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

Abstract

To provide a salt capable of producing a resist pattern having good line edge roughness (LER), an acid generator, and a resist composition containing the same.SOLUTION: The salt represented by formula (I), the acid generator, and the resist composition are provided. [In the formula, Q1 and Q2 each represent a fluorine atom or a C1-6 perfluoroalkyl group; R1 and R2 each represent a hydrogen atom, a fluorine atom or a C1-6 perfluoroalkyl group; z represents an integer of 0-6; X1 represents *-CO-O-, *-O-CO- or the like; R3 and R4 each independently represent a hydrogen atom or a C1-6 alkyl group; R5 represents a C1-6 alkyl group or a C1-3 alkoxy group; R6 represents a fluorine atom, a C1-6 fluorinated alkyl group or a C1-12 alkyl group; m6 represents an integer of 0-4; and Z+ represents an organic cation.]SELECTED DRAWING: None

Description

Technical Field

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

Background Art

[0002] Patent Document 1 describes a resist composition containing a salt represented by the following formula as an acid generator. TIFF0007702812000001.tif2564 Patent Document 2 describes a resist composition containing a salt represented by the following formula as an acid generator, respectively. TIFF0007702812000002.tif25125

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a salt capable of producing a resist pattern with better line edge roughness (LER) than a resist pattern formed from a resist composition containing the above salt.

Means for Solving the Problems

[0005] The present invention includes the following inventions. [1] A salt represented by formula (I). TIFF0007702812000003.tif20112 [In formula (I), Q 1 and Q 2Each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. R 1 and R 2 Each independently represents a hydrogen atom, a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. z represents any integer from 0 to 6. When z is 2 or more, a plurality of R 1 and R 2 may be the same as or different from each other. X 1 represents *-CO-O-, *-O-CO-, *-O-CO-O- or *-O-, where * represents a bonding site with C(R 1 )(R 2 ) or C(Q 1 )(Q 2 ). R 3 and R 4 Each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. R 5 represents an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 3 carbon atoms. R 6 represents a fluorine atom, an iodine atom, a fluoroalkyl group having 1 to 6 carbon atoms or an alkyl group having 1 to 12 carbon atoms, and -CH2- contained in the fluoroalkyl group and the alkyl group may be replaced by -O- or -CO-. m6 represents any integer from 0 to 4. When m6 is 2 or more, a plurality of R 6 may be the same as or different from each other. Z + represents an organic cation. [2] The salt according to [1], wherein R 5 is a methoxy group. [3] The salt according to [1] or [2], wherein either R 3 or R 4 is a hydrogen atom. [4] The salt according to [1] or [2], wherein either R 3 or R 4 is an alkyl group having 1 to 6 carbon atoms. [5] At least one R 6The bonding position is -C(R 3 )(R 4 )- in the benzene ring, and is the salt described in any one of [1] to [4] at the m-position. An acid generator containing the salt described in any one of [1] to [5]. A resist composition containing the acid generator described in [6] and a resin having an acid-labile group. [8] The resist composition according to [7], wherein the resin having an acid-labile group contains 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). TIFF0007702812000004.tif4191[In formula (a1-1) and formula (a1-2), L a1 and L a2 each independently represents -O- or *-O-(CH2) k1 -CO-O-, k1 represents an integer of any one of 1 to 7, and * represents a bond to -CO-. R a4 and R a5 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R 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 combining these. m1 represents an integer of any one of 0 to 14. n1 represents an integer of any one of 0 to 10. n1’ represents an integer of any one of 0 to 3.] [9] The resist composition according to [7] or [8], wherein the resin having an acid-labile group contains a structural unit represented by formula (a2-A). TIFF0007702812000005.tif4146[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 represents a single bond or * -X a51 -(A a52 -X a52 ) nb - and * represents the bonding site with the carbon atom to which -R a50 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 any integer from 0 to 4. When mb is an integer of 2 or more, a plurality of R a51 may be the same as or different from each other. The resist composition according to any one of [7] to [9], further containing a salt that generates an acid having a lower acidity than the acid generated from the

[10] acid generator.

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

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

Advantages of the Invention

[0006] By using the resist composition containing the salt of the present invention, a resist pattern can be produced with good line edge roughness (LER).

Modes for Carrying Out the Invention

[0007] In this specification, unless otherwise specified, "(meth)acrylate" means "at least one selected from the group consisting of acrylate and methacrylate". Notations such as "(meth)acrylic acid" and "(meth)acryloyl" have the same meaning. When a structural unit having "CH2=C(CH3)-CO-" or "CH2=CH-CO-" is exemplified, a structural unit having both groups is also exemplified. Further, among the groups described in this specification, those that can take both a linear structure and a branched structure may be either of them. When -CH2- contained in a hydrocarbon group or the like is replaced by -O-, -S-, -CO- or -SO2-, the same examples are applicable to each group. "Combined group" means a group formed by bonding two or more of the exemplified groups, and the valences of these groups may be appropriately changed depending on the bonding form. "Derived from" or "derived" means that the polymerizable C=C bond contained in the molecule becomes a -C-C- group by polymerization. When stereoisomers exist, all stereoisomers are included. In this specification, "the solid content of the resist composition" means the total of the components excluding the solvent (E) described later from the total amount of the resist composition.

[0008] [Salt represented by formula (I)] The present invention relates to a salt represented by formula (I) (hereinafter sometimes referred to as "salt (I)"). Among salts (I), the side having a negative charge may be referred to as "anion (I)", and the side having a positive charge may be referred to as "cation (I)". TIFF0007702812000006.tif20112[In formula (I), all symbols have the same meanings as described above.]

[0009] In formula (I), Q 1 , Q 2 , R 1 and R 2Examples of the perfluoroalkyl group include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, a perfluorohexyl group, and the like. Q 1 and Q 2 are each independently preferably a trifluoromethyl group or a fluorine atom, more preferably a fluorine atom. R 1 and R 2 are each independently preferably a hydrogen atom or a fluorine atom, more preferably a hydrogen atom. z is preferably 0 or 1. X 1 is preferably *-CO-O-, *-O-CO-O- or *-O-CO- (* represents the bonding position to C(R 1 )(R 2 ) or C(Q 1 )(Q 2 )), more preferably *-CO-O- or *-O-CO-O-.

[0010] R 3 、R 4 and R 5 Examples of the alkyl group having 1 to 6 carbon atoms for R R 5 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, and a hexyl group. The number of carbon atoms of the alkyl group is preferably 1 to 4, more preferably 1 to 3, and still more preferably 1 or 2. R 3 and R 4 are each independently preferably a hydrogen atom, a methyl group or an ethyl group. It is preferable that either one of R 3 and R 4 is a hydrogen atom, and R3 and R 4 is preferably either a methyl group or an ethyl group. R 5 is preferably a methoxy group or an ethoxy group, more preferably a methoxy group.

[0011] R 6 Examples of the alkyl group having 1 to 12 carbon atoms for R include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, octyl group, nonyl group and the like. The number of carbon atoms of the alkyl group is preferably 1 to 9, more preferably 1 to 6, and still more preferably 1 to 4. R 6 When -CH2- contained in the alkyl group in R is replaced by -O- or -CO-, the total number of carbon atoms before replacement is defined as the total number of carbon atoms of the alkyl group.

[0012] R 6 Examples of the group in which -CH2- contained in the alkyl group in R is replaced by -O- or -CO- include a hydroxy group (the group in which -CH2- contained in the methyl group is replaced by -O-), a carboxy group (the group in which -CH2-CH2- contained in the ethyl group is replaced by -O-CO-), an alkoxy group (the group in which -CH2- at any position contained in the alkyl group is replaced by -O-), an alkoxycarbonyl group (the group in which -CH2-CH2- at any position contained in the alkyl group is replaced by -O-CO-), an alkylcarbonyl group (the group in which -CH2- at any position contained in the alkyl group is replaced by -CO-), an alkylcarbonyloxy group (the group in which -CH2-CH2- at any position contained in the alkyl group is replaced by -CO-O-), and a group formed by combining two or more of these groups. R 6Examples of the alkyl fluoride group having 1 to 6 carbon atoms include alkyl fluoride groups such as trifluoromethyl group, difluoromethyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, perfluorohexyl group and the like. The number of carbon atoms of the alkyl fluoride group is preferably 1 to 4, more preferably 1 to 3.

[0013] R 6 When -CH2- contained in the alkyl fluoride group in is replaced by -O- or -CO-, the total number of carbon atoms before replacement is defined as the total number of carbon atoms of the alkyl group. R 6 Examples of the group in which -CH2- contained in the alkyl fluoride group in is replaced by -O- or -CO- include fluoroalkoxy group (a group in which -CH2- at any position contained in the alkyl fluoride group is replaced by -O-), fluoroalkoxycarbonyl group (a group in which -CH2-CH2- at any position contained in the alkyl fluoride group is replaced by -O-CO-), fluoroalkylcarbonyl group (a group in which -CH2- at any position contained in the alkyl fluoride group is replaced by -CO-), fluoroalkylcarbonyloxy group (a group in which -CH2-CH2- at any position contained in the alkyl fluoride group is replaced by -CO-O-), and groups formed by combining two or more of these groups. Examples of the alkoxy group include alkoxy groups having 1 to 11 carbon atoms, such as methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, nonyloxy group, decyloxy group and undecyloxy group. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 11 carbon atoms, such as methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group and butoxycarbonyl group. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 12 carbon atoms, such as an acetyl group, a propionyl group, and a butyryl group. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 11 carbon atoms, such as a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, and a butylcarbonyloxy group. Examples of the fluoroalkoxy group, fluoroalkoxycarbonyl group, fluoroalkylcarbonyl group, and fluoroalkylcarbonyloxy group include fluoroalkoxy groups having 1 to 5 carbon atoms, fluoroalkoxycarbonyl groups having 2 to 5 carbon atoms, fluoroalkylcarbonyl groups having 2 to 6 carbon atoms, and fluoroalkylcarbonyloxy groups having 2 to 5 carbon atoms. For example, groups in which one or more hydrogen atoms of the groups exemplified above are replaced with fluorine atoms can be mentioned.

[0014] R 6 is preferably a fluorine atom, an iodine atom, a fluoroalkyl group having 1 to 4 carbon atoms, or an alkyl group having 1 to 8 carbon atoms (wherein -CH2- contained in the fluoroalkyl group and the alkyl group may be replaced with -O- or -CO-), more preferably a fluorine atom, an iodine atom, a trifluoromethyl group, or an alkoxy group having 1 to 6 carbon atoms, and even more preferably a fluorine atom, an iodine atom, a trifluoromethyl group, or an alkoxy group having 1 to 3 carbon atoms. m6 is preferably any integer from 0 to 2. When m6 is 1 or 2, the bonding position of at least one R 6 is preferably the m-position with respect to the bonding position of -C(R 3 )(R 4 )- in the benzene ring.

[0015] Examples of the anion (I) include anions represented by the following formulas (Ia-1) to (Ia-22). TIFF0007702812000007.tif238118

[0016] TIFF0007702812000008.tif119127

[0017] Z + Examples of the organic cation include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, organic sulfonium cations and organic iodonium cations are preferred, and arylsulfonium cations are more preferred. Specifically, cations represented by any of formula (b2-1) to formula (b2-4) (hereinafter, may be referred to as "cation (b2-1)" etc. according to the formula number) can be mentioned.

[0018] TIFF0007702812000009.tif45161In formula (b2-1) to formula (b2-4), R b4 ~R b6 each independently represents a chain hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms, and the hydrogen atom contained in the chain hydrocarbon group may be substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, or a glycidyloxy group, and the hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. R b4 and R b5 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and -CH2- contained in the ring may be replaced with -O-, -S-, or -CO-. R b7 and R b8 each independently represents a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. m2 and n2 each independently represent an integer of any one of 0 to 5. When m2 is 2 or more, a plurality of Rs b7 may be the same or different, and when n2 is 2 or more, a plurality of Rs b8 may be the same or different. R b9 and R b10 each independently represent 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 by -O-, -S- or -CO-. R b11 represents a hydrogen atom, a chain hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms. R b12 represents a chain hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and a hydrogen atom contained in the chain hydrocarbon group may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and a hydrogen atom contained in the aromatic hydrocarbon group may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms. R b11 and R b12 may be bonded to each other to form a ring including -CH-CO- to which they are bonded, and -CH2- contained in the ring may be replaced by -O-, -S- or -CO-. R b13 ~R b18 each independently represent a halogen atom, a hydroxy group, a fluorinated alkyl group having 1 to 12 carbon atoms, 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 any one of 0 to 5. q2 and r2 each independently represent an integer from 0 to 4. u2 represents 0 or 1. When o2 is 2 or more, a plurality of Rs b13 are the same or different, and when p2 is 2 or more, a plurality of Rs b14 are the same or different, and when q2 is 2 or more, a plurality of Rs b15 are the same or different, and when r2 is 2 or more, a plurality of Rs b16 are the same or different, and when s2 is 2 or more, a plurality of Rs b17 are the same or different, and when t2 is 2 or more, a plurality of Rs b18 are the same or different. When u2 is 0, any one of o2, p2, q2, and r2 is 1 or more, and among Rs b13 ~Rs b16 at least one of them is preferably a halogen atom. When u2 is 1, any one of o2, p2, s2, t2, q2, and r2 is 1 or more, and among Rs b13 ~Rs b18 at least one of them is preferably a halogen atom.

[0019] An aliphatic hydrocarbon group represents a chain hydrocarbon group and an alicyclic hydrocarbon group. Examples of the chain hydrocarbon group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, and 2-ethylhexyl group. In particular, the chain hydrocarbon group of Rs b9 ~Rs b12 is preferably 1 to 12 carbon atoms. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group, and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups. TIFF0007702812000010.tif10157 In particular, Rsb9 ~R b12 The alicyclic hydrocarbon group is preferably a C3-C18 alicyclic hydrocarbon group, more preferably a C4-C12 alicyclic hydrocarbon group.

[0020] Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-methyladamantan-2-yl group, a 2-ethyladamantan-2-yl group, a 2-isopropyladamantan-2-yl group, a methylnorbornil group, an isobornyl group, etc. In the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group, the total number of carbon atoms of the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less. The alkyl fluoride group represents an alkyl group having 1 to 12 carbon atoms and having a fluorine atom, and examples thereof include a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a perfluorobutyl group, etc. The number of carbon atoms of the alkyl fluoride group is preferably 1 to 9, more preferably 1 to 6, and still more preferably 1 to 4.

[0021] Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a biphenyl group, a naphthyl group, a phenanthryl group, etc. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and examples of the aromatic hydrocarbon group having a chain hydrocarbon group (a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a p-ethylphenyl group, a p-tert-butylphenyl group, a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, etc.) and the aromatic hydrocarbon group having an alicyclic hydrocarbon group (a p-cyclohexylphenyl group, a p-adamantylphenyl group, etc.) are included. When the aromatic hydrocarbon group has a chain hydrocarbon group or an alicyclic hydrocarbon group, a C1-C18 chain hydrocarbon group and a C3-C18 alicyclic hydrocarbon group are preferable. Examples of the aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group include a p-methoxyphenyl group, etc. Examples of the chain hydrocarbon group in which a hydrogen atom is substituted with an aromatic hydrocarbon group include aralkyl groups such as benzyl group, phenethyl group, phenylpropyl group, trityl group, naphthylmethyl group, and naphthylethyl group.

[0022] Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group, and dodecyloxy group. Examples of the alkylcarbonyl group include acetyl group, propionyl group, and butyryl group. Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom, and iodine atom. Examples of the alkylcarbonyloxy group include methylcarbonyloxy group, ethylcarbonyloxy group, propylcarbonyloxy group, isopropylcarbonyloxy group, butylcarbonyloxy group, sec-butylcarbonyloxy group, tert-butylcarbonyloxy group, pentylcarbonyloxy group, hexylcarbonyloxy group, octylcarbonyloxy group, and 2-ethylhexylcarbonyloxy group.

[0023] R b4 and R b5 The ring formed by R TIFF0007702812000011.tif20120

[0024] R b9 and R b10The ring formed by combining and may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring includes 3-membered rings to 12-membered rings, preferably 3-membered rings to 7-membered rings. For example, thiolan-1-ium ring (tetrahydrothiophenium ring), thian-1-ium ring, 1,4-oxathian-4-ium ring, etc. may be mentioned. R b11 and R b12 The ring formed by combining and may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring includes 3-membered rings to 12-membered rings, preferably 3-membered rings to 7-membered rings. Oxocycloheptane ring, oxocyclohexane ring, oxonorbornane ring, oxoadamantane ring, etc. may be mentioned.

[0025] Among cations (b2-1) to (b2-4), preferably, it is cation (b2-1). Examples of cation (b2-1) include the following cations. TIFF0007702812000012.tif77151

[0026] TIFF0007702812000013.tif103156

[0027] Examples of cation (b2-2) include the following cations. TIFF0007702812000014.tif15120

[0028] Examples of cation (b2-3) include the following cations. TIFF0007702812000015.tif20107

[0029] Examples of cation (b2-4) include the following cations. TIFF0007702812000016.tif124161

[0030] Salt (I) is a combination of the above-mentioned anion and the above-mentioned organic cation, and these can be arbitrarily combined. As the salt (I), preferably, a combination of an anion represented by any of Formula (Ia-1) to Formula (Ia-4) and cation (b2-1), cation (b2-2), cation (b2-3) or cation (b2-4) is mentioned.

[0031] Examples of the salt (I) include the salts described in Table 1. In the following table, each symbol represents a symbol attached to the structure representing the above-mentioned anion or cation. For example, the salt (I-1) means a salt composed of an anion represented by Formula (Ia-1) and a cation represented by Formula (b2-c-1), and represents the following salts. TIFF0007702812000017.tif2579 [Table 1] TIFF0007702812000019.tif218150 TIFF0007702812000020.tif218150 TIFF0007702812000021.tif218150 TIFF0007702812000022.tif218150 TIFF0007702812000023.tif218150 TIFF0007702812000024.tif218150 TIFF0007702812000025.tif36126 Among them, the salt (I) is preferably the salt (I-1) to the salt (I-4), the salt (I-11) to the salt (I-16), the salt (I-23) to the salt (I-28), the salt (I-35) to the salt (I-40), the salt (I-47) to the salt (I-52), the salt (I-59) to the salt (I-64), the salt (I-71) to the salt (I-76), the salt (I-83) to the salt (I-88), the salt (I-95) to the salt (I-100), the salt (I-107) to the salt (I-112), the salt (I-121) to the salt (I-224), the salt (I-231) to the salt (I-246), the salt (I-253) to the salt (I-268), the salt (I-275) to the salt (I-286).

[0032] <Method for producing salt (I)> In the salt (I), X 1 The salt in which X is *-CO-O- (the salt represented by the formula (I1)) can be produced, for example, by reacting the salt represented by the formula (I1-a) with carbonyldiimidazole in a solvent and then further reacting with the compound represented by the formula (I1-b). TIFF0007702812000026.tif30132 (In the formula, all the symbols have the same meanings as described above.) Examples of the solvent in this reaction include chloroform and acetonitrile. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours.

[0033] Examples of the salt represented by the formula (I1-a) include the salts represented below, and it can be produced by the method described in JP-A-2008-127367. TIFF0007702812000027.tif56137 Examples of the compound represented by the formula (I1-b) include the compounds represented by the following formula, etc., which can be easily obtained from the market and can also be easily produced by known production methods. TIFF0007702812000028.tif119133

[0034] In the salt (I), X 1The salt where *-O-CO-O- is (the salt represented by formula (I2)) can be produced, for example, by reacting the salt represented by formula (I2-a) with carbonyldiimidazole in a solvent and then further reacting with the compound represented by formula (I1-b). Also, the salt represented by formula (I2) can be produced, for example, by reacting the compound represented by formula (I1-b) with carbonyldiimidazole in a solvent and then further reacting with the salt represented by formula (I2-a). TIFF0007702812000029.tif61157 (In the formula, all symbols have the same meanings as described above respectively.) Examples of the solvent in this reaction include chloroform, acetonitrile, etc. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours. Examples of the salt represented by formula (I2-a) include salts represented below, etc., and it can be produced by the method described in JP-A-2012-193170. TIFF0007702812000030.tif2539

[0035] In salt (I), X 1 The salt where *-O-CO- is (the salt represented by formula (I3)) can be produced, for example, by reacting the compound represented by formula (I3-b) with carbonyldiimidazole in a solvent and then further reacting with the salt represented by formula (I2-a). TIFF0007702812000031.tif30139 (In the formula, all symbols have the same meanings as described above respectively.) Examples of the solvent in this reaction include chloroform, acetonitrile, etc. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours. Examples of the compound represented by formula (I3-b) include compounds represented by the following formula, etc., and they can be easily obtained from the market. TIFF0007702812000032.tif1023

[0036] In salt (I), X 1 being -O- (the salt represented by formula (I4)) can be obtained by reacting the salt represented by formula (I2-a) with the compound represented by formula (I1-b) in a solvent in the presence of a base. TIFF0007702812000033.tif41141 (wherein all the symbols have the same meanings as described above respectively). Examples of the base in this reaction include potassium hydroxide. Examples of the solvent in this reaction include acetonitrile. The reaction temperature is usually 5°C to 80°C, and the reaction time is usually 0.5 hour to 24 hours.

[0037] [Acid generator] The acid generator of the present invention is an acid generator containing salt (I). It may contain one kind of salt (I) or may contain two or more kinds of salt (I). The acid generator of the present invention may contain, in addition to salt (I), an acid generator known in the resist field (hereinafter sometimes referred to as "acid generator (B)"). The acid generator (B) may be used alone or in combination of two or more kinds.

[0038] Either nonionic or ionic acid generator (B) may be used. Examples of the nonionic acid generator include sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxy ketone, diazonaphthoquinone 4-sulfonate), sulfones (for example, disulfone, ketosulfone, sulfonyldiazomethane), etc. Representative examples of the ionic acid generator include onium salts containing onium cations (for example, diazonium salts, phosphonium salts, sulfonium salts, iodonium salts). Examples of the anion of the onium salt include sulfonic acid anion, sulfonylimide anion, sulfonylmethide anion, etc.

[0039] As the acid generator (B), compounds that generate acid upon irradiation, as described in JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853, JP-A-63-146029, U.S. Patent No. 3,779,778, U.S. Patent No. 3,849,137, German Patent No. 3914407, European Patent No. 126,712, etc., can be used. Further, compounds produced by known methods may also be used. The acid generator (B) may be used in combination of two or more kinds.

[0040] The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a salt represented by the formula (B1) (hereinafter sometimes referred to as "acid generator (B1)". However, salt (I) is excluded.). TIFF0007702812000034.tif2861[In the 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- contained in the divalent saturated hydrocarbon group may be replaced by -O- or -CO-, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group. Y represents a methyl group which may have a substituent or an alicyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -SO2- or -CO-. Z1 + represents an organic cation.]

[0041] Q b1 and Q b2Examples of the perfluoroalkyl group in [compound name] include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, a perfluorohexyl group, and the like. Q b1 and Q b2 are each independently preferably a fluorine atom or a trifluoromethyl group, and more preferably both are fluorine atoms.

[0042] L b1 Examples of the divalent saturated hydrocarbon group in [compound name] include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and a group formed by combining two or more of these groups. Specifically, linear alkanediyl groups such as a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, a decane-1,10-diyl group, an undecane-1,11-diyl group, a dodecane-1,12-diyl group, a tridecane-1,13-diyl group, a tetradecane-1,14-diyl group, a pentadecane-1,15-diyl group, a hexadecane-1,16-diyl group, and a heptadecane-1,17-diyl group; branched alkanediyl groups such as 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; monocyclic divalent alicyclic saturated hydrocarbon groups that are cycloalkanediyl groups such as a cyclobutane-1,3-diyl group, a cyclopentane-1,3-diyl group, a cyclohexane-1,4-diyl group, and a cyclooctane-1,5-diyl group; Examples thereof include polycyclic divalent alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group.

[0043] L b1 Examples of the group in which -CH2- contained in the divalent saturated hydrocarbon group represented by is replaced with -O- or -CO- include groups represented by any of formula (b1-1) to formula (b1-3). In the groups represented by formula (b1-1) to formula (b1-3) and their specific examples formula (b1-4) to formula (b1-11), * and ** represent a bond, and * represents a bond to -Y.

[0044] TIFF0007702812000035.tif26117[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 replaced with -O- or -CO-. However, b2 L b3 and the total number of carbon atoms of L 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 replaced with -O- or -CO-. However, b4 L b5The total number of carbon atoms with [the relevant group] 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 the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups. L b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms or hydroxy groups, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-. However, the total number of carbon atoms of L b6 and L b7 is 23 or less.

[0045] In the groups represented by formula (b1-1) to formula (b1-3), when -CH2- contained in the saturated hydrocarbon group is replaced with -O- or -CO-, the number of carbon atoms before replacement is taken as the number of carbon atoms of the saturated hydrocarbon group. Examples of the divalent saturated hydrocarbon group include the same ones as the divalent saturated hydrocarbon group of L b1 . 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 the hydrogen atoms contained in the divalent saturated hydrocarbon group may be substituted with fluorine atoms. 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 the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms. L b7is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and —CH2— contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO—.

[0046] L b1 As a group in which —CH2— contained in the divalent saturated hydrocarbon group represented by b1 is replaced with —O— or —CO—, a group represented by formula (b1-1) or formula (b1-3) is preferable. Examples of the group represented by formula (b1-1) include groups represented by formulas (b1-4) to (b1-8), respectively. TIFF0007702812000036.tif49120[In formula (b1-4), L b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. In formula (b1-5), L b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and —CH2— contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO—. L b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, b9 L b10 and the total carbon number of 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, b11 L b12 and the total carbon number of 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 by -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 replaced by a fluorine atom or a hydroxy group. However, the total number of carbon atoms of L b13 to L b15 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 replaced by a fluorine atom or a hydroxy group. However, the total number of carbon atoms of L b16 to L b18 is 19 or less. L b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms. L b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b10 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b13is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. L b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms. L b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, 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, more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.

[0047] Examples of the group represented by the formula (b1-3) include the groups represented by the formulas (b1-9) to (b1-11). TIFF0007702812000037.tif22140[In the formula (b1-9), L b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxy group or an alkylcarbonyloxy group. -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group. However, the total carbon number of L b19 and L b20 is 23 or less. In the formula (b1-10), L b21represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms. 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 the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms, hydroxy groups or alkylcarbonyloxy groups. The -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and the hydrogen atoms contained in the alkylcarbonyloxy group may be substituted with hydroxy groups. However, L b21 、L b22 and L b23 The total number of carbon atoms of 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 the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms. 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 the hydrogen atoms contained in the saturated hydrocarbon group may be substituted with fluorine atoms, hydroxy groups or alkylcarbonyloxy groups. The -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and the hydrogen atoms contained in the alkylcarbonyloxy group may be substituted with hydroxy groups. However, L b24 、L b25 and L b26 The total number of carbon atoms of is 21 or less.]

[0048] In addition, in the group represented by formula (b1-9) to the group represented by formula (b1-11), when the hydrogen atoms contained in the saturated hydrocarbon group are substituted with alkylcarbonyloxy groups, the number of carbon atoms before replacement is taken as the number of carbon atoms of the saturated hydrocarbon group. Examples of the alkyloxycarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group, and an adamantylcarbonyloxy group.

[0049] Examples of the group represented by formula (b1-4) include the following. TIFF0007702812000038.tif17150

[0050] Examples of the group represented by formula (b1-5) include the following. TIFF0007702812000039.tif68152

[0051] Examples of the group represented by formula (b1-6) include the following. TIFF0007702812000040.tif29150

[0052] Examples of the group represented by formula (b1-7) include the following. TIFF0007702812000041.tif57146

[0053] Examples of the group represented by formula (b1-8) include the following. TIFF0007702812000042.tif23150

[0054] Examples of the group represented by formula (b1-2) include the following. TIFF0007702812000043.tif31161

[0055] Examples of the group represented by formula (b1-9) include the following. TIFF0007702812000044.tif44137

[0056] Examples of the group represented by formula (b1-10) include the following. TIFF0007702812000045.tif89157

[0057] Examples of the group represented by formula (b1-11) include the following. TIFF0007702812000046.tif82158

[0058] Examples of the alicyclic hydrocarbon group represented by Y include the groups represented by formula (Y1) to formula (Y11), formula (Y36) to formula (Y38). When -CH2- contained in the alicyclic hydrocarbon group represented by Y is replaced by -O-, -SO2- or -CO-, the number thereof may be one or two or more. Examples of such groups include the groups represented by formula (Y12) to formula (Y35), formula (Y39) to formula (Y43). * represents the bonding position to L b1 represents the bonding position to

[0059] TIFF0007702812000047.tif81163 Examples of the alicyclic hydrocarbon group represented by Y are preferably groups represented by any of formula (Y1) to formula (Y20), formula (Y26), formula (Y27), formula (Y30), formula (Y31), formula (Y39) to formula (Y43), more preferably groups represented by formula (Y11), formula (Y15), formula (Y16), formula (Y20), formula (Y26), formula (Y27), formula (Y30), formula (Y31), formula (Y39), formula (Y40), formula (Y42) or formula (Y43), and even more preferably groups 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 having an oxygen atom such as formula (Y28) to formula (Y35), formula (Y39), formula (Y40), formula (Y42), formula (Y43), etc., the alkanediyl group between the two oxygen atoms preferably has one or more fluorine atoms. Further, among the alkanediyl groups contained in the ketal structure, the methylene group adjacent to the oxygen atom is preferably not substituted with a fluorine atom.

[0060] Examples of the substituent of the methyl group represented by Y include 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-O-R b1 group or -(CH2) ja -O-CO-R b1 group (wherein 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 group combining these, and -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 any integer from 0 to 4.) and the like. Examples of the substituent of the alicyclic hydrocarbon group represented by Y include a halogen atom, a hydroxy group, an alkyl group having 1 to 16 carbon atoms which may be substituted by a hydroxy group (wherein -CH2- contained in the alkyl group may be replaced by -O- or -CO-), an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, a glycidyloxy group, -(CH2) ja -CO-O-R b1 group or -(CH2) ja -O-CO-R b1 group (wherein 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 group combining these, and -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 any integer from 0 to 4.) and the like.

[0061] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like. 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, an adamantyl group, and the like. The alicyclic hydrocarbon group may have a chain hydrocarbon group, and examples thereof include a methylcyclohexyl group and a dimethylcyclohexyl group. The number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 12, 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 aromatic hydrocarbon groups having a chain hydrocarbon group having 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 having 3 to 18 carbon atoms (p-adamantylphenyl group, p-cyclohexylphenyl group, etc.) are preferable. The number of carbon atoms of the aromatic hydrocarbon group is preferably 6 to 14, 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, and the like. The number of carbon atoms of the alkyl group is preferably 1 to 12, more preferably 1 to 6, and still more preferably 1 to 4. Examples of the alkyl group substituted with a hydroxy group include hydroxyalkyl groups such as a hydroxymethyl group and a hydroxyethyl group. Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, and a naphthylethyl group. Examples of the group in which -CH2- contained in the alkyl group is replaced by -O-, -SO2-, -CO- or the like include an alkoxy group, an alkylsulfonyl group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group or a group combining these. 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 still more preferably 1 to 4. Examples of the alkylsulfonyl group include a methylsulfonyl group, an ethylsulfonyl group, a propylsulfonyl group and the like. The number of carbon atoms in the alkylsulfonyl group is preferably 1 to 12, more preferably 1 to 6, and still more preferably 1 to 4. Examples of the alkoxycarbonyl group include, for example, a methoxycarbonyl group, an ethoxycarbonyl group, a butoxycarbonyl group and the like. The number of carbon atoms in the alkoxycarbonyl group is preferably 2 to 12, more preferably 2 to 6, and still more preferably 2 to 4. Examples of the alkylcarbonyl group include, for example, an acetyl group, a propionyl group and a butyryl group. The number of carbon atoms in the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, and still more preferably 2 to 4. Examples of the alkylcarbonyloxy group include, for example, an acetyloxy group, a propionyloxy group, a butyryloxy group and the like. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2 to 12, more preferably 2 to 6, and still more preferably 2 to 4. Examples of the combined group include, for example, a group combining an alkoxy group and an alkyl group, a group combining an alkoxy group and an alkoxy group, a group combining an alkoxy group and an alkylcarbonyl group, a group combining an alkoxy group and an alkylcarbonyloxy group and the like. Examples of the group combining an alkoxy group and an alkyl group include alkoxyalkyl groups such as methoxymethyl group, methoxyethyl group, ethoxyethyl group, ethoxy methyl group, etc. The number of carbon atoms of the alkoxyalkyl group is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 to 4. Examples of the group combining an alkoxy group and an alkoxy group include alkoxyalkoxy groups such as methoxymethoxy group, methoxyethoxy group, ethoxymethoxy group, ethoxyethoxy group, etc. The number of carbon atoms of the alkoxyalkoxy group is preferably 2 to 12, more preferably 2 to 6, and even more preferably 2 to 4. Examples of the group combining an alkoxy group and an alkylcarbonyl group include alkoxyalkylcarbonyl groups such as methoxyacetyl group, methoxypropionyl group, ethoxyacetyl group, ethoxypropionyl group, etc. The number of carbon atoms of the alkoxyalkylcarbonyl group is preferably 3 to 13, more preferably 3 to 7, and even more preferably 3 to 5. Examples of the group combining an alkoxy group and an alkylcarbonyloxy group include alkoxyalkylcarbonyloxy groups such as methoxyacetyloxy group, methoxypropionyloxy group, ethoxyacetyloxy group, ethoxypropionyloxy group, etc. The number of carbon atoms of the alkoxyalkylcarbonyloxy group is preferably 3 to 13, more preferably 3 to 7, and even more preferably 3 to 5. Examples of the group in which -CH2- contained in the alicyclic hydrocarbon group is replaced by -O-, -SO2- or -CO- etc. include the groups represented by formula (Y12) to formula (Y35), formula (Y39) to formula (Y43).

[0062] Examples of Y include the following. TIFF0007702812000048.tif98157

[0063] TIFF0007702812000049.tif62154

[0064] 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, still more preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, still more preferably an adamantyl group which may have a substituent, and -CH2- constituting the alicyclic hydrocarbon group or adamantyl group may be replaced by -CO-, -SO2- or -CO-. Specifically, Y is preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group or a group represented by formula (Y42), formula (Y100) to formula (Y114).

[0065] As the anion in the salt represented by formula (B1), anions represented by formula (B1-A-1) to formula (B1-A-59) [hereinafter, may be referred to as "anion (B1-A-1)" etc. according to the formula number] are preferable, and an anion represented by any of formula (B1-A-1) to formula (B1-A-4), formula (B1-A-9), formula (B1-A-10), formula (B1-A-24) to formula (B1-A-33), formula (B1-A-36) to formula (B1-A-40), formula (B1-A-47) to formula (B1-A-59) is more preferable. TIFF0007702812000050.tif83151

[0066] TIFF0007702812000051.tif114153

[0067] TIFF0007702812000052.tif119149

[0068] TIFF0007702812000053.tif124135

[0069] TIFF0007702812000054.tif104147

[0070] TIFF0007702812000055.tif61128 Here, R i2 ~R i7are, independently of each other, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. R i8 is, for example, 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. L A41 is a single bond or an alkanediyl group having 1 to 4 carbon atoms. Q b1 and Q b2 represent the same meaning as described above. Specific examples of the anion in the salt represented by the formula (B1) include the anions described in JP-A-2010-204646.

[0071] Preferred examples of the anion in the salt represented by the formula (B1) include the anions represented by the formulas (B1a-1) to (B1a-38), respectively. TIFF0007702812000056.tif82141

[0072] TIFF0007702812000057.tif88131

[0073] TIFF0007702812000058.tif135148

[0074] TIFF0007702812000059.tif56136

[0075] Among them, an anion represented by any one of the formulas (B1a-1) to (B1a-3), (B1a-7) to (B1a-16), (B1a-18), (B1a-19), and (B1a-22) to (B1a-38) is preferred.

[0076] Z1 +Examples of the organic cation include organic onium cations, organic sulfonium cations, organic iodonium cations, organic ammonium cations, benzothiazolium cations, and organic phosphonium cations. Among these, organic sulfonium cations and organic iodonium cations are preferred, and arylsulfonium cations are more preferred. Examples of the arylsulfonium cation include those similar to the cation of Z in formula (I). + include those similar to the cation of Z in formula (I).

[0077] The acid generator (B) is a combination of the above-mentioned anion and the above-mentioned organic cation, and these can be arbitrarily combined. Preferred examples of the acid generator (B) include combinations of an anion represented by any of formula (B1a-1) to formula (B1a-3), formula (B1a-7) to formula (B1a-16), formula (B1a-18), formula (B1a-19), formula (B1a-22) to formula (B1a-38) and cation (b2-1), cation (b2-3) or cation (b2-4).

[0078] Preferred examples of the acid generator (B) include those 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), formula (B1-31) to formula (B1-56) are particularly preferred. TIFF0007702812000060.tif62148

[0079] TIFF0007702812000061.tif181160

[0080] TIFF0007702812000062.tif88150

[0081] TIFF0007702812000063.tif140158

[0082] TIFF0007702812000064.tif93122

[0083] TIFF0007702812000065.tif88152

[0084] When containing salt (I) and acid generator (B) as the acid generator, the ratio of the content of salt (I) to the acid generator (B) (mass ratio; salt (I): acid generator (B)) is usually 1:99 to 99:1, preferably 2:98 to 98:2, more preferably 5:95 to 95:5, still more preferably 10:90 to 90:10, and particularly preferably 15:85 to 85:15.

[0085] 〔Resist composition〕 The resist composition of the present invention contains an acid generator containing salt (I) and a resin having an acid-labile group (hereinafter sometimes referred to as "resin (A)"). Here, the "acid-labile group" means a group having a leaving group, and when contacted with an acid, the leaving group is eliminated and the structural unit is converted into a structural unit having a hydrophilic group (for example, a hydroxy group or a carboxy group). The resist composition of the present invention preferably contains a quencher such as a salt that generates an acid having a lower acidity than the acid generated from the acid generator (hereinafter sometimes referred to as "quencher (C)"), and preferably contains a solvent (hereinafter sometimes referred to as "solvent (E)").

[0086] <Acid generator> In the resist composition of the present invention, the total content rate of the acid generator is preferably 1 part by mass or more and 45 parts by mass or less, more preferably 1 part by mass or more and 40 parts by mass or less, still more preferably 3 parts by mass or more and 40 parts by mass or less, even more preferably 3 parts by mass or more and 35 parts by mass or less, and still even more preferably 5 parts by mass or more and 35 parts by mass or less with respect to 100 parts by mass of the resin (A) described later.

[0087] <Resin (A)> Resin (A) has a structural unit having an acid-labile group (hereinafter sometimes referred to as "structural unit (a1)"). Resin (A) preferably further contains a structural unit other than structural unit (a1). Examples of the structural unit other than structural unit (a1) include a structural unit having no acid-labile group (hereinafter sometimes referred to as "structural unit (s)"), a structural unit other than structural unit (a1) and structural unit (s) (for example, a structural unit having a halogen atom described later (hereinafter sometimes referred to as "structural unit (a4)"), a structural unit having a non-leaving hydrocarbon group described later (hereinafter sometimes referred to as "structural unit (a5)"), and a structural unit derived from other monomers known in the art, etc.).

[0088] 〈Structural unit (a1)〉 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 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)"). TIFF0007702812000066.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 group combining these, or R a1 and R a2 are bonded to each other to form a non-aromatic hydrocarbon ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded. ma and na each independently represent 0 or 1, and at least one of ma and na represents 1. * represents a bonding site. ] TIFF0007702812000067.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’They are bonded to each other to form a heterocyclic ring having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded and X, and the —CH2— contained in the hydrocarbon group and the heterocyclic ring may be replaced by —O— or —S—. X represents an oxygen atom or a sulfur atom. na’ represents 0 or 1. * represents a bonding site.]

[0089] R a1 、R a2 and R a3 Examples of the alkyl group in R R a1 、R a2 and R a3 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, etc. R a1 、R a2 and R a3 The alicyclic hydrocarbon group in R a1 、R a2 and R a3 may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, etc. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* represents a bonding site.). R a1 、R a2 and R a3 The number of carbon atoms of the alicyclic hydrocarbon group is preferably 3 to 16. TIFF0007702812000068.tif10150R a1 、R a2 and R a3 Examples of the aromatic hydrocarbon group in R Examples of the combined group include a group combining the above-described alkyl group and alicyclic hydrocarbon group (e.g., alkylcycloalkyl group or cycloalkylalkyl group), aralkyl group such as benzyl group, aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon group having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl group such as phenylcyclohexyl group, and the like. Preferably, ma is 0 and na is 1. R a1 and R a2 When they are bonded to each other to form a non-aromatic hydrocarbon ring, examples of -C(R a1 )(R a2 )(R a3 ) include the following rings. The non-aromatic hydrocarbon ring preferably has 3 to 12 carbon atoms. * represents the bonding site with -O-. TIFF0007702812000069.tif31139

[0090] R a1’ 、R a2’ and R a3’ Examples of the hydrocarbon group in R include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these. a1 、R a2 and R a3 are the same as those exemplified for R Examples of the aromatic hydrocarbon group include aryl groups such as phenyl group, naphthyl group, anthryl group, biphenyl group, and phenanthryl group. Examples of the combined group include a group combining the above-described alkyl group and alicyclic hydrocarbon group (e.g., alkylcycloalkyl group or cycloalkylalkyl group), aralkyl group such as benzyl group, aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon group having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl group such as phenylcyclohexyl group, and the like. R a2’ and R a3’ are bonded to each other to form a heterocyclic ring together with the carbon atom to which they are bonded and X, -C(R a1’ )(R a2’ )-X-R a3’ includes the following rings. * represents the bonding site. TIFF0007702812000070.tif18130R a1’ and R a2’ at least one of them is preferably a hydrogen atom. na' is preferably 0.

[0091] Examples of the group (1) include the following groups. In formula (1), R a1 , R a2 and R a3 are alkyl groups, ma = 0, and na = 1. The tert-butoxycarbonyl group is preferred as the group. In formula (1), R a1 , R a2 together with the carbon atom to which they are bonded 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 the bonding site. TIFF0007702812000071.tif167160

[0092] Specific examples of the group (2) include the following groups. * represents the bonding site. TIFF0007702812000072.tif68162

[0093] 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.

[0094] Among the (meth)acrylic monomers having an acid-labile group, those having an alicyclic hydrocarbon group with 5 to 20 carbon atoms are preferred. If a resin (A) having a structural unit derived from a monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group is used in the resist composition, the resolution of the resist pattern can be improved.

[0095] As the structural unit derived from the (meth)acrylic monomer having the group (1), a structural unit represented by the formula (a1-0) (hereinafter sometimes referred to as the structural unit (a1-0)), a structural unit represented by the formula (a1-1) (hereinafter sometimes referred to as the structural unit (a1-1)), or a structural unit represented by the formula (a1-2) (hereinafter sometimes referred to as the structural unit (a1-2)) can be mentioned. Preferably, it is 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. TIFF0007702812000073.tif46149[In the formula (a1-0), the formula (a1-1), and the formula (a1-2), L a01 、L a1 and L a2 each independently represents -O- or *-O-(CH2) k1 -CO-O-, k1 represents an integer of 1 to 7, and * represents the bonding site with -CO-. R a01 、R a4 and R a5 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a02 、R a03 and R a04 each independently represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these. R a6 and R a7 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these. m1 represents any integer from 0 to 14. n1 represents any integer from 0 to 10. n1’ represents any integer from 0 to 3.

[0096] R a01 、R a4 and R a5 are preferably a hydrogen atom or a methyl group, more preferably a methyl group. L a01 、L a1 and L a2 are preferably an oxygen atom or *-O-(CH2) k01 -CO-O- (wherein k01 is preferably any integer from 1 to 4, more preferably 1), more preferably an oxygen atom. R a02 、R a03 、R a04 、R a6 and R a7 Examples of the alkyl group, alkenyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group, and a group formed by combining these in a1 、R a2 and R a3 are the same as the groups exemplified for R R a02 、R a03 、and Ra04 The alkyl group in is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and still more preferably a methyl group. R a6 and R a7 The alkyl group in is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group or a t-butyl group, and still more preferably an ethyl group, an isopropyl group or a t-butyl group. R a6 and R a7 The alkenyl group in is preferably an alkenyl group having 2 to 6 carbon atoms, more preferably an ethenyl group, a propenyl group, an isopropenyl group or a butenyl group. R a02 , R a03 , R a04 , R a6 and R a7 The number of carbon atoms of the alicyclic hydrocarbon group of and is preferably 5 to 12, and more preferably 5 to 10. R a02 , R a03 , R a04 , R a6 and R a7 The number of carbon atoms of the aromatic hydrocarbon group of and is preferably 6 to 12, and more preferably 6 to 10. For the group formed by combining an alkyl group and an alicyclic hydrocarbon group, it is preferable that the total number of carbon atoms of these alkyl group and alicyclic hydrocarbon group is 18 or less. For the group formed by combining an alkyl group and an aromatic hydrocarbon group, it is preferable that the total number of carbon atoms of these alkyl group and aromatic hydrocarbon group is 18 or less. R a02 and R a03 are preferably an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, 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, more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. Ra6 and R a7 is 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 still more preferably an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group or a phenyl group. m1 is preferably any integer from 0 to 3, more preferably 0 or 1. n1 is preferably any integer from 0 to 3, more preferably 0 or 1. n1' is preferably 0 or 1.

[0097] Examples of the structural unit (a1-0) include a structural unit represented by any of the formulas (a1-0-1) to (a1-0-18) and a methyl group corresponding to R in the structural unit (a1-0) a01 which is replaced by a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group, and a structural unit represented by any of the formulas (a1-0-1) to (a1-0-10), (a1-0-13), (a1-0-14) is preferred. TIFF0007702812000074.tif92157

[0098] Examples of the structural unit (a1-1) include a structural unit derived from the monomers described in JP-A-2010-204646. Among them, a structural unit represented by any of the formulas (a1-1-1) to (a1-1-7) and a methyl group corresponding to R in the structural unit (a1-1) a4 which is replaced by a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group is preferred, and a structural unit represented by any of the formulas (a1-1-1) to (a1-1-4) is more preferred. TIFF0007702812000075.tif36152

[0099] Examples of the structural unit (a1-2) include a structural unit represented by any of Formula (a1-2-1) to Formula (a1-2-14) and a structural unit in which the methyl group corresponding to R a5 in the structural unit (a1-2) is replaced with a hydrogen atom, a halogen atom, a haloalkyl group, or another alkyl group, and the structural units represented by Formula (a1-2-2), Formula (a1-2-5), Formula (a1-2-6), and Formula (a1-2-10) to Formula (a1-2-14) are preferred. TIFF0007702812000076.tif62150

[0100] When the resin (A) contains the structural unit (a1-0), its content is usually 5 to 80 mol%, preferably 5 to 75 mol%, more preferably 10 to 70 mol% with respect to all the structural units of 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%, still more preferably 20 to 75 mol%, and even more preferably 20 to 70 mol% with respect to all the structural units of the resin (A).

[0101] Examples of the structural unit having the group (2) in the structural unit (a1) include a structural unit represented by Formula (a1-4) (hereinafter sometimes referred to as "structural unit (a1-4)"). TIFF0007702812000077.tif3650[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 represents a single bond or* -X a31 -(A a32 -X a32 ) nc - represents, and * represents the bonding site with the carbon atom to which -R a32 is bonded. A a32 represents an alkanediyl group having 1 to 6 carbon atoms. X a31 and X a32 each independently represent -O-, -CO-O- or -O-CO-. nc represents 0 or 1. la represents any integer from 0 to 4. When la is 2 or more, a plurality of R a33 may be the same as or different from each other. R a34 and R a35 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R a36 represents a hydrocarbon group having 1 to 20 carbon atoms, or R a35 and R a36 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms together with the -C-O- to which they are bonded, and the -CH2- contained in the hydrocarbon group and the divalent hydrocarbon group may be replaced by -O- or -S-.

[0102] R a32 and R a33 Examples of the halogen atom in R include a fluorine atom, a chlorine atom, a bromine atom, and the like. a32 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in R include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, a hexyl group, and a perfluorohexyl group.a32 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group. R a33 Examples of the alkyl group in R a33 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 alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group. R a33 Examples of the alkoxyalkyl group in R a33 include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and even more preferably a methoxymethyl group. R a33 Examples of the alkylcarbonyl group in R a33Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, more preferably an acetyloxy group. R 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 ethoxy methoxy group, still more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group.

[0103] *-X a31 -(A a32 -X a32 ) nc Examples of - include *-O-, *-CO-O-, *-O-CO-, *-CO-O-A a32 -CO-O-, *-O-CO-A a32 -O-, *-O-A a32 -CO-O-, *-CO-O-A a32 -O-CO-, *-O-CO-A a32 -O-CO-, etc. Among them, *-CO-O-, *-CO-O-A a32 -CO-O- or *-O-A a32 -CO-O- is preferred.

[0104] Examples of the alkanediyl group include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, 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.

[0105] A a30is a single bond, *-CO-O- or *-CO-O-A a32 -CO-O- is preferred, more preferably a single bond, *-CO-O- or *-CO-O-CH2-CO-O-, and even more preferably a single bond or *-CO-O-.

[0106] 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 for R include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group combining these. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and the like. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* represents the bonding site). TIFF0007702812000078.tif10151Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. Examples of the combined group include a group combining the above-mentioned alkyl group and alicyclic hydrocarbon group (e.g., cycloalkylalkyl group), an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), an aryl-cycloalkyl group such as a phenylcyclohexyl group, and the like. In particular, R a36Examples thereof 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.

[0107] R a34 is preferably a hydrogen atom. R a35 is preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a methyl group or an ethyl group. R a36 The hydrocarbon group of R is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these groups, and more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic aliphatic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. The alkyl group and alicyclic hydrocarbon group in R a36 are preferably unsubstituted. The aromatic hydrocarbon group in R a36 preferably has an aromatic ring having an aryloxy group having 6 to 10 carbon atoms. -OC(R a34 )(R a35 )-O-R a36 is eliminated by contact with an acid (e.g., p-toluenesulfonic acid) to form a hydroxy group. -OC(R a34 )(R a35 )-O-R a36 is preferably bonded to the o-position or p-position of the benzene ring, and more preferably bonded to the p-position.

[0108] Examples of the structural unit (a1-4) include structural units derived from the monomers described in JP-A-2010-204646. Preferably, the structural units represented by formula (a1-4-1) to formula (a1-4-18) and R in the structural unit (a1-4) a32Examples of the structural unit in which the hydrogen atom corresponding to the formula is replaced with a halogen atom, a haloalkyl group, or an alkyl group include, and more preferably, structural units represented by formula (a1-4-1) to formula (a1-4-5), formula (a1-4-10), formula (a1-4-13), and formula (a1-4-14). TIFF0007702812000079.tif93156

[0109] When the resin (A) contains the structural unit (a1-4), its content is preferably 3 to 80 mol%, more preferably 5 to 75 mol%, still more preferably 7 to 70 mol%, still more preferably 7 to 65 mol%, and particularly preferably 10 to 60 mol% with respect to the total of all the structural units of the resin (A).

[0110] Examples of the structural unit derived from the (meth)acrylic monomer having the group (2) include the structural unit represented by formula (a1-5) (hereinafter sometimes referred to as "structural unit (a1-5)"). TIFF0007702812000080.tif4658In formula (a1-5), R a8 represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom, or a halogen atom. Z a1 represents a single bond or *-(CH2) h3 -CO-L 54 -, h3 represents an integer of 1 to 4, and * represents the bonding site with L 51 . L 51 L 52 L 53 and L 54 each independently represent -O- or -S-. s1 represents an integer of 1 to 3. s1' represents an integer of 0 to 3.

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

[0112] Examples of the structural unit (a1-5) include structural units derived from the monomers described in JP-A-2010-61117. Among them, the structural units represented by formula (a1-5-1) to formula (a1-5-4) are preferable, and the structural unit represented by formula (a1-5-1) or formula (a1-5-2) is more preferable. TIFF0007702812000081.tif33133

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

[0114] Examples of the structural unit (a1) also include the following structural units. TIFF0007702812000082.tif31162

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

[0116] In addition, examples of the structural unit (a1) also include the following structural units. TIFF0007702812000083.tif5295 When the resin (A) contains structural units such as the above (a1-6-1) to (a1-6-3), the content is preferably 10 to 60 mol%, more preferably 15 to 55 mol%, still more preferably 20 to 50 mol%, even more preferably 20 to 45 mol%, and particularly preferably 20 to 40 mol% based on all the structural units of the resin (A).

[0117] 〈Structural unit (s)〉 The structural unit (s) is derived from a monomer having no acid-labile group (hereinafter sometimes referred to as "monomer (s)"). As the monomer that leads to the structural unit (s), 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. By using 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, the resolution of the resist pattern and the adhesion to the substrate can be improved.

[0118] 〈Structural unit (a2)〉 The hydroxy group of the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group. When producing a resist pattern from the resist composition of the present invention, when using a high-energy ray such as a KrF excimer laser (248 nm), an electron beam, or EUV (extreme ultraviolet light) as an exposure light source, as the structural unit (a2), a structural unit (a2) having a phenolic hydroxy group is preferable, and it is more preferable to use the structural unit (a2-A) described later. When using an ArF excimer laser (193 nm) or the like, as the structural unit (a2), a structural unit (a2) having an alcoholic hydroxy group is preferable, and it is more preferable to use the structural unit (a2-1) described later. The structural unit (a2) may be included alone by 1 type, or may be included by 2 or more types.

[0119] Examples of the structural unit having a phenolic hydroxy group in the structural unit (a2) include a structural unit represented by the formula (a2-A) (hereinafter sometimes referred to as "structural unit (a2-A)"). TIFF0007702812000084.tif4551[In the 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 represents a single bond or *-X a51 -(A a52 -X a52 ) nb -, and * represents the bonding position with the carbon atom to which -R a50 is bonded. A a52 each independently 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 any integer from 0 to 4. When mb is any integer of 2 or more, a plurality of Rs a51 may be the same as or different from each other.]

[0120] R a50 and R a51 Examples of the halogen atom in R and R 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 R include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, a hexyl group, and a perfluorohexyl group. R a50 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group. R a51 Examples of the alkyl group in R include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. R a51 Examples of the alkoxy group in R include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, and a tert-butoxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and even more preferably a methoxy group. R a51Examples of the alkoxyalkyl group in [context] include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and even more preferably a methoxymethyl group. R a51 Examples of the alkoxyalkoxy group in [context] 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 [context] include an acetyl group, a propionyl group, and a butyryl group. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group. R a51 Examples of the alkylcarbonyloxy group in [context] include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group. R a51 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group, and even more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group.

[0121] *-X a51 -(A a52 -X a52 ) nb- includes, *-O-, *-CO-O-, *-O-CO-, *-CO-O-A a52 -CO-O-, *-O-CO-A a52 -O-, *-O-A a52 -CO-O-, *-CO-O-A a52 -O-CO-, *-O-CO-A a52 -O-CO- are included. Among them, *-CO-O-, *-CO-O-A a52 -CO-O- or *-O-A a52 -CO-O- is preferred.

[0122] Examples of the alkanediyl group include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, 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.

[0123] A a50 is preferably a single bond, *-CO-O- or *-CO-O-A a52 -CO-O-, more preferably a single bond, *-CO-O- or *-CO-O-CH2-CO-O-, and even more preferably a single bond or *-CO-O-.

[0124] mb is preferably 0, 1 or 2, more preferably 0 or 1, and particularly preferably 0. The hydroxy group is preferably bonded to the o-position or p-position of the benzene ring, and more preferably bonded to the p-position.

[0125] Examples of the structural unit (a2-A) include structural units derived from monomers described in JP-A-2010-204634 and JP-A-2012-12577.

[0126] As the structural unit (a2-A), there are structural units represented by formula (a2-2-1) to formula (a2-2-16), and in the structural units represented by formula (a2-2-1) to formula (a2-2-16), the methyl group corresponding to R in the structural unit (a2-A) a50 is replaced by a hydrogen atom, a halogen atom, a haloalkyl group or another alkyl group. The structural unit (a2-A) is preferably a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) is replaced by a hydrogen atom in the structural unit represented by formula (a2-2-1), the structural unit represented by formula (a2-2-3), the structural unit represented by formula (a2-2-6), the structural unit represented by formula (a2-2-8), the structural units represented by formula (a2-2-12) to formula (a2-2-14), and the structural unit represented by formula (a2-2-1), the structural unit represented by formula (a2-2-3), the structural unit represented by formula (a2-2-6), the structural unit represented by formula (a2-2-8), the structural units represented by formula (a2-2-12) to formula (a2-2-14). a50 More preferably, it is a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) is replaced by a hydrogen atom in the structural unit represented by formula (a2-2-3), the structural unit represented by formula (a2-2-8), the structural units represented by formula (a2-2-12) to formula (a2-2-14), and the structural unit represented by formula (a2-2-3) or the structural unit represented by formula (a2-2-8), the structural units represented by formula (a2-2-12) to formula (a2-2-14). a50 Even more preferably, it is a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) is replaced by a hydrogen atom in the structural unit represented by formula (a2-2-8) and the structural unit represented by formula (a2-2-8). a50 Even more preferably, it is a structural unit in which the methyl group corresponding to R in the structural unit (a2-A) is replaced by a hydrogen atom. TIFF0007702812000085.tif51155

[0127] When the resin (A) contains the structural unit (a2-A), the content of the structural unit (a2-A) is preferably 5 to 80 mol%, more preferably 10 to 70 mol%, even more preferably 15 to 65 mol%, and even more preferably 20 to 65 mol% based on all the structural units. The structural unit (a2-A) can be incorporated into the resin (A) by, for example, polymerizing using the structural unit (a1-4) and then treating with an acid such as p-toluenesulfonic acid. Also, after polymerizing using acetoxystyrene or the like, the structural unit (a2-A) can be incorporated into the resin (A) by treating with an alkali such as tetramethylammonium hydroxide.

[0128] Examples of the structural unit having an alcoholic hydroxy group in the structural unit (a2) include a structural unit represented by the formula (a2-1) (hereinafter sometimes referred to as "structural unit (a2-1)"). TIFF0007702812000086.tif4258In the formula (a2-1), L a3 represents -O- or *-O-(CH2) k2 -CO-O-, k2 represents an integer of any one 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 any one of 0 to 10.

[0129] In the formula (a2-1), L a3 is preferably -O-, -O-(CH2) f1 -CO-O- (wherein f1 represents an integer of any one of 1 to 4), 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 any one of 0 to 3, more preferably 0 or 1.

[0130] Examples of the structural unit (a2-1) include structural units derived from the monomers described in JP-A-2010-204646. The structural unit represented by any of formula (a2-1-1) to formula (a2-1-6) is preferable, the structural unit represented by any of formula (a2-1-1) to formula (a2-1-4) is more preferable, and the structural unit represented by formula (a2-1-1) or formula (a2-1-3) is even more preferable. TIFF0007702812000087.tif50140

[0131] When the resin (A) contains the structural unit (a2-1), the content 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 even more preferably 1 to 10 mol% based on all the structural units of the resin (A).

[0132] 〈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. Preferably, a γ-butyrolactone ring, an adamantane lactone ring, or a bridged ring containing a γ-butyrolactone ring structure (for example, a structural unit represented by the following formula (a3-2)) can be mentioned.

[0133] The structural unit (a3) is preferably a structural unit represented by formula (a3-1), formula (a3-2), formula (a3-3), or formula (a3-4). These may be contained alone or in combination of two or more. TIFF0007702812000088.tif52165[In formula (a3-1), formula (a3-2), formula (a3-3), and formula (a3-4), L a4 , L a5 and L a6 each independently represents a group represented by -O- or *-O-(CH2) k3 -CO-O- (where k3 represents an integer of 1 to 7). L a7 is -O-, *-O-La8 -O-, *-O-L a8 -CO-O-, *-O-L a8 -CO-O-L a9 -CO-O- or *-O-L a8 -O-CO-L a9 represents -O-. L a8 and L a9 each independently represents an alkanediyl group having 1 to 6 carbon atoms. * represents the bonding position with 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 any integer from 0 to 5. q1 represents any integer from 0 to 3. r1 represents any integer from 0 to 3. w1 represents any integer from 0 to 8. When p1, q1, r1 and / or w1 is 2 or more, the plurality of Rs a21 , R a22 , R a23 and / or R a25 may be the same as or different from each other.

[0134] R a21 , R a22 , R a23 and R a25Examples of the aliphatic hydrocarbon group in [context] include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, and tert-butyl group. R a24 Examples of the halogen atom in [context] include fluorine atom, chlorine atom, bromine atom, and iodine atom. R a24 Examples of the alkyl group in [context] include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, and hexyl group, etc. Preferably, an alkyl group having 1 to 4 carbon atoms is mentioned, and more preferably, a methyl group or an ethyl group is mentioned. R a24 Examples of the alkyl group having a halogen atom in [context] include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group, perfluorohexyl group, trichloromethyl group, tribromomethyl group, triiodomethyl group, etc.

[0135] L a8 and L a9 Examples of the alkanediyl group in [context] and [context] include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, and 2-methylbutane-1,4-diyl group, etc.

[0136] In formulas (a3-1) to (a3-3), L a4 ~L a6 are each independently, preferably -O- or, *-O-(CH2) k3 -CO-O- in which k3 is an integer of any one of 1 to 4, more preferably -O- and, *-O-CH2-CO-O-, and even more preferably an oxygen atom. R a18 ~Ra21 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 are each independently preferably any integer from 0 to 2, more preferably 0 or 1.

[0137] 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, still 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 *-O-L a8 -CO-O-, more preferably -O-, -O-CH2-CO-O- or -O-C2H4-CO-O-. w1 is preferably any integer from 0 to 2, more preferably 0 or 1. In particular, formula (a3-4) is preferably formula (a3-4)’. TIFF0007702812000089.tif3849 (wherein R a24 , L a7 have the same meanings as described above.)

[0138] Examples of the structural unit (a3) include structural units derived from the monomers described in JP-A-2010-204646, the monomers described in JP-A-2000-122294, and the monomers described in JP-A-2012-41274. Examples of the structural unit (a3) include structural units represented by any of formula (a3-1-1), formula (a3-1-2), formula (a3-2-1), formula (a3-2-2), formula (a3-3-1), formula (a3-3-2) and formula (a3-4-1) to formula (a3-4-12), and in the above structural units, R a18 , R a19 , R a20 and Ra24 A structural unit in which the methyl group corresponding thereto is replaced by a hydrogen atom is preferred.

[0139] TIFF0007702812000090.tif114160

[0140] When the resin (A) contains the structural unit (a3), the total content is usually 5 to 70 mol%, preferably 10 to 65 mol%, more preferably 10 to 60 mol% with respect to all the structural units of the resin (A). In addition, 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 5 to 60 mol%, more preferably 5 to 50 mol%, and still more preferably 10 to 50 mol% with respect to all the structural units of the resin (A).

[0141] 〈Structural unit (a4)〉 Examples of the structural unit (a4) include the following structural units. TIFF0007702812000091.tif2861[In formula (a4), R 41 represents a hydrogen atom or a methyl group. R 42 represents a saturated hydrocarbon group having a halogen atom with 1 to 24 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. R 42 The saturated hydrocarbon group represented by includes a chain saturated hydrocarbon group, a monocyclic or polycyclic alicyclic saturated hydrocarbon group, and a group formed by combining these.

[0142] 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 cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclooctyl group; polycyclic alicyclic saturated hydrocarbon groups such as decahydronaphthyl group, adamantyl group, norbornyl group, and the following group (* represents the bonding site). Examples of the group formed by the combination of include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic saturated hydrocarbon groups, such as -alkanediyl group-alicyclic saturated hydrocarbon group, -alicyclic saturated hydrocarbon group-alkyl group, -alkanediyl group-alicyclic saturated hydrocarbon group-alkyl group, etc.

[0143] Examples of the structural unit (a4) include the structural unit represented by formula (a4-0), the structural unit represented by formula (a4-1), and the structural unit represented by formula (a4-4). TIFF0007702812000093.tif4247[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.]

[0144] L 4a Examples of the alkanediyl group in L include linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, and branched alkanediyl groups such as ethane-1,1-diyl group, propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, and 2-methylpropane-1,2-diyl group.

[0145] L 3aExamples of the perfluoroalkanediyl group in [description] include difluoromethylene group, perfluoroethylene group, perfluoroethylfluoromethylene group, perfluoropropane-1,3-diyl group, perfluoropropane-1,2-diyl group, perfluoropropane-2,2-diyl group, perfluorobutane-1,4-diyl group, perfluorobutane-2,2-diyl group, perfluorobutane-1,2-diyl group, perfluoropentane-1,5-diyl group, perfluoropentane-2,2-diyl group, 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, perfluorooctane-4,4-diyl group, and the like. L 3a Examples of the perfluorocycloalkanediyl group in [description] include perfluorocyclohexanediyl group, perfluorocyclopentanediyl group, perfluorocycloheptanediyl group, perfluoroadamantanediyl group, and the like.

[0146] L 4a is preferably a single bond, a methylene group or an ethylene group, more preferably a single bond or a methylene group. L 3a is preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

[0147] Examples of the structural unit (a4-0) include the structural units shown below and the structural units in the following structural units where the methyl group corresponding to R in the structural unit (a4-0) is replaced by a hydrogen atom. 54 include the structural units in which the methyl group corresponding to R in the structural unit (a4-0) is replaced by a hydrogen atom. TIFF0007702812000094.tif93155

[0148] TIFF0007702812000095.tif4866 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 alkanediyl group having 1 to 6 carbon atoms which may have a substituent or a group represented by formula (a-g1). However, at least one of A a41 and R a42 has a halogen atom (preferably a fluorine atom) as a substituent. TIFF0007702812000096.tif1488 [In formula (a-g1), s represents 0 or 1. A a42 and A a44 each independently represent 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 represent -O-, -CO-, -CO-O- or -O-CO-. However, the total number of carbon atoms of A a42 , A a43 , A a44 , X a41 and X a42 is 7 or less. ] * represents a bonding site, and the * on the right side is the bonding site with -O-CO-R a42 . ]

[0149] R a42 Examples of the saturated hydrocarbon group in R include a chain hydrocarbon group, a monocyclic or polycyclic saturated alicyclic hydrocarbon group, and a group formed by combining these.

[0150] 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, an octadecyl group, and the like. Examples of the monocyclic or polycyclic saturated alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group; and polycyclic alicyclic hydrocarbon groups such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* represents a bonding site). Examples of the group formed by the combination of TIFF0007702812000097.tif10160 include a group formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic saturated hydrocarbon groups, such as -alkanediyl group-alicyclic saturated hydrocarbon group, -alicyclic saturated hydrocarbon group-alkyl group, -alkanediyl group-alicyclic saturated hydrocarbon group-alkyl group, and the like.

[0151] R a42 Examples of the substituent that R has include at least one selected from the group consisting of a halogen atom and a group represented by the formula (a-g3). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable. TIFF0007702812000098.tif855 [In the 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. * is the bonding site with R a42 . However, in R a42 -X a43 -A a45 , when R a42 does not have a halogen atom, A a45 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which has at least one halogen atom.

[0152] A a45 Examples of the saturated hydrocarbon group in [compound] A include alkyl groups such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, dodecyl group, pentadecyl group, hexadecyl group, heptadecyl group, and octadecyl group; monocyclic alicyclic hydrocarbon groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group, and cyclooctyl group; and polycyclic alicyclic hydrocarbon groups such as decahydronaphthyl group, adamantyl group, norbornyl group, and the following group (* represents the bonding site). Examples of the group formed by the combination of TIFF0007702812000099.tif10160 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, -alkanediyl group-alicyclic hydrocarbon group-alkyl group, and the like.

[0153] R a42 is preferably a saturated hydrocarbon group which may have a halogen atom, more preferably an alkyl group having a halogen atom and / or a saturated hydrocarbon group having a group represented by formula (a-g3). R a42 When R 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, still more preferably a perfluoroalkyl group having 1 to 6 carbon atoms, and particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Examples of the perfluoroalkyl group include perfluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluorobutyl group, perfluoropentyl group, perfluorohexyl group, perfluoroheptyl group, and perfluorooctyl group. Examples of the perfluorocycloalkyl group include perfluorocyclohexyl group. R a42When it is a saturated hydrocarbon group having a group represented by the formula (a-g3), including the number of carbon atoms contained in the group represented by the formula (a-g3), R a42 The total number of carbon atoms is preferably 15 or less, more preferably 12 or less. When having a group represented by the formula (a-g3) as a substituent, the number thereof is preferably 1.

[0154] R a42 When it is a saturated hydrocarbon group having a group represented by the formula (a-g3), R a42 is more preferably a group represented by the formula (a-g2). TIFF0007702812000100.tif872[In the 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 the bonding site with A a46 .). A a47 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. However, the total number of carbon atoms of A a46 , A a47 and X a44 is 18 or less, and at least one of A a46 and A a47 has at least one halogen atom. * represents the bonding site with the carbonyl group.]

[0155] A a46 The number of carbon atoms of the saturated hydrocarbon group is preferably 1 to 6, more preferably 1 to 3. A a47 The number of carbon atoms of the saturated hydrocarbon group is preferably 4 to 15, more preferably 5 to 12, and A a47 is more preferably a cyclohexyl group or an adamantyl group.

[0156] A preferred structure of the group represented by the formula (a-g2) is the following structure (* is the bonding site with the carbonyl group). TIFF0007702812000101.tif14161

[0157] 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.

[0158] 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.

[0159] In the group represented by formula (a-g1), X a42Examples of the group being -O-, -CO-, -CO-O- or -O-CO- include the following groups. In the following examples, * and ** each represent a bonding site, and ** is the bonding site with -O-CO-R a42 is the bonding site with TIFF0007702812000102.tif46140

[0160] Examples of the structural unit represented by formula (a4-1) include the following structural units and the structural units in the following structural units where the methyl group corresponding to R a41 in formula (a4-1) is replaced by a hydrogen atom. TIFF0007702812000103.tif103152

[0161] TIFF0007702812000104.tif132149

[0162] Examples of the structural unit represented by formula (a4-1) include the structural unit represented by formula (a4-2) and the structural unit represented by formula (a4-3). TIFF0007702812000105.tif4356[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 having a fluorine atom. However, the upper limit of the total number of carbon atoms of L 44 and R f6 is 21.]

[0163] L 44 The alkanediyl group having 1 to 6 carbon atoms of L a41 includes the same groups as those exemplified by A R f6 The saturated hydrocarbon group of R 42 includes the same groups as those exemplified by R L44 As the alkanediyl group in 44 , an alkanediyl group having 2 to 4 carbon atoms is preferable, and an ethylene group is more preferable.

[0164] Examples of the structural unit represented by formula (a4-2) include structural units represented by formulas (a4-1-1) to (a4-1-11), respectively. The methyl group corresponding to R in structural unit (a4-2) f5 The structural unit in which the methyl group is replaced by a hydrogen atom is also included as the structural unit represented by formula (a4-2).

[0165] TIFF0007702812000106.tif5671 [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 have a fluorine atom. X f12 represents *-O-CO- or *-CO-O- (* represents the bonding site with A f13 ).). A f14 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom. However, at least one of A f13 and A f14 has a fluorine atom, and the upper limit of the total number of carbon atoms of L 5 , A f13 and A f14 is 20.]

[0166] L 5 Examples of the alkanediyl group in 5 include the same groups as those exemplified for the alkanediyl group of A a41 .

[0167] A f13The divalent saturated hydrocarbon group which may have a fluorine atom 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 methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group; perfluoroalkanediyl groups such as difluoromethylene group, perfluoroethylene group, perfluoropropanediyl group, perfluorobutanediyl group and 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 cyclohexanediyl group and perfluorocyclohexanediyl group. Examples of the polycyclic group include adamantanediyl group, norbornanediyl group, perfluoroadamantanediyl group.

[0168] A f14 The saturated hydrocarbon group and the saturated hydrocarbon group which may have a fluorine atom of A are R a42Groups similar to those exemplified above can be mentioned. Among them, alkyl fluoride groups such as trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, heptyl group, perfluoroheptyl group, octyl group and perfluorooctyl group; cyclopropylmethyl group, cyclopropyl group, cyclobutylmethyl group, cyclopentyl group, cyclohexyl group, perfluorocyclohexyl group, adamantyl group, adamantylmethyl group, adamantyldimethyl group, norbornyl group, norbornylmethyl group, perfluoroadamantyl group, perfluoroadamantylmethyl group and the like are preferable.

[0169] In formula (a4-3), L 5 is preferably an ethylene group. A f13 The divalent saturated hydrocarbon group of 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 group containing a chain saturated hydrocarbon group having 3 to 10 carbon atoms and an alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms. Among them, A f14 is preferably a group containing an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and more preferably a cyclopropylmethyl group, cyclopentyl group, cyclohexyl group, norbornyl group and adamantyl group.

[0170] Examples of the structural unit represented by formula (a4-3) include structural units represented by formulas (a4-1'-1) to (a4-1'-11), respectively. The methyl group corresponding to R f7 in the structural unit (a4-3) that is replaced by a hydrogen atom is also included as a structural unit represented by formula (a4-3).

[0171] Examples of the structural unit (a4) also include a structural unit represented by formula (a4-4). TIFF0007702812000107.tif4466 [In formula (a4-4), R f21 represents a hydrogen atom or a methyl group. A f21 represents -(CH2) j1 -, -(CH2) j2 -O-(CH2) j3 - or -(CH2) j4 -CO-O-(CH2) j5 -. j1 to j5 each independently represent an integer from 1 to 6. R f22 represents a saturated hydrocarbon group having 1 to 10 carbon atoms and having a fluorine atom.]

[0172] The saturated hydrocarbon group of R f22 is the same as the saturated hydrocarbon group represented by R a42 . 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 even more preferably an alkyl group having 1 to 6 carbon atoms and having a fluorine atom.

[0173] In formula (a4-4), A f21 is preferably -(CH2) j1 -, more preferably an ethylene group or a methylene group, and even more preferably a methylene group.

[0174] Examples of the structural unit represented by the formula (a4-4) include structural units represented by the following structural units and the following formulas, in which the methyl group corresponding to R in the structural unit (a4-4) is replaced by a hydrogen atom. f21 Examples thereof include a structural unit in which the methyl group corresponding to R in the structural unit (a4-4) is replaced by a hydrogen atom. TIFF0007702812000108.tif87160

[0175] When the resin (A) has the structural unit (a4), its content is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, and even more preferably 3 to 10 mol% based on all the structural units of the resin (A).

[0176] 〈Structural unit (a5)〉 Examples of the non-leaving hydrocarbon group in the structural unit (a5) include a group having a linear, branched or cyclic hydrocarbon group. Among them, the structural unit (a5) preferably has a group having an alicyclic hydrocarbon group. Examples of the structural unit (a5) include a structural unit represented by the formula (a5-1). TIFF0007702812000109.tif3351[In the formula (a5-1), R 51 represents a hydrogen atom or a methyl group. R 52 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and the hydrogen atoms contained in the alicyclic hydrocarbon group may be substituted with aliphatic hydrocarbon groups having 1 to 8 carbon atoms. L 55 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-.]

[0177] R 52 Examples of the alicyclic hydrocarbon group in R include both monocyclic and polycyclic groups. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group and a norbornyl group, etc. The aliphatic hydrocarbon group having 1 to 8 carbon atoms includes, for example, alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. Examples of the alicyclic hydrocarbon group having a substituent include 3-methyladamantyl group. R 52 is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, more preferably an adamantyl group, a norbornyl group or a cyclohexyl group.

[0178] L 55 Examples of the divalent saturated hydrocarbon group in L include a divalent chain saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, preferably a divalent chain saturated hydrocarbon group. Examples of the divalent chain saturated hydrocarbon group include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group. The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkanediyl groups such as cyclopentanediyl group and cyclohexanediyl group. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include adamantanediyl group and norbornanediyl group.

[0179] L 55 Examples of the group in which -CH2- contained in the divalent saturated hydrocarbon group represented by L is replaced by -O- or -CO- include the groups represented by formula (L1-1) to formula (L1-4). In the following formulas, * and ** each represent a bonding site, and * represents a bonding site with an oxygen atom. In formula (L1-1), X x1 represents *-O-CO- or *-CO-O- (* represents a bonding site with L x1 .). L x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. L x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. However, the total number of carbon atoms in L x1 and L x2 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, the total number of carbon atoms in L x3 and L x4 is 17 or less. In formula (L1-3), L x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. L x6 and L x7 each independently represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms. However, the total number of carbon atoms in L x5 , L x6 and L x7 is 15 or less. In formula (L1-4), L x8 and L x9 each represent a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms. W x1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms. However, the total number of carbon atoms in L x8 , L x9 and W x1 is 15 or less.

[0180] L x1 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x2 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond. L 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, more preferably a methylene group or an ethylene group. L x7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x8 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group. L x9 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group. W x1 is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, more preferably a cyclohexanediyl group or an adamantanediyl group.

[0181] Examples of the group represented by the formula (L1-1) include the following divalent groups. TIFF0007702812000111.tif53135

[0182] Examples of the group represented by the formula (L1-2) include the following divalent groups. TIFF0007702812000112.tif23130

[0183] Examples of the group represented by the formula (L1-3) include the following divalent groups. TIFF0007702812000113.tif15162

[0184] Examples of the group represented by formula (L1-4) include, for example, the following divalent groups. TIFF0007702812000114.tif26114

[0185] L 55 is preferably a single bond or a group represented by formula (L1-1).

[0186] Examples of the structural unit (a5-1) include the following structural units and the structural units (a5-1) in the following structural units, where the methyl group corresponding to R 51 is replaced by a hydrogen atom. TIFF0007702812000115.tif77158

[0187] TIFF0007702812000116.tif39159 When the resin (A) has the structural unit (a5), its content is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, and even more preferably 3 to 15 mol% with respect to all the structural units of the resin (A). 〈Structural unit (a6)〉 The structural unit (a6) is a structural unit having a -SO2- group, and preferably has a -SO2- group in the side chain. The structural unit having a -SO2- group may have a linear structure having a -SO2- group, a branched structure having a -SO2- group, or a cyclic structure (monocyclic and polycyclic structures) having a -SO2- group. Preferably, it is a structural unit having a cyclic structure having a -SO2- group, and more preferably, it is a structural unit having a cyclic structure (sultone ring) containing -SO2-O-.

[0188] Examples of the sultone ring include the following formula (T 1 -1), formula (T 1 -2), formula (T 1 -3) and formula (T 1Examples of the ring represented by (1-4) include. The bonding site can be at any position. The sultone ring may be monocyclic, but is preferably polycyclic. The polycyclic sultone ring means a bridged ring containing -SO2-O- as an atomic group constituting the ring, and the formula (T 1 -1) and the rings represented by the formula (T 1 -2). The sultone ring may contain, in addition to -SO2-O-, further heteroatoms as atomic groups constituting the ring, as in the ring represented by the formula (T 1 -2). Examples of the heteroatom include an oxygen atom, a sulfur atom, or a nitrogen atom, preferably an oxygen atom. TIFF0007702812000117.tif2571

[0189] The sultone ring may have a substituent, and examples of the substituent include an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms, and an alkylcarbonyl group having 2 to 4 carbon atoms, etc.

[0190] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, and a decyl group, preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group. Examples of the alkyl group having a halogen atom include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group, preferably a trifluoromethyl group. Examples of the alkyl group having a hydroxy group include hydroxyalkyl groups such as hydroxymethyl group and 2-hydroxyethyl group. Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group. Examples of the aryl group include phenyl group, naphthyl group, anthryl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumyl group, mesityl group, biphenyl group, phenanthryl group, 2,6-diethylphenyl group and 2-methyl-6-ethylphenyl group. Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group and naphthylethyl group. Examples of the alkoxycarbonyl group include a group in which an alkoxy group such as methoxycarbonyl group and ethoxycarbonyl group is bonded to a carbonyl group, preferably an alkoxycarbonyl group having 6 or less carbon atoms, more preferably methoxycarbonyl group. Examples of the alkylcarbonyl group include acetyl group, propionyl group and butyryl group.

[0191] From the viewpoint that the production of the monomer leading to the structural unit (a6) is easy, a sultone ring having no substituent is preferred. As the sultone ring, a ring represented by the following formula (T1') is preferred. TIFF0007702812000118.tif2558[In the formula (T1'), X 11 represents an oxygen atom, a sulfur atom or a methylene group. R 41 represents a halogen atom, an alkyl group having 1 to 12 carbon atoms which may have a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms or an alkylcarbonyl group having 2 to 4 carbon atoms. ma represents an integer from 0 to 9. When ma is 2 or more, a plurality of Rs 41 may be the same or different. The bonding site is at an arbitrary position.] X 11 is preferably an oxygen atom or a methylene group, more preferably a methylene group. R 41 Examples of R include the same as the substituents of the sultone ring, and an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group is preferred.

[0192] As the sultone ring, a ring represented by the formula (T1) is more preferred. TIFF0007702812000119.tif2540[In the formula (T1), R 8 represents an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms or an alkylcarbonyl group having 2 to 4 carbon atoms. m represents an integer from 0 to 9. When m is 2 or more, a plurality of Rs 8 may be the same or different. The bonding site is at an arbitrary position.]

[0193] R 8 is, 41 the same as those of R. ma in the formula (T1') and m in the formula (T1) are preferably 0 or 1, more preferably 0.

[0194] Examples of the ring represented by the formula (T1') and the ring represented by the formula (T1) include the following rings. The bonding site is at an arbitrary position. TIFF0007702812000120.tif51149

[0195] The structural unit having a sultone ring preferably has the following group. * in the following group represents a bonding site. TIFF0007702812000121.tif46147

[0196] The structural unit having a -SO2- group preferably further has a group derived from a polymerizable group. Examples of the polymerizable group include a vinyl group, an acryloyl group, a methacryloyl group, an acryloyloxy group, a methacryloyloxy group, an acryloylamino group, a methacryloylamino group, an acryloylthio group, a methacryloylthio group, and the like. Among them, the monomer leading to the structural unit (a6) is preferably a monomer having an ethylenically unsaturated bond, more preferably a (meth)acrylic monomer.

[0197] The structural unit (a6) is preferably a structural unit represented by the formula (Ix). TIFF0007702812000122.tif4653[In the formula (Ix), R x represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom or a halogen atom. A xx represents an oxygen atom, -N(R c )- or a sulfur atom. A x represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O-, -CO- or -N(R d )-. X 11 represents an oxygen atom, a sulfur atom or a methylene group. R 41 represents an alkyl group having 1 to 12 carbon atoms which may have a halogen atom or a hydroxy group, a halogen atom, a hydroxy group, a cyano group, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a glycidyloxy group, an alkoxycarbonyl group having 2 to 12 carbon atoms or an alkylcarbonyl group having 2 to 4 carbon atoms. ma represents any integer from 0 to 9. When ma is 2 or more, a plurality of R41 may be the same or different. R c and R d each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

[0198] R x Examples of the halogen atom of R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R x Examples of the alkyl group of R include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group, etc. Preferably, it is an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group. R x Examples of the alkyl group having a halogen atom of R 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, etc. R x is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group.

[0199] A x Examples of the divalent saturated hydrocarbon group of A include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and those obtained by combining two or more of these groups may also be used. Specifically, linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1,17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group and propane-2,2-diyl group; Branched alkanediyl groups such as butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group; Monocyclic divalent alicyclic saturated hydrocarbon groups which are cycloalkanediyl groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group; Polycyclic divalent alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. may be mentioned.

[0200] R 41 、X 11 And ma are the same as those in formula (T1’). Examples of the sultone ring include those described above, and among them, those with a specified bonding position are preferred.

[0201] Examples of the structural unit (a6) include the following structural units. TIFF0007702812000123.tif98158

[0202] Among them, the structural units represented by formula (a6-1), formula (a6-2), formula (a6-6), formula (a6-7), formula (a6-8) and formula (a6-12) are preferred, and the structural units represented by formula (a6-1), formula (a6-2), formula (a6-7) and (a6-8) are more preferred. When the resin (A) has the structural unit (a6), its content is preferably 1 to 50 mol%, more preferably 2 to 40 mol%, and still more preferably 3 to 30 mol% based on all the structural units of the resin (A).

[0203] <Structural unit (II)> The resin (A) may further contain a structural unit that decomposes upon exposure to generate an acid (hereinafter sometimes referred to as "structural unit (II)"). Specific examples of the structural unit (II) include the structural units described in JP-A-2016-79235, and a structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain or a structural unit having a sulfonio group and an organic anion in the side chain is preferred.

[0204] The structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain is preferably a structural unit represented by formula (II-2-A'). TIFF0007702812000124.tif3189[In formula (II-2-A'), X III3 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -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 replaced by a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. RA - represents a sulfonate group or a carboxylate group. R III3represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. ZA + represents an organic cation.

[0205] R III3 Examples of the halogen atom represented by R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R III3 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R include the same ones as the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R. a8 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R include the same ones as the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R. A x1 Examples of the alkanediyl group having 1 to 8 carbon atoms represented by A 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, a 2-methylbutane-1,4-diyl group, etc. A x1 Examples of the perfluoroalkyl group having 1 to 6 carbon atoms which may be substituted on A include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, a perfluorohexyl group, etc.

[0206] X III3 Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by X include a linear or branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and combinations thereof may also be possible. Specifically, linear alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group; branched alkanediyl groups such as butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group; divalent monocyclic alicyclic saturated hydrocarbon groups such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group; Examples thereof include divalent polycyclic alicyclic saturated hydrocarbon groups such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group.

[0207] Examples of those in which -CH2- contained in the saturated hydrocarbon group is replaced by -O-, -S- or -CO- include divalent groups represented by formula (X1) to formula (X53). However, the number of carbon atoms before -CH2- contained in the saturated hydrocarbon group is replaced by -O-, -S- or -CO- is 17 or less, respectively. In the following formula, * and ** represent bonding sites, and * represents the bonding site with A x1 and represents the bonding site with A. TIFF0007702812000125.tif145161

[0208] 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.

[0209] ZA in formula (II-2-A’) + is the same as the cation Z1 in the salt represented by formula (B1). + Examples thereof include the same ones.

[0210] The structural unit represented by formula (II-2-A’) is preferably the structural unit represented by formula (II-2-A). JPEG0007702812000126.jpg37109 [In formula (II-2-A), R III3 , X III3 and ZA + represent the same meanings as described above. z represents any integer from 0 to 6. R III2 and R III4 each independently represent 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 R III2 and R III4 may be the same as or different from each other. Q a and Q b each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.]

[0211] R III2 , R III4 , Q a and Q b Examples of the perfluoroalkyl group having 1 to 6 carbon atoms represented by b1 are the same as those of the perfluoroalkyl group having 1 to 6 carbon atoms represented by Q

[0212] The structural unit represented by formula (II-2-A) is preferably the structural unit represented by formula (II-2-A-1). TIFF0007702812000127.tif5676[In formula (II-2-A-1), R III2 、R III3 、R III4 、Q a 、Q b 、z and ZA + have the same meanings as described 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, wherein -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 hydroxy group.]

[0213] R III5 Examples of the saturated hydrocarbon group having 1 to 12 carbon atoms represented by include linear or branched alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group and dodecyl group. X I2 Examples of the divalent saturated hydrocarbon group represented by include the same as those of the divalent saturated hydrocarbon group represented by X III3 .

[0214] As the structural unit represented by formula (II-2-A-1), the structural unit represented by formula (II-2-A-2) is preferable. TIFF0007702812000128.tif5287[In formula (II-2-A-2), R III3 、R III5 and ZA + have the same meanings as described above. m and nA each independently represent 1 or 2.]

[0215] Examples of the structural unit represented by formula (II-2-A') include, for example, the following structural unit, R III3Groups corresponding to the methyl group are 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 structural units described in International Publication No. 2012 / 050015, etc. ZA + represents an organic cation. TIFF0007702812000129.tif86163

[0216] The structural unit having a sulfonio group and an organic anion in the side chain is preferably a structural unit represented by the formula (II-1-1). TIFF0007702812000130.tif3381[In the 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, and R II2 and R II3 may combine with each other to form a ring together with the sulfur atom to which they are attached. R II4 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. A - represents an organic anion.] R II1 Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by include a phenylene group and a naphthylene group, etc. R II2 and R II3 Examples of the hydrocarbon group represented by include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these, etc. Examples of the alkyl group and the alicyclic hydrocarbon group are the same as those described above. Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group, etc. Examples of the combined group include a group combining the above-described alkyl group and alicyclic hydrocarbon group, an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), an aryl-cycloalkyl group such as a phenylcyclohexyl group, and the like. R II4 Examples of the halogen atom represented by R II4 include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like. R II4 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R II4 are the same as those of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R a8 . a8 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R a8 are the same as those of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R II4 . A II1 Examples of the divalent linking group represented by A II1 include, for example, 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-. Specifically, examples are the same as those of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by X III3 . III3 Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by X III3 are the same as those of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by X III3 .

[0217] Examples of the structural unit containing a cation in formula (II-1-1) include a structural unit represented by the following, a group corresponding to the methyl group of R II4 being replaced by a hydrogen atom, a halogen atom (for example, a fluorine atom) or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (for example, a trifluoromethyl group, etc.), and the like. II4 Examples of the structural unit in which a group corresponding to the methyl group of R II4 is replaced by a hydrogen atom, a halogen atom (for example, a fluorine atom) or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (for example, a trifluoromethyl group, etc.) are given. TIFF0007702812000131.tif84130

[0218] A - Examples of the organic anion represented by A - include a sulfonate anion, a sulfonylimide anion, a sulfonylmethide anion, a carboxylate anion, and the like. A - -The organic anion represented by is preferably a sulfonic acid anion. Examples of the sulfonic acid anion include those similar to the anion represented by the aforementioned formula (B1). A - Examples of the sulfonylimide anion represented by include the following. TIFF0007702812000132.tif33136 Examples of the sulfonylmethide anion include the following. TIFF0007702812000133.tif29123 Examples of the carboxylic acid anion include the following. TIFF0007702812000134.tif42154

[0219] Examples of the structural unit represented by the formula (II-1-1) include the structural units represented below. TIFF0007702812000135.tif88149

[0220] 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 all the structural units of the resin (A).

[0221] The resin (A) may have structural units other than the above-mentioned structural units. Examples of such structural units include structural units well-known in the art.

[0222] The resin (A) is preferably a resin composed of the structural unit (a1) and the structural unit (s), that is, a copolymer of the monomer (a1) and the monomer (s). The structural unit (a1) is preferably at least one selected from the group consisting of the structural unit (a1-0), the structural unit (a1-1), and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group and a cyclopentyl group), more preferably at least two kinds, and even more preferably at least two kinds selected from the group consisting of the structural unit (a1-1) and the structural unit (a1-2). The structural unit(s) is preferably at least one selected from the group consisting of structural unit (a2) and structural unit (a3). The structural unit (a2) is preferably a structural unit represented by formula (a2-1) or a structural unit represented by formula (a2-A). The structural unit (a3) is preferably at least one selected from the group consisting of a structural unit represented by formula (a3-1), a structural unit represented by formula (a3-2), and a structural unit represented by formula (a3-4).

[0223] Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and can be produced by a known polymerization method (for example, radical polymerization method) using monomers that lead to these structural units. The content of each structural unit of the resin (A) can be adjusted by the amount of monomers used in the polymerization. The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, still more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less, still more preferably 15,000 or less). In this specification, the weight average molecular weight is a value determined by gel permeation chromatography under the conditions described in the examples.

[0224] <Resin other than resin (A)> The resist composition of the present invention may contain a resin other than the resin (A). Examples of the resin other than the resin (A) include resins containing a structural unit (a4) or a structural unit (a5) (hereinafter sometimes referred to as resin (X)).

[0225] Among them, the resin containing the structural unit (a4) is preferred as the resin (X). In the resin (X), the content of the structural unit (a4) is preferably 30 mol% or more, more preferably 40 mol% or more, and still more preferably 45 mol% or more based on the total of all structural units of the resin (X). Examples of the structural units that resin (X) may further have include structural unit (a2), structural unit (a3), and structural units derived from other known monomers. Among them, resin (X) is preferably a resin composed only of structural unit (a4) and / or structural unit (a5), and more preferably a resin composed only of structural unit (a4). Each structural unit constituting resin (X) may be used alone or in combination of two or more, and can be produced by a known polymerization method (for example, radical polymerization method) using monomers that induce these structural units. The content of each structural unit of resin (X) can be adjusted by the amount of monomers used in the polymerization. The weight average molecular weight of resin (X) is preferably 6,000 or more (more preferably 7,000 or more) and 80,000 or less (more preferably 60,000 or less). The measuring means for the weight average molecular weight of resin (X) is the same as that for resin (A). When the resist composition contains resin (X), its content is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, still more preferably 1 to 40 parts by mass, even more preferably 1 to 30 parts by mass, and particularly preferably 1 to 8 parts by mass with respect to 100 parts by mass of resin (A).

[0226] 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 the resist composition contains a resin other than resin (A), 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 content of the resin relative thereto can be measured by known analytical means such as liquid chromatography or gas chromatography.

[0227] <Solvent (E)> The content rate of the solvent (E) 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 in the resist composition. The content rate of the solvent (E) can be measured by known analysis means 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; and the like. One kind of the solvent (E) may be used alone, or two or more kinds may be used.

[0228] <Quencher (C)> Examples of the quencher (C) include basic nitrogen-containing organic compounds and salts that generate an acid having a lower acidity than the acid generated from the acid generator (B). When the resist composition contains the quencher (C), the content of the quencher (C) is preferably about 0.01 to 15% by mass, more preferably about 0.01 to 10% by mass, still more preferably about 0.1 to 5% by mass, and still more preferably about 0.1 to 3% by mass based on the solid content of the resist composition. Examples of the basic nitrogen-containing organic compounds include amines and ammonium salts. Examples of the amines include aliphatic amines and aromatic amines. Examples of the aliphatic amines include primary amines, secondary amines, and tertiary amines. Examples of the amine include 1-naphthylamine, 2-naphthylamine, aniline, diisopropyl aniline, 2-, 3- or 4-methyl aniline, 4-nitroaniline, N-methylaniline, N,N-dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris[2-(2-methoxyethoxy)ethyl]amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 2,2'-methylenebisaniline, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-di(2-pyridyl)ethane, 1,2-di(4-pyridyl)ethane, 1,2-di(2-pyridyl)ethene, 1,2-di(4-pyridyl)ethene, 1,3-di(4-pyridyl)propane, 1,2-di(4-pyridyloxy)ethane, di(2-pyridyl)ketone, 4,4'-dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipicolylamine, bipyridine, etc. Of these, diisopropyl aniline is preferable, and 2,6-diisopropyl aniline is more preferable. 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.

[0229] 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. As the salt that generates an acid with a lower acidity than the acid generated from the acid generator (B), 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). TIFF0007702812000136.tif93161

[0230] Examples of the weak acid inner salt (D) include the following salts. TIFF0007702812000137.tif72165

[0231] 〈Other components〉 The resist composition of the present invention may contain, if necessary, components other than the above-described components (hereinafter sometimes referred to as "other components (F)"). There are no particular limitations on the other components (F), and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes, etc. can be used.

[0232] 〈Preparation of Resist Composition〉 The resist composition of the present invention can be prepared by mixing salt (I), resin (A), acid generator (B), and, if necessary, a resin other than resin (A) used, solvent (E), quencher (C), and other components (F). The mixing order is arbitrary and not particularly limited. The temperature during mixing can be appropriately selected from 10 to 40 °C according to the type of resin, etc. and the solubility of the resin, etc. in solvent (E). The mixing time can be appropriately selected from 0.5 to 24 hours according to the mixing temperature. Note that the mixing means is also not particularly limited, and stirring and mixing, etc. can be used. After mixing the respective components, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

[0233] 〈Method for Manufacturing Resist Pattern〉 The method for manufacturing a resist pattern of the present invention (1) A step of 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) A step of exposing the composition layer, (4) A step of heating the exposed composition layer, and (5) A step of developing the heated composition layer. To apply the resist composition onto a substrate, it can be carried out by a commonly used apparatus such as a spin coater. Examples of the substrate include inorganic substrates such as silicon wafers and already formed resist films. Before applying the resist composition, the substrate may be cleaned, or an antireflection film, etc. may be formed on the substrate. By drying the coated composition, the solvent is removed to 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 decompression device. The heating temperature is preferably 50 to 200 °C, and the heating time is preferably 10 to 180 seconds. Also, the pressure during vacuum drying is preferably about 1 to 1.0×10 5 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, those that emit laser light in the ultraviolet region such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F2 excimer laser (wavelength 157 nm), those that convert laser light from a solid laser light source (YAG or semiconductor laser, etc.) into harmonic laser light in the far ultraviolet region or vacuum ultraviolet region and emit it, those that irradiate electron beams, extreme ultraviolet light (EUV), etc., various ones can be used. In this specification, irradiating these radiations may be collectively referred to as "exposure". During exposure, usually, exposure is performed through a mask corresponding to the required pattern. When the exposure light source is an electron beam, exposure may be performed by direct drawing without using a mask. The exposed composition layer is heat-treated (so-called post-exposure bake) to promote the deprotection reaction in the acid-labile group. The heating temperature is usually about 50 to 200 °C, preferably about 70 to 150 °C. Chemical treatment (silylation) may be performed to adjust the hydrophilicity or hydrophobicity of the resin on the surface side of the composition after heating. Also, before development, the steps of coating, drying, exposing, and heating the resist composition may be repeated on the exposed composition layer. The heated composition layer is usually developed using a developing solution with a developing device. Examples of the developing method include dip method, paddle method, spray method, dynamic dispense method, etc. 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 developing solution as follows, a positive resist pattern or a negative resist pattern can be manufactured. When producing a positive resist pattern 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) can be mentioned. The alkaline developer may contain a surfactant. After development, it is preferable to wash the resist pattern with ultrapure water and then remove the water remaining on the substrate and the pattern. 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-based developer") is used as the developer. Examples of the organic solvent contained in the organic-based developer 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. In the organic-based developer, the content of the organic solvent is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and even more preferably substantially only the organic solvent. Among them, as the organic-based developer, a developer containing butyl acetate and / or 2-heptanone is preferable. In the organic-based developer, the total content of butyl acetate and 2-heptanone 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-based developer may contain a surfactant. Further, the organic-based developer may contain a trace amount of water. During development, development may be stopped by substituting with a solvent of a different type from the organic-based developer. It is preferable to wash the developed resist pattern with a rinse solution. The rinse solution is not particularly limited 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 washing, it is preferable to remove the rinse solution remaining on the substrate and the pattern.

[0234] <Usage> 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, particularly as a resist composition for electron beam (EB) exposure or a resist composition for EUV exposure, and is useful for semiconductor microfabrication.

Examples

[0235] The present invention will be described more specifically with reference to examples. In the examples, “%” and “parts” representing content or usage amount are based on mass unless otherwise specified. The weight average molecular weight is a value determined by gel permeation chromatography. The analysis conditions for gel permeation chromatography are as follows. Column: TSKgel Multipore HXL-M x 3 + guard column (manufactured by Tosoh Corporation) Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min Detector: RI detector Column temperature: 40 °C Injection volume: 100 μl Molecular weight standard: Standard polystyrene (manufactured by Tosoh Corporation) The structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC is Agilent 1100 type, MASS is Agilent LC / MSD type). In the following examples, the value of this molecular ion peak is indicated by “MASS”.

[0236] Example 1: Synthesis of the salt represented by formula (I-1) 4.38 parts of the salt represented by formula (I-1-a) and 30 parts of chloroform were mixed and stirred at 23 °C for 30 minutes. To the resulting mixed solution, 1.78 parts of the compound represented by formula (I-1-b) were added, and further stirred at 50 °C for 2 hours. To the resulting mixed solution, 1.38 parts of the compound represented by formula (I-1-c) were added, and further stirred at 50 °C for 3 hours, then cooled to 23 °C. To the resulting mixture, 15 parts of a 5% aqueous oxalic acid solution were added and stirred at 23 °C for 30 minutes, then separated to extract the organic layer. To the obtained organic layer, 15 parts of ion-exchanged water were added and stirred at 23 °C for 30 minutes, then separated to extract the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, and to the concentrated residue, 30 parts of tert-butyl methyl ether were added and stirred at 23 °C for 30 minutes, then the supernatant was removed and concentrated to obtain 5.19 parts of the salt represented by formula (I-1). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 295.0

[0237] Example 2: Synthesis of the salt represented by formula (I-25) 4.36 parts of the salt represented by formula (I-25-a) and 30 parts of chloroform were mixed and stirred at 23 °C for 30 minutes. To the resulting mixed solution, 1.78 parts of the compound represented by formula (I-1-b) were added, and further stirred at 50 °C for 2 hours. To the resulting mixed solution, 1.38 parts of the compound represented by formula (I-1-c) were added, and further stirred at 50 °C for 3 hours, then cooled to 23 °C. To the resulting mixture, 15 parts of a 5% aqueous oxalic acid solution were added and stirred at 23 °C for 30 minutes, then separated to extract the organic layer. To the obtained organic layer, 15 parts of ion-exchanged water were added and stirred at 23 °C for 30 minutes, then separated to extract the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, and to the concentrated residue, 30 parts of tert-butyl methyl ether were added and stirred at 23 °C for 30 minutes, then the supernatant was removed and concentrated to obtain 5.22 parts of the salt represented by formula (I-25). MS(ESI(+) Spectrum): M + 261.1 MS(ESI(-) Spectrum): M - 295.0

[0238] Example 3: Synthesis of the salt represented by formula (I-73) 4.92 parts of the salt represented by formula (I-73-a) and 30 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 1.78 parts of the compound represented by formula (I-1-b) were added, and further stirred at 50°C for 2 hours. To the resulting mixed solution, 1.38 parts of the compound represented by formula (I-1-c) were added, and further stirred at 50°C for 3 hours, then cooled to 23°C. To the resulting mixture, 15 parts of a 5% aqueous oxalic acid solution were added and stirred at 23°C for 30 minutes, then separated to obtain the organic layer. 15 parts of ion-exchanged water were added to the obtained organic layer and stirred at 23°C for 30 minutes, then separated to obtain the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether were added to the concentrated residue, stirred at 23°C for 30 minutes, then the supernatant was removed and concentrated to obtain 5.47 parts of the salt represented by formula (I-73).

[0239] MS(ESI(+) Spectrum): M + 317.1 MS(ESI(-) Spectrum): M - 295.0

[0240] Example 4: Synthesis of the salt represented by formula (I-11) 4.38 parts of the salt represented by formula (I-1-a) and 30 parts of chloroform were mixed and stirred at 23°C for 30 minutes. 1.78 parts of the compound represented by formula (I-1-b) was added to the resulting mixed solution, and the mixture was further stirred at 50°C for 2 hours. 1.56 parts of the compound represented by formula (I-11-c) was added to the resulting mixed solution, and the mixture was further stirred at 50°C for 3 hours and then cooled to 23°C. 15 parts of a 5% aqueous oxalic acid solution was added to the resulting mixture, and the mixture was stirred at 23°C for 30 minutes, followed by liquid separation to obtain the organic layer. 15 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23°C for 30 minutes, followed by liquid separation to obtain the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and the mixture was stirred at 23°C for 30 minutes. Then, the supernatant was removed and concentrated to obtain 5.46 parts of the salt represented by formula (I-11). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 313.0

[0241] Example 5: Synthesis of the salt represented by formula (I-12) 4.38 parts of the salt represented by formula (I-1-a) and 30 parts of chloroform were mixed and stirred at 23°C for 30 minutes. 1.78 parts of the compound represented by formula (I-1-b) was added to the resulting mixed solution, and the mixture was further stirred at 50°C for 2 hours. 1.74 parts of the compound represented by formula (I-12-c) was added to the resulting mixed solution, and the mixture was further stirred at 50°C for 3 hours and then cooled to 23°C. 15 parts of a 5% aqueous oxalic acid solution was added to the resulting mixture, and the mixture was stirred at 23°C for 30 minutes, followed by liquid separation to obtain the organic layer. 15 parts of ion-exchanged water was added to the obtained organic layer, and the mixture was stirred at 23°C for 30 minutes, followed by liquid separation to obtain the organic layer. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and the mixture was stirred at 23°C for 30 minutes. Then, the supernatant was removed and concentrated to obtain 5.33 parts of the salt represented by formula (I-12). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 331.0

[0242] Example 6: Synthesis of the salt represented by formula (I-122) 4.38 parts of the salt represented by formula (I-1-a) and 30 parts of chloroform were mixed and stirred at 23 °C for 30 minutes. To the resulting mixed solution, 1.78 parts of the compound represented by formula (I-1-b) was added, and further stirred at 50 °C for 2 hours. To the resulting mixed solution, 1.88 parts of the compound represented by formula (I-122-c) was added, and further stirred at 50 °C for 3 hours and then cooled to 23 °C. To the resulting mixture, 15 parts of 5% aqueous oxalic acid solution was added and stirred at 23 °C for 30 minutes, then separated and the organic layer was taken out. 15 parts of ion-exchanged water was added to the obtained organic layer and stirred at 23 °C for 30 minutes, then separated and the organic layer was taken out. This water washing operation was repeated 5 times. The obtained organic layer was concentrated, 30 parts of tert-butyl methyl ether was added to the concentrated residue, stirred at 23 °C for 30 minutes, then the supernatant was removed and concentrated to obtain 5.19 parts of the salt represented by formula (I-122). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 345.0

[0243] Example 7: Synthesis of the salt represented by formula (I-125) 4.38 parts of the salt represented by formula (I-1-a) and 30 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 1.78 parts of the compound represented by formula (I-1-b) was added, and further stirred at 50°C for 2 hours. To the resulting mixed solution, 2.78 parts of the compound represented by formula (I-125-c) was added, and further stirred at 50°C for 3 hours, then cooled to 23°C. To the resulting mixture, 15 parts of a 5% aqueous oxalic acid solution was added and stirred at 23°C for 30 minutes, then separated to extract the organic layer. To the resulting organic layer, 15 parts of ion-exchanged water was added and stirred at 23°C for 30 minutes, then separated to extract the organic layer. This water washing operation was repeated 5 times. The resulting organic layer was concentrated, and to the concentrated residue, 30 parts of tert-butyl methyl ether was added and stirred at 23°C for 30 minutes, then the supernatant was removed and concentrated to obtain 6.11 parts of the salt represented by formula (I-125). MASS(ESI(+)Spectrum):M + 263.1 MASS(ESI(-)Spectrum):M - 434.9

[0244] Example 8: Synthesis of the salt represented by formula (I-129) 4.38 parts of the salt represented by formula (I-1-a) and 30 parts of chloroform were mixed and stirred at 23°C for 30 minutes. To the resulting mixed solution, 1.78 parts of the compound represented by formula (I-1-b) was added, and further stirred at 50°C for 2 hours. To the resulting mixed solution, 2.20 parts of the compound represented by formula (I-129-c) was added, and further stirred at 50°C for 3 hours, then cooled to 23°C. To the resulting mixture, 15 parts of a 5% aqueous oxalic acid solution was added and stirred at 23°C for 30 minutes, then separated to extract the organic layer. To the resulting organic layer, 15 parts of ion-exchanged water was added and stirred at 23°C for 30 minutes, then separated to extract the organic layer. This water washing operation was repeated 5 times. The resulting organic layer was concentrated, and to the concentrated residue, 30 parts of tert-butyl methyl ether was added and stirred at 23°C for 30 minutes, then the supernatant was removed and concentrated to obtain 5.88 parts of the salt represented by formula (I-129). MASS(ESI(+) Spectrum): M + 263.1 MASS(ESI(-) Spectrum): M - 377.0

[0245] Synthesis of Resin The compounds (monomers) used for the synthesis of Resin (A) are shown below. Hereinafter, these compounds are referred to as "monomer (a1-1-3)" etc. according to their formula numbers. TIFF0007702812000146.tif41138

[0246] Synthesis Example 1 [Synthesis of Resin A1] As monomers, monomer (a1-4-2), monomer (a1-1-3) and monomer (a1-2-6) were used, and they were mixed so that the molar ratio [monomer (a1-4-2): monomer (a1-1-3): monomer (a1-2-6)] was 38:24:38. Further, 1.5 times the mass of methyl isobutyl ketone with respect to the total mass of all monomers was mixed into this monomer mixture. To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol% with respect to the total number of moles of all monomers, and polymerization was carried out by heating this at 85 °C for about 5 hours. Thereafter, an aqueous solution of p-toluenesulfonic acid (2.5 wt%) 2.0 times the mass with respect to the total mass of all monomer amounts was added to the polymerization reaction solution, and after stirring for 6 hours, liquid separation was carried out. The obtained organic layer was poured into a large amount of n-heptane to precipitate the resin, and the resin was obtained by filtration and recovery. Thus, Resin A1 (copolymer) having a weight average molecular weight of about 5.3×10 3 was obtained at a yield of 78%. This Resin A1 has the following structural units. TIFF0007702812000147.tif25107

[0247] Synthesis Example 2 [Synthesis of Resin A2] As monomers, monomer (a1-4-2) and monomer (a1-2-6) were used and mixed so that their molar ratio [monomer (a1-4-2): monomer (a1-2-6)] was 38:62. Further, 1.5 mass times of methyl isobutyl ketone was mixed with this monomer mixture based on the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile was added as an initiator so as to be 7 mol% based on the total number of moles of all monomers, and polymerization was carried out by heating this at 85 °C for about 5 hours. Thereafter, an aqueous solution of p-toluenesulfonic acid (2.5 wt%) 2.0 mass times the total mass of all monomers was added to the polymerization reaction solution, stirred for 6 hours, and then separated. The obtained organic layer was poured into a large amount of n-heptane to precipitate the resin, and the resin was filtered and recovered, whereby resin A2 (copolymer) having a weight average molecular weight of about 5.4×10 3 was obtained in a yield of 89%. This resin A2 has the following structural units. TIFF0007702812000148.tif2578

[0248] Synthesis Example 3 [Synthesis of Resin A3] As monomers, monomer (a1-1-3), monomer (a1-2-6), monomer (a2-1-3), monomer (a3-4-2) and monomer (a1-4-2) were used and mixed so that their molar ratio [monomer (a1-1-3): monomer (a1-2-6): monomer (a2-1-3): monomer (a3-4-2): monomer (a1-4-2)] was 20:35:3:15:27. Further, 1.5 mass times of methyl isobutyl ketone was mixed with this monomer mixture based on the total mass of all monomers. To the obtained mixture, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators, each at 1.2 mol% and 3.6 mol% based on the total amount of all monomers, and these were heated at 73 °C for about 5 hours. Thereafter, an aqueous solution of p-toluenesulfonic acid (2.5 wt%) 2.0 mass times the total mass of all monomers was added to the polymerization reaction solution, stirred for 12 hours, and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate the resin, and the resin was filtered and recovered, whereby the weight average molecular weight was about 5.3×103 Resin A3, which has the following structure, was obtained in a yield of 63%. TIFF0007702812000149.tif30125

[0249] Synthesis Example 4 [Synthesis of Resin A4] As monomers, monomer (a1-1-3), monomer (a1-2-6), monomer (a2-1-3), monomer (a3-4-2) and monomer (a1-4-13) were used, and they were mixed so that the molar ratio [monomer (a1-1-3): monomer (a1-2-6): monomer (a2-1-3): monomer (a3-4-2): monomer (a1-4-13)] was 20:35:3:15:27. Further, 1.5 times the mass of methyl isobutyl ketone with respect to the total mass of all monomers was mixed into this monomer mixture. To the obtained mixture, azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators in amounts of 1.2 mol% and 3.6 mol%, respectively, based on the total monomer amount, and they were heated at 73 °C for about 5 hours. Thereafter, an aqueous solution of p-toluenesulfonic acid (2.5 wt%) 2.0 times the mass of the total monomer amount was added to the polymerization reaction solution, and after stirring for 12 hours, liquid separation was performed. The recovered organic layer was poured into a large amount of n-heptane to precipitate the resin, and the resin was filtered and recovered, whereby a resin A4 having a weight average molecular weight of about 5.1×10 3 Resin A4, which has the following structure, was obtained in a yield of 61%. TIFF0007702812000150.tif36142

[0250] <Preparation of Resist Composition>[[]] As shown in Table 2, the following components were mixed, and the resulting mixture was filtered through a fluororesin filter with a pore size of 0.2 μm to prepare a resist composition. [Table 2][[]]

[0251] <Resin>[[]] A1 to A4: Resin A1 to Resin A4 <Salt (I)> I-1: Salt represented by formula (I-1) I-11: Salt represented by formula (I-11) I-12: Salt represented by formula (I-12) I-25: Salt represented by formula (I-25) I-73: Salt represented by formula (I-73) I-122: Salt represented by formula (I-122) I-125: Salt represented by formula (I-125) I-129: Salt represented by formula (I-129) <Acid generator> B1-X1 B1-X2 B1-X3 TIFF0007702812000152.tif62141<Quencher (C)> C1: Synthesized by the method described in JP-A-2011-39502 TIFF0007702812000153.tif3038<Solvent> 400 parts of propylene glycol monomethyl ether acetate 100 parts of propylene glycol monomethyl ether 5 parts of γ-butyrolactone

[0252] (Electron beam exposure evaluation of resist composition) A 6-inch silicon wafer was treated on a direct hot plate with hexamethyldisilazane at 90 °C for 60 seconds. The resist composition was spin-coated on this silicon wafer so that the film thickness of the composition layer was 0.04 μm. Then, it was prebaked on a direct hot plate at the temperature shown in the "PB" column of Table 2 for 60 seconds to form a composition layer. A line and space pattern was directly drawn on the composition layer formed on the wafer using an electron beam lithography machine ["HL-800D 50 keV" manufactured by Hitachi, Ltd.] while 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 2 for 60 seconds, and then paddle development was carried out for 60 seconds with a 2.38 mass% aqueous solution of tetramethylammonium hydroxide to obtain a resist pattern. The obtained resist pattern (line and space pattern) was observed with a scanning electron microscope, and the exposure amount at which the line width and space width of the 60-nm line and space pattern became 1:1 was defined as the effective sensitivity.

[0253] Line edge roughness evaluation (LER): The swing width of the unevenness on the side wall surface of the resist pattern manufactured at the effective sensitivity was measured with a scanning electron microscope to determine the line edge roughness. The results are shown in Table 3.

Table 3

[0254] (Electron beam exposure evaluation of resist composition: Organic solvent development) A 6-inch silicon wafer was treated on a direct hot plate with hexamethyldisilazane at 90°C for 60 seconds. The resist composition was spin-coated on this silicon wafer so that the film thickness of the composition layer became 0.04 μm. Then, pre-baking was performed on a direct hot plate at the temperature shown in the "PB" column of Table 2 for 60 seconds to form a composition layer. Using an electron beam lithography machine ["ELS-F125 125 keV" manufactured by Elionix, Inc.], the exposure amount was changed stepwise on the composition layer formed on the wafer, and direct drawing was performed so as to obtain a line and space pattern (pitch 60 nm / line width 30 nm) after development. After exposure, post-exposure baking was carried out on a hot plate at the temperature shown in the "PEB" column of Table 2 for 60 seconds. Next, the composition layer on this silicon wafer was developed by the dynamic dispense method at 23°C for 20 seconds using butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as the developer to obtain a resist pattern. The obtained resist pattern (line and space pattern) was observed with a scanning electron microscope, and the exposure dose at which the line width and space width of the line and space pattern with a pitch of 60 nm were 1:1 was defined as the effective sensitivity.

[0255] Line edge roughness evaluation (LER): The fluctuation width of the unevenness of the side wall surface of the resist pattern manufactured with the effective sensitivity was measured with a scanning electron microscope to determine the line edge roughness. The results are shown in Table 4. [Table 4] Compared with Comparative Compositions 4 to 6, the fluctuation width of the unevenness of the side wall surface of the resist pattern in Compositions 10 to 18 was small, and the line edge roughness evaluation was good.

Industrial Applicability

[0256] The resist composition containing the salt of the present invention can obtain a resist pattern having good line edge roughness (LER), and thus is suitable for semiconductor microfabrication and extremely useful industrially.

Claims

1. A salt represented by formula (I). [In formula (I), Q １ and Q ２ each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. R １ and R ２ each independently represents a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms. z represents any integer from 0 to 6, and when z is 2 or more, a plurality of R １ and R ２ may be the same as or different from each other. X 1 represents *-CO-O-, *-O-CO-, *-O-CO-O- or *-O-, where * represents a bonding site with C(R １ )(R ２ ), or C(Q １ )(Q ２ ). R ３ and R ４ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, provided that either one of R 3 and R 4 is an alkyl group having 1 to 6 carbon atoms. R ５ represents an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 3 carbon atoms. R ６ represents a fluorine atom, an iodine atom, a C1-C6 fluoroalkyl group or a C1-C12 alkyl group, and the -CH 2 - in the fluoroalkyl group and the alkyl group may be replaced by -O- or -CO-. m6 represents any integer from 0 to 4, and when m6 is 2 or more, a plurality of Rs ６ may be the same as or different from each other. Z ＋ represents an organic cation.

2. A salt represented by formula (I’). [In formula (I), Q1 and Q2 each independently represent a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. R1’ and R2’ each independently represent a hydrogen atom, a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. However, at least one of R1’ and R2’ is a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. z represents any integer from 0 to 6, and when z is 2 or more, a plurality of R1’ and R2’ may be the same as or different from each other. X1 represents *-CO-O-, *-O-CO-, *-O-CO-O- or *-O-, and * represents the bonding site with C(R1’)(R2’ ) or C(Q1)(Q2). R3 and R4 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. R5 represents an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 3 carbon atoms. R6’ represents a fluorine atom, an iodine atom, a fluoroalkyl group having 1 to 6 carbon atoms or an alkyl group having 1 to 12 carbon atoms, and -CH2- contained in the fluoroalkyl group may be replaced by -O- or -CO-. m6 represents any integer from 0 to 4, and when m6 is 2 or more, a plurality of R6’ may be the same as or different from each other. Z+ represents an organic cation.]

3. R ５ The salt according to claim 1 or 2, wherein R is a methoxy group.

4. R ３ and R ４ The salt according to any one of claims 1 to 3, wherein either one of them is a hydrogen atom.

5. R ３ and R ４ The salt according to any one of claims 2, 3 and 4 which cite claim 2, wherein either one of them is an alkyl group having 1 to 6 carbon atoms.

6. m6 is 1 or more, At least one R ６ The bonding position of is the meta position with respect to the bonding position of -C(R ３ )(R ４ )- in the benzene ring. The salt according to any one of claims 1 to 5.

7. An acid generator containing the salt according to any one of Claims 1 to 6.

8. A resist composition containing the acid generator according to Claim 7 and a resin having an acid-labile group.

9. The resist composition according to Claim 8, wherein the resin having an acid-labile group contains 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 each independently represents -O- or *-O-(CH ２ ) k1 -CO-O-, k1 represents any integer from 1 to 7, and * represents a bond to -CO-. R a4 and R a5 each independently represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R 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 combining these. m1 represents any integer from 0 to 14. n1 represents any integer from 0 to 10. n1’ represents any integer from 0 to 3.]

10. The resist composition according to Claim 8 or 9, wherein the resin having an acid-labile group contains 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 represents a single bond or *-X a51 -(A a52 -X a52 ) nｂ -, where * represents the bonding site with the carbon atom to which -R a50 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 any integer from 0 to 4. When mb is any integer of 2 or more, the plurality of Rs a51 may be the same as or different from each other.]

11. The resist composition according to any one of claims 8 to 10, further containing a salt that generates an acid having a lower acidity than the acid generated from the acid generator.

12. (1) A step of applying the resist composition according to any one of claims 8 to 11 onto a substrate, (2) A step of drying the applied composition to form a composition layer, (3) A step of exposing the composition layer, (4) A step of heating the exposed composition layer, and (5) A step of developing the heated composition layer, A method for manufacturing a resist pattern, comprising:

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