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

Abstract

To provide an acid generator, a resist composition and the like which allow a resist pattern having a good pattern collapse margin to be produced.SOLUTION: The acid generator contains a salt represented by formula (I) [where Lb1 and Lb2 each represent a single bond or a substituted / unsubstituted hydrocarbon group; R3 represents a halogen atom, a haloalkyl group or a substituted / unsubstituted hydrocarbon group; m3 represents an integer of 0-4; nb1 represents an integer of 1-6; R4-R7 each represent an H atom or a substituted / unsubstituted hydrocarbon group, -CH2- contained in the group may be substituted with -O-, -S- or the like, R3 and R4, or R3, R4 and R5 may be bonded together to form a cyclic hydrocarbon group which may have a double bond, the cyclic hydrocarbon group may have double bonds between one or more pairs of two adjacent carbon atoms, and -CH= contained in the cyclic hydrocarbon group may be substituted with -N=; and Z+ represents an organic cation].SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a salt for an acid generator used in semiconductor microfabrication, an acid generator containing the salt, a resist composition, and a method for manufacturing 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. TIFF2025104292000001.tif3182

[0003] Patent Document 2 describes a salt represented by the following formula and a composition containing the salt as an acid generator. TIFF2025104292000002.tif2879

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 manufacturing a resist pattern with better pattern collapse resistance (PCM) 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). TIFF2025104292000003.tif26140 [In formula (I), Lb1 represents a single bond or an (nb1+1)-valent hydrocarbon group which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. L b2 represents a single bond or a divalent hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. 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 optionally having a substituent, and -CH2- contained in the haloalkyl group and the hydrocarbon group may be replaced by -O-, -CO-, -S- or -SO2-. m3 represents an integer of 0 to 4, and when m3 is 2 or more, a plurality of R 3 may be the same or different from each other. nb1 represents an integer of 1 to 6. When nb1 is 2 or more, the groups in the multiple parentheses may be the same or different. R 4 , R 5 , R 6 and R 7 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group is not -O-, -S-, -NR 8 may be replaced by -, -SO2- or -CO-; R 3 and R 4 or R 3 and R 4 and R 5 and may be bonded to form a cyclic hydrocarbon group having 3 to 20 carbon atoms, and the cyclic hydrocarbon group may have one or more double bonds between two adjacent carbon atoms, and -CH2- contained in the cyclic hydrocarbon group is -O-, -CO- or -NR 7 - may be replaced by -, and -CH= contained in the cyclic hydrocarbon group may be replaced by -N=. R 8represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-. Z + represents an organic cation.] The acid generator according to [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). TIFF2025104292000004.tif23143[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 an (nb2 + 1)-valent hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. L b2 represents a single bond or a divalent hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. 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. nb2 represents any integer from 1 to 3. When nb2 is 2 or more, the groups in the plurality of parentheses may be the same as or different from each other. R 4 , R 5 , R 6 and R 7 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -NR 8 -, -SO2- or -CO-, and R 3 and R 4 or R 3 and R 4 and R 5 and may combine to form a cyclic hydrocarbon group having 3 to 20 carbon atoms, the cyclic hydrocarbon group may have a double bond between one or more adjacent two carbon atoms, and -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -CO- or -NR 7 -, and -CH= contained in the cyclic hydrocarbon group may be replaced by -N=. R 8 represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-. TIFF2025104292000005.tif28150[In formula (I-A2), L b2 represents a single bond or a divalent hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. 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, the 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 within a plurality of parentheses may be the same as or different from each other. However, 1 ≦ nb4 + nb3 ≦ 5 is satisfied. R 4 、R 5 、R 6 and R 7 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -NR 8 -, -SO2-, or -CO-. R 3 and R 4 or R 3 and R 4 and R 5 may combine to form a cyclic hydrocarbon group having 3 to 20 carbon atoms. The cyclic hydrocarbon group may have a double bond between one or more adjacent carbon atoms. -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -CO-, or -NR 7 -. -CH= contained in the cyclic hydrocarbon group may be replaced by -N=. R 8 represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -SO2-, or -CO-. [3] The acid generator according to [1] or [2] wherein nb1 is 1. [4] A resist composition containing the acid generator according to [1] or [2]. [5] 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). TIFF2025104292000006.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 an integer from 1 to 7, and * represents the bonding site with -CO-. R a01 、R a4 and R a5 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a02 、R a03 and R a04 each independently represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these. The alkyl group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group may have a halogen atom. R a6 and R a7 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these, and the alkyl group, the alkenyl group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group may have a halogen atom. m1’ represents an integer from 0 to 14. n1 represents an integer from 0 to 10. n1’ represents an integer from 0 to 3.] TIFF2025104292000007.tif31117[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 a35 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R a36 represents a hydrocarbon group having 1 to 20 carbon atoms, or R a35 and R a36 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms together with -C-O- to which they are bonded, and -CH2- contained in the hydrocarbon group and the divalent hydrocarbon group may be replaced by -O- or -S-. na1 represents any integer from 1 to 5, and when na1 is 2 or more, the groups in the plurality of parentheses may be the same as or different from each other. na11 represents any integer from 0 to 4, and 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.] TIFF2025104292000008.tif4558[In formula (a1-5), R a8represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom. Z a1 is a single bond or *-(CH2) h3 -CO-L 54 -, h3 represents an integer of any one of 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 an integer of any one of 1 to 3. s1’ represents an integer of any one of 0 to 3. TIFF2025104292000009.tif3479[In formula (a1-6), R a61 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a62 , R a63 and R a64 each independently represents an alkyl group having 1 to 6 carbon atoms or a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, or R a62 and R a63 are bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded. X a61 is a single bond, -CO-O-* or -CO-NR a65 -*, * represents the bond with -Ar, and R a65 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X a62 is a single bond, *-O-L a61 - or *-CO-O-L a62 -, * represents the bond with -Ar, and L a61 and L a62 each independently represents an alkanediyl group having 1 to 4 carbon atoms. Ar represents an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent. The resist composition according to [4] or [5], comprising a resin containing a structural unit represented by formula (a2-A). TIFF2025104292000010.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 any integer from 1 to 5, and when nA2 is 2 or more, the groups in the plurality of parentheses may be the same as or different from each other. na21 represents any integer from 0 to 4, and when na21 is 2 or more, the plurality of R 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 any one of [4] to [6] 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, A method for producing a resist pattern, comprising: [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 produced with good pattern collapse resistance (PCM). [Modes 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. In the groups described in this specification, those that can take both a linear structure and a branched structure may be either. When -CH2- contained in a hydrocarbon group or the like is replaced by -O-, -S-, -CO-, -SO-, -NR X -(X is an arbitrary symbol) or -SO2-, the same examples are applied to each group, and the number of carbon atoms before replacement is defined as the number of carbon atoms of the hydrocarbon group or the like. The 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 (for example, trifluoromethanesulfonic acid or the like), the leaving group is eliminated to form a hydrophilic group (for example, a hydroxy group or a carboxy group). As will be described later, the base-labile group means a group that, when contacted with a base (for example, trimethylamine, tetramethylammonium hydroxide or the like), the base-labile group is eliminated to form a carboxy group or a hydroxy group. In this specification, the "solid content of the resist composition" means the total of the components excluding the solvent (E) described below 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 combining two or more of these groups, nb1 hydrogen atoms are removed, and one or more L b2 And the group which couple | bonds is mentioned. The number of carbon atoms of 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 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, 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. are mentioned. 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 of 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 a cyclobutyl group, a cyclopentane group, a cyclohexane group, a cyclopentyl group, and a cyclooctyl group. 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 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 and a cycloalkyl group having 5 to 8 carbon atoms are spiro-bonded. A double bond may be formed between two carbon atoms contained in the alicyclic hydrocarbon group. More specifically, examples of the alicyclic hydrocarbon group include those represented by the following formula. TIFF2025104292000011.tif28158 When the alicyclic hydrocarbon group is a monocyclic cycloalkyl group, the number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 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- contained in the hydrocarbon group of L is replaced by -O-, -CO-, -S-, or -SO2-, the number of carbon atoms before replacement is defined as the number of carbon atoms in the hydrocarbon group. L 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 alkanedioxy group is replaced by -O-), an alkanedioxycarbonyl group (a group in which -CH2-CH2- at any position contained in the alkanedioxy group is replaced by -O-CO-), an alkanediylcarbonyl group (a group in which -CH2- at any position contained in the alkanediyl group is replaced by -CO-), an alkanediylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in the alkanediyl group is replaced by -CO-O-), an alkanediylsulfonyl group (a group in which -CH2- at any position contained in the alkanediyl group is replaced by -SO2-), an alkanediylthio group (a group in which -CH2- at any position contained in the alkanediyl 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. 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. The number of carbon atoms of the alkoxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyloxy group and the alkoxycarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3, respectively. Examples of the alkylthio group include alkylthio groups having 1 to 23 carbon atoms, such as methylthio group, ethylthio group, propylthio group, butylthio group and the like. The number of carbon atoms of the alkylthio group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkylsulfonyl group include alkylsulfonyl groups having 1 to 23 carbon atoms, such as methylsulfonyl group, ethylsulfonyl group, propylsulfonyl group and the like. The number of carbon atoms of the alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 23 carbon atoms, such as acetyloxy group, propionyloxy group, butyryloxy group and the like. The number of carbon atoms of the alkylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. Examples of the alkanedioxy group include alkanedioxy groups having 1 to 23 carbon atoms, such as methyleneoxy group, ethyleneoxy group, propanediyl-oxy group, butanediyl-oxy group, pentanediyl-oxy group and the like. The number of carbon atoms of the alkanedioxy group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediyl-oxycarbonyl group include alkanediyl-oxycarbonyl groups having 2 to 23 carbon atoms, such as a methylene-oxycarbonyl group, an ethylene-oxycarbonyl group, a propanediyl-oxycarbonyl group, and a butanediyl-oxycarbonyl group. Examples of the alkanediyl-carbonyl group include alkanediyl-carbonyl groups having 2 to 24 carbon atoms, such as a methylene-carbonyl group, an ethylene-carbonyl group, a propanediyl-carbonyl group, a butanediyl-carbonyl group, and a pentanediyl-carbonyl group. Examples of the alkanediyl-carbonyloxy group include alkanediyl-carbonyloxy groups having 2 to 23 carbon atoms, such as a methylene-carbonyloxy group, an ethylene-carbonyloxy group, a propanediyl-carbonyloxy group, and a butanediyl-carbonyloxy group. The number of carbon atoms of the alkanediyl-oxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkanediyl-carbonyl group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkanediyl-carbonyloxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. Examples of the alkanediyl-thio group include alkanediyl-thio groups having 1 to 23 carbon atoms, such as a methylene-thio group, an ethylene-thio group, and a propanediyl-thio group. The number of carbon atoms of the alkanediyl-thio group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediyl-sulfonyl group include alkanediyl-sulfonyl groups having 1 to 23 carbon atoms, such as a methylene-sulfonyl group, an ethylene-sulfonyl group, and a propylene-sulfonyl group. The number of carbon atoms of the alkanediyl-sulfonyl group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. L 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. TIFF2025104292000012.tif46146L 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 and the like. The bonding site can be any position. TIFF2025104292000013.tif26163Examples 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 group combining the above alicyclic hydrocarbon group and the above 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 group combining two or more of these and bonding to a benzene ring. L b2 The divalent chain hydrocarbon group, divalent alicyclic hydrocarbon group, divalent aromatic hydrocarbon group, and divalent group combining two or more of these 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 combining two or more of these. 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, etc. L b1 and L b2 When and are a group combining an alicyclic hydrocarbon group or an aromatic hydrocarbon group and 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. Also, when the -CH2- of the chain hydrocarbon group contained in the hydrocarbon group of and is replaced by -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, etc. b1 and L b2 the hydrocarbon group of b1 and L b2 Examples of the substituent that the hydrocarbon group of may have include 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. In formula (I), L b1 is preferably a single bond when nb1 is 1, and is preferably a (nb1 + 1)-valent hydrocarbon group (the -CH2- contained in the hydrocarbon group may have a substituent that may be replaced by -O-, -S-, -CO- or -SO2-) when nb1 is 2 or more.

[0011] R 3 Examples of the halogen atom of include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. R 3The C1-C12 haloalkyl group represents an alkyl group having 1 to 12 carbon atoms and a halogen atom, and examples include a C1-C12 fluoroalkyl group, a C1-C12 chloroalkyl group, a C1-C12 bromoalkyl group, a C1-C12 iodoalkyl group, etc. Examples of the haloalkyl group include a C1-C12 perfluoroalkyl group (such as a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, a nonafluorobutyl group, etc.), a 2,2,2-trifluoroethyl group, a 3,3,3-trifluoropropyl group, a 4,4,4-trifluorobutyl group, a 3,3,4,4,4-pentafluorobutyl group, a chloromethyl group, a bromomethyl group, an iodomethyl group, etc. The number of carbon atoms of the haloalkyl group is preferably 1 to 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 linear or branched alkyl group, and examples 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. TIFF2025104292000014.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 spiro-bonded 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 - alkanediyl group - *, alkyl group - aromatic hydrocarbon group - *, and -CH2- contained in the alkanediyl 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 - alkanediyl group - *, alkyl group - alicyclic hydrocarbon group - *, and -CH2- contained in the alkanediyl 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 - alkanediyl group - * include aralkyl groups such as benzyl group and phenethyl group. Examples of the alkyl group - aromatic hydrocarbon group - * include tolyl group, xylyl group, cumenyl group and the like. Examples of the alicyclic hydrocarbon group - alkanediyl group - * include cycloalkylalkyl groups such as cyclohexylmethyl group, cyclohexylethyl group, 1-(adamantan-1-yl)methyl group, 1-(adamantan-1-yl)-1-methylethyl 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 taken as the total number of carbon atoms of the haloalkyl group or the hydrocarbon group. Also, the number may be one or two or more. Examples of groups in which -CH2- contained in a haloalkyl group 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- in the haloalkyl group is replaced by -O-), a haloalkoxycarbonyl group (a group in which any -CH2-CH2- in the haloalkyl group is replaced by -O-CO-), a haloalkylcarbonyl group (a group in which any -CH2- in the haloalkyl group is replaced by -CO-), a haloalkylcarbonyloxy group (a group in which any -CH2-CH2- in the haloalkyl group is replaced by -CO-O-), a group formed by combining two or more of these groups, and the like can be mentioned. Examples of these substituted groups are the same as those described above. Examples of the cycloalkoxy group include cycloalkoxy groups having 3 to 18 carbon atoms, such as a cyclohexyloxy group. Examples of the cycloalkylalkoxy group include cycloalkylalkoxy groups having 4 to 17 carbon atoms, such as a cyclohexylmethoxy group. Examples of the alkoxycarbonyloxy group include alkoxycarbonyloxy groups having 2 to 18 carbon atoms, such as a butoxycarbonyloxy group. Examples of the aromatic hydrocarbon group-carbonyl-oxy group include aromatic hydrocarbon group-carbonyl-oxy groups having 7 to 17 carbon atoms, such as a benzoyloxy group. Examples of the aromatic hydrocarbon group-carbonyl group include aromatic hydrocarbon group-carbonyl groups having 7 to 18 carbon atoms, such as a benzoyl group. Examples of the aromatic hydrocarbon group-oxy group include aromatic hydrocarbon group-oxy groups having 6 to 18 carbon atoms, such as a phenyloxy group. Examples of the haloalkoxy group, haloalkoxycarbonyl group, haloalkylcarbonyl group, and 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 can be mentioned.

[0014] In addition, examples of the group in which -CH2- contained in the alicyclic hydrocarbon group is replaced by -O-, -S- or -CO- include the groups represented below. The bonding site can be at any position. TIFF2025104292000015.tif46168Examples of the group in which -CH2- contained in the group combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2- also include the following groups. The bonding site can be at any position. TIFF2025104292000016.tif26163

[0015] R 3 Examples of the substituent that the hydrocarbon group of R may have include a halogen atom and a cyano group. R 3 When R is a group combining an alicyclic hydrocarbon group or an aromatic hydrocarbon group and an alkyl group, the alkyl group can be a substituent of the alicyclic hydrocarbon group or the aromatic hydrocarbon group. Examples of the halogen atom include the same groups as those described above. In addition, R 3 When -CH2- contained in the alkyl group contained in R is replaced by -O-, -CO-, -S- or -SO2-, R 3 can substantially have substituents such as a hydroxy group, a carboxyl group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, a thiol group, a sulfonyl group 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 by -O- or -CO-), or a haloalkyl group having 1 to 4 carbon atoms, and more preferably an iodine atom, a fluorine atom, a hydroxy group or a fluorinated alkyl group having 1 to 4 carbon atoms. m3 is preferably any integer represented by 0 to 4, and more preferably an integer of 1 or more. R3 When it is 1 or more, the bonding site to the benzene ring is L b2 It may be any of the o-position, m-position, and p-position with respect to L.

[0016] R 4 R 5 R 6 R 7 and R 8 Examples of the hydrocarbon group having 1 to 20 carbon atoms for R, R, R, R, and R include chain hydrocarbon groups such as alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these. Examples of the alkyl 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, octyl group, nonyl group and the like. Examples of the alkanediyl group include linear or branched alkanediyl groups, 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; and 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 and the like. The number of carbon atoms of the chain hydrocarbon group is preferably 1 to 9, more preferably 1 to 4, and even more preferably 1 to 3. The alicyclic hydrocarbon group may be monocyclic or polycyclic, and examples of the alicyclic hydrocarbon group include the groups represented below. The bonding site can be at any position. TIFF2025104292000017.tif46168Specifically, examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, etc. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, etc. The number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 18, more preferably 3 to 16, and even more preferably 3 to 12. Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, biphenyl group, anthryl group, phenanthryl group, binaphthyl group, etc. The number of carbon atoms of the aromatic hydrocarbon group is preferably 6 to 18, more preferably 6 to 14, and even more preferably 6 to 10. Among the chain hydrocarbon group, alicyclic hydrocarbon group, and aromatic hydrocarbon group, groups formed by combining two or more of these groups include a group formed by combining an aromatic hydrocarbon group and a chain hydrocarbon group (for example, aromatic hydrocarbon group - alkanediyl group - *, alkyl group - aromatic hydrocarbon group - *, alkyl group - aromatic hydrocarbon group - alkanediyl group - *, and -CH2- contained in the alkanediyl group and the alkyl group may be replaced by -O-, -CO-, -S-, or -SO2-.), a group formed by combining an alicyclic hydrocarbon group and a chain hydrocarbon group (for example, alicyclic hydrocarbon group - alkanediyl group - *, alkyl group - alicyclic hydrocarbon group - *, alkyl group - alicyclic hydrocarbon group - alkanediyl group - *, and -CH2- contained in the alkanediyl group and the alkyl group may be replaced by -O-, -CO-, -S-, or -SO2-.), and a group formed by combining an aromatic hydrocarbon group and an alicyclic hydrocarbon group (for example, aromatic hydrocarbon group - alicyclic hydrocarbon group - *, alicyclic hydrocarbon group - aromatic hydrocarbon group - *). * represents a bonding site. Examples of the aromatic hydrocarbon group - alkanediyl group - * include aralkyl groups such as benzyl group and phenethyl group. Examples of the alkyl group - aromatic hydrocarbon group - * include tolyl group, xylyl group, cumenyl group, etc. 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, etc. 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, etc. Examples of the aromatic hydrocarbon group-alicyclic hydrocarbon group-* include phenylcyclohexyl group, etc. Examples of the alicyclic hydrocarbon group-aromatic hydrocarbon group-* include cyclohexylphenyl group, etc. In addition, in the combination, two or more alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and chain hydrocarbon groups may be combined respectively. Also, any of these groups may be bonded to the benzene ring.

[0017] R 4 、R 5 、R 6 and R 7 When -CH2- contained in the hydrocarbon group represented by is replaced by -O-, -CO-, -S-, -NR 8 - or -SO2-, the number of carbon atoms before replacement is taken as the total number of carbon atoms of the hydrocarbon group. Also, the number may be one or two or more. When -CH2- contained in the hydrocarbon group is -O-, -CO-, -NR 8- As the group replaced by -S- or -SO2-, there are a hydroxy group (a group in which -CH2- contained in a methyl group is replaced by -O-), an amino group (a group in which -CH2- contained in a methyl group is replaced by -NH-), a thiol group (a group in which -CH2- contained in a methyl group is replaced by -S-), a carboxyl 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- contained in an alkyl group is replaced by -O-), an alkoxycarbonyl group (a group in which -CH2-CH2- contained in an alkyl group is replaced by -O-CO-), an alkylcarbonyl group (a group in which -CH2- contained in an alkyl group having 2 to 12 carbon atoms is replaced by -CO-), an alkylcarbonyloxy group (a group in which -CH2-CH2- contained in an alkyl group is replaced by -CO-O-), an alkoxycarbonyloxy group (a group in which -CH2-CH2-CH2- contained in an alkyl group is replaced by -O-CO-O-), an alkylamino group (a group in which -CH2- contained in an alkyl group is replaced by -NR 8 - as the group), an alkylthio group (a group in which -CH2- contained in an alkyl group is replaced by -S-), an alkylsulfonyl group (a group in which -CH2- contained in an alkyl 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 peptide group (a group in which -CH2-CH2- contained in an ethylene group is replaced by -CO-NR 8-replaced group), sulfonyl group (the -CH2- contained in the methylene group is replaced by -SO2-), alkanediyl-oxy group (any -CH2- in the alkanediyl group is replaced by -O-), alkanediyl-oxycarbonyl group (any -CH2-CH2- in the alkanediyl group is replaced by -O-CO-), alkanediyl-carbonyl group (any -CH2- in the alkanediyl group is replaced by -CO-), alkanediyl-carbonyl-oxy group (any -CH2-CH2- in the alkanediyl group is replaced by -CO-O-), alkanediyl-amino group (any -CH2- in the alkanediyl group is replaced by -NR 8 -replaced group), alkanediyl-thio group (any -CH2- in the alkanediyl group is replaced by -S-), alkanediyl-sulfonyl group (any -CH2- in the alkanediyl group is replaced by -SO2-), cycloalkoxy group, cycloalkylalkoxy group, aromatic hydrocarbon group-carbonyl-oxy group, aromatic hydrocarbon group-carbonyl group, aromatic hydrocarbon group-oxy group, or a group formed by combining two or more of these groups, etc. can be mentioned. These replaced groups include the same ones as above within the range allowed by the upper limit of the number of carbon atoms. Examples of the alkylamino group include alkylamino groups having 1 to 19 carbon atoms, such as methylamino group, ethylamino group, propylamino group, butylamino group, pentylamino group, hexylamino group, and octylamino group. Examples of the alkanediylamino group include alkanediylthio groups having 1 to 19 carbon atoms, such as methyleneamino group, ethyleneamino group, and propyleneamino group. The number of carbon atoms of the alkanediylamino group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3.

[0018] In addition, -CH2- contained in an alicyclic hydrocarbon group or a group formed by combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group is -O-, -CO-, -S-, -NR8 Examples of the group replaced by - or -SO2- include the groups represented below. The bonding site can be at any position. TIFF2025104292000018.tif74168R 8 Those in which -CH2- contained in the hydrocarbon group represented by is replaced by -O-, -CO-, -S- or -SO2- are R 4 、R 5 、R 6 and R 7 Examples of those similar to those exemplified by the hydrocarbon group represented by are included. R 4 and R 5 and / or R 4 and R 5 and R 6 and R 8 - may be replaced by -O-, -CO- or -NR R 4 and R 5 and / or R 4 and R 5 and R 6 and R TIFF2025104292000019.tif44158R 4 、R 5 、R 6 、R 7 and R 8 Examples of the substituent that the hydrocarbon group of may optionally 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. The hydrocarbon group may have one substituent or a plurality of substituents.

[0019] R 4 、R 5 、R6 and R 7 is, independently of one another, a hydrogen atom, an alkyl group having 1 to 9 carbon atoms, a phenyl group which may have a substituent, or an aralkyl group having 7 to 12 carbon atoms which may have a substituent (—CH2— contained in the aralkyl group may be replaced by —O— or —CO—). R 4 and R 5 when is a hydrogen atom or an alkyl group having 1 to 9 carbon atoms, at least one of R 6 and R 7 is preferably a phenyl group which may have a substituent or an aralkyl group having 7 to 12 carbon atoms which may have a substituent (—CH2— contained in the aralkyl group may be replaced by —O— or —CO—). Also, in another embodiment, R 4 and R 5 form a 5- or 6-membered alicyclic hydrocarbon group containing N + (—CH2— contained in the alicyclic hydrocarbon group may be replaced by —O—), and R 6 and R 7 are, independently of one another, preferably a hydrogen atom, an alkyl group having 1 to 9 carbon atoms, a phenyl group which may have a substituent, or an aralkyl group having 7 to 12 carbon atoms (—CH2— contained in the aralkyl group may be replaced by —O— or —CO—). Furthermore, in another embodiment, R 4 , R 5 and R 6 form a 5- or 6-membered aromatic hydrocarbon group containing N + (—CH═ contained in the aromatic hydrocarbon group may be replaced by —N═), and R 6 is preferably a hydrogen atom, an alkyl group having 1 to 9 carbon atoms, a phenyl group which may have a substituent, or an aralkyl group having 7 to 12 carbon atoms (—CH2— contained in the aralkyl group may be replaced by —O— or —CO—). R 7 is preferably a hydrogen atom.

[0020] Examples of the cation of the ammonium carboxylate salt include cations represented by the following formulas (I-c-1) to (I-c-25). TIFF2025104292000020.tif92161

[0021] 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). TIFF2025104292000021.tif28138[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 Q b1 、Q b2 、Q b3 and Q b4 Examples of the C1-C6 perfluoroalkyl group represented by Q 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 fluorine atoms. Q b3 and Q b4 are each independently preferably a hydrogen atom, a fluorine atom or a C1-C3 perfluoroalkyl group, and Q b3is 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 from 0 to 3, more preferably 0, 1, or 2. X 1 is preferably -O-CO- or -CO-O-.

[0022] L b3 As the hydrocarbon group in, within the range allowed by the upper limit of the number of carbon atoms, the L in formula (I) b1 is exemplified by the same hydrocarbon groups as those exemplified for L of formula (I). In formula (I-A1), L b3 is preferably 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 alicyclic hydrocarbon group may be replaced by -O- or -S-), and a group formed by combining two or more of these groups, and more preferably a chain hydrocarbon group having 1 to 6 carbon atoms or a group represented by the following formula (Lb3-1). 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 preferably 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-. TIFF2025104292000022.tif1682 [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 may have a substituent. W b3 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms. -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. -CH2- contained in the aromatic hydrocarbon group may be replaced by -O- or -S-. 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), the chain hydrocarbon group of L b31 , as long as it has an upper limit of the number of carbon atoms, includes the same groups as the chain hydrocarbon groups exemplified by L b1 . In formula (Lb3-1), the alicyclic hydrocarbon group and aromatic hydrocarbon group of W b3 , as long as the upper limit of the number of carbon atoms permits, includes the alicyclic hydrocarbon groups and aromatic hydrocarbon groups exemplified by L b1 . In formula (Lb3-1), the substituents that the chain hydrocarbon group of L b31 may have and the substituents that the alicyclic hydrocarbon group and aromatic hydrocarbon group of W b1 may have include 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 (wherein -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-). Among them, the alicyclic hydrocarbon group and aromatic hydrocarbon group of W b1 are preferably the alicyclic hydrocarbon group and aromatic hydrocarbon group represented below. In the alicyclic hydrocarbon group and 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. In addition, 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 preferably forms an ether ring, an ester ring (lactone), a carbonate ester ring, a sultone ring or an acetal ring. TIFF2025104292000023.tif36168 In formula (I-A1), L b2 is 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-), more 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-), and further preferably a single bond, -O-, -O-CO-, -CO-O-, -O-CO-O- or *-L b21 -X 2 -L b22 -**(L b21 and L b22 either one of which represents at least an alkanediyl group having 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 to the benzene ring. However, the total carbon number of L b21 and X 2 and L b22 is 12 or less. ) is even more preferred. R 4 R 5 R 6 R 7 and R 8 represent the same meaning as in formula (I).

[0023] 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, anions 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) are preferred. TIFF2025104292000024.tif227165

[0024] TIFF2025104292000025.tif237165

[0025] TIFF2025104292000026.tif115153

[0026] The anion represented by formula (I-A2) is represented by the following formula. TIFF2025104292000027.tif31145[In formula (I-A2), all symbols have the same meanings as described above.] In formula (I-A2), L b2 Examples of the hydrocarbon group are the same as those of the hydrocarbon group of L b2 in formula (I) within the range allowed by the upper limit of the number of carbon atoms. Examples of the substituents that the hydrocarbon group of L b2 may have are also the same as those 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 b41 is a single bond or a chain hydrocarbon group having 1 to 6 carbon atoms, -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-, and * represents the bonding site with the phenyl group to which SO3 - is bonded. L b41 is preferably a single bond or a chain hydrocarbon group having 1 to 3 carbon atoms.

[0027] 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, -L b2 - The bonding position is preferably the following structure which is the m-position substitution of the benzene ring with respect to the bonding position of SO3 - . TIFF2025104292000028.tif61143 [In the above formula, the symbols have the same meaning 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.

[0028] Examples of the alkyl group having 1 to 6 carbon atoms for R b1 include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, and hexyl group. The number of carbon atoms of the alkyl group is preferably 1 to 4, and more preferably 1 to 3. Examples of the halogen atom for R b1 include fluorine atom, chlorine atom, bromine atom, and iodine atom, etc. R b1 is preferably each independently a halogen atom or an alkyl group having 1 to 4 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), more preferably a fluorine atom, an iodine atom or an alkyl group having 1 to 3 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methoxy group or a methyl group. nb3 is any integer from 0 to 4, preferably any integer from 0 to 3, and more preferably any integer from 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 b1is 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 4 、R 5 、R 6 、R 7 and R 8 have the same meanings as in formula (I).

[0029] Examples of the anion (I-A2) include the following anions. Among them, 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. TIFF2025104292000029.tif178165

[0030] TIFF2025104292000030.tif196155

[0031] [[Cation (I)]] Examples of the organic cation of Z + in formula (I) 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 preferable, and arylsulfonium cations are more preferable. 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. TIFF2025104292000031.tif82159[In formula (b2-1) to formula (b2-5), R b4 ~R b6Each independently represents an acyclic 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 acyclic hydrocarbon group may be substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, or a glycidyloxy group. The hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. R b4 and R b5 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and the -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 any integer from 0 to 5. When m2 is 2 or more, the plurality of R b7 may be the same or different, and when n2 is 2 or more, the plurality of R b8 may be the same or different. R b9 and R b10 each independently represents an acyclic 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 with -O-, -S-, or -CO-. R b11represents a hydrogen atom, a chain hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. R b12 represents a chain hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and a hydrogen atom contained in the chain hydrocarbon group may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and a hydrogen atom contained in the aromatic hydrocarbon group may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms. R b11 and R b12 and may be bonded to each other to form a ring including -CH-CO- to which they are bonded, and -CH2- contained in the ring may be replaced with -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 and 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 -CH2- contained in the ring may be replaced with -O-, -S-, or -CO-. R b27 ~R b29 each independently represents a hydrogen atom or a group containing an acid-labile group. L b31 and L b41 ~L b43 represent 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, a plurality of R b13are the same or different, and when p2 is 2 or more, a plurality of Rs b14 are the same or different, and when q2 is 2 or more, a plurality of Rs b15 are the same or different, and when r2 is 2 or more, a plurality of Rs b16 are the same or different, and when s2 is 2 or more, a plurality of Rs b17 are the same or different, and when t2 is 2 or more, a plurality of Rs 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, a plurality of Rs 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 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 at least one of b13 ~R b18 is preferably a halogen atom. Furthermore, when u2 is 0, r2 is preferably 1 or more, more preferably 1. Also, when u2 is 0 and r2 is 1 or more, b16 R is preferably a halogen atom.

[0032] 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, R b9 ~R b12 The chain hydrocarbon group is preferably a 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. TIFF2025104292000032.tif11157 In particular, R b9 ~R b12 The alicyclic hydrocarbon group is preferably a group having 3 to 18 carbon atoms, more preferably a group having 4 to 12 carbon atoms.

[0033] 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, and isobornyl group. In the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group, the total number of carbon atoms of the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less. The alkyl fluoride group represents an alkyl group having 1 to 12 carbon atoms and having a fluorine atom, and examples thereof include fluoromethyl group, difluoromethyl group, trifluoromethyl group, and perfluorobutyl. 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.

[0034] Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, biphenyl group, naphthyl group, and phenanthryl group. 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 include 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 examples of the aromatic hydrocarbon group having an alicyclic hydrocarbon group include p-cyclohexylphenyl group, p-adamantylphenyl group, etc. 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 preferred. Examples of the aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group include p-methoxyphenyl group. 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, and naphthylethyl group.

[0035] Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group, and dodecyloxy group. Examples of the alkylcarbonyl group include acetyl group, propionyl group, and butyryl group. Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom, and iodine atom. Examples of the alkylcarbonyloxy group include methylcarbonyloxy group, ethylcarbonyloxy group, propylcarbonyloxy group, isopropylcarbonyloxy group, butylcarbonyloxy group, sec-butylcarbonyloxy group, tert-butylcarbonyloxy group, pentylcarbonyloxy group, hexylcarbonyloxy group, octylcarbonyloxy group, and 2-ethylhexylcarbonyloxy group.

[0036] Rb4 and R b5 The ring formed by combining with each other and together with the sulfur atom to which they are attached 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. TIFF2025104292000033.tif24142

[0037] R b9 and R b10 The ring formed by combining 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 thiolan-1-ium ring (tetrahydrothiophenium ring), thian-1-ium ring, 1,4-oxathian-4-ium ring and the like. R b11 and R b12 The ring formed by combining 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 oxocycloheptane ring, oxocyclohexane ring, oxonorbornane ring, oxoadamantane ring and the like. R b27 ~R b29 Examples of the group containing an acid-labile group of c30 are -R c30 or -L c10 -CO-O-R c30 represented by (L c10 represents an alkanediyl group having 1 to 6 carbon atoms, and R c30 represents an acid-labile group.). R b27 ~R b29 Examples of the acid-labile group of

[0038] Among cations (b2-1) to (b2-5), preferably, it is cation (b2-1). Examples of cation (b2-1) include the following cations. TIFF2025104292000034.tif149164 Examples of cation (b2-2) include the following cations. TIFF2025104292000035.tif18150 Examples of cation (b2-3) include the following cations. TIFF2025104292000036.tif26140 Examples of cation (b2-4) include the following cations. TIFF2025104292000037.tif123163 Examples of cation (b2-5) include the following cations. TIFF2025104292000038.tif115158

[0039] Specific examples of salt (I) include salts formed by arbitrarily combining the above-mentioned cations and anions. Specific examples of 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 salt (I) and anion (I) corresponds. For example, salt (I-1) is a salt composed of the anion represented by formula (I-A1-1) and the cation represented by formula (b2-c-1), salt (I-2) is a salt composed of the anion represented by formula (I-A1-2) and the cation represented by formula (b2-c-1), and salt (I-31) is a salt composed of the anion represented by formula (I-A1-1) and the cation represented by formula (b2-c-10). TIFF2025104292000039.tif3692 [Table 1] TIFF2025104292000041.tif239159 TIFF2025104292000042.tif239159 TIFF2025104292000043.tif239159 TIFF2025104292000044.tif177158

[0040] Among them, the salt (I) is preferably a salt formed by combining an anion represented by any of formula (I-A1-1) to formula (I-A1-11), formula (I-A1-16) to formula (I-A1-24), formula (I-A1-31) to formula (I-A1-40), formula (I-A2-1) to formula (I-A2-11), and formula (I-A2-16) to formula (I-A2-26) with a cation represented by any of formula (b2-c-1) to formula (b2-c-79).

[0041] <Method for producing salt (I)> In the salt represented by formula (I-A1), X 1 being *-CO-O- (the salt represented by formula (I1 -A1) can be produced, for example, by reacting the salt represented by formula (I1-A1-a) with carbonyldiimidazole in a solvent and then further reacting with the salt represented by formula (I1-A1-b). TIFF2025104292000045.tif64163 (wherein all the symbols have the same meanings as described above respectively). Examples of the solvent in this reaction include chloroform and acetonitrile. 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 formula (I1-A1-a) include salts represented by the following formula, which can be easily obtained from the market and can also be easily produced by known production methods. TIFF2025104292000046.tif54156

[0042] Examples of the salt represented by formula (I1-A1-b) include compounds represented below, which can be easily obtained from the market and can also be easily produced by known production methods.

[0043] TIFF2025104292000047.tif202161

[0044] TIFF2025104292000048.tif89155

[0045] In the salt represented by formula (I-A1), X 1 is a salt in which *-O-CO- (salt represented by formula (I2-A1)) can be produced, for example, by reacting a salt represented by formula (I2-A1-b) with carbonyldiimidazole in a solvent and then reacting with a salt represented by formula (I2-A1-a). TIFF2025104292000049.tif59165 (wherein all the symbols have the same meanings as described above). Examples of the solvent in this reaction include chloroform, acetonitrile, etc. Examples of the acid in this reaction include oxalic acid, hydrochloric acid, acetic acid, etc. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours. Examples of the salt represented by formula (I2-A1-b) include salts represented by the following formula, which can be easily obtained from the market and can also be easily produced by known production methods. TIFF2025104292000050.tif52162

[0046] Examples of the salt represented by formula (I2-A1-a) include compounds represented below, which can be easily obtained from the market and can also be easily produced by known production methods. TIFF2025104292000051.tif87163

[0047] TIFF2025104292000052.tif46160

[0048] In the salt represented by formula (I-A1), X 1The salt represented by *-O-CO-O- (the salt represented by formula (I3-A1)) can be produced, for example, by reacting the salt represented by formula (I2-A1-a) with carbonyldiimidazole in a solvent and then further reacting with the compound represented by formula (I1-A1-b). TIFF2025104292000053.tif54156(In the formula, all the symbols have the same meanings as described above respectively.) Examples of the solvent in this reaction include chloroform, acetonitrile and the like. Examples of the acid in this reaction include oxalic acid, hydrochloric acid, acetic acid and the like. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours.

[0049] In the salt represented by formula (I-A1), X 1 The salt in which X is -O- (the salt represented by formula (I4-A1)) can be produced, for example, by reacting the salt represented by formula (I2-A1-a) with the compound represented by formula (I1-A1-b) in a solvent in the presence of a base. TIFF2025104292000054.tif44157(In the formula, all the symbols have the same meanings as described above respectively.) Examples of the base in this reaction include potassium hydroxide and the like. Examples of the acid in this reaction include oxalic acid, hydrochloric acid, acetic acid and the like. Examples of the solvent in this reaction include chloroform, acetonitrile and the like. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours.

[0050] In the salt represented by formula (I-A2), L b2 The salt in which L is *-CO-O-L b2’ - (the salt represented by formula (I1-A2)) can be produced, for example, by reacting the salt represented by formula (I1-A2-a) with carbonyldiimidazole in a solvent and then further reacting with the salt represented by formula (I1-A2-b). TIFF2025104292000055.tif62163(wherein all the symbols have the same meanings as described above. L b2’ is the group obtained by removing -CO-O- from L b2 .) Examples of the solvent in this reaction include chloroform and acetonitrile. Examples of the acid in this reaction include oxalic acid, hydrochloric acid, and acetic acid. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours. The salts represented by the formula (I1-A2-a) include salts represented by the following formula, etc., can be easily obtained from the market, and can also be easily produced by known production methods. TIFF2025104292000056.tif144165

[0051] TIFF2025104292000057.tif55159

[0052] The salts represented by the formula (I1-A2-b) include, for example, compounds represented by the following, etc., can be easily obtained from the market, and can also be easily produced by known production methods. TIFF2025104292000058.tif56142

[0053] In the salt represented by the formula (I-A2), L b2 is *-O-CO-L b2’’ - the salt represented by the formula (I2-A2) can be produced, for example, by reacting the salt represented by the formula (I2-A2-b) with carbonyldiimidazole in a solvent and then further reacting with the salt represented by the formula (I2-A2-a). TIFF2025104292000059.tif53163(wherein all the symbols have the same meanings as described above. L b2’’ is the group obtained by removing -O-CO- from L b2 .) Examples of the solvent in this reaction include chloroform and acetonitrile. Examples of the acid in this reaction include oxalic acid, hydrochloric acid, acetic acid, and the like. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours. The salts represented by formula (I2-A2-a) include salts represented by the following formula, etc., can be easily obtained from the market, and can also be easily manufactured by known production methods. TIFF2025104292000060.tif201163

[0054] Examples of the salts represented by formula (I2-A2-b) include compounds represented below, etc., can be easily obtained from the market, and can also be easily manufactured by known production methods. TIFF2025104292000061.tif26155 Salt (I) can be synthesized by known synthetic methods in addition to the above production method.

[0055] <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). However, compound (B) does not contain salt (I). Compound (B) may be used alone or in combination of two or more.

[0056] Either a nonionic compound or an ionic compound may be used for compound (B). Examples of the nonionic compound 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 the ionic compound include onium salts containing an onium cation (e.g., diazonium salt, phosphonium salt, sulfonium salt, iodonium salt). Examples of the anion of the onium salt include sulfonic acid anion, sulfonylimide anion, sulfonylmethide anion, and carboxylic acid anion, etc. Further, as the compound (B), it may be a monomer that induces a structural unit constituting the resin contained in the resist composition of the present invention, such as the structural unit (a7) described later.

[0057] As the compound (B), compounds that generate an acid by radiation described in, for example, 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, a compound produced by a known method may also be used. The compound (B) may be an acid generator having an acid-labile group. For example, the compound or resin serving as the acid generator may contain a partial structure that becomes an acid-labile group, and the acid-labile group preferably contains the above-mentioned group (1) or group (2). When the resist composition of the present invention has a compound having an acid-labile group, the resin containing a structural unit having an acid-labile group may not be included.

[0058] A preferred form of the compound (B) includes a salt represented by the formula (B1) (hereinafter sometimes referred to as "acid generator (B1)"). TIFF2025104292000062.tif1394[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 b1represents a methyl group which may have a substituent or a cyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-. nb1 represents any integer from 1 to 6. When nb1 is 2 or more, the groups 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 b1 , 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 a 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, still more preferably 1 to 36, even more preferably 1 to 30, and even 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 a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, an iso-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a heptadecyl group, etc. Examples of the alkenyl group include an ethenyl group, a propenyl group, an isopropenyl group, a butenyl group, an isobutenyl group, a tert-butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an octenyl group, an isooctenyl group, and a nonenyl group. The number of carbon atoms of the chain hydrocarbon group is preferably 1 to 36, more preferably 1 to 24, still more preferably 1 to 20, even more preferably 1 to 18, even more preferably 1 to 12, and even 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 a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. 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 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 and a cycloalkyl group having 5 to 8 carbon atoms are spiro-bonded. 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. TIFF2025104292000063.tif26168 When the alicyclic hydrocarbon group is a monocyclic cycloalkyl group, the number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 24, more preferably 3 to 20, still more preferably 3 to 18, even more preferably 3 to 12, even still more preferably 3 to 10, and even still more preferably 3 to 8. When the alicyclic hydrocarbon group is a polycyclic cycloalkyl group, the number of carbon atoms in the alicyclic hydrocarbon group is preferably 6 to 24, more preferably 6 to 20, still more preferably 6 to 18, even more preferably 6 to 12, and even still 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. TIFF2025104292000064.tif1085 The number of carbon atoms in the aromatic hydrocarbon group is preferably 4 to 24, more preferably 4 to 20, still more preferably 4 to 18, even more preferably 5 to 14, even more preferably 5 to 10, and even more preferably 6 to 10. L b1 When -CH2- contained in the hydrocarbon group of L is replaced by -O-, -CO-, -S- or -SO2-, the number of carbon atoms before replacement is taken as the number of carbon atoms of the hydrocarbon group. L b1 When -CH2- contained in the hydrocarbon group of L is replaced by -O-, -CO-, -S- or -SO2-, the number of carbon atoms before replacement is 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 alkanedioxy group (a group in which -CH2- at any position contained in the alkanediyl group is replaced by -O-), an alkanedioxycarbonyl group (a group in which -CH2-CH2- at any position contained in the alkanediyl group is replaced by -O-CO-), an alkanediylcarbonyl group (a group in which -CH2- at any position contained in the alkanediyl group is replaced by -CO-), an alkanediylcarbonyloxy 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), etc. Specifically, alicyclic hydrocarbon groups represented by the following formulas can be mentioned. The bonding positions of the alicyclic hydrocarbon groups mentioned in the following formulas can be at arbitrary positions. TIFF2025104292000065.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. TIFF2025104292000066.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 the chain hydrocarbon group, alicyclic hydrocarbon group and aromatic hydrocarbon group include the group combining the above chain hydrocarbon group and the above alicyclic hydrocarbon group, the group combining the above chain hydrocarbon group and the above aromatic hydrocarbon group, the group combining the above alicyclic hydrocarbon group and the above aromatic hydrocarbon group, and the group combining the above chain hydrocarbon group, the above alicyclic hydrocarbon group and the above aromatic hydrocarbon group. The above combined groups 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 divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, a divalent aromatic hydrocarbon group, and a group formed by removing one hydrogen atom from a combination of two or more of these groups, which binds to Y b1 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 are, respectively, within the range allowed by the number of carbon atoms, a group formed by removing one hydrogen atom from the chain hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and group formed by combining two or more of these groups exemplified by L b1 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, an iodine atom, etc. L 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 of the alicyclic hydrocarbon group or the aromatic hydrocarbon group. Further, when -CH2- of the chain hydrocarbon group contained in the hydrocarbon group of L b1 and L b2 is replaced by -O-, -CO-, -S-, or -SO2-, the hydrocarbon group of L L b1 and L b2 may substantially have substituents such as a hydroxy group, a carboxyl group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a thiol group, a sulfonyl group, etc. 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 hydrogen group and aromatic hydrocarbon group of Y b1Examples thereof include the same as the alicyclic hydrocarbon group and the aromatic hydrocarbon group exemplified above, and 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 (wherein -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-). b1 In the hydrocarbon group that the cyclic hydrocarbon group of Y may have, the number of carbon atoms b1 is not included in the number of hydrocarbon groups of the cyclic hydrocarbon group of Y. Y b1 Examples of the hydrocarbon group having 1 to 18 carbon atoms that the cyclic hydrocarbon group of Y may have as a substituent include a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group combining these groups. Examples of the chain hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and a group combining two or more of these groups include, within the range permitted by the upper limit of the number of carbon atoms, L b1 Examples thereof include 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 in L. Further, 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, L b1 Examples thereof include the same groups as the groups exemplified for the group in which -CH2- contained in the hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2-. Further, b1 Examples of the hydrocarbon group having 1 to 18 carbon atoms that the cyclic hydrocarbon group of Y may have as a substituent may constitute a protecting group or a leaving group (an acid-labile group or a base-labile group) generally used in the art. The anion of the salt represented by formula (B1) is preferably an anion represented by the following formula (B1-A1) or an anion represented by formula (B1-A2). TIFF2025104292000067.tif31125[In formula (B1-A1), L b2 and Y b1 have the same meanings as in formula (I-A). Q b1 Q b2 Q b3 and Q b4 each independently represents a hydrogen atom, a fluorine atom, a C1-C6 perfluoroalkyl group, or a C1-C6 alkyl group. z1 represents any integer from 0 to 6. When z1 is 2 or more, the groups 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 a (nb2 + 1)-valent hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO-, or -SO2-. nb2 represents any integer from 1 to 3. When nb2 is 2 or more, the groups 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 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 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, a perfluorohexyl group and the like. 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, 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 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-.

[0059] L b3 Examples of the hydrocarbon group in L include the same hydrocarbon groups as exemplified for L of formula (I-A) within the range where the upper limit of the number of carbon atoms permits. b1 The same hydrocarbon groups as those exemplified for L of formula (I-A) are included. In formula (B1-A1), L b3is a single bond, an optionally substituted chain hydrocarbon group having 1 to 12 carbon atoms (the -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 (the -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 (the -CH2- contained in the aromatic hydrocarbon group may be replaced by -O- or -S-), or a group obtained by combining two or more of these groups, preferably a single bond, a chain hydrocarbon group having 1 to 6 carbon atoms or a group represented by the following formula (Lb3-1). When -CH2- contained in the chain hydrocarbon group is replaced by -O- or -CO-, the number thereof is preferably 1 to 4, and preferably one -CH2-CH2- contained in the chain hydrocarbon group is replaced by -O-CO- or -CO-O-, or one -CH2-CH2-CH2- contained in the chain hydrocarbon group is replaced by -O-CO-O-. TIFF2025104292000068.tif1682[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, the -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, 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-, 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 represents the bonding site with.] In the formula (Lb3-1), the chain hydrocarbon group of L b31 is, as long as the upper limit of the number of carbon atoms permits, L b1Examples thereof include groups similar to the chain hydrocarbon group exemplified above. In formula (Lb3-1), W b3 The alicyclic hydrocarbon group and the aromatic hydrocarbon group of may be groups similar to the alicyclic hydrocarbon group and the aromatic hydrocarbon group exemplified above as long as the upper limit of the number of carbon atoms permits. b1 Examples thereof include groups similar to the alicyclic hydrocarbon group and the aromatic hydrocarbon group exemplified above. In formula (Lb3-1), L b31 The substituent(s) that the chain hydrocarbon group of may have and the substituent(s) that the alicyclic hydrocarbon group and the aromatic hydrocarbon group of W b3 may have are groups similar to the substituents exemplified as the substituent(s) that the hydrocarbon group of L b1 may have. L b31 is preferably a single bond or an alkanediyl group having 1 to 6 carbon atoms (the -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-). Among them, as the alicyclic hydrocarbon group and the aromatic hydrocarbon group of W b3 the alicyclic hydrocarbon group and the aromatic hydrocarbon group represented below are preferred. In the alicyclic hydrocarbon group and the aromatic hydrocarbon group 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 Also, in the alicyclic hydrocarbon group 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 is preferably forming an ether ring, an ester ring (lactone), a carbonate ester ring, a sulfonic acid ester ring (sultone) or an acetal ring. In formula (B1-A1), L b2is 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-), preferably a single bond, -O-, -O-CO-, -CO-O-, -O-CO-O- or *-L b21 -X 2 -L b22 -**(L b21 and L b22 One of them 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 But L b21 X 2 and L b22 The total carbon number of is 12 or less.) is more preferable. In formula (B1-A1), Y b1 is preferably a cyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent (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 which the cyclic hydrocarbon group of Y b1 may have, and R Yc represents a hydrogen atom or a substituent which 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 other substituents that the cyclic hydrocarbon group of Y b1 may have. TIFF2025104292000070.tif94165

[0060] 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 an anion 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) is more preferable. TIFF2025104292000071.tif234161

[0061] TIFF2025104292000072.tif249151

[0062] TIFF2025104292000073.tif254163

[0063] 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 above. Specific examples of the anion in the salt represented by formula (B1-A1) include the anions described in JP-A-2010-204646.

[0064] Preferred anions in the salt represented by formula (B1-A1) include the anions represented by formula (B1a-1) to formula (B1a-70). TIFF2025104292000074.tif186163

[0065] TIFF2025104292000075.tif252165

[0066] TIFF2025104292000076.tif69165

[0067] Among them, anions represented by any of formula (B1a-1) to formula (B1a-3), formula (B1a-7) to formula (B1a-19), and formula (B1a-22) to formula (B1a-70) are preferred.

[0068] The anion represented by formula (B1-A2) is represented by the following formula. TIFF2025104292000077.tif2399[In formula (B1-A2), L b2 and Y b1 have the same meanings as in formula (B1). R b1 represents a halogen atom or an alkyl group having 1 to 6 carbon atoms, and -CH2- contained in the alkyl group may be replaced by -O- or -CO-. nb4 represents any integer from 1 to 5. When nb4 is 2 or more, a plurality of -L b2 -Y b12 may be the same as or different from each other. nb3 represents any integer from 0 to 4. When nb3 is 2 or more, a plurality of R b1 may be the same as or different from each other. However, 1 ≦ nb4 + nb3 ≦ 5 is satisfied.]

[0069] In formula (B1-A2), L b2 Examples of the hydrocarbon group and Y b1 Examples of the cyclic hydrocarbon group are, within the range allowed 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 The same examples as those 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 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 preferably represents 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-. 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 phenyl group to which SO3 - is bonded. L b41 is preferably a single bond or a chain hydrocarbon group having 1 to 3 carbon atoms. In formula (B1-A2), 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 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).

[0070] 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 The bonding position of is preferably the following structure which is the m-position substitution of the benzene ring with respect to the bonding position of SO3 - . TIFF2025104292000078.tif28107[In the above formula, L b2 , Y b1 , R b1 , and nb3 represent the same meanings as in formula (B1-A2).] When nb4 is 2 or more, the plurality of L b2 and Y b1 are preferably the same group as each other.

[0071] 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 those similar to the groups exemplified in this specification within the range where the upper limit of the number of carbon atoms permits. For R b1Each is 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, 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 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.

[0072] Examples of the anion (B1 - A2) include the following anions. Among them, anions represented by formula (B2a - 1) to formula (B2a - 20) are preferable, and anions represented by formula (B2a - 1) to formula (B2a - 11), formula (B2a - 16) to formula (B2a - 20) are more preferable. The following anions have some R b1 omitted and may contain substituents not shown. TIFF2025104292000079.tif95162

[0073] 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 preferred. TIFF2025104292000080.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), L b2’ and Y b1’ are exemplified by the same groups as L b2 and Y b1 in the formula (B1-A1). In the formula (B1-A3), L b2’ is a single bond, *-L b23 -X 2 -, or *-L b23 -X2 -W 2 -X 3 -(L b23 represents an alkanediyl group having 1 to 6 carbon atoms which may have a fluorine atom, and X 2 and X 3 each independently represent -O-, -CO-O-, -O-CO-, -O-CO-O- or -O-, and W 2 represents an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and the -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O- or -CO-, and * represents the bonding site with SO2. It is preferably the following). 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 together to form a ring, for example, an anion represented by formula (B1-A3’) can be mentioned. TIFF2025104292000081.tif21122 [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 the disulfonylmethide ring of W preferably has 3 to 6 carbon atoms, and the hydrogen atom of the methylene group contained in the ring is preferably replaced by a fluorine atom.

[0074] Examples of the anion represented by formula (B1-A3) include the following. Among them, the anions represented by formula (B3a-1) and formula (B3a-2) are preferred. TIFF2025104292000082.tif132161

[0075] Examples of the carboxylic acid anion include the following. TIFF2025104292000084.tif41155

[0076] 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, the cations represented by any of the above-mentioned cations (b2-1) to (b2-5) can be mentioned.

[0077] Salt (B1) is a combination of the above-mentioned anion and the above-mentioned organic cation, and these can be arbitrarily combined. Preferred examples of salt (B1) include any anion represented by any of formula (B1a-1) to formula (B1a-3), formula (B1a-7) to formula (B1a-19), formula (B1a-22) to formula (B1a-70), formula (B2a-1) to formula (B2a-11), formula (B2a-16) to formula (B2a-20), formula (B3a-1) to formula (B3a-3), or formula (B3a-11) to formula (B3a-14), and a combination with cation (b2-1), cation (b2-2), cation (b2-3), cation (b2-4), or cation (b2-5).

[0078] As the compound (B), those represented by formula (B1-1) to formula (B1-105), formula (B2-1) to formula (B2-20) and formula (B3-1) to formula (B3-28) are preferably exemplified. Among them, those containing an arylsulfonium cation are preferred, and those represented by formula (B1-1) to formula (B1-3), formula (B1-5) to formula (B1-7), formula (B1-11) to formula (B1-14), formula (B1-20) to formula (B1-26), formula (B1-29), formula (B1-31) to formula (B1-105), formula (B2-1) to formula (B2-20) and formula (B3-1) to formula (B3-28) are particularly preferred. TIFF2025104292000085.tif247168

[0079] TIFF2025104292000086.tif242160

[0080] TIFF2025104292000087.tif254168

[0081] TIFF2025104292000088.tif254160

[0082] TIFF2025104292000089.tif249163

[0083] TIFF2025104292000090.tif250151

[0084] TIFF2025104292000091.tif187159

[0085] 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.

[0086] <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 structural unit is converted into a structural 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)").

[0087] <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, 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.

[0088] <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 other structural units derived from monomers known in the art.

[0089] 〈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)). TIFF2025104292000092.tif2298[In the 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.] TIFF2025104292000093.tif2278[In the 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.]

[0090] 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 TIFF2025104292000094.tif10159R a1 、 R a2 and R a3 Examples of the aromatic hydrocarbon group in R As the combined group, there may be mentioned a group formed by combining the above-mentioned alkyl group and alicyclic hydrocarbon group (for example, 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-. TIFF2025104292000095.tif28138

[0091] R a1’ 、R a2’ and R a3’ Examples of the hydrocarbon group in R 、R a1 、R a2 and R a3 include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these. R a2’ and R a3’ When they are bonded to each other to form a heterocyclic ring together with the carbon atom to which they are bonded and X, -C(R a1’ )(R a2’ )-X-Ra3’ Examples thereof include the following groups. * represents a bond. TIFF2025104292000096.tif19124R a1 , R a2 , R a3 , R a1 , R a2’ and R a3’ Examples of the halogen atom that may be included in R include 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.

[0092] Examples of the 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, and R a3 is an alkyl group, ma = 0, and na = 1. In formula (1), R a1 and R a2 are each independently an alkyl group, R a3 is an adamantyl group, ma = 0, and na = 1. Specific examples of the group (1) include the following groups. * represents a bond. TIFF2025104292000097.tif149163

[0093] Specific examples of the group (2) include the following groups. * represents a bond. TIFF2025104292000098.tif56153

[0094] 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.

[0095] 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.

[0096] 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. TIFF2025104292000099.tif44143 [In formula (a1-0), formula (a1-1) and formula (a1-2), all symbols have the same meanings as defined above.]

[0097] 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 in the above formula include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, a hexyl group, a perfluorohexyl group, a chloromethyl group, a bromomethyl group, and an iodomethyl group. The number of carbon atoms in the alkyl group is preferably 1 to 4, more preferably 1 to 3, and even more preferably 1 or 2. The alkyl group is preferably a methyl group or an ethyl group, and more preferably a methyl group. R a01 , R a4 and R a5 is preferably a hydrogen atom or a methyl group, and more preferably a methyl group. L a01 , L a1 and L a2 is preferably an oxygen atom or *-O-(CH2) k01 It is -CO-O- (wherein k01 is preferably an integer of any one of 1 to 4, more preferably 1), and more preferably an oxygen atom. R a02 , R a03 , R a04 , R a6 and R a7 The alkyl group, alkenyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and combinations thereof in the formula (1) include R a1 , R a2 and R a3 Examples of the groups include the same groups as those listed in the above. R a02 , R a03 , and R a04 The alkyl group in the formula (I) is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. R a6 and Ra7 The alkyl group in a7 is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group or a t-butyl group, and still more preferably an ethyl group, an isopropyl group or a t-butyl group. R a6 and R a7 The alkenyl group in a7 is preferably an alkenyl group having 2 to 6 carbon atoms, more preferably an ethenyl group, a propenyl group, an isopropenyl group or a butenyl group. R a02 、R a03 、R a04 、R a6 and R a7 The number of carbon atoms of the alicyclic hydrocarbon group of a7 is preferably 5 to 12, more preferably 5 to 10. R a02 、R a03 、R a04 、R a6 and R a7 The number of carbon atoms of the aromatic hydrocarbon group of a7 is preferably 6 to 12, more preferably 6 to 10. For the group formed by combining an alkyl group and an alicyclic hydrocarbon group, it is preferable that the total number of carbon atoms of these alkyl group and alicyclic hydrocarbon group is 18 or less. For the group formed by combining an alkyl group and an aromatic hydrocarbon group, it is preferable that the total number of carbon atoms of these alkyl group and aromatic hydrocarbon group is 18 or less. R a02 and R a03 R and R are preferably an alkyl group having 1 to 6 carbon atoms which may have a halogen atom or an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a halogen atom, more preferably a methyl group, an ethyl group, a phenyl group or a naphthyl group which may have a halogen atom. R a04 R is preferably an alkyl group having 1 to 6 carbon atoms which may have a halogen atom or an alicyclic hydrocarbon group having 5 to 12 carbon atoms which may have a halogen atom, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group which may have a halogen atom. R a6 and R a7is preferably an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, an alkenyl group having 2 to 6 carbon atoms which may have a halogen atom, or an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a halogen atom, more preferably a methyl group, an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group, a phenyl group or a naphthyl group which may have a halogen atom, and still more preferably an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group or a phenyl group which may have a halogen atom. m1' is preferably any integer from 0 to 3, more preferably 0 or 1. n1 is preferably any integer from 0 to 3, more preferably 0 or 1. n1' is preferably 0 or 1.

[0098] 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 a01 in the structural unit (a1-0) is replaced by 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. TIFF2025104292000100.tif119160

[0099] 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 a4 in the structural unit (a1-1) is replaced by 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. TIFF2025104292000101.tif34168

[0100] As the structural unit (a1-2), there are 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. The structural unit 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) is preferred. a5 Examples thereof include a structural unit in which the methyl group corresponding to R is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group. The structural unit 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) is preferred. TIFF2025104292000102.tif92163

[0101] 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, and even more preferably 65 mol% or less. Specifically, it is 10 to 95 mol%, preferably 15 to 90 mol%, more preferably 20 to 85 mol%, still more preferably 25 to 70 mol%, and even more preferably 30 to 70 mol%. When the resin (A) contains the structural unit (a1-0), 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, still even 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, 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 80 mol% or less, even more preferably 75 mol% or less, still even 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 still even more preferably 20 to 70 mol%.

[0102] Examples of the structural unit having the group (2) in the structural unit (a1) include the structural unit represented by the formula (a1-4) (hereinafter sometimes referred to as "structural unit (a1-4)"). TIFF2025104292000103.tif32119[In the formula (a1-4), all the symbols have the same meanings as described above.]

[0103] 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 those similar to those exemplified by R, R, and 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 still 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 still 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 still more preferably a methoxymethyl group. R a17 Examples of the alkoxyalkoxy group in R include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a methoxyethoxy group or an ethoxyethoxy group. R a17 Examples of the alkylcarbonyl group in R include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, more preferably an acetyl group. R a17Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group. R a17 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxy-methoxy group, and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group. na12 is preferably 0, 1, or 2, more preferably 0 or 1, and even more preferably 0.

[0104] A a11 Examples of the alkanediyl group of A include branched alkanediyl groups such as a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, a 2-methylbutane-1,4-diyl group, a heptane-1,6-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, and a decane-1,10-diyl group. The number of carbon atoms of the alkanediyl group is preferably 1 to 6, more preferably 1 to 4, even more preferably 1 to 3, and even more preferably 1 or 2. Among them, A a11 is preferably a methylene group or an ethylene group. R a18 Examples of the alkyl group of R include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a tert-butyl group. A a11 When -CH2- contained in the alkanediyl group of A is replaced by -O-, -CO-, or -NR a18 the number of carbon atoms before replacement is defined as the number of carbon atoms of the hydrocarbon group. A a11 Examples of the group in which -CH2- contained in the alkanediyl group of A is replaced by -O- or -CO- include a hydroxy group, a carboxy group, a carbonyl group, an oxy group, an amino group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylamino group, a peptide group, an alkanediyl-oxy group, an alkanediyl-oxycarbonyl group, an alkanediyl-carbonyl group, an alkanediyl-carbonyl-oxy group, an alkanediyl-sulfonyl group, an alkanediyl-thio group, and an alkanediyl-amino group. As long as the upper limit of the number of carbon atoms permits, those similar to those exemplified herein can 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 alkandiyl group of can be the same alkandiyl 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.

[0105] 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 group (* represents a bonding site). etc. TIFF2025104292000104.tif10151 Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, a phenanthryl group, etc. ​Examples of the combined group include a group formed by combining the above-described alkyl group and alicyclic hydrocarbon group (e.g., an alkylcycloalkyl group or cycloalkylalkyl group such as methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornil group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornylethyl group, etc.), an aralkyl group such as benzyl group, an aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), an aryl-cycloalkyl group such as phenylcyclohexyl group, etc. In particular, R a36 Examples of R include an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these. R a35 and R a36 Examples of the divalent hydrocarbon group having 2 to 20 carbon atoms formed by R and R bonding to each other together with the -C-O- to which they are bonded include the following groups. * represents the bonding site, and one side is the bonding site with R a34 and the other side is the bonding site with R. TIFF2025104292000105.tif15105

[0106] R a34 is preferably a hydrogen atom. R a35 is preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a methyl group or an ethyl group. R a36 The hydrocarbon group of R is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these, and more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. R a36The alkyl group and alicyclic hydrocarbon group in [the compound] are preferably unsubstituted. R a36 The aromatic hydrocarbon group in [the compound] preferably has an aromatic ring having an aryloxy group with 6 to 10 carbon atoms.

[0107] -OC(R a34 )(R a35 )-O-R a36 in the structural unit (a1-4) eliminates upon contact with an acid (e.g., p-toluenesulfonic acid) to form a hydroxy group or a carboxy group. -X a1 -OC(R a34 )(R a35 )-O-R a36 In the case of a benzene ring, it may be bonded to any of the o-position, m-position, or p-position with respect to the bonding position of A a11 . Among them, it is preferably bonded to at least one of 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 2-position to 8-position, and when the bonding position of A a11 is at the 2-position, it may be bonded to any of the 1-position and 3-position to 8-position. Among them, when the bonding position of A a11 is at the 1-position, it is preferably bonded to at least one of the 3-position to 6-position, and more preferably bonded to the 3-position or 4-position. When the bonding position of A a11 is at the 2-position, it is preferably bonded to the 4-position to 7-position, and more preferably bonded to the 5-position or 6-position. .

[0108] Examples of the structural unit (a1-4) include structural units derived from the monomers described in JP-A-2010-204646. Preferably, there are structural units represented by Formula (a1-4-1) to Formula (a1-4-42) and structural units in which the hydrogen atom corresponding to R a1 in the structural unit (a1-4) is replaced with a halogen atom, a haloalkyl group, or an alkyl group. More preferably, there are 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). TIFF2025104292000106.tif228165

[0109] 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).

[0110] Examples of the structural unit derived from the (meth)acrylic monomer having the group (2) also include the structural unit represented by the formula (a1-5) (hereinafter sometimes referred to as "structural unit (a1-5)"). TIFF2025104292000107.tif4558In the formula (a1-5), all the symbols have the same meanings as described above.

[0111] 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 are the same as those exemplified for R in the formula (a1-0). a01 and the like. 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 of them 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-.

[0112] Examples of the structural unit (a1-5) include structural units derived from monomers described in JP-A-2010-61117. Among them, structural units represented by formula (a1-5-1) to formula (a1-5-4) are preferable, and a structural unit represented by formula (a1-5-1) or formula (a1-5-2) is more preferable. When the resin (A) contains the structural unit (a1-5), the content thereof is 1 mol% or more, preferably 2 mol% or more, more preferably 3 mol% or more, still more preferably 5 mol% or more, even more preferably 10 mol% or more, still even more preferably 20 mol% or more, and even more preferably 25 mol% or more, based on all the structural units of the resin (A). Further, it is 80 mol% or less, preferably 70 mol% or less, more preferably 60 mol% or less, still more preferably 50 mol% or less, even more preferably 45 mol% or less, still even more preferably 40 mol% or less, and even more preferably 30 mol% or less. Specifically, 1 to 50 mol% is preferable, 3 to 45 mol% is more preferable, 5 to 40 mol% is still more preferable, and 5 to 30 mol% is even more preferable.

[0113] 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)"). TIFF2025104292000109.tif3479[In formula (a1-6), all the symbols have the same meanings as described above.]

[0114] 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 and R​a63 , R a64 and R a65 Examples of the alkyl group in R, R, and R include methyl group, ethyl group, propyl group, butyl group, heptyl group, hexyl group, and the like. R a62 , R a63 and R a64 Examples of the cyclic hydrocarbon group in R, R, and R include alicyclic hydrocarbon groups and aromatic hydrocarbon groups. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, and the like. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, 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 phenylene group, naphthylene group, and the like. Examples of the substituent that the cyclic hydrocarbon group may have include halogen atom, hydroxy group, alkyl group having 1 to 6 carbon atoms, alkoxy group having 1 to 6 carbon atoms, alkoxyalkyl group having 2 to 12 carbon atoms, alkoxyalkoxy group having 2 to 12 carbon atoms, alkylcarbonyl group having 2 to 4 carbon atoms, alkylcarbonyloxy group having 2 to 4 carbon atoms, acryloyloxy group, or 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 adamantane ring, 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 the 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 the 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 the oxygen atom. The number of carbon atoms of the ring is preferably 3 to 16, more preferably 3 to 12. TIFF2025104292000110.tif30108X 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, etc. L a61 and L a62 are preferably a methylene group or an ethylene group.

[0115] 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, etc. 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, etc. The halogen atom and the alkyl group having 1 to 6 carbon atoms which may have a halogen atom are the same as those exemplified by R a61 and the like. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, and a hexyloxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group. Examples of the alkoxyalkyl group include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and even more preferably a methoxymethyl group. Examples of the alkoxyalkoxy group include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a methoxyethoxy group or an ethoxyethoxy group. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, more preferably an acetyl group. Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, more preferably an acetyloxy group. Examples of the substituent include a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms. More preferred 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, more preferably a phenylene group which may have a hydroxy group.

[0116] 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, and structural units represented by Formula (a1-6-1), Formula (a1-6-2), Formula (a1-6-4), Formula (a1-6-5), Formula (a1-6-7) or Formula (a1-6-8) are more preferred, and structural units represented by Formula (a1-6-1) or Formula (a1-6-2) are even more preferred. In the following structural units, R a61 structural units in which the hydrogen atom corresponding to is replaced with a methyl group or the like, and structural units in which the methyl group corresponding to R a61 is replaced with a hydrogen atom or the like are also included as the structural unit (a1-6). TIFF2025104292000111.tif227164

[0117] 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, and even more preferably 10 mol% or more, based on all the structural units of the resin (A). Also, 80 mol% or less is included, preferably 75 mol% or less, more preferably 70 mol% or less, even more preferably 65 mol% or less, and still more preferably 60 mol% or less. Specifically, it is preferably 3 to 80 mol%, more preferably 5 to 75 mol%, even more preferably 7 to 70 mol%, even more preferably 7 to 65 mol%, and particularly preferably 10 to 60 mol%.

[0118] In addition, examples of the structural unit (a1) also include the following structural units. 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, it is 95 mol% or less, preferably 90 mol% or less, more preferably 85 mol% or less, still more preferably 80 mol% or less, even more preferably 75 mol% or less, still even more preferably 70 mol% or less, and 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 preferable, and 20 to 60 mol% is particularly preferable.

[0119] Examples of the structural unit (a1) also include the following structural units. 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, it is 95 mol% or less, preferably 90 mol% or less, more preferably 85 mol% or less, still more preferably 80 mol% or less, even more preferably 75 mol% or less, still even more preferably 70 mol% or less, and even more preferably 60 mol% or less. Specifically, 10 to 60 mol% is preferable, 15 to 55 mol% is more preferable, 20 to 50 mol% is still more preferable, 20 to 45 mol% is even more preferable, and 20 to 40 mol% is particularly preferable.

[0120] <Structural unit(s)> The structural unit(s) is derived from a monomer having no acid-labile group (hereinafter sometimes referred to as "monomer(s)"). As the monomer from which the structural unit(s) is derived, a monomer having no acid-labile group known in the resist field can be used. The structural unit(s) preferably has 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 having no acid-labile group (hereinafter sometimes referred to as "structural unit (a2)") and / or a structural unit having a lactone ring and having no acid-labile group (hereinafter sometimes referred to as "structural unit (a3)") in the resist composition of the present invention, the resolution of the resist pattern and the adhesion to the substrate can be improved.

[0121] <Structural unit (a2)> The structural unit (a2) is a structural unit represented by the formula (a2) and has an alcoholic hydroxy, phenolic hydroxy group or phenolic carboxy group. TIFF2025104292000114.tif4194[In the 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.]

[0122] 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 still more preferably a hydrogen atom or a methyl group.

[0123] 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 the -CH2- contained in the alkanediyl group of A a21 is replaced by -O- or -CO- include a hydroxy group (a group in which the -CH2- contained in the methyl group is replaced by -O-), a carboxy group (a group in which the -CH2-CH2- contained in the ethyl group is replaced by -O-CO-), a carbonyl group (a group in which the -CH2- contained in the methylene group is replaced by -CO-), an oxy group (a group in which the -CH2- contained in the methylene group is replaced by -O-), an amino group (a group in which the -CH2- contained in the alkanediyl group is replaced by -NR a28 -), an alkoxy group (a group in which any -CH2- contained in the alkyl group is replaced by -O-), an alkoxycarbonyl group (a group in which any -CH2-CH2- contained in the alkyl group is replaced by -O-CO-), an alkylcarbonyl group (a group in which any -CH2- contained in the alkyl group is replaced by -CO-), an alkylamino group (a group in which the -CH2- contained in the alkyl group is replaced by -NR a28 -), a peptide group (a group in which the -CH2-CH2- contained in the ethylene group is replaced by -CO-NR a28 -), an alkanediylamino group (a group in which any -CH2- contained in the 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 -O-, -CO- or -NR a28 The groups replaced therewith 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 - etc. Among them, *-CO-O-, *-CO-O-A a22 -CO-O- or *-O-A a22 -CO-O-, *-CO-NR a28 - etc. 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-.

[0124] L a21 The hydrocarbon group in is a (na2 + 1)-valent hydrocarbon group, and examples thereof include chain hydrocarbon groups, alicyclic hydrocarbon groups such as monocyclic or polycyclic (including spiro rings, condensed rings, bridged rings, etc.), and cyclic hydrocarbon groups such as aromatic hydrocarbon groups. A group formed by combining two or more of these groups (for example, a hydrocarbon group formed from an alicyclic hydrocarbon group or an aromatic hydrocarbon group and a chain hydrocarbon group) may also be used. 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 The same alkandiyl group can be mentioned. L a21 Examples of the alkanetriyl group of 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. Moreover, groups in which one or more hydrogen atoms of the above-mentioned groups are replaced with bonding sites, and the like, can also be mentioned. L a21 The number of carbon atoms of the chain hydrocarbon group of L a21 Examples of the monocyclic and polycyclic divalent alicyclic hydrocarbon groups in TIFF2025104292000115.tif46168For 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. may 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 groups combined with 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, and the like. In the combination, the alicyclic hydrocarbon group, the aromatic hydrocarbon group, and the chain hydrocarbon group may each be combined with two or more types. Also, any group 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 thereof 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. Further examples include a group in which one or more hydrogen atoms of these groups are replaced by a bonding site. 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, and an undecyloxy group. The number of carbon atoms of the alkoxy group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkylthio group include alkylthio groups having 1 to 27 carbon atoms, such as a methylthio group, an ethylthio group, a propylthio group, and a butylthio group. The number of carbon atoms of the alkylthio group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 27 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, and a butoxycarbonyl group. 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, and a butyryloxy group. The number of carbon atoms of the alkoxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. Examples of the alkylsulfonyl group include alkylsulfonyl groups having 1 to 27 carbon atoms, such as methylsulfonyl group, ethylsulfonyl group, propylsulfonyl group and the like. The number of carbon atoms of the alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediyl-oxy group include alkanediyl-oxy groups having 1 to 27 carbon atoms, such as methylene-oxy group, ethylene-oxy 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 methylene-oxycarbonyl group, ethylene-oxycarbonyl group, propanediyl-oxycarbonyl group, butanediyl-oxycarbonyl group and the like. Examples of the alkanediyl-carbonyl group include alkanediyl-carbonyl groups having 2 to 28 carbon atoms, such as methylene-carbonyl group, ethylene-carbonyl group, propanediyl-carbonyl group, butanediyl-carbonyl group, pentanediyl-carbonyl group and the like. Examples of the alkanediyl-carbonyl-oxy group include alkanediyl-carbonyl-oxy groups having 2 to 27 carbon atoms, such as methylene-carbonyl-oxy group, ethylene-carbonyl-oxy group, propanediyl-carbonyl-oxy group, butanediyl-carbonyl-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 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-carbonyl-oxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. Examples of the alkanediylthio group include alkanediylthio groups having 1 to 27 carbon atoms, such as a methylenethio group, an ethylenethio group, and a propanediylthio group. The number of carbon atoms in the alkanediylthio group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediylsulfonyl group include alkanediylsulfonyl groups having 1 to 27 carbon atoms, such as a methylenesulfonyl group, an ethylenesulfonyl group, and a propylenesulfonyl group. The number of carbon atoms in 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.

[0125] Examples of the cycloalkoxy group include cycloalkoxy groups having 3 to 27 carbon atoms, such as a cyclohexyloxy group. Examples of the cycloalkylalkoxy group include cycloalkylalkoxy groups having 4 to 27 carbon atoms, such as a cyclohexylmethoxy group. Examples of the alkoxycarbonyloxy group include alkoxycarbonyloxy groups having 2 to 26 carbon atoms, such as a butoxycarbonyloxy group. Examples of the aromatic hydrocarbon group-carbonyl-oxy group include aromatic hydrocarbon group-carbonyl-oxy groups having 7 to 27 carbon atoms, such as a benzoyloxy group. Examples of the aromatic hydrocarbon group-carbonyl group include aromatic hydrocarbon group-carbonyl groups having 7 to 27 carbon atoms, such as a benzoyl group. Examples of the aromatic hydrocarbon group-oxy group include aromatic hydrocarbon group-oxy groups having 6 to 27 carbon atoms, such as a phenyloxy group.

[0126] 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. -CH2- contained in the base combined with TIFF2025104292000116.tif46168 can be replaced by -O-, -S-, -CO- or -SO2-. Examples of such groups include the following groups. The bonding site can be at any position. TIFF2025104292000117.tif26164L 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, etc. 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, etc. A haloalkyl group having 1 to 4 carbon atoms is preferred, and a haloalkyl group having 1 to 3 carbon atoms is more preferred. L a21 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, etc. 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 The substituents that the hydrocarbon group in a21 may have are preferably 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-), more preferably 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-), and even more preferably a fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, a hydroxy group or a methoxy group. L a21is preferably a group formed by combining a single bond, an optionally substituted chain hydrocarbon group having 1 to 12 carbon atoms (provided that -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-), an optionally substituted cyclic hydrocarbon group having 3 to 20 carbon atoms (provided that -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-), or an optionally substituted chain hydrocarbon group having 1 to 8 carbon atoms and an optionally substituted cyclic hydrocarbon group having 3 to 20 carbon atoms (provided that -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-, and -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-); more preferably, it is a group formed by combining an optionally substituted chain hydrocarbon group having 1 to 10 carbon atoms (provided that -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-), an optionally substituted cyclic hydrocarbon group having 3 to 18 carbon atoms (provided that -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-), or an optionally substituted chain hydrocarbon group having 1 to 6 carbon atoms and an optionally substituted cyclic hydrocarbon group having 3 to 18 carbon atoms (provided that -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-, and -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-).

[0127] L a22Examples of the C1-C12 alkanediyl group include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, etc., and ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-dimethylpropane-1,3-diyl group, pentane-2,4-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, etc. The number of carbon atoms of the alkanediyl group is preferably 1-10, more preferably 1-8, still more preferably 1-6, and even more preferably 1-4. L a22 The fluorine atom(s) that L has may be one or two or more. na2 is preferably any integer from 1 to 3, and more preferably 1 or 2. L a21 Examples of the structural unit (a2) when L is a single bond or a chain hydrocarbon group include, for example, the following structural units. Among the following groups, the structural units in which the methyl group corresponding to R a2 is replaced by a hydrogen atom or the like are also suitable structural units of the structural unit (a2) in the same manner as the following structural units. TIFF2025104292000118.tif67163

[0128] 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.

[0129] 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)"). TIFF2025104292000119.tif30128[In the formula (a2-A), all the symbols represent the same meaning 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 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 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 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 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 still 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 still more preferably 1 or 2. na21 is preferably 0, 1, 2, or 3, more preferably 0, 1, or 2, and still 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 2-position to 8-position, and when the bonding position of A a21 is at the 2-position, it may be bonded to any of the 1-position and the 3-position to 8-position. Among them, when the bonding position of A a21 is at the 1-position, at least one is preferably bonded to the 3-position to 6-position, more preferably bonded to the 3-position or 4-position. When the bonding position of A a21 is at the 2-position, it is preferably bonded to the 4-position to 7-position, more preferably bonded to the 5-position or 6-position.

[0130] Examples of the structural unit (a2-A) include structural units derived from monomers described in JP-A-2010-204634 and JP-A-2012-12577. Examples of the structural unit (a2-A) include structural units represented by formula (a2-2-1) to formula (a2-2-32), formula (a2-3-1) to formula (a2-3-24), and structural units in which the methyl group corresponding to R in the structural unit (a2-A) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group. a2 Examples thereof include structural units in which the methyl group corresponding to R in the structural unit (a2-A) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group. TIFF2025104292000120.tif107170

[0131] 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 with respect to 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 a2By polymerizing a compound (such as (a2-A’)) in the state of ), it can be incorporated into the resin (A). Further, for example, after polymerization using the structural unit (a1-4), it can be incorporated into the resin (A) by treatment with an acid such as p-toluenesulfonic acid. Also, after polymerization using acetoxystyrene or the like, the structural unit (a2-A) can be incorporated into the resin (A) by treatment with an alkali such as tetramethylammonium hydroxide.

[0132] 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)”). TIFF2025104292000122.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 of 1 to 7. * represents the bonding position to -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 of 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 of 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 C1-4 alkyl group, a C1-4 alkoxy group or a C2-8 alkoxyalkoxy group, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group or an 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.

[0133] 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 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%.

[0134] TIFF2025104292000124.tif51106[In formula (a2-D), R a2 and A a21 each represent the same meaning as in formula (a2). R a27 represents the same meaning as in formula (a2-A). R a21 and R a22 each independently represent a fluoroalkyl group having 1 to 4 carbon atoms. L a24 represents a single bond or an alkanediyl group having 1 to 3 carbon atoms, and the alkanediyl group may be substituted with a fluorine atom. nD2 represents any integer from 1 to 5. When nD2 is 2 or more, the plural parentheses may be the same as or different from each other. nD22 represents any integer from 0 to 4. When nD22 is 2 or more, the plural R a27 may be the same as or different from each other. However, 1 ≤ nD2 + nD22 ≤ 5.] R a21and R a22 Examples of the alkyl fluoride group of a22 include, 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 Preferably, a22 is 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 Preferably, a24 is a single bond or a methylene group. R a27 R is preferably a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 4 carbon atoms which may have a halogen atom, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an 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. 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. Further, 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.

[0135] As the structural unit (a2-D), it is more preferably a structural unit represented by the following formula (a2-D1) (hereinafter, may be referred to as "structural unit (a2-D1)"). TIFF2025104292000125.tif51108[In formula (a2-D1), R a2 、A a21 、R a27, na2 and na21 represent the same meaning as formula (a2-D). In formula (a2-D1), R a2 is preferably a hydrogen atom or a methyl group. A a21 is preferably a single bond.

[0136] Examples of the structural unit (a2-D) include the structural units described below. TIFF2025104292000126.tif62167

[0137] 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.

[0138] When the resin (A) contains the structural unit (a2-D), its content is preferably 3 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more based on all the structural units of the resin (A). Also, it is preferably 80 mol% or less, more preferably 75 mol% or less, even more preferably 70 mol% or less, and still more preferably 65 mol% or less. Specifically, it is preferably 3 to 80 mol%, more preferably 5 to 75 mol%, even more preferably 10 to 70 mol%, and still more preferably 10 to 65 mol%.

[0139] 〈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 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.

[0140] The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), the formula (a3-3), or the formula (a3-4). These may be contained alone or in combination of two or more. TIFF2025104292000127.tif51164[In the formula (a3-1), the formula (a3-2), the formula (a3-3), and the formula (a3-4), L a4 、L a5 and L a6 each independently represents a group represented by -O- or *-O-(CH2) k3 -CO-O- (where k3 represents an integer from 1 to 7). L a7 represents -O-, *-O-L a8 -O-, *-O-L a8 -CO-O-, *-O-L a8 -CO-O-L a9 -CO-O- or *-O-L a8 -O-CO-L a9 -O-. L a8 and L a9 each independently represents an alkanediyl group having 1 to 6 carbon atoms. * represents the bonding site with the carbonyl group. R a18 、R a19 、R a20 and R a24 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. X a3 represents -CH2- or an oxygen atom. R a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms. R a22 、R a23 and R a25 each independently represents a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms. p1 represents any integer from 0 to 5. q1 represents any integer from 0 to 3. r1 represents any integer from 0 to 3. w1 represents any integer from 0 to 8. When p1, q1, r1 and / or w1 is 2 or more, the plurality of R a21 、R a22 、R a23 and / or R a25 may be the same as or different from each other.

[0141] R a21 、R a22 、R a23 and R a25 Examples of the aliphatic hydrocarbon group in include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group and tert-butyl group. R a18 、R a19 、R a20 and R a24 Examples of the halogen atom and the alkyl group which may have a halogen atom in are the same as those exemplified by R of formula (a1-0) a01 and the like. L a8 and L a9 Examples of the alkanediyl group in include 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, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group and 2-methylbutane-1,4-diyl group. 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)’. TIFF2025104292000128.tif4051 (wherein R a24 、L a7 represent the same meaning as above.)

[0142] 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 The structural unit in which the methyl group corresponding to is replaced by a hydrogen atom is 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.

[0143] 〈Structural unit (a4)〉 The structural unit represented by formula (a4) is shown below. TIFF2025104292000130.tif2770[In formula (a4), R 41 represents a hydrogen atom or a methyl group. R 42 represents an aliphatic hydrocarbon group having a halogen atom with 1 to 48 carbon atoms, and -CH2- contained in the aliphatic hydrocarbon group may be replaced by -O- or -CO-.

[0144] R 42 The aliphatic hydrocarbon group represented by is a linear or branched chain hydrocarbon group, a monocyclic or polycyclic alicyclic hydrocarbon group, and a group formed by combining these, etc. Examples of the chain hydrocarbon group include linear alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, heptadecyl group, and octadecyl group, and branched alkyl groups such as isopropyl group and isobutyl group. Examples of the monocyclic or polycyclic alicyclic hydrocarbon group include monocyclic alicyclic hydrocarbon groups that are monocyclic cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; and polycyclic alicyclic hydrocarbon groups that are polycyclic cycloalkyl groups such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* represents a bonding site). Examples of the group formed by the combination of and include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic hydrocarbon groups, such as -alkanediyl group-alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, and -alkanediyl group-alicyclic hydrocarbon group-alkyl group. Examples of the alkanediyl group include linear alkanediyl groups such as a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-1,6-diyl group; and branched alkanediyl groups such as a propane-1,2-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a 1-methylbutane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. The terminal of the branched alkanediyl group may be a methyl group. R 42 Examples of the halogen atom included in the aliphatic hydrocarbon group contained in 42 include a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. R 42 Examples of the group in which -CH2- of the aliphatic hydrocarbon group contained in 42 is replaced by -O- or -CO- include a hydroxy group, a carboxy group, a carbonyl group, an oxy group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, an alkanediyl-oxy group, an alkanediyl-oxycarbonyl group, an alkanediyl-carbonyl group, an alkanediyl-carbonyl-oxy group, a cycloalkoxy group, a 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 as long as the upper limit of the number of carbon atoms permits.

[0145] As the structural unit (a4), R 42 is preferably an aliphatic hydrocarbon group having a fluorine atom, and R 42 Examples of the structural unit (a4) in which is an aliphatic hydrocarbon group having a fluorine atom include a structural unit represented by the formula (a4-1) (hereinafter sometimes referred to as "structural unit (a4-1)"), a structural unit represented by the formula (a4-2) (hereinafter sometimes referred to as "structural unit (a4-2)"), a structural unit represented by the formula (a4-3) (hereinafter sometimes referred to as "structural unit (a4-3)"), and a structural unit represented by the formula (a4-A) (hereinafter sometimes referred to as "structural unit (a4-A)"). The structural unit represented by the formula (a4-1) is the structural unit shown below. TIFF2025104292000132.tif3092 [In the formula (a4-1), R 41 represents a hydrogen atom or a methyl group. L 41 represents a single bond or an alkanediyl group having 1 to 4 carbon atoms. L 42f represents an alkanediyl group having 1 to 8 carbon atoms having a fluorine atom or a cycloalkanediyl group having 3 to 12 carbon atoms having a fluorine atom. R 42f represents a hydrogen atom or a fluorine atom.]

[0146] Examples of the alkanediyl group in L 41 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 [[]] include 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, and other linear alkanediyl groups having a fluorine atom; Examples of the branched alkanediyl group having a fluorine atom include 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, and the like. 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 [[]] include monocyclic cycloalkanediyl groups 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 cyclooctane-1,5-diyl group having a fluorine atom, Examples of the polycyclic cycloalkanediyl group having a fluorine atom include 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, and the like. L 42f The number of fluorine atoms of the alkanediyl group and the cycloalkanediyl group having a fluorine atom in [[]] may be 1 or more, and preferably 2 or more. L42f The alkanediyl group and the cycloalkanediyl group having a fluorine atom in are preferably a perfluoroalkanediyl group and a perfluorocycloalkanediyl group, respectively.

[0147] 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.

[0148] 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.

[0149] 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 the formula (a4-2) is the following structural unit. TIFF2025104292000134.tif33101[In the formula (a4-2), R 41 represents a hydrogen atom or a methyl group. L 43f represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a fluorine atom, and -CH2- contained in the aliphatic hydrocarbon group may be replaced 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 number of carbon atoms of L 43f and R 43f is 21.]

[0150] Examples of the aliphatic hydrocarbon group in L 43f and R 43f include linear or branched chain hydrocarbon groups, monocyclic or polycyclic alicyclic hydrocarbon groups, and groups formed by combining these. Examples of the aliphatic hydrocarbon group in L 43f and R 43f are, as long as the upper limit of the total number of carbon atoms of L 43f and R 43f allows, R in the formula (a4)​42 Examples of the aliphatic hydrocarbon group of 42 include the same groups as the exemplified aliphatic hydrocarbon groups.

[0151] L 43f As the aliphatic hydrocarbon group of 43f , an alkanediyl group having 1 to 6 carbon atoms or a group represented by the formula (L43f-1) is preferable. TIFF2025104292000135.tif14120 [In the formula (L43f-1), s represents 0 or 1. L 45f and L 46f each independently represent a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a fluorine atom. L 47f represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a fluorine atom. X 46f and X 47f each independently represent -O-, -CO-, -CO-O- or -O-CO-. However, the total number of carbon atoms of L 45f , L 46f , L 47f , X 46f and X 47f is 7 or less. * and ** are bonding sites, and ** is the bonding site with -O-CO-R 43f .

[0152] Examples of the divalent aliphatic hydrocarbon group represented by L 45f , L 46f and L 47f in the group represented by the formula (L43f-1) include a linear or branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic hydrocarbon group, and a divalent aliphatic hydrocarbon group formed by combining an alkanediyl group and a divalent alicyclic hydrocarbon group. Specifically, a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a 1-methylpropane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, etc. may be mentioned. s is preferably 0.

[0153] Examples of the group represented by the formula (L43f-1) include the following groups. In the following examples, * and ** each represent a bonding site, and ** is -O-CO-R 43f and is the bonding site with -O-CO-R. TIFF2025104292000136.tif47140

[0154] R 43f is preferably an aliphatic hydrocarbon group having a fluorine atom. Examples of the structural unit represented by the formula (a4-2) in this case include the structural units represented by the formula (a4-2A) or (formula a4-2B). TIFF2025104292000137.tif41157[In the formula (a4-2A) and the formula (a4-2B), R 41 and L 43f represent the same as those in the formula (a4-2). R 43fA represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms and having a fluorine atom. A 43f represents a divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom, and -CH2- contained in the aliphatic hydrocarbon group may be replaced by -O- or -CO-. X 43 represents **-O-CO- or **-CO-O-, and ** represents the bonding site with A 43f and represents the bonding site with A. R 43fB represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom. However, in the formula (a4-2A), the total number of carbon atoms of L 43f and R 43fA is 21 or less, and in the formula (a4-2B), the total number of carbon atoms of L 43f A 43f X 43 and R 43fB is 21 or less, and among A 43f and R 43fB at least one has at least one fluorine atom. R 43fA The aliphatic hydrocarbon group of R, as long as the upper limit of the number of carbon atoms permits, is an aliphatic hydrocarbon group similar to the aliphatic hydrocarbon group exemplified by R 42 above. R 43fA is preferably an alkyl group having 1 to 13 carbon atoms and having fluorine atoms, a cycloalkyl group having 3 to 12 carbon atoms and having fluorine atoms, or a group combining them, *-(CF2) n43f -R 42’ (* represents the bonding site with the carbonyl group. n43f represents any integer from 1 to 6. R 42’ represents a hydrogen atom or a fluorine atom.) or a perfluorocycloalkyl group having 3 to 12 carbon atoms is more preferable. A 43f and the aliphatic hydrocarbon group of R, as long as the upper limit of the number of carbon atoms permits, is an aliphatic hydrocarbon group similar to the aliphatic hydrocarbon group exemplified by R 43fB in formula (a4). 42 above. A 43f is preferably a divalent chain hydrocarbon group which may have fluorine atoms, a divalent alicyclic hydrocarbon group, or a group combining them, more preferably a divalent chain hydrocarbon group having fluorine atoms, and even more preferably a fluoroalkanediyl group having 1 to 6 carbon atoms. R 43fBThe aliphatic hydrocarbon group which may have a fluorine atom is preferably a chain hydrocarbon group, an alicyclic hydrocarbon group or a combination thereof which may have a fluorine atom, more preferably an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms or a combination thereof which may have a fluorine atom, and 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.

[0155] 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). TIFF2025104292000138.tif15170

[0156] 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. TIFF2025104292000139.tif99167

[0157] 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 structural unit represented by formula (a4-2B) is replaced by a hydrogen atom. TIFF2025104292000140.tif111163

[0158] Examples of the structural unit (a4) also include the structural unit represented by formula (a4-3). TIFF2025104292000141.tif3689[In formula (a4-3), R 41 represents a hydrogen atom or a methyl group. L 44f represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a fluorine atom, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. R 44f represents an aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a fluorine atom, and -CH2- contained in the aliphatic hydrocarbon group may be replaced by -O- or -CO-. However, at least one of 44f L and 44f R has a fluorine atom, and the upper limit of the total carbon number of 44f L and 44f R is 21.]

[0159] Examples of the aliphatic hydrocarbon group in 44f L and 44f R include linear or branched chain aliphatic hydrocarbon groups, monocyclic or polycyclic alicyclic hydrocarbon groups, and groups formed by combining these. Examples of the aliphatic hydrocarbon group in 44f L and 44f R are, as long as the upper limit of the total carbon number of 44f L and 44f R permits, the same groups as the aliphatic hydrocarbon groups exemplified as the aliphatic hydrocarbon group of R in formula (a4) in 42 Examples include the same groups as the aliphatic hydrocarbon groups exemplified as the aliphatic hydrocarbon group of R in formula (a4). L 44fis preferably an alkanediyl group having 1 to 14 carbon atoms (wherein -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-), and -(CH2) j1 -, -(CH2) j2 -O-(CH2) j3 - or -(CH2) j4 -CO-O-(CH2) j5 - (where j1 to j5 each independently represent an integer of 1 to 6). More preferably, it is an alkanediyl group having 1 to 4 carbon atoms (where one -CH2- contained in the alkanediyl group may be replaced by -O-, and one -CH2-CH2- contained in the alkanediyl group may be replaced by -CO-O- or -O-CO-). R 44f is preferably an aliphatic hydrocarbon group having 1 to 10 carbon atoms having a fluorine atom, more preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom, an alicyclic hydrocarbon group having 3 to 10 carbon atoms having a fluorine atom, or a group combining them, still more preferably an alkyl group having 1 to 10 carbon atoms having a fluorine atom, and even more preferably an alkyl group having 1 to 6 carbon atoms having a fluorine atom.

[0160] Examples of the structural unit represented by formula (a4-3) include the following structural units and the structural units represented by the following formulas, in which the methyl group corresponding to R in structural unit (a4-3) is replaced by a hydrogen atom. 41 TIFF2025104292000142.tif86170

[0161] Examples of structural unit (a4) also include the structural unit represented by formula (a4-A). TIFF2025104292000143.tif3686 [In formula (a4-A), all symbols represent the same meaning as described above.]

[0162] R 1 ​The alkyl group having 1 to 6 carbon atoms in [X] includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. R 1 Examples of the halogen atom in [X] include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like. R 1 Examples of the alkyl group having 1 to 6 carbon atoms and having a halogen atom in [X] 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, and the like. R 1 R is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, still more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group.

[0163] L 1 Examples of the aliphatic hydrocarbon group in [X] 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, and the like. Examples of the alkanediyl group include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, and heptadecane-1,17-diyl group, and branched alkanediyl groups such as ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, and 2-methylbutane-1,4-diyl group. Also included are groups in which one or more hydrogen atoms of the above-described groups are replaced by bonding sites, etc. 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.

[0164] Examples of the monocyclic or polycyclic alicyclic hydrocarbon group include the following alicyclic hydrocarbon groups, etc. The bonding site can be at any position. TIFF2025104292000144.tif45164 For example, alicyclic hydrocarbon groups such as cycloalkanediyl groups, 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, etc. and Examples of the polycyclic alicyclic hydrocarbon group include a spiro ring having a cycloalkanediyl group such as a norbornane-1,4-diyl group, a norbornane-2,5-diyl group, an adamantane-1,5-diyl group, an adamantane-2,6-diyl group, a decahydronaphthalenediyl group, a bicyclo[3.3.0]octanediyl group, a spirocyclohexane-1,2'-cyclopentane-diyl group, a spiroadamantane-2,3'-cyclopentane-diyl group, etc., a norbornyl group or an adamantyl group, each having a cycloalkanediyl group spiro-bonded thereto. 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.

[0165] Examples of the group formed by combining two or more thereof 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 thereof. Also, any of the groups may be bonded to X 11 in any manner. Examples of the group formed by combining an alicyclic hydrocarbon group and a chain hydrocarbon group include, for example, a group in which an alicyclic hydrocarbon group is bonded to a chain hydrocarbon group (e.g., *-chain hydrocarbon group-alicyclic hydrocarbon group-), a group in which a chain hydrocarbon group is bonded to an alicyclic hydrocarbon group (e.g., *-alicyclic hydrocarbon group-chain hydrocarbon group-), a group in which an alicyclic hydrocarbon group and a chain hydrocarbon group are bonded to a chain hydrocarbon group (e.g., *-chain hydrocarbon group-alicyclic hydrocarbon group-chain hydrocarbon group-), a group in which a chain hydrocarbon group and an alicyclic hydrocarbon group are bonded to an alicyclic hydrocarbon group (e.g., *-alicyclic hydrocarbon group-chain hydrocarbon group-alicyclic hydrocarbon group-), a group in which an alicyclic hydrocarbon group, a chain hydrocarbon group, and an alicyclic hydrocarbon group are bonded to a chain hydrocarbon group (e.g., *-chain hydrocarbon group-alicyclic hydrocarbon group-chain hydrocarbon group-alicyclic hydrocarbon group-), a group in which a chain hydrocarbon group, an alicyclic hydrocarbon group, and a chain hydrocarbon group are bonded to an alicyclic hydrocarbon group (e.g., *-alicyclic hydrocarbon group-chain hydrocarbon group-alicyclic hydrocarbon group-chain hydrocarbon group-), etc. * represents the bonding site with X 11 and the like.

[0166] L 1 In the aliphatic hydrocarbon group having 1 to 28 carbon atoms of L, -CH2- may be replaced by -O-, -S-, -SO2- or -CO-. L 1 When -CH2- contained in the aliphatic hydrocarbon group of L is replaced by -O-, -S-, -SO2- or -CO-, the number of carbon atoms before replacement shall be 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 alkoxycarbonyloxy group, an oxy group, a carbonyl group, a thio group, a sulfonyl group, an alkanedioxy group, an alkanedioxycarbonyl group, an alkanediylcarbonyl group, an alkanediylcarbonyloxy group, an alkanediylsulfonyl group, an alkanediylthio group, a cycloalkoxy group, a cycloalkylalkoxy group, an alkoxycarbonyloxy group, a group formed by combining two or more of these groups, and the like. These replaced groups include those similar to the groups exemplified in this specification within the range where the upper limit of the number of carbon atoms permits. Also included are groups in which one or more hydrogen atoms of the above-described groups are replaced by a bonding site. Examples of the group in which -CH2- contained in the alicyclic hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2- include those similar to the groups exemplified in this specification within the range where the upper limit of the number of carbon atoms permits.

[0167] L 1 The aliphatic hydrocarbon group in may have one or more substituents. Examples of the substituent include a halogen atom, a haloalkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms (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, etc. The haloalkyl group having 1 to 4 carbon atoms includes a fluoroalkyl group having 1 to 4 carbon atoms, a chloroalkyl group having 1 to 4 carbon atoms, a bromoalkyl group having 1 to 4 carbon atoms, an iodoalkyl group having 1 to 4 carbon atoms, etc. Examples of the haloalkyl group include a perfluoroalkyl group having 1 to 4 carbon atoms (such as a trifluoromethyl group, a pentafluoroethyl group, a heptafluoropropyl group, a nonafluorobutyl group, etc.), a 2,2,2-trifluoroethyl group, a 3,3,3-trifluoropropyl group, a 4,4,4-trifluorobutyl group, a 3,3,4,4,4-pentafluorobutyl group, a chloromethyl group, a bromomethyl group, an iodomethyl group, etc. The number of carbon atoms of the haloalkyl group is preferably 1 to 3, more preferably 1 or 2. Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, etc. The number of carbon atoms of the alkyl group is preferably 1 to 9, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. When -CH2- contained in the alkyl group is replaced by -O- or -CO-, the total number of carbon atoms before replacement is defined as the total number of carbon atoms of the alkyl group. Examples of the replaced group include a hydroxy group, a carboxy group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, an alkoxycarbonyloxy group, etc. L 1Examples of the substituent that the aliphatic hydrocarbon group in [compound name] may have include a halogen atom, a haloalkyl group having 1 to 3 carbon atoms, an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms (wherein -CH2- contained in the alkyl group or the alicyclic hydrocarbon group may be replaced by -O- or -CO-). A fluorine atom, an iodine atom, a perfluoroalkyl group having 1 to 3 carbon atoms, or an alkyl group having 1 to 4 carbon atoms (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-) is more preferable. A fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, a hydroxy group, or a methoxy group is even more preferable. L 1 is R 3When it does not form an alkyl fluoride group and an alicyclic hydrocarbon group, it may have a substituent and has 1 to 12 carbon atoms. A chain hydrocarbon group (in the chain hydrocarbon group, -CH2- may be replaced by -O- or -CO-), an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (in the alicyclic hydrocarbon group, -CH2- may be replaced by -O- or -CO-), or a group formed by combining a chain hydrocarbon group having 1 to 6 carbon atoms which may have a substituent and an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (in the chain hydrocarbon group, -CH2- may be replaced by -O- or -CO-, and in the alicyclic hydrocarbon group, -CH2- may be replaced by -O- or -CO-), preferably a chain hydrocarbon group having 1 to 8 carbon atoms which may have a substituent (in the chain hydrocarbon group, -CH2- may be replaced by -O- or -CO-), an alicyclic hydrocarbon group having 3 to 12 carbon atoms which may have a substituent, or a group formed by combining a chain hydrocarbon group having 1 to 6 carbon atoms which may have a substituent and an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (in the chain hydrocarbon group, -CH2- may be replaced by -O- or -CO-), more preferably a chain hydrocarbon group having 1 to 8 carbon atoms which may have a substituent (in the chain hydrocarbon group, -CH2- may be replaced by -O- or -CO-), an alicyclic hydrocarbon group having 5 to 12 carbon atoms which may have a substituent, a group formed by combining a chain hydrocarbon group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 5 to 12 carbon atoms which may have a substituent (in the chain hydrocarbon group, -CH2- may be replaced by -O- or -CO-), or a group formed by combining an alicyclic hydrocarbon group having 5 to 12 carbon atoms, a chain hydrocarbon group having 1 to 6 carbon atoms, and an alicyclic hydrocarbon group having 5 to 12 carbon atoms which may have a substituent (in the chain hydrocarbon group, -CH2- may be replaced by -O- or -CO-) is even more preferable.

[0168] R 2Examples of the C1-C8 fluoroalkyl group 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, perfluorooctyl group. The number of carbon atoms 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 In the case where the C1-C6 fluoroalkyl group has a carbon number within the allowable upper limit, the C1-C6 fluoroalkyl groups exemplified in the examples of the fluoroalkyl group of R 2 are similarly exemplified. R 2 is preferably a C1-C6 fluoroalkyl group, more preferably a C1-C3 fluoroalkyl group, still more preferably a trifluoromethyl group, a perfluoroethyl group or a perfluoropropyl group, and even more preferably a trifluoromethyl group when R 3 is a C1-C6 fluoroalkyl group. R2 When R 3 is a hydrogen atom, it is preferably an alkyl fluoride group having 1 to 6 carbon atoms, more preferably an alkyl fluoride group having 1 to 5 carbon atoms, and still more preferably an alkyl fluoride group having 3 to 5 carbon atoms. R 3 is bonded to L 1 to form an alicyclic hydrocarbon group having 3 to 6 carbon atoms, the group formed by the bonding of R 3 and L 1 includes, for example, groups represented by the following formulas. In 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 2 ; L 1A 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. TIFF2025104292000145.tif22138R 3 is preferably a hydrogen atom or an alkyl fluoride group having 1 to 3 carbon atoms. mi is preferably any integer from 1 to 3, more preferably 1 or 2, and still more preferably 1.

[0169] Examples of the structural unit (a4-A) include the following structural units. In the following structural units, structural units in which the methyl group corresponding to R 1 is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or an alkyl group other than a methyl group, and structural units in which the hydrogen atom corresponding to R 1 is replaced with a halogen atom, a haloalkyl group, or an alkyl group can also be cited as specific examples of the structural unit (a4-A). TIFF2025104292000146.tif192167

[0170] When the resin (A) etc. has the structural unit (a4), its content is preferably 1 to 97 mol%, more preferably 2 to 95 mol%, and still more preferably 3 to 90 mol% based on all the structural units of the resin (A) etc.

[0171] <Structural unit (a5)> Examples of the non-detachable hydrocarbon group included in the structural unit (a5) include groups having a linear, branched or cyclic hydrocarbon group. Among them, the structural unit (a5) preferably has a group having an alicyclic hydrocarbon group. Examples of the structural unit (a5) include a structural unit represented by formula (a5-1). TIFF2025104292000147.tif3971[In formula (a5-1), R 51 represents a hydrogen atom or a methyl group. R 52 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the hydrogen atoms contained in the alicyclic hydrocarbon group may be substituted with aliphatic hydrocarbon groups having 1 to 8 carbon atoms. L 55 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-.]

[0172] R 52 The alicyclic hydrocarbon group in R may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group and a norbornyl group. Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, and a 2-ethylhexyl group. Examples of the alicyclic hydrocarbon group having a substituent include a 3-methyladamantyl group. R 52 is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, more preferably an adamantyl group, a norbornyl group or a cyclohexyl group. L 55Examples of the divalent saturated hydrocarbon group in [compound name] include a divalent chain saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, preferably a divalent chain saturated hydrocarbon group. Examples of the divalent chain saturated hydrocarbon group include alkane diyl groups such as a methylene group, an ethylene group, a propane diyl group, a butane diyl group, and a pentane diyl group. The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic divalent alicyclic saturated hydrocarbon group include cycloalkane diyl groups such as a cyclopentane diyl group and a cyclohexane diyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include an adamantane diyl group and a norbornane diyl group.

[0173] L 55 Examples of the group in which -CH2- contained in the divalent saturated hydrocarbon group represented by [compound name] is replaced by -O- or -CO- include 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. TIFF2025104292000148.tif18165[In formula (L1-1), X x1 represents *-O-CO- or *-CO-O- (* represents a bonding site with [compound name] x1 .). L x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. L x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. However, the total number of carbon atoms of x1 L x2 and L L x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms. L x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. However, the total number of carbon atoms of x3 L x4 is 17 or less. In formula (L1-3), L x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. L x6 and L x7 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms. However, the total number of carbon atoms of L x5 , L x6 and L x7 is 15 or less. In formula (L1-4), L x8 and L x9 each represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms. W x1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms. However, the total number of carbon atoms of L x8 , L x9 and W x1 is 15 or less.

[0174] 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.

[0175] Examples of the group represented by the formula (L1-1) include the following divalent groups. TIFF2025104292000149.tif36147 Examples of the group represented by the formula (L1-2) include the following divalent groups. TIFF2025104292000150.tif23130 Examples of the group represented by the formula (L1-3) include the following divalent groups. TIFF2025104292000151.tif16147 Examples of the group represented by the formula (L1-4) include the following divalent groups. TIFF2025104292000152.tif13168L 55 is preferably a single bond or a group represented by the formula (L1-1).

[0176] Examples of the structural unit (a5-1) include the following structural units and the structural units in the following structural units where the methyl group corresponding to R 51 in the structural unit (a5-1) is replaced by a hydrogen atom. TIFF2025104292000153.tif104151 When the resin (A) contains the structural unit (a5), its content is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, and still more preferably 3 to 15 mol% based on all the structural units of the resin (A).

[0177] 〈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-.

[0178] Examples of the sultone ring include the following formula (T 1 -1), formula (T 1 -2), formula (T 1 -3) and formula (T 1 -4). The bonding site can be at any position. The sultone ring may be monocyclic, but is preferably polycyclic. The polycyclic sultone ring means a bridged ring containing -SO2-O- as an atomic group constituting the ring, and examples include the rings represented by formula (T 1 -1) and formula (T 1 -2). The sultone ring may contain, in addition to -SO2-O-, further heteroatoms as an atomic group constituting the ring, like the ring represented by formula (T 1 -2). Examples of the heteroatom include an oxygen atom, a sulfur atom or a nitrogen atom, and preferably an oxygen atom. TIFF2025104292000154.tif2977

[0179] The sultone ring may have a substituent, and examples of the substituent include a halogen atom or an alkyl group having 1 to 12 carbon atoms which may have a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms, and an alkylcarbonyl group having 2 to 4 carbon atoms, etc.

[0180] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, and a decyl group, preferably an alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group. Examples of the alkyl group having a halogen atom include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group, and preferably a trifluoromethyl group. Examples of the alkyl group having a hydroxy group include a hydroxymethyl group and a hydroxyalkyl group such as a 2-hydroxyethyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group. Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-tert-butylphenyl group, a p-adamantylphenyl group, a tolyl group, a xylyl group, a cumyl group, a mesityl group, a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group. Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, and a naphthylethyl group. Examples of the alkoxycarbonyl group include a group in which an alkoxy group such as a methoxycarbonyl group and an ethoxycarbonyl group is bonded to a carbonyl group, preferably an alkoxycarbonyl group having 6 or less carbon atoms, and more preferably a methoxycarbonyl group. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. From the viewpoint that the production of the monomer leading to the structural unit (a6) is easy, a sultone ring having no substituent is preferred.

[0181] As the sultone ring, a ring represented by the following formula (T1') is preferred. TIFF2025104292000155.tif2666[In the formula (T1'), X 11 represents an oxygen atom, a sulfur atom or a methylene group. R 41 represents an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms or an alkylcarbonyl group having 2 to 4 carbon atoms. ma represents any integer from 0 to 9. When ma is 2 or more, a plurality of R 41 may be the same or different. The bonding site is at an arbitrary position.] X 11 is preferably an oxygen atom or a methylene group, more preferably a methylene group. R 41 Examples thereof are the same as those of 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 preferred. ma is preferably 0 or 1, more preferably 0.

[0182] Examples of the ring represented by the formula (T1') include the following rings. The bonding site is at an arbitrary position. Among them, those in which the bonding site is at the 1-position or the 3-position are preferred. TIFF2025104292000156.tif44147

[0183] 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 that leads to the structural unit (a6) is preferably a monomer having an ethylenically unsaturated bond, more preferably a (meth)acrylic monomer.

[0184] The structural unit (a6) is preferably a structural unit represented by the formula (a6-0). TIFF2025104292000157.tif4077[In the formula (a6-0), R x represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom. A xx represents an oxygen atom, -N(R c )- or a sulfur atom. A x represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O-, -CO- or -N(R d )-. X 11 represents an oxygen atom, a sulfur atom or a methylene group. R 41 has the same meaning as described above. ma represents any integer from 0 to 9. When ma is 2 or more, a plurality of R 41 may be the same or different. R c and R d each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.]

[0185] 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, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group and an n-hexyl group, etc., preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group. R xExamples of the alkyl group having a halogen atom include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, a triiodomethyl group, and the like. R x is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group. A x Examples of the divalent saturated hydrocarbon group of A include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and a combination of two or more of these groups may also be used. Specifically, linear alkanediyl groups such as a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, a decane-1,10-diyl group, an undecane-1,11-diyl group, a dodecane-1,12-diyl group, a tridecane-1,13-diyl group, a tetradecane-1,14-diyl group, a pentadecane-1,15-diyl group, a hexadecane-1,16-diyl group, a heptadecane-1,17-diyl group, an ethane-1,1-diyl group, a propane-1,1-diyl group, and a propane-2,2-diyl group; Branched alkanediyl groups such as a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group; Monocyclic divalent alicyclic saturated hydrocarbon groups which are cycloalkanediyl groups such as a cyclobutane-1,3-diyl group, a cyclopentane-1,3-diyl group, a cyclohexane-1,4-diyl group, and a cyclooctane-1,5-diyl group; Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include a norbornane-1,4-diyl group, a norbornane-2,5-diyl group, an adamantane-1,5-diyl group, an adamantane-2,6-diyl group, and the like. A x The bonding position to the sultone ring of x can be any position, but the position at the 1-position is preferred.

[0186] Examples of the structural unit (a6-0) include the following structural units. TIFF2025104292000158.tif93150

[0187] 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 further preferably 3 to 30 mol% based on all the structural units of the resin (A).

[0188] <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.

[0189] The structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain is preferably a structural unit represented by formula (a7-A). TIFF2025104292000159.tif26123[In formula (a7-A), R a7represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. X a71 represents a single bond, *-O-, *-CO-O-, *-O-CO-O-**, *-CO-NR a71 -**, *-NR a71 -CO-O-**, *-O-CO-NR a71 -** or *-Ax-Ph-Ay-**. R a71 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Ph represents a phenylene group which may have a substituent. Ax and Ay each independently represent one type of bond selected from the group consisting of a single bond, an ether bond, a thioether bond, an ester bond, an amide bond, and a carbonate ester bond. * and ** represent bonding sites, and * represents the bonding site with the carbon atom to which R a7 is bonded. L a71 and L a72 each independently represent a hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. X a72 represents ***-CO-O-, ***-O-CO-, ***-O-CO-O-, ***-O-, and *** represents the bonding site with L a71 RA - represents a sulfonate anion or a carboxylate anion. ZA + represents an organic cation.

[0190] R a7 Examples of the alkyl group having 1 to 6 carbon atoms in R include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. R a7 Examples of the halogen atom in R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R​a7 Examples of the alkyl group having 1 to 6 carbon atoms and a halogen atom in [compound name] include trifluoromethyl group, difluoromethyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, perfluorohexyl group, trichloromethyl group, dichloromethyl group, triiodomethyl group, diiodomethyl group, tribromomethyl group, dibromomethyl group, and the like. R a7 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, still more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group.

[0191] X a71 When X is a group represented by *-Ax-Ph-Ay-**, it is preferably a linking group represented by the following formula (X10). TIFF2025104292000160.tif3351[In formula (X10), Ax represents the bonding species that binds to the carbon atom to which R a7 is attached, 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 the 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 fluorinated alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. mx represents any integer from 0 to 4. When mx is an integer of 2 or more, the plurality of Rx may be the same as or different from each other. When either Ax or Ay is a single bond, the other is preferably at least one selected from the group consisting of an ether bond, a thioether bond, an ester bond, a carbonate ester bond, and an amide bond. When either Ax or Ay is an amide bond, the bond represented by -CO-NR a71 - is preferred. The bonding position of Ay in the phenylene group is preferably the meta or para position with respect to the bonding position of Ax, and more preferably the para position. Among others, Rx is preferably a fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, or an ethyl group. mx is preferably 0, 1, or 2. X a71 For example, as X, a single bond, the following formula (X 10 -1) to formula (X 10 -10) can be mentioned. * represents the bonding site with the carbon atom to which -R a7 is bonded. ** represents the bonding site with L a71 . X 20 represents -O- or -NR a71 -. TIFF2025104292000161.tif43162 Specific examples of the group represented by formula (X 10 -1) to formula (X 10 -10) include the following groups. TIFF2025104292000162.tif78162 Among others, X 10 is preferably a single bond or a group represented by formula (X 10 -1’) and formula (X 10 -3’) to formula (X 10 -10’), more preferably a single bond or a group represented by formula (X 10 -1’), formula (X 10 -4’), formula (X 10 -5’), formula (X 10 -6’), and formula (X 10 -10’), still more preferably a single bond, a group represented by formula (X 10 -1’), a group represented by formula (X 10 -5’), or formula (X10 It is more preferable that it is a group represented by -6’).

[0192] L a71 As the hydrocarbon group of, from a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group combining two or more of these groups, one hydrogen atom is removed, and X a71 and X a72 and a group bonded to are mentioned. Further, as the hydrocarbon group of L a72 from a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group combining two or more of these groups, one hydrogen atom is removed, and X a72 and RA - and a group bonded to are mentioned. L a71 and L a72 As the chain hydrocarbon group of, a group obtained by removing one hydrogen atom of an alkyl group or an alkenyl group is mentioned. As the alkyl group, it may be linear or branched, and specifically, 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. 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 20, and even more preferably 1 to 10. L a71 and L a72 As the alicyclic hydrocarbon group of, a group obtained by removing one hydrogen atom of a monocyclic or polycyclic cycloalkyl group is mentioned. As the monocyclic cycloalkyl group, cyclobutyl group, cyclopentane group, cyclohexane group, cyclopentyl group, cyclooctyl group, etc. are mentioned. L a71 and La72 Examples of the polycyclic cycloalkyl group of L and L 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 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 and a cycloalkyl group having 5 to 8 carbon atoms are spiro-bonded. In addition, a double bond may be formed between two carbon atoms contained in the alicyclic hydrocarbon group. More specifically, examples of the alicyclic hydrocarbon group represented by the following formula can be given. TIFF2025104292000163.tif28158 When the alicyclic hydrocarbon group is a monocyclic cycloalkyl group, the number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 12, more preferably 3 to 8. When the alicyclic hydrocarbon group is a polycyclic cycloalkyl group, the number of carbon atoms of the alicyclic hydrocarbon group is preferably 7 to 12. L a71 and L a72 Examples of the aromatic hydrocarbon group of L and L include an aryl group from which one hydrogen atom has been removed. Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a fluorene group. The number of carbon atoms of the aromatic hydrocarbon group is preferably 5 to 14, more preferably 5 to 10. L a71 and L a72 When -CH2- contained in the hydrocarbon group of L and L is replaced by -O-, -CO-, -S- or -SO2-, the number of carbon atoms before replacement is defined as the number of carbon atoms of the hydrocarbon group. L a71 and L a72Among the hydrocarbon groups, examples of the group in which -CH2- contained in the chain hydrocarbon group is replaced by -O-, -CO-, -S- or -SO2- include a hydroxy group, a carboxy group, a thiol group, a carbonyl group, an oxy group, a thio group, a sulfonyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, an alkanediyl oxy group, an alkanediyl oxycarbonyl group, an alkanediylcarbonyl group, an alkanediylcarbonyloxy group and the like. These replaced groups include those similar to the groups exemplified in the present specification within the range where the upper limit of the number of carbon atoms permits. L a71 and L a72 Among the hydrocarbon groups, examples of the group in which -CH2- contained in the alicyclic hydrocarbon group and the group combining the alicyclic hydrocarbon group and the aromatic hydrocarbon group is replaced by -O-, -CO-, -S- or -SO2- include those similar to those exemplified in the present specification within the range where the upper limit of the number of carbon atoms permits. L a71 and L a72 Among the hydrocarbon groups, -CH2- contained in the aromatic hydrocarbon group may be replaced by -O- or -S-. Examples of the group in which -CH2- is replaced by -O- or -S- include a furan ring or a thiophene ring, respectively. L a71 and L a72 Examples of the group combining two or more of the chain hydrocarbon group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group include the group combining the above chain hydrocarbon group and the above alicyclic hydrocarbon group, the group combining the above chain hydrocarbon group and the above aromatic hydrocarbon group, the group combining the above alicyclic hydrocarbon group and the above aromatic hydrocarbon group, and the group combining the above chain hydrocarbon group, the above alicyclic hydrocarbon group and the above aromatic hydrocarbon group. The above combined groups are included. The group combining 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 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. L a71 and L a72 When is a group combining an alicyclic hydrocarbon group or an aromatic hydrocarbon group and a chain hydrocarbon group, substantially, the chain hydrocarbon group may be regarded as a substituent that the alicyclic hydrocarbon group or the aromatic hydrocarbon group has. Also, L b1‘ and L b2‘ By replacing -CH2- of the chain hydrocarbon group contained in the hydrocarbon group of with -O-, -CO-, -S- or -SO2-, L b1‘ and L b2‘ The hydrocarbon group of may substantially have substituents such as a hydroxy group, a carboxyl group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, a thiol group, a sulfonyl group and the like.

[0193] ZA in formula (a7-A) + is the same as the cation Z1 in the salt represented by formula (B1) described later + and the like can be mentioned.

[0194] Examples of the structural unit represented by formula (a7-A) include the following structural units, R a7 Structural units in which a group corresponding to the methyl group of is replaced by a hydrogen atom, a halogen atom (for example, a fluorine atom) or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (for example, a trifluoromethyl group, etc.) and the structural units described in International Publication No. 2012 / 050015. ZA + represents an organic cation. TIFF2025104292000164.tif244163

[0195] TIFF2025104292000165.tif131157

[0196] 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). TIFF2025104292000166.tif27105[In formula (a7-B), R a7represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. A II1 represents a single bond or a divalent linking group. R II1 represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent. R II2 and R II3 each independently represent a hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, and R II2 and R II3 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. A - represents an organic anion. R a7 Examples of the halogen atom and the alkyl group which may have a halogen atom of R include the same halogen atom and the alkyl group which may have a halogen atom as those in formula (a7-A). R II1 Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by R include a phenylene group and a naphthylene group. R II2 and R II3 Examples of the hydrocarbon group represented by R include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these. Examples of the alkyl group, the alicyclic hydrocarbon group, the aromatic hydrocarbon group, and the group formed by combining these are the same as those described above. A II1 Examples of the divalent linking group represented by A include a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O-, -S-, or -CO-. Examples of the divalent saturated hydrocarbon group include a linear or branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and combinations thereof. Specifically, linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group; branched alkanediyl groups such as butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group; cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group; divalent polycyclic alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. can be mentioned. Examples of those in which -CH2- contained in the saturated hydrocarbon group is replaced by -O-, -S- or -CO- include divalent groups represented by formula (X1) to formula (X53). However, the number of carbon atoms before -CH2- contained in the saturated hydrocarbon group is replaced by -O-, -S- or -CO- is each 17 or less. In the following formula, * and ** represent bonding sites, and * represents the bonding site with R II2 and represents the bonding site with. JPEG2025104292000167.jpg123161[wherein X 3 represents a divalent saturated hydrocarbon group having 1 to 16 carbon atoms. X 4 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. X 5 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms. X 6 represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms. X 7 represents a trivalent saturated hydrocarbon group having 1 to 14 carbon atoms. X 8 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.]

[0197] Examples of the structural unit containing the cation in formula (a7-B) include the structural unit represented by the following and a group corresponding to the methyl group of R a7 wherein the group corresponding to the methyl group of R is replaced with a hydrogen atom, a halogen atom (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.). JPEG2025104292000168.jpg72163

[0198] A - Examples of the organic anion represented by A include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion. A - The organic anion represented by A is preferably a sulfonate anion, and more preferably an anion contained in the salt represented by the above-described formula (B1). Examples of the sulfonylimide anion, the sulfonylmethide anion, and the carboxylate anion are the same as those exemplified as the anion of compound (B).

[0199] Examples of the structural unit represented by formula (a7-B) include the structural unit represented by the following. TIFF2025104292000169.tif95157

[0200] When the resin (A) contains the structural unit (a7), the structural unit (a7) may be contained alone or in combination of two or more. The content rate of the total structural unit (a7) is preferably 1 to 30 mol%, more preferably 2 to 25 mol%, and still more preferably 3 to 20 mol% with respect to all the structural units of the resin (A).

[0201] The resin (A) is preferably a resin composed of the structural unit (a1) and the structural unit (s). The structural unit (a1) is preferably at least one selected from the group consisting of the structural unit represented by the formula (a1-0), the structural unit represented by the formula (a1-1), the structural unit represented by the formula (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group), the structural unit represented by the formula (a1-4), the structural unit represented by the formula (a1-5), and the structural unit represented by the formula (a1-6). More preferably, it is at least one selected from the group consisting of the structural unit (a1-0), the structural unit (a1-1), and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group or a cyclopentyl group), still more preferably at least two kinds, and still more preferably, the structural unit (a1-1) and / or the structural unit (a1-2). The structural unit (s) is preferably at least one selected from the group consisting of the structural unit (a2) and the structural unit (a3). The structural unit (a2) is preferably the structural unit represented by the formula (a2-A) or the structural unit represented by the formula (a2-1). The structural unit (a3) is preferably at least one selected from the group consisting of the structural unit represented by the formula (a3-1), the structural unit represented by the formula (a3-2), and the structural unit represented by the formula (a3-4).

[0202] Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and can be produced by a known polymerization method (for example, radical polymerization method) using the monomers that lead to these structural units. The content of each structural unit of the resin (A) can be adjusted by the amount of the monomers used in the polymerization. The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, still more preferably 3,000 or more), and 50,000 or less (more preferably 30,000 or less, still more preferably 15,000 or less). In this specification, the weight average molecular weight is the value determined by gel permeation chromatography under the conditions described in the examples.

[0203] <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, for example, a resin 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 composed only of the structural unit (a4) and a resin composed of the structural unit (a4) and the structural unit (a5) (hereinafter, the resin composed only of the structural unit (a4) and the resin composed of the structural unit (a4) and the structural unit (a5) may be collectively referred to as resin (X)). Examples of the structural unit that the resin (X) may further have include a structural unit (a2), a structural unit (a3), and a structural unit derived from other known monomers. When the resin (X) contains the structural unit (a4), in the resin (X), the content of the structural unit (a4) is 20 mol% or more, preferably 30 mol% or more, more preferably 40 mol% or more, and still more preferably 45 mol% or more, based on the total of all the structural units of the resin (X). Also, it is 100 mol% or less, preferably 80 mol% or less, more preferably 70 mol% or less, still more preferably 60 mol% or less, and even more preferably 55 mol% or less. Specifically, it is 20 to 100 mol%, preferably 20 to 80 mol%, more preferably 30 to 70 mol%, still more preferably 40 to 60 mol%, and even more preferably 45 to 55 mol%. When the resin (X) contains the structural unit (a5), the content of the structural unit (a5) is 20 mol% or more, preferably 30 mol% or more, more preferably 40 mol% or more, and still more preferably 45 mol% or more, based on the total of all the structural units of the resin (X). Also, it is 100 mol% or less, preferably 80 mol% or less, more preferably 70 mol% or less, still more preferably 60 mol% or less, and even more preferably 55 mol% or less. Specifically, it is 20 to 100 mol%, preferably 20 to 80 mol%, more preferably 30 to 70 mol%, still more preferably 40 to 60 mol%, and even more preferably 45 to 55 mol%. Further, when the resin (X) contains the structural unit (a4) and the structural unit (a5), the total content of the structural unit (a4) and the structural unit (a5) is 40 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more, and still more preferably 80 mol% or more, based on the total of all the structural units of the resin (X). Also, it is 100 mol% or less. Specifically, it is 40 to 100 mol%, preferably 60 to 100 mol%, more preferably 70 to 100 mol%, and still more preferably 80 to 100 mol%. Among them, the resin (X) is preferably a resin composed 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 rate 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).

[0204] 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).

[0205] The content rate 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 rate 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 rate of the resin with respect to this can be measured by known analysis means such as liquid chromatography or gas chromatography.

[0206] <Solvent (E)> The content rate 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 rate of the solvent (E) can be measured by known analysis means such as liquid chromatography or gas chromatography.

[0207] 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.

[0208] <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 amines include aliphatic amines and aromatic amines. Examples of the aliphatic amines include primary amines, secondary amines, and tertiary amines.

[0209] 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.

[0210] 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.

[0211] The acidity of a salt that generates an acid with a lower acidity than the acid generated from the acid generator is indicated by the acid dissociation constant (pKa). A salt that generates an acid with a lower acidity than the acid generated from the acid generator is a salt having an acid dissociation constant of the acid generated from the salt usually of -3 < pKa, preferably -1 < pKa < 7, and more preferably 0 < pKa < 5. Examples of the salt that generates an acid with a lower acidity than the acid generated from the acid generator include salts represented by the following formula, salts represented by formula (D) described in JP-A-2015-147926 (hereinafter sometimes referred to as "weak acid inner salt (D)"), and salts described in JP-A-2012-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-39502, and JP-A-2011-191745. The salt that generates an acid with a lower acidity than the acid generated from the acid generator is preferably a salt that generates a carboxylic acid with a lower acidity than the acid generated from the acid generator (a salt having a carboxylic acid anion), more preferably a weak acid inner salt (D), and even more preferably a diphenyliodonium salt containing a phenyl group substituted with a carboxylic acid anion among the weak acid inner salts (D). JPEG2025104292000170.jpg99157

[0212] 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, salts represented by the following formula are included.

[0213] TIFF2025104292000171.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 thereof 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 groups formed by combining these include alkyl-cycloalkyl groups, cycloalkyl-alkyl groups, aralkyl groups (e.g., phenylmethyl group, 1-phenylethyl group, 2-phenylethyl group, 1-phenyl-1-propyl group, 1-phenyl-2-propyl group, 2-phenyl-2-propyl group, 3-phenyl-1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, 6-phenyl-1-hexyl group, etc.). 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 groups in which an oxy group (-O-) is bonded to the above acyl group, etc. Examples of the alkoxycarbonyl group include groups in which a carbonyl group (-CO-) is bonde...

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 -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 - 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 the plurality of parentheses may be the same as or different from each other. R ４ 、R ５ 、R ６ and R ７ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH 2 - in the hydrocarbon group may be replaced by -O-, -S-, -NR ８ -, -SO ２ - or -CO-, R ３ and R ４ or R ３ and R ４ and R ５ may combine to form a cyclic hydrocarbon group having 3 to 20 carbon atoms, the cyclic hydrocarbon group may have a double bond between one or more adjacent pairs of carbon atoms, and -CH ２ - in the cyclic hydrocarbon group may be replaced by -O-, -CO- or -NR ７ -, and -CH= in the cyclic hydrocarbon group may be replaced by -N=. R ８ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and the -CH 2 - in the hydrocarbon group may be replaced by -O-, -S-, -SO ２ - or -CO-. Z ＋ 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 an (nb2 + 1)-valent hydrocarbon group 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 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 the plurality of parentheses may be the same as or different from each other. R ４ 、R ５ 、R ６ and R ７ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH 2 - in the hydrocarbon group may be replaced by -O-, -S-, -NR ８ -, -SO ２ - or -CO-, R ３ and R ４ or R ３ and R ４ and R ５ may combine to form a cyclic hydrocarbon group having 3 to 20 carbon atoms, the cyclic hydrocarbon group may have a double bond between one or more adjacent carbon atoms, and -CH ２ - in the cyclic hydrocarbon group may be replaced by -O-, -CO- or -NR ７ -, and -CH= in the cyclic hydrocarbon group may be replaced by -N=. R ８ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH 2 - in the hydrocarbon group may be replaced by -O-, -S-, -SO ２ - or -CO-.] [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 the -CH 2 - contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO 2 -. R b1 represents a halogen atom or an alkyl group having 1 to 6 carbon atoms, and the -CH 2 - contained in the alkyl group may be replaced by -O- or -CO-. nb3 represents any integer from 0 to 4, and when nb3 is 2 or more, the plurality of Rs b1 may be the same as or different from each other. R ３ represents a halogen atom, a haloalkyl group having 1 to 12 carbon atoms, or a hydrocarbon group having 1 to 18 carbon atoms, the hydrocarbon group may have a substituent, and the -CH 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. R ４ 、R ５ 、R ６ and R ７ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH 2 - in the hydrocarbon group may be replaced by -O-, -S-, -NR ８ -, -SO ２ - or -CO-, and R ３ and R ４ or R ３ and R ４ and R ５ may combine to form a cyclic hydrocarbon group having 3 to 20 carbon atoms, the cyclic hydrocarbon group may have a double bond between one or more adjacent pairs of carbon atoms, and -CH ２ - in the cyclic hydrocarbon group may be replaced by -O-, -CO- or -NR ７ -, and -CH= in the cyclic hydrocarbon group may be replaced by -N=. R ８ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and the -CH 2 - in the hydrocarbon group may be replaced by -O-, -S-, -SO ２ - or -CO-.]

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 the -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 the plurality of parentheses may be the same as or different from each other. na11 represents any integer from 0 to 4, and when na11 is 2 or more, a plurality of Rs ａ１７ may be the same as or different from each other. mc represents 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 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. ] [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 atoms 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 aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent. ]

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 the plurality of parentheses may be the same as or different from each other. Na21 represents any integer from 0 to 4, and when Na21 is 2 or more, a plurality of Rs ａ２７ may be the same as or different from each other. mc represents an integer of either 0, 1, or 2. **Claim 7** (1) A step of applying the resist composition according to claim 4 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, The method for manufacturing a resist pattern including these steps. **Claim 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 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 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. nb1 represents an integer of either 1, 2, 3, 4, 5, or 6. When nb1 is 2 or more, the groups within multiple parentheses may be the same as or different from each other. R ４ 、R ５ 、R ６ and R ７ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH 2 - contained in the hydrocarbon group may be replaced by -O-, -S-, -NR ８ -, -SO ２ - or -CO-, and R ３ and R ４ or R ３ and R ４ and R ５ may combine to form a cyclic hydrocarbon group having 3 to 20 carbon atoms. The cyclic hydrocarbon group may have a double bond between one or more adjacent carbon atoms, and -CH ２ - contained in the cyclic hydrocarbon group may be replaced by -O-, -CO- or -NR ７ -, and -CH= contained in the cyclic hydrocarbon group may be replaced by -N=. R ８ represents a hydrocarbon group having 1 to 20 carbon atoms which may have a hydrogen atom or a substituent, and the —CH 2 — in the hydrocarbon group may be replaced by —O—, —S—, —SO ２ — or —CO—. Z ＋ represents an organic cation. **Claim 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 an integer of either 0, 1, 2, 3, 4, 5, or 6. X 1 represents -O-CO-, -CO-O-, -O-CO-O- or -O-. L b3 represents a single bond or an (nb2 + 1)-valent hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -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 the -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 - 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. nb2 represents an integer of either 1, 2, or 3. When nb2 is 2 or more, the groups within multiple parentheses may be the same as or different from each other. R ４ 、R ５ 、R ６ and R ７ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH 2 - in the hydrocarbon group may be replaced by -O-, -S-, -NR ８ -, -SO ２ - or -CO-, and R ３ and R ４ or R ３ and R ４ and R ５ may combine to form a cyclic hydrocarbon group having 3 to 20 carbon atoms, the cyclic hydrocarbon group may have a double bond between one or more adjacent pairs of carbon atoms, and -CH ２ - in the cyclic hydrocarbon group may be replaced by -O-, -CO- or -NR ７ -, and -CH= in the cyclic hydrocarbon group may be replaced by -N=. R ８ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and the -CH 2 - in the hydrocarbon group may be replaced by -O-, -S-, -SO ２ - or -CO-.] [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, a 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 - represents -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. nb4 represents an integer of either 1, 2, 3, 4, or 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. R ４ 、 R ５ 、 R ６ and R ７ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and the -CH 2 - in the hydrocarbon group may be replaced by -O-, -S-, -NR ８ -, -SO ２ - or -CO-, and R ３ and R ４ or R ３ and R ４ and R ５ may combine to form a cyclic hydrocarbon group having 3 to 20 carbon atoms, the cyclic hydrocarbon group may have a double bond between one or more adjacent pairs of carbon atoms, and the -CH ２ - in the cyclic hydrocarbon group may be replaced by -O-, -CO- or -NR ７ -, and the -CH= in the cyclic hydrocarbon group may be replaced by -N=. R ８ represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH 2 - in the hydrocarbon group may be replaced by -O-, -S-, -SO ２ - or -CO-.] **Claim 10** The salt according to claim 8, wherein nb1 is 1.

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