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

Abstract

To provide a salt capable of producing a resist pattern having good CD uniformity, and a resist composition containing the same.SOLUTION: There are provided: a salt represented by formula (I); and an acid generator and a resist composition containing the salt. [In the formula, R1 represents a fluorine atom or a fluorinated alkyl group; R2, R3 and R4 each represent a halogen atom, a fluorinated alkyl group or the like; m2 and m3 each represent an integer of 0-4; m4 represents an integer of 0-5; Q1 and Q2 each represent a fluorine atom or a perfluoroalkyl group; L1 represents a saturated hydrocarbon group, provided that -CH2- contained in the group may be substituted with -O- or -CO-, and a hydrogen atom contained in the group may be substituted with a fluorine atom or the like; and Y1 represents a methyl group or an alicyclic hydrocarbon group.]SELECTED DRAWING: None

Description

[Technical field]

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

[0002] Patent Document 1 describes a resist composition that contains a salt represented by the following formula as an acid generator. TIFF0007659395000001.tif30139 Patent Document 2 describes a resist composition that contains a salt represented by the following formula as an acid generator. TIFF0007659395000002.tif2972 [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-003920 A [Patent Document 2] JP 2018-118962 A Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention provides a salt that forms a resist pattern having better CD uniformity (CDU) than a resist pattern formed from a resist composition containing the above salt, and a resist composition containing the same. [Means for solving the problem]

[0005] The present invention includes the following inventions. [1] A salt represented by formula (I). TIFF0007659395000003.tif4998[In formula (I), R 1 represents a fluorine atom or a fluorinated alkyl group having 1 to 4 carbon atoms. R 2, R 3 and R 4 each independently represents a halogen atom, a fluorinated alkyl group having 1 to 4 carbon atoms, or a hydrocarbon group having 1 to 12 carbon atoms, and -CH2- contained in the hydrocarbon group may be replaced by -O- or -CO-. m2 represents an integer of 0 to 4, and when m2 is 2 or more, a plurality of R 2 may be the same or different from each other. m3 represents an integer of 0 to 4, and when m3 is 2 or more, a plurality of R 3 may be the same or different from each other. m4 represents an integer of 0 to 5, and when m4 is 2 or more, a plurality of R 4 may be the same or different from each other. Q 1 and Q 2 each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. L 1 represents a saturated hydrocarbon group having 1 to 24 carbon atoms, in which -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-, and a hydrogen atom contained in the saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group. Y 1 represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 24 carbon atoms, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -SO2- or -CO-.] [2]R 2 , R 3 and R 4 each independently represents a fluorine atom, an iodine atom, or a perfluoroalkyl group having 1 to 4 carbon atoms. [3] An acid generator comprising the salt according to [1] or [2]. [4] A resist composition comprising the acid generator according to [3] and a resin having an acid labile group. [5] The resist composition according to [4], wherein the resin having an acid labile group comprises 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): TIFF0007659395000004.tif4699 [In formula (a1-1) and formula (a1-2), L a1 and L a2 are each independently -O- or *-O-(CH2) k1 represents --CO--O--, k1 represents an integer of 1 to 7, and * represents a bonding site with --CO--. R 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 combination thereof. m1 represents an integer of 0 to 14. n1 represents an integer of 0 to 10. n1' represents an integer of 0 to 3. [6] The resist composition according to [4] or [5], wherein the resin having an acid labile group contains a structural unit represented by formula (a2-A): TIFF0007659395000005.tif4653[In formula (a2-A), R a50 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a51 represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A a50 is a single bond or* -X a51 -(A a52 -X a52 ) nb - stands for -R. a50 represents the bonding site with the carbon atom to which it is bonded. A a52 represents an alkanediyl group having 1 to 6 carbon atoms. X a51 and X a52 each independently represents -O-, -CO-O-, or -O-CO-. nb represents 0 or 1. mb represents an integer of 0 to 4. When mb is an integer of 2 or more, a plurality of R a51 may be the same or different.] [7] The resist composition according to any one of [4] to [6], further comprising a salt that generates an acid having a weaker acidity than the acid generated from the acid generator. [8] (1) A step of applying the resist composition according to any one of [4] to [7] onto a substrate; (2) A step of drying the applied composition to form a composition layer; (3) exposing the composition layer to light; (4) heating the composition layer after exposure; and (5) A method for producing a resist pattern, comprising the step of developing the composition layer after heating. Effect of the Invention

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

[0007] In this specification, "(meth)acrylic monomer" means at least one selected from the group consisting of monomers having the structure "CH2=CH-CO-" and monomers having the structure "CH2=C(CH3)-CO-". Similarly, "(meth)acrylate" and "(meth)acrylic acid" mean "at least one selected from the group consisting of acrylate and methacrylate" and "at least one selected from the group consisting of acrylic acid and methacrylic acid", respectively. When a structural unit having "CH2=C(CH3)-CO-" or "CH2=CH-CO-" is exemplified, a structural unit having both groups is also exemplified. In addition, in the group described in this specification, either a linear structure or a branched structure may be used for those that can have both. "Derived from" or "derived from" refers to a polymerizable C=C bond contained in the molecule being polymerized to a -CC- group. "Combined group" means a group in which two or more of the exemplified groups are combined, and the valence of these groups may be appropriately changed depending on the bond form. Where stereoisomers exist, all stereoisomers are included.

[0008] [Salt represented by formula (I)] The present invention relates to a salt represented by formula (I) (hereinafter sometimes referred to as "salt (I)"). In salt (I), the negatively charged side is sometimes called the "anion (I)" and the positively charged side is sometimes called the "cation (I)". TIFF0007659395000006.tif5098 [wherein all symbols have the same meanings as defined above.]

[0009] In formula (I), R 1 , R 2 , R 3 and R 4The fluorinated alkyl group having 1 to 4 carbon atoms refers to an alkyl group having 1 to 4 carbon atoms and containing a fluorine atom, and examples thereof include perfluoroalkyl groups having 1 to 4 carbon atoms (trifluoromethyl group, pentafluoroethyl group, heptafluoropropyl group, nonafluorobutyl group), as well as 2,2,2-trifluoroethyl group, 3,3,3-trifluoropropyl group, 4,4,4-trifluorobutyl group, and 3,3,4,4,4-pentafluorobutyl group. The number of carbon atoms in the fluorinated alkyl group is preferably 1 to 3, and more preferably 1 or 2. In formula (I), R 2 , R 3 and R 4 Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. In formula (I), R 2 , R 3 and R 4 Examples of the hydrocarbon group having 1 to 12 carbon atoms include chain hydrocarbon groups such as alkyl groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups formed by combining these. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group, etc. The number of carbon atoms in the alkyl group is preferably 1 to 9, more preferably 1 to 6, further preferably 1 to 4, and further preferably 1 to 3. The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and cyclodecyl groups. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl, adamantyl, and norbornyl groups. Examples of the alicyclic hydrocarbon group include the groups shown below. The bonding site can be any position. The alicyclic hydrocarbon group preferably has 3 to 10 carbon atoms, and more preferably 3 to 8 carbon atoms. Examples of the aromatic hydrocarbon group include a phenyl group, a naphthyl group, etc. The aromatic hydrocarbon group preferably has 6 to 10 carbon atoms. Groups formed by combination include groups that combine an aromatic hydrocarbon group with a chain hydrocarbon group (e.g., aromatic hydrocarbon group-alkanediyl group-*, alkyl group-aromatic hydrocarbon group-*), groups that combine an alicyclic hydrocarbon group with a chain hydrocarbon group (e.g., alicyclic hydrocarbon group-alkanediyl group-*, alkyl group-alicyclic hydrocarbon group-*), and groups that combine an aromatic hydrocarbon group with a alicyclic hydrocarbon group (e.g., aromatic hydrocarbon group-alicyclic hydrocarbon group-*, alicyclic hydrocarbon group-aromatic hydrocarbon group-*). * represents a bonding site. The aromatic hydrocarbon group -alkanediyl group-* includes aralkyl groups such as benzyl group and phenethyl group. Examples of the alkyl group-aromatic hydrocarbon group-* include a tolyl group, a xylyl group, and a cumenyl group. Examples of the alicyclic hydrocarbon group -alkanediyl group-* include cycloalkylalkyl groups such as a cyclohexylmethyl group, a cyclohexylethyl group, a 1-(adamantan-1-yl)methyl group, and a 1-(adamantan-1-yl)-1-methylethyl group. Examples of the alkyl group-alicyclic hydrocarbon group-* include cycloalkyl groups having an alkyl group such as a methylcyclohexyl group, a dimethylcyclohexyl group, and a 2-alkyladamantan-2-yl group. Examples of the aromatic hydrocarbon group-alicyclic hydrocarbon group-* include a phenylcyclohexyl group. Examples of the alicyclic hydrocarbon group-aromatic hydrocarbon group-* include a cyclohexylphenyl group. In addition, in the combination, two or more types of alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and chain hydrocarbon groups may be combined, and any of the groups may be bonded to a benzene ring. Examples of groups in which -CH2- in a hydrocarbon group is replaced by -O- or -CO- include a hydroxy group (a group in which -CH2- in a methyl group is replaced by -O-), a carboxy group (a group in which -CH2-CH2- in an ethyl group is replaced by -O-CO-), an alkoxy group (a group in which -CH2- at any position in an alkyl group is replaced by -O-), an alkoxycarbonyl group (a group in which -CH2-CH2- at any position in an alkyl group is replaced by -O-CO-), an alkylcarbonyl group (a group in which -CH2- at any position in an alkyl group is replaced by -CO-), an alkylcarbonyloxy group (a group in which -CH2-CH2- at any position in an alkyl group is replaced by -CO-), a cycloalkoxy group, a cycloalkylalkoxy group, an alkoxycarbonyloxy group, an aromatic hydrocarbon group-carbonyloxy group, and groups in which two or more of these groups are combined. Examples of the alkoxy group include alkoxy groups having 1 to 11 carbon atoms, such as a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, a 2-ethylhexyloxy group, a nonyloxy group, a decyloxy group, an undecyloxy group, etc. The number of carbon atoms in the alkoxy group is preferably 1 to 9, more preferably 1 to 6, further preferably 1 to 4, and further more preferably 1 to 3. The alkoxycarbonyl group, alkylcarbonyl group and alkylcarbonyloxy group represent groups in which a carbonyl group or a carbonyloxy group is bonded to the above-mentioned alkyl group or alkoxy group. Examples of the alkoxycarbonyl group include alkoxycarbonyl groups having 2 to 11 carbon atoms, such as methoxycarbonyl, ethoxycarbonyl, and butoxycarbonyl groups. Examples of the alkylcarbonyl group include alkylcarbonyl groups having 2 to 12 carbon atoms, such as acetyl, propionyl, and butyryl groups. Examples of the alkylcarbonyloxy group include alkylcarbonyloxy groups having 2 to 11 carbon atoms, such as acetyloxy, propionyloxy, and butyryloxy groups. The number of carbon atoms in the alkoxycarbonyl group is preferably 2 to 9, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkylcarbonyl group is preferably 2 to 9, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2 to 9, more preferably 2 to 6, even more preferably 2 to 4, and even more preferably 2 or 3. Examples of the cycloalkoxy group include cycloalkoxy groups having 3 to 11 carbon atoms, such as a cyclohexyloxy group. Examples of the cycloalkylalkoxy group include cycloalkylalkoxy groups having 4 to 11 carbon atoms, such as a cyclohexylmethoxy group. Examples of the alkoxycarbonyloxy group include alkoxycarbonyloxy groups having 2 to 10 carbon atoms, such as a butoxycarbonyloxy group. Examples of the aromatic hydrocarbon group-carbonyloxy group include aromatic hydrocarbon group-carbonyloxy groups having 7 to 11 carbon atoms, such as a benzoyloxy group. Examples of the group in which --CH2-- in the alicyclic hydrocarbon group is replaced with --O-- or --CO-- include the groups shown below. The bonding site can be any position. TIFF0007659395000008.tif48152When -CH2- in a hydrocarbon group is replaced with -O- or -CO-, the number of carbon atoms before the replacement is regarded as the total number of carbon atoms in the hydrocarbon group. In addition, the number may be 1 or 2 or more.

[0010] R 1 is preferably a fluorine atom or a perfluoroalkyl group having 1 to 4 carbon atoms, more preferably a fluorine atom or a perfluoroalkyl group having 1 to 3 carbon atoms, even more preferably a fluorine atom or a trifluoromethyl group, and even more preferably a trifluoromethyl group. m2 is preferably an integer of 0 to 3, more preferably an integer of 0 to 2, and further preferably 0 or 2. m3 is preferably an integer of 0 to 2, more preferably 0 or 1, and even more preferably 0. m4 is preferably an integer of 0 to 4, more preferably an integer of 0 to 3, even more preferably 0, 1 or 3, and even more preferably 1 or 3. R 2 , R 3 and R 4 are each independently preferably a halogen atom, a fluorinated alkyl group having 1 to 4 carbon atoms, or an alkyl group having 1 to 6 carbon atoms (-CH2- contained in the alkyl group may be replaced with -O- or -CO-), more preferably a halogen atom, a fluorinated alkyl group having 1 to 4 carbon atoms, or an alkyl group having 1 to 4 carbon atoms (-CH2- contained in the alkyl group may be replaced with -O- or -CO-), still more preferably a fluorine atom, an iodine atom, a perfluoroalkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms, a hydroxy group, or an alkoxy group having 1 to 3 carbon atoms, still more preferably a fluorine atom, an iodine atom, or a perfluoroalkyl group having 1 to 4 carbon atoms, and still more preferably a fluorine atom, an iodine atom, or a trifluoromethyl group.

[0011] In formula (I), the iodine atom is S + Although it may be bonded to the o-position, m-position or p-position of the benzene ring, it is preferably bonded to the m- or p-position, and more preferably bonded to the p-position. R1 is S + Although it may be bonded to the o-position, m-position or p-position of the benzene ring, it is preferably bonded to the m- or p-position, and more preferably bonded to the p-position. R 2 , R 3 and R 4 are respectively, S + The bond may be made to the o-position, m-position, or p-position of the benzene ring relative to R 2 is preferably bonded to the m-position or p-position, and R 1 S + When R is bonded to the p-position of the benzene ring, it is more preferable that R is bonded to the m-position. 3 is preferably bonded to the o-position or m-position, and the iodine atom is preferably bonded to the S + When R is bonded to the p-position of the benzene ring, it is more preferable that R is bonded to the o-position. 4 is preferably bonded to the m-position or p-position, and more preferably bonded to at least the p-position.

[0012] Examples of the cation in the salt (I) include the cations represented by the following formulas (Ic-1) to (Ic-20). TIFF0007659395000009.tif246155

[0013] Among these, cations represented by formulas (Ic-1) to (Ic-6), (Ic-13), (Ic-14), (Ic-17), and (Ic-18) are preferred, cations represented by formulas (Ic-1) to (Ic-4), (Ic-13), (Ic-14), (Ic-17), and (Ic-18) are more preferred, cations represented by formulas (Ic-1), (Ic-3), (Ic-13), (Ic-14), (Ic-17), and (Ic-18) are even more preferred, and cations represented by formulas (Ic-1), (Ic-13), (Ic-14), (Ic-17), and (Ic-18) are even more preferred.

[0014] Q1 and Q 2 Examples of the perfluoroalkyl group having 1 to 6 carbon atoms include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. Q 1 and Q 2 and are preferably each independently a fluorine atom or a trifluoromethyl group, and more preferably both are fluorine atoms.

[0015] L 1 Examples of the divalent saturated hydrocarbon group in include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and may be a group formed by combining two or more of these groups. Specific examples of such straight-chain alkanediyl groups include methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexadecane-1,16-diyl, and heptadecane-1,17-diyl groups; branched alkanediyl groups such as ethane-1,1-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-2,2-diyl, pentane-2,4-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, and 2-methylbutane-1,4-diyl; monocyclic divalent alicyclic saturated hydrocarbon groups such as cycloalkanediyl groups, such as cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, and cyclooctane-1,5-diyl; Examples of the polycyclic divalent alicyclic saturated hydrocarbon groups include norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group.

[0016] L 1 Examples of the divalent saturated hydrocarbon group represented by the formula (b1-1) to (b1-3) in which -CH2- is replaced with -O- or -CO- include groups represented by the formula (b1-1) to (b1-3). In the groups represented by the formula (b1-1) to (b1-3) and specific examples thereof represented by the formula (b1-4) to (b1-11), * and ** represent binding sites, * represents -Y 1 represents the binding site with

[0017] TIFF0007659395000010.tif26118[In formula (b1-1), L b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the saturated hydrocarbon group may be substituted with -O- or -CO-. However, L b2 and L b3 The total number of carbon atoms is 22 or less. In formula (b1-2), L b4 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the saturated hydrocarbon group may be substituted with -O- or -CO-. However, L b4 and Lb5 The total number of carbon atoms is 22 or less. In formula (b1-3), L b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. L b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the saturated hydrocarbon group may be substituted with -O- or -CO-. However, L b6 and L b7 The total number of carbon atoms is 23 or less.

[0018] In the groups represented by formulae (b1-1) to (b1-3), when -CH2- contained in the saturated hydrocarbon group is replaced with -O- or -CO-, the number of carbon atoms before replacement is regarded as the number of carbon atoms of the saturated hydrocarbon group. As the divalent saturated hydrocarbon group, L 1 The divalent saturated hydrocarbon group may be the same as that of the above.

[0019] L b2 is preferably a single bond. L b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms. L b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom. L b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b6 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b7is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the divalent saturated hydrocarbon group may be substituted with -O- or -CO-.

[0020] L 1 As the divalent saturated hydrocarbon group represented by the formula (b1-1) or (b1-3), a group in which --CH2-- in the divalent saturated hydrocarbon group represented by the formula (b1-1) or (b1-3) is preferable.

[0021] Examples of the group represented by formula (b1-1) include the groups represented by formulas (b1-4) to (b1-8). TIFF0007659395000011.tif48120[In formula (b1-4), L b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. In formula (b1-5), L b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O- or -CO-. L b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b9 and L b10 The total number of carbon atoms is 20 or less. In formula (b1-6), L b11 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b11 and L b12The total number of carbon atoms is 21 or less. In formula (b1-7), L b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms. L b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-. L b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b13 ~L b15 The total number of carbon atoms is 19 or less. In formula (b1-8), L b16 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O- or -CO-. L b17 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms. L b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b16 ~L b18 The total number of carbon atoms is 19 or less.

[0022] L b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms. L b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b10 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b12is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. L b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms. L b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b16 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. L b17 is preferably a divalent saturated hydrocarbon group having 1 to 6 carbon atoms. L b18 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.

[0023] Examples of the group represented by formula (b1-3) include the groups represented by formulas (b1-9) to (b1-11). TIFF0007659395000012.tif23139 [In formula (b1-9), L b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an alkylcarbonyloxy group. -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group. However, L b19 and L b20 The total number of carbon atoms is 23 or less. In formula (b1-10), L b21represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b22 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b23 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an alkylcarbonyloxy group. -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group. However, L b21 , L b22 and L b23 The total number of carbon atoms is 21 or less. In formula (b1-11), L b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b26 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an alkylcarbonyloxy group. -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group. However, L b24 , L b25 and L b26 The total number of carbon atoms is 21 or less.

[0024] In addition, in the groups represented by formulae (b1-9) to (b1-11), when a hydrogen atom contained in the saturated hydrocarbon group is substituted with an alkylcarbonyloxy group, the number of carbon atoms before substitution is regarded as the number of carbon atoms of the saturated hydrocarbon group.

[0025] Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group, and an adamantylcarbonyloxy group.

[0026] Examples of the group represented by formula (b1-4) include the following. TIFF0007659395000013.tif17153

[0027] Examples of the group represented by formula (b1-5) include the following. TIFF0007659395000014.tif78162

[0028] Examples of the group represented by formula (b1-6) include the following. TIFF0007659395000015.tif53149

[0029] Examples of the group represented by formula (b1-7) include the following. TIFF0007659395000016.tif62153

[0030] Examples of the group represented by formula (b1-8) include the following. TIFF0007659395000017.tif23150

[0031] Examples of the group represented by formula (b1-2) include the following. JPEG0007659395000018.jpg31161

[0032] Examples of the group represented by formula (b1-9) include the following. TIFF0007659395000019.tif44137

[0033] Examples of the group represented by formula (b1-10) include the following. JPEG0007659395000020.jpg92165

[0034] Examples of the group represented by formula (b1-11) include the following. JPEG0007659395000021.jpg84164

[0035] Y 1 Examples of the alicyclic hydrocarbon group represented by the formula include groups represented by the formulae (Y1) to (Y11) and (Y36) to (Y38). Y 1 In the case where -CH2- contained in the alicyclic hydrocarbon group represented by the formula (Y12) to (Y35) and (Y39) to (Y43) are replaced with -O-, -S(O)2-, or -CO-, the number of such groups may be 1 or 2 or more. Examples of such groups include groups represented by the formulas (Y12) to (Y35) and (Y39) to (Y43). * is L 1 It represents the binding site with

[0036] TIFF0007659395000022.tif84168

[0037] Y 1 The alicyclic hydrocarbon group represented by the formula (Y1) is preferably a group represented by any one of the formulas (Y1) to (Y20), (Y26), (Y27), (Y30), (Y31), (Y39) to (Y43), more preferably a group represented by the formula (Y11), (Y15), (Y16), (Y20), (Y26), (Y27), (Y30), (Y31), (Y39), (Y40), (Y42) or (Y43), and still more preferably a group represented by the formula (Y11), (Y15), (Y20), (Y26), (Y27), (Y30), (Y31), (Y39), (Y40), (Y42) or (Y43). Y 1is a spiro ring containing an oxygen atom such as those of formula (Y28) to (Y35), (Y39) to (Y40), (Y42) or (Y43), the alkanediyl group between the two oxygen atoms preferably has one or more fluorine atoms. In addition, among the alkanediyl groups contained in the ketal structure, it is preferable that the methylene group adjacent to the oxygen atom is not substituted with a fluorine atom.

[0038] Y 1 The substituent of the methyl group represented by the formula (I) is a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, a glycidyloxy group, -(CH2) ja -CO-OR b1 Group or -(CH2) ja -O-CO-R b1 group (in the formula, R b1 represents an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof, -CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -SO2- or -CO-, and a hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group may be replaced by a hydroxy group or a fluorine atom. ja represents an integer of 0 to 4.) Y 1 Examples of the substituent of the alicyclic hydrocarbon group represented by the formula (I) include a halogen atom, a hydroxy group, an alkyl group having 1 to 16 carbon atoms which may be substituted with a hydroxy group (-CH2- contained in the alkyl group may be replaced with -O- or -CO-), an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, a glycidyloxy group, -(CH2) ja -CO-OR b1 Group or -(CH2) ja -O-CO-R b1 group (in the formula, R b1represents an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof, -CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -SO2- or -CO-, and a hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group may be replaced by a hydroxy group or a fluorine atom. ja represents an integer of 0 to 4.)

[0039] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a norbornyl group, and an adamantyl group. The alicyclic hydrocarbon group may have a chain hydrocarbon group, and examples of the chain include a methylcyclohexyl group and a dimethylcyclohexyl group. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 12, and more preferably 3 to 10. Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and examples thereof include aromatic hydrocarbon groups having a chain hydrocarbon group with 1 to 18 carbon atoms (tolyl group, xylyl group, cumenyl group, mesityl group, p-methylphenyl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.) and aromatic hydrocarbon groups having an alicyclic hydrocarbon group with 3 to 18 carbon atoms (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.). The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 14, and more preferably 6 to 10. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, etc. The number of carbon atoms in the alkyl group is preferably 1 to 12, more preferably 1 to 6, and further preferably 1 to 4. Examples of the alkyl group substituted with a hydroxy group include hydroxyalkyl groups such as a hydroxymethyl group and a hydroxyethyl group. Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, and a naphthylethyl group. Examples of the alkyl group in which --CH.sub.2-- is replaced by --O--, --S(O).sub.2--, --CO--, or the like include an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, or a combination thereof. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group. The number of carbon atoms in the alkoxy group is preferably 1 to 12, more preferably 1 to 6, and further preferably 1 to 4. Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, a butoxycarbonyl group, etc. The number of carbon atoms in the alkoxycarbonyl group is preferably 2 to 12, more preferably 2 to 6, and further preferably 2 to 4. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, a butyryl group, etc. The number of carbon atoms in the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, and further preferably 2 to 4. Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, etc. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2 to 12, more preferably 2 to 6, and further preferably 2 to 4. Examples of the combined group include a group that combines an alkoxy group with an alkyl group, a group that combines an alkoxy group with an alkoxy group, a group that combines an alkoxy group with an alkylcarbonyl group, and a group that combines an alkoxy group with an alkylcarbonyloxy group. Examples of the group formed by combining an alkoxy group with an alkyl group include alkoxyalkyl groups such as a methoxymethyl group, a methoxyethyl group, an ethoxyethyl group, an ethoxymethyl group, etc. The number of carbon atoms in the alkoxyalkyl group is preferably 2 to 12, more preferably 2 to 6, and further preferably 2 to 4. Examples of the group formed by combining an alkoxy group with another alkoxy group include alkoxyalkoxy groups such as a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, etc. The number of carbon atoms in the alkoxyalkoxy group is preferably 2 to 12, more preferably 2 to 6, and further preferably 2 to 4. Examples of the group formed by combining an alkoxy group with an alkylcarbonyl group include alkoxyalkylcarbonyl groups such as a methoxyacetyl group, a methoxypropionyl group, an ethoxyacetyl group, an ethoxypropionyl group, etc. The number of carbon atoms in the alkoxyalkylcarbonyl group is preferably 3 to 13, more preferably 3 to 7, and further preferably 3 to 5. Examples of the group formed by combining an alkoxy group with an alkylcarbonyloxy group include alkoxyalkylcarbonyloxy groups such as a methoxyacetyloxy group, a methoxypropionyloxy group, an ethoxyacetyloxy group, an ethoxypropionyloxy group, etc. The number of carbon atoms in the alkoxyalkylcarbonyloxy group is preferably 3 to 13, more preferably 3 to 7, and further preferably 3 to 5. Examples of the group in which -CH2- in the alicyclic hydrocarbon group is replaced by -O-, -S(O)2-, -CO- or the like include groups represented by formulae (Y12) to (Y35) and (Y39) to (Y43).

[0040] Y 1 Examples include the following: JPEG0007659395000023.jpg162168

[0041] Y 1 is preferably an alicyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent, even more preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and even more preferably an adamantyl group which may have a substituent, and -CH2- constituting the alicyclic hydrocarbon group or the adamantyl group may be replaced by -CO-, -S(O)2- or -CO-. 1 Specifically, preferably, is an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group, or a group represented by the formula (Y42) or the formula (Y100) to the formula (Y114).

[0042] The anion in salt (I) is preferably an anion represented by formula (IA-1) to formula (IA-59) (hereinafter, may be referred to as "anion (IA-1)" depending on the formula number), and more preferably an anion represented by any of formulas (IA-1) to (IA-4), (IA-9), (IA-10), (IA-24) to (IA-33), (IA-36) to (IA-40), and (IA-47) to (IA-59).

[0043] JPEG0007659395000024.jpg79143

[0044] TIFF0007659395000025.tif95154

[0045] TIFF0007659395000026.tif61158

[0046] TIFF0007659395000027.tif64151

[0047] TIFF0007659395000028.tif129155

[0048] TIFF0007659395000029.tif92157

[0049] TIFF0007659395000030.tif75154

[0050] TIFF0007659395000031.tif62128

[0051] Here, R i2 ~R i7 are each independently, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. i8 L is, for example, a chain hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a group formed by combining these, more preferably a methyl group, an ethyl group, a cyclohexyl group, or an adamantyl group. A41 Q is a single bond or an alkanediyl group having 1 to 4 carbon atoms. 1 and Q 2 has the same meaning as above. Specific examples of the anion in the salt (I) include the anions described in JP-A-2010-204646.

[0052] Preferable anions in the salt (I) include the anions represented by formulae (Ia-1) to (Ia-38). TIFF0007659395000032.tif89154

[0053] TIFF0007659395000033.tif106144

[0054] TIFF0007659395000034.tif115165

[0055] TIFF0007659395000035.tif140163

[0056] Among these, anions represented by any one of formulae (Ia-1) to (Ia-3), (Ia-7) to (Ia-19), and (Ia-22) to (Ia-38) are preferred.

[0057] Specific examples of the salt (I) include salts of any combination of the above-mentioned cations and anions. Specific examples of the salt (I) are shown in the table below. In the following table, each symbol represents the symbol attached to the structure representing the above-mentioned anion or cation. For example, salt (I-1) is a salt consisting of an anion represented by formula (Ia-1) and a cation represented by formula (Ic-1), and is the salt shown below. TIFF0007659395000036.tif4592 [Table 1] TIFF0007659395000038.tif223154 TIFF0007659395000039.tif223154 TIFF0007659395000040.tif223154 TIFF0007659395000041.tif223154 TIFF0007659395000042.tif223154 TIFF0007659395000043.tif223154 TIFF0007659395000044.tif223154 TIFF0007659395000045.tif223154 TIFF0007659395000046.tif223154 TIFF0007659395000047.tif223154 TIFF0007659395000048.tif223154 TIFF0007659395000049.tif223154 TIFF0007659395000050.tif223154 TIFF0007659395000051.tif223154

[0058] Among them, salt (I) is salt (I-1) to salt (I-5), salt (I-13) to salt (I-25), salt (I-30) to salt (I-34), salt (I-42) to salt (I-54), salt (I-59) to salt (I-63), salt (I-71) to salt (I-83), salt (I-88) to salt (I-92), salt (I-100) to salt (I-112), salt (I-117) to salt (I-121), salt (I-129) to salt (I-141), salt (I-146) to salt (I-150), salt (I-152) to salt (I-154), salt (I-156) to salt (I-158), salt (I-159) to salt (I-160), salt (I-161) to salt (I-162), salt (I-163) to salt (I-164), salt (I-165) to salt (I-166), salt (I-167) to salt (I-168), salt (I-169) to salt (I-170), salt (I-171) to salt (I-172), salt (I-173) to salt (I-174), salt (I-175) to salt (I-176), salt (I-177) to salt (I-178), salt (I-179) to salt (I-180), salt (I-181) to salt (I-182), salt (I-183) to salt (I-184), salt (I-185) to salt (I-186), salt (I-187) to salt (I-188), salt (I-189) to salt (I-190), salt (I-191) to salt (I-192), salt (I-193) to I-150), salt(I-158)~salt(I-170), salt(I-175)~salt(I-179), salt(I-187)~salt(I-199), salt(I-204)~salt(I-208), salt(I-216)~salt(I-228), salt(I-233)~salt(I-237), salt(I-245)~salt(I-257), salt(I-262)~salt(I-266), salt(I-274)~salt(I-286), salt(I-291)~salt(I-295) , salt(I-303)~salt(I-315), salt(I-320)~salt(I-324), salt(I-332)~salt(I-344), salt(I-349)~salt(I-353), salt(I-361)~salt(I-373), salt(I-378)~salt(I-382), salt(I-390)~salt(I-402), salt(I-407)~salt(I-411), salt(I-419)~salt(I-431), salt(I-436)~salt(I-440), salt(I- It is preferable that the salt is from 448) to salt (I-460), from salt (I-465) to salt (I-480), from salt (I-481) to salt (I-486), from salt (I-494) to salt (I-506), from salt (I-511) to salt (I-516), from salt (I-524) to salt (I-536), from salt (I-541) to salt (I-546), from salt (I-554) to salt (I-566), from salt (I-571) to salt (I-576), or from salt (I-584) to salt (I-596).

[0059] <Method for producing salt (I)> The salt (I) can be produced by reacting a salt represented by the formula (Ia) with a salt represented by the formula (Ib) in a solvent in the presence of a base catalyst. TIFF0007659395000052.tif57162 [wherein all symbols have the same meanings as defined above. X represents a chlorine atom, a bromine atom or an iodine atom. R A , R B and R C each independently represents a hydrocarbon group having 1 to 12 carbon atoms, or R A , R B and R C may combine together to form an aromatic ring. D represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms.] Examples of the solvent used in this reaction include chloroform, acetonitrile, and ion-exchanged water. The reaction temperature is usually 0° C. to 80° C., and the reaction time is usually 0.5 hours to 24 hours.

[0060] Examples of the salt represented by formula (Ia) include salts represented by the following formula: These are readily available on the market, and can be easily produced by known methods. TIFF0007659395000053.tif122146 Examples of the salt represented by formula (Ib) include the salts represented by the following formulas, which are readily available on the market or can be easily synthesized by known methods. TIFF0007659395000054.tif97135

[0061] <Acid generator> The acid generator of the present invention is an acid generator containing a salt (I). It may contain one type of salt (I) or may contain two or more types of salt (I). The acid generator of the present invention may contain, in addition to the salt (I), an acid generator known in the resist field (hereinafter, sometimes referred to as "acid generator (B)"). The acid generator (B) may be used alone or in combination of two or more kinds.

[0062] The acid generator (B) may be either nonionic or ionic. Examples of nonionic acid generators include sulfonate esters (e.g., 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate), sulfones (e.g., disulfone, ketosulfone, sulfonyldiazomethane), etc. Examples of ionic acid generators include onium salts containing onium cations (e.g., diazonium salts, phosphonium salts, sulfonium salts, iodonium salts). Examples of anions of onium salts include sulfonate anion, sulfonylimide anion, sulfonylmethide anion, etc.

[0063] As the acid generator (B), compounds that generate acid by radiation, such as those described in JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, JP-A-62-153853, JP-A-63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. No. 3,849,137, German Patent No. 3914407, and European Patent No. 126,712, can be used. Compounds produced by known methods can also be used. Two or more types of acid generators (B) can be used in combination.

[0064] The acid generator (B) is preferably a fluorine-containing acid generator, and more preferably a salt represented by formula (B1) (hereinafter sometimes referred to as "acid generator (B1)", excluding salt (I)). TIFF0007659395000055.tif2962[In formula (B1), Q b1 and Q b2 each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. L b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, in which -CH2- may be replaced by -O- or -CO-, and a hydrogen atom in the divalent saturated hydrocarbon group may be replaced by a fluorine atom or a hydroxy group. Y represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 24 carbon atoms, and -CH2- contained in the alicyclic hydrocarbon group may be replaced by -O-, -S(O)2- or -CO-. Z1 + represents an organic cation.

[0065] Q b1 and Q b2 Examples of the perfluoroalkyl group represented by the formula (I) include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. Q b1 and Q b2 and are preferably each independently a fluorine atom or a trifluoromethyl group, and more preferably both are fluorine atoms.

[0066] L b1 Examples of the divalent saturated hydrocarbon group in include a linear alkanediyl group, a branched alkanediyl group, and a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and may be a group formed by combining two or more of these groups. Specific examples of such straight-chain alkanediyl groups include methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexadecane-1,16-diyl, and heptadecane-1,17-diyl groups; branched alkanediyl groups such as ethane-1,1-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-2,2-diyl, pentane-2,4-diyl, 2-methylpropane-1,3-diyl, 2-methylpropane-1,2-diyl, pentane-1,4-diyl, and 2-methylbutane-1,4-diyl; monocyclic divalent alicyclic saturated hydrocarbon groups such as cycloalkanediyl groups, such as cyclobutane-1,3-diyl, cyclopentane-1,3-diyl, cyclohexane-1,4-diyl, and cyclooctane-1,5-diyl; Examples of the polycyclic divalent alicyclic saturated hydrocarbon groups include norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, and adamantane-2,6-diyl group.

[0067] L b1 Examples of the divalent saturated hydrocarbon group in which -CH2- is replaced with -O- or -CO- include groups represented by formulae (b1-1) to (b1-3). In the groups represented by formulae (b1-1) to (b1-3) and specific examples thereof, such as the groups represented by formulae (b1-4) to (b1-11), * and ** represent bonds, and * represents a bond to -Y.

[0068] TIFF0007659395000056.tif26118[In formula (b1-1), L b2represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the saturated hydrocarbon group may be substituted with -O- or -CO-. However, L b2 and L b3 The total number of carbon atoms is 22 or less. In formula (b1-2), L b4 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b5 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the saturated hydrocarbon group may be substituted with -O- or -CO-. However, L b4 and L b5 The total number of carbon atoms is 22 or less. In formula (b1-3), L b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. L b7 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the saturated hydrocarbon group may be substituted with -O- or -CO-. However, L b6 and L b7 The total number of carbon atoms is 23 or less. * and ** represent bonds, and * represents a bond to Y.]

[0069] In the groups represented by formulae (b1-1) to (b1-3), when -CH2- contained in the saturated hydrocarbon group is replaced with -O- or -CO-, the number of carbon atoms before replacement is regarded as the number of carbon atoms of the saturated hydrocarbon group. As the divalent saturated hydrocarbon group, L b1 The divalent saturated hydrocarbon group may be the same as that of the above.

[0070] L b2 is preferably a single bond. L b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms. L b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom. L b5 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b6 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b7 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group, and -CH2- contained in the divalent saturated hydrocarbon group may be substituted with -O- or -CO-.

[0071] L b1 As the divalent saturated hydrocarbon group represented by the formula (b1-1) or (b1-3), a group in which --CH2-- in the divalent saturated hydrocarbon group represented by the formula (b1-1) or (b1-3) is preferable. Examples of the group represented by formula (b1-1) include the groups represented by formulas (b1-4) to (b1-8). TIFF0007659395000057.tif48120[In formula (b1-4), L b8represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. In formula (b1-5), L b9 represents a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O- or -CO-. L b10 represents a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b9 and L b10 The total number of carbon atoms is 20 or less. In formula (b1-6), L b11 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b11 and L b12 The total number of carbon atoms is 21 or less. In formula (b1-7), L b13 represents a divalent saturated hydrocarbon group having 1 to 19 carbon atoms. L b14 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced with -O- or -CO-. L b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b13 ~L b15 The total number of carbon atoms is 19 or less. In formula (b1-8), L b16represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O- or -CO-. L b17 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms. L b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. However, L b16 ~L b18 The total number of carbon atoms is 19 or less. * and ** represent bonds, and * represents a bond to Y.] L b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms. L b9 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b10 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 19 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b11 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b12 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b13 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. L b14 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms. L b15 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 8 carbon atoms. L b16 is preferably a divalent saturated hydrocarbon group having 1 to 12 carbon atoms. L b17 is preferably a divalent saturated hydrocarbon group having 1 to 6 carbon atoms. L b18is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and more preferably a single bond or a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.

[0072] Examples of the group represented by formula (b1-3) include the groups represented by formulas (b1-9) to (b1-11). TIFF0007659395000058.tif23139 [In formula (b1-9), L b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b20 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an alkylcarbonyloxy group. -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group. However, L b19 and L b20 The total number of carbon atoms is 23 or less. In formula (b1-10), L b21 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b22 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b23 represents a single bond or a divalent saturated hydrocarbon group having 1 to 21 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an alkylcarbonyloxy group. -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group. However, L b21 , L b22 and Lb23 The total number of carbon atoms is 21 or less. In formula (b1-11), L b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom. L b25 represents a divalent saturated hydrocarbon group having 1 to 21 carbon atoms. L b26 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted with a fluorine atom, a hydroxyl group or an alkylcarbonyloxy group. -CH2- contained in the alkylcarbonyloxy group may be replaced with -O- or -CO-, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxyl group. However, L b24 , L b25 and L b26 The total number of carbon atoms is 21 or less. * and ** represent bonds, and * represents a bond to Y.]

[0073] In addition, in the groups represented by formulae (b1-9) to (b1-11), when a hydrogen atom contained in the saturated hydrocarbon group is substituted with an alkylcarbonyloxy group, the number of carbon atoms before substitution is regarded as the number of carbon atoms of the saturated hydrocarbon group. Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, a cyclohexylcarbonyloxy group, and an adamantylcarbonyloxy group.

[0074] Examples of the group represented by formula (b1-4) include the following. TIFF0007659395000059.tif16151(* and ** represent bonds, * represents a bond to Y.)

[0075] Examples of the group represented by formula (b1-5) include the following. TIFF0007659395000060.tif71149(* and ** represent bonds, * represents a bond to Y.)

[0076] Examples of the group represented by formula (b1-6) include the following. TIFF0007659395000061.tif29150 (* and ** represent bonds, * represents a bond to Y.)

[0077] Examples of the group represented by formula (b1-7) include the following. TIFF0007659395000062.tif63151 (* and ** represent bonds, * represents a bond to Y.)

[0078] Examples of the group represented by formula (b1-8) include the following. TIFF0007659395000063.tif23150 (* and ** represent bonds, * represents a bond to Y.)

[0079] Examples of the group represented by formula (b1-2) include the following. TIFF0007659395000064.tif31160 (* and ** represent bonds, * represents a bond to Y.)

[0080] Examples of the group represented by formula (b1-9) include the following. TIFF0007659395000065.tif44137 (* and ** represent bonds, and * represents a bond to Y.)

[0081] Examples of the group represented by formula (b1-10) include the following. TIFF0007659395000066.tif88158 (* and ** represent bonds, * represents a bond to Y.)

[0082] Examples of the group represented by formula (b1-11) include the following. TIFF0007659395000067.tif81158 (* and ** represent bonds, * represents a bond to Y.)

[0083] Examples of the alicyclic hydrocarbon group represented by Y include groups represented by formulae (Y1) to (Y11) and (Y36) to (Y38). When -CH2- contained in the alicyclic hydrocarbon group represented by Y is replaced by -O-, -S(O)2- or -CO-, the number may be 1 or 2 or more. Examples of such a group include groups represented by formulae (Y12) to (Y35) and formulae (Y39) to (Y43). * is L b1 Represents a bond with . The alicyclic hydrocarbon group represented by TIFF0007659395000068.tif86166Y is preferably a group represented by any one of formulas (Y1) to (Y20), (Y26), (Y27), (Y30), (Y31), (Y39) to (Y43), and more preferably a group represented by formulas (Y11), (Y15), (Y16), (Y20), (Y22), (Y23), (Y24), (Y25), (Y26), (Y27), (Y30), (Y31), (Y39), (Y32), (Y33), (Y34), (Y35), (Y36), (Y37), (Y38), (Y39), (Y40), (Y41), (Y42), (Y43), (Y44), (Y45), (Y46), (Y47), (Y48), (Y49), (Y5 and more preferably a group represented by formula (Y11), formula (Y15), formula (Y20), formula (Y26), formula (Y27), formula (Y30), formula (Y31), formula (Y39), formula (Y40), formula (Y42) or formula (Y43). When the alicyclic hydrocarbon group represented by Y is a spiro ring containing an oxygen atom such as those of formulae (Y28) to (Y35), (Y39), (Y40), (Y42) or (Y43), the alkanediyl group between the two oxygen atoms preferably has one or more fluorine atoms. In addition, among the alkanediyl groups contained in the ketal structure, it is preferable that the methylene group adjacent to the oxygen atom is not substituted with a fluorine atom.

[0084] The substituent of the methyl group represented by Y is a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, a glycidyloxy group, -(CH2) ja -CO-OR b1Group or -(CH2) ja -O-CO-R b1 group (in the formula, R b1 represents an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof, -CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -SO2- or -CO-, and a hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group may be replaced by a hydroxy group or a fluorine atom. ja represents an integer of 0 to 4.) Substituents of the alicyclic hydrocarbon group represented by Y include halogen atoms, hydroxy groups, alkyl groups having 1 to 16 carbon atoms which may be substituted with a hydroxy group (-CH2- contained in the alkyl group may be replaced with -O- or -CO-), alicyclic hydrocarbon groups having 3 to 16 carbon atoms, aromatic hydrocarbon groups having 6 to 18 carbon atoms, aralkyl groups having 7 to 21 carbon atoms, glycidyloxy groups, -(CH2) ja -CO-OR b1 Group or -(CH2) ja -O-CO-R b1 group (in the formula, R b1 represents an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof, -CH2- contained in the alkyl group and the alicyclic hydrocarbon group may be replaced by -O-, -SO2- or -CO-, and a hydrogen atom contained in the alkyl group, the alicyclic hydrocarbon group and the aromatic hydrocarbon group may be replaced by a hydroxy group or a fluorine atom. ja represents an integer of 0 to 4.)

[0085] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, a cyclooctyl group, a norbornyl group, and an adamantyl group. The alicyclic hydrocarbon group may have a chain hydrocarbon group, and examples of the chain include a methylcyclohexyl group and a dimethylcyclohexyl group. The number of carbon atoms in the alicyclic hydrocarbon group is preferably 3 to 12, and more preferably 3 to 10. Examples of the aromatic hydrocarbon group include aryl groups such as phenyl, naphthyl, anthryl, biphenyl, and phenanthryl. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group. Examples of the aromatic hydrocarbon group having a chain hydrocarbon group include tolyl, xylyl, cumenyl, mesityl, p-ethylphenyl, p-tert-butylphenyl, 2,6-diethylphenyl, and 2-methyl-6-ethylphenyl. Examples of the aromatic hydrocarbon group having an alicyclic hydrocarbon group include p-cyclohexylphenyl and p-adamantylphenyl. The number of carbon atoms in the aromatic hydrocarbon group is preferably 6 to 14, and more preferably 6 to 10. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, a dodecyl group, etc. The number of carbon atoms in the alkyl group is preferably 1 to 12, more preferably 1 to 6, and further preferably 1 to 4. Examples of the alkyl group substituted with a hydroxy group include hydroxyalkyl groups such as a hydroxymethyl group and a hydroxyethyl group. Examples of the aralkyl group include a benzyl group, a phenethyl group, a phenylpropyl group, a naphthylmethyl group, and a naphthylethyl group. Examples of the alkyl group in which --CH.sub.2-- is replaced by --O--, --S(O).sub.2--, --CO--, or the like include an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylcarbonyloxy group, or a combination thereof. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group. The number of carbon atoms in the alkoxy group is preferably 1 to 12, more preferably 1 to 6, and further preferably 1 to 4. Examples of the alkoxycarbonyl group include a methoxycarbonyl group, an ethoxycarbonyl group, a butoxycarbonyl group, etc. The number of carbon atoms in the alkoxycarbonyl group is preferably 2 to 12, more preferably 2 to 6, and further preferably 2 to 4. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. The number of carbon atoms in the alkylcarbonyl group is preferably 2 to 12, more preferably 2 to 6, and further preferably 2 to 4. Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, a butyryloxy group, etc. The number of carbon atoms in the alkylcarbonyloxy group is preferably 2 to 12, more preferably 2 to 6, and further preferably 2 to 4. Examples of the combined group include a group that combines an alkoxy group with an alkyl group, a group that combines an alkoxy group with an alkoxy group, a group that combines an alkoxy group with an alkylcarbonyl group, and a group that combines an alkoxy group with an alkylcarbonyloxy group. Examples of the group formed by combining an alkoxy group with an alkyl group include alkoxyalkyl groups such as a methoxymethyl group, a methoxyethyl group, an ethoxyethyl group, an ethoxymethyl group, etc. The number of carbon atoms in the alkoxyalkyl group is preferably 2 to 12, more preferably 2 to 6, and further preferably 2 to 4. Examples of the group formed by combining an alkoxy group with another alkoxy group include alkoxyalkoxy groups such as a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, etc. The number of carbon atoms in the alkoxyalkoxy group is preferably 2 to 12, more preferably 2 to 6, and further preferably 2 to 4. Examples of the group formed by combining an alkoxy group with an alkylcarbonyl group include alkoxyalkylcarbonyl groups such as a methoxyacetyl group, a methoxypropionyl group, an ethoxyacetyl group, an ethoxypropionyl group, etc. The number of carbon atoms in the alkoxyalkylcarbonyl group is preferably 3 to 13, more preferably 3 to 7, and further preferably 3 to 5. Examples of the group formed by combining an alkoxy group with an alkylcarbonyloxy group include alkoxyalkylcarbonyloxy groups such as a methoxyacetyloxy group, a methoxypropionyloxy group, an ethoxyacetyloxy group, an ethoxypropionyloxy group, etc. The number of carbon atoms in the alkoxyalkylcarbonyloxy group is preferably 3 to 13, more preferably 3 to 7, and further preferably 3 to 5. Examples of the group in which -CH2- in the alicyclic hydrocarbon group is replaced by -O-, -S(O)2-, -CO- or the like include groups represented by formulae (Y12) to (Y35) and (Y39) to (Y43).

[0086] Y includes the following: TIFF0007659395000069.tif104167

[0087] TIFF0007659395000070.tif66164Y is preferably an alicyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, more preferably an alicyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent, even more preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and even more preferably an adamantyl group which may have a substituent, and -CH2- constituting the alicyclic hydrocarbon group or the adamantyl group may be replaced by -CO-, -S(O)2- or -CO-. Specifically, Y is preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group or a group represented by formula (Y42), formula (Y100) to formula (Y114).

[0088] The anion in the salt represented by formula (B1) is preferably an anion represented by formula (B1-A-1) to formula (B1-A-59) (hereinafter, may be referred to as "anion (B1-A-1)" depending on the formula number), and more preferably an anion represented by any of formula (B1-A-1) to formula (B1-A-4), (B1-A-9), (B1-A-10), (B1-A-24) to formula (B1-A-33), (B1-A-36) to formula (B1-A-40), and (B1-A-47) to formula (B1-A-59).

[0089] TIFF0007659395000071.tif78147

[0090] JPEG0007659395000072.jpg64151

[0091] TIFF0007659395000073.tif77129

[0092] TIFF0007659395000074.tif56155

[0093] JPEG0007659395000075.jpg102166

[0094] JPEG0007659395000076.jpg89145

[0095] TIFF0007659395000077.tif49140

[0096] TIFF0007659395000078.tif185170 Here R i2 ~R i7 are each independently, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. i8 L is, for example, a chain hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a group formed by combining these, more preferably a methyl group, an ethyl group, a cyclohexyl group, or an adamantyl group. A41Q is a single bond or an alkanediyl group having 1 to 4 carbon atoms. b1 and Q b2 has the same meaning as above. Specific examples of the anion in the salt represented by formula (B1) include the anions described in JP-A-2010-204646.

[0097] Preferable anions in the salt represented by formula (B1) include the anions represented by formulas (B1a-1) to (B1a-38). TIFF0007659395000079.tif126154

[0098] TIFF0007659395000080.tif93139

[0099] TIFF0007659395000081.tif168155

[0100] Of these, anions represented by any of Formulae (B1a-1) to (B1a-3), (B1a-7) to (B1a-16), (B1a-18), (B1a-19), and (B1a-22) to (B1a-38) are preferred.

[0101] Z1 + Examples of the organic cation include organic onium cation, organic sulfonium cation, organic iodonium cation, organic ammonium cation, benzothiazolium cation, and organic phosphonium cation. Among these, organic sulfonium cation and organic iodonium cation are preferred, and arylsulfonium cation is more preferred. Specific examples include cations represented by any of formulas (b2-1) to (b2-4) (hereinafter, sometimes referred to as "cation (b2-1)" depending on the formula number).

[0102] TIFF0007659395000082.tif48169In equations (b2-1) to (b2-4), R b4 ~R b6each independently represent a chain hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms, a hydrogen atom contained in the chain hydrocarbon group may be substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, or a glycidyloxy group, and a hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, a fluorinated alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. R b4 and R b5 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 0 to 5. When m2 is 2 or more, multiple R b7 may be the same or different, and when n2 is 2 or more, multiple R b8 may be the same or different. R b9 and R b10 each independently represents a chain hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms. R b9 and R b10 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded, and -CH2- contained in the ring may be replaced with -O-, -S- or -CO-. R b11 represents a hydrogen atom, a chain hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. Rb12 represents an open chain hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, a hydrogen atom contained in the open chain hydrocarbon group may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and a hydrogen atom contained in the aromatic hydrocarbon group may be substituted with an alkoxy group having 1 to 12 carbon atoms or an alkylcarbonyloxy group having 1 to 12 carbon atoms. R b11 and R b12 may be bonded to each other to form a ring including the -CH-CO- to which they are bonded, and -CH2- contained in the ring may be replaced by -O-, -S- or -CO-. R b13 ~R b18 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. L b31 represents a sulfur atom or an oxygen atom. o2, p2, s2, and t2 each independently represent an integer of 0 to 5. q2 and r2 each independently represent an integer of 0 to 4. u2 represents 0 or 1. When o2 is 2 or more, multiple R b13 are the same or different, and when p2 is 2 or more, multiple R b14 are the same or different, and when q2 is 2 or more, multiple R b15 are the same or different, and when r2 is 2 or more, multiple R b16 are the same or different, and when s2 is 2 or more, multiple R b17 are the same or different, and when t2 is 2 or more, multiple R b18 are the same or different. The aliphatic hydrocarbon group refers to a chain hydrocarbon group and an alicyclic hydrocarbon group. Examples of the chain hydrocarbon group include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl, and 2-ethylhexyl. In particular, R b9 ~Rb12 The chain hydrocarbon group preferably has 1 to 12 carbon atoms. The alicyclic hydrocarbon group may be either monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and cyclodecyl. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl, adamantyl, and norbornyl groups, as well as the following groups: TIFF0007659395000083.tif10158 In particular, R b9 ~R b12 The alicyclic hydrocarbon group preferably has 3 to 18 carbon atoms, and more preferably has 4 to 12 carbon atoms. Examples of the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group include a methylcyclohexyl group, a dimethylcyclohexyl group, a 2-methyladamantan-2-yl group, a 2-ethyladamantan-2-yl group, a 2-isopropyladamantan-2-yl group, a methylnorbornyl group, an isobornyl group, etc. In the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group, the total number of carbon atoms in the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less. The fluorinated alkyl group refers to an alkyl group having 1 to 12 carbon atoms and a fluorine atom, and examples of such groups include a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a perfluorobutyl group, etc. The number of carbon atoms in the fluorinated alkyl group is preferably 1 to 9, more preferably 1 to 6, and further preferably 1 to 4. Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a biphenyl group, a naphthyl group, and a phenanthryl group. The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and examples thereof include aromatic hydrocarbon groups having a chain hydrocarbon group with 1 to 18 carbon atoms (tolyl group, xylyl group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.) and aromatic hydrocarbon groups having an alicyclic hydrocarbon group with 3 to 18 carbon atoms (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.). When the aromatic hydrocarbon group has a chain hydrocarbon group or an alicyclic hydrocarbon group, a chain hydrocarbon group with 1 to 18 carbon atoms and an alicyclic hydrocarbon group with 3 to 18 carbon atoms are preferred. An example of the aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group is a p-methoxyphenyl group. Examples of the chain hydrocarbon group in which a hydrogen atom has been substituted with an aromatic hydrocarbon group include aralkyl groups such as a benzyl group, a phenethyl group, a phenylpropyl group, a trityl group, a naphthylmethyl group, and a naphthylethyl group. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, a hexyloxy group, a heptyloxy group, an octyloxy group, a decyloxy group, and a dodecyloxy group. Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, an isopropylcarbonyloxy group, a butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group. R b4 and R b5The ring formed by bonding to each other together with the sulfur atom to which they are bonded may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. Examples of this ring include rings having 3 to 18 carbon atoms, and preferably rings having 4 to 18 carbon atoms. Examples of the ring containing a sulfur atom include 3-membered to 12-membered rings, and preferably 3-membered to 7-membered rings, and examples of such rings include the following rings. * represents a bond. TIFF0007659395000084.tif23143R b9 and R b10 The ring formed by these together may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring may be a 3-membered to 12-membered ring, preferably a 3-membered to 7-membered ring. For example, it may be a thiolane-1-ium ring (tetrahydrothiophenium ring), a thiane-1-ium ring, a 1,4-oxathiane-4-ium ring, etc. R b11 and R b12 The ring formed by combining with may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. The ring may be a 3-membered to 12-membered ring, preferably a 3-membered to 7-membered ring. Examples of the ring include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

[0103] Among the cations (b2-1) to (b2-4), the cation (b2-1) is preferred. Examples of the cation (b2-1) include the following cations. TIFF0007659395000085.tif81160

[0104] TIFF0007659395000086.tif110165

[0105] Examples of the cation (b2-2) include the following cations. TIFF0007659395000087.tif18151

[0106] Examples of the cation (b2-3) include the following cations. TIFF0007659395000088.tif26143

[0107] Examples of the cation (b2-4) include the following cations. TIFF0007659395000089.tif125165

[0108] The acid generator (B) is a combination of the above-mentioned anion and the above-mentioned organic cation, which can be combined arbitrarily. The acid generator (B) is preferably a combination of an anion represented by any one of formulas (B1a-1) to (B1a-3), (B1a-7) to (B1a-16), (B1a-18), (B1a-19), and (B1a-22) to (B1a-38) and a cation (b2-1), a cation (b2-3), or a cation (b2-4).

[0109] The acid generator (B) is preferably any of those represented by formulas (B1-1) to (B1-56). Of these, those containing an arylsulfonium cation are preferred, and those represented by formulas (B1-1) to (B1-3), (B1-5) to (B1-7), (B1-11) to (B1-14), (B1-20) to (B1-26), (B1-29), and (B1-31) to (B1-56) are particularly preferred. TIFF0007659395000090.tif62150

[0110] TIFF0007659395000091.tif72164

[0111] JPEG0007659395000092.jpg79152

[0112] TIFF0007659395000093.tif63150

[0113] TIFF0007659395000094.tif67153

[0114] JPEG0007659395000095.jpg95148

[0115] JPEG0007659395000096.jpg153151

[0116] TIFF0007659395000097.tif94160

[0117] When the acid generator contains a salt (I) and an acid generator (B), the content ratio of the salt (I) to the acid generator (B) (mass ratio; salt (I):acid generator (B)) is usually 1:99 to 99:1, preferably 2:98 to 98:2, more preferably 5:95 to 95:5, still more preferably 10:90 to 90:10, and particularly preferably 15:85 to 85:15. In the resist composition of the present invention, the total content of the acid generators is preferably 1 part by mass or more and 45 parts by mass or less, more preferably 1 part by mass or more and 40 parts by mass or less, and even more preferably 3 parts by mass or more and 35 parts by mass or less, relative to 100 parts by mass of the resin (A) described below.

[0118] <Resist Composition> The resist composition of the present invention contains an acid generator containing a salt (I) and a resin having an acid labile group (hereinafter sometimes referred to as "resin (A)"). Here, the "acid labile group" refers to a group that has a leaving group and that is eliminated by contact with an acid, converting the structural unit into a structural unit having a hydrophilic group (e.g., a hydroxyl group or a carboxyl group). The resist composition of the present invention preferably contains a quencher such as a salt that generates an acid having a weaker acidity than the acid generated from the acid generator (hereinafter may be referred to as "quencher (C)"), and preferably contains a solvent (hereinafter may be referred to as "solvent (E)").

[0119] <Resin (A)> Resin (A) contains a structural unit having an acid labile group (hereinafter may be referred to as "structural unit (a1)"). Resin (A) preferably further contains a structural unit other than the structural unit (a1). Examples of structural units other than the structural unit (a1) include structural units not having an acid labile group (hereinafter may be referred to as "structural unit (s)"), structural units other than the structural unit (a1) and the structural unit (s) (for example, a structural unit having a halogen atom (hereinafter may be referred to as "structural unit (a4)") described below, a structural unit having a non-leaving hydrocarbon group (hereinafter may be referred to as "structural unit (a5)") described below, and other structural units derived from monomers known in the art.

[0120] <Structural unit (a1)> The structural unit (a1) is derived from a monomer having an acid labile group (hereinafter sometimes referred to as "monomer (a1)"). The acid labile group contained in the resin (A) is preferably a group represented by formula (1) (hereinafter also referred to as group (1)) and / or a group represented by formula (2) (hereinafter also referred to as group (2)). TIFF0007659395000098.tif1988[In formula (1), R a1 , R a2 and R a3 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof, or R a1 and R a2 are bonded to each other to form, together with the carbon atom to which they are bonded, a non-aromatic hydrocarbon ring having 3 to 20 carbon atoms. ma and na each independently represent 0 or 1, and at least one of ma and na represents 1. * denotes a binding site.] TIFF0007659395000099.tif2171 [In formula (2), R a1’ and R a2’ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms; R a3’ represents a hydrocarbon group having 1 to 20 carbon atoms, or R a2’ and R a3’are bonded to each other to form a heterocycle having 3 to 20 carbon atoms together with the carbon atom to which they are bonded and X, and -CH2- contained in the hydrocarbon group and the heterocycle may be replaced by -O- or -S-. X represents an oxygen atom or a sulfur atom. na′ represents 0 or 1. * denotes a binding site.]

[0121] R a1 , R a2 and R a3 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. R a1 , R a2 and R a3 Examples of the alkenyl group in include an ethenyl group, a propenyl group, an isopropenyl group, a butenyl group, an isobutenyl group, a tert-butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an octenyl group, an isooctenyl group, and a nonenyl group. R a1 , R a2 and R a3 The alicyclic hydrocarbon group in may be either monocyclic or polycyclic. Examples of monocyclic alicyclic hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Examples of polycyclic alicyclic hydrocarbon groups include decahydronaphthyl, adamantyl, and norbornyl groups, as well as the following groups (* indicates a bonding site). R a1 , R a2 and R a3 The alicyclic hydrocarbon group preferably has 3 to 16 carbon atoms. TIFF0007659395000100.tif10150R a1 , R a2 and R a3 Examples of the aromatic hydrocarbon group in include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. Examples of the combined group include a group in which the above-mentioned alkyl group and an alicyclic hydrocarbon group are combined (for example, an alkylcycloalkyl group or a cycloalkylalkyl group such as a methylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group, an adamantyldimethyl group, or a norbornylethyl group), an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (a p-methylphenyl group, a p-tert-butylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, or the like), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (a p-cyclohexylphenyl group, a p-adamantylphenyl group, or the like), and an aryl-cycloalkyl group such as a phenylcyclohexyl group. Preferably, ma is 0 and na is 1. R a1 and R a2 When they are bonded to each other to form a non-aromatic hydrocarbon ring, -C(R a1 )(R a2 )(R a3 ) includes the following rings. The non-aromatic hydrocarbon ring preferably has 3 to 12 carbon atoms. * represents the bonding site with -O-. TIFF0007659395000101.tif30138

[0122] R a1’ , R a2’ and R a3’ Examples of the hydrocarbon group in include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups. The alkyl group and the alicyclic hydrocarbon group are R a1 , R a2 and R a3 Examples of the groups include the same groups as those listed in the above. Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. Examples of the combined group include a group in which the above-mentioned alkyl group and an alicyclic hydrocarbon group are combined (for example, an alkylcycloalkyl group or a cycloalkylalkyl group such as a methylcyclohexyl group, a methylnorbornyl group, a cyclohexylmethyl group, an adamantylmethyl group, an adamantyldimethyl group, or a norbornylethyl group), an aralkyl group such as a benzyl group, an aromatic hydrocarbon group having an alkyl group (a p-methylphenyl group, a p-tert-butylphenyl group, a tolyl group, a xylyl group, a cumenyl group, a mesityl group, a 2,6-diethylphenyl group, a 2-methyl-6-ethylphenyl group, or the like), an aromatic hydrocarbon group having an alicyclic hydrocarbon group (a p-cyclohexylphenyl group, a p-adamantylphenyl group, or the like), and an aryl-cycloalkyl group such as a phenylcyclohexyl group. R a2’ and R a3’ When they are bonded to each other to form a heterocycle together with the carbon atom to which they are attached and X, -C(R a1’ )(R a2’ )-XR a3’ Examples of the ring include the following: * represents a binding site. TIFF0007659395000102.tif18130R a1’ and R a2’ At least one of these is preferably a hydrogen atom. na' is preferably 0.

[0123] Examples of the group (1) include the following groups. In formula (1), R a1 , R a2 and R a3 is an alkyl group, ma = 0, and na = 1. As the group, a tert-butoxycarbonyl group is preferable. In formula (1), R a1 , R a2 together with the carbon atom to which they are attached form an adamantyl group, R a3 is an alkyl group, ma=0, and na=1. In formula (1), R a1 and R a2are each independently an alkyl group; R a3 is an adamantyl group, ma=0, and na=1. Specific examples of the group (1) include the following groups: * represents a binding site. TIFF0007659395000103.tif113163

[0124] TIFF0007659395000104.tif64155

[0125] Specific examples of the group (2) include the following groups: * represents a bonding site. TIFF0007659395000105.tif67162

[0126] 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.

[0127] Of the (meth)acrylic monomers having an acid labile group, preferred are those having an alicyclic hydrocarbon group having 5 to 20 carbon atoms. By using a resin (A) having a structural unit derived from a monomer (a1) having a bulky structure such as an alicyclic hydrocarbon group in a resist composition, the resolution of the resist pattern can be improved.

[0128] Examples of the structural unit derived from the (meth)acrylic monomer having the group (1) include a structural unit represented by formula (a1-0) (hereinafter, sometimes referred to as structural unit (a1-0)), a structural unit represented by formula (a1-1) (hereinafter, sometimes referred to as structural unit (a1-1)), or a structural unit represented by formula (a1-2) (hereinafter, sometimes referred to as structural unit (a1-2)). Preferably, at least one structural unit selected from the group consisting of the structural unit (a1-1) and the structural unit (a1-2). These may be used alone or in combination of two or more. TIFF0007659395000106.tif47153 [In formula (a1-0), formula (a1-1) and formula (a1-2), L a01 , L a1 and L a2 are each independently -O- or *-O-(CH2) k1 represents --CO--O--, k1 represents an integer of 1 to 7, and * represents a bonding site with --CO--. R a01 , R a4 and R a5 each independently represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a02 , R a03 and R a04 each independently represents an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof. R a6 and R a7 each independently represents an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these. m1 represents an integer of 0 to 14. n1 represents an integer of 0 to 10. n1' represents an integer of 0 to 3.

[0129] R a01 , R a4 and R a5 is preferably a hydrogen atom or a methyl group, and more preferably a methyl group. L a01 , L a1 and L a2 is preferably an oxygen atom or *-O-(CH2) k01 It is -CO-O- (wherein k01 is preferably an integer of any one of 1 to 4, more preferably 1), and more preferably an oxygen atom. R a02 , R a03 , R a04 , R a6 and R a7The alkyl group, alkenyl group, alicyclic hydrocarbon group, aromatic hydrocarbon group and combinations thereof in the formula (1) are R a1 , R a2 and R a3 Examples of the groups include the same groups as those listed in the above. R a02 , R a03 , and R a04 The alkyl group in the formula (I) is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl group, and even more preferably a methyl group. R a6 and R a7 The alkyl group in the formula (I) is preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group, or a t-butyl group, and even more preferably an ethyl group, an isopropyl group, or a t-butyl group. R a6 and R a7 The alkenyl group in is preferably an alkenyl group having 2 to 6 carbon atoms, and more preferably an ethenyl group, a propenyl group, an isopropenyl group, or a butenyl group. R a02 , R a03 , R a04 , R a6 and R a7 The alicyclic hydrocarbon group preferably has 5 to 12 carbon atoms, and more preferably 5 to 10 carbon atoms. R a02 , R a03 , R a04 , R a6 and R a7 The aromatic hydrocarbon group preferably has 6 to 12 carbon atoms, and more preferably 6 to 10 carbon atoms. In the group in which an alkyl group and an alicyclic hydrocarbon group are combined, the total number of carbon atoms in the combination of the alkyl group and the alicyclic hydrocarbon group is preferably 18 or less. In the group in which an alkyl group and an aromatic hydrocarbon group are combined, the total number of carbon atoms in the combination of the alkyl group and the aromatic hydrocarbon group is preferably 18 or less. R a02 and R a03is preferably an alkyl group having 1 to 6 carbon atoms or an aromatic hydrocarbon group having 6 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a phenyl group or a naphthyl group. R a04 is preferably an alkyl group having 1 to 6 carbon atoms or an alicyclic hydrocarbon group having 5 to 12 carbon atoms, and more preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. R a6 and R a7 are each independently preferably an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an aromatic hydrocarbon group having 6 to 12 carbon atoms, more preferably a methyl group, an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group, a phenyl group, or a naphthyl group, and further preferably an ethyl group, an isopropyl group, a t-butyl group, an ethenyl group, or a phenyl group. m1 is preferably an integer of 0 to 3, and more preferably 0 or 1. n1 is preferably an integer of 0 to 3, and more preferably 0 or 1. n1' is preferably 0 or 1.

[0130] Examples of the structural unit (a1-0) include a structural unit represented by any one of formulas (a1-0-1) to (a1-0-18) and R a01 and structural units in which a methyl group corresponding to the formula (a1-0-1) is replaced with a hydrogen atom, and structural units represented by any one of formulas (a1-0-1) to (a1-0-10), (a1-0-13) and (a1-0-14) are preferred. TIFF0007659395000107.tif101167

[0131] Examples of the structural unit (a1-1) include structural units derived from monomers described in JP 2010-204646 A. Among them, structural units represented by any one of formulas (a1-1-1) to (a1-1-7) and R in the structural unit (a1-1) are a4In the above formula (a1-1-1), a structural unit in which a methyl group is replaced with a hydrogen atom is preferred, and a structural unit represented by any one of formulas (a1-1-1) to (a1-1-4) is more preferred. JPEG0007659395000108.jpg41169

[0132] The structural unit (a1-2) includes a structural unit represented by any one of formulas (a1-2-1) to (a1-2-12) and R a5 and structural units in which a methyl group corresponding to the formula (a1-2-2), (a1-2-5), (a1-2-6), and (a1-2-10) to (a1-2-12) are preferred. TIFF0007659395000109.tif69156

[0133] When the resin (A) contains the structural unit (a1-0), the content thereof is usually 5 to 80 mol %, preferably 5 to 75 mol %, and more preferably 10 to 70 mol %, based on all structural units in the resin (A). When the resin (A) contains the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is usually 10 to 90 mol %, preferably 15 to 85 mol %, more preferably 20 to 80 mol %, even more preferably 20 to 75 mol %, and still more preferably 20 to 70 mol %, based on all structural units in the resin (A).

[0134] An example of the structural unit (a1) having a group (2) is a structural unit represented by formula (a1-4) (hereinafter, sometimes referred to as "structural unit (a1-4)"). TIFF0007659395000110.tif4767[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 a33represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A a30 is a single bond or * -X a31 -(A a32 -X a32 ) nc - stands for -R. a32 represents the bonding site with the carbon atom to which it is bonded. A a32 represents an alkanediyl group having 1 to 6 carbon atoms. X a31 and X a32 each independently represents -O-, -CO-O-, or -O-CO-. nc represents 0 or 1. la represents an integer of 0 to 4. When la is an integer of 2 or more, a plurality of R a33 may be the same or different from each other. R a34 and R a35 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms; R a36 represents a hydrocarbon group having 1 to 20 carbon atoms, or R a35 and R a36 are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms together with the -CO- to which they are bonded, and the -CH2- contained in the hydrocarbon group and the divalent hydrocarbon group may be replaced by -O- or -S-.]

[0135] R a32 and R a33 Examples of the halogen atom in include a fluorine atom, a chlorine atom, and a bromine atom. R a32Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in the formula (I) include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, a hexyl group, and a perfluorohexyl group. R a32 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and further preferably a hydrogen atom or a methyl group. R a33 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. R a33 Examples of the alkoxy group in include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, a tert-butoxy group, a pentyloxy group, and a hexyloxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and further preferably a methoxy group. R a33 Examples of the alkoxyalkyl group in the formula (I) include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and further preferably a methoxymethyl group. R a33In the above, examples of the alkoxyalkoxy group include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, and more preferably a methoxyethoxy group or an ethoxyethoxy group. R a33 Examples of the alkylcarbonyl group in include an acetyl group, a propionyl group, a butyryl group, etc. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group. R a33 In the above formula, examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group. R a33 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group, and further preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group.

[0136] *-X a31 -(A a32 -X a32 ) nc - includes *-O-, *-CO-O-, *-O-CO-, *-CO-OA a32 -CO-O-, *-O-CO-A a32 -O-, *-OA a32 -CO-O-, *-CO-OA a32 -O-CO-, *-O-CO-A a32 -O-CO-, and *-CO-O- and *-CO-OA are particularly well known. a32 -CO-O- or *-OA a32-CO-O- is preferred.

[0137] A a32 Examples of the alkanediyl group in the formula (I) include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. A a32 is preferably a methylene group or an ethylene group.

[0138] A a30 is a single bond, *-CO-O- or *-CO-OA a32 -CO-O- is preferred, a single bond, *-CO-O- or *-CO-O-CH2-CO-O- is more preferred, and a single bond or *-CO-O- is even more preferred.

[0139] la is preferably 0, 1 or 2, more preferably 0 or 1, and even more preferably 0. R a34 , R a35 and R a36 Examples of the hydrocarbon group in include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group consisting of a combination thereof. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. The alicyclic hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl, adamantyl, and norbornyl groups, as well as the following groups (* indicates a bonding site): TIFF0007659395000111.tif10151 Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. Examples of the combined group include a group in which the above-mentioned alkyl group and alicyclic hydrocarbon group are combined (e.g., alkylcycloalkyl groups or cycloalkylalkyl groups such as methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, and norbornylethyl group), aralkyl groups such as benzyl group, aromatic hydrocarbon groups having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon groups having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), and aryl-cycloalkyl groups such as phenylcyclohexyl group. In particular, R a36 Examples of the alkyl group include an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these groups.

[0140] R a34 is preferably a hydrogen atom. R a35 is preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an alicyclic hydrocarbon group having 3 to 12 carbon atoms, and more preferably a methyl group or an ethyl group. R a36 The hydrocarbon group in R is preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a group formed by combining these, and more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. a36 The alkyl group and the alicyclic hydrocarbon group in R are preferably unsubstituted. a36The aromatic hydrocarbon group in is preferably an aromatic ring having an aryloxy group having 6 to 10 carbon atoms. -OC(R a34 )(R a35 )-OR a36 is eliminated on contact with an acid (e.g., p-toluenesulfonic acid) to form a hydroxy group. -OC(R a34 )(R a35 )-OR a36 is preferably bonded to the o-position or p-position of the benzene ring, and more preferably bonded to the p-position.

[0141] Examples of the structural unit (a1-4) include structural units derived from monomers described in JP 2010-204646 A. Preferably, the structural units represented by formulas (a1-4-1) to (a1-4-18) and R in the structural unit (a1-4) are a32 and more preferably, the structural units represented by formulae (a1-4-1) to (a1-4-5), (a1-4-10), (a1-4-13), and (a1-4-14), respectively. TIFF0007659395000112.tif103165

[0142] When the resin (A) contains the structural unit (a1-4), the content thereof is preferably 3 to 80 mol %, more preferably 5 to 75 mol %, even more preferably 7 to 70 mol %, even more preferably 7 to 65 mol %, and particularly preferably 10 to 60 mol %, based on the total of all structural units in the resin (A).

[0143] An example of a structural unit derived from a (meth)acrylic monomer having the group (2) is a structural unit represented by formula (a1-5) (hereinafter, may be referred to as "structural unit (a1-5)"). TIFF0007659395000113.tif4658 formula (a1-5), R a8represents an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydrogen atom, or a halogen atom. Z a1 is a single bond or -(CH2) h3 -CO-L 54 -, h3 represents an integer of 1 to 4, * represents L 51 It represents the binding site with L 51 , L 52 , L 53 and L 54 each independently represents -O- or -S-. s1 represents an integer of 1 to 3. s1' represents an integer of 0 to 3.

[0144] Examples of the halogen atom include a fluorine atom and a chlorine atom, with a fluorine atom being preferred. Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a fluoromethyl group, and a trifluoromethyl group. In formula (a1-5), R a8 is preferably a hydrogen atom, a methyl group, or a trifluoromethyl group. L 51 is preferably an oxygen atom. L 52 and L 53 Of these, it is preferred that one is -O- and the other is -S-. It is preferable that s1 is 1. s1' is preferably an integer of 0 to 2. Z a1 is preferably a single bond or -CH2-CO-O-.

[0145] Examples of the structural unit (a1-5) include structural units derived from monomers described in JP 2010-61117 A. Among them, the structural units represented by formulae (a1-5-1) to (a1-5-4) are preferred, and the structural unit represented by formula (a1-5-1) or (a1-5-2) is more preferred. TIFF0007659395000114.tif33133

[0146] When the resin (A) contains the structural unit (a1-5), the content thereof is preferably 1 to 50 mol %, more preferably 3 to 45 mol %, even more preferably 5 to 40 mol %, and still more preferably 5 to 30 mol %, based on all structural units in the resin (A).

[0147] Further, examples of the structural unit (a1) include the following structural units. TIFF0007659395000115.tif31162

[0148] When resin (A) contains structural units such as (a1-3-1) to (a1-3-7) above, the content thereof is preferably from 10 to 95 mol %, more preferably from 15 to 90 mol %, even more preferably from 20 to 85 mol %, even more preferably from 20 to 70 mol %, and particularly preferably from 20 to 60 mol %, based on the total structural units of resin (A).

[0149] Further, examples of the structural unit (a1) include the following structural units. TIFF0007659395000116.tif5295 When resin (A) contains structural units such as (a1-6-1) to (a1-6-3) above, the content thereof is preferably 10 to 60 mol %, more preferably 15 to 55 mol %, even more preferably 20 to 50 mol %, even more preferably 20 to 45 mol %, and particularly preferably 20 to 40 mol %, based on the total structural units of resin (A).

[0150] Structural unit(s) The structural unit (s) is derived from a monomer having no acid labile group (hereinafter, may be referred to as "monomer (s)"). As the monomer from which the structural unit (s) is derived, a monomer having no acid labile group known in the resist field can be used. The structural unit (s) preferably has a hydroxy group or a lactone ring. The use of a resin containing a structural unit having a hydroxy group and no acid labile group (hereinafter sometimes referred to as "structural unit (a2)") and / or a structural unit having a lactone ring and no acid labile group (hereinafter sometimes referred to as "structural unit (a3)") in the resist composition of the present invention can improve the resolution of the resist pattern and the adhesion to the substrate.

[0151] <Structural unit (a2)> The hydroxy group contained in the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group. When a resist pattern is produced from the resist composition of the present invention, in the case where a high energy ray such as a KrF excimer laser (248 nm), an electron beam, or EUV (extreme ultraviolet light) is used as an exposure light source, the structural unit (a2) having a phenolic hydroxyl group is preferred, and the structural unit (a2-A) described below is more preferred. In addition, in the case where an ArF excimer laser (193 nm) or the like is used, the structural unit (a2) having an alcoholic hydroxyl group is preferred, and the structural unit (a2-1) described below is more preferred. The structural unit (a2) may contain one type alone or two or more types.

[0152] In the structural unit (a2), an example of a structural unit having a phenolic hydroxy group is a structural unit represented by formula (a2-A) (hereinafter, sometimes referred to as "structural unit (a2-A)"). JPEG0007659395000117.jpg4954 [In formula (a2-A), R a50 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. R a51represents a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an alkoxyalkoxy group having 2 to 12 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, an acryloyloxy group, or a methacryloyloxy group. A a50 is a single bond or *-X a51 -(A a52 -X a52 ) nb - stands for -R. a50 represents the bonding site with the carbon atom to which it is bonded. A a52 represents an alkanediyl group having 1 to 6 carbon atoms. X a51 and X a52 each independently represents -O-, -CO-O-, or -O-CO-. nb represents 0 or 1. mb represents an integer of 0 to 4. When mb is an integer of 2 or more, a plurality of R a51 may be the same or different.]

[0153] R a50 and R a51 Examples of the halogen atom in include a fluorine atom, a chlorine atom, and a bromine atom. R a50 Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in the formula (I) include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, a hexyl group, and a perfluorohexyl group. R a50is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and further preferably a hydrogen atom or a methyl group. R a51 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and further preferably a methyl group. R a51 Examples of the alkoxy group in include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a sec-butoxy group, and a tert-butoxy group. The alkoxy group is preferably an alkoxy group having 1 to 4 carbon atoms, more preferably a methoxy group or an ethoxy group, and further preferably a methoxy group. R a51 Examples of the alkoxyalkyl group in the formula (I) include a methoxymethyl group, an ethoxyethyl group, a propoxymethyl group, an isopropoxymethyl group, a butoxymethyl group, a sec-butoxymethyl group, and a tert-butoxymethyl group. The alkoxyalkyl group is preferably an alkoxyalkyl group having 2 to 8 carbon atoms, more preferably a methoxymethyl group or an ethoxyethyl group, and further preferably a methoxymethyl group. R a51 In the above, examples of the alkoxyalkoxy group include a methoxymethoxy group, a methoxyethoxy group, an ethoxymethoxy group, an ethoxyethoxy group, a propoxymethoxy group, an isopropoxymethoxy group, a butoxymethoxy group, a sec-butoxymethoxy group, and a tert-butoxymethoxy group. The alkoxyalkoxy group is preferably an alkoxyalkoxy group having 2 to 8 carbon atoms, and more preferably a methoxyethoxy group or an ethoxyethoxy group. R a51 Examples of the alkylcarbonyl group in include an acetyl group, a propionyl group, a butyryl group, etc. The alkylcarbonyl group is preferably an alkylcarbonyl group having 2 to 3 carbon atoms, and more preferably an acetyl group. R a51In the above formula, examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group. The alkylcarbonyloxy group is preferably an alkylcarbonyloxy group having 2 to 3 carbon atoms, and more preferably an acetyloxy group. R a51 is preferably a halogen atom, a hydroxy group, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or an alkoxyalkoxy group having 2 to 8 carbon atoms, more preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, an ethoxy group, an ethoxyethoxy group, or an ethoxymethoxy group, and further preferably a fluorine atom, an iodine atom, a hydroxy group, a methyl group, a methoxy group, or an ethoxyethoxy group.

[0154] *-X a51 -(A a52 -X a52 ) nb - includes *-O-, *-CO-O-, *-O-CO-, *-CO-OA a52 -CO-O-, *-O-CO-A a52 -O-, *-OA a52 -CO-O-, *-CO-OA a52 -O-CO-, *-O-CO-A a52 -O-CO-, and *-CO-O- and *-CO-OA are particularly well known. a52 -CO-O- or *-OA a52 -CO-O- is preferred.

[0155] A a52 Examples of the alkanediyl group in the formula (I) include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. A a52 is preferably a methylene group or an ethylene group.

[0156] Aa50 is a single bond, *-CO-O- or *-CO-OA a52 -CO-O- is preferred, a single bond, *-CO-O- or *-CO-O-CH2-CO-O- is more preferred, and a single bond or *-CO-O- is even more preferred.

[0157] mb is preferably 0, 1 or 2, more preferably 0 or 1, and even more preferably 0. The hydroxy group is preferably bonded to the o- or p-position of the benzene ring, and more preferably to the p-position.

[0158] Examples of the structural unit (a2-A) include structural units derived from monomers described in JP-A-2010-204634 and JP-A-2012-12577.

[0159] The structural unit (a2-A) is represented by the structural units represented by the formulae (a2-2-1) to (a2-2-16) and the structural units represented by the formulae (a2-2-1) to (a2-2-16), R a50 The structural unit (a2-A) includes a structural unit represented by formula (a2-2-1), a structural unit represented by formula (a2-2-3), a structural unit represented by formula (a2-2-6), a structural unit represented by formula (a2-2-8), and a structural unit represented by formula (a2-2-12) to (a2-2-14), and in these structural units, R in the structural unit (a2-A) can be exemplified. a50 It is preferable that the structural unit is a structural unit in which a methyl group corresponding to the following formula is replaced with a hydrogen atom. TIFF0007659395000118.tif56169

[0160] When the structural unit (a2-A) is contained in the resin (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 still more preferably 20 to 65 mol %, based on all structural units. The structural unit (a2-A) can be incorporated into the resin (A) by, for example, polymerizing the structural unit (a1-4) and then treating with an acid such as p-toluenesulfonic acid. Alternatively, the structural unit (a2-A) can be incorporated into the resin (A) by polymerizing the structural unit (a1-4) and then treating with an alkali such as tetramethylammonium hydroxide.

[0161] An example of the structural unit (a2) having an alcoholic hydroxy group is a structural unit represented by formula (a2-1) (hereinafter sometimes referred to as "structural unit (a2-1)"). TIFF0007659395000119.tif4664 formula (a2-1), L a3 is -O- or *-O-(CH2) k2 represents -CO-O-, k2 represents an integer of 1 to 7. * represents a bonding site with -CO-. R a14 represents a hydrogen atom or a methyl group. R a15 and R a16 each independently represents a hydrogen atom, a methyl group, or a hydroxy group. o1 represents an integer of 0 to 10.

[0162] In formula (a2-1), L a3 is preferably -O-, -O-(CH2) f1 It is -CO-O- (wherein f1 represents an integer of 1 to 4), and more preferably -O-. R a14 is preferably a methyl group. R a15 is preferably a hydrogen atom. R a16 is preferably a hydrogen atom or a hydroxy group. o1 is preferably an integer of 0 to 3, and more preferably 0 or 1.

[0163] Examples of the structural unit (a2-1) include structural units derived from monomers described in JP 2010-204646 A. A structural unit represented by any one of formulas (a2-1-1) to (a2-1-6) is preferred, a structural unit represented by any one of formulas (a2-1-1) to (a2-1-4) is more preferred, and a structural unit represented by formula (a2-1-1) or formula (a2-1-3) is even more preferred. TIFF0007659395000120.tif50139

[0164] When the resin (A) contains the structural unit (a2-1), the content thereof is usually 1 to 45 mol %, preferably 1 to 40 mol %, more preferably 1 to 35 mol %, even more preferably 1 to 20 mol %, and still more preferably 1 to 10 mol %, based on all structural units in the resin (A).

[0165] <Structural unit (a3)> The lactone ring of the structural unit (a3) ​​may be a monocyclic ring such as a β-propiolactone ring, a γ-butyrolactone ring, or a δ-valerolactone ring, or may be a condensed ring of a monocyclic lactone ring and another ring. Preferred examples include a γ-butyrolactone ring, an adamantane lactone ring, or a bridged ring containing a γ-butyrolactone ring structure (for example, a structural unit represented by the following formula (a3-2)).

[0166] The structural unit (a3) ​​is preferably a structural unit represented by formula (a3-1), formula (a3-2), formula (a3-3) or formula (a3-4). One of these may be contained alone, or two or more of them may be contained. TIFF0007659395000121.tif50163 [In formula (a3-1), formula (a3-2), formula (a3-3) and formula (a3-4), L a4 , L a5 and L a6 are each independently -O- or *-O-(CH2) k3 It represents a group represented by -CO-O- (k3 represents an integer of any of 1 to 7). L a7 , -O-, *-OLa8 -O-, *-OL a8 -CO-O-, *-OL a8 -CO-OL a9 -CO-O- or *-OL a8 -O-CO-L a9 Represents -O-. L a8 and L a9 each independently represents an alkanediyl group having 1 to 6 carbon atoms. * indicates the bonding site with the carbonyl group. R a18 , R a19 and R a20 each independently represents a hydrogen atom or a methyl group. R a24 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. X a3 represents -CH2- or an oxygen atom. R a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms. R a22 , R a23 and R a25 each independently represents a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms. p1 represents an integer of 0 to 5. q1 represents an integer of 0 to 3. r1 represents an integer of 0 to 3. w1 represents an integer of 0 to 8. When p1, q1, r1 and / or w1 are 2 or more, multiple R a21 , R a22 , R a23 and / or R a25 may be the same or different.]

[0167] R a21 , R a22 , R a23 and R a25Examples of the aliphatic hydrocarbon group in include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, and a tert-butyl group. R a24 Examples of the halogen atom in include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. R a24 Examples of the alkyl group in include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group, and preferably includes an alkyl group having 1 to 4 carbon atoms, and more preferably includes a methyl group or an ethyl group. R a24 Examples of the alkyl group having a halogen atom in the formula (I) include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, a perfluorohexyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group.

[0168] L a8 and L a9 Examples of the alkanediyl group in the formula (I) include a methylene group, an ethylene group, a propane-1,3-diyl group, a propane-1,2-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group.

[0169] In formulas (a3-1) to (a3-3), L a4 ~L a6 are each independently preferably -O- or *-O-(CH2) k3 In the -CO-O- group, k3 is a group in which k3 is any integer of 1 to 4, more preferably -O- and *-O-CH2-CO-O-, and further preferably an oxygen atom. R a18 ~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 each independently represent an integer of preferably 0 to 2, and more preferably 0 or 1.

[0170] In formula (a3-4), R a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group, or an ethyl group, and even more preferably a hydrogen atom or a methyl group. R a25 is preferably a carboxy group, a cyano group or a methyl group. L a7 is preferably -O- or *-OL a8 It is —CO—O—, and more preferably —O—, —O—CH2—CO—O— or —O—C2H4—CO—O—. w1 is preferably an integer of 0 to 2, and more preferably 0 or 1. In particular, the formula (a3-4) is preferably the formula (a3-4)'. TIFF0007659395000122.tif3848 (in the formula, R a24 , L a7 has the same meaning as above.)

[0171] Examples of the structural unit (a3) ​​include structural units derived from monomers described in JP 2010-204646 A, JP 2000-122294 A, and JP 2012-41274 A. Examples of the structural unit (a3) ​​include structural units represented by any one of formulas (a3-1-1), (a3-1-2), (a3-2-1), (a3-2-2), (a3-3-1), (a3-3-2), and (a3-4-1) to (a3-4-12), and in the structural unit, R in formulas (a3-1) to (a3-4) a18 , R a19 , R a20 and Ra24 A structural unit in which a methyl group corresponding to the following formula is replaced with a hydrogen atom is preferred.

[0172] JPEG0007659395000123.jpg117168

[0173] When the resin (A) contains the structural unit (a3), the total content thereof is usually 5 to 70 mol %, preferably 10 to 65 mol %, and more preferably 10 to 60 mol %, based on all structural units in the resin (A). Furthermore, the content of the structural unit (a3-1), the structural unit (a3-2), the structural unit (a3-3) or the structural unit (a3-4) is preferably from 5 to 60 mol %, more preferably from 5 to 50 mol %, and even more preferably from 10 to 50 mol %, based on the total structural units of the resin (A).

[0174] <Structural unit (a4)> Examples of the structural unit (a4) include the following structural units. TIFF0007659395000124.tif3166[In formula (a4), R 41 represents a hydrogen atom or a methyl group. R 42 represents a saturated hydrocarbon group having 1 to 24 carbon atoms and containing a halogen atom, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-.] R 42 Examples of the saturated hydrocarbon group represented by the formula (I) include chain saturated hydrocarbon groups, monocyclic or polycyclic alicyclic saturated hydrocarbon groups, and groups formed by combining these groups.

[0175] Examples of the chain saturated hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group. Examples of the monocyclic or polycyclic alicyclic saturated hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; and polycyclic alicyclic saturated hydrocarbon groups such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bonding site): TIFF0007659395000125.tif10146 Examples of groups formed by combinations include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic saturated hydrocarbon groups, such as -alkanediyl group-alicyclic saturated hydrocarbon group, -alicyclic saturated hydrocarbon group-alkyl group, and -alkanediyl group-alicyclic saturated hydrocarbon group-alkyl group.

[0176] Examples of the structural unit (a4) include a structural unit represented by formula (a4-0), a structural unit represented by formula (a4-1), and a structural unit represented by formula (a4-4). TIFF0007659395000126.tif4653[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.

[0177] L 4a Examples of the alkanediyl group in the formula (I) include linear alkanediyl groups such as a methylene group, an ethylene group, a propane-1,3-diyl group, and a butane-1,4-diyl group, and branched alkanediyl groups such as an ethane-1,1-diyl group, a propane-1,2-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, and a 2-methylpropane-1,2-diyl group.

[0178] L 3aExamples of the perfluoroalkanediyl group in the formula (I) include a difluoromethylene group, a perfluoroethylene group, a perfluoroethylfluoromethylene group, a perfluoropropane-1,3-diyl group, a perfluoropropane-1,2-diyl group, a perfluoropropane-2,2-diyl group, a perfluorobutane-1,4-diyl group, a perfluorobutane-2,2-diyl group, a perfluorobutane-1,2-diyl group, a perfluoropentane-1,5-diyl group, a perfluoropentane-2,2-diyl group, a perfluoropentane-3 ,3-diyl group, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane-1,7-diyl group, perfluoroheptane-2,2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane-2,2-diyl group, perfluorooctane-3,3-diyl group, and perfluorooctane-4,4-diyl group. L 3a Examples of the perfluorocycloalkanediyl group in the formula (I) include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, and a perfluoroadamantanediyl group.

[0179] L 4a is preferably a single bond, a methylene group, or an ethylene group, and more preferably a single bond or a methylene group. L 3a is preferably a perfluoroalkanediyl group having 1 to 6 carbon atoms, and more preferably a perfluoroalkanediyl group having 1 to 3 carbon atoms.

[0180] The structural unit (a4-0) includes the structural units shown below and R in the structural unit (a4-0) in the structural units shown below. 54 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. JPEG0007659395000127.jpg95166

[0181] TIFF0007659395000128.tif4867[In formula (a4-1), R a41 represents a hydrogen atom or a methyl group. R a42 represents a saturated hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and -CH2- contained in the saturated hydrocarbon group may be replaced by -O- or -CO-. A a41 represents an optionally substituted alkanediyl group having 1 to 6 carbon atoms or a group represented by formula (a-g1), a41 and R a42 At least one of the groups has a halogen atom (preferably a fluorine atom) as a substituent. TIFF0007659395000129.tif1488 [In formula (a-g1), s represents 0 or 1. A a42 and A a44 each independently represents a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. A a43 represents a single bond or a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a substituent. X a41 and X a42 each independently represents -O-, -CO-, -CO-O- or -O-CO-. However, A a42 , A a43 , A a44 , X a41 and X a42 The total number of carbon atoms is 7 or less. * indicates the binding site, and the * on the right is -O-CO-R a42 This is the binding site for

[0182] R a42 Examples of the saturated hydrocarbon group in include chain saturated hydrocarbon groups, monocyclic or polycyclic alicyclic saturated hydrocarbon groups, and groups formed by combining these.

[0183] Examples of the chain saturated hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a dodecyl group, a pentadecyl group, a hexadecyl group, a heptadecyl group, and an octadecyl group. Examples of the monocyclic or polycyclic alicyclic saturated hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; and polycyclic alicyclic saturated hydrocarbon groups such as a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups (* represents a bonding site): TIFF0007659395000130.tif10160 Examples of groups formed by combinations include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic saturated hydrocarbon groups, such as -alkanediyl group-alicyclic saturated hydrocarbon group, -alicyclic saturated hydrocarbon group-alkyl group, and -alkanediyl group-alicyclic saturated hydrocarbon group-alkyl group.

[0184] R a42 The substituent that is has includes at least one selected from the group consisting of a halogen atom and a group represented by formula (a-g3). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable. TIFF0007659395000131.tif855[In formula (a-g3), X a43 represents an oxygen atom, a carbonyl group, *-O-CO-, or *-CO-O-. A a45 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. * stands for R a42 represents the binding site for However, R a42 -X a43 -A a45 In R a42 When A does not have a halogen atom, a45 represents a saturated hydrocarbon group having 1 to 17 carbon atoms and at least one halogen atom.

[0185] A a45 Examples of the saturated hydrocarbon group in include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl groups; monocyclic alicyclic hydrocarbon groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups; and polycyclic alicyclic hydrocarbon groups such as decahydronaphthyl, adamantyl, norbornyl, and the following groups (* represents a bonding site): TIFF0007659395000132.tif10160 Examples of groups formed by combinations include groups formed by combining one or more alkyl groups or one or more alkanediyl groups with one or more alicyclic hydrocarbon groups, such as -alkanediyl group-alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, and -alkanediyl group-alicyclic hydrocarbon group-alkyl group.

[0186] R a42 is preferably a saturated hydrocarbon group which may have a halogen atom, and more preferably a saturated hydrocarbon group having an alkyl group having a halogen atom and / or a group represented by formula (a-g3). R a42 When is a saturated hydrocarbon group having a halogen atom, it is preferably a saturated hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, further preferably a perfluoroalkyl group having 1 to 6 carbon atoms, and particularly preferably a perfluoroalkyl group having 1 to 3 carbon atoms. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluorobutyl group, a perfluoropentyl group, a perfluorohexyl group, a perfluoroheptyl group, and a perfluorooctyl group. Examples of the perfluorocycloalkyl group include a perfluorocyclohexyl group. R a42is a saturated hydrocarbon group having a group represented by formula (a-g3), the number of carbon atoms contained in the group represented by formula (a-g3) is a42 The total number of carbon atoms is preferably not more than 15, more preferably not more than 12. In the case where the group represented by formula (a-g3) is contained as a substituent, the number thereof is preferably 1.

[0187] R a42 is a saturated hydrocarbon group having a group represented by formula (a-g3), R a42 is more preferably a group represented by formula (a-g2). TIFF0007659395000133.tif871[In formula (a-g2), A a46 represents a divalent saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. X a44 represents **-O-CO- or **-CO-O- (** represents A a46 ) which represents the binding site with A a47 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom. However, A a46 , A a47 and X a44 The total number of carbon atoms in A is 18 or less. a46 and A a47 At least one of these has at least one halogen atom. * indicates the bonding site with the carbonyl group.]

[0188] A a46 The saturated hydrocarbon group preferably has 1 to 6 carbon atoms, and more preferably has 1 to 3 carbon atoms. A a47 The saturated hydrocarbon group preferably has 4 to 15 carbon atoms, more preferably 5 to 12 carbon atoms. a47 is more preferably a cyclohexyl group or an adamantyl group.

[0189] A preferred structure of the group represented by formula (a-g2) is the following structure (* indicates the bonding site with the carbonyl group). JPEG0007659395000134.jpg14160

[0190] 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.

[0191] 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.

[0192] In the group represented by formula (a-g1), X a42Examples of the group in which is -O-, -CO-, -CO-O-, or -O-CO- include the following groups. In the following examples, * and ** each represent a bonding site, and ** represents -O-CO-R a42 This is the binding site for TIFF0007659395000135.tif46140

[0193] The structural unit represented by formula (a4-1) includes the structural units shown below and R in the structural unit represented by formula (a4-1) in the structural units shown below. a41 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. JPEG0007659395000136.jpg97142

[0194] TIFF0007659395000137.tif134152

[0195] Examples of the structural unit represented by formula (a4-1) include a structural unit represented by formula (a4-2) and a structural unit represented by formula (a4-3). TIFF0007659395000138.tif4256[In formula (a4-2), R f5 represents a hydrogen atom or a methyl group. L 44 represents an alkanediyl group having 1 to 6 carbon atoms, and -CH2- contained in the alkanediyl group may be replaced by -O- or -CO-. R f6 represents a saturated hydrocarbon group having 1 to 20 carbon atoms and containing a fluorine atom. However, L 44 and R f6 The total number of carbon atoms in the molecule is limited to 21.

[0196] L 44 The alkanediyl group having 1 to 6 carbon atoms is represented by A a41 Examples of the groups include the same groups as those exemplified in the above. R f6 The saturated hydrocarbon group of R 42 Examples of the groups include the same groups as those exemplified in the above. L44 The alkanediyl group in is preferably an alkanediyl group having 2 to 4 carbon atoms, and more preferably an ethylene group.

[0197] Examples of the structural unit represented by formula (a4-2) include structural units represented by formulas (a4-1-1) to (a4-1-11). f5 The structural unit represented by formula (a4-2) also includes a structural unit in which a methyl group corresponding to the following is replaced with a hydrogen atom.

[0198] TIFF0007659395000139.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 contain a fluorine atom. X f12 represents *-O-CO- or *-CO-O- (* represents A f13 ) which represents the binding site with A f14 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may contain a fluorine atom. However, A f13 and A f14 At least one of L has a fluorine atom. 5 , A f13 and A f14 The total number of carbon atoms in the molecule is limited to 20.

[0199] L 5 The alkanediyl group in a41 Examples of the alkanediyl group include the same groups as those exemplified as the alkanediyl group.

[0200] A f13The divalent saturated hydrocarbon group which may have a fluorine atom in is preferably a divalent chain saturated hydrocarbon group which may have a fluorine atom and a divalent alicyclic saturated hydrocarbon group which may have a fluorine atom, and more preferably a perfluoroalkanediyl group. Examples of the divalent chain saturated hydrocarbon group which may have a fluorine atom include alkanediyl groups such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group, and a pentanediyl group; and perfluoroalkanediyl groups such as a difluoromethylene group, a perfluoroethylene group, a perfluoropropanediyl group, a perfluorobutanediyl group, and a perfluoropentanediyl group. The divalent alicyclic saturated hydrocarbon group which may have a fluorine atom may be either monocyclic or polycyclic. Examples of the monocyclic group include a cyclohexanediyl group and a perfluorocyclohexanediyl group. Examples of the polycyclic group include an adamantanediyl group, a norbornanediyl group, and a perfluoroadamantanediyl group.

[0201] A f14 The saturated hydrocarbon group and the saturated hydrocarbon group which may have a fluorine atom are represented by R a42Among them, a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1,2,2-tetrafluoroethyl group, an ethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a propyl group, a perfluorobutyl group, a 1,1,2,2,3,3,4,4-octafluorobutyl group, a butyl group, a perfluoropentyl group, a 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, a pentyl group, Preferred are fluorinated alkyl groups such as a hexyl group, a perfluorohexyl group, a heptyl group, a perfluoroheptyl group, an octyl group, and a perfluorooctyl group, a cyclopropylmethyl group, a cyclopropyl group, a cyclobutylmethyl group, a cyclopentyl group, a cyclohexyl group, a perfluorocyclohexyl group, an adamantyl group, an adamantylmethyl group, an adamantyldimethyl group, a norbornyl group, a norbornylmethyl group, a perfluoroadamantyl group, and a perfluoroadamantylmethyl group.

[0202] In formula (a4-3), L 5 is preferably an ethylene group. A f13 The divalent saturated hydrocarbon group is preferably a group containing a divalent chain saturated hydrocarbon group having 1 to 6 carbon atoms and a divalent alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and more preferably a divalent chain saturated hydrocarbon group having 2 to 3 carbon atoms. A f14 The saturated hydrocarbon group of is preferably a group containing a chain saturated hydrocarbon group having 3 to 12 carbon atoms and an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and more preferably a chain saturated hydrocarbon group having 3 to 10 carbon atoms and an alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms. f14 is preferably a group containing an alicyclic saturated hydrocarbon group having 3 to 12 carbon atoms, and more preferably a cyclopropylmethyl group, a cyclopentyl group, a cyclohexyl group, a norbornyl group, or an adamantyl group.

[0203] Examples of the structural unit represented by formula (a4-3) include structural units represented by formulas (a4-1'-1) to (a4-1'-11). R in the structural unit (a4-3) f7 The structural unit represented by formula (a4-3) also includes a structural unit in which a methyl group corresponding to the following is replaced with a hydrogen atom.

[0204] The structural unit (a4) also includes a structural unit represented by the formula (a4-4). TIFF0007659395000140.tif4569[In formula (a4-4), R f21 represents a hydrogen atom or a methyl group. A f21 is -(CH2) j1 -, -(CH2) j2 -O-(CH2) j3 -or-(CH2) j4 -CO-O-(CH2) j5 - represents. j1 to j5 each independently represent an integer of 1 to 6. R f22 represents a saturated hydrocarbon group having 1 to 10 carbon atoms and containing a fluorine atom.]

[0205] R f22 The saturated hydrocarbon group of R a42 The saturated hydrocarbon group represented by R f22 is preferably an alkyl group having 1 to 10 carbon atoms and having a fluorine atom, or an alicyclic saturated hydrocarbon group having 1 to 10 carbon atoms and having a fluorine atom, more preferably an alkyl group having 1 to 10 carbon atoms and having a fluorine atom, and further preferably an alkyl group having 1 to 6 carbon atoms and having a fluorine atom.

[0206] In formula (a4-4), A f21 As an example, -(CH2) j1 - is preferred, an ethylene group or a methylene group is more preferred, and a methylene group is even more preferred.

[0207] Examples of the structural unit represented by formula (a4-4) include the following structural units and structural units represented by the following formulas: f21 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. TIFF0007659395000141.tif89164

[0208] When the resin (A) contains the structural unit (a4), the content thereof is preferably from 1 to 20 mol %, more preferably from 2 to 15 mol %, and even more preferably from 3 to 10 mol %, based on all structural units in the resin (A).

[0209] <Structural unit (a5)> The non-leaving hydrocarbon group contained in the structural unit (a5) may be a group containing a linear, branched or cyclic hydrocarbon group. Among these, the structural unit (a5) is preferably a group containing an alicyclic hydrocarbon group. An example of the structural unit (a5) is a structural unit represented by the formula (a5-1). TIFF0007659395000142.tif3655[In formula (a5-1), R 51 represents a hydrogen atom or a methyl group. R 52 represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and a hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with an aliphatic hydrocarbon group having 1 to 8 carbon atoms. L 55 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the saturated hydrocarbon group may be replaced with -O- or -CO-.]

[0210] R 52 The alicyclic hydrocarbon group in may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group, a norbornyl group, and the like. Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms include alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, and a 2-ethylhexyl group. An example of the alicyclic hydrocarbon group having a substituent is a 3-methyladamantyl group. R 52 is preferably an unsubstituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and more preferably an adamantyl group, a norbornyl group, or a cyclohexyl group.

[0211] L 55 In the above formula, the divalent saturated hydrocarbon group includes a divalent chain saturated hydrocarbon group and a divalent alicyclic saturated hydrocarbon group, and is preferably a divalent chain saturated hydrocarbon group. Examples of the divalent chain saturated hydrocarbon group include alkanediyl groups such as a methylene group, an ethylene group, a propanediyl group, a butanediyl group, and a pentanediyl group. The divalent alicyclic saturated hydrocarbon group may be either monocyclic or polycyclic. Examples of the monocyclic alicyclic saturated hydrocarbon group include cycloalkanediyl groups such as cyclopentanediyl and cyclohexanediyl. Examples of the polycyclic divalent alicyclic saturated hydrocarbon group include adamantanediyl and norbornanediyl.

[0212] L 55 Examples of the divalent saturated hydrocarbon group represented by formula (L1-1) to formula (L1-4) include groups represented by formula (L1-2) to (L1-4). In the following formulae, * and ** each represent a bonding site, and * represents a bonding site with an oxygen atom. TIFF0007659395000143.tif18165 formula (L1-1), X x1 represents *-O-CO- or *-CO-O- (* represents L x1 ) which represents the binding site with L x1 represents a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. L x2 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. However, L x1 and L x2 The total number of carbon atoms is 16 or less. In formula (L1-2), L x3 represents a divalent aliphatic saturated hydrocarbon group having 1 to 17 carbon atoms. L x4 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 16 carbon atoms. However, L x3 and L x4 The total number of carbon atoms is 17 or less. In formula (L1-3), L x5 represents a divalent aliphatic saturated hydrocarbon group having 1 to 15 carbon atoms. L x6 and L x7 each independently represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 14 carbon atoms. However, L x5 , L x6 and L x7 The total number of carbon atoms is 15 or less. In formula (L1-4), L x8 and L x9 represents a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 12 carbon atoms. W x1 represents a divalent alicyclic saturated hydrocarbon group having 3 to 15 carbon atoms. However, L x8 , L x9 and W x1 The total number of carbon atoms is 15 or less.

[0213] L x1 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x2 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond. L x3is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x5 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group. L x6 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a methylene group or an ethylene group. L x7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms. L x8 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond or a methylene group. L x9 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, and more preferably a single bond or a methylene group. W x1 is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, and more preferably a cyclohexanediyl group or an adamantanediyl group.

[0214] Examples of the group represented by formula (L1-1) include the divalent groups shown below. TIFF0007659395000144.tif53136

[0215] Examples of the group represented by formula (L1-2) include the divalent groups shown below. TIFF0007659395000145.tif23130

[0216] Examples of the group represented by formula (L1-3) include the divalent groups shown below. TIFF0007659395000146.tif16145

[0217] Examples of the group represented by formula (L1-4) include the divalent groups shown below. TIFF0007659395000147.tif26114

[0218] L 55 is preferably a single bond or a group represented by formula (L1-1).

[0219] The structural unit (a5-1) may be any of the structural units shown below and R in the structural unit (a5-1) in the structural unit shown below. 51 In the structural unit, a methyl group corresponding to the above formula is replaced with a hydrogen atom. TIFF0007659395000148.tif79161

[0220] TIFF0007659395000149.tif40161 When the resin (A) contains the structural unit (a5), the content thereof is preferably from 1 to 30 mol %, more preferably from 2 to 20 mol %, and even more preferably from 3 to 15 mol %, based on all structural units in the resin (A).

[0221] <Structural unit (II)> Resin (A) may further contain a structural unit that decomposes upon exposure to generate an acid (hereinafter, may be referred to as "structural unit (II)"). Specific examples of structural unit (II) include structural units described in JP-A-2016-79235, and are preferably structural units having a sulfonate group or carboxylate group and an organic cation in the side chain, or a structural unit having a sulfonio group and an organic anion in the side chain.

[0222] The structural unit having a sulfonate group or carboxylate group and an organic cation in the side chain is preferably a structural unit represented by formula (II-2-A'). TIFF0007659395000150.tif3189 [In formula (II-2-A'), X III3represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, in which -CH2- contained in the saturated hydrocarbon group may be replaced by -O-, -S- or -CO-, and a hydrogen atom contained in the saturated hydrocarbon group may be replaced by a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, or a hydroxy group. A x1 represents an alkanediyl group having 1 to 8 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted by a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. RA - represents a sulfonate group or a carboxylate group. R III3 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. Z.A. + represents an organic cation.

[0223] R III3 Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R III3 The alkyl group having 1 to 6 carbon atoms which may have a halogen atom and is represented by the formula: a8 Examples of the alkyl group include the same alkyl groups having 1 to 6 carbon atoms which may have a halogen atom and are represented by the following formula: A x1 Examples of the alkanediyl group having 1 to 8 carbon atoms represented by the formula (I) include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, an ethane-1,1-diyl group, a propane-1,1-diyl group, a propane-1,2-diyl group, a propane-2,2-diyl group, a pentane-2,4-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group. A x1Examples of the perfluoroalkyl group having 1 to 6 carbon atoms which may be substituted include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluorohexyl group.

[0224] X III3 Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by the formula (I) include linear or branched alkanediyl groups, and monocyclic or polycyclic divalent alicyclic saturated hydrocarbon groups, and combinations of these may also be used. Specifically, straight-chain alkanediyl groups such as methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, and dodecane-1,12-diyl group; butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, and the like. divalent monocyclic alicyclic saturated hydrocarbon groups such as cycloalkanediyl groups, such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group, etc.; and divalent polycyclic alicyclic saturated hydrocarbon groups, such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, etc.

[0225] Examples of saturated hydrocarbon groups in which -CH2- is replaced with -O-, -S-, or -CO- include divalent groups represented by formulae (X1) to (X53). However, the number of carbon atoms before -CH2- in the saturated hydrocarbon group is replaced with -O-, -S-, or -CO- is 17 or less. In the following formulae, * and ** represent binding sites, * represents A x1It represents the binding site with TIFF0007659395000151.tif145161

[0226] 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.

[0227] Z.A. + Examples of the organic cation represented by the formula (b2-1) include an organic onium cation, an organic sulfonium cation, an organic iodonium cation, an organic ammonium cation, a benzothiazolium cation, and an organic phosphonium cation. Among these, an organic sulfonium cation and an organic iodonium cation are preferred, and an arylsulfonium cation is more preferred. Specifically, examples of the organic cation represented by the formula (b2-1) to the formula (b2-4) above (hereinafter, may be referred to as "cation (b2-1)" depending on the formula number) are included.

[0228] The structural unit represented by formula (II-2-A') is preferably a structural unit represented by formula (II-2-A). JPEG0007659395000152.jpg37109 [In formula (II-2-A), R III3 , X III3 and Z.A. + has the same meaning as above. z represents an integer of 0 to 6. R III2 and R III4each independently represents a hydrogen atom, a fluorine atom, or a perfluoroalkyl group having 1 to 6 carbon atoms; when z is 2 or more, a plurality of R III2 and R III4 may be the same or different from each other. Q a and Q b each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.]

[0229] R III2 , R III4 , Q a and Q b As the perfluoroalkyl group having 1 to 6 carbon atoms represented by the formula b1 Examples of the perfluoroalkyl group include those having 1 to 6 carbon atoms represented by the following formula:

[0230] The structural unit represented by formula (II-2-A) is preferably a structural unit represented by formula (II-2-A-1). TIFF0007659395000153.tif5576 [In formula (II-2-A-1), R III2 , R III3 , R III4 , Q a , Q b , z and Z A + has the same meaning as above. R III5 represents a saturated hydrocarbon group having 1 to 12 carbon atoms. X I2 represents a divalent saturated hydrocarbon group having 1 to 11 carbon atoms, -CH2- contained in the saturated hydrocarbon group may be replaced by -O-, -S- or -CO-, and a hydrogen atom contained in the saturated hydrocarbon group may be replaced by a halogen atom or a hydroxyl group.]

[0231] R III5Examples of the saturated hydrocarbon group having 1 to 12 carbon atoms represented by the formula (I) include linear or branched alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, an undecyl group, and a dodecyl group. X I2 As the divalent saturated hydrocarbon group represented by the formula: III3 Examples of the divalent saturated hydrocarbon group include those similar to those represented by the following formula:

[0232] The structural unit represented by formula (II-2-A-1) is preferably a structural unit represented by formula (II-2-A-2). TIFF0007659395000154.tif5287 [In formula (II-2-A-2), R III3 , R III5 and Z.A. + has the same meaning as above. m and n each independently represent 1 or 2.

[0233] Examples of the structural unit represented by formula (II-2-A') include the following structural units, R III3 Examples of the structural units include those in which the group corresponding to the methyl group in the above formula (1) is replaced with a hydrogen atom, a halogen atom (e.g., a fluorine atom), or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (e.g., a trifluoromethyl group, etc.), and the structural units described in WO 2012 / 050015. + represents an organic cation. TIFF0007659395000155.tif86163

[0234] The structural unit having a sulfonio group and an organic anion in the side chain is preferably a structural unit represented by formula (II-1-1). JPEG0007659395000156.jpg3380 [In formula (II-1-1), A II1 represents a single bond or a divalent linking group. R II1represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms. R II2 and R II3 each independently represents a hydrocarbon group having 1 to 18 carbon atoms; R II2 and R II3 may be bonded to each other to form a ring together with the sulfur atom to which they are attached. R II4 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. A - represents an organic anion. R II1 Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by the formula (I) include a phenylene group and a naphthylene group. R II2 and R II3 Examples of the hydrocarbon group represented by the formula (I) include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these groups. Examples of the alkyl group and the alicyclic hydrocarbon group include the same as those mentioned above. Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, an anthryl group, a biphenyl group, and a phenanthryl group. Examples of the combined group include a combination of the above-mentioned alkyl group and alicyclic hydrocarbon group, aralkyl groups such as a benzyl group, aromatic hydrocarbon groups having an alkyl group (p-methylphenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), aromatic hydrocarbon groups having an alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), and aryl-cycloalkyl groups such as a phenylcyclohexyl group. R II4 Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R II4 The alkyl group having 1 to 6 carbon atoms which may have a halogen atom and is represented by the formula: a8Examples of the alkyl group include the same alkyl groups having 1 to 6 carbon atoms which may have a halogen atom and are represented by the following formula: A II1 Examples of the divalent linking group represented by the formula (I) include a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and -CH2- contained in the divalent saturated hydrocarbon group may be replaced by -O-, -S- or -CO-. III3 Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms include those represented by the following formula:

[0235] The structural unit containing a cation in formula (II-1-1) is a structural unit represented by the following formula: R II4 Examples of such structural units include those in which a group corresponding to the methyl group in the above formula (I) is replaced with a hydrogen atom, a halogen atom (e.g., a fluorine atom), or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom (e.g., a trifluoromethyl group, etc.). TIFF0007659395000157.tif87134

[0236] A - Examples of the organic anion represented by the formula (I) include a sulfonate anion, a sulfonylimide anion, a sulfonylmethide anion, and a carboxylate anion. - The organic anion represented by the formula (B1) is preferably a sulfonate anion, and examples of the sulfonate anion include the same anions as those represented by the formula (B1) above.

[0237] A - Examples of the sulfonylimide anion represented by the formula (I) include the following. JPEG0007659395000158.jpg36136

[0238] Examples of sulfonylmethide anions include the following: TIFF0007659395000159.tif29123

[0239] Examples of carboxylate anions include the following: TIFF0007659395000160.tif46152

[0240] Examples of the structural unit represented by formula (II-1-1) include structural units represented below. JPEG0007659395000161.jpg88149

[0241] When the resin (A) contains the structural unit (II), the content of the structural unit (II) is preferably 1 to 20 mol %, more preferably 2 to 15 mol %, and even more preferably 3 to 10 mol %, based on the total structural units of the resin (A).

[0242] Resin (A) may contain structural units other than the above-mentioned structural units, and examples of such structural units include structural units well known in the art.

[0243] 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 a structural unit having a cyclohexyl group or a cyclopentyl group), more preferably at least two, and even more preferably at least two selected from the group consisting of the structural unit (a1-1) and the structural unit (a1-2). The structural unit (s) is preferably at least one selected from the group consisting of the structural unit (a2) and the structural unit (a3). The structural unit (a2) is preferably 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 the structural unit represented by formula (a3-1), the structural unit represented by formula (a3-2), and the structural unit represented by formula (a3-4).

[0244] Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and can be produced by a known polymerization method (e.g., radical polymerization method) using a monomer that leads to these structural units. The content of each structural unit contained in the resin (A) can be adjusted by the amount of the monomer used for polymerization. The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, and even more preferably 3,000 or more) and 50,000 or less (more preferably 30,000 or less, and even more preferably 15,000 or less). In the present specification, the weight average molecular weight is a value determined by gel permeation chromatography under the conditions described in the Examples.

[0245] <Resins other than resin (A)> The resist composition of the present invention may contain a resin other than the resin (A). Examples of resins other than resin (A) include resins containing the structural unit (a4) or the structural unit (a5) (hereinafter, sometimes referred to as resin (X)).

[0246] As the resin (X), a resin containing the structural unit (a4) is particularly preferred. In the resin (X), the content of the structural unit (a4) is preferably 30 mol % or more, more preferably 40 mol % or more, and even more preferably 45 mol % or more, based on the total of all structural units in the resin (X). Examples of structural units that may be further contained in the resin (X) include the structural unit (a2), the structural unit (a3), and structural units derived from other known monomers. Among these, the resin (X) is preferably a resin consisting only of the structural unit (a4) and / or the structural unit (a5), and more preferably a resin consisting only of the structural unit (a4). Each structural unit constituting the resin (X) may be used alone or in combination of two or more, and can be produced by a known polymerization method (e.g., radical polymerization method) using a monomer that derives these structural units. The content of each structural unit in the resin (X) can be adjusted by the amount of the monomer used for polymerization. The weight average molecular weight of the resin (X) is preferably 6,000 or more (more preferably 7,000 or more) and 80,000 or less (more preferably 60,000 or less). The method for measuring the weight average molecular weight of the resin (X) is the same as that for the resin (A). When the resist composition contains resin (X), the content thereof is preferably 1 to 60 parts by mass, more preferably 1 to 50 parts by mass, even more preferably 1 to 40 parts by mass, still more preferably 1 to 30 parts by mass, and even more preferably 1 to 8 parts by mass, relative to 100 parts by mass of resin (A).

[0247] The content of resin (A) in the resist composition is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 99% by mass or less, based on the solid content of the resist composition. When a resin other than resin (A) is contained, the total content of resin (A) and the resin other than resin (A) is preferably 80% by mass or more and 99% by mass or less, more preferably 90% by mass or more and 99% by mass or less, based on the solid content of the resist composition. The solid content of the resist composition and the resin content therein can be measured by a known analytical means such as liquid chromatography or gas chromatography.

[0248] <Solvent (E)> The content of the solvent (E) in the resist composition is usually 90% by mass or more and 99.9% by mass or less, preferably 92% by mass or more and 99% by mass or less, and more preferably 94% by mass or more and 99% by mass or less. The content of the solvent (E) can be measured by a known analytical method such as liquid chromatography or gas chromatography. Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate, and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; esters such as ethyl lactate, butyl acetate, amyl acetate, and ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone, and cyclohexanone; cyclic esters such as γ-butyrolactone; etc. One type of solvent (E) may be used alone, or two or more types may be used.

[0249] <Quencher (C)> Examples of the quencher (C) include a basic nitrogen-containing organic compound and a salt that generates an acid having a weaker acidity than the acid generated from the acid generator (B). When the resist composition contains the quencher (C), the content of the quencher (C) is preferably about 0.01 to 15 mass%, more preferably about 0.01 to 10 mass%, even more preferably about 0.01 to 7 mass%, and even more preferably about 0.1 to 3 mass%, based on the solid content of the resist composition. The basic nitrogen-containing organic compound includes amines and ammonium salts. The amines include aliphatic amines and aromatic amines. The aliphatic amines include primary amines, secondary amines, and tertiary amines. Examples of amines include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N,N-dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributaryamine, ethylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldi Decylamine, dicyclohexylmethylamine, tris[2-(2-methoxyethoxy)ethyl]amine, triisopropanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane, 4,4'-diamino-3,3'-diethyldiphenylmethane, 2,2'-methylenebisaniline, imidazole, 4-methylimidazole, pyridine, 4-methylpyridine, 1,2-di(2-pyridinyl)amine ... Examples of the dipyridyl amine include 4,4'-dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipicolylamine, and bipyridine. Of these, diisopropylaniline is preferred, and 2,6-diisopropylaniline is more preferred. 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.

[0250] The acidity of a salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) is indicated by the acid dissociation constant (pKa). A salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) is a salt having an acid dissociation constant of the acid generated from the salt usually of -3 < pKa, preferably -1 < pKa < 7, and more preferably 0 < pKa < 5. Examples of the salt that generates an acid with a lower acidity than the acid generated from the acid generator (B) include salts represented by the following formula, salts represented by formula (D) described in JP-A-2015-147926 (hereinafter sometimes referred to as "weak acid inner salt (D)"), and salts described in JP-A-2012-229206, JP-A-2012-6908, JP-A-2012-72109, JP-A-2011-39502, and JP-A-2011-191745. Preferably, it is a salt that generates a carboxylic acid with a lower acidity than the acid generated from the acid generator (B) (a salt having a carboxylic acid anion), and more preferably, it is the weak acid inner salt (D). JPEG0007659395000162.jpg89165

[0251] Examples of the weak acid inner salt (D) include the following salts. TIFF0007659395000163.tif71165

[0252] 〈Other components〉 The resist composition of the present invention may contain components other than the above-mentioned components (hereinafter, sometimes referred to as "other components (F)") as necessary. There are no particular limitations on the other components (F), and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes, etc., can be used.

[0253] Preparation of Resist Composition The resist composition of the present invention can be prepared by mixing the salt (I), the resin (A), the acid generator (B), and, if necessary, the resin other than the resin (A), the solvent (E), the quencher (C), and other components (F). The order of mixing is arbitrary and is not particularly limited. The temperature during mixing can be selected from 10 to 40°C depending on the type of resin, the solubility of the resin in the solvent (E), and the like. The mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used. After mixing the components, it is preferable to filter the mixture using a filter having a pore size of about 0.003 to 0.2 μm.

[0254] <Method for Producing Resist Pattern> The method for producing a resist pattern of the present invention comprises the steps of: (1) applying the resist composition of the present invention onto a substrate; (2) A step of drying the applied composition to form a composition layer; (3) exposing the composition layer to light; (4) heating the composition layer after exposure; and (5) A step of developing the composition layer after heating. The resist composition can be applied onto a substrate using a commonly used device such as a spin coater. Examples of the substrate include inorganic substrates such as silicon wafers. Before applying the resist composition, the substrate may be cleaned, and an anti-reflective film or the like may be formed on the substrate. The composition after coating is dried to remove the solvent and form a composition layer. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking), or by using a vacuum device. The heating temperature is preferably 50 to 200°C, and the heating time is preferably 10 to 180 seconds. The pressure during drying under reduced pressure is preferably 1 to 1.0×10 5 It is preferable that the pressure is about Pa. The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. As the exposure light source, various types can be used, such as those that emit ultraviolet laser light such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), and F2 excimer laser (wavelength 157 nm), those that convert the wavelength of laser light from a solid laser light source (YAG or semiconductor laser, etc.) to emit harmonic laser light in the far ultraviolet or vacuum ultraviolet range, and those that irradiate electron beams or extreme ultraviolet light (EUV). In this specification, irradiation with these types of radiation may be collectively referred to as "exposure". During exposure, exposure is usually performed through a mask corresponding to the desired pattern. When the exposure light source is an electron beam, exposure may be performed by direct drawing without using a mask. The composition layer after exposure is subjected to a heat treatment (so-called post-exposure bake) in order to promote the deprotection reaction of the acid labile groups. The heating temperature is usually about 50 to 200°C, preferably about 70 to 150°C. The composition layer after heating is usually developed using a developing device and a developer. Examples of the developing method include a dip method, a paddle method, a spray method, and a dynamic dispense method. The developing temperature is preferably, for example, 5 to 60° C., and the developing time is preferably, for example, 5 to 300 seconds. By selecting the type of developer as follows, a positive resist pattern or a negative resist pattern can be produced. When a positive resist pattern is produced from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be any of various alkaline aqueous solutions used in this field. For example, an aqueous solution of tetramethylammonium hydroxide or (2-hydroxyethyl)trimethylammonium hydroxide (commonly known as choline) may be used. The alkaline developer may contain a surfactant. After development, the resist pattern is preferably washed with ultrapure water, and then water remaining on the substrate and the pattern is removed. When producing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent (hereinafter sometimes referred to as an "organic developer") is used as the developer. Examples of organic solvents contained in organic developers include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycol ether solvents such as propylene glycol monomethyl ether; amide solvents such as N,N-dimethylacetamide; and aromatic hydrocarbon solvents such as anisole. The content of the organic solvent in the organic developer is preferably from 90% by mass to 100% by mass, more preferably from 95% by mass to 100% by mass, and further preferably consists essentially of the organic solvent. Among them, the organic developer is preferably a developer containing butyl acetate and / or 2-heptanone. The total content of butyl acetate and 2-heptanone in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and even more preferably substantially only butyl acetate and / or 2-heptanone. The organic developer may contain a surfactant and may contain a small amount of water. During development, the development may be stopped by replacing the organic developer with a different type of solvent. The resist pattern after development is preferably washed with a rinse solution. There are no particular limitations on the rinse solution as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, preferably an alcohol solvent or an ester solvent. After cleaning, it is preferable to remove any rinsing liquid remaining on the substrate and the pattern.

[0255] <Application> The resist composition of the present invention is suitable as a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, in particular as a resist composition for electron beam (EB) exposure or a resist composition for EUV exposure, and is useful for semiconductor microfabrication. EXAMPLES

[0256] The present invention will be described in more detail with reference to examples. In the examples, "%" and "parts" expressing the content or amount used are based on mass unless otherwise specified. The weight average molecular weight is a value determined by gel permeation chromatography under the following analytical conditions: Column: TSKgel Multipore HXL-M x 3 + guard column (Tosoh Corporation) Eluent: Tetrahydrofuran Flow rate: 1.0mL / min Detector: RI detector Column temperature: 40℃ Injection volume: 100μl Molecular weight standard: Standard polystyrene (Tosoh Corporation) The structure of the compound was confirmed by measuring the molecular ion peak using mass spectrometry (LC: Agilent 1100 model, MASS: Agilent LC / MSD model). In the following examples, the value of this molecular ion peak is indicated by "MASS".

[0257] Example 1: Synthesis of a salt represented by formula (I-3) TIFF0007659395000164.tif43169 6.74 parts of the salt represented by formula (I-3-a), 4.25 parts of the salt represented by formula (I-3-b) and 60 parts of chloroform were mixed and stirred at 23 ° C. for 2 hours. 30 parts of ion-exchanged water was added to the obtained mixture and stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 20 parts of tert-butyl methyl ether and 20 parts of n-heptane were added to the concentrated residue and stirred at 23 ° C. for 30 minutes, and then filtered to obtain 6.72 parts of the salt represented by formula (I-3).

[0258] MASS(ESI(+)Spectrum):M + 525.0 MASS(ESI(-)Spectrum):M - 323.0

[0259] Example 2: Synthesis of a salt represented by formula (I-465) TIFF0007659395000165.tif44169 6.74 parts of the salt represented by formula (I-3-a), 4.49 parts of the salt represented by formula (I-465-b) and 60 parts of chloroform were mixed and stirred at 23 ° C. for 2 hours. 30 parts of ion-exchanged water was added to the obtained mixture and stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 25 parts of tert-butyl methyl ether and 15 parts of n-heptane were added to the concentrated residue and stirred at 23 ° C. for 30 minutes, and then filtered to obtain 6.61 parts of the salt represented by formula (I-465).

[0260] MASS(ESI(+)Spectrum):M + 525.0 MASS(ESI(-)Spectrum):M - 347.0

[0261] Example 3: Synthesis of a salt represented by formula (I-13) TIFF0007659395000166.tif45169 6.74 parts of the salt represented by formula (I-3-a), 5.69 parts of the salt represented by formula (I-13-b) and 60 parts of chloroform were mixed and stirred at 23 ° C. for 2 hours. 30 parts of ion-exchanged water was added to the obtained mixture and stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 10 parts of tert-butyl methyl ether and 30 parts of n-heptane were added to the concentrated residue and stirred at 23 ° C. for 30 minutes, and then filtered to obtain 7.86 parts of the salt represented by formula (I-13).

[0262] MASS(ESI(+)Spectrum):M + 525.0 MASS(ESI(-)Spectrum):M - 467.1

[0263] Example 4: Synthesis of a salt represented by formula (I-5) TIFF0007659395000167.tif44169 6.74 parts of the salt represented by formula (I-3-a), 6.41 parts of the salt represented by formula (I-5-b) and 60 parts of chloroform were mixed and stirred at 23 ° C. for 2 hours. 30 parts of ion-exchanged water was added to the obtained mixture and stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 20 parts of tert-butyl methyl ether and 20 parts of n-heptane were added to the concentrated residue and stirred at 23 ° C. for 30 minutes, and then filtered to obtain 7.28 parts of the salt represented by formula (I-5).

[0264] MASS(ESI(+)Spectrum):M + 525.0 MASS(ESI(-)Spectrum):M - 517.1

[0265] Example 5: Synthesis of a salt represented by formula (I-63) TIFF0007659395000168.tif43169 5.74 parts of the salt represented by formula (I-63-a), 6.41 parts of the salt represented by formula (I-5-b) and 60 parts of chloroform were mixed and stirred at 23 ° C. for 2 hours. 30 parts of ion-exchanged water was added to the obtained mixture and stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 30 parts of tert-butyl methyl ether was added to the concentrated residue and stirred at 23 ° C. for 30 minutes, and the supernatant was removed and concentrated to obtain 5.11 parts of the salt represented by formula (I-63).

[0266] MASS(ESI(+)Spectrum):M + 425.0 MASS(ESI(-)Spectrum):M - 517.1

[0267] Example 6: Synthesis of salt represented by formula (I-71) TIFF0007659395000169.tif43169 5.74 parts of the salt represented by formula (I-63-a), 5.69 parts of the salt represented by formula (I-13-b) and 60 parts of chloroform were mixed and stirred at 23 ° C. for 2 hours. 30 parts of ion-exchanged water was added to the obtained mixture and stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 30 parts of tert-butyl methyl ether was added to the concentrated residue and stirred at 23 ° C. for 30 minutes, and the supernatant was removed and concentrated to obtain 5.24 parts of the salt represented by formula (I-71).

[0268] MASS(ESI(+)Spectrum):M + 425.0 MASS(ESI(-)Spectrum):M - 467.1

[0269] Example 7: Synthesis of salt represented by formula (I-361) TIFF0007659395000170.tif79146 5.80 parts of the compound represented by formula (I-361-a) and 11.60 parts of tetrahydrofuran were mixed and stirred at 23 ° C for 30 minutes, and then the mixture was cooled to 10 ° C. and added dropwise to 0.63 parts of magnesium to obtain a Grignard solution represented by formula (I-361-b). 1.97 parts of zinc bromide were added to the obtained Grignard solution represented by formula (I-361-b), and the mixture was further stirred at 50 ° C. for 3 hours to obtain a solution containing the compound represented by formula (I-361-c). 2.93 parts of the compound represented by formula (I-361-d), 7.16 parts of the compound represented by formula (I-361-e), and 10 parts of tetrahydrofuran were mixed and stirred at 23 ° C. for 30 minutes, and then the solution containing the compound represented by formula (I-361-c) was added. To the obtained reaction mixture, 2.87 parts of the compound represented by formula (I-361-e) was further added, and the mixture was further stirred at 23° C. for 18 hours. To the obtained reaction mixture, 5 parts of 1N hydrochloric acid and 30 parts of chloroform were added, and the mixture was stirred at 23° C. for 30 minutes, and then the organic layer was separated and taken out. To the obtained organic layer, 15 parts of ion-exchanged water was added, and the mixture was stirred at 23° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. After concentrating the obtained organic layer, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and the mixture was stirred at 23° C. for 30 minutes, and then filtered to obtain 0.89 parts of the salt represented by formula (I-361-f). TIFF0007659395000171.tif40169 0.73 parts of the salt represented by formula (I-361-f), 0.57 parts of the salt represented by formula (I-13-b) and 20 parts of chloroform were mixed and stirred at 23 ° C. for 2 hours. 10 parts of ion-exchanged water was added to the obtained mixture and stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated three times. The obtained organic layer was concentrated, and 5 parts of tert-butyl methyl ether and 15 parts of n-heptane were added to the concentrated residue and stirred at 23 ° C. for 30 minutes, and then filtered to obtain 0.77 parts of the salt represented by formula (I-361).

[0270] MASS(ESI(+)Spectrum):M + 582.9 MASS(ESI(-)Spectrum):M - 467.1

[0271] Example 8: Synthesis of a salt represented by formula (I-390) TIFF0007659395000172.tif79146 4.51 parts of the compound represented by formula (I-390-a) and 9.02 parts of tetrahydrofuran were mixed and stirred at 23 ° C for 30 minutes, and then the mixture was cooled to 10 ° C. and added dropwise to 0.63 parts of magnesium to obtain a Grignard solution represented by formula (I-390-b). 1.97 parts of zinc bromide were added to the obtained Grignard solution represented by formula (I-390-b), and the mixture was further stirred at 50 ° C. for 3 hours to obtain a solution containing the compound represented by formula (I-390-c). 2.93 parts of the compound represented by formula (I-361-d), 7.16 parts of the compound represented by formula (I-361-e), and 10 parts of tetrahydrofuran were mixed and stirred at 23 ° C. for 30 minutes, and then a solution containing the compound represented by formula (I-390-c) was added. To the obtained reaction mixture, 2.87 parts of the compound represented by formula (I-361-e) was further added, and the mixture was further stirred at 23° C. for 18 hours. To the obtained reaction mixture, 5 parts of 1N hydrochloric acid and 30 parts of chloroform were added, and the mixture was stirred at 23° C. for 30 minutes, and then the organic layer was separated and taken out. To the obtained organic layer, 15 parts of ion-exchanged water was added, and the mixture was stirred at 23° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. After concentrating the obtained organic layer, 30 parts of tert-butyl methyl ether was added to the concentrated residue, and the mixture was stirred at 23° C. for 30 minutes, and then filtered to obtain 0.75 parts of the salt represented by formula (I-390-f). TIFF0007659395000173.tif42169 0.68 parts of the salt represented by formula (I-390-f), 0.57 parts of the salt represented by formula (I-13-b) and 20 parts of chloroform were mixed and stirred at 23 ° C. for 2 hours. 10 parts of ion-exchanged water was added to the obtained mixture and stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated three times. The obtained organic layer was concentrated, and 5 parts of tert-butyl methyl ether and 15 parts of n-heptane were added to the concentrated residue and stirred at 23 ° C. for 30 minutes, and then filtered to obtain 0.67 parts of the salt represented by formula (I-390).

[0272] MASS(ESI(+)Spectrum):M + 532.9 MASS(ESI(-)Spectrum):M - 467.1

[0273] Example 9: Synthesis of a salt represented by formula (I-494) TIFF0007659395000174.tif48135 2.69 parts of the compound represented by formula (I-494-a), 15.18 parts of the compound represented by formula (I-494-b) and 30 parts of tetrahydrofuran were mixed, stirred at 23 ° C. for 30 minutes, and then cooled to 5 ° C. To the resulting mixture, 2.44 parts of the compound represented by formula (I-494-c) were added, stirred at 5 ° C. for 30 minutes, and then further stirred at 50 ° C. for 10 hours. After cooling the resulting reaction mixture to 23 ° C., 20 parts of ion-exchanged water and 50 parts of chloroform were added and stirred at 23 ° C. for 30 minutes, and then separated to take out the organic layer. 20 parts of ion-exchanged water was added to the resulting organic layer and stirred at 23 ° C. for 30 minutes, and then separated to take out the organic layer. This water washing operation was repeated five times. The obtained organic layer was concentrated, and then 30 parts of tert-butyl methyl ether was added to the concentrated residue and stirred at 23° C. for 30 minutes. The supernatant was then removed, and the mixture was concentrated to obtain 0.96 parts of a salt represented by formula (I-494-d). TIFF0007659395000175.tif46170 0.65 parts of the salt represented by formula (I-494-d), 0.57 parts of the salt represented by formula (I-13-b) and 20 parts of chloroform were mixed and stirred at 23 ° C. for 2 hours. 10 parts of ion-exchanged water was added to the obtained mixture and stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated three times. The obtained organic layer was concentrated, and 5 parts of tert-butyl methyl ether and 15 parts of n-heptane were added to the concentrated residue and stirred at 23 ° C. for 30 minutes, and then filtered to obtain 0.73 parts of the salt represented by formula (I-494).

[0274] MASS(ESI(+)Spectrum):M + 496.9 MASS(ESI(-)Spectrum):M - 467.1

[0275] Synthesis Example 1: Synthesis of a salt represented by formula (IX-4) TIFF0007659395000176.tif41169 5.47 parts of the salt represented by formula (IX-4-a), 6.41 parts of the salt represented by formula (I-5-b), 50 parts of chloroform, and 20 parts of ethyl acetate were mixed and stirred at 23 ° C. for 2 hours. 30 parts of ion-exchanged water was added to the obtained mixture and stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 30 parts of tert-butyl methyl ether was added to the concentrated residue and stirred at 23 ° C. for 30 minutes, and the supernatant was removed and concentrated to obtain 3.22 parts of the salt represented by formula (IX-4).

[0276] MASS(ESI(+)Spectrum):M + 467.1 MASS(ESI(-)Spectrum):M - 517.1

[0277] Synthesis Example 2: Synthesis of a salt represented by formula (IX-5) TIFF0007659395000177.tif43167 4.11 parts of the salt represented by formula (IX-5-a), 6.41 parts of the salt represented by formula (I-5-b), 50 parts of chloroform, and 20 parts of ethyl acetate were mixed and stirred at 23 ° C. for 2 hours. 30 parts of ion-exchanged water was added to the obtained mixture and stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 30 parts of tert-butyl methyl ether was added to the concentrated residue and stirred at 23 ° C. for 30 minutes, and the supernatant was removed and concentrated to obtain 2.19 parts of the salt represented by formula (IX-5).

[0278] MASS(ESI(+)Spectrum):M + 331.1 MASS(ESI(-)Spectrum):M - 517.1

[0279] Synthesis Example 3: Synthesis of a salt represented by formula (IX-6) TIFF0007659395000178.tif43168 4.69 parts of the salt represented by formula (IX-6-a), 6.41 parts of the salt represented by formula (I-5-b), 50 parts of chloroform, and 20 parts of ethyl acetate were mixed and stirred at 23 ° C. for 2 hours. 30 parts of ion-exchanged water was added to the obtained mixture and stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 30 parts of tert-butyl methyl ether was added to the concentrated residue and stirred at 23 ° C. for 30 minutes, and the supernatant was removed and concentrated to obtain 3.39 parts of the salt represented by formula (IX-6).

[0280] MASS(ESI(+)Spectrum):M + 389.0 MASS(ESI(-)Spectrum):M - 517.1

[0281] Synthesis Example 4: Synthesis of a salt represented by formula (IX-7) TIFF0007659395000179.tif42167 3.97 parts of the salt represented by formula (IX-7-a), 6.41 parts of the salt represented by formula (I-5-b), 50 parts of chloroform, and 20 parts of ethyl acetate were mixed and stirred at 23 ° C. for 2 hours. 30 parts of ion-exchanged water was added to the obtained mixture and stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 30 parts of tert-butyl methyl ether was added to the concentrated residue and stirred at 23 ° C. for 30 minutes, and the supernatant was removed and concentrated to obtain 4.89 parts of the salt represented by formula (IX-7).

[0282] MASS(ESI(+)Spectrum):M + 317.1 MASS(ESI(-)Spectrum):M - 517.1

[0283] Synthesis Example 5: Synthesis of a salt represented by formula (IX-8) TIFF0007659395000180.tif41168 3.61 parts of the salt represented by formula (IX-8-a), 6.41 parts of the salt represented by formula (I-5-b), 50 parts of chloroform, and 20 parts of ethyl acetate were mixed and stirred at 23 ° C. for 2 hours. 30 parts of ion-exchanged water was added to the obtained mixture and stirred at 23 ° C. for 30 minutes, and then the organic layer was separated and taken out. This water washing operation was repeated five times. The obtained organic layer was concentrated, and 30 parts of tert-butyl methyl ether was added to the concentrated residue and stirred at 23 ° C. for 30 minutes, and the supernatant was removed and concentrated to obtain 3.72 parts of the salt represented by formula (IX-8).

[0284] MASS(ESI(+)Spectrum):M + 281.1 MASS(ESI(-)Spectrum):M - 517.1

[0285] Resin synthesis The compounds (monomers) used in the synthesis of resin (A) are shown below. Hereinafter, these compounds will be referred to as "monomer (a1-1-3)" etc. according to their formula numbers. TIFF0007659395000181.tif48163

[0286] Synthesis Example 6 [Synthesis of Resin A1] Monomer (a1-4-2), monomer (a1-1-3) and monomer (a1-2-6) were used as monomers, and mixed so that the molar ratio [monomer (a1-4-2):monomer (a1-1-3):monomer (a1-2-6)] was 38:24:38. Furthermore, 1.5 times the mass of methyl isobutyl ketone was mixed with this monomer mixture based on the total mass of all monomers. Azobisisobutyronitrile was added as an initiator to the obtained mixture so that the amount was 7 mol% based on the total mole number of all monomers, and polymerization was carried out by heating at 85°C for about 5 hours. Thereafter, 2.0 times the mass of p-toluenesulfonic acid aqueous solution (2.5 wt%) based on the total mass of all monomers was added to the polymerization reaction liquid, and the mixture was stirred for 6 hours and then separated. The obtained organic layer was poured into a large amount of n-heptane to precipitate a resin, which was then filtered and collected to obtain a polymer with a weight average molecular weight of about 5.3 × 10 3 Resin A1 (copolymer) having the following structural units was obtained in a yield of 78%. TIFF0007659395000182.tif29126

[0287] Synthesis Example 7 [Synthesis of Resin A2] Monomers were used, and the molar ratio [monomer (a1-2-6):monomer (a2-1-3):monomer (a3-4-2):monomer (a1-4-2)] was mixed at a ratio of 53:3:12:32. Furthermore, 1.5 times the mass of methyl isobutyl ketone was mixed with this monomer mixture relative to the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture at 1.2 mol% and 3.6 mol%, respectively, relative to the total monomer amount, and these were heated at 73°C for about 5 hours. Thereafter, 2.0 times the mass of p-toluenesulfonic acid aqueous solution (2.5 wt%) relative to the total mass of all monomers was added to the polymerization reaction liquid, and the mixture was stirred for 12 hours, and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate the resin, which was then filtered and recovered to obtain a resin with a weight-average molecular weight of approximately 5.3 × 10 3 Resin A2 having the following structural units was obtained in a yield of 88%. TIFF0007659395000183.tif38135

[0288] Synthesis Example 8 [Synthesis of Resin A3] Monomers were used, and the molar ratio [monomer (a1-2-6):monomer (a2-1-3):monomer (a3-4-2):monomer (a1-4-13)] was mixed at a ratio of 53:3:12:32. Furthermore, 1.5 times the mass of methyl isobutyl ketone was mixed with this monomer mixture relative to the total mass of all monomers. Azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) were added as initiators to the obtained mixture at 1.2 mol% and 3.6 mol%, respectively, relative to the total monomer amount, and these were heated at 73°C for about 5 hours. Thereafter, 2.0 times the mass of p-toluenesulfonic acid aqueous solution (2.5 wt%) relative to the total mass of all monomers was added to the polymerization reaction liquid, and the mixture was stirred for 12 hours, and then separated. The recovered organic layer was poured into a large amount of n-heptane to precipitate the resin, which was then filtered and recovered to obtain a resin with a weight-average molecular weight of approximately 5.1 × 10 3 Resin A3 having the following structural units was obtained in a yield of 79%. JPEG0007659395000184.jpg40135

[0289] <Preparation of resist composition> As shown in Table 2, the following components were mixed and the resulting mixture was filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition.

[0290] [Table 2]

[0291] <Resin> A1 to A3: Resin A1 to Resin A3 <Salt (I)> I-3: A salt represented by formula (I-3) I-5: A salt represented by formula (I-5) I-13: A salt represented by formula (I-13) I-63: A salt represented by the formula (I-63) I-71: A salt represented by formula (I-71) I-361: A salt represented by the formula (I-361) I-390: A salt represented by the formula (I-390) I-465: A salt represented by the formula (I-465) I-494: A salt represented by the formula (I-494) <Acid generator> IX-1: IX-2: IX-3: TIFF0007659395000186.tif76138IX-4: Salt represented by formula (IX-4) IX-5: A salt represented by formula (IX-5) IX-6: A salt represented by formula (IX-6) IX-7: A salt represented by formula (IX-7) IX-8: A salt represented by the formula (IX-8) <Quencher (C)> C1: Synthesized by the method described in JP 2011-39502 A TIFF0007659395000187.tif4355<solvent> Propylene glycol monomethyl ether acetate 400 parts Propylene glycol monomethyl ether 100 parts γ-Butyrolactone 5 parts

[0292] (Electron beam exposure evaluation of resist composition: Alkaline development) A 6-inch silicon wafer was treated with hexamethyldisilazane at 90°C for 60 seconds on a direct hot plate. A resist composition was spin-coated onto this silicon wafer so that the film thickness of the composition layer was 0.04 μm. Then, the wafer was pre-baked 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 contact hole pattern (hole pitch 40 nm / hole diameter 17 nm) was directly written on the composition layer formed on the wafer using an electron beam lithography machine ("ELS-F125 125 keV" manufactured by Elionix Co., Ltd.) by changing the exposure dose stepwise. After exposure, post-exposure baking was performed on a hot plate at the temperature shown in the "PEB" column of Table 2 for 60 seconds, and paddle development was then carried out for 60 seconds using an aqueous solution of 2.38 mass% tetramethylammonium hydroxide as the developer, thereby obtaining a resist pattern.

[0293] In the resist pattern obtained after development, the exposure dose at which the formed hole diameter became 17 nm was defined as the effective sensitivity.

[0294] <CD Uniformity (CDU) Evaluation> At the effective sensitivity, the hole diameter of the pattern formed with a hole diameter of 17 nm was measured 24 times for each hole, and the average value was defined as the average hole diameter of one hole. Using as the population the average hole diameters of the patterns formed with a hole diameter of 17 nm measured at 400 locations within the same wafer, the standard deviation was determined. The results are shown in Table 3. The numerical values in the table indicate the standard deviation (nm).

Table 3

[0295] (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 onto this silicon wafer so that the film thickness of the composition layer became 0.04 μm. Thereafter, pre-baking was carried out 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.] on the composition layer formed on the wafer, a contact hole pattern (hole pitch 40 nm / hole diameter 17 nm) was directly drawn while changing the exposure dose stepwise. After exposure, post-exposure baking was performed for 60 seconds at the temperature shown in the "PEB" column of Table 2 on a hot plate. 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.

[0296] In the resist pattern obtained after development, the exposure dose at which the formed hole diameter became 17 nm was defined as the effective sensitivity.

[0297] <CD Uniformity (CDU) Evaluation> At the effective sensitivity, the hole diameter of the pattern formed with a hole diameter of 17 nm was measured 24 times for each hole, and the average value was defined as the average hole diameter of one hole. The standard deviation was obtained using, as the population, the average hole diameters of the patterns formed with a hole diameter of 17 nm measured at 400 locations within the same wafer. The results are shown in Table 4. The numerical values in the table indicate the standard deviation (nm).

Table 4

Industrial Applicability

[0298] The salt of the present invention and the resist composition containing the salt can obtain a resist pattern having good CD uniformity (CDU), and thus are suitable for fine processing of semiconductors and are extremely useful industrially.

Claims

1. A salt represented by formula (I): [In formula (I), R １ represents a fluorine atom or a fluorinated alkyl group having 1 to 4 carbon atoms. R ２ , R ３ and R ４ each independently represents a halogen atom, a fluorinated alkyl group having 1 to 4 carbon atoms, or a hydrocarbon group having 1 to 12 carbon atoms, and —CH 2 - may be replaced by -O- or -CO-, provided that at least one R 4 is a halogen atom or a fluorinated alkyl group having 1 to 4 carbon atoms. m2 represents an integer of 0 to 4, and when m2 is 2 or more, a plurality of R ２ may be the same or different from each other. m3 represents an integer of 0 to 4, and when m3 is 2 or more, a plurality of R ３ may be the same or different from each other. m4 represents an integer of 1 to 5, and when m4 is 2 or more, a plurality of R ４ may be the same or different from each other. Q １ and Q. ２ each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms. L １ represents a saturated hydrocarbon group having 1 to 24 carbon atoms, and the —CH ２ - may be replaced by -O- or -CO-, and a hydrogen atom contained in the saturated hydrocarbon group may be substituted by a fluorine atom or a hydroxy group. Y １ represents an alicyclic hydrocarbon group having 3 to 24 carbon atoms which may have a substituent, and the —CH ２ - is -O-, -SO ２ - or -CO- may be substituted.]

2. R ２ , R ３ and R ４ The salt according to claim 1, wherein each of the is independently a fluorine atom, an iodine atom, or a perfluoroalkyl group having 1 to 4 carbon atoms.

3. An acid generator comprising the salt according to claim 1 or 2.

4. A resist composition comprising the acid generator according to claim 3 and a resin having an acid labile group.

5. 5. The resist composition according to claim 4, wherein the resin having an acid labile group comprises at least one member selected from the group consisting of a structural unit represented by formula (a1-1) and a structural unit represented by formula (a1-2). [In formula (a1-1) and formula (a1-2), L ａ１ and L ａ２ are each independently -O- or *-O-(CH ２ ) ｋ１ represents --CO--O--, k1 represents an integer of 1 to 7, and * represents the bonding site with --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 combination thereof. m1 represents an integer of 0 to 14. n1 represents an integer of 0 to 10. n1' represents an integer of 0 to 3.

6. 6. The resist composition according to claim 4, 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 is a single bond or *-X a51 - (A a52 -X a52 ) nｂ -, * represents -R a50 represents the bonding site with the carbon atom to which it is bonded. A a52 represents an alkanediyl group having 1 to 6 carbon atoms. X a51 and X a52 each independently represents -O-, -CO-O- or -O-CO-. nb represents 0 or 1. mb represents an integer of 0 to 4. When mb is an integer of 2 or more, a plurality of R a51 may be the same or different.

7. 7. The resist composition according to claim 4, further comprising a salt capable of generating an acid having a weaker acidity than the acid generated from the acid generator.

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

Images