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

Abstract

To provide an acid generator, a resist composition and the like which allow a resist pattern having good line edge roughness to be produced.SOLUTION: The acid generator contains a salt represented by formula (I), and the resist composition contains the acid generator. [In the formula, Q1, Q2, R1 and R2 each represent an H atom, an F atom or the like; z represents an integer of 0-6; X1 and X2 each represent -CO-O-, -O-CO- or the like; L1 and L2 each represent a single bond or a substituted / unsubstituted hydrocarbon group; W1 represents a cyclic hydrocarbon group; X represents a halogen atom or a haloalkyl group; R3 and R4 each represent a halogen atom, a haloalkyl group or the like; R5 represents a hydrogen atom or a group forming an acetal structure or the like; m3 and m4 represent integers of 0-3, m5 represents an integer of 0-4, and m6 represents 2 or 3; Z+ represents an organic cation; L10 represents a single bond or an alkanediyl group; Raa1 and Raa2 each represent an H atom or a hydrocarbon group; Xa represents a single bond, an O atom or the like; Raa3 represents a hydrocarbon group; and m51 and m52 each represent 0 or 1.]SELECTED DRAWING: None

Description

Technical Field

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

Background Art

[0002] Patent Document 1 describes a salt represented by the following formula and a composition containing the salt as an acid generator. TIFF2025088761000001.tif3166

[0003] Patent Document 2 describes a salt represented by the following formula and a composition containing the salt as an acid generator. TIFF2025088761000002.tif2678

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

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

Means for Solving the Problems

[0006] The present invention includes the following inventions. [1] An acid generator containing a salt represented by formula (I). TIFF2025088761000003.tif35156[In formula (I), Q1 , Q 2 , R 1 and R 2 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. z represents any integer from 0 to 6. When z is 2 or more, a plurality of R 1 and R 2 may be the same as or different from each other. X 1 represents *-CO-O-, *-O-CO-, *-O-CO-O- or *-O-, where * represents a bonding site with C(R 1 )(R 2 ) or C(Q 1 )(Q 2 ). L 1 and L 2 each independently represents a single bond or a hydrocarbon group having 1 to 28 carbon atoms which may have a substituent, and -CH 2 - contained in the hydrocarbon group may be replaced by -O-, -S-, -SO 2 - or -CO-. X 2 represents *-CO-O-, *-O-CO-, *-O-CO-O- or *-O-, where * represents a bonding site with the benzene ring to which L 1 is bonded. W 1 represents a cyclic hydrocarbon group having 3 to 18 carbon atoms, and -CH 2 - contained in the cyclic hydrocarbon group may be replaced by -O-, -CO-, -S- or -SO 2 -. X represents a halogen atom or a haloalkyl group having 1 to 12 carbon atoms. R 3 and R 4 each independently represents a halogen atom, a haloalkyl group having 1 to 12 carbon atoms, or a hydrocarbon group having 1 to 18 carbon atoms. The hydrocarbon group may have a substituent, and -CH 2 - contained in the haloalkyl group and the hydrocarbon group may be replaced by -O-, -CO-, -S- or -SO 2 -. R 5represents a hydrogen atom or a group represented by the formula (5a). m3 represents any integer from 0 to 3. When m3 is 2 or more, a plurality of Rs 3 may be the same as or different from each other. m4 represents any integer from 0 to 3. When m4 is 2 or more, a plurality of Rs 4 may be the same as or different from each other. m5 represents any integer from 0 to 4. When m5 is 2 or more, a plurality of Rs 5 may be the same as or different from each other. However, 1 ≦ m4 + m5 ≦ 4. m6 represents 2 or 3, and the groups within the plurality of parentheses may be the same as or different from each other. Z + represents an organic cation.] TIFF2025088761000004.tif26102[In the formula (5a), L 10 represents a single bond or an alkanediyl group having 1 to 6 carbon atoms. R aa1 and R aa2 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. X a represents a single bond, an oxygen atom, a sulfur atom, or a methylene group. R aa3 represents a hydrocarbon group having 1 to 20 carbon atoms, or R aa2 and R aa3 are bonded to each other and together with -C-(X a ) m52 - represent a group forming a ring having 3 to 20 carbon atoms. The -CH 2 - contained in the hydrocarbon group and the group forming the ring may be replaced by -O- or -S-, and the hydrocarbon group and the group forming the ring may have a substituent. m51 and m52 each independently represent 0 or 1. * represents the bonding site with the oxygen atom.] [2]When m6 is 2, the bonding site of X 2 to the benzene ring is L 1The acid generator described in [1] which is both in the m-position with respect to the bonding site. [3]X 1 is, *-CO-O- or *-O-CO- (where * is C(R 1 )(R 2 ) or C(Q 1 )(Q 2 ) and represents the bonding site with.), and L 1 is a single bond, an alkanediyl group having 1 to 8 carbon atoms (the -CH 2 - contained in the alkanediyl group may be replaced by -O- or -CO-.) or a group combining an alkanediyl group having 1 to 4 carbon atoms and an alicyclic hydrocarbon group having 5 to 12 carbon atoms (the -CH 2 - contained in the alkanediyl group and the alicyclic hydrocarbon group may be replaced by -O- or -CO-.), and X 2 is *-CO-O- or *-O-CO- (where * represents the bonding site with the benzene ring to which L 1 is bonded.) The acid generator described in [1] or [2]. [4]L 2 is a single bond or an alkanediyl group having 1 to 10 carbon atoms (the -CH 2 - contained in the alkanediyl group may be replaced by -O- or -CO-.) The acid generator described in any one of [1] to [3]. [5] The group represented by formula (5a) is the group represented by formula (5a-A). The acid generator described in any one of [1] to [4]. TIFF2025088761000005.tif2668 [In formula (5a-A), R aa1A and R aa2A each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms. X a represents a single bond, an oxygen atom, a sulfur atom or a methylene group. R aa3A represents a hydrocarbon group having 1 to 20 carbon atoms, or R aa2A and R aa3A are bonded to each other, -C-X a- together with, represents a group forming a ring having 3 to 20 carbon atoms. The -CH contained in the hydrocarbon group and the group forming the ring 2 - may be replaced by -O- or -S-, and the hydrocarbon group and the group forming the ring may have a substituent. * represents a bonding site with an oxygen atom.] [6] The acid generator according to any one of [1] to [4], wherein the group represented by formula (5a) is the group represented by formula (5a-B). TIFF2025088761000006.tif2585[In formula (5a-B), L 10 represents the same meaning as in formula (5a). R aa1B , R aa2B and R aa3B each independently represents a hydrocarbon group having 1 to 20 carbon atoms, or R aa2B and R aa3B are bonded to each other, and together with the carbon atom to which R aa2B and R aa3B are bonded, represents a group forming an alicyclic hydrocarbon group having 3 to 20 carbon atoms. The -CH contained in the hydrocarbon group and the alicyclic hydrocarbon group 2 - may be replaced by -O- or -S-, and the hydrocarbon group and the alicyclic hydrocarbon group may have a substituent. * represents a bonding site with an oxygen atom.] [7] A resist composition containing the acid generator according to any one of [1] to [6]. [8] A resin containing a structural unit having an acid-labile group, and the structural unit having an acid-labile group is at least one selected from the group consisting of a structural unit represented by formula (a1-0), a structural unit represented by formula (a1-1), a structural unit represented by formula (a1-2), a structural unit represented by formula (a1-4), a structural unit represented by formula (a1-5), and a structural unit represented by formula (a1-6). The resist composition according to [7]. TIFF2025088761000007.tif44144[In formula (a1-0), formula (a1-1) and formula (a1-2), La01 、L a1 and L a2 each independently represents -O- or *-O-(CH 2 ) k1 -CO-O-, k1 represents an integer from 1 to 7, and * represents the bonding site with -CO-. R a01 、R a4 and R a5 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a02 、R a03 and R a04 each independently represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these, and the alkyl group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group may have a halogen atom. R a6 and R a7 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these, and the alkyl group, the alkenyl group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group may have a halogen atom. m1’ represents an integer from 0 to 14. n1 represents an integer from 0 to 10. n1’ represents an integer from 0 to 3. TIFF2025088761000008.tif31119[In formula (a1-4), R a1 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a17represents a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group. A a11 represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and the -CH 2 - in the alkanediyl group may be replaced by -O-, -CO- or -NR a18 -. R a18 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X a1 represents a single bond or a carbonyl group. R a34 and R a35 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R a36 represents a hydrocarbon group having 1 to 20 carbon atoms, or R a35 and R a36 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms together with the -C-O- to which they are bonded, and the -CH 2 - in the hydrocarbon group and the divalent hydrocarbon group may be replaced by -O- or -S-. na1 represents any integer from 1 to 5. When na1 is 2 or more, the groups in the plurality of parentheses may be the same as or different from each other. na11 represents any integer from 0 to 4. When na11 is 2 or more, the plurality of R a17 may be the same as or different from each other. mc represents any integer from 0 to 2. TIFF2025088761000009.tif4558[In formula (a1-5), R a8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom. Z a1 represents a single bond or *-(CH2 ) h3 -CO-L 54 represents -, h3 represents an integer from 1 to 4, and * represents the bonding site with L 51 . L 51 , L 52 , L 53 and L 54 each independently represents -O- or -S-. s1 represents an integer from 1 to 3. s1’ represents an integer from 0 to 3.] TIFF2025088761000010.tif3479[In formula (a1-6), R a61 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a62 , R a63 and R a64 each independently represents an alkyl group having 1 to 6 carbon atoms or a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, or R a62 and R a63 are bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded. X a61 represents a single bond, -CO-O-*, or -CO-NR a65 -*, where * represents the bonding site with Ar, and R a65 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X a62 represents a single bond, *-O-L a61 - or *-CO-O-L a62 -, where * represents the bonding site with Ar, and L a61 and L a62 each independently represents an alkanediyl group having 1 to 4 carbon atoms. Ar represents an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent.] [9] The resist composition according to [7] or [8], containing a resin containing a structural unit represented by formula (a2-A). TIFF2025088761000011.tif30128[In formula (a2-A), R a2 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a27 represents a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A a21 represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and -CH 2 - included in the alkanediyl group may be replaced by -O-, -CO-, or -NR a28 -. R a28 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X a2 represents a single bond or a carbonyl group. nA2 represents any integer from 1 to 5, and when nA2 is 2 or more, the groups in a plurality of parentheses may be the same as or different from each other. na21 represents any integer from 0 to 4, and when na21 is 2 or more, a plurality of R a27 may be the same as or different from each other. mc represents any integer from 0 to 2. The resin containing a structural unit having an acid labile group further contains a structural unit having a lactone ring, and the resist composition according to [8] or [9], wherein the structural unit having a lactone ring contains at least one selected from the group consisting of a structural unit represented by formula (a3-1), a structural unit represented by formula (a3-2), a structural unit represented by formula (a3-3), and a structural unit represented by formula (a3-4). TIFF2025088761000012.tif51164[In formula (a3-1), formula (a3-2), formula (a3-3), and formula (a3-4), L a4 、L a5 and La6 is, independently of each other, -O- or *-O-(CH 2 ) k3 -CO-O-(where k3 represents an integer from 1 to 7). L a7 is -O-, *-O-L a8 -O-, *-O-L a8 -CO-O-, *-O-L a8 -CO-O-L a9 -CO-O- or *-O-L a8 -O-CO-L a9 -O-. L a8 and L a9 each independently represent an alkanediyl group having 1 to 6 carbon atoms. * represents the bonding site with the carbonyl group. R a18 , R a19 , R a20 and R a24 each independently represent a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. X a3 is -CH 2 - 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 represent a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms. p1 represents an integer from 0 to 5. q1 represents an integer from 0 to 3. r1 represents an integer from 0 to 3. w1 represents an integer from 0 to 8. When p1, q1, r1 and / or w1 are 2 or more, the plurality of R a21 , R a22 , R a23 and / or R a25 may be the same as or different from each other.]

[11] The resist composition according to any one of [7] to

[10] , further containing a salt that generates an acid having a lower acidity than the acid generated from the acid generator.

[12] (1) A step of applying the resist composition according to any one of [7] to

[11] on a substrate, (2) A step of drying the applied resist composition to form a composition layer, (3) A step of exposing the composition layer, (4) A step of heating the exposed composition layer, and (5) A step of developing the heated composition layer, A method for producing a resist pattern including the above steps.

[13] The salt represented by the above formula (I).

[14] m6 is 2, and the bonding site of X 2 to the benzene ring is both in the m-position with respect to the bonding site of L 1 The salt according to

[13] .

[15] X 1 is *-CO-O- or *-O-CO- (where * represents the bonding site to C(R 1 )(R 2 ) or C(Q 1 )(Q 2 ).), and L 1 is a single bond, an alkanediyl group having 1 to 8 carbon atoms (the -CH 2 - contained in the alkanediyl group may be replaced by -O- or -CO-), or a group combining an alkanediyl group having 1 to 4 carbon atoms and an alicyclic hydrocarbon group having 5 to 12 carbon atoms (the -CH 2 - contained in the alkanediyl group and the alicyclic hydrocarbon group may be replaced by -O- or -CO-), and X 2 is *-CO-O- or *-O-CO- (where * represents the bonding site to the benzene ring to which L 1 is bonded).) The salt according to

[13] or

[14] .

[16] L 2 is a single bond or an alkanediyl group having 1 to 10 carbon atoms (the -CH 2- may be replaced by -O- or -CO-. The salt described in any one of

[13] to

[15] ).

[17] The salt described in any one of

[13] to

[16] , wherein the group represented by formula (5a) is the group represented by the above-described formula (5a-A).

[18] The salt described in any one of

[13] to

[16] , wherein the group represented by formula (5a) is the group represented by the above-described formula (5a-B).

Advantages of the Invention

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

Modes for Carrying Out the Invention

[0008] In the present specification, the term “(meth)acrylic monomer” means “at least one of acrylic monomers and methacrylic monomers”. Expressions such as “(meth)acrylate” and “(meth)acrylic acid” also represent the same meaning. In the groups described in the present specification, those that can take both a linear structure and a branched structure may be either of them. -CH contained in a hydrocarbon group, etc. 2 - is -O-, -S-, -CO-, -SO- or -SO 2When it is replaced by -, the same examples shall be applied to each group, and the number of carbon atoms before replacement shall be defined as the number of carbon atoms of the hydrocarbon group or the like. The "combined group" means a group formed by bonding two or more of the exemplified groups, and the valences of these groups may be appropriately changed depending on the bonding form. "Derived from" or "derived" means that the polymerizable C=C bond contained in the molecule becomes a -C-C- group (single bond) by polymerization. When stereoisomers exist, all stereoisomers are included. The "acid-labile group" means a group having a leaving group, and when it comes into contact with an acid (e.g., trifluoromethanesulfonic acid, etc.), the leaving group leaves to form a hydrophilic group (e.g., hydroxy group or carboxy group, etc.). The "base-labile group" means a group having a leaving group, and when it comes into contact with a base (e.g., trimethylamine, etc.), the leaving group leaves to form a hydrophilic group (e.g., hydroxy group or carboxy group, etc.). Each group may have any position and number of hydrogen atoms contained in the group replaced by a bond depending on the number of substituents, etc. The number of carbon atoms in the substituent is not included in the number of carbon atoms of the group being substituted. In this specification, the "solid content of the resist composition" means the total of the components excluding the solvent (E) described later from the total amount of the resist composition.

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

[0010] 〔Anion (I)〕 In formula (I), Q 1 , Q 2 , R 1 and R 2Examples of the perfluoroalkyl group include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, etc. The number of carbon atoms in the perfluoroalkyl group is preferably 1 to 4, and more preferably 1 to 3. Q 1 , Q 2 , R 1 and R 2 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, etc. The number of carbon atoms in the alkyl group is preferably 1 to 4, and more preferably 1 to 3. Q 1 and Q 2 It is preferable that at least one of them contains a fluorine atom or a perfluoroalkyl group, it is more preferable that at least one of them is a fluorine atom or a perfluoroalkyl group, it is further preferable that they are each independently a trifluoromethyl group or a fluorine atom, and it is even more preferable that both are fluorine atoms. R 1 and R 2 are each independently preferably a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, more preferably a hydrogen atom or a fluorine atom, and further preferably a hydrogen atom. z is preferably an integer of 0 to 4, more preferably an integer of 0 to 3, even more preferably an integer of 0 to 2, and even more preferably 0 or 1. X 1 is preferably *-CO-O-, *-O-CO- or *-O-CO-O-, more preferably *-CO-O- or *-O-CO- (* is C(R 1 )(R 2 ) or C(Q 1 )(Q 2 ) represents the binding site.

[0011] L 1 and L 2 Examples of the hydrocarbon group in L and L include linear or branched chain hydrocarbon groups such as alkanediyl groups, monocyclic or polycyclic (including spiro rings, condensed rings, bridged rings, etc.) alicyclic hydrocarbon groups, and aromatic hydrocarbon groups. A group formed by combining two or more of these groups (for example, a hydrocarbon group formed from an alicyclic hydrocarbon group or an aromatic hydrocarbon group and a chain hydrocarbon group) may also be used. The chain hydrocarbon group and the alicyclic hydrocarbon group are also referred to as aliphatic hydrocarbon groups, and the alicyclic hydrocarbon group and the aromatic hydrocarbon group are also referred to as cyclic hydrocarbon groups. Examples of the alkanediyl group include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, and heptadecane-1,17-diyl group, and branched alkanediyl groups such as ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, and 2-methylbutane-1,4-diyl group. The terminal of the branched alkanediyl group may be an alkyl group such as a methyl group. The number of carbon atoms of the chain hydrocarbon group may be 1 to 24, preferably 1 to 18, more preferably 1 to 12, still more preferably 1 to 10, even more preferably 1 to 8, yet even more preferably 1 to 6, and still even more preferably 1 to 4. Examples of the monocyclic or polycyclic alicyclic hydrocarbon group include the following groups, etc. The bonding site can be at any position. TIFF2025088761000013.tif46168Specifically, examples of the alicyclic hydrocarbon group include monocyclic divalent alicyclic hydrocarbon groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group, and polycyclic divalent alicyclic hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, spirocyclohexane-1,2'-cyclopentane group, spiroadamantane-2,3'-cyclopentane group, and spiro rings having a cycloalkyl group, norbornyl group or adamantyl group each spiro-bonded thereto. The number of carbon atoms of the alicyclic hydrocarbon group may be 3 to 24, preferably 3 to 18, more preferably 3 to 16, and still more preferably 3 to 12. Examples of the aromatic hydrocarbon group include arylene groups such as phenylene group, naphthylene group, anthrylene group, biphenylene group, phenanthrylene group, and the like. The number of carbon atoms of the aromatic hydrocarbon group may be 6 to 24, preferably 6 to 18, more preferably 6 to 14, and still more preferably 6 to 10. Examples of the group formed by combining two or more types include a group formed by combining an alicyclic hydrocarbon group and an alkanediyl group, a group formed by combining an aromatic hydrocarbon group and an alkanediyl group, a group formed by combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group, and a group formed by combining an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and an alkanediyl group. In the combination, two or more types of alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and chain hydrocarbon groups may be combined respectively. Also, any group may be bonded to X 1 or X 2 . Examples of the group formed by combining an alicyclic hydrocarbon group and an alkanediyl group include, for example, -divalent alicyclic hydrocarbon group-alkanediyl group-, -alkanediyl group-divalent alicyclic hydrocarbon group-alkanediyl group-, -alkanediyl group-divalent alicyclic hydrocarbon group-, and the like. Examples of the group combining an aromatic hydrocarbon group and an alkanediyl group include - divalent aromatic hydrocarbon group - alkanediyl group -, - alkanediyl group - divalent aromatic hydrocarbon group - alkanediyl group -, - alkanediyl group - divalent aromatic hydrocarbon group -, etc. Examples of the group combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group include - aromatic hydrocarbon group - alicyclic hydrocarbon group -, - alicyclic hydrocarbon group - aromatic hydrocarbon group -, - alicyclic hydrocarbon group - aromatic hydrocarbon group - alicyclic hydrocarbon group -, etc. L 1 and L 2 The -CH 2 - in the hydrocarbon group having 1 to 28 carbon atoms of L 2 - may be replaced by -O-, -S-, -SO L 1 and L 2 When the -CH 2 - in the hydrocarbon group having 1 to 28 carbon atoms of L 2 - is replaced by -O-, -S-, -SO - or -CO-, the number of carbon atoms before replacement is regarded as the number of carbon atoms of the hydrocarbon group. 2 Examples of the group in which -CH 2 - in the hydrocarbon group is replaced by -O-, -S-, -SO 2 - or -CO- include a hydroxy group (a group in which -CH 2 -CH 2 - in the methyl group is replaced by -O-), a carboxy group (a group in which -CH 2 -CH 2 - in the ethyl group is replaced by -O-CO-), a thiol group (a group in which -CH 2 - in the methyl group is replaced by -S-), an oxy group (a group in which -CH 2 - in the methylene group is replaced by -O-), a carbonyl group (a group in which -CH 2 - in the methylene group is replaced by -CO-), a thio group (a group in which -CH 2-replaced group), an alkoxy group (any position in the alkyl group where -CH 2 - is replaced by -O-), an alkylthio group (any position in the alkyl group where -CH 2 - is replaced by -S-), an alkylsulfonyl group (any position in the alkyl group where -CH 2 - is replaced by -SO 2 -), an alkoxycarbonyl group (any position in the alkyl group where -CH 2 -CH 2 - is replaced by -O-CO-), an alkylcarbonyl group (any position in the alkyl group where -CH 2 - is replaced by -CO-), an alkylcarbonyloxy group (any position in the alkyl group where -CH 2 -CH 2 - is replaced by -CO-O-), an alkoxycarbonyloxy group (any position in the alkyl group where -CH 2 -CH 2 -CH 2 - is replaced by -O-CO-O-), an alkanediyl-oxy group (any position in the alkanediyl group where -CH 2 - is replaced by -O-), an alkanediyl-oxycarbonyl group (any position in the alkanediyl group where -CH 2 -CH 2 - is replaced by -O-CO-), an alkanediyl-carbonyl group (any position in the alkanediyl group where -CH 2 - is replaced by -CO-), an alkanediyl-carbonyloxy group (any position in the alkanediyl group where -CH 2 -CH 2 - is replaced by -CO-O-), an alkanediyl-sulfonyl group (any position in the alkanediyl group where -CH 2 - is replaced by -SO 2 -), an alkanediyl-thio group (any position in the alkanediyl group where -CH 2 - is replaced by -S-), a thio group (-CH contained in the methylene group 2- is a group replaced by -S-), a sulfonyl group (a -CH contained in the methylene group) 2 - is replaced by -SO 2 -), a cycloalkoxy group, a cycloalkylalkoxy group, an alkoxycarbonyloxy group, an aromatic hydrocarbon group - carbonyloxy group, an aromatic hydrocarbon group - carbonyl group, an aromatic hydrocarbon group - oxy group, a haloalkoxy group (any -CH at any position contained in the haloalkyl group) 2 - is a group replaced by -O-), a haloalkoxycarbonyl group (any -CH at any position contained in the haloalkyl group) 2 -CH 2 - is a group replaced by -O-CO-), a haloalkylcarbonyl group (any -CH at any position contained in the haloalkyl group) 2 - is a group replaced by -CO-), a haloalkylcarbonyloxy group (any -CH at any position contained in the haloalkyl group) 2 -CH 2 - is a group replaced by -CO-O-), and groups formed by combining two or more of these groups, etc. can be mentioned. Examples of the alkoxy group include alkoxy groups having 1 to 27 carbon atoms, such as methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, 2 - ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group, etc. The number of carbon atoms of the alkoxy group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkylthio group include alkylthio groups having 1 to 27 carbon atoms, such as methylthio group, ethylthio group, propylthio group, butylthio group, pentylthio group, hexylthio group, octylthio group, 2 - ethylhexylthio group, nonylthio group, decylthio group, undecylthio group, etc. The number of carbon atoms of the alkylthio group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 27 carbon atoms, such as methoxycarbonyl group, ethoxycarbonyl group, butoxycarbonyl group and the like. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 28 carbon atoms, such as acetyl group, propionyl group and butyryl group and the like. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 27 carbon atoms, such as acetyloxy group, propionyloxy group, butyryloxy group and the like. Examples of the alkoxycarbonyloxy group include alkoxycarbonyloxy groups having 2 to 26 carbon atoms, such as butoxycarbonyloxy group and the like. The number of carbon atoms of the alkoxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkoxycarbonyloxy group is preferably 2 to 10, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. Examples of the alkylsulfonyl group include alkylsulfonyl groups having 1 to 27 carbon atoms, such as methylsulfonyl group, ethylsulfonyl group, propylsulfonyl group, butylsulfonyl group, pentylsulfonyl group, hexylsulfonyl group, octylsulfonyl group, 2-ethylhexylsulfonyl group, nonylsulfonyl group, decylsulfonyl group, undecylsulfonyl group and the like. The number of carbon atoms of the alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediyl-oxy group include alkanediyl-oxy groups having 1 to 27 carbon atoms, such as a methylene-oxy group, an ethylene-oxy group, a propanediyl-oxy group, a butanediyl-oxy group, and a pentanediyl-oxy group. The number of carbon atoms in the alkanediyl-oxy group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediyl-oxycarbonyl group include alkanediyl-oxycarbonyl groups having 2 to 27 carbon atoms, such as a methylene-oxycarbonyl group, an ethylene-oxycarbonyl group, a propanediyl-oxycarbonyl group, and a butanediyl-oxycarbonyl group. Examples of the alkanediyl-carbonyl group include alkanediyl-carbonyl groups having 2 to 28 carbon atoms, such as a methylene-carbonyl group, an ethylene-carbonyl group, a propanediyl-carbonyl group, a butanediyl-carbonyl group, and a pentanediyl-carbonyl group. Examples of the alkanediyl-carbonyloxy group include alkanediyl-carbonyloxy groups having 2 to 27 carbon atoms, such as a methylene-carbonyloxy group, an ethylene-carbonyloxy group, a propanediyl-carbonyloxy group, and a butanediyl-carbonyloxy group. The number of carbon atoms in the alkanediyl-oxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkanediyl-carbonyl group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkanediyl-carbonyloxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. Examples of the alkanediyl-sulfonyl group include alkanediyl-sulfonyl groups having 1 to 27 carbon atoms, such as a methylene-sulfonyl group, an ethylene-sulfonyl group, and a propylene-sulfonyl group. The number of carbon atoms in the alkanediyl-sulfonyl group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediylthio group include alkanediylthio groups having 1 to 27 carbon atoms, such as methylene thio group, ethylene thio group, and propylene thio group. The number of carbon atoms of the alkanediylthio group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the cycloalkoxy group include cycloalkoxy groups having 3 to 27 carbon atoms, such as cyclohexyloxy group. Examples of the cycloalkylalkoxy group include cycloalkylalkoxy groups having 4 to 27 carbon atoms, such as cyclohexylmethoxy group. Examples of the aromatic hydrocarbon group-carbonyl oxy group include aromatic hydrocarbon group-carbonyl oxy groups having 7 to 27 carbon atoms, such as benzoyloxy group. Examples of the aromatic hydrocarbon group-carbonyl group include aromatic hydrocarbon group-carbonyl groups having 7 to 28 carbon atoms, such as benzoyl group. Examples of the aromatic hydrocarbon group-oxy group include aromatic hydrocarbon group-oxy groups having 6 to 27 carbon atoms, such as phenyloxy group.

[0012] In addition, -CH 2 - contained in the alicyclic hydrocarbon group replaced by -O-, -S-, -CO- or -SO 2 - includes the following groups and the like. -O- or -CO- in the groups represented below may be replaced by -S- or -SO 2 - respectively. The bonding site can be at any position. TIFF2025088761000014.tif46168 -CH contained in the group combining the alicyclic hydrocarbon group and the aromatic hydrocarbon group 2 - replaced by -O-, -S-, -CO- or -SO 2 - also includes the following groups and the like. The bonding site can be at any position. TIFF2025088761000015.tif26164

[0013] L 1 and L 2Examples of the substituent that may be included are a halogen atom, a cyano group, a nitro group, etc. L 1 and L 2 When L and L are a group combining an alicyclic hydrocarbon group or an aromatic hydrocarbon group with a chain hydrocarbon group such as an alkyl group, the chain hydrocarbon group such as an alkyl group can be a substituent of the alicyclic hydrocarbon group or the aromatic hydrocarbon group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Also, L 1 and L 2 When the -CH contained in the chain hydrocarbon group such as an alkyl group contained in L and L 2 - is replaced by -O-, -CO-, -S- or -SO 2 -, L 1 and L 2 can substantially have substituents such as a hydroxy group, a carboxy group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, a thiol group, an alkylthio group, and an alkylsulfonyl group. L 1 and L 2 The substituent in L and L is preferably an alkyl group having 1 to 4 carbon atoms, a hydroxy group or a halogen atom, more preferably an alkyl group having 1 to 4 carbon atoms or a halogen atom, and even more preferably a methyl group or a fluorine atom.

[0014] L 1 Examples of L include a single bond, a chain hydrocarbon group having 1 to 12 carbon atoms which may have a substituent (the -CH contained in the chain hydrocarbon group 2 - may be replaced by -O- or -CO-), a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (the -CH contained in the cyclic hydrocarbon group 2 - may be replaced by -O-, -S-, -SO 2 - or -CO-), or a group combining a chain hydrocarbon group having 1 to 10 carbon atoms which may have a substituent and a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (the -CH contained in the chain hydrocarbon group 2- may be replaced by -O- or -CO-, and -CH contained in the cyclic hydrocarbon group 2 - may be replaced by -O-, -S-, -SO 2 - or -CO-. It is preferably (), a single bond, an alkanediyl group having 1 to 10 carbon atoms (-CH contained in the alkanediyl group 2 - may be replaced by -O- or -CO-. ) or a group combining an alkanediyl group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 3 to 12 carbon atoms (-CH contained in the alkanediyl group and the alicyclic hydrocarbon group 2 - may be replaced by -O- or -CO-. It is more preferably (), a single bond, an alkanediyl group having 1 to 8 carbon atoms (-CH contained in the alkanediyl group 2 - may be replaced by -O- or -CO-. ) or a group combining an alkanediyl group having 1 to 4 carbon atoms and an alicyclic hydrocarbon group having 5 to 12 carbon atoms (-CH contained in the alkanediyl group and the alicyclic hydrocarbon group 2 - may be replaced by -O- or -CO-. It is even more preferably (), a single bond, a methylene group, -adamantanediyl group -CO-O-, -adamantanediyl group -O-CO-O-, -CH 2 - adamantanediyl group -O-CO- 2 - adamantanediyl group -O-CO-O- or -norbornanelactonediyl group -CO-O-. It is even more preferably L 2 As, a single bond, a chain hydrocarbon group having 1 to 12 carbon atoms which may have a substituent (-CH contained in the chain hydrocarbon group 2 - may be replaced by -O- or -CO-. ), a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (-CH contained in the cyclic hydrocarbon group 2 - may be replaced by -O-, -S-, -SO 2 - or -CO-. ) or a group combining a chain hydrocarbon group having 1 to 10 carbon atoms which may have a substituent and a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (-CH contained in the chain hydrocarbon group 2- may be replaced by -O- or -CO-, and -CH contained in the cyclic hydrocarbon group 2 - may be replaced by -O-, -S-, -SO 2 - or -CO-. It is preferably (), a single bond, an alkanediyl group having 1 to 10 carbon atoms (-CH contained in the alkanediyl group 2 - may be replaced by -O- or -CO-.), or a group combining an alkanediyl group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 3 to 12 carbon atoms (-CH contained in the alkanediyl group and the alicyclic hydrocarbon group 2 - may be replaced by -O- or -CO-. It is more preferably (), a single bond or an alkanediyl group having 1 to 8 carbon atoms (-CH contained in the alkanediyl group 2 - may be replaced by -O- or -CO-. It is even more preferably (), a single bond or a methylene group is even more preferably.

[0015] X 2 is preferably *-CO-O- or *-O-CO- (* represents the bonding site with the benzene ring to which L 1 is bonded.). It is more preferably *-CO-O- (* represents the bonding site with the benzene ring to which L 1 is bonded.). X 2 The bonding site of to the benzene ring is L 1 It may be any of the o-position, m-position, and p-position with respect to the bonding site of, but is preferably the o-position or m-position.

[0016] W 1 The cyclic hydrocarbon group in may be monocyclic or polycyclic (including spiro rings, condensed rings, bridged rings, etc.), and may be saturated or unsaturated. Examples of the cyclic hydrocarbon group include alicyclic hydrocarbon groups and aromatic hydrocarbon groups. For example, cyclic hydrocarbon groups such as monocyclic or polycyclic alicyclic hydrocarbon groups having 3 to 18 carbon atoms and aromatic hydrocarbon groups having 6 to 18 carbon atoms, and groups combining these are included. The alicyclic hydrocarbon group may be either monocyclic or polycyclic (including spiro rings, fused rings, bridged rings, etc.), and may be either saturated or unsaturated. Examples of the alicyclic hydrocarbon group include groups derived from monocyclic cycloalkane rings such as cyclopropane ring, cyclobutane ring, cyclopentane ring, cyclohexane ring, cyclooctane ring, cyclononane ring, cyclodecane ring, cyclododecane ring, etc., and groups derived from polycyclic cycloalkane rings such as norbornane ring, adamantane ring, etc. Specific examples of the alicyclic hydrocarbon group include the following groups, etc. The bonding site can be at any position. TIFF2025088761000016.tif48167 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. Examples of the aromatic hydrocarbon group include groups derived from aromatic rings such as benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, etc. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 14, more preferably 6 to 10.

[0017] Examples of the combined group include a group formed by combining an alicyclic hydrocarbon group with an alicyclic hydrocarbon group, and a group formed by combining an alicyclic hydrocarbon group with an aromatic hydrocarbon group. For example, the following groups, etc. are included. In the combination, two or more alicyclic hydrocarbon groups and two or more aromatic hydrocarbon groups may be combined respectively. Also, any of the groups may be bonded to L 2 . W 1 When it is a group formed by combining W 1 , the total number of carbon atoms in the cyclic hydrocarbon group in W TIFF2025088761000017.tif26144 -CH 2 - contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO 2 -. Examples of such replaced groups include the following groups and -O- of the following groups being replaced by -S-, -CO- being replaced by -SO 2-The groups replaced, etc. may be mentioned. The bonding site can be at any position. In TIFF2025088761000018.tif57167, -CH2- contained in the aromatic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-, and examples of such replaced groups include groups derived from a furan ring or a thiophene ring, etc., for example, the following groups, etc. may be mentioned. In TIFF2025088761000019.tif1326, -CH contained in the combined group 2 - may be replaced by -O-, -S-, -CO- or -SO 2 - and examples of such replaced groups include, for example, the following groups, etc. In TIFF2025088761000020.tif27164

[0018] W 1 A cyclic hydrocarbon group having 3 to 18 carbon atoms represented by (in the cyclic hydrocarbon group, -CH 2 - may be replaced by -O-, -S-, -CO- or -SO 2 -. ) includes An alicyclic hydrocarbon group having 3 to 18 carbon atoms (in the alicyclic hydrocarbon group, -CH 2 - may be replaced by -O-, -S-, -CO- or -SO 2 -. ) or an aromatic hydrocarbon group having 6 to 18 carbon atoms is preferable, An alicyclic hydrocarbon group having 3 to 12 carbon atoms (in the alicyclic hydrocarbon group, -CH 2 - may be replaced by -O- or -CO-. ) or an aromatic hydrocarbon group having 6 to 14 carbon atoms is more preferable, It is more preferable that it is a group derived from a benzene ring, a naphthalene ring, a cyclohexane ring or an adamantane ring. It is also preferable that the cyclic hydrocarbon group is a group represented by any one of formula (w1-1) to formula (w1-33). In TIFF2025088761000021.tif66167 [In formula (w1-1) to formula (w1-33), -CH contained in the group2 - may be replaced by -O-, -S-, -CO- or -SO 2 - and the bonding site may be at any position.]

[0019] X, R 3 and R 4 Examples of the halogen atoms of X, R and R include fluorine atom, chlorine atom, bromine atom and iodine atom, etc. X, R 3 and R 4 The haloalkyl group having 1 to 12 carbon atoms of X, R and R represents an alkyl group having 1 to 12 carbon atoms with a halogen atom, and examples include alkyl fluoride groups having 1 to 12 carbon atoms, alkyl chloride groups having 1 to 12 carbon atoms, alkyl bromide groups having 1 to 12 carbon atoms, alkyl iodide groups having 1 to 12 carbon atoms, etc. Examples of the haloalkyl group include perfluoroalkyl groups having 1 to 12 carbon atoms (such as trifluoromethyl group, pentafluoroethyl group, heptafluoropropyl group, nonafluorobutyl group, etc.), 2,2,2-trifluoroethyl group, 3,3,3-trifluoropropyl group, 4,4,4-trifluorobutyl group, 3,3,4,4,4-pentafluorobutyl group, chloromethyl group, bromomethyl group, iodomethyl group, etc. The number of carbon atoms of the haloalkyl group is preferably 1 to 9, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. R 3 and R 4 Examples of the hydrocarbon group having 1 to 18 carbon atoms of R and R include chain hydrocarbon groups such as alkyl groups and alkanediyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups and groups formed by combining these. The alkyl group is a linear or branched alkyl group, and examples include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group and dodecyl group, etc. The alkanediyl group is a linear or branched alkanediyl group, including linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1,17-diyl group and branched alkanediyl groups such as ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group. The terminal of the branched alkanediyl group may be an alkyl group such as a methyl group. The number of carbon atoms of the chain hydrocarbon group is preferably 1 to 12, more preferably 1 to 9, still more preferably 1 to 6, even more preferably 1 to 4, and even more preferably 1 to 3. The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and examples include the groups represented below. The bonding site can be at any position. TIFF2025088761000022.tif46168Specifically, examples of the monocyclic alicyclic hydrocarbon group include monocyclic cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, cyclododecyl group and the like. Examples of the polycyclic alicyclic hydrocarbon group include cycloalkyl groups such as decahydronaphthyl group, adamantyl group, norbornyl group, spirocyclohexane-1,2'-cyclopentane group, spiroadamantane-2,3'-cyclopentane group, and polycyclic cycloalkyl groups such as spiro rings having a cycloalkyl group bonded thereto by spiro, respectively, with a norbornyl group or an adamantyl group. The number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 18, more preferably 3 to 16, and even more preferably 3 to 12. Examples of the aromatic hydrocarbon group include phenyl group, naphthyl group, biphenyl group, anthryl group, phenanthryl group, binaphthyl group and the like. The number of carbon atoms of the aromatic hydrocarbon group is preferably 6 to 18, more preferably 6 to 14, and even more preferably 6 to 10.

[0020] Examples of the group formed by combination include a group formed by combining an aromatic hydrocarbon group and a chain hydrocarbon group (for example, aromatic hydrocarbon group - alkanediyl group - *, alkyl group - aromatic hydrocarbon group - *, alkyl group - aromatic hydrocarbon group - alkanediyl group - *, -CH contained in the alkanediyl group and the alkyl group 2 - may be replaced by -O-, -CO-, -S- or -SO 2 -). Examples of the group formed by combining an alicyclic hydrocarbon group and a chain hydrocarbon group include alicyclic hydrocarbon group - alkanediyl group - *, alkyl group - alicyclic hydrocarbon group - *, alkyl group - alicyclic hydrocarbon group - alkanediyl group - *, -CH contained in the alicyclic hydrocarbon group, the alkanediyl group and the alkyl group 2 - may be replaced by -O-, -CO-, -S- or -SO 2- may be replaced by). A group combining an aromatic hydrocarbon group and an alicyclic hydrocarbon group (for example, aromatic hydrocarbon group - alicyclic hydrocarbon group - *, alicyclic hydrocarbon group - aromatic hydrocarbon group - *, -CH contained in the alicyclic hydrocarbon group 2 - is -O-, -CO-, -S- or -SO 2 - may be replaced by). * represents a bonding site. Examples of the aromatic hydrocarbon group - alkane diyl group - * include aralkyl groups such as benzyl group and phenethyl group. Examples of the alkyl group - aromatic hydrocarbon group - * include tolyl group, xylyl group, cumenyl group and the like. Examples of the alicyclic hydrocarbon group - alkane diyl group - * include cycloalkylalkyl groups such as cyclohexylmethyl group, cyclohexylethyl group, 1-(adamantan-1-yl)methyl group, 1-(adamantan-1-yl)-1-methylethyl group and the like. Examples of the alkyl group - alicyclic hydrocarbon group - * include cycloalkyl groups having an alkyl group such as methylcyclohexyl group, dimethylcyclohexyl group, 2-alkyladamantan-2-yl group and the like. Examples of the aromatic hydrocarbon group - alicyclic hydrocarbon group - * include phenylcyclohexyl group and the like. Examples of the alicyclic hydrocarbon group - aromatic hydrocarbon group - * include cyclohexylphenyl group and the like. In addition, in the combination, two or more of the alicyclic hydrocarbon group, aromatic hydrocarbon group and chain hydrocarbon group may be combined. Also, any group may be bonded to the benzene ring.

[0021] R 3 and R 4 In the haloalkyl group or hydrocarbon group represented by, -CH 2 - is -O-, -CO-, -S- or -SO 2 When it is replaced by -, the number of carbon atoms before replacement is taken as the total number of carbon atoms of the haloalkyl group or the hydrocarbon group. Also, the number may be one or two or more. -CH contained in the haloalkyl group and the hydrocarbon group2 - is a group replaced by -O-, -S-, -SO 2 - or -CO-, and examples of such groups include a hydroxy group (a -CH group contained in a methyl group 2 - replaced by -O-), a thiol group (a -CH group contained in a methyl group 2 - replaced by -S-), a carboxy group (a -CH group contained in an ethyl group 2 -CH 2 - replaced by -O-CO-), an alkoxy group (any -CH group at any position contained in an alkyl group 2 - replaced by -O-), an alkoxycarbonyl group (any -CH group at any position contained in an alkyl group 2 -CH 2 - replaced by -O-CO-), an alkylcarbonyl group (any -CH group at any position contained in an alkyl group 2 - replaced by -CO-), an alkylcarbonyloxy group (any -CH group at any position contained in an alkyl group 2 -CH 2 - replaced by -CO-O-), an alkoxycarbonyloxy group (any -CH group at any position contained in an alkyl group 2 -CH 2 -CH 2 - replaced by -O-CO-O-), an alkoxyalkoxy group (two -CH groups at any position contained in an alkyl group 2 - replaced by -O-), an alkylthio group (any -CH group at any position contained in an alkyl group 2 - replaced by -S-), an alkylsulfonyl group (any -CH group at any position contained in an alkyl group 2 - replaced by -SO 2 -), an oxy group (a -CH group contained in a methylene group 2 - replaced by -O-), a carbonyl group (a -CH group contained in a methylene group 2 - replaced by -CO-), a thio group (a -CH group contained in a methylene group 2 - replaced by -S-), a sulfonyl group (a -CH group contained in a methylene group 2 - replaced by -SO 2-replaced group), an alkanediyl oxy group (wherein any -CH in the alkanediyl group 2 -is replaced by -O-), an alkanediyl oxycarbonyl group (wherein any -CH in the alkanediyl group 2 -CH 2 -is replaced by -O-CO-), an alkanediyl carbonyl group (wherein any -CH in the alkanediyl group 2 -is replaced by -CO-), an alkanediyl carbonyl oxy group (wherein any -CH in the alkanediyl group 2 -CH 2 -is replaced by -CO-O-), an alkanediyl thio group (wherein any -CH in the alkanediyl group 2 -is replaced by -S-), an alkanediyl sulfonyl group (wherein any -CH in the alkanediyl group 2 -is replaced by -SO 2 -), a cycloalkoxy group, a cycloalkylalkoxy group, an aromatic hydrocarbon group-carbonyl oxy group, an aromatic hydrocarbon group-carbonyl group, an aromatic hydrocarbon group-oxy group, a haloalkoxy group (wherein any -CH in the haloalkyl group 2 -is replaced by -O-), a haloalkoxycarbonyl group (wherein any -CH in the haloalkyl group 2 -CH 2 -is replaced by -O-CO-), a haloalkylcarbonyl group (wherein any -CH in the haloalkyl group 2 -is replaced by -CO-), a haloalkylcarbonyl oxy group (wherein any -CH in the haloalkyl group 2 -CH 2 -is replaced by -CO-O-), and groups formed by combining two or more of these groups, etc. Examples of the alkoxy group include alkoxy groups having 1 to 17 carbon atoms, such as methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group and the like. The number of carbon atoms of the alkoxy group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 17 carbon atoms, such as methoxycarbonyl group, ethoxycarbonyl group, butoxycarbonyl group and the like. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 18 carbon atoms, such as acetyl group, propionyl group and butyryl group and the like. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 17 carbon atoms, such as acetyloxy group, propionyloxy group, butyryloxy group and the like. Examples of the alkoxycarbonyloxy group include alkoxycarbonyloxy groups having 2 to 16 carbon atoms, such as butoxycarbonyloxy group and the like. Examples of the alkoxyalkoxy group include alkoxyalkoxy groups having 2 to 16 carbon atoms, such as methoxymethoxy group, methoxyethoxy group, ethoxymethoxy group, ethoxyethoxy group and the like. The number of carbon atoms of the alkoxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkoxycarbonyloxy group is preferably 2 to 10, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkoxyalkoxy group is preferably 2 to 10, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. Examples of the alkylthio group include alkylthio groups having 1 to 17 carbon atoms, such as methylthio group, ethylthio group, propylthio group, butylthio group, pentylthio group, hexylthio group, octylthio group, 2-ethylhexylthio group, nonylthio group, decylthio group, undecylthio group and the like. The number of carbon atoms of the alkylthio group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkylsulfonyl group include alkylsulfonyl groups having 1 to 17 carbon atoms, such as methylsulfonyl group, ethylsulfonyl group, propylsulfonyl group, butylsulfonyl group, pentylsulfonyl group, hexylsulfonyl group, octylsulfonyl group, 2-ethylhexylsulfonyl group, nonylsulfonyl group, decylsulfonyl group, undecylsulfonyl group and the like. The number of carbon atoms of the alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanedioxy group include alkanedioxy groups having 1 to 17 carbon atoms, such as methyleneoxy group, ethyleneoxy group, propanedioloxy group, butanedioloxy group, pentanedioloxy group and the like. The number of carbon atoms of the alkanedioxy group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediyl-oxycarbonyl group include alkanediyl-oxycarbonyl groups having 2 to 17 carbon atoms, such as a methylene-oxycarbonyl group, an ethylene-oxycarbonyl group, a propanediyl-oxycarbonyl group, and a butanediyl-oxycarbonyl group. Examples of the alkanediyl-carbonyl group include alkanediyl-carbonyl groups having 2 to 18 carbon atoms, such as a methylene-carbonyl group, an ethylene-carbonyl group, a propanediyl-carbonyl group, a butanediyl-carbonyl group, and a pentanediyl-carbonyl group. Examples of the alkanediyl-carbonyl-oxy group include alkanediyl-carbonyl-oxy groups having 2 to 17 carbon atoms, such as a methylene-carbonyl-oxy group, an ethylene-carbonyl-oxy group, a propanediyl-carbonyl-oxy group, and a butanediyl-carbonyl-oxy group. The number of carbon atoms in the alkanediyl-oxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkanediyl-carbonyl group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkanediyl-carbonyl-oxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. Examples of the alkanediyl-thio group include alkanediyl-thio groups having 1 to 17 carbon atoms, such as a methylene-thio group, an ethylene-thio group, and a propylene-thio group. The number of carbon atoms in the alkanediyl-thio group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediyl-sulfonyl group include alkanediyl-sulfonyl groups having 1 to 17 carbon atoms, such as a methylene-sulfonyl group, an ethylene-sulfonyl group, and a propylene-sulfonyl group. The number of carbon atoms in the alkanediyl-sulfonyl group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the cycloalkoxy group include cycloalkoxy groups having 3 to 17 carbon atoms, such as a cyclohexyloxy group. Examples of the cycloalkylalkoxy group include cycloalkylalkoxy groups having 4 to 17 carbon atoms, such as a cyclohexylmethoxy group. Examples of the aromatic hydrocarbon group-carbonyl oxy group include aromatic hydrocarbon group-carbonyl oxy groups having 7 to 17 carbon atoms, such as a benzoyloxy group. Examples of the aromatic hydrocarbon group-carbonyl group include aromatic hydrocarbon group-carbonyl groups having 7 to 18 carbon atoms, such as a benzoyl group. Examples of the aromatic hydrocarbon group-oxy group include aromatic hydrocarbon group-oxy groups having 6 to 17 carbon atoms, such as a phenyloxy group. Examples of the haloalkoxy group, haloalkoxycarbonyl group, haloalkylcarbonyl group, and haloalkylcarbonyloxy group include haloalkoxy groups having 1 to 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. For example, groups in which one or more hydrogen atoms of the groups exemplified above are replaced with halogen atoms can be mentioned.

[0022] In addition, -CH 2 - in the alicyclic hydrocarbon group being replaced with -O-, -S-, -SO 2 - or -CO- include groups represented below. Among the groups represented below, groups in which -O- is replaced with -S- and -CO- is replaced with -SO 2 - respectively can also be mentioned. The bonding site can be at any position. TIFF2025088761000023.tif46168 -CH in the group combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group 2 - being replaced with -O-, -S-, -CO- or -SO 2 - include, within the range where the upper limit of the number of carbon atoms permits, the same groups as those exemplified in this specification.

[0023] R 3 and R 4Examples of the substituent that the hydrocarbon group may have include a halogen atom, a cyano group, a nitro group, etc. R 3 and R 4 When is a group combining an alicyclic hydrocarbon group or an aromatic hydrocarbon group with a chain hydrocarbon group such as an alkyl group, the chain hydrocarbon group such as an alkyl group can be a substituent of the alicyclic hydrocarbon group or the aromatic hydrocarbon group. Examples of the halogen atom include the same groups as those described above. Also, R 3 and R 4 When -CH 2 - contained in the chain hydrocarbon group such as an alkyl group contained in and is replaced by -O-, -CO-, -S- or -SO 2 -, R 3 and R 4 can substantially have substituents such as a hydroxy group, a carboxy group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, a thiol group, an alkylthio group, an alkylsulfonyl group, etc. The hydrocarbon group may have one substituent or a plurality of substituents. X is preferably a halogen atom or a haloalkyl group having 1 to 6 carbon atoms, more preferably an iodine atom, a fluorine atom or a fluoroalkyl group having 1 to 4 carbon atoms, and even more preferably an iodine atom, a fluorine atom or a trifluoromethyl group. R 3 is preferably a halogen atom, an alkyl group having 1 to 8 carbon atoms or a haloalkyl group having 1 to 8 carbon atoms (wherein -CH 2 - contained in the alkyl group or the haloalkyl group may be replaced by -O- or -CO-). More preferably, it is a halogen atom, an alkyl group having 1 to 6 carbon atoms (wherein -CH 2 - contained in the alkyl group may be replaced by -O- or -CO-) or a haloalkyl group having 1 to 6 carbon atoms, and even more preferably an iodine atom, a fluorine atom, a hydroxy group or a fluoroalkyl group having 1 to 4 carbon atoms. R 4is a halogen atom, an alkyl group having 1 to 8 carbon atoms, or a haloalkyl group having 1 to 8 carbon atoms (wherein -CH contained in the alkyl group or the haloalkyl group 2 - may be replaced by -O- or -CO-.), preferably a halogen atom, an alkyl group having 1 to 6 carbon atoms (wherein -CH contained in the alkyl group 2 - may be replaced by -O- or -CO-), or a haloalkyl group having 1 to 6 carbon atoms, more preferably an iodine atom, a fluorine atom, a hydroxy group, an alkoxy group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 4 carbon atoms, a carboxy group, or a fluoroalkyl group having 1 to 4 carbon atoms, even more preferably an iodine atom, a fluorine atom, a hydroxy group, a methoxy group, an ethoxy group, a carboxy group, or a perfluoroalkyl group having 1 to 3 carbon atoms. m3 is preferably any integer from 0 to 2, more preferably 0 or 1, and even more preferably 0. When m3 is an integer of 1 or more, the bonding site of R 3 to the benzene ring may be any of the o-position, m-position, and p-position with respect to L 1 . m4 is preferably any integer from 0 to 2, more preferably 0 or 1. When m4 is an integer of 1 or more, at least one of R 4 is preferably an iodine atom.

[0024] R 5 is a hydrogen atom or a group represented by the formula (5a). TIFF2025088761000024.tif26102 [In the formula (5a), all symbols have the same meanings as described above.]

[0025] R aa1 , R aa2 and R aa3 Examples of the hydrocarbon group include an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these. R aa1 、R aa2 and R aa3 Examples of the alkyl group of R aa1 、R aa2 and R aa3 include methyl group, ethyl group, propyl group, n-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group and the like. The number of carbon atoms of the alkyl group of R R aa1 、R aa2 and R aa3 Examples of the alkenyl group of R R aa1 、R aa2 and R aa3 include ethenyl group, propenyl group, isopropenyl group, butenyl group, isobutenyl group, tert-butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, isooctenyl group, nonenyl group. The alicyclic hydrocarbon group of R aa1 、R aa2 and R aa3 may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and the like. Examples of the polycyclic alicyclic hydrocarbon group include, for example, decahydronaphthyl group, adamantyl group, norbornyl group and the following group (* represents the bonding site). The number of carbon atoms of the alicyclic hydrocarbon group of R TIFF2025088761000025.tif9159R aa1 、R aa2 and R aa3 Examples of the aromatic hydrocarbon group of R aa1 、R aa2 and R aa3 include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, phenanthryl group and the like. The number of carbon atoms of the aromatic hydrocarbon group of R R aa1 、R aa2 and R aa3Among them, examples of the group formed by combining two or more groups include a group formed by combining the above-described alkyl group and alicyclic hydrocarbon group (for example, an alkylcycloalkyl group or cycloalkylalkyl group such as methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornil group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornylethyl group, etc.), an aralkyl group such as benzyl group, an aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), an aryl-cycloalkyl group such as phenylcyclohexyl group, and the like.

[0026] R aa2 and R aa3 When they are bonded to each other to form a ring together with the carbon atom etc. to which they are bonded, -C(R aa1 )(R aa2 )-(X a ) m52 -(R aa3 ) includes the following groups. The number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 16, more preferably 3 to 12. * represents the bonding site with the oxygen atom or L 10 . TIFF2025088761000026.tif33168R aa1 , R aa2 and R aa3 The hydrocarbon group contained in and R aa2 and R aa3 The substituents that the ring formed by bonding to each other may have include a hydroxy group, a thiol group, a halogen atom, a cyano group, a nitro group, and the like.

[0027] In formula (5a), specific examples of the partial structure of *-C(R aa1 )(R aa2 )-(X) m52 -R aa3 include the following groups. * is an oxygen atom or L 10It represents the binding site with TIFF2025088761000027.tif72164

[0028] L 10 Examples of the alkanediyl group include linear alkanediyl groups such as a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-1,6-diyl group. L 10 is preferably a single bond or an alkanediyl group having 1 to 3 carbon atoms, and more preferably a single bond, a methylene group, or an ethylene group. The group represented by formula (5a) is more preferably a group represented by formula (5a-A) or formula (5a-B). TIFF2025088761000028.tif2668 [In formula (5a-A), all symbols have the same meaning as defined above.] TIFF2025088761000029.tif2585 [In formula (5a-B), all symbols have the same meaning as defined above.] R aa1A , R aa1B , R aa2A , R aa2B , R aa3A , R aa3B As long as the upper limit of the carbon number allows, the group represented by R aa1 , R aa2 and R aa3 Examples of the groups include the same groups as those listed in 1.

[0029] m5 is preferably an integer of 0 to 3, more preferably 0, 1 or 2, further preferably 0 or 1, and even more preferably 1. -OR 5 The bonding position of, for example, W 1 is a group derived from a benzene ring, L on the benzene ring 2 The bonding position of W may be either o-position, m-position or p-position, but is preferably o-position or p-position. 1 When L is a group derived from a naphthalene ring, 2When it is bonded to the 1st or 2nd position, it is preferably any of the 3rd to 8th positions, more preferably any of the 3rd to 7th positions, and even more preferably any of the 3rd to 6th positions. Also, W 1 When 1 is a group derived from an adamantane ring, it may be either the 1st or 2nd position, but preferably the 1st position. The bonding position of X is, for example, when W 1 is a group derived from a benzene ring, it may be any of the ortho, meta, or para positions with respect to the bonding position of L in the benzene ring, but the ortho or meta position is preferred, and the meta position is more preferred. Also, W 2 When 2 is a group derived from a naphthalene ring, when L 1 is bonded to the 1st or 2nd position, it is preferably any of the 3rd to 8th positions, more preferably any of the 3rd to 7th positions, and even more preferably any of the 4th to 7th positions. Also, W 2 When 2 is a group derived from an adamantane ring, it may be either the 1st or 2nd position, but preferably the 1st position. 1 When 1 is a group derived from an adamantane ring, it may be either the 1st or 2nd position, but preferably the 1st position. R 4 The bonding position of R is, for example, when W 1 is a group derived from a benzene ring, it may be any of the ortho, meta, or para positions with respect to the bonding position of L in the benzene ring, but the ortho or meta position is preferred, and the meta position is more preferred. Also, W 1 When 1 is a group derived from a naphthalene ring, when L 1 is bonded to the 1st or 2nd position, it is preferably any of the 3rd to 8th positions, more preferably any of the 3rd to 7th positions, and even more preferably any of the 4th to 7th positions. Also, W 2 When 2 is a group derived from an adamantane ring, it may be either the 1st or 2nd position, but preferably the 1st position. 1 When 1 is a group derived from an adamantane ring, it may be either the 1st or 2nd position, but preferably the 1st position.

[0030] Examples of the anion (I) include anions represented by the following formulas (Ia-1) to (Ia-45). Among them, anions represented by formulas (Ia-1) to (Ia-8), formulas (Ia-17) to (Ia-30), and formulas (Ia-37) to (Ia-45) are preferred. TIFF2025088761000030.tif244160

[0031] TIFF2025088761000031.tif247160

[0032] TIFF2025088761000032.tif246158

[0033] TIFF2025088761000033.tif229156

[0034] 〔Cation (I)〕 Z in formula (I) + Examples of the organic cation include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, organic sulfonium cations and organic iodonium cations are preferred, and arylsulfonium cations are more preferred. Specifically, cations represented by any of formula (b2-1) to formula (b2-5) (hereinafter may be referred to as "cation (b2-1)" etc. according to the formula number) can be mentioned. TIFF2025088761000034.tif81160 [In formula (b2-1) to formula (b2-5), R b4 ~R b6 each independently represents 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, and the 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, and the hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, or a glycidyloxy group, and the hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. Rb4 and R b5 may combine with each other to form a ring together with the sulfur atom to which they are attached, and -CH 2 - in the ring may be replaced by -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 any one of 0 to 5. When m2 is 2 or more, a plurality of R b7 may be the same or different, and when n2 is 2 or more, a plurality of R b8 may be the same or different. R b9 and R b10 each independently represents a chain hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms. R b9 and R b10 may combine with each other to form a ring together with the sulfur atom to which they are attached, and -CH 2 - in the ring may be replaced by -O-, -S- or -CO-. R b11 represents a hydrogen atom, a chain hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms. R b12 represents a chain hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and a hydrogen atom contained in the chain hydrocarbon group may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and a hydrogen atom contained in the aromatic hydrocarbon group may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms. R b11 and R b12 may combine with each other to form a ring including -CH-CO- to which they are attached, and -CH 2- may be replaced by -O-, -S- or -CO-. R b13 ~R b18 and R b21 ~R b26 each independently represents a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms or an alkoxy group having 1 to 12 carbon atoms. R b13 and R b14 and R b21 and R b22 may be bonded to each other to form a ring containing a sulfur atom together with the benzene ring to which they are bonded, and -CH 2 - may be replaced by -O-, -S- or -CO-. R b27 ~R b29 each independently represents a hydrogen atom or a group containing an acid-labile group. L b31 and L b41 ~L b43 each independently represents a sulfur atom or an oxygen atom. o2, p2, s2, and t2 each independently represents an integer of 0 to 5. q2 and r2 each independently represents an integer of 0 to 4. u2 represents 0 or 1. When o2 is 2 or more, a plurality of R b13 are the same or different, when p2 is 2 or more, a plurality of R b14 are the same or different, when q2 is 2 or more, a plurality of R b15 are the same or different, when r2 is 2 or more, a plurality of R b16 are the same or different, when s2 is 2 or more, a plurality of R b17 are the same or different, when t2 is 2 or more, a plurality of R b18 are the same or different. u3 represents an integer of 1 to 3 and satisfies 1 ≦ u3 + q23 ≦ 5. u4 and u5 each independently represents an integer of 0 to 3 and satisfies 0 ≦ u4 + o21 ≦ 5 and 0 ≦ u5 + p22 ≦ 5. When u3, u4, and u5 are each 2 or more, the groups within the plurality of parentheses are each the same or different. o21, p22, q23, r24, t25, and s26 each independently represent an integer from 0 to 4. When o21, p22, q23, r24, t25, and s26 are each 2 or more, the plurality of R b21 ~R b26 are each the same or different. When u2 is 0, any one of o2, p2, q2, and r2 is 1 or more, and at least one of R b13 ~R b16 is preferably a halogen atom. When u2 is 1, any one of o2, p2, s2, t2, q2, and r2 is 1 or more, and at least one of R b13 ~R b18 is preferably a halogen atom. Furthermore, when u2 is 0, r2 is preferably 1 or more, more preferably 1. Also, when u2 is 0 and r2 is 1 or more, R b16 is preferably a halogen atom.

[0035] The aliphatic hydrocarbon group represents a chain hydrocarbon group and an alicyclic hydrocarbon group. Examples of the chain hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, and 2-ethylhexyl group. In particular, the chain hydrocarbon group of R b9 ~R b12 is preferably 1 to 12 carbon atoms. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups. TIFF2025088761000035.tif11157 In particular, R b9 ~R b12 The alicyclic hydrocarbon group of ~R preferably has 3 to 18 carbon atoms, more preferably 4 to 12 carbon atoms.

[0036] Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-methyladamantan-2-yl group, a 2-ethyladamantan-2-yl group, a 2-isopropyladamantan-2-yl group, a methylnorbornil group, an isobornyl group, etc. In the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group, the total number of carbon atoms of the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less.

[0037] The alkyl fluoride group represents an alkyl group having 1 to 12 carbon atoms and having a fluorine atom, and examples thereof include a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a perfluorobutyl group, etc. The number of carbon atoms of the alkyl fluoride group is preferably 1 to 9, more preferably 1 to 6, and even more preferably 1 to 4.

[0038] Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a biphenyl group, a naphthyl group, a phenanthryl group, etc. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and examples of the aromatic hydrocarbon group having a chain hydrocarbon group (a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a p-ethylphenyl group, a p-tert-butylphenyl group, a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, etc.) and the aromatic hydrocarbon group having an alicyclic hydrocarbon group (a p-cyclohexylphenyl group, a p-adamantylphenyl group, etc.) etc. are mentioned. When the aromatic hydrocarbon group has a chain hydrocarbon group or an alicyclic hydrocarbon group, a chain hydrocarbon group having 1 to 18 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms are preferred. Examples of the aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group include a p-methoxyphenyl group, etc. Examples of the chain hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include aralkyl groups such as benzyl group, phenethyl group, phenylpropyl group, trityl group, naphthylmethyl group, and naphthylethyl group.

[0039] Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group, and dodecyloxy group. Examples of the alkylcarbonyl group include acetyl group, propionyl group, and butyryl group. Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom, and iodine atom. Examples of the alkylcarbonyloxy group include methylcarbonyloxy group, ethylcarbonyloxy group, propylcarbonyloxy group, isopropylcarbonyloxy group, butylcarbonyloxy group, sec-butylcarbonyloxy group, tert-butylcarbonyloxy group, pentylcarbonyloxy group, hexylcarbonyloxy group, octylcarbonyloxy group, and 2-ethylhexylcarbonyloxy group.

[0040] R b4 and R b5 The ring formed by R TIFF2025088761000036.tif24142

[0041] R b9 and R b10The ring formed by combining may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring may be a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring. For example, a thiolan-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, a 1,4-oxathian-4-ium ring, etc. may be mentioned. R b11 and R b12 The ring formed by combining may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring may be a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring. Examples include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, an oxoadamantane ring, etc. R b27 ~R b29 Examples of the group containing an acid-labile group of include -R c30 , -CO-O-R c30 or -L c10 -CO-O-R c30 wherein L c10 represents an alkanediyl group having 1 to 6 carbon atoms, and R c30 represents an acid-labile group. etc. may be mentioned. R b27 ~R b29 Examples of the acid-labile group of include the group (1) or the group (2) described later, etc.

[0042] Among the cations (b2-1) to (b2-5), preferably, the cation (b2-1), the cation (b2-4) or the cation (b2-5). Examples of the cation (b2-1) include the following cations. TIFF2025088761000037.tif158165 Examples of the cation (b2-2) include the following cations. TIFF2025088761000038.tif14136 Examples of the cation (b2-3) include the following cations. TIFF2025088761000039.tif21130 Examples of the cation (b2-4) include the following cations. TIFF2025088761000040.tif121162 Examples of the cation (b2-5) include the following cations. TIFF2025088761000041.tif114159

[0043] Specific examples of the salt (I) include salts obtained by arbitrarily combining the above-mentioned cations and anions. Specific examples of the salt (I) are shown in the following table. In the following table, each symbol represents the symbol attached to the structure representing the above-mentioned anion or cation, and "~" indicates that each of the salt (I) and the anion (I) corresponds. For example, the salt (I-1) is a salt composed of the anion represented by the formula (Ia-1) and the cation represented by the formula (b2-c-1), the salt (I-2) is a salt composed of the anion represented by the formula (Ia-2) and the cation represented by the formula (b2-c-1), and the salt (I-41) is a salt composed of the anion represented by the formula (Ia-1) and the cation represented by the formula (b2-c-10). TIFF2025088761000042.tif5090 [Table 1] TIFF2025088761000044.tif229159

[0044] Among them, the salt (I) is preferably a salt obtained by combining an anion represented by any of the formulas (Ia-1) to (Ia-8), (Ia-17) to (Ia-30), and (Ia-37) to (Ia-45) and a cation represented by any of the formulas (b2-c-1) to (b2-c-79).

[0045] <Method for producing the salt (I)> In the salt (I), X 1 The salt in which is *-CO-O- (the salt represented by the formula (I1)) can be produced, for example, by reacting the salt represented by the formula (I1-a) with carbonyldiimidazole in a solvent and then further reacting with the compound represented by the formula (I1-b). TIFF2025088761000045.tif67158(wherein all the symbols have the same meanings as described above.) Examples of the solvent in this reaction include chloroform and acetonitrile. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours. Examples of the salt represented by formula (I1-a) include salts represented by the following formula, which can be easily obtained from the market and can also be easily produced by known production methods. TIFF2025088761000046.tif68159

[0046] The compound represented by formula (I1-b) can be produced, for example, by reacting the compound represented by formula (I1-c) with the compound represented by formula (I1-d) in a solvent in the presence of a catalyst. TIFF2025088761000047.tif61154(wherein all the symbols have the same meanings as described above. L 3 represents a group obtained by removing -O-L 2 - from L 4 L 4 represents a single bond, a carbonyl group or a methylene group.) Examples of the catalyst in this reaction include carbonyldiimidazole, dimethylaminopyridine, pyridine, and triethylamine. Examples of the solvent in this reaction include chloroform, acetonitrile, and dimethylformamide. Examples of the acid include hydrochloric acid and p-toluenesulfonic acid. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours.

[0047] Examples of the compound represented by formula (I1-c) include compounds represented below and can be easily obtained from the market. TIFF2025088761000048.tif2584Examples of the compound represented by formula (I1-d) include compounds represented by the following formula and can be easily obtained from the market. TIFF2025088761000049.tif42161

[0048] In salt (I), X 1 The salt in which *-O-CO- (the salt represented by formula (I2)) can be produced, for example, by reacting the compound represented by formula (I2-b) with carbonyldiimidazole in a solvent and then reacting with the salt represented by formula (I2-a). TIFF2025088761000050.tif64157 (wherein all the symbols have the same meanings as described above). Examples of the solvent in this reaction include chloroform and acetonitrile. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours. Examples of the salt represented by formula (I2-a) include salts represented by the following formula, which can be easily obtained from the market and can also be easily produced by known production methods. TIFF2025088761000051.tif75161

[0049] The compound represented by formula (I2-b) can be produced, for example, by reacting the compound represented by formula (I2-c) with the compound represented by formula (I1-d) in a solvent in the presence of a catalyst and then subjecting it to base treatment. TIFF2025088761000052.tif63153 (wherein all the symbols have the same meanings as described above. R a represents an acetal group.) Examples of the catalyst in this reaction include carbonyldiimidazole, triethylamine, pyridine, dimethylaminopyridine, etc. Examples of the solvent in this reaction include dimethylformamide, tetrahydrofuran, chloroform, acetonitrile, etc. Examples of the base include sodium hydroxide and potassium hydroxide. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours. The compound represented by formula (I2-c) includes, for example, the compounds represented below, and can be more easily obtained from the market. TIFF2025088761000053.tif2590

[0050] In salt (I), X 1 being *-O-CO-O- (the salt represented by formula (I3)) can be produced, for example, by reacting the salt represented by formula (I2-a) with carbonyldiimidazole in a solvent and then further reacting with the compound represented by formula (I1-b). TIFF2025088761000054.tif67161 (wherein all the symbols have the same meanings as described above respectively). Examples of the solvent in this reaction include chloroform, acetonitrile, etc. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours.

[0051] In salt (I), X 1 being -O- (the salt represented by formula (I4)) can be produced, for example, by reacting the salt represented by formula (I2-a) with the compound represented by formula (I1-b) in a solvent in the presence of a base. TIFF2025088761000055.tif67162 (wherein all the symbols have the same meanings as described above respectively). Examples of the base in this reaction include potassium hydroxide, etc. Examples of the solvent in this reaction include chloroform, acetonitrile, etc. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours.

[0052] <Acid generator> The acid generator of the present invention is an acid generator containing the salt (I) of the present invention. It may contain one kind of salt (I) or may contain two or more kinds of salt (I). In addition to the salt (I), the acid generator of the present invention may contain a known compound (hereinafter sometimes referred to as "compound (B)" or "acid generator (B)") that acts as an acid generator in the resist field. Compound (B) may be used alone or in combination of two or more kinds.

[0053] As compound (B), either a nonionic compound or an ionic compound may be used. Examples of nonionic compounds include sulfonate esters (e.g., 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxy ketone, diazonaphthoquinone 4-sulfonate), sulfones (e.g., disulfone, ketosulfone, sulfonyldiazomethane), etc. Representative examples of ionic compounds include onium salts containing an onium cation (e.g., diazonium salt, phosphonium salt, sulfonium salt, iodonium salt). Examples of anions of onium salts include sulfonic acid anion, sulfonylimide anion, sulfonylmethide anion, and carboxylic acid anion. Compound (B) may be a part of the structural unit constituting the resin contained in the resist composition of the present invention, such as the structural unit (a7) described later.

[0054] As compound (B), compounds that generate an acid by radiation described in, for example, JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853, JP-A-63-146029, U.S. Patent No. 3,779,778, U.S. Patent No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712, etc. can be used. Also, compounds produced by known methods may be used. Compound (B) may be an acid generator having an acid-labile group. For example, the compound or resin serving as the acid generator may contain a partial structure that becomes an acid-labile group, and the acid-labile group preferably contains group (1) or group (2) described later. When the resist composition of the present invention contains a compound having an acid-labile group, a resin containing a structural unit having an acid-labile group may not be contained.

[0055] As a preferred form of compound (B), a salt represented by formula (B1) (hereinafter sometimes referred to as "salt (B1)", "compound (B1)", or "acid generator (B1)". The salt represented by formula (B1) excludes salt (I).) can be mentioned. TIFF2025088761000056.tif1395[In formula (B1), L b1 represents a single bond or an (nb1 + 1)-valent hydrocarbon group which may have a substituent, and -CH 2 - contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO 2 -. L b2 represents a single bond or a divalent hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH 2 - contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO 2 -. Y b1 represents a methyl group which may have a substituent or a cyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and -CH 2 - contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -SO 2 - or -CO-. nb1 represents any integer from 1 to 6. When nb1 is 2 or more, the groups in the plurality of parentheses may be the same as or different from each other. ZI + represents an organic cation.] L b1Examples of the (nb1 + 1)-valent hydrocarbon group include a monovalent group obtained by removing nb1 hydrogen atoms from a monovalent chain hydrocarbon group, a monovalent alicyclic hydrocarbon group, a monovalent aromatic hydrocarbon group, and a monovalent group formed by combining two or more of these groups, and the group binds to 1 or more L b2 The carbon number of the hydrocarbon group is preferably from 1 to 48, more preferably from 1 to 42, still more preferably from 1 to 36, even more preferably from 1 to 30, still even more preferably from 1 to 24, and even more preferably from 1 to 18. Examples of the chain hydrocarbon group include a group obtained by removing nb1 hydrogen atoms from an alkyl group or an alkenyl group. The alkyl group may be linear or branched, and specifically includes a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a sec-butyl group, an iso-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentadecyl group, a heptadecyl group, etc. Examples of the alkenyl group include an ethenyl group, a propenyl group, an isopropenyl group, a butenyl group, an isobutenyl group, a tert-butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an octenyl group, an isooctenyl group, a nonenyl group. The carbon number of the chain hydrocarbon group is preferably from 1 to 36, more preferably from 1 to 24, still more preferably from 1 to 20, even more preferably from 1 to 18, still even more preferably from 1 to 12, and even more preferably from 1 to 10. Examples of the alicyclic hydrocarbon group include a group obtained by removing nb1 hydrogen atoms from a monocyclic or polycyclic cycloalkyl group. Examples of the monocyclic cycloalkyl group include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, etc. Examples of the polycyclic cycloalkyl group include a cycloalkyl group having a crosslinked structure, a cycloalkyl group in which two or more rings are condensed, or a cycloalkyl group in which two rings are spiro-bonded. Examples of the cycloalkyl group having a crosslinked structure include a norbornyl group and an adamantyl group. Examples of the cycloalkyl group in which two or more rings are condensed include a bicyclo[4,4,0]decane group and a steroid group (steroid skeleton). Examples of the cycloalkyl group in which two rings are spiro-bonded include a spirocyclic cycloalkyl group in which one cycloalkyl group selected from the group consisting of a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group is spiro-bonded to a cycloalkyl group having 5 to 8 carbon atoms. Further, a double bond may be formed between two carbon atoms included in the alicyclic hydrocarbon group. More specifically, examples of the alicyclic hydrocarbon group include those represented by the following formula. TIFF2025088761000057.tif27168 When the alicyclic hydrocarbon group is a monocyclic cycloalkyl group, the number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 24, more preferably 3 to 20, still more preferably 3 to 18, even more preferably 3 to 12, still even more preferably 3 to 10, and still even more preferably 3 to 8. When the alicyclic hydrocarbon group is a polycyclic cycloalkyl group, the number of carbon atoms in the alicyclic hydrocarbon group is preferably 6 to 24, more preferably 6 to 20, still more preferably 6 to 18, even more preferably 6 to 12, and still even more preferably 7 to 12. Examples of the aromatic hydrocarbon group include a group obtained by removing nb1 hydrogen atoms from an aryl group. Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a fluorenyl group. More specifically, examples of the aromatic hydrocarbon group include those represented by the following formula. As for the number of carbon atoms of the aromatic hydrocarbon group, it is preferably 4 to 24, more preferably 4 to 20, even more preferably 4 to 18, still more preferably 5 to 14, even still more preferably 5 to 10, and even more preferably 6 to 10. L b1 In the hydrocarbon group of, -CH 2 - is replaced by -O-, -CO-, -S- or -SO 2 - When replaced, the number of carbon atoms before replacement shall be the number of carbon atoms of the hydrocarbon group. L b1 Among the hydrocarbon groups of, -CH 2 - contained in the chain hydrocarbon group is replaced by -O-, -CO-, -S- or -SO 2 - The groups replaced are hydroxyl group (-CH contained in the methyl group 2 - replaced by -O-), carboxyl group (-CH contained in the ethyl group 2 -CH 2 - replaced by -O-CO-), carbonyl group (-CH contained in the methylene group 2 - replaced by -CO-), oxy group (-CH contained in the methylene group 2 - replaced by -O-), alkoxy group (any position -CH contained in the alkyl group 2 - replaced by -O-), alkoxycarbonyl group (any position -CH contained in the alkyl group 2 -CH 2 - replaced by -O-CO-), alkylcarbonyl group (any position -CH contained in the alkyl group 2 - replaced by -CO-), alkylcarbonyloxy group (any position -CH contained in the alkyl group 2 -CH 2 - replaced by -CO-O-), alkoxycarbonyloxy group (any position -CH contained in the alkyl group 2 -CH 2 -CH 2- is a group replaced by -O-CO-O-, an alkanediyl-oxy group (any -CH at any position in the alkanediyl group) 2 - is a group replaced by -O-, an alkanediyl-oxycarbonyl group (any -CH at any position in the alkanediyl group) 2 -CH 2 - is a group replaced by -O-CO-, an alkanediyl-carbonyl group (any -CH at any position in the alkanediyl group) 2 - is a group replaced by -CO-, an alkanediyl-carbonyl-oxy group (any -CH at any position in the alkanediyl group) 2 -CH 2 - is a group replaced by -CO-O-, etc. These replaced groups include, within the range permitted by the upper limit of the number of carbon atoms, those similar to the groups exemplified in this specification. L b1 Among the hydrocarbon groups of, the -CH 2 - replaced by -O-, -CO-, -S- or -SO 2 - includes groups having structures such as cyclic ethers, cyclic ketones, cyclic esters (lactones), cyclic thioethers, cyclic acetals, cyclic sulfonic acid esters ( sultones), etc. Specifically, alicyclic hydrocarbon groups represented by the following formulas can be mentioned. The bonding positions of the alicyclic hydrocarbon groups mentioned in the following formulas can be at any position. TIFF2025088761000059.tif48165L b1 Among the hydrocarbon groups of, the -CH 2 - in the aromatic hydrocarbon group may be replaced by -O- or -S-, and the -CH 2 - replaced by -O- or -S- includes groups derived from a furan ring or a thiophene ring, respectively. Specifically, aromatic hydrocarbon groups represented by the following formulas can be mentioned. TIFF2025088761000060.tif1325The -CH 2 - in the group combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group is -O-, -S-, -CO- or -SO 2Examples of the group replaced by "-" include the same groups as those exemplified in the present specification within the range allowed by the upper limit of the number of carbon atoms. Examples of the group formed by combining two or more of an acyclic hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group include a group formed by combining the above acyclic hydrocarbon group and the above alicyclic hydrocarbon group, a group formed by combining the above acyclic hydrocarbon group and the above aromatic hydrocarbon group, a group formed by combining the above alicyclic hydrocarbon group and the above aromatic hydrocarbon group, and a group formed by combining the above acyclic hydrocarbon group, the above alicyclic hydrocarbon group, and the above aromatic hydrocarbon group. The group formed by combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group may be a condensed ring. L b2 Examples of the divalent hydrocarbon group of include a divalent acyclic hydrocarbon group, a divalent alicyclic hydrocarbon group, a divalent aromatic hydrocarbon group, and a group formed by combining two or more of these groups, and a group obtained by removing one hydrogen atom from a monovalent hydrocarbon group and bonding to Y b1 are mentioned. L b2 Examples of the divalent acyclic hydrocarbon group, divalent alicyclic hydrocarbon group, divalent aromatic hydrocarbon group, and divalent group formed by combining two or more of these groups of L b1 are groups obtained by removing one hydrogen atom from the monovalent acyclic hydrocarbon group, monovalent alicyclic hydrocarbon group, monovalent aromatic hydrocarbon group, and monovalent group formed by combining two or more of these groups exemplified by L L b1 and L b2 Examples of the substituent that the hydrocarbon group of may have include a halogen atom, a cyano group, a nitro group, etc. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. L b1 and L b2 When L b1 and L b2 are a group formed by combining an alicyclic hydrocarbon group or an aromatic hydrocarbon group and an acyclic hydrocarbon group, the acyclic hydrocarbon group may be substantially regarded as a substituent that the alicyclic hydrocarbon group or the aromatic hydrocarbon group has. Also, the -CH 2 - of the acyclic hydrocarbon group contained in the hydrocarbon group of L2 - is replaced by, L b1 and L b2 The hydrocarbon groups of and may substantially have substituents such as a hydroxy group, a carboxy group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, a thiol group, an alkylthio group, an alkylsulfonyl group, etc. Y b1 Examples of the cyclic hydrocarbon group of include an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group. Y b1 The alicyclic hydrocarbon group and the aromatic hydrocarbon group of are respectively the same as the alicyclic hydrocarbon group and the aromatic hydrocarbon group exemplified by L b1 and when having no substituent, they may be a monovalent alicyclic hydrocarbon group and an aromatic hydrocarbon group. Y b1 Examples of the substituent that the methyl group of may have include a halogen atom, a cyano group, a hydroxy group, a nitro group, etc. Y b1 Examples of the substituent that the cyclic hydrocarbon group of may have include a halogen atom, a cyano group, a nitro group, or a hydrocarbon group having 1 to 18 carbon atoms that may have a halogen atom, a cyano group, or a nitro group (the -CH 2 - in may be replaced by -O-, -S-, -CO- or -SO 2 -.). etc. Y b1 The carbon number of the hydrocarbon group that the cyclic hydrocarbon group of may have is not included in the carbon number of the cyclic hydrocarbon group of Y b1 Y b1 Examples of the hydrocarbon group having 1 to 18 carbon atoms that the cyclic hydrocarbon group of may have as a substituent include a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group combining these groups. Examples of the chain hydrocarbon group, the alicyclic hydrocarbon group, the aromatic hydrocarbon group, and a group combining two or more of these groups include, within the range permitted by the upper limit of the carbon number, the chain hydrocarbon group, the alicyclic hydrocarbon group, the aromatic hydrocarbon group, and a group combining two or more of these groups exemplified by L b1 and the same groups as those exemplified by. Also, Yb1 The -CH contained in the hydrocarbon group having 1 to 18 carbon atoms in which the cyclic hydrocarbon group of 2 - may be replaced by -O-, -S-, -CO- or -SO 2 Examples of the group replaced by - are, within the range permitted by the upper limit of the number of carbon atoms, L b1 The -CH contained in the hydrocarbon group of 2 - may be replaced by -O-, -S-, -CO- or -SO 2 - include the same groups as those exemplified for the group replaced by -O-, -S-, -CO- or -SO b1 Examples of the hydrocarbon group having 1 to 18 carbon atoms in which the cyclic hydrocarbon group of Y may be included as a substituent include protecting groups or leaving groups generally used in the art (for example, acid-labile groups or base-labile groups such as group (1) or group (2)). Here, the "base-labile group" means a group having a leaving group, and when the leaving group is eliminated by contact with a base, the structural unit is converted into a structural unit having a hydrophilic group (for example, a hydroxy group or a carboxy group). The anion of the salt represented by formula (B1) is preferably an anion represented by the following formula (B1-A1) (hereinafter sometimes referred to as "anion (B1-A1)") or an anion represented by formula (B1-A2) (hereinafter sometimes referred to as "anion (B1-A2)"). TIFF2025088761000061.tif30124[In formula (B1-A1), L b2 and Y b1 have the same meanings as in formula (B1). Q b1 、Q b2 、Q b3 and Q b4 each independently represents a hydrogen atom, a fluorine atom, a perfluoroalkyl group having 1 to 6 carbon atoms or an alkyl group having 1 to 6 carbon atoms. z1 represents any integer from 0 to 6. When z1 is 2 or more, the groups within the plurality of parentheses may be the same as or different from each other. X 1 represents -O-CO-, -CO-O-, -O-CO-O- or -O-. L b3represents a (nb2 + 1)-valent hydrocarbon group having 1 to 24 carbon atoms which may have a single bond or a substituent, and -CH 2 - may be replaced by -O-, -S-, -CO- or -SO 2 -. nb2 represents any integer from 1 to 3. When nb2 is 2 or more, the groups in the plurality of parentheses may be the same as or different from each other.] Q b1 、Q b2 、Q b3 and Q b4 Examples of the alkyl group of are methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group and the like. Q b1 、Q b2 、Q b3 and Q b4 Examples of the perfluoroalkyl group of are trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluoro sec-butyl group, perfluoro tert-butyl group, perfluoropentyl group, perfluorohexyl group and the like. Q b1 and Q b2 are preferably included in at least one of Q b1 and Q b2 a fluorine atom or a perfluoroalkyl group, more preferably a fluorine atom or a perfluoroalkyl group, even more preferably a fluorine atom or a trifluoromethyl group, and even more preferably both are fluorine atoms. Q b3 and Q b4 are each independently preferably a hydrogen atom, a fluorine atom or a perfluoroalkyl group having 1 to 3 carbon atoms, and Q b3 is preferably a hydrogen atom, a fluorine atom or a perfluoroalkyl group having 1 to 3 carbon atoms, and Q b4 is preferably a hydrogen atom or a fluorine atom. z1 is preferably any integer from 0 to 3, more preferably 0, 1 or 2. X 1 is preferably -O-CO- or -CO-O-.

[0056] L b3 As the hydrocarbon group in L, within the range allowed by the upper limit of the number of carbon atoms, the same hydrocarbon groups as the examples of L in formula (B1) b1 can be mentioned. In formula (B1-A1), L b3 is a single bond, an optionally substituted chain hydrocarbon group having 1 to 12 carbon atoms (the -CH 2 - in the chain hydrocarbon group may be replaced by -O- or -CO-), an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms (the -CH 2 - in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO 2 -), an optionally substituted aromatic hydrocarbon group having 6 to 10 carbon atoms (the -CH 2 - in the aromatic hydrocarbon group may be replaced by -O- or -S-), or a group formed by combining two or more of these groups, and is preferably a single bond, a chain hydrocarbon group having 1 to 6 carbon atoms or a group represented by the following formula (Lb3-1). In addition, when -CH 2 - in the chain hydrocarbon group is replaced by -O- or -CO-, the number of -CH 2 - in the chain hydrocarbon group replaced by -O- or -CO- is preferably 1 to 4, and one -CH 2 -CH 2 - in the chain hydrocarbon group is preferably replaced by -O-CO- or -CO-O-, or one -CH 2 -CH 2 -CH 2 - in the chain hydrocarbon group is preferably replaced by -O-CO-O-. TIFF2025088761000062.tif1482 [In formula (Lb3-1), nb2 has the same meaning as in formula (B1-A1). Lb31 represents a single bond or a chain hydrocarbon group having 1 to 12 carbon atoms, and -CH contained in the chain hydrocarbon group 2 - may be replaced by -O- or -CO-, and the chain hydrocarbon group may have a substituent. W b3 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms, and -CH contained in the alicyclic hydrocarbon group 2 - may be replaced by -O-, -S-, -CO- or -SO 2 -, and -CH contained in the aromatic hydrocarbon group 2 - may be replaced by -O- or -S-, and the alicyclic hydrocarbon group and the aromatic hydrocarbon group may have a substituent. * and ** represent bonding sites, and * represents the bonding site with X 1 . In formula (Lb3-1), the chain hydrocarbon group of L b31 , as long as the upper limit of the number of carbon atoms permits, includes the same groups as the chain hydrocarbon groups exemplified by L b1 . W b3 , the alicyclic hydrocarbon group and the aromatic hydrocarbon group of, as long as the upper limit of the number of carbon atoms permits, includes the same groups as the alicyclic hydrocarbon groups and the aromatic hydrocarbon groups exemplified by L b1 . L b31 , the substituents that the chain hydrocarbon group of may have, and W b3 , the substituents that the alicyclic hydrocarbon group and the aromatic hydrocarbon group of may have, are the same groups as the substituents exemplified as the substituents that the hydrocarbon group of L b1 may have. L b31 is preferably a single bond or an alkanediyl group having 1 to 6 carbon atoms (in the alkanediyl group, -CH 2 - may be replaced by -O- or -CO-). Among them, the alicyclic hydrocarbon group and the aromatic hydrocarbon group of W b3 include the alicyclic hydrocarbon group and the aromatic hydrocarbon group represented below. In the alicyclic hydrocarbon group and the aromatic hydrocarbon group represented below, * and ** represent bonding sites, and * represents the bonding site with X1 or L b31 represents a bonding site with, and ** represents a hydrogen atom, a substituent, or L b2 represents a bonding site with, and at least one ** is L b2 represents a bonding site with. Further, in the alicyclic hydrocarbon group represented below, -CH 2 - in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -CO-, or -SO 2 -. When -CH 2 - in the alicyclic hydrocarbon group is replaced by -O-, -S-, -CO-, or -SO 2 -, it preferably forms an ether ring, an ester ring (lactone), a carbonate ester ring, a sulfonic acid ester ring (sultone), or an acetal ring. In formula (B1-A1), L b2 is a single bond or a chain hydrocarbon group having 1 to 12 carbon atoms (where -CH 2 - in the chain hydrocarbon group may be replaced by -O- or -CO-).), and is preferably a single bond, -O-, -O-CO-, -CO-O-, -O-CO-O-, or *-L b21 -X 2 -L b22 -** (wherein either one of L b21 and L b22 represents a chain hydrocarbon group having 1 to 6 carbon atoms, the other represents a single bond or a chain hydrocarbon group having 1 to 6 carbon atoms, X 2 represents -O-, -CO-O-, -O-CO-, or -O-CO-O-, * and ** represent bonding sites, and ** represents a bonding site with Y b1 . However, the total number of carbon atoms of L b21 , X 2 and L b22 is 12 or less.).) is more preferable. In formula (B1-A1), Y b1 is an optionally substituted cyclic hydrocarbon group having 3 to 20 carbon atoms (where -CH 2 - in the cyclic hydrocarbon group may be replaced by -O-, -CO-, -S-, or -SO 2- may be replaced therewith. It is preferably a C3-C18 alicyclic hydrocarbon group which may have a substituent (the -CH 2 - in the alicyclic hydrocarbon group may be replaced by -O-, -CO-, -S- or -SO 2 - therewith. ) or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent is more preferable, and a C3-C16 alicyclic hydrocarbon group which may have a substituent (the -CH 2 - in the alicyclic hydrocarbon group may be replaced by -O-, -CO-, -S- or -SO 2 - therewith. ) or an aromatic hydrocarbon group having 6 to 10 carbon atoms which may have a substituent is even more preferable. Specifically, it is more preferably a group represented by the following formula (Y1) to formula (Y36). In formula (Y1) to formula (Y36), R Yb represents a hydrogen atom or a substituent which the cyclic hydrocarbon group of Y b1 may have, and represents an alkyl group having 1 to 4 carbon atoms, R Yc represents a hydrogen atom or a substituent which the cyclic hydrocarbon group of Y b1 may have, and * represents the bonding site with L b2 . The alicyclic hydrocarbon group and aromatic hydrocarbon group represented by the following formula may have other substituents although not particularly illustrated in the following formula. TIFF2025088761000064.tif83160

[0057] As the anion represented by formula (B1-A1), anions represented by formula (B1-A1-1) to formula (B1-A1-85) [hereinafter, may be referred to as "anion (B1-A1-1)" etc. according to the formula number] are preferable, and an anion represented by any of formula (B1-A1-1) to formula (B1-A1-4), formula (B1-A1-9), formula (B1-A1-10), formula (B1-A1-24) to formula (B1-A1-33), formula (B1-A1-36) to formula (B1-A1-40), formula (B1-A1-47) to formula (B1-A1-85) is more preferable. TIFF2025088761000065.tif226160

[0058] TIFF2025088761000066.tif250152

[0059] TIFF2025088761000067.tif254163

[0060] In formulas (B1-A1-1) to (B1-A1-85), R i2 ~R i7 are, independently of each other, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. R i8 is, for example, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a group formed by combining these, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. L A41 is a single bond or an alkanediyl group having 1 to 4 carbon atoms. Q b1 and Q b2 represent the same meaning as described above. Specific examples of the anion represented by formula (B1-A1) include the anions described in JP-A-2010-204646.

[0061] Preferred anions represented by formula (B1-A1) include the anions represented by formulas (B1a-1) to (B1a-70), respectively. Among them, anions represented by any of formulas (B1a-1) to (B1a-4), formulas (B1a-7) to (B1a-11), formulas (B1a-14) to (B1a-30), and formulas (B1a-35) to (B1a-70) are preferred. TIFF2025088761000068.tif185163

[0062] TIFF2025088761000069.tif252166

[0063] TIFF2025088761000070.tif70166

[0064] The anion represented by formula (B1-A2) is represented by the following formula. TIFF2025088761000071.tif24100[In formula (B1-A2), L b2 and Y b1 have the same meaning as in formula (B1). R b1 represents a halogen atom or an alkyl group having 1 to 6 carbon atoms, and -CH 2 - contained in the alkyl group may be replaced by -O- or -CO-. nb4 represents any integer from 1 to 5. When nb4 is 2 or more, the groups 2 in the plurality of parentheses may be the same as or different from each other. nb3 represents any integer from 0 to 4. When nb3 is 2 or more, the plurality of R b1 may be the same as or different from each other. However, 1 ≦ nb4 + nb3 ≦ 5 is satisfied.]

[0065] In formula (B1-A2), the hydrocarbon group of L b2 and the cyclic hydrocarbon group of Y b1 are exemplified by the same ones as the hydrocarbon group of L b2 and the cyclic hydrocarbon group of Y b1 in formula (B1) within the range allowed by the upper limit of the number of carbon atoms. For the hydrocarbon group of L b2 , the methyl group of Y b1 and the substituents that the cyclic hydrocarbon group may have, the same ones as the examples of the hydrocarbon group of L b2 in formula (B1), the methyl group of Y b1 and the substituents that the cyclic hydrocarbon group may have are exemplified. L b2 is preferably a chain hydrocarbon group having 1 to 12 carbon atoms (-CH 2 - contained in the chain hydrocarbon group may be replaced by -O- or -CO-).), more preferably, *-CO-O-L b41 -(L b41 is a single bond or a chain hydrocarbon group having 1 to 6 carbon atoms, and -CH 2 - contained in the chain hydrocarbon group may be replaced by -O- or -CO-). * is SO 3- represents the bonding site with the benzene ring to which it is bonded. L b41 is preferably a single bond or a chain hydrocarbon group having 1 to 3 carbon atoms. Y b1 is an optionally substituted cyclic hydrocarbon group having 3 to 20 carbon atoms (the -CH 2 - in the cyclic hydrocarbon group may be replaced by -O-, -CO-, -S- or -SO 2 -). Preferably, it is an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms (the -CH 2 - in the alicyclic hydrocarbon group may be replaced by -O-, -CO-, -S- or -SO 2 -), or an optionally substituted aromatic hydrocarbon group having 6 to 18 carbon atoms. More preferably, Y in formula (B1 - A1) b1 or L b1 is more preferably an alicyclic hydrocarbon group or an aromatic hydrocarbon group exemplified by formula (B1 - A1). Specifically, it is preferably a group represented by the above-mentioned formula (Y1) to formula (Y36), and more preferably a group represented by the above-mentioned formula (Y1) to formula (Y19).

[0066] In formula (B1 - A2), nb4 is preferably any integer from 1 to 4, more preferably any integer from 1 to 3, still more preferably 1 or 2, and even more preferably 2. When nb4 is 1 or 2, the -L b2 -Y b1 bonding position is preferably the following structure which is the m-position substitution of the benzene ring with respect to the bonding position of SO 3 - . TIFF2025088761000072.tif26105[In the above formula, L b2 , Y b1 , R b1 , and nb3 represent the same meanings as in formula (B1 - A2).] When nb4 is 2 or more, the plurality of L b2 and Y b1 are preferably the same group as each other.

[0067] R b1Examples of the alkyl group having 1 to 6 carbon atoms include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, and hexyl group. The number of carbon atoms of the alkyl group is preferably 1 to 4, more preferably 1 to 3. R b1 Examples of the halogen atom of b1 include fluorine atom, chlorine atom, bromine atom, and iodine atom. Examples of the group in which -CH 2 - contained in the alkyl group is replaced by -O- or -CO- include hydroxy group, carboxy group, alkoxy group, alkoxycarbonyl group, alkylcarbonyl group, alkylcarbonyloxy group, oxy group, carbonyl group, etc. These replaced groups include the same groups as those exemplified in this specification within the range where the upper limit of the number of carbon atoms permits. R b1 is each independently preferably a halogen atom or an alkyl group having 1 to 4 carbon atoms (wherein -CH 2 - contained in the alkyl group may be replaced by -O- or -CO-), more preferably a fluorine atom, iodine atom or an alkyl group having 1 to 3 carbon atoms (wherein -CH 2 - contained in the alkyl group may be replaced by -O- or -CO-), and even more preferably a fluorine atom, iodine atom, hydroxy group, methoxy group or methyl group. nb3 is preferably any integer from 0 to 3, more preferably any integer from 0 to 2. In one embodiment, nb3 is preferably 0. In another embodiment, nb3 is preferably 1 or 2. When nb3 is 1, R b1 is preferably a halogen atom, and R b1 is more preferably a fluorine atom or iodine atom. When nb3 is 2, one of R b1 is preferably a halogen atom and the other is preferably a halogen atom or an alkyl group having 1 to 4 carbon atoms, and one of R b1 is more preferably a fluorine atom or iodine atom and the other is more preferably a fluorine atom, iodine atom or an alkyl group having 1 to 3 carbon atoms.

[0068] Examples of the anion represented by formula (B1-A2) include the following anions. Among them, the anions represented by formulas (B2a-1) to (B2a-20) are preferred, and the anions represented by formulas (B2a-1) to (B2a-11) and formulas (B2a-16) to (B2a-20) are more preferred. The following anions have some Rs b1 omitted and may contain substituents not shown in the figure. TIFF2025088761000073.tif102153

[0069] In another form of compound (B), salts in which the anion of the salt represented by formula (B1) is replaced with a sulfonylimide anion, a sulfonylmethide anion, or a carboxylic acid anion are also preferably used as compound (B). Examples of the salt in which the anion is replaced with a sulfonylimide anion or a sulfonylmethide anion include the salt represented by formula (B2) (hereinafter sometimes referred to as "salt (B2)", "compound (B2)", or "acid generator (B2)"). TIFF2025088761000074.tif1292[In formula (B2), A 1 represents a nitrogen atom or a carbon atom. L b2’ represents a single bond or a divalent hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH 2 - contained in the hydrocarbon group may be replaced with -O-, -S-, -CO-, or -SO 2 -. Y b1’ represents a methyl group which may have a substituent or a cyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and -CH 2 - contained in the cyclic hydrocarbon group may be replaced with -O-, -S-, -CO-, or -SO 2 -. nb5 represents an integer of 2 or 3. When A 1 is a nitrogen atom, nb5 is 2, and when A 1When it is a carbon atom, nb5 is 3. The groups in the plurality of parentheses may be the same as or different from each other, and the groups in two parentheses may combine to form a ring containing A 1 may be formed. ZI + represents an organic cation. ]

[0070] In formula (B2), L b2’ and Y b1’ Examples of the hydrocarbon group, cyclic hydrocarbon group and substituent of are the same groups as L b2 and Y b1 in formula (B1 - A1). L b2 ’ is a single bond, * - L b23 -, * - L b23 - X 2 - or * - L b23 - X 2 - W 2 - X 3 - (L b23 represents a chain hydrocarbon group having 1 to 6 carbon atoms which may have a fluorine atom. X 2 and X 3 each independently represent - O -, - CO - O -, - O - CO -, - O - CO - O - or - O -. W 2 represents an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and - CH 2 - contained in the alicyclic hydrocarbon group may be replaced by - O - or - CO -. * represents the bonding site with SO 2 . ) is preferred. Y b1 ’ is a methyl group having a fluorine atom or a cyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent ( - CH 2 - contained in the cyclic hydrocarbon group may be replaced by - O -, - CO -, - S - or - SO 2 -. ). Preferably, it is a trifluoromethyl group, an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent ( - CH 2 - contained in the alicyclic hydrocarbon group may be replaced by - O -, - S -, - CO - or - SO 2It may be replaced by "-). Or it is more preferably an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent. Specifically, it is more preferably a trifluoromethyl group or a group represented by formula (Y1) to formula (Y36) exemplified in formula (B1-A1). In formula (B2), two -SO 2 -L b2 ’-Y b1 ’ together form a ring containing A 1 When forming a ring, for example, an anion represented by formula (B2’) can be mentioned. TIFF2025088761000075.tif21112 [In formula (B2’), A 1 、Y b1 ’、L b2 ’ and nb5 represent the same meaning as in formula (B2). W b4 represents a disulfonylimide ring or a disulfonylmethide ring having 2 to 12 carbon atoms which may have a fluorine atom.] W b4 The disulfonylimide ring or disulfonylmethide ring of W includes those having 3 to 12 carbon atoms, preferably 3 to 6 carbon atoms, and the hydrogen atom of the methylene group contained in the ring is preferably replaced by a fluorine atom.

[0071] Examples of the anion in the salt represented by formula (B2) include the following. Among them, anions represented by formula (B3a-1) and formula (B3a-2) are preferred. TIFF2025088761000076.tif189164 Examples of the carboxylic acid anion include the following. TIFF2025088761000077.tif41156

[0072] ZI +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. ZI + Examples of the organic cation include the same ones as the Z + organic cation in formula (I).

[0073] Compound (B) is a combination of the above-mentioned anion and the above-mentioned organic cation, and these can be arbitrarily combined. As the salt (B1), preferably, any one of the anions represented by formula (B1a-1) to formula (B1a-4), formula (B1a-7) to formula (B1a-11), formula (B1a-14) to formula (B1a-30), formula (B1a-35) to formula (B1a-70), formula (B2a-1) to formula (B2a-11), formula (B2a-16) to formula (B2a-20), formula (B3a-1) to formula (B3a-3), or formula (B3a-11) to formula (B3a-14) and the combination with cation (b2-1), cation (b2-2), cation (b2-3), cation (b2-4), or cation (b2-5) can be mentioned.

[0074] Examples of compound (B) preferably include those represented by formula (B1-1) to formula (B1-105), formula (B2-1) to formula (B2-20), and formula (B3-1) to formula (B3-28). Among them, those containing an arylsulfonium cation are preferred, and those represented by formula (B1-1) to formula (B1-3), formula (B1-5) to formula (B1-7), formula (B1-11) to formula (B1-14), formula (B1-20) to formula (B1-26), formula (B1-29), formula (B1-31) to formula (B1-105), formula (B2-1) to formula (B2-20), and formula (B3-1) to formula (B3-28) are particularly preferred. TIFF2025088761000078.tif176161

[0075] TIFF2025088761000079.tif254159

[0076] TIFF2025088761000080.tif250154

[0077] TIFF2025088761000081.tif252160

[0078] TIFF2025088761000082.tif249157

[0079] TIFF2025088761000083.tif250151

[0080] TIFF2025088761000084.tif187160

[0081] When containing salt (I) and compound (B) as an acid generator, the ratio of the contents of salt (I) and compound (B) (mass ratio; salt (I): compound (B)) is usually from 1:99 to 99:1, preferably from 2:98 to 98:2, more preferably from 5:95 to 95:5, still more preferably from 10:90 to 90:10, particularly preferably from 15:85 to 85:15, and even more preferably from 40:60 to 60:40.

[0082] <Resist composition> The resist composition of the present invention contains an acid generator containing salt (I). The resist composition of the present invention may further contain a resin. Examples of the resin include a resin containing a structural unit having an acid-labile group (hereinafter sometimes referred to as "resin (A)") and / or a resin other than resin (A). Here, the "acid-labile group" means a group having a leaving group, and upon contact with an acid, the leaving group is eliminated to convert the constitutional unit into a constitutional unit having a hydrophilic group (for example, a hydroxy group or a carboxy group). The resist composition of the present invention preferably contains a quencher (hereinafter sometimes referred to as "quencher (C)") such as a salt that generates an acid having a lower acidity than the acid generated from the acid generator, and preferably contains a solvent (hereinafter sometimes referred to as "solvent (E)").

[0083] In the resist composition of the present invention, the content of the salt (I) is preferably 0.1% by mass or more and 99.9% by mass or less, more preferably 1% by mass or more and 45% by mass or less, still more preferably 1% by mass or more and 40% by mass or less, and even more preferably 3% by mass or more and 40% by mass or less, based on the solid content of the resist composition. When the resin (A) described below is included, the content of the salt (I) is preferably 1 part by mass or more and 45 parts by mass or less, more preferably 1 part by mass or more and 40 parts by mass or less, still more preferably 3 parts by mass or more and 40 parts by mass or less, based on 100 parts by mass of the resin (A) described below. In the resist composition of the present invention, the total content of the acid generators is preferably 0.1% by mass or more and 99.9% by mass or less, more preferably 1% by mass or more and 45% by mass or less, still more preferably 1% by mass or more and 40% by mass or less, and even more preferably 3% by mass or more and 40% by mass or less, based on the solid content of the resist composition. When the resin (A) described below is included, the total content of the acid generators is preferably 1 part by mass or more and 45 parts by mass or less, more preferably 1 part by mass or more and 40 parts by mass or less, still more preferably 3 parts by mass or more and 40 parts by mass or less, based on 100 parts by mass of the resin (A) described below.

[0084] <Resin (A)> The resin (A) contains a structural unit having an acid-labile group (hereinafter sometimes referred to as "structural unit (a1)"). The resin (A) preferably further contains a structural unit other than the structural unit (a1). Examples of the structural unit other than the structural unit (a1) include a structural unit having no acid-labile group (hereinafter sometimes referred to as "structural unit (s)") and a structural unit derived from other monomers known in the art.

[0085] 〈Structural unit (a1)〉 The structural unit (a1) is derived from a monomer having an acid-labile group (hereinafter sometimes referred to as "monomer (a1)"). The acid-labile group contained in the resin (A) is preferably a group represented by the formula (1) (hereinafter also referred to as "group (1)") and / or a group represented by the formula (2) (hereinafter also referred to as "group (2)"). TIFF2025088761000085.tif2298[In the formula (1), R a1, R a2 and R a3 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group combining these, or R a1 and R a2 are bonded to each other to form, together with the carbon atom to which they are bonded, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, and the alkyl group, the alkenyl group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group may have a halogen atom. ma and na each independently represent 0 or 1, and at least one of ma and na represents 1. * represents a bonding site.] TIFF2025088761000086.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 the -CH 2 - in the hydrocarbon group and the heterocyclic group may be replaced by -O- or -S-, and the hydrocarbon group and the heterocyclic group may have a halogen atom. X represents an oxygen atom or a sulfur atom. na’ represents 0 or 1. * represents a bonding site.]

[0086] R a1 , R a2 and R a3 Examples of the alkyl group for R R a1 , R a2 and R a3Examples of the alkenyl group in [compound name] include ethenyl, propenyl, isopropenyl, butenyl, isobutenyl, tert-butenyl, pentenyl, hexenyl, heptenyl, octenyl, isooctenyl, and nonenyl. R a1 , R a2 and R a3 The alicyclic hydrocarbon group in [compound name], R a1 , R a2 and R a3 may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl, adamantyl, norbornyl, and the following group (* represents the bonding site). The number of carbon atoms in the alicyclic hydrocarbon group of R TIFF2025088761000087.tif10159R a1 , R a2 and R a3 Examples of the aromatic hydrocarbon group in [compound name], R include aryl groups such as phenyl, naphthyl, anthryl, biphenyl, and phenanthryl. Examples of the combined group include a group formed by combining the above-mentioned alkyl group and alicyclic hydrocarbon group (for example, alkylcycloalkyl groups or cycloalkylalkyl groups such as methylcyclohexyl, dimethylcyclohexyl, methylnorbornyl, cyclohexylmethyl, adamantylmethyl, adamantyldimethyl, norbornylethyl, etc.), aralkyl groups such as benzyl, aromatic hydrocarbon groups having an alkyl group (p-methylphenyl, p-tert-butylphenyl, tolyl, xylyl, cumenyl, mesityl, 2,6-diethylphenyl, 2-methyl-6-ethylphenyl, etc.), aromatic hydrocarbon groups having an alicyclic hydrocarbon group (p-cyclohexylphenyl, p-adamantylphenyl, etc.), aryl-cycloalkyl groups such as phenylcyclohexyl, etc. Preferably, ma is 0 and na is 1. R a1 and Ra2 When -C(R a1 )(R a2 )(R a3 ) are bonded to each other to form an alicyclic hydrocarbon group, the following groups may be mentioned. The alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * represents the bonding site to -O-. TIFF2025088761000088.tif27138

[0087] R a1’ 、R a2’ and R a3’ Examples of the hydrocarbon group in include alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these. Examples of the alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and the group formed by combining these are the same as the groups mentioned for R a1 、R a2 and R a3 . R a2’ and R a3’ When they are bonded to each other to form a heterocyclic group together with the carbon atom to which they are bonded and X, -C(R a1’ )(R a2’ )-X-R a3’ Examples of the group are as follows. * represents the bonding site. TIFF2025088761000089.tif19124R a1’ and R a2’ Among them, at least one is preferably a hydrogen atom. na’ is preferably 0. R a1 、R a2 、R a3 、R a1 、R a2’ and R a3’ Examples of the halogen atom that may be possessed include a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

[0088] Examples of group (1) include the following groups. In formula (1), R a1 、R a2 and Ra3 A group in which it is an alkyl group, ma = 0, and na = 1. As such a group, a tert-butoxycarbonyl group is preferable. In formula (1), R a1 , R a2 together with the carbon atom to which they are attached form an adamantyl group, and R a3 is an alkyl group, ma = 0, and na = 1. In formula (1), R a1 and R a2 are each independently an alkyl group, R a3 is an adamantyl group, ma = 0, and na = 1. Specific examples of the group (1) include the following groups. * represents a bonding site. TIFF2025088761000090.tif149164

[0089] Specific examples of the group (2) include the following groups. * represents a bonding site. TIFF2025088761000091.tif55153

[0090] 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.

[0091] Among the (meth)acrylic monomers having an acid-labile group, those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms are preferable. If a resin (A) having a structural unit derived from a monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used in the resist composition, the resolution of the resist pattern can be improved.

[0092] As the structural unit derived from the (meth)acrylic monomer having the group (1), there are a structural unit represented by the formula (a1-0) (hereinafter, may be referred to as the structural unit (a1-0)), a structural unit represented by the formula (a1-1) (hereinafter, may be referred to as the structural unit (a1-1)), or a structural unit represented by the formula (a1-2) (hereinafter, may be referred to as the structural unit (a1-2)). Preferably, it is at least one structural unit selected from the group consisting of the structural unit (a1-0), the structural unit (a1-1), and the structural unit (a1-2), and more preferably, it is at least one or two structural units selected from the group consisting of the structural unit (a1-1) and the structural unit (a1-2). These may be used alone or in combination of two or more. TIFF2025088761000092.tif44144[In the formula (a1-0), the formula (a1-1), and the formula (a1-2), L a01 、L a1 and L a2 each independently represents -O- or *-O-(CH 2 ) k1 -CO-O-, k1 represents an integer of any one 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, and the alkyl group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group may have a halogen atom. R a6 and R a7each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these, and the alkyl group, the alkenyl group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group may have a halogen atom. m1’ represents any integer from 0 to 14. n1 represents any integer from 0 to 10. n1’ represents any integer from 0 to 3.

[0093] R a01 、R a4 、R a5 Examples of the halogen atom in R R a01 、R a4 、R a5 include a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. Examples of the alkyl group that may have a halogen atom in R R a01 、R a4 and R a5 are preferably a hydrogen atom or a methyl group, more preferably a methyl group. L a01 、L a1 and L a2 are preferably an oxygen atom or *-O-(CH 2 )k01 -CO-O- (wherein k01 is preferably any integer from 1 to 4, more preferably 1), and more preferably an oxygen atom. R a02 、R a03 、R a04 、R a6 and R a7 Examples of the alkyl group, alkenyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and combinations thereof in R a1 、R a2 and R a3 are the same as those exemplified for the groups in R R a02 、R a03 、and R a04 The alkyl group in is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. R a6 and R a7 The alkyl group in 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 is preferably an alkenyl group having 2 to 6 carbon atoms, more preferably an ethenyl group, a propenyl group, an isopropenyl group, or a butenyl group. R a02 、R a03 、R a04 、R a6 and R a7 The number of carbon atoms of the alicyclic hydrocarbon group of is preferably 5 to 12, more preferably 5 to 10. R a02 、R a03 、R a04 、R a6 and R a7 The number of carbon atoms of the aromatic hydrocarbon group of is preferably 6 to 12, more preferably 6 to 10. The group formed by combining an alkyl group and an alicyclic hydrocarbon group preferably has a total carbon number of 18 or less when these alkyl group and alicyclic hydrocarbon group are combined. The group formed by combining an alkyl group and an aromatic hydrocarbon group preferably has a total carbon number of 18 or less when these alkyl group and aromatic hydrocarbon group are combined. R a02 and R a03 are preferably an alkyl group having 1 to 6 carbon atoms which may have a halogen atom or an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a halogen atom, and more preferably a methyl group, an ethyl group, a phenyl group or a naphthyl group which may have a halogen atom. R a04 is preferably an alkyl group having 1 to 6 carbon atoms which may have a halogen atom or an alicyclic hydrocarbon group having 5 to 12 carbon atoms which may have a halogen atom, and more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group which may have a halogen atom. R a6 and R a7 are preferably an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, an alkenyl group having 2 to 6 carbon atoms which may have a halogen atom or an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a halogen atom, and more preferably a methyl group, an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group, a phenyl group or a naphthyl group which may have a halogen atom, and still more preferably an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group or a phenyl group which may have a halogen atom. m1’ is preferably any integer from 0 to 3, and more preferably 0 or 1. n1 is preferably any integer from 0 to 3, and more preferably 0 or 1. n1’ is preferably 0 or 1.

[0094] Examples of the structural unit (a1-0) include a structural unit represented by any of Formula (a1-0-1) to Formula (a1-0-24) and R in the structural unit (a1-0). a01Examples of the structural unit in which the methyl group corresponding to is replaced with a hydrogen atom, a halogen atom, a haloalkyl group (alkyl group having a halogen atom), or another alkyl group include structural units represented by any of formula (a1-0-1) to formula (a1-0-10), formula (a1-0-13), formula (a1-0-14), and formula (a1-0-19) to formula (a1-0-24). TIFF2025088761000093.tif119159

[0095] Examples of the structural unit (a1-1) include structural units derived from the monomers described in JP-A-2010-204646. Among them, the structural units represented by any of formula (a1-1-1) to formula (a1-1-7) and R in the structural unit (a1-1) a4 Preferably, the methyl group corresponding to is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group, and more preferably, the structural units represented by any of formula (a1-1-1) to formula (a1-1-4). TIFF2025088761000094.tif35170

[0096] Examples of the structural unit (a1-2) include structural units represented by any of formula (a1-2-1) to formula (a1-2-20) and structural units in which the methyl group corresponding to R in the structural unit (a1-2) a5 is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group, and preferably, the structural units represented by any of formula (a1-2-2), formula (a1-2-5), formula (a1-2-6), and formula (a1-2-10) to formula (a1-2-20). TIFF2025088761000095.tif91163

[0097] When the resin (A) contains the structural unit (a1-0) and / or the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more, still more preferably 25 mol% or more, even more preferably 30 mol% or more, still even more preferably 40 mol% or more, and even more preferably 50 mol% or more, based on all the structural units of the resin (A). Also, it is 95 mol% or less, preferably 90 mol% or less, more preferably 85 mol% or less, still more preferably 70 mol% or less, even more preferably 65 mol% or less. Specifically, it is 10 to 95 mol%, preferably 15 to 90 mol%, more preferably 20 to 85 mol%, still more preferably 25 to 70 mol%, and even more preferably 30 to 70 mol%. When the resin (A) contains the structural unit (a1-0), the content thereof is 5 mol% or more, preferably 10 mol% or more, more preferably 15 mol% or more, still more preferably 20 mol% or more, even more preferably 25 mol% or more, still even more preferably 30 mol% or more, and even more preferably 35 mol% or more, based on all the structural units of the resin (A). Also, it is 80 mol% or less, preferably 75 mol% or less, more preferably 70 mol% or less, still more preferably 65 mol% or less, and even more preferably 60 mol% or less. Specifically, it is 5 to 80 mol%, preferably 5 to 75 mol%, more preferably 10 to 70 mol%, still more preferably 10 to 65 mol%, and even more preferably 10 to 60 mol%. When the resin (A) contains the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more, still more preferably 25 mol% or more, even more preferably 30 mol% or more, still even more preferably 40 mol% or more, and even more preferably 50 mol% or more, based on all the structural units of the resin (A). Further, it is 95 mol% or less, preferably 90 mol% or less, more preferably 85 mol% or less, still more preferably 80 mol% or less, even more preferably 75 mol% or less, still even more preferably 70 mol% or less, and even more preferably 65 mol% or less. Specifically, it is 10 to 90 mol%, preferably 15 to 85 mol%, more preferably 15 to 80 mol%, still more preferably 20 to 80 mol%, even more preferably 20 to 75 mol%, and still even more preferably 20 to 70 mol%.

[0098] Examples of the structural unit having the group (2) in the structural unit (a1) include a structural unit represented by the formula (a1-4) (hereinafter sometimes referred to as "structural unit (a1-4)"). TIFF2025088761000096.tif31119[In the formula (a1-4), all the symbols have the same meanings as described above.]

[0099] R a1 and R a17 Examples of the halogen atom and the alkyl group which may have a halogen atom in R a01 are the same as those exemplified by R of the formula (a1-0).

[0100] R a1 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group. R a17Examples of the alkoxy group in [compound name] include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, sec-butoxy group, tert-butoxy group, pentyloxy group, and hexyloxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably an alkoxy group having 1 to 3 carbon atoms, still more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group. R a17 Examples of the alkoxyalkyl group in [compound name] include methoxymethyl group, ethoxyethyl group, propoxymethyl group, isopropoxymethyl group, butoxymethyl group, sec-butoxymethyl group, and tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably an alkoxyalkyl group having 2 to 4 carbon atoms, still more preferably a methoxymethyl group or an ethoxyethyl group, and even more preferably a methoxymethyl group. R a17 Examples of the alkoxyalkoxy group in [compound name] include methoxymethoxy group, methoxyethoxy group, ethoxymethoxy group, ethoxyethoxy group, propoxymethoxy group, isopropoxymethoxy group, butoxymethoxy group, sec-butoxymethoxy group, and tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably an alkoxyalkoxy group having 2 to 4 carbon atoms, still more preferably a methoxyethoxy group or an ethoxyethoxy group. R a17 Examples of the alkylcarbonyl group in [compound name] include acetyl group, propionyl group, and butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 4 carbon atoms, more preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and still more preferably an acetyl group. R a17 Examples of the alkylcarbonyloxy group in [compound name] include acetyloxy group, propionyloxy group, and butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 4 carbon atoms, more preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and still more preferably an acetyloxy group. Ra17 is preferably a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 4 carbon atoms which may have a halogen atom, an alkoxy group having 1 to 4 carbon atoms or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group or an ethoxy methoxy group, and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group or an ethoxyethoxy group.

[0101] A a11 Examples of the alkanediyl group of A include linear alkanediyl groups such as a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, 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, etc., and branched alkanediyl groups such as a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, a 2-methylbutane-1,4-diyl group, a heptane-1,6-diyl group, an octane-1,7-diyl group, a nonane-1,8-diyl group, a decane-1,9-diyl group, an undecane-1,10-diyl group, etc. The number of carbon atoms of the alkanediyl group is preferably 1 to 10, more preferably 1 to 8, even more preferably 1 to 6, still more preferably 1 to 4, yet more preferably 1 to 3, and even more preferably 1 or 2. R a18 Examples of the alkyl group of R include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a tert-butyl group. A a11 When -CH in the alkanediyl group of A 2 - is replaced by -O-, -CO- or -NR a18 -, the number of carbon atoms before replacement is taken as the number of carbon atoms of the alkanediyl group. A a11 -CH contained in the alkanediyl group of A 2- is replaced by -O-, -CO- or -NR a18 Examples of the group replaced by - include a hydroxy group, a carboxy group, a carbonyl group, an oxy group, an amino group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylamino group, a peptide group, an alkanediyl-oxy group, an alkanediyl-oxycarbonyl group, an alkanediylcarbonyl group, an alkanediylcarbonyl-oxy group, an alkanediylsulfonyl group, an alkanediylthio group, an alkanediylamino group, etc. These replaced groups include those similar to those exemplified in the present specification within the range where the upper limit of the number of carbon atoms is allowed. Examples of the alkylamino group include an alkylamino group having 1 to 11 carbon atoms, such as a methylamino group, an ethylamino group, a propylamino group, a butylamino group, a pentylamino group, a hexylamino group, an octylamino group. The number of carbon atoms of the alkylamino group is preferably 1 to 8, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediylamino group include an alkanediylamino group having 1 to 11 carbon atoms, such as a methyleneamino group, an ethyleneamino group, a propyleneamino group, etc. The number of carbon atoms of the alkanediylamino group is preferably 1 to 8, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. For example, A a11 Examples of the group in which -CH 2 - in the alkanediyl group of is replaced by -O-, -CO- or -NR a18 - include *-O-, *-CO-O-, *-O-CO-, *-CO-O-A a12 -CO-O-, *-O-CO-A a12 -O-, *-O-A a12 -CO-O-, *-CO-O-A a12 -O-CO-, *-O-CO-A a12 -O-CO-, *-CO-NR a18 - are included. Among them, *-CO-O-, *-CO-O-A a12 -CO-O-, *-O-A a12 -CO-O-, *-CO-NRa18 - is preferred. Here, A a12 represents an alkanediyl group having 1 to 8 carbon atoms, and * represents the bonding site with the carbon atom to which R a1 is bonded. The alkanediyl group of A a12 includes the same alkanediyl groups as A a11 within the range allowed by the upper limit of the number of carbon atoms. A a11 is preferably a single bond, *-CO-O- or *-CO-O-A a12 -CO-O-, more preferably a single bond, *-CO-O- or *-CO-O-CH 2 -CO-O-, and even more preferably a single bond or *-CO-O-. na1 is preferably 1, 2, 3 or 4, more preferably 1, 2 or 3, and even more preferably 1 or 2. na11 is preferably 0, 1, 2 or 3, more preferably 0, 1 or 2, and even more preferably 0 or 1. mc is preferably 0 or 1.

[0102] R a34 , R a35 and R a36 include alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups combining these as the hydrocarbon groups. Examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group and the like. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group and the like. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group and the following groups (* represents the bonding site.). TIFF2025088761000097.tif10151 Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, phenanthryl group and the like. Examples of the combined group include groups formed by combining the above-described alkyl group and alicyclic hydrocarbon group (e.g., alkylcycloalkyl groups or cycloalkylalkyl groups such as methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornil group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornylethyl group, etc.), aralkyl groups such as benzyl group, aromatic hydrocarbon groups having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon groups having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl groups such as phenylcyclohexyl group, etc. In particular, R a36 Examples of R include an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these. R a35 and R a36 Examples of the divalent hydrocarbon group having 2 to 20 carbon atoms formed by R and R bonding to each other together with the -C-O- to which they are bonded include, for example, the following groups. * represents the bonding site, and one side is the bonding site with R a34 and the other side is the bonding site with R TIFF2025088761000098.tif15105

[0103] R a34 is preferably a hydrogen atom. R a35 is preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a methyl group or an ethyl group. R a36 The hydrocarbon group of R is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these, and more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. R a36The alkyl group and alicyclic hydrocarbon group in [compound] are preferably unsubstituted. R a36 The aromatic hydrocarbon group in [compound] preferably has an aromatic ring having an aryloxy group with 6 to 10 carbon atoms.

[0104] -O-C(R a34 )(R a35 )-O-R a36 in the structural unit (a1-4) eliminates upon contact with an acid (e.g., p-toluenesulfonic acid) to form a hydroxy group or a carboxy group. -X a1 -O-C(R a34 )(R a35 )-O-R a36 in the case of a benzene ring, may be bonded to any of the o-position, m-position, or p-position with respect to the bonding position of A a11 . Among them, it is preferable that at least one is bonded to the o-position or p-position, and more preferably bonded to the p-position. In the case of a naphthalene ring, when the bonding position of A a11 is the 1-position, it may be bonded to any of the 2nd to 8th positions, and when the bonding position of A a11 is the 2nd position, it may be bonded to any of the 1st and 3rd to 8th positions. Among them, when the bonding position of A a11 is the 1st position, it is preferable that at least one is bonded to the 3rd to 6th positions, and more preferably bonded to the 3rd or 4th position. When the bonding position of A a11 is the 2nd position, it is preferable that it is bonded to the 4th to 7th positions, and more preferably bonded to the 5th or 6th position.

[0105] Examples of the structural unit (a1-4) include structural units derived from the monomers described in JP-A-2010-204646. Preferably, the structural units represented by the formulas (a1-4-1) to (a1-4-42) and R in the structural unit (a1-4) a1Examples of the structural unit in which the hydrogen atom corresponding to is replaced with a halogen atom, a haloalkyl group, or an alkyl group include, more preferably, structural units represented by Formula (a1-4-1) to Formula (a1-4-5), Formula (a1-4-10), Formula (a1-4-13), Formula (a1-4-14), Formula (a1-4-19), and Formula (a1-4-20). TIFF2025088761000099.tif229165

[0106] When the resin (A) contains the structural unit (a1-4), the content thereof is 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more, still more preferably 25 mol% or more, even more preferably 30 mol% or more, still even more preferably 40 mol% or more, and still more preferably 50 mol% or more, based on the total of all the structural units of the resin (A). Also, it is 95 mol% or less, preferably 90 mol% or less, more preferably 85 mol% or less, still more preferably 80 mol% or less, even more preferably 75 mol% or less, still even more preferably 70 mol% or less, and still more preferably 65 mol% or less. Specifically, it is preferably 10 to 95 mol%, more preferably 15 to 90 mol%, still more preferably 20 to 85 mol%, still more preferably 20 to 70 mol%, and particularly preferably 20 to 60 mol%.

[0107] Examples of the structural unit derived from the (meth)acrylic monomer having the group (2) also include a structural unit represented by Formula (a1-5) (hereinafter sometimes referred to as "structural unit (a1-5)"). TIFF2025088761000100.tif4759[In Formula (a1-5), all the symbols have the same meanings as described above.]

[0108] R in Formula (a1-5) a8 Examples of the halogen atom and the alkyl group which may have a halogen atom in are the same as those exemplified for R in Formula (a1-0). a01 ​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 them, it is preferable that one is -O- and the other is -S-. s1 is preferably 1. s1’ is preferably any integer from 0 to 2. Z a1 is preferably a single bond or *-CH 2 -CO-O-.

[0109] Examples of the structural unit (a1-5) include structural units derived from the monomers described in JP-A-2010-61117. Among them, the structural units represented by formula (a1-5-1) to formula (a1-5-4) are preferable, and the structural unit represented by formula (a1-5-1) or formula (a1-5-2) is more preferable. When the resin (A) contains the structural unit (a1-5), the content thereof is 1 mol% or more, preferably 2 mol% or more, more preferably 3 mol% or more, still more preferably 5 mol% or more, even more preferably 10 mol% or more, still even more preferably 20 mol% or more, and even more preferably 25 mol% or more, based on all the structural units of the resin (A). Also, it is 80 mol% or less, preferably 70 mol% or less, more preferably 60 mol% or less, still more preferably 50 mol% or less, even more preferably 45 mol% or less, still even more preferably 40 mol% or less, and even more preferably 30 mol% or less. Specifically, 1 to 50 mol% is preferable, 3 to 45 mol% is more preferable, 5 to 40 mol% is still more preferable, and 5 to 30 mol% is even more preferable.

[0110] Examples of the structural unit having the group (1) in the structural unit (a1) include the structural unit represented by formula (a1-6) (hereinafter sometimes referred to as "structural unit (a1-6)"). TIFF2025088761000102.tif3481[In formula (a1-6), all the symbols have the same meanings as described above respectively.]

[0111] R in formula (a1-6) a61 Examples of the halogen atom and the alkyl group which may have a halogen atom in R a01 are the same as those exemplified for R in formula (a1-0). R a61 is preferably a hydrogen atom, a methyl group or a trifluoromethyl group. R a62 、R a63 、R a64 and R a65 Examples of the alkyl group in R R a62 、R a63 and R a64 include an alicyclic hydrocarbon group and an aromatic hydrocarbon group as the cyclic hydrocarbon group in R The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group and the like. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group and the like. The number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 16, more preferably 3 to 12. Examples of the aromatic hydrocarbon group include a phenylene group, a naphthylene group and the like. Examples of the substituent which the cyclic hydrocarbon group may have include a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group and the like. Ra62 and R a63 Examples of the ring formed by the bonding of R a62 and R a63 include an adamantane ring, a cyclopentane ring, a cyclohexane ring, etc. Specifically, when R a62 and R a63 are bonded to each other to form a ring, examples of -C(R a64 )(R TIFF2025088761000103.tif32110

[0112] L a61 and L a62 Examples of the alkanediyl group having 1 to 4 carbon atoms in L L a61 and L a62 are preferably each independently a methylene group or an ethylene group. X a61 is preferably a single bond or -CO-O-*, and more preferably a single bond. X a62 is preferably a single bond or *-O-L a61 -, and more preferably a single bond.

[0113] Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms in Ar include a phenylene group, a 1-naphthylene group, a 2-naphthylene group, a 1-anthrylene group, a 9-anthrylene group, a biphenylene group, a 1-phenanthrylene group, and a 2-phenanthrylene group, etc. Examples of the substituent that the aromatic hydrocarbon group may have include a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group, etc.

[0114] Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, a bromine atom, etc. 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. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, a hexyloxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group. Examples of the alkoxyalkyl group include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and even more preferably a methoxymethyl group. Examples of the alkoxyalkoxy group include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a methoxyethoxy group or an ethoxyethoxy group. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group. Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group. The substituent is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxy methoxy group, and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group. Ar is preferably a phenylene group which may have a substituent, and more preferably a phenylene group which may have a hydroxy group.

[0115] Examples of the structural unit (a1-6) include structural units represented by Formula (a1-6-1) to Formula (a1-6-44). The structural units represented by Formula (a1-6-1) to Formula (a1-6-9) are preferred, the structural units represented by Formula (a1-6-1), Formula (a1-6-2), Formula (a1-6-4), Formula (a1-6-5), Formula (a1-6-7), or Formula (a1-6-8) are more preferred, and the structural units represented by Formula (a1-6-1) or Formula (a1-6-2) are even more preferred. TIFF2025088761000104.tif227164In the above structural unit, R a61 The structural unit in which the hydrogen atom corresponding to is replaced with a methyl group or the like, and the structural unit in which the methyl group corresponding to R a61 in the following structural unit is replaced with a hydrogen atom or the like are also included as the structural unit (a1-6).

[0116] When the resin (A) contains the structural unit (a1-6), its content is 3 mol% or more, preferably 5 mol% or more, more preferably 7 mol% or more, still more preferably 10 mol% or more, even more preferably 20 mol% or more, still even more preferably 30 mol% or more, and even more preferably 40 mol% or more, based on all the structural units of the resin (A). Also, it is 80 mol% or less, preferably 75 mol% or less, more preferably 70 mol% or less, still more preferably 65 mol% or less. Specifically, it is preferably 3 to 80 mol%, more preferably 5 to 75 mol%, still more preferably 7 to 70 mol%, even more preferably 7 to 65 mol%, and particularly preferably 10 to 65 mol%.

[0117] Moreover, examples of the structural unit (a1) also include the following structural units. TIFF2025088761000105.tif33167

[0118] When the resin (A) contains the structural units represented by the formulas (a1-7-1) to (a1-7-7), its content is 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more, still more preferably 25 mol% or more, even more preferably 30 mol% or more, still even more preferably 40 mol% or more, and even more preferably 50 mol% or more, based on all the structural units of the resin (A). Also, it is 95 mol% or less, preferably 90 mol% or less, more preferably 85 mol% or less, still more preferably 80 mol% or less, even more preferably 75 mol% or less, still even more preferably 70 mol% or less, and even more preferably 60 mol% or less. Specifically, it is preferably 10 to 95 mol%, more preferably 15 to 90 mol%, still more preferably 20 to 85 mol%, even more preferably 20 to 70 mol%, and particularly preferably 20 to 60 mol%.

[0119] Moreover, examples of the structural unit (a1) also include the following structural units. When the resin (A) contains structural units represented by the formulas (a1-8-1) to (a1-8-3), the content thereof is 10 mol% or more, preferably 15 mol% or more, more preferably 20 mol% or more, still more preferably 25 mol% or more, even more preferably 30 mol% or more, still even more preferably 40 mol% or more, and even more preferably 50 mol% or more, based on all the structural units of the resin (A). Also, it is 95 mol% or less, preferably 90 mol% or less, more preferably 85 mol% or less, still more preferably 80 mol% or less, even more preferably 75 mol% or less, still even more preferably 70 mol% or less, and even more preferably 60 mol% or less. Specifically, 10 to 60 mol% is preferable, 15 to 55 mol% is more preferable, 20 to 50 mol% is still more preferable, 20 to 45 mol% is even more preferable, and 20 to 40 mol% is particularly preferable.

[0120] 〈Structural unit(s)〉 The structural unit(s) is derived from a monomer having no acid-labile group (hereinafter sometimes referred to as "monomer(s)"). As the monomer from which the structural unit(s) is derived, a monomer having no acid-labile group known in the resist field can be used. As the structural unit(s), it is preferable to have a hydroxy group, a carboxy group or a lactone ring. By using a resin containing a structural unit having a hydroxy group or a carboxy group and not having an acid-labile group (hereinafter sometimes referred to as "structural unit (a2)") and / or a structural unit having a lactone ring and not having an acid-labile group (hereinafter sometimes referred to as "structural unit (a3)") in the resist composition of the present invention, the resolution of the resist pattern and the adhesion to the substrate can be improved. In addition to the above-described structural units, the structural unit(s) include a structural unit having a halogen atom (hereinafter sometimes referred to as "structural unit (a4)"), a structural unit having a non-leaving hydrocarbon group (hereinafter sometimes referred to as "structural unit (a5)"), a structural unit having a sultone structure (hereinafter sometimes referred to as "structural unit (a6)"), a structural unit that decomposes upon exposure to generate an acid (hereinafter sometimes referred to as "structural unit (a7)"), or other structural units well-known in the art.

[0121] 〈Structural unit (a2)〉 The structural unit (a2) is a structural unit represented by the formula (a2) and has an alcoholic hydroxy group, a phenolic hydroxy group or a carboxy group. TIFF2025088761000107.tif4094[In the formula (a2), R a2 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. A a21 represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and -CH 2 - contained in the alkanediyl group may be replaced by -O-, -CO- or -NR a28 -. R a28 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. L a21 represents a single bond or a hydrocarbon group having 1 to 28 carbon atoms, the hydrocarbon group may have a substituent, and -CH 2 - contained in the hydrocarbon group may be replaced by -O-, -CO-, -S- or -SO 2 -. L a22 represents a chain hydrocarbon group having 1 to 12 carbon atoms which may have a single bond or a fluorine atom, and -CH 2 - in the chain hydrocarbon group may be replaced by -O- or -CO-. na2 represents any integer from 1 to 5. When na2 is 2 or more, a plurality of Ls a22 may be the same as or different from each other.

[0122] R a2 Examples of the halogen atom in R include a fluorine atom, an iodine atom, a chlorine atom, a bromine atom and the like. R a2 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in R include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, a hexyl group, a perfluorohexyl group, a chloromethyl group, a bromomethyl group, an iodomethyl group. The number of carbon atoms of the alkyl group is preferably 1 to 4, more preferably 1 to 3, and still more preferably 1 or 2. R a2 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group.

[0123] A a21Examples of the alkanediyl group include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, and branched alkanediyl groups such as butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, heptane-1,6-diyl group, octane-1,7-diyl group, nonane-1,8-diyl group, decane-1,9-diyl group, undecane-1,10-diyl group. The number of carbon atoms in the alkanediyl group is preferably 1 to 10, more preferably 1 to 8, still more preferably 1 to 6, even more preferably 1 to 4, still even more preferably 1 to 3, and even more preferably 1 or 2. R a28 Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, and tert-butyl group. A a21 When -CH 2 - included in the alkanediyl group of a21 is replaced by -O-, -CO- or -NR a28 -, the number of carbon atoms before replacement is regarded as the number of carbon atoms of the alkanediyl group. A a21 When -CH 2 - included in the alkanediyl group of a21 is replaced by -O-, -CO- or -NR a28Examples of the group that replaces the - include a hydroxy group, a carboxy group, a carbonyl group, an oxy group, an amino group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylamino group, a peptide group, an alkanediyl-oxy group, an alkanediyl-oxycarbonyl group, an alkanediylcarbonyl group, an alkanediylcarbonyl-oxy group, an alkanediylsulfonyl group, an alkanediylthio group, an alkanediylamino group, and the like. These replaced groups include those similar to the groups exemplified in this specification within the range where the upper limit of the number of carbon atoms is allowed. Among them, A a21 in the alkanediyl group of 2 -CH a28 - being replaced by -O-, -CO-, or -NR a22 - includes *-O-, *-CO-O-, *-O-CO-, *-CO-O-A a22 -CO-O-, *-O-CO-A a22 -O-, *-O-A a22 -CO-O-, *-CO-O-A a22 -O-CO-, *-O-CO-A a28 -O-CO-, *-CO-NR a22 -. Among them, *-CO-O-, *-CO-O-A a22 -CO-O-, *-O-A a28 -CO-O-, *-CO-NR a22 - are preferred. Here, A a2 represents an alkanediyl group having 1 to 8 carbon atoms, and * represents the bonding site with the carbon atom to which R a22 is bonded. The alkanediyl group of A a21 includes alkanediyl groups similar to A A a21 is preferably a single bond, *-CO-O-, or *-CO-O-A a22 -CO-O-, more preferably a single bond, *-CO-O-, or *-CO-O-CH 2 -CO-O-, and even more preferably a single bond or *-CO-O-.

[0124] L a21The hydrocarbon group in [description] is a (na2+1)-valent hydrocarbon group, and examples thereof include linear or branched chain hydrocarbon groups, monocyclic or polycyclic (including spiro rings, condensed rings, bridged rings, etc.) alicyclic hydrocarbon groups, and cyclic hydrocarbon groups such as aromatic hydrocarbon groups. A group formed by combining two or more of these groups (for example, a hydrocarbon group formed from an alicyclic hydrocarbon group or an aromatic hydrocarbon group and a chain hydrocarbon group) may also be used. L a21 Examples of the chain hydrocarbon group of [description] include divalent to hexavalent chain hydrocarbon groups such as alkanediyl groups, alkanetriyl groups, alkanetetrayl groups, alkanepentayl groups, and alkanexayl groups. Examples of the alkanediyl group include, for example, an alkanediyl group similar to A a21 as described above. Examples of the alkanetriyl group include methanetriyl group, ethanetriyl group, propanetriyl group, butanetriyl group, pentanetriyl group, hexanetriyl group, heptanetriyl group, octanetriyl group, nonanetriyl group, decanetriyl group, undecanetriyl group, dodecanetriyl group, tridecanetriyl group, tetradecanetriyl group, pentadecanetriyl group, hexadecanetriyl group, and heptadecanetriyl group. Examples of the alkanetetrayl group include methanetetrayl group, ethanetetrayl group, propanetetrayl group, butanetetrayl group, pentanetetrayl group, hexanetetrayl group, heptanetetrayl group, octanetetrayl group, nonanetetrayl group, decanetetrayl group, undecanetetrayl group, dodecanetetrayl group, tridecanetetrayl group, tetradecanetetrayl group, pentadecanetetrayl group, hexadecanetetrayl group, and heptadecanetetrayl group. Examples of the alkanepentayl group include methanepentayl group, ethanepentayl group, propanepentayl group, butanepentayl group, pentanepentayl group, and hexanepentayl group. In addition, groups in which one or more hydrogen atoms of the above-described groups are replaced with a bonding site, etc. are also included. L a21The number of carbon atoms in the chain hydrocarbon group is preferably from 1 to 18, more preferably from 1 to 12, still more preferably from 1 to 10, even more preferably from 1 to 9, still even more preferably from 1 to 8, still more preferably from 1 to 6, even more preferably from 1 to 5, and particularly preferably from 1 to 4. L a21 Examples of the monocyclic and polycyclic alicyclic hydrocarbon groups in a21 include the following alicyclic hydrocarbon groups and the like. The bonding site can be at any position. TIFF2025088761000108.tif46168For example, divalent to hexavalent alicyclic hydrocarbon groups such as cycloalkanediyl groups, cycloalkanetriyl groups, cycloalkanetetrayl groups, cycloalkanepentayl groups, cycloalkanehexayl groups and the like can be mentioned. Specifically, monocyclic alicyclic hydrocarbon groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group, cyclopropanetriyl group, cyclobutanetriyl group, cyclopentanetriyl group, cyclohexanetriyl group, cycloheptanetriyl group, cyclooctanetriyl group, cyclodecanetriyl group, cyclopropanetetrayl group, cyclobutanetetrayl group, cyclopentanetetrayl group, cyclohexanetetrayl group, cycloheptanetetrayl group, cyclooctanetetrayl group, cyclodecanetetrayl group and polycyclic alicyclic hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, decahydronaphthalenediyl group, bicyclo[3.3.0]octanediy group, norbornanetriyl group, adamantanetriyl group, decahydronaphthalenetriyl group, bicyclo[3.3.0]octanetriyl group, norbornanetetrayl group, adamantanetetrayl group, decahydronaphthalenetetrayl group, bicyclo[3.3.0]octanetetrayl group and the like can be mentioned. In addition, groups in which one or more hydrogen atoms of the above-mentioned groups are replaced by a bonding site and the like can also be mentioned. The number of carbon atoms in the alicyclic hydrocarbon group is preferably from 3 to 20, more preferably from 3 to 18, still more preferably from 3 to 16, even more preferably from 3 to 12, yet even more preferably from 6 to 12, and particularly preferably from 6 to 10. L a21 Examples of the aromatic hydrocarbon group in a21 include divalent to hexavalent aromatic hydrocarbon groups such as an arylene group, an arenetriyl group, an arenetetrayl group, an arenepentayl group, and an arenexayl group. Specifically, a phenylene group, a naphthylene group, an anthrylene group, a biphenylene group, a phenanthrylene group, a benzenetriyl group, a naphthalenetriyl group, an anthracenetriyl group, a biphenylenetriyl group, a phenanthrenetriyl group, a benzenetetrayl group, a naphthalenetetrayl group, an anthracenetetrayl group, a biphenylenetetrayl group, a phenanthrenetetrayl group, etc. can be mentioned. Moreover, groups in which one or more hydrogen atoms of the above-described groups are replaced with a bonding site, etc. can also be mentioned. The number of carbon atoms in the aromatic hydrocarbon group is preferably from 6 to 20, more preferably from 6 to 18, still more preferably from 6 to 14, even more preferably from 6 to 12, yet even more preferably from 6 to 10. Examples of the group formed by combining two or more types include a group formed by combining an alicyclic hydrocarbon group and a chain hydrocarbon group, a group formed by combining an aromatic hydrocarbon group and a chain hydrocarbon group, a group formed by combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group, a group formed by combining an alicyclic hydrocarbon group, a chain hydrocarbon group, and an aromatic hydrocarbon group, etc. In the combination, the alicyclic hydrocarbon group, the aromatic hydrocarbon group, and the chain hydrocarbon group may each be combined with two or more types. Also, any group may be A a21 and L a22 and may be bonded to a22 . Examples of the group in which -CH 2 - contained in the hydrocarbon group is replaced with -O-, -S-, -SO 2 -, or -CO- include a hydroxy group (a group in which -CH 2 - contained in the methyl group is replaced with -O-), a carboxy group (a group in which -CH 2 -CH2 - is a group replaced by -O-CO-), a thiol group (-CH contained in the methyl group 2 - is a group replaced by -S-), an alkoxy group (-CH at any position contained in the alkyl group 2 - is a group replaced by -O-), an alkylthio group (-CH at any position contained in the alkyl group 2 - is a group replaced by -S-), an alkoxycarbonyl group (-CH at any position contained in the alkyl group 2 -CH 2 - is a group replaced by -O-CO-), an alkylsulfonyl group (-CH at any position contained in the alkyl group 2 - is 2 - replaced by -SO-), an alkylcarbonyl group (-CH at any position contained in the alkyl group 2 - is a group replaced by -CO-), an alkylcarbonyloxy group (-CH at any position contained in the alkyl group 2 -CH 2 - is a group replaced by -CO-O-), an oxy group (-CH contained in the methylene group 2 - is a group replaced by -O-), a carbonyl group (-CH contained in the methylene group 2 - is a group replaced by -CO-), a thio group (-CH contained in the methylene group 2 - is a group replaced by -S-), a sulfonyl group (-CH contained in the methylene group 2 - is 2 - replaced by -SO-), an alkanedioxy group (-CH at any position contained in the alkanediyl group 2 - is a group replaced by -O-), an alkanedioxycarbonyl group (-CH at any position contained in the alkanediyl group 2 -CH 2 - is a group replaced by -O-CO-), an alkanediylcarbonyl group (-CH at any position contained in the alkanediyl group 2 - is a group replaced by -CO-), an alkanediylcarbonyloxy group (-CH at any position contained in the alkanediyl group 2 -CH 2- is a group replaced by -CO-O-), an alkanediylsulfonyl group (any -CH at any position contained in the alkanediyl group) 2 - is 2 - a group replaced by -SO 2 - a group replaced by -S-), a cycloalkoxy group, a cycloalkylalkoxy group, an alkoxycarbonyloxy group, an aromatic hydrocarbon group - carbonyloxy group, an aromatic hydrocarbon group - carbonyl group, an aromatic hydrocarbon group - oxy group, a group formed by combining two or more of these groups, etc. Also included are groups in which one or more hydrogen atoms of these groups are replaced at the bonding site, etc. Examples of the alkoxy group include alkoxy groups having 1 to 27 carbon atoms, such as 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 of the alkoxy group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkylthio group include alkylthio groups having 1 to 27 carbon atoms, such as methylthio group, ethylthio group, propylthio group, butylthio group, etc. The number of carbon atoms of the alkylthio group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 27 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, and a butoxycarbonyl group. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 28 carbon atoms, such as an acetyl group, a propionyl group, and a butyryl group. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 27 carbon atoms, such as an acetyloxy group, a propionyloxy group, and a butyryloxy group. The number of carbon atoms in the alkoxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. Examples of the alkylsulfonyl group include alkylsulfonyl groups having 1 to 27 carbon atoms, such as a methylsulfonyl group, an ethylsulfonyl group, and a propylsulfonyl group. The number of carbon atoms in the alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanedioxy group include alkanedioxy groups having 1 to 27 carbon atoms, such as a methyleneoxy group, an ethyleneoxy group, a propanediioxy group, a butanediioxy group, and a pentanediioxy group. The number of carbon atoms in the alkanedioxy group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediyl-oxycarbonyl group include alkanediyl-oxycarbonyl groups having 2 to 27 carbon atoms, such as a methylene-oxycarbonyl group, an ethylene-oxycarbonyl group, a propanediyl-oxycarbonyl group, and a butanediyl-oxycarbonyl group. Examples of the alkanediyl-carbonyl group include alkanediyl-carbonyl groups having 2 to 28 carbon atoms, such as a methylene-carbonyl group, an ethylene-carbonyl group, a propanediyl-carbonyl group, a butanediyl-carbonyl group, and a pentanediyl-carbonyl group. Examples of the alkanediyl-carbonyloxy group include alkanediyl-carbonyloxy groups having 2 to 27 carbon atoms, such as a methylene-carbonyloxy group, an ethylene-carbonyloxy group, a propanediyl-carbonyloxy group, and a butanediyl-carbonyloxy group. The number of carbon atoms of the alkanediyl-oxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkanediyl-carbonyl group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkanediyl-carbonyloxy group is preferably 2 to 11, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. Examples of the alkanediyl-thio group include alkanediyl-thio groups having 1 to 27 carbon atoms, such as a methylene-thio group, an ethylene-thio group, and a propanediyl-thio group. The number of carbon atoms of the alkanediyl-thio group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediyl-sulfonyl group include alkanediyl-sulfonyl groups having 1 to 27 carbon atoms, such as a methylene-sulfonyl group, an ethylene-sulfonyl group, and a propylene-sulfonyl group. The number of carbon atoms of the alkanediyl-sulfonyl group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3.

[0125] Examples of the cycloalkoxy group include cycloalkoxy groups having 3 to 27 carbon atoms, such as a cyclohexyloxy group. Examples of the cycloalkylalkoxy group include cycloalkylalkoxy groups having 4 to 27 carbon atoms, such as a cyclohexylmethoxy group. Examples of the alkoxycarbonyloxy group include alkoxycarbonyloxy groups having 2 to 26 carbon atoms, such as a butoxycarbonyloxy group. Examples of the aromatic hydrocarbon group-carbonyl oxy group include aromatic hydrocarbon group-carbonyl oxy groups having 7 to 27 carbon atoms, such as a benzoyloxy group. Examples of the aromatic hydrocarbon group-carbonyl group include aromatic hydrocarbon group-carbonyl groups having 7 to 28 carbon atoms, such as a benzoyl group. Examples of the aromatic hydrocarbon group-oxy group include aromatic hydrocarbon group-oxy groups having 6 to 27 carbon atoms, such as a phenyloxy group.

[0126] In addition, -CH 2 - contained in the alicyclic hydrocarbon group is replaced with -O-, -S-, -CO- or -SO 2 Examples of the group thus replaced include the following groups. Among the groups represented below, groups in which -O- is replaced with -S- and -CO- is replaced with -SO 2 - are also included. The bonding site can be at any position. TIFF2025088761000109.tif47168 -CH contained in the group combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group 2 - is replaced with -O-, -S-, -CO- or -SO 2 Examples of the group thus replaced also include the following groups. The bonding site can be at any position. TIFF2025088761000110.tif26164L a21 The hydrocarbon group in may have one or more substituents. Examples of the substituent include a halogen atom, a haloalkyl group having 1 to 12 carbon atoms, and an alkyl group having 1 to 16 carbon atoms (the -CH contained in the alkyl group 2- may be replaced by -O- or -CO-. ), an acryloyloxy group, a methacryloyloxy group, etc. may be mentioned. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. L a21 The hydrocarbon group in may have a substituent such as a haloalkyl group by having a halogen atom as a substituent. Examples of the haloalkyl group include a fluoroalkyl group, a chloroalkyl group, a bromoalkyl group, an iodoalkyl group, etc. For example, a chloromethyl group, a bromomethyl group, an iodomethyl group, a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, etc. may be mentioned. The number of carbon atoms of the haloalkyl group is preferably 1 to 8, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. L a21 By including a branched structure in the hydrocarbon group of, L a21 may have a substituent such as an alkyl group substantially. 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, a dodecyl group, etc. The number of carbon atoms of the alkyl group is preferably 1 to 12, more preferably 1 to 10, still more preferably 1 to 8, even more preferably 1 to 6, still even more preferably 1 to 4, and even more preferably 1 to 3. L a21 The -CH 2 - in the hydrocarbon group of being replaced by a group such as -O- or -CO- etc., L a21can substantially have substituents such as a hydroxy group, a carboxy group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, a thiol group, a sulfonyl group, an alkoxyalkyl group, an alkoxyalkoxy group, an acryloyloxy group, a methacryloyloxy group, etc. Such groups include, within the range allowed by the upper limit of the number of carbon atoms, the same groups as those exemplified in this specification. L a21 The substituents that the hydrocarbon group in may optionally have include a halogen atom, a haloalkyl group having 1 to 8 carbon atoms, or an alkyl group having 1 to 12 carbon atoms (the -CH 2 - in it may be replaced by -O- or -CO-.) are preferred, a halogen atom, a haloalkyl group having 1 to 6 carbon atoms, or an alkyl group having 1 to 10 carbon atoms (the -CH2- in the alkyl group may be replaced by -O- or -CO-.) are more preferred, a halogen atom, a haloalkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms, a hydroxy group, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms are even more preferred, a fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, a hydroxy group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group are still more preferred, and a fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, a hydroxy group, a methoxy group, or an ethoxyethoxy group are even still more preferred.

[0127] Also, when the alkanediyl group of L a21 is replaced by -O- or -CO- etc., for example, *-L a23 -X a21 -(L a23 represents an alkanediyl group having 1 to 8 carbon atoms, X a21 represents -O-, -O-CO-, -CO-O-, or -O-CO-O-, and * represents the bonding site with A a21 .) is also preferred. L a21is a single bond, an optionally substituted chain hydrocarbon group having 1 to 12 carbon atoms (provided that -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-), an optionally substituted cyclic hydrocarbon group having 3 to 20 carbon atoms (provided that -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO 2 -), or a group formed by combining an optionally substituted chain hydrocarbon group having 1 to 8 carbon atoms and an optionally substituted cyclic hydrocarbon group having 3 to 20 carbon atoms (provided that -CH 2 - in the chain hydrocarbon group may be replaced by -O- or -CO-, and -CH 2 - in the cyclic hydrocarbon group may be replaced by -O-, -S-, -SO 2 - or -CO-). Preferably, it is an optionally substituted chain hydrocarbon group having 1 to 10 carbon atoms (provided that -CH 2 - in the chain hydrocarbon group may be replaced by -O- or -CO-), an optionally substituted cyclic hydrocarbon group having 3 to 18 carbon atoms (provided that -CH 2 - in the cyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO 2 -), or a group formed by combining an optionally substituted chain hydrocarbon group having 1 to 6 carbon atoms and an optionally substituted cyclic hydrocarbon group having 3 to 18 carbon atoms (provided that -CH 2 - in the chain hydrocarbon group may be replaced by -O- or -CO-, and -CH 2 - in the cyclic hydrocarbon group may be replaced by -O-, -S-, -SO 2 - or -CO-). More preferably, it is as described above.

[0128] L a22Examples of the chain hydrocarbon group having 1 to 12 carbon atoms include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, etc., and branched alkanediyl groups such as ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-dimethylpropane-1,3-diyl group, pentane-2,4-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, pentane-2,4-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, etc. The number of carbon atoms of the chain hydrocarbon group is preferably 1 to 10, more preferably 1 to 8, still more preferably 1 to 6, and even more preferably 1 to 4. -CH 2 Examples of the group in which - in the chain hydrocarbon group is replaced by -O- or -CO- include those similar to those exemplified herein within the range allowed by the upper limit of the number of carbon atoms. L a22 The fluorine atom that L has may be one or two or more. na2 is preferably any integer from 1 to 4, and more preferably any integer from 1 to 3. L a21 Examples of the structural unit (a2) when L is a single bond or a chain hydrocarbon group include, for example, the following structural units. Among the following structural units, the structural unit in which the methyl group corresponding to R a2 is replaced by a hydrogen atom or the like is also a preferred structural unit of the structural unit (a2) in the same manner as the following structural units. TIFF2025088761000111.tif67168

[0129] When producing a resist pattern from the resist composition of the present invention, when using a high-energy ray such as a KrF excimer laser (248 nm), an electron beam, or EUV (extreme ultraviolet light) as an exposure light source, as the structural unit (a2), a structural unit (a2) having a phenolic hydroxy group is preferable, and it is more preferable to use the structural unit (a2-A) described later. When using an ArF excimer laser (193 nm) or the like, as the structural unit (a2), a structural unit (a2) having an alcoholic hydroxy group is preferable, and it is more preferable to use the structural unit (a2-C) described later. As the structural unit (a2), one kind may be contained alone, or two or more kinds may be contained.

[0130] In the structural unit (a2), when L a21 is a cyclic hydrocarbon group, examples of the structural unit having a phenolic hydroxy group or a carboxy group include the structural unit represented by the formula (a2-A) (hereinafter sometimes referred to as "structural unit (a2-A)"). TIFF2025088761000112.tif30128[In the formula (a2-A), all the symbols have the same meanings as described above.]

[0131] R a2 and A a21 are each a group similar to those exemplified by the formula (a2). R a27 Examples of the halogen atom of R include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom. R a27Examples of the C1-C6 alkyl group which may have a halogen atom include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, chloromethyl group, bromomethyl group, and iodomethyl group. The number of carbon atoms of the alkyl group is preferably 1-4, more preferably 1-3, still more preferably methyl group or ethyl group, and even more preferably methyl group. R a27 Examples of the alkoxy group of a27 include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, sec-butoxy group, and tert-butoxy group. The alkoxy group is preferably an alkoxy group having 1-4 carbon atoms, more preferably an alkoxy group having 1-3 carbon atoms, still more preferably methoxy group or ethoxy group, and even more preferably methoxy group. R a27 Examples of the alkoxyalkyl group of a27 include methoxymethyl group, ethoxyethyl group, propoxymethyl group, isopropoxymethyl group, butoxymethyl group, sec-butoxymethyl group, and tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2-8 carbon atoms, more preferably an alkoxyalkyl group having 2-4 carbon atoms, still more preferably methoxymethyl group or ethoxyethyl group, and even more preferably methoxymethyl group. R a27Examples of the alkoxyalkoxy group include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably an alkoxyalkoxy group having 2 to 4 carbon atoms, and even more preferably a methoxyethoxy group or an ethoxyethoxy group. R a27 Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 4 carbon atoms, more preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and even more preferably an acetyl group. R a27 Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 4 carbon atoms, more preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and even more preferably an acetyloxy group. R a27 R is preferably a halogen atom, a hydroxy group, a carboxy group, an optionally halogenated 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. nA2 is preferably 1, 2, 3, or 4, more preferably 1, 2, or 3, and even more preferably 1 or 2. na21 is preferably 0, 1, 2, or 3, more preferably 0, 1, or 2, and even more preferably 0 or 1. mc is preferably 0 or 1. -X a2 -OH, in the case of a benzene ring, A a21With respect to the bonding position of , it may be bonded to any of the o-position, m-position or p-position. Among them, it is preferable that at least one is bonded to the m-position or p-position, and more preferably bonded to the m-position. In the case of a naphthalene ring, A a21 When the bonding position of is the 1st position, it may be bonded to any of the 2nd to 8th positions, A a21 When the bonding position of is the 2nd position, it may be bonded to any of the 1st and 3rd to 8th positions. Among them, A a21 When the bonding position of is the 1st position, it is preferable that at least one is bonded to the 3rd to 6th positions, and more preferably bonded to the 3rd or 4th position. A a21 When the bonding position of is the 2nd position, it is preferable that it is bonded to the 4th to 7th positions, and more preferably bonded to the 5th or 6th position.

[0132] Examples of the structural unit (a2-A) include structural units derived from the monomers described in JP-A-2010-204634 and JP-A-2012-12577. Examples of the structural unit (a2-A) include structural units represented by formula (a2-2-1) to formula (a2-2-32), formula (a2-3-1) to formula (a2-3-24), and in the structural units represented by formula (a2-2-1) to formula (a2-2-32), formula (a2-3-1) to formula (a2-3-24), R in the structural unit (a2-A) a2 Examples include structural units in which the methyl group corresponding to is replaced by a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group. TIFF2025088761000113.tif107170

[0133] When the structural unit (a2-A) is contained in the resin (A), the content of the structural unit (a2-A) is preferably 5 mol% or more, more preferably 10 mol% or more, still more preferably 15 mol% or more, and even more preferably 20 mol% or more, based on all the structural units. Also, it is preferably 80 mol% or less, more preferably 70 mol% or less, still more preferably 65 mol% or less, even more preferably 60 mol% or less, still even more preferably 50 mol% or less, still more preferably 45 mol% or less, and even more preferably 40 mol% or less. Specifically, it is preferably 5 to 80 mol%, more preferably 10 to 70 mol%, still more preferably 15 to 65 mol%, and even more preferably 20 to 65 mol%. The structural unit (a2-A) is derived from a compound represented by the formula (a2-A') (hereinafter sometimes referred to as "compound (a2-A)"). TIFF2025088761000115.tif32121[In the formula (a2-A'), all the symbols have the same meanings as described above.] The compound (a2-A') may be a commercially available product or may be produced by a known method. The structural unit (a2-A) can be incorporated into the resin (A) by polymerizing the compound (a2-A') or the like. Also, for example, after polymerization using the structural unit (a1-4), it can be incorporated into the resin (A) by treatment with an acid such as p-toluenesulfonic acid. Also, after polymerization using acetoxystyrene or the like, the structural unit (a2-A) can be incorporated into the resin (A) by treatment with an alkali such as tetramethylammonium hydroxide.

[0134] In the structural unit (a2), L a21When it is a cyclic hydrocarbon group, examples of the structural unit having an alcoholic hydroxy group or a carboxy group include a structural unit represented by formula (a2-B) (hereinafter sometimes referred to as "structural unit (a2-B)"), a structural unit represented by formula (a2-C) (hereinafter sometimes referred to as "structural unit (a2-C)"), and a structural unit represented by formula (a2-D) (hereinafter sometimes referred to as "structural unit (a2-D)"). TIFF2025088761000116.tif46100[In formula (a2-B) and formula (a2-C), R a2 represents the same meaning as formula (a2). R a27 represents the same meaning as formula (a2-A). L a25 represents -O- or *-O-(CH 2 ) k2 -CO-O-, k2 represents an integer of any one of 1 to 7. * represents the bonding site with -CO-. X a2 represents a single bond or -CO-. R a25 and R a26 each independently represent a hydrogen atom, a methyl group or a hydroxy group. nB2 represents an integer of any one of 1 to 5. When nB2 is 2 or more, a plurality of X a2 may be the same as or different from each other. nB22 represents an integer of any one of 0 to 8. When nB22 is 2 or more, a plurality of R a27 may be the same as or different from each other. nC22 represents an integer of any one of 0 to 10. When nC22 is 2 or more, a plurality of R a27 may be the same as or different from each other.]

[0135] L a25 is preferably -O-, -O-(CH 2 ) f1 -CO-O- (wherein f1 represents an integer of any one of 1 to 4), more preferably -O-. R a2is preferably a methyl group. X a2 is preferably a single bond. R a25 is preferably a hydrogen atom. R a26 is preferably a hydrogen atom or a hydroxy group. R a27 is preferably a halogen atom, a hydroxy group, a carboxy group, an optionally halogenated C1-C4 alkyl group, a C1-C4 alkoxy group or a C2-C8 alkoxyalkoxy group, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group or an ethoxy methoxy group, still more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group or an ethoxyethoxy group. nB2 is preferably 1, 2, 3 or 4, more preferably 1, 2 or 3, still more preferably 1 or 2. nB22 is preferably any integer from 0 to 3, more preferably 0, 1 or 2, still more preferably 0 or 1. nC22 is preferably any integer from 0 to 6, more preferably any integer from 0 to 3, still more preferably 0 or 1.

[0136] Examples of the structural unit (a2-B) and the structural unit (a2-C) include structural units derived from the monomers described in JP-A-2010-204646, the following structural units, and structural units in which the methyl group or hydrogen atom corresponding to R a2 in the following structural units is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group. Among them, structural units represented by any of formula (a2-B-1) to formula (a2-B-5) and formula (a2-C-1) to formula (a2-C-9) are preferred. When the resin (A) contains the structural unit (a2-B) or the structural unit (a2-C), the content thereof is 1 mol% or more, preferably 2 mol% or more, based on all the structural units of the resin (A). Further, it is 45 mol% or less, preferably 40 mol% or less, more preferably 35 mol% or less, still more preferably 20 mol% or less, and even more preferably 10 mol% or less. Specifically, 1 to 45 mol% is mentioned, preferably 1 to 40 mol%, more preferably 1 to 35 mol%, still more preferably 1 to 20 mol%, and even more preferably 1 to 10 mol%.

[0137] Examples of the structural unit having an alcoholic hydroxy group in the structural unit (a2) include a structural unit represented by the formula (a2-D) (hereinafter sometimes referred to as "structural unit (a2-D)"). TIFF2025088761000118.tif51106[In the formula (a2-D), R a2 and A a21 each represent the same meaning as in the formula (a2). R a27 represents the same meaning as in the formula (a2-A). R a21 and R a22 each independently represent a fluoroalkyl group having 1 to 4 carbon atoms. L a24 represents a single bond or an alkanediyl group having 1 to 3 carbon atoms, and the alkanediyl group may be substituted with a fluorine atom. nD2 represents any integer from 1 to 5. When nD2 is 2 or more, the groups in the plurality of parentheses may be the same as or different from each other. nD22 represents any integer from 0 to 4. When nD22 is 2 or more, the plurality of R a27 may be the same as or different from each other. However, 1 ≦ nD2 + nD22 ≦ 5.]

[0138] R a21 and R a22Examples of the alkyl fluoride group include, independently of each other, a trifluoromethyl group, a 2,2,2-trifluoroethyl group, a 3,3,3-trifluoropropyl group, a 4,4,4-trifluorobutyl group, and the like. R a21 and R a22 is preferably a trifluoromethyl group. L a24 Examples of the alkanediyl group of L include a methylene group, an ethane-1,1-diyl group, a propane-1,1-diyl group, a propane-2,2-diyl group, and the like. L a24 is preferably a single bond or a methylene group. R a27 is preferably a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 4 carbon atoms which may have a halogen atom, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxy-methoxy group, and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group. nD2 is preferably 1, 2, 3, or 4, more preferably 1, 2, or 3, even more preferably 1 or 2, and even more preferably 1. Also, preferably, nD2 is 1 and the group in parentheses is bonded to the para position. nD22 is preferably any integer from 0 to 3, more preferably any integer from 0 to 2, even more preferably 0 or 1, and even more preferably 0. As the structural unit (a2-D), a structural unit represented by the following formula (a2-D1) (hereinafter sometimes referred to as "structural unit (a2-D1)") is more preferable. TIFF2025088761000119.tif51107[In formula (a2-D1), R a2 , A a21 , R a27 , nD2 and nD22 represent the same meanings as in formula (a2-D).] In formula (a2-D1), Ra2 is preferably a hydrogen atom or a methyl group. A a21 is preferably a single bond. Examples of the structural unit (a2-D) include the structural units described below. TIFF2025088761000120.tif62167

[0139] In the structural units represented by formula (a2-D-1) to formula (a2-D-8), the hydrogen atom corresponding to R a2 replaced by a methyl group or the like, and in the structural units represented by formula (a2-D-9) to formula (a2-D-16), the methyl group corresponding to R a2 replaced by a hydrogen atom or the like can also be cited as specific examples of the structural unit (a2-D). Among them, the structural units represented by formula (a2-D-1) to formula (a2-D-8) are preferred, the structural units represented by formula (a2-D-1) to formula (a2-D-4) are more preferred, and the structural unit represented by formula (a2-D-1) is even more preferred.

[0140] When the resin (A) contains the structural unit (a2-D), its content is preferably 3 mol% or more, more preferably 5 mol% or more, still more preferably 10 mol% or more, based on all the structural units of the resin (A). Also, it is preferably 80 mol% or less, more preferably 75 mol% or less, still more preferably 70 mol% or less, and even more preferably 65 mol% or less. Specifically, it is preferably 3 to 80 mol%, more preferably 5 to 75 mol%, still more preferably 10 to 70 mol%, and even more preferably 10 to 65 mol%.

[0141] 〈Structural unit (a3)〉 The lactone ring of the structural unit (a3) may be a monocyclic ring such as a β-propiolactone ring, a γ-butyrolactone ring, or a δ-valerolactone ring, or a condensed ring of a monocyclic lactone ring and another ring. Preferably, a γ-butyrolactone ring, an adamantane lactone ring, or a bridged ring containing a γ-butyrolactone ring structure (for example, the structural unit represented by the following formula (a3-2)) can be cited. The structural unit (a3) is preferably a structural unit represented by formula (a3-1), formula (a3-2), formula (a3-3) or formula (a3-4). These may be contained alone or in combination of two or more. TIFF2025088761000121.tif51164[In formula (a3-1), formula (a3-2), formula (a3-3) and formula (a3-4), L a4 、L a5 and L a6 each independently represents a group represented by -O- or *-O-(CH 2 ) k3 -CO-O- (where k3 represents an integer from 1 to 7). L a7 represents -O-, *-O-L a8 -O-, *-O-L a8 -CO-O-, *-O-L a8 -CO-O-L a9 -CO-O- or *-O-L a8 -O-CO-L a9 -O-. L a8 and L a9 each independently represents an alkanediyl group having 1 to 6 carbon atoms. * represents the bonding site with the carbonyl group. R a18 、R a19 、R a20 and R a24 each independently represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. X a3 represents -CH 2 - 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 from 0 to 5. q1 represents an integer from 0 to 3. r1 represents an integer of any one of 0 to 3. w1 represents an integer of any one of 0 to 8. When p1, q1, r1, and / or w1 is 2 or more, a plurality of Rs a21 , Rs a22 , Rs a23 and / or Rs a25 may be the same as or different from each other.

[0142] Rs a21 , Rs a22 , Rs a23 and Rs a25 Examples of the aliphatic hydrocarbon group in include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, and tert-butyl group. Rs a18 , Rs a19 , Rs a20 and Rs a24 Examples of the halogen atom and the alkyl group which may have a halogen atom in include the same as those exemplified by R of formula (a1-0) a01 and the like. Ls a8 and Ls a9 Examples of the alkanediyl group in include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, and the like. Ls a4 to Ls a6 are each independently preferably -O- or, *-O-(CH 2 ) k3 -CO-O- in which k3 is an integer of any one of 1 to 4, more preferably -O- and, *-O-CH 2 -CO-O-, still more preferably an oxygen atom. Ls a7 is preferably -O- or *-O-Ls a8-CO-O-, more preferably -O-, -O-CH 2 -CO-O- or -O-C 2 H 4 -CO-O-. R a18 、R a19 、R a20 and R a24 are preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group. R a21 is preferably a methyl group. R a22 、R a23 and R a25 are each independently preferably a carboxy group, a cyano group or a methyl group. p1, q1 and r1 are each independently preferably any integer from 0 to 2, more preferably 0 or 1. w1 is preferably any integer from 0 to 2, more preferably 0 or 1. In particular, formula (a3-4) is preferably formula (a3-4)'. TIFF2025088761000122.tif4051(wherein R a24 、L a7 represents the same meaning as described above.) Examples of the structural unit (a3) include structural units derived from the monomers described in JP-A-2010-204646, the monomers described in JP-A-2000-122294, and the monomers described in JP-A-2012-41274. Examples of the structural unit (a3) include structural units represented by any of formula (a3-1-1), formula (a3-1-2), formula (a3-2-1), formula (a3-2-2), formula (a3-3-1), formula (a3-3-2) and formula (a3-4-1) to formula (a3-4-12), and, in the above structural units, structural units in which the methyl group corresponding to R a18 、R a19 、R a20 and R a24 is replaced by a hydrogen atom are preferred. When the resin (A) contains the structural unit (a3), the total content is 1 mol% or more, preferably 3 mol% or more, more preferably 5 mol% or more, still more preferably 10 mol% or more, based on all the structural units of the resin (A). Also, it is 70 mol% or less, preferably 65 mol% or less, more preferably 60 mol% or less, still more preferably 50 mol% or less, even more preferably 40 mol% or less, still even more preferably 30 mol% or less, still more preferably 25 mol% or less, and still even more preferably 20 mol% or less. Specifically, it is 1 to 70 mol%, preferably 3 to 70 mol%, more preferably 3 to 65 mol%, still more preferably 5 to 65 mol%, even more preferably 5 to 60 mol%, and still even more preferably 10 to 60 mol%. Also, 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, still more preferably 5 mol% or more, and still even more preferably 10 mol% or more, based on all the structural units of the resin (A). Also, it is preferably 60 mol% or less, more preferably 55 mol% or less, still more preferably 50 mol% or less, even more preferably 40 mol% or less, still even more preferably 30 mol% or less, still more preferably 25 mol% or less, and still even more preferably 20 mol% or less. Specifically, 1 to 60 mol% is preferred, 3 to 60 mol% is more preferred, 3 to 55 mol% is still more preferred, 5 to 55 mol% is still even more preferred, 5 to 50 mol% is even more preferably, and 10 to 50 mol% is still even more preferably.

[0143] 〈Structural unit (a4)〉 The structural unit represented by the formula (a4) is shown below. TIFF2025088761000124.tif3454[In the formula (a4), R 41 represents a hydrogen atom or a methyl group. R42 represents a saturated hydrocarbon group having a halogen atom with 1 to 24 carbon atoms, and -CH 2 - may be replaced by -O- or -CO-.]

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

[0145] As the structural unit (a4), R 42 is preferably a saturated hydrocarbon group having a fluorine atom, and an example of the structural unit (a4) where R 42 is a saturated hydrocarbon group having a fluorine atom includes a structural unit represented by the formula (a4-1) (hereinafter sometimes referred to as "structural unit (a4-1)"), a structural unit represented by the formula (a4-2) (hereinafter sometimes referred to as "structural unit (a4-2)"), and a structural unit represented by the formula (a4-3) (hereinafter sometimes referred to as "structural unit (a4-3)"). The structural unit represented by the formula (a4-1) is the structural unit shown below. TIFF2025088761000126.tif4964[In the formula (a4-1), R 41 represents a hydrogen atom or a methyl group. L 41 represents a single bond or an alkanediyl group having 1 to 4 carbon atoms. L 42f represents an alkanediyl group having 1 to 8 carbon atoms and having a fluorine atom or a cycloalkanediyl group having 3 to 12 carbon atoms and having a fluorine atom. R 42f represents a hydrogen atom or a fluorine atom.]

[0146] L 41Examples of the alkanediyl group in [description] include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, etc., and branched alkanediyl groups such as ethane-1,1-diyl group, propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, and 2-methylpropane-1,2-diyl group. The terminal of the branched alkanediyl group may be a methyl group. L 42f Examples of the alkanediyl group having a fluorine atom in [description] include linear alkanediyl groups having a fluorine atom such as methylene group having a fluorine atom, ethylene group having a fluorine atom, propane-1,3-diyl group having a fluorine atom, butane-1,4-diyl group having a fluorine atom, pentane-1,5-diyl group having a fluorine atom, hexane-1,6-diyl group having a fluorine atom, heptane-1,7-diyl group having a fluorine atom, octane-1,8-diyl group having a fluorine atom, etc.; branched alkanediyl groups having a fluorine atom such as ethane-1,1-diyl group having a fluorine atom, propane-1,1-diyl group having a fluorine atom, propane-1,2-diyl group having a fluorine atom, propane-2,2-diyl group having a fluorine atom, pentane-2,4-diyl group having a fluorine atom, 2-methylpropane-1,3-diyl group having a fluorine atom, 2-methylpropane-1,2-diyl group having a fluorine atom, pentane-1,4-diyl group having a fluorine atom, 2-methylbutane-1,4-diyl group having a fluorine atom. The terminal of the branched alkanediyl group may be a methyl group which may have a fluorine atom. L 42f Examples of the cycloalkanediyl group having a fluorine atom in [description] include monocyclic cycloalkanediyl groups having a fluorine atom such as cyclobutane-1,3-diyl group having a fluorine atom, cyclopentane-1,3-diyl group having a fluorine atom, cyclohexane-1,4-diyl group having a fluorine atom, cyclohexene-3,6-diyl group having a fluorine atom, cycloheptane-1,4-diyl group having a fluorine atom, cyclooctane-1,5-diyl group having a fluorine atom, etc., Examples of the polycyclic cycloalkanediyl group having a fluorine atom include a norbornane-1,4-diyl group having a fluorine atom, a norbornane-2,5-diyl group having a fluorine atom, a 5-norbornene-2,3-diyl group having a fluorine atom, an adamantane-1,5-diyl group having a fluorine atom, an adamantane-2,6-diyl group having a fluorine atom, and the like. L 42f The number of fluorine atoms in the alkanediyl group having a fluorine atom and the cycloalkanediyl group having a fluorine atom in 42f may be 1 or more, and is preferably 2 or more. L 42f The alkanediyl group having a fluorine atom and the cycloalkanediyl group having a fluorine atom in 42f are preferably a perfluoroalkanediyl group and a perfluorocycloalkanediyl group, respectively.

[0147] L 42f Examples of the perfluoroalkanediyl group in 42f include a difluoromethylene group, a perfluoroethylene group, a perfluoroethylfluoromethylene group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, a perfluoropropane-2,2-diyl group, a perfluorobutane-1,4-diyl group, a perfluorobutane-2,2-diyl group, a perfluorobutane-1,2-diyl group, a perfluoropentane-1,5-diyl group, a perfluoropentane-2,2-diyl group, a perfluoropentane-3,3-diyl group, a perfluorohexane-1,6-diyl group, a perfluorohexane-2,2-diyl group, a perfluorohexane-3,3-diyl group, a perfluoroheptane-1,7-diyl group, a perfluoroheptane-2,2-diyl group, a perfluoroheptane-3,4-diyl group, a perfluoroheptane-4,4-diyl group, a perfluorooctane-1,8-diyl group, a perfluorooctane-2,2-diyl group, a perfluorooctane-3,3-diyl group, a perfluorooctane-4,4-diyl group, and the like. L 42fExamples of the perfluorocycloalkanediyl group include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, a perfluoroadamantanediyl group, and the like.

[0148] L 41 is preferably a single bond or an alkanediyl group having 1 to 3 carbon atoms, more preferably a single bond, a methylene group or an ethylene group, and still more preferably a single bond or a methylene group. L 42f is preferably a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms, more preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, and still more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

[0149] Examples of the structural unit (a4-1) include the following structural units and the structural units in which the methyl group corresponding to R in the following structural units is replaced by a hydrogen atom in the structural unit (a4-1). 41 The structural unit represented by the formula (a4-2) is the following structural unit. TIFF2025088761000127.tif97158 The structural unit represented by the formula (a4-2) is the following structural unit. TIFF2025088761000128.tif5674 [In the formula (a4-2), R 41 represents a hydrogen atom or a methyl group. L 43f represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a fluorine atom, and -CH 2 - contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. R 43f represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a fluorine atom, and -CH 2 - contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. However, at least one of L 43f and R 43f has a fluorine atom, and L 43f and R43f The upper limit of the total carbon number is 21.

[0150] L 43f and R 43f Examples of the saturated hydrocarbon group in L and R include linear or branched chain saturated hydrocarbon groups, monocyclic or polycyclic alicyclic saturated hydrocarbon groups, and groups formed by combining these. L 43f and R 43f Examples of the saturated hydrocarbon group in L and R include, as long as the upper limit of the total carbon number of L and R permits, groups similar to the saturated hydrocarbon groups exemplified as the saturated hydrocarbon group of R in formula (a4). 43f and R 43f As the saturated hydrocarbon group of R in formula (a4), groups similar to the exemplified saturated hydrocarbon groups are included. 42

[0151] L 43f As the saturated hydrocarbon group of L, an alkanediyl group having 1 to 6 carbon atoms or a group represented by formula (L43f-1) is preferable. TIFF2025088761000129.tif13120 [In formula (L43f-1), s represents 0 or 1. L 45f and L 46f each independently represent a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a fluorine atom. L 47f represents a single bond or a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a fluorine atom. X 46f and X 47f each independently represent -O-, -CO-, -CO-O- or -O-CO-. However, the total carbon number of L, L, L, X and X is 7 or less. 45f L 46f L 47f X 46f and X 47f * and ** are bonding sites, and ** is the bonding site with -O-CO-R 43f .

[0152] In the group represented by formula (L43f-1), L 45f L46f and L 47f Examples of the divalent saturated hydrocarbon group represented by 47f include linear or branched alkanediyl groups, monocyclic or polycyclic divalent alicyclic saturated hydrocarbon groups, and divalent saturated hydrocarbon groups formed by combining an alkanediyl group and a divalent alicyclic saturated hydrocarbon group. Specifically, 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, a 2-methylpropane-1,2-diyl group, and the like. s is preferably 0.

[0153] Examples of the group represented by formula (L43f-1) include the following groups. In the following examples, * and ** each represent a bonding site, and ** is the bonding site with -O-CO-R 43f and is the bonding site with -O-CO-R. TIFF2025088761000130.tif47140

[0154] R 43f is preferably a saturated hydrocarbon group having a fluorine atom. Examples of the structural unit represented by formula (a4-2) in this case include the structural units represented by formula (a4-2A) or (formula a4-2B). TIFF2025088761000131.tif69102[In formula (a4-2A) and formula (a4-2B), R 41 and L 43f represent the same as those in formula (a4-2). R 43fA represents a saturated hydrocarbon group having 1 to 20 carbon atoms and having a fluorine atom. A 43f represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom, and -CH 2 - contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. X 43 represents **-O-CO- or **-CO-O-, and ** represents the bonding site with A 43f and is the bonding site with A. R 43fB represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom. However, in formula (a4-2A), L 43f and R 43fA have a total carbon number of 21 or less. In formula (a4-2B), L 43f , A 43f , X 43 and R 43fB have a total carbon number of 21 or less. Among A 43f and R 43fB , at least one has at least one fluorine atom. R 43fA The saturated hydrocarbon group of R is, as long as the upper limit of the carbon number allows, the same saturated hydrocarbon group as the saturated hydrocarbon group exemplified by R 42 in formula (a4). R 43fA is preferably an alkyl group having 1 to 13 carbon atoms with a fluorine atom, a cycloalkyl group having 3 to 12 carbon atoms with a fluorine atom, or a group combining them, *-(CF 2 ) n43f -R 42’ (* represents the bonding site to the carbonyl group. n43f represents any integer from 1 to 6. R 42’ represents a hydrogen atom or a fluorine atom.) or a perfluorocycloalkyl group having 3 to 12 carbon atoms is more preferable. A 43f and R 43fB The saturated hydrocarbon group of is, as long as the upper limit of the carbon number allows, the same saturated hydrocarbon group as the saturated hydrocarbon group exemplified by R 42 in formula (a4). A 43f is preferably a divalent chain-like saturated hydrocarbon group which may have a fluorine atom, a divalent alicyclic saturated hydrocarbon group, or a group combining them, more preferably a divalent chain-like saturated hydrocarbon group having a fluorine atom, and even more preferably a fluorinated alkanediyl group having 1 to 6 carbon atoms. R 43fBThe saturated hydrocarbon group which may have a fluorine atom is preferably a chain saturated hydrocarbon group, an alicyclic saturated hydrocarbon group or a combination thereof which may have a fluorine atom, more preferably an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 3 to 12 carbon atoms or a combination thereof which may have a fluorine atom, and even more preferably a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, a hexyl group, a perfluorohexyl group, a heptyl group, a perfluoroheptyl group, an octyl group, a perfluorooctyl group and other alkyl fluoride groups, a cyclopropylmethyl group, a cyclopropyl group, a cyclobutylmethyl group, a cyclopentyl group, a cyclohexyl group, a perfluorocyclohexyl group, an adamantyl group, an adamantylmethyl group, an adamantyldimethyl group, a norbornyl group, a norbornylmethyl group, a perfluoroadamantyl group, a perfluoroadamantylmethyl group and the like. In formula (a4-2B), *-A 43f -X 43 -R 43fB An example of the structure that the group represented by can take is the following structure (* is the bonding site with the carbonyl group). TIFF2025088761000132.tif15168

[0155] Examples of the structural unit represented by formula (a4-2A) include the following structural units and the structural units in which the methyl group corresponding to R in the structural unit represented by formula (a4-2A) below is replaced by a hydrogen atom. 41 are mentioned. TIFF2025088761000133.tif99167

[0156] Examples of the structural unit represented by formula (a4-2B) include the following structural units and the structural units in the following structural units where the methyl group corresponding to R in the structural unit represented by formula (a4-2B) is replaced by a hydrogen atom. 41 Examples include structural units in which the methyl group corresponding to 41 is replaced by a hydrogen atom. TIFF2025088761000134.tif111163

[0157] Examples of the structural unit (a4) also include the structural unit represented by formula (a4-3). TIFF2025088761000135.tif5677 [In formula (a4-3), R 41 represents a hydrogen atom or a methyl group. L 44f represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a fluorine atom, and -CH 2 - contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. R 44f represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a fluorine atom, and -CH 2 - contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. However, at least one of L 44f and R 44f has a fluorine atom, and the upper limit of the total number of carbon atoms of L 44f and R 44f is 21.]

[0158] Examples of the saturated hydrocarbon groups in L 44f and R 44f include linear or branched chain saturated hydrocarbon groups, monocyclic or polycyclic alicyclic saturated hydrocarbon groups, and groups formed by combining these. Examples of the saturated hydrocarbon groups in L 44f and R 44f are, as long as the upper limit of the total number of carbon atoms of L 44f and R 44f allows it, the same groups as the saturated hydrocarbon groups exemplified as the saturated hydrocarbon groups of R 42 in formula (a4). L 44fis an alkanediyl group having 1 to 14 carbon atoms (in the alkanediyl group, -CH 2 - may be replaced by -O- or -CO-).), and it is preferably -(CH 2 ) j1 -, -(CH 2 ) j2 -O-(CH 2 ) j3 -, or -(CH 2 ) j4 -CO-O-(CH 2 ) j5 - (where j1 to j5 each independently represent an integer from 1 to 6).) is more preferable. Further, an alkanediyl group having 1 to 4 carbon atoms (one -CH 2 - in the alkanediyl group may be replaced by -O-, and one -CH 2 -CH 2 - in the alkanediyl group may be replaced by -CO-O- or -O-CO-).) is also preferable. R 44f is preferably a saturated hydrocarbon group having 1 to 10 carbon atoms and having a fluorine atom, more preferably an alkyl group having 1 to 10 carbon atoms and having a fluorine atom, an alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms and having a fluorine atom, or a group combining them, still more preferably an alkyl group having 1 to 10 carbon atoms and having a fluorine atom, and even more preferably an alkyl group having 1 to 6 carbon atoms and having a fluorine atom.

[0159] Examples of the structural unit represented by formula (a4-3) include structural units represented by the following structural units and the following formulas, in which the methyl group corresponding to R 41 in structural unit (a4-3) is replaced by a hydrogen atom. TIFF2025088761000136.tif86170

[0160] Examples of the structural unit (a4) also include a structural unit represented by formula (a4-A). TIFF2025088761000137.tif3686[In formula (a4-A), R 1represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. X 11 represents a single bond or *-CO-O-. * represents R 1 and represents the bonding site with the carbon atom to which it is bonded. L 1 represents an aliphatic hydrocarbon group having 1 to 28 carbon atoms which may have a substituent, and -CH 2 - in the aliphatic hydrocarbon group may be replaced by -O-, -S-, -SO 2 - or -CO-. R 2 represents a fluorinated alkyl group having 1 to 8 carbon atoms. R 3 represents a hydrogen atom or a fluorinated alkyl group having 1 to 6 carbon atoms, and the fluorinated alkyl group may combine with L 1 to form an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and -CH 2 - in the alicyclic hydrocarbon group may be replaced by -O-. mi represents any integer from 1 to 4. When mi is 2 or more, the groups in the plurality of parentheses may be the same as or different from each other.

[0161] R 1 Examples of the alkyl group having 1 to 6 carbon atoms in R include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. R 1 Examples of the halogen atom in R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R 1Examples of the alkyl group having 1 to 6 carbon atoms and a halogen atom include trifluoromethyl group, difluoromethyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, perfluorohexyl group, trichloromethyl group, dichloromethyl group, triiodomethyl group, diiodomethyl group, tribromomethyl group, dibromomethyl group, and the like. R 1 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, still more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group.

[0162] L 1 Examples of the aliphatic hydrocarbon group in include a chain hydrocarbon group, an alicyclic hydrocarbon group which is monocyclic or polycyclic (including a spiro ring, a condensed ring, a bridged ring, etc.), and a group formed by combining two or more of these groups (for example, a hydrocarbon group formed from an alicyclic hydrocarbon group and a chain hydrocarbon group) may also be used. Examples of the chain hydrocarbon group include divalent to pentavalent chain hydrocarbon groups such as an alkanediyl group, an alkanetriyl group, an alkanetetrayl group, an alkanepentayl group, and the like. Examples of the alkanediyl group include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, and heptadecane-1,17-diyl group, and Examples of the branched alkanediyl group include an ethane-1,1-diyl group, a propane-1,1-diyl group, a propane-1,2-diyl group, a propane-2,2-diyl group, a pentane-2,4-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, a 2-methylbutane-1,4-diyl group, and the like. Examples also include a group in which one or more hydrogen atoms of the above-described group are replaced with a bonding site. The number of carbon atoms in the chain hydrocarbon group is preferably from 1 to 18, more preferably from 1 to 12, still more preferably from 1 to 10, even more preferably from 1 to 9, still even more preferably from 1 to 8, still more preferably from 1 to 6, still even more preferably from 1 to 5, and particularly preferably from 1 to 4.

[0163] Examples of the monocyclic or polycyclic alicyclic hydrocarbon group include the following alicyclic hydrocarbon groups and the like. The bonding site can be at any position. TIFF2025088761000138.tif46164For example, divalent to pentavalent alicyclic hydrocarbon groups such as a cycloalkanediyl group, a cycloalkanetriyl group, a cycloalkanetetrayl group, a cycloalkanepentayl group, and the like are included. Specifically, monocyclic alicyclic hydrocarbon groups such as a cyclobutane-1,3-diyl group, a cyclopentane-1,3-diyl group, a cyclohexane-1,4-diyl group, a cyclooctane-1,5-diyl group, and polycyclic alicyclic hydrocarbon groups such as a norbornane-1,4-diyl group, a norbornane-2,5-diyl group, an adamantane-1,5-diyl group, an adamantane-2,6-diyl group, a decahydronaphthalenediyl group, a bicyclo[3.3.0]octanediy group, a spirocyclohexane-1,2'-cyclopentane-diyl group, a spiroadamantane-2,3'-cyclopentane-diyl group, and a spiro ring having a cycloalkanediyl group, a norbornanediyl group or an adamantanediyl group each spiro-bonded to a cycloalkanediyl group are included. Examples also include a group in which one or more hydrogen atoms of the above-described group are replaced with a bonding site. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 20, more preferably 3 to 18, still more preferably 3 to 16, and even more preferably 3 to 12.

[0164] Examples of the group formed by combining two or more of them include a group formed by combining an alicyclic hydrocarbon group and a chain hydrocarbon group. In the combination, two or more alicyclic hydrocarbon groups and two or more chain hydrocarbon groups may be combined respectively. Also, any of the groups may be bonded to X 11 and may be bonded thereto. Examples of the group formed by combining an alicyclic hydrocarbon group and a chain hydrocarbon group include a group in which an alicyclic hydrocarbon group is bonded to a chain hydrocarbon group (for example, *-chain hydrocarbon group-alicyclic hydrocarbon group-), a group in which a chain hydrocarbon group is bonded to an alicyclic hydrocarbon group (for example, *-alicyclic hydrocarbon group-chain hydrocarbon group-), a group in which an alicyclic hydrocarbon group and a chain hydrocarbon group are bonded to a chain hydrocarbon group (for example, *-chain hydrocarbon group-alicyclic hydrocarbon group-chain hydrocarbon group-), a group in which a chain hydrocarbon group and an alicyclic hydrocarbon group are bonded to an alicyclic hydrocarbon group (for example, *-alicyclic hydrocarbon group-chain hydrocarbon group-alicyclic hydrocarbon group-), a group in which an alicyclic hydrocarbon group, a chain hydrocarbon group, and an alicyclic hydrocarbon group are bonded to a chain hydrocarbon group (for example, *-chain hydrocarbon group-alicyclic hydrocarbon group-chain hydrocarbon group-alicyclic hydrocarbon group-), a group in which a chain hydrocarbon group, an alicyclic hydrocarbon group, and a chain hydrocarbon group are bonded to an alicyclic hydrocarbon group (for example, *-alicyclic hydrocarbon group-chain hydrocarbon group-alicyclic hydrocarbon group-chain hydrocarbon group-), etc. * represents the bonding site to X 11 and represents the bonding site to X. Also, a group in which one or more hydrogen atoms of the above-mentioned group are replaced with a bonding site, etc. may be mentioned.

[0165] L 1 The -CH 2 - in the aliphatic hydrocarbon group having 1 to 28 carbon atoms of L 2 - may be replaced by -O-, -S-, -SO L 1 The -CH 2- is replaced by -O-, -S-, -SO 2 - or -CO-, the number of carbon atoms before replacement is regarded as the number of carbon atoms of the aliphatic hydrocarbon group. -CH contained in the aliphatic hydrocarbon group 2 - is replaced by -O-, -S-, -SO 2 - or -CO-, examples of the group include a hydroxy group, a carboxy group, a thiol group, an alkoxy group, an alkylthio group, an alkoxycarbonyl group, an alkylsulfonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, an alkoxycarbonyloxy group, an oxy group, a carbonyl group, a thio group, a sulfonyl group, an alkanedioxy group, an alkanedioxycarbonyl group, an alkanediylcarbonyl group, an alkanediylcarbonyloxy group, an alkanediylsulfonyl group, an alkanediylthio group, a cycloalkoxy group, a cycloalkylalkoxy group, an alkoxycarbonyloxy group, a group formed by combining two or more of these groups, etc. These replaced groups include those similar to the groups exemplified in this specification within the range allowed by the upper limit of the number of carbon atoms. In addition, examples also include a group in which one or more hydrogen atoms of the above-mentioned group are replaced by a bonding site, etc. -CH contained in the alicyclic hydrocarbon group 2 - is replaced by -O-, -S-, -CO- or -SO 2 - as the replaced group includes those similar to the groups exemplified in this specification within the range allowed by the upper limit of the number of carbon atoms.

[0166] L 1 The aliphatic hydrocarbon group in may have one or more substituents. Examples of the substituent include a halogen atom, a haloalkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms (the -CH 2 - contained in the alkyl group or the alicyclic hydrocarbon group may be replaced by -O- or -CO-). etc. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. The haloalkyl groups having 1 to 4 carbon atoms include fluoroalkyl groups having 1 to 4 carbon atoms, chloroalkyl groups having 1 to 4 carbon atoms, bromoalkyl groups having 1 to 4 carbon atoms, iodoalkyl groups having 1 to 4 carbon atoms, and the like. Examples of the haloalkyl group include perfluoroalkyl groups having 1 to 4 carbon atoms (such as trifluoromethyl group, pentafluoroethyl group, heptafluoropropyl group, nonafluorobutyl group, etc.), 2,2,2-trifluoroethyl group, 3,3,3-trifluoropropyl group, 4,4,4-trifluorobutyl group, 3,3,4,4,4-pentafluorobutyl group, chloromethyl group, bromomethyl group, iodomethyl group, and the like. The number of carbon atoms of the haloalkyl group is preferably 1 to 3, more preferably 1 or 2. Examples of the alkyl group having 1 to 12 carbon atoms include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, and the like. The number of carbon atoms of the alkyl group is preferably 1 to 9, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alicyclic hydrocarbon group having 3 to 18 carbon atoms include monocyclic cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, cyclodecyl group, and polycyclic cycloalkyl groups such as decahydronaphthyl group, adamantyl group, norbornyl group, and the like. The number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 16, more preferably 3 to 12, and still more preferably 3 to 10. Examples of the aromatic hydrocarbon group having 6 to 18 carbon atoms include phenyl group, naphthyl group, biphenyl group, anthryl group, phenanthryl group, binaphthyl group, and the like. The number of carbon atoms of the aromatic hydrocarbon group is preferably 6 to 14, more preferably 6 to 12, and still more preferably 6 to 10. -CH contained in the alkyl group 2- When it is replaced by -O- or -CO-, the number of carbon atoms before replacement is defined as the total number of carbon atoms of the alkyl group. Examples of the replaced group include a hydroxy group, a carboxy group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, an alkoxycarbonyloxy group, and the like. These replaced groups include those similar to the groups exemplified in this specification as long as the upper limit of the number of carbon atoms permits. The number of carbon atoms of the alkoxy group is preferably 1 to 9, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. The number of carbon atoms of the alkoxycarbonyl group is preferably 2 to 9, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyl group is preferably 2 to 10, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms of the alkylcarbonyloxy group is preferably 2 to 9, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. In addition, as the group in which -CH 2 - in the alicyclic hydrocarbon group is replaced by -O- or -CO-, those similar to the groups exemplified in this specification are included as long as the upper limit of the number of carbon atoms permits. L 1 Examples of the substituent that the aliphatic hydrocarbon group in may optionally have include a halogen atom, a haloalkyl group having 1 to 3 carbon atoms, an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms (the -CH 2 - in the alkyl group or the alicyclic hydrocarbon group may be replaced by -O- or -CO-). Among them, a fluorine atom, an iodine atom, a perfluoroalkyl group having 1 to 3 carbon atoms, or an alkyl group having 1 to 4 carbon atoms (the -CH 2 - in the alkyl group may be replaced by -O- or -CO-) are more preferred, and a fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, a hydroxy group, or a methoxy group are even more preferred. L 1 is R3 When it does not form an alkyl fluoride group and an alicyclic hydrocarbon group, a chain hydrocarbon group having 1 to 12 carbon atoms which may have a substituent (—CH contained in the chain hydrocarbon group 2 — may be replaced by —O— or —CO—), an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (—CH contained in the alicyclic hydrocarbon group 2 — may be replaced by —O— or —CO—), or a group formed by combining a chain hydrocarbon group having 1 to 6 carbon atoms which may have a substituent and an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (—CH contained in the chain hydrocarbon group 2 — may be replaced by —O— or —CO—, and —CH contained in the alicyclic hydrocarbon group 2 — may be replaced by —O— or —CO—), and it is preferably such a group, a chain hydrocarbon group having 1 to 8 carbon atoms which may have a substituent (—CH contained in the chain hydrocarbon group 2 — may be replaced by —O— or —CO—), an alicyclic hydrocarbon group having 3 to 12 carbon atoms which may have a substituent, or a group formed by combining a chain hydrocarbon group having 1 to 6 carbon atoms which may have a substituent and an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (—CH contained in the chain hydrocarbon group 2 — may be replaced by —O— or —CO—), and it is more preferably such a group, a chain hydrocarbon group having 1 to 8 carbon atoms which may have a substituent (—CH contained in the chain hydrocarbon group 2 — may be replaced by —O— or —CO—), an alicyclic hydrocarbon group having 5 to 12 carbon atoms which may have a substituent, a group formed by combining a chain hydrocarbon group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 5 to 12 carbon atoms which may have a substituent (—CH contained in the chain hydrocarbon group 2 — may be replaced by —O— or —CO—), or a group formed by combining an alicyclic hydrocarbon group having 5 to 12 carbon atoms which may have a substituent, a chain hydrocarbon group having 1 to 6 carbon atoms, and an alicyclic hydrocarbon group having 5 to 12 carbon atoms which may have a substituent (—CH contained in the chain hydrocarbon group 2- may be replaced by -O- or -CO-. It is more preferable that it is.)

[0167] R 2 Examples of the C1-C8 fluoroalkyl group in include difluoromethyl group, trifluoromethyl group, 1,1-difluoroethyl group, 2,2-difluoroethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group, 1,1,2,2-tetrafluoropropyl group, 1,1,2,2,3,3-hexafluoropropyl group, perfluoroethylmethyl group, 1-(trifluoromethyl)-1,2,2,2-tetrafluoroethyl group, perfluoropropyl group, 1,1,2,2-tetrafluorobutyl group, 1,1,2,2,3,3-hexafluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluorobutyl group, 1,1-bis(trifluoro)methyl-2,2,2-trifluoroethyl group, 2-(perfluoropropyl)ethyl group, 1,1,2,2,3,3,4,4-octafluoropentyl group, perfluoropentyl group, 1,1,2,2,3,3,4,4,5,5-decafluoropentyl group, 1,1-bis(trifluoromethyl)-2,2,3,3,3-pentafluoropropyl group, perfluoropentyl group, 2-(perfluorobutyl)ethyl group, 1,1,2,2,3,3,4,4,5,5-decafluorohexyl group, 1,1,2,2,3,3,4,4,5,5,6,6-dodecafluorohexyl group, perfluoropentylmethyl group, perfluorohexyl group, perfluoroheptyl group, perfluorooctyl group. The carbon number of the fluoroalkyl group is preferably 1-6, more preferably 1-5, still more preferably 1-4, and even more preferably 1-3. R 3 The C1-C6 fluoroalkyl group in, as long as the upper limit of the carbon number permits, the C1-C6 fluoroalkyl groups exemplified in the fluoroalkyl group of R 2 are similarly exemplified. R 2 is R 3When it is an alkyl fluoride group having 1 to 6 carbon atoms, it is preferably an alkyl fluoride group having 1 to 6 carbon atoms, more preferably an alkyl fluoride group having 1 to 3 carbon atoms, still more preferably a trifluoromethyl group, a perfluoroethyl group or a perfluoropropyl group, and even more preferably a trifluoromethyl group. R 2 When R 3 is a hydrogen atom, it is preferably an alkyl fluoride group having 1 to 6 carbon atoms, more preferably an alkyl fluoride group having 1 to 5 carbon atoms, and still more preferably an alkyl fluoride group having 3 to 5 carbon atoms. R 3 When R 1 is bonded to L 3 to form an alicyclic hydrocarbon group having 3 to 12 carbon atoms, R 1 As the group formed by bonding to L 2 , for example, groups represented by the following formulas can be mentioned. Among the following formulas, * and ** represent bonding sites, and two **, one represents the bonding site with a hydroxy group and the other represents the bonding site with R 1A L 1 is a part of the hydrocarbon group of L 3 and represents a single bond or an alkanediyl group having 1 to 4 carbon atoms. R 1 The number of carbon atoms of the alicyclic hydrocarbon group formed by bonding R TIFF2025088761000139.tif25130R 3 is preferably a hydrogen atom or an alkyl fluoride group having 1 to 3 carbon atoms. mi is preferably any integer from 1 to 3, more preferably 1 or 2, and still more preferably 1.

[0168] Examples of the structural unit (a4-A) include the following structural units and the like. In the following structural units, the methyl group corresponding to R 1 is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or an alkyl group other than a methyl group, and R 1A structural unit in which a hydrogen atom corresponding to the following is replaced with a halogen atom, a haloalkyl group, or an alkyl group can also be cited as a specific example of the structural unit (a4-A). TIFF2025088761000140.tif227159

[0169] 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 still more preferably 3 to 10 mol% based on all the structural units of the resin (A).

[0170] 〈Structural unit (a5)〉 Examples of the non-leaving hydrocarbon group of the structural unit (a5) include a group having a linear, branched, or cyclic hydrocarbon group. Among them, the structural unit (a5) is preferably a group having an alicyclic hydrocarbon group. Examples of the structural unit (a5) include a structural unit represented by the formula (a5-1). TIFF2025088761000141.tif3971[In the formula (a5-1), R 51 represents a hydrogen atom or a methyl group. R 52 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the hydrogen 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 -CH 2 - contained in the saturated hydrocarbon group may be replaced with -O- or -CO-.]

[0171] R 52 The alicyclic hydrocarbon group in may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group and a norbornyl group, etc. The aliphatic hydrocarbon groups having 1 to 8 carbon atoms include, for example, alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. Examples of the alicyclic hydrocarbon group having a substituent include 3-methyladamantyl group. R 52 is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, more preferably an adamantyl group, a norbornyl group or a cyclohexyl group. L 55 Examples of the divalent saturated hydrocarbon group in L include a divalent chain saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, and preferably a divalent chain saturated hydrocarbon group. Examples of the divalent chain saturated hydrocarbon group include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group. The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkanediyl groups such as cyclopentanediyl group and cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include adamantanediyl group and norbornanediyl group.

[0172] L 55 Examples of the group in which -CH 2 - contained in the divalent saturated hydrocarbon group represented by L is replaced by -O- or -CO- include, for example, the groups represented by formula (L1-1) to formula (L1-4). In the following formulas, * and ** each represent a bonding site, and * represents a bonding site with an oxygen atom. TIFF2025088761000142.tif18165[In formula (L1-1), X x1 represents *-O-CO- or *-CO-O- (* represents a bonding site with L x1 .). L x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. L x2represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. However, L x1 and L x2 have a total carbon number of 16 or less. In formula (L1-2), L x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms. L x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. However, L x3 and L x4 have a total carbon number of 17 or less. In formula (L1-3), L x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. L x6 and L x7 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms. However, L x5 , L x6 and L x7 have a total carbon number of 15 or less. In formula (L1-4), L x8 and L x9 each represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms. W x1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms. However, L x8 , L x9 and W x1 have a total carbon number of 15 or less.

[0173] 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.

[0174] Examples of the group represented by the formula (L1-1) include the following divalent groups. Examples of the group represented by the formula (L1-2) include the following divalent groups. Examples of the group represented by the formula (L1-3) include the following divalent groups. Examples of the group represented by the formula (L1-4) include the following divalent groups. TIFF2025088761000146.tif13168L 55 is preferably a single bond or a group represented by the formula (L1-1).

[0175] As the structural unit (a5-1), there are the following structural units and the methyl group corresponding to R in the structural unit (a5-1) in the following structural units 51 in which the methyl group is replaced by a hydrogen atom. TIFF2025088761000147.tif111150 When the resin (A) contains the structural unit (a5), its content is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, and still more preferably 3 to 15 mol% based on all the structural units of the resin (A).

[0176] 〈Structural unit (a6)〉 The structural unit (a6) is a structural unit having a -SO 2 - group, and preferably has a -SO 2 - group in the side chain. -SO 2 - group-containing structural units may have a linear structure having a -SO 2 - group, or may have a branched structure having a -SO 2 - group, or may have a cyclic structure (monocyclic and polycyclic structures) having a -SO 2 - group. Preferably, it is a structural unit having a cyclic structure having a -SO 2 - group, and more preferably, it is a structural unit having a cyclic structure (sultone ring) containing -SO 2 -O-.

[0177] Examples of the sultone ring include rings represented by the following formula (T 1 -1), formula (T 1 -2), formula (T 1 -3) and formula (T 1 -4). The bonding site can be at any position. The sultone ring may be monocyclic, but is preferably polycyclic. The polycyclic sultone ring means a bridged ring containing -SO 2 -O- as an atomic group constituting the ring, and examples include rings represented by formula (T 1 -1) and formula (T 1 -2). The sultone ring, like the ring represented by formula (T 1 -2), has -SO 2In addition to -O-, it may further contain a heteroatom. Examples of the heteroatom include an oxygen atom, a sulfur atom, or a nitrogen atom, preferably an oxygen atom. TIFF2025088761000148.tif2977

[0178] The sultone ring may have a substituent. 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, etc.

[0179] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, and a decyl group. Preferably, it is an alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group. Examples of the alkyl group having a halogen atom include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group. Preferably, a trifluoromethyl group is mentioned. Examples of the alkyl group having a hydroxy group include a hydroxymethyl group and a hydroxyalkyl group such as a 2-hydroxyethyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group. Examples of the aryl group include a phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumyl group, mesityl group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group, and 2-methyl-6-ethylphenyl group. Examples of the aralkyl group include a benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, and naphthylethyl group. Examples of the alkoxycarbonyl group include a group in which an alkoxy group such as a methoxycarbonyl group or an ethoxycarbonyl group is bonded to a carbonyl group, preferably an alkoxycarbonyl group having 6 or fewer carbon atoms, and more preferably a methoxycarbonyl group. Examples of the alkylcarbonyl group include an acetyl group, propionyl group, and butyryl group. From the viewpoint of easy production of the monomer leading to the structural unit (a6), a sultone ring having no substituent is preferred.

[0180] As the sultone ring, a ring represented by the following formula (T1') is preferred. TIFF2025088761000149.tif2665[In the formula (T1'), X 11 represents an oxygen atom, sulfur atom, or methylene group. R 41 represents an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms, or an alkylcarbonyl group having 2 to 4 carbon atoms. ma represents any integer from 0 to 9. When ma is 2 or more, a plurality of R 41 may be the same or different. The bonding site is at an arbitrary position.] X 11 is preferably an oxygen atom or a methylene group, and more preferably a methylene group. R 41 Examples thereof include the same as the substituents of the sultone ring, and an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group is preferable. ma is preferably 0 or 1, more preferably 0.

[0181] Examples of the ring represented by formula (T1’) include the following rings. The bonding site can be at any position. Among them, the bonding site is preferably at the 1-position or the 3-position. TIFF2025088761000150.tif44148

[0182] -SO 2 The structural unit having a - group preferably further has a group derived from a polymerizable group. Examples of the polymerizable group include a vinyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an acryloylamino group, a methacryloylamino group, an acryloylthio group, a methacryloylthio group, and the like. Among them, the monomer leading to the structural unit (a6) is preferably a monomer having an ethylenically unsaturated bond, more preferably a (meth)acrylic monomer.

[0183] The structural unit (a6) is preferably a structural unit represented by formula (a6-0). TIFF2025088761000151.tif4177[In formula (a6-0), R x represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom, or a halogen atom. A xx represents an oxygen atom, -N(R c )-, or a sulfur atom. A x represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH 2 - contained in the saturated hydrocarbon group may be replaced by -O-, -CO-, or -N(R d ). X 11 represents an oxygen atom, a sulfur atom, or a methylene group. R 41 represents the same group as described above. ma represents an integer from 0 to 9. When ma is 2 or more, a plurality of R 41 may be the same or different. R c and R d each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0184] R x Examples of the halogen atom of R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R x Examples of the alkyl group of R include, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group, etc. Preferably, it is an alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group or an ethyl group. R x Examples of the alkyl group having a halogen atom of R include, for example, a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group, etc. R x is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group. A x Examples of the divalent saturated hydrocarbon group of A include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and those obtained by combining two or more of these groups may also be used. Specifically, linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1,17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-diyl group; Branched alkanediyl groups such as butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group; Monocyclic divalent alicyclic saturated hydrocarbon groups which are cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group; Polycyclic divalent alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group and the like can be mentioned. A x The bonding position to the sultone ring of A can be any position, but the one at the 1-position is preferred.

[0185] Examples of the structural unit (a6-0) include the following structural units. TIFF2025088761000152.tif93150

[0186] Among them, the structural units represented by formula (a6-1), formula (a6-2), formula (a6-6), formula (a6-7), formula (a6-8) and formula (a6-12) are preferred, and the structural units represented by formula (a6-1), formula (a6-2), formula (a6-7) and (a6-8) are more preferred. When the resin (A) contains the structural unit (a6), its content is preferably 1 to 50 mol%, more preferably 2 to 40 mol%, and still more preferably 3 to 30 mol% based on all the structural units of the resin (A).

[0187] <Structural unit (a7)> The resin (A) may further contain a structural unit that decomposes upon exposure to generate an acid (hereinafter sometimes referred to as "structural unit (a7)"). Specific examples of the structural unit (a7) include the structural units described in JP-A-2016-79235, and it is preferably a structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain or a structural unit having a sulfonio group and an organic anion in the side chain.

[0188] The structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain is preferably a structural unit represented by the formula (a7-A). TIFF2025088761000153.tif26124[In the formula (a7-A), R a7 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. X a71 represents a single bond, *-O-*, *-CO-O-*, *-O-CO-O-*, *-CO-NR a71 -*, *-NR a71 -CO-O-*, *-O-CO-NR a71 -* or *-Ax-Ph-Ay-*. R a71 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Ph represents a phenylene group which may have a substituent. Ax and Ay each independently represent one type of bond species selected from the group consisting of a single bond, an ether bond, a thioether bond, an ester bond, an amide bond, and a carbonate ester bond. * and ** represent bonding sites, and * represents the bonding site with the carbon atom to which R a7 is bonded. L a71 and La72 each independently represents a hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH contained in the hydrocarbon group 2 - may be replaced by -O-, -S-, -CO- or -SO 2 -. X a72 represents -CO-O-, -O-CO-, -O-CO-O-, -O-, and *** represents the bonding site with L a71 . na7 represents any integer from 0 to 2. When na7 is 2, the groups in the plurality of parentheses may be the same as or different from each other. RA - represents a sulfonate anion or a carboxylate anion. ZA + represents an organic cation.

[0189] R a7 Examples of the halogen atom and the alkyl group which may have a halogen atom in R are the same groups as those exemplified in R of formula (a1-0). Among them, R a01 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, still more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group. a7 R a71 Examples of the alkyl group having 1 to 6 carbon atoms in R include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. X a71 When the group represented by *-Ax-Ph-Ay-** is preferably a linking group represented by the following formula (X10). TIFF2025088761000154.tif3351 [In formula (X10), Ax is R a7 ​represents a bonding species that binds to the carbon atom to which it is bonded, and represents one or more bonding species selected from the group consisting of a single bond, an ether bond, a thioether bond, an ester bond, a carbonate ester bond, and an amide bond. Ay is L a71 represents a bonding species that binds to, and represents one or more bonding species selected from the group consisting of a single bond, an ether bond, a thioether bond, an ester bond, a carbonate ester bond, and an amide bond. Rx represents a halogen atom, a hydroxy group, a C1-C6 fluoroalkyl group, a C1-C18 alkyl group, or a C1-C6 alkoxy group. mx represents any integer from 0 to 4, and when mx is an integer of 2 or more, the plurality of Rx may be the same as or different from each other. When either Ax or Ay is a single bond, the other is preferably one selected from the group consisting of an ether bond, a thioether bond, an ester bond, a carbonate ester bond, and an amide bond. When either Ax or Ay is an amide bond, it is preferably a bond represented by -CO-NR a71 -. The bonding position of Ay in the phenylene group is preferably the m-position or the p-position with respect to the bonding position of Ax, and more preferably the p-position. Among them, Rx is preferably a fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, or an ethyl group. mx is preferably 0, 1, or 2. X a71 Examples of X 10 -1) to formula (X 10 -10). * represents the bonding site with the carbon atom to which -R a7 is bonded. ** represents the bonding site with L a71 . X 20 represents -O- or -NR a71 -. TIFF2025088761000155.tif42162 Formula (X 10 -1) to formula (X 10Specific examples of the group represented by ( TIFF2025088761000156.tif78162Among them, X a71 is a single bond and the formula (X 10 -1'), the formula (X 10 -3') to the formula (X 10 -9') is preferably a group represented by any of them, a single bond or the formula (X 10 -1'), the formula (X 10 -4'), the formula (X 10 -5'), the formula (X 10 -6') and the formula (X 10 -9') is more preferably a group represented by any of them, a single bond, the group represented by the formula (X 10 -1'), the group represented by the formula (X 10 -5'), the group represented by the formula (X 10 -6') or the formula (X 10 -9') is even more preferably a group represented by any of them.

[0190] L a71 As the hydrocarbon group of, a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining two or more of these groups, one hydrogen atom is removed, and X a71 and X a72 and the group bonded to X a72 As the hydrocarbon group of, a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining two or more of these groups, one hydrogen atom is removed, and X a72 and RA - and the group bonded to RA L a71 and L a72Examples of the chain hydrocarbon group include a group obtained by removing one hydrogen atom from an alkyl group or an alkenyl group. The alkyl group may be linear or branched, and specific examples include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, sec-butyl group, iso-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, heptadecyl group, and the like. Examples of the alkenyl group include ethenyl group, propenyl group, isopropenyl group, butenyl group, isobutenyl group, tert-butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, isooctenyl group, nonenyl group, and the like. The number of carbon atoms in the chain hydrocarbon group is preferably 1 to 20, more preferably 1 to 18, and even more preferably 1 to 10. L a71 and L a72 Examples of the alicyclic hydrocarbon group of L and L include a group obtained by removing one hydrogen atom from a monocyclic or polycyclic cycloalkyl group. Examples of the monocyclic cycloalkyl group include cyclobutyl group, cycloheptyl group, cyclohexyl group, cyclopentyl group, cyclooctyl group, and the like. L a71 and L a72Examples of the polycyclic cycloalkyl group include a cycloalkyl group having a crosslinked structure, a cycloalkyl group in which two or more rings are condensed, or a cycloalkyl group in which two rings are spiro-bonded. Examples of the cycloalkyl group having a crosslinked structure include a norbornyl group and an adamantyl group. Examples of the cycloalkyl group in which two or more rings are condensed include a bicyclo[4,4,0]decane group and a steroid group (steroid skeleton). Examples of the cycloalkyl group in which two rings are spiro-bonded include a spirocycloalkyl group in which one cycloalkyl group selected from the group consisting of a cyclopentyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group is spiro-bonded to a cycloalkyl group having 5 to 8 carbon atoms. Further, a double bond may be formed between two carbon atoms included in the alicyclic hydrocarbon group. More specifically, examples of the alicyclic hydrocarbon group represented by the following formula can be given. TIFF2025088761000157.tif28158When the alicyclic hydrocarbon group is a monocyclic cycloalkyl group, the number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 18, more preferably 3 to 12, and even more preferably 3 to 8. When the alicyclic hydrocarbon group is a polycyclic cycloalkyl group, the number of carbon atoms of the alicyclic hydrocarbon group is preferably 6 to 18, and more preferably 7 to 12. L a71 and L a72 Examples of the aromatic hydrocarbon group of and include a group in which one hydrogen atom of an aryl group is removed. Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a fluorenyl group. The number of carbon atoms of the aromatic hydrocarbon group is preferably 5 to 14, more preferably 6 to 14, and even more preferably 6 to 10. L a71 and L a72 When the -CH 2 - contained in the hydrocarbon group of and is replaced by -O-, -CO-, -S-, or -SO 2 -, the number of carbon atoms before replacement is taken as the number of carbon atoms of the hydrocarbon group. L a71 and L a72Among the hydrocarbon groups, the -CH contained in the chain hydrocarbon group 2 - being replaced by -O-, -CO-, -S- or -SO 2 - as the replaced group includes a hydroxy group (the -CH contained in the methyl group 2 - being replaced by -O-), a carboxy group (the -CH contained in the ethyl group 2 -CH 2 - being replaced by -O-CO-), a thiol group (the -CH contained in the methyl group 2 - being replaced by -S-), a carbonyl group (the -CH contained in the methylene group 2 - being replaced by -CO-), an oxy group (the -CH contained in the methylene group 2 - being replaced by -O-), a thio group (the -CH contained in the methylene group 2 - being replaced by -S-), a sulfonyl group (the -CH contained in the methylene group 2 - being replaced by -SO 2 - as the replaced group), an alkoxy group (any -CH at any position contained in the alkyl group 2 - being replaced by -O-), an alkoxycarbonyl group (any -CH at any position contained in the alkyl group 2 -CH 2 - being replaced by -O-CO-), an alkylcarbonyl group (any -CH at any position contained in the alkyl group 2 - being replaced by -CO-), an alkylcarbonyloxy group (any -CH at any position contained in the alkyl group 2 -CH 2 - being replaced by -CO-O-), an alkanedioxy group (any -CH at any position contained in the alkanedioyl group 2 - being replaced by -O-), an alkanedioxycarbonyl group (any -CH at any position contained in the alkanedioyl group 2 -CH 2 - being replaced by -O-CO-), an alkanedioylcarbonyl group (any -CH at any position contained in the alkanedioyl group 2 - being replaced by -CO-), an alkanedioylcarbonyloxy group (any -CH at any position contained in the alkanedioyl group2 -CH 2 - groups replaced by -CO-O- groups, etc. These replaced groups include those similar to the groups exemplified in this specification within the range allowed by the upper limit of the number of carbon atoms. L a71 and L a72 Among the hydrocarbon groups of 2 -CH 2 - groups replaced by -O-, -CO-, -S- or -SO 2 - groups include groups containing a cyclic ether, cyclic ketone, cyclic ester (lactone), cyclic thioether, cyclic acetal, cyclic sulfonic acid ester (sultone) structure, etc. Specifically, alicyclic hydrocarbon groups represented by the following formulas can be mentioned. The bonding positions of the alicyclic hydrocarbon groups mentioned in the following formulas can be at any position. TIFF2025088761000158.tif46146L a71 and L a72 Among the hydrocarbon groups of 2 -CH 2 - may be replaced by -O- or -S-, and groups in which -CH 2 - is replaced by -O- or -S- include groups derived from a furan ring or a thiophene ring, respectively. L a71 and L a72 Groups combining two or more of the chain hydrocarbon group, alicyclic hydrocarbon group and aromatic hydrocarbon group of a72 L L a71 and L a72 include groups combining the above chain hydrocarbon group and the above alicyclic hydrocarbon group, groups combining the above chain hydrocarbon group and the above aromatic hydrocarbon group, groups combining the above alicyclic hydrocarbon group and the above aromatic hydrocarbon group, and groups combining the above chain hydrocarbon group, the above alicyclic hydrocarbon group and the above aromatic hydrocarbon group. The group combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group may be a condensed ring. L a71 and L a72 Substituents that the hydrocarbon groups of La71 and L a72 When is a group combining an alicyclic hydrocarbon group or an aromatic hydrocarbon group and a chain hydrocarbon group, substantially, the chain hydrocarbon group may be regarded as a substituent that the alicyclic hydrocarbon group or the aromatic hydrocarbon group has. Also, L a71 and L a72 In the chain hydrocarbon group included in the hydrocarbon group of, -CH 2 - is replaced by -O-, -CO-, -S- or -SO 2 -, by L a71 and L a72 The hydrocarbon groups of can substantially have substituents such as a hydroxy group, a carboxy group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a thiol group, a sulfonyl group and the like. na7 is preferably 0 or 1. ZA in formula (a7-A) + Examples thereof include the same ones as the cations in the salts represented by formula (B1) and the like.

[0191] In formula (a7-A), when the hydrocarbon groups of L a71 and L a72 are saturated hydrocarbon groups, in formula (a7-B) described later, A b7 may include the same groups as the groups exemplified as the divalent linking group of. Examples of the structural unit represented by formula (a7-A) also include the structural unit represented by formula (a7-A1). TIFF2025088761000159.tif30137 [In formula (a7-A1), R a7 、X a71 、L a71 、X a72 、na7、RA - and ZA + represent the same meaning as above. z7 represents any integer from 0 to 6. Q a7 、Q b7 、R z71 and R z72each independently represents a hydrogen atom, a fluorine atom, a perfluoroalkyl group having 1 to 6 carbon atoms, or an alkyl group having 1 to 6 carbon atoms; when z7 is 2 or more, a plurality of R z71 and R z72 may be the same as or different from each other.] Q a7 、Q b7 、R z71 and R z72 Examples of the perfluoroalkyl group having 1 to 6 carbon atoms or the alkyl group having 1 to 6 carbon atoms in a7 include the same groups as those exemplified for R

[0192] Examples of the structural unit represented by formula (a7-A) include, for example, the following structural units, a group corresponding to the methyl group of R a7 is replaced by a hydrogen atom, a halogen atom (for example, a fluorine atom), or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (for example, a trifluoromethyl group, etc.), and the structural units described in WO 2012 / 050015. ZA + represents an organic cation. TIFF2025088761000160.tif130158

[0193] TIFF2025088761000161.tif244162

[0194] The structural unit having a sulfonio group and an organic anion in the side chain is preferably a structural unit represented by formula (a7-B). TIFF2025088761000162.tif28104[In formula (a7-B), R a7 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. A b7 represents a single bond or a divalent linking group. R b71 represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent. R b72 and R b73each independently represents a hydrocarbon group having 1 to 18 carbon atoms which may have a substituent, and R b72 and R b73 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. A - represents an organic anion. R a7 Examples of the halogen atom of R and the alkyl group which may have a halogen atom include the same halogen atom and the alkyl group which may have a halogen atom as those of formula (a7-A). R b71 Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by R include a phenylene group and a naphthylene group. R b72 and R b73 Examples of the hydrocarbon group represented by R include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these. Examples of the alkyl group, the alicyclic hydrocarbon group, the aromatic hydrocarbon group, and the group formed by combining these are the same as those described above. A b7 Examples of the divalent linking group represented by A include a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH 2 - contained in the divalent saturated hydrocarbon group may be replaced by -O-, -S- or -CO-. Examples of the divalent saturated hydrocarbon group include a divalent chain-like saturated hydrocarbon group such as a linear or branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and combinations thereof may also be used. Specifically, linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group; branched alkanediyl groups such as butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group; divalent monocyclic alicyclic saturated hydrocarbon groups which are monocyclic cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group; divalent polycyclic alicyclic saturated hydrocarbon groups which are polycyclic cycloalkanediyl groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. are included. -CH contained in the saturated hydrocarbon group 2 Examples of those in which - is replaced by -O-, -S- or -CO- include divalent groups represented by the following. However, the number of carbon atoms before -CH contained in the saturated hydrocarbon group is each 17 or less. In the following formulas, * and ** represent bonding sites, and * represents the bonding site with R 2 and. b71 TIFF2025088761000163.tif123162[In the formula, X 3 represents a divalent saturated hydrocarbon group having 1 to 16 carbon atoms. X 4 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. X 5 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms. X 6 represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms. X 7 represents a trivalent saturated hydrocarbon group having 1 to 14 carbon atoms.​ X 8 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.

[0195] Examples of the structural unit containing the cation in formula (a7-B) include the structural unit represented below and a group corresponding to the methyl group of R a7 wherein the hydrogen atom, halogen atom (e.g., fluorine atom) or alkyl group having 1 to 6 carbon atoms which may have a halogen atom (e.g., trifluoromethyl group, etc.) is replaced with a structural unit and the like. TIFF2025088761000164.tif80144

[0196] A - Examples of the organic anion represented by A include sulfonate anion, sulfonylimide anion, sulfonylmethide anion, and carboxylate anion. A - The organic anion represented by A is preferably a sulfonate anion, and more preferably the same as the anion exemplified by compound (B) as the sulfonate anion. Examples of the sulfonylimide anion, sulfonylmethide anion, and carboxylate anion include the same anions as those exemplified by compound (B).

[0197] Examples of the structural unit represented by formula (a7-B) include the structural unit represented below and the like. TIFF2025088761000165.tif95157

[0198] When the resin (A) contains the structural unit (a7),...

Claims

1. An acid generator comprising a salt represented by formula (I): [In formula (I), Q １ , Q ２ , R １ and R ２ 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. z represents an integer of 0 to 6, and when z is 2 or more, a plurality of R １ and R ２ may be the same or different from each other. X １ represents *-CO-O-, *-O-CO-, *-O-CO-O-, or *-O-, and * represents C(R １ ) (R ２ ) or C(Q １ ) (Q ２ ) binding site. L １ and L ２ each independently represents a single bond or a hydrocarbon group having 1 to 28 carbon atoms which may have a substituent, and -CH 2 - is -O-, -S-, -SO ２ It may be replaced by --or --CO--. X ２ represents *-CO-O-, *-O-CO-, *-O-CO-O- or *-O-, and * represents L １ represents the bonding site with the benzene ring to which it is attached. W １ represents a cyclic hydrocarbon group having 3 to 18 carbon atoms, and the —CH 2 - is -O-, -CO-, -S- or -SO ２ It may be replaced by -. X represents a halogen atom or a haloalkyl group having 1 to 12 carbon atoms. R ３ and R ４ each independently 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 —CH 2 - is -O-, -CO-, -S- or -SO ２ It may be replaced with -. R ５ represents a hydrogen atom or a group represented by formula (5a). m3 represents an integer of 0 to 3, and when m3 is 2 or more, a plurality of R ３ may be the same or different from each other. m4 represents an integer of 0 to 3, and when m4 is 2 or more, a plurality of R ４ may be the same or different from each other. m5 represents an integer of 0 to 4, and when m5 is 2 or more, a plurality of R ５ may be the same or different, provided that 1≦m4+m5≦4. m6 represents 2 or 3, and the groups in the parentheses may be the same or different. Z ＋ represents an organic cation. [In formula (5a), L １０ represents a single bond or an alkanediyl group having 1 to 6 carbon atoms. R ａａ１ and R ａａ２ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. X ａ represents a single bond, an oxygen atom, a sulfur atom, or a methylene group. R ａａ３ represents a hydrocarbon group having 1 to 20 carbon atoms, or R ａａ２ and R ａａ３ are bonded to each other, and -C-(X ａ ) ｍ５２ It represents a group which, together with the -, forms a ring having 3 to 20 carbon atoms. The —CH ２ - may be replaced by -O- or -S-, and the hydrocarbon group and the group forming the ring may have a substituent. m51 and m52 each independently represent 0 or 1. * indicates the bonding site with the oxygen atom.

2. m6 is 2, and X ２ The bonding site of the benzene ring of １ 2. The acid generator according to claim 1, wherein both of the bonding sites are m-positioned with respect to the bonding sites of

3. X １ is *-CO-O- or *-O-CO- (where * is C(R １ ) (R ２ ) or C(Q １ ) (Q ２ ) represents the binding site with L １ is a single bond, an alkanediyl group having 1 to 8 carbon atoms (the —CH 2 - may be replaced by -O- or -CO-; or a group combining an alkanediyl group having 1 to 4 carbon atoms with an alicyclic hydrocarbon group having 5 to 12 carbon atoms (the -CH 2 - may be replaced by -O- or -CO-; X ２ is *-CO-O- or *-O-CO- (where * is L １ represents a bonding site with respect to the benzene ring to which it is bonded.

4. L ２ is a single bond or an alkanediyl group having 1 to 10 carbon atoms (the —CH 2 2. The acid generator according to claim 1, wherein - may be replaced by -O- or -CO-.

5. The group represented by formula (5a) is The acid generator according to claim 1, which is a group represented by formula (5a-A): [In formula (5a-A), R ａａ１Ａ and R ａａ２Ａ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms. X ａ represents a single bond, an oxygen atom, a sulfur atom, or a methylene group. R ａａ３Ａ represents a hydrocarbon group having 1 to 20 carbon atoms, or R ａａ２Ａ and R ａａ３Ａ are bonded to each other, and —C—X ａ It represents a group which, together with the -, forms a ring having 3 to 20 carbon atoms. The —CH ２ - may be replaced by -O- or -S-, and the hydrocarbon group and the group forming the ring may have a substituent. * indicates the bonding site with the oxygen atom.

6. The group represented by formula (5a) is The acid generator according to claim 1, which is a group represented by formula (5a-B): [In formula (5a-B), L １０ has the same meaning as in formula (5a). R ａａ１Ｂ , R ａａ２Ｂ and R ａａ３Ｂ each independently represents a hydrocarbon group having 1 to 20 carbon atoms, or R ａａ２Ｂ and R ａａ３Ｂ are bonded to each other, and R ａａ２Ｂ and R ａａ３Ｂ represents a group which, together with the carbon atom to which it is bonded, forms an alicyclic hydrocarbon group having 3 to 20 carbon atoms. The —CH ２ - may be replaced by -O- or -S-, and the hydrocarbon group and the alicyclic hydrocarbon group may have a substituent. * indicates the bonding site with the oxygen atom.

7. A resist composition comprising the acid generator according to any one of claims 1 to 6.

8. The composition contains a resin including a structural unit having an acid labile group, The resist composition according to claim 7, wherein the structural unit having an acid labile group includes at least one selected from the group consisting of a structural unit represented by formula (a1-0), a structural unit represented by formula (a1-1), a structural unit represented by formula (a1-2), a structural unit represented by formula (a1-4), a structural unit represented by formula (a1-5), and a structural unit represented by formula (a1-6). [In formula (a1-0), formula (a1-1) and formula (a1-2), L a01 , L ａ１ and L ａ２ 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 combination thereof, and the alkyl group, alicyclic hydrocarbon group and aromatic hydrocarbon group may contain a halogen atom. R ａ６ and R ａ７ each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these, and the alkyl group, alkenyl group, alicyclic hydrocarbon group and aromatic hydrocarbon group may have a halogen atom. m1′ represents an integer of 0 to 14. n1 represents an integer of 0 to 10. n1' represents an integer of 0 to 3. [In formula (a1-4), R ａ１ represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R ａ１７ represents a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A ａ１１ represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and the —CH ２ - is -O-, -CO- or -NR ａ１８ May be replaced with -. R ａ１８ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X ａ１ represents a single bond or a carbonyl group. R a34 and R a35 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms; R a36 represents a hydrocarbon group having 1 to 20 carbon atoms, or R a35 and R a36 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms together with the -C-O- to which they are bonded, and the hydrocarbon group and the -CH 2 - may be replaced by -O- or -S-. na1 represents an integer of 1 to 5, and when na1 is 2 or more, the groups in the parentheses may be the same or different. na11 represents an integer of 0 to 4, and when na11 is 2 or more, a plurality of R ａ１７ may be the same or different from each other. mc represents an integer of 0 to 2. [In formula (a1-5), R a8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom. Z a1 is a single bond or *-(CH 2 ) 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.] [In formula (a1-6), R a61 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a6２ , R a63 and R a6４ each independently represents an alkyl group having 1 to 6 carbon atoms or a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, or R a6２ and R a63 are bonded to each other to form, together with the carbon atoms to which they are attached, a ring having 3 to 20 carbon atoms. X a61 is a single bond, -CO-O-* or -CO-NR a65 - represents *, * represents a bonding site with Ar, R a65 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X a62 is a single bond, *-O-L a61 - or *-CO-OL a62 -, * represents a bonding site with Ar, L a61 and L a62 each independently represents an alkanediyl group having 1 to 4 carbon atoms. Ar represents an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent.

9. The resist composition according to claim 7, which contains a resin containing a structural unit represented by formula (a2-A). [In formula (a2-A), R ａ２ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R ａ２７ represents a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A ａ２１ represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and the —CH ２ - is -O-, -CO- or -NR ａ２８ May be replaced with -. R ａ２８ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X ａ２ represents a single bond or a carbonyl group. nA2 represents an integer of 1 to 5, and when nA2 is 2 or more, the groups in the parentheses may be the same or different. na21 represents an integer of 0 to 4, and when na21 is 2 or more, a plurality of R ａ２７ may be the same or different from each other. mc represents an integer of 0 to 2.

10. the resin including a structural unit having an acid labile group further includes a structural unit having a lactone ring, The resist composition according to claim 8, wherein the structural unit having a lactone ring comprises at least one selected from the group consisting of a structural unit represented by formula (a3-1), a structural unit represented by formula (a3-2), a structural unit represented by formula (a3-3), and a structural unit represented by formula (a3-4). [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-(CH ２ ) ｋ３ It represents a group represented by —CO—O— (k3 represents an integer of 1 to 7). L ａ７ represents -O-, *-O-L ａ８ -O-, *-O-L ａ８ -CO-O-, *-O-L ａ８ -CO-O-L ａ９ -CO-O- or *-O-L ａ８ -O-CO-L ａ９ 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 is -CH ２ - 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, a plurality of R ａ２１ , R ａ２２ , R ａ２３ and / or R ａ２５ may be the same or different.

11. 8. The resist composition according to claim 7, further comprising a salt capable of generating an acid having a weaker acidity than the acid generated from the acid generator.

12. (1) A step of applying the resist composition according to claim 7 onto a substrate; (2) A step of drying the applied resist composition to form a composition layer; (3) exposing the composition layer to light; (4) heating the composition layer after exposure; and (5) developing the composition layer after heating; A method for producing a resist pattern comprising the steps of:

13. A salt represented by formula (I): [In formula (I), Q １ , Q ２ , R １ and R ２ 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. z represents an integer of 0 to 6, and when z is 2 or more, a plurality of R １ and R ２ may be the same or different from each other. X １ represents *-CO-O-, *-O-CO-, *-O-CO-O-, or *-O-, and * represents C(R １ ) (R ２ ) or C(Q １ ) (Q ２ ) binding site. L １ and L ２ each independently represents a single bond or a hydrocarbon group having 1 to 28 carbon atoms which may have a substituent, and -CH 2 - is -O-, -S-, -SO ２ It may be replaced by --or --CO--. X ２ represents *-CO-O-, *-O-CO-, *-O-CO-O- or *-O-, and * represents L １ represents the bonding site with the benzene ring to which it is attached. W １ represents a cyclic hydrocarbon group having 3 to 18 carbon atoms, and the —CH 2 - is -O-, -CO-, -S- or -SO ２ It may be replaced by -. X represents a halogen atom or a haloalkyl group having 1 to 12 carbon atoms. R ３ and R ４ each independently 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 —CH 2 - is -O-, -CO-, -S- or -SO ２ It may be replaced by -. R ５ represents a hydrogen atom or a group represented by formula (5a). m3 represents an integer of 0 to 3, and when m3 is 2 or more, a plurality of R ３ may be the same or different from each other. m4 represents an integer of 0 to 3, and when m4 is 2 or more, a plurality of R ４ may be the same or different from each other. m5 represents an integer of 0 to 4, and when m5 is 2 or more, a plurality of R ５ may be the same or different, provided that 1≦m4+m5≦4. m6 represents 2 or 3, and the groups in the parentheses may be the same or different. Z ＋ represents an organic cation. [In formula (5a), L １０ represents a single bond or an alkanediyl group having 1 to 6 carbon atoms. R ａａ１ and R ａａ２ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms. X ａ represents a single bond, an oxygen atom, a sulfur atom, or a methylene group. R ａａ３ represents a hydrocarbon group having 1 to 20 carbon atoms, or R ａａ２ and R ａａ３ are bonded to each other, and -C-(X ａ ) ｍ５２ It represents a group which, together with the -, forms a ring having 3 to 20 carbon atoms. The —CH ２ - may be replaced by -O- or -S-, and the hydrocarbon group and the group forming the ring may have a substituent. m51 and m52 each independently represent 0 or 1. * indicates the bonding site with the oxygen atom.

14. m6 is 2, and X ２ The bonding site of the benzene ring of １ The salt according to claim 13, wherein both of the binding sites are m-positioned relative to the binding sites of

15. X １ is *-CO-O- or *-O-CO- (where * is C(R １ ) (R ２ ) or C(Q １ ) (Q ２ ) represents the binding site with L １ is a single bond, an alkanediyl group having 1 to 8 carbon atoms (the —CH 2 - may be replaced by -O- or -CO-; or a group combining an alkanediyl group having 1 to 4 carbon atoms with an alicyclic hydrocarbon group having 5 to 12 carbon atoms (the -CH 2 - may be replaced by -O- or -CO-; X ２ is *-CO-O- or *-O-CO- (where * is L １ represents a bonding site to the benzene ring to which it is bonded.

16. L ２ is a single bond or an alkanediyl group having 1 to 10 carbon atoms (the —CH 2 The salt according to claim 13 or 14, wherein - may be replaced by -O- or -CO-.

17. The group represented by formula (5a) is The salt according to claim 13 or 14, which is a group represented by formula (5a-A): [In formula (5a-A), R ａａ１Ａ and R ａａ２Ａ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms. X ａ represents a single bond, an oxygen atom, a sulfur atom, or a methylene group. R ａａ３Ａ represents a hydrocarbon group having 1 to 20 carbon atoms, or R ａａ２Ａ and R ａａ３Ａ are bonded to each other, and —C—X ａ It represents a group which, together with the -, forms a ring having 3 to 20 carbon atoms. The —CH ２ - may be replaced by -O- or -S-, and the hydrocarbon group and the group forming the ring may have a substituent. * indicates the bonding site with the oxygen atom.

18. The group represented by formula (5a) is The salt according to claim 13 or 14, which is a group represented by formula (5a-B): [In formula (5a-B), L １０ has the same meaning as in formula (5a). R ａａ１Ｂ , R ａａ２Ｂ and R ａａ３Ｂ each independently represents a hydrocarbon group having 1 to 20 carbon atoms, or R ａａ２Ｂ and R ａａ３Ｂ are bonded to each other, and R ａａ２Ｂ and R ａａ３Ｂ represents a group which, together with the carbon atom to which it is bonded, forms an alicyclic hydrocarbon group having 3 to 20 carbon atoms. The —CH ２ - may be replaced by -O- or -S-, and the hydrocarbon group and the alicyclic hydrocarbon group may have a substituent. * indicates the bonding site with the oxygen atom.

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