and the aromatic hydrocarbon group of Y b1Examples thereof include the same as the alicyclic hydrocarbon group and the aromatic hydrocarbon group exemplified above. When it has no substituent, it may be a monovalent alicyclic hydrocarbon group or aromatic hydrocarbon group. 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 (in the hydrocarbon group, -CH2- 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 permitted 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 permitted 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 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). TIFF2025100439000048.tif30123[In formula (B1-A1), L b2 and Y b1 have the same meaning as in formula (I-A). Q b1 Q b2 Q b3 and Q b4 each independently represent 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 within multiple 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 substituents, 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 within multiple 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 represented by Q, Q, Q and Q include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group and hexyl group, etc. Q b1 Q b2 Q b3 and Q b4Examples of the perfluoroalkyl group having 1 to 6 carbon atoms include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. Q b1 and Q b2 is Q b1 and Q b2 It is preferable that at least one of Q and Q contains 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 are 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, and preferably 0, 1 or 2. X 1 is preferably -O-CO- or -CO-O-.

[0043] L b3 Examples of the hydrocarbon group in include the same hydrocarbon groups as exemplified for L of formula (I-A) within the range allowed by the upper limit of the number of carbon atoms. b1 In formula (B1-A1), L b3 ​is 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 it is preferable that 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-. TIFF2025100439000049.tif1582[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, wherein -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, wherein -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 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 aromatic hydrocarbon groups exemplified by L b1 Examples thereof include the same groups as the alicyclic hydrocarbon groups and 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 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 aromatic hydrocarbon group of W b3 the alicyclic hydrocarbon groups and aromatic hydrocarbon groups represented below 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 and represents the bonding site with L. Further, 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. TIFF2025100439000050.tif36165 In formula (B1-A1), L b2is preferably a single bond or a chain hydrocarbon group having 1 to 12 carbon atoms (wherein -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-), and is a single bond, -O-, -O-CO-, -CO-O-, -O-CO-O- or *-L b21 -X 2 -L b22 -**(L b21 and L b22 in which either one 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 have a total carbon number of 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 (wherein -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 (wherein -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 even more preferably an alicyclic hydrocarbon group having 3 to 16 carbon atoms which may have a substituent (wherein -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 to. The alicyclic hydrocarbon group and aromatic hydrocarbon group represented by the following formula are not particularly illustrated in the following formula, but may have substituents that the cyclic hydrocarbon group of Y b1 may also have. TIFF2025100439000051.tif94165

[0044] 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. TIFF2025100439000052.tif233160

[0045] TIFF2025100439000053.tif249152

[0046] TIFF2025100439000054.tif254163

[0047] 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. As the anion in the salt represented by the formula (B1-A1), specifically, anions described in JP-A-2010-204646 can be mentioned.

[0048] Preferred anions in the salt represented by the formula (B1-A1) include anions represented by the formula (B1a-1) to the formula (B1a-70). TIFF2025100439000055.tif185164

[0049] TIFF2025100439000056.tif252165

[0050] TIFF2025100439000057.tif70165

[0051] Among them, anions represented by any of the formula (B1a-1) to the formula (B1a-3), the formula (B1a-7) to the formula (B1a-19), and the formula (B1a-22) to the formula (B1a-70) are preferred.

[0052] The anion represented by the formula (B1-A2) is represented by the following formula. TIFF2025100439000058.tif23100[In the formula (B1-A2), L b2 and Y b1 have the same meaning as in the formula (B1). nb4 represents any integer from 1 to 5. When nb4 is 2 or more, a plurality of L b2 -Y b1 may be the same as or different from each other. 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. However, 1 ≦ nb3 + nb4 ≦ 5 is satisfied.]

[0053] In formula (B1-A2), L b2 Examples of the hydrocarbon group and Y b1 Examples of the cyclic hydrocarbon group are, within the range permitted by the upper limit of the number of carbon atoms, the same as the examples of the hydrocarbon group of L b2 in formula (B1) and the examples of the cyclic hydrocarbon group of Y b1 . Examples of the hydrocarbon group of L b2 , the methyl group of Y b1 and the substituents that the cyclic hydrocarbon group may have are also the same as the examples of the hydrocarbon group of L b2 in formula (B1), the methyl group of Y b1 and the substituents that the cyclic hydrocarbon group may have. These hydrocarbon groups, methyl groups and cyclic hydrocarbon groups may have one substituent or a plurality of substituents. In formula (B1-A2), L b2 is preferably a chain hydrocarbon group having 1 to 12 carbon atoms (wherein -CH2- contained in the chain hydrocarbon 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 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 (wherein -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 (wherein -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. 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).

[0054] 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 - in the following structure. TIFF2025100439000059.tif28106[In the above formula, L b2 and Y b1 and R b1 and nb3 have the same meanings as in formula (B1-A2).] When nb4 is 2 or more, a plurality of L b2 and Y b1 are preferably the same group as each other.

[0055] 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, iodine atom and the like. 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, carbonyl group and the like. These replaced groups include the same ones as the groups exemplified in the present specification within the range where the upper limit of the number of carbon atoms permits. 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.

[0056] 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. The following anions have some R b1 omitted and may contain substituents not shown. TIFF2025100439000060.tif95162

[0057] In another form of the acid generator (B), an anion obtained by replacing the anion represented by the formula (B1) 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, a sulfonylimide anion or sulfonylmethide anion represented by the formula (B1-A3) (hereinafter sometimes referred to as "anion (B1-A3)") is preferable. TIFF2025100439000061.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 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, and -CH2- contained in the cyclic hydrocarbon group may be replaced by -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), examples of L b2’ and Y b1’ are 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 -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O- or -CO-, and * represents a bonding site with SO2.) It is preferably this. 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, an anion represented by formula (B1-A3’) can be mentioned. TIFF2025100439000062.tif22123 [In formula (B1-A3’), A 1 , nb5 represents the same meaning as in formula (B1-A3). L b2 and Y b1 represent the same meaning as in formula (B1). 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 disulfonylmethide ring of is preferably having 3 to 6 carbon atoms, and the hydrogen atom of the methylene group contained in the ring is preferably replaced by a fluorine atom.

[0058] Examples of the anion represented by formula (B1-A3) include the following. Among them, anions represented by formula (B3a-1) and formula (B3a-2) are preferred. TIFF2025100439000063.tif189163

[0059] Examples of the carboxylic acid anion include the following. TIFF2025100439000064.tif41155

[0060] ZI + 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 the above-mentioned cations (b2-1) to (b2-5) can be mentioned.

[0061] Salt (B1) is a combination of the above-mentioned anion and the above-mentioned organic cation, and these can be arbitrarily combined. Examples of salt (B1) preferably 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 (B1-3a-1) to formula (B1-3a-3), or formula (B1-3a-11) to formula (B1-3a-14), and a combination with cation (b2-1), cation (b2-2), cation (b2-3), cation (b2-4), or cation (b2-5).

[0062] 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 preferable. Among them, those containing an arylsulfonium cation are preferable, 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 preferable. TIFF2025100439000065.tif248168

[0063] TIFF2025100439000066.tif244159

[0064] TIFF2025100439000067.tif254168

[0065] TIFF2025100439000068.tif254160

[0066] TIFF2025100439000069.tif249163

[0067] TIFF2025100439000070.tif250150

[0068] TIFF2025100439000071.tif187159

[0069] When the salt (I) and the compound (B) are contained as the acid generator, the ratio of the contents of the salt (I) and the compound (B) (mass ratio; salt (I): 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.

[0070] <Resist composition> The resist composition of the present invention contains an acid generator containing salt (I). 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 such as a salt that generates an acid having a lower acidity than the acid generated from the acid generator (hereinafter sometimes referred to as "quencher (C)"), and preferably contains a solvent (hereinafter sometimes referred to as "solvent (E)").

[0071] <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.

[0072] <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 structural units derived from other monomers known in the art, etc.).

[0073] 〈Structural unit (a1)〉 The structural unit (a1) is derived from a monomer having an acid-labile group (hereinafter sometimes referred to as "monomer (a1)"). The acid-labile group contained in the resin (A) is preferably a group represented by the formula (1) (hereinafter also referred to as group (1)) and / or a group represented by the formula (2) (hereinafter also referred to as group (2)). TIFF2025100439000072.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.] TIFF2025100439000073.tif2278[In formula (2), R a1’ and R a2’ each independently represent 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, and -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.]

[0074] Ra1 、 R a2 and R a3 Examples of the alkyl group in R R a1 、 R a2 and R a3 Examples of the alkenyl group in R R a1 、 R a2 and R a3 The alicyclic hydrocarbon group in R a1 、 R a2 and R a3 may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, etc. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group and the following group (* represents the bonding site). The number of carbon atoms of the alicyclic hydrocarbon group of R TIFF2025100439000074.tif10159R a1 、 R a2 and R a3 Examples of the aromatic hydrocarbon group in R 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. 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-. TIFF2025100439000075.tif28138

[0075] R a1’ R a2’ and R a3’ Examples of the hydrocarbon group in R include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these. a1 The alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and the group formed by combining these are the same as those exemplified for R a2 R a3 . R a2’ and R a3’ When they are bonded to each other to form a heterocycle together with the carbon atom to which they are bonded and X, -C(R a1’ )(R a2’ )-X-Ra3’ Examples thereof include the following groups. * represents a bond. TIFF2025100439000076.tif19124R a1 , R a2 , R a3 , R a1 , R a2’ and R a3’ The halogen atom that may be possessed by R may be a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. R a1’ and R a2’ It is preferable that at least one of them is a hydrogen atom. na' is preferably 0.

[0076] Examples of group (1) include the following groups. In formula (1), R a1 , R a2 and R a3 are alkyl groups, ma = 0, and na = 1. A tert-butoxycarbonyl group is preferable as such a group. In formula (1), R a1 , R a2 together with the carbon atom to which they are attached form an adamantyl group, R a3 is an alkyl group, ma = 0, and na = 1. In formula (1), R a1 and R a2 are each independently an alkyl group, R a3 is an adamantyl group, ma = 0, and na = 1. Specific examples of group (1) include the following groups. * represents a bond. TIFF2025100439000077.tif149164

[0077] Specific examples of group (2) include the following groups. * represents a bond. TIFF2025100439000078.tif55153

[0078] The monomer (a1) is preferably a monomer having an acid labile group and an ethylenically unsaturated bond, more preferably a (meth)acrylic monomer having an acid labile group.

[0079] Of the (meth)acrylic monomers having an acid labile group, preferred are those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms. By using a resin (A) having a structural unit derived from a monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group in a resist composition, the resolution of the resist pattern can be improved.

[0080] Examples of the structural unit derived from the (meth)acrylic monomer having the group (1) include a structural unit represented by formula (a1-0) (hereinafter, sometimes referred to as structural unit (a1-0)), a structural unit represented by formula (a1-1) (hereinafter, sometimes referred to as structural unit (a1-1)), or a structural unit represented by formula (a1-2) (hereinafter, sometimes referred to as structural unit (a1-2)). Preferably, it is at least one structural unit selected from the group consisting of the structural unit (a1-0), the structural unit (a1-1) and the structural unit (a1-2), more preferably at least one or two structural units selected from the group consisting of the structural unit (a1-1) and the structural unit (a1-2). These may be used alone or in combination of two or more. TIFF2025100439000079.tif44145 [In formula (a1-0), formula (a1-1) and formula (a1-2), all symbols have the same meanings as defined above.]

[0081] R a01 , R a4 and R a5 The halogen atom in the formula (I) includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R a01 , R a4 and R a5Examples of the alkyl group 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, and iodomethyl group. The number of carbon atoms of the alkyl group is preferably 1 to 4, more preferably 1 to 3, and still 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 are preferably a hydrogen atom or a methyl group, and more preferably a methyl group. L a01 、L a1 and L a2 are preferably an oxygen atom or *-O-(CH2) k01 -CO-O- (wherein k01 is preferably any integer from 1 to 4, more preferably 1). More preferably, it is an oxygen atom. R a02 、R a03 、R a04 、R a6 and R a7 Examples of the alkyl group, alkenyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group and the group formed by combining these in R a1 、R a2 and R a3 are the same as those exemplified by the formula (1). R a02 、R a03 、and R a04 The alkyl group in is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and still 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, and 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, and 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.

[0082] 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) 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. a01 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) 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. TIFF2025100439000080.tif119160

[0083] 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) 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. a4 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) 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. TIFF2025100439000081.tif34170

[0084] Examples of the structural unit (a1-2) include a structural unit represented by any of Formula (a1-2-1) to Formula (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. Among them, structural units represented by any of Formula (a1-2-2), Formula (a1-2-5), Formula (a1-2-6), and Formula (a1-2-10) to Formula (a1-2-20) are preferable. a5 Examples of the structural unit (a1-2) include a structural unit represented by any of Formula (a1-2-1) to Formula (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. Among them, structural units represented by any of Formula (a1-2-2), Formula (a1-2-5), Formula (a1-2-6), and Formula (a1-2-10) to Formula (a1-2-20) are preferable. TIFF2025100439000082.tif92163

[0085] 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, still even 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 70 mol% or less, 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), the content thereof 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%.

[0086] Examples of the structural unit having the group (2) in the structural unit (a1) include a structural unit represented by the formula (a1-4) (hereinafter sometimes referred to as "structural unit (a1-4)"). TIFF2025100439000083.tif32119[In the formula (a1-4), all the symbols have the same meanings as described above.]

[0087] 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 include the same ones 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, 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 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. na12 is preferably 0, 1, or 2, more preferably 0 or 1, and even more preferably 0.

[0088] 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 the -CH2- contained in the alkanediyl group of A is replaced by -O-, -CO-, or -NR a18 , the number of carbon atoms before replacement is taken 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, and an alkanediylamino group. As long as the upper limit of the number of carbon atoms permits, those similar to those exemplified herein may be mentioned. 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 R a1represents a bonding site bonded to the carbon atom to which it is bonded. A a12 The alkane diyl group of can be the same alkane diyl group as A within the range allowed by the upper limit of the number of carbon atoms. a11 A a11 is preferably a single bond, *-CO-O- or *-CO-O-A a12 -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-. 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.

[0089] 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. 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 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 groups. 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 the bonding site, and one is the bonding site with R a34 and the other is the bonding site with R. TIFF2025100439000085.tif15105

[0090] 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 groups, 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 a36The alkyl group and alicyclic hydrocarbon group in are preferably unsubstituted. R a36 The aromatic hydrocarbon group in preferably has an aromatic ring having an aryloxy group having 6 to 10 carbon atoms.

[0091] -OC(R a34 )(R a35 )-O-R a36 in the structural unit (a1-4) eliminates upon contact with an acid (for example, 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 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, it is preferable that at least one is 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 1-position, it is preferable that at least one is 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 preferable that it is bonded to the 4th to 7th positions, and more preferably bonded to the 5th or 6th position. .

[0092] Examples of the structural unit (a1-4) include structural units derived from the monomers described in JP-A-2010-204646. Preferably, the structural units represented by formula (a1-4-1) to formula (a1-4-42) and the hydrogen atom corresponding to R a1 in the structural unit (a1-4) are replaced with a halogen atom, a haloalkyl group, or an alkyl group, and more preferably, the 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 included. TIFF2025100439000086.tif228165

[0093] 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).

[0094] Examples of the structural unit derived from the (meth)acrylic monomer having the group (2) include the structural unit represented by the formula (a1-5) (hereinafter sometimes referred to as "structural unit (a1-5)"). TIFF2025100439000087.tif4558[In the formula (a1-5), all the symbols have the same meanings as described above.]

[0095] 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-.

[0096] Examples of the structural unit (a1-5) include structural units derived from monomers described in JP-A-2010-61117. Among them, the structural units represented by Formula (a1-5-1) to Formula (a1-5-4) are preferable, and the structural unit represented by Formula (a1-5-1) or Formula (a1-5-2) is more preferable. TIFF2025100439000088.tif31130When 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 still more preferably 25 mol% or more, based on all the structural units of the resin (A). Also, 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 still 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 still more preferably.

[0097] 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)"). TIFF2025100439000089.tif3479[In Formula (a1-6), all the symbols have the same meanings as described above.]

[0098] R in Formula (a1-6) a61 Examples of the halogen atom and the alkyl group which may have a halogen atom in are the same as those exemplified for the halogen atom and the alkyl group which may have a halogen atom in R of Formula (a1-0). a01 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, and the like. 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 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 )(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. TIFF2025100439000090.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 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.

[0099] 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, and 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, and 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 examples include 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 examples include 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, and more preferably a phenylene group which may have a hydroxy group.

[0100] Examples of the structural unit (a1-6) include structural units represented by Formula (a1-6-1) to Formula (a1-6-43), etc. Structural units represented by Formula (a1-6-1) to Formula (a1-6-9) are preferred, 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, R a61 structural units in which the hydrogen atom corresponding to is replaced by a methyl group or the like, and also, structural units 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). TIFF2025100439000091.tif227164

[0101] 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, 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 can be mentioned. 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%.

[0102] Also, examples of the structural unit (a1) include the following structural units. TIFF2025100439000092.tif33167

[0103] When the resin (A) etc. contains structural units represented by the formulas (a1-7-1) to (a1-7-7), the content rate 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, with respect to all the structural units of the 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 95 mol% is preferable, 15 to 90 mol% is more preferable, 20 to 85 mol% is still more preferable, 20 to 70 mol% is even more preferably, and 20 to 60 mol% is particularly preferable.

[0104] Moreover, as the structural unit (a1), the following structural units are also mentioned. TIFF2025100439000093.tif51120 When the resin (A) etc. contains structural units represented by the formulas (a1-8-1) to (a1-8-3), the content rate 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, with respect to all the structural units of the 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 preferably, and 20 to 40 mol% is particularly preferable.

[0105] 〈Structural unit (s)〉 The structural unit(s) is / are derived from a monomer having no acid-labile group (hereinafter sometimes referred to as "monomer(s)"). As the monomer from which the structural unit(s) is / are derived, a monomer having no acid-labile group known in the resist field can be used. Preferably, the structural unit(s) has / have a hydroxy group, a carboxy group or a lactone ring. By using a resin containing a structural unit having a hydroxy group or a carboxy group and no acid-labile group (hereinafter sometimes referred to as "structural unit (a2)") and / or a structural unit having a lactone ring and no acid-labile group (hereinafter sometimes referred to as "structural unit (a3)") in the resist composition of the present invention, the resolution of the resist pattern and the adhesion to the substrate can be improved.

[0106] 〈Structural unit (a2)〉 The structural unit (a2) is a structural unit represented by formula (a2) and has an alcoholic hydroxy, phenolic hydroxy group or phenolic carboxy group. TIFF2025100439000094.tif4193[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 Ls a22 may be the same as or different from each other.]

[0107] R a2 Examples of the halogen atom in R include a fluorine atom, a chlorine atom, and a bromine atom, etc. 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 even more preferably a hydrogen atom or a methyl group.

[0108] A a21 Examples of the alkanediyl group of A include 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, an octane-1,8-diyl group, a nonane-1,9-diyl group, a decane-1,10-diyl group, an undecane-1,11-diyl group, and a dodecane-1,12-diyl group, and 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, 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. A a21is 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 a28 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a tert-butyl group. A a21 When the -CH2- contained in the alkanediyl group of A a21 is replaced by -O-, -CO- or -NR a28 the number of carbon atoms before replacement is defined as the number of carbon atoms of the hydrocarbon group. A a21 Examples of the group in which -CH2- contained in the alkanediyl group of A a21 is replaced by -O- 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 carbonyl group (a group in which -CH2- contained in a methylene group is replaced by -CO-), an oxy group (a group in which -CH2- contained in a methylene group is replaced by -O-), an amino group (a group in which -CH2- contained in an alkanediyl group is replaced by -NR a28 -), an alkoxy group (a group in which any -CH2- contained in an alkyl group is replaced by -O-), an alkoxycarbonyl group (a group in which any -CH2-CH2- contained in an alkyl group is replaced by -O-CO-), an alkylcarbonyl group (a group in which any -CH2- contained in an alkyl group is replaced by -CO-), an alkylamino group (a group in which -CH2- contained in an alkyl group is replaced by -NR a28 -), a peptide group (a group in which -CH2-CH2- contained in an ethylene group is replaced by -CO-NR a28 -), an alkanediylamino group (a group in which any -CH2- contained in an alkanediyl group is replaced by -NR a28 -), etc. These replaced groups include those similar to those exemplified in this specification as long as the upper limit of the number of carbon atoms permits. For example, A a21The -CH2- contained in the alkanediyl group is replaced by -O-, -CO- or -NR a28 Examples of the group thus replaced include *-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 - are included. Among them, *-CO-O-, *-CO-O-A a22 -CO-O- or *-O-A a22 -CO-O-, *-CO-NR a28 - are preferred. Here, A a22 represents an alkanediyl group having 1 to 8 carbon atoms, and * represents the bonding site bonded to the carbon atom to which R a2 is bonded. The alkanediyl group of A a22 includes 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-.

[0109] L a21 The hydrocarbon group in is a (na2 + 1)-valent hydrocarbon group, and examples include chain hydrocarbon groups, alicyclic hydrocarbon groups such as monocyclic or polycyclic (including spiro rings, condensed rings, bridged rings, etc.) alicyclic hydrocarbon groups, and aromatic hydrocarbon groups, and groups formed by combining two or more of these groups (for example, hydrocarbon groups formed from alicyclic hydrocarbon groups or aromatic hydrocarbon groups and chain hydrocarbon groups) are also acceptable. L a21 Examples of the chain hydrocarbon group of include divalent to pentavalent chain hydrocarbon groups such as alkanediyl groups, alkanetriyl groups, alkanetetrayl groups, and alkanepentayl groups. L a21 Examples of the alkanediyl group of include, for example, Aa21 Examples thereof include the same alkandiyl group. L a21 Examples of the alkanetriyl group of L include a methanetriyl group, an ethanetriyl group, a propanetriyl group, a butanetriyl group, a pentanetriyl group, a hexanetriyl group, a heptanetriyl group, an octanetriyl group, a nonanetriyl group, a decanetriyl group, an undecanetriyl group, a dodecanetriyl group, a tridecanetriyl group, a tetradecanetriyl group, a pentadecanetriyl group, a hexadecanetriyl group, a heptadecanetriyl group, and the like. 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, a heptadecanetetrayl group, and the like. Examples of the alkanepentayl group include a methanepentayl group, an ethanepentayl group, a propanepentayl group, a butanepentayl group, a pentanepentayl group, a hexanepentayl group, and the like. Examples also include a group in which one or more hydrogen atoms of the above-described group are replaced with a bonding site, and the like. L a21 The number of carbon atoms of 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 and the like. The bonding site can be at any position. TIFF2025100439000095.tif44167For example, monocyclic alicyclic hydrocarbon groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group, cyclopropanetriyl group, cyclobutanetriyl group, cyclopentanetriyl group, cyclohexanetriyl group, cycloheptanetriyl group, cyclooctanetriyl group, cyclodecanetriyl group, cyclopropanetetrayl group, cyclobutanetetrayl group, cyclopentanetetrayl group, cyclohexanetetrayl group, cycloheptanetetrayl group, cyclooctanetetrayl group, cyclodecanetetrayl group, etc. and polycyclic alicyclic hydrocarbon groups such as 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, norbornanetriyl group, adamantanetriyl group, decahydronaphthalenetriyl group, bicyclo[3.3.0]octanetriyl group, norbornanetetrayl group, adamantanetetrayl group, decahydronaphthalenetetrayl group, bicyclo[3.3.0]octanetetrayl group, etc. can be mentioned. The number of carbon atoms of 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 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, etc. The number of carbon atoms of 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. The 3- to 5-valent 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 combined groups of two or more types include groups combining an alicyclic hydrocarbon group and a chain hydrocarbon group, groups combining an aromatic hydrocarbon group and a chain hydrocarbon group, groups combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group, groups combining an alicyclic hydrocarbon group, a chain hydrocarbon group, and an aromatic hydrocarbon group, etc. In the combination, the alicyclic hydrocarbon group, aromatic hydrocarbon group, and chain hydrocarbon group may each be combined with two or more types. Also, any of the groups may be bonded to A a21 and L a22 and may be bonded. L a21 The alkanediyl group of L may be replaced by -O- or -CO-. When the alkanediyl group of L is replaced by -O- or -CO-, for example, *-L a21 -X a23 -(L a21 represents an alkanediyl group having 1 to 8 carbon atoms, X a23 represents -O-, -O-CO-, -CO-O-, or -O-CO-O-, and * represents the bonding site with X a21 .) is preferred. a2 The 3- to 5-valent 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 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 at the 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 in 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 in 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 in 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 in 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 in 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 methylene thio group, ethylene thio group, and propanediyl thio 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 methylene sulfonyl group, ethylene sulfonyl group, and 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.

[0110] Examples of the cycloalkoxy group include cycloalkoxy groups having 3 to 27 carbon atoms, such as cyclohexyloxy group. Examples of the cycloalkylalkoxy group include cycloalkylalkoxy groups having 4 to 27 carbon atoms, such as cyclohexylmethoxy group. Examples of the alkoxycarbonyloxy group include alkoxycarbonyloxy groups having 2 to 26 carbon atoms, such as 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 benzoyloxy group. Examples of the aromatic hydrocarbon group-carbonyl group include aromatic hydrocarbon group-carbonyl groups having 7 to 27 carbon atoms, such as benzoyl group. Examples of the aromatic hydrocarbon group-oxy group include aromatic hydrocarbon group-oxy groups having 6 to 27 carbon atoms, such as phenyloxy group.

[0111] 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 47,168 combinations of TIFF2025100439000096.tif, examples of groups in which -CH2- contained in the base is replaced by -O-, -S-, -CO- or -SO2- include the following groups and the like. The bonding site can be at any position. TIFF2025100439000097.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 and the like. A haloalkyl group having 1 to 4 carbon atoms is preferable, and a haloalkyl group having 1 to 3 carbon atoms is more preferable. L a21 By including a branched structure in the hydrocarbon group of, 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 Examples of the substituent that the hydrocarbon group in a21 may have include a halogen atom, a haloalkyl group having 1 to 4 carbon atoms, or an alkyl group having 1 to 6 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-). 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 (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-) are more preferable, and a fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, a hydroxy group, or a methoxy group are even more preferable. L a21is a single bond, a linear hydrocarbon group having 1 to 12 carbon atoms which may have a substituent (provided that -CH2- contained in the linear hydrocarbon group may be replaced by -O- or -CO-), a cyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent (provided that -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-), or a group formed by combining a linear hydrocarbon group having 1 to 8 carbon atoms which may have a substituent and a cyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent (provided that -CH2- contained in the linear 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-), preferably a linear hydrocarbon group having 1 to 10 carbon atoms which may have a substituent (provided that -CH2- contained in the linear hydrocarbon group may be replaced by -O- or -CO-), a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (provided that -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-), or a group formed by combining a linear hydrocarbon group having 1 to 6 carbon atoms which may have a substituent and a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (provided that -CH2- contained in the linear 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-), more preferably.

[0112] L a22Examples of the alkanediyl having 1 to 12 carbon atoms 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 is preferably 1 to 10, more preferably 1 to 8, still more preferably 1 to 6, and even more preferably 1 to 4. L a22 The fluorine atom(s) that a22 [[]]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 a21 [[]]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 suitable structural units of the structural unit (a2) in the same manner as the following structural units. TIFF2025100439000098.tif66164

[0113] 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. 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.

[0114] 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)"). TIFF2025100439000099.tif30128[In the formula (a2-A), all the symbols represent the same meanings as described above.] R a2 and A a21 are each a group similar to those exemplified by 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, and iodomethyl group. The number of carbon atoms of the alkyl group is preferably 1 to 4, more preferably 1 to 3, still more preferably a methyl group or an ethyl group, and even more preferably a 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, and 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 a methoxy group or an ethoxy group, and even more preferably a 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, and 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 still more preferably a 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, and tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, and more preferably a methoxyethoxy group or an ethoxyethoxy group. R 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, 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, more preferably an acetyloxy group. R a27 is preferably a halogen atom, 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 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. 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, 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, 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, more preferably bonded to the 5th or 6th position.

[0115] 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 represented by formula (a2-2-1) to formula (a2-2-32), formula (a2-3-1) to formula (a2-3-24), in which the methyl group corresponding to R in the structural unit (a2-A) a2 is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group. TIFF2025100439000100.tif107170

[0116] 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 a2It can be incorporated into the resin (A) by polymerizing a compound (such as (a2-A')) in the state of ). Further, for example, after polymerization using the structural unit (a1-4), it can be incorporated into the resin (A) by treating with an acid such as p-toluenesulfonic acid. Further, after polymerization using acetoxystyrene or the like, the structural unit (a2-A) can be incorporated into the resin (A) by treating with an alkali such as tetramethylammonium hydroxide.

[0117] In the structural unit (a2), when L a21 is a cyclic hydrocarbon group, examples of the structural unit having an alcoholic hydroxy group include a structural unit represented by the formula (a2-B) (hereinafter sometimes referred to as "structural unit (a2-B)"), a structural unit represented by the formula (a2-C) (hereinafter sometimes referred to as "structural unit (a2-C)"), and a structural unit represented by the formula (a2-D) (hereinafter sometimes referred to as "structural unit (a2-D)"). TIFF2025100439000102.tif45100 [In the formulas (a2-B) and (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-, k2 represents an integer from 1 to 7. * represents the bonding position with -CO-. X a2 represents a single bond or -CO-. R a25 and R a26 each independently represent a hydrogen atom, a methyl group, or a hydroxy group. nB2 represents an integer from 1 to 5. When nB2 is 2 or more, a plurality of Xs a2 may be the same as or different from each other. nB22 represents an integer from 0 to 8. When nB22 is 2 or more, a plurality of Rs 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-C4 alkyl group, a C1-C4 alkoxy group or a C2-C8 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 ethoxymethoxy group, and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group or an ethoxyethoxy group. 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.

[0118] 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 to the following is replaced by 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%.

[0119] TIFF2025100439000104.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 plurality of 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 plurality of 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, independently of each other, a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a 3,3,3-trifluoropropyl group, a 4,4,4-trifluorobutyl group, and the like. R a21 and R a22 is preferably a trifluoromethyl group. 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, and the like. L a24 is preferably a single bond or a methylene group. R a27 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 ethoxymethoxy group, 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.

[0120] The structural unit (a2-D) is more preferably a structural unit represented by the following formula (a2-D1) (hereinafter, may be referred to as "structural unit (a2-D1)"). TIFF2025100439000105.tif51108[In formula (a2-D1), R a2 、A a21 、R a27, na2 and na21 have 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.

[0121] Examples of the structural unit (a2-D) include the structural units described below. TIFF2025100439000106.tif62167

[0122] 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.

[0123] 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 with respect to 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%.

[0124] 〈Structural unit (a3)〉 The lactone ring of 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 adamantane lactone ring, or a bridged ring containing a γ-butyrolactone ring structure (for example, a structural unit represented by the following formula (a3-2)) can be mentioned.

[0125] The structural unit (a3) is preferably a structural unit represented by formula (a3-1), formula (a3-2), formula (a3-3), or formula (a3-4). These may be contained alone or in combination of two or more. TIFF2025100439000107.tif51164[In formula (a3-1), formula (a3-2), formula (a3-3), and 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 to 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, the plurality of R a21 、R a22 、R a23 and / or R a25 may be the same as or different from each other.

[0126] 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 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)’. TIFF2025100439000108.tif4051 (wherein R a24 、L a7 represent the same meaning as above.)

[0127] 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 in which the corresponding methyl groups are replaced with hydrogen atoms are preferred. 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). Further, 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 structural unit (a3-1), structural unit (a3-2), structural unit (a3-3), or 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 resin (A). Also, 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.

[0128] 〈Structural unit (a4)〉 The structural unit represented by formula (a4) is shown below. TIFF2025100439000110.tif2753[In formula (a4), R 41 represents a hydrogen atom or a methyl group. R 42 represents a saturated hydrocarbon group having a halogen atom with 1 to 24 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-.

[0129] R 42 The saturated hydrocarbon group represented by includes a linear or branched chain saturated hydrocarbon group, a monocyclic or polycyclic alicyclic saturated hydrocarbon group, and a group formed by combining these, etc. Examples of the chain saturated 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 saturated hydrocarbon group include monocyclic alicyclic saturated hydrocarbon groups that are monocyclic cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, etc.; polycyclic alicyclic saturated hydrocarbon groups that are polycyclic cycloalkyl groups such as decahydronaphthyl group, adamantyl group, norbornyl group and the following group (*represents the bonding site). Examples of the group formed by the combination of TIFF2025100439000111.tif10146 include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic saturated hydrocarbon groups, such as -alkanediyl group-alicyclic saturated hydrocarbon group, -alicyclic saturated hydrocarbon group-alkyl group, -alkanediyl group-alicyclic saturated hydrocarbon group-alkyl group, etc. 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, etc.; branched alkanediyl groups such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-methylbutane-1,4-diyl group, 2-methylbutane-1,4-diyl group, etc. The terminal of the branched alkanediyl group may be a methyl group. R 42 Examples of the halogen atom contained in the saturated hydrocarbon group included in R include fluorine atom, chlorine atom, bromine atom or iodine atom. R 42 Examples of the group in which -CH2- of the saturated hydrocarbon group contained in R is replaced by -O- or -CO- include hydroxy group, carboxy group, carbonyl group, oxy group, alkoxy group, alkoxycarbonyl group, alkylcarbonyl group, alkylcarbonyloxy group, alkanediyl-oxy group, alkanediyl-oxycarbonyl group, alkanediylcarbonyl group, alkanediylcarbonyloxy group, cycloalkoxy group, cycloalkylalkoxy group, and groups formed by combining two or more of these groups. 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.

[0130] As the structural unit (a4), R 42 is preferably a saturated hydrocarbon group having a fluorine atom, and R 42 Examples of the structural unit (a4) in which is a saturated 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. TIFF2025100439000112.tif3967[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.]

[0131] 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 [specific context] 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, 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, 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 [specific context] 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, a cycloheptane-1,4-diyl group having a fluorine atom, 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, an adamantane-2,6-diyl group having a fluorine atom. L 42fThe number of fluorine atoms in the alkanediyl group and the cycloalkanediyl group having a fluorine atom is preferably 1 or more, and more preferably 2 or more. L 42f The alkanediyl group and the cycloalkanediyl group having a fluorine atom in are preferably a perfluoroalkanediyl group and a perfluorocycloalkanediyl group, respectively.

[0132] L 42f Examples of the perfluoroalkanediyl 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 perfluorocycloalkanediyl group in include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, a perfluoroadamantanediyl group, and the like.

[0133] L 41 is preferably a single bond or an alkanediyl group having 1 to 3 carbon atoms, more preferably a single bond, a methylene group or an ethylene group, and even 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.

[0134] Examples of the structural unit (a4-1) include the following structural units and structural units in which the methyl group corresponding to R in the following structural units is replaced with a hydrogen atom. 41 The structural unit represented by formula (a4-2) is the following structural unit. TIFF2025100439000114.tif3892[In formula (a4-2), R 41 represents a hydrogen atom or a methyl group. L 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 with -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 with -O- or -CO-. However, at least one of L 43f and R 43f has a fluorine atom, and the upper limit of the total carbon number of L 43f and R 43f is 21.

[0135] Examples of the saturated hydrocarbon group in L 43f and R 43f include linear or branched chain saturated hydrocarbon groups, monocyclic or polycyclic alicyclic saturated hydrocarbon groups, and groups formed by combining these. Examples of the saturated hydrocarbon group in L 43f and R 43f are, as long as the upper limit of the total carbon number of L 43f and R 43f allows, R in formula (a4)​42 Examples of the saturated hydrocarbon group include the same groups as the saturated hydrocarbon groups exemplified as the saturated hydrocarbon group of

[0136] L 43f As the saturated hydrocarbon group of , an alkanediyl group having 1 to 6 carbon atoms or a group represented by the formula (L43f-1) is preferable. TIFF2025100439000115.tif13120[In the formula (L43f-1), s represents 0 or 1. L 45f and L 46f each independently represent a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a fluorine atom. L 47f represents a single bond or a divalent saturated 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 .

[0137] Examples of the divalent saturated 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 saturated hydrocarbon groups, and divalent saturated hydrocarbon groups formed by combining an alkanediyl group and a divalent alicyclic saturated 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.

[0138] 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 the bonding site with -O-CO-R 43f and. TIFF2025100439000116.tif47140

[0139] R 43f is preferably a saturated hydrocarbon group having a fluorine atom. Examples of the structural unit represented by formula (a4-2) in this case include the structural units represented by formula (a4-2A) or (formula a4-2B). TIFF2025100439000117.tif39143[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 a saturated hydrocarbon group having 1 to 20 carbon atoms and having a fluorine atom. A 43f represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom, and -CH2- contained in the saturated 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. R 43fB represents a saturated hydrocarbon group having 1 to 17 carbon atoms which 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 saturated hydrocarbon group of R, as long as the upper limit of the number of carbon atoms permits, is a saturated hydrocarbon group similar to the saturated hydrocarbon group exemplified by R 42 as shown. 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 saturated hydrocarbon group of R, as long as the upper limit of the number of carbon atoms permits, is a saturated hydrocarbon group similar to the saturated hydrocarbon group exemplified by R 43fB in formula (a4). 42 as shown. A 43f is preferably a divalent chain saturated hydrocarbon group which may have fluorine atoms, a divalent alicyclic saturated hydrocarbon group, or a group combining them, more preferably a divalent chain saturated hydrocarbon group having fluorine atoms, and even more preferably a fluorinated alkanediyl group having 1 to 6 carbon atoms. R 43fBThe saturated hydrocarbon group which may have a fluorine atom is preferably a chain saturated hydrocarbon group, an alicyclic saturated 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 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, heptyl group, perfluoroheptyl group, octyl group and perfluorooctyl group and other alkyl fluoride groups, cyclopropylmethyl group, cyclopropyl group, cyclobutylmethyl group, cyclopentyl group, cyclohexyl group, perfluorocyclohexyl group, adamantyl group, adamantylmethyl group, adamantyldimethyl group, norbornyl group, norbornylmethyl group, perfluoroadamantyl group, perfluoroadamantylmethyl group and the like are more preferable.

[0140] 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). TIFF2025100439000118.tif14169

[0141] 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. TIFF2025100439000119.tif99167

[0142] 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. TIFF2025100439000120.tif111163

[0143] Examples of the structural unit (a4) also include the structural unit represented by formula (a4-3). TIFF2025100439000121.tif3282[In formula (a4-3), R 41 represents a hydrogen atom or a methyl group. L 44f 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-. R 44f 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 44f L 44f and 44f R 44f has a fluorine atom, and the upper limit of the total number of carbon atoms of 44f L 44f R

[0144] L 44f and 44f R 44f Examples of the saturated hydrocarbon group in 44f include linear or branched chain saturated hydrocarbon groups, monocyclic or polycyclic alicyclic saturated hydrocarbon groups, and groups formed by combining these. Examples of the saturated hydrocarbon group in 44f L 44f and 42 R 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 - represented groups (j1 to j5 each independently represent an integer of 1 to 6).) is more preferable. Further, an alkanediyl group having 1 to 4 carbon atoms (wherein 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-) is even more preferable. R 44f is preferably a saturated 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 saturated hydrocarbon group having 3 to 10 carbon atoms having a fluorine atom, or a combination thereof, 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.

[0145] 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 are mentioned. TIFF2025100439000122.tif85165

[0146] TIFF2025100439000123.tif3686[In the formula (a4-A), R 1 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. X 11 represents a single bond or *-CO-O-. * represents the bonding site with the carbon atom to which R 1 is bonded. L 1represents an aliphatic hydrocarbon group having 1 to 28 carbon atoms which may have a substituent, and -CH2- contained in the aliphatic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-. R 2 represents a perfluoroalkyl group having 1 to 8 carbon atoms. R 3 represents a hydrogen atom or a perfluoroalkyl group having 1 to 6 carbon atoms, and the perfluoroalkyl group may be bonded to L 1 to form an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-. mi represents any integer from 1 to 4. When mi is 2 or more, the groups in the plurality of parentheses may be the same as or different from each other.

[0147] R 1 Examples of the halogen atom and the alkyl group which may have a halogen atom in R include the same ones as those exemplified by R of formula (a1-0) to formula (a1-2). a01 R a4 and R a5 and the same ones as those exemplified by R of formula (a1-0) to formula (a1-2). R 1 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.

[0148] L 1 Examples of the aliphatic hydrocarbon group in L 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 divalent to pentavalent chain hydrocarbon groups such as an alkanediyl group, an alkanetriyl group, an alkanetetrayl group, an alkanepentayl group, etc. 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, 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, 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 bonding sites. 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.

[0149] Examples of the monocyclic or polycyclic alicyclic hydrocarbon group include the following alicyclic hydrocarbon groups, etc. The bonding site can be at any position. TIFF2025100439000124.tif46163For example, divalent to pentavalent alicyclic hydrocarbon groups such as cycloalkanediyl group, cycloalkanetriyl group, cycloalkanetetrayl group, cycloalkanepentayl group, etc. Specifically, monocyclic alicyclic hydrocarbon groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, 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 norbornanediyl group or an adamantanediyl group, and a cycloalkanediyl group spiro-bonded thereto respectively. Examples also include a group in which one or more hydrogen atoms of the above-described group are replaced with a bonding site. The number of carbon atoms of 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.

[0150] 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. In the combination, the alicyclic hydrocarbon group and the chain hydrocarbon group may each be combined with two or more types. Also, any group may be bonded to X 11 . Examples of a group 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 - etc.), a group in which a chain hydrocarbon group is bonded to an alicyclic hydrocarbon group (e.g., *-alicyclic hydrocarbon group - chain hydrocarbon group - etc.), 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 - etc.), 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 - etc.), 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 - etc.), 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.), and the like. * represents the bonding site with X. 11 In addition, groups in which one or more hydrogen atoms of the above-described groups are replaced with a bonding site, and the like, can also be mentioned.

[0151] 1 In the aliphatic hydrocarbon group having 1 to 28 carbon atoms of L, -CH2- may be replaced with -O-, -S-, -SO2- or -CO-. 1 When -CH2- contained in the aliphatic hydrocarbon group having 1 to 28 carbon atoms of L is replaced with -O-, -S-, -SO2- or -CO-, the number of carbon atoms before replacement is taken 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 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 herein within the range allowed by the upper limit of the number of carbon atoms. Examples also include a group in which one or more hydrogen atoms of the above-described group are replaced by a bonding site. 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 herein within the range allowed by the upper limit of the number of carbon atoms.

[0152] L 1 The aliphatic hydrocarbon group in L 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 (wherein -CH2- contained in the alkyl group or the alicyclic hydrocarbon group 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, and the like. The haloalkyl groups having 1 to 4 carbon atoms include fluoroalkyl groups having 1 to 4 carbon atoms, chloroalkyl groups having 1 to 4 carbon atoms, bromoalkyl groups having 1 to 4 carbon atoms, iodoalkyl groups having 1 to 4 carbon atoms, and the like. Examples of the haloalkyl group include perfluoroalkyl groups having 1 to 4 carbon atoms (such as trifluoromethyl group, pentafluoroethyl group, heptafluoropropyl group, nonafluorobutyl group, etc.), 2,2,2-trifluoroethyl group, 3,3,3-trifluoropropyl group, 4,4,4-trifluorobutyl group, 3,3,4,4,4-pentafluorobutyl group, chloromethyl group, bromomethyl group, iodomethyl group, and the like. 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 methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, and the like. 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. Examples of the alicyclic hydrocarbon group having 3 to 18 carbon atoms include monocyclic cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, etc., and polycyclic cycloalkyl groups such as decahydronaphthyl group, adamantyl group, norbornyl group, etc. The number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 16, more preferably 3 to 12, and still more preferably 3 to 10. Examples of the aromatic hydrocarbon group having 6 to 18 carbon atoms 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 14, more preferably 6 to 12, and still more preferably 6 to 10. When -CH2- contained in an alkyl group is replaced by -O- or -CO-, the 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, etc. 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 allows. The number of carbon atoms of the alkoxy group is preferably 1 to 9, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. The number of carbon atoms of the alkoxycarbonyl group is preferably 2 to 9, 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 10, 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 9, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. In addition, examples of the group in which -CH2- contained in the alicyclic hydrocarbon group is replaced by -O- or -CO- include those similar to the groups exemplified in this specification as long as the upper limit of the number of carbon atoms allows. L 1 Examples of the substituent that the aliphatic hydrocarbon group in 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-) are more preferred, and a fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, a hydroxy group, or a methoxy group are still more preferred. L 1 is R 3When it does not form an alkyl fluoride group and an alicyclic hydrocarbon group, 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- or -CO-), or a group formed by combining an optionally substituted chain hydrocarbon group having 1 to 6 carbon atoms and an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms (wherein -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O- or -CO-) is preferred; an optionally substituted chain hydrocarbon group having 1 to 8 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 12 carbon atoms, or a group formed by combining an optionally substituted chain hydrocarbon group having 1 to 6 carbon atoms and an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms (wherein -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-) is more preferred; an optionally substituted chain hydrocarbon group having 1 to 8 carbon atoms (wherein -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-), an optionally substituted alicyclic hydrocarbon group having 5 to 12 carbon atoms, a group formed by combining a chain hydrocarbon group having 1 to 6 carbon atoms and an optionally substituted alicyclic hydrocarbon group having 5 to 12 carbon atoms (wherein -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-), or a group formed by combining an optionally substituted alicyclic hydrocarbon group having 5 to 12 carbon atoms, a chain hydrocarbon group having 1 to 6 carbon atoms, and an optionally substituted alicyclic hydrocarbon group having 5 to 12 carbon atoms (wherein -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-) is even more preferred.

[0153] 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 When the C1-C6 fluoroalkyl group in [reference], as long as the upper limit of the carbon number allows, the C1-C6 fluoroalkyl groups listed in the examples of the fluoroalkyl group of R 2 are similarly listed. 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 is, when R 3 is a hydrogen atom, 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 12 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 that 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 1 and represents a single bond or an alkanediyl group having 1 to 4 carbon atoms. R 3 is L 1 The number of carbon atoms of the alicyclic hydrocarbon group formed by the combination with L TIFF2025100439000125.tif25130R 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.

[0154] Examples of the structural unit (a4-A) include the following structural units and the like. In these structural units, the structural units in which the methyl group corresponding to R 1 is replaced by a hydrogen atom, a halogen atom, a haloalkyl group or an alkyl group other than a methyl group, and the structural units in which the hydrogen atom corresponding to R 1 is replaced by a halogen atom, a haloalkyl group or an alkyl group can also be cited as specific examples of the structural unit (a4-A). TIFF2025100439000126.tif227159

[0155] In the above structural units, R 1A structural unit in which the methyl group corresponding to is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or an alkyl group other than a methyl group, and R 1 Structural units in which the hydrogen atom corresponding to 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).

[0156] When the resin (A) or the like 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) or the like.

[0157] 〈Structural unit (a5)〉 Examples of the non-leaving hydrocarbon group contained in the structural unit (a5) include groups having a linear, branched, or cyclic hydrocarbon group. Among them, the structural unit (a5) is preferably a group having an alicyclic hydrocarbon group. Examples of the structural unit (a5) include a structural unit represented by the formula (a5-1). TIFF2025100439000127.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 the -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-.]

[0158] R 52 The alicyclic hydrocarbon group in 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. The aliphatic hydrocarbon group having 1 to 8 carbon atoms includes, for example, 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. Examples of the alicyclic hydrocarbon group having a substituent include 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 55 Examples of the divalent saturated hydrocarbon group in L include a divalent chain saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, and preferably a divalent chain saturated hydrocarbon group. Examples of the divalent chain saturated hydrocarbon group include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group. The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkanediyl groups such as cyclopentanediyl group and cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include adamantanediyl group and norbornanediyl group.

[0159] 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. TIFF2025100439000128.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 x2represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. However, L x1 and L x2 have a total carbon number of 16 or less. In formula (L1-2), L x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms. L x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. However, L x3 and L x4 have a total carbon number of 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, L x5 , L x6 and L x7 have a total carbon number of 15 or less. In formula (L1-4), L x8 and L x9 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, L x8 , L x9 and W x1 have a total carbon number of 15 or less.

[0160] 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.

[0161] Examples of the group represented by the formula (L1-1) include the following divalent groups. Examples of the group represented by the formula (L1-2) include the following divalent groups. Examples of the group represented by the formula (L1-3) include the following divalent groups. Examples of the group represented by the formula (L1-4) include the following divalent groups. TIFF2025100439000132.tif13168L 55 is preferably a single bond or a group represented by the formula (L1-1).

[0162] As the structural unit (a5-1), there are the following structural units and the structural units in the structural unit (a5-1) among the following structural units where the methyl group corresponding to R 51 is replaced by a hydrogen atom. TIFF2025100439000133.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% with respect to all the structural units of the resin (A).

[0163] 〈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-.

[0164] As the sultone ring, 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 hetero atom in addition to -SO2-O- as an atomic group constituting the ring, like the ring represented by formula (T 1 -2). Examples of the hetero atom include an oxygen atom, a sulfur atom or a nitrogen atom, and preferably an oxygen atom. TIFF2025100439000134.tif2977

[0165] The sultone ring may have a substituent, and examples of the substituent include an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms, and an alkylcarbonyl group having 2 to 4 carbon atoms.

[0166] 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 perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group, 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 benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group and naphthylethyl group. Examples of the alkoxycarbonyl group include a group formed by bonding an alkoxy group such as methoxycarbonyl group and ethoxycarbonyl group to a carbonyl group. Preferably, an alkoxycarbonyl group having 6 or less carbon atoms is mentioned, and more preferably methoxycarbonyl group is mentioned. Examples of the alkylcarbonyl group include acetyl group, propionyl group and 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 preferable.

[0167] As the sultone ring, a ring represented by the following formula (T1') is preferable. TIFF2025100439000135.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, and more preferably a methylene group. R 41 is the same as the substituent 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 preferable. ma is preferably 0 or 1, and more preferably 0.

[0168] Examples of the ring represented by formula (T1’) include the following rings. The bonding site can be at any position. Among them, those in which the bonding site is at the 1-position or 3-position are preferred. TIFF2025100439000136.tif44147

[0169] 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.

[0170] The structural unit (a6) is preferably a structural unit represented by formula (a6-0). TIFF2025100439000137.tif4177[In 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 represents 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 dEach independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0171] R x Examples of the halogen atom of R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R x 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, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group, etc. Preferably, it is an alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group or an ethyl group. R x Examples of the alkyl group having a halogen atom of R 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, etc. R x R 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. 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 those obtained by combining two or more of these groups may also be used. 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, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1,17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-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; Monocyclic divalent alicyclic saturated hydrocarbon groups which are cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group; Polycyclic divalent 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. A x The bonding position to the sultone ring of A can be any position, but the one at the 1-position is preferred.

[0172] Examples of the structural unit (a6-0) include the following structural units. TIFF2025100439000138.tif93150

[0173] 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 even more preferably 3 to 30 mol% based on all the structural units of the resin (A).

[0174] <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.

[0175] 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 the formula (a7-A). TIFF2025100439000139.tif26123[In the formula (a7-A), R a7 represents 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 La72 each independently represents 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-, where *** is L a71 and represents the bonding site with RA - represents a sulfonate anion or a carboxylate anion. ZA + represents an organic cation.

[0176] R a7 Examples of the alkyl group having 1 to 6 carbon atoms in R a7 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 alkyl group having 1 to 6 carbon atoms and having a halogen atom in R a7 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, a dibromomethyl group, etc. 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 still more preferably a hydrogen atom or a methyl group.

[0177] X a71When it is a group represented by *-Ax-Ph-Ay-*, it is preferably a linking group represented by the following formula (X10). TIFF2025100439000140.tif3351[In formula (X10), Ax represents a bonding species that binds to the carbon atom to which R a7 is bonded, and represents one or more bonding species 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 a bonding species that binds to L a71 and represents one or more bonding species 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 C1-C6 fluoroalkyl group, a C1-C18 alkyl group, or a C1-C6 alkoxy group. mx represents an integer of any one of 0 to 4. When mx is an integer of 2 or more, a 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 one or more 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, it is preferably a bond represented by -CO-NR a71 -. 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 them, 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) are mentioned. * represents the bonding site with the carbon atom to which -R a7 is bonded. ** represents the bonding site with L a71 X20 represents -O- or -NR a71 -. TIFF2025100439000141.tif43162 Formula (X 10 -1) to formula (X 10 -10), specific examples of the group represented by are as follows. TIFF2025100439000142.tif79162 Among them, X 10 is a single bond or a group represented by formula (X 10 -1’) and formula (X 10 -3’) to formula (X 10 -10’), preferably a group represented by any one of, 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 a group represented by formula (X 10 -6’).

[0178] L a71 As the hydrocarbon group of, a group obtained by removing one hydrogen atom 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 X a71 and X a72 is mentioned. Further, as the hydrocarbon group of L a72 a group obtained by removing one hydrogen atom 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 X a72 and RA - is mentioned. L a71 and L a72Examples of the chain hydrocarbon group include a group in which one hydrogen atom of an alkyl group or an alkenyl group is removed. The alkyl group may be linear or branched, and specific examples include methyl group, ethyl group, 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, decanyl group, undecanyl group, dodecanyl group, tridecanyl group, tetradecanyl group, pentadecanyl group, heptadecanyl group, etc. Examples of the alkenyl group include 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. The number of carbon atoms in 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 in which one hydrogen atom of a monocyclic or polycyclic cycloalkyl group is removed. Examples of the monocyclic cycloalkyl group include cyclobutyl group, cyclopentane group, cyclohexane group, cyclopentyl group, cyclooctyl group, etc. L a71 and L a72 Examples of the polycyclic cycloalkyl group of L and L include a cycloalkyl group having a cross-linked 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 cross-linked structure include norbornyl group, adamantyl group, etc. Examples of the cycloalkyl group in which two or more rings are condensed include bicyclo[4.4.0]decanyl group, steroid group (steroid skeleton), etc. 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 cyclopentyl group, cyclohexyl group, norbornyl group, adamantyl group and a cycloalkyl group having 5 to 8 carbon atoms are spiro-bonded. 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. TIFF2025100439000143.tif28158When the alicyclic hydrocarbon group is a monocyclic cycloalkyl group, the number of carbon atoms in 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 in the alicyclic hydrocarbon group is preferably 7 to 12. L a71 and L a72 Examples of the aromatic hydrocarbon group of 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, a fluorene group, and the like. The number of carbon atoms in 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 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 in the hydrocarbon group. L a71 and L a72 Examples of the group in which -CH2- contained in the chain hydrocarbon group among the hydrocarbon groups of and L 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 those similar to the groups exemplified in this specification within the range where the upper limit of the number of carbon atoms permits. L a71 and L a72 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 among the hydrocarbon groups of and L is replaced by -O-, -CO-, -S- or -SO2- include those similar to those exemplified in this specification within the range where the upper limit of the number of carbon atoms permits. La71 and L a72 Among the hydrocarbon groups of and L, -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 formed by combining two or more of the chain hydrocarbon group, alicyclic hydrocarbon group, and aromatic hydrocarbon group of and L include the group formed by combining the above chain hydrocarbon group and the above alicyclic hydrocarbon group, the group formed by combining the above chain hydrocarbon group and the above aromatic hydrocarbon group, the group formed by combining the above alicyclic hydrocarbon group and the above aromatic hydrocarbon group, and the group formed by combining the above chain hydrocarbon group, the above alicyclic hydrocarbon group, and the above aromatic hydrocarbon group. Examples of the combined group include those mentioned above. The group formed by combining the alicyclic hydrocarbon group and the aromatic hydrocarbon group may be a condensed ring. L a71 and L a72 Examples of the substituent that the hydrocarbon group of and L 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, etc. L a71 and L a72 When the of and L is a group formed by 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 b1‘ and L b2‘ When -CH2- of the chain hydrocarbon group contained in the hydrocarbon group of and L is replaced by -O-, -CO-, -S-, or -SO2-, L b1‘ and L b2‘ The hydrocarbon group of and L 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.

[0179] ZA in formula (a7-A) + is the cation Z1 in the salt represented by formula (B1) described later+ The same ones can be mentioned.

[0180] As the structural unit represented by formula (a7-A), for example, the following structural units, R a7 The 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 unit described in International Publication No. 2012 / 050015. ZA + represents an organic cation. TIFF2025100439000144.tif244164

[0181] TIFF2025100439000145.tif131157

[0182] 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). TIFF2025100439000146.tif27105 [In formula (a7-B), R a7 represents 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 are the same halogen atom and alkyl group which may have a halogen atom as in formula (a7-A). RII1 Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by [X] include a phenylene group and a naphthylene group. R II2 and R II3 Examples of the hydrocarbon group represented by [Y] and [Z] include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups. Examples of the alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and a group formed by combining these groups are the same as those described above. A II1 Examples of the divalent linking group represented by [A] include, for example, 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, or a combination thereof. 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; 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, a 2-methylbutane-1,4-diyl group; cycloalkanediyl 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; and divalent polycyclic alicyclic saturated hydrocarbon groups 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. 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 formulas, * and ** represent bonding sites, and * represents the bonding site with R II2 and represents the bonding site with it. JPEG2025100439000147.jpg123161[In the formula, 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.]

[0183] Examples of the structural unit containing the cation in formula (a7-B) include the structural unit represented below and the group corresponding to the methyl group of R a7 wherein the methyl group 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 like. JPEG2025100439000148.jpg72163

[0184] A - Examples of the organic anion represented by include sulfonate anions, sulfonylimide anions, sulfonylmethide anions and the like. A -The organic anion represented by is preferably a sulfonate anion, and more preferably an anion contained in the salt represented by the above formula (B1) as the sulfonate anion. Examples of the sulfonylimide anion, sulfonylmethide anion, and carboxylate anion are the same as those exemplified as the anion of compound (B).

[0185] Examples of the structural unit represented by the formula (a7-B) include structural units represented as follows. TIFF2025100439000149.tif95157

[0186] 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 of the total structural unit (a7) is preferably 1 to 30 mol%, more preferably 2 to 25 mol%, and still more preferably 3 to 20 mol% based on all the structural units of the resin (A).

[0187] The resin (A) may contain structural units other than the above-mentioned structural units, and examples of such structural units include structural units well-known in the art.

[0188] 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). The structural unit(s) is preferably at least one selected from the group consisting of structural unit (a2) and structural unit (a3). The structural unit (a2) is preferably a structural unit represented by formula (a2-A) or a structural unit represented by formula (a2-1). The structural unit (a3) is preferably at least one selected from the group consisting of a structural unit represented by formula (a3-1), a structural unit represented by formula (a3-2), and a structural unit represented by formula (a3-4).

[0189] 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 leading 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 under the conditions described in the examples by gel permeation chromatography.

[0190] <Resin 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 resins containing a structural unit (a4) or a structural unit (a5) (hereinafter sometimes referred to as resin (X)). Among them, examples of the resin (X) include a resin consisting only of the structural unit (a4) and a resin consisting of the structural unit (a4) and the structural unit (a5) (hereinafter sometimes referred to as resin (X) together with the resin consisting only of the structural unit (a4) and the resin consisting of the structural unit (a4) and the structural unit (a5)). Examples of the structural unit that the resin (X) may further have include the structural unit (a2), the structural unit (a3), and structural units 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). Further, 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). Further, 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). Further, 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 of only 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 of the weight average molecular weight of the resin (X) is the same as that of the resin (A).

[0191] 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).

[0192] 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 to this can be measured by known analysis means such as liquid chromatography or gas chromatography.

[0193] <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 analysis means such as liquid chromatography or gas chromatography.

[0194] Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate, and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; esters such as ethyl lactate, butyl acetate, amyl acetate, and ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone, and cyclohexanone; cyclic esters such as γ-butyrolactone; and the like. One kind of the solvent (E) may be used alone, or two or more kinds may be used.

[0195] <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) 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 still 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 amine include aliphatic amines and aromatic amines. Examples of the aliphatic amine include primary amines, secondary amines, and tertiary amines.

[0196] 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, etc. Preferably, diisopropylaniline is mentioned, and more preferably 2,6-diisopropylaniline is mentioned.

[0197] 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.

[0198] 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 still more preferably a diphenyliodonium salt containing a phenyl group substituted with a carboxylic acid anion among the weak acid inner salts (D). JPEG2025100439000150.jpg99157

[0199] 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.

[0200] TIFF2025100439000151.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 an integer of any one of 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 and the like. 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, norbornyl group, adamantyl group and the like. 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 and the like. Examples of the group 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.). Examples of the alkoxy group include methoxy group, ethoxy group, etc. Examples of the acyl group include acetyl group, propanoyl group, benzoyl group, cyclohexanecarbonyl group, etc. Examples of the acyloxy group include a group in which an oxy group (-O-) is bonded to the above acyl group, etc. Examples of the alkoxycarbonyl group include a group in which a carbonyl group (-CO-) is bonded to the above alkoxy group, etc. Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom, etc. 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.

[0201] More specifically, the following salts are included. TIFF2025100439000152.tif72165

[0202] 〈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.

[0203] 〈Preparation of Resist Composition〉 The resist composition of the present invention can be prepared by mixing salt (I), and, if necessary, compound (B), resin (A), a resin 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.

[0204] 〈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 washed, 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 (YAG or semiconductor laser, etc.) to emit harmonic laser light in the far ultraviolet region or vacuum ultraviolet region, 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 repeatedly performed 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-based developer") is used as the developer. Examples of the organic solvent contained in the organic-based 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-based 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-based developer, a developer containing butyl acetate and / or 2-heptanone is preferable. In the organic-based 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-based developer may contain a surfactant. Also, the organic-based developer may contain a trace amount of water. During development, the development may be stopped by substituting with a solvent of a different type from the organic-based developer. It is preferable to wash the developed resist pattern with a rinsing solution. The rinsing 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 rinsing solution remaining on the substrate and the pattern.

[0205] <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 as a resist composition for electron beam (EB) exposure or a resist composition for EUV exposure, and is useful for semiconductor microfabrication.

Examples

[0206] 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 model 1100, MASS is Agilent LC / MSD model). In the following examples, the value of this molecular ion peak is indicated by “MASS”.

[0207] Example 1: Synthesis of the salt represented by formula (I-1) 5.73 parts of the salt represented by formula (I-1-a), 25 parts of chloroform, 50 parts of methanol and 1.16 parts of silver oxide were mixed and stirred at 23 °C for 30 minutes. 3.90 parts of the salt represented by formula (I-1-b) was added to the obtained mixed solution, and further stirred at 23 °C for 18 hours. 30 parts of ion-exchanged water was added to the obtained reaction product, stirred at 23 °C for 30 minutes, and then separated to extract the organic layer. This 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, then the supernatant was removed and concentrated to obtain 7.84 parts of the salt represented by formula (I-1). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):[M 2- +H] - 309.0

[0208] Example 2: Synthesis of the salt represented by formula (I-10) 7.51 parts of the salt represented by formula (I-10-a), 50 parts of chloroform, 50 parts of methanol and 1.16 parts of silver oxide were mixed and stirred at 23 °C for 30 minutes. 3.90 parts of the salt represented by formula (I-1-b) was added to the obtained mixed solution, and further stirred at 23 °C for 18 hours. 30 parts of ion-exchanged water was added to the obtained reaction product, stirred at 23 °C for 30 minutes, and then separated to extract the organic layer. This 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, then the supernatant was removed and concentrated to obtain 9.19 parts of the salt represented by formula (I-10). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):[M 2- +H] - 487.1

[0209] Example 3: Synthesis of the salt represented by formula (I-22) 9.44 parts of the salt represented by TIFF2025100439000155.tif60118 formula (I-22-a), 50 parts of chloroform, 50 parts of methanol and 1.16 parts of silver oxide were mixed and stirred at 23 °C for 30 minutes. To the obtained mixed solution, 3.90 parts of the salt represented by formula (I-1-b) was added, and further stirred at 23 °C for 18 hours. To the obtained reaction product, 30 parts of ion-exchanged water was added and 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, then the supernatant was removed, and concentrated to obtain 10.59 parts of the salt represented by formula (I-22). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):[M 2- +H] - 680.8

[0210] Example 4: Synthesis of the salt represented by formula (I-1117) 5.85 parts of the salt represented by TIFF2025100439000156.tif34151 formula (I-1117-a), 50 parts of chloroform, 50 parts of methanol and 1.16 parts of silver oxide were mixed and stirred at 23 °C for 30 minutes. To the obtained mixed solution, 3.90 parts of the salt represented by formula (I-1-b) was added, and further stirred at 23 °C for 18 hours. To the obtained reaction product, 30 parts of ion-exchanged water was added and 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, then the supernatant was removed, and concentrated to obtain 7.02 parts of the salt represented by formula (I-1117). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):[M 2- +H] - 321.0

[0211] Example 5: Synthesis of the salt represented by formula (I-1120) 7.77 parts of the salt represented by formula (I-1120-a), 50 parts of chloroform, 50 parts of methanol, and 1.16 parts of silver oxide were mixed and stirred at 23 °C for 30 minutes. To the resulting mixed solution, 3.90 parts of the salt represented by formula (I-1-b) were added, and further stirred at 23 °C for 18 hours. To the resulting reaction product, 30 parts of ion-exchanged water were added and stirred at 23 °C for 30 minutes, then separated to obtain the organic layer. This washing operation with water was repeated 5 times. After concentrating the obtained organic layer, 30 parts of tert-butyl methyl ether were added to the concentrated residue, stirred at 23 °C for 30 minutes, then the supernatant was removed and concentrated to obtain 9.30 parts of the salt represented by formula (I-1120). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):[M 2- +H] - 513.1

[0212] Example 6: Synthesis of the salt represented by formula (I-2262) 6.57 parts of the salt represented by formula (I-2262-a), 50 parts of chloroform, 50 parts of methanol, and 1.16 parts of silver oxide were mixed and stirred at 23 °C for 30 minutes. To the resulting mixed solution, 3.90 parts of the salt represented by formula (I-1-b) were added, and further stirred at 23 °C for 18 hours. To the...

Claims

1. An acid generator containing a salt represented by formula (I). [In formula (I), L b1 represents a (nb1 + 1)-valent hydrocarbon group which may have a single bond or substituents, and the -CH 2 - in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO 2 -. 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 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 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. nb1 represents any integer from 1 to 6. When nb1 is 2 or more, the groups within multiple parentheses may be the same as or different from each other. Z ＋ and Z' ＋ each independently represents an organic cation. ]

2. The acid generator according to claim 1, wherein the anion of the salt represented by formula (I) is an anion represented by formula (I-A1) or an anion represented by formula (I-A2). [In formula (I-A1), Q b1 , Q b2 , Q b3 and Q b4 each independently represents a hydrogen atom, a fluorine atom, a perfluoroalkyl group having 1 to 6 carbon atoms, or an alkyl group having 1 to 6 carbon atoms. z1 represents any integer from 0 to 6. X 1 represents -O-CO-, -CO-O-, -O-CO-O- or -O-. L b3 represents a single bond or a hydrocarbon group of (nb2 + 1) carbon atoms having 1 to 24 carbon atoms which may have a substituent, and -CH 2 - in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO 2 -. 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 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 contained in the haloalkyl group and the hydrocarbon group 2 - is -O- or -CO-, -S-, -SO ２ - may be replaced by. 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. nb2 represents any integer from 1 to 3. When nb2 is 2 or more, the groups within multiple parentheses may be the same as or different from each other. Z’ ＋ represents an organic cation. [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 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 any integer from 1 to 5. When nb4 is 2 or more, the groups within multiple parentheses may be the same as or different from each other. However, 1 ≤ nb4 + nb3 ≤ 5 is satisfied. Z’ ＋ represents an organic cation.

3. The acid generator according to claim 1, wherein nb1 is 1.

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

5. Containing a resin including a structural unit having an acid-labile group, The resist composition according to claim 4, 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 any integer from 0 to 14. n1 represents any integer from 0 to 10. n1' represents any integer from 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 -CH 2 - 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 within multiple 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 any integer from 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 binding site with 51 L. 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. ] [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 represents an alkanediyl group having 1 to 4 carbon atoms. Ar represents an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms. ]

6. The resist composition according to claim 5, containing a resin including 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 any integer from 1 to 5. When nA2 is 2 or more, the groups within multiple 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 any integer from 0 to 2.

7. (1) A step of applying the resist composition according to claim 4 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.

8. A salt represented by formula (I). [In formula (I), L b1 represents a (nb1 + 1)-valent hydrocarbon group which may have a single bond or substituents, and -CH 2 - in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO 2 -. 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 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 - 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. 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. Z ＋ and Z' ＋ each independently represents an organic cation.]

9. The salt according to claim 8, wherein the anion of the salt represented by formula (I) is an anion represented by formula (I-A1) or an anion represented by formula (I-A2). [In formula (I-A1), Q b1 , Q b2 , Q b3 and Q b4 each independently represents a hydrogen atom, a fluorine atom, a perfluoroalkyl group having 1 to 6 carbon atoms, or an alkyl group having 1 to 6 carbon atoms. z1 represents any integer from 0 to 6. X 1 represents -O-CO-, -CO-O-, -O-CO-O- or -O-. L b3 represents a single bond or a hydrocarbon group of (nb2 + 1) carbon atoms having 1 to 24 carbon atoms which may have a substituent, and -CH 2 - in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO 2 -. 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 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. nb2 represents any integer from 1 to 3. When nb2 is 2 or more, the groups within the plurality of parentheses may be the same as or different from each other. Z’ ＋ represents an organic cation. ] [In formula (I-A2), L b2 represents a divalent hydrocarbon group having 1 to 24 carbon atoms which may have a single bond or substituents, 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 - 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 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.]

10. The salt according to claim 8, wherein nb1 is 1.

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