Resist composition and method for producing resist pattern

Abstract

To provide a resist composition from which a resist pattern having good line edge roughness can be obtained.SOLUTION: The resist composition contains an acid generator and one or more resins containing a structural unit represented by formula (I). One or more of the resins contain a structural unit of formula (a2-A) and a structural unit of formula (a2-D). [In the formulae, X1 represents a single bond, -O- or the like; R3 represents an H atom or an alkyl group; L1 represents a single bond or a substituted / unsubstituted hydrocarbon group; RA represents a saturated hydrocarbon group; Ra27 represents a halogen atom or the like; Aa21 represents a single bond or an alkanediyl group; Xa2 represents a single bond or a carbonyl group; nA2 represents an integer of 1-5, na21 represents an integer of 0-4, and mc represents an integer of 0-2; L2 represents a substituted / unsubstituted hydrocarbon group; L21 represents a single bond or an F atom-substituted / unsubstituted alkanediyl group; and Rf1 and Rf2 each represent a fluorinated alkyl group or the like.]SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a resist composition and a method for producing a resist pattern using the resist composition. [Background technology]

[0002] Patent Document 1 describes a resist composition that contains a resin that includes the following structural unit and an acid generator. TIFF2025036219000001.tif3259 [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2001-343748 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a resist composition that forms a resist pattern that has better line edge roughness (LER) than a resist pattern formed from the above resist composition. [Means for solving the problem]

[0005] The present invention includes the following inventions. [1] An acid generator and one or more resins containing a structural unit represented by formula (I), A resist composition, wherein at least one of the resins comprising a structural unit represented by formula (I) comprises a structural unit represented by formula (a2-A), and at least one of the resins comprising a structural unit represented by formula (I) comprises a structural unit represented by formula (a2-D). TIFF2025036219000002.tif3786 [In formula (I), R 1 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom, or a halogen atom. X 1 is a single bond, *-O-**, *-CO-O-**, *-O-CO-O-**, *-CO-NR 3 -**, *-NR 3 -CO-O-**, *-O-CO-NR 3 -** or *-Ax-Ph-Ay-**. R 3 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 represents one type of bond selected from the group consisting of a single bond, an ether bond, a thioether bond, an ester bond, an amide bond, and a carbonate bond. Ay represents one type of bond selected from the group consisting of a single bond, an ether bond, a thioether bond, an ester bond, an amide bond, and a carbonate bond. * and ** represent binding sites, * represents R 1 represents the bonding site with the carbon atom to which it is bonded. L 1 represents a single bond or a hydrocarbon group having 1 to 36 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-. R A represents a saturated hydrocarbon group having 1 to 12 carbon atoms. u1 represents an integer of 0 to 2, and when u1 is 2, a plurality of R A are either the same or different. s1 represents 1 or 2. t1 represents 0 or 1, provided that the sum of s1 and t1 is 1 or 2. TIFF2025036219000003.tif30123[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 a27represents a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group. A a21 represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and -CH2- contained in the alkanediyl group is -O-, -CO- or -NR a29 - may be replaced. R a29 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 greater, the groups in multiple parentheses may be the same or different from each other. 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 from 0 to 2. TIFF2025036219000004.tif46103[In formula (a2-D), R a2 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom, or a halogen atom. A a21 represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and -CH2- contained in the alkanediyl group is -O-, -CO- or -NR a30 - may be replaced. R a30 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. L 2 represents a hydrocarbon group having 1 to 28 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-. L21 represents a single bond or an alkanediyl group having 1 to 3 carbon atoms which may have a fluorine atom. R f1 represents a fluorinated alkyl group having 1 to 8 carbon atoms. R f2 represents a hydrogen atom or a fluorinated alkyl group having 1 to 6 carbon atoms, and the fluorinated alkyl group is L 2 may be bonded to form an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and -CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-. nD2 represents an integer of 1 to 4. When nD2 is 2 or more, the groups in the parentheses may be the same or different.] [2] X 1 is a single bond or a group represented by the formula (X 1 -1)~Formula(X 1 The resist composition according to [1], wherein the group is any one of the groups represented by any one of [1-10]. TIFF2025036219000005.tif45166[expression(X 1 -1)~Formula(X 1 -10) Medium, *, ** are binding sites, * is R 0 represents the bonding site with the carbon atom to which it is bonded. Rx represents a halogen atom, a hydroxy group, a fluorinated alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. mx represents an integer of 0 to 4. X 20 is -O- or -NR 3 - represents. R 3 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.] [3] L 1is a single bond, a chain hydrocarbon group having 1 to 4 carbon atoms (-CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-), a group formed by combining a chain hydrocarbon group having 1 to 4 carbon atoms with an alicyclic hydrocarbon group having 3 to 18 carbon atoms (-CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-, and -CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-- or -CO-), or a group formed by combining a chain hydrocarbon group having 1 to 4 carbon atoms with an aromatic hydrocarbon group having 6 to 14 carbon atoms which may have a substituent (provided that -CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-). [4] The resist composition according to any one of [1] to [3], wherein the structural unit represented by formula (a2-D) is one selected from the group consisting of a structural unit represented by formula (a2-D1), a structural unit represented by formula (a2-D2), a structural unit represented by formula (a2-D3), and a structural unit represented by formula (a2-D4). TIFF2025036219000006.tif127165 [In formula (a2-D1), formula (a2-D2), formula (a2-D3) and formula (a2-D4), R a2 , A a21 , R f1 , R f2 , L 21 , nD2 each independently have the same meaning as in formula (a2-D). R a28 each independently represents a halogen atom, 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. a28 is a methanediyl group, which may bridge the cyclohexyl ring. L 22 represents a single bond or a (nD2+1)-valent hydrocarbon group having 1 to 3 carbon atoms. nD22 represents an integer of 0 to 4, nD23 represents 0 or 1, and nD24 represents an integer of 0 to 5, and 1≦nD2+nD22≦5 is satisfied. When nD22 or nD24 is 2 or more, a plurality of R a27 may be the same or different. [5] The resist composition according to any one of [1] to [4], comprising a first resin containing a structural unit represented by formula (I) and a structural unit represented by formula (a2-A), and a second resin containing a structural unit represented by formula (I) and a structural unit represented by formula (a2-D). [6] The resist composition according to any one of [1] to [5], which contains a resin including a structural unit represented by formula (I), a structural unit represented by formula (a2-A), and a structural unit represented by formula (a2-D). [7] The resist composition according to any one of [1] to [6], further comprising a third resin that includes a structural unit represented by formula (a4). TIFF2025036219000007.tif3355[In formula (a4), R 41 represents a hydrogen atom or a methyl group. R 42 represents a saturated hydrocarbon group having 1 to 24 carbon atoms and containing a halogen atom, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-.] [8] The resist composition according to any one of [1] to [7], wherein the acid generator comprises a salt represented by formula (B1) or a salt represented by formula (B2). TIFF2025036219000008.tif1395[In formula (B1), L b1 represents a single bond or an (nb1+1)-valent hydrocarbon group which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. L b2 represents a single bond or a divalent hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. Y b1represents a methyl group which may have a substituent or a cyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-. nb1 represents an integer of 1 to 6. When nb1 is 2 or more, the groups in the multiple parentheses may be the same or different. Z1 + represents an organic cation. TIFF2025036219000009.tif1291[In formula (B2), A 1 represents a nitrogen atom or a carbon atom. L b2’ represents a single bond or a hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. Y b1’ represents a methyl group which may have a substituent or a cyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. nb5 represents an integer of 2 or 3, and when A is a nitrogen atom, nb5 is 2, and when A is a carbon atom, nb5 is 3; b2’ -Y b1’ may be the same or different, and two -SO2-L b2’ -Y b1’ Together, A 1 may form a ring comprising: Z2 + represents an organic cation. [9] The resist composition according to any one of [1] to [8], further comprising a salt that generates an acid having a weaker acidity than the acid generated from the acid generator.

[10] (1) A step of applying the resist composition according to any one of [1] to [9] 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 heated composition layer; A method for producing a resist pattern comprising the steps of: Effect of the Invention

[0006] By using the resist composition of the present invention, a resist pattern with excellent line edge roughness (LER) can be produced. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] In this specification, "(meth)acrylic monomer" means "at least one of acrylic monomer and methacrylic monomer". The terms "(meth)acrylate" and "(meth)acrylic acid" have the same meaning. In the groups described in this specification, those that can have both a linear structure and a branched structure may be either. When -CH2- contained in a hydrocarbon group or the like is replaced with -O-, -S-, -CO-, or -SO2-, the same examples are applied to each group, and the number of carbon atoms before the replacement is the number of carbon atoms of the hydrocarbon group or the like. "Combined group" means a group in which two or more of the exemplified groups are bonded, and the valence of these groups may be appropriately changed depending on the bond form. "Derived from" or "derived from" refers to a polymerizable C=C bond contained in the molecule becoming a single bond (-CC- group) by polymerization. When stereoisomers exist, all stereoisomers are included. The acid labile group means a group which, when contacted with an acid (e.g., trifluoromethanesulfonic acid, etc.), is eliminated to form a hydrophilic group (e.g., a carboxy group or a hydroxy group, etc.), as described below. The base labile group means a group which, when contacted with a base (e.g., trimethylamine, etc.), is eliminated to form a hydrophilic group (e.g., a carboxy group or a hydroxy group, etc.), as described below. Depending on the number of substituents, etc., any position and number of hydrogen atoms contained in each group may be replaced by a bond. The number of carbon atoms in a substituent is not included in the number of carbon atoms of the substituted group. In this specification, the term "solids content of a resist composition" refers to the sum of the components excluding the solvent (E), which will be described later, from the total amount of the resist composition.

[0008] [Resist Composition] The resist composition of the present invention contains an acid generator (hereinafter may be referred to as "acid generator (B)") and one or more resins (hereinafter may be referred to as "resin (A)") that contain at least a structural unit represented by formula (I) (hereinafter may be referred to as "structural unit (I)"). The resist composition of the present invention preferably contains a quencher such as a salt that generates an acid having a weaker acidity than the acid generated from the acid generator (hereinafter may be referred to as "quencher (C)"), and preferably contains a solvent (hereinafter may be referred to as "solvent (E)").

[0009] <Resin (A)> Resin (A) contains at least a structural unit represented by formula (I) (hereinafter, sometimes referred to as "structural unit (I)"). Resin (A) contains a first resin (hereinafter, sometimes referred to as "resin (A1)") containing structural unit (I) and structural unit (a2-A), and a second resin (hereinafter, sometimes referred to as "resin (A2)") containing structural unit (I) and structural unit (a2-D). Resin (A1) and resin (A2) may be the same resin or different resins. That is, resin (A1) may be a resin containing structural unit (I) and structural unit (a2-A), or may be a resin containing structural unit (I), structural unit (a2-A), and structural unit (a2-D). Resin (A2) is preferably a resin that does not contain structural unit (a2-A), and may be a resin containing a structural unit represented by formula (I) and a structural unit represented by formula (a2-D). However, resin (A), resin (A1) and resin (A2) may contain structural units conventionally known in the art in addition to the above structural units. In addition, resin (A) may contain any of the structural units described below, as long as it does not contain structural unit (I), for example, (a1).

[0010] (Structural unit (I)) The structural unit (I) is represented by the formula (I). TIFF2025036219000010.tif3786 [In formula (I), all symbols have the same meanings as defined above.]

[0011] In formula (I), R 1 Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group, and are preferably an alkyl group having 1 to 4 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and further preferably a methyl group or an ethyl group. The number of carbon atoms in the alkyl group is preferably 1 to 4, more preferably 1 to 3, and further preferably 1 or 2. R 1 Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. R 1 Examples of the alkyl group having a halogen atom include an alkyl fluoride, an alkyl chloride, an alkyl bromide, and an alkyl iodide. Specific examples of the alkyl group having a halogen atom include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a perchloromethyl group, a perbromomethyl group, and a periodomethyl group. 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, even more preferably a hydrogen atom, a methyl group, or an ethyl group, and even more preferably a hydrogen atom or a methyl group.

[0012] In formula (I), X 1 is a group represented by *-Ax-Ph-Ay-**, it is preferably a linking group represented by the following formula (X10). TIFF2025036219000011.tif3351[In formula (X10), Ax is R1 represents a bond type and a carbon atom to which is bonded, and represents one type of bond selected from the group consisting of a single bond, an ether bond, a thioether bond, an ester bond, an amide bond, and a carbonate bond. Ay is L 1 represents a bond type that bonds with, and represents one type of bond selected from the group consisting of a single bond, an ether bond, a thioether bond, an ester bond, an amide bond, and a carbonate bond. Rx represents a halogen atom, a hydroxy group, a fluorinated alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. mx represents an integer of 0 to 4, and when mx is an integer of 2 or more, multiple Rx's may be the same or different. 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, an amide bond, and a carbonate ester bond. When either Ax or Ay is an amide bond, -CO-NR 3 A bond represented by - is preferred. R 3 The alkyl group of R 1 Examples of the alkyl group include the same alkyl groups as those exemplified in the above. Among these, 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. The bonding position of Ay in the phenylene group is preferably the m-position or p-position relative to the bonding position of Ax, and more preferably the p-position. X 1 Examples of the group include a single bond and the group represented by the following formula (X 1 -1)~Formula(X 1 -10) is a group represented by * -R 1 represents the bond position with the carbon atom to which L is bonded. 1 represents the bond position to which the molecule is bonded. TIFF2025036219000012.tif45166[formula(X 1 -1)~Formula(X1 -10) in which all symbols have the same meaning as above.] Expression(X 1 -3)~Formula(X 1 Specific examples of the group represented by -10) include the following groups. TIFF2025036219000013.tif79157 Among them, X 1 is a single bond or a group of the formula (X 1 -1'), expression (X 1 -3')~expression(X 1 -10'), a single bond or a group represented by the formula (X 1 -1'), expression (X 1 -4'), expression (X 1 -5'), expression (X 1 -6') and formula (X 1 -10'), and more preferably a single bond, a group represented by the formula (X 1 -1'), a group represented by the formula (X 1 -5') or a group represented by the formula (X 1 -6') is more preferable.

[0013] L 1 Examples of the hydrocarbon group in include chain hydrocarbon groups such as alkanediyl groups, monocyclic or polycyclic (including spiro rings, condensed rings, bridged rings, etc.) alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups combining two or more of these groups (for example, a hydrocarbon group formed from an alicyclic hydrocarbon group and a chain hydrocarbon group). The number of carbon atoms in the hydrocarbon group is preferably 1 to 24, more preferably 1 to 18, still more preferably 1 to 12, even more preferably 1 to 9, still more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediyl group include linear alkanediyl groups such as a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, a decane-1,10-diyl group, an undecane-1,11-diyl group, a dodecane-1,12-diyl group, a tridecane-1,13-diyl group, a tetradecane-1,14-diyl group, a pentadecane-1,15-diyl group, a hexadecane-1,16-diyl group, and a heptadecane-1,17-diyl group; Examples of branched alkanediyl groups include ethane-1,1-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-2,2-diyl, pentane-2,4-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, and 2-methylbutane-1,4-diyl groups. The terminal of the branched alkanediyl group may be a methyl group. The chain hydrocarbon group preferably has 1 to 18 carbon atoms, more preferably 1 to 12 carbon atoms, even more preferably 1 to 9 carbon atoms, still more preferably 1 to 6 carbon atoms, and even more preferably 1 to 4 carbon atoms.

[0014] Examples of the monocyclic or polycyclic alicyclic hydrocarbon group include the following groups: The binding site may be any position. TIFF2025036219000014.tif47169Preferred as the monocyclic alicyclic hydrocarbon group are cycloalkanediyl groups such as a cyclobutane-1,3-diyl group, a cyclopentane-1,3-diyl group, a cyclohexane-1,4-diyl group, and a cyclooctane-1,5-diyl group. As the polycyclic alicyclic hydrocarbon group, a norbornane-1,4-diyl group, a norbornane-2,5-diyl group, an adamantane-1,5-diyl group, or an adamantane-2,6-diyl group is preferred. The alicyclic hydrocarbon group preferably has 3 to 18 carbon atoms, more preferably 3 to 16 carbon atoms, and further preferably 3 to 12 carbon atoms. Examples of the aromatic hydrocarbon group include arylene groups such as a phenylene group, a naphthylene group, an anthrylene group, a biphenylene group, a phenanthrylene group, etc. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 18, more preferably 6 to 14, and further preferably 6 to 10. Examples of groups that combine two or more of these groups include a group that combines an alicyclic hydrocarbon group with a chain hydrocarbon group, a group that combines an aromatic hydrocarbon group with a chain hydrocarbon group, a group that combines an alicyclic hydrocarbon group with an aromatic hydrocarbon group, and a group that combines an alicyclic hydrocarbon group with a chain hydrocarbon group and an aromatic hydrocarbon group. In the combination, two or more of each of the alicyclic hydrocarbon group, aromatic hydrocarbon group, and chain hydrocarbon group may be combined. In addition, when any group is X 1 may be bound to Examples of groups combining an alicyclic hydrocarbon group and a chain hydrocarbon group include a group in which an alicyclic hydrocarbon group is bonded to a chain hydrocarbon group (e.g., *-chain hydrocarbon group-alicyclic hydrocarbon group-, etc.), a group in which a chain hydrocarbon group is bonded to an alicyclic hydrocarbon group (e.g., *-alicyclic hydrocarbon group-chain hydrocarbon group-, etc.), a group in which an alicyclic hydrocarbon group and a chain hydrocarbon group are bonded to a chain hydrocarbon group (e.g., *-chain hydrocarbon group-alicyclic hydrocarbon group-chain hydrocarbon group-, etc.), a group in which an alicyclic hydrocarbon group and a chain hydrocarbon group are bonded to an alicyclic hydrocarbon group (e.g., *-chain hydrocarbon group-alicyclic hydrocarbon group-chain hydrocarbon group-, etc.), Examples of such an alkyl group include a group in which a hydroxyl group is bonded to an alicyclic hydrocarbon group (for example, *-alicyclic hydrocarbon group-chain hydrocarbon group-alicyclic hydrocarbon group- etc.), a group in which an alicyclic hydrocarbon group, a chain hydrocarbon group and an alicyclic hydrocarbon group are bonded to an chain hydrocarbon group (for example, *-chain hydrocarbon group-alicyclic hydrocarbon group-chain hydrocarbon group-alicyclic hydrocarbon group- etc.), and 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.). Examples of groups combining an aromatic hydrocarbon group and a chain hydrocarbon group include a group in which an aromatic hydrocarbon group is bonded to a chain hydrocarbon group (e.g., *-chain hydrocarbon group-aromatic hydrocarbon group-), a group in which a chain hydrocarbon group is bonded to an aromatic hydrocarbon group (e.g., *-aromatic hydrocarbon group-chain hydrocarbon group-), and a group in which an aromatic hydrocarbon group and a chain hydrocarbon group are bonded to a chain hydrocarbon group (e.g., *-chain hydrocarbon group-aromatic hydrocarbon group-chain hydrocarbon group-). Examples of groups combining an alicyclic saturated hydrocarbon group with an aromatic hydrocarbon group include groups in which an aromatic hydrocarbon group is bonded to an alicyclic hydrocarbon group (e.g., *-alicyclic hydrocarbon group-aromatic hydrocarbon group-), groups in which an alicyclic hydrocarbon group is bonded to an aromatic hydrocarbon group (e.g., *-aromatic hydrocarbon group-alicyclic hydrocarbon group-), and groups in which an alicyclic hydrocarbon group and an aromatic hydrocarbon group are condensed (e.g., the following groups (the bonding site is at any position)). TIFF2025036219000015.tif19140 Examples of groups combining an alicyclic hydrocarbon group, an open chain hydrocarbon group, and an aromatic hydrocarbon group include groups in which an aromatic hydrocarbon group and an open chain hydrocarbon group are bonded to an alicyclic hydrocarbon group (for example, *-alicyclic hydrocarbon group-aromatic hydrocarbon group-open chain hydrocarbon group- etc.), and groups in which an alicyclic hydrocarbon group and an open chain hydrocarbon group are bonded to an aromatic hydrocarbon group (for example, *-aromatic hydrocarbon group-alicyclic hydrocarbon group-open chain hydrocarbon group- etc.). * is X 1 represents the binding site with

[0015] L 1 The --CH2-- contained in the hydrocarbon group having 1 to 36 carbon atoms may be replaced by --O--, --S--, --SO2-- or --CO--. L 1 When --CH2-- contained in the hydrocarbon group having 1 to 36 carbon atoms is replaced with --O--, --S--, --SO2-- or --CO--, the number of carbon atoms before replacement is regarded as the number of carbon atoms of the hydrocarbon group. Examples of groups in which -CH2- in a hydrocarbon group is replaced by -O-, -S-, -SO2- or -CO- include a hydroxy group (a group in which -CH2- in a methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- in an ethyl group is replaced by -O-CO-), a thiol group (a group in which -CH2- in a methyl group is replaced by -S-), an oxy group (a group in which -CH2- in a methylene group is replaced by -O-), a carbonyl group (a group in which -CH2- in a methylene group is replaced by -CO-), a thio group (a group in which -CH2- in a methylene group is replaced by -S-), a sulfo group, nyl group (a group in which -CH2- in a methylene group is replaced with -SO2-), alkoxy group (a group in which -CH2- at any position in an alkyl group is replaced with -O-), alkylthio group (a group in which -CH2 at any position in an alkyl group is replaced with -S-), alkoxycarbonyl group (a group in which -CH2-CH2- at any position in an alkyl group is replaced with -O-CO-), alkylcarbonyl group (a group in which -CH2- at any position in an alkyl group is replaced with -CO-), alkylsulfonyl group (a group in which -CH2- at any position in an alkyl group is replaced with -SO2-), alkylcarbonyloxy group (a group in which -CH2-CH2- at any position in an alkyl group is replaced with -CO-O-), alkanediyloxy group (a group in which -CH2- at any position in an alkanediyl group is replaced with -O-), alkanediyloxycarbonyl group (a group in which -CH2-CH2- at any position in an alkanediyl group is replaced with -O-CO-), alkanediylcarbonyl group (a group in which -CH2- at any position in an alkanediyl group is replaced with -CO-), alkanediylcarbonyloxy group (a group in which -CH2-CH2- at any position in an alkanediyl group is replaced with -CO-), alkanediylsulfonyl group (a group in which -CH2- at any position in an alkanediyl group is replaced with -CO-O-), is replaced with -SO-), an alkanediylthio group (a group in which -CH- at any position in an alkanediyl group is replaced with -S-), an oxy group (a group in which -CH- in a methylene group is replaced with -O-), a carbonyl group (a group in which -CH- in a methylene group is replaced with -CO-), a thio group (a group in which -CH- in a methylene group is replaced with -S-), a sulfonyl group (a group in which -CH- in a methylene group is replaced with -SO-), 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, and a group in which two or more of these groups are combined.

[0016] Examples of the alkoxy group include alkoxy groups having 1 to 35 carbon atoms, such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, etc. The number of carbon atoms in the alkoxy group may be 1 to 17, preferably 1 to 11, more preferably 1 to 6, further preferably 1 to 4, and further more preferably 1 to 3. The alkylthio group includes an alkylthio group having 1 to 35 carbon atoms, such as a methylthio group, an ethylthio group, a propylthio group, a butylthio group, a pentylthio group, a hexylthio group, an octylthio group, a 2-ethylhexylthio group, a nonylthio group, a decylthio group, an undecylthio group, etc. The number of carbon atoms in the alkylthio group may be 1 to 17, preferably 1 to 11, more preferably 1 to 6, further preferably 1 to 4, and further more preferably 1 to 3. Examples of the alkoxycarbonyl group include an alkoxycarbonyl group having 2 to 35 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, and a butoxycarbonyl group. Examples of the alkylcarbonyl group include an alkylcarbonyl group having 2 to 36 carbon atoms, such as an acetyl group, a propionyl group, and a butyryl group. Examples of the alkylcarbonyloxy group include an alkylcarbonyloxy group having 2 to 35 carbon atoms, such as an acetyloxy group, a propionyloxy group, and a butyryloxy group. The number of carbon atoms in the alkoxycarbonyl group may be 2 to 17, preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkylcarbonyl group may be 2 to 17, preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The alkylcarbonyloxy group may have 2 to 17 carbon atoms, preferably 2 to 11, more preferably 2 to 6, further preferably 2 to 4, and even more preferably 2 or 3 carbon atoms. Examples of the alkylsulfonyl group include alkylsulfonyl groups having 1 to 35 carbon atoms, such as a methylsulfonyl group, an ethylsulfonyl group, a propylsulfonyl group, a butylsulfonyl group, a pentylsulfonyl group, a hexylsulfonyl group, an octylsulfonyl group, a 2-ethylhexylsulfonyl group, a nonylsulfonyl group, a decylsulfonyl group, an undecylsulfonyl group, etc. The number of carbon atoms in the alkylsulfonyl group may be 1 to 17, preferably 1 to 11, more preferably 1 to 6, further preferably 1 to 4, and further more preferably 1 to 3. The alkanediyloxy group includes an alkanediyloxy group having 1 to 35 carbon atoms, such as a methyleneoxy group, an ethyleneoxy group, a propanediyloxy group, a butanediyloxy group, a pentanediyloxy group, etc. The number of carbon atoms in the alkanediyloxy group may be 1 to 17, preferably 1 to 11, more preferably 1 to 6, further preferably 1 to 4, and further more preferably 1 to 3. Examples of the alkanediyloxycarbonyl group include alkanediyloxycarbonyl groups having 2 to 35 carbon atoms, such as methyleneoxycarbonyl group, ethyleneoxycarbonyl group, propanediyloxycarbonyl group, butanediyloxycarbonyl group, etc. Examples of the alkanediylcarbonyl group include alkanediylcarbonyl groups having 2 to 36 carbon atoms, such as methylenecarbonyl group, ethylenecarbonyl group, propanediylcarbonyl group, butanediylcarbonyl group, pentanediylcarbonyl group, etc. Examples of the alkanediylcarbonyloxy group include alkanediylcarbonyloxy groups having 2 to 35 carbon atoms, such as methylenecarbonyloxy group, ethylenecarbonyloxy group, propanediylcarbonyloxy group, butanediylcarbonyloxy group, etc. The number of carbon atoms in the alkanediyloxycarbonyl group may be 2 to 17, preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkanediylcarbonyl group may be 2 to 17, preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkanediylcarbonyloxy group may be 2 to 17, preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The alkanediylsulfonyl group includes an alkanediylsulfonyl group having 1 to 35 carbon atoms, such as a methylenesulfonyl group, an ethylenesulfonyl group, a propylenesulfonyl group, etc. The number of carbon atoms in the alkanediylsulfonyl group may be 1 to 17, preferably 1 to 11, more preferably 1 to 6, further preferably 1 to 4, and further more preferably 1 to 3. The alkanediylthio group includes an alkanediylthio group having 1 to 35 carbon atoms, such as a methylenethio group, an ethylenethio group, a propylenethio group, etc. The number of carbon atoms in the alkanediylthio group may be 1 to 17, preferably 1 to 11, more preferably 1 to 6, further preferably 1 to 4, and further more preferably 1 to 3. Examples of the cycloalkoxy group include a cycloalkoxy group having 3 to 35 carbon atoms, such as a cyclohexyloxy group. Examples of the cycloalkylalkoxy group include a cycloalkylalkoxy group having 4 to 35 carbon atoms, such as a cyclohexylmethoxy group. Examples of the alkoxycarbonyloxy group include an alkoxycarbonyloxy group having 2 to 16 carbon atoms, such as a butoxycarbonyloxy group. Examples of the aromatic hydrocarbon group-carbonyloxy group include an aromatic hydrocarbon group-carbonyloxy group having 7 to 35 carbon atoms, such as a benzoyloxy group. Examples of the aromatic hydrocarbon group-carbonyl group include an aromatic hydrocarbon group-carbonyl group having 7 to 35 carbon atoms, such as a benzoyl group. Examples of the aromatic hydrocarbon group-oxy group include an aromatic hydrocarbon group-oxy group having 6 to 34 carbon atoms, such as a phenyloxy group.

[0017] Examples of groups in which -CH2- in an alicyclic hydrocarbon group is replaced by -O-, -S-, -CO- or -SO2- include the following groups. -O- or -CO- in the groups shown below may be replaced by -S- or -SO2-, respectively. The bonding site may be at any position. TIFF2025036219000016.tif47168 Examples of the group in which -CH2- contained in the group in which an alicyclic hydrocarbon group and an aromatic hydrocarbon group are condensed is replaced by -O-, -S-, -CO- or -SO2- include the following groups. The binding site may be any position. TIFF2025036219000017.tif27164

[0018] L 1The substituents which may be contained in L include a halogen atom and a cyano group. 1 In the case of a group in which an alicyclic hydrocarbon group or an aromatic hydrocarbon group is combined with a chain hydrocarbon group, an alkanediyl group can be used as a substituent of the alicyclic hydrocarbon group or the aromatic hydrocarbon group. 1 The -CH2- in the chain hydrocarbon group in the formula (I) is replaced with -O-, -CO-, -S- or -SO2-, thereby forming L 1 can substantially have a substituent such as a hydroxy group, a carboxyl group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, a thiol group, or a sulfonyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. L 1 The substituent which may be possessed by is preferably an alkyl group having 1 to 4 carbon atoms, a hydroxyl group or a halogen atom, more preferably an alkyl group having 1 to 4 carbon atoms or a halogen atom, and further preferably a methyl group or a fluorine atom. L 1 The number of substituents that may be possessed by may be one or more, for example, may be a plurality.

[0019] L 1represents a single bond, a chain hydrocarbon group having 1 to 8 carbon atoms which may have a substituent (provided that -CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-), a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (provided that -CH2- contained in the cyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or -SO2-), or a group formed by combining a chain hydrocarbon group having 1 to 6 carbon atoms which may have a substituent and a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (provided that the chain hydrocarbon group -CH2- contained in the cyclic hydrocarbon group may be replaced by -O- or -CO-, and -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -SO2- or -CO-.) is preferred, and it is preferably a single bond, a chain hydrocarbon group having 1 to 6 carbon atoms (wherein -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-), a group formed by combining a chain hydrocarbon group having 1 to 6 carbon atoms with an alicyclic hydrocarbon group having 3 to 18 carbon atoms (wherein -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-). and -CH2- in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -SO2- or -CO-, or a group formed by combining a chain hydrocarbon group having 1 to 6 carbon atoms with an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent (provided that -CH2- in the chain hydrocarbon group may be replaced with -O- or -CO-), more preferably a single bond, a chain hydrocarbon group having 1 to 4 carbon atoms (provided that -CH2- in the chain hydrocarbon group may be replaced with -O- or -CO-), a group having 6 to 18 carbon atoms which may have a substituent, It is more preferably a group formed by combining a chain hydrocarbon group having 1 to 4 carbon atoms with an alicyclic hydrocarbon group having 3 to 18 carbon atoms (wherein -CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-, and -CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-- or -CO-) or a group formed by combining a chain hydrocarbon group having 1 to 4 carbon atoms with an aromatic hydrocarbon group having 6 to 14 carbon atoms which may have a substituent (wherein -CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-).

[0020] Also, L 1 is a single bond, an alkanediyl group having 1 to 8 carbon atoms, or *-L 12 -W 11 -L 13 -X 13 -L 14 (L 12 and L 13 represents a single bond or an alkanediyl group having 1 to 8 carbon atoms which may have a substituent; W 11 represents a cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, in which -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-, and -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-. * represents X 1 It represents the binding site with X 13 represents **-CO-O-, **-O-CO-, **-O-CO-O- or **-O-, and ** represents W 11 In this case, L 1 is a single bond, an alkanediyl group having 1 to 4 carbon atoms, or **-W 14 -X 13 -L 15 (*, W 14 and X 13 has the same meaning as above. 15 represents an alkanediyl group having 1 to 4 carbon atoms.) is also preferred, and a single bond or a methylene group is preferred. W 11 Cyclic hydrocarbon groups and L 11 -L 15 As the chain hydrocarbon group in the above, the same groups as those exemplified above can be mentioned, within the upper limit of the carbon number. L 12 is preferably a single bond, a methylene group or an ethylene group. L 13 is preferably a single bond or a methylene group. L 14 and L 15 is preferably a methylene group. W 11is preferably a monocyclic or polycyclic cyclic hydrocarbon group having 6 to 12 carbon atoms (the cyclic hydrocarbon group may have a substituent, and -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-), more preferably a polycyclic alicyclic hydrocarbon group having 7 to 11 carbon atoms (the -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O- or -CO-), and is preferably a methylene group, a group represented by the following formula (W 11 -1), a group represented by the formula (W 11 -2), a group represented by the formula (W 11 -3), or a group represented by the formula (W 11 It is more preferable that the group is represented by the formula (W 11 The group represented by -2) is more preferred. * represents a bonding site. TIFF2025036219000018.tif3598 [wherein * represents a binding site. X 14 represents -CH2-, -O-, or -S-. The above formula (W 11 -1), formula (W 11 -2), formula (W 11 -3) or formula (W 11 -4) is a group represented by the following formula (W 11 -1'), formula (W 11 -2'), formula (W 11 -3') or formula (W 11 -4') is more preferable. TIFF2025036219000019.tif3598

[0021] L 1 The cyclic ether bonded to is a group represented by the following formula (IC): TIFF2025036219000020.tif2972[In formula (IC), s1, t1, R A and u1 have the same meaning as above. * represents L 1 represents the binding site for s1 is preferably 1, t1 is preferably 1, and the sum of s1 and t1 is preferably 2. The group represented by formula (IC) is preferably a group represented by the following formula: TIFF2025036219000021.tif2694 [wherein all symbols have the same meaning as in formula (IC)]

[0022] In the group represented by formula (IC), u1 is preferably 0 or 1. In the structural unit represented by formula (IC), when u1 or more, at least one R A , L 1 is preferably bonded to the carbon atom adjacent to, u1 is 1, and R A L 1 The group bonded to the carbon atom adjacent to is represented by the following formula (IC-1). TIFF2025036219000022.tif3165 [In formula (IC-1), all symbols have the same meaning as in formula (IC)] R A Examples of the saturated hydrocarbon group include chain saturated hydrocarbon groups such as alkyl groups, alicyclic saturated hydrocarbon groups, and groups in which two or more of these groups are combined. R A Examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, octyl, nonyl, etc. The number of carbon atoms in the chain saturated hydrocarbon 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 alicyclic saturated hydrocarbon group may be any of monocyclic, polycyclic and spirocyclic. Examples of the alicyclic saturated hydrocarbon group include monocyclic cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclononyl, cyclodecyl and cyclododecyl, and polycyclic cycloalkyl groups such as norbornyl and adamantyl. The number of carbon atoms in the alicyclic saturated hydrocarbon group is preferably 3 to 10, more preferably 3 to 8, and even more preferably 3 to 6. The combined group may be a group in which one each of the above-mentioned alkyl groups and alicyclic saturated hydrocarbon groups is combined, or a group in which two or more of either one or two or more of both are combined.

[0023] Examples of the structural unit (I) include the following structural units. TIFF2025036219000023.tif171167

[0024] In the structural units represented by formulae (I-1) to (I-18), R 1 and R 1 Specific examples of the structural unit (I) include structural units in which a hydrogen atom corresponding to the following formula is replaced with a halogen atom, a haloalkyl group or an alkyl group. Of these, structural units represented by formulae (I-1) to (I-3), (I-9), and (I-12) to (I-18) are preferred, structural units represented by formulae (I-1), (I-3), (I-9), and (I-12) to (I-15) are more preferred, and structural units represented by formulae (I-1), (I-9), and (I-12) to (I-15) are even more preferred.

[0025] The structural unit (I) is derived from a compound represented by formula (I') (hereinafter, sometimes referred to as "compound (I')"). TIFF2025036219000024.tif3890 [In formula (I'), the symbols have the same meanings as above.] Compound (I') may be a commercially available product or may be produced by a known method.

[0026] (Structural unit (a2-A)) The structural unit (a2-A) contained in the resin (A1) is a structural unit represented by the following formula (a2-A). TIFF2025036219000025.tif3793 [In formula (a2-A), all symbols have the same meaning as defined above.]

[0027] R a2 is R in formula (I). 1 Examples of the above-mentioned examples are the same as those exemplified above. A a21 Examples of the alkanediyl group include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, 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, and the like. Examples of the alkanediyl group include a chain alkanediyl group, and a branched alkanediyl group such as butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, heptane-1,6-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, and decane-1,10-diyl group. The number of carbon atoms in the alkanediyl group is preferably 1 to 6, more preferably 1 to 4, even more preferably 1 to 3, and even more preferably 1 or 2. Among them, A a21 is preferably a methylene group or an ethylene group. R a29 Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a tert-butyl group. A a21 The alkanediyl group -CH2- is -O-, -CO- or -NR a29 When the hydrocarbon group is replaced with, the number of carbon atoms before the replacement is regarded as the number of carbon atoms of the hydrocarbon group. A a21Examples of the alkanediyl group in which -CH2- is replaced by -O- or -CO- include a hydroxy group (a group in which -CH2- in a methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- in an ethyl group is replaced by -O-CO-), a carbonyl group (a group in which -CH2- in a methylene group is replaced by -CO-), an oxy group (a group in which -CH2- in a methylene group is replaced by -O-), an amino group (a group in which -CH2- in an alkanediyl group is replaced by -NR a29 -), alkoxy group (a group in which -CH2- at any position in the alkyl group is replaced with -O-), alkoxycarbonyl group (a group in which -CH2-CH2- at any position in the alkyl group is replaced with -O-CO-), alkylcarbonyl group (a group in which -CH2- at any position in the alkyl group is replaced with -CO-), alkylamino group (a group in which -CH2- in the alkyl group is replaced with -NR a29 -), alkanediyloxy group (a group in which -CH2- at any position contained in an alkanediyl group is replaced with -O-), alkanediyloxycarbonyl group (a group in which -CH2-CH2- at any position contained in an alkanediyl group is replaced with -O-CO-), alkanediylcarbonyl group (a group in which -CH2- at any position contained in an alkanediyl group is replaced with -CO-), alkanediylcarbonyl Oxy group (a group in which -CH2-CH2- at any position in an alkanediyl group is replaced with -CO-O-), alkanediylsulfonyl group (a group in which -CH2- at any position in an alkanediyl group is replaced with -SO2-), alkanediylthio group (a group in which -CH2- at any position in an alkanediyl group is replaced with -S-), alkanediylamino group (a group in which -CH2- in an alkanediyl group is replaced with -NR a29 These substituted groups include the same groups as those exemplified in this specification, within the range permitted by the upper limit of the number of carbon atoms. The alkylamino group includes alkylamino groups having 1 to 11 carbon atoms, such as a methylamino group, an ethylamino group, a propylamino group, a butylamino group, a pentylamino group, a hexylamino group, and an octylamino group. The alkanediylamino group includes an alkanediylthio group having 1 to 11 carbon atoms, such as a methyleneamino group, an ethyleneamino group, a propyleneamino group, etc. The number of carbon atoms in the alkanediylamino group is preferably 1 to 8, more preferably 1 to 6, further preferably 1 to 4, and further more preferably 1 to 3. For example, A a21 The -CH2- in the alkanediyl group is -O-, -CO- or -NR a28 The groups substituted are *-O-, *-CO-O-, *-O-CO-, *-CO-OA. a22 -CO-O-, *-O-CO-A a22 -O-, *-OA a22 -CO-O-, *-CO-OA a22 -O-CO-, *-O-CO-A a22 -O-CO-, and *-CO-O- and *-CO-OA are particularly well known. a22 -CO-O- or *-OA a22 -CO-O-, *-CO-NR a29 - is preferred, where A a22 represents an alkanediyl group having 1 to 8 carbon atoms, and * represents R a2 represents the bonding site that bonds to the carbon atom to which A is attached. a22 The alkanediyl group of A is as follows, within the upper limit of the carbon number. a21 The same alkanediyl groups as those shown in the above are also included. A a21 is a single bond, *-CO-O- or *-CO-OA a22 -CO-O- is preferred, a single bond, *-CO-O- or *-CO-O-CH2-CO-O- is more preferred, and a single bond or *-CO-O- is even more preferred. R a27 The halogen atom and the alkyl group which may have a halogen atom in R 1Examples of the above-mentioned examples are the same as those exemplified above. R a27 Examples of the alkoxy group in include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, and a hexyloxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and further preferably a methoxy group. R a27 Examples of the alkoxyalkyl group in the formula (I) include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and further preferably a methoxymethyl group. R a27 In the above, examples of the alkoxyalkoxy group include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, and more preferably a methoxyethoxy group or an ethoxyethoxy group. R a27 Examples of the alkylcarbonyl group in include an acetyl group, a propionyl group, a butyryl group, etc. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group. R a27 In the above formula, examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group. R a27is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group, and further 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 further preferably 0 or 1. -X a2 -OH is a benzene ring, A a21 It is preferable that at least one of them is bonded to the m-position or p-position, and more preferable that it is bonded to the m-position. In the case of a naphthalene ring, A a21 When the bonding position of A is the 1st position, it may be bonded to any of the 2nd to 8th positions. a21 When the bonding position of A is the 2-position, it may be bonded to any of the 1-position and the 3-8-positions. a21 When the bonding position of A is the 1st position, at least one of them is preferably bonded to the 3rd to 6th positions, and more preferably bonded to the 3rd or 4th position. a21 When the bonding position is the 2-position, it is preferably bonded to the 4- to 7-positions, and more preferably bonded to the 5- or 6-position. It is preferred that mc is 0 or 1.

[0028] Examples of the structural unit (a2-A) include structural units derived from monomers described in JP-A-2010-204634 and JP-A-2012-12577. The structural unit (a2-A) includes structural units represented by formulae (a2-2-1) to (a2-2-32), (a2-3-1) to (a2-3-24), and structural units represented by formulae (a2-2-1) to (a2-2-32), (a2-3-1) to (a2-3-24), and R in the structural unit (a2-A) a2The structural unit (a2-A) includes structural units represented by formulae (a2-2-1) to (a2-2-4), (a2-2-6), (a2-2-8), (a2-2-12) to (a2-2-18), (a2-2-25) to (a2-2-32), (a2-3-1) to (a2-3-5), (a2-3-13) to (a2-3-15), (a2-3-19), and (a2-3-20), and structural units represented by formulae (a2-3-1). In the structural units represented by formulae (a2-2-1) to (a2-2-4), (a2-2-6), (a2-2-8), (a2-2-12) to (a2-2-18), (a2-2-25) to (a2-2-32), (a2-3-1) to (a2-3-5), (a2-3-13) to (a2-3-15), (a2-3-19), and (a2-3-20), R in the structural unit (a2-A) a2 and the structural unit in which a methyl group corresponding to the formula (a2-2-3), (a2-2-4), (a2-2-8), (a2-2-12) to (a2-2-14), (a2-2-18), (a2-2-25) to (a2-2-32), (a2-3-1), (a2-3-2), (a2-3-3), (a2-3-13), (a2-3-14), (a2-3-19), (a2-3- 20) and the structural units represented by the formulae (a2-2-3), (a2-2-4), (a2-2-8), (a2-2-12) to (a2-2-14), (a2-2-18), (a2-2-25) to (a2-2-32), (a2-3-1), (a2-3-2), (a2-3-3), (a2-3-13), (a2-3-14), (a2-3-19), and (a2-3-20), R in the structural unit (a2-A) a2 In the structural units represented by the formulae (a2-2-3), (a2-2-4), (a2-2-8), (a2-3-1), and (a2-3-13) and the structural units represented by the formulae (a2-2-3), (a2-2-4), (a2-2-8), (a2-3-1), and (a2-3-13), R in the structural unit (a2-A) is more preferably a structural unit in which a methyl group corresponding to a2It is more preferable that the structural unit is a structural unit in which a methyl group corresponding to the following formula is replaced with a hydrogen atom. TIFF2025036219000026.tif109169

[0029] TIFF2025036219000027.tif90167

[0030] The structural unit (a2-A) is derived from a compound represented by formula (a2-A') (hereinafter, may be referred to as "compound (a2-A)"). TIFF2025036219000028.tif31121 [In formula (a2-A'), the symbols have the same meanings as 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 (A1) by polymerizing the compound (a2-A'). The structural unit (a2-A) can be incorporated into the resin (A1) by polymerizing a monomer that induces a structural unit in which a hydroxyl group is protected by an acid labile group (for example, a structural unit represented by the formula (a1-4) described later) and then treating with an acid such as p-toluenesulfonic acid, or the structural unit (a2-A) can be incorporated into the resin (A1) by polymerizing the monomer using acetoxystyrene or the like and then treating with an alkali such as tetramethylammonium hydroxide.

[0031] (Structural unit (a2-D)) The structural unit (a2-D) contained in the resin (A1) or (A2) is a structural unit represented by the following formula (a2-D). TIFF2025036219000029.tif46103 [In formula (a2-D), all symbols have the same meaning as defined above.]

[0032] R a2 is R represented by formula (a2-A). a2 The same as those exemplified in formula (a2-D) are included. a2 is preferably a hydrogen atom or a methyl group. Aa21 and -CH2- contained in the alkanediyl group is -O-, -CO- or -NR a30 The groups substituted with are each represented by the formula (a2-A): a21 and -CH2- contained in the alkanediyl group are -O-, -CO- or -NR a29 The examples of the groups substituted with aryl are the same as those of the groups substituted with aryl. A in formula (a2-D) a21 As the alkyl group, a single bond, *-CO-O- or *-CO-O-(CH2) k2 -CO-O- is preferred, and * is R a2 represents a bonding site to the carbon atom to which the group is bonded; and k2 represents an integer of 1 to 7.

[0033] L 2 As the hydrocarbon group, L in formula (I) is preferably as long as the upper limit of the carbon number is permitted. 1 The hydrocarbon groups represented by the formula (I) are the same as those represented by the formula (I). 2 The substituents that the hydrocarbon group may have include, for example, 1 The substituents which may be substituted by the hydrocarbon group of the formula (I) are the same as those exemplified above. 2 As for the hydrocarbon group in which -CH2- is replaced by -O-, -S-, -SO2- or -CO-, the upper limit of the carbon number is permitted. 1 The -CH2- contained in the hydrocarbon group includes the same groups as those replaced by -O-, -S-, -SO2- or -CO-. L 2 Preferred examples of the alkyl group include an alkanediyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 10 carbon atoms, a group combining an alkanediyl group having 1 to 6 carbon atoms with an alicyclic hydrocarbon group having 3 to 18 carbon atoms, a chain hydrocarbon group having 1 to 6 carbon atoms and having an alicyclic hydrocarbon group having 3 to 18 carbon atoms in a side chain, a group combining an alkanediyl group having 1 to 6 carbon atoms with an aromatic hydrocarbon group having 6 to 10 carbon atoms, and a chain hydrocarbon group having 1 to 6 carbon atoms and having an aromatic hydrocarbon group having 6 to 10 carbon atoms in a side chain.

[0034] Rf1 and R f2 Examples of the fluorinated alkyl groups are each independently 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 f2 Fluorinated alkyl groups and L 2 Examples of the alicyclic hydrocarbon group formed by bonding with Aa include the following alicyclic hydrocarbon groups. 21 and L 21 The binding site with may be at any position. TIFF2025036219000030.tif46168 For example, monocyclic alicyclic hydrocarbon groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group, cyclopropanetriyl group, cyclobutanetriyl group, cyclopentanetriyl group, cyclohexanetriyl group, cycloheptanetriyl group, cyclooctanetriyl group, cyclodecanetriyl group, cyclopropanetetrayl group, cyclobutanetetrayl group, cyclopentanetetrayl group, cyclohexanetetrayl group, cycloheptanetetrayl group, cyclooctanetetrayl group, and cyclodecanetetrayl group; Examples of polycyclic alicyclic hydrocarbon groups include norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, decahydronaphthalenediyl group, bicyclo[3.3.0]octanediyl group, norbornanetriyl group, adamantanetriyl group, decahydronaphthalenetriyl group, bicyclo[3.3.0]octanetriyl group, norbornanetetrayl group, adamantanetetrayl group, decahydronaphthalenetetrayl group, and bicyclo[3.3.0]octanetetrayl group. The alicyclic hydrocarbon group has preferably 3 to 20 carbon atoms, more preferably 3 to 18, even more preferably 3 to 16, still more preferably 3 to 12, still more preferably 6 to 12, and particularly preferably 6 to 10. R f2Fluorinated alkyl groups and L 2 Examples of the alicyclic hydrocarbon group formed by bonding with the above and in which -CH2- is replaced with -O- include the following. TIFF2025036219000031.tif26159R f1 and R f2 As the substituents, a trifluoromethyl group is preferable. L 21 Examples of the alkanediyl group include a methylene group, an ethane-1,1-diyl group, a propane-1,1-diyl group, and a propane-2,2-diyl group. L 21 is preferably a single bond or a methylene group. nD2 is preferably 1 or 2.

[0035] In the structural unit (a2-D), L 2 Examples of the chain hydrocarbon group include the structural units shown below and R a2 and the like, in which a methyl group corresponding to the following formula (I) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group. TIFF2025036219000032.tif72166

[0036] In the structural unit (a2-D), L 2 contains an alicyclic hydrocarbon group or an aromatic hydrocarbon group, it is preferably a structural unit represented by formula (a2-D1), a structural unit represented by formula (a2-D2), a structural unit represented by formula (a2-D3), or a structural unit represented by formula (a2-D4). TIFF2025036219000033.tif127165 [In formula (a2-D1), formula (a2-D2), formula (a2-D3) and formula (a2-D4), all symbols have the same meaning as defined above.]

[0037] R a28Examples of the halogen atom, the alkyl group having 1 to 6 carbon atoms which may have a halogen atom, the alkoxy group having 1 to 6 carbon atoms, the alkoxyalkyl group having 2 to 12 carbon atoms, the alkoxyalkoxy group having 2 to 12 carbon atoms, the alkylcarbonyl group having 2 to 4 carbon atoms, the alkylcarbonyloxy group having 2 to 4 carbon atoms, the acryloyloxy group and the methacryloyloxy group include R represented by the formula (a2-A). a27 Examples of the halogen atom include the halogen atom, the alkyl group having 1 to 6 carbon atoms which may have a halogen atom, the alkoxy group having 1 to 6 carbon atoms, the alkoxyalkyl group having 2 to 12 carbon atoms, the alkoxyalkoxy group having 2 to 12 carbon atoms, the alkylcarbonyl group having 2 to 4 carbon atoms, the alkylcarbonyloxy group having 2 to 4 carbon atoms, the acryloyloxy group and the methacryloyloxy group. R a28 As the alkyl group, a fluorine atom, an iodine atom, a hydroxy group, a carboxy group, and an alkoxy group having 1 to 3 carbon atoms are preferable. L 22 As the chain hydrocarbon group, for example, an alkanediyl group having 1 to 3 carbon atoms, an alkanetriyl group having 1 to 3 carbon atoms, or an alkanetetrayl group having 2 to 3 carbon atoms is preferable.

[0038] Examples of the structural unit (a2-D1) include the structural units shown below. TIFF2025036219000034.tif62168

[0039] In the structural units represented by formulae (a2-D1-1) to (a2-D1-16), R a2 In the structural units represented by formulae (a2-D1-9) to (a2-D1-16), the hydrogen atom corresponding to R a2 Specific examples of the structural unit (a2-D1) include structural units in which the methyl group corresponding to the following formula is replaced with a hydrogen atom, etc. Among these, the structural units represented by the formulae (a2-D1-1) to (a2-D1-8) are preferred, the structural units represented by the formulae (a2-D1-1) to (a2-D1-4) are more preferred, and the structural unit represented by the formula (a2-D1-1) is even more preferred.

[0040] Examples of the structural unit (a2-D2) include the structural units shown below. TIFF2025036219000035.tif33168

[0041] In the structural units represented by formulae (a2-D2-1) to (a2-D2-8), R a2 Specific examples of the structural unit (a2-D2) include structural units in which the methyl group corresponding to the following formula is replaced with a hydrogen atom, etc. Among these, structural units represented by formulae (a2-D2-1) and (a2-D2-3) are preferred.

[0042] Examples of the structural unit (a2-D3) and the structural unit (a2-D4) include the structural units shown below. TIFF2025036219000036.tif37144 In the structural units represented by formulae (a2-D3-1), (a2-D3-2), (a2-D4-1) to (a2-D4-3), R a2 A structural unit in which the methyl group corresponding to the following formula is replaced with a hydrogen atom or the like can also be given as a specific example of the structural unit (a2-D3) and the formula (a2-D4).

[0043] The structural unit (a2-D) is derived from a compound represented by formula (a2-D') (hereinafter, may be referred to as "compound (a2-D)"). TIFF2025036219000037.tif43101 [In formula (a2-D'), the symbols have the same meanings as above.] The compound (a2-D') may be a commercially available product or may be produced by a known method.

[0044] The content of the structural unit (I) in the resin (A1) is preferably 1 mol% or more, more preferably 3 mol% or more, even more preferably 5 mol% or more, and even more preferably 5 mol% or more, based on the total structural units of the resin (A1). It is also preferably 90 mol% or less, more preferably 80 mol% or less, and even more preferably 70 mol% or less. It is also preferably 1 to 90 mol%, more preferably 3 to 80 mol%, and even more preferably 5 to 70 mol%. The content of the structural unit (a2-A) in the resin (A1) is preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 20 mol% or more, and even more preferably 30 mol% or more, based on the total structural units of the resin (A1). It is also preferably 99 mol% or less, more preferably 97 mol% or less, and even more preferably 95 mol% or less. It is also preferably 5 to 99 mol%, more preferably 10 to 97 mol%, and even more preferably 20 to 95 mol%. stomach. When the resin (A1) contains the structural unit (a2-D), the content of the structural unit (a2-D) is preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 20 mol% or more, and even more preferably 30 mol% or more, based on the total structural units of the resin (A1). It is also preferably 99 mol% or less, more preferably 97 mol% or less, and even more preferably 95 mol% or less. It is also preferably 5 to 99 mol%, more preferably 10 to 97 mol%, and even more preferably 20 to 95 mol%. stomach. In particular, it is preferable that the content of the structural unit (I) in the resin (A1) is 40 mol % to 70 mol %, relative to all structural units in the resin (A1), and the total content of the structural units (a2-A) and (a2-D) in the resin (A1) is 10 mol % to 50 mol %, relative to all structural units in the resin (A1), and the total content of the structural units (I), (a2-A) and (a2-D) in the resin (A1) is 70 mol % to 100 mol %, relative to all structural units in the resin (A1). Resin (A1) can be produced by combining at least one of compound (I'), compound (a2-A') and compound (a2-D') and, optionally, at least one of monomers not having an acid labile group, as described below, through a known polymerization method (e.g., radical polymerization method). The contents of structural unit (I), structural unit (a2-A), structural unit (a2-D) and other structural units in resin (A1) can be appropriately adjusted by the amounts of monomers used in polymerization. The weight average molecular weight of the resin (A1) is preferably 5,000 or more (more preferably 6,000 or more, even more preferably 7,000 or more) and 80,000 or less (more preferably 50,000 or less, even more preferably 30,000 or less), but may contain oligomers having a weight average molecular weight smaller than these. The weight average molecular weight is determined by gel permeation chromatography analysis as a converted value based on standard polystyrene, and the detailed analytical conditions for the analysis are described in detail in the Examples of the present application.

[0045] The content of the structural unit (I) in the resin (A2) is preferably 1 mol% or more, more preferably 3 mol% or more, even more preferably 5 mol% or more, and even more preferably 5 mol% or more, based on the total structural units of the resin (A2), and is preferably 90 mol% or less, more preferably 80 mol% or less, and even more preferably 70 mol% or less. Also, it is preferably 1 to 90 mol%, more preferably 3 to 80 mol%, and even more preferably 5 to 70 mol%. The content of the structural unit (a2-D) in the resin (A2) is preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 20 mol% or more, and even more preferably 30 mol% or more, based on the total structural units of the resin (A2), and is preferably 99 mol% or less, more preferably 97 mol% or less, and even more preferably 95 mol% or less. Also, it is preferably 5 to 99 mol%, more preferably 10 to 97 mol%, and even more preferably 20 to 95 mol%. In particular, it is preferable that the content of structural unit (I) in resin (A2) is 40 mol % to 70 mol % relative to all structural units in resin (A2), and the total content of structural unit (a2-D) in resin (A2) is 10 mol % to 50 mol % relative to all structural units in resin (A2), and the total content of structural unit (I) and structural unit (a2-D) in resin (A2) is 70 mol % to 100 mol % relative to all structural units in resin (A2).

[0046] When the resist composition contains resin (A2), the content of structural unit (a2-A) in resin (A1) is preferably greater than the content of structural unit (a2-D), and the total content of structural unit (I) and structural unit (a2-A) is preferably 70 mol % or more and 100 mol % or less, based on all structural units in resin (A1). The total content of the structural unit (I) contained in the resin (A1) and the resin (A2) is preferably 40 mol% to 80 mol%, more preferably 50 mol% to 80 mol%, based on all the structural units constituting the resin (A1) and the resin (A2). The total content of the structural unit (a2-A) contained in the resin (A1) and the resin (A2) is preferably 1 mol% to 40 mol%, more preferably 3 mol% to 30 mol%, based on all the structural units constituting the resin (A1) and the resin (A2). The total content of the structural unit (a2-D) contained in the resin (A1) and the resin (A2) is preferably 1 mol% to 40 mol%, more preferably 3 mol% to 30 mol%, based on all the structural units constituting the resin (A1) and the resin (A2). Resin (A2) can be produced by combining at least one of compound (I') and compound (a2-D') and, optionally, at least one of monomers not having an acid labile group, as described below, through a known polymerization method (e.g., radical polymerization method). The contents of structural unit (I), structural unit (a2-D) and other structural units in resin (A2) can be appropriately adjusted by the amounts of monomers used in polymerization. The weight average molecular weight of the resin (A2) is preferably 5,000 or more (more preferably 6,000 or more, even more preferably 7,000 or more) and 80,000 or less (more preferably 50,000 or less, even more preferably 30,000 or less), but may contain oligomers having a weight average molecular weight smaller than these. The weight average molecular weight is determined by gel permeation chromatography analysis as a converted value based on standard polystyrene, and the detailed analytical conditions for the analysis are described in detail in the Examples of the present application.

[0047] The content ratio (mass ratio) of resin (A2) to resin (A1) in the solid components of the resist composition of the present invention may be 0:10 to 5:10, for example, 0.1:10 to 5:10, preferably 0.2:10 to 4:10, more preferably 0.3:10 to 3:10, and even more preferably 0.5:10 to 2:10.

[0048] In the resist composition of the present invention, the resin (A1), the resin (A2) and the resin other than the resin (A1) and the resin (A2) may further contain a conventionally known resin. Examples of conventionally known structural units include a structural unit having an acid labile group (hereinafter may be referred to as "structural unit (a1)"); a structural unit (a2) other than the structural unit (a2-A) and the structural unit (a2-D), which does not have an acid labile group and has an acidic group (ahydroxy group or a carboxy group); a structural unit having a lactone ring and not having an acid labile group (hereinafter may be referred to as "structural unit (a3)"); a structural unit having a halogen atom and not containing an acid labile group (hereinafter may be referred to as "structural unit (a4)"); a structural unit having a non-leaving hydrocarbon group described below (hereinafter may be referred to as "structural unit (a5)"); a structural unit having a sultone ring and not containing an acid labile group (hereinafter may be referred to as "structural unit (a6)"); a structural unit that decomposes upon exposure to generate acid (hereinafter may be referred to as "structural unit (a7)"); and other structural units derived from monomers known in the field.

[0049] <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) etc. is preferably a group represented by formula (1) (hereinafter also referred to as group (1)) and / or a group represented by formula (2) (hereinafter also referred to as group (2)). TIFF2025036219000038.tif2298[In formula (1), R a1 , R a2 and R a3each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof, 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. * denotes a binding site.] TIFF2025036219000039.tif2278[In formula (2), R a1’ and R a2’ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms; R a3’ represents a hydrocarbon group having 1 to 20 carbon atoms, or R a2’ and R a3’ are bonded to each other to form, together with the carbon atom to which they are bonded and X, a heterocyclic group having 3 to 20 carbon atoms, and -CH2- contained in the hydrocarbon group and the heterocyclic group may be replaced 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. * denotes a binding site.]

[0050] R a1 , R a2 and R a3 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. R a1 , R a2 and R a3 Examples of the alkenyl group in include an ethenyl group, a propenyl group, an isopropenyl group, a butenyl group, an isobutenyl group, a tert-butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an octenyl group, an isooctenyl group, and a nonenyl group. Ra1 , R a2 and R a3 The alicyclic hydrocarbon group in may be either monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Examples of polycyclic alicyclic hydrocarbon groups include decahydronaphthyl, adamantyl, and norbornyl groups, as well as the following groups (* indicates a bonding site). R a1 , R a2 and R a3 The alicyclic hydrocarbon group preferably has 3 to 16 carbon atoms. TIFF2025036219000040.tif10159R a1 , R a2 and R a3 Examples of the aromatic hydrocarbon group in include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. Examples of the combined group include a group in which the above-mentioned alkyl group and an alicyclic hydrocarbon group are combined (for example, an alkylcycloalkyl group or a cycloalkylalkyl group such as a methylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group, an adamantyldimethyl group, or a norbornylethyl group), an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (a p-methylphenyl group, a p-tert-butylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, or the like), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (a p-cyclohexylphenyl group, a p-adamantylphenyl group, or the like), and an aryl-cycloalkyl group such as a phenylcyclohexyl group. Preferably, ma is 0 and na is 1. R a1 and R a2 When they are bonded to each other to form an alicyclic hydrocarbon group, -C(R a1 )(R a2 )(R a3) includes the following groups. The alicyclic hydrocarbon group preferably has 3 to 12 carbon atoms. * represents a bond to -O-. TIFF2025036219000041.tif27139

[0051] R a1’ , R a2’ and R a3’ Examples of the hydrocarbon group in include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups. Alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups combining these groups are R a1 , R a2 and R a3 Examples of the groups include the same groups as those listed in the above. R a2’ and R a3’ When they are bonded to each other to form a heterocycle together with the carbon atom to which they are attached and X, -C(R a1’ )(R a2’ )-XR a3’ Examples of the group include the following: * represents a bond. TIFF2025036219000042.tif19124R a1’ and R a2’ At least one of these is preferably a hydrogen atom. na' is preferably 0. R a1 , R a2 , R a3 , R a1 , R a2’ and R a3’ The halogen atom which may be contained includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0052] Examples of the group (1) include the following groups. In formula (1), R a1 , R a2 and R a3 is an alkyl group, ma = 0, and na = 1. As the group, a tert-butoxycarbonyl group is preferable. In formula (1), Ra1 , R a2 together with the carbon atom to which they are attached form an adamantyl group, R a3 is an alkyl group, ma=0, and na=1. In formula (1), R a1 and R a2 are each independently an alkyl group; R a3 is an adamantyl group, ma=0, and na=1. Specific examples of the group (1) include the following groups. * represents a bond. TIFF2025036219000043.tif149165

[0053] Specific examples of the group (2) include the following groups. * represents a bond. TIFF2025036219000044.tif55153

[0054] 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.

[0055] Of the (meth)acrylic monomers having an acid labile group, preferred are those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms. By using a resin (A) or the like having a structural unit derived from a monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group in a resist composition, the resolution of the resist pattern can be improved.

[0056] Examples of the structural unit derived from the (meth)acrylic monomer having the group (1) include a structural unit represented by formula (a1-0) (hereinafter, sometimes referred to as structural unit (a1-0)), a structural unit represented by formula (a1-1) (hereinafter, sometimes referred to as structural unit (a1-1)), or a structural unit represented by formula (a1-2) (hereinafter, sometimes referred to as structural unit (a1-2)). Preferably, it is at least one structural unit selected from the group consisting of the structural unit (a1-0), the structural unit (a1-1) and the structural unit (a1-2), more preferably at least one or two structural units selected from the group consisting of the structural unit (a1-1) and the structural unit (a1-2). These may be used alone or in combination of two or more. TIFF2025036219000045.tif43144 [In formula (a1-0), formula (a1-1) and formula (a1-2), L a01 , L a1 and L a2 are each independently -O- or *-O-(CH2) k1 represents --CO--O--, k1 represents an integer of 1 to 7, and * represents a 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 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, 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.

[0057] The halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R a01 , R a4 , R a5 The alkyl group may be a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, or a hexyl group. R a01 , R a4 and R a5 is preferably a hydrogen atom or a methyl group, and more preferably a methyl group. L a01 , L a1 and L a2 is preferably an oxygen atom or *-O-(CH2) k01 It is -CO-O- (wherein k01 is preferably an integer of any one of 1 to 4, more preferably 1), and more preferably an oxygen atom. R a02 , R a03 and R a04 The alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group and combinations thereof in the formula (1) are R a1 , R a2 and R a3 Examples of the groups include the same groups as those listed in the above. R a6 and R a7 The alkyl group, alkenyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and combinations thereof in the formula (1) include R a1 , R a2 and R a3Examples of the groups include the same groups as those listed in the above. R a02 , R a03 , and R a04 The alkyl group in the formula (I) is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. R a6 and R a7 The alkyl group in the formula (I) is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group, or a t-butyl group, and even more preferably an ethyl group, an isopropyl group, or a t-butyl group. R a6 and R a7 The alkenyl group in the formula (I) is preferably an alkenyl group having 2 to 6 carbon atoms, and more preferably an ethenyl group, a propenyl group, an isopropenyl group, or a butenyl group. R a02 , R a03 , R a04 , R a6 and R a7 The alicyclic hydrocarbon group preferably has 5 to 12 carbon atoms, and more preferably 5 to 10 carbon atoms. R a02 , R a03 , R a04 , R a6 and R a7 The aromatic hydrocarbon group preferably has 6 to 12 carbon atoms, and more preferably 6 to 10 carbon atoms. In the group in which an alkyl group and an alicyclic hydrocarbon group are combined, the total number of carbon atoms in the combination of the alkyl group and the alicyclic hydrocarbon group is preferably 18 or less. In the group in which an alkyl group and an aromatic hydrocarbon group are combined, the total number of carbon atoms in the combination of the alkyl group and the aromatic hydrocarbon group is preferably 18 or less. R a02 and R a03 are each independently 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 each independently preferably an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, an alkenyl group having 2 to 6 carbon atoms which may have a halogen atom, or an aromatic hydrocarbon group having 6 to 12 carbon atoms which may have a halogen atom, more preferably a methyl group, ethyl group, isopropyl group, t-butyl group, ethenyl group, phenyl group or naphthyl group which may have a halogen atom, and even more preferably an ethyl group, isopropyl group, t-butyl group, ethenyl group or phenyl group. m1' is preferably an integer of 0 to 3, and more preferably 0 or 1. n1 is preferably an integer of 0 to 3, and more preferably 0 or 1. n1' is preferably 0 or 1.

[0058] Examples of the structural unit (a1-0) include a structural unit represented by any one of formulas (a1-0-1) to (a1-0-21) and R a01 and structural units in which a methyl group corresponding to the formula (a1-0-1) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group. Structural units represented by any of formulas (a1-0-1) to (a1-0-10), (a1-0-13), (a1-0-14), (a1-0-19) to (a1-0-21) are preferred. TIFF2025036219000046.tif83163

[0059] Examples of the structural unit (a1-1) include structural units derived from monomers described in JP 2010-204646 A. Among them, structural units represented by any one of formulas (a1-1-1) to (a1-1-7) and R in the structural unit (a1-1) area4 In the above formula (a1-1-1), a methyl group is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group. In the above formula (a1-1-2), a methyl group is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group. In the above formula (a1-1-3), a methyl group is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group. In the above formula (a1-1-4), a structural unit is more preferred. TIFF2025036219000047.tif38168

[0060] The structural unit (a1-2) includes a structural unit represented by any one of formulas (a1-2-1) to (a1-2-20) and R a5 and structural units in which a methyl group corresponding to the formula (a1-2-2), (a1-2-5), (a1-2-6), and (a1-2-10) to (a1-2-20) are replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group. TIFF2025036219000048.tif92164

[0061] An example of the structural unit (a1) having a group (2) is a structural unit represented by formula (a1-4) (hereinafter, sometimes referred to as "structural unit (a1-4)"). TIFF2025036219000049.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 a17 represents a halogen atom, a hydroxy group, a carboxy group, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group or a methacryloyloxy group. A a11 represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and -CH2- contained in the alkanediyl group is -O-, -CO- or -NR a18 - may be replaced. R a18 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. X a1 represents a single bond or -CO-. na1 represents an integer of any one of 1 to 5, and when na1 is 2 or more, the groups in the multiple parentheses may be the same or different. na11 represents an integer of 0 to 4. When na11 is 2 or more, multiple R a17 may be the same or different from each other. R a34 and R a35 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms; R a36 represents a hydrocarbon group having 1 to 20 carbon atoms, or R a35 and R a36 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms together with the -CO- to which they are bonded, and the -CH2- contained in the hydrocarbon group and the divalent hydrocarbon group may be replaced by -O- or -S-. mc represents an integer from 0 to 2.

[0062] R a1 and R a17 Examples of the halogen atom in include a fluorine atom, a chlorine atom, and a bromine atom. R a1 and R a17Examples of the alkyl group having 1 to 6 carbon atoms, which may have a halogen atom, include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, a hexyl group, a perfluorohexyl group, a chloromethyl group, a bromomethyl group, and an iodomethyl group. The number of carbon atoms in the alkyl group is preferably 1 to 4, more preferably 1 to 3, further preferably a methyl group or an ethyl group, and even more preferably a methyl group. 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 further preferably a hydrogen atom or a methyl group.

[0063] A a11 Examples of the alkanediyl group include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, 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, and the like. Examples of the alkanediyl group include a chain alkanediyl group, and a branched alkanediyl group such as butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, heptane-1,6-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, and decane-1,10-diyl group. The number of carbon atoms in the alkanediyl group is preferably 1 to 6, more preferably 1 to 4, even more preferably 1 to 3, and even more preferably 1 or 2. Among them, A a11 is preferably a methylene group or an ethylene group. R a18Examples of the alkyl group 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 The alkanediyl group -CH2- is -O-, -CO- or -NR a18 When the hydrocarbon group is replaced with, the number of carbon atoms before the replacement is regarded as the number of carbon atoms of the hydrocarbon group. A a11 Examples of the alkanediyl group in which -CH2- is replaced by -O- or -CO- include a hydroxy group (a group in which -CH2- in a methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- in an ethyl group is replaced by -O-CO-), a carbonyl group (a group in which -CH2- in a methylene group is replaced by -CO-), an oxy group (a group in which -CH2- in a methylene group is replaced by -O-), an amino group (a group in which -CH2- in an alkanediyl group is replaced by -NR a28 -), alkoxy group (a group in which -CH2- at any position in the alkyl group is replaced with -O-), alkoxycarbonyl group (a group in which -CH2-CH2- at any position in the alkyl group is replaced with -O-CO-), alkylcarbonyl group (a group in which -CH2- at any position in the alkyl group is replaced with -CO-), alkylamino group (a group in which -CH2- in the alkyl group is replaced with -NR a18 These substituted groups include the same groups as those exemplified in this specification, within the range permitted by the upper limit of the number of carbon atoms. The alkylamino group includes alkylamino groups having 1 to 11 carbon atoms, such as a methylamino group, an ethylamino group, a propylamino group, a butylamino group, a pentylamino group, a hexylamino group, and an octylamino group. The alkanediylamino group includes an alkanediylthio group having 1 to 11 carbon atoms, such as a methyleneamino group, an ethyleneamino group, a propyleneamino group, etc. The number of carbon atoms in the alkanediylamino group is preferably 1 to 8, more preferably 1 to 6, further preferably 1 to 4, and further more preferably 1 to 3. For example, A a11 The -CH2- in the alkanediyl group is -O-, -CO- or -NR a18 The groups substituted are *-O-, *-CO-O-, *-O-CO-, *-CO-OA. a22 -CO-O-, *-O-CO-A a22 -O-, *-OA a22 -CO-O-, *-CO-OA a22 -O-CO-, *-O-CO-A a22 -O-CO-, and *-CO-O- and *-CO-OA are particularly well known. a22 -CO-O- or *-OA a22 -CO-O-, *-CO-NR a28 - is preferred, where A a22 represents an alkanediyl group having 1 to 8 carbon atoms, and * represents R a2 represents the bonding site that bonds to the carbon atom to which A is attached. a22 The alkanediyl group of A is as follows, within the upper limit of the carbon number. a11 The same alkanediyl groups as those shown in the above are also included. A a11 is a single bond, *-CO-O- or *-CO-OA a12 -CO-O- is preferred, a single bond, *-CO-O- or *-CO-O-CH2-CO-O- is more preferred, and a single bond or *-CO-O- is even more preferred. R a17 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, and a tert-butoxy group. The number of carbon atoms in the alkoxy group is preferably 1 to 4, more preferably 1 to 3, still more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group. R a17Examples of the alkoxyalkyl group include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and further preferably a methoxymethyl group. R a17 Examples of the alkoxyalkoxy group include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, and more preferably a methoxyethoxy group or an ethoxyethoxy group. R a17 Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, a butyryl group, etc. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group. R a17 The alkylcarbonyloxy group includes an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group. R a17 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group, and further preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group. 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 further preferably 0 or 1. mc is preferably 0 or 1. R a34 , R a35 and R a36 Examples of the hydrocarbon group in include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group consisting of a combination thereof. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of 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, and norbornyl groups, as well as the following groups (* indicates a bonding site): TIFF2025036219000050.tif10151 Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. Examples of the combined group include a group in which the above-mentioned alkyl group and alicyclic hydrocarbon group are combined (e.g., alkylcycloalkyl groups or cycloalkylalkyl groups such as methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, and norbornylethyl group), aralkyl groups such as benzyl group, aromatic hydrocarbon groups having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon groups having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), and aryl-cycloalkyl groups such as phenylcyclohexyl group. In particular, R a36 Examples of the alkyl group include an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these groups. R a35 and R a36Examples of the divalent cyclic hydrocarbon group having 2 to 20 carbon atoms that is formed by bonding together with the -CO- to which they are bonded include the following groups. * represents a bonding site, and one of the groups is R a34 This is the binding site for TIFF2025036219000051.tif15105

[0064] R a34 is preferably a hydrogen atom. R a35 is preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a methyl group or an ethyl group. R a36 The hydrocarbon group in R is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these, and more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. a36 The alkyl group and the alicyclic hydrocarbon group in R are preferably unsubstituted. a36 The aromatic hydrocarbon group in is preferably an aromatic ring having an aryloxy group having 6 to 10 carbon atoms.

[0065] -OC(R a34 )(R a35 )-OR a36 is eliminated on contact with an acid (e.g., p-toluenesulfonic acid) to form a hydroxy group or a carboxy group, respectively. -X a2 -OC(R a34 )(R a35 )-OR a36 In the case of a benzene ring, A a11 It is preferable that at least one of them is bonded to the o-position or the m-position, and more preferable that it is bonded to the p-position. In the case of a naphthalene ring, A a11 When the bonding position of A is the 1st position, it may be bonded to any of the 2nd to 8th positions.a11 When the bonding position of A is the 2-position, it may be bonded to any of the 1-position and the 3-8-positions. a11 When the bonding position of A is the 1st position, at least one of them is preferably bonded to the 3rd to 6th positions, and more preferably bonded to the 3rd or 4th position. a11 When the bonding position is the 2-position, it is preferably bonded to the 4- to 7-positions, and more preferably bonded to the 5- or 6-position.

[0066] Examples of the structural unit (a1-4) include structural units derived from monomers described in JP 2010-204646 A. Preferably, the structural units represented by formulas (a1-4-1) to (a1-4-42) and R in the structural unit (a1-4) are a1 and more preferably, the structural units represented by formulae (a1-4-1) to (a1-4-5), (a1-4-10), (a1-4-13), and (a1-4-14), respectively. TIFF2025036219000052.tif228165

[0067] An example of a structural unit derived from a (meth)acrylic monomer having the group (2) is a structural unit represented by formula (a1-5) (hereinafter, may be referred to as "structural unit (a1-5)"). TIFF2025036219000053.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 is a single bond or -(CH2) h3 -CO-L 54 -, h3 represents an integer of 1 to 4, * represents L 51 Represents a bond 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.

[0068] Examples of the halogen atom include a fluorine atom and a chlorine atom, with a fluorine atom being preferred. Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a fluoromethyl group, and a trifluoromethyl group. In formula (a1-5), R a8 is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group. L 51 is preferably an oxygen atom. L 52 and L 53 Of these, it is preferred that one is -O- and the other is -S-. It is preferable that s1 is 1. s1' is preferably an integer of 0 to 2. Z a1 is preferably a single bond or -CH2-CO-O-.

[0069] Examples of the structural unit (a1-5) include structural units derived from monomers described in JP 2010-61117 A. Among them, the structural units represented by formulae (a1-5-1) to (a1-5-4) are preferred, and the structural unit represented by formula (a1-5-1) or (a1-5-2) is more preferred. TIFF2025036219000054.tif33133

[0070] An example of the structural unit (a1) having a group (1) is a structural unit represented by formula (a1-6) (hereinafter, sometimes referred to as "structural unit (a1-6)"). TIFF2025036219000055.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 atoms to which they are attached. X a61 is a single bond, -CO-O-* or -CO-NR 5 -*, * represents the bonding site with Ar, R 5 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. X a62 is a single bond, *-OL a61 -or*-CO-OL a62 -, * represents the 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.]

[0071] R a61 Examples of the halogen atom in include a fluorine atom, a chlorine atom, and a bromine atom. Of these, a fluorine atom is preferred. R a61 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in the formula (I) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, and a perfluorohexyl group. R a61 is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group. R a62, R a63 and R a64 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, etc. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and further preferably a methyl group or an ethyl group. R a62 , R a63 and R a64 The cyclic hydrocarbon group in the formula (I) includes an alicyclic hydrocarbon group and an aromatic hydrocarbon group. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, and a norbornyl group. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 16, and more preferably 3 to 12. Examples of the aromatic hydrocarbon group include a phenylene group and a naphthylene group. Examples of the substituent that the cyclic hydrocarbon group may have include a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. R a62 and R a63 Examples of the ring formed by bonding with each other include an adamantane ring, a cyclopentane ring, and a cyclohexane ring. a62 and R a63 When they are bonded to each other to form a ring, -C(R a62 )(R a63 )(R a64 ) includes the following groups. * represents a bonding site with an oxygen atom. The number of carbon atoms in the ring is preferably 3 to 16, and more preferably 3 to 12. TIFF2025036219000056.tif33110

[0072] L a61 and L a62 Examples of the alkanediyl group having 1 to 4 carbon atoms 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 butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, and a 2-methylpropane-1,2-diyl group. L a61 and L a62 is 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 *-OL a61 -, and more preferably a single bond.

[0073] Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms for Ar include a phenylene group, an o-methylphenylene group, an m-methylphenylene group, a p-methylphenylene group, a p-ethylphenylene group, a p-tert-butylphenylene group, a 1-naphthylene group, a 2-naphthylene group, a 1-anthrylene group, a 9-anthrylene group, a 1-phenanthrylene group, and a 2-phenanthrylene group. Examples of the substituent that the aromatic hydrocarbon group may have include a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group.

[0074] Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and further preferably a methyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, and a hexyloxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and further preferably a methoxy group. Examples of the alkoxyalkyl group include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and further preferably a methoxymethyl group. Examples of the alkoxyalkoxy group include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, and more preferably a methoxyethoxy group or an ethoxyethoxy group. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, a butyryl group, etc. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group. 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 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. Ar is preferably a phenylene group which may have a substituent, and more preferably a phenylene group which may have a hydroxy group.

[0075] Examples of the structural unit (a1-6) include structural units represented by formulae (a1-6-1) to (a1-6-44), preferably structural units represented by formulae (a1-6-1) to (a1-6-9), more preferably structural units represented by formulae (a1-6-1), (a1-6-2), (a1-6-4), (a1-6-5), (a1-6-7) or (a1-6-8), and even more preferably structural units represented by formulae (a1-6-1) or (a1-6-2). a61 The structural unit in which the hydrogen atom corresponding to is replaced by a methyl group, etc., and the structural unit in which R a61 The structural unit (a1-6) also includes a structural unit in which a methyl group corresponding to the following is replaced with a hydrogen atom. TIFF2025036219000057.tif227165

[0076] Further, examples of the structural unit (a1) include the following structural units. TIFF2025036219000058.tif32168

[0077] Further, examples of the structural unit (a1) include the following structural units. TIFF2025036219000059.tif51105 When the resin (A1) and the resin (A2) contain the structural unit (a1), the total content of the structural unit (a1) is, based on all structural units of the resin (A1) and the resin (A2), 20 mol % or less, preferably 15 mol % or less, and more preferably 10 mol % or less.

[0078] <Structural unit (a2)> The structural unit (a2) is a structural unit represented by formula (a2) and has a hydroxy group or a carboxy group that is not protected by an acid labile group, except for the structural units (a2-A) and (a2-D). TIFF2025036219000060.tif40103[In formula (a2), R a2 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. A a21 represents a single bond or an alkanediyl group having 1 to 12 carbon atoms, and -CH2- contained in the alkanediyl group is -O-, -CO- or -NR a28 - may be replaced. R a28 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. L a21 represents a single bond or a hydrocarbon group having 1 to 28 carbon atoms, the hydrocarbon group optionally having a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -CO-, -S- or -SO2-. L a22 represents a chain hydrocarbon group having 1 to 12 carbon atoms which may have a single bond or a fluorine atom, and -CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-. na2 represents an integer of 1 to 4. When na2 is 2 or more, a plurality of L a22 may be the same or different.

[0079] R a2 Examples of the halogen atom in include a fluorine atom, a chlorine atom, and a bromine atom. R a2Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in the formula (I) include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, a hexyl group, a perfluorohexyl group, a chloromethyl group, a bromomethyl group, and an iodomethyl group. R a2 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, still more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group.

[0080] A a21 Examples of the alkanediyl group include straight-chain alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, propane-1,2-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, and dodecane-1,12-diyl groups. branched alkanediyl groups such as butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, heptane-1,6-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, and decane-1,10-diyl group. The number of carbon atoms in the alkanediyl group is preferably 1 to 6, more preferably 1 to 4, even more preferably 1 to 3, and even more preferably 1 or 2. a21 is preferably a methylene group or an ethylene group. R a28Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and a tert-butyl group. A a21 The alkanediyl group -CH2- is -O-, -CO- or -NR a28 When the hydrocarbon group is replaced with, the number of carbon atoms before the replacement is regarded as the number of carbon atoms of the hydrocarbon group. A a21 Examples of the alkanediyl group in which -CH2- is replaced by -O- or -CO- include a hydroxy group (a group in which -CH2- in a methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- in an ethyl group is replaced by -O-CO-), a carbonyl group (a group in which -CH2- in a methylene group is replaced by -CO-), an oxy group (a group in which -CH2- in a methylene group is replaced by -O-), an amino group (a group in which -CH2- in an alkanediyl group is replaced by -NR a28 -), alkoxy group (a group in which -CH2- at any position in the alkyl group is replaced with -O-), alkoxycarbonyl group (a group in which -CH2-CH2- at any position in the alkyl group is replaced with -O-CO-), alkylcarbonyl group (a group in which -CH2- at any position in the alkyl group is replaced with -CO-), alkylamino group (a group in which -CH2- in the alkyl group is replaced with -NR a28 These substituted groups include the same groups as those exemplified in this specification, within the range permitted by the upper limit of the number of carbon atoms. The alkylamino group includes alkylamino groups having 1 to 19 carbon atoms, such as a methylamino group, an ethylamino group, a propylamino group, a butylamino group, a pentylamino group, a hexylamino group, and an octylamino group. The alkanediylamino group includes an alkanediylthio group having 1 to 19 carbon atoms, such as a methyleneamino group, an ethyleneamino group, a propyleneamino group, etc. The number of carbon atoms in the alkanediylamino group is preferably 1 to 11, more preferably 1 to 6, further preferably 1 to 4, and further more preferably 1 to 3. A a21 The -CH2- in the alkanediyl group is -O-, -CO- or -NR a28 The groups substituted are *-O-, *-CO-O-, *-O-CO-, *-CO-OA. a22 -CO-O-, *-O-CO-A a22 -O-, *-OA a22 -CO-O-, *-CO-OA a22 -O-CO-, *-O-CO-A a22 -O-CO-, and *-CO-O- and *-CO-OA are particularly well known. a22 -CO-O- or *-OA a22 -CO-O-, *-CO-NR a28 - is preferred, where A a22 represents an alkanediyl group having 1 to 8 carbon atoms, and * represents R a2 represents the bonding site that bonds to the carbon atom to which A is attached. a22 The alkanediyl group of A is as follows, within the upper limit of the carbon number. a21 The same alkanediyl groups as those shown in the above are also included. A a21 is a single bond, *-CO-O- or *-CO-OA a22 -CO-O- is preferred, a single bond, *-CO-O- or *-CO-O-CH2-CO-O- is more preferred, and a single bond or *-CO-O- is even more preferred.

[0081] L a21 The hydrocarbon group in the formula (I) is a hydrocarbon group having a valence of (na2+1), and examples of such cyclic hydrocarbon groups include chain hydrocarbon groups, monocyclic or polycyclic (including spiro rings, fused rings or bridged rings) alicyclic hydrocarbon groups, and aromatic hydrocarbon groups, and may be groups 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). L a21 Examples of the chain hydrocarbon group include divalent to pentavalent chain hydrocarbon groups such as an alkanediyl group, an alkanetriyl group, an alkanetetrayl group, and an alkanepentyl group. L a21Examples of the alkanediyl group include A a21 The same alkanediyl groups as those shown in the above are also included. L a21 Examples of the alkanetriyl group include a methanetriyl group, an ethanetriyl group, a propanetriyl group, a butanetriyl group, a pentanetriyl group, a hexanetriyl group, a heptanetriyl group, an octanetriyl group, a nonanetriyl group, a decanetriyl group, an undecanetriyl group, a dodecanetriyl group, a tridecanetriyl group, a tetradecanetriyl group, a pentadecanetriyl group, a hexadecanetriyl group, and a heptadecanetriyl group. Examples of the alkanetetrayl group include a methanetetrayl group, an ethanetetrayl group, a propanetetrayl group, a butanetetrayl group, a pentanetetrayl group, a hexanetetrayl group, a heptanetetrayl group, an octanetetrayl group, a nonanetetrayl group, a decanetetrayl group, an undecanetetrayl group, a dodecanetetrayl group, a tridecanetetrayl group, a tetradecanetetrayl group, a pentadecanetetrayl group, a hexadecanetetrayl group, and a heptadecanetetrayl group. Examples of the alkanol groups include a methane pentaylene group, an ethane pentaylene group, a propane pentaylene group, a butane pentaylene group, a pentane pentaylene group, and a hexane pentaylene group. L a21 The number of carbon atoms in the chain hydrocarbon group is preferably 1 to 18, more preferably 1 to 12, even more preferably 1 to 10, still more preferably 1 to 9, even more preferably 1 to 8, even more preferably 1 to 6, even more preferably 1 to 5, and particularly preferably 1 to 4. L a21 Examples of the monocyclic and polycyclic divalent alicyclic hydrocarbon group in the formula (I) include the following alicyclic hydrocarbon groups. The binding site may be any position. TIFF2025036219000061.tif46167For example, monocyclic alicyclic hydrocarbon groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group, cyclopropanetriyl group, cyclobutanetriyl group, cyclopentanetriyl group, cyclohexanetriyl group, cycloheptanetriyl group, cyclooctanetriyl group, cyclodecanetriyl group, cyclopropanetetrayl group, cyclobutanetetrayl group, cyclopentanetetrayl group, cyclohexanetetrayl group, cycloheptanetetrayl group, cyclooctanetetrayl group, and cyclodecanetetrayl group; Examples of polycyclic alicyclic hydrocarbon groups include norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, decahydronaphthalenediyl group, bicyclo[3.3.0]octanediyl group, norbornanetriyl group, adamantanetriyl group, decahydronaphthalenetriyl group, bicyclo[3.3.0]octanetriyl group, norbornanetetrayl group, adamantanetetrayl group, decahydronaphthalenetetrayl group, and bicyclo[3.3.0]octanetetrayl group. The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 18 carbon atoms, further preferably 3 to 16 carbon atoms, and further preferably 3 to 12 carbon atoms. L a21 Examples of the divalent aromatic hydrocarbon group in include 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. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 20, more preferably 6 to 18, even more preferably 6 to 14, and even more preferably 6 to 10. Examples of groups in which -CH2- in a hydrocarbon group is replaced by -O-, -S-, -SO2- or -CO- include a hydroxy group (a group in which -CH2- in a methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- in an ethyl group is replaced by -O-CO-), a thiol group (a group in which -CH2- in a methyl group is replaced by -S-), an alkoxy group (a group in which -CH2- at any position in an alkyl group is replaced by -O-), an alkylthio group (a group in which -CH2- at any position in an alkyl group is replaced by -S-), and a group in which -CH2-CH2- at any position in the alkyl group is replaced with -O-CO-), an alkoxycarbonyl group (a group in which -CH2- at any position in the alkyl group is replaced with -O-CO-), an alkylsulfonyl group (a group in which -CH2- at any position in the alkyl group is replaced with -SO2-), an alkylcarbonyl group (a group in which -CH2- at any position in the alkyl group is replaced with -CO-), an alkylcarbonyloxy group (a group in which -CH2-CH2- at any position in the alkyl group is replaced with -CO-O-), an oxy group (a group in which -CH2- in a methylene group is replaced with -O- a carbonyl group (a group in which -CH2- in a methylene group is replaced with -CO-), a thio group (a group in which -CH2- in a methylene group is replaced with -S-), a sulfonyl group (a group in which -CH2- in a methylene group is replaced with -SO2-), an alkanediyloxy group (a group in which -CH2- at any position in an alkanediyl group is replaced with -O-), an alkanediyloxycarbonyl group (a group in which -CH2-CH2- at any position in an alkanediyl group is replaced with -O-CO-), an alkanediylcarbonyl group (a an alkanediyl group in which -CH2- at any position is replaced with -CO-), an alkanediylcarbonyloxy group (an alkanediyl group in which -CH2-CH2- at any position is replaced with -CO-O-), an alkanediylsulfonyl group (an alkanediyl group in which -CH2- at any position is replaced with -SO2-), an alkanediylthio group (an alkanediyl group in which -CH2- at any position is replaced with -S-), a cycloalkoxy group, a cycloalkylalkoxy group, an alkoxycarbonyloxy group,Examples of the aromatic hydrocarbon group-carbonyloxy group, aromatic hydrocarbon group-carbonyl group, aromatic hydrocarbon group-oxy group, and combinations of two or more of these groups are also included. In addition, examples of the aromatic hydrocarbon group-carbonyloxy group include groups in which one or more hydrogen atoms of these groups are replaced with a bonding site. Examples of the alkoxy group include alkoxy groups having 1 to 27 carbon atoms, such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, etc. The number of carbon atoms in the alkoxy group is preferably 1 to 11, more preferably 1 to 6, further preferably 1 to 4, and even more preferably 1 to 3. The alkylthio group includes an alkylthio group having 1 to 27 carbon atoms, such as a methylthio group, an ethylthio group, a propylthio group, a butylthio group, etc. The number of carbon atoms in the alkylthio group is preferably 1 to 11, more preferably 1 to 6, further 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, ethoxycarbonyl, and butoxycarbonyl groups. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 28 carbon atoms, such as acetyl, propionyl, and butyryl groups. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 27 carbon atoms, such as acetyloxy, propionyloxy, and butyryloxy groups. The number of carbon atoms in the alkoxycarbonyl group is preferably 2 to 11, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The alkylcarbonyloxy group preferably has 2 to 11 carbon atoms, more preferably 2 to 6 carbon atoms, further preferably 2 to 4 carbon atoms, and even more preferably 2 or 3 carbon atoms. The alkylsulfonyl group includes alkylsulfonyl groups having 1 to 27 carbon atoms, such as a methylsulfonyl group, an ethylsulfonyl group, a propylsulfonyl group, etc. The number of carbon atoms in the alkylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, further preferably 1 to 4, and even more preferably 1 to 3. The alkanediyloxy group includes an alkanediyloxy group having 1 to 27 carbon atoms, such as a methyleneoxy group, an ethyleneoxy group, a propanediyloxy group, a butanediyloxy group, a pentanediyloxy group, etc. The number of carbon atoms in the alkanediyloxy group is preferably 1 to 11, more preferably 1 to 6, further preferably 1 to 4, and even more preferably 1 to 3. Examples of the alkanediyloxycarbonyl group include alkanediyloxycarbonyl groups having 2 to 27 carbon atoms, such as methyleneoxycarbonyl group, ethyleneoxycarbonyl group, propanediyloxycarbonyl group, butanediyloxycarbonyl group, etc. Examples of the alkanediylcarbonyl group include alkanediylcarbonyl groups having 2 to 28 carbon atoms, such as methylenecarbonyl group, ethylenecarbonyl group, propanediylcarbonyl group, butanediylcarbonyl group, pentanediylcarbonyl group, etc. Examples of the alkanediylcarbonyloxy group include alkanediylcarbonyloxy groups having 2 to 27 carbon atoms, such as methylenecarbonyloxy group, ethylenecarbonyloxy group, propanediylcarbonyloxy group, butanediylcarbonyloxy group, etc. The number of carbon atoms in the alkanediyloxycarbonyl 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 alkanediylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, still more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkanediylcarbonyloxy 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 alkanediylthio group includes an alkanediylthio group having 1 to 27 carbon atoms, such as a methylenethio group, an ethylenethio group, a propanediylthio group, etc. The number of carbon atoms in the alkanediylthio group is preferably 1 to 11, more preferably 1 to 6, still more preferably 1 to 4, and even more preferably 1 to 3. The alkanediylsulfonyl group includes an alkanediylsulfonyl group having 1 to 27 carbon atoms, such as a methylenesulfonyl group, an ethylenesulfonyl group, a propylenesulfonyl group, etc. The number of carbon atoms in the alkanediylsulfonyl group is preferably 1 to 11, more preferably 1 to 6, further preferably 1 to 4, and even more preferably 1 to 3.

[0082] 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-carbonyloxy group include aromatic hydrocarbon group-carbonyloxy groups having 7 to 27 carbon atoms, such as a benzoyloxy group. Examples of the aromatic hydrocarbon group-carbonyl group include aromatic hydrocarbon group-carbonyl groups having 7 to 27 carbon atoms, such as a benzoyl group. Examples of the aromatic hydrocarbon group-oxy group include aromatic hydrocarbon group-oxy groups having 6 to 27 carbon atoms, such as a phenyloxy group.

[0083] Examples of groups in which -CH2- in an alicyclic hydrocarbon group is replaced with -O-, -S-, -CO- or -SO2- include the following groups. Also included are the following groups in which -O- is replaced with -S- and -CO- is replaced with -SO2-. The bonding site may be any position. TIFF2025036219000062.tif47168 Examples of the combined group in which -CH2- is replaced by -O-, -S-, -CO- or -SO2- include the following groups: The binding site may be any position. TIFF2025036219000063.tif27164L a21 The hydrocarbon group in may have one or more substituents. Examples of the substituent include a halogen atom, a haloalkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 12 carbon atoms (-CH2- contained in the alkyl group may be replaced by -O- or -CO-), and a cyclic hydrocarbon group having 3 to 18 carbon atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. L a21 The hydrocarbon group in the formula (I) can have a halogen atom as a substituent, and thus can substantially have a substituent such as a haloalkyl group. Examples of the haloalkyl group include a chloromethyl group, a bromomethyl group, a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, and a perfluorobutyl group. A haloalkyl group having 1 to 4 carbon atoms is preferable, and a haloalkyl group having 1 to 3 carbon atoms is more preferable. L a21 The hydrocarbon group of L a21 can substantially have a substituent such as an alkyl group. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group. The number of carbon atoms in the alkyl group is preferably 1 to 10, more preferably 1 to 8, still more preferably 1 to 6, still more preferably 1 to 4, and still more preferably 1 to 3. L a21 In the above hydrocarbon group, -CH2- is replaced with -O- or -CO-. a21can substantially have a substituent such as a hydroxy group, a carboxy group, an alkoxy group, a thiol group, a sulfonyl group, an alkoxycarbonyl group, an alkylcarbonyl group, or an alkylcarbonyloxy group. L a21 The substituent that the hydrocarbon group in the formula (I) may have is preferably a halogen atom, a haloalkyl group having 1 to 4 carbon atoms, or an alkyl group having 1 to 6 carbon atoms (-CH2- contained in the alkyl group may be replaced with -O- or -CO-), more preferably a fluorine atom, an iodine atom, a haloalkyl group having 1 to 3 carbon atoms, or an alkyl group having 1 to 4 carbon atoms (-CH2- contained in the alkyl group may be replaced with -O- or -CO-), and further preferably a fluorine atom, an iodine atom, a trifluoromethyl group, a methyl group, a hydroxy group, or a methoxy group. L a21is preferably a single bond, a chain hydrocarbon group having 1 to 12 carbon atoms which may have a substituent (however, -CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-), a cyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent (however, -CH2- contained in the cyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or -SO2-), or a group formed by combining a chain hydrocarbon group having 1 to 8 carbon atoms which may have a substituent and a cyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent (however, -CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO- and -CH2- contained in the cyclic hydrocarbon group may be replaced with -O-, -S-, -SO2- or -CO-). and more preferably an optionally substituted chain hydrocarbon group having 1 to 10 carbon atoms (provided that -CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-), an optionally substituted cyclic hydrocarbon group having 3 to 18 carbon atoms (provided that -CH2- contained in the cyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or -SO2-), 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 -CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO- and -CH2- contained in the cyclic hydrocarbon group may be replaced with -O-, -S-, -SO2- or -CO-).

[0084] L a22Examples of the chain hydrocarbon group having 1 to 12 carbon atoms include linear alkyl 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, and dodecane-1,12-diyl group. Examples of the alkyl group include alkanediyl group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, 1-methylpropane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-dimethylpropane-1,3-diyl group, pentane-2,4-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, etc. The number of carbon atoms in the chain hydrocarbon group is preferably 1 to 10, more preferably 1 to 8, even more preferably 1 to 6, and even more preferably 1 to 4. L a22 may have one fluorine atom or two or more fluorine atoms. na2 is preferably an integer of 1 to 4, and more preferably an integer of 1 to 3.

[0085] The structural unit (a2) is L a21 When R is a chain hydrocarbon group, the structural units shown below and R in the structural units shown below a2 and the like, in which a methyl group corresponding to the following formula (I) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group. TIFF2025036219000064.tif67169

[0086] Examples of the structural unit having an alcoholic hydroxy group in the structural unit (a2) 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)"), a structural unit represented by formula (a2-D) (hereinafter sometimes referred to as "structural unit (a2-D)"), and a structural unit represented by formula (a2-E) (hereinafter sometimes referred to as "structural unit (a2-E)"). TIFF2025036219000065.tif46100[In formula (a2-B) and formula (a2-C), 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, an alkyl group having 1 to 6 carbon atoms, a haloalkyl 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. L a25 is -O- or *-O-(CH2) k2 represents -CO-O-, k2 represents an integer of 1 to 7. * represents the bonding position with -CO-. X a2 represents a single bond or -CO-. R a25 and R a26 each independently represents a hydrogen atom, a methyl group, or a hydroxy group. nB2 represents an integer of 1 to 5. When nB2 is 2 or more, a plurality of X a2 may be the same or different from each other. nB22 represents an integer of 0 to 8. When nB22 is 2 or more, a plurality of R a27 may be the same or different from each other. nC22 represents an integer of 0 to 10. When nC22 is 2 or more, multiple R a27may be the same or different. L a25 is preferably -O-, -O-(CH2) f1 It is -CO-O- (wherein f1 represents an integer of 1 to 4), and more preferably -O-. R a2 is preferably a methyl group. X a2 is preferably a single bond. R a25 is preferably a hydrogen atom. R a26 is preferably a hydrogen atom or a hydroxy group. R a27 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group, and further preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group. nB2 is preferably an integer of 0 to 3, and more preferably 0 or 1. nB22 is preferably an integer of 0 to 3, and more preferably 0 or 1. nC22 is preferably an integer of 0 to 3, and more preferably 0 or 1.

[0087] Examples of the structural unit (a2-B) and the structural unit (a2-C) include structural units derived from monomers described in JP-A-2010-204646, the following structural units, and R a2 In particular, structural units represented by any one of formulae (a2-B-1) to (a2-B-5) and formulae (a2-C-1) to (a2-C-9) are preferred. TIFF2025036219000066.tif80164 When the resin (A1) and the resin (A2) each contain the structural unit (a2-B) or the formula (a2-C), the content thereof is 1 mol% or more, preferably 2 mol% or more, based on the total structural units of the resin (A1) and the resin (A2). Also, 45 mol% or less is mentioned, preferably 40 mol% or less, more preferably 35 mol% or less, even more preferably 20 mol% or less, and even more preferably 10 mol% or less. Specifically, 1 to 45 mol% is mentioned, preferably 1 to 40 mol%, more preferably 1 to 35 mol%, even more preferably 1 to 20 mol% or 2 to 20 mol%, and even more preferably 1 to 10 mol% or 2 to 10 mol%.

[0088] <Structural unit (a3)> The lactone ring of the structural unit (a3) ​​may be a monocyclic ring such as a β-propiolactone ring, a γ-butyrolactone ring, or a δ-valerolactone ring, or may be a condensed ring of a monocyclic lactone ring and another ring. Preferred examples include a γ-butyrolactone ring, an adamantane lactone ring, or a bridged ring containing a γ-butyrolactone ring structure (for example, a structural unit represented by the following formula (a3-2)).

[0089] The structural unit (a3) ​​is preferably a structural unit represented by formula (a3-1), formula (a3-2), formula (a3-3) or formula (a3-4). One of these may be contained alone, or two or more of them may be contained. TIFF2025036219000067.tif48155[In formula (a3-1), formula (a3-2), formula (a3-3) and formula (a3-4), L a4 , L a5 and L a6 are each independently -O- or *-O-(CH2) k3 It represents a group represented by -CO-O- (k3 represents an integer of any of 1 to 7). L a7 , -O-, *-OL a8 -O-, *-OL a8 -CO-O-, *-OL a8-CO-OL a9 -CO-O- or *-OL a8 -O-CO-L a9 Represents -O-. L a8 and L a9 each independently represents an alkanediyl group having 1 to 6 carbon atoms. * indicates the bond position to the carbonyl group. R a18 , R a19 , R a20 and R a24 each independently represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom, or a halogen atom. X a3 represents -CH2- or an oxygen atom. R a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms. R a22 , R a23 and R a25 each independently represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms. p1 represents an integer of 0 to 5. q1 represents an integer of 0 to 3. r1 represents an integer of 0 to 3. w1 represents an integer of 0 to 8. When p1, q1, r1 and / or w1 are 2 or more, multiple R a21 , R a22 , R a23 and / or R a25 may be the same or different.]

[0090] R a21 , R a22 , R a23 and R a25 Examples of the aliphatic hydrocarbon group in include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, and a tert-butyl group. R a18 , R a19 , R a20 and R a24Examples of the halogen atom in include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. R a18 , R a19 , R a20 and R a24 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group, and preferably includes an alkyl group having 1 to 4 carbon atoms, and more preferably includes a methyl group or an ethyl group. R a18 , R a19 , R a20 and R a24 Examples of the alkyl group having a halogen atom in the formula (I) include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group. L a8 and L a9 Examples of the alkanediyl group in the formula (I) include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. In formulas (a3-1) to (a3-3), L a4 ~L a6 are each independently preferably -O- or *-O-(CH2) k3 In the -CO-O- group, k3 is a group in which k3 is any integer of 1 to 4, more preferably -O- and *-O-CH2-CO-O-, and further preferably an oxygen atom. R a18 ~R a21 is preferably a methyl group. R a22 and R a23are each independently preferably a carboxy group, a cyano group, or a methyl group. p1, q1 and r1 each independently represent an integer of preferably 0 to 2, and more preferably 0 or 1. In formula (a3-4), R a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group, or an ethyl group, and even more preferably a hydrogen atom or a methyl group. R a25 is preferably a carboxy group, a cyano group or a methyl group. L a7 is preferably -O- or *-OL a8 It is —CO—O—, and more preferably —O—, —O—CH2—CO—O— or —O—C2H4—CO—O—. w1 is preferably an integer of 0 to 2, and more preferably 0 or 1. In particular, the formula (a3-4) is preferably the formula (a3-4)'. TIFF2025036219000068.tif3848(in the formula, R a24 , L a7 has the same meaning as above.)

[0091] Examples of the structural unit (a3) ​​include structural units derived from monomers described in JP 2010-204646 A, JP 2000-122294 A, and JP 2012-41274 A. Examples of the structural unit (a3) ​​include structural units represented by any one of formulas (a3-1-1), (a3-1-2), (a3-2-1), (a3-2-2), (a3-3-1), (a3-3-2), and (a3-4-1) to (a3-4-12), and in the structural unit, R in formulas (a3-1) to (a3-4) a18 , R a19 , R a20 and R a24 A structural unit in which a methyl group corresponding to the following formula is replaced with a hydrogen atom is preferred. TIFF2025036219000069.tif108163

[0092] When the resin (A1) and the resin (A2) each contain the structural unit (a3), the total content of the structural unit (a3) ​​is 1 mol% or more, preferably 3 mol% or more, more preferably 5 mol% or more or 10 mol%, based on the total structural units of the resin (A1) and the resin (A2). It is also 70 mol% or less, preferably 65 mol% or less, more preferably 60 mol% or less. Specifically, it is 1 to 70 mol% or 5 to 70 mol%, preferably 1 to 65 mol% or 10 to 65 mol%, more preferably 1 to 60 mol% or 10 to 60 mol%. The content of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3) or the structural unit (a3-4) is preferably 1 mol% or more, more preferably 3 mol% or more, and even more preferably 5 mol% or more, based on the total structural units of the resin (A). Also, it is preferably 60 mol% or less, more preferably 50 mol% or less. Specifically, it is preferably 1 to 60 mol% or 5 to 60 mol%, more preferably 1 to 50 mol%, 3 to 50 mol% or 5 to 50 mol%, and even more preferably 1 to 50 mol%, 5 to 50 mol% or 10 to 50 mol%.

[0093] <Structural unit (a4)> The structural unit represented by formula (a4) is shown below. TIFF2025036219000070.tif3355 [In formula (a4), all symbols have the same meaning as defined above.]

[0094] R 42 Examples of the saturated hydrocarbon group represented by the formula (I) include linear or branched chain saturated hydrocarbon groups, monocyclic or polycyclic alicyclic saturated hydrocarbon groups, and groups formed by combining these groups. Examples of the chain saturated hydrocarbon group include linear alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group, and branched alkyl groups such as an isopropyl group and an 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 a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; and polycyclic alicyclic saturated hydrocarbon groups which are polycyclic cycloalkyl groups, such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bonding site): TIFF2025036219000071.tif10146 Examples of groups formed by combinations include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic saturated hydrocarbon groups, such as -alkanediyl group-alicyclic saturated hydrocarbon group, -alicyclic saturated hydrocarbon group-alkyl group, and -alkanediyl group-alicyclic saturated hydrocarbon group-alkyl group. Examples of the alkanediyl group include linear alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, and hexane-1,6-diyl groups, and branched alkanediyl groups such as propane-1,2-diyl, butane-1,3-diyl, 2-methylpropane-1,2-diyl, 1-methylbutane-1,4-diyl, and 2-methylbutane-1,4-diyl groups. The terminal of the branched alkanediyl group may be a methyl group. R 42 Examples of the halogen atom contained in the saturated hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R 42Examples of the saturated hydrocarbon group in which -CH2- is replaced by -O- or -CO- include a hydroxy group (a group in which -CH2- in a methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- in an ethyl group is replaced by -O-CO-), a carbonyl group (a group in which -CH2- in a methylene group is replaced by -CO-), an oxy group (a group in which -CH2- in a methylene group is replaced by -O-), an alkoxy group (a group in which -CH2- at any position in an alkyl group is replaced by -O-), an alkoxycarbonyl group (a group in which -CH2-CH2- at any position in an alkyl group is replaced by -O-CO-), and an alkylcarbonyl group (a group in which -CH2- at any position in an alkyl group is replaced by -CO-). ), alkylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in an alkyl group is replaced with -CO-O-), alkanediyloxy group (a group in which -CH2- at any position contained in an alkanediyl group is replaced with -O-), alkanediyloxycarbonyl group (a group in which -CH2-CH2- at any position contained in an alkanediyl group is replaced with -O-CO-), alkanediylcarbonyl group (a group in which -CH2- at any position contained in an alkanediyl group is replaced with -CO-), alkanediylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in an alkanediyl group is replaced with -CO-), cycloalkoxy group, cycloalkylalkoxy group, and the like, which are combinations of two or more of these groups. Examples of these substituted groups include the same as the groups exemplified in this specification, within the range permitted by the upper limit of the number of carbon atoms.

[0095] The structural unit (a4) is R 42 is preferably a saturated hydrocarbon group having a fluorine atom. 42However, examples of the structural unit (a4) which is a saturated hydrocarbon group having a fluorine atom include a structural unit represented by formula (a4-1) (hereinafter may be referred to as "structural unit (a4-1)"), a structural unit represented by formula (a4-2) (hereinafter may be referred to as "structural unit (a4-2)"), and a structural unit represented by formula (a4-3) (hereinafter may be referred to as "structural unit (a4-3)"). The structural unit represented by formula (a4-1) is a structural unit represented by the following formula: TIFF2025036219000072.tif4964[In 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 a fluorine atom-containing alkanediyl group having 1 to 8 carbon atoms or a fluorine atom-containing cycloalkanediyl group having 3 to 12 carbon atoms. R 42f represents a hydrogen atom or a fluorine atom.

[0096] L 41 Examples of the alkanediyl group in the formula (I) include linear alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, and butane-1,4-diyl, and branched alkanediyl groups such as ethane-1,1-diyl, propane-1,2-diyl, butane-1,3-diyl, 2-methylpropane-1,3-diyl, and 2-methylpropane-1,2-diyl. The terminal of the branched alkanediyl group may be a methyl group. L 42f Examples of the alkanediyl group having a fluorine atom in the formula (I) include a methylene group having a fluorine atom, an ethylene group having a fluorine atom, a propane-1,3-diyl group having a fluorine atom, a butane-1,4-diyl group having a fluorine atom, a pentane-1,5-diyl group having a fluorine atom, a hexane-1,6-diyl group having a fluorine atom, a heptane-1,7-diyl group having a fluorine atom, and an octane-1,8-diyl group having a fluorine atom; Examples of branched alkanediyl groups having fluorine atoms include ethane-1,1-diyl groups having fluorine atoms, propane-1,1-diyl groups having fluorine atoms, propane-1,2-diyl groups having fluorine atoms, propane-2,2-diyl groups having fluorine atoms, pentane-2,4-diyl groups having fluorine atoms, 2-methylpropane-1,3-diyl groups having fluorine atoms, 2-methylpropane-1,2-diyl groups having fluorine atoms, pentane-1,4-diyl groups having fluorine atoms, and 2-methylbutane-1,4-diyl groups having fluorine atoms. 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 the formula (I) include monocyclic cycloalkanediyl groups having a fluorine atom, such as a cyclobutane-1,3-diyl group having a fluorine atom, a cyclopentane-1,3-diyl group having a fluorine atom, a cyclohexane-1,4-diyl group having a fluorine atom, a cyclohexene-3,6-diyl group having a fluorine atom, a cycloheptane-1,4-diyl group having a fluorine atom, and a cyclooctane-1,5-diyl group having a fluorine atom; Examples of polycyclic cycloalkanediyl groups 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, and an adamantane-2,6-diyl group having a fluorine atom. L 42f The number of fluorine atoms contained in the alkanediyl group and cycloalkanediyl group having a fluorine atom in the above formula may be 1 or more, and is preferably 2 or more. L 42f The alkanediyl group and cycloalkanediyl group having a fluorine atom in the above formula (I) are preferably a perfluoroalkanediyl group and a perfluorocycloalkanediyl group, respectively. L 42fExamples of the perfluoroalkanediyl group in the formula (I) 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, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane-1,7-diyl group, perfluoroheptane-2,2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane-2,2-diyl group, perfluorooctane-3,3-diyl group, and perfluorooctane-4,4-diyl group. L 42f Examples of the perfluorocycloalkanediyl group in the formula (I) include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, and a perfluoroadamantanediyl group. L 41 is preferably a single bond or an alkanediyl group having 1 to 3 carbon atoms, more preferably a single bond, a methylene group, or an ethylene group, and even more preferably a single bond or a methylene group. L 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 even more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms. The structural unit (a4-1) may be any of the structural units shown below and R in the structural unit (a4-1) in the structural unit shown below. 41 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. TIFF2025036219000073.tif97158

[0097] The structural unit represented by formula (a4-2) is a structural unit shown below. TIFF2025036219000074.tif5674[In formula (a4-2), R 41 represents a hydrogen atom or a methyl group. L 43f represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may contain a fluorine atom, and -CH2- 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 -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. However, L 43f and R 43f At least one of L has a fluorine atom. 43f and R 43f The maximum total carbon number is 21.

[0098] L 43f and R 43f Examples of the saturated hydrocarbon group in include linear or branched chain saturated hydrocarbon groups, monocyclic or polycyclic alicyclic saturated hydrocarbon groups, and groups formed by combining these groups. 43f and R 43f Examples of saturated hydrocarbon groups in the formula are L 43f and R 43f As long as the upper limit of the total number of carbon atoms in 42 Examples of the saturated hydrocarbon group include the same groups as the exemplified saturated hydrocarbon groups. L 43f The saturated hydrocarbon group is preferably an alkanediyl group having 1 to 6 carbon atoms or a group represented by the formula (L43f-1). TIFF2025036219000075.tif13120[In formula (L43f-1), s represents 0 or 1. L 45fand L 46f each independently represents a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. L 47f represents a single bond or a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. X 46f and X 47f each independently represents -O-, -CO-, -CO-O- or -O-CO-. However, L 45f , L 46f , L 47f , X 46f and X 47f The total number of carbon atoms is 7 or less. * and ** are binding sites, ** is -O-CO-R 43f This is the binding site for L in the group represented by formula (L43f-1) 45f , L 46f and L 47f Examples of the divalent saturated hydrocarbon group represented by include a linear or branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and a divalent saturated hydrocarbon group formed by combining an alkanediyl group and a divalent alicyclic saturated hydrocarbon group, etc. Specific examples include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a 1-methylpropane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, etc. It is preferred that s is 0. Examples of the group represented by formula (L43f-1) include the following groups. In the following examples, * and ** each represent a bonding site, and ** represents -O-CO-R 43f This is the binding site for TIFF2025036219000076.tif47140

[0099] R 43f is preferably a saturated hydrocarbon group having a fluorine atom. In this case, examples of the structural unit represented by formula (a4-2) include structural units represented by formula (a4-2A) or (a4-2B). TIFF2025036219000077.tif69102 [In formula (a4-2A) and formula (a4-2B), R 41 and L 43f represents the same as in formula (a4-2). R 43fA represents a saturated hydrocarbon group having 1 to 20 carbon atoms and containing a fluorine atom. A 43f represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. X 43 represents **-O-CO- or **-CO-O-, and ** represents A 43f represents the binding site with R 43fB represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may contain a fluorine atom. However, in formula (a4-2A), L 43f and R 43fA The total number of carbon atoms in formula (a4-2B) is 21 or less, and in formula (a4-2B), L 43f , A 43f , X 43 and R 43fB The total number of carbon atoms in A is 21 or less. 43f and R 43fB At least one of them has at least one fluorine atom. R 43fA The saturated hydrocarbon group represented by R in formula (a4) is as large as possible within the upper limit of the number of carbon atoms. 42 Examples of the saturated hydrocarbon groups include the saturated hydrocarbon groups exemplified by the above. R 43fA is preferably an alkyl group having 1 to 13 carbon atoms and containing a fluorine atom, a cycloalkyl group having 3 to 12 carbon atoms and containing a fluorine atom, or a group combining these, *-(CF2) n43f -R 42’ (* represents the bonding site with the carbonyl group. n43f represents an integer of 1 to 6. R42’ 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 As long as the upper limit of the number of carbon atoms permits, R in formula (a4) 42 Examples of the saturated hydrocarbon group include the same saturated hydrocarbon groups as the exemplified saturated hydrocarbon groups. A 43f is preferably a divalent chain saturated hydrocarbon group which may have a fluorine atom, a divalent alicyclic saturated hydrocarbon group, or a combination thereof, more preferably a divalent chain saturated hydrocarbon group which has a fluorine atom, and further preferably a fluorinated alkanediyl group having 1 to 6 carbon atoms. R 43fB The saturated hydrocarbon group which may have a fluorine atom is preferably a chain saturated hydrocarbon group which may have a fluorine atom, an alicyclic saturated hydrocarbon group or a group combining these, more preferably an alkyl group having 1 to 12 carbon atoms which may have a fluorine atom, a cycloalkyl group having 3 to 12 carbon atoms or a group combining these, and 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- More preferred are fluorinated alkyl groups such as an 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, and a perfluorooctyl group; a cyclopropylmethyl group, a cyclopropyl group, a cyclobutylmethyl group, a cyclopentyl group, a cyclohexyl group, a perfluorocyclohexyl group, an adamantyl group, an adamantylmethyl group, an adamantyldimethyl group, a norbornyl group, a norbornylmethyl group, a perfluoroadamantyl group, and a perfluoroadamantylmethyl group. In formula (a4-2B), *-A 43f -X 43 -R43fB An example of a structure that the group represented by the formula (I) can take is the following structure (* indicates the bonding site with the carbonyl group). TIFF2025036219000078.tif15168 The structural unit represented by formula (a4-2A) includes the structural units shown below and R in the structural unit represented by formula (a4-2A) in the structural units shown below. 41 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. TIFF2025036219000079.tif99167

[0100] The structural unit represented by formula (a4-2B) includes the structural units shown below and R in the structural unit represented by formula (a4-2B) in the structural units shown below. 41 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. TIFF2025036219000080.tif111164

[0101] The structural unit (a4) also includes a structural unit represented by formula (a4-3). TIFF2025036219000081.tif5677[In formula (a4-3), R 41 represents a hydrogen atom or a methyl group. L 44f each independently represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a fluorine atom, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. R 44f each independently represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a fluorine atom, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. However, L 44f and R 44f At least one of L has a fluorine atom. 44f and R 44f The total number of carbon atoms in each is limited to 21. L 44f and R 44fExamples of the saturated hydrocarbon group in include linear or branched chain saturated hydrocarbon groups, monocyclic or polycyclic alicyclic saturated hydrocarbon groups, and groups formed by combining these groups. 44f and R 44f Examples of saturated hydrocarbon groups in the formula are L 44f and R 44f As long as the upper limit of the total number of carbon atoms in 42 Examples of the saturated hydrocarbon group include the same groups as the exemplified saturated hydrocarbon groups. L 44f is preferably an alkanediyl group having 1 to 14 carbon atoms (-CH2- contained in the alkanediyl group may be replaced by -O- or -CO-), and is preferably -(CH2)1-, -(CH2) j2 -O-(CH2) j3 -or-(CH2) j4 -CO-O-(CH2) j5 - (j1 to j5 each independently represent an integer of 1 to 6), and more preferably an alkanediyl group having 1 to 4 carbon atoms (one -CH2- contained in the alkanediyl group may be replaced by -O-, and one -CH2-CH2- contained in the alkanediyl group may be replaced by -CO-O- or -O-CO-). R 44f is preferably 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 1 to 10 carbon atoms and having a fluorine atom, or a group combining these, further 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.

[0102] Examples of the structural unit represented by formula (a4-3) include the following structural units and structural units represented by the following formulas: 41 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. TIFF2025036219000082.tif85170 When the resin (A2) has the structural unit (a4), the content thereof is preferably from 1 to 20 mol %, more preferably from 2 to 15 mol %, and even more preferably from 3 to 10 mol %, based on all structural units in the resin (A2).

[0103] <Structural unit (a5)> The non-leaving hydrocarbon group contained in the structural unit (a5) may be a group containing a linear, branched or cyclic hydrocarbon group. Among these, the structural unit (a5) is preferably a group containing an alicyclic hydrocarbon group. An example of the structural unit (a5) is a structural unit represented by the formula (a5-1). TIFF2025036219000083.tif3351[In formula (a5-1), R 51 represents a hydrogen atom or a methyl group. R 52 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms. L 55 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-.]

[0104] 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, a norbornyl group, and the like. Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, and a 2-ethylhexyl group. An example of the alicyclic hydrocarbon group having a substituent is a 3-methyladamantyl group. R52 is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and more preferably an adamantyl group, a norbornyl group, or a cyclohexyl group. L 55 Examples of the divalent saturated hydrocarbon group in include a divalent chain saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, and a divalent chain saturated hydrocarbon group is preferred. Examples of the divalent chain saturated hydrocarbon group include alkanediyl groups such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group, and a pentanediyl group. The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkanediyl groups such as cyclopentanediyl and cyclohexanediyl. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include adamantanediyl and norbornanediyl. L 55 Examples of the divalent saturated hydrocarbon group represented by formula (L1-1) to formula (L1-4) include groups represented by formula (L1-2) to (L1-4). In the following formulae, * and ** each represent a bonding site, and * represents a bonding site with an oxygen atom. TIFF2025036219000084.tif18164[In formula (L1-1), X x1 represents *-O-CO- or *-CO-O- (* represents L x1 ) which represents the binding site with L x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. L x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. However, L x1 and L x2 The total number of carbon atoms is 16 or less. In formula (L1-2), L x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms. L x4represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. However, L x3 and L x4 The total number of carbon atoms is 17 or less. In formula (L1-3), L x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. L x6 and L x7 each independently represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms. However, L x5 , L x6 and L x7 The total number of carbon atoms is 15 or less. In formula (L1-4), L x8 and L x9 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms. W x1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms. However, L x8 , L x9 and W x1 The total number of carbon atoms is 15 or less. 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, and 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 x6is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and 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, and 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, and 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, and more preferably a cyclohexanediyl group or an adamantanediyl group. Examples of the group represented by formula (L1-1) include the divalent groups shown below. TIFF2025036219000085.tif36146 Examples of the group represented by formula (L1-2) include the divalent groups shown below. TIFF2025036219000086.tif23130 Examples of the group represented by formula (L1-3) include the divalent groups shown below. TIFF2025036219000087.tif16147Examples of the group represented by formula (L1-4) include the divalent groups shown below. TIFF2025036219000088.tif13167L 55 is preferably a single bond or a group represented by formula (L1-1).

[0105] The structural unit (a5-1) may be any of the structural units shown below and R in the structural unit (a5-1) in the structural unit shown below. 51 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. TIFF2025036219000089.tif111150 When the resin (A2) has the structural unit (a5), the content thereof is preferably from 1 to 30 mol %, more preferably from 2 to 20 mol %, and even more preferably from 3 to 15 mol %, based on all structural units in the resin (A2).

[0106] <Structural unit (a6)> The structural unit (a6) is a structural unit having a -SO2- group, and preferably has the -SO2- group in a side chain. The structural unit having a -SO2- group may have a linear structure having a -SO2- group, may have a branched structure having a -SO2- group, or may have a cyclic structure (monocyclic and polycyclic structure) having a -SO2- group. A structural unit having a cyclic structure having a -SO2- group is preferred, and a structural unit having a cyclic structure (sultone ring) containing -SO2-O- is more preferred. The sultone ring may be represented by the following formula (T 1 -1), formula (T 1 -2), formula (T 1 -3) and the formula (T 1 The bonding site can be any position. The sultone ring may be monocyclic, but is preferably polycyclic. A polycyclic sultone ring refers to a bridged ring containing -SO2-O- as an atomic group constituting the ring, and is represented by the formula (T 1 -1) and the formula (T 1 The sultone ring is represented by the formula (T 1 As in the ring represented by formula (2), the atomic group constituting the ring may further contain a heteroatom in addition to -SO2-O-. Examples of the heteroatom include an oxygen atom, a sulfur atom, or a nitrogen atom, and an oxygen atom is preferred. TIFF2025036219000090.tif3077 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. Examples of halogen atoms include fluorine, chlorine, bromine and iodine atoms. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, and a decyl group, and preferably an alkyl group having 1 to 6 carbon atoms, and more preferably a methyl group. Examples of the alkyl group having a halogen atom include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group, and preferably a trifluoromethyl group. Examples of the alkyl group having a hydroxy group include a hydroxymethyl group and a 2-hydroxyethyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group. Examples of the aryl group include a phenyl group, a naphthyl group, an anthryl group, a p-methylphenyl group, a p-tert-butylphenyl group, a p-adamantylphenyl group, a tolyl group, a xylyl group, a cumyl group, a mesityl group, a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group. Aralkyl groups include benzyl, phenethyl, phenylpropyl, naphthylmethyl and naphthylethyl groups. Examples of the alkoxycarbonyl group include groups in which an alkoxy group, such as a methoxycarbonyl group or an ethoxycarbonyl group, is bonded to a carbonyl group, and preferably, an alkoxycarbonyl group having 6 or less carbon atoms is used, and more preferably, a methoxycarbonyl group is used. Alkylcarbonyl groups include acetyl, propionyl and butyryl groups.

[0107] From the viewpoint of ease of production of the monomer from which the structural unit (a6) is derived, a sultone ring having no substituent is preferred. The sultone ring is preferably a ring represented by the following formula (T1'). TIFF2025036219000091.tif2666[In formula (T1'), X 11 represents an oxygen atom, a sulfur atom, or a methylene group. R 41 represents an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms, or an alkylcarbonyl group having 2 to 4 carbon atoms. ma represents an integer of 0 to 9. When ma is 2 or more, multiple R 41 may be the same or different. The binding site is at any position.] X 11 is preferably an oxygen atom or a methylene group, and more preferably a methylene group. R 41 Examples of the substituent include the same ones as the substituents on the sultone ring, and an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxyl group is preferred. ma is preferably 0 or 1, and more preferably 0. Examples of the ring represented by formula (T1') include the following rings. The binding site may be any position. Among them, the binding site is preferably the 1st or 3rd position. TIFF2025036219000092.tif45147

[0108] The structural unit having a -SO2- group preferably further has a group derived from a polymerizable group, such as a vinyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an acryloylamino group, a methacryloylamino group, an acryloylthio group, or a methacryloylthio group. Among these, the monomer from which the structural unit (a6) is derived is preferably a monomer having an ethylenically unsaturated bond, and more preferably a (meth)acrylic monomer.

[0109] The structural unit (a6) is preferably a structural unit represented by the formula (a6-0). TIFF2025036219000093.tif3878[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 is an oxygen atom, -N(R c )- or a sulfur atom. A x represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH- contained in the saturated hydrocarbon group is -O-, -CO- or -N(R d )- may also be replaced. X 11 represents an oxygen atom, a sulfur atom, or a methylene group. R 41 represents an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms, or an alkylcarbonyl group having 2 to 4 carbon atoms. ma represents an integer of 0 to 9. When ma is 2 or more, multiple R 41 may be the same or different. Rc and R d each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.] R x Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. R x Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group. An alkyl group having 1 to 4 carbon atoms is preferred, and a methyl group or an ethyl group is more preferred. R x Examples of the alkyl group having a halogen atom include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group. R x is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group, or an ethyl group, and even more preferably a hydrogen atom or a methyl group. A x Examples of the divalent saturated hydrocarbon group include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and may be a combination of two or more of these groups. Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, linear alkanediyl groups such as a dodecane-1,12-diyl group, a tridecane-1,13-diyl group, a tetradecane-1,14-diyl group, a pentadecane-1,15-diyl group, a hexadecane-1,16-diyl group, a heptadecane-1,17-diyl group, an ethane-1,1-diyl group, a propane-1,1-diyl group, and a propane-2,2-diyl group; branched alkanediyl groups such as butane-1,3-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, and 2-methylbutane-1,4-diyl; monocyclic divalent alicyclic saturated hydrocarbon groups such as cycloalkanediyl groups, such as cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, and cyclooctane-1,5-diyl; Examples of the polycyclic divalent alicyclic saturated hydrocarbon groups include norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group. A x The bonding position of to the sultone ring may be any position, but is preferably the 1-position. Examples of the structural unit (a6-0) include the following structural units. TIFF2025036219000094.tif79129Of these, structural units represented by formulae (a6-1), (a6-2), (a6-6), (a6-7), (a6-8) and (a6-12) are preferred, and structural units represented by formulae (a6-1), (a6-2), (a6-7) and (a6-8) are more preferred. When the resin (A2) has the structural unit (a6), the content thereof is preferably from 1 to 50 mol %, more preferably from 2 to 40 mol %, and even more preferably from 3 to 30 mol %, based on all structural units in the resin (A2).

[0110] <Structural unit (a7)> The structural unit (a7) functions in the resist composition in the same manner as the acid generator described below. Specific examples of the structural unit (a7) include structural units described in JP 2016-79235 A, and are preferably a structural unit having a sulfonate group or a carboxylate group and an organic cation in a side chain, or a structural unit having a sulfonio group and an organic anion in a side chain. The structural unit having a sulfonate group or carboxylate group and an organic cation in the side chain is preferably a structural unit represented by formula (a7-A). TIFF2025036219000095.tif26124[In 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 is a single bond, *-O-**, *-CO-O-**, *-O-CO-O-**, *-CO-NR a71 -**, *-NR a71 -CO-O-**, *-O-CO-NR a71 -** or *-Ax-Ph-Ay-**. R a71 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Ph represents a phenylene group which may have a substituent. Ax and Ay each independently represent one type of bond selected from the group consisting of a single bond, an ether bond, a thioether bond, an ester bond, an amide bond, and a carbonate bond. * and ** represent binding sites, * represents R a7 represents the bonding site with the carbon atom to which it is bonded. L a71 and L a72each independently represents a hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. X a72 represents ***-CO-O-, ***-O-CO-, ***-O-CO-O-, ***-O-, and *** represents L a71 represents the binding site with na7 represents an integer of 0 to 2. When na7 is 2, the groups in the parentheses may be the same or different. RA - represents a sulfonate anion or a carboxyl anion. Z.A. + represents an organic cation.

[0111] R a7 and R a71 Examples of the alkyl group having 1 to 6 carbon atoms in the formula include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. R a7 Examples of the halogen atom in include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R a7 Examples of the alkyl group having 1 to 6 carbon atoms and having a halogen atom in the formula (I) include a trifluoromethyl group, a difluoromethyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a dichloromethyl group, a triiodomethyl group, a diiodomethyl group, a tribromomethyl group, and a dibromomethyl group. R a7is 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.

[0112] X a71 is a group represented by *-Ax-Ph-Ay-**, it is preferably a linking group represented by the following formula (X10). TIFF2025036219000096.tif3251[In formula (X10), Ax is R a7 represents a bond type bonded to the carbon atom to which is bonded, and represents one type of bond selected from the group consisting of a single bond, an ether bond, a thioether bond, an ester bond, a carbonate bond, and an amide bond. Ay is L a71 represents a bond type that bonds with, and represents one type of bond selected from the group consisting of a single bond, an ether bond, a thioether bond, an ester bond, a carbonate bond, and an amide bond. Rx represents a halogen atom, a hydroxy group, a fluorinated alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. mx represents an integer of 0 to 4, and when mx is an integer of 2 or more, multiple Rx's may be the same or different. 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, -CO-NR a71 A bond represented by - is preferred. The bonding position of Ay in the phenylene group is preferably the m-position or p-position relative to the bonding position of Ax, and more preferably the p-position. Among these, 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 a71Examples of the group include a single bond and the group represented by the following formula (X 10 -1)~Formula(X 10 -10) is a group represented by * -R a7 represents the bonding site with the carbon atom to which L is bonded. a71 It represents the binding site with X 20 is -O- or -NR a71 - represents. TIFF2025036219000097.tif43162 expression (X 10 -1)~Formula(X 10 Specific examples of the group represented by -10) include the following groups. TIFF2025036219000098.tif87162 Among them, X a71 is a single bond and the formula (X 10 -1'), expression (X 10 -3')~expression(X 10 -9'), which is preferably a single bond or a group represented by the formula (X 10 -1'), expression (X 10 -4'), expression (X 10 -5'), expression (X 10 -6') and formula (X 10 -9'), a single bond, a group represented by the formula (X 10 -1'), a group represented by the formula (X 10 -5'), a group represented by the formula (X 10 -6') or formula (X 10 -9') is more preferable.

[0113] L a71 The hydrocarbon group is a group formed by removing one hydrogen atom from a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a group combining two or more of these groups, to form X. a71 and X a72 Also, L a72 The hydrocarbon group is a group formed by removing one hydrogen atom from a chain hydrocarbon group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, or a group combining two or more of these groups, to form X. a72 and R.A. - Examples of such groups include groups that bond to the L a71 and L a72 Examples of the chain hydrocarbon group include a group in which one hydrogen atom has been removed from an alkyl group or an alkenyl group. The alkyl group may be linear or branched, and specific examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl 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 pentanedecyl group, and a heptadecyl group. Examples of the alkenyl group include an ethenyl group, a propenyl group, an isopropenyl group, a butenyl group, an isobutenyl group, a tert-butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an octenyl group, an isooctenyl group, and a nonenyl group. The chain hydrocarbon group preferably has 1 to 20 carbon atoms, more preferably 1 to 18 carbon atoms, and even more preferably 1 to 10 carbon atoms. L a71 and L a72 Examples of the alicyclic hydrocarbon group include a group in which one hydrogen atom has been removed from a monocyclic or polycyclic cycloalkyl group. Examples of the monocyclic cycloalkyl group include a cyclobutyl group, a cycloheptyl group, a cyclohexyl group, a cyclopentyl group, and a cyclooctyl group. L a71 and L a72Examples of the polycyclic cycloalkyl group include a cycloalkyl group having a bridged structure, a cycloalkyl group in which two or more rings are condensed, or a cycloalkyl group in which two rings are bonded by a spiro bond. Examples of the cycloalkyl group having a bridged 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 bonded by a spiro bond 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 bonded by a spiro bond to a cycloalkyl group having 5 to 8 carbon atoms. A double bond may be formed between two carbon atoms contained in the alicyclic hydrocarbon group. More specifically, examples of the alicyclic hydrocarbon group include the following formula: TIFF2025036219000099.tif28158 When the alicyclic hydrocarbon group is a monocyclic cycloalkyl group, the alicyclic hydrocarbon group preferably has 3 to 18 carbon atoms, more preferably 3 to 12, and even more preferably 3 to 8. When the alicyclic hydrocarbon group is a polycyclic cycloalkyl group, the alicyclic hydrocarbon group preferably has 6 to 18 carbon atoms, and more preferably 7 to 12. L a71 and L a72 The aromatic hydrocarbon group may be a group in which one hydrogen atom has been removed 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. The number of carbon atoms in the aromatic hydrocarbon group is preferably 5 to 14, more preferably 6 to 14, and further preferably 6 to 10. L a71 and L a72 When --CH2-- in the hydrocarbon group is replaced with --O--, --CO--, --S-- or --SO2--, the number of carbon atoms before the replacement is regarded as the number of carbon atoms in the hydrocarbon group. L a71 and L a72Among the hydrocarbon groups in the above, groups in which -CH2- in a chain hydrocarbon group is replaced by -O-, -CO-, -S- or -SO2- include a hydroxy group (a group in which -CH2- in a methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- in an ethyl group is replaced by -O-CO-), a thiol group (a group in which -CH2- in a methyl group is replaced by -S-), a carbonyl group (a group in which -CH2- in a methylene group is replaced by -O-), and a group in which -CH2- in a methylene group is replaced with -CO-), an oxy group (a group in which -CH2- in a methylene group is replaced with -O-), a thio group (a group in which -CH2- in a methylene group is replaced with -S-), a sulfonyl group (a group in which -CH2- in a methylene group is replaced with -SO2-), an alkoxy group (a group in which -CH2- at any position in an alkyl group is replaced with -O-), an alkoxycarbonyl group (an alkyl group in which -CH2- at any position is replaced with -O-), any position in the alkyl group is replaced with -O-CO-), an alkylcarbonyl group (an alkyl group in which -CH2- at any position is replaced with -CO-), an alkylcarbonyloxy group (an alkyl group in which -CH2-CH2- at any position is replaced with -CO-O-), an alkanediyloxy group (an alkanediyl group in which -CH2- at any position is replaced with -O-), Examples of the substituted groups include an alkanediyloxycarbonyl group (a group in which -CH-CH- at any position contained in an alkanediyl group is replaced with -O-CO-), an alkanediylcarbonyl group (a group in which -CH- at any position contained in an alkanediyl group is replaced with -CO-), and an alkanediylcarbonyloxy group (a group in which -CH-CH- at any position contained in an alkanediyl group is replaced with -CO-O-). Examples of these substituted groups include the same groups as those exemplified in this specification, within the range permitted by the upper limit of the number of carbon atoms. L a71 and L a72Among the above hydrocarbon groups, examples of groups in which -CH2- in an alicyclic hydrocarbon group is replaced with -O-, -CO-, -S- or -SO2- include groups containing a cyclic ether, cyclic ketone, cyclic ester (lactone), cyclic thioether, cyclic acetal, and cyclic sulfonate ester (sultone) structure. Specific examples include alicyclic hydrocarbon groups represented by the following formula. The bonding position of the alicyclic hydrocarbon groups listed in the following formula may be any position. TIFF2025036219000100.tif46146L a71 and L a72 Among these hydrocarbon groups, -CH2- contained in the aromatic hydrocarbon group may be replaced by -O- or -S-, and examples of the group in which -CH2- is replaced by -O- or -S- include groups derived from a furan ring or a thiophene ring, respectively. L a71 and L a72 Examples of the group in which two or more of the chain hydrocarbon group, alicyclic hydrocarbon group, and aromatic hydrocarbon group are combined include a group in which the chain hydrocarbon group and the alicyclic hydrocarbon group are combined, a group in which the chain hydrocarbon group and the aromatic hydrocarbon group are combined, a group in which the alicyclic hydrocarbon group and the aromatic hydrocarbon group are combined, and a group in which the chain hydrocarbon group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group are combined. The group in which the alicyclic hydrocarbon group and the aromatic hydrocarbon group are combined may be a condensed ring. L a71 and L a72 The substituents which the hydrocarbon group may have include a halogen atom, a cyano group, and a nitro group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. L a71 and L a72 When L is a group in which an alicyclic hydrocarbon group or an aromatic hydrocarbon group is combined with a chain hydrocarbon group, the chain hydrocarbon group may be regarded as a substituent that the alicyclic hydrocarbon group or the aromatic hydrocarbon group has. a71 and L a72The -CH2- of the chain hydrocarbon group contained in the hydrocarbon group is replaced with -O-, -CO-, -S- or -SO2-, thereby forming L a71 and L a72 The hydrocarbon group may substantially have a substituent such as a hydroxy group, a carboxy group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a thiol group, or a sulfonyl group. na7 is preferably 0 or 1. ZA in formula (a7-A) + Examples of the cation include the same as the cation in the salt represented by formula (B1) etc.

[0114] In formula (a7-A), L a71 and L a72 When the hydrocarbon group is a saturated hydrocarbon group, in the formula (a7-B) described later, b7 The divalent linking group may include the same groups as those exemplified above. Examples of the structural unit represented by formula (a7-A) include a structural unit represented by formula (a7-A1). TIFF2025036219000101.tif30138[In formula (a7-A1), R a7 , X a71 , L a71 , X a72 , na7, R.A. - and Z.A. + has the same meaning as above. z7 represents an integer of 0 to 6. Q a7 , Q b7 , R z71 and R z72 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; when z7 is 2 or more, z71 and R z72 may be the same or different.] Q a7 , Q b7 , R z71 and R z72As the perfluoroalkyl group having 1 to 6 carbon atoms or the alkyl group having 1 to 6 carbon atoms in R a7 Examples of the groups include the same groups as those exemplified in the above.

[0115] Examples of the structural unit represented by formula (a7-A) include the following structural units, R a7 Examples of the structural units include those in which the group corresponding to the methyl group in the above formula (I) is replaced with a hydrogen atom, a halogen atom (e.g., a fluorine atom) or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (e.g., a trifluoromethyl group, etc.), and the structural units described in WO 2012 / 050015. + represents an organic cation. TIFF2025036219000102.tif205162

[0116] TIFF2025036219000103.tif164166

[0117] The structural unit having a sulfonio group and an organic anion on the side chain is preferably a structural unit represented by formula (a7-B). TIFF2025036219000104.tif27104[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 b73 each independently represents a hydrocarbon group having 1 to 18 carbon atoms which may have a substituent; R b72 and R b73 may be bonded to each other to form a ring together with the sulfur atom to which they are attached. A - represents an organic anion. R a7Examples of the halogen atom and the alkyl group which may have a halogen atom in the formula (a7-A) include the same halogen atom and the alkyl group which may have a halogen atom as in the formula (a7-A). R b71 Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by the formula (I) include a phenylene group and a naphthylene group. R b72 and R b73 Examples of the hydrocarbon group represented by the formula (I) include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups. Examples of the alkyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and groups formed by combining these groups include the same as those described above. A b7 Examples of the divalent linking group represented by the formula (I) include divalent saturated hydrocarbon groups having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O-, -S- or -CO-. Examples of the divalent saturated hydrocarbon group include divalent chain saturated hydrocarbon groups such as linear or branched alkanediyl groups, and monocyclic or polycyclic divalent alicyclic saturated hydrocarbon groups, and combinations of these are also possible. Specifically, straight-chain 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, and dodecane-1,12-diyl group; divalent monocyclic alicyclic saturated hydrocarbon groups such as monocyclic cycloalkanediyl groups, such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, and cyclooctane-1,5-diyl group; and divalent polycyclic alicyclic saturated hydrocarbon groups, such as polycyclic cycloalkanediyl groups, such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group. Examples of saturated hydrocarbon groups in which -CH2- has been replaced with -O-, -S-, or -CO- include the following divalent groups. However, the number of carbon atoms before the -CH2- in the saturated hydrocarbon group is replaced with -O-, -S-, or -CO- is 17 or less. In the following formulas, * and ** represent binding sites, * represents R b71 represents the binding site with TIFF2025036219000105.tif123162[where, X 3 represents a divalent saturated hydrocarbon group having 1 to 16 carbon atoms. X 4 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. X 5 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms. X 6 represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms. X 7 represents a trivalent saturated hydrocarbon group having 1 to 14 carbon atoms. X 8represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.

[0118] The structural unit containing a cation in formula (a7-B) includes the structural units represented by the following formula: a7 Examples of such structural units include those in which a group corresponding to the methyl group in the above formula (I) is replaced with a hydrogen atom, a halogen atom (e.g., a fluorine atom), or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (e.g., a trifluoromethyl group, etc.). TIFF2025036219000106.tif73163

[0119] A - Examples of the organic anion represented by the formula (I) include a sulfonate anion, a sulfonylimide anion, a sulfonylmethide anion, and a carboxylate anion. - The organic anion represented by the formula (I) is preferably a sulfonate anion, and the sulfonate anion is more preferably the same as the anion exemplified for the acid generator (B). Examples of the sulfonylimide anion, sulfonylmethide anion, and carboxylate anion include the same anions exemplified for the acid generator (B).

[0120] Examples of the structural unit represented by formula (a7-B) include structural units represented below. TIFF2025036219000107.tif95157 When the resin (A1) and the resin (A2) contain the structural unit (a7), the structural unit (a7) may be contained alone or in combination of two or more kinds. The total content of the structural unit (a7) is preferably 1 to 30 mol%, more preferably 1 to 25 mol%, even more preferably 2 to 20 mol%, still more preferably 3 to 15 mol%, and even more preferably 3 to 10 mol%, based on the total structural units of the resin (A1) and the resin (A2).

[0121] <Resins other than resins (A1) and (A2)> The resist composition of the present invention may contain a resin other than the above-mentioned resins (A1) and (A2), such as a resin having at least one selected from a structural unit derived from an acid-labile monomer, a structural unit derived from an acid-stable monomer, and a structural unit derived from a monomer known in the art. For example, a resin containing the structural unit (a4) or the structural unit (a5) (hereinafter, sometimes referred to as resin (X)) can be mentioned. As the resin (X), a resin containing the structural unit (a4) is preferable, and examples thereof include a resin consisting of only the structural unit (a4) or a resin containing the structural unit (a4) and the structural unit (a5). Examples of structural units that the resin (X) may further have include the structural unit (a2), the structural unit (a3), and structural units derived from other known monomers. When the resin (X) contains the structural unit (a4), the content of the structural unit (a4) in the resin (X) is 20 mol% or more, preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 45 mol% or more, based on the total of all structural units in the resin (X). Also, it is 100 mol% or less, preferably 80 mol% or less, more preferably 70 mol% or less, even more preferably 60 mol% or less, and even more preferably 55 mol% or less. Specifically, it is 20 to 100 mol%, preferably 20 to 80 mol%, more preferably 30 to 70 mol%, even more preferably 40 to 60 mol%, and even more preferably 45 to 55 mol%. When the resin (X) contains the structural unit (a5), the content of the structural unit (a5) in the total of all structural units in the resin (X) is 20 mol% or more, preferably 30 mol% or more, more preferably 40 mol% or more, and even more preferably 45 mol% or more. Also, 100 mol% or less may be mentioned, preferably 80 mol% or less, more preferably 70 mol% or less, even more preferably 60 mol% or less, and even more preferably 55 mol% or less. Specifically, 20 to 100 mol% may be mentioned, preferably 20 to 80 mol%, more preferably 30 to 70 mol%, even more preferably 40 to 60 mol%, and even more preferably 45 to 55 mol%. Also, when the resin (X) contains the structural unit (a4) and the structural unit (a5), the total content of the structural unit (a4) and the structural unit (a5) may be 40 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more, and even more preferably 80 mol% or more, based on the total of all the structural units of the resin (X). Also, 100 mol% or less may be mentioned. Specifically, 40 to 100 mol% may be mentioned, preferably 60 to 100 mol%, more preferably 70 to 100 mol%, and even more preferably 80 to 100 mol%. Each structural unit constituting the resin (X) may be used alone or in combination of two or more, and can be produced by a known polymerization method (e.g., radical polymerization method) using a monomer that derives these structural units. The content of each structural unit in the resin (X) can be adjusted by the amount of the monomer used for polymerization. The weight average molecular weight of the resin (X) is preferably 6,000 or more (more preferably 7,000 or more) and 80,000 or less (more preferably 60,000 or less). The method for measuring the weight average molecular weight of the resin (X) is the same as that for the resins (A1) and (A2). When the resist composition contains resin (X), the content thereof is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, even more preferably 1 to 40 parts by mass, still more preferably 1 to 30 parts by mass, and even more preferably 1 to 8 parts by mass, per 100 parts by mass of the combined total of resin (A1) and resin (A2).

[0122] When the resist composition of the present invention contains resins other than the resins (A1), (A2) and (X), the content of these resins is typically 0.1 to 50 mass%, preferably 0.5 to 30 mass%, and more preferably 1 to 20 mass%, relative to the total amount of the resins (A1) and (A2) contained in the resist composition of the present invention.

[0123] The total content of all resins in the resist composition is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 99% by mass or less, based on the solid content of the resist composition. The total content of resin (A1) and resin (A2) in the resist composition is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 99% by mass or less, based on the solid content of the resist composition. The solid content of the resist composition and the resin content therein can be measured by a known analytical method such as liquid chromatography or gas chromatography.

[0124] <Acid Generator (B)> The acid generator (B) may be either a nonionic compound or an ionic compound. Examples of nonionic acid generators include sulfonate esters (e.g., 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate), sulfones (e.g., disulfone, ketosulfone, sulfonyldiazomethane), and the like. Examples of ionic acid generators include onium salts containing onium cations (e.g., diazonium salts, phosphonium salts, sulfonium salts, iodonium salts). Examples of anions of onium salts include sulfonate anion, benzenesulfonyl anion, sulfonylimide anion, sulfonylmethide anion, and carboxylate anion. Furthermore, the acid generator (B) may be one of the structural units constituting the resin contained in the resist composition of the present invention, like the structural unit (a7) described above.

[0125] As the acid generator (B), compounds that generate acid by radiation, such as those described in JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853, JP-A-63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. No. 3,849,137, German Patent No. 3914407, and European Patent No. 126,712, can be used. Compounds produced by known methods can also be used. The acid generator (B) can be used alone or in combination of two or more. The acid generator (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.

[0126] A preferred embodiment of the acid generator (B) includes a salt represented by formula (B1) (hereinafter sometimes referred to as "acid generator (B1)") and a salt represented by formula (B2) (hereinafter sometimes referred to as "acid generator (B2)"). JPEG2025036219000108.jpg1392 [In formula (B1), all symbols have the same meanings as defined above.]

[0127] L b1 The (nb1+1)-valent hydrocarbon group is a monovalent chain hydrocarbon group, a monovalent alicyclic hydrocarbon group, a monovalent aromatic hydrocarbon group, or a monovalent group that is a combination of two or more of these groups, from which nb1 hydrogen atoms have been removed to form one or more L b2 The hydrocarbon group may have 1 to 48 carbon atoms, preferably 1 to 42 carbon atoms, more preferably 1 to 36 carbon atoms, even more preferably 1 to 30 carbon atoms, still more preferably 1 to 24 carbon atoms, and even more preferably 1 to 18 carbon atoms. Examples of the chain hydrocarbon group include a group in which nb1 hydrogen atoms have been removed from an alkyl group or an alkenyl group. The alkyl group may be linear or branched, and specific examples thereof include a methane group, a methyl group, an ethyl group, a n-propyl group, a n-butyl group, a sec-butyl group, a isobutyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a undecyl group, a dodecyl group, a tridecyl group, a tetradecyl group, a pentanedecyl group, and a heptadecyl group. 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, a octenyl group, an isooctenyl group, and a nonenyl group. The number of carbon atoms in the chain hydrocarbon group is preferably 1 to 36, more preferably 1 to 24, even more preferably 1 to 20, still more preferably 1 to 18, even more preferably 1 to 12, and even more preferably 1 to 10. Examples of the alicyclic hydrocarbon group include a group in which nb1 hydrogen atoms have been removed from a monocyclic or polycyclic cycloalkyl group. Examples of the monocyclic cycloalkyl group include a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of polycyclic cycloalkyl groups include cycloalkyl groups having a bridged structure, cycloalkyl groups in which two or more rings are condensed, and cycloalkyl groups in which two rings are bonded by a spiro bond. Examples of cycloalkyl groups having a bridged structure include a norbornyl group and an adamantyl group. Examples of cycloalkyl groups in which two or more rings are condensed include a bicyclo[4,4,0]decane group and a steroid group (steroid skeleton). Examples of cycloalkyl groups in which two rings are bonded by a spiro bond include spirocyclic cycloalkyl groups 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 bonded by a spiro bond to a cycloalkyl group having 5 to 8 carbon atoms. A double bond may be formed between two carbon atoms contained in the alicyclic hydrocarbon group. More specifically, alicyclic hydrocarbon groups represented by the following formulas are included. TIFF2025036219000109.tif26168When the alicyclic hydrocarbon group is a monocyclic cycloalkyl group, the number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 18, more preferably 3 to 12, even more preferably 3 to 10, and even more preferably 3 to 8.When the alicyclic hydrocarbon group is a polycyclic cycloalkyl group, the number of carbon atoms in the alicyclic hydrocarbon group is preferably 6 to 18, more preferably 6 to 12, and even more preferably 7 to 12. Examples of the aromatic hydrocarbon group include groups in which nb2 hydrogen atoms have been removed 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 the following formula: TIFF2025036219000110.tif1186 The number of carbon atoms in the aromatic hydrocarbon group is preferably 4 to 24, more preferably 4 to 20, even more preferably 4 to 18, even more preferably 5 to 14, even more preferably 5 to 10, and even more preferably 6 to 10. L b1When --CH2-- in the hydrocarbon group is replaced with --O--, --CO--, --S-- or --SO2--, the number of carbon atoms before the replacement is regarded as the number of carbon atoms in the hydrocarbon group. L b1 Among the hydrocarbon groups in which -CH2- in a chain hydrocarbon group is replaced by -O-, -CO-, -S- or -SO2-, there may be mentioned a hydroxy group (a group in which -CH2- in a methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- in an ethyl group is replaced by -O-CO-), a carbonyl group (a group in which -CH2- in a methylene group is replaced by -CO-), an oxy group (a group in which -CH2- in a methylene group is replaced by -O-), an alkoxy group (a group in which -CH2- at any position in an alkyl group is replaced by -O-), an alkoxycarbonyl group (a group in which -CH2-CH2- at any position in an alkyl group is replaced by -O-CO-), an alkylcarbonyl group (an alkyl group in which -CH2- Examples of the substituted groups include -CH- at any position in the alkyl group, which is replaced with -CO-), alkylcarbonyloxy groups (wherein -CH-CH- at any position in the alkyl group is replaced with -CO-O-), alkanediyloxy groups (wherein -CH- at any position in the alkanediyl group is replaced with -O-), alkanediyloxycarbonyl groups (wherein -CH-CH- at any position in the alkanediyl group is replaced with -O-CO-), alkanediylcarbonyl groups (wherein -CH- at any position in the alkanediyl group is replaced with -CO-), and alkanediylcarbonyloxy groups (wherein -CH-CH- at any position in the alkanediyl group is replaced with -CO-). Examples of the substituted groups include the same groups as those exemplified in this specification, within the range permitted by the upper limit of the number of carbon atoms. L b1Among the above hydrocarbon groups, examples of groups in which -CH2- in an alicyclic hydrocarbon group is replaced with -O-, -CO-, -S- or -SO2- include groups containing structures such as cyclic ether, cyclic ketone, cyclic ester (lactone), cyclic thioether, cyclic acetal, and cyclic sulfonate ester (sultone). Specific examples include alicyclic hydrocarbon groups represented by the following formulas. The bonding position of the alicyclic hydrocarbon groups listed in the following formulas can be any position. TIFF2025036219000111.tif48165L b1 Among these hydrocarbon groups, -CH2- contained in the aromatic hydrocarbon group may be replaced by -O- or -S-, and examples of the group in which -CH2- is replaced by -O- or -S- include groups derived from a furan ring or a thiophene ring, respectively. Specific examples include aromatic hydrocarbon groups represented by the following formulas: TIFF2025036219000112.tif1325 Examples of the group that combines two or more groups selected from the chain hydrocarbon group, the alicyclic hydrocarbon group, and the aromatic hydrocarbon group include a group that combines the above chain hydrocarbon group with the above alicyclic hydrocarbon group, a group that combines the above chain hydrocarbon group with the above aromatic hydrocarbon group, a group that combines the above alicyclic hydrocarbon group with the above aromatic hydrocarbon group, and a group that combines the above chain hydrocarbon group with the above alicyclic hydrocarbon group with the above aromatic hydrocarbon group. The group that combines the alicyclic hydrocarbon group with the aromatic hydrocarbon group may be a condensed ring. L b2 The divalent hydrocarbon group includes a divalent chain hydrocarbon group, a divalent alicyclic hydrocarbon group, a divalent aromatic hydrocarbon group, and a group formed by combining two or more of these groups. A monovalent hydrocarbon group is formed by removing one hydrogen atom to give Y b1 Examples of such groups include groups that bond to the L b2 The divalent chain hydrocarbon group, the divalent alicyclic hydrocarbon group, the divalent aromatic hydrocarbon group, and the divalent group consisting of two or more of these groups are each, within the range permitted by the number of carbon atoms, L b1Examples of the monovalent hydrocarbon group include a monovalent chain hydrocarbon group, a monovalent alicyclic hydrocarbon group, a monovalent aromatic hydrocarbon group, and a monovalent group obtained by combining two or more of these groups from which one hydrogen atom has been removed. L b1 and L b2 The substituents which the hydrocarbon group may have include a halogen atom, a cyano group, and a nitro group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. L b1 and L b2 When L is a group in which an alicyclic hydrocarbon group or an aromatic hydrocarbon group is combined with a chain hydrocarbon group, the chain hydrocarbon group may be regarded as a substituent that the alicyclic hydrocarbon group or the aromatic hydrocarbon group has. b1 and L b2 The -CH2- of the chain hydrocarbon group contained in the hydrocarbon group is replaced with -O-, -CO-, -S- or -SO2-, thereby forming L b1 and L b2 The hydrocarbon group of can have a substituent such as a hydroxy group, a carboxy group, an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a thiol group, or a sulfonyl group. b1 and L b2 The number of substituents that may be possessed by the group is not particularly limited, and the group may have a plurality of substituents. Y b1 Examples of the cyclic hydrocarbon group include an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group and an aromatic hydrocarbon group are combined. Y b1 The alicyclic hydrogen group and aromatic hydrocarbon group of b1 Examples of the alicyclic hydrocarbon groups and aromatic hydrocarbon groups are the same as those exemplified in 1. When the alicyclic hydrocarbon groups and aromatic hydrocarbon groups do not have a substituent, they may be monovalent alicyclic hydrocarbon groups and aromatic hydrocarbon groups. Y b1 The substituents that the methyl group in Y may have include a halogen atom, a cyano group, a hydroxyl group, and a nitro group. b1Examples of the substituent that the cyclic hydrocarbon group may have include a halogen atom, a cyano group, a nitro group, and a hydrocarbon group having 1 to 18 carbon atoms that may have a halogen atom, a cyano group, or a nitro group (-CH2- contained in the hydrocarbon group may be replaced with -O-, -S-, -CO-, or -SO2-). b1 The number of carbon atoms in the hydrocarbon group that may be contained in the cyclic hydrocarbon group of Y b1 The number of cyclic hydrocarbon groups is not included in the above. Y b1 Examples of the hydrocarbon group having 1 to 18 carbon atoms that may be substituted on the cyclic hydrocarbon group include chain hydrocarbon groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups combining these groups. Examples of the chain hydrocarbon group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and groups combining two or more of these groups include, within the range permitted by the upper limit of the carbon number, b1 Examples of the alkyl group include the chain hydrocarbon group, the alicyclic hydrocarbon group, the aromatic hydrocarbon group, and the group obtained by combining two or more of these groups. b1 Examples of the hydrocarbon group having 1 to 18 carbon atoms in which -CH2- is replaced with -O-, -S-, -CO- or -SO2- that may be substituted on the cyclic hydrocarbon group include, within the upper limit of the carbon number, L b1 Examples of the hydrocarbon group include the same groups as those exemplified above in which -CH2- in the hydrocarbon group is replaced with -O-, -S-, -CO- or -SO2-. b1 The hydrocarbon group having 1 to 18 carbon atoms which the cyclic hydrocarbon group may have as a substituent may constitute a protecting group or leaving group (acid labile group or base labile group) generally used in the art. The anion of the salt represented by formula (B1) is preferably an anion represented by the following formula (B1-A1) or an anion represented by formula (B1-A2). TIFF2025036219000113.tif30126[In formula (B1-A1), L b2 and Y b1 has the same meaning 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 an integer of 0 to 6. When z1 is 2 or more, the groups in the multiple parentheses may be the same or different. X 1 represents -O-CO-, -CO-O-, -O-CO-O- or -O-. L b3 represents a (nb2+1) hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. nb2 represents an integer of 1 to 3. When nb2 is 2 or more, the groups in the parentheses may be the same or different.] Q b1 , Q b2 , Q b3 and Q b4 Examples of the alkyl group represented by the formula (I) include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. Q b1 , Q b2 , Q b3 and Q b4 Examples of the perfluoroalkyl group having 1 to 6 carbon atoms include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. Q b1 and Q b2 Q b1 and Q b2 At least one of the groups preferably contains a fluorine atom or a perfluoroalkyl group, more preferably a fluorine atom or a perfluoroalkyl group, even more preferably a fluorine atom or a trifluoromethyl group, and even more preferably both are fluorine atoms. Qb3 and Q b4 are each preferably independently 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 0 to 3, and more preferably 0, 1 or 2. X 1 is preferably -O-CO- or -CO-O-.

[0128] L b3 As the hydrocarbon group in the formula (B1), within the range permitted by the upper limit of the number of carbon atoms, b1 The same hydrocarbon groups as those exemplified above are included. In formula (B1-A1), L b3 is preferably a single bond, a chain hydrocarbon group having 1 to 12 carbon atoms which may have a substituent (-CH2- contained in the chain hydrocarbon group may be replaced with -O- or -CO-), an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or -SO2-), an aromatic hydrocarbon group having 6 to 10 carbon atoms which may have a substituent (-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O- or -S-), and a group formed by combining two or more of these groups, and more 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 the chain hydrocarbon group is replaced by -O- or -CO-, the number of -CH2- contained in the chain hydrocarbon group replaced by -O- or -CO- is preferably 1 to 4, and it is preferable that one -CH2-CH2- contained in the chain hydrocarbon group is replaced by -O-CO- or -CO-O-, or one -CH2-CH2-CH2- contained in the chain hydrocarbon group is replaced by -O-CO-O-. TIFF2025036219000114.tif1581[In formula (Lb3-1), nb2 has the same meaning as in formula (B1-A1). L b31 represents a single bond or a chain hydrocarbon group having 1 to 12 carbon atoms, -CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-, and the chain hydrocarbon group may have a substituent. W b3 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 10 carbon atoms, -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-, -CH2- contained in the aromatic hydrocarbon group may be replaced by -O- or -S-, and the alicyclic hydrocarbon group and the aromatic hydrocarbon group may have a substituent. * and ** represent binding sites, * represents X 1 represents the binding site for In formula (Lb3-1), L b31 As long as the chain hydrocarbon group has the upper limit of the number of carbon atoms, L b1 Examples of the chain hydrocarbon groups include the same chain hydrocarbon groups as those exemplified in the chain hydrocarbon groups 1. In formula (Lb3-1), W b3 The alicyclic and aromatic hydrocarbon groups of L are as long as the upper limit of the carbon number permits. b1 Examples of the alicyclic hydrocarbon groups and aromatic hydrocarbon groups are the same as those exemplified by 1. In formula (Lb3-1), L b31 The substituents which the chain hydrocarbon group may have and W b1 The substituents that the alicyclic hydrocarbon group and aromatic hydrocarbon group may have are b1 The substituents which the hydrocarbon group may have include the same groups as those exemplified above. L b31 is preferably a single bond or an alkanediyl group having 1 to 6 carbon atoms (-CH2- contained in the alkanediyl group may be replaced by -O- or -CO-). In formula (Lb3-1), W b3 Examples of the alicyclic hydrocarbon group and aromatic hydrocarbon group include the alicyclic hydrocarbon group and aromatic hydrocarbon group shown below. In the alicyclic hydrocarbon group and aromatic hydrocarbon group shown below, * and ** represent a bonding site, * represents X 1Or L b31 represents a bonding site with L, and ** represents a hydrogen atom, a substituent, or L b2 At least one ** represents a binding site for L b2 represents a bonding site with the alicyclic hydrocarbon group. In the alicyclic hydrocarbon groups represented below, -CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or -SO2-. When -CH2- contained in the alicyclic hydrocarbon group is replaced with -O-, -S-, -CO- or -SO2-, it is preferable that an ether ring, an ester ring (lactone), a carbonate ring, a sultone ring or an acetal ring is formed. In the formula (B1-A1) of TIFF2025036219000115.tif37164, L b2 is preferably a single bond or a chain hydrocarbon group having 1 to 12 carbon atoms (-CH2- contained in the chain hydrocarbon group may be replaced by -O- or -CO-), and is preferably a single bond, -O-, -O-CO-, -CO-O-, -O-CO-O- or *-L b21 -X 2 -L b22 -**(L b21 and L b22 one of X represents a chain hydrocarbon group having at least 1 to 6 carbon atoms, and the other represents a single bond or a chain hydrocarbon group having 1 to 6 carbon atoms; 2 represents -O-, -CO-O-, -O-CO-, or -O-CO-O-; * and ** represent binding sites; ** represents Y b1 where L b21 , X 2 and L b22 The total number of carbon atoms is 12 or less. In formula (B1-A1), Y b1is preferably a cyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent (-CH2- contained in the cyclic hydrocarbon group may be replaced with -O-, -CO-, -S- or -SO2-), more preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -CO-, -S- or -SO2-) or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, and even more preferably an alicyclic hydrocarbon group having 3 to 16 carbon atoms which may have a substituent (-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -CO-, -S- or -SO2-) or an aromatic hydrocarbon group having 6 to 10 carbon atoms which may have a substituent. Specifically, it is more preferable that it is a group represented by formulas (Y1) to (Y36) represented by the following groups. In formulas (Y1) to (Y36), R Yb is a hydrogen atom or Y b1 Among the substituents that the cyclic hydrocarbon group may have, R represents an alkyl group having 1 to 4 carbon atoms. Yc is a hydrogen atom or Y b1 represents a substituent that the cyclic hydrocarbon group may have, and * represents L b2 The alicyclic hydrocarbon group and aromatic hydrocarbon group represented by the following formulae may have other substituents, although these are not specifically shown in the following formulae. TIFF2025036219000116.tif83160

[0129] The anion in the salt represented by formula (B1) is preferably an anion represented by formula (B1-A1-1) to formula (B1-A1-85) (hereinafter, may be referred to as "anion (B1-A1-1)" depending on the formula number), and more preferably an anion represented by any of formulas (B1-A1-1) to (B1-A1-4), (B1-A1-9), (B1-A1-10), (B1-A1-24) to (B1-A1-33), (B1-A1-36) to (B1-A1-40), and (B1-A1-47) to (B1-A1-85). TIFF2025036219000117.tif216160

[0130] TIFF2025036219000118.tif248149

[0131] TIFF2025036219000119.tif253158

[0132] Here, R i2 ~R i7 are each independently, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. i8 L 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. A41 is a single bond or an alkanediyl group having 1 to 4 carbon atoms. Q b1 and Q b2 has the same meaning as above. Specific examples of the anion represented by formula (B1-A1) include the anions described in JP-A-2010-204646.

[0133] Preferred anions in the salt represented by formula (B1) include the anions represented by formulas (B1a-1) to (B1a-70), respectively. Among them, the anions represented by any of formulas (B1a-1) to (B1a-3), (B1a-7) to (B1a-19), and (B1a-22) to (B1a-70) are preferred. TIFF2025036219000120.tif185163

[0134] TIFF2025036219000121.tif251162

[0135] TIFF2025036219000122.tif70163

[0136] The anion represented by formula (B1-A2) is represented by the following formula: TIFF2025036219000123.tif24100[In formula (B1-A2), L b2 and Y b1 has the same meaning as in formula (B1). R b1 represents a halogen atom or an alkyl group having 1 to 6 carbon atoms, and -CH2- contained in the alkyl group may be replaced with -O- or -CO-. nb4 represents an integer of 1 to 5. When nb4 is 2 or more, a plurality of -L b2 -Y b1 may be the same or different from each other. nb3 represents an integer of 0 to 4, and when nb3 is 2 or more, a plurality of R b1 may be the same or different from each other. However, 1≦nb4+nb3≦5 is satisfied.

[0137] In formula (B1-A2), L b2 and Y b1 Examples of the cyclic hydrocarbon group include, within the upper limit of the carbon number, L in formula (B1). b2 Examples of hydrocarbon groups and Y b1 Examples of the cyclic hydrocarbon group are the same as those of L. b2 Hydrocarbon radical, Y b1 The substituents which the methyl group and the cyclic hydrocarbon group may have are also defined as follows: b2 Hydrocarbon radical, Y b1 Examples of the substituent that the methyl group and the cyclic hydrocarbon group may have include the same as those mentioned above. L b2 represents preferably an alkanediyl group having 1 to 12 carbon atoms, in which -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-, and more preferably *-CO-OL b41 -(L b41 is a single bond or a chain hydrocarbon group having 1 to 6 carbon atoms, in which -CH2- may be replaced by -O- or -CO-, and * is SO3 - represents the bonding site with the phenyl group to which L is bonded. b41is preferably a single bond or a chain hydrocarbon group having 1 to 3 carbon atoms. Y b1 is preferably a cyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent (-CH2- contained in the cyclic hydrocarbon group may be replaced with -O-, -CO-, -S- or -SO2-), more preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -CO-, -S- or -SO2-) or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, and Y in formula (B1-A1) is b1 Or L b1 More preferably, it is an alicyclic hydrocarbon group or an aromatic hydrocarbon group exemplified by the following: Specifically, it is preferably the groups represented by the above formulae (Y1) to (Y36), and more preferably the groups represented by the above formulae (Y1) to (Y19). Y b1 The substituent that the cyclic hydrocarbon group may have is preferably a halogen atom or an alkyl group having 1 to 6 carbon atoms (-CH2- contained in the alkyl group may be replaced with -O-, -S-, -CO- or -SO2-), more preferably a fluorine atom, an iodine atom or an alkyl group having 1 to 4 carbon atoms (-CH2- contained in the alkyl group may be replaced with -O-, -S-, -CO- or -SO2-), still more preferably a fluorine atom, an iodine atom, a hydroxy group, an alkoxy group having 1 to 3 carbon atoms or an alkyl group having 1 to 4 carbon atoms, and still more preferably a fluorine atom, an iodine atom, a hydroxy group or an alkyl group having 1 to 4 carbon atoms. b2 The substituent which the cyclic hydrocarbon group may have may constitute a protecting group or a leaving group (acid labile group or base labile group) generally used in the art.

[0138] In formula (B1-A2), nb4 is preferably any integer of 1 to 4, more preferably any integer of 1 to 3, further preferably 1 or 2, and further more preferably 2. When nb4 is 1 or 2, -L b2 -Y b1The bond position of SO3 - It is preferable that the structure be the following structure in which the m-position of the benzene ring is substituted with respect to the bonding position of the above. TIFF2025036219000124.tif24105[In the above formula, L b2 , Y b1 , R b1 , nb3 has the same meaning as in formula (B1-A2). In formula (B1-A2), when nb4 is 2 or more, a plurality of L b2 and Y b1 It is preferable that each of them represents the same group.

[0139] R b1 Examples of the alkyl group having 1 to 6 carbon atoms include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a hexyl group, etc. The number of carbon atoms in the alkyl group is preferably 1 to 4, and more preferably 1 to 3. R b1 Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group in which -CH2- is replaced with -O- or -CO- include a hydroxy group, a carboxy group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, an oxy group, a carbonyl group, etc. Specific examples of these are the same as those mentioned above. R b1 are each independently preferably a halogen atom or an alkyl group having 1 to 4 carbon atoms (-CH2- contained in the alkyl group may be replaced with -O- or -CO-), more preferably a fluorine atom, an iodine atom, or an alkyl group having 1 to 3 carbon atoms (-CH2- contained in the alkyl group may be replaced with -O- or -CO-), and further preferably a fluorine atom, an iodine atom, a hydroxy group, a methoxy group, or a methyl group. nb3 is an integer of 0 to 4, preferably an integer of 0 to 3, and more preferably an integer of 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 More preferably, nb3 is a fluorine atom or an iodine atom. When nb3 is 2, R b1 It is preferable that one of R is a halogen atom and the other is a halogen atom or an alkyl group having 1 to 4 carbon atoms. b1 It is more preferable that one of them is a fluorine atom or an iodine atom, and the other is a fluorine atom, an iodine atom, or an alkyl group having 1 to 3 carbon atoms.

[0140] Examples of the anion (B1-A2) include the following anions. Among them, the anions represented by the formulas (B2a-1) to (B2a-20) are preferred, and the anions represented by the formulas (B2a-1) to (B2a-11) and (B2a-16) to (B2a-20) are more preferred. TIFF2025036219000125.tif147160

[0141] Examples of the acid generator (B2) include salts represented by the following formula: TIFF2025036219000126.tif1292[In formula (B2), A 1 represents a nitrogen atom or a carbon atom. L b2 represents a single bond or a hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and -CH2- contained in the hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. Y b1 represents a methyl group which may have a substituent or a cyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and -CH2- contained in the cyclic hydrocarbon group may be replaced by -O-, -S-, -CO- or -SO2-. nb5 represents 2 or 3. 1When is a nitrogen atom, nb5 is 2, and A 1 When is a carbon atom, nb5 is 3. Multiple -L b2 '-Y b1 ' may be the same or different from each other, and two -SO2-L b2 '-Y b1 ' may be joined together to form a ring. Z2 + represents an organic cation. In formula (B2), L b2 ' and Y b1 Examples of the hydrocarbon group, cyclic hydrocarbon group and substituent of L in formula (B1-A1) are b2 and Y b1 The same groups as those shown in the above are included. In formula (B2), L b2’ is a single bond, *-L b23 -X 2 -or*-L b23 -X 2 -W 2 -X 3 -(L b23 represents an alkanediyl group having 1 to 6 carbon atoms which may have a fluorine atom; X 2 and X 3 each independently represents -O-, -CO-O-, -O-CO-, -O-CO-O- or -O-; W 2 represents an alicyclic hydrocarbon group having 3 to 12 carbon atoms, -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O- or -CO-, and * represents a bonding site with SO2.) is preferable. In formula (B2), Y b1’is preferably a methyl group having a fluorine atom or a cyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent (-CH2- contained in the cyclic hydrocarbon group may be replaced with -O-, -CO-, -S- or -SO2-), is preferably a trifluoromethyl group, an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (-CH2- contained in the alicyclic hydrocarbon group may be replaced with -O-, -S-, -CO- or -SO2-), or a phenyl group which may have a substituent, and is even more preferably a trifluoromethyl group or a group represented by Formulae (Y1) to (Y36) in Formula (B1-A1). nb5 is preferably 2 or 3. In formula (B2), two -SO2-L b2’ -Y b1’ Together, A 1 When a ring containing the formula (B2') is formed, examples of the anion include an anion represented by the formula (B2'). TIFF2025036219000127.tif21113[In formula (B2'), A 1 , Y b1 , L b2 and nb5 have the same meaning as in formulae (B1) and (B2). W b4 represents a disulfonylimide ring or disulfonylmethide ring having 3 to 12 carbon atoms which may have a fluorine atom.] W b4 The disulfonylimide ring or disulfonylmethide ring may have 3 to 12 carbon atoms, and preferably has 3 to 6 carbon atoms, and the hydrogen atom of the methylene group contained in the ring is preferably replaced with a fluorine atom.

[0142] Examples of the anion represented by formula (B2) include the following: Among these, the anions represented by formulae (Ba3-1) and (Ba3-2) are preferred. TIFF2025036219000128.tif174165

[0143] In another embodiment of the acid generator (B), an anion in which the anion represented by formula (B1) is replaced with a carboxylate anion is also preferably used as the acid generator (B). Examples of carboxylate anions include the following: TIFF2025036219000129.tif41155

[0144] Z1 + and Z2 + Examples of the organic cation include organic onium cation, organic sulfonium cation, organic iodonium cation, organic ammonium cation, benzothiazolium cation, and organic phosphonium cation. Among these, organic sulfonium cation and organic iodonium cation are preferred, and arylsulfonium cation or aryl iodonium cation are more preferred. Specifically, the organic cation includes cations represented by any of formulas (b2-1) to (b2-5) (hereinafter, may be referred to as "cation (b2-1)" depending on the formula number). TIFF2025036219000130.tif84161 [In formula (b2-1) to formula (b2-5), R b4 ~R b6 each independently represent a chain hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms, a hydrogen atom contained in the chain hydrocarbon group may be substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, or a glycidyloxy group, and a hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. R b4 and R b5may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and -CH2- contained in the ring may be replaced with -O-, -S- or -CO-. R b7 and R b8 each independently represents a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. m2 and n2 each independently represent an integer of 0 to 5. When m2 is 2 or more, multiple R b7 may be the same or different, and when n2 is 2 or more, multiple R b8 may be the same or different. R b9 and R b10 each independently represents a chain hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms. R b9 and R b10 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and -CH2- contained in the ring may be replaced with -O-, -S- or -CO-. R 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 an open 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, a hydrogen atom contained in the open chain hydrocarbon group may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and a hydrogen atom contained in the aromatic hydrocarbon group may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms. R b11 and R b12 may be bonded to each other to form a ring including the -CH-CO- to which they are bonded, and -CH2- contained in the ring may be replaced by -O-, -S- or -CO-. R b13 ~R b18 and Rb21 ~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 attached, and -CH2- contained in the ring may be replaced by -O-, -S- or -CO-. R b27 ~R b29 each independently represents a hydrogen atom or a group containing an acid labile group. L b31 and L b41 ~L b43 each independently represents a sulfur atom or an oxygen atom. o2, p2, s2, and t2 each independently represent an integer of 0 to 5. q2 and r2 each independently represent an integer of 0 to 4. u2 represents 0 or 1. When o2 is 2 or more, multiple R b13 are the same or different, and when p2 is 2 or more, multiple R b14 are the same or different, and when q2 is 2 or more, multiple R b15 are the same or different, and when r2 is 2 or more, multiple R b16 are the same or different, and when s2 is 2 or more, multiple R b17 are the same or different, and when t2 is 2 or more, multiple 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 represent an integer of 0 to 3, and satisfy 0≦u4+o21≦5 and 0≦u5+p22≦5. o21, p22, q23, r24, t25 and s26 each independently represent an integer of 0 to 4. When u3, u4 and u5 are each 2 or more, the groups in the parentheses are the same or different. When o21, p22, q23, r24, t25, and s26 are each 2 or more, multiple R b21 ~R b26 are the same or different. When u2, u3, u4, and u5 are each 2 or more, the groups in the parentheses are the same or different. When u2 is 0, any one of o2, p2, q2, and r2 is 1 or more, and R b13 ~R b16 At least one of them is preferably a halogen atom, and when u2 is 1, any one of o2, p2, s2, t2, q2, and r2 is 1 or more, and R b13 ~R b18 At least one of these is preferably a halogen atom. Furthermore, when u2 is 0, r2 is preferably 1 or more, and more preferably 1. When u2 is 0 and r2 is 1 or more, R b16 is preferably a halogen atom. The aliphatic hydrocarbon group refers to a chain hydrocarbon group and an alicyclic hydrocarbon group. Examples of the chain hydrocarbon group include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, and 2-ethylhexyl. In particular, R b9 ~R b12 The chain hydrocarbon group preferably has 1 to 12 carbon atoms. The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and cyclodecyl. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl, adamantyl, and norbornyl groups, as well as the following groups: TIFF2025036219000131.tif11157 In particular, R b9 ~Rb12 The alicyclic hydrocarbon group preferably has 3 to 18 carbon atoms, and more preferably has 4 to 12 carbon atoms. Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-methyladamantan-2-yl group, a 2-ethyladamantan-2-yl group, a 2-isopropyladamantan-2-yl group, a methylnorbornyl group, an isobornyl group, etc. In the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group, the total number of carbon atoms in the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less. The fluorinated alkyl group refers to an alkyl group having 1 to 12 carbon atoms and a fluorine atom, and examples of such groups include a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a perfluorobutyl group, etc. The number of carbon atoms in the fluorinated alkyl group is preferably 1 to 9, more preferably 1 to 6, and further preferably 1 to 4. Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a biphenyl group, a naphthyl group, and a phenanthryl group. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and examples thereof include aromatic hydrocarbon groups having a chain hydrocarbon group (such as 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, and a 2-methyl-6-ethylphenyl group) and aromatic hydrocarbon groups having an alicyclic hydrocarbon group (such as a p-cyclohexylphenyl group and a p-adamantylphenyl group). 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. An example of the aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group is a p-methoxyphenyl group. Examples of the chain hydrocarbon group in which a hydrogen atom has been substituted with an aromatic hydrocarbon group include aralkyl groups such as a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl 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 alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, an isopropylcarbonyloxy group, a butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group. R b4 and R b5 The ring formed by bonding to each other together with the sulfur atom to which they are bonded may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. Examples of this ring include rings having 3 to 18 carbon atoms, and preferably rings having 4 to 18 carbon atoms. Examples of the ring containing a sulfur atom include 3-membered to 12-membered rings, and preferably 3-membered to 7-membered rings, and examples of such rings include the following rings. * represents a bonding site. TIFF2025036219000132.tif24142R b9 and R b10 The ring formed by these together may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring may be a 3-membered to 12-membered ring, preferably a 3-membered to 7-membered ring. For example, it may be a thiolane-1-ium ring (tetrahydrothiophenium ring), a thiane-1-ium ring, a 1,4-oxathiane-4-ium ring, etc. R b11 and R b12The ring formed by combining with may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. The ring may be a 3-membered to 12-membered ring, preferably a 3-membered to 7-membered ring. Examples of the ring include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring. R b27 ~R b29 Examples of groups containing an acid labile group include -R c30 , -CO-OR c30 Or -L c10 -CO-OR c30 A group represented by (L c10 represents an alkanediyl group having 1 to 6 carbon atoms, R c30 represents an acid labile group. R b27 ~R b29 Examples of the acid labile group include the group represented by formula (1) and / or the group represented by formula (2) described above.

[0145] Among the cations (b2-1) to (b2-5), the cation (b2-1), the cation (b2-4) or the cation (b2-5) is preferred. Examples of the cation (b2-1) include cations represented by the formulae (b2-c-1) to (b2-c-27), (b2-c-47) to (b2-c-53), (b2-c-59) to (b2-c-64), (b2-c-78), and (b2-c-79). Examples of the cation (b2-2) include cations represented by the formulae (b2-c-28) to (b2-c-30), and (b2-c-50). Examples of the cation (b2-4) include cations represented by formulas (b2-c-35) to (b2-c-46), (b2-c-54) to (b2-c-58), and (b2-c-65) to (b2-c-68). Examples of the cation (b2-1) include the following cations represented by formulas (b2-c-69) to (b2-c-77). TIFF2025036219000133.tif249165

[0146] TIFF2025036219000134.tif188160

[0147] The acid generator (B) is a combination of the above-mentioned anion and the above-mentioned organic cation, which can be combined arbitrarily. The acid generator (B) is preferably a combination of an anion represented by any of the formulas (B1a-1) to (B1a-3), (B1a-7) to (B1a-19), (B1a-22) to (B1a-70), (B2a-1) to (B2a-11), (B2a-16) to (B2a-20), (B3a-1) to (B3a-20), (B3a-1) to (B3a-3), or (B3a-11) to (B3a-14) and a cation (b2-1), a cation (b2-2), a cation (b2-3), a cation (b2-4), or a cation (b2-5).

[0148] The acid generator (B) is preferably one represented by the formulae (B1-1) to (B1-105), (B2-1) to (B2-20), (B3-1) to (B3-20), and (B3-1) to (B3-28). Among them, one containing an arylsulfonium cation is preferred, and one represented by the formulae (B1-1) to (B1-3), (B1-5) to (B1-7), (B1-11) to (B1-14), (B1-20) to (B1-26), (B1-29), (B1-31) to (B1-105), (B2-1) to (B2-20), and (B3-1) to (B3-28) is particularly preferred. TIFF2025036219000135.tif170160

[0149] TIFF2025036219000136.tif252158

[0150] TIFF2025036219000137.tif253158

[0151] TIFF2025036219000138.tif254160

[0152] TIFF2025036219000139.tif252164

[0153] TIFF2025036219000140.tif247150

[0154] TIFF2025036219000141.tif185159

[0155] In the resist composition of the present invention, the content of the acid generator is preferably from 1 to 45 parts by mass, more preferably from 1 to 40 parts by mass, and even more preferably from 3 to 35 parts by mass, relative to 100 parts by mass of the resin (A). The resist composition of the present invention may contain one type of acid generator (B) alone, or may contain multiple types.

[0156] <Solvent (E)> The content of the solvent (E) in the resist composition is usually 90% by mass or more and 99.9% by mass or less, preferably 92% by mass or more and 99% by mass or less, and more preferably 94% by mass or more and 99% by mass or less. The content of the solvent (E) can be measured by a known analytical method such as liquid chromatography or gas chromatography. Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate, and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; esters such as ethyl lactate, butyl acetate, amyl acetate, and ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone, and cyclohexanone; cyclic esters such as γ-butyrolactone; etc. One type of solvent (E) may be used alone, or two or more types may be used.

[0157] <Quencher (C)> Examples of the quencher (C) include salts that generate an acid with a lower acidity than the acid generated from the acid generator (acid generator (B)), and basic nitrogen-containing organic compounds. The content of the quencher (C) is preferably about 0.01 to 15% by mass, more preferably about 0.01 to 10% by mass, still more preferably about 0.1 to 8% by mass, and even more preferably about 0.1 to 7% by mass, based on the solid content of the resist composition.

[0158] The acidity of the salt that generates an acid with a lower acidity than the acid generated from the acid generator is indicated by the acid dissociation constant (pKa). The salt that generates an acid with a lower acidity than the acid generated from the acid generator is usually a salt with an acid dissociation constant of the acid generated from the salt of -3 < pKa, preferably a salt of -1 < pKa < 7, and more preferably a salt of 0 < pKa < 5. Examples of the salt that generates an acid with a lower acidity than the acid generated from the acid generator include salts represented by the following formula, salts represented by formula (D) described in JP-A-2015-147926 (hereinafter sometimes referred to as "weak acid inner salt (D)"), and salts described in JP-A-2012-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-39502, and JP-A-2011-191745. As the salt that generates an acid with a lower acidity than the acid generated from the acid generator, preferably, it is a salt that generates a carboxylic acid with a lower acidity than the acid generated from the acid generator (a salt having a carboxylic acid anion), more preferably a weak acid inner salt (D), and still more preferably, among the weak acid inner salts (D), a diphenyliodonium salt containing a phenyl group substituted with a carboxylic acid anion. TIFF2025036219000142.tif95157

[0159] The weak acid inner salt (D) is preferably a diphenyliodonium salt having an iodonium cation to which two phenyl groups are bonded and a carboxy anion substituted for at least one of the two phenyl groups bonded to the iodonium cation, and specifically includes salts represented by the following formula:

[0160] TIFF2025036219000143.tif1980[In formula (D), R D1 and R D2 each independently represents a hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 7 carbon atoms, an acyloxy group having 2 to 7 carbon atoms, an alkoxycarbonyl group having 2 to 7 carbon atoms, a nitro group, or a halogen atom. m' and n' each independently represent an integer of 0 to 4. When m' is 2 or more, a plurality of R D1 may be the same or different, and when n' is 2 or more, a plurality of R D2 may be the same or different.] R D1 and R D2 Examples of the hydrocarbon group include chain hydrocarbon groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these groups. Examples of the chain hydrocarbon group include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a hexyl group, and a nonyl group. The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and may be either saturated or unsaturated. Examples of the alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclononyl, and cyclododecyl, norbornyl, and adamantyl groups. Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, a 4-ethylphenyl group, a 4-propylphenyl group, a 4-isopropylphenyl group, a 4-butylphenyl group, a 4-t-butylphenyl group, a 4-hexylphenyl group, a 4-cyclohexylphenyl group, an anthryl group, a p-adamantylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a biphenyl group, a phenanthryl group, a 2,6-diethylphenyl group, and a 2-methyl-6-ethylphenyl group. Groups formed by combining these groups include alkyl-cycloalkyl groups, cycloalkyl-alkyl groups, and aralkyl groups (e.g., phenylmethyl group, 1-phenylethyl group, 2-phenylethyl group, 1-phenyl-1-propyl group, 1-phenyl-2-propyl group, 2-phenyl-2-propyl group, 3-phenyl-1-propyl group, 4-phenyl-1-butyl group, 5-phenyl-1-pentyl group, and 6-phenyl-1-hexyl group). Examples of the alkoxy group include a methoxy group and an ethoxy group. Examples of the acyl group include an acetyl group, a propanoyl group, a benzoyl group, and a cyclohexanecarbonyl group. Examples of the acyloxy group include the above-mentioned acyl group to which an oxy group (-O-) is bonded. Examples of the alkoxycarbonyl group include the above alkoxy groups bonded to a carbonyl group (-CO-). Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom. R D1 and R D2 are each independently preferably an alkyl group having 1 to 8 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an alkoxycarbonyl group having 2 to 4 carbon atoms, a nitro group or a halogen atom. m' and n' are each preferably an integer of 0 to 2, more preferably 0. When m' is 2 or more, a plurality of RD1 may be the same or different, and when n' is 2 or more, a plurality of R D2 may be the same or different.

[0161] More specifically, the following salts are included: TIFF2025036219000144.tif72165

[0162] The basic nitrogen-containing organic compound includes amines and ammonium salts. The amines include aliphatic amines and aromatic amines. The aliphatic amines include primary amines, secondary amines, and tertiary amines. Amines include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N,N-dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, Amines, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine amine, dicyclohexylmethylamine, tris[2-(2-methoxyethoxy)ethyl]amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 2,2'-methylenebisaniline, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-di(2-pyridyl)ethane Examples of the amines include 1,2-di(4-pyridyl)ethane, 1,2-di(2-pyridyl)ethene, 1,2-di(4-pyridyl)ethene, 1,3-di(4-pyridyl)propane, 1,2-di(4-pyridyloxy)ethane, di(2-pyridyl)ketone, 4,4'-dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipicolylamine, and bipyridine. Preferred are aromatic amines such as diisopropylaniline, and more preferred are 2,6-diisopropylaniline. Examples of ammonium salts include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3-(trifluoromethyl)phenyltrimethylammonium hydroxide, tetra-n-butylammonium salicylate, and choline.

[0163] <Other Ingredients> The resist composition of the present invention may contain components other than the above-mentioned components (hereinafter, sometimes referred to as "other components (F)") as necessary. There are no particular limitations on the other components (F), and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes, etc., can be used.

[0164] Preparation of Resist Composition The resist composition of the present invention can be prepared by mixing the resin (A1), resin (A2), acid generator (B), and salt generating an acid weaker in acidity than the acid generated from the acid generator, as well as resins other than the resins (A1) and (A2), quencher (C), solvent (E), and other components (F) as necessary. The order of mixing is arbitrary and is not particularly limited. The temperature during mixing can be selected from 10 to 40°C depending on the type of resin, the solubility of the resin in the solvent (E), and the like. The mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used. After mixing the components, it is preferable to filter the mixture using a filter having a pore size of about 0.003 to 0.2 μm.

[0165] <Method for Producing Resist Pattern> The method for producing a resist pattern of the present invention comprises the steps of: (1) applying the resist composition of the present invention onto a substrate; (2) 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) A step of developing the composition layer after heating.

[0166] The resist composition can be applied onto a substrate using a commonly used device such as a spin coater. Examples of the substrate include inorganic substrates such as silicon wafers and organic substrates having a resist film formed on the surface. Before applying the resist composition, the substrate may be cleaned, and an anti-reflective film or the like may be formed on the substrate. The composition after coating is dried to remove the solvent and form a composition layer. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking), or by using a vacuum device. The heating temperature is preferably 50 to 200°C, and the heating time is preferably 10 to 180 seconds. The pressure during drying under reduced pressure is preferably 1 to 1.0×10 5 It is preferable that the pressure is about Pa. The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. As the exposure light source, various types can be used, such as those that emit ultraviolet laser light such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), and F2 excimer laser (wavelength 157 nm), those that convert the wavelength of laser light from a solid laser light source (YAG or semiconductor laser, etc.) to emit harmonic laser light in the far ultraviolet or vacuum ultraviolet range, and those that irradiate electron beams or extreme ultraviolet light (EUV). In this specification, irradiation with these types of radiation may be collectively referred to as "exposure". During exposure, exposure is usually performed through a mask corresponding to the desired pattern. When the exposure light source is an electron beam, exposure may be performed by direct drawing without using a mask. The composition layer after exposure is subjected to a heat treatment (so-called post-exposure bake) in order to promote a deprotection reaction in the acid labile group. The heating temperature is usually about 50 to 200°C, preferably about 70 to 150°C. A chemical treatment (silylation) may be performed to adjust the hydrophilicity or hydrophobicity of the resin on the surface side of the composition after heating. In addition, before development, the steps of applying a resist composition, drying, exposing, and heating may be repeated on the composition layer after exposure. The composition layer after heating is usually developed using a developing device and a developer. Examples of the developing method include a dip method, a paddle method, a spray method, and a dynamic dispense method. The developing temperature is preferably, for example, 5 to 60° C., and the developing time is preferably, for example, 5 to 300 seconds. By selecting the type of developer as follows, a positive resist pattern or a negative resist pattern can be produced. When a positive resist pattern is produced from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be any of various alkaline aqueous solutions used in this field. For example, an aqueous solution of tetramethylammonium hydroxide or (2-hydroxyethyl)trimethylammonium hydroxide (commonly known as choline) may be used. The alkaline developer may contain a surfactant. After development, the resist pattern is preferably washed with ultrapure water, and then water remaining on the substrate and the pattern is removed. When producing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent (hereinafter sometimes referred to as an "organic developer") is used as the developer. Examples of organic solvents contained in organic developers include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycol ether solvents such as propylene glycol monomethyl ether; amide solvents such as N,N-dimethylacetamide; and aromatic hydrocarbon solvents such as anisole. The content of the organic solvent in the organic developer is preferably from 90% by mass to 100% by mass, more preferably from 95% by mass to 100% by mass, and further preferably consists essentially of the organic solvent. Among them, the organic developer is preferably a developer containing butyl acetate and / or 2-heptanone. The total content of butyl acetate and 2-heptanone in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and even more preferably substantially only butyl acetate and / or 2-heptanone. The organic developer may contain a surfactant and may contain a small amount of water. During development, the development may be stopped by replacing the organic developer with a different type of solvent. The resist pattern after development is preferably washed with a rinse solution. There are no particular limitations on the rinse solution as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, preferably an alcohol solvent or an ester solvent. After cleaning, it is preferable to remove any rinsing liquid remaining on the substrate and the pattern.

[0167] <Application> The resist composition of the present invention is suitable as a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, and is particularly suitable as a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, and is useful for semiconductor microfabrication. EXAMPLES

[0168] The present invention will be described in more detail with reference to examples. In the examples, "%" and "parts" expressing the content or amount used are based on mass unless otherwise specified. The weight average molecular weight is a value determined by gel permeation chromatography under the following conditions. Equipment: HLC-8120GPC model (Tosoh Corporation) Column: TSKgel Multipore H XL -M x 3 + guard column (Tosoh) Eluent: Tetrahydrofuran Flow rate: 1.0mL / min Detector: RI detector Column temperature: 40℃ Injection volume: 100μl Molecular weight standard: Standard polystyrene (Tosoh Corporation) The structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC: Agilent 1100 model, MASS: Agilent LC / MSD model). In the following examples, the value of this molecular ion peak is indicated by "MASS".

[0169] Resin synthesis The compounds (monomers) used in the synthesis of the resin are shown below. TIFF2025036219000145.tif37166Hereinafter, these compounds will be referred to as "monomer (a1-4-2)" etc. according to their formula numbers.

[0170] Synthesis Example 1 [Synthesis of Resin A1-1] Monomer (I-1) and monomer (a1-4-2) were used as monomers, and mixed so that the molar ratio [monomer (I-1):monomer (a1-4-2)] was 60:40. Furthermore, propylene glycol monomethyl ether acetate was mixed with this monomer mixture in an amount of 1.5 times the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture in an amount of 3.3 mol% and 9.9 mol% relative to the total monomer amount, respectively, and these were heated at 80°C for about 5 hours. Thereafter, an aqueous p-toluenesulfonic acid solution (2.5 wt%) was added to the polymerization reaction liquid in an amount of 2.0 times the total mass of all monomers, and the mixture was stirred for 6 hours and then separated. The obtained organic layer was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and collected to obtain a polymer with a weight average molecular weight of about 3.9×10 3Resin A1-1 having the following structural unit was obtained in a yield of 58%. TIFF2025036219000146.tif3187

[0171] Synthesis Example 2 [Synthesis of Resin A1-2] Monomer (I-1) and monomer (a1-4-2) were used as monomers, and mixed so that the molar ratio [monomer (I-1):monomer (a1-4-2)] was 70:30. Furthermore, propylene glycol monomethyl ether acetate was mixed into this monomer mixture in an amount of 1.5 times the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture in an amount of 3.3 mol% and 9.9 mol% relative to the total monomer amount, respectively, and these were heated at 80°C for about 5 hours. Thereafter, an aqueous p-toluenesulfonic acid solution (2.5 wt%) was added to the polymerization reaction liquid in an amount of 2.0 times the total mass of all monomers, and the mixture was stirred for 6 hours and then separated. The obtained organic layer was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and collected to obtain a polymer with a weight average molecular weight of about 4.2 x 10 3 Resin A1-2 having the following structural unit was obtained in a yield of 53%. TIFF2025036219000147.tif3187

[0172] Synthesis Example 3 [Synthesis of Resin A1-3] Monomer (I-1) and monomer (a2-3-1) were used as monomers, and mixed so that the molar ratio [monomer (I-1):monomer (a2-3-1)] was 60:40. Furthermore, 1.5 times the mass of propylene glycol monomethyl ether acetate was mixed with this monomer mixture based on the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture in amounts of 3 mol% and 9 mol%, respectively, based on the total monomer amount, and these were heated at 80°C for about 5 hours. Thereafter, 2.0 times the mass of p-toluenesulfonic acid aqueous solution (2.5 wt%) based on the total mass of all monomers was added to the polymerization reaction liquid, and the mixture was stirred for 6 hours and then separated. The obtained organic layer was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and collected to obtain a polymer with a weight average molecular weight of about 4.9×10 3 Resin A1-3 having the following structural unit was obtained in a yield of 90%. TIFF2025036219000148.tif3591

[0173] Synthesis Example 4 [Synthesis of Resin A1-4] Monomer (I-1) and monomer (a2-2-4) were used as monomers, and mixed so that the molar ratio [monomer (I-1):monomer (a2-2-4)] was 60:40. Furthermore, propylene glycol monomethyl ether acetate was mixed with this monomer mixture in an amount of 1.5 times the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture in amounts of 3.3 mol% and 9.9 mol%, respectively, relative to the total monomer amount, and the mixture was heated at 80°C for about 5 hours. The polymerization reaction liquid was then poured into a large amount of n-heptane to precipitate a resin, which was then filtered and collected to obtain a polymer with a weight average molecular weight of about 4.0×10 3 Resin A1-4 having the following structural unit was obtained in a yield of 83%. TIFF2025036219000149.tif3087

[0174] Synthesis Example 5 [Synthesis of Resin A1-5] Monomer (I-1) and monomer (a2-2-1) were used as monomers, and mixed so that the molar ratio [monomer (I-1):monomer (a2-2-1)] was 60:40. Furthermore, propylene glycol monomethyl ether acetate was mixed with this monomer mixture in an amount of 1.5 times the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture in an amount of 3 mol% and 9 mol% relative to the total monomer amount, respectively, and these were heated at 80°C for about 5 hours. Thereafter, an aqueous solution of p-toluenesulfonic acid (2.5 wt%) was added to the polymerization reaction liquid in an amount of 2.0 times the total mass of all monomers, and the mixture was stirred for 6 hours and then separated. The obtained organic layer was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and collected to obtain a polymer with a weight average molecular weight of about 4.6×10 3 Resin A1-5 having the following structural unit was obtained in a yield of 94%. TIFF2025036219000150.tif3591

[0175] Synthesis Example 6 [Synthesis of Resin A1-6] Monomer (I-1) and monomer (a1-4-2) were used as monomers, and mixed so that the molar ratio [monomer (I-1):monomer (a1-4-2)] was 70:30. Furthermore, propylene glycol monomethyl ether acetate was mixed with this monomer mixture in an amount of 1.5 times the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture in an amount of 3 mol% and 9 mol% relative to the total monomer amount, respectively, and these were heated at 80°C for about 5 hours. Thereafter, an aqueous solution of p-toluenesulfonic acid (2.5 wt%) was added to the polymerization reaction liquid in an amount of 2.0 times the total mass of all monomers, and the mixture was stirred for 6 hours and then separated. The obtained organic layer was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and collected to obtain a polymer with a weight average molecular weight of about 6.6×10 3Resin A1-6 having the following structural unit was obtained in a yield of 66%. TIFF2025036219000151.tif3087

[0176] Synthesis Example 7 [Synthesis of Resin A1-7] Monomer (I-1) and monomer (a1-4-2) were used as monomers, and mixed in a molar ratio of 50:50 [monomer (I-1):monomer (a1-4-2)]. Further, 1.5 times the mass of propylene glycol monomethyl ether acetate was mixed with this monomer mixture based on the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture in amounts of 3.3 mol% and 9.9 mol%, respectively, based on the total monomer amount, and these were heated at 80°C for about 5 hours. Thereafter, 2.0 times the mass of p-toluenesulfonic acid aqueous solution (2.5 wt%) based on the total mass of all monomers was added to the polymerization reaction liquid, and the mixture was stirred for 6 hours and then separated. The obtained organic layer was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and collected to obtain a polymer with a weight average molecular weight of about 3.8×10 3 Resin A1-7 having the following structural unit was obtained in a yield of 57%. TIFF2025036219000152.tif3087

[0177] Synthesis Example 8 [Synthesis of Resin A2-1] Monomer (I-1) and monomer (a2-D2-3) were used as monomers, and mixed so that the molar ratio [monomer (I-1):monomer (a2-D2-3)] was 70:30. Furthermore, 1.5 times the mass of methyl isobutyl ketone was mixed with this monomer mixture based on the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture in amounts of 5 mol% and 15 mol%, respectively, based on the total monomer amount, and the mixture was heated at 75°C for about 5 hours. Thereafter, the polymerization reaction liquid was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and collected to obtain a polymer with a weight average molecular weight of about 6.5×10 3 Resin A2-1 having the following structural unit was obtained in a yield of 96%. TIFF2025036219000153.tif3587

[0178] Synthesis Example 9 [Synthesis of Resin A2-2] Monomer (I-1) and monomer (a2-D1-3) were used as monomers, and mixed so that the molar ratio [monomer (I-1):monomer (a2-D1-3)] was 70:30. Furthermore, 1.5 times the mass of methyl isobutyl ketone was mixed with this monomer mixture based on the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture in amounts of 5 mol% and 15 mol%, respectively, based on the total monomer amount, and the mixture was heated at 75°C for about 5 hours. Thereafter, the polymerization reaction liquid was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and collected to obtain a polymer with a weight average molecular weight of about 5.3×10 3 Resin A2-2 having the following structural unit was obtained in a yield of 78%. TIFF2025036219000154.tif2887

[0179] Synthesis Example 10 [Synthesis of Resin A2-3] Monomer (I-1) and monomer (a2-D1-1) were used as monomers, and mixed so that the molar ratio [monomer (I-1):monomer (a2-D1-1)] was 60:40. Furthermore, 1.5 times the mass of methyl isobutyl ketone was mixed with this monomer mixture based on the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture in amounts of 3 mol% and 9 mol%, respectively, based on the total monomer amount, and the mixture was heated at 73°C for about 5 hours. Thereafter, the polymerization reaction liquid was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and collected to obtain a polymer with a weight average molecular weight of about 4.6×10 3 Resin A2-3 having the following structural unit was obtained in a yield of 66%. TIFF2025036219000155.tif2888

[0180] Synthesis Example 11 [Synthesis of Resin A2-4] Monomer (I-1) and monomer (a2-D2-3) were used as monomers, and mixed so that the molar ratio [monomer (I-1):monomer (a2-D2-3)] was 70:30. Furthermore, 1.5 times the mass of methyl isobutyl ketone was mixed with this monomer mixture based on the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture in amounts of 7 mol% and 21 mol%, respectively, based on the total monomer amount, and the mixture was heated at 75°C for about 5 hours. Thereafter, the polymerization reaction liquid was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and collected to obtain a polymer with a weight average molecular weight of about 3.9×10 3 Resin A2-4 having the following structural unit was obtained in a yield of 88%. TIFF2025036219000156.tif3587

[0181] Synthesis Example 12 [Synthesis of Resin A12-1] Monomer (I-1), monomer (a2-E-3) and monomer (a1-4-2) were used as monomers, and the molar ratio [monomer (I-1):monomer (a2-D3-3):monomer (a1-4-2)] was mixed at a ratio of 60:20:20. Furthermore, 1.5 times the mass of propylene glycol monomethyl ether acetate was mixed with this monomer mixture based on the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture at 3.3 mol% and 9.9 mol%, respectively, based on the total monomer amount, and these were heated at 80°C for about 5 hours. Thereafter, 2.0 times the mass of p-toluenesulfonic acid aqueous solution (2.5 wt%) based on the total mass of all monomers was added to the polymerization reaction liquid, and the mixture was stirred for 6 hours, and then separated. The obtained organic layer was poured into a large amount of n-heptane to precipitate the resin, which was then filtered and collected to obtain a resin with a weight-average molecular weight of approximately 4.2 × 10 3 Resin A12-1 having the following structural unit was obtained in a yield of 66%. TIFF2025036219000157.tif34140

[0182] Synthesis Example 13 [Synthesis of Resin A12-2] Monomer (I-1), monomer (a2-E-3) and monomer (a1-4-2) were used as monomers, and mixed so that the molar ratio [monomer (I-1):monomer (a2-E-3):monomer (a1-4-2)] was 66:18:16. Furthermore, 1.5 times the mass of propylene glycol monomethyl ether acetate was mixed with this monomer mixture based on the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture in amounts of 3.3 mol% and 9.9 mol%, respectively, based on the total monomer amount, and these were heated at 80°C for about 5 hours. Thereafter, 2.0 times the mass of p-toluenesulfonic acid aqueous solution (2.5 wt%) based on the total mass of all monomers was added to the polymerization reaction liquid, and the mixture was stirred for 6 hours, and then separated. The obtained organic layer was poured into a large amount of n-heptane to precipitate the resin, which was then filtered and collected to obtain a resin with a weight-average molecular weight of approximately 4.9 × 103 Resin A12-2 having the following structural unit was obtained in a yield of 68%. TIFF2025036219000158.tif37135

[0183] Synthesis Example 14 [Synthesis of Resin A12-3] Monomer (I-1), monomer (a2-E-3) and monomer (a2-2-1) were used as monomers, and mixed so that the molar ratio [monomer (I-1):monomer (a2-E-3):monomer (a2-2-1)] was 66:18:16. Furthermore, 1.5 times the mass of propylene glycol monomethyl ether acetate was mixed with this monomer mixture based on the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture in amounts of 3.3 mol% and 9.9 mol%, respectively, based on the total monomer amount, and these were heated at 80°C for about 5 hours. Thereafter, the polymerization reaction liquid was poured into a large amount of n-heptane to precipitate the resin, which was then filtered and collected to obtain a polymer with a weight average molecular weight of about 4.8×10 3 Resin A12-3 having the following structural unit was obtained in a yield of 78%. TIFF2025036219000159.tif37135

[0184] Synthesis Example 15 [Synthesis of Resin A12-4] Monomer (I-1), monomer (a2-E-3) and monomer (a2-3-1) were used as monomers, and mixed so that the molar ratio [monomer (I-1):monomer (a2-E-3):monomer (a2-3-1)] was 66:18:16. Furthermore, propylene glycol monomethyl ether acetate was mixed with this monomer mixture in an amount of 1.5 times the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture in amounts of 3.3 mol% and 9.9 mol%, respectively, with respect to the total monomer amount, and these were heated at 80°C for about 5 hours. Thereafter, the polymerization reaction liquid was poured into a large amount of n-heptane to precipitate the resin, which was then filtered and collected to obtain a polymer having a weight average molecular weight of about 4.9×10 3 Resin A12-4 having the following structural unit was obtained in a yield of 75%. TIFF2025036219000160.tif37135

[0185] <Preparation of resist composition> The components shown in Table 1 were mixed and dissolved to obtain a mixture, which was then filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition. [Table 1]

[0186] <Resin> A1-1~A1-7, A2-1~A2-4, A12-1~A12-4, X1: Resin A1-1~Resin A1-7, Resin A2-1~Resin A2-4, Resin A12-1~Resin A12-4, Resin X1 <Acid Generator (B)> B1-1: Salt represented by formula (B1-1) (synthesized according to the examples in JP 2010-152341 A) TIFF2025036219000162.tif2793<Quencher(C)> C1: Dicyclohexylmethylamine (Tokyo Chemical Industry Co., Ltd.) D1: (Tokyo Chemical Industry Co., Ltd.) TIFF2025036219000163.tif1753<solvent> Propylene glycol monomethyl ether acetate 110 parts Propylene glycol monomethyl ether 50 parts γ-butyrolactone 4 parts

[0187] <Resist pattern production and evaluation: Immersion exposure evaluation> A composition for organic anti-reflective coating (ARC-29; manufactured by Nissan Chemical Industries, Ltd.) was applied to a silicon wafer and baked at 205° C. for 60 seconds to form an organic anti-reflective coating having a thickness of 780 Å. Next, the resist composition was spin-coated on the organic anti-reflective coating so that the film thickness after drying (pre-baking) was 200 nm. The silicon wafer coated with the resist composition was pre-baked on a direct hot plate at the temperature shown in the “PB” column of Table 1 for 60 seconds to form a resist film (composition layer). The silicon wafer on which the resist film was formed was exposed to light by changing the exposure dose stepwise using a mask for forming a line and space pattern (pitch 400 nm / line 100 nm) with an immersion exposure ArF excimer laser stepper [XT:1900Gi; manufactured by ASML, NA=1.35, 3 / 4 Annular XY polarization]. Note that ultrapure water was used as the immersion medium. After exposure, the silicon wafer was post-exposure baked on a hot plate for 60 seconds at the temperature shown in the "PEB" column of Table 1. The silicon wafer was then paddle developed for 60 seconds with a 2.38% aqueous tetramethylammonium hydroxide solution to obtain a resist pattern.

[0188] In the obtained resist pattern, the exposure amount at which the line pattern width became 100 nm was defined as effective sensitivity.

[0189] <Line Edge Roughness Evaluation (LER)> The resulting resist pattern was observed and measured with a scanning electron microscope for the amplitude of unevenness on the wall surface. The results are shown in Table 2. The values ​​in the table indicate the amplitude (nm). [Table 2] Compared with the comparative compositions 1 and 2, the fluctuation range of compositions 1 to 10 and 15 to 21 was small, and the line edge roughness (LER) evaluation was good.

[0190] <Resist pattern production and evaluation: Dry exposure evaluation> A composition for organic antireflective coating (ARC-29; manufactured by Nissan Chemical Industries, Ltd.) was applied to a silicon wafer and baked at 205° C. for 60 seconds to form an organic antireflective coating having a thickness of 78 nm. Next, the above-mentioned chemically amplified photoresist composition was spin-coated on the organic antireflective coating so that the film thickness after drying would be 85 nm. After the resist composition was applied, the obtained silicon wafer was pre-baked (PB) for 60 seconds on a direct hot plate at the temperature shown in the “PB” column of Table 1, as shown in Table 1. The silicon wafer thus formed with the film of the chemically amplified photoresist composition was exposed to light by changing the exposure amount stepwise using an ArF excimer stepper [FPA5000-AS3; manufactured by Canon Inc., NA=0.75, 2 / 3 Annular], using a mask for forming a line and space pattern (pitch 400 nm / line 100 nm). After exposure, the silicon wafer was post-exposure baked on a hot plate for 60 seconds at the temperature shown in the "PEB" column of Table 1. The silicon wafer was then paddle developed for 60 seconds with a 2.38% aqueous tetramethylammonium hydroxide solution to obtain a resist pattern.

[0191] In the obtained resist pattern, the exposure amount at which the line pattern width became 100 nm was defined as effective sensitivity.

[0192] <Line Edge Roughness Evaluation (LER)> The resulting resist pattern was observed and measured with a scanning electron microscope for the amplitude of unevenness on the wall surface. The results are shown in Table 3. The values ​​in the table indicate the amplitude (nm). [Table 3] Compared with the comparative compositions 3 and 4, the fluctuation range of compositions 11 to 14, 22, and 23 was small, and the line edge roughness (LER) evaluation was good. [Industrial Applicability]

[0193] INDUSTRIAL APPLICABILITY The resist composition of the present invention provides a resist pattern with excellent line edge roughness (LER), and is therefore suitable for semiconductor microfabrication and extremely useful industrially.

Claims

1. An acid generator; One or more resins containing a structural unit represented by formula (I), At least one of the resins containing a structural unit represented by formula (I) contains a structural unit represented by formula (a2-A), A resist composition, wherein at least one of the resins comprising a structural unit represented by formula (I) comprises a structural unit represented by formula (a2-D). [In formula (I), R １ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom. X １ represents a single bond, *-O-**, *-CO-O-**, *-O-CO-O-**, *-CO-NR ３ -**, *-NR ３ -CO-O-**, *-O-CO-NR ３ -** or *-Ax-Ph-Ay-**. R ３ 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 represents one type of bond selected from the group consisting of a single bond, an ether bond, a thioether bond, an ester bond, an amide bond, and a carbonate bond. Ay represents one type of bond selected from the group consisting of a single bond, an ether bond, a thioether bond, an ester bond, an amide bond, and a carbonate bond. * and ** represent binding sites, * represents R １ represents the bonding site with the carbon atom to which it is bonded. L １ represents a single bond or a hydrocarbon group having 1 to 36 carbon atoms which may have a substituent, and —CH 2 - is -O-, -S-, -SO ２ It may be replaced by --or --CO--. R Ａ represents a saturated hydrocarbon group having 1 to 12 carbon atoms. u1 represents an integer of 0 to 2, and when u1 is 2, a plurality of R Ａ are either the same or different. s1 represents 1 or 2. t1 represents 0 or 1, provided that the sum of s1 and t1 is 1 or 2. [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 ａ２９ May be replaced with -. R ａ２９ 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 multiple parentheses may be the same or different from each other. 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. [In formula (a2-D), R ａ２ represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom. 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 ａ３０ May be replaced with -. R ａ３０ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. L ２ represents a hydrocarbon group having 1 to 28 carbon atoms which may have a substituent, and the —CH 2 - is -O-, -S-, -SO ２ It may be replaced by --or --CO--. L ２１ represents a single bond or an alkanediyl group having 1 to 3 carbon atoms which may have a fluorine atom. R ｆ１ represents a fluorinated alkyl group having 1 to 8 carbon atoms. R ｆ２ represents a hydrogen atom or a fluorinated alkyl group having 1 to 6 carbon atoms, and the fluorinated alkyl group is L ２ may be bonded to form an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and the —CH 2 - may be replaced by -O-. nD2 represents an integer of 1 to 4. When nD2 is 2 or more, the groups in the parentheses may be the same or different.

2. X １ is a single bond or a group represented by the formula (X １ -1) ~Formula (X １ 2. The resist composition according to claim 1, wherein the aryl group is a group represented by any one of the groups represented by formula (I-10). [Formula (X １ -1) ~ Type (X １ -10) *, ** are binding sites, * is R １ represents the bonding site with the carbon atom to which it is bonded. Rx represents a halogen atom, a hydroxy group, a fluorinated alkyl group having 1 to 6 carbon atoms, an alkyl group having 1 to 18 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. mx represents an integer of 0 to 4. X ２０ is -O- or -NR ３ Represents -. R ３ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

3. L １ is a single bond, a chain hydrocarbon group having 1 to 4 carbon atoms (the —CH 2 - may be replaced by -O- or -CO-), a group formed by combining a chain hydrocarbon group having 1 to 4 carbon atoms with an alicyclic hydrocarbon group having 3 to 18 carbon atoms (the -CH 2 - may be replaced by -O- or -CO-, and -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 4 carbon atoms with an aromatic hydrocarbon group having 6 to 14 carbon atoms which may have a substituent (provided that the -CH 2 3. The resist composition according to claim 1, wherein - may be replaced by -O- or -CO-.

4. 3. The resist composition according to claim 1, wherein the structural unit represented by formula (a2-D) is one selected from the group consisting of a structural unit represented by formula (a2-D1), a structural unit represented by formula (a2-D2), a structural unit represented by formula (a2-D3), and a structural unit represented by formula (a2-D4). [In formula (a2-D1), formula (a2-D2), formula (a2-D3) and formula (a2-D4), R ａ２ , A ａ２１ , R ｆ１ , R ｆ２ , L ２１ , nD2 each independently have the same meaning as in formula (a2-D). R ａ２８ each independently represents a halogen atom, 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. ａ２８ is a methanediyl group, which may bridge the cyclohexyl ring. L ２２ represents a single bond or a (nD2+1)-valent hydrocarbon group having 1 to 3 carbon atoms. nD22 represents an integer of 0 to 4, nD23 represents 0 or 1, and nD24 represents an integer of 0 to 5, and 1≦nD2+nD22≦5 is satisfied. When nD22 or nD24 is 2 or more, a plurality of R ａ２７ may be the same or different.

5. 3. The resist composition according to claim 1, comprising: a first resin containing a structural unit represented by formula (I) and a structural unit represented by formula (a2-A); and a second resin containing a structural unit represented by formula (I) and a structural unit represented by formula (a2-D).

6. 3. The resist composition according to claim 1, comprising a resin containing a structural unit represented by formula (I), a structural unit represented by formula (a2-A), and a structural unit represented by formula (a2-D).

7. The resist composition according to claim 1 or 2, further comprising a third resin that includes a structural unit represented by formula (a4). [In formula (a4), R 41 represents a hydrogen atom or a methyl group. R 42 represents a saturated hydrocarbon group having 1 to 24 carbon atoms and containing a halogen atom, and the —CH 2 - may be replaced by -O- or -CO-.]

8. 3. The resist composition according to claim 1, wherein the acid generator comprises a salt represented by formula (B1) or a salt represented by formula (B2). [In formula (B1), L b1 represents a single bond or a (nb1+1)-valent hydrocarbon group which may have a substituent, and —CH 2 - is -O-, -S-, -CO- or -SO 2 It may be replaced with -. L b2 represents a single bond or a divalent hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and the —CH 2 - is -O-, -S-, -CO- or -SO 2 It may be replaced with -. 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 - is -O-, -S-, -SO 2 It may be replaced by --or --CO--. nb1 represents an integer of 1 to 6. When nb1 is 2 or more, the groups in the parentheses may be the same or different. Z1 ＋ represents an organic cation. [In formula (B2), A １ represents a nitrogen atom or a carbon atom. L ｂ２’ represents a single bond or a hydrocarbon group having 1 to 24 carbon atoms which may have a substituent, and —CH 2 - is -O-, -S-, -CO- or -SO 2 It may be replaced by -. 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 - is -O-, -S-, -CO- or -SO 2 It may be replaced by -. nb5 represents an integer of 2 or 3, and when A is a nitrogen atom, nb5 is 2, and when A is a carbon atom, nb5 is 3; ｂ２’ -Y ｂ１’ may be the same or different, and two -SO 2 -L ｂ２’ -Y ｂ１’ Together, A １ may form a ring comprising: Z2 ＋ represents an organic cation.

9. 3. The resist composition according to claim 1, further comprising a salt capable of generating an acid having a weaker acidity than the acid generated from the acid generator.

10. (1) A step of applying the resist composition according to claim 1 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:

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