Salt, acid generator, resist composition, and method for producing resist pattern

Abstract

To provide a salt, an acid generator, and a resist composition which allow a resist pattern having good CD uniformity (CDU) to be produced.SOLUTION: There are provided: a salt represented by formula (I); an acid generator containing the salt; and a resist composition. [In the formula, m1 and m2 respectively represent an integer of 1-5 and an integer of 0-4, where they satisfy 1≤m1+m2≤5; X1 represents *-CO-O-, *-O-CO-, *-O-CO-O- or *-O-; L1 represents a single bond or an optionally substituted hydrocarbon group; Ar represents an optionally substituted aromatic hydrocarbon group; R1 represents -O-R10, -O-CO-R10, -O-CO-O-R10 or -O-L10-CO-O-R10; L10 represents an alkanediyl group; R10 represents a base-labile group; R2 represents a halogen atom, a haloalkyl group or a hydrocarbon group; and Z+ represents an organic cation.]SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a salt, an acid generator, a resist composition, and a method for producing a resist pattern. [Background technology]

[0002] Patent Document 1 describes a salt represented by the following formula and a resist composition containing the salt as an acid generator. TIFF2023117395000001.tif3456 Patent Document 2 describes a salt represented by the following formula and a resist composition containing the salt as an acid generator. TIFF2023117395000002.tif2755 Patent Document 3 describes a salt represented by the following formula and a resist composition containing the salt as an acid generator. TIFF2023117395000003.tif3157 Patent Document 4 describes a salt represented by the following formula and a resist composition containing the salt as an acid generator. TIFF2023117395000004.tif2762 [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-203858 [Patent Document 2] Japanese Patent Application Publication No. 09-244234 [Patent Document 3] Japanese Patent Application Publication No. 2018-155908 [Patent Document 4] Japanese Patent Application Publication No. 2018-159744 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a salt that forms a resist pattern with better CD uniformity (CDU) than a resist pattern formed from a resist composition containing the above salt. [Means for solving the problem]

[0005] The present invention includes the following inventions. [1] An acid generator comprising a salt represented by formula (I). TIFF2023117395000005.tif28121 [In formula (I), m1 represents an integer of 1 to 5, and when m1 is 2 or greater, the groups in the parentheses may be the same or different. X 1 represents *-CO-O-, *-O-CO-, *-O-CO-O- or *-O-, and * represents the bonding site to the benzene ring. L 1 represents a single bond or a hydrocarbon group having 1 to 36 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. Ar represents an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent. R 1 -OR 10 , -O-CO-R 10 , -O-CO-OR 10 or -OL 10 -CO-OR 10 Represents. L 10 represents an alkanediyl group having 1 to 6 carbon atoms. R 10 represents a base labile group. R 2 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 optionally being replaced by -O-, -CO-, -S-, or -SO2-. m2 represents an integer of 0 to 4, and when m2 is 2 or more, a plurality of R 2may be the same or different, provided that 1≦m1+m2≦5 is satisfied. Z + represents an organic cation. [2]X 1 [1] The acid generator according to [1], wherein *-CO-O- or *-O-CO-O-. [3]L 1 is a single bond or an alkanediyl group having 1 to 6 carbon atoms (-CH2- contained in the alkanediyl group may be replaced by -O- or -CO-). [4]L 1 is a single bond or a methylene group. [5]R 1 But, -O-CO-OR 10 or -OL 10 -CO-OR 10 The acid generator according to any one of [1] to [4], wherein [6]R 10 The acid generator according to any one of [1] to [5], wherein the base labile group is a group represented by formula (1b): TIFF2023117395000006.tif2056 [In formula (1b), R ba1 and R ba2 each independently represents a hydrogen atom, a fluorine atom or an alkyl group having 1 to 6 carbon atoms and a fluorine atom. R ba3 represents a fluorine atom or an alkyl group having 1 to 6 carbon atoms and a fluorine atom. * denotes a binding site.] [7] The acid generator according to any one of [1] to [6], wherein m1 is an integer of 1 to 3. [8] The acid generator according to any one of [1] to [7], wherein the salt represented by formula (I) is a salt represented by formula (IA). TIFF2023117395000007.tif41118[In formula (IA), X 1 , L 1 , R 1 , R 2 , m1, m2 and Z +represents the same as formula (I). R 3 represents a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, a haloalkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group combining these, and -CH2- contained in the alkyl group, haloalkyl group, alicyclic hydrocarbon group, or combined group may be replaced by -O-, -S-, -CO-, or -SO2-. m3 represents an integer of 0 to 6. m4 represents 0 or 1.] [9] m3 is an integer between 1 and 4, and R 3 is a fluorine atom, an iodine atom, an alkyl group having 1 to 6 carbon atoms, or a haloalkyl group having 1 to 6 carbon atoms (-CH2- contained in the alkyl group and the haloalkyl group may be replaced by -O-, -S-, -CO-, or -SO2-).

[10] A resist composition containing the acid generator according to any one of [1] to [9].

[11] The resist composition according to

[10] , which contains a resin containing a structural unit having an acid labile group, wherein the structural unit having an acid labile group comprises 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), and a structural unit represented by formula (a1-2): TIFF2023117395000008.tif43141 [In formula (a1-0), formula (a1-1) and formula (a1-2), L a01 , L a1 and L a2 are each independently -O- or -O-(CH2) k1 represents —CO—O—, k1 represents an integer of 1 to 7, and * represents 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 a04each independently represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these. R a6 and R a7 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these. m1' represents an integer of 0 to 14. n1 represents an integer of 0 to 10. n1' represents an integer of 0 to 3.

[12] The resist composition according to

[10] or

[11] , which contains a resin containing a structural unit represented by formula (a2-A). TIFF2023117395000009.tif4653[In formula (a2-A), R a50 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a51 represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A a50 is a single bond or *-X a51 -(A a52 -X a52 ) nb - represents -R a50 represents the bonding site with the carbon atom to which it is bonded. A a52 represents an alkanediyl group having 1 to 6 carbon atoms. X a51 and X a52 each independently represents -O-, -CO-O- or -O-CO-. nb represents 0 or 1. mb represents an integer of 0 to 4. When mb is an integer of 2 or more, a plurality of R a51 may be the same or different from each other.

[13] The resist composition according to any one of

[10] to

[12] , further comprising a salt that generates an acid that is weaker in acidity than the acid generated from the acid generator.

[14] (1) A step of applying the resist composition according to any one of

[10] to

[13] onto a substrate; (2) drying the applied composition to form a composition layer; (3) exposing the composition layer to light; (4) heating the composition layer after exposure; and (5) A method for producing a resist pattern, comprising the step of developing the composition layer after heating.

[15] A salt represented by the above formula (I).

[16] X 1 is *-CO-O- or *-O-CO-O-.

[17] L 1 is a single bond or an alkanediyl group having 1 to 6 carbon atoms (-CH2- contained in the alkanediyl group may be replaced by -O- or -CO-).

[18] L 1 is a single bond or a methylene group.

[19] R 1 But, -O-CO-OR 10 or -OL 10 -CO-OR 10 The salt according to any one of

[15] to

[18] , wherein

[20] R 10 The salt according to any one of

[15] to

[19] , wherein the base labile group is a group represented by the above formula (1b).

[21] The salt according to any one of

[15] to

[20] , wherein m1 is an integer of 1 to 3.

[22] The salt according to any one of

[15] to

[21] , wherein the salt represented by formula (I) is the salt represented by formula (IA) above.

[23] m3 is an integer between 1 and 4, and R3 is a fluorine atom, an iodine atom, an alkyl group having 1 to 6 carbon atoms, or a haloalkyl group having 1 to 6 carbon atoms (-CH2- contained in the alkyl group and the haloalkyl group may be replaced by -O-, -S-, -CO-, or -SO2-). [Effects of the Invention]

[0006] By using a resist composition containing the salt of the present invention, a resist pattern with good CD uniformity (CDU) can be produced. DETAILED DESCRIPTION OF THE INVENTION

[0007] As used herein, "(meth)acrylic monomer" means "at least one of an acrylic monomer and a methacrylic monomer." The terms "(meth)acrylate" and "(meth)acrylic acid" have the same meaning. Regarding groups described herein, those that can have either a linear or branched structure are acceptable. When -CH2- in a hydrocarbon group or the like is replaced with -O-, -S-, -CO-, or -SO2-, the same examples apply to each group. A "combined group" refers to a group formed by combining two or more of the exemplified groups with their valences appropriately changed, and the valence of these groups may be changed appropriately depending on the bonding form. "Derived from" or "derived from" refers to a polymerizable C=C bond in the molecule becoming a -CC- group (single bond) through polymerization. When stereoisomers exist, all stereoisomers are included. In this specification, the term "solid content of the resist composition" refers to the sum of all components in the resist composition excluding the solvent (E), which will be described later.

[0008] [Salt represented by formula (I)] The present invention relates to a salt represented by formula (I) (hereinafter sometimes referred to as "salt (I)"). In the salt (I), the negatively charged side is sometimes called the "anion (I)" and the positively charged side is sometimes called the "cation (I)". TIFF2023117395000010.tif28121 [wherein all symbols have the same meanings as defined above.]

[0009] In formula (I), X 1 is preferably *-CO-O-, *-O-CO-O- or *-O-, more preferably *-CO-O- or *-O-CO-O-, and further preferably *-CO-O-.

[0010] L 1 Examples of the hydrocarbon group having 1 to 36 carbon atoms include aliphatic hydrocarbon groups (chain hydrocarbon groups such as alkanediyl groups, alkenediyl groups, and alkynediyl groups, and monocyclic or polycyclic alicyclic hydrocarbon groups), aromatic hydrocarbon groups, and the like, and may also be hydrocarbon groups formed by combining two or more of these groups. 1 The —CH 2 — contained in the hydrocarbon group in the formula (I) may be replaced by —O—, —S—, —CO— or —SO 2 —.

[0011] 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, and a dodecane-1,12-diyl group; Branched alkanediyl groups such as ethane-1,1-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-2,2-diyl, pentane-2,4-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, and 2-methylbutane-1,4-diyl groups. Examples include: Examples of the alkenediyl group include an ethenediyl group, a propenediyl group, an isopropenediyl group, a butenediyl group, an isobutenediyl group, a tert-butenediyl group, a pentenediyl group, a hexenediyl group, a heptenediyl group, an octenediyl group, an isooctenediyl group, and a nonenediyl group. Examples of the alkynediyl group include an ethynediyl group, a propynediyl group, an isopropynediyl group, a butynediyl group, an isobutynediyl group, a tert-butynediyl group, a pentynediyl group, a hexynediyl group, an octynediyl group, and a nonynediyl group. The chain hydrocarbon group preferably has 1 to 18 carbon atoms, more preferably 1 to 12 carbon atoms, even more preferably 1 to 9 carbon atoms, even more preferably 1 to 6 carbon atoms, and even more preferably 1 to 4 carbon atoms.

[0012] Examples of the alkanediyl group in which -CH2- is replaced by -O-, -S-, -CO-, or -SO2- include a hydroxy group (a group in which -CH2- in a methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- in an ethyl group is replaced by -O-CO-), a thiol group (a group in which -CH2- in a methyl group is replaced by -S-), an alkoxy group (a group in which -CH2- at any position in an alkyl group is replaced by -O-), an alkylthio group (a group in which -CH2- at any position in an alkyl group is replaced by -O-), and - is replaced with -S-), alkoxycarbonyl group (a group in which -CH2-CH2- at any position in an alkyl group is replaced with -O-CO-), alkylcarbonyl group (a group in which -CH2- at any position in an alkyl group is replaced with -CO-), alkylsulfonyl group (a group in which -CH2- at any position in an alkyl group is replaced with -SO2-), alkylcarbonyloxy group (a group in which -CH2-CH2- at any position in an alkyl group is replaced with -CO-O-), oxy group (a group in which -CH2-CH2- at any position in a methylene group is replaced with -CO-O-), a carbonyl group (a group in which a -CH2- in a methylene group is replaced with -CO-), a thio group (a group in which a -CH2- in a methylene group is replaced with -S-), a sulfonyl group (a group in which a -CH2- in a methylene group is replaced with -SO2-), an alkanediyloxy group (a group in which a -CH2- in any position in an alkanediyl group is replaced with -O-), an alkanediyloxycarbonyl group (a group in which a -CH2-CH2- in any position in an alkanediyl group is replaced with -O-CO- substituted with -CO-), an alkanediylcarbonyl group (an alkanediyl group in which -CH- at any position is replaced with -CO-), an alkanediylcarbonyloxy group (an alkanediyl group in which -CH-CH- at any position is replaced with -CO-O-), an alkanediylthio group (an alkanediyl group in which -CH- at any position is replaced with -S-), and an alkanediylsulfonyl group (an alkanediyl group in which -CH- at any position is replaced with -SO-). Examples of the alkoxy group include alkoxy groups having 1 to 35 carbon atoms, such as a methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group, etc. The number of carbon atoms in the alkoxy group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkylthio group include alkylthio groups having 1 to 35 carbon atoms, such as a methylthio group, an ethylthio group, a propylthio group, a butylthio group, etc. The number of carbon atoms in the alkylthio group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and still more preferably 1 to 3. The alkoxycarbonyl group, alkylcarbonyl group and alkylcarbonyloxy group represent groups in which a carbonyl group or carbonyloxy group is bonded to the above-mentioned alkyl group or alkoxy group. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 35 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 36 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 35 carbon atoms, such as an acetyloxy group, a propionyloxy group, and a butyryloxy group. The number of carbon atoms in the alkoxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The alkylcarbonyloxy group preferably has 2 to 11 carbon atoms, more preferably 2 to 6 carbon atoms, even more preferably 2 to 4 carbon atoms, and even more preferably 2 or 3 carbon atoms. Examples of the alkylsulfonyl group include alkylsulfonyl groups having 1 to 35 carbon atoms, such as a methylsulfonyl group, an ethylsulfonyl group, a propylsulfonyl group, etc. The number of carbon atoms in the alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and still more preferably 1 to 3. Examples of the alkanediyloxy group include alkanediyloxy groups having 1 to 35 carbon atoms, such as a methyleneoxy group, an ethyleneoxy group, a propanediyloxy group, a butanediyloxy group, a pentanediyloxy group, a hexanediyloxy group, an octanediyloxy group, a 2-ethylhexanediyloxy group, a nonanediyloxy group, a decanediyloxy group, an undecanediyloxy group, etc. The number of carbon atoms in the alkanediyloxy group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediyloxycarbonyl group include alkanediyloxycarbonyl groups having 2 to 35 carbon atoms, such as a methyleneoxycarbonyl group, an ethyleneoxycarbonyl group, a propanediyloxycarbonyl group, a butanediyloxycarbonyl group, a pentanediyloxycarbonyl group, a hexanediyloxycarbonyl group, an octanediyloxycarbonyl group, a 2-ethylhexanediyloxycarbonyl group, a nonanediyloxycarbonyl group, a decanediyloxycarbonyl group, an undecanediyloxycarbonyl group, etc. The number of carbon atoms in the alkanediyloxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. Examples of the alkanediylcarbonyl group include alkanediylcarbonyl groups having 2 to 36 carbon atoms, such as a methylenecarbonyl group, an ethylenecarbonyl group, a propanediylcarbonyl group, a butanediylcarbonyl group, a pentanediylcarbonyl group, a hexanediylcarbonyl group, an octanediylcarbonyl group, a 2-ethylhexanediylcarbonyl group, a nonanediylcarbonyl group, a decanediylcarbonyl group, an undecanediylcarbonyl group, etc. The number of carbon atoms in the alkanediylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. Examples of the alkanediylcarbonyloxy group include alkanediylcarbonyloxy groups having 2 to 35 carbon atoms, such as a methylenecarbonyloxy group, an ethylenecarbonyloxy group, a propanediylcarbonyloxy group, a butanediylcarbonyloxy group, a pentanediylcarbonyloxy group, a hexanediylcarbonyloxy group, an octanediylcarbonyloxy group, a 2-ethylhexanediylcarbonyloxy group, a nonanediylcarbonyloxy group, a decanediylcarbonyloxy group, an undecanediylcarbonyloxy group, etc. The number of carbon atoms in the alkanediylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. Examples of the alkanediylthio group include alkanediylthio groups having 1 to 35 carbon atoms, such as a methylenethio group, an ethylenethio group, a propanediylthio group, a butanediylthio group, a pentanediylthio group, a hexanediylthio group, a heptanediylthio group, an octanediylthio group, a nonanediylthio group, a decanediylthio group, an undecanediylthio group, a dodecanediylthio group, and a 2-methylpropanediylthio group. The number of carbon atoms in the alkanediylthio group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediylsulfonyl group include alkanediylsulfonyl groups having 1 to 35 carbon atoms, such as a methylenesulfonyl group, an ethylenesulfonyl group, a propylenesulfonyl group, etc. The number of carbon atoms in the alkanediylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and still more preferably 1 to 3. The substitutions in the alkenediyl group and alkynediyl group may include a carbon-carbon double bond or a carbon-carbon triple bond at any position in the above-mentioned examples of substitutions in the alkanediyl group.

[0013] The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and examples thereof include the groups shown below: The bonding site may be at any position. TIFF2023117395000011.tif46168Specifically, monocyclic alicyclic hydrocarbon groups include monocyclic cycloalkanediyl groups such as cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, cyclohexene-3,6-diyl, and cyclooctane-1,5-diyl; and polycyclic alicyclic hydrocarbon groups include polycyclic cycloalkanediyl groups such as norbornane-1,4-diyl, norbornane-2,5-diyl, 5-norbornene-2,3-diyl, adamantane-1,5-diyl, and adamantane-2,6-diyl. The alicyclic hydrocarbon group preferably has 3 to 18 carbon atoms, more preferably 3 to 16 carbon atoms, and even more preferably 3 to 12 carbon atoms. Examples of groups in which -CH2- in an alicyclic hydrocarbon group is replaced with -O-, -S-, -CO-, or -SO2- include the groups shown below. Also included are groups in which, among the groups shown below, -O- is replaced with -S- and -CO- is replaced with -SO2-. The bonding site can be at any position. TIFF2023117395000012.tif47168 Examples of the aromatic hydrocarbon group include a phenylene group, a naphthylene group, an anthrylene group, a biphenylene group, a phenanthrylene group, etc. The aromatic hydrocarbon group preferably has 6 to 18 carbon atoms, more preferably 6 to 14 carbon atoms, and even more preferably 6 to 10 carbon atoms. When a -CH2- in a hydrocarbon group is replaced with -O-, -S-, -CO-, or -SO2-, the total number of carbon atoms in the hydrocarbon group is the number of carbon atoms before the replacement, which may be one or more.

[0014] Examples of hydrocarbon groups that combine two or more groups include groups that combine a chain hydrocarbon group such as an alkanediyl group with an alicyclic hydrocarbon group and / or an aromatic hydrocarbon group, and in the combination, two or more types of alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and chain hydrocarbon groups may each be combined. Examples include -alicyclic hydrocarbon group-alkanediyl group-, -alkanediyl group-alicyclic hydrocarbon group-, -alkanediyl group-alicyclic hydrocarbon group-, -alkanediyl group-alicyclic hydrocarbon group-alkanediyl group-, -alkanediyl group-aromatic hydrocarbon group-, -aromatic hydrocarbon group-alkanediyl group-, etc. When any of the groups is X 1 may be bound to

[0015] L 1 The substituents on the hydrocarbon group include a halogen atom and a cyano group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. L 1 The hydrocarbon group of the formula (I) is a group in which -CH2- is replaced by -O- or -CO-. 1 can substantially have a substituent such as a hydroxy group, a carboxy group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, or an alkylcarbonyloxy group. L 1 The hydrocarbon group in may have one or more substituents.

[0016] L 1is preferably a single bond, a chain hydrocarbon group having 1 to 8 carbon atoms (-CH2- contained in the chain hydrocarbon group may be replaced with -O-, -S-, -SO2- or -CO-), an alicyclic hydrocarbon group having 3 to 18 carbon atoms (-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -SO2- or -CO-), or a group combining a chain hydrocarbon group having 1 to 8 carbon atoms with an alicyclic hydrocarbon group having 3 to 18 carbon atoms (-CH2- contained in the chain hydrocarbon group and the alicyclic hydrocarbon group may be replaced with -O-, -S-, -SO2- or -CO-), more preferably a single bond or an alkanediyl group having 1 to 6 carbon atoms (-CH2- contained in the alkanediyl group may be replaced with -O- or -CO-), and even more preferably a single bond or a methylene group.

[0017] In formula (I), the aromatic hydrocarbon group in Ar may be either monocyclic or polycyclic, and examples thereof include arylene groups such as phenylene, naphthylene, biphenylene, anthrylene, phenanthrylene, and binaphthylene. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 14, and more preferably 6 to 10. Examples of the substituent that the aromatic hydrocarbon group may have include a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, a haloalkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and a group combining these (-CH2- contained in the alkyl group, haloalkyl group, alicyclic hydrocarbon group, and combined group may be replaced with -O-, -S-, -CO-, or -SO2-). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, a nonyl group, etc. The number of carbon atoms in the alkyl group is preferably 1 to 9, more preferably 1 to 6, even more preferably 1 to 4, and still more preferably 1 to 3. A haloalkyl group having 1 to 12 carbon atoms refers to an alkyl group having 1 to 12 carbon atoms and containing a halogen atom, and examples thereof include a fluorinated alkyl group having 1 to 12 carbon atoms, a chlorinated alkyl group having 1 to 12 carbon atoms, a brominated alkyl group having 1 to 12 carbon atoms, and an iodinated alkyl group having 1 to 12 carbon atoms. Examples of haloalkyl groups include perfluoroalkyl groups having 1 to 12 carbon atoms (e.g., trifluoromethyl, pentafluoroethyl, heptafluoropropyl, and nonafluorobutyl), 2,2,2-trifluoroethyl, 3,3,3-trifluoropropyl, 4,4,4-trifluorobutyl, and 3,3,4,4,4-pentafluorobutyl, chloromethyl, bromomethyl, and iodomethyl. The number of carbon atoms in the haloalkyl group is preferably 1 to 9, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alicyclic hydrocarbon group having 3 to 18 carbon atoms include monocyclic cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and cyclodecyl, and polycyclic cycloalkyl groups such as decahydronaphthyl, adamantyl, and norbornyl. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 16, more preferably 3 to 12, and even more preferably 3 to 10. When -CH2- contained in an alkyl group or haloalkyl group as a substituent is replaced with -O-, -S-, -CO- or -SO2-, the number of carbon atoms before replacement is counted as the total number of carbon atoms in the alkyl group or haloalkyl group.The substituted groups include a hydroxy group (a group in which -CH2- in a methyl group is replaced with -O-), a carboxy group (a group in which -CH2-CH2- in an ethyl group is replaced with -O-CO-), a thiol group (a group in which -CH2- in a methyl group is replaced with -S-), an alkoxy group (a group in which -CH2- at any position in an alkyl group is replaced with -O-), an alkoxycarbonyl group (a group in which -CH2-CH2- at any position in an alkyl group is replaced with -O-CO-), Alkylcarbonyl groups (groups in which -CH2- at any position in an alkyl group is replaced with -CO-), alkylcarbonyloxy groups (groups in which -CH2-CH2- at any position in an alkyl group is replaced with -CO-O-), alkylthio groups (groups in which -CH2- at any position in an alkyl group is replaced with -S-), alkylsulfonyl groups (groups in which -CH2- at any position in an alkyl group is replaced with -SO2-), haloalkoxy groups (groups in which -CH2- at any position in a haloalkyl group is replaced with -CO ... an alkyl group is replaced with -CO-), alkylthio groups (groups in which -CH2- at any position in an alkyl group is replaced with -S-), alkylsulfonyl groups (groups in which -CH2- at any position in an alkyl group is replaced with -SO2-), haloalkoxy groups (groups in which -CH2- at any position in an alkyl group is replaced with -CO-), alkylthio groups (groups in which -CH2- at any position in an alkyl group is replaced with - a haloalkoxycarbonyl group (a group in which -CH2-CH2- at any position in a haloalkyl group is replaced with -O-CO-), a haloalkylcarbonyl group (a group in which -CH2- at any position in a haloalkyl group is replaced with -CO-), a haloalkylcarbonyloxy group (a group in which -CH2-CH2- at any position in a haloalkyl group is replaced with -CO-O-), a haloalkylthio group (a group in which -CH2- at any position in a haloalkyl group is replaced with -CO-O-), , -S-), haloalkylsulfonyl groups (groups in which -CH- at any position in a haloalkyl group is replaced with -SO-), alkoxycarbonyloxy groups (groups in which -CH-CH-CH- at any position in an alkyl group is replaced with -O-CO-O-), haloalkoxycarbonyloxy groups (groups in which -CH-CH-CH- at any position in a haloalkyl group is replaced with -O-CO-O-), and groups in which two or more of these groups are combined. Examples of the alkoxy group include alkoxy groups having 1 to 11 carbon atoms, such as a methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group, etc. The number of carbon atoms in the alkoxy group is preferably 1 to 6, more preferably 1 to 4, and even more preferably 1 to 3. The alkoxycarbonyl group, alkylcarbonyl group and alkylcarbonyloxy group represent groups in which a carbonyl group or carbonyloxy group is bonded to the above-mentioned alkyl group or alkoxy group. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 11 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 12 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 11 carbon atoms, such as an acetyloxy group, a propionyloxy group, and a butyryloxy group. The number of carbon atoms in the alkoxycarbonyl group is preferably 2 to 6, more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkylcarbonyl group is preferably 2 to 6, more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2 to 6, more preferably 2 to 4, and even more preferably 2 or 3. The alkylthio group includes alkylthio groups having 1 to 11 carbon atoms, such as a methylthio group, an ethylthio group, a propylthio group, a butylthio group, etc. The alkylthio group preferably has 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms. Examples of the alkylsulfonyl group include alkylsulfonyl groups having 1 to 11 carbon atoms, such as a methylsulfonyl group, an ethylsulfonyl group, a propylsulfonyl group, etc. The number of carbon atoms in the alkylsulfonyl group is preferably 1 to 6, more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkoxycarbonyloxy group include alkoxycarbonyloxy groups having 2 to 10 carbon atoms, such as a butoxycarbonyloxy group. The number of carbon atoms in the alkoxycarbonyloxy group is preferably 2 to 6, more preferably 2 to 4, and even more preferably 2 or 3. Examples of the haloalkoxy group, haloalkoxycarbonyl group, haloalkylcarbonyl group, haloalkylcarbonyloxy group, haloalkylthio group, haloalkylsulfonyl group, and haloalkoxycarbonyloxy group include haloalkoxy groups having 1 to 11 carbon atoms, haloalkoxycarbonyl groups having 2 to 11 carbon atoms, haloalkylcarbonyl groups having 2 to 12 carbon atoms, haloalkylcarbonyloxy groups having 2 to 11 carbon atoms, haloalkylthio groups having 1 to 11 carbon atoms, haloalkylsulfonyl groups having 1 to 11 carbon atoms, and haloalkoxycarbonyloxy groups having 2 to 10 carbon atoms, and examples thereof include groups in which one or more hydrogen atoms of the above-exemplified groups have been replaced with halogen atoms. Examples of groups combining two or more types include a group combining an alkoxy group with another alkoxy group, a group combining an alkoxy group with an alkoxycarbonyl group, a group combining an alkoxy group with an alkylcarbonyl group, a group combining an alkoxy group with an alkylcarbonyloxy group, and groups in which one or more hydrogen atoms of these groups have been replaced with halogen atoms. Examples of a group formed by combining an alkoxy group with another alkoxy group include alkoxyalkoxy groups such as a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, etc. The number of carbon atoms in the alkoxyalkoxy group is preferably 2 to 10, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. Examples of a group combining an alkoxy group and an alkoxycarbonyl group include alkoxyalkoxycarbonyl groups such as a methoxymethoxycarbonyl group and an ethoxymethoxycarbonyl group, and alkoxycarbonylalkoxy groups such as a methoxycarbonylmethoxy group and an ethoxycarbonylmethoxy group. The number of carbon atoms in the alkoxyalkoxycarbonyl group and alkoxycarbonylalkoxy group is preferably 3 to 10, more preferably 3 to 7, even more preferably 3 to 5, and even more preferably 3 or 4. Examples of a group combining an alkoxy group and an alkylcarbonyl group include alkoxyalkylcarbonyl groups such as a methoxyacetyl group, a methoxypropionyl group, an ethoxyacetyl group, an ethoxypropionyl group, etc. The number of carbon atoms in the alkoxyalkylcarbonyl group is preferably 3 to 11, more preferably 3 to 7, even more preferably 3 to 5, and even more preferably 3 or 4. Examples of a group combining an alkoxy group and an alkylcarbonyloxy group include alkoxyalkylcarbonyloxy groups such as a methoxyacetyloxy group, a methoxypropionyloxy group, an ethoxyacetyloxy group, an ethoxypropionyloxy group, etc. The number of carbon atoms in the alkoxyalkylcarbonyloxy group is preferably 3 to 10, more preferably 3 to 7, even more preferably 3 to 5, and even more preferably 3 or 4. When, as a substituent, -CH2- contained in an alkyl group, haloalkyl group, or alicyclic hydrocarbon group is replaced with -O-, -CO-, or the like, the number of carbon atoms before replacement is counted as the total number of carbon atoms in the alkyl group, haloalkyl group, or alicyclic hydrocarbon group. The aromatic hydrocarbon group may have one or more substituents. The substituent that the aromatic hydrocarbon group may have is preferably a halogen atom, an alkyl group having 1 to 8 carbon atoms, a haloalkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or a combination thereof (-CH2- contained in the alkyl group, the haloalkyl group, the alicyclic hydrocarbon group, and the combination may be replaced with -O-, -S-, -CO-, or -SO2-), more preferably a halogen atom, an alkyl group having 1 to 6 carbon atoms, or a haloalkyl group having 1 to 6 carbon atoms (-CH2- contained in the alkyl group and the haloalkyl group may be replaced with -O-, -S-, -CO-, or -SO2-), even more 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, a haloalkyl group having 1 to 4 carbon atoms, or a haloalkoxycarbonylalkoxy group having 3 to 4 carbon atoms, and even more preferably a fluorine atom, an iodine atom, a methoxy group, an ethoxy group, a hydroxy group, or a trifluoromethyl group.

[0018] The aromatic hydrocarbon group having 6 to 18 carbon atoms (the aromatic hydrocarbon group may have a substituent) is It is preferably an aromatic hydrocarbon group having 6 to 14 carbon atoms (the aromatic hydrocarbon group may have a substituent), It is more preferable that the aromatic hydrocarbon group has 6 to 14 carbon atoms (the aromatic hydrocarbon group may have one or more selected from the group consisting of a halogen atom, an alkyl group having 1 to 8 carbon atoms, a haloalkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and a group obtained by combining these (in which -CH- contained in the alkyl group, the haloalkyl group, the alicyclic hydrocarbon group, and the group obtained by combining these groups may be replaced by -O-, -S-, -CO-, or -SO-)), It is more preferable that the aromatic hydrocarbon group has 6 to 14 carbon atoms (the aromatic hydrocarbon group may have one or more selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a haloalkyl group having 1 to 4 carbon atoms, a hydroxy group, and a halogen atom), It is even more preferable that the aromatic hydrocarbon group has 6 to 10 carbon atoms (the aromatic hydrocarbon group may have one or more groups selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a haloalkyl group having 1 to 4 carbon atoms, a hydroxy group, and a halogen atom), It is even more preferably a phenylene group (the phenylene group having one or more groups selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a haloalkyl group having 1 to 4 carbon atoms, a hydroxy group and a halogen atom).

[0019] In formula (I), R 1 L included in 10 Examples of the alkanediyl group in the formula (I) include linear alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, and hexane-1,6-diyl; and Examples of branched alkanediyl groups 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, and a 2-methylbutane-1,4-diyl group. L 10 is preferably an alkanediyl group having 1 to 3 carbon atoms, and more preferably a methylene group.

[0020] R 1 R included in 10 The base-labile group of R is a group that, when contacted with a base (e.g., 2.38% aqueous tetramethylammonium hydroxide solution), 10 When a leaving group including a group represented by the following formula is eliminated, it forms a carboxy group or a hydroxy group. The base labile group is preferably a group represented by formula (1b) (hereinafter sometimes referred to as "base labile group (1b)"). TIFF2023117395000013.tif2056 [In formula (1b), R ba1 and R ba2each independently represents a hydrogen atom, a fluorine atom or an alkyl group having 1 to 6 carbon atoms and a fluorine atom. R ba3 represents a fluorine atom or an alkyl group having 1 to 6 carbon atoms and a fluorine atom. * denotes a binding site.]

[0021] R ba1 , R ba2 and R ba3 Examples of the alkyl group having a fluorine atom include a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a perfluoroethyl group, a 2,2,3,3,3-pentafluoropropyl group, a 1-trifluoromethyl-2,2,2-trifluoroethyl group, a perfluoropropyl group, a 2,2,3,3,4,4,4-heptafluorobutyl group, a perfluorobutyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a perfluoropentyl group, a perfluorohexyl group, etc. The number of carbon atoms in the alkyl group having a fluorine atom is preferably 1 to 5, more preferably 1 to 4, and even more preferably 1 to 3. R ba1 is preferably a hydrogen atom or a fluorine atom, more preferably a hydrogen atom. R ba2 is preferably a hydrogen atom, a fluorine atom or a trifluoromethyl group, more preferably a hydrogen atom or a trifluoromethyl group. R ba3 is preferably a fluorine atom, a perfluoroalkyl group having 1 to 4 carbon atoms or a perfluoroalkylmethyl group having 2 to 5 carbon atoms, and more preferably a perfluoroalkyl group having 1 to 4 carbon atoms or a perfluoroalkylmethyl group having 2 to 5 carbon atoms. -C(R ba1 )(R ba2 )(R ba3) is preferably a perfluoroalkyl group having 1 to 4 carbon atoms, a perfluoroalkylmethyl group having 1 to 4 carbon atoms, or a 1-trifluoromethyl-2,2,2-trifluoroethyl group, and more preferably a perfluoroalkylmethyl group having 1 to 4 carbon atoms or a 1-trifluoromethyl-2,2,2-trifluoroethyl group. R 1 is -O-CO-R 10 , -O-CO-OR 10 , -OL 10 -CO-OR 10 is preferably —O—CO—OR 10 or -OL 10 -CO-OR 10 It is more preferable that: R 1 The bonding position of to Ar is L 1 For example, when Ar is a phenylene group, R 1 The bonding position of L 1 When Ar is a naphthylene group or the like, R 1 The binding position is preferably the 2-, 3-, 6- or 7-position. m1 is an integer of 1 to 5, preferably an integer of 1 to 4, more preferably an integer of 1 to 3, even more preferably 1 or 2, and even more preferably 2. X 1 The bond position to the benzene ring is SO3 - It may be at the o-position, m-position or p-position relative to the bonding position of X. 1 is SO3 - It is preferably bonded to the m-position or p-position, more preferably to the m-position, relative to the bonding position of X. 1 is SO3 - With respect to the bonding positions of X, it is preferred that one is bonded to the o-position or m-position, and one is bonded to the m-position or p-position, and it is more preferred that two are bonded to the m-position. 1 is SO3 -With respect to the bonding positions of the above, it is preferred that two are bonded to the o-position or m-position and one is bonded to the p-position or m-position, and it is more preferred that two are bonded to the o-position and one is bonded to the p-position.

[0022] R 2 Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R 2 The haloalkyl group having 1 to 12 carbon atoms refers to an alkyl group having 1 to 12 carbon atoms and containing a halogen atom, and examples thereof include fluorinated alkyl groups having 1 to 12 carbon atoms, chlorinated alkyl groups having 1 to 12 carbon atoms, brominated alkyl groups having 1 to 12 carbon atoms, and iodinated alkyl groups having 1 to 12 carbon atoms. Examples of haloalkyl groups include perfluoroalkyl groups having 1 to 12 carbon atoms (e.g., trifluoromethyl, pentafluoroethyl, heptafluoropropyl, and nonafluorobutyl), 2,2,2-trifluoroethyl, 3,3,3-trifluoropropyl, 4,4,4-trifluorobutyl, and 3,3,4,4,4-pentafluorobutyl, chloromethyl, bromomethyl, and iodomethyl. The number of carbon atoms in the haloalkyl group is preferably 1 to 9, more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3. R 2 Examples of the hydrocarbon group having 1 to 18 carbon atoms include chain hydrocarbon groups such as alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these groups. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group. The chain hydrocarbon group preferably has 1 to 12 carbon atoms, more preferably 1 to 9 carbon atoms, even more preferably 1 to 6 carbon atoms, even more preferably 1 to 4 carbon atoms, and even more preferably 1 to 3 carbon atoms. The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and examples thereof include the groups shown below: The bonding site may be at any position. TIFF2023117395000014.tif46168Specifically, examples of monocyclic alicyclic hydrocarbon groups include monocyclic cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and cyclodecyl.Examples of polycyclic alicyclic hydrocarbon groups include polycyclic cycloalkyl groups such as decahydronaphthyl, adamantyl, and norbornyl.The number of carbon atoms in 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 a phenyl group, a naphthyl group, a biphenyl group, an anthryl group, a phenanthryl group, a binaphthyl group, etc. The aromatic hydrocarbon group preferably has 6 to 18 carbon atoms, more preferably 6 to 14 carbon atoms, and even more preferably 6 to 10 carbon atoms.

[0023] Groups formed by combination include groups formed by combining an aromatic hydrocarbon group with an open-chain hydrocarbon group (for example, aromatic hydrocarbon group-alkanediyl group-*, alkyl group-aromatic hydrocarbon group-*; -CH2- contained in the alkanediyl group and the alkyl group may be replaced by -O-, -CO-, -S-, or -SO2-), groups formed by combining an alicyclic hydrocarbon group with an open-chain hydrocarbon group (for example, alicyclic hydrocarbon group-alkanediyl group-*, alkyl group-alicyclic hydrocarbon group-*; -CH2- contained in the alicyclic hydrocarbon group, alkanediyl group, and alkyl group may be replaced by -O-, -CO-, -S-, or -SO2-), and groups formed by combining an aromatic hydrocarbon group with an alicyclic hydrocarbon group (for example, aromatic hydrocarbon group-alicyclic hydrocarbon group-*, alicyclic hydrocarbon group-aromatic hydrocarbon group-*; -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -CO-, -S-, or -SO2-). * denotes the binding site. The aromatic hydrocarbon group -alkanediyl group-* includes aralkyl groups such as benzyl group and phenethyl group. Examples of the alkyl group-aromatic hydrocarbon group-* include a tolyl group, a xylyl group, and a cumenyl group. Examples of the alicyclic hydrocarbon group -alkanediyl group-* include cycloalkylalkyl groups such as a cyclohexylmethyl group, a cyclohexylethyl group, a 1-(adamantan-1-yl)methyl group, and a 1-(adamantan-1-yl)-1-methylethyl group. Examples of the alkyl group-alicyclic hydrocarbon group-* include cycloalkyl groups having an alkyl group such as a methylcyclohexyl group, a dimethylcyclohexyl group, and a 2-alkyladamantan-2-yl group. Examples of the aromatic hydrocarbon group-alicyclic hydrocarbon group-* include a phenylcyclohexyl group. Examples of the alicyclic hydrocarbon group-aromatic hydrocarbon group-* include a cyclohexylphenyl group. In addition, two or more types of alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and chain hydrocarbon groups may be combined, and any of the groups may be bonded to a benzene ring.

[0024] Examples of groups in which -CH2- in a hydrocarbon group is replaced by -O-, -CO-, -S-, or -SO2- include a hydroxy group (a group in which -CH2- in a methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- in an ethyl group is replaced by -O-CO-), an alkoxy group (a group in which -CH2- at any position in an alkyl group is replaced by -O-), a thiol group (a group in which -CH2- in a methyl group is replaced by -S-), an alkoxycarbonyl group (a group in which -CH2-CH2- at any position in an alkyl group is replaced by , -O-CO-), alkylcarbonyl group (a group in which -CH2- at any position in an alkyl group is replaced with -CO-), alkylthio group (a group in which -CH2- at any position in an alkyl group is replaced with -S-), alkylsulfonyl group (a group in which -CH2- at any position in an alkyl group is replaced with -SO2-), alkylcarbonyloxy group (a group in which -CH2-CH2- at any position in an alkyl group is replaced with -CO-O-), oxy group (a group in which -CH2- in a methylene group is replaced with -O- a carbonyl group (a group in which -CH2- in a methylene group is replaced with -CO-), a thio group (a group in which -CH2- in a methylene group is replaced with -S-), a sulfonyl group (a group in which -CH2- in a methylene group is replaced with -SO2-), an alkanediyloxy group (a group in which -CH2- at any position in an alkanediyl group is replaced with -O-), an alkanediyloxycarbonyl group (a group in which -CH2-CH2- at any position in an alkanediyl group is replaced with -O-CO-), an alkanediylcarbonyl group (a group in which -CH2-CH2- at any position in an alkanediyl group is replaced with -O-CO-), an alkanediyloxycarbonyl group (a group in which -CH2-CH2- at any position in an alkanediyl group is replaced with -O-CO-), an alkanediylcarbonyl group (a group in which an alkanediyl group in which -CH2- at any position is replaced with -CO-), an alkanediylcarbonyloxy group (a group in which -CH2-CH2- at any position in an alkanediyl group is replaced with -CO-O-), an alkanediylthio group (a group in which -CH2- at any position in an alkanediyl group is replaced with -S-), an alkanediylsulfonyl group (a group in which -CH2- at any position in an alkanediyl group is replaced with -SO2-), a cycloalkoxy group, a cycloalkylalkoxy group, an alkoxycarbonyloxy group,Examples include an aromatic hydrocarbon group-carbonyloxy 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. Examples of the alkoxy group include alkoxy groups having 1 to 17 carbon atoms, such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, etc. The number of carbon atoms in the alkoxy group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and still more preferably 1 to 3. Examples of the alkylthio group include alkylthio groups having 1 to 17 carbon atoms, such as a methylthio group, an ethylthio group, a propylthio group, a butylthio group, etc. The number of carbon atoms in the alkylthio group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and still more preferably 1 to 3. Examples of the alkylsulfonyl group include alkylsulfonyl groups having 1 to 17 carbon atoms, such as a methylsulfonyl group, an ethylsulfonyl group, a propylsulfonyl group, etc. The number of carbon atoms in the alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and still more preferably 1 to 3. The alkoxycarbonyl group, alkylcarbonyl group and alkylcarbonyloxy group represent groups in which a carbonyl group or carbonyloxy group is bonded to the above-mentioned alkyl group or alkoxy group. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 17 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, and butoxycarbonyl. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 18 carbon atoms, such as acetyl, propionyl, and butyryl. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 17 carbon atoms, such as acetyloxy, propionyloxy, and butyryloxy. The number of carbon atoms in the alkoxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The alkylcarbonyloxy group preferably has 2 to 11 carbon atoms, more preferably 2 to 6 carbon atoms, even more preferably 2 to 4 carbon atoms, and even more preferably 2 or 3 carbon atoms. Examples of the alkanediyloxy group include alkanediyloxy groups having 1 to 17 carbon atoms, such as a methyleneoxy group, an ethyleneoxy group, a propanediyloxy group, a butanediyloxy group, a pentanediyloxy group, etc. The number of carbon atoms in the alkanediyloxy group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and still more preferably 1 to 3. Examples of the alkanediyloxycarbonyl group include alkanediyloxycarbonyl groups having 2 to 17 carbon atoms, such as a methyleneoxycarbonyl group, an ethyleneoxycarbonyl group, a propanediyloxycarbonyl group, and a butanediyloxycarbonyl group. Examples of the alkanediylcarbonyl group include alkanediylcarbonyl groups having 2 to 18 carbon atoms, such as a methylenecarbonyl group, an ethylenecarbonyl group, a propanediylcarbonyl group, a butanediylcarbonyl group, and a pentanediylcarbonyl group. Examples of the alkanediylcarbonyloxy group include alkanediylcarbonyloxy groups having 2 to 17 carbon atoms, such as a methylenecarbonyloxy group, an ethylenecarbonyloxy group, a propanediylcarbonyloxy group, and a butanediylcarbonyloxy group. The number of carbon atoms in the alkanediyloxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and still more preferably 2 or 3. The number of carbon atoms in the alkanediylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, and still more preferably 2 or 3. The number of carbon atoms in the alkanediylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and still more preferably 2 or 3. Examples of the alkanediylthio group include alkanediylthio groups having 1 to 17 carbon atoms, such as a methylenethio group, an ethylenethio group, a propylenethio group, etc. The number of carbon atoms in the alkanediylthio group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and still more preferably 1 to 3. Examples of the alkanediylsulfonyl group include alkanediylsulfonyl groups having 1 to 17 carbon atoms, such as a methylenesulfonyl group, an ethylenesulfonyl group, a propylenesulfonyl group, etc. The number of carbon atoms in the alkanediylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, even more preferably 1 to 4, and still more preferably 1 to 3. Examples of cycloalkoxy groups include cycloalkoxy groups having 3 to 17 carbon atoms, such as a cyclohexyloxy group. Examples of cycloalkylalkoxy groups include cycloalkylalkoxy groups having 4 to 17 carbon atoms, such as a cyclohexylmethoxy group. Examples of alkoxycarbonyloxy groups include alkoxycarbonyloxy groups having 2 to 16 carbon atoms, such as a butoxycarbonyloxy group. Examples of aromatic hydrocarbon group-carbonyloxy groups include aromatic hydrocarbon group-carbonyloxy groups having 7 to 17 carbon atoms, such as a benzoyloxy group. Examples of aromatic hydrocarbon group-carbonyl groups include aromatic hydrocarbon group-carbonyl groups having 7 to 18 carbon atoms, such as a benzoyl group. Examples of aromatic hydrocarbon group-oxy groups include aromatic hydrocarbon group-oxy groups having 6 to 17 carbon atoms, such as a phenyloxy group.

[0025] Examples of groups in which -CH2- in an alicyclic hydrocarbon group is replaced with -O-, -CO-, -S-, or -SO2- include the groups shown below. Also included are groups in which, among the groups shown below, -O- is replaced with -S- and -CO- is replaced with -SO2-. The bonding site can be at any position. When a -CH2- in a hydrocarbon group or haloalkyl group is replaced with -O-, -S-, -CO-, or -SO2-, the total number of carbon atoms in the hydrocarbon group is the number of carbon atoms before the replacement. This number may be one, two, or more. Examples of groups in which -CH2- in a haloalkyl group is replaced with -O-, -CO-, -S-, or -SO2- include haloalkoxy groups (groups in which -CH2- at any position in a haloalkyl group is replaced with -O-), haloalkoxycarbonyl groups (groups in which -CH2-CH2- at any position in a haloalkyl group is replaced with -O-CO-), haloalkylcarbonyl groups (groups in which -CH2- at any position in a haloalkyl group is replaced with -CO-), haloalkylcarbonyloxy groups (groups in which -CH2-CH2- at any position in a haloalkyl group is replaced with -CO-O-), and groups in which two or more of these groups are combined. Examples of the haloalkoxy group, haloalkoxycarbonyl group, haloalkylcarbonyl group, and haloalkylcarbonyloxy group include haloalkoxy groups having 1 to 11 carbon atoms, haloalkoxycarbonyl groups having 2 to 11 carbon atoms, haloalkylcarbonyl groups having 2 to 12 carbon atoms, and haloalkylcarbonyloxy groups having 2 to 11 carbon atoms, and include groups in which one or more hydrogen atoms of the above-exemplified groups have been replaced with a halogen atom.

[0026] R 2 The substituents that the hydrocarbon group may have include a halogen atom and a cyano group. Examples of the halogen atom include the same groups as those mentioned above. R 2 The hydrocarbon group R is a group in which -CH2- is replaced by -O- or -CO-. 2 can substantially have a substituent such as a hydroxy group, a carboxy group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, or an alkylcarbonyloxy group. The hydrocarbon group may have one or more substituents. m2 is an integer of 0 to 4, and preferably an integer of 0 to 2 or 4. In one embodiment, m2 is preferably 0. In another embodiment, m2 is preferably 1, 2, or 4. When m2 is 1 or 4, R 2 is preferably a halogen atom, and R2 is more preferably a fluorine atom or an iodine atom. When m2 is 2, R 2 Preferably, one of R is a halogen atom and the other is a halogen atom or an alkyl group having 1 to 4 carbon atoms, 2 It is more preferable that one of the groups is a fluorine atom or an iodine atom, and the other is a fluorine atom, an iodine atom, or an alkyl group having 1 to 3 carbon atoms.

[0027] One embodiment of the salt represented by formula (I) includes a salt represented by formula (IA). TIFF2023117395000016.tif41118[In formula (IA), X 1 , L 1 , R 1 , R 2 , m1, m2 and Z + represents the same as formula (I). R 3 represents a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, a haloalkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group combining these, and -CH2- contained in the alkyl group, haloalkyl group, alicyclic hydrocarbon group, or combined group may be replaced by -O-, -S-, -CO-, or -SO2-. m3 represents an integer of 0 to 6. However, when m4 is 0, m3 represents an integer of 0 to 4, and when m4 is 1, m3 represents an integer of 0 to 6. m4 represents 0 or 1.] R 3 The halogen atom, cyano group, alkyl group having 1 to 12 carbon atoms, haloalkyl group having 1 to 12 carbon atoms, alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group combining these (-CH2- contained in the alkyl group, haloalkyl group, alicyclic hydrocarbon group, or combined group may be replaced by -O-, -S-, -CO-, or -SO2-) in R 3When -CH2- in the alkyl group, haloalkyl group, alicyclic hydrocarbon group or combined group is replaced by -O-, -S-, -CO- or -SO2-, R 3 As long as the upper limit of the carbon number of -OR 10 , -O-CO-OR 10 or -OL 10 -CO-OR 10 may be. R 3 is preferably a fluorine atom, an iodine atom, an alkyl group having 1 to 6 carbon atoms, or a haloalkyl group having 1 to 6 carbon atoms (wherein —CH— contained in the alkyl group or the haloalkyl group may be replaced by —O—, —S—, —CO—, or —SO—), more preferably a fluorine atom, an iodine atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a haloalkyl group having 1 to 4 carbon atoms, or a haloalkoxycarbonylalkoxy group having 3 to 4 carbon atoms, and still more preferably a fluorine atom, an iodine atom, a methoxy group, an ethoxy group, a hydroxy group, or a trifluoromethyl group. m4 is preferably 0. m3 is preferably an integer of 0 to 4, more preferably an integer of 1 to 4, even more preferably an integer of 1 to 3, still more preferably 1 or 2, and is preferably 2. moreover Even more preferable. In the salt represented by formula (IA), m1 is preferably 1 or 2, and X 1 The bond position to the benzene ring is SO3 - It is preferably m-position relative to the bonding position of the formula (IA1) or (IA2), and is preferably a salt represented by formula (IA1) or (IA2).

[0028] TIFF2023117395000017.tif98121 [In formula (IA1) and formula (IA2), X 1 , L 1 , R 1 , R 2 , R 3 , m2, m3, m4 and Z + represents the same as formula (I) and formula (IA). In formula (IA2), X 1A and X 1B , L 1A and L 1B , R 1A and R 1B , R 3A and R 3B m3A and m3B, m4A and m4B are each independently selected from X in formula (I) and formula (IA). 1 , L 1 , R 1 , R 3 , m3, and m4 represent the same thing. m2A represents an integer of 0 to 3, and when m2A is 2 or more, a plurality of R 2 may be the same or different from each other.] If m4, m4A, and m4B are 0, R 1 , R 1A and R 1B The bonding positions of each of the groups are independently 1 , L 1A and L 1B Preferably, the ortho- or para-position of the benzene ring relative to the bonding position of R is more preferably the para-position. 3 , R 3A and R 3B The bonding positions of each of the groups are independently 1 , L 1A and L 1B At least one of the bonding positions is preferably the ortho- or meta-position of the benzene ring, more preferably the meta-position. When m4, m4A, and m4B are 1, L 1 , L 1A and L 1B are preferably each independently bonded to the 2-position of the naphthyl ring, and R 1 , R 1A and R 1B The bonding positions of m3, m3A and m3B are preferably each independently the 6-position of the naphthalene ring. 3 , R 3A and R 3BPreferably, at least one of the bonding positions is independently the 5th or 7th position of the naphthalene ring.

[0029] Examples of the anion (I) include the following anions. Among them, anions represented by formulae (Ia-1) to (Ia-6), (Ia-10) to (Ia-21), (Ia-25) to (Ia-36), (Ia-40) to (Ia-45), (Ia-50), (Ia-61), and (Ia-64) to (Ia-66) are preferred. TIFF2023117395000018.tif234162

[0030] TIFF2023117395000019.tif234162

[0031] TIFF2023117395000020.tif235164

[0032] TIFF2023117395000021.tif246165

[0033] TIFF2023117395000022.tif155164

[0034] Z + Examples of the organic cation include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, organic sulfonium cations and organic iodonium cations are preferred, and arylsulfonium cations are more preferred. Specific examples include cations represented by any of formulas (b2-1) to (b2-4) (hereinafter, sometimes referred to as "cation (b2-1)" depending on the formula number). TIFF2023117395000023.tif45166In equations (b2-1) to (b2-4), R b4 ~R b6each independently represent a chain hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms, a hydrogen atom contained in the chain hydrocarbon group may be substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, or a glycidyloxy group, and a hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. R b4 and R b5 and may be bonded to each other to form a ring together with the sulfur atom to which they are attached, and -CH2- contained in the ring may be replaced with -O-, -S- or -CO-. R b7 and R b8 each independently represents a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. m2 and n2 each independently represent an integer of 0 to 5; When m2 is 2 or more, multiple R b7 may be the same or different, and when n2 is 2 or more, multiple R b8 may be the same or different. R b9 and R b10 each independently represents a chain hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms. R b9 and R b10 and may be bonded to each other to form a ring together with the sulfur atom to which they are attached, and -CH2- contained in the ring may be replaced with -O-, -S- or -CO-. R 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, or a hydrogen atom contained in the aromatic hydrocarbon group may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms. R b11 and R b12 and may be bonded to each other to form a ring including the -CH-CO- to which they are bonded, and -CH2- contained in the ring may be replaced by -O-, -S- or -CO-. R b13 ~R b18 each independently represents a halogen atom, a hydroxy group, 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 may be bonded to each other to form a ring containing a sulfur atom together with the benzene ring to which they are attached, and -CH2- contained in the ring may be replaced by -O-, -S- or -CO-. L b31 represents a sulfur atom or an oxygen atom. o2, p2, s2, and t2 each independently represent an integer of 0 to 5. q2 and r2 each independently represent an integer of 0 to 4; u2 represents 0 or 1. When o2 is 2 or more, multiple R b13 are the same or different, and when p2 is 2 or more, multiple R b14 are the same or different, and when q2 is 2 or more, multiple R b15 are the same or different, and when r2 is 2 or more, multiple R b16 are the same or different, and when s2 is 2 or more, multiple R b17 are the same or different, and when t2 is 2 or more, multiple Rb18 are the same or different. When u2 is 0, any one of o2, p2, q2, and r2 is 1 or more, and R b13 ~R b16 At least one of o2, p2, s2, t2, q2 and r2 is preferably a halogen atom, and when u2 is 1, any one of o2, p2, s2, t2, q2 and r2 is 1 or more, and R b13 ~R b18 At least one of these is preferably a halogen atom. Furthermore, when u2 is 0, r2 is preferably 1 or more, and more preferably 1. When u2 is 0 and r2 is 1 or more, R b16 is preferably a halogen atom. The aliphatic hydrocarbon group refers to a chain hydrocarbon group and an alicyclic hydrocarbon group. Examples of the chain hydrocarbon group include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, and 2-ethylhexyl. In particular, R b9 ~R b12 The chain hydrocarbon group preferably has 1 to 12 carbon atoms. The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and cyclodecyl. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl, adamantyl, and norbornyl groups, as well as the following groups: TIFF2023117395000024.tif10158 In particular, R b9 ~R b12 The alicyclic hydrocarbon group preferably has 3 to 18 carbon atoms, and more preferably has 4 to 12 carbon atoms. Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-methyladamantan-2-yl group, a 2-ethyladamantan-2-yl group, a 2-isopropyladamantan-2-yl group, a methylnorbornyl group, an isobornyl group, etc. In the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group, the total number of carbon atoms in the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less. The fluorinated alkyl group refers to an alkyl group having 1 to 12 carbon atoms and a fluorine atom, and examples thereof include a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a perfluorobutyl group, etc. The number of carbon atoms in the fluorinated alkyl group is preferably 1 to 9, more preferably 1 to 6, and even more preferably 1 to 4.

[0035] Examples of aromatic hydrocarbon groups include aryl groups such as phenyl, biphenyl, naphthyl, and phenanthryl. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and examples include aromatic hydrocarbon groups having a chain hydrocarbon group of 1 to 18 carbon atoms (such as tolyl, xylyl, cumenyl, mesityl, p-ethylphenyl, p-tert-butylphenyl, 2,6-diethylphenyl, and 2-methyl-6-ethylphenyl), and aromatic hydrocarbon groups having an alicyclic hydrocarbon group of 3 to 18 carbon atoms (such as p-cyclohexylphenyl and p-adamantylphenyl). When the aromatic hydrocarbon group has a chain hydrocarbon group or an alicyclic hydrocarbon group, chain hydrocarbon groups having 1 to 18 carbon atoms and alicyclic hydrocarbon groups having 3 to 18 carbon atoms are preferred. Examples of aromatic hydrocarbon groups in which hydrogen atoms are substituted with alkoxy groups include p-methoxyphenyl groups. Examples of the chain hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include aralkyl groups such as benzyl, phenethyl, phenylpropyl, trityl, naphthylmethyl, and naphthylethyl. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, an isopropylcarbonyloxy group, a butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group. R b4 and R b5 and bond to each other together with the sulfur atom to which they are bonded to form a ring which may be monocyclic, polycyclic, aromatic, non-aromatic, saturated, or unsaturated. This ring may be a ring having 3 to 18 carbon atoms, preferably a ring having 4 to 18 carbon atoms. The ring containing a sulfur atom may be a 3- to 12-membered ring, preferably a 3- to 7-membered ring, for example, the following rings. * represents a bonding site. TIFF2023117395000025.tif23143R b9 and R b10 The ring formed by these together may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring may be a 3- to 12-membered ring, preferably a 3- to 7-membered ring. Examples thereof include a thiolan-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring. R b11 and R b12The ring formed by combining these may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. Examples of this ring include a 3- to 12-membered ring, and preferably a 3- to 7-membered ring. Examples include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

[0036] Among the cations (b2-1) to (b2-4), the cation (b2-1) is preferred. Examples of the cation (b2-1) include the following cations. TIFF2023117395000026.tif130162Examples of the cation (b2-2) include the following cations. TIFF2023117395000027.tif18150Examples of the cation (b2-3) include the following cations. TIFF2023117395000028.tif24126 Examples of the cation (b2-4) include the following cations. TIFF2023117395000029.tif120170

[0037] Salt (I) is a combination of the above-mentioned anion and the above-mentioned organic cation, which can be combined arbitrarily. Preferred examples of salt (I) include a combination of an anion represented by any of formulas (Ia-1) to (Ia-6), (Ia-10) to (Ia-21), (Ia-25) to (Ia-36), (Ia-40) to (Ia-45), (Ia-50), (Ia-61), and (Ia-64) to (Ia-66) with cation (b2-1), (b2-2), (b2-3), or (b2-4).

[0038] Examples of salt (I) include salts listed in Table 1. In the table below, each symbol represents the symbol attached to the structure representing the above-mentioned anion or cation. For example, salt (I-1) means a salt consisting of an anion represented by formula (Ia-1) and a cation represented by formula (b2-c-1), and represents the salt shown below. TIFF2023117395000030.tif42104

Table 1

[0039] Among them, salt (I) is salt (I-1) to salt (I-6), salt (I-10) to salt (I-21), salt (I-25) to salt (I-36), salt (I-40) to salt (I-45), salt (I-50), salt (I-61), salt (I-63) to salt (I-68), salt (I-72) to salt (I-83), salt (I- 87)~Salt(I-98), Salt(I-102)~Salt(I-107), Salt(I-112), Salt(I-123), Salt(I-125)~Salt(I-130), Salt(I-134)~Salt(I-145), Salt(I-149)~Salt(I-160), Salt(I-164)~Salt(I-169), Salt(I-1 74), salt (I-185), salt (I-187) ~ salt (I-192), salt (I-196) ~ salt (I-207), salt (I-211) ~ salt (I-222), salt (I-226) ~ salt (I-231), salt (I-236), salt (I-247), salt (I-249) ~ salt (I-254), salt (I- 258)~Salt(I-269), Salt(I-273)~Salt(I-284), Salt(I-288)~Salt(I-293), Salt(I-298), Salt(I-309), Salt(I-311)~Salt(I-216), Salt(I-320)~Salt(I-331), Salt(I-335)~Salt(I-346), Salt(I -350)~Salt(I-355), Salt(I-360), Salt(I-371), Salt(I-373)~Salt(I-378), Salt(I-382)~Salt(I-393), Salt(I-397)~Salt(I-408), Salt(I-412)~Salt(I-417), Salt(I-422), Salt(I-433), Salt( I-435) ~ Salt (I-440), Salt (I-444) ~ Salt (I-455), Salt (I-459) ~ Salt (I-470), Salt (I-474) ~ Salt (I-479), Salt (I-484), Salt (I-495), Salt (I-497) ~ Salt (I-502), Salt (I-506) ~ Salt (I-517), Salt (I-521)~Salt(I-532), Salt(I-536)~Salt(I-541), Salt(I-546), Salt(I-557), Salt(I-559)~Salt(I-564), Salt(I-568)~Salt(I-579), Salt(I-583)~Salt(I-594), Salt(I-598)~Salt(I-603), Salt (I-608), Salt (I-619), Salt (I-621) ~ Salt (I-626), Salt (I-630) ~ Salt (I-641), Salt (I-645) ~ Salt (I-656), Salt (I-660) ~ Salt (I-665), Salt (I-670), Salt (I-681), Salt (I-683) ~ Salt (I-688),Salt (I-692) ~ Salt (I-703), Salt (I-707) ~ Salt (I-718), Salt (I-722) ~ Salt (I-727), Salt (I-732), Salt (I-743), Salt (I-745) ~ Salt (I-750), Salt (I-754) ~ Salt (I-765), Salt (I-769) ~ Salt (I-780), Salt (I-784) ~ Salt (I-789), Salt (I-794), Salt (I-805), Salt (I-807) ~ Salt (I-812), Salt (I-816) ~ Salt (I-827), Salt (I-831) ~ Salt (I-842), Salt (I-846) ~ Salt (I-851), salt (I-856), salt (I-867), salt (I-869) ~ salt (I-874), salt (I-878) ~ salt (I-889), salt (I-893) ~ salt (I-904), salt (I-908) ~ salt (I-913), salt (I-918), salt (I-929), salt (I-931) ~ salt (I-936), salt (I-940) ~ salt (I-951), salt (I-955) ~ salt (I-966), salt (I-970) ~ salt (I-975), salt (I-980), salt (I-991), salt (I-993) ~ salt (I-998), salt ( I-1002)~Salt(I-1013), Salt(I-1017)~Salt(I-1028), Salt(I-1032)~Salt(I-1037), Salt(I-1042), Salt(I-1053), Salt(I-1112), Salt(I-1121), Salt(I-1124), Salt(I-1125), Salt(I-1128)~Salt(I-1131), Salt(I-1138), Salt(I-1141), Salt(I-1142), Salt(I-1161), Salt(I-1162), Salt(I-1165)~Salt(I-1169), Salt(I-1178), Salt(I-1181 ), salt (I-1182), salt (I-1185) to salt (I-1188), salt (I-1195), salt (I-1198), salt (I-1199), salt (I-1218), salt (I-1219), salt (I-1222) to salt (I-1226), salt (I-1235), salt (I-1238), salt (I-1239), salt (I-1242) to salt (I-1245), salt (I-1252), salt (I-1255), salt (I-1256), salt (I-1275), salt (I-1276), salt (I-1279) to salt (I-1282) are preferred.

[0040] <Method for producing salt (I)> The salt (I) can be produced by reacting a salt represented by formula (Ia) with a salt represented by formula (Ib) in a solvent. TIFF2023117395000058.tif31163 [In the formula, all symbols have the same meanings as defined above, and X represents a chlorine atom, a bromine atom, an iodine atom, or CH3SO4.] Examples of the solvent include chloroform, monochlorobenzene, dimethylformamide, acetonitrile, ethyl acetate, and water. The reaction temperature is usually 15° C. to 80° C., and the reaction time is usually 0.5 to 24 hours.

[0041] Examples of the salt represented by formula (Ia) include salts represented by the following formula, which are readily available on the market and can be easily produced by known production methods. JPEG2023117395000059.jpg90155

[0042] The salt represented by formula (Ib) can be produced, for example, by reacting a salt represented by formula (Ic) with carbonyldiimidazole in a solvent, and then further reacting the resulting mixture with a compound represented by formula (Id). TIFF2023117395000060.tif53154 [wherein all symbols have the same meanings as defined above.] X 1 represents *-CO-O- or *-O-CO-O-. * represents the bonding site to the benzene ring.] Examples of solvents used 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 to 24 hours.

[0043] Examples of the salt represented by formula (Ic) include the salts represented below, which are readily available on the market. TIFF2023117395000061.tif45162 Examples of compounds represented by formula (Id) include the compounds represented by the following formulas, which are readily available on the market and can also be easily produced by known production methods. JPEG2023117395000062.jpg69164

[0044] <Acid generator> The acid generator of the present invention is an acid generator containing a salt (I), and may contain one kind of salt (I) or two or more kinds of salts (I). The acid generator of the present invention may contain, in addition to the salt (I), an acid generator known in the resist field (hereinafter, sometimes referred to as "acid generator (B)"). The acid generator (B) may be used alone or in combination of two or more kinds.

[0045] The acid generator (B) may be either nonionic or ionic. Nonionic acid generators include sulfonate esters (e.g., 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate), sulfones (e.g., disulfone, ketosulfone, sulfonyldiazomethane), etc. Ionic acid generators include onium salts containing onium cations (e.g., diazonium salts, phosphonium salts, sulfonium salts, iodonium salts). Anions of onium salts include sulfonate anions, sulfonylimide anions, sulfonylmethide anions, etc.

[0046] The acid generator (B) may be a compound that generates an acid when exposed to radiation, as described in JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853, JP-A-63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. No. 3,849,137, German Patent No. 3,914,407, or European Patent No. 126,712. Compounds produced by known methods may also be used. Two or more types of acid generator (B) may be used in combination.

[0047] The acid generator (B) is preferably a salt represented by formula (B1) (hereinafter, sometimes referred to as "acid generator (B1)"). TIFF2023117395000063.tif2861[In formula (B1), Q b1 and Q b2 each independently represents a hydrogen atom, a fluorine atom, an alkyl group having 1 to 6 carbon atoms, or a perfluoroalkyl group having 1 to 6 carbon atoms. L b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, in which -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-, and in which a hydrogen atom contained in the saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group. Y represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 24 carbon atoms, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-. Z1 + represents an organic cation.

[0048] Q b1 and Q b2 Examples of the perfluoroalkyl group include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. Q b1 and Q b2 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. Q b1 and Q b2 and either one of them is preferably a fluorine atom or a perfluoroalkyl group, more preferably each independently is a fluorine atom or a trifluoromethyl group, and further preferably both are fluorine atoms.

[0049] L b1 Examples of the divalent saturated hydrocarbon group in include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and may also be a group formed by combining two or more of these groups. Specific examples include linear alkanediyl groups such as a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, a decane-1,10-diyl group, an undecane-1,11-diyl group, a dodecane-1,12-diyl group, a tridecane-1,13-diyl group, a tetradecane-1,14-diyl group, a pentadecane-1,15-diyl group, a hexadecane-1,16-diyl group, and a heptadecane-1,17-diyl group; branched alkanediyl groups such as ethane-1,1-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-2,2-diyl, pentane-2,4-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, and 2-methylbutane-1,4-diyl; monocyclic divalent alicyclic saturated hydrocarbon groups such as cycloalkanediyl groups, such as cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, and cyclooctane-1,5-diyl; Examples include polycyclic divalent alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group.

[0050] L b1 Examples of the divalent saturated hydrocarbon group represented by the formula (b1-1) in which one -CH2- is replaced with -O- or -CO- include groups represented by any of formulas (b1-1) to (b1-3). In the groups represented by formulas (b1-1) to (b1-3) and specific examples thereof, groups represented by formulas (b1-4) to (b1-11), * and ** represent bonding sites, and * represents the bonding site to -Y.

[0051] TIFF2023117395000064.tif26116[In formula (b1-1), L b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the saturated hydrocarbon group may be substituted with -O- or -CO-. However, L b2 and L b3 The total number of carbon atoms is 22 or less. In formula (b1-2), L b4 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the saturated hydrocarbon group may be substituted with -O- or -CO-. However, L b4 and L b5The total number of carbon atoms is 22 or less. In formula (b1-3), L b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. L b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the saturated hydrocarbon group may be substituted with -O- or -CO-. However, L b6 and L b7 The total number of carbon atoms is 23 or less.

[0052] In the groups represented by formulae (b1-1) to (b1-3), when -CH2- contained in the saturated hydrocarbon group is replaced with -O- or -CO-, the number of carbon atoms before replacement is defined as the number of carbon atoms of the saturated hydrocarbon group. As the divalent saturated hydrocarbon group, L b1 Examples of the divalent saturated hydrocarbon group include the same as the divalent saturated hydrocarbon group.

[0053] L b2 is preferably a single bond, a methylene group, —CH(CF3)—, or —C(CF3)2—. L b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms. L b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, and is more preferably a methylene group, -CH(CF3)-, or -C(CF3)2-. L b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b6 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b7is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the divalent saturated hydrocarbon group may be substituted with -O- or -CO-.

[0054] L b1 As the divalent saturated hydrocarbon group represented by the formula (b1-1) or (b1-3), in which one --CH.sub.2-- contained in the group is replaced by --O-- or --CO--, a group represented by the formula (b1-1) or (b1-3) is preferred. Examples of the group represented by formula (b1-1) include groups represented by formulas (b1-4) to (b1-8). TIFF2023117395000065.tif49119[In formula (b1-4), L b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. In formula (b1-5), L b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-. L b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b9 and L b10 The total number of carbon atoms is 20 or less. In formula (b1-6), L b11 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b11 and L b12 The total number of carbon atoms is 21 or less. In formula (b1-7), L b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms. L b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-. L b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b13 ~L b15 The total number of carbon atoms is 19 or less. In formula (b1-8), L b16 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-. L b17 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms. L b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b16 ~L b18 The total number of carbon atoms is 19 or less. L b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms. L b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b10 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b13is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. L b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms. L b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b16 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. L b17 is preferably a divalent saturated hydrocarbon group having 1 to 6 carbon atoms. L b18 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.

[0055] Examples of the group represented by formula (b1-3) include groups represented by formulas (b1-9) to (b1-11). TIFF2023117395000066.tif24140[In formula (b1-9), L b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxy group, or an alkylcarbonyloxy group. -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group. However, L b19 and L b20 The total number of carbon atoms is 23 or less. In formula (b1-10), L b21represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b22 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b23 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxy group, or an alkylcarbonyloxy group. -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group. However, L b21 , L b22 and L b23 The total number of carbon atoms is 21 or less. In formula (b1-11), L b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b26 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxy group, or an alkylcarbonyloxy group. -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group. However, L b24 , L b25 and L b26 The total number of carbon atoms is 21 or less.

[0056] In addition, in the groups represented by formulae (b1-9) to (b1-11), when a hydrogen atom contained in the saturated hydrocarbon group is substituted with an alkylcarbonyloxy group, the number of carbon atoms before substitution is defined as the number of carbon atoms in the saturated hydrocarbon group. Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group, and an adamantylcarbonyloxy group.

[0057] Examples of the group represented by formula (b1-4) include the following. TIFF2023117395000067.tif14133

[0058] Examples of the group represented by formula (b1-5) include the following. TIFF2023117395000068.tif60150

[0059] Examples of the group represented by formula (b1-6) include the following. TIFF2023117395000069.tif29165

[0060] Examples of the group represented by formula (b1-7) include the following. TIFF2023117395000070.tif41169

[0061] Examples of the group represented by formula (b1-8) include the following. TIFF2023117395000071.tif20123

[0062] Examples of the group represented by formula (b1-2) include the following. TIFF2023117395000072.tif31161

[0063] Examples of the group represented by formula (b1-9) include the following. TIFF2023117395000073.tif34152

[0064] Examples of the group represented by formula (b1-10) include the following. TIFF2023117395000074.tif80165

[0065] Examples of the group represented by formula (b1-11) include the following. TIFF2023117395000075.tif67153

[0066] Examples of the alicyclic hydrocarbon group represented by Y in which -CH2- is not replaced by -O-, -S-, -SO2-, or -CO- include groups represented by formulae (Y1) to (Y11) and formulae (Y36) to (Y38). When -CH2- contained in the alicyclic hydrocarbon group represented by Y is replaced by -O-, -S-, -SO2- or -CO-, the number may be one or more. Examples of such groups include groups represented by formulae (Y12) to (Y35) and formulae (Y39) to (Y43). -O- or -CO- in the groups represented by formulae (Y12) to (Y35) and formulae (Y39) to (Y43) may be replaced by -S- or -SO2-. * represents L b1 represents the binding site with TIFF2023117395000076.tif84163

[0067] The alicyclic hydrocarbon group represented by Y is preferably a group represented by any one of formulas (Y1) to (Y20), (Y26), (Y27), (Y30), (Y31), and (Y39) to (Y43), more preferably a group represented by formula (Y11), (Y15), (Y16), (Y20), (Y26), (Y27), (Y30), (Y31), (Y39), (Y40), (Y42), or (Y43), and even more preferably a group represented by formula (Y11), (Y15), (Y20), (Y26), (Y27), (Y30), (Y31), (Y39), (Y40), (Y42), or (Y43). When the alicyclic hydrocarbon group represented by Y is a spiro ring having an oxygen atom such as those of formula (Y28) to formula (Y35), formula (Y39), formula (Y40), formula (Y42) or formula (Y43), the alkanediyl group between the two oxygen atoms preferably has one or more fluorine atoms. Furthermore, among the alkanediyl groups contained in the ketal structure, it is preferred that the methylene group adjacent to the oxygen atom is not substituted with a fluorine atom.

[0068] The substituent of the methyl group represented by Y is a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, a glycidyloxy group, -(CH2) ja -CO-OR b1 group or -(CH2) ja -O-CO-R b1 group (in the formula, R b1 represents an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof. ja represents an integer of 0 to 4. -CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -SO2-, or -CO-, and a hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group may be replaced by a hydroxy group or a fluorine atom. Substituents of the alicyclic hydrocarbon group represented by Y include a halogen atom, a hydroxy group, an alkyl group having 1 to 16 carbon atoms which may be substituted with a hydroxy group (-CH2- contained in the alkyl group may be replaced with -O- or -CO-), an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, a glycidyloxy group, -(CH2) ja -CO-OR b1 group or -(CH2) ja -O-CO-R b1 group (in the formula, R b1represents an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof. ja represents an integer of 0 to 4. -CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -SO2-, or -CO-, and a hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group may be replaced by a hydroxy group or a fluorine atom.

[0069] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a norbornyl group, and an adamantyl group. The alicyclic hydrocarbon group may have a chain hydrocarbon group, such as a methylcyclohexyl group or a dimethylcyclohexyl group. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 12, and more preferably 3 to 10. Examples of aromatic hydrocarbon groups include aryl groups such as phenyl, naphthyl, anthryl, biphenyl, and phenanthryl. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and examples include aromatic hydrocarbon groups having a chain hydrocarbon group with 1 to 18 carbon atoms (such as tolyl, xylyl, cumenyl, mesityl, p-methylphenyl, p-ethylphenyl, p-tert-butylphenyl, 2,6-diethylphenyl, and 2-methyl-6-ethylphenyl), and aromatic hydrocarbon groups having an alicyclic hydrocarbon group with 3 to 18 carbon atoms (such as p-cyclohexylphenyl and p-adamantylphenyl). The aromatic hydrocarbon group preferably has 6 to 14 carbon atoms, and more preferably 6 to 10 carbon atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, etc. The number of carbon atoms in the alkyl group is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 4. Examples of the alkyl group substituted with a hydroxy group include hydroxyalkyl groups such as a hydroxymethyl group and a hydroxyethyl group. Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, and a naphthylethyl group. Examples of groups in which -CH2- in an alkyl group is replaced by -O-, -SO2-, -CO-, etc. include an alkoxy group, an alkylsulfonyl group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, or a combination thereof. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group. The number of carbon atoms in the alkoxy group is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 4. Examples of the alkylsulfonyl group include a methylsulfonyl group, an ethylsulfonyl group, a propylsulfonyl group, etc. The alkylsulfonyl group preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 4 carbon atoms. Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, a butoxycarbonyl group, etc. The alkoxycarbonyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and even more preferably 2 to 4 carbon atoms. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and even more preferably 2 to 4 carbon atoms. Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, etc. The alkylcarbonyloxy group preferably has 2 to 12 carbon atoms, more preferably 2 to 6 carbon atoms, and even more preferably 2 to 4 carbon atoms. Examples of the combined group include a group combining an alkoxy group and an alkyl group, a group combining an alkoxy group and an alkoxy group, a group combining an alkoxy group and an alkylcarbonyl group, and a group combining an alkoxy group and an alkylcarbonyloxy group. Examples of the group combining an alkoxy group and an alkyl group include alkoxyalkyl groups such as a methoxymethyl group, a methoxyethyl group, an ethoxyethyl group, an ethoxymethyl group, etc. The number of carbon atoms in the alkoxyalkyl group is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 to 4. Examples of a group formed by combining an alkoxy group with another alkoxy group include alkoxyalkoxy groups such as a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, etc. The number of carbon atoms in the alkoxyalkoxy group is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 to 4. Examples of the group combining an alkoxy group and an alkylcarbonyl group include alkoxyalkylcarbonyl groups such as a methoxyacetyl group, a methoxypropionyl group, an ethoxyacetyl group, an ethoxypropionyl group, etc. The number of carbon atoms in the alkoxyalkylcarbonyl group is preferably 3 to 13, more preferably 3 to 7, and even more preferably 3 to 5. Examples of the group combining an alkoxy group and an alkylcarbonyloxy group include alkoxyalkylcarbonyloxy groups such as a methoxyacetyloxy group, a methoxypropionyloxy group, an ethoxyacetyloxy group, an ethoxypropionyloxy group, etc. The number of carbon atoms in the alkoxyalkylcarbonyloxy group is preferably 3 to 13, more preferably 3 to 7, and even more preferably 3 to 5. Examples of the group in which -CH2- in the alicyclic hydrocarbon group is replaced by -O-, -SO2-, -CO- or the like include groups represented by formulae (Y12) to (Y35) and formulae (Y39) to (Y43).

[0070] Y is preferably an alicyclic hydrocarbon group of 3 to 24 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon group of 3 to 20 carbon atoms which may have a substituent, even more preferably an alicyclic hydrocarbon group of 3 to 18 carbon atoms which may have a substituent, and even more preferably an adamantyl group which may have a substituent or a norbornyl group which may have a substituent, wherein -CH2- constituting the alicyclic hydrocarbon group, adamantyl group or norbornyl group may be replaced by -O-, -S-, -SO2- or -CO-. Specific examples include the following. TIFF2023117395000077.tif116158

[0071] TIFF2023117395000078.tif55155 Among these, Y is preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group, a norbornane lactone group, or a group represented by formula (Y42), formula (Y100) to formula (Y114), or formula (Y134) to formula (Y139), and particularly preferably a hydroxyadamantyl group, oxoadamantyl group, a group containing these, or a group represented by formula (Y42), formula (Y100) to formula (Y114), or formula (Y134) to formula (Y139).

[0072] The anion in the salt represented by formula (B1) is preferably an anion represented by formula (B1-A-1) to formula (B1-A-65) (hereinafter, sometimes referred to as "anion (B1-A-1)" depending on the formula number).), and more preferably an anion represented by any of formula (B1-A-1) to formula (B1-A-4), formula (B1-A-9), formula (B1-A-10), formula (B1-A-24) to formula (B1-A-33), formula (B1-A-36) to formula (B1-A-40), and formula (B1-A-47) to formula (B1-A-65). TIFF2023117395000079.tif231165

[0073] TIFF2023117395000080.tif238165

[0074] TIFF2023117395000081.tif202165Here R i2 ~R i7 are each independently, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. i8 is, for example, a chain hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a group formed by combining these, more preferably a methyl group, an ethyl group, a cyclohexyl group, or an adamantyl group. A41 is a single bond or an alkanediyl group having 1 to 4 carbon atoms. b1 and Q b2 has the same meaning as above. Specific examples of the anion in the salt represented by formula (B1) include the anions described in JP-A-2010-204646.

[0075] Preferable anions in the salt represented by formula (B1) include anions represented by formulas (B1a-1) to (B1a-43). TIFF2023117395000082.tif236167

[0076] TIFF2023117395000083.tif103155

[0077] Among these, anions represented by any one of formulas (B1a-1) to (B1a-4), (B1a-7) to (B1a-11), (B1a-14) to (B1a-30), and (B1a-35) to (B1a-41) are preferred. Examples of the sulfonylimide anion and sulfonylmethide anion include those described below.

[0078] Z1 + Examples of the organic cation include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, organic sulfonium cations and organic iodonium cations are preferred, and arylsulfonium cations are more preferred. Examples of the arylsulfonium cation include Z in formula (I). + The cations are the same as those of the above.

[0079] The acid generator (B) is a combination of the above-mentioned anions and the above-mentioned organic cations, which can be combined arbitrarily. Preferred examples of the acid generator (B) include a combination of an anion represented by any of formulas (B1a-1) to (B1a-4), (B1a-7) to (B1a-11), (B1a-14) to (B1a-30), and (B1a-35) to (B1a-41) with a cation (b2-1), (b2-2), (b2-3), or (b2-4).

[0080] Preferred examples of the acid generator (B) include those represented by formulas (B1-1) to (B1-60). Among these, those containing an arylsulfonium cation are preferred, and those represented by formulas (B1-1) to (B1-3), (B1-5) to (B1-7), (B1-11) to (B1-14), (B1-20) to (B1-26), (B1-29), and (B1-31) to (B1-60) are particularly preferred. TIFF2023117395000084.tif208167

[0081] TIFF2023117395000085.tif235159

[0082] TIFF2023117395000086.tif238165

[0083] When the acid generator contains a salt (I) and an acid generator (B), the ratio of the salt (I) to the acid generator (B) (mass ratio; salt (I):acid generator (B)) is usually 1:99 to 99:1, preferably 2:98 to 98:2, more preferably 5:95 to 95:5, even more preferably 10:90 to 90:10, and particularly preferably 15:85 to 85:15.

[0084] [Resist Composition] The resist composition of the present invention contains an acid generator containing a salt (I). The resist composition of the present invention may also contain a resin (hereinafter sometimes referred to as "resin (A)") that contains a structural unit having an acid labile group. Here, the term "acid labile group" refers to a group that has a leaving group and that is eliminated upon contact with an acid, converting the structural unit into a structural unit having a hydrophilic group (e.g., 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 with a weaker acidity than the acid generated from the acid generator (hereinafter may be referred to as "quencher (C)"), and preferably contains a solvent (hereinafter may be referred to as "solvent (E)").

[0085] <Acid generator> In the resist composition of the present invention, the total content of the acid generators is preferably 0.1 to 99.9% by mass, more preferably 1 to 45% by mass, even more preferably 1 to 40% by mass, and even more preferably 3 to 40% by mass, based on the solid content of the resist composition. When the resist composition contains the resin (A) described below, the total content of the acid generators is preferably 1 to 45 parts by mass, more preferably 1 to 40 parts by mass, even more preferably 3 to 40 parts by mass, even more preferably 3 to 35 parts by mass, and even more preferably 5 to 35 parts by mass, based on 100 parts by mass of the resin (A).

[0086] <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 structural units other than structural unit (a1) include a structural unit not having an acid labile group (hereinafter sometimes referred to as "structural unit (s)"), structural units other than structural unit (a1) and structural unit (s) (for example, a structural unit having a halogen atom (hereinafter sometimes referred to as "structural unit (a4)") described below, a structural unit having a non-leaving hydrocarbon group (hereinafter sometimes referred to as "structural unit (a5)") described below, and other structural units derived from monomers known in the art.

[0087] <Structural unit (a1)> The structural unit (a1) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as "monomer (a1)"). The acid labile group contained in the resin (A) is preferably a group represented by formula (1) (hereinafter also referred to as group (1)) and / or a group represented by formula (2) (hereinafter also referred to as group (2)). TIFF2023117395000087.tif2298[In formula (1), R a1 , R a2 and R a3each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining any of these; or R a1 and R a2 are bonded to each other to form, together with the carbon atoms to which they are bonded, an alicyclic hydrocarbon group having 3 to 20 carbon atoms. ma and na each independently represent 0 or 1, and at least one of ma and na represents 1. * denotes a binding site.] TIFF2023117395000088.tif2278[In formula (2), R a1’ and R a2’ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms; R a3’ represents a hydrocarbon group having 1 to 20 carbon atoms, or R a2’ and R a3’ are bonded to each other to form, together with the carbon atom to which they are bonded and X, a heterocyclic group having 3 to 20 carbon atoms, and -CH2- contained in the hydrocarbon group and the heterocyclic group may be replaced with -O- or -S-. X represents an oxygen atom or a sulfur atom. na' represents 0 or 1. * denotes a binding site.]

[0088] R a1 , R a2 and R a3 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. R a1 , R a2 and R a3 Examples of the alkenyl group in the formula (I) include ethenyl, propenyl, isopropenyl, butenyl, isobutenyl, tert-butenyl, pentenyl, hexenyl, heptenyl, octenyl, isooctenyl, and nonenyl groups. R a1 , R a2 and R a3The alicyclic hydrocarbon group in may be either monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Examples of polycyclic alicyclic hydrocarbon groups include decahydronaphthyl, adamantyl, and norbornyl groups, as well as the following groups (* indicates a bonding site): a1 , R a2 and R a3 The alicyclic hydrocarbon group preferably has 3 to 16 carbon atoms. TIFF2023117395000089.tif10159R a1 , R a2 and R a3 Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. Examples of the combined group include a group in which the above-mentioned alkyl group and alicyclic hydrocarbon group are combined (for example, an alkylcycloalkyl group or cycloalkylalkyl group such as a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group, an adamantyldimethyl group, or a norbornylethyl group), an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (a p-methylphenyl group, a p-tert-butylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, or the like), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (a p-cyclohexylphenyl group, a p-adamantylphenyl group, or the like), and an aryl-cycloalkyl group such as a phenylcyclohexyl group. Preferably, ma is 0 and na is 1. R a1 and R a2 -C(R a1 )(R a2 )(R a3 ) includes the following groups. The alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * represents the bonding site with -O-. TIFF2023117395000090.tif30138

[0089] R a1’ , R a2’ and R a3’ Examples of the hydrocarbon group in include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups. Alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups and combination groups are R a1 , R a2 and R a3 Examples of the groups include the same as those listed in the above. R a2’ and R a3’ When they are bonded to each other to form a heterocyclic group together with the carbon atoms to which they are bonded and X, -C(R a1’ )(R a2’ )-XR a3’ Examples of the groups include the following: * represents a binding site. TIFF2023117395000091.tif19124R a1’ and R a2’ At least one of these is preferably a hydrogen atom. na' is preferably 0.

[0090] Examples of the group (1) include the following groups. In formula (1), R a1 , R a2 and R a3 is an alkyl group, ma=0, and na=1. The group is preferably a tert-butoxycarbonyl group. In formula (1), R a1 , R a2 together with the carbon atom to which they are attached form an adamantyl group, and R a3 is an alkyl group, ma=0, and na=1. In formula (1), R a1 and R a2 are each independently an alkyl group, and R a3 is an adamantyl group, ma=0, and na=1. Specific examples of the group (1) include the following: * represents a binding site. TIFF2023117395000092.tif130165

[0091] Specific examples of group (2) include the following groups: * represents a binding site. TIFF2023117395000093.tif55153

[0092] 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.

[0093] Of the (meth)acrylic monomers having an acid labile group, preferred are those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms. When a resin (A) containing a structural unit derived from a monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used in a resist composition, the resolution of the resist pattern can be improved.

[0094] The structural unit derived from a (meth)acrylic monomer having group (1) is preferably a structural unit represented by formula (a1-0) (hereinafter, sometimes referred to as structural unit (a1-0)), a structural unit represented by formula (a1-1) (hereinafter, sometimes referred to as structural unit (a1-1)), or a structural unit represented by formula (a1-2) (hereinafter, sometimes referred to as structural unit (a1-2)). Preferably, at least one structural unit selected from the group consisting of structural unit (a1-0), structural unit (a1-1), and structural unit (a1-2) is used, and more preferably, at least one or two structural units selected from the group consisting of structural unit (a1-1) and structural unit (a1-2). These may be used alone or in combination of two or more. TIFF2023117395000094.tif43141 [In formula (a1-0), formula (a1-1) and formula (a1-2), L a01 , L a1 and La2 are each independently -O- or -O-(CH2) k1 represents —CO—O—, k1 represents an integer of 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. R a6 and R a7 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these. m1' represents an integer of 0 to 14. n1 represents an integer of 0 to 10. n1' represents an integer of 0 to 3.

[0095] R a01 , R a4 and R a5 is preferably a hydrogen atom or a methyl group, more preferably a methyl group. L a01 , L a1 and L a2 is preferably an oxygen atom or —O—(CH2) k01 It is —CO—O— (wherein k01 is preferably an integer of 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 Ra1 , 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 R a7 The alkyl group in the formula (I) is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group, or a t-butyl group, and even more preferably an ethyl group, an isopropyl group, or a t-butyl group. R a6 and R a7 The alkenyl group in the formula (I) is preferably an alkenyl group having 2 to 6 carbon atoms, and more preferably an ethenyl group, a propenyl group, an isopropenyl group, or a butenyl group. R a02 , R a03 , R a04 , R a6 and R a7 The alicyclic hydrocarbon group preferably has 5 to 12 carbon atoms, and more preferably 5 to 10 carbon atoms. R a02 , R a03 , R a04 , R a6 and R a7 The aromatic hydrocarbon group preferably has 6 to 12 carbon atoms, and more preferably 6 to 10 carbon atoms. In the group in which an alkyl group and an alicyclic hydrocarbon group are combined, the total number of carbon atoms in the combination of the alkyl group and the alicyclic hydrocarbon group is preferably 18 or less. In the group in which an alkyl group and an aromatic hydrocarbon group are combined, the total number of carbon atoms in the combination of the alkyl group and the aromatic hydrocarbon group is preferably 18 or less. R a02 and R a03 is preferably an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a phenyl group or a naphthyl group. Ra04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. R a6 and R a7 is preferably an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an aromatic hydrocarbon group having 6 to 12 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group, a phenyl group, or a naphthyl group, and even more preferably an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group, or a phenyl group. m1' is preferably an integer of 0 to 3, and more preferably 0 or 1. n1 is preferably an integer of 0 to 3, and more preferably 0 or 1. n1' is preferably 0 or 1.

[0096] Examples of the structural unit (a1-0) include structural units represented by any one of formulas (a1-0-1) to (a1-0-18) and R a01 and structural units in which the methyl group corresponding to the formula (a1-0-1) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group (an alkyl group having a halogen atom) or another alkyl group, and structural units represented by any of formulas (a1-0-1) to (a1-0-10), (a1-0-13) and (a1-0-14) are preferred. TIFF2023117395000095.tif95156

[0097] Examples of the structural unit (a1-1) include structural units derived from monomers described in JP-A-2010-204646. Among these, structural units represented by any one of formulas (a1-1-1) to (a1-1-7) and R in the structural unit (a1-1) are preferred. a4 A structural unit in which the methyl group corresponding to the formula (a1-1-1) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group is preferred, and a structural unit represented by any one of formulas (a1-1-1) to (a1-1-4) is more preferred. JPEG2023117395000096.jpg38164

[0098] The structural unit (a1-2) includes a structural unit represented by any one of formulas (a1-2-1) to (a1-2-14) and R a5 and structural units in which the methyl group corresponding to the formula (a1-2-1) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group, and structural units represented by any of formulas (a1-2-2), (a1-2-5), (a1-2-6), and (a1-2-10) to (a1-2-14) are preferred. TIFF2023117395000097.tif60163

[0099] 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 of these, based on the total structural units of the resin (A), is 5 mol% or more, preferably 10 mol% or more. It may also be 95 mol% or less, preferably 90 mol% or less, and more preferably 85 mol% or less. Specifically, it may be 10 to 95 mol%, preferably 15 to 90 mol%, more preferably 20 to 85 mol%, even 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, based on the total structural units of the resin (A). Also, the content is 80 mol% or less, preferably 75 mol% or less, and more preferably 70 mol% or less. Specifically, the content 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 of these structural units, based on all structural units in the resin (A), can be 10 mol% or more, preferably 15 mol% or more, and more preferably 20 mol% or more. It can also be 90 mol% or less, preferably 85 mol% or less, more preferably 80 mol% or less, even more preferably 75 mol% or less, and even more preferably 70 mol% or less. Specifically, it can be 10 to 90 mol%, preferably 15 to 85 mol%, more preferably 20 to 80 mol%, even more preferably 20 to 75 mol%, and even more preferably 20 to 70 mol%.

[0100] An example of the structural unit (a1) having the group (2) is a structural unit represented by formula (a1-4) (hereinafter, sometimes referred to as "structural unit (a1-4)"). TIFF2023117395000098.tif4868[In formula (a1-4), R a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a33 represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A a30 is a single bond or *-X a31 -(A a32 -X a32 ) nc - represents -R a32 represents the bonding site with the carbon atom to which it is bonded. A a32 represents an alkanediyl group having 1 to 6 carbon atoms. X a31 and X a32 each independently represents -O-, -CO-O- or -O-CO-. nc represents 0 or 1. la represents an integer of 0 to 4. When la is an integer of 2 or more, a plurality of R a33 may be the same or different from each other. R a34 and R a35 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms; R a36 represents a hydrocarbon group having 1 to 20 carbon atoms, or R a35 and R a36 are bonded to each other to form, together with the -CO- to which they are bonded, a divalent hydrocarbon group having 2 to 20 carbon atoms, and the hydrocarbon group and the -CH2- contained in the divalent hydrocarbon group may be replaced by -O- or -S-.]

[0101] R a32 and R a33 Examples of the halogen atom in the formula include a fluorine atom, a chlorine atom, and a bromine atom. R a32 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in the formula (I) include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, a hexyl group, and a perfluorohexyl group. R a32 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group. R a33 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. R a33 Examples of the alkoxy group in include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, and a hexyloxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group. R a33 Examples of the alkoxyalkyl group in the formula (I) include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and even more preferably a methoxymethyl group. R a33 Examples of the alkoxyalkoxy group in include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, and more preferably a methoxyethoxy group or an ethoxyethoxy group. R a33 Examples of the alkylcarbonyl group in the formula (I) include an acetyl group, a propionyl group, a butyryl group, etc. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group. R a33 Examples of the alkylcarbonyloxy group in the formula (I) include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group. R a33is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group, and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group.

[0102] *-X a31 -(A a32 -X a32 ) nc -Examples include *-O-, *-CO-O-, *-O-CO-, *-CO-OA a32 -CO-O-, *-O-CO-A a32 -O-, *-OA a32 -CO-O-, *-CO-OA a32 -O-CO-, *-O-CO-A a32 -O-CO-, and *-CO-O- and *-CO-OA are particularly mentioned. a32 -CO-O- or *-OA a32 -CO-O- is preferred.

[0103] A a32 Examples of the alkanediyl group in the formula (I) include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. A a32 is preferably a methylene group or an ethylene group.

[0104] A a30 is a single bond, *-CO-O- or *-CO-OA a32 -CO-O- is preferred, a single bond, *-CO-O- or *-CO-O-CH2-CO-O- is more preferred, and a single bond or *-CO-O- is even more preferred.

[0105] la is preferably 0, 1 or 2, more preferably 0 or 1, and even more preferably 0. R a34 , R a35 and R a36 Examples of the hydrocarbon group in include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group in which these groups are combined. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Examples of polycyclic alicyclic hydrocarbon groups include decahydronaphthyl, adamantyl, and norbornyl groups, as well as the following groups (* indicates a bonding site): TIFF2023117395000099.tif10151 Examples of aromatic hydrocarbon groups include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. Examples of the combined group include a group in which the above-mentioned alkyl group and alicyclic hydrocarbon group are combined (for example, an alkylcycloalkyl group or cycloalkylalkyl group such as a methylcyclohexyl group, a dimethylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group, an adamantyldimethyl group, or a norbornylethyl group), an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (a p-methylphenyl group, a p-tert-butylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, or the like), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (a p-cyclohexylphenyl group, a p-adamantylphenyl group, or the like), and an aryl-cycloalkyl group such as a phenylcyclohexyl group. In particular, R a36Examples of the group include an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these groups.

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

[0107] -OC(R a34 )(R a35 )-OR a36 is eliminated on contact with an acid (e.g., p-toluenesulfonic acid) to form a hydroxy group. -OC(R a34 )(R a35 )-OR a36 is preferably bonded to the m-position or p-position of the benzene ring, and more preferably to the p-position.

[0108] Examples of the structural unit (a1-4) include structural units derived from monomers described in JP-A-2010-204646. Preferred are structural units represented by formulas (a1-4-1) to (a1-4-24) and R in the structural unit (a1-4). a32and more preferably, the structural units represented by formulae (a1-4-1) to (a1-4-5), (a1-4-10), (a1-4-13), (a1-4-14), (a1-4-19), and (a1-4-20). TIFF2023117395000100.tif127160

[0109] When the resin (A) contains the structural unit (a1-4), the content thereof is preferably 10 to 95 mol %, more preferably 15 to 90 mol %, even more preferably 20 to 85 mol %, still more preferably 20 to 70 mol %, and even more preferably 20 to 60 mol %, based on the total of all structural units in the resin (A).

[0110] Examples of the structural unit derived from a (meth)acrylic monomer having the group (2) include a structural unit represented by formula (a1-5) (hereinafter, sometimes referred to as "structural unit (a1-5)"). TIFF2023117395000101.tif4253[In formula (a1-5), R a8 represents an alkyl group having 1 to 6 carbon atoms which may have one or more halogen atoms, a hydrogen atom, or a halogen atom. Z a1 is a single bond or -(CH2) h3 -CO-L 54 -, h3 represents an integer of 1 to 4, * represents L 51 represents the binding site with L 51 , L 52 , L 53 and L 54 each independently represents -O- or -S-. s1 represents an integer of 1 to 3. s1' represents an integer of 0 to 3.

[0111] Examples of halogen atoms include fluorine atoms and chlorine atoms, with fluorine atoms being preferred. Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a fluoromethyl group, and a trifluoromethyl group. In formula (a1-5), R a8 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group. L 51 is preferably an oxygen atom. L 52 and L 53 Among these, it is preferred that one is —O— and the other is —S—. s1 is preferably 1. s1' is preferably an integer of 0 to 2. Z a1 is preferably a single bond or —CH2—CO—O—.

[0112] Examples of the structural unit (a1-5) include structural units derived from monomers described in JP-A-2010-61117. Among these, the structural units represented by formulas (a1-5-1) to (a1-5-4) are preferred, and the structural unit represented by formula (a1-5-1) or (a1-5-2) is more preferred. TIFF2023117395000102.tif31130

[0113] When the resin (A) contains the structural unit (a1-5), the content thereof is preferably 1 to 50 mol %, more preferably 3 to 45 mol %, even more preferably 5 to 40 mol %, and even more preferably 5 to 30 mol %, based on the total structural units of the resin (A).

[0114] Further, examples of the structural unit (a1) include the following structural units. TIFF2023117395000103.tif27161

[0115] When the resin (A) contains structural units such as (a1-3-1) to (a1-3-7), the content thereof is preferably 10 to 95 mol %, more preferably 15 to 90 mol %, even more preferably 20 to 85 mol %, even more preferably 20 to 70 mol %, and particularly preferably 20 to 60 mol %, based on the total structural units of the resin (A).

[0116] <Structural unit(s)> The structural unit (s) is derived from a monomer (hereinafter sometimes referred to as "monomer (s)") that does not have an acid labile group. As the monomer from which the structural unit (s) is derived, a monomer that does not have an acid labile group known in the resist field can be used. The structural unit (s) preferably has a hydroxy group or a lactone ring. The use of a resin containing a structural unit having a hydroxy group but no acid labile group (hereinafter sometimes referred to as "structural unit (a2)") and / or a structural unit having a lactone ring but no acid labile group (hereinafter sometimes referred to as "structural unit (a3)") in the resist composition of the present invention can improve the resolution of the resist pattern and the adhesion to the substrate.

[0117] <Structural unit (a2)> The hydroxy group contained in the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group. When producing a resist pattern from the resist composition of the present invention, if a high-energy ray such as a KrF excimer laser (248 nm), an electron beam, or EUV (extreme ultraviolet) is used as an exposure light source, the structural unit (a2) preferably has a phenolic hydroxy group, and more preferably the structural unit (a2-A) described below. Furthermore, if an ArF excimer laser (193 nm) or the like is used, the structural unit (a2) preferably has an alcoholic hydroxy group, and more preferably the structural unit (a2-1) described below. The structural unit (a2) may contain one type alone or two or more types.

[0118] In the structural unit (a2), the structural unit having a phenolic hydroxy group includes a structural unit represented by formula (a2-A) (hereinafter, sometimes referred to as "structural unit (a2-A)"). TIFF2023117395000104.tif4955[In formula (a2-A), R a50 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a51 represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A a50 is a single bond or *-X a51 -(A a52 -X a52 ) nb - represents -R a50 represents the bonding site with the carbon atom to which it is bonded. A a52 represents an alkanediyl group having 1 to 6 carbon atoms. X a51 and X a52 each independently represents -O-, -CO-O- or -O-CO-. nb represents 0 or 1. mb represents an integer of 0 to 4. When mb is an integer of 2 or more, a plurality of R a51 may be the same or different from each other.

[0119] R a50 and R a51 Examples of the halogen atom in the formula include a fluorine atom, a chlorine atom, and a bromine atom. R a50Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in the formula (I) include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, a hexyl group, and a perfluorohexyl group. R a50 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group. R a51 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. R a51 Examples of the alkoxy group in include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, and a tert-butoxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group. R a51 Examples of the alkoxyalkyl group in the formula (I) include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and even more preferably a methoxymethyl group. R a51Examples of the alkoxyalkoxy group in include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, and more preferably a methoxyethoxy group or an ethoxyethoxy group. R a51 Examples of the alkylcarbonyl group in the formula (I) include an acetyl group, a propionyl group, a butyryl group, etc. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group. R a51 Examples of the alkylcarbonyloxy group in the formula (I) include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group. R a51 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group, and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group.

[0120] *-X a51 -(A a52 -X a52 ) nb -Examples include *-O-, *-CO-O-, *-O-CO-, *-CO-OA a52 -CO-O-, *-O-CO-A a52 -O-, *-OA a52 -CO-O-, *-CO-OA a52 -O-CO-, *-O-CO-A a52 -O-CO-, and *-CO-O- and *-CO-OA are particularly mentioned. a52 -CO-O- or *-OA a52-CO-O- is preferred.

[0121] A a52 Examples of the alkanediyl group in the formula (I) include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. A a52 is preferably a methylene group or an ethylene group.

[0122] A a50 is a single bond, *-CO-O- or *-CO-OA a52 -CO-O- is preferred, a single bond, *-CO-O- or *-CO-O-CH2-CO-O- is more preferred, and a single bond or *-CO-O- is even more preferred.

[0123] mb is preferably 0, 1 or 2, and more preferably 0 or 1. At least one hydroxy group is preferably bonded to the meta or para position of the benzene ring, and when the phenyl group has two or more hydroxy groups, the two hydroxy groups are preferably bonded to the meta and para positions, respectively.

[0124] Examples of the structural unit (a2-A) include structural units derived from monomers described in JP-A Nos. 2010-204634 and 2012-12577. The structural unit (a2-A) includes structural units represented by formulae (a2-2-1) to (a2-2-24) and R in the structural unit (a2-A) in the structural units represented by formulae (a2-2-1) to (a2-2-24). a50The structural unit (a2-A) includes structural units represented by formulas (a2-2-1) to (a2-2-4), structural units represented by formula (a2-2-6), structural units represented by formula (a2-2-8), structural units represented by formulas (a2-2-12) to (a2-2-18), and structural units represented by formulas (a2-2-1) to (a2-2-4), structural units represented by formula (a2-2-6), structural units represented by formula (a2-2-8), and structural units represented by formulas (a2-2-12) to (a2-2-18), in which R in the structural unit (a2-A) is a50 In the structural unit represented by formula (a2-2-3), the structural unit represented by formula (a2-2-4), the structural unit represented by formula (a2-2-8), the structural unit represented by formula (a2-2-12) to formula (a2-2-14), the structural unit represented by formula (a2-2-18), and the structural unit represented by formula (a2-2-3), the structural unit represented by formula (a2-2-4), the structural unit represented by formula (a2-2-8), the structural unit represented by formula (a2-2-12) to formula (a2-2-14), and the structural unit represented by formula (a2-2-18), a50 In the structural unit represented by formula (a2-2-3), the structural unit represented by formula (a2-2-4), the structural unit represented by formula (a2-2-8), and the structural unit represented by formula (a2-2-3), the structural unit represented by formula (a2-2-4), and the structural unit represented by formula (a2-2-8), a50 More preferably, the structural unit is a structural unit in which a methyl group corresponding to the following formula is replaced with a hydrogen atom: TIFF2023117395000105.tif79169

[0125] When the structural unit (a2-A) is contained in the resin (A), the content of the structural unit (a2-A) relative to all structural units is preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 15 mol% or more, and still more preferably 20 mol% or more. It is also preferably 80 mol% or less, more preferably 70 mol% or less, and even more preferably 65 mol% or less. Specifically, it is preferably 5 to 80 mol%, more preferably 10 to 70 mol%, even more preferably 15 to 65 mol%, and even more preferably 20 to 65 mol%. The structural unit (a2-A) can be incorporated into the resin (A) by, for example, polymerizing the structural unit (a1-4) and then treating with an acid such as p-toluenesulfonic acid. Alternatively, the structural unit (a2-A) can be incorporated into the resin (A) by polymerizing the structural unit (a1-4) and then treating with an alkali such as tetramethylammonium hydroxide.

[0126] An example of the structural unit (a2) having an alcoholic hydroxy group is a structural unit represented by formula (a2-1) (hereinafter, sometimes referred to as "structural unit (a2-1)"). TIFF2023117395000106.tif4562[In formula (a2-1), L a3 is -O- or *-O-(CH2) k2 represents -CO-O-, k2 represents an integer of 1 to 7. * represents the bonding site with —CO—. R a14 represents a hydrogen atom or a methyl group. R a15 and R a16 each independently represents a hydrogen atom, a methyl group, or a hydroxy group. o1 represents an integer between 0 and 10.

[0127] In equation (a2-1), L a3 is preferably -O-, -O-(CH2) f1It is —CO—O— (wherein f1 represents an integer of 1 to 4), and more preferably —O—. R a14 is preferably a methyl group. R a15 is preferably a hydrogen atom. R a16 is preferably a hydrogen atom or a hydroxy group. o1 is preferably an integer of 0 to 3, and more preferably 0 or 1.

[0128] Examples of the structural unit (a2-1) include structural units derived from monomers described in JP 2010-204646 A. A structural unit represented by any one of formulas (a2-1-1) to (a2-1-6) is preferred, a structural unit represented by any one of formulas (a2-1-1) to (a2-1-4) is more preferred, and a structural unit represented by formula (a2-1-1) or formula (a2-1-3) is even more preferred. TIFF2023117395000107.tif53147

[0129] When the resin (A) contains the structural unit (a2-1), the content thereof is 1 mol% or more, preferably 2 mol% or more, based on the total structural units of the resin (A). Alternatively, the content may be 45 mol% or less, preferably 40 mol% or less, more preferably 35 mol% or less, even more preferably 20 mol% or less, and even more preferably 10 mol% or less. Specifically, the content may be 1 to 45 mol%, preferably 1 to 40 mol%, more preferably 1 to 35 mol%, even more preferably 1 to 20 mol%, and even more preferably 1 to 10 mol%.

[0130] <Structural unit (a3)> The lactone ring contained in the structural unit (a3) ​​may be a monocyclic ring such as a β-propiolactone ring, a γ-butyrolactone ring, or a δ-valerolactone ring, or a condensed ring of a monocyclic lactone ring with another ring. Preferred examples include a γ-butyrolactone ring, an adamantane lactone ring, or a bridged ring containing a γ-butyrolactone ring structure (for example, a structural unit represented by the following formula (a3-2)).

[0131] The structural unit (a3) ​​is preferably a structural unit represented by formula (a3-1), formula (a3-2), formula (a3-3), or formula (a3-4). One of these may be contained alone, or two or more may be contained. TIFF2023117395000108.tif50161 [In formula (a3-1), formula (a3-2), formula (a3-3) and formula (a3-4), L a4 , L a5 and L a6 are each independently -O- or -O-(CH2) k3 It represents a group represented by —CO—O— (k3 represents an integer of 1 to 7). L a7 -O-, *-OL a8 -O-, *-OL a8 -CO-O-, *-OL a8 -CO-OL a9 -CO-O- or *-OL a8 -O-CO-L a9 Represents -O-. L a8 and L a9 each independently represents an alkanediyl group having 1 to 6 carbon atoms. * indicates the bonding site with the carbonyl group. R a18 , R a19 , 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 an integer of 0 to 5. q1 represents an integer of 0 to 3. r1 represents an integer of 0 to 3. w1 represents an integer of 0 to 8. When p1, q1, r1 and / or w1 are 2 or more, multiple R a21 , R a22 , R a23 and / or R a25 may be the same as or different from each other.

[0132] R a21 , R a22 , R a23 and R a25 Examples of the aliphatic hydrocarbon group in include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, and a tert-butyl group. R a18 , R a19 , R a20 and R a24 Examples of the halogen atom in the formula include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R a18 , R a19 , R a20 and R a24 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group, and preferably an alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group or an ethyl group. R a18 , R a19 , R a20 and R a24Examples of the alkyl group having a halogen atom in the formula (I) include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group. L a8 and L a9 Examples of the alkanediyl group in the formula (I) include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group.

[0133] In formulas (a3-1) to (a3-3), L a4 ~L a6 are each independently preferably -O- or -O-(CH2) k3 In -CO-O-, k3 is a group in which k3 is any integer of 1 to 4, more preferably -O- and *-O-CH2-CO-O-, and even more preferably an oxygen atom. R a18 ~R a21 is preferably a methyl group. R a22 and R a23 are each independently preferably a carboxy group, a cyano group, or a methyl group. p1, q1 and r1 each independently represent an integer of preferably 0 to 2, and more preferably 0 or 1.

[0134] In formula (a3-4), R a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group. R a25is preferably a carboxy group, a cyano group or a methyl group. L a7 is preferably -O- or *-OL a8 It is —CO—O—, and more preferably —O—, —O—CH 2 —CO—O— or —O—C 2 H 4 —CO—O—. w1 is preferably an integer of 0 to 2, and more preferably 0 or 1. In particular, the formula (a3-4) is preferably the formula (a3-4)'. TIFF2023117395000109.tif4051 (in the formula, R a24 , L a7 has the same meaning as above.)

[0135] Examples of the structural unit (a3) ​​include structural units derived from monomers described in JP 2010-204646 A, JP 2000-122294 A, and JP 2012-41274 A. Examples of the structural unit (a3) ​​include structural units represented by any of formulas (a3-1-1), (a3-1-2), (a3-2-1), (a3-2-2), (a3-3-1), (a3-3-2), and (a3-4-1) to (a3-4-12), and in the structural units, R in formulas (a3-1) to (a3-4) a18 , R a19 , R a20 and R a24 A structural unit in which a methyl group corresponding to the following is replaced with a hydrogen atom is preferred.

[0136] JPEG2023117395000110.jpg115165

[0137] When the resin (A) contains the structural unit (a3), the total content thereof is, based on all structural units in the resin (A), 1 mol% or more, preferably 3 mol% or more, more preferably 5 mol% or more, and even more preferably 10 mol% or more. It may also be 70 mol% or less, preferably 65 mol% or less, and more preferably 60 mol% or less. Specifically, it may be 1 to 70 mol%, preferably 3 to 65 mol%, and more preferably 5 to 60 mol%. Furthermore, the content of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3), or the structural unit (a3-4) is preferably 1 mol% or more, more preferably 3 mol% or more, and even more preferably 5 mol% or more, based on the total structural units of the resin (A). It is also preferably 60 mol% or less, more preferably 55 mol% or less, and even more preferably 50 mol% or less. Specifically, it is preferably 3 to 60 mol%, more preferably 3 to 55 mol%, and even more preferably 5 to 50 mol%.

[0138] <Structural unit (a4)> Examples of the structural unit (a4) include the following structural units. TIFF2023117395000111.tif3066[In formula (a4), R 41 represents a hydrogen atom or a methyl group. R 42 represents a saturated hydrocarbon group having 1 to 24 carbon atoms and containing a fluorine atom, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-.] R 42 Examples of the saturated hydrocarbon group represented by the formula (I) include chain hydrocarbon groups, monocyclic or polycyclic alicyclic hydrocarbon groups, and groups formed by combining these groups.

[0139] Examples of the chain hydrocarbon group include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl groups. Examples of the monocyclic or polycyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups; decahydronaphthyl, adamantyl, norbornyl, and polycyclic alicyclic hydrocarbon groups such as the following groups (* indicates a bonding site): TIFF2023117395000112.tif11159 Examples of groups formed by combination include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic hydrocarbon groups, such as -alkanediyl group-alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, and -alkanediyl group-alicyclic hydrocarbon group-alkyl group.

[0140] The structural unit (a4) includes at least one structural unit selected from the group consisting of formula (a4-0), formula (a4-1), formula (a4-2), formula (a4-3) and formula (a4-4). TIFF2023117395000113.tif4652[In formula (a4-0), R 5 represents a hydrogen atom or a methyl group. L 4a represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 4 carbon atoms. L 3a represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms. R 6 represents a hydrogen atom or a fluorine atom.

[0141] L 4aExamples of the divalent aliphatic saturated hydrocarbon group in the formula (I) include linear alkanediyl groups such as a methylene group, an ethylene group, a propane-1,3-diyl group, and a butane-1,4-diyl group, and branched alkanediyl groups such as an ethane-1,1-diyl group, a propane-1,2-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, and a 2-methylpropane-1,2-diyl group. L 3a Examples of the perfluoroalkanediyl group in the formula (I) include a difluoromethylene group, a perfluoroethylene group, a perfluoropropane-1,1-diyl group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, a perfluoropropane-2,2-diyl group, a perfluorobutane-1,4-diyl group, a perfluorobutane-2,2-diyl group, a perfluorobutane-1,2-diyl group, a perfluoropentane-1,5-diyl group, a perfluoropentane-2,2-diyl group, a perfluoropentane-3 ,3-diyl group, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane-1,7-diyl group, perfluoroheptane-2,2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane-2,2-diyl group, perfluorooctane-3,3-diyl group, and perfluorooctane-4,4-diyl group. L 3a Examples of the perfluorocycloalkanediyl group in the formula (I) include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, and a perfluoroadamantanediyl group.

[0142] L 4a is preferably a single bond, a methylene group, or an ethylene group, and more preferably a single bond or a methylene group. L 3a is preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, and more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

[0143] The structural unit (a4-0) includes the structural units shown below and R in the structural unit (a4-0) in the structural units shown below. 5 The structural unit in which the methyl group corresponding to the above is replaced with a hydrogen atom is an example. TIFF2023117395000114.tif97165

[0144] Examples of the structural unit (a4) include a structural unit represented by formula (a4-1). TIFF2023117395000115.tif4162[In formula (a4-1), R a41 represents a hydrogen atom or a methyl group. R a42 represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-. A a41 represents an alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a group represented by formula (a-g1), a41 and R a42 At least one of the groups has a halogen atom (preferably a fluorine atom) as a substituent. TIFF2023117395000116.tif1384 [In formula (a-g1), s represents 0 or 1. A a42 and A a44 each independently represents a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. A a43 represents a single bond or a divalent aliphatic hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. X a41 and X a42 each independently represents -O-, -CO-, -CO-O- or -O-CO-. However, A a42 , A a43 , A a44 , X a41 and X a42The total number of carbon atoms is 7 or less. * indicates the binding site, and the * on the right is -O-CO-R a42 ]

[0145] R a42 Examples of the saturated hydrocarbon group in include a chain saturated hydrocarbon group, a monocyclic or polycyclic alicyclic saturated hydrocarbon group, and groups formed by combining these groups. Examples of the chain saturated hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group. Examples of the monocyclic or polycyclic alicyclic saturated hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; and polycyclic alicyclic saturated hydrocarbon groups such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* indicates a bonding site): TIFF2023117395000117.tif11159 Examples of groups formed by combination include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic saturated hydrocarbon groups, such as -alkanediyl group-alicyclic saturated hydrocarbon group, -alicyclic saturated hydrocarbon group-alkyl group, and -alkanediyl group-alicyclic saturated hydrocarbon group-alkyl group.

[0146] R a42 Examples of the substituent that may be possessed by include at least one selected from a halogen atom and a group represented by formula (a-g3): Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferred. TIFF2023117395000118.tif965[In formula (a-g3), X a43 represents an oxygen atom, a carbonyl group, *-O-CO- or *-CO-O-. A a45represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. * represents R a42 represents the binding site with However, R a42 -X a43 -A a45 In R a42 If A does not have a halogen atom, a45 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms and at least one halogen atom.

[0147] A a45 Examples of the aliphatic hydrocarbon group in the formula (I) include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group; Examples include monocyclic alicyclic hydrocarbon groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups; and polycyclic alicyclic hydrocarbon groups such as decahydronaphthyl, adamantyl, and norbornyl groups, and the following groups (* indicates a bonding site): TIFF2023117395000119.tif11159 Examples of groups formed by combination include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic hydrocarbon groups, such as -alkanediyl group-alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, and -alkanediyl group-alicyclic hydrocarbon group-alkyl group.

[0148] R a42 is preferably an aliphatic hydrocarbon group which may have a halogen atom, and more preferably an aliphatic hydrocarbon group having an alkyl group having a halogen atom and / or a group represented by formula (a-g3). R a42When is an aliphatic hydrocarbon group having a halogen atom, it is preferably an aliphatic hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, still more preferably a perfluoroalkyl group having 1 to 6 carbon atoms, and particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Examples of perfluoroalkyl groups include perfluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluorobutyl group, perfluoropentyl group, perfluorohexyl group, perfluoroheptyl group, and perfluorooctyl group. Examples of perfluorocycloalkyl groups include perfluorocyclohexyl group. R a42 is an aliphatic hydrocarbon group having a group represented by formula (a-g3), the number of carbon atoms contained in the group represented by formula (a-g3) is a42 The total number of carbon atoms is preferably 15 or less, more preferably 12 or less. When the group represented by formula (a-g3) is contained as a substituent, the number thereof is preferably 1.

[0149] R a42 is an aliphatic hydrocarbon group having a group represented by formula (a-g3), R a42 is more preferably a group represented by formula (a-g2). TIFF2023117395000120.tif879[In formula (a-g2), A a46 represents a divalent aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. X a44 represents **-O-CO- or **-CO-O- (** represents A a46 (representing the binding site with A a47 represents an aliphatic hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. However, A a46 , A a47 and X a44 The total number of carbon atoms in A is 18 or less. a46 and A a47 At least one of the groups has at least one halogen atom. * indicates the bonding site with the carbonyl group.]

[0150] A a46 The aliphatic hydrocarbon group preferably has 1 to 6 carbon atoms, and more preferably 1 to 3 carbon atoms. A a47 The aliphatic hydrocarbon group preferably has 4 to 15 carbon atoms, more preferably 5 to 12 carbon atoms, and A a47 is more preferably a cyclohexyl group or an adamantyl group.

[0151] A preferred structure of the group represented by formula (a-g2) is the following structure (* indicates the bonding site with the carbonyl group): TIFF2023117395000121.tif14164

[0152] A a41 Examples of the alkanediyl group in the formula (I) include linear alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, and hexane-1,6-diyl; and branched alkanediyl groups such as propane-1,2-diyl, butane-1,3-diyl, 2-methylpropane-1,2-diyl, 1-methylbutane-1,4-diyl, and 2-methylbutane-1,4-diyl. A a41 Examples of the substituent in the alkanediyl group include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms. A a41 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 2 to 4 carbon atoms, and even more preferably an ethylene group.

[0153] A in the group represented by formula (a-g1) a42 , A a43 and A a44Examples of the divalent saturated hydrocarbon group represented by include a linear or branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic hydrocarbon group, and a group formed by combining an alkanediyl group with a divalent alicyclic hydrocarbon group. Specific examples include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a 1-methylpropane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, and a 2-methylpropane-1,2-diyl group. A a42 , A a43 and A a44 Examples of the substituent of the divalent saturated hydrocarbon group represented by the formula include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms. Preferably, s is 0.

[0154] In the group represented by formula (a-g1), X a42 In the following examples, * and ** each represent a bonding site, and ** represents -O-CO-R a42 This is the binding site for TIFF2023117395000122.tif54162

[0155] The structural unit represented by formula (a4-1) includes the structural units shown below and R in the structural unit represented by formula (a4-1) in the structural units shown below. a41 The structural unit in which the methyl group corresponding to the above is replaced with a hydrogen atom is an example. JPEG2023117395000123.jpg167144

[0156] TIFF2023117395000124.tif66133

[0157] Examples of the structural unit (a4) include a structural unit represented by formula (a4-2). TIFF2023117395000125.tif4365[In formula (a4-2), R f5represents a hydrogen atom or a methyl group. L 44 represents an alkanediyl group having 1 to 6 carbon atoms, and -CH2- contained in the alkanediyl group may be replaced with -O- or -CO-. R f6 represents a saturated hydrocarbon group having 1 to 20 carbon atoms and containing a fluorine atom. However, L 44 and R f6 The maximum total carbon number is 21.]

[0158] L 44 The alkanediyl group having 1 to 6 carbon atoms is A a41 Examples of the alkanediyl group include the same groups as those exemplified as the alkanediyl group in the above. R f6 The saturated hydrocarbon group of R a42 Examples of the groups include the same groups as those exemplified in L 44 As the alkanediyl group having 1 to 6 carbon atoms, an alkanediyl group having 2 to 4 carbon atoms is preferred, and an ethylene group is more preferred.

[0159] Examples of the structural unit represented by formula (a4-2) include structural units represented by formulas (a4-1-1) to (a4-1-11). f5 The structural unit represented by formula (a4-2) also includes a structural unit in which a methyl group corresponding to the following is replaced with a hydrogen atom:

[0160] Examples of the structural unit (a4) include a structural unit represented by formula (a4-3). TIFF2023117395000126.tif5771[In formula (a4-3), R f7 represents a hydrogen atom or a methyl group. L 5 represents an alkanediyl group having 1 to 6 carbon atoms. A f13 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms which may contain a fluorine atom. X f12represents *-O-CO- or *-CO-O- (* represents A f13 represents the binding site with ). A f14 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may contain a fluorine atom. However, A f13 and A f14 At least one of L has a fluorine atom, 5 , A f13 and A f14 The total number of carbon atoms in a molecule is limited to 20.

[0161] L 5 The alkanediyl group in a41 Examples of the alkanediyl group include the same groups as those exemplified as the alkanediyl group in the above. A f13 The divalent saturated hydrocarbon group optionally having a fluorine atom in the formula (I) is preferably a divalent chain saturated hydrocarbon group optionally having a fluorine atom and a divalent alicyclic saturated hydrocarbon group optionally having a fluorine atom, and more preferably a perfluoroalkanediyl group. Examples of the divalent chain saturated hydrocarbon group which may have a fluorine atom include alkanediyl groups such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group, and a pentanediyl group; and perfluoroalkanediyl groups such as a difluoromethylene group, a perfluoroethylene group, a perfluoropropanediyl group, a perfluorobutanediyl group, and a perfluoropentanediyl group. The divalent alicyclic saturated hydrocarbon group optionally having a fluorine atom may be either monocyclic or polycyclic. Examples of the monocyclic group include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the polycyclic group include an adamantanediyl group, a norbornanediyl group, and a perfluoroadamantanediyl group. A f14 The saturated hydrocarbon group and the saturated hydrocarbon group which may have a fluorine atom are R a42Among these, a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, Preferred are fluorinated alkyl groups such as a hexyl group, a perfluorohexyl group, a heptyl group, a perfluoroheptyl group, an octyl group, and a perfluorooctyl group, a cyclopropylmethyl group, a cyclopropyl group, a cyclobutylmethyl group, a cyclopentyl group, a cyclohexyl group, a perfluorocyclohexyl group, an adamantyl group, an adamantylmethyl group, an adamantyldimethyl group, a norbornyl group, a norbornylmethyl group, a perfluoroadamantyl group, and a perfluoroadamantylmethyl group.

[0162] In formula (a4-3), L 5 is preferably an ethylene group. A f13 The divalent saturated hydrocarbon group is preferably a group containing a divalent chain saturated hydrocarbon group having 1 to 6 carbon atoms and a divalent alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and more preferably a divalent chain saturated hydrocarbon group having 2 to 3 carbon atoms. A f14 The saturated hydrocarbon group is preferably a group containing a chain saturated hydrocarbon group having 3 to 12 carbon atoms and a group containing an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and more preferably a group containing a chain saturated hydrocarbon group having 3 to 10 carbon atoms and a group containing an alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms. f14 is preferably a group containing an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and more preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, or an adamantyl group.

[0163] Examples of the structural unit represented by formula (a4-3) include structural units represented by formulas (a4-1'-1) to (a4-1'-11). f7 The structural unit represented by formula (a4-3) also includes a structural unit in which a methyl group corresponding to the following is replaced with a hydrogen atom:

[0164] The structural unit (a4) also includes a structural unit represented by formula (a4-4). TIFF2023117395000127.tif4466[In formula (a4-4), R f21 represents a hydrogen atom or a methyl group. A f21 is -(CH2) j1 -, -(CH2) j2 -O-(CH2) j3 -or-(CH2) j4 -CO-O-(CH2) j5 - represents. j1 to j5 each independently represent an integer of 1 to 6. R f22 represents a saturated hydrocarbon group having 1 to 10 carbon atoms and containing a fluorine atom.]

[0165] R f22 The saturated hydrocarbon group of R a42 Examples of saturated hydrocarbon groups include the same as those represented by R f22 is preferably an alkyl group having 1 to 10 carbon atoms and containing a fluorine atom or an alicyclic hydrocarbon group having 1 to 10 carbon atoms and containing a fluorine atom, more preferably an alkyl group having 1 to 10 carbon atoms and containing a fluorine atom, and even more preferably an alkyl group having 1 to 6 carbon atoms and containing a fluorine atom.

[0166] In formula (a4-4), A f21 As -(CH2) j1 - is preferred, an ethylene group or a methylene group is more preferred, and a methylene group is even more preferred.

[0167] Examples of the structural unit represented by formula (a4-4) include the following structural units and structural units represented by the following formulas: f21 The structural unit in which the methyl group corresponding to the above is replaced with a hydrogen atom is an example. TIFF2023117395000128.tif90164

[0168] When the resin (A) contains the structural unit (a4), the content thereof is preferably 1 to 20 mol %, more preferably 2 to 15 mol %, and even more preferably 3 to 10 mol %, based on all structural units in the resin (A).

[0169] <Structural unit (a5)> The non-leaving hydrocarbon group contained in the structural unit (a5) may be a group containing a linear, branched, or cyclic hydrocarbon group, and among these, the structural unit (a5) is preferably a group containing an alicyclic hydrocarbon group. Examples of the structural unit (a5) include a structural unit represented by formula (a5-1). TIFF2023117395000129.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 a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms. L 55 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-.]

[0170] R 52 The alicyclic hydrocarbon group in may be either monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. Examples of polycyclic alicyclic hydrocarbon groups include adamantyl and norbornyl. Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, and 2-ethylhexyl. Examples of the alicyclic hydrocarbon group having a substituent include a 3-methyladamantyl group. R 52 is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and more preferably an adamantyl group, a norbornyl group, or a cyclohexyl group. L 55 The divalent saturated hydrocarbon group in the formula (I) includes a divalent saturated chain hydrocarbon group and a divalent saturated alicyclic hydrocarbon group, and is preferably a divalent saturated chain hydrocarbon group. Examples of the divalent chain saturated hydrocarbon group include a methylene group, an ethylene group, and an alkanediyl group such as a propanediyl group, a butanediyl group, and a pentanediyl group. The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkanediyl groups such as cyclopentanediyl and cyclohexanediyl. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include adamantanediyl and norbornanediyl.

[0171] L 55 Examples of the divalent saturated hydrocarbon group represented by formula (L1-1) in which one -CH2- is replaced with -O- or -CO- include groups represented by formula (L1-1) to formula (L1-4). In the following formulae, * and ** each represent a bonding site, and * represents a bonding site to an oxygen atom. TIFF2023117395000130.tif18165[In formula (L1-1), X x1 represents *-O-CO- or *-CO-O- (* represents L x1 represents the binding site with ). L x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. L x2represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. However, L x1 and L x2 The total number of carbon atoms is 16 or less. In formula (L1-2), L x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms. L x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. However, L x3 and L x4 The total number of carbon atoms is 17 or less. In formula (L1-3), L x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. L x6 and L x7 each independently represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms. However, L x5 , L x6 and L x7 The total number of carbon atoms is 15 or less. In formula (L1-4), L x8 and L x9 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms. W x1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms. However, L x8 , L x9 and W x1 The total number of carbon atoms is 15 or less.

[0172] 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.

[0173] Examples of the group represented by formula (L1-1) include the divalent groups shown below. TIFF2023117395000131.tif37147 Examples of the group represented by formula (L1-2) include the divalent groups shown below. TIFF2023117395000132.tif23130 Examples of the group represented by formula (L1-3) include the divalent groups shown below. TIFF2023117395000133.tif16147 Examples of the group represented by formula (L1-4) include the divalent groups shown below. TIFF2023117395000134.tif13168L 55 is preferably a single bond or a group represented by formula (L1-1).

[0174] The structural unit (a5-1) includes the structural units shown below and R in the structural unit (a5-1) in the structural units shown below. 51 The structural unit in which the methyl group corresponding to the above is replaced with a hydrogen atom is an example. When the resin (A) contains the structural unit (a5), the content thereof is preferably 1 to 30 mol %, more preferably 2 to 20 mol %, and even more preferably 3 to 15 mol %, based on all structural units in the resin (A).

[0175] <Structural unit (a6)> The structural unit (a6) is a structural unit having an -SO2- group, and preferably has an -SO2- group in a side chain. The structural unit having an -SO2- group may have a linear structure having an -SO2- group, a branched structure having an -SO2- group, or a cyclic structure (monocyclic or polycyclic structure) having an -SO2- group. A structural unit having a cyclic structure having an -SO2- group is preferred, and a structural unit having a cyclic structure containing an -SO2-O- group (sultone ring) is more preferred.

[0176] The sultone ring may be a ring having the following formula (T 1 -1), formula (T 1 -2), formula (T 1 -3) and the formula (T 1 The bonding site can be any position. The sultone ring may be monocyclic, but is preferably polycyclic. A polycyclic sultone ring refers to a bridged ring containing -SO2-O- as an atomic group constituting the ring, and is represented by the formula (T 1 -1) and the formula (T 1 The sultone ring is represented by the formula (T 1 As in the ring represented by formula (2), the atomic group constituting the ring may further contain a heteroatom in addition to —SO—O—. Examples of the heteroatom include an oxygen atom, a sulfur atom, and a nitrogen atom, and an oxygen atom is preferred. TIFF2023117395000136.tif3186

[0177] The sultone ring may have a substituent, and examples of the substituent include an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms, and an alkylcarbonyl group having 2 to 4 carbon atoms.

[0178] Halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, and a decyl group, and preferably an alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group. Examples of the alkyl group having a halogen atom include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group, and preferably a trifluoromethyl group. Examples of the alkyl group having a hydroxy group include a hydroxymethyl group and a 2-hydroxyethyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group. Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-tert-butylphenyl group, a p-adamantylphenyl group, a tolyl group, a xylyl group, a cumyl group, a mesityl group, a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group. Aralkyl groups include benzyl, phenethyl, phenylpropyl, naphthylmethyl, and naphthylethyl groups. Examples of the alkoxycarbonyl group include groups in which an alkoxy group, such as a methoxycarbonyl group or an ethoxycarbonyl group, is bonded to a carbonyl group, and preferred are alkoxycarbonyl groups having 6 or less carbon atoms, more preferably a methoxycarbonyl group. Alkylcarbonyl groups include acetyl, propionyl and butyryl groups.

[0179] From the viewpoint of ease of production of the monomer from which the structural unit (a6) is derived, a sultone ring having no substituent is preferred. The sultone ring is preferably a ring represented by the following formula (T1'). TIFF2023117395000137.tif3171[In formula (T1'), X 11 represents an oxygen atom, a sulfur atom or a methylene group. R 41 represents an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms, or an alkylcarbonyl group having 2 to 4 carbon atoms. ma represents an integer of 0 to 9. When ma is 2 or more, multiple R 41 may be the same or different. The binding site is at any position.] X 11 is preferably an oxygen atom or a methylene group, more preferably a methylene group. R 41 Examples of the substituent include the same as the substituent on the sultone ring, and an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group is preferred. ma is preferably 0 or 1, and more preferably 0.

[0180] Examples of the ring represented by formula (T1') include the following rings: The binding site may be any position, and the binding site is preferably the 1st or 3rd position. TIFF2023117395000138.tif47147

[0181] The structural unit having an -SO2- group preferably further has a group derived from a polymerizable group, such as a vinyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an acryloylamino group, a methacryloylamino group, an acryloylthio group, or a methacryloylthio group. Among these, the monomer from which the structural unit (a6) is derived is preferably a monomer having an ethylenically unsaturated bond, and more preferably a (meth)acrylic monomer.

[0182] The structural unit (a6) is preferably a structural unit represented by the formula (a6-0). TIFF2023117395000139.tif4963[In formula (a6-0), R x represents an alkyl group having 1 to 6 carbon atoms which may have one or more halogen atoms, a hydrogen atom, or a halogen atom. A xx is an oxygen atom, -N(R c )- or a sulfur atom. A x represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group is not -O-, -CO- or -N(R d )- may be replaced. X 11 , R 41 and ma have the same meanings as above. R c and R d each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0183] R x Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R x Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group, and are preferably alkyl groups having 1 to 4 carbon atoms, and more preferably a methyl group or an ethyl group. R x 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. R x is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group.

[0184] A x Examples of the divalent saturated hydrocarbon group include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and may be a combination of two or more of these groups. Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group linear alkanediyl groups such as a dodecane-1,12-diyl group, a tridecane-1,13-diyl group, a tetradecane-1,14-diyl group, a pentadecane-1,15-diyl group, a hexadecane-1,16-diyl group, a heptadecane-1,17-diyl group, an ethane-1,1-diyl group, a propane-1,1-diyl group, and a propane-2,2-diyl group; branched alkanediyl groups such as butane-1,3-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, and 2-methylbutane-1,4-diyl; monocyclic divalent alicyclic saturated hydrocarbon groups such as cycloalkanediyl groups, such as cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, and cyclooctane-1,5-diyl; Examples include polycyclic divalent alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group. A x The bonding position of to the sultone ring can be any position, but the 1-position is preferred.

[0185] Examples of the structural unit (a6-0) include the following structural units. TIFF2023117395000140.tif92150

[0186] Of these, structural units represented by formula (a6-1), formula (a6-2), formula (a6-6), formula (a6-7), formula (a6-8), and formula (a6-12) are preferred, and structural units represented by formula (a6-1), formula (a6-2), formula (a6-7), and formula (a6-8) are more preferred. When the resin (A) has the structural unit (a6), the content thereof is preferably from 1 to 50 mol %, more preferably from 2 to 40 mol %, and even more preferably from 3 to 30 mol %, based on all structural units in the resin (A).

[0187] <Structural unit (II)> The resin (A) may further contain a structural unit that decomposes upon exposure to generate an acid (hereinafter, sometimes referred to as "structural unit (II)"). Specific examples of the structural unit (II) include the structural units described in JP-A-2016-79235, and the structural unit (II) is preferably a structural unit having a sulfonate group or carboxylate group and an organic cation in a side chain, or a structural unit having a sulfonio group and an organic anion in a side chain.

[0188] The structural unit having a sulfonate group or carboxylate group and an organic cation on the side chain is preferably a structural unit represented by formula (II-2-A'). TIFF2023117395000141.tif35104 [In formula (II-2-A'), X III3 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, wherein one -CH2- contained in the saturated hydrocarbon group may be replaced by -O-, -S-, or -CO-, and a hydrogen atom contained in the saturated hydrocarbon group may be replaced by a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, or a hydroxy group. A x1 represents an alkanediyl group having 1 to 8 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. RA - represents a sulfonate group or a carboxylate group. R III3 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. ZA + represents an organic cation.

[0189] R III3 Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R III3 The alkyl group having 1 to 6 carbon atoms which may have a halogen atom and is represented by the formula: a8 Examples of the alkyl group include the same alkyl groups having 1 to 6 carbon atoms which may have a halogen atom and which are represented by the following formula: A x1Examples of the alkanediyl group having 1 to 8 carbon atoms represented by the formula (I) include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, an ethane-1,1-diyl group, a propane-1,1-diyl group, a propane-1,2-diyl group, a propane-2,2-diyl group, a pentane-2,4-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. A X1 Examples of the optionally substituted 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 perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. X III3 Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by the formula (I) include a linear or branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and these may be used in combination. Specific examples thereof include linear alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, and dodecane-1,12-diyl; butane-1,3-diyl, 2-methylpropane-1,3-diyl, and 2-methylpropane-1,3-diyl; Examples include branched alkanediyl groups such as pentane-1,2-diyl, pentane-1,4-diyl, and 2-methylbutane-1,4-diyl; cycloalkanediyl groups such as cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, and cyclooctane-1,5-diyl; and divalent polycyclic alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl, norbornane-2,5-diyl, adamantane-1,5-diyl, and adamantane-2,6-diyl. Examples of saturated hydrocarbon groups in which -CH2- is replaced with -O-, -S-, or -CO- include divalent groups represented by formulae (X1) to (X53). However, the number of carbon atoms before the -CH2- in the saturated hydrocarbon group is replaced with -O-, -S-, or -CO- is 17 or less. In the following formulae, * and ** represent bonding sites, and * represents A x1 represents the binding site with JPEG2023117395000142.jpg145161

[0190] 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 8represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.

[0191] ZA in formula (II-2-A') + is the cation Z1 in the salt represented by formula (B1) + The same can be mentioned.

[0192] The structural unit represented by formula (II-2-A') is preferably a structural unit represented by formula (II-2-A). TIFF2023117395000143.tif38109 [In formula (II-2-A), R III3 , X III3 and ZA + has the same meaning as above. z2A represents an integer of 0 to 6. R III2 and R III4 each independently represents a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms; when z2A is 2 or more, a plurality of R III2 and R III4 may be the same as or different from each other. Q a and Q b each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.] R III2 , R III4 , Q a and Q b As the perfluoroalkyl group having 1 to 6 carbon atoms represented by the formula, the above-mentioned Q b1 Examples include the same perfluoroalkyl groups having 1 to 6 carbon atoms as those represented by the following formula:

[0193] The structural unit represented by formula (II-2-A) is preferably a structural unit represented by formula (II-2-A-1). TIFF2023117395000144.tif5577 [In formula (II-2-A-1), R III2 , R III3 , R III4 , Q a , Qb and ZA + has the same meaning as above. R III5 represents a saturated hydrocarbon group having 1 to 12 carbon atoms. z2A1 represents an integer of 0 to 6. X I2 represents a divalent saturated hydrocarbon group having 1 to 11 carbon atoms, wherein -CH2- contained in the saturated hydrocarbon group may be replaced by -O-, -S-, or -CO-, and wherein a hydrogen atom contained in the saturated hydrocarbon group may be substituted by a halogen atom or a hydroxy group. R III5 Examples of the saturated hydrocarbon group having 1 to 12 carbon atoms represented by the formula (I) include linear or branched alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group. X I2 As the divalent saturated hydrocarbon group represented by X III3 Examples of the divalent saturated hydrocarbon group include those similar to those represented by the following formula:

[0194] As the structural unit represented by formula (II-2-A-1), a structural unit represented by formula (II-2-A-2) is more preferred. TIFF2023117395000145.tif5287 [In formula (II-2-A-2), R III3 , R III5 and ZA + has the same meaning as above. m and nA each independently represent 1 or 2.

[0195] Examples of the structural unit represented by formula (II-2-A') include the following structural units, R III3 Examples of such a structural unit include a structural unit in which the group corresponding to the methyl group in the formula (1) is replaced with a hydrogen atom, a halogen atom (e.g., a fluorine atom), or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (e.g., a trifluoromethyl group), and the structural units described in WO 2012 / 050015.+ represents an organic cation. TIFF2023117395000146.tif86163

[0196] The structural unit having a sulfonio group and an organic anion on the side chain is preferably a structural unit represented by formula (II-1-1). TIFF2023117395000147.tif3791 [In formula (II-1-1), A II1 represents a single bond or a divalent linking group. R II1 represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms. R II2 and R II3 each independently represents a hydrocarbon group having 1 to 18 carbon atoms; R II2 and R II3 may be bonded to each other to form a ring together with the sulfur atom to which they are attached. R II4 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. A - represents an organic anion. R II1 Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by the formula include a phenylene group and a naphthylene group. R II2 and R II3 Examples of the hydrocarbon group represented by the formula (I) include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups. Examples of the alkyl group and the alicyclic hydrocarbon group include the same as those described above. Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. Examples of the combined group include a group combining the above-mentioned alkyl group and alicyclic hydrocarbon group, aralkyl groups such as benzyl group, aromatic hydrocarbon groups having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon groups having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), and aryl-cycloalkyl groups such as phenylcyclohexyl group. II4 Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R II4 The alkyl group having 1 to 6 carbon atoms which may have a halogen atom and is represented by the formula: a8 Examples of the alkyl group include the same alkyl groups having 1 to 6 carbon atoms which may have a halogen atom and which are represented by the following formula: A II1 Examples of the divalent linking group represented by the formula (I) include a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O-, -S- or -CO-. III3 Examples include the same divalent saturated hydrocarbon groups having 1 to 18 carbon atoms as those represented by the following formula:

[0197] The structural unit containing a cation in formula (II-1-1) includes the structural unit represented by the following formula and R II4 Examples of structural units include those in which a group corresponding to the methyl group in the above formula (I) 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). TIFF2023117395000148.tif71163

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

[0199] A - Examples of the sulfonylimide anion represented by the formula (I) include the following. JPEG2023117395000149.jpg23136 Examples of sulfonylmethide anions include the following: TIFF2023117395000150.tif26133Carboxylate anions include the following: TIFF2023117395000151.tif43155

[0200] Examples of the structural unit represented by formula (II-1-1) include structural units represented by the following formulas. JPEG2023117395000152.jpg88149

[0201] When the structural unit (II) is contained in the resin (A), the content of the structural unit (II) is preferably 1 to 20 mol %, more preferably 2 to 15 mol %, and even more preferably 3 to 10 mol %, based on the total structural units of the resin (A).

[0202] The resin (A) is preferably a resin containing the structural unit (a1). In particular, the resin (A) is preferably a resin composed of the structural unit (a1) and the structural unit (s), i.e., a copolymer of the monomer (a1) and the monomer (s). The structural unit (a1) is preferably 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), more preferably at least two selected from the group consisting of the structural unit (a1-1) and 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 (a2-1) or the structural unit (a2-A). The structural unit (a3) ​​is preferably at least one selected from the group consisting of the structural unit represented by formula (a3-1), the structural unit represented by formula (a3-2), and the structural unit represented by formula (a3-4). The structural units constituting the resin (A) may be used singly or in combination of two or more, and can be produced by a known polymerization method (e.g., radical polymerization) using monomers that lead to these structural units. The content of each structural unit in the resin (A) can be adjusted by the amount of monomer used in the polymerization. The weight-average molecular weight of resin (A) is preferably 2,000 or more (more preferably 2,500 or more, even more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less, even more preferably 15,000 or less), but it may contain oligomers with lower weight-average molecular weights. In this specification, the weight-average molecular weight is a value determined by gel permeation chromatography under the conditions described in the Examples.

[0203] <Resins other than Resin (A)> The resist composition of the present invention may contain a resin other than the resin (A) in combination. Examples of resins other than resin (A) include resins containing the structural unit (a4) or the structural unit (a5) (hereinafter, sometimes referred to as resin (X)). Among these, resins (X) containing the structural unit (a4) are preferred, including resins consisting of only the structural unit (a4) and resins containing the structural unit (a4) and the structural unit (a5). Examples of structural units that the resin (X) may further contain include the structural unit (a2), the structural unit (a3), and structural units derived from other known monomers. When resin (X) contains structural unit (a4), the content of structural unit (a4) in resin (X) is, based on the total of all structural units in resin (X), 20 mol% or more, preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 45 mol% or more. Also, it may be 100 mol% or less, preferably 80 mol% or less, more preferably 70 mol% or less, even more preferably 60 mol% or less, and even more preferably 55 mol% or less. Specifically, it may be 20 to 100 mol%, preferably 20 to 80 mol%, more preferably 30 to 70 mol%, even more preferably 40 to 60 mol%, and even more preferably 45 to 55 mol%. When resin (X) contains structural unit (a5), the content of structural unit (a5) in resin (X) is, based on the total of all structural units in resin (X), 20 mol% or more, preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 45 mol% or more. Further, it may be 100 mol% or less, preferably 80 mol% or less, more preferably 70 mol% or less, even more preferably 60 mol% or less, and even more preferably 55 mol% or less. Specific examples include 20 to 100 mol%, preferably 20 to 80 mol%, more preferably 30 to 70 mol%, even more preferably 40 to 60 mol%, and even more preferably 45 to 55 mol%. Furthermore, 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) relative to the total of all structural units in the resin (X) may be 40 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more, and even more preferably 80 mol% or more. Specific examples include 100 mol% or less. Specific examples include 40 to 100 mol%, preferably 60 to 100 mol%, more preferably 70 to 100 mol%, and even more preferably 80 to 100 mol%. The structural units constituting the resin (X) may be used singly or in combination of two or more, and can be produced by a known polymerization method (e.g., radical polymerization) using monomers that derive these structural units. The content of each structural unit in the resin (X) can be adjusted by the amount of monomer used in the polymerization. The weight-average molecular weight of 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 with a lower weight-average molecular weight. The weight-average molecular weight of resin (X) can be measured by the same method as for resin (A).

[0204] When the resist composition of the present invention contains resin (X), the content thereof is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, even more preferably 1 to 40 parts by mass, still more preferably 1 to 30 parts by mass, and even more preferably 1 to 8 parts by mass, relative to 100 parts by mass of resin (A).

[0205] The content of resin (A) in the resist composition is preferably from 80 to 99 mass%, and more preferably from 90 to 99 mass%, based on the solid content of the resist composition. Furthermore, when a resin other than resin (A) is contained, the total content of resin (A) and the resin other than resin (A) is preferably from 80 to 99 mass%, and more preferably from 90 to 99 mass%, based on the solid content of the resist composition. The solid content of the resist composition and the resin content relative to the solid content can be measured using known analytical methods such as liquid chromatography or gas chromatography.

[0206] <Solvent (E)> The content of the solvent (E) in the resist composition is usually from 90 to 99.9% by mass, preferably from 92 to 99% by mass, and more preferably from 94 to 99% by mass. The content of the solvent (E) can be measured by known analytical means such as liquid chromatography or gas chromatography.

[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; etc. One type of solvent (E) may be used alone, or two or more types may be used.

[0208] <Quencher (C)> Examples of the quencher (C) include basic nitrogen-containing organic compounds and salts that generate an acid that is weaker in acidity than the acid generated from the acid generator. When the resist composition contains the quencher (C), the content of the quencher (C) is preferably about 0.01 to 15 mass%, more preferably about 0.01 to 10 mass%, even more preferably about 0.1 to 8 mass%, and even more preferably about 0.1 to 7 mass%, based on the solids content of the resist composition. The basic nitrogen-containing organic compound includes amines and ammonium salts. The amines include aliphatic amines and aromatic amines. The aliphatic amines include primary amines, secondary amines, and tertiary amines.

[0209] Examples of amines include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N,N-dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributaryamine, benzophenone ... ethylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldi Decylamine, 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-pyridinyl)-2-methylpropanol, 2,2 ... 2,2'-methylenebisaniline, 2,2'-methylenebisaniline, 2,2'-methylenebisaniline, 2,2'-methylenebisaniline, 2,2'-methylenebisaniline, 2,2'-methylenebisaniline, 2,2'-methylenebisaniline, 2,2'-methylenebisaniline, 2,2'-methylenebisaniline, 2,2'-methylenebisaniline, 2,2'-methylenebisaniline, 2,2'-methylenebisaniline, 2,2'-methylenebisaniline, 2,2'-methylenebisaniline, 2,2'-methylenebisaniline, 2,2'-methylenebisaniline, Examples thereof include 1,2-di(4-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'-dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipicolylamine, and bipyridine, preferably diisopropylaniline, and more preferably 2,6-diisopropylaniline.

[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 weaker in acidity than the acid generated from the acid generator is represented by the acid dissociation constant (pKa). A salt that generates an acid weaker in 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 weaker in acidity than the acid generated from the acid generator include the salt represented by the following formula, the salt represented by formula (D) described in JP-A-2015-147926 (hereinafter sometimes referred to as "weak acid inner salt (D)"), and the 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 weaker in acidity than the acid generated from the acid generator is preferably a salt that generates a carboxylic acid weaker in acidity than the acid generated from the acid generator (a salt having a carboxylic acid anion), more preferably a weak acid inner salt (D), and still more preferably a diphenyliodonium salt containing a phenyl group substituted with a carboxylic acid anion among the weak acid inner salts (D). TIFF2023117395000153.tif95149

[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, examples thereof include salts represented by the following formulas.

[0213] TIFF2023117395000154.tif2362[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 0 to 4, and 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 groups. Examples of the chain hydrocarbon group include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, and nonyl groups. The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and may be either saturated or unsaturated. Examples of the alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclononyl, and cyclododecyl, norbornyl, and adamantyl. Examples of aromatic hydrocarbon groups include aryl groups such as a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, a 4-ethylphenyl group, a 4-propylphenyl group, a 4-isopropylphenyl group, a 4-butylphenyl group, a 4-t-butylphenyl group, a 4-hexylphenyl group, a 4-cyclohexylphenyl group, an anthryl group, a p-adamantylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group. Examples of groups formed by combining these groups include alkyl-cycloalkyl groups, cycloalkyl-alkyl groups, and 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, and 6-phenyl-1-hexyl group). Examples of the alkoxy group include a methoxy group and an ethoxy group. Examples of the acyl group include an acetyl group, a propanoyl group, a benzoyl group, and a cyclohexanecarbonyl group. Examples of the acyloxy group include groups in which an oxy group (—O—) is bonded to the above-mentioned acyl group. Examples of the alkoxycarbonyl group include a group in which a carbonyl group (—CO—) is bonded to the above alkoxy group. Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom. R D1 and R D2 are each independently preferably an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a nitro group, or a halogen atom. m' and n' are each preferably an integer of 0 to 2, more preferably 0. When m' is 2 or more, multiple 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.

[0214] More specifically, the following salts are included: TIFF2023117395000155.tif72165

[0215] <Other ingredients> The resist composition of the present invention may optionally contain components other than those described above (hereinafter, these may be referred to as "other components (F)"). There are no particular limitations on the other components (F), and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, and dyes, can be used.

[0216] <Preparation of Resist Composition> The resist composition of the present invention can be prepared by mixing the salt (I) and resin (A), and, if necessary, the acid generator (B), a resin other than the resin (A), the solvent (E), the quencher (C), and other components (F). The order of mixing is arbitrary and is not particularly limited. The temperature during mixing can be selected from 10 to 40°C, depending on the type of resin, the solubility of the resin in the solvent (E), and other factors. The mixing time can be selected from 0.5 to 24 hours, depending on the mixing temperature. The mixing method is also not particularly limited, and stirring and mixing can be used. After mixing the components, it is preferable to filter the mixture using a filter with a pore size of about 0.003 to 0.2 μm.

[0217] <Method for producing a resist pattern> The method for producing a resist pattern of the present invention comprises the steps of: (1) applying the resist composition of the present invention onto a substrate; (2) drying the applied composition to form a composition layer; (3) exposing the composition layer to light; (4) heating the composition layer after exposure; and (5) A step of developing the composition layer after heating is included. The resist composition can be applied to a substrate using a commonly used device such as a spin coater. Examples of the substrate include inorganic substrates such as silicon wafers and organic substrates having a resist film formed on their surfaces. Before applying the resist composition, the substrate may be cleaned, and an anti-reflective film or the like may be formed on the substrate. The composition after coating is dried to remove the solvent and form a composition layer. Drying is carried out, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking), or by using a vacuum device. The heating temperature is preferably 50 to 200°C, and the heating time is preferably 10 to 180 seconds. The pressure during vacuum drying is preferably 1 to 1.0 x 10 5 It is preferable that the pressure is about Pa. The resulting composition layer is typically exposed using an exposure machine. The exposure machine may be an immersion exposure machine. Various exposure light sources can be used, including those that emit ultraviolet laser light such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), and F2 excimer laser (wavelength 157 nm); those that convert the wavelength of laser light from a solid-state laser source (such as a YAG or semiconductor laser) to emit harmonic laser light in the far ultraviolet or vacuum ultraviolet range; and those that irradiate with electron beams or extreme ultraviolet light (EUV). In this specification, irradiation with these types of radiation may be collectively referred to as "exposure." During exposure, exposure is typically performed through a mask corresponding to the desired pattern. When the exposure light source is an electron beam, exposure may be performed by direct writing without using a mask. The composition layer after exposure is subjected to a heat treatment (so-called post-exposure bake) to promote the deprotection reaction of the acid labile groups. The heating temperature is usually about 50 to 200°C, preferably about 70 to 150°C. A chemical treatment (silylation) may be performed to adjust the hydrophilicity or hydrophobicity of the resin on the surface side of the heated composition. Furthermore, before development, the steps of applying a resist composition, drying, exposing, and heating may be repeated on the composition layer after exposure. The heated composition layer is usually developed using a developer in a developing device. Development methods include dipping, puddling, spraying, and dynamic dispensing. The development temperature is preferably, for example, 5 to 60°C, and the development time is preferably, for example, 5 to 300 seconds. By selecting the type of developer as follows, a positive resist pattern or a negative resist pattern can be produced. When a positive resist pattern is produced from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be any of various alkaline aqueous solutions used in this field. Examples include aqueous solutions of tetramethylammonium hydroxide and (2-hydroxyethyl)trimethylammonium hydroxide (commonly known as choline). The alkaline developer may also contain a surfactant. After development, the resist pattern is preferably washed with ultrapure water, and then water remaining on the substrate and pattern is removed. When a negative resist pattern is produced from the resist composition of the present invention, a developer containing an organic solvent (hereinafter sometimes referred to as an "organic developer") is used as the developer. Examples of organic solvents contained in organic developers include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycol ether solvents such as propylene glycol monomethyl ether; amide solvents such as N,N-dimethylacetamide; and aromatic hydrocarbon solvents such as anisole. The content of the organic solvent in the organic developer is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and even more preferably substantially only the organic solvent. Among these, the organic developer is preferably a developer containing butyl acetate and / or 2-heptanone. The total content of butyl acetate and 2-heptanone in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and even more preferably substantially only butyl acetate and / or 2-heptanone. The organic developer may contain a surfactant and a small amount of water. During development, development may be stopped by replacing the organic developer with a different type of solvent. The developed resist pattern is preferably washed with a rinse solution. There are no particular limitations on the rinse solution as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, preferably an alcohol solvent or an ester solvent. After cleaning, it is preferable to remove the rinse liquid remaining on the substrate and the pattern.

[0218] <Application> The resist composition of the present invention is suitable as a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, and is particularly suitable as a resist composition for electron beam (EB) exposure or a resist composition for EUV exposure, and is useful for semiconductor microfabrication. [Example]

[0219] The present invention will be explained in more detail with reference to examples. In the examples, "%" and "parts" representing the content or amount used are by mass unless otherwise specified. The weight-average molecular weight is a value determined by gel permeation chromatography under the following analytical conditions: Column: TSKgel Multipore HXL-M x 3 + guard column (Tosoh Corporation) Eluent: tetrahydrofuran Flow rate: 1.0mL / min Detector: RI detector Column temperature: 40℃ Injection volume: 100μl Molecular weight standard: Standard polystyrene (Tosoh Corporation) The structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC: Agilent 1100, MASS: Agilent LC / MSD). In the following examples, the value of this molecular ion peak is indicated by "MASS."

[0220] Example 1: Synthesis of salt represented by formula (I-1) TIFF2023117395000156.tif29153 4.48 parts of the salt represented by formula (I-1-a) and 20 parts of dimethylformamide were mixed and stirred at 23 ° C. for 30 minutes. 3.24 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 10.32 parts of the compound represented by formula (I-1-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 50 parts of chloroform and 20 parts of ion-exchanged water were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, after which the organic layer was separated and extracted. The resulting organic layer was concentrated to obtain 12.66 parts of the salt represented by formula (I-1-d). 7.22 parts of the salt represented by formula (I-1-d), 3.74 parts of the salt represented by formula (I-1-e), 10 parts of ion-exchanged water, 30 parts of chloroform, and 15 parts of ethyl acetate were mixed and stirred at 23°C for 8 hours. 15 parts of ion-exchanged water was added to the resulting mixed solution and stirred at 23°C for 30 minutes, after which the organic layer was separated and extracted. This water washing procedure was repeated five times. 30 parts of tert-butyl methyl ether was added to the resulting concentrated residue and stirred at 23°C for 30 minutes. The supernatant was removed and the mixture was concentrated to obtain 7.95 parts of the salt represented by formula (I-1). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 698.8

[0221] Example 2: Synthesis of salt represented by formula (I-4) 5.36 parts of the salt represented by formula (I-4-a) and 40 parts of chloroform were mixed and stirred at 23 ° C. for 30 minutes. 6.48 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 20.64 parts of the compound represented by formula (I-1-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 20 parts of ion-exchanged water were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, after which the organic layer was separated and extracted. The resulting organic layer was concentrated to obtain 21.12 parts of the salt represented by formula (I-4-d). TIFF2023117395000159.tif38166 12.64 parts of the salt represented by formula (I-4-d), 3.74 parts of the salt represented by formula (I-1-e), 10 parts of ion-exchanged water, 30 parts of chloroform, and 15 parts of ethyl acetate were mixed and stirred at 23 ° C. for 8 hours. 25 parts of a 5% aqueous oxalic acid solution was added to the resulting mixed solution, and the mixture was stirred at 23 ° C. for 30 minutes, followed by separation to extract the organic layer. 25 parts of ion-exchanged water was added to the resulting organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, followed by separation to extract the organic layer. This water washing procedure was repeated five times. 30 parts of tert-butyl methyl ether was added to the resulting concentrated residue, and the mixture was stirred at 23 ° C. for 30 minutes. The supernatant was then removed, and the mixture was concentrated to obtain 13.19 parts of the salt represented by formula (I-4). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 1240.7

[0222] Example 3: Synthesis of salt represented by formula (I-745) 7.22 parts of the salt represented by formula (I-1-d), 6.36 parts of the salt represented by formula (I-745-e), 10 parts of ion-exchanged water, 30 parts of chloroform, and 15 parts of ethyl acetate were mixed and stirred at 23°C for 8 hours. 15 parts of ion-exchanged water was added to the resulting mixed solution and stirred at 23°C for 30 minutes, after which the organic layer was separated and extracted. This water washing procedure was repeated five times. 30 parts of tert-butyl methyl ether was added to the resulting concentrated residue and stirred at 23°C for 30 minutes. The supernatant was removed and the mixture was concentrated to obtain 8.64 parts of the salt represented by formula (I-745). MASS(ESI(+)Spectrum):M + 525.0 MASS(ESI(-)Spectrum):M - 698.8

[0223] Example 4: Synthesis of salt represented by formula (I-748) TIFF2023117395000161.tif38167 12.64 parts of the salt represented by formula (I-4-d), 6.36 parts of the salt represented by formula (I-745-e), 10 parts of ion-exchanged water, 30 parts of chloroform, and 15 parts of ethyl acetate were mixed and stirred at 23 ° C. for 8 hours. 25 parts of a 5% aqueous oxalic acid solution was added to the resulting mixed solution, and the mixture was stirred at 23 ° C. for 30 minutes, followed by separation to separate the organic layer. 25 parts of ion-exchanged water was added to the resulting organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, followed by separation to separate the organic layer. This water washing procedure was repeated five times. 30 parts of tert-butyl methyl ether was added to the resulting concentrated residue, and the mixture was stirred at 23 ° C. for 30 minutes. The supernatant was removed, and the mixture was concentrated to obtain 15.11 parts of the salt represented by formula (I-748). MASS(ESI(+)Spectrum):M + 525.0 MASS(ESI(-)Spectrum):M - 1240.7

[0224] Example 5: Synthesis of salt represented by formula (I-438) TIFF2023117395000162.tif38168 12.64 parts of the salt represented by formula (I-4-d), 4.28 parts of the salt represented by formula (I-438-e), 10 parts of ion-exchanged water, 30 parts of chloroform, and 15 parts of ethyl acetate were mixed and stirred at 23 ° C. for 8 hours. 25 parts of a 5% aqueous oxalic acid solution was added to the resulting mixed solution, and the mixture was stirred at 23 ° C. for 30 minutes, followed by separation to separate the organic layer. 25 parts of ion-exchanged water was added to the resulting organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, followed by separation to separate the organic layer. This water washing procedure was repeated five times. 30 parts of tert-butyl methyl ether was added to the resulting concentrated residue, and the mixture was stirred at 23 ° C. for 30 minutes. The supernatant was removed, and the mixture was concentrated to obtain 13.88 parts of the salt represented by formula (I-438). MASS(ESI(+)Spectrum):M + 317.1 MASS(ESI(-)Spectrum):M - 1240.7

[0225] Example 6: Synthesis of salt represented by formula (I-794) 5.92 parts of the salt represented by formula (I-50-a) and 20 parts of dimethylformamide were mixed and stirred at 23 ° C. for 30 minutes. 3.24 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 10.32 parts of the compound represented by formula (I-1-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 50 parts of chloroform and 20 parts of ion-exchanged water were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, after which the organic layer was separated and extracted. The resulting organic layer was concentrated to obtain 12.45 parts of the salt represented by formula (I-794-d). 7.94 parts of the salt represented by formula (I-794-d), 6.36 parts of the salt represented by formula (I-745-e), 10 parts of ion-exchanged water, 30 parts of chloroform, and 15 parts of ethyl acetate were mixed and stirred at 23°C for 8 hours. 15 parts of ion-exchanged water was added to the resulting mixed solution, and the mixture was stirred at 23°C for 30 minutes, followed by separation and extraction of the organic layer. This water washing procedure was repeated five times. 30 parts of tert-butyl methyl ether was added to the resulting concentrated residue, and the mixture was stirred at 23°C for 30 minutes. The supernatant was removed, and the mixture was concentrated to obtain 10.89 parts of the salt represented by formula (I-794). MASS(ESI(+)Spectrum):M + 525.0 MASS(ESI(-)Spectrum):M - 770.8

[0226] Example 7: Synthesis of salt represented by formula (I-805) TIFF2023117395000165.tif37135 4.48 parts of the salt represented by formula (I-1-a) and 20 parts of dimethylformamide were mixed and stirred at 23 ° C. for 30 minutes. 3.24 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 10.32 parts of the compound represented by formula (I-61-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 50 parts of chloroform and 20 parts of ion-exchanged water were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, after which the organic layer was separated and extracted. The resulting organic layer was concentrated to obtain 11.98 parts of the salt represented by formula (I-61-d). 7.22 parts of the salt represented by formula (I-61-d), 6.36 parts of the salt represented by formula (I-745-e), 10 parts of ion-exchanged water, 30 parts of chloroform, and 15 parts of ethyl acetate were mixed and stirred at 23°C for 8 hours. 15 parts of ion-exchanged water was added to the resulting mixed solution, and the mixture was stirred at 23°C for 30 minutes, followed by separation and extraction of the organic layer. This water washing procedure was repeated five times. 30 parts of tert-butyl methyl ether was added to the resulting concentrated residue, and the mixture was stirred at 23°C for 30 minutes. The supernatant was removed, and the mixture was concentrated to obtain 11.42 parts of the salt represented by formula (I-805). MASS(ESI(+)Spectrum):M + 525.0 MASS(ESI(-)Spectrum):M - 698.8

[0227] Example 8: Synthesis of salt represented by formula (I-1162) TIFF2023117395000167.tif43131 4.48 parts of the salt represented by formula (I-1-a) and 20 parts of dimethylformamide were mixed and stirred at 23 ° C. for 30 minutes. 3.24 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 10.02 parts of the compound represented by formula (I-64-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 50 parts of chloroform and 20 parts of ion-exchanged water were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, after which the organic layer was separated and extracted. The resulting organic layer was concentrated to obtain 11.22 parts of the salt represented by formula (I-64-d). 7.08 parts of the salt represented by formula (I-64-d), 6.36 parts of the salt represented by formula (I-745-e), 10 parts of ion-exchanged water, 30 parts of chloroform, and 15 parts of ethyl acetate were mixed and stirred at 23°C for 8 hours. 15 parts of ion-exchanged water was added to the resulting mixed solution, and the mixture was stirred at 23°C for 30 minutes, followed by separation and extraction of the organic layer. This water washing procedure was repeated five times. 30 parts of tert-butyl methyl ether was added to the resulting concentrated residue, and the mixture was stirred at 23°C for 30 minutes. The supernatant was removed, and the mixture was concentrated to obtain 10.91 parts of the salt represented by formula (I-1162). MASS(ESI(+)Spectrum):M + 525.0 MASS(ESI(-)Spectrum):M - 684.8

[0228] Example 9: Synthesis of salt represented by formula (I-1219) 5.92 parts of the salt represented by formula (I-50-a) and 20 parts of dimethylformamide were mixed and stirred at 23 ° C. for 30 minutes. 3.24 parts of the compound represented by formula (I-1-b) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 2 hours. 10.02 parts of the compound represented by formula (I-64-c) were added to the resulting mixed solution, and the mixture was further stirred at 50 ° C. for 3 hours, and then cooled to 23 ° C. 50 parts of chloroform and 20 parts of ion-exchanged water were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 30 minutes, after which the organic layer was separated and the organic layer was extracted. The resulting organic layer was concentrated to obtain 12.76 parts of the salt represented by formula (I-1219-d). 7.80 parts of the salt represented by formula (I-1219-d), 6.36 parts of the salt represented by formula (I-745-e), 10 parts of ion-exchanged water, 30 parts of chloroform, and 15 parts of ethyl acetate were mixed and stirred at 23°C for 8 hours. 15 parts of ion-exchanged water was added to the resulting mixed solution, and the mixture was stirred at 23°C for 30 minutes, followed by separation and extraction of the organic layer. This water washing procedure was repeated five times. 30 parts of tert-butyl methyl ether was added to the resulting concentrated residue, and the mixture was stirred at 23°C for 30 minutes. The supernatant was removed, and the mixture was concentrated to obtain 11.66 parts of the salt represented by formula (I-1219). MASS(ESI(+)Spectrum):M + 525.0 MASS(ESI(-)Spectrum):M - 756.8

[0229] Resin synthesis The compounds (monomers) used in the synthesis of resin (A) are shown below. Hereinafter, these compounds will be referred to as "monomer (a1-1-3)" etc. according to their formula numbers. TIFF2023117395000171.tif3775

[0230] Synthesis Example 1 [Synthesis of Resin A1] Monomers (a1-4-2), (a1-1-3), and (a1-2-6) were used and mixed in a molar ratio of 38:24:38 [monomer (a1-4-2):monomer (a1-1-3):monomer (a1-2-6)]. This monomer mixture was then mixed with 1.5 times the total mass of all monomers in methyl isobutyl ketone. Azobisisobutyronitrile was added as an initiator to the resulting mixture in an amount of 7 mol% based on the total moles of all monomers, and the mixture was heated at 85°C for approximately 5 hours to polymerize. Subsequently, a 2.0-fold increase in mass of aqueous p-toluenesulfonic acid solution (2.5 wt%) based on the total mass of all monomers was added to the polymerization reaction mixture, stirred for 6 hours, and then separated. The resulting organic layer was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and recovered, yielding a polymer with a weight-average molecular weight of approximately 5.3 x 10. 3 Resin A1 (copolymer) having the following structural units was obtained in a yield of 78%. TIFF2023117395000172.tif29117

[0231] Synthesis Example 2 [Synthesis of Resin A2] Monomer (a1-4-2) and monomer (a1-2-6) were used as monomers, and they were mixed in a molar ratio of 38:62 [monomer (a1-4-2):monomer (a1-2-6)]. This monomer mixture was then mixed with 1.5 times the total mass of all monomers in methyl isobutyl ketone. Azobisisobutyronitrile was added as an initiator to the resulting mixture in an amount of 7 mol% based on the total moles of all monomers, and the mixture was heated at 85°C for approximately 5 hours to polymerize. Subsequently, an aqueous solution of p-toluenesulfonic acid (2.5 wt%) was added to the polymerization reaction mixture in an amount of 2.0 times the total mass of all monomers in toluenesulfonic acid. The mixture was stirred for 6 hours and then separated. The resulting organic layer was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and recovered, yielding a polymer with a weight-average molecular weight of approximately 5.4 x 10. 3 Resin A2 (copolymer) having the following structural units was obtained in a yield of 89%. TIFF2023117395000173.tif2888

[0232] <Preparation of Resist Composition> As shown in Table 2, the following components were mixed and the resulting mixture was filtered through a fluororesin filter with a pore size of 0.2 μm to prepare a resist composition. [Table 2]

[0233] <Resin> A1, A2: Resin A1, Resin A2 <Salt (I)> I-1: A salt represented by formula (I-1) I-4: Salt represented by formula (I-4) I-438: A salt represented by the formula (I-438) I-745: A salt represented by the formula (I-745) I-748: A salt represented by the formula (I-748) I-794: A salt represented by the formula (I-794) I-805: A salt represented by the formula (I-805) I-1162: A salt represented by the formula (I-1162) I-1219: A salt represented by the formula (I-1219) <Acid generator> IX-1: Synthesis method described in JP-A-2004-203858 IX-2: Synthesis method described in JP-A-09-244234 IX-3: Synthesis method described in JP 2018-155908 A IX-4: Synthesis method described in JP 2018-159744 A TIFF2023117395000175.tif65159<Quencher (C)> C1: Synthesized by the method described in JP 2011-39502 A TIFF2023117395000176.tif3646<solvent> Propylene glycol monomethyl ether acetate 400 parts 100 parts of propylene glycol monomethyl ether 5 parts of γ-butyrolactone

[0234] (Electron beam exposure evaluation of resist composition) A 6-inch silicon wafer was treated on a direct hot plate with hexamethyldisilazane at 90 °C for 60 seconds. The resist composition was spin-coated on this silicon wafer so that the film thickness of the composition layer was 0.04 μm. Then, it was pre-baked for 60 seconds at the temperature shown in the "PB" column of Table 2 on a direct hot plate to form a composition layer. A contact hole pattern (hole pitch 40 nm / hole diameter 17 nm) was directly drawn on the composition layer formed on the wafer using an electron beam lithography machine ["ELS-F125 125 keV" manufactured by Elionix Co., Ltd.] while changing the exposure dose step by step. After exposure, post-exposure baking was performed for 60 seconds at the temperature shown in the "PEB" column of Table 2 on a hot plate, and further paddle development was performed for 60 seconds with a 2.38 mass% aqueous solution of tetramethylammonium hydroxide to obtain a resist pattern.

[0235] In the resist pattern obtained after development, the exposure dose at which the formed hole diameter became 17 nm was defined as the effective sensitivity.

[0236] <CD uniformity (CDU) evaluation> In the effective sensitivity, the hole diameter of the pattern formed with a hole diameter of 17 nm was measured 24 times for each hole, and the average value was defined as the average hole diameter of one hole. The standard deviation was obtained using, as the population, the average hole diameters of the patterns formed with a hole diameter of 17 nm measured at 400 locations within the same wafer. The results are shown in Table 3. The numerical values in the table indicate the standard deviation (nm).

Table 3

Industrial applicability

[0237] A resist composition containing the salt of the present invention is capable of obtaining a resist pattern with good CD uniformity (CDU), and is therefore suitable for semiconductor microfabrication and extremely useful industrially.

Claims

1. An acid generator comprising a salt represented by formula (I): [In formula (I), m1 represents an integer of 1 to 5, and when m1 is 2 or more, the groups in the parentheses may be the same or different. X 1 represents *-CO-O-, *-O-CO-, *-O-CO-O- or *-O-, and * represents the bonding site to the benzene ring. L １ represents a single bond or a hydrocarbon group having 1 to 36 carbon atoms which may have a substituent, and —CH 2 - is -O-, -S-, -CO- or -SO ２ It may be replaced with -. Ar represents an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent. R １ is -O-R １０ , —O—CO—R １０ , -O-CO-OR １０ or -OL １０ -CO-O-R １０ Represents. L １０ represents an alkanediyl group having 1 to 6 carbon atoms. R １０ represents a base labile group. R ２ represents a halogen atom, a haloalkyl group having 1 to 12 carbon atoms, or a hydrocarbon group having 1 to 18 carbon atoms, and the hydrocarbon group may have a substituent, and the —CH 2 - represents -O-, -CO-, -S- or -SO ２ It may be replaced with -. m2 represents an integer of 0 to 4, and when m2 is 2 or more, a plurality of R ２ may be the same or different, provided that 1≦m1+m2≦5 is satisfied. Z + represents an organic cation.

2. X 1 2. The acid generator according to claim 1, wherein *-CO-O- or *-O-CO-O-.

3. L １ is a single bond or an alkanediyl group having 1 to 6 carbon atoms (the —CH 2 2. The acid generator according to claim 1, wherein - may be replaced by -O- or -CO-.

4. L １ 2. The acid generator according to claim 1, wherein is a single bond or a methylene group.

5. R １ But -O-CO-OR １０ or -OL １０ -CO-O-R １０ 2. The acid generator according to claim 1, wherein

6. R １０ 2. The acid generator according to claim 1, wherein the base labile group is a group represented by formula (1b): [In formula (1b), R ｂａ１ and R ｂａ２ each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 6 carbon atoms and a fluorine atom. R ｂａ３ represents a fluorine atom or an alkyl group having 1 to 6 carbon atoms and a fluorine atom. * indicates a binding site.]

7. 2. The acid generator according to claim 1, wherein m1 is an integer of 1 to 3.

8. 2. The acid generator according to claim 1, wherein the salt represented by formula (I) is a salt represented by formula (IA): [In formula (IA), X １ , L １ , R １ , R ２ , m1, m2 and Z ＋ represents the same as in formula (I). R ３ represents a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, a haloalkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group combining these, and —CH contained in the alkyl group, the haloalkyl group, the alicyclic hydrocarbon group, or the combined group ２ - is -O-, -S-, -CO- or -SO ２ It may be replaced with -. m3 represents an integer of 0 to 6. m4 represents 0 or 1.

9. m3 is an integer of 1 to 4, R ３ is a fluorine atom, an iodine atom, an alkyl group having 1 to 6 carbon atoms, or a haloalkyl group having 1 to 6 carbon atoms (the —CH ２ - is -O-, -S-, -CO- or -SO ２ 9. The acid generator according to claim 8, wherein:

10. A resist composition comprising the acid generator according to any one of claims 1 to 9.

11. The composition contains a resin including a structural unit having an acid labile group, 11. The resist composition according to claim 10, wherein the structural unit having an acid labile group comprises 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), and a structural unit represented by formula (a1-2): [In formula (a1-0), formula (a1-1) and formula (a1-2), L a01 , L ａ１ and L ａ２ are each independently —O— or *—O—(CH ２ ) ｋ１ represents —CO—O—, k1 represents an integer of 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. R ａ６ and R ａ７ each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these. m1′ represents an integer of 0 to 14. n1 represents an integer of 0 to 10. n1′ represents an integer of 0 to 3.

12. 11. The resist composition according to claim 10, comprising a resin containing a structural unit represented by formula (a2-A): [In formula (a2-A), R a50 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a51 represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A a50 is a single bond or *-X a51 - (A a52 -X a52 ) nｂ -, * represents -R a50 represents the bonding site with the carbon atom to which it is bonded. A a52 represents an alkanediyl group having 1 to 6 carbon atoms. X a51 and X a52 each independently represents —O—, —CO—O—, or —O—CO—. nb represents 0 or 1. mb represents an integer of 0 to 4. When mb is an integer of 2 or more, a plurality of R a51 may be the same or different.]

13. 11. The resist composition according to claim 10, further comprising a salt that generates an acid that is weaker in acidity than the acid generated from the acid generator.

14. (1) a step of applying the resist composition according to claim 10 onto a substrate; (2) a step of drying the applied composition to form a composition layer; (3) exposing the composition layer to light; (4) a step of heating the composition layer after exposure; and (5) developing the composition layer after heating; A method for producing a resist pattern comprising:

15. A salt represented by formula (I): [In formula (I), m1 represents an integer of 1 to 5, and when m1 is 2 or more, the groups in the parentheses may be the same or different. X 1 represents *-CO-O-, *-O-CO-, *-O-CO-O- or *-O-, and * represents the bonding site to the benzene ring. L １ represents a single bond or a hydrocarbon group having 1 to 36 carbon atoms which may have a substituent, and —CH 2 - is -O-, -S-, -CO- or -SO ２ It may be replaced with -. Ar represents an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent. R １ is -O-R １０ , —O—CO—R １０ , -O-CO-OR １０ or -OL １０ -CO-O-R １０ Represents. L １０ represents an alkanediyl group having 1 to 6 carbon atoms. R １０ represents a base labile group. R ２ represents a halogen atom, a haloalkyl group having 1 to 12 carbon atoms, or a hydrocarbon group having 1 to 18 carbon atoms, and the hydrocarbon group may have a substituent, and the —CH 2 - represents -O-, -CO-, -S- or -SO ２ It may be replaced with -. m2 represents an integer of 0 to 4, and when m2 is 2 or more, a plurality of R ２ may be the same or different, provided that 1≦m1+m2≦5 is satisfied. Z + represents an organic cation.

16. X 1 The salt according to claim 15, wherein *-CO-O- or *-O-CO-O-.

17. L １ is a single bond or an alkanediyl group having 1 to 6 carbon atoms (the —CH 2 The salt according to claim 15 or 16, wherein - may be replaced by -O- or -CO-.

18. L １ The salt according to claim 15 or 16, wherein is a single bond or a methylene group.

19. R １ But -O-CO-OR １０ or -OL １０ -CO-O-R １０ 17. The salt according to claim 15 or 16, wherein

20. R １０ 17. The salt according to claim 15 or 16, wherein the base labile group is a group represented by formula (1b): [In formula (1b), R ｂａ１ and R ｂａ２ each independently represents a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 6 carbon atoms and a fluorine atom. R ｂａ３ represents a fluorine atom or an alkyl group having 1 to 6 carbon atoms and a fluorine atom. * indicates a binding site.]

21. The salt according to claim 15 or 16, wherein m1 is an integer of 1 to 3.

22. The salt according to claim 15 or 16, wherein the salt represented by formula (I) is a salt represented by formula (IA): [In formula (IA), X １ , L １ , R １ , R ２ , m1, m2 and Z ＋ represents the same as in formula (I). R ３ represents a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, a haloalkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group combining these, and —CH contained in the alkyl group, the haloalkyl group, the alicyclic hydrocarbon group, or the combined group ２ - is -O-, -S-, -CO- or -SO ２ It may be replaced with -. m3 represents an integer of 0 to 6. m4 represents 0 or 1.

23. m3 is an integer of 1 to 4, R ３ is a fluorine atom, an iodine atom, an alkyl group having 1 to 6 carbon atoms, or a haloalkyl group having 1 to 6 carbon atoms (the —CH ２ - is -O-, -S-, -CO- or -SO ２ 23. The salt according to claim 22, wherein:

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