Resist composition and method for producing resist pattern

Abstract

To provide a resin and a resist composition capable of producing a resist pattern with good resolution.SOLUTION: The resin contains a structural unit represented by formula (I) and a structural unit represented by formula (III), and the resist composition contains the resin. [X11 represents a single bond, -CO-O-* or the like; X12 represents a single bond, *-O-L11- or the like; L11 represents an alkanediyl group; Ar11 represents an optionally substituted aromatic hydrocarbon group; and A11 represents a single bond or *-CO-O-.]SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a resin, 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 containing a resin having the following structural unit. TIFF0007672214000001.tif3263

[0003] Patent Document 2 describes a resist composition containing a resin having the following structural unit. TIFF0007672214000002.tif34138 [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2002-214788 A [Patent Document 2] JP 2016-089125 A Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a resin that forms a resist pattern with better resolution than a resist pattern formed using a resist composition containing the above resin. [Means for solving the problem]

[0006] The present invention includes the following inventions. [1] A resin containing a structural unit represented by formula (I) and a structural unit represented by formula (III). TIFF0007672214000003.tif3489 [In formula (I), R 11represents a hydrogen atom or a methyl group. R 12 , R 13 and R 14 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof, or R 12 and R 13 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. X 11 is a single bond, -CO-O-* or -CO-NR 15 -*, where * is Ar 11 represents a bond with R 15 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. X 12 is a single bond, *-OL 11 -or*-CO-OL 12 -, * is Ar 11 represents a bond with L 11 and L 12 each independently represents an alkanediyl group having 1 to 4 carbon atoms. Ar 11 represents an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent.] TIFF0007672214000004.tif4758 [In formula (III), R 3 represents a hydrogen atom or a methyl group. A 11 is a single bond or * -CO-O-, * is -R 3 represents the bonding site with the carbon atom to which it is bonded. R 4 represents a halogen atom, a hydroxy group, a haloalkyl group having 1 to 4 carbon atoms, or an alkyl group having 1 to 12 carbon atoms, and -CH2- contained in the alkyl group may be replaced by -O- or -CO-. mi represents an integer of 1 to 3. ni represents an integer from 0 to 4. When ni is 2 or more, multiple R 4may be the same or different, provided that mi+ni≦5. [2]X 11 and X 12 and both of said groups are single bonds. [3] The resin according to [1] or [2], further comprising a structural unit represented by formula (a2-A). TIFF0007672214000005.tif4653[In formula (a2-A), R a50 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a51 represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A a50 is a single bond or * -X a51 -(A a52 -X a52 ) nb - stands for -R. a50 represents the bonding site with the carbon atom to which it is bonded. A a52 represents an alkanediyl group having 1 to 6 carbon atoms. X a51 and X a52 each independently represents -O-, -CO-O-, or -O-CO-. nb represents 0 or 1. mb represents an integer of 0 to 4. When mb is an integer of 2 or more, a plurality of R a51 may be the same or different.] [4] The resin according to any one of [1] to [3], further comprising at least one selected from the group consisting of a structural unit represented by formula (a1-1) and a structural unit represented by formula (a1-2). TIFF0007672214000006.tif46102 [In formula (a1-1) and formula (a1-2), L a1 and L a2 are each independently -O- or *-O-(CH2) k1 It represents --CO--O--, k1 represents an integer of 1 to 7, and * represents a bond to --CO--. R a4 and R a5 each independently represents a hydrogen atom or a methyl group. R a6 and R a7 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof. m1 represents an integer of 0 to 14. n1 represents an integer of 0 to 10. n1' represents an integer of 0 to 3. [5] A resist composition comprising the resin according to any one of [1] to [4] and an acid generator. [6] The resist composition according to [5], wherein the acid generator contains a salt represented by formula (B1): TIFF0007672214000007.tif2859[In formula (B1), Q b1 and Q b2 each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. L b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, in which -CH2- may be replaced by -O- or -CO-, and a hydrogen atom in the divalent saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group. Y represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 24 carbon atoms, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S(O)2- or -CO-. Z + represents an organic cation. [7] The resist composition according to [5] or [6], further comprising a salt capable of generating an acid having a weaker acidity than the acid generated from the acid generator. [8] (1) A step of applying the resist composition according to any one of [5] to [7] onto a substrate; (2) A step of drying the applied composition to form a composition layer; (3) exposing the composition layer to light; (4) heating the composition layer after exposure; and (5) A method for producing a resist pattern, comprising the step of developing the composition layer after heating. Effect of the Invention

[0007] By using a resist composition that uses the resin of the present invention, a resist pattern with excellent resolution can be produced. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] In this specification, "(meth)acrylic monomer" means at least one selected from the group consisting of monomers having the structure "CH2=CH-CO-" and monomers having the structure "CH2=C(CH3)-CO-". Similarly, "(meth)acrylate" and "(meth)acrylic acid" mean "at least one selected from the group consisting of acrylate and methacrylate" and "at least one selected from the group consisting of acrylic acid and methacrylic acid", respectively. When a structural unit having "CH2=C(CH3)-CO-" or "CH2=CH-CO-" is exemplified, a structural unit having both groups is also exemplified. In addition, in the group described in this specification, either a linear structure or a branched structure may be used for those that can have both. "Combined group" means a group in which two or more of the exemplified groups are bonded, and the valence of the group 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 being polymerized to a -CC- group. Where stereoisomers exist, all stereoisomers are included. 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.

[0009] 〔resin〕 The resin of the present invention is a resin (hereinafter, sometimes referred to as "resin (A)") that contains a structural unit represented by formula (I) (hereinafter, sometimes referred to as structural unit (I)) and a structural unit represented by formula (III) (hereinafter, sometimes referred to as structural unit (III)).

[0010] <Structural unit (I)> The structural unit (I) is represented by the following formula: TIFF0007672214000008.tif3489 [In formula (I), R 11 represents a hydrogen atom or a methyl group. R 12 , R 13 and R 14 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof, or R 12 and R 13 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. X 11 is a single bond, -CO-O-* or -CO-NR 15 -*, where * is Ar 11 represents a bond with R 15 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. X 12 is a single bond, *-OL 11 -or*-CO-OL 12 -, * is Ar 11 represents a bond with L 11 and L 12 each independently represents an alkanediyl group having 1 to 4 carbon atoms. Ar 11 represents an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent.]

[0011] R 12 , R 13 and R 14 Examples of the alkyl group in R include a methyl group, an ethyl group, a propyl group, a butyl group, a heptyl group, a hexyl group, a heptyl group, and an octyl group. 12 , R 13 and R 14 The alkyl group preferably has 1 to 6 carbon atoms, and more preferably has 1 to 3 carbon atoms. R 12 , R 13 and R 14 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 octynyl group, an isooctynyl group, and a nonenyl group. R 12 , R 13 and R 14 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 12 , R 13 and R 14 The alicyclic hydrocarbon group preferably has 3 to 16 carbon atoms, and more preferably has 3 to 12 carbon atoms. TIFF0007672214000009.tif10159R 12 , R 13 and R 14 Examples of the aromatic hydrocarbon group in R include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. 12 , R 13 and R 14 The aromatic hydrocarbon group preferably has 6 to 14 carbon atoms, and more preferably 6 to 10 carbon atoms. 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. R 12 and R 13 When they are bonded to each other to form an alicyclic hydrocarbon group together with the carbon atoms to which they are attached, -C(R 12 )(R 13 )(R 14 ) includes the following groups. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 16, and more preferably 3 to 12. * represents the bonding site with -O-. TIFF0007672214000010.tif32159

[0012] L 11 and L 12 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 butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, and a 2-methylpropane-1,2-diyl group. L 11 and L 12 are each independently preferably a methylene group or an ethylene group, and more preferably a methylene group. X 11 is preferably a single bond or -CO-O-*, and more preferably a single bond. X 12is preferably a single bond or *-OL 11 -, and more preferably a single bond.

[0013] Ar 11 Examples of the aromatic hydrocarbon group in include a phenylene 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, 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. Ar 11 Examples of the substituent that may be possessed by the alkyl group include a hydroxy group, a halogen atom, a cyano group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkoxycarbonyl group having 2 to 13 carbon atoms, an alkylcarbonyl group having 2 to 13 carbon atoms, an alkylcarbonyloxy group having 2 to 13 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 10 carbon atoms, or a combination thereof. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms. Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group. Examples of the alkoxy group having 1 to 12 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, and a dodecyloxy group. The alkoxycarbonyl group having 2 to 13 carbon atoms, the alkylcarbonyl group having 2 to 13 carbon atoms, and the alkylcarbonyloxy group having 2 to 13 carbon atoms represent a group in which a carbonyl group or a carbonyloxy group is bonded to the above-mentioned alkyl group or alkoxy group. Examples of the alkoxycarbonyl group having 2 to 13 carbon atoms include a methoxycarbonyl group, an ethoxycarbonyl group, and a butoxycarbonyl group. Examples of the alkylcarbonyl group having 2 to 13 carbon atoms include an acetyl group, a propionyl group, and a butyryl group. Examples of the alkylcarbonyloxy group having 2 to 13 carbon atoms include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alicyclic hydrocarbon group having 3 to 12 carbon atoms may be either monocyclic or polycyclic, and examples thereof include the groups shown below, where ** represents a bond to the aromatic hydrocarbon group. TIFF0007672214000011.tif16157 Examples of the aromatic hydrocarbon group having 6 to 10 carbon atoms include a phenyl group and a naphthyl group. Examples of the combined group in the substituent of the aromatic hydrocarbon group include a group combining a hydroxy group with an alkyl group having 1 to 12 carbon atoms, a group combining an alkoxy group having 1 to 12 carbon atoms with an alkoxy group having 1 to 12 carbon atoms, and a group combining an alkyl group having 1 to 12 carbon atoms with an aromatic hydrocarbon group having 6 to 10 carbon atoms. Examples of the group combining a hydroxy group with an alkyl group having 1 to 12 carbon atoms include hydroxyalkyl groups having 1 to 12 carbon atoms, such as a hydroxymethyl group and a hydroxyethyl group. Examples of the group formed by combining an alkoxy group having 1 to 12 carbon atoms with an alkoxy group having 1 to 12 carbon atoms include an alkoxyalkoxy group having 2 to 24 carbon atoms, such as an ethoxyethoxy group. Examples of the group formed by combining an alkyl group having 1 to 12 carbon atoms with an aromatic hydrocarbon group having 6 to 10 carbon atoms include aralkyl groups having 7 to 22 carbon atoms, such as a benzyl group. Ar 11 is preferably an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, more preferably a phenylene group or a naphthylene group, and even more preferably a phenylene group.

[0014] Examples of the structural unit (I) include structural units represented by formulas (I-1) to (I-36), preferably structural units represented by formulas (I-1) to (I-9), more preferably structural units represented by formulas (I-1), (I-2), (I-4), (I-5), (I-7) or (I-8), and further preferably structural units represented by formulas (I-1), (I-2), (I-5) or (I-8). TIFF0007672214000012.tif231142

[0015] TIFF0007672214000013.tif218137

[0016] TIFF0007672214000014.tif189147

[0017] In the structural units represented by formulae (I-1) to (I-9), (I-16) to (I-21), and (I-28) to (I-30), R 11 and the structural units represented by formulae (I-10) to (I-15), (I-22) to (I-27), and (I-31) to (I-36), respectively, in which a hydrogen atom corresponding to R 11 The structural unit (I) also includes a structural unit in which a methyl group corresponding to the following formula is replaced with a hydrogen atom.

[0018] In terms of the shape of the resist pattern, the content of the structural unit (I) in the resin (A) is preferably 3 to 80 mol %, more preferably 5 to 75 mol %, and even more preferably 10 to 70 mol %, based on all structural units in the resin (A). The resin (A) may contain only one type of structural unit (I), or may contain two or more types.

[0019] <Structural unit (III)> TIFF0007672214000015.tif4758 [wherein all symbols have the same meanings as defined above.] In formula (III), R 3 is preferably a hydrogen atom. R 4 Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R 4 The haloalkyl group having 1 to 4 carbon atoms represents an alkyl group having 1 to 4 carbon atoms and a halogen atom, and examples thereof include a chloromethyl group, a bromomethyl group, a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, and a perfluorobutyl group. R 4 Examples of the alkyl group having 1 to 12 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, an octyl group, and a nonyl group. The number of carbon atoms in the alkyl group is preferably 1 to 9, more preferably 1 to 6, and further preferably 1 to 4. R 4 When -CH2- in the alkyl group represented by the formula (I) is replaced with -O- or -CO-, the number of carbon atoms before the replacement is the total number of carbon atoms in the alkyl group. 4 may have a hydroxy group (a group in which -CH2- in a methyl group is replaced with -O-), a carboxy group (a group in which -CH2-CH2- in an ethyl group is replaced with -O-CO-), an alkoxy group (a group in which -CH2- at any position in an alkyl group is replaced with -O-), an alkoxycarbonyl group (a group in which -CH2-CH2- at any position in an alkyl group is replaced with -O-CO-), an alkylcarbonyl group (a group in which -CH2- at any position in an alkyl group is replaced with -CO-), or an alkylcarbonyloxy group (a group in which -CH2-CH2- at any position in an alkyl group is replaced with -CO-O-). The alkoxy group includes an alkoxy group having 1 to 11 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 6, and more preferably 1 to 4. The alkoxycarbonyl group includes an alkoxycarbonyl group having 2 to 11 carbon atoms, such as a methoxycarbonyl group, an ethoxycarbonyl group, and a butoxycarbonyl group. The alkylcarbonyl group includes an alkylcarbonyl group having 2 to 12 carbon atoms, such as an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyloxy group includes an alkylcarbonyloxy group having 2 to 11 carbon atoms, such as an acetyloxy group, a propionyloxy group, and a butyryloxy group. The number of carbon atoms in the alkoxycarbonyl group is preferably 2 to 6, and more preferably 2 to 4. The number of carbon atoms in the alkylcarbonyl group is preferably 2 to 6, and more preferably 2 to 4. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2 to 6, and more preferably 2 to 4. R 4 Among them, a halogen atom, a haloalkyl group having 1 to 4 carbon atoms, or an alkyl group having 1 to 12 carbon atoms (-CH2- contained in the alkyl group may be replaced with -O- or -CO-), is preferable, and a fluorine atom, a haloalkyl group having 1 to 3 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-), is more preferable. mi is preferably 1 or 2. ni is preferably an integer of 0 to 2, and more preferably 0.

[0020] Examples of the structural unit (III) include the structural units shown below. TIFF0007672214000016.tif163152

[0021] In the structural units represented by formulae (III-1) to (III-8), R 3 In the structural units represented by formulae (III-9) to (III-16), the structural unit in which the hydrogen atom corresponding to the formula is replaced by a methyl group is also represented by R 3 Specific examples of the structural unit (III) include structural units in which a methyl group corresponding to the following formula is replaced with a hydrogen atom. Among these, the structural units represented by formulae (III-1) to (III-8) are preferred, the structural units represented by formulae (III-1) to (III-4) are more preferred, and the structural unit represented by formula (III-1) is even more preferred.

[0022] The content of the structural unit (III) in the resin (A) is preferably 3 to 80 mol %, more preferably 5 to 70 mol %, even more preferably 5 to 60 mol %, and still more preferably 5 to 50 mol %, based on all structural units. The resin (A) may contain only one type of structural unit (III), or may contain two or more types.

[0023] The resin (A) of the present invention may be a polymer containing one or more structural units other than the structural unit (I) and the structural unit (III). Examples of structural units other than the structural unit (I) and the structural unit (III) include structural units having an acid labile group other than the structural unit (I) and the structural unit (III) (hereinafter sometimes referred to as "structural unit (a1)"); structural units having a halogen atom other than structural units having an acid labile group (hereinafter sometimes referred to as "structural unit (a4)"); structural units not having an acid labile group other than the structural unit (I) (hereinafter sometimes referred to as "structural unit (s)"); structural units having a non-leaving hydrocarbon group (hereinafter sometimes referred to as "structural unit (a5)"); etc. Here, the acid labile group means a group having a leaving group, which is released by contact with an acid to form a hydrophilic group (e.g., a hydroxyl group or a carboxyl group).

[0024] <Structural unit (a1)> The structural unit (a1) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as "monomer (a1)"). The acid labile group contained in the resin (A) is preferably a group represented by formula (1) (hereinafter also referred to as group (1)) and / or a group represented by formula (2) (hereinafter also referred to as group (2)). TIFF0007672214000017.tif1988[In formula (1), R a1 , R a2 and R a3 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a 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, a non-aromatic hydrocarbon ring having 3 to 20 carbon atoms. ma and na each independently represent 0 or 1, and at least one of ma and na represents 1. * denotes a binding site.] TIFF0007672214000018.tif2171[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 a heterocycle having 3 to 20 carbon atoms together with the carbon atom to which they are bonded and X, and -CH2- contained in the hydrocarbon group and the heterocycle may be replaced by -O- or -S-. X represents an oxygen atom or a sulfur atom. na′ represents 0 or 1. * denotes a binding site.]

[0025] 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 a3Examples 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 octynyl group, an isooctynyl group, and a nonenyl group. R a1 , 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. TIFF0007672214000019.tif10150R 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 Ra2 When they are bonded to each other to form a non-aromatic hydrocarbon ring, -C(R a1 )(R a2 )(R a3 ) includes the following rings. The non-aromatic hydrocarbon ring preferably has 3 to 12 carbon atoms. * represents the bonding site with -O-. TIFF0007672214000020.tif33148

[0026] 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. The alkyl group and the alicyclic hydrocarbon group are R a1 , R a2 and R a3 Examples of the groups include the same groups as those listed in the above. Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. Examples of the combined group include a group 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. R a2’ and R a3’ When they are bonded to each other to form a heterocycle together with the carbon atom to which they are bonded and X, -C(R a1’ )(R a2’ )-XRa3’ Examples of the ring include the following: * represents a binding site. TIFF0007672214000021.tif18130R a1’ and R a2’ At least one of these is preferably a hydrogen atom. na' is preferably 0.

[0027] 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), R a1 , R a2 together with the carbon atom to which they are attached form an adamantyl group, R a3 is an alkyl group, ma=0, and na=1. In formula (1), R a1 and R a2 are each independently an alkyl group; R a3 is an adamantyl group, ma=0, and na=1. Specific examples of the group (1) include the following groups: * represents a binding site. TIFF0007672214000022.tif171163

[0028] Specific examples of the group (2) include the following groups: * represents a bonding site. TIFF0007672214000023.tif67162

[0029] 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.

[0030] Of the (meth)acrylic monomers having an acid labile group, preferred are those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms. By using a resin (A) having a structural unit derived from a monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group in a resist composition, the resolution of the resist pattern can be improved.

[0031] 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, at least one structural unit 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. TIFF0007672214000024.tif46147 [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 or a methyl group. 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. R a6 and R a7 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these. m1 represents an integer of 0 to 14. n1 represents an integer of 0 to 10. n1' represents an integer of 0 to 3.

[0032] R a01 , R a4 and R a5 is preferably a methyl group. L a01 , L a1 and L a2 is preferably an oxygen atom or *-O-(CH2) k01 It is -CO-O- (wherein k01 is preferably an integer of any one of 1 to 4, more preferably 1), and more preferably an oxygen atom. R a02 , R a03 , R a04 , R a6 and R a7 The alkyl group, alkenyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group and combinations thereof in the formula (1) are R a1 , R a2 and R a3 Examples of the groups include the same groups as those listed in the above. R a02 , R a03 , and R a04 The alkyl group in the formula (I) is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. R a6 and 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 is preferably an alkenyl group having 2 to 6 carbon atoms, and more preferably an ethenyl group, a propenyl group, an isopropenyl group, or a butenyl group. R a02 , R a03 , R a04, R a6 and R a7 The alicyclic hydrocarbon group preferably has 5 to 12 carbon atoms, and more preferably 5 to 10 carbon atoms. R a02 , R a03 , R a04 , R a6 and R a7 The aromatic hydrocarbon group preferably has 6 to 12 carbon atoms, and more preferably 6 to 10 carbon atoms. In the group in which an alkyl group and an alicyclic hydrocarbon group are combined, the total number of carbon atoms in the combination of the alkyl group and the alicyclic hydrocarbon group is preferably 18 or less. In the group in which an alkyl group and an aromatic hydrocarbon group are combined, the total number of carbon atoms in the combination of the alkyl group and the aromatic hydrocarbon group is preferably 18 or less. R a02 and R a03 is preferably an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a phenyl group or a naphthyl group. R a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. R a6 and R a7 are each independently preferably an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an aromatic hydrocarbon group having 6 to 12 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group, a phenyl group, or a naphthyl group, and further preferably an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group, or a phenyl group. m1 is preferably an integer of 0 to 3, and more preferably 0 or 1. n1 is preferably an integer of 0 to 3, and more preferably 0 or 1. n1' is preferably 0 or 1.

[0033] Examples of the structural unit (a1-0) include a structural unit represented by any one of formulas (a1-0-1) to (a1-0-18) and R a01 and structural units in which a methyl group corresponding to the formula (a1-0-1) is replaced with a hydrogen atom, and structural units represented by any one of formulas (a1-0-1) to (a1-0-10), (a1-0-13) and (a1-0-14) are preferred. TIFF0007672214000025.tif98164

[0034] 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) are a4 In the above formula (a1-1-1), a structural unit in which a methyl group is replaced with a hydrogen atom is preferred, and a structural unit represented by any one of formulas (a1-1-1) to (a1-1-4) is more preferred. TIFF0007672214000026.tif41169

[0035] The structural unit (a1-2) includes a structural unit represented by any one of formulas (a1-2-1) to (a1-2-12) 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 (a1-2-12) are preferred. TIFF0007672214000027.tif65157

[0036] When the resin (A) contains the structural unit (a1-0), the content thereof is usually 5 to 80 mol %, preferably 5 to 75 mol %, and more preferably 10 to 70 mol %, based on all structural units in the resin (A). When the resin (A) contains the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is usually 10 to 90 mol %, preferably 15 to 85 mol %, more preferably 20 to 80 mol %, even more preferably 20 to 75 mol %, and still more preferably 20 to 70 mol %, based on all structural units in the resin (A).

[0037] 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)"). TIFF0007672214000028.tif4766[In formula (a1-4), R a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a33 represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A a30 is a single bond or * -X a31 -(A a32 -X a32 ) nc - stands for -R. a32 represents the bonding site with the carbon atom to which it is bonded. A a32 represents an alkanediyl group having 1 to 6 carbon atoms. X a31 and X a32 each independently represents -O-, -CO-O-, or -O-CO-. nc represents 0 or 1. la represents an integer of 0 to 4. When la is an integer of 2 or more, a plurality of R a33 may be the same or different from each other. R a34 and R a35each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms; R a36 represents a hydrocarbon group having 1 to 20 carbon atoms, or R a35 and R a36 are bonded to each other to form 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-.]

[0038] R a32 and R a33 Examples of the halogen atom in include a fluorine atom, a chlorine atom, and a bromine atom. R a32 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in the formula (I) include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, a hexyl group, and a perfluorohexyl group. R a32 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and further preferably a hydrogen atom or a methyl group. R a33 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. R a33 Examples of the alkoxy group in include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, and a hexyloxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and further preferably a methoxy group. Ra33 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 a33 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 a33 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 a33 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 a33 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.

[0039] *-X a31 -(A a32 -X a32 ) nc- includes *-O-, *-CO-O-, *-O-CO-, *-CO-OA a32 -CO-O-, *-O-CO-A a32 -O-, *-OA a32 -CO-O-, *-CO-OA a32 -O-CO-, *-O-CO-A a32 -O-CO-, and *-CO-O- and *-CO-OA are particularly well known. a32 -CO-O- or *-OA a32 -CO-O- is preferred.

[0040] A a32 Examples of the alkanediyl group in the formula (I) include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. A a32 is preferably a methylene group or an ethylene group.

[0041] A a30 is a single bond, *-CO-O- or *-CO-OA a32 -CO-O- is preferred, a single bond, *-CO-O- or *-CO-O-CH2-CO-O- is more preferred, and a single bond or *-CO-O- is even more preferred.

[0042] la is preferably 0, 1 or 2, more preferably 0 or 1, and even more preferably 0. R a34 , R a35 and R a36 Examples of the hydrocarbon group in include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group 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): TIFF0007672214000029.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.

[0043] 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 a36The 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. -OC(R a34 )(R a35 )-OR a36 is eliminated on contact with an acid (e.g., p-toluenesulfonic acid) to form a hydroxy group. -OC(R a34 )(R a35 )-OR a36 is preferably bonded to the o-position or p-position of the benzene ring, and more preferably bonded to the p-position.

[0044] 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 (a1-4-18) and R in the structural unit (a1-4) are a32 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. TIFF0007672214000030.tif103166 When resin (A) contains the structural unit (a1-4), the content thereof is preferably 1 to 60 mol %, more preferably 2 to 50 mol %, and even more preferably 3 to 40 mol %, based on the total of all structural units in resin (A).

[0045] 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)"). TIFF0007672214000031.tif4658 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 the binding site with L 51 , L 52 , L 53 and L 54 each independently represents -O- or -S-. s1 represents an integer of 1 to 3. s1' represents an integer of 0 to 3.

[0046] 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-.

[0047] 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. TIFF0007672214000032.tif33133When the resin (A) contains the structural unit (a1-5), the content thereof is preferably 1 to 50 mol %, more preferably 3 to 45 mol %, even more preferably 5 to 40 mol %, and even more preferably 5 to 30 mol %, based on all structural units of the resin (A).

[0048] Further, examples of the structural unit (a1) include the following structural units. TIFF0007672214000033.tif31162 When resin (A) contains structural units such as (a1-3-1) to (a1-3-7) above, the content thereof is preferably 10 to 95 mol %, more preferably 15 to 90 mol %, even more preferably 20 to 85 mol %, even more preferably 20 to 70 mol %, and particularly preferably 20 to 60 mol %, based on the total structural units of resin (A).

[0049] Further, examples of the structural unit (a1) include the following structural units. TIFF0007672214000034.tif5295 When resin (A) contains structural units such as (a1-6-1) to (a1-6-3) above, the content thereof is preferably 10 to 60 mol %, more preferably 15 to 55 mol %, even more preferably 20 to 50 mol %, even more preferably 20 to 45 mol %, and particularly preferably 20 to 40 mol %, based on the total structural units of resin (A).

[0050] Structural unit(s) The structural unit (s) is derived from a monomer having no acid labile group (hereinafter, may be referred to as "monomer (s)"). As the monomer from which the structural unit (s) is derived, a monomer having no acid labile group known in the resist field can be used. The structural unit (s) preferably has a hydroxy group or a lactone ring. The use of a resin having a structural unit having a hydroxy group and no acid labile group (hereinafter sometimes referred to as "structural unit (a2)") and / or a structural unit having a lactone ring and no acid labile group (hereinafter sometimes referred to as "structural unit (a3)") in the resist composition of the present invention can improve the resolution of the resist pattern and the adhesion to the substrate.

[0051] <Structural unit (a2)> The hydroxy group contained in the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group. When a resist pattern is produced from the resist composition of the present invention, when a high energy ray such as a KrF excimer laser (248 nm), an electron beam, or EUV (extreme ultraviolet light) is used as an exposure light source, the structural unit (a2) having a phenolic hydroxyl group is preferable, and the structural unit (a2-A) described below is more preferable. When an ArF excimer laser (193 nm) or the like is used, the structural unit (a2) having an alcoholic hydroxyl group is preferable, and the structural unit (a2-1) described below is more preferable. The structural unit (a2) may contain one type alone or two or more types.

[0052] In the structural unit (a2), an example of a structural unit having a phenolic hydroxy group is a structural unit represented by formula (a2-A) (hereinafter, may be referred to as "structural unit (a2-A)"). TIFF0007672214000035.tif4651[In formula (a2-A), R a50 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a51represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A a50 is a single bond or *-X a51 -(A a52 -X a52 ) nb - stands for -R. a50 represents the bond position with respect to the carbon atom to which it is bonded. A a52 represents an alkanediyl group having 1 to 6 carbon atoms. X a51 and X a52 each independently represents -O-, -CO-O-, or -O-CO-. nb represents 0 or 1. mb represents an integer of 0 to 4. When mb is an integer of 2 or more, a plurality of R a51 may be the same or different.]

[0053] R a50 and R a51 Examples of the halogen atom in include a fluorine atom, a chlorine atom, and a bromine atom. R a50 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in the formula (I) include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, a hexyl group, and a perfluorohexyl group. R a50is 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. R a51 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and further preferably a methyl group. R a51 Examples of the alkoxy group in include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, and a tert-butoxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and further preferably a methoxy group. R a51 Examples of the alkoxyalkyl group in the formula (I) include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and further preferably a methoxymethyl group. R a51 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 a51 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 a51In 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 a51 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group, and further preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group.

[0054] *-X a51 -(A a52 -X a52 ) nb - includes *-O-, *-CO-O-, *-O-CO-, *-CO-OA a52 -CO-O-, *-O-CO-A a52 -O-, *-OA a52 -CO-O-, *-CO-OA a52 -O-CO-, *-O-CO-A a52 -O-CO-, and *-CO-O- and *-CO-OA are particularly well known. a52 -CO-O- or *-OA a52 -CO-O- is preferred.

[0055] A a52 Examples of the alkanediyl group in the formula (I) include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. A a52 is preferably a methylene group or an ethylene group.

[0056] Aa50 is a single bond, *-CO-O- or *-CO-OA a52 -CO-O- is preferred, a single bond, *-CO-O- or *-CO-O-CH2-CO-O- is more preferred, and a single bond or *-CO-O- is even more preferred.

[0057] mb is preferably 0, 1 or 2, more preferably 0 or 1, and even more preferably 0. The hydroxy group is preferably bonded to the o- or p-position of the benzene ring, and more preferably to the p-position.

[0058] Examples of the structural unit (a2-A) include structural units derived from monomers described in JP-A-2010-204634 and JP-A-2012-12577.

[0059] The structural unit (a2-A) includes structural units represented by formulae (a2-2-1) to (a2-2-16) and R in the structural unit (a2-A) in the structural units represented by formulae (a2-2-1) to (a2-2-16). a50 The structural unit (a2-A) includes a structural unit represented by formula (a2-2-1), a structural unit represented by formula (a2-2-3), a structural unit represented by formula (a2-2-6), a structural unit represented by formula (a2-2-8), and a structural unit represented by formula (a2-2-12) to (a2-2-14), and in these structural units, R in the structural unit (a2-A) can be exemplified. a50 It is 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. TIFF0007672214000036.tif57169 When the structural unit (a2-A) is contained in the resin (A), the content of the structural unit (a2-A) is preferably 1 to 80 mol %, more preferably 3 to 70 mol %, even more preferably 5 to 60 mol %, and still more preferably 10 to 50 mol %, based on all structural units. The structural unit (a2-A) can be incorporated into the resin (A) by, for example, polymerizing the structural unit (a1-4) and then treating with an acid such as p-toluenesulfonic acid. Alternatively, the structural unit (a2-A) can be incorporated into the resin (A) by polymerizing the structural unit (a1-4) and then treating with an alkali such as tetramethylammonium hydroxide.

[0060] An example of the structural unit (a2) having an alcoholic hydroxy group is a structural unit represented by formula (a2-1) (hereinafter sometimes referred to as "structural unit (a2-1)"). TIFF0007672214000037.tif4157 formula (a2-1), L a3 is -O- or *-O-(CH2) k2 represents -CO-O-, k2 represents an integer of 1 to 7. * represents the bonding position with -CO-. R a14 represents a hydrogen atom or a methyl group. R a15 and R a16 each independently represents a hydrogen atom, a methyl group, or a hydroxy group. o1 represents an integer of 0 to 10.

[0061] In formula (a2-1), L a3 is preferably -O-, -O-(CH2) f1 It is -CO-O- (wherein f1 represents an integer of 1 to 4), and more preferably -O-. R a14 is preferably a methyl group. R a15 is preferably a hydrogen atom. R a16 is preferably a hydrogen atom or a hydroxy group. o1 is preferably an integer of 0 to 3, and more preferably 0 or 1.

[0062] Examples of the structural unit (a2-1) include structural units derived from monomers described in JP 2010-204646 A. A structural unit represented by any one of formulas (a2-1-1) to (a2-1-6) is preferred, a structural unit represented by any one of formulas (a2-1-1) to (a2-1-4) is more preferred, and a structural unit represented by formula (a2-1-1) or formula (a2-1-3) is even more preferred. TIFF0007672214000038.tif48132 When the resin (A) contains the structural unit (a2-1), the content thereof is usually 1 to 45 mol %, preferably 1 to 40 mol %, more preferably 1 to 35 mol %, even more preferably 1 to 20 mol %, and still more preferably 1 to 10 mol %, based on all structural units of the resin (A).

[0063] <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)).

[0064] 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. TIFF0007672214000039.tif50159[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 and R a20 each independently represents a hydrogen atom or a methyl group. R a24 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.]

[0065] 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 a24Examples of the halogen atom in include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. 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 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.

[0066] 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.

[0067] 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 a23 are each independently preferably a carboxy group, a cyano group, or a methyl group. p1, q1 and r1 each independently represent an integer of preferably 0 to 2, and more preferably 0 or 1.

[0068] 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 -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)'. TIFF0007672214000040.tif4052 (in the formula, R a24 , L a7 has the same meaning as above.)

[0069] 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.

[0070] TIFF0007672214000041.tif118168

[0071] When the resin (A) contains the structural unit (a3), the total content thereof is usually 1 to 70 mol %, preferably 3 to 65 mol %, and more preferably 5 to 60 mol %, based on all structural units in the resin (A). Furthermore, the content of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3) or the structural unit (a3-4) is preferably from 1 to 60 mol %, more preferably from 3 to 50 mol %, and even more preferably from 5 to 50 mol %, based on the total structural units of the resin (A).

[0072] <Structural unit (a4)> Examples of the structural unit (a4) include the following structural units. TIFF0007672214000042.tif2757[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-.] R 42 Examples of the saturated hydrocarbon group represented by the formula (I) include chain saturated hydrocarbon groups, monocyclic or polycyclic alicyclic saturated hydrocarbon groups, and groups formed by combining these groups.

[0073] Examples of the chain saturated hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group. Examples of the monocyclic or polycyclic alicyclic saturated hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; and polycyclic alicyclic saturated hydrocarbon groups such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bonding site): TIFF0007672214000043.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.

[0074] Examples of the structural unit (a4) include a structural unit represented by formula (a4-0), a structural unit represented by formula (a4-1), and a structural unit represented by formula (a4-4). TIFF0007672214000044.tif4147[In formula (a4-0), R 54 represents a hydrogen atom or a methyl group. L 4a represents a single bond or an alkanediyl group having 1 to 4 carbon atoms. L 3a represents a perfluoroalkanediyl group having 1 to 8 carbon atoms or a perfluorocycloalkanediyl group having 3 to 12 carbon atoms. R 64 represents a hydrogen atom or a fluorine atom.

[0075] L 4a Examples of the alkanediyl group in the formula (I) include linear alkanediyl groups such as a methylene group, an ethylene group, a propane-1,3-diyl group, and a butane-1,4-diyl group, and branched alkanediyl groups such as an ethane-1,1-diyl group, a propane-1,2-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, and a 2-methylpropane-1,2-diyl group.

[0076] L 3aExamples 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 3a Examples of the perfluorocycloalkanediyl group in the formula (I) include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, and a perfluoroadamantanediyl group.

[0077] L 4a is preferably a single bond, a methylene group, or an ethylene group, and more preferably a single bond or a methylene group. L 3a is preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, and more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

[0078] The structural unit (a4-0) includes the structural units shown below and R in the structural unit (a4-0) in the structural units shown below. 54 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. TIFF0007672214000045.tif96166

[0079] TIFF0007672214000046.tif4867[In formula (a4-1), R a41 represents a hydrogen atom or a methyl group. R a42 represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. A a41 represents an optionally substituted alkanediyl group having 1 to 6 carbon atoms or a group represented by formula (a-g1), a41 and R a42 At least one of the groups has a halogen atom (preferably a fluorine atom) as a substituent. TIFF0007672214000047.tif1592 [In formula (a-g1), s represents 0 or 1. A a42 and A a44 each independently represents a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. A a43 represents a single bond or a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. X a41 and X a42 each independently represents -O-, -CO-, -CO-O- or -O-CO-. However, A a42 , A a43 , A a44 , X a41 and X a42 The total number of carbon atoms is 7 or less. * indicates the binding site, and the * on the right is -O-CO-R a42 This is the binding site for

[0080] R a42 Examples of the saturated hydrocarbon group in include chain hydrocarbon groups, monocyclic or polycyclic saturated alicyclic hydrocarbon groups, and groups formed by combining these groups.

[0081] Examples of the chain hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group. Examples of the monocyclic or polycyclic saturated alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; and polycyclic alicyclic hydrocarbon groups such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bonding site): TIFF0007672214000048.tif10159 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 saturated alicyclic hydrocarbon groups, such as -alkanediyl group-saturated alicyclic hydrocarbon group, -saturated alicyclic hydrocarbon group-alkyl group, and -alkanediyl group-saturated alicyclic hydrocarbon group-alkyl group.

[0082] R a42 The substituents of may be at least one selected from the group consisting of halogen atoms and groups represented by formula (a-g3): Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and preferably a fluorine atom. TIFF0007672214000049.tif855[In formula (a-g3), X a43 represents an oxygen atom, a carbonyl group, *-O-CO-, or *-CO-O-. A a45 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. * stands for R a42 represents the binding site for However, R a42 -X a43 -A a45 In R a42 When A does not have a halogen atom, a45 represents a saturated hydrocarbon group having 1 to 17 carbon atoms and at least one halogen atom.

[0083] A a45 Examples of the saturated hydrocarbon group in the formula (I) include alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group; Examples of such groups include monocyclic alicyclic hydrocarbon groups, such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; and polycyclic alicyclic hydrocarbon groups, such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* indicates a bonding site): TIFF0007672214000050.tif10159 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 hydrocarbon groups, such as -alkanediyl group-alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, and -alkanediyl group-alicyclic hydrocarbon group-alkyl group.

[0084] R a42 is preferably a saturated hydrocarbon group which may have a halogen atom, and more preferably a saturated hydrocarbon group having an alkyl group having a halogen atom and / or a group represented by formula (a-g3). R a42 When is a saturated hydrocarbon group having a halogen atom, it is preferably a saturated hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, further preferably a perfluoroalkyl group having 1 to 6 carbon atoms, and particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, and a perfluorooctyl group. Examples of the perfluorocycloalkyl group include a perfluorocyclohexyl group. R a42is a saturated hydrocarbon group having a group represented by formula (a-g3), the number of carbon atoms contained in the group represented by formula (a-g3) is a42 The total number of carbon atoms is preferably 15 or less, and more preferably 12 or less. In the case where the group represented by formula (a-g3) is contained as a substituent, the number thereof is preferably 1.

[0085] R a42 is a saturated hydrocarbon group having a group represented by formula (a-g3), R a42 is more preferably a group represented by formula (a-g2). TIFF0007672214000051.tif871[In formula (a-g2), A a46 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. X a44 represents **-O-CO- or **-CO-O- (** represents A a46 ) which represents the binding site with A a47 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. However, A a46 , A a47 and X a44 The total number of carbon atoms in A is 18 or less. a46 and A a47 At least one of these has at least one halogen atom. * indicates the bonding site with the carbonyl group.]

[0086] A a46 The saturated hydrocarbon group preferably has 1 to 6 carbon atoms, and more preferably has 1 to 3 carbon atoms. A a47 The saturated hydrocarbon group preferably has 4 to 15 carbon atoms, more preferably 5 to 12 carbon atoms. a47 is more preferably a cyclohexyl group or an adamantyl group.

[0087] A preferred structure of the group represented by formula (a-g2) is the following structure (* indicates the bonding site with the carbonyl group). TIFF0007672214000052.tif14160

[0088] A a41 Examples of the alkanediyl group in the formula (I) include linear alkanediyl groups such as a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and a hexane-1,6-diyl group; and branched alkanediyl groups such as a propane-1,2-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a 1-methylbutane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. A a41 Examples of the substituent in the alkanediyl group represented by the formula (I) include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms. A a41 is preferably an alkanediyl group having 1 to 4 carbon atoms, more preferably an alkanediyl group having 2 to 4 carbon atoms, and further preferably an ethylene group.

[0089] A in the group represented by formula (a-g1) a42 , A a43 and A a44 Examples of the divalent saturated hydrocarbon group represented by include a linear or branched alkanediyl group, a monocyclic 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. A a42 , A a43 and A a44 Examples of the substituent of the divalent saturated hydrocarbon group represented by the formula (1) include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms. It is preferred that s is 0.

[0090] In the group represented by formula (a-g1), X a42Examples of the group in which is -O-, -CO-, -CO-O-, or -O-CO- include the following groups. In the following examples, * and ** each represent a bonding site, and ** represents -O-CO-R a42 This is the binding site for TIFF0007672214000053.tif46140

[0091] The structural unit represented by formula (a4-1) includes the structural units shown below and R in the structural unit represented by formula (a4-1) in the structural units shown below. a41 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. TIFF0007672214000054.tif98143

[0092] TIFF0007672214000055.tif132150

[0093] Examples of the structural unit represented by formula (a4-1) include a structural unit represented by formula (a4-2) and a structural unit represented by formula (a4-3). TIFF0007672214000056.tif4256[In formula (a4-2), R f5 represents a hydrogen atom or a methyl group. L 44 represents an alkanediyl group having 1 to 6 carbon atoms, and -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-. R f6 represents a saturated hydrocarbon group having 1 to 20 carbon atoms and containing a fluorine atom. However, L 44 and R f6 The total number of carbon atoms in the molecule is limited to 21.

[0094] L 44 The alkanediyl group having 1 to 6 carbon atoms is represented by A a41 Examples of the groups include the same groups as those exemplified in the above. R f6 The saturated hydrocarbon group of R 42 Examples of the groups include the same groups as those exemplified in the above. L44 The alkanediyl group in is preferably an alkanediyl group having 2 to 4 carbon atoms, and more preferably an ethylene group.

[0095] Examples of the structural unit represented by formula (a4-2) include structural units represented by formulas (a4-1-1) to (a4-1-11). f5 The structural unit represented by formula (a4-2) also includes a structural unit in which a methyl group corresponding to the following is replaced with a hydrogen atom.

[0096] TIFF0007672214000057.tif5974[In formula (a4-3), R f7 represents a hydrogen atom or a methyl group. L 5 represents an alkanediyl group having 1 to 6 carbon atoms. A f13 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms which may contain a fluorine atom. X f12 represents *-O-CO- or *-CO-O- (* represents A f13 ) which represents the binding site with A f14 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may contain a fluorine atom. However, A f13 and A f14 At least one of L has a fluorine atom. 5 , A f13 and A f14 The total number of carbon atoms in the molecule is limited to 20.

[0097] L 5 The alkanediyl group in a41 Examples of the alkanediyl group include the same groups as those exemplified as the alkanediyl group.

[0098] A f13The divalent saturated hydrocarbon group which may have a fluorine atom in is preferably a divalent chain saturated hydrocarbon group which may have a fluorine atom and a divalent alicyclic saturated hydrocarbon group which may have a fluorine atom, and more preferably a perfluoroalkanediyl group. Examples of the divalent chain saturated hydrocarbon group which may have a fluorine atom include alkanediyl groups such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group, and a pentanediyl group; and perfluoroalkanediyl groups such as a difluoromethylene group, a perfluoroethylene group, a perfluoropropanediyl group, a perfluorobutanediyl group, and a perfluoropentanediyl group. The divalent alicyclic saturated hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. Examples of the monocyclic group include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the polycyclic group include an adamantanediyl group, a norbornanediyl group, and a perfluoroadamantanediyl group.

[0099] A f14 The saturated hydrocarbon group and the saturated hydrocarbon group which may have a fluorine atom are represented by R a42Among them, a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, Preferred are fluorinated alkyl groups such as a hexyl group, a perfluorohexyl group, a heptyl group, a perfluoroheptyl group, an octyl group, and a perfluorooctyl group, a cyclopropylmethyl group, a cyclopropyl group, a cyclobutylmethyl group, a cyclopentyl group, a cyclohexyl group, a perfluorocyclohexyl group, an adamantyl group, an adamantylmethyl group, an adamantyldimethyl group, a norbornyl group, a norbornylmethyl group, a perfluoroadamantyl group, and a perfluoroadamantylmethyl group.

[0100] In formula (a4-3), L 5 is preferably an ethylene group. A f13 The divalent saturated hydrocarbon group is preferably a group containing a divalent chain saturated hydrocarbon group having 1 to 6 carbon atoms and a divalent alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and more preferably a divalent chain saturated hydrocarbon group having 2 to 3 carbon atoms. A f14 The saturated hydrocarbon group of is preferably a group containing a chain saturated hydrocarbon group having 3 to 12 carbon atoms and an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and more preferably a chain saturated hydrocarbon group having 3 to 10 carbon atoms and an alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms. f14 is preferably a group containing an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and more preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, or an adamantyl group.

[0101] Examples of the structural unit represented by formula (a4-3) include structural units represented by formulas (a4-1'-1) to (a4-1'-11). R in the structural unit (a4-3) f7 The structural unit represented by formula (a4-3) also includes a structural unit in which a methyl group corresponding to the following is replaced with a hydrogen atom.

[0102] The structural unit (a4) also includes a structural unit represented by the formula (a4-4). TIFF0007672214000058.tif4466[In formula (a4-4), R f21 represents a hydrogen atom or a methyl group. A f21 is -(CH2) j1 -, -(CH2) j2 -O-(CH2) j3 -or-(CH2) j4 -CO-O-(CH2) j5 - represents. j1 to j5 each independently represent an integer of 1 to 6. R f22 represents a saturated hydrocarbon group having 1 to 10 carbon atoms and containing a fluorine atom.]

[0103] R f22 The saturated hydrocarbon group of R a42 The saturated hydrocarbon group represented by R f22 is preferably an alkyl group having 1 to 10 carbon atoms and having a fluorine atom, or an alicyclic 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, and further preferably an alkyl group having 1 to 6 carbon atoms and having a fluorine atom.

[0104] In formula (a4-4), A f21 As an example, -(CH2) j1 - is preferred, an ethylene group or a methylene group is more preferred, and a methylene group is even more preferred.

[0105] Examples of the structural unit represented by formula (a4-4) include the following structural units and structural units represented by the following formulas: f21 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. TIFF0007672214000059.tif86160 When the resin (A) 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 the total structural units of the resin (A).

[0106] <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). TIFF0007672214000060.tif3555[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-.]

[0107] 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. R 52 is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and more preferably an adamantyl group, a norbornyl group, or a cyclohexyl group.

[0108] 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.

[0109] 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. TIFF0007672214000061.tif18164 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 x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. However, L x3 and L x4 The total number of carbon atoms is 17 or less. In formula (L1-3), L x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. L x6 and L x7 each independently represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms. However, L x5 , L x6 and L x7 The total number of carbon atoms is 15 or less. In formula (L1-4), L x8 and L x9 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms. W x1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms. However, L x8 , L x9 and W x1 The total number of carbon atoms is 15 or less.

[0110] 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 x3is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x5 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x6 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, 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.

[0111] Examples of the group represented by formula (L1-1) include the divalent groups shown below. TIFF0007672214000062.tif53136

[0112] Examples of the group represented by formula (L1-2) include the divalent groups shown below. TIFF0007672214000063.tif23131

[0113] Examples of the group represented by formula (L1-3) include the divalent groups shown below. TIFF0007672214000064.tif16145

[0114] Examples of the group represented by formula (L1-4) include the divalent groups shown below. TIFF0007672214000065.tif26114

[0115] L 55 is preferably a single bond or a group represented by formula (L1-1).

[0116] 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. TIFF0007672214000066.tif77158

[0117] TIFF0007672214000067.tif39159 When the resin (A) 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 (A).

[0118] <Structural unit (II)> Resin (A) may further contain a structural unit that decomposes upon exposure to generate an acid (hereinafter, may be referred to as "structural unit (II)"). Specific examples of structural unit (II) include structural units described in JP-A-2016-79235, and are preferably structural units having a sulfonate group or carboxylate group and an organic cation in the side chain, or a structural unit having a sulfonio group and an organic anion in the side chain.

[0119] 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 (II-2-A'). TIFF0007672214000068.tif3189 [In formula (II-2-A'), X III3represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, in which -CH2- contained in the saturated hydrocarbon group may be replaced by -O-, -S- or -CO-, and a hydrogen atom contained in the saturated hydrocarbon group may be replaced by a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, or a hydroxy group. A x1 represents an alkanediyl group having 1 to 8 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted by a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. RA - represents a sulfonate group or a carboxylate group. R III3 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. Z.A. + represents an organic cation.

[0120] R III3 Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R III3 The alkyl group having 1 to 6 carbon atoms which may have a halogen atom and is represented by the formula: a8 Examples of the alkyl group include the same alkyl groups having 1 to 6 carbon atoms which may have a halogen atom and are represented by the following formula: A x1 Examples of the alkanediyl group having 1 to 8 carbon atoms represented by the formula (I) include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, an ethane-1,1-diyl group, a propane-1,1-diyl group, a propane-1,2-diyl group, a propane-2,2-diyl group, a pentane-2,4-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. A x1Examples of the perfluoroalkyl group having 1 to 6 carbon atoms which may be substituted 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.

[0121] X III3 Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by the formula (I) include linear or branched alkanediyl groups, and monocyclic or polycyclic divalent alicyclic saturated hydrocarbon groups, and combinations of these may also be used. 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; butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, and the like. divalent monocyclic alicyclic saturated hydrocarbon groups such as cycloalkanediyl groups, such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group, etc.; and divalent polycyclic alicyclic saturated hydrocarbon groups, such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, etc.

[0122] Examples of saturated hydrocarbon groups in which -CH2- is replaced with -O-, -S-, or -CO- include divalent groups represented by formulae (X1) to (X53). However, the number of carbon atoms before -CH2- in the saturated hydrocarbon group is replaced with -O-, -S-, or -CO- is 17 or less. In the following formulae, * and ** represent binding sites, * represents A x1represents the binding site with TIFF0007672214000069.tif145161

[0123] X 3 represents a divalent saturated hydrocarbon group having 1 to 16 carbon atoms. X 4 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. X 5 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms. X 6 represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms. X 7 represents a trivalent saturated hydrocarbon group having 1 to 14 carbon atoms. X 8 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.

[0124] Z.A. + Examples of the organic cation represented by the formula (b2-1) include an organic onium cation, an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, and an organic phosphonium cation. Among these, the organic sulfonium cation and the organic iodonium cation are preferred, and the arylsulfonium cation is more preferred. Specifically, examples of the organic cation represented by the formula (b2-1) to the formula (b2-4) described later include cations.

[0125] The structural unit represented by formula (II-2-A') is preferably a structural unit represented by formula (II-2-A). JPEG0007672214000070.jpg37108 [In formula (II-2-A), R III3 , X III3 and Z.A. + has the same meaning as above. z represents an integer of 0 to 6. R III2 and R III4 each independently represents a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms; when z is 2 or more, a plurality of RIII2 and R III4 may be the same or different from each other. Q a and Q b each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.]

[0126] R III2 , R III4 , Q a and Q b As the perfluoroalkyl group having 1 to 6 carbon atoms represented by the formula b1 Examples of the perfluoroalkyl group include those having 1 to 6 carbon atoms represented by the following formula:

[0127] The structural unit represented by formula (II-2-A) is preferably a structural unit represented by formula (II-2-A-1). TIFF0007672214000071.tif5575 [In formula (II-2-A-1), R III2 , R III3 , R III4 , Q a , Q b , z and Z A + has the same meaning as above. R III5 represents a saturated hydrocarbon group having 1 to 12 carbon atoms. X I2 represents a divalent saturated hydrocarbon group having 1 to 11 carbon atoms, -CH2- contained in the saturated hydrocarbon group may be replaced by -O-, -S- or -CO-, and a hydrogen atom contained in the saturated hydrocarbon group may be replaced by a halogen atom or a hydroxyl group.]

[0128] R III5 Examples of the saturated hydrocarbon group having 1 to 12 carbon atoms represented by the formula (I) include linear or branched alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group. X I2As the divalent saturated hydrocarbon group represented by the formula: III3 Examples of the divalent saturated hydrocarbon group include those similar to those represented by the following formula:

[0129] The structural unit represented by formula (II-2-A-1) is preferably a structural unit represented by formula (II-2-A-2). TIFF0007672214000072.tif5287 [In formula (II-2-A-2), R III3 , R III5 and Z.A. + has the same meaning as above. m and nA each independently represent 1 or 2.

[0130] Examples of the structural unit represented by formula (II-2-A') include the following structural units, R III3 Examples of the structural units include those in which the group corresponding to the methyl group in the above formula (1) is replaced with a hydrogen atom, a halogen atom (e.g., a fluorine atom), or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (e.g., a trifluoromethyl group, etc.), and the structural units described in WO 2012 / 050015. + represents an organic cation. TIFF0007672214000073.tif86163

[0131] The structural unit having a sulfonio group and an organic anion in the side chain is preferably a structural unit represented by formula (II-1-1). TIFF0007672214000074.tif3380[In formula (II-1-1), A II1 represents a single bond or a divalent linking group. R II1 represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms. R II2 and R II3 each independently represents a hydrocarbon group having 1 to 18 carbon atoms; R II2 and R II3 may be bonded to each other to form a ring together with the sulfur atom to which they are attached. RII4 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. A - represents an organic anion. R II1 Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by the formula (I) include a phenylene group and a naphthylene group. R II2 and R II3 Examples of the hydrocarbon group represented by the formula (I) include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups. Examples of the alkyl group and the alicyclic hydrocarbon group include the same as those mentioned above. Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. Examples of the combined group include a combination of the above-mentioned alkyl group and alicyclic hydrocarbon group, aralkyl groups such as a 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 a phenylcyclohexyl group. R II4 Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R II4 The alkyl group having 1 to 6 carbon atoms which may have a halogen atom and is represented by the formula: a8 Examples of the alkyl group include the same alkyl groups having 1 to 6 carbon atoms which may have a halogen atom and are represented by the following formula: A II1 Examples of the divalent linking group represented by the formula (I) include a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O-, -S- or -CO-. III3Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms include those represented by the following formula:

[0132] The structural unit containing a cation in formula (II-1-1) is a structural unit represented by the following formula: R II4 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.). TIFF0007672214000075.tif84130

[0133] 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 (B1) below is preferably a sulfonate anion. Examples of the sulfonate anion include the same anion represented by the formula (B1) below.

[0134] A - Examples of the sulfonylimide anion represented by the formula (I) include the following. TIFF0007672214000076.tif36136

[0135] Examples of sulfonylmethide anions include the following: TIFF0007672214000077.tif29123

[0136] Examples of carboxylate anions include the following: TIFF0007672214000078.tif51152

[0137] Examples of the structural unit represented by formula (II-1-1) include structural units represented below. TIFF0007672214000079.tif88149

[0138] When the resin (A) contains the structural unit (II), the content of the structural unit (II) is preferably 1 to 20 mol %, more preferably 2 to 15 mol %, and even more preferably 3 to 10 mol %, based on the total structural units of the resin (A).

[0139] The resin (A) may have structural units other than the above-mentioned structural units, and examples of such structural units include structural units well known in the art.

[0140] The resin (A) is preferably a resin composed of the structural unit (I) and the structural unit (III), a resin composed of the structural unit (I), the structural unit (III), the structural unit (a1-1) and the structural unit (a1-2), a resin composed of the structural unit (I), the structural unit (III) and the structural unit (a1-1), a resin composed of the structural unit (I), the structural unit (III) and the structural unit (a1-2), a resin composed of the structural unit (I), the structural unit (III) and the structural unit (s), a resin comprising structural units (I), (III), (a1-1), (a1-2) and (s); a resin comprising structural units (I), (III), (a1-1) and (s); a resin comprising structural units (I), (III), (a1-2) and (s); a resin comprising structural units (I), (III), (a1-1) and (s); a resin consisting of structural units (I), (a1-2), (a1-3), (a1-4), (a1-5), (a1-6), (a1-7), (a1-8), (a1-9), (a1-10), (a1-11), (a1-2), and (a4); and more preferably a resin consisting of structural units (I) and (III), a resin consisting of structural units (I), (III), (a1-1), (a1-2), (a1-8), (a1-9), (a1-11), (a1-2), (a1-12), (a1-13), (a1-14), (a1-15), (a1-16), (a1-17), (a1-18), (a1-19), (a1-20), (a1-21), (a1-22), (a1-23), (a1-24), (a1-25), (a1-26), (a1-27), (a1-28), (a1-29 ...9), (a1-21), (a1-22), (a1-23), (a1-24), (a1-25), (a1-26), (a1-27), (a1-29), (a1-29), (a1-29), (a1-29), (a1-29), (a1-29),

[0141] The structural unit (s) is preferably at least one selected from the group consisting of the structural unit (a2) and the structural unit (a3). The structural unit (a2) is preferably at least one selected from the group consisting of the structural unit (a2-1) and the structural unit (a2-A). The structural unit (a3) ​​is preferably at least one selected from the group consisting of the structural unit represented by formula (a3-1), the structural unit represented by formula (a3-2), and the structural unit represented by formula (a3-4).

[0142] Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and can be produced by a known polymerization method (e.g., radical polymerization method) using a monomer that leads to these structural units. The content of each structural unit contained in the resin (A) can be adjusted by the amount of the monomer used for polymerization. The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, and even more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less, and even more preferably 15,000 or less). In this specification, the weight average molecular weight is a value determined by gel permeation chromatography, which can be measured under the analytical conditions described in the Examples.

[0143] [Resist Composition] The resist composition of the present invention preferably contains a resin (A) and an acid generator known in the resist field (hereinafter sometimes referred to as “acid generator (B)”). The resist composition of the present invention may further contain a resin other than the resin (A). 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)").

[0144] <Resins other than resin (A)> The resin other than the resin (A) may be any resin that does not contain the structural unit (I) or the structural unit (III). Examples of such a resin include a resin obtained by removing the structural unit (I) from the resin (A) (hereinafter sometimes referred to as "resin (AY)"), a resin obtained by removing the structural unit (III) from the resin (A) (hereinafter sometimes referred to as "resin (AZ)"), and a resin consisting of only the structural unit (a4) and the structural unit (a5) (hereinafter sometimes referred to as "resin (X)").

[0145] As the resin (X), a resin containing the structural unit (a4) is particularly preferred. In the resin (X), the content of the structural unit (a4) is 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). 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. Among these, the resin (X) is preferably a resin consisting only of the structural unit (a4) and / or the structural unit (a5). 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 resin (AY), resin (AZ) and 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) independently. The method for measuring the weight average molecular weight of resin (AY) and resin (X) is the same as that for resin (A). When the resist composition of the present invention contains resin (AY), the total content thereof is generally from 1 to 2500 parts by mass (more preferably from 10 to 1000 parts by mass) per 100 parts by mass of resin (A). Furthermore, 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, relative to 100 parts by mass of resin (A).

[0146] In the resist composition of the present invention, the resin (A) may be used in combination with a resin other than the resin (A). When a resin other than the resin (A) is used in combination, it is preferable to use a resin containing a structural unit having an acid labile group and / or a resin containing a structural unit having a fluorine atom in combination, and it is more preferable to use the resin (AY), resin (AZ) and / or resin (X) in combination. The content of resin (A) in the resist composition is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 99% by mass or less, based on the solid content of the resist composition. When a resin other than resin (A) is contained, the total content of resin (A) and the resin other than resin (A) is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 99% by mass or less, 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 means such as liquid chromatography or gas chromatography.

[0147] <Acid Generator (B)> The acid generator (B) may be either nonionic or ionic. 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), etc. 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, sulfonylimide anion, sulfonylmethide anion, etc.

[0148] 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. Two or more types of acid generators (B) can be used in combination.

[0149] The acid generator (B) is preferably a fluorine-containing acid generator, and more preferably a salt represented by formula (B1) (hereinafter sometimes referred to as "acid generator (B1)"). TIFF0007672214000080.tif2961[In formula (B1), Q b1 and Q b2 each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. L b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, in which -CH2- may be replaced by -O- or -CO-, and a hydrogen atom in the divalent saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group. Y represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 24 carbon atoms, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S(O)2- or -CO-. Z1 + represents an organic cation.

[0150] Q b1 and Q b2Examples of the perfluoroalkyl group represented by 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, and a perfluorohexyl group. Q b1 and Q b2 and are preferably each independently a fluorine atom or a trifluoromethyl group, and more preferably both are fluorine atoms.

[0151] L b1 Examples of the divalent saturated hydrocarbon group in include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and may be a group formed by combining two or more of these groups. Specific examples of such straight-chain alkanediyl groups include methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexadecane-1,16-diyl, and heptadecane-1,17-diyl groups; branched alkanediyl groups such as ethane-1,1-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-2,2-diyl, pentane-2,4-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, and 2-methylbutane-1,4-diyl; monocyclic divalent alicyclic saturated hydrocarbon groups such as cycloalkanediyl groups, such as cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, and cyclooctane-1,5-diyl; Examples 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.

[0152] L b1 Examples of the divalent saturated hydrocarbon group represented by the formula (b1-1) in which -CH2- is replaced with -O- or -CO- include groups represented by any of formulas (b1-1) to (b1-3). In the groups represented by formulas (b1-1) to (b1-3) and specific examples thereof represented by formulas (b1-4) to (b1-11), * represents a bond to -Y.

[0153] TIFF0007672214000081.tif26118[In formula (b1-1), L b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the saturated hydrocarbon group may be substituted with -O- or -CO-. However, L b2 and L b3 The total number of carbon atoms is 22 or less. In formula (b1-2), L b4 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the saturated hydrocarbon group may be substituted with -O- or -CO-. However, L b4 and L b5 The total number of carbon atoms is 22 or less. In formula (b1-3), L b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. L b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the saturated hydrocarbon group may be substituted with -O- or -CO-. However, L b6 and L b7 The total number of carbon atoms is 23 or less. * and ** represent bonds, and * represents a bond to Y.]

[0154] In the groups represented by formulae (b1-1) to (b1-3), when -CH2- contained in the saturated hydrocarbon group is replaced with -O- or -CO-, the number of carbon atoms before replacement is regarded as the number of carbon atoms of the saturated hydrocarbon group. As the divalent saturated hydrocarbon group, L b1 The divalent saturated hydrocarbon group may be the same as that of the above. L b2 is preferably a single bond. L b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms. L b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom. L b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b6 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b7is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the divalent saturated hydrocarbon group may be substituted with -O- or -CO-.

[0155] L b1 As the divalent saturated hydrocarbon group represented by the formula (b1-1) or (b1-3), a group in which --CH2-- contained in the divalent saturated hydrocarbon group represented by the formula (b1-1) is preferably replaced by --O-- or --CO--. Examples of the group represented by formula (b1-1) include the groups represented by formulas (b1-4) to (b1-8). TIFF0007672214000082.tif48120[In formula (b1-4), L b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. In formula (b1-5), L b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O- or -CO-. L b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b9 and L b10 The total number of carbon atoms is 20 or less. In formula (b1-6), L b11 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b11 and L b12 The total number of carbon atoms is 21 or less. In formula (b1-7), L b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms. L b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-. L b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b13 ~L b15 The total number of carbon atoms is 19 or less. In formula (b1-8), L b16 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O- or -CO-. L b17 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms. L b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b16 ~L b18 The total number of carbon atoms is 19 or less. * and ** represent bonds, and * represents a bond to Y.] L b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms. L b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b10 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b12is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. L b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms. L b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b16 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. L b17 is preferably a divalent saturated hydrocarbon group having 1 to 6 carbon atoms. L b18 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.

[0156] Examples of the group represented by formula (b1-3) include the groups represented by formulas (b1-9) to (b1-11). TIFF0007672214000083.tif23140[In formula (b1-9), L b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an alkylcarbonyloxy group. -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group. However, L b19 and L b20 The total number of carbon atoms is 23 or less. In formula (b1-10), L b21represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b22 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b23 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an alkylcarbonyloxy group. -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group. However, L b21 , L b22 and L b23 The total number of carbon atoms is 21 or less. In formula (b1-11), L b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b26 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an alkylcarbonyloxy group. -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group. However, L b24 , L b25 and L b26 The total number of carbon atoms is 21 or less. * and ** represent bonds, and * represents a bond to Y.]

[0157] In addition, in the groups represented by formulae (b1-9) to (b1-11), when a hydrogen atom contained in the saturated hydrocarbon group is substituted with an alkylcarbonyloxy group, the number of carbon atoms before substitution is regarded as the number of carbon atoms of the saturated hydrocarbon group. Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group, and an adamantylcarbonyloxy group.

[0158] Examples of the group represented by formula (b1-4) include the following. TIFF0007672214000084.tif16150 (* and ** represent bonds, * represents a bond to Y.)

[0159] Examples of the group represented by formula (b1-5) include the following. TIFF0007672214000085.tif72149 (* and ** represent bonds, * represents a bond to Y.)

[0160] Examples of the group represented by formula (b1-6) include the following. TIFF0007672214000086.tif29150 (* and ** represent bonds, * represents a bond to Y.)

[0161] Examples of the group represented by formula (b1-7) include the following. TIFF0007672214000087.tif64151(* and ** represent bonds, * represents a bond to Y.)

[0162] Examples of the group represented by formula (b1-8) include the following. TIFF0007672214000088.tif23150 (* and ** represent bonds, * represents a bond to Y.)

[0163] Examples of the group represented by formula (b1-2) include the following. TIFF0007672214000089.tif31161(* and ** represent bonds, * represents a bond to Y.)

[0164] Examples of the group represented by formula (b1-9) include the following. TIFF0007672214000090.tif44137(* and ** represent bonds, * represents a bond to Y.)

[0165] Examples of the group represented by formula (b1-10) include the following. TIFF0007672214000091.tif89157 (* and ** represent bonds, * represents a bond to Y.)

[0166] Examples of the group represented by formula (b1-11) include the following. TIFF0007672214000092.tif82158 (* and ** represent bonds, * represents a bond to Y.)

[0167] Examples of the alicyclic hydrocarbon group represented by Y include groups represented by formulae (Y1) to (Y11) and (Y36) to (Y38). When -CH2- contained in the alicyclic hydrocarbon group represented by Y is replaced by -O-, -S(O)2- or -CO-, the number may be 1 or 2 or more. Examples of such a group include groups represented by formulae (Y12) to (Y35) and formulae (Y39) to (Y43). * is L b1 Represents a bond with . The alicyclic hydrocarbon group represented by Y is preferably a group represented by any one of formulas (Y1) to (Y20), (Y26), (Y27), (Y30), (Y31), (Y39) to (Y43), and more preferably a group represented by formulas (Y11), (Y15), (Y16), (Y20), (Y22), (Y23), (Y24), (Y25), (Y26), (Y27), (Y30), (Y31), (Y39), (Y32), (Y33), (Y34), (Y35), (Y36), (Y37), (Y38), (Y39), (Y40), (Y41), (Y42), (Y43), (Y44), (Y45), (Y46), (Y47), (Y48), (Y49), (Y50), (Y51), (Y52), (Y53), (Y54), (Y55), and more preferably a group represented by formula (Y11), formula (Y15), formula (Y20), formula (Y26), formula (Y27), formula (Y30), formula (Y31), formula (Y39), formula (Y40), formula (Y42) or formula (Y43). When the alicyclic hydrocarbon group represented by Y is a spiro ring containing an oxygen atom such as those of formulae (Y28) to (Y35), (Y39) to (Y40), (Y42) or (Y43), the alkanediyl group between the two oxygen atoms preferably has one or more fluorine atoms. In addition, among the alkanediyl groups contained in the ketal structure, it is preferable that the methylene group adjacent to the oxygen atom is not substituted with a fluorine atom.

[0168] The substituent of the methyl group represented by Y is a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, a glycidyloxy group, -(CH2) ja -CO-OR b1 Group or -(CH2) ja -O-CO-R b1 group (in the formula, R b1 represents an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof, -CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -SO2- or -CO-, and a hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group may be replaced by a hydroxy group or a fluorine atom. ja represents an integer of 0 to 4.) Substituents of the alicyclic hydrocarbon group represented by Y include halogen atoms, hydroxy groups, alkyl groups having 1 to 16 carbon atoms which may be substituted with a hydroxy group (-CH2- contained in the alkyl group may be replaced with -O- or -CO-), alicyclic hydrocarbon groups having 3 to 16 carbon atoms, aromatic hydrocarbon groups having 6 to 18 carbon atoms, aralkyl groups having 7 to 21 carbon atoms, glycidyloxy groups, -(CH2) ja -CO-OR b1 Group or -(CH2) ja -O-CO-R b1 group (in the formula, R b1 represents an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof, -CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -SO2- or -CO-, and a hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group may be replaced by a hydroxy group or a fluorine atom. ja represents an integer of 0 to 4.)

[0169] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a norbornyl group, and an adamantyl group. The alicyclic hydrocarbon group may have a chain hydrocarbon group, and examples of the chain include a methylcyclohexyl group and a dimethylcyclohexyl group. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 12, and more preferably 3 to 10. Examples of 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. 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 with 1 to 18 carbon atoms (tolyl group, xylyl group, cumenyl group, mesityl group, p-methylphenyl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.) and aromatic hydrocarbon groups having an alicyclic hydrocarbon group with 3 to 18 carbon atoms (p-adamantylphenyl group, p-cyclohexylphenyl group, etc.). The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 14, and more preferably 6 to 10. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, etc. The number of carbon atoms in the alkyl group is preferably 1 to 12, more preferably 1 to 6, and further preferably 1 to 4. Examples of the alkyl group substituted with a hydroxy group include hydroxyalkyl groups such as a hydroxymethyl group and a hydroxyethyl group. Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, and a naphthylethyl group. Examples of the alkyl group in which --CH.sub.2-- is replaced by --O--, --S(O).sub.2--, --CO--, or the like include an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, or a combination thereof. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group. The number of carbon atoms in the alkoxy group is preferably 1 to 12, more preferably 1 to 6, and further preferably 1 to 4. Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, a butoxycarbonyl group, etc. The number of carbon atoms in the alkoxycarbonyl group is preferably 2 to 12, more preferably 2 to 6, and further preferably 2 to 4. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, a butyryl group, etc. The number of carbon atoms in the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, and further preferably 2 to 4. Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, etc. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2 to 12, more preferably 2 to 6, and further preferably 2 to 4. Examples of the combined group include a group that combines an alkoxy group with an alkyl group, a group that combines an alkoxy group with an alkoxy group, a group that combines an alkoxy group with an alkylcarbonyl group, and a group that combines an alkoxy group with an alkylcarbonyloxy group. Examples of the group formed by combining an alkoxy group with an alkyl group include alkoxyalkyl groups such as a methoxymethyl group, a methoxyethyl group, an ethoxyethyl group, an ethoxymethyl group, etc. The number of carbon atoms in the alkoxyalkyl group is preferably 2 to 12, more preferably 2 to 6, and further preferably 2 to 4. Examples of the group formed by combining an alkoxy group with another alkoxy group include alkoxyalkoxy groups such as a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, etc. The number of carbon atoms in the alkoxyalkoxy group is preferably 2 to 12, more preferably 2 to 6, and further preferably 2 to 4. Examples of the group formed by combining an alkoxy group with an alkylcarbonyl group include alkoxyalkylcarbonyl groups such as a methoxyacetyl group, a methoxypropionyl group, an ethoxyacetyl group, an ethoxypropionyl group, etc. The number of carbon atoms in the alkoxyalkylcarbonyl group is preferably 3 to 13, more preferably 3 to 7, and further preferably 3 to 5. Examples of the group formed by combining an alkoxy group with an alkylcarbonyloxy group include alkoxyalkylcarbonyloxy groups such as a methoxyacetyloxy group, a methoxypropionyloxy group, an ethoxyacetyloxy group, an ethoxypropionyloxy group, etc. The number of carbon atoms in the alkoxyalkylcarbonyloxy group is preferably 3 to 13, more preferably 3 to 7, and further preferably 3 to 5. Examples of the group in which -CH2- in the alicyclic hydrocarbon group is replaced by -O-, -S(O)2-, -CO- or the like include groups represented by formulae (Y12) to (Y35) and (Y39) to (Y43).

[0170] Y includes the following: TIFF0007672214000094.tif160165

[0171] Y is preferably an alicyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent, even more preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and even more preferably an adamantyl group which may have a substituent, and -CH2- constituting the alicyclic hydrocarbon group or the adamantyl group may be replaced by -CO-, -S(O)2- or -CO-. Specifically, Y is preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group or a group represented by the formulae (Y42) and (Y100) to (Y114).

[0172] The anion in the salt represented by formula (B1) is preferably an anion represented by formula (B1-A-1) to formula (B1-A-59) (hereinafter, may be referred to as "anion (B1-A-1)" depending on the formula number), and more preferably an anion represented by any of formula (B1-A-1) to formula (B1-A-4), (B1-A-9), (B1-A-10), (B1-A-24) to formula (B1-A-33), (B1-A-36) to formula (B1-A-40), and (B1-A-47) to formula (B1-A-59).

[0173] TIFF0007672214000095.tif143153

[0174] TIFF0007672214000096.tif66157

[0175] TIFF0007672214000097.tif100158

[0176] TIFF0007672214000098.tif121153

[0177] TIFF0007672214000099.tif50138

[0178] TIFF0007672214000100.tif185167

[0179] 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, a chain hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a group formed by combining these, more preferably a methyl group, an ethyl group, a cyclohexyl group, or an adamantyl group. A41 Q is a single bond or an alkanediyl group having 1 to 4 carbon atoms. b1 and Q b2 has the same meaning as above. Specific examples of the anion in the salt represented by formula (B1) include the anions described in JP-A-2010-204646.

[0180] Preferable anions in the salt represented by formula (B1) include the anions represented by formulas (B1a-1) to (B1a-38). TIFF0007672214000101.tif125153

[0181] TIFF0007672214000102.tif92138

[0182] TIFF0007672214000103.tif168155

[0183] Of these, anions represented by any of Formulae (B1a-1) to (B1a-3), (B1a-7) to (B1a-16), (B1a-18), (B1a-19), and (B1a-22) to (B1a-38) are preferred.

[0184] Z1 + 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 is more preferred. Specific examples include cations represented by any of formulas (b2-1) to (b2-4) (hereinafter, sometimes referred to as "cation (b2-1)" depending on the formula number). TIFF0007672214000104.tif48169In equations (b2-1) to (b2-4), 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 hydroxyl group, an aliphatic hydrocarbon 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 b18each independently represents a halogen atom, a hydroxyl group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. L b31 represents a sulfur atom or an oxygen atom. o2, p2, s2, and t2 each independently represent an integer of 0 to 5. q2 and r2 each independently represent an integer of 0 to 4. u2 represents 0 or 1. When o2 is 2 or more, multiple R b13 are the same or different, and when p2 is 2 or more, multiple R b14 are the same or different, and when q2 is 2 or more, multiple R b15 are the same or different, and when r2 is 2 or more, multiple R b16 are the same or different, and when s2 is 2 or more, multiple R b17 are the same or different, and when t2 is 2 or more, multiple R b18 are the same or different.

[0185] 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: TIFF0007672214000105.tif10158 In particular, R b9 ~R b12The alicyclic hydrocarbon group preferably has 3 to 18 carbon atoms, and more preferably has 4 to 12 carbon atoms.

[0186] 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.

[0187] 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.

[0188] 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.

[0189] 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 bond. TIFF0007672214000106.tif23143

[0190] R 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 Rb12 The 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.

[0191] Among the cations (b2-1) to (b2-4), the cation (b2-1) is preferred. Examples of the cation (b2-1) include the following cations. TIFF0007672214000107.tif80158

[0192] TIFF0007672214000108.tif74165

[0193] TIFF0007672214000109.tif3496

[0194] Examples of the cation (b2-2) include the following cations. TIFF0007672214000110.tif18150

[0195] Examples of the cation (b2-3) include the following cations. TIFF0007672214000111.tif26140

[0196] Examples of the cation (b2-4) include the following cations. TIFF0007672214000112.tif82164

[0197] TIFF0007672214000113.tif3041

[0198] 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 one of formulas (B1a-1) to (B1a-3), (B1a-7) to (B1a-16), (B1a-18), (B1a-19), and (B1a-22) to (B1a-38) and a cation (b2-1), a cation (b2-3), or a cation (b2-4).

[0199] The acid generator (B) is preferably one represented by formula (B1-1) to formula (B1-56). Among them, those containing an arylsulfonium cation are preferred, and those represented by formula (B1-1) to formula (B1-3), formula (B1-5) to formula (B1-7), formula (B1-11) to formula (B1-14), formula (B1-20) to formula (B1-26), formula (B1-29), and formula (B1-31) to formula (B1-56) are particularly preferred. TIFF0007672214000114.tif119149

[0200] TIFF0007672214000115.tif77147

[0201] TIFF0007672214000116.tif147147

[0202] TIFF0007672214000117.tif65166

[0203] TIFF0007672214000118.tif110147

[0204] TIFF0007672214000119.tif93158

[0205] In the resist composition of the present invention, the content of the acid generator, relative to 100 parts by mass of the aforementioned resin (A), is preferably 1 part by mass or more and 45 parts by mass or less, more preferably 1 part by mass or more and 40 parts by mass or less, even more preferably 3 parts by mass or more and 40 parts by mass or less, and even more preferably 10 parts by mass or more and 40 parts by mass or less.

[0206] <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.

[0207] <Quencher (C)> The quencher (C) may be a basic nitrogen-containing organic compound or a salt that generates an acid having a weaker acidity than the acid generated from the acid generator (B). When the resist composition contains the quencher (C), the content of the quencher (C) is preferably about 0.01 to 15 mass%, more preferably about 0.01 to 10 mass%, even more preferably about 0.1 to 5 mass%, and even more preferably about 0.1 to 3 mass%, based on the solid content of the resist composition. The basic nitrogen-containing organic compound includes amines and ammonium salts. The amines include aliphatic amines and aromatic amines. The aliphatic amines include primary amines, secondary amines, and tertiary amines. 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 the ammonium salt include tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3-(trifluoromethyl)phenyltrimethylammonium hydroxide, tetra-n-butylammonium salicylate, choline, and the like.

[0208] The acidity of a salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) is indicated by the acid dissociation constant (pKa). A salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) is a salt having an acid dissociation constant of the acid generated from the salt usually of -3 < pKa, preferably -1 < pKa < 7, and more preferably 0 < pKa < 5. Examples of the salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) 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. Preferably, it is a salt that generates a carboxylic acid with a lower acidity than the acid generated from the acid generator (B) (a salt having a carboxylic acid anion), and more preferably, it is the weak acid inner salt (D). TIFF0007672214000120.tif89165

[0209] Examples of the weak acid inner salt (D) include the following salts. TIFF0007672214000121.tif72165

[0210] 〈Other Components〉 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.

[0211] Preparation of Resist Composition The resist composition of the present invention can be prepared by mixing the resin (A), the acid generator (B), and, if necessary, the resin other than the resin (A), the solvent (E), the quencher (C), and other components (F). The order of mixing is arbitrary and is not particularly limited. The temperature during mixing can be appropriately 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 appropriately selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is also not particularly limited, and stirring and mixing can be used. After mixing the components, it is preferable to filter the mixture using a filter having a pore size of about 0.003 to 0.2 μm.

[0212] <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 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. 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. 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 the deprotection reaction of the acid labile groups. The heating temperature is usually about 50 to 200°C, preferably about 70 to 150°C. 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.

[0213] <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, in particular as a resist composition for electron beam (EB) exposure or a resist composition for EUV exposure, and is useful for semiconductor microfabrication. EXAMPLES

[0214] 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 analytical conditions: Column: TSKgel Multipore HXL-M x 3 + guard column (Tosoh Corporation) Eluent: Tetrahydrofuran Flow rate: 1.0mL / min Detector: RI detector Column temperature: 40℃ Injection volume: 100μl Molecular weight standard: Standard polystyrene (Tosoh Corporation) The structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC: Agilent 1100 model, MASS: Agilent LC / MSD model). In the following examples, the value of this molecular ion peak is indicated by "MASS".

[0215] Synthesis Example 1: Synthesis of compound represented by formula (I-8) TIFF0007672214000122.tif48135 5 parts of the compound represented by formula (I-8-a), 5.47 parts of the compound represented by formula (I-8-b) and 25 parts of acetonitrile were mixed and stirred at 23 ° C for 30 minutes, and then stirred at 60 ° C for 1 hour. 4.62 parts of the compound represented by formula (I-8-c) and 5.14 parts of the compound represented by formula (I-8-d) were added to the obtained mixture and stirred at 60 ° C for 1 hour. After cooling the obtained reaction mass to 23 ° C, 150 parts of ethyl acetate and 35 parts of 1N hydrochloric acid were added and stirred at 23 ° C for 30 minutes, and then the organic layer was separated and taken out. 45 parts of ion-exchanged water was added to the collected organic layer and stirred at 23 ° C for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated four times. The obtained organic layer was concentrated, and the concentrated mass was separated using a column (silica gel 60N (spherical, neutral) 100-210 μm; Kanto Chemical Co., Ltd., developing solvent: n-heptane / ethyl acetate=5 / 1) to obtain 5.30 parts of the compound represented by formula (I-8). MASS (mass spectrometry):245.2[M+H] +

[0216] Resin synthesis The compounds (monomers) used in the synthesis of the resin are shown below. TIFF0007672214000123.tif92166Hereinafter, these monomers will be referred to as "monomer (a1-1-1)" etc. according to their formula numbers.

[0217] Example 1 [Synthesis of Resin A1] Monomers were used, and monomer (a1-4-2), monomer (I-8), monomer (a1-2-6) and monomer (III-1) were mixed in a molar ratio of 19:25:38:18 [monomer (a1-4-2):monomer (I-8):monomer (a1-2-6):monomer (III-1)]. Furthermore, 1.5 times the mass of methyl isobutyl ketone was mixed with this monomer mixture relative to the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture in amounts of 1.2 mol% and 3.6 mol%, respectively, relative to the total monomer amount, and these were heated at 73°C for about 5 hours. Thereafter, an aqueous p-toluenesulfonic acid solution was added to the polymerization reaction liquid, and the mixture was stirred for 12 hours, and then separated. The collected 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 having a weight average molecular weight of about 5.5 x 10 3 Resin A1 having the following structural units was obtained in a yield of 88%. JPEG0007672214000124.jpg39145

[0218] Example 2 [Synthesis of Resin A2] Monomer (a1-4-2), monomer (I-8) and monomer (III-1) were used as monomers, and mixed so that the molar ratio [monomer (a1-4-2):monomer (I-8):monomer (III-1)] was 19:63:18. 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 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and these were heated at 73°C for about 5 hours. Thereafter, an aqueous p-toluenesulfonic acid solution was added to the polymerization reaction liquid, and the mixture was stirred for 12 hours and then separated. The collected 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 having a weight average molecular weight of about 5.4 x 10 3 Resin A2 having the following structural units was obtained in a yield of 86%. TIFF0007672214000125.tif40114

[0219] Example 3 [Synthesis of Resin A3] Monomer (I-8) and monomer (III-1) were used as monomers, and mixed so that the molar ratio [monomer (I-8):monomer (III-1)] was 63:37. 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 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and these were heated at 73°C for about 5 hours. Thereafter, an aqueous p-toluenesulfonic acid solution was added to the polymerization reaction liquid, and the mixture was stirred for 12 hours and then separated. The collected organic layer was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and collected to obtain a resin having a weight average molecular weight of about 5.5 x 10 3 Resin A3 having the following structural units was obtained in a yield of 85%. TIFF0007672214000126.tif4082

[0220] Example 4 [Synthesis of Resin A4] Monomer (I-1) and monomer (III-1) were used as monomers, and mixed so that the molar ratio [monomer (I-1):monomer (III-1)] was 63:37. Furthermore, 1.5 times the mass of methyl isobutyl ketone was mixed with this monomer mixture relative to the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture in amounts of 1.2 mol% and 3.6 mol%, respectively, relative to the total monomer amount, and these were heated at 73°C for about 5 hours. Thereafter, an aqueous p-toluenesulfonic acid solution was added to the polymerization reaction liquid, and the mixture was stirred for 12 hours and then separated. The collected 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 having a weight average molecular weight of about 5.7 x 10 3 Resin A4 having the following structural units was obtained in a yield of 91%. TIFF0007672214000127.tif4279

[0221] Example 5 [Synthesis of Resin A5] Monomers were used, and the molar ratio of monomers [monomer (a1-4-2):monomer (I-8):monomer (a1-2-6):monomer (a2-1-3):monomer (a3-4-2):monomer (III-1)] was 12:20:35:3:15:15. Furthermore, 1.5 times the mass of methyl isobutyl ketone was mixed with this monomer mixture relative to the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture in amounts of 1.2 mol% and 3.6 mol% relative to the total monomer amount, respectively, and the mixture was heated at 73°C for about 5 hours. After that, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, and the mixture was stirred for 12 hours and then separated. The collected organic layer was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and collected to obtain a resin with a weight average molecular weight of about 5.2×10 3 Resin A5 having the following structural units was obtained in a yield of 82%. JPEG0007672214000128.jpg38163

[0222] Example 6 [Synthesis of Resin A6] Monomer (I-8), monomer (a2-1-3), monomer (a3-4-2) and monomer (III-1) were used as monomers, and mixed so that the molar ratio [monomer (I-8):monomer (a2-1-3):monomer (a3-4-2):monomer (III-1)] was 55:3:15:27. Furthermore, 1.5 times the mass of methyl isobutyl ketone was mixed with this monomer mixture relative to the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture in amounts of 1.2 mol% and 3.6 mol%, respectively, relative to the total monomer amount, and these were heated at 73°C for about 5 hours. Thereafter, an aqueous p-toluenesulfonic acid solution was added to the polymerization reaction liquid, and the mixture was stirred for 12 hours, and then separated. The collected 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 having a weight average molecular weight of about 5.3 x 10 3 Resin A6 having the following structural units was obtained in a yield of 80%. TIFF0007672214000129.tif38114

[0223] Example 7 [Synthesis of Resin A7] Monomers were used, and monomer (III-1), monomer (I-1), monomer (a1-1-1), monomer (a2-1-1), monomer (a7-1) and monomer (a3-1-1) were mixed in a molar ratio of 20:15:35:5:5:20 [monomer (III-1):monomer (I-1):monomer (a1-1-1):monomer (a2-1-1):monomer (a7-1):monomer (a3-1-1)], and propylene glycol monomethyl ether acetate was added in an amount of 1.5 times the total monomer amount to obtain a solution. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in amounts of 1.1 mol% and 3.3 mol%, respectively, relative to the total monomer amount, to this solution, and these were heated at 75°C for about 5 hours. The resulting reaction mixture was poured into a large amount of a methanol / water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin was dissolved again in propylene glycol monomethyl ether acetate, and an aqueous p-toluenesulfonic acid solution was added and stirred for about 6 hours, after which the liquids were separated and the organic layer was collected. The collected organic layer was poured into a methanol / water mixed solvent to precipitate the resin, and the resin was filtered to obtain a weight-average molecular weight of 5.6 × 10 3 Resin A7 (copolymer) was obtained in a yield of 81%. This resin A7 has the following structural units. TIFF0007672214000130.tif33157

[0224] Example 8 [Synthesis of Resin A8] Monomer (a1-4-13), monomer (I-8) and monomer (III-1) were used as monomers, and mixed so that the molar ratio [monomer (a1-4-13):monomer (I-8):monomer (III-1)] was 19:63:18. 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 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and these were heated at 73°C for about 5 hours. Thereafter, an aqueous p-toluenesulfonic acid solution was added to the polymerization reaction liquid, and the mixture was stirred for 12 hours and then separated. The collected organic layer 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 5.2 x 10 3 Resin A8 having the following structural unit was obtained in a yield of 80%. TIFF0007672214000131.tif40114

[0225] Example 9 [Synthesis of Resin A9] Monomer (I-8) and monomer (III-3) were used as monomers, and mixed so that the molar ratio [monomer (I-8):monomer (III-3)] was 63:37. 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 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and these were heated at 73°C for about 5 hours. After that, an aqueous p-toluenesulfonic acid solution was added to the polymerization reaction liquid, and the mixture was stirred for 12 hours and then separated. The collected 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 about 5.3 x 10 3 Resin A9 having the following structural units was obtained in a yield of 79%. TIFF0007672214000132.tif4082

[0226] Example 10 [Synthesis of Resin A10] Monomers were used, and the molar ratio of monomers [monomer (a1-4-13):monomer (I-8):monomer (a1-2-6):monomer (a2-1-3):monomer (a3-4-2):monomer (III-1)] was 12:20:35:3:15:15. Furthermore, 1.5 times the mass of methyl isobutyl ketone was mixed with this monomer mixture relative to the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture in amounts of 1.2 mol% and 3.6 mol% relative to the total monomer amount, respectively, and the mixture was heated at 73°C for about 5 hours. After that, an aqueous solution of p-toluenesulfonic acid was added to the polymerization reaction solution, and the mixture was stirred for 12 hours and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and recovered to give a resin with a weight average molecular weight of about 5.3×10 3 Resin A10 having the following structural units was obtained in a yield of 77%. TIFF0007672214000133.tif38166

[0227] Example 11 [Synthesis of Resin A11] Monomer (I-8), monomer (a2-1-3), monomer (a3-4-2) and monomer (III-3) were used as monomers, and mixed so that the molar ratio [monomer (I-8):monomer (a2-1-3):monomer (a3-4-2):monomer (III-3)] was 55:3:15:27. 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 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and these were heated at 73°C for about 5 hours. Thereafter, an aqueous p-toluenesulfonic acid solution was added to the polymerization reaction liquid, and the mixture was stirred for 12 hours, and then separated. The collected 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 having a weight average molecular weight of about 5.1 x 10 3 Resin A11 having the following structural unit was obtained in a yield of 74%. TIFF0007672214000134.tif38130

[0228] Synthesis Example 2 [Synthesis of Resin AX1] Monomer (a1-1-1) and monomer (III-1) were used as monomers, and mixed so that the molar ratio [monomer (a1-1-1):monomer (III-1)] was 31:69. Furthermore, 1.5 times the mass of methyl isobutyl ketone was mixed with this monomer mixture relative to the total mass of all monomers. Azobisisobutyronitrile was added as an initiator to the resulting mixture so that the amount was 7 mol% relative to the total molar number of all monomers, and polymerization was carried out by heating at 85°C for about 5 hours. Thereafter, the polymerization solution was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and recovered to obtain a polymer having a weight average molecular weight of about 5.9 x 10 3 Resin AX1 having the following structural units was obtained in a yield of 89%. TIFF0007672214000135.tif2995

[0229] Synthesis Example 3 [Synthesis of Resin AX2] Monomers were used, and the molar ratio [monomer (a1-4-2):monomer (I-1):monomer (a1-1-1):monomer (a2-1-1):monomer (a7-1):monomer (a3-1-1)] was 20:15:35:5:5:20. Propylene glycol monomethyl ether acetate was added in an amount of 1.5 times the total monomer amount to obtain a solution. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in amounts of 1.1 mol% and 3.3 mol% relative to the total monomer amount, respectively, to this solution, and these were heated at 75°C for about 5 hours. The resulting reaction mixture was poured into a large amount of a methanol / water mixed solvent to precipitate a resin, and the resin was filtered. The obtained resin was dissolved again in propylene glycol monomethyl ether acetate, and an aqueous p-toluenesulfonic acid solution was added and stirred for about 6 hours, after which the liquids were separated and the organic layer was collected. The collected organic layer was poured into a methanol / water mixed solvent to precipitate the resin, and the resin was filtered to obtain a weight-average molecular weight of 6.7 × 10 3 Resin AX2 (copolymer) was obtained in a yield of 83%. This resin AX2 has the following structural unit (the elimination rate of ethoxyethyl groups in all ethoxyethyl groups of monomer (a1-4-2) is 100%). TIFF0007672214000136.tif32166

[0230] <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]

[0231] <Resin> A1~A11, AX1, AX2: Resin A1~Resin A11, Resin AX1, Resin AX2 <Acid Generator (B)> B1-43: Salt represented by formula (B1-43) (synthesized according to the examples in JP 2016-47815 A) JPEG0007672214000138.jpg4483<Quencher(C)> C1: Synthesized by the method described in JP 2011-39502 A TIFF0007672214000139.tif4347<solvent> Propylene glycol monomethyl ether acetate 400 parts Propylene glycol monomethyl ether 150 parts γ-Butyrolactone 5 parts

[0232] (Electron beam exposure evaluation of resist composition: Alkaline development) A 6-inch silicon wafer was treated with hexamethyldisilazane at 90°C for 60 seconds on a direct hot plate. The resist composition was spin-coated on the silicon wafer so that the film thickness of the composition layer was 0.04μm. Then, the wafer 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 composition layer. A line and space pattern (pitch 36-72nm / line width 18-36nm) was directly written on the composition layer formed on the wafer using an electron beam lithography machine (ELS-F125 125keV, manufactured by Elionix Co., Ltd.) by changing the exposure dose stepwise. After exposure, post-exposure baking was performed on a hot plate at the temperature shown in the "PEB" column of Table 1 for 60 seconds, and then paddle development was performed for 60 seconds using a 2.38 mass % aqueous tetramethylammonium hydroxide solution to obtain a resist pattern. In the obtained resist pattern, the exposure amount at which the line width and space width of a 36 nm line and space pattern became 1:1 was defined as effective sensitivity.

[0233] <Resolution evaluation> In the effective sensitivity, the resist pattern was observed with a scanning electron microscope, and the minimum line width that could be resolved was taken as the resolution. The results are shown in Table 2. The resolution (nm) is shown. [Table 2] Compared with Comparative Compositions 1 and 2, the resist pattern resolution of Compositions 1 to 11 was smaller, and the resolution evaluation was good.

[0234] (Electron beam exposure evaluation of resist composition: butyl acetate development) A 6-inch silicon wafer was treated with hexamethyldisilazane at 90°C for 60 seconds on a direct hot plate. The resist composition was spin-coated on the silicon wafer so that the film thickness of the composition layer was 0.04μm. Then, the wafer 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 composition layer. An electron beam lithography machine (ELS-F125 125keV, manufactured by Elionix Co., Ltd.) was used to directly lithograph the composition layer formed on the wafer by gradually changing the exposure dose so that a line and space pattern (pitch 36-72nm / line width 18-36nm) would be formed after development. After exposure, post-exposure baking was performed on a hot plate for 60 seconds at the temperature shown in the "PEB" column of Table 1. Next, the composition layer on the silicon wafer was developed by a dynamic dispense method at 23°C for 20 seconds using butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developer to obtain a resist pattern. In the obtained resist pattern, the exposure amount at which the line width and space width of a 36 nm line and space pattern became 1:1 was defined as effective sensitivity.

[0235] <Resolution evaluation> In the effective sensitivity, the resist pattern was observed with a scanning electron microscope, and the minimum line width that could be resolved was taken as the resolution. The results are shown in Table 3. The resolution (nm) is shown. [Table 3] Compared with Comparative Compositions 1 and 2, the resist pattern resolution of Compositions 3, 5, 6, 7, and 9 to 11 was smaller, and the resolution evaluation was good. [Industrial Applicability]

[0236] INDUSTRIAL APPLICABILITY The resin of the present invention and the resist composition containing it are capable of obtaining a resist pattern with excellent resolution, and are therefore suitable for semiconductor microfabrication and extremely useful industrially.

Claims

1. A resin containing a structural unit represented by formula (I), a structural unit represented by formula (III), and a structural unit represented by formula (a2-1), Acid generator and A resist composition comprising a salt which generates a carboxylic acid having a weaker acidity than the acid generated from the acid generator. [In formula (I), R 11 represents a hydrogen atom or a methyl group. R 12 , R 13 and R 14 each independently represents an alkyl group having 1 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; R 12 and R 13 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. X 11 represents a single bond. X 12 represents a single bond. Ar 11 represents an aromatic hydrocarbon group having 6 carbon atoms which may have a substituent. [In formula (III), R ３ represents a hydrogen atom or a methyl group. A １１ represents a single bond. R ４ represents a halogen atom, a hydroxyl group, a haloalkyl group having 1 to 4 carbon atoms, or an alkyl group having 1 to 12 carbon atoms, and —CH 2 - may be replaced by -O- or -CO-. mi represents an integer of 1 to 3. ni represents an integer of 0 to 4, and when ni is 2 or more, a plurality of R ４ may be the same or different, provided that mi + ni ≦ 5. [In formula (a2-1), L a3 represents --O-- or *-O--(CH 2 ) k2 --CO--O--, where k2 represents an integer of 1 to 7. * represents the bonding position with --CO--. R a14 represents a hydrogen atom or a methyl group. R a15 and R a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group. o1 represents an integer of 0 to 10.

2. A resin comprising a structural unit represented by formula (I), a structural unit represented by formula (III), and a structural unit represented by formula (a3-4), Acid generator and A resist composition comprising a salt which generates a carboxylic acid having a weaker acidity than the acid generated from the acid generator. [In formula (I), R 11 represents a hydrogen atom or a methyl group. R 12, R 13, and R 14 each independently represent an alkyl group having 1 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 12 and R 13 bond to each other to form an alicyclic hydrocarbon group having 3 to 20 carbon atoms together with the carbon atom to which they are bonded. X 11 represents a single bond. X 12 represents a single bond. Ar 11 represents an aromatic hydrocarbon group having 6 carbon atoms which may have a substituent. [In formula (III), R 3 represents a hydrogen atom or a methyl group. A 11 represents a single bond. R 4 represents a halogen atom, a hydroxy group, a haloalkyl group having 1 to 4 carbon atoms or an alkyl group having 1 to 12 carbon atoms, and --CH 2 -- contained in the alkyl group may be replaced by --O-- or --CO--. mi represents an integer of 1 to 3. ni represents an integer of 0 to 4, and when ni is 2 or more, the multiple R 4 s may be the same or different from each other, provided that mi+ni≦5.] [In formula (a3-4), L a7 represents -O-, *-O-L a8 -O-, *-O-L a8 -CO-O-, *-O-L a8 -CO-O-L a9 -CO-O-, or *-O-L a8 -O-CO-L a9 -O-. L a8 and L a9 each independently represent an alkanediyl group having 1 to 6 carbon atoms. * indicates the bonding site with the carbonyl group. R a24 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a25 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms. w1 represents an integer of 0 to 8. When w1 is 2 or more, multiple R a25 may be the same or different.

3. The resist composition according to claim 1, further comprising a structural unit represented by formula (a3-4): [In formula (a3-4), L a7 represents -O-, *-O-L a8 -O-, *-O-L a8 -CO-O-, *-O-L a8 -CO-O-L a9 -CO-O-, or *-O-L a8 -O-CO-L a9 -O-. L a8 and L a9 each independently represent an alkanediyl group having 1 to 6 carbon atoms. * indicates the bonding site with the carbonyl group. R a24 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a25 represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms. w1 represents an integer of 0 to 8. When w1 is 2 or more, multiple R a25 may be the same or different.

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

5. 5. The resist composition according to claim 1, further comprising at least one selected from the group consisting of a structural unit represented by formula (a1-1) and a structural unit represented by formula (a1-2): [In formula (a1-1) and formula (a1-2), L ａ１ and L ａ２ are each independently -O- or *-O-(CH ２ ) ｋ１ It represents --CO--O--, k1 represents an integer of 1 to 7, and * represents a bond to --CO--. R ａ４ and R ａ５ each independently represents a hydrogen atom or a methyl group. R ａ６ and R ａ７ each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof. m1 represents an integer of 0 to 14. n1 represents an integer of 0 to 10. n1' represents an integer of 0 to 3.

6. 6. The resist composition according to claim 1, wherein the acid generator contains a salt represented by formula (B1). [In formula (B1), Q ｂ１ and Q. ｂ２ each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. L ｂ１ represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and the —CH ２ - may be replaced by -O- or -CO-, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted by a fluorine atom or a hydroxy group. Y represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 24 carbon atoms, and the —CH ２ - is -O-, -S(O) ２ It may be replaced by --or --CO--. Z ＋ represents an organic cation.

7. (1) A step of applying the resist composition according to any one of claims 1 to 6 onto a substrate; (2) A step of drying the applied composition to form a composition layer; (3) exposing the composition layer to light; (4) heating the composition layer after exposure; and (5) developing the composition layer after heating; A method for producing a resist pattern comprising the steps of:

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