JP2019131543A - Salt, acid generator, resist composition, and method for producing resist pattern - Google Patents

Abstract

To provide a salt and an acid generator capable of giving a resist composition capable of producing a resist pattern with a good mask error factor (MEF).SOLUTION: A salt is represented by formula (I), and an acid generator and a resist composition contain the salt. [In the formula, Qand Q, and Rand Reach represent a fluorine atom, a perfluoroalkyl group or the like; z represents an integer of 0-6; Xrepresents *-CO-O-, *-O-CO- or the like; Lrepresents a single bond or an optionally substituted hydrocarbon group; Rand Reach represent a group represented by formula (1a) or formula (2a); Rrepresents a hydrogen atom or an optionally substituted hydrocarbon group; Zrepresents an organic cation; R, Rand Reach represent an alkyl group or the like; Rand Reach represent a hydrogen atom or an alkyl group; Rrepresents an alkyl group; and Xrepresents an oxygen atom or a sulfur atom.]SELECTED DRAWING: None

Description

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

Patent Document 1 describes a resist composition containing a salt represented by the following formula as an acid generator.

JP 2014-040405 A

  An object of this invention is to provide the salt which can manufacture the resist pattern of a favorable mask error factor (MEF) rather than the resist pattern formed from the resist composition containing said salt.

The present invention includes the following inventions.
[1] A salt represented by the formula (I).
[In the formula (I),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
R ¹ and R ² each independently represents a hydrogen atom, a fluorine atom, or a C 1-6 perfluoroalkyl group.
z represents an integer of 0 to 6, and when z is 2 or more, the plurality of R ¹ and R ² may be the same as or different from each other.
X ¹ represents * —CO—O—, * —O—CO—, * —O—CO—O— or * —O—, and * represents C (R ¹ ) (R ² ) or C (Q ¹ ) Represents the binding site with (Q ² ).
L ¹ represents a divalent hydrocarbon group having 1 to 36 carbon atoms which may have a single bond or a substituent, and —CH ₂ — contained in the hydrocarbon group is —O— or —S. -, - CO- or -SO ₂ - may be replaced to.
R ³ and R ⁴ represent a group represented by the formula (1a) or a group represented by the formula (2a).
[In Formula (1a), R ^aa1 , R ^aa2 and R ^aa3 each independently represent an alkyl group having 1 to 8 carbon atoms, or R ^aa1 and R ^aa2 are bonded to each other together with the carbon atom to which they are bonded. A non-aromatic hydrocarbon ring having 3 to 20 carbon atoms is formed.
* Represents a binding site. ]
[In Formula (2a), R ^{aa1 ′} and R ^{aa2 ′} each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, R ^{aa3 ′} represents an alkyl group having 1 to 8 carbon atoms, —CH ₂ — contained in the alkyl group may be replaced by —O— or —S—.
^Xc represents an oxygen atom or a sulfur atom.
* Represents a binding site. ]
R ⁵ represents a hydrogen atom or an optionally substituted hydrocarbon group having 1 to 36 carbon atoms, and —CH ₂ — contained in the hydrocarbon group is —O—, —S—, — CO— or —SO ₂ — may be substituted.
Z ⁺ represents an organic cation. ]
[2] L ¹ is a single bond, a divalent alicyclic hydrocarbon group or an alkanediyl group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms (the alkanediyl group and alicyclic ring). The salt according to [1], wherein —CH ₂ — contained in the formula hydrocarbon group is a group in combination with —O—, —S—, —CO— or —SO ₂ —.
[3] R ⁵ is a group in which a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkanediyl group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms is combined (the alkyl group In the alkanediyl group and the alicyclic hydrocarbon group, —CH ₂ — may be replaced by —O—, —S—, —CO—, or —SO ₂ —. 2] The salt according to the above.
[4] An acid generator containing the salt according to any one of [1] to [3].
[5] A resist composition comprising the acid generator according to [4] and a resin having an acid labile group.
[6] The resist composition according to [5], comprising a salt that generates an acid having a lower acidity than an acid generated from an acid generator.
[7] (1) A step of applying the resist composition according to [5] or [6] on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer;
(4) A method for producing a resist pattern, comprising: a step of heating the composition layer after exposure; and (5) a step of developing the composition layer after heating.

  If the resist composition containing the salt of the present invention is used, a resist pattern having an excellent mask error factor (MEF) can be produced.

[Salt represented by formula (I)]
The salt of the present invention is a salt represented by the formula (I) (hereinafter sometimes referred to as “salt (I)”).
In the formula (I), examples of the perfluoroalkyl group of Q ¹ , Q ² , R ¹ and R ² include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, and a perfluorosec-butyl group. Perfluoro tert-butyl group, perfluoropentyl group, perfluorohexyl group and the like.
Q ¹ and Q ² are independently of each other preferably a trifluoromethyl group or a fluorine atom, and more preferably a fluorine atom.
R ¹ and R ² are independently of each other preferably a hydrogen atom or a fluorine atom.
z is preferably 0.

X ¹ is preferably * 1-CO—O—, * 1-O—CO— or * 1-O—CO—O—, * 1-CO—O— or * 1-O—CO. -O- is more preferable (* 1 represents a binding site with C (R ¹ ) (R ² ) or C (Q ¹ ) (Q ² )).

Examples of the divalent hydrocarbon group having 1 to 36 carbon atoms of L ¹ include a divalent aliphatic hydrocarbon group (an alkanediyl group, an alkenediyl group, an alkynediyl group, and a monocyclic or polycyclic divalent alicyclic ring. Formula hydrocarbon group), divalent aromatic hydrocarbon groups and the like, and a divalent hydrocarbon group in which two or more of these groups are combined may be used.

Examples of the alkanediyl group include methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane- 1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl Linear alkanediyl groups such as groups;
Ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane- Examples thereof include branched alkanediyl groups such as 1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, and 2-methylbutane-1,4-diyl group.
Examples of the alkenediyl group include ethenediyl group, propenediyl group, isopropenediyl group, butenediyl group, isobutenediyl group, tert-butenediyl group, pentenediyl group, hexenediyl group, heptenediyl group, octynediyl group, isooctynediyl group, and nonenediyl group. .
Examples of the alkynediyl group include ethynediyl group, propynediyl group, isopropynediyl group, butynediyl group, isobutynediyl group, tert-butynediyl group, pentynediyl group, hexynediyl group, octynediyl group, and nonindiyl group.
Examples of the monocyclic divalent alicyclic hydrocarbon group include a cyclobutane-1,3-diyl group, a cyclopentane-1,3-diyl group, a cyclohexane-1,4-diyl group, a cyclohexene-3,6- A monocyclic cycloalkanediyl group such as a diyl group and a cyclooctane-1,5-diyl group is exemplified.
Examples of the polycyclic divalent alicyclic hydrocarbon group include norbornane-1,4-diyl group, norbornane-2,5-diyl group, 5-norbornene-2,3-diyl group, and adamantane-1,5. -A polycyclic cycloalkanediyl group such as a diyl group and an adamantane-2,6-diyl group.
Examples of the divalent aromatic hydrocarbon group include a phenylene group, a naphthylene group, an anthrylene group, a biphenylene group, and a phenanthrylene group.
Examples of the hydrocarbon group in combination of two or more include groups in which an alkanediyl group is combined with a divalent alicyclic hydrocarbon group and / or a divalent aromatic hydrocarbon group. Group-alkanediyl group-, -alkanediyl group-cycloalkanediyl group-, -alkanediyl group-cycloalkanediyl group-alkanediyl group-, -alkanediyl group-divalent aromatic hydrocarbon group-, -2 Valent aromatic hydrocarbon group-alkanediyl group- and the like.

Examples of the substituent of the divalent hydrocarbon group having 1 to 36 carbon atoms of L ¹ include a halogen atom and a cyano group.
A hydroxy group (a group in which —CH ₂ — contained in a methyl group is replaced with —O—), a carboxy group (—CH ₂ —CH ₂ — in an ethyl group is replaced with —O—CO—) Group), an alkoxy group having 1 to 12 carbon atoms (a group in which —CH ₂ — contained in an alkyl group having 2 to 13 carbon atoms is replaced by —O—), an alkoxycarbonyl group having 2 to 13 carbon atoms (carbon) A group in which —CH ₂ —CH ₂ — contained in an alkyl group having 4 to 15 is replaced by —O—CO—, an alkylcarbonyl group having 2 to 13 carbon atoms (in an alkyl group having 3 to 14 carbon atoms) A group in which —CH ₂ — contained in is replaced with —CO—, an alkylcarbonyloxy group having 2 to 13 carbon atoms (—CH ₂ —CH ₂ — contained in an alkyl group having 4 to 15 carbon atoms), Group substituted by —CO—O—) is a hydrocarbon -CH ₂ contained in - is a group replaced by -O- or -CO-.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alkoxy group having 1 to 12 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group Group, dodecyloxy group and the like.
The alkoxycarbonyl group having 2 to 13 carbon atoms, the alkylcarbonyl group having 2 to 13 carbon atoms, and the alkylcarbonyloxy group having 2 to 13 carbon atoms are groups in which a carbonyl group or a carbonyloxy group is bonded to the above-described alkyl group or alkoxy group. Represents.
Examples of the alkoxycarbonyl group having 2 to 13 carbon atoms include a methoxycarbonyl group, an ethoxycarbonyl group, and a butoxycarbonyl group. Examples of the alkylcarbonyl group having 2 to 13 carbon atoms include an acetyl group, a propionyl group, and a butyryl group. Examples of the alkylcarbonyloxy group having 2 to 13 carbon atoms include an acetyloxy group, a propionyloxy group, and a butyryloxy group.

—CH ₂ — contained in the divalent hydrocarbon group having 1 to 36 carbon atoms of L ¹ may be replaced by —O—, —S—, —CO— or —SO ₂ —.
When the divalent hydrocarbon group having 1 to 36 carbon atoms of L ¹ has a substituent, or —CH ₂ — contained in the divalent hydrocarbon group having 1 to 36 carbon atoms is —O—, —S—. , -CO- or -SO 2 _- If replaced, the number of carbon atoms before replacing the carbon number of the hydrocarbon group.

L ¹ is a single bond, an alkanediyl group having 1 to 6 carbon atoms (—CH ₂ — contained in the alkanediyl group may be replaced by —O— or —CO—), a divalent alicyclic ring A hydrocarbon group or an alkanediyl group having 1 to 6 carbon atoms (—CH ₂ — contained in the alkanediyl group may be replaced by —O— or —CO—) and an oil having 3 to 18 carbon atoms A group in combination with a cyclic hydrocarbon group (—CH ₂ — contained in the alicyclic hydrocarbon group may be replaced with —O—, —S—, —CO— or —SO ₂ —). And is more preferably a single bond or * -alicyclic hydrocarbon group —CO—O— (* represents a bonding site to X ¹ ), and a single bond or * -Ad—CO. -O- (Ad represents an adamantane-diyl group, * represents a bonding site with X ^1.) Dearuko But more preferable.

In the group represented by the formula (1a) and the group represented by the formula (2a), ^{examples of} the alkyl group represented by R ^aa1 , R ^aa2 , R ^aa3 , R ^{aa1 ′} , R ^{aa1 ′} , and R ^{aa3 ′} include Methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, pentyl group, hexyl group, heptyl group, octyl group and the like.
In the case where R ^aa1 and R ^aa2 are bonded to each other to form a non-aromatic hydrocarbon ring, examples of —C (R ^aa1 ) (R ^aa2 ) (R ^aa3 ) include the following rings. The non-aromatic hydrocarbon ring preferably has 3 to 12 carbon atoms. * Represents a binding site to -O-.
^Xc is preferably an oxygen atom.

Examples of the group represented by the formula (1a) include the following groups. * Represents a binding site.

Examples of the group represented by the formula (2a) include the following groups. * Represents a binding site.

Examples of the hydrocarbon group represented by R ⁵ include an aliphatic hydrocarbon group (an alkyl group, an alkenyl group, an alkynyl group, and an alicyclic hydrocarbon group), an aromatic hydrocarbon group, and a group obtained by combining these. .
Examples of the alkyl group include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, octyl group, and nonyl group. Carbon number of an alkyl group becomes like this. Preferably it is 1-9, More preferably, it is 1-4.
Examples of the alkenyl group include an ethenyl group, a propenyl group, an isopropenyl group, a butenyl group, an isobutenyl group, a tert-butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, an octynyl group, an isooctynyl group, and a nonenyl group.
Examples of the alkynyl group include ethynyl group, propynyl group, isopropynyl group, butynyl group, isobutynyl group, tert-butynyl group, pentynyl group, hexynyl group, octynyl group, noninyl group and the like.
The alicyclic hydrocarbon group may be monocyclic, polycyclic or spirocyclic, and may be either saturated or unsaturated. The alicyclic hydrocarbon group includes a monocyclic cycloalkyl group such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclononyl group, a cyclodecyl group, and a cyclododecyl group. And a polycyclic cycloalkyl group such as a norbornyl group and an adamantyl group.
As the alicyclic hydrocarbon group represented by R ⁵ , groups represented by formulas (Y1) to (Y41) (* represents a binding site) are preferable, and formula (Y1) to formula (Y20), A group represented by any one of Formula (Y26), Formula (Y27), Formula (Y30), Formula (Y31), and Formula (Y39) to Formula (Y41) is more preferable, and Formula (Y3), ( Y4), Formula (Y9), Formula (Y11), Formula (Y14), Formula (Y15), Formula (Y19), Formula (Y20), Formula (Y30), Formula (Y39), or Formula (Y40). More preferably, it is a group. Carbon number of an alicyclic hydrocarbon group becomes like this. Preferably it is 3-18, More preferably, it is 3-16.

  Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a naphthyl group, a biphenyl group, an anthryl group, a phenanthryl group, and a binaphthyl group. The number of carbon atoms of the aromatic hydrocarbon group is preferably 6 to 14, and more preferably 6 to 10.

What is a combined group?
A group formed by combining an alicyclic hydrocarbon group and an aliphatic hydrocarbon group (the —CH ₂ — contained in the aliphatic hydrocarbon group and the alicyclic hydrocarbon group is —O—, —S—, — CO— or —SO ₂ — may be substituted)
A group in which an aromatic hydrocarbon group and an aliphatic hydrocarbon group are combined (-CH ₂ — contained in the aliphatic hydrocarbon group is replaced with —O—, —S—, —CO— or —SO ₂ —. And a group obtained by combining an alicyclic hydrocarbon group and an aromatic hydrocarbon group (—CH ₂ — contained in the alicyclic hydrocarbon group is —O—, —S—, — CO— or —SO ₂ — may be substituted).
As a combined group,
Alicyclic hydrocarbon group such as adamantylmethyl group and cyclohexylmethyl group-aliphatic hydrocarbon group- * (-CH ₂ — contained in the aliphatic hydrocarbon group and the alicyclic hydrocarbon group is —O— , -S -, - CO- or -SO ₂ - may be replaced by)
Aliphatic hydrocarbon group such as methyladamantyl group-alicyclic hydrocarbon group- * (-CH ₂ — contained in the aliphatic hydrocarbon group and the alicyclic hydrocarbon group is —O—, —S— , -CO- or -SO ₂ - may be replaced by)
An aliphatic hydrocarbon group such as a tolyl group or a xylyl group-aromatic hydrocarbon group- * (—CH ₂ — contained in the aliphatic hydrocarbon group is —O—, —S—, —CO— or —SO; _2- may be replaced)
Aliphatic hydrocarbon group such as methylcyclohexylmethyl group and methyladamantylmethyl group-alicyclic hydrocarbon group-aliphatic hydrocarbon group- * (included in the aliphatic hydrocarbon group and the alicyclic hydrocarbon group- CH ₂ — may be replaced by —O—, —S—, —CO— or —SO ₂ —),
Aromatic hydrocarbon group such as benzyl group-aliphatic hydrocarbon group- * (—CH ₂ — contained in the aliphatic hydrocarbon group is —O—, —S—, —CO— or —SO ₂ —. May be replaced),
Aliphatic hydrocarbon group such as tolylmethyl group-aromatic hydrocarbon group-aliphatic hydrocarbon group- * (—CH ₂ — contained in the aliphatic hydrocarbon group is —O—, —S—, —CO— Or -SO _2- may be substituted)
Etc. Here, * represents a bonding site with an oxygen atom.

When —CH ₂ — contained in the hydrocarbon group represented by R ⁵ is replaced by —O—, —S—, —CO— or —SO ₂ —, the number of carbons before the replacement is changed to the hydrocarbon group. The total number of carbons. Also, if the substituent in the hydrocarbon group represented by R ⁵ are attached to the total number of carbon atoms of the hydrocarbon group of carbon number prior to replacement.
The hydrocarbon group represented by R ⁵ may have one or more substituents.
Examples of the substituent include a halogen atom and a cyano group.
A hydroxy group (a group in which —CH ₂ — contained in a methyl group is replaced with —O—), a carboxy group (—CH ₂ —CH ₂ — in an ethyl group is replaced with —O—CO—) Group), an alkoxy group having 1 to 12 carbon atoms (a group in which —CH ₂ — contained in an alkyl group having 2 to 13 carbon atoms is replaced by —O—), an alkoxycarbonyl group having 2 to 13 carbon atoms (carbon) A group in which —CH ₂ —CH ₂ — contained in an alkyl group having 4 to 15 is replaced by —O—CO—, an alkylcarbonyl group having 2 to 13 carbon atoms (in an alkyl group having 3 to 14 carbon atoms) A group in which —CH ₂ — contained in is replaced with —CO—, an alkylcarbonyloxy group having 2 to 13 carbon atoms (—CH ₂ —CH ₂ — contained in an alkyl group having 4 to 15 carbon atoms), Group substituted by —CO—O—) is a hydrocarbon -CH ₂ contained in - is a group replaced by -O- or -CO-.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
Examples of the alkoxy group having 1 to 12 carbon atoms include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, octyloxy group, 2-ethylhexyloxy group, nonyloxy group, decyloxy group, undecyloxy group Group, dodecyloxy group and the like.
The alkoxycarbonyl group having 2 to 13 carbon atoms, the alkylcarbonyl group having 2 to 13 carbon atoms, and the alkylcarbonyloxy group having 2 to 13 carbon atoms are groups in which a carbonyl group or a carbonyloxy group is bonded to the above-described alkyl group or alkoxy group. Represents.
Examples of the alkoxycarbonyl group having 2 to 13 carbon atoms include a methoxycarbonyl group, an ethoxycarbonyl group, and a butoxycarbonyl group. Examples of the alkylcarbonyl group having 2 to 13 carbon atoms include an acetyl group, a propionyl group, and a butyryl group. Examples of the alkylcarbonyloxy group having 2 to 13 carbon atoms include an acetyloxy group, a propionyloxy group, and a butyryloxy group.

The hydrocarbon group represented by R ⁵ is preferably an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a hydrogen atom or a halogen atom (however, included in the aliphatic hydrocarbon group) —CH ₂ — may be replaced by —O—, —S—, —CO— or —SO ₂ —) and an alicyclic hydrocarbon group and aliphatic group which may have a halogen atom. A group in combination with a hydrocarbon group (—CH ₂ — contained in the aliphatic hydrocarbon group and the alicyclic hydrocarbon group is replaced by —O—, —S—, —CO— or —SO ₂ —; May be)
More preferably, a group having a hydrogen atom, an alkyl group, a polycyclic hydrocarbon group or a polycyclic hydrocarbon group (polycyclic hydrocarbon group-aliphatic hydrocarbon group- *, aliphatic hydrocarbon group-polycyclic Formula hydrocarbon group- * or aliphatic hydrocarbon group-polycyclic hydrocarbon group-aliphatic hydrocarbon group- * (however, -CH _2- contained in the polycyclic hydrocarbon group and aliphatic hydrocarbon group) May be replaced with —O—, —S—, —CO— or —SO ₂ —, and the hydrogen atom contained in the polycyclic hydrocarbon group may be replaced with a fluorine atom)). Yes,
More preferably, a group comprising a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an alkanediyl group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms (the alkyl group, alkanediyl group). —CH ₂ — contained in the group and the alicyclic hydrocarbon group may be replaced by —O—, —S—, —CO— or —SO ₂ —), more preferably a hydrogen atom. Alternatively, a group in which an alkanediyl group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms are combined (alkanediyl group-polycyclic hydrocarbon group- *, alkanediyl group-polycyclic carbonization). Hydrogen group—alkanediyl group— * (wherein —CH ₂ — contained in the alkanediyl group is replaced by —O— or —CO—), where * represents a bonding site with an oxygen atom. Represent.

Examples of the anion moiety of the salt (I) include anions represented by the following formulas (Ia-1) to (Ia-31). Among these, the anions represented by formula (Ia-1) to formula (Ia-9), formula (Ia-17) to formula (Ia-19), formula (Ia-21) to formula (Ia-26) are preferable. .

Examples of the organic cation of Z ⁺ 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 preferable, and an arylsulfonium cation is more preferable. Specifically, a cation represented by any one of formulas (b2-1) to (b2-4) (hereinafter may be referred to as “cation (b2-1)” or the like depending on the formula number). Can be mentioned.

In formula (b2-1) to formula (b2-4),
R ^{b4 to} R ^b6 each independently represent a chain hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 36 carbon atoms, The hydrogen atom contained in the chain hydrocarbon group is 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. The hydrogen atom contained in the alicyclic hydrocarbon group which may be substituted is 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. The hydrogen atom contained in the aromatic hydrocarbon group may be substituted with a halogen atom, a hydroxy group or an alkoxy group having 1 to 12 carbon atoms.
R ^b4 and R ^b5 may combine with each other to form a ring together with the sulfur atom to which they are bonded, and —CH ₂ — contained in the ring is —O—, —S— or -CO- may be substituted.
R ^b7 and R ^b8 each independently represent 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 represents an integer of 0 to 5.
When m2 is 2 or more, the plurality of R ^b7 may be the same or different, and when n2 is 2 or more, the plurality of R ^b8 may be the same or different.
R ^b9 and R ^b10 each independently represent a chain hydrocarbon group having 1 to 36 carbon atoms or an alicyclic hydrocarbon group having 3 to 36 carbon atoms.
R ^b9 and R ^b10 may be bonded together to form a ring together with the sulfur atom to which they are bonded, and —CH ₂ — contained in the ring is —O—, —S— or -CO- may be substituted.
R ^b11 represents a hydrogen atom, a chain hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^b12 represents a chain hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and is included in the chain hydrocarbon. The hydrogen atom may be substituted with an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aromatic hydrocarbon group is an alkoxy group having 1 to 12 carbon atoms or 1 to 1 carbon atoms. It may be substituted with 12 alkylcarbonyloxy groups.
R ^b11 and R ^b12 may be bonded to each other to form a ring including —CH—CO— to which they are bonded, and —CH ₂ — contained in the ring is —O—, —S -Or -CO- may be substituted.
R ^{b13 to} R ^b18 each independently represent 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 represents an integer of 0 to 5.
q2 and r2 each independently represents an integer of 0 to 4.
u2 represents 0 or 1.
When o2 is 2 or more, multiple R ^b13 are the same or different, 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 , When r2 is 2 or more, a plurality of R ^b16 are the same or different, when s2 is 2 or more, a plurality of R ^b17 are the same or different, and when t2 is 2 or more, a plurality of R ^b18 are the same or different Different.
An aliphatic hydrocarbon group represents a chain hydrocarbon group and an alicyclic hydrocarbon group.
Examples of chain hydrocarbon groups include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl and 2-ethylhexyl alkyl groups. Can be mentioned.
In particular, the chain hydrocarbon group of R ^{b9 to} R ^b12 preferably has 1 to 12 carbon atoms.
The alicyclic hydrocarbon group may be monocyclic or polycyclic, and the monocyclic alicyclic hydrocarbon group may be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclo group. Examples thereof include cycloalkyl groups such as heptyl group, cyclooctyl group and cyclodecyl group. Examples of the polycyclic alicyclic hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, and the following groups.
In particular, the alicyclic hydrocarbon group of R ^{b9 to} R ^b12 preferably has 3 to 18 carbon atoms, more preferably 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, and a 2-ethyladamantan-2-yl group. , 2-isopropyladamantan-2-yl group, methylnorbornyl group, isobornyl group and the like. In the alicyclic hydrocarbon group in which a hydrogen atom is substituted with an aliphatic hydrocarbon group, the total number of carbon atoms of the alicyclic hydrocarbon group and the aliphatic hydrocarbon group is preferably 20 or less.
Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a biphenylyl group, a naphthyl group, and a phenanthryl group.
The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and an aromatic hydrocarbon group (tolyl group) having a chain hydrocarbon group having 1 to 18 carbon atoms. , Xylyl group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), and 3 to 18 carbon atoms Aromatic hydrocarbon groups having a alicyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.) are preferred.
Examples of the aromatic hydrocarbon group in which a hydrogen atom is substituted with an alkoxy group include a p-methoxyphenyl group.
Examples of the chain hydrocarbon group in which a hydrogen atom is 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 methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group.
Examples of the alkylcarbonyl group include 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.
As the alkylcarbonyloxy group, methylcarbonyloxy group, ethylcarbonyloxy group, propylcarbonyloxy group, isopropylcarbonyloxy group, butylcarbonyloxy group, sec-butylcarbonyloxy group, tert-butylcarbonyloxy group, pentylcarbonyloxy group Hexylcarbonyloxy group, octylcarbonyloxy group, 2-ethylhexylcarbonyloxy group and the like.
The ring formed by combining R ^b4 and R ^b5 together with the sulfur atom to which they are bonded is monocyclic, polycyclic, aromatic, non-aromatic, saturated or unsaturated. The ring may be Examples of the ring include a ring having 3 to 18 carbon atoms, and a ring having 4 to 18 carbon atoms is preferable. Moreover, the ring containing a sulfur atom includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring, and examples thereof include the following rings.
The ring formed by combining R ^b9 and R ^b10 may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring. Examples thereof include a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring.
The ring formed by ^combining R ^b11 and R ^b12 may be any of monocyclic, polycyclic, aromatic, non-aromatic, saturated and unsaturated rings. This ring includes a 3-membered ring to a 12-membered ring, preferably a 3-membered ring to a 7-membered ring. Examples thereof include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

Among the cation (b2-1) to cation (b2-4), the cation (b2-1) is preferable.
Examples of the cation (b2-1) include the following cations.

Examples of the cation (b2-2) include the following cations.

Examples of the cation (b2-3) include the following cations.

Examples of the cation (b2-4) include the following cations.

Examples of the salt (I) include the salts described in Table 1. For example, in Table 1, salt (I-1) means a salt composed of an anion represented by formula (Ia-1) and a cation represented by formula (b2-c-1), and is shown below. Represents salt.

  Especially, salt (I) is salt (I-1)-salt (I-9), salt (I-17)-salt (I-19), salt (I-21)-salt (I-29). , Salt (I-37) to salt (I-39), salt (I-41) to salt (I-49), salt (I-57) to salt (I-59), salt (I-61) to Salt (I-69), Salt (I-77) to Salt (I-79), Salt (I-81) to Salt (I-89), Salt (I-97) to Salt (I-99), Salt (I-101) to salt (I-109), salt (I-117) to salt (I-119), salt (I-121) to salt (I-129), salt (I-137) to salt ( I-139), salt (I-141) to salt (I-164), salt (I-170) to salt (I-172), salt (I-178) to salt (I-180), salt (I -186) to salt (I-188), salt (I-194) to salt (I-196), salt ( -202) - salt (I-204), salt (I-210) - salt (I-212) are preferred.

<Method for producing salt (I)>
In the salt (I), X ¹ is * —CO—O— (* represents a binding site with C (R ¹ ) (R ² ) or C (Q ¹ ) (Q ² )). (Salt represented by formula (I1)), for example, after reacting a salt represented by formula (I1-a) with carbonyldiimidazole in a solvent, and further represented by formula (I1-b) It can be produced by reacting with a compound to be prepared.
(In the formula, all symbols have the same meaning as described above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.

Examples of the salt represented by the formula (I1-a) include salts represented by the following, and the like and are produced by the methods described in JP2008-127367A and JP2011-046694A. Can do.
Examples of the compound represented by the formula (I1-b) include compounds represented by the following formula and the like, which can be easily obtained from the market, and can be easily produced by a known synthesis method.

In the salt (I), X ¹ is * —O—CO— (* represents a binding site with C (R ¹ ) (R ² ) or C (Q ¹ ) (Q ² )). (Salt represented by formula (I2)) is, for example, a compound represented by formula (I2-b) and carbonyldiimidazole reacted in a solvent, and then further represented by formula (I2-a). Can be produced by reacting with a salt to be produced.
(In the formula, all symbols have the same meaning as described above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.

Examples of the salt represented by the formula (I2-a) include salts represented by the following, and can be produced by the method described in JP2012-193170A.
Examples of the compound represented by the formula (I2-b) include a compound represented by the following formula, and the like.

In the salt (I), X ¹ is * —O—CO—O— (* represents a binding site with C (R ¹ ) (R ² ) or C (Q ¹ ) (Q ² )). A certain salt (salt represented by the formula (I3)) is obtained by, for example, reacting a salt represented by the formula (I2-a) with carbonyldiimidazole in a solvent, and then further reacting with the formula (I1-b) It can manufacture by making it react with the compound represented by these.
(In the formula, all symbols have the same meaning as described above.)
Examples of the solvent in this reaction include chloroform and acetonitrile.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.

In the salt (I), a salt (formula) in which X ¹ is * —O— (* represents a binding site to C (R ¹ ) (R ² ) or C (Q ¹ ) (Q ² )). (Salt represented by (I4)), for example, reacting a salt represented by formula (I2-a) and a compound represented by formula (I1-b) in a solvent in the presence of a base catalyst. Can be manufactured.
(In the formula, all symbols have the same meaning as described above.)
Examples of the base in this reaction include potassium hydroxide.
Examples of the solvent in this reaction include chloroform, acetonitrile, tetrahydrofuran, dimethylformamide and the like.
The reaction temperature is usually 5 ° C to 80 ° C, and the reaction time is usually 0.5 hours to 24 hours.

[Acid generator]
The acid generator of the present invention is an acid generator containing a salt (I). One type of salt (I) may be contained, or two or more types of salt (I) may be used in combination.
The acid generator of the present invention may contain an acid generator known in the resist field (hereinafter sometimes referred to as “acid generator (B)”) in addition to the salt (I). An acid generator (B) may be used independently and may be used in combination of 2 or more type.

  The acid generator (B) may be either nonionic or ionic. Examples of the nonionic acid generator include sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, sulfonyloxyketone, diazonaphthoquinone 4-sulfonate), sulfones (for example, disulfone, Ketosulfone, sulfonyldiazomethane) and the like. Typical examples of the ionic acid generator include onium salts containing onium cations (for example, diazonium salts, phosphonium salts, sulfonium salts, and iodonium salts). Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

  As the acid generator (B), JP-A-63-26653, JP-A-55-164824, JP-A-62-69263, JP-A-63-146038, JP-A-63-163452, Kaisho 62-153853, JP 63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. No. 3,849,137, German Patent 3914407, European Patent 126,712, etc. The compound which generate | occur | produces an acid by the radiation as described in 1 can be used. Moreover, you may use the compound manufactured by the well-known method. Two or more acid generators (B) may be used in combination.

The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a salt represented by the formula (B1) (hereinafter sometimes referred to as “acid generator (B1)”).
[In the formula (B1),
Q ^b1 and Q ^b2 each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group.
L ^b1 represents a divalent saturated hydrocarbon group having 1 to 24 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced by —O— or —CO—. The hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group.
Y represents an optionally substituted methyl group or an optionally substituted alicyclic hydrocarbon group having 3 to 18 carbon atoms, and is included in the alicyclic hydrocarbon group − CH ₂ — may be replaced by —O—, —S (O) ₂ —, or —CO—.
Z1 ⁺ represents an organic cation. ]

^Examples of the perfluoroalkyl group represented by Q ^b1 and Q ^b2 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 etc. are mentioned.
Q ^b1 and Q ^b2 are each independently preferably a fluorine atom or a trifluoromethyl group, and more preferably a fluorine atom.

Examples of the divalent saturated hydrocarbon group for L ^b1 include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group, and these It may be a group formed by combining two or more of the groups.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1 , 7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group , Tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group and heptadecane-1,17-diyl group Alkanediyl group;
Ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2,4-diyl group, 2-methylpropane- Branched alkanediyl groups such as 1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group;
Monocyclic 2 which is a cycloalkanediyl group such as cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,4-diyl group, cyclooctane-1,5-diyl group Valent alicyclic saturated hydrocarbon group;
Polycyclic divalent alicyclic saturated hydrocarbon such as norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. Groups and the like.

Examples of the group in which —CH ₂ — contained in the divalent saturated hydrocarbon group represented by L ^b1 is replaced by —O— or —CO— include, for example, formula (b1-1) to formula (b1-3) Or a group represented by any of the above. In the groups represented by formula (b1-1) to formula (b1-3) and the groups represented by formula (b1-4) to formula (b1-11) as specific examples thereof, * and * * Represents a binding site, and * represents a binding site to -Y.
[In the formula (b1-1),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the divalent 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, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. In addition, —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced by —O— or —CO—.
However, the total number of carbon atoms of L ^b2 and L ^b3 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 divalent 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, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. In addition, —CH ₂ — contained in the saturated hydrocarbon group may be replaced by —O— or —CO—.
However, the total number of carbon atoms of L ^b4 and L ^b5 is 22 or less.
In formula (b1-3),
L ^b6 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
L ^b7 represents a single bond or a C1-C23 divalent saturated hydrocarbon group, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. In addition, —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced by —O— or —CO—.
However, the total number of carbon atoms of L ^b6 and L ^b7 is 23 or less. ]

In the groups represented by formula (b1-1) to formula (b1-3), when —CH ₂ — contained in the saturated hydrocarbon group is replaced by —O— or —CO—, the number of carbons before the replacement Is the carbon number of the saturated hydrocarbon group.
Examples of the divalent saturated hydrocarbon group include the same divalent saturated hydrocarbon group of L ^b1.

L ^b2 is preferably a single bond.
L ^b3 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b4 is preferably a divalent saturated hydrocarbon group having 1 to 8 carbon atoms, and the hydrogen 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 the hydrogen atom contained in the divalent 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, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. Well, —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced with —O— or —CO—.

The group in which —CH ₂ — contained in the divalent saturated hydrocarbon group represented by L ^b1 is replaced by —O— or —CO— is represented by the formula (b1-1) or the formula (b1-3). Preferred are the groups

Examples of the group represented by the formula (b1-1) include groups represented by the formula (b1-4) to the formula (b1-8).
[In the formula (b1-4),
L ^b8 represents a single bond or a divalent saturated hydrocarbon group having 1 to 22 carbon atoms, and the hydrogen atom contained in the divalent 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 —CH ₂ — 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 the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^b9 and L ^b10 is 20 or less.
In formula (b1-6),
L ^b11 represents a C1-C21 divalent saturated hydrocarbon group.
L ^b12 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^b11 and L ^b12 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 —CH ₂ — contained in the divalent saturated hydrocarbon group is replaced by —O— or —CO—. Also good.
L ^b15 represents a single bond or a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^{b13 to} L ^b15 is 19 or less.
In formula (b1-8),
L ^b16 represents a C 1-18 divalent saturated hydrocarbon group, and —CH ₂ — contained in the divalent saturated hydrocarbon group may be replaced by —O— or —CO—.
L ^b17 represents a C1- ^C18 divalent saturated hydrocarbon group.
L ^b18 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom or a hydroxy group. .
However, the total carbon number of L ^{b16 to} L ^b18 is 19 or less. ]

L ^b8 is preferably a divalent saturated hydrocarbon group having 1 to 4 carbon atoms.
L ^b9 is preferably a C 1-8 divalent saturated hydrocarbon group.
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 ^C 1-6 divalent saturated hydrocarbon group.
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.

Examples of the group represented by formula (b1-3) include groups represented by formula (b1-9) to formula (b1-11), respectively.
In formula (b1-9),
L ^b19 represents a single bond or a divalent saturated hydrocarbon group having 1 to 23 carbon atoms, and the hydrogen atom contained in the divalent 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 the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an alkylcarbonyloxy group. May be. —CH ₂ — contained in the alkylcarbonyloxy group may be replaced with —O— or —CO—, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group.
However, the total carbon number of L ^b19 and L ^b20 is 23 or less.
In formula (b1-10),
L ^b21 represents a single bond or a divalent saturated hydrocarbon group having 1 to ²¹ carbon atoms, and the hydrogen atom contained in the divalent 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 the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an alkylcarbonyloxy group. May be. —CH ₂ — contained in the alkylcarbonyloxy group may be replaced with —O— or —CO—, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group.
However, the total carbon number of L ^b21 , L ^b22 and L ^b23 is 21 or less.
In formula (b1-11),
L ^b24 represents a single bond or a divalent saturated hydrocarbon group having 1 to 20 carbon atoms, and the hydrogen atom contained in the divalent 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 the hydrogen atom contained in the divalent saturated hydrocarbon group is substituted with a fluorine atom, a hydroxy group or an alkylcarbonyloxy group. May be. —CH ₂ — contained in the alkylcarbonyloxy group may be replaced with —O— or —CO—, and a hydrogen atom contained in the alkylcarbonyloxy group may be substituted with a hydroxy group.
However, L ^b24, the total number of carbon atoms of L ^b25 and L ^b26 is 21 or less.

  In addition, in the group represented by the formula (b1-11) to the group represented by the formula (b1-9), when the hydrogen atom contained in the saturated hydrocarbon group is substituted with an alkylcarbonyloxy group, the group is replaced. The previous carbon number is defined as the carbon number 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.

Examples of the group represented by the formula (b1-4) include the following.

Examples of the group represented by the formula (b1-5) include the following.

Examples of the group represented by the formula (b1-6) include the following.

Examples of the group represented by the formula (b1-7) include the following.

Examples of the group represented by the formula (b1-8) include the following.

Examples of the group represented by the formula (b1-2) include the following.

Examples of the group represented by the formula (b1-9) include the following.

Examples of the group represented by the formula (b1-10) include the following.

Examples of the group represented by the formula (b1-11) include the following.

Examples of the alicyclic hydrocarbon group represented by Y include groups represented by formulas (Y1) to (Y11) and formulas (Y36) to (Y38).
When —CH ₂ — contained in the alicyclic hydrocarbon group represented by Y is replaced by —O—, —S (O) ₂ — or —CO—, the number may be one, or two or more. Good. Examples of such a group include groups represented by formula (Y12) to formula (Y35) and formula (Y39) to formula (Y41).

The alicyclic hydrocarbon group represented by Y is preferably formula (Y1) to formula (Y20), formula (Y26), formula (Y27), formula (Y30), formula (Y31), formula (Y39). To a group represented by any one of formula (Y41), more preferably formula (Y11), formula (Y15), formula (Y16), formula (Y20), formula (Y26), formula (Y27), formula It is a group represented by (Y30) to formula (Y31) or formula (Y39) or formula (Y40), more preferably formula (Y11), formula (Y15), formula (Y20), formula (Y30), formula (Y39) or a group represented by the formula (Y40).
When the alicyclic hydrocarbon group represented by Y is a spiro ring containing an oxygen atom such as formula (Y28) to formula (Y35), formula (Y39) or formula (Y40), two oxygen atoms The alkanediyl group in between preferably has one or more fluorine atoms. Of the alkanediyl groups contained in the ketal structure, the methylene group adjacent to the oxygen atom is preferably not substituted with a fluorine atom.

Examples of the substituent of the methyl group represented by Y include a halogen atom, a hydroxy group, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, a glycidyloxy group,-( CH ₂ ) _ja —CO—O—R ^b1 group or — (CH ₂ ) _ja —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, or 3 to 16 carbon atoms). Represents an alicyclic hydrocarbon group, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof, and ja represents an integer of 0 to 4. An alkyl group having 1 to 16 carbon atoms, And —CH ₂ — contained in the alicyclic hydrocarbon group having 3 to 16 carbon atoms may be replaced by —O—, —S (O) ₂ —, or —CO—).
Examples of the substituent for the alicyclic hydrocarbon group represented by Y include a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms which may be substituted with a hydroxy group, and an alicyclic group having 3 to 16 carbon atoms. A hydrocarbon group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, an alkylcarbonyl group having 2 to 4 carbon atoms, a glycidyloxy group,-( CH ₂ ) _ja —CO—O—R ^b1 group or — (CH ₂ ) _ja —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, or 3 to 16 carbon atoms). Represents an alicyclic hydrocarbon group, an aromatic hydrocarbon group having 6 to 18 carbon atoms, or a combination thereof, and ja represents an integer of 0 to 4. An alkyl group having 1 to 16 carbon atoms, -C contained in the alicyclic hydrocarbon group having 3 to 16 carbon atoms ₂ -, -O -, - S (O ) 2 -. Or -CO- in may be replaced), and the like.

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 cycloheptyl group, a cyclooctyl group, a norbornyl group, an adamantyl group, and the like.
The alicyclic hydrocarbon group may have a chain hydrocarbon group, and examples thereof include a methylcyclohexyl group and a dimethylcyclohexyl group.
Examples of the aromatic hydrocarbon group include aryl groups such as a phenyl group, a biphenylyl group, a naphthyl group, an anthryl group, and a phenanthryl group.
The aromatic hydrocarbon group may have a chain hydrocarbon group or an alicyclic hydrocarbon group, and an aromatic hydrocarbon group having a chain hydrocarbon group having 1 to 18 carbon atoms (tolyl group, xylyl group). Group, cumenyl group, mesityl group, p-ethylphenyl group, p-tert-butylphenyl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), and fatty acids having 3 to 18 carbon atoms An aromatic hydrocarbon group having a cyclic hydrocarbon group (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.) and the like can be mentioned.
Examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, and nonyl. Group, decyl group, undecyl group, dodecyl group and the like.
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 alkoxy group include methoxy group, ethoxy group, propoxy group, butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, octyloxy group, decyloxy group and dodecyloxy group.
Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, naphthylmethyl group, and naphthylethyl group.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group.

Examples of Y include the following.

Y is preferably an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, more preferably an adamantyl group which may have a substituent, and the alicyclic carbonization —CH ₂ — constituting the hydrogen group or adamantyl group may be replaced by —CO—, —S (O) ₂ — or —CO—. Y is more preferably an adamantyl group, a hydroxyadamantyl group, an oxoadamantyl group, or a group represented by the following.

The sulfonate anion in the salt represented by the formula (B1) is an anion represented by the formula (B1-A-1) to the formula (B1-A-55) [hereinafter, anion (B1 -A-1) "or the like. ] Is preferable, Formula (B1-A-1)-Formula (B1-A-4), Formula (B1-A-9), Formula (B1-A-10), Formula (B1-A-24)-Formula (B1-A-33), Formula (B1-A-36) to Formula (B1-A-40), Formula (B1-A-47) to Formula (B1-A-55) An anion is more preferable.

Here, R ^{i2 to} R ⁱ⁷ are each independently, for example, an alkyl group having 1 to 4 carbon atoms, preferably a methyl group or an ethyl group. R ⁱ⁸ is formed by, for example, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 4 carbon atoms, an alicyclic hydrocarbon group having 5 to 12 carbon atoms, or a combination thereof. More preferably a methyl group, an ethyl group, a cyclohexyl group or an adamantyl group. L ^A41 is a single bond or an alkanediyl group having 1 to 4 carbon atoms.
Q ^b1 and Q ^b2 represent the same meaning as described above.
Specific examples of the sulfonate anion in the salt represented by the formula (B1) include the anions described in JP 2010-204646 A.

Preferred examples of the sulfonate anion in the salt represented by the formula (B1) include anions each represented by the formula (B1a-1) to the formula (B1a-34).

  Especially, Formula (B1a-1)-Formula (B1a-3) and Formula (B1a-7)-Formula (B1a-16), Formula (B1a-18), Formula (B1a-19), Formula (B1a-22) ) To (B1a-30) are preferred.

Examples of the organic cation of Z1 ⁺ include the same as Z ⁺ in the salt (I).

  The acid generator (B) is a combination of the above-described sulfonate anion and the above-mentioned organic cation, and these can be arbitrarily combined. The acid generator (B) is preferably a formula (B1a-1) to a formula (B1a-3) and a formula (B1a-7) to a formula (B1a-16), a formula (B1a-18), a formula (B1a- 19), a combination of an anion represented by any one of formulas (B1a-22) to (B1a-34) and a cation (b2-1) or a cation (b2-3).

As the acid generator (B), those represented by formulas (B1-1) to (B1-48) are preferably exemplified. Among them, those containing an arylsulfonium cation are preferable. Formula (B1-1) to Formula (B1-3), Formula (B1-5) to Formula (B1-7), Formula (B1-11) to Formula (B1-14) ), Formula (B1-20) to formula (B1-26), formula (B1-29), and formula (B1-31) to formula (B1-48) are particularly preferable.

  In the resist composition of the present invention, the content of the acid generator is preferably 1 part by mass or more and 40 parts by mass or less, more preferably 3 parts by mass or more and 35 parts by mass or less with respect to 100 parts by mass of the resin (A). It is. The resist composition of the present invention may contain one kind of acid generator (B) alone or may contain plural kinds.

  When the salt (I) and the acid generator (B) are contained as the acid generator, the ratio of the content of the salt (I) and 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, and even more preferably 10:90 to 90. : 10, and particularly preferably 15:85 to 85:15.

[Resist composition]
The resist composition of the present invention contains an acid generator containing salt (I) and a resin having an acid labile group (hereinafter sometimes referred to as “resin (A)”). Here, the “acid labile group” has a leaving group, the leaving group is eliminated by contact with an acid, and the structural unit has a hydrophilic group (for example, a hydroxy group or a carboxy group). This means a group that converts to a unit.
The resist composition of the present invention preferably contains a quencher such as a salt that generates an acid having a lower acidity than the acid generated from the acid generator (hereinafter sometimes referred to as “quencher (C)”). And a solvent (hereinafter sometimes referred to as “solvent (E)”).

<Resin (A)>
The resin (A) has a structural unit having an acid labile group (hereinafter sometimes referred to as “structural unit (a1)”). The resin (A) preferably further contains a structural unit other than the structural unit (a1). As the structural unit other than the structural unit (a1), a structural unit having no acid labile group (hereinafter sometimes referred to as “structural unit (s)”), structural unit (a1), and structural unit (s). Structural unit (for example, a structural unit having a halogen atom described later (hereinafter sometimes referred to as “structural unit (a4)”), a structural unit having a non-elimination hydrocarbon group described later (hereinafter referred to as “structural unit (a5)”) And other structural units derived from monomers known in the art.

<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 a group represented by formula (1) (hereinafter also referred to as group (1)) and / or a group represented by formula (2) (hereinafter referred to as group (2). )) Is preferred.
[In the formula (1), R ^a1 , R ^a2 and R ^a3 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a group in which these are combined. R ^a1 and R ^a2 are bonded to each other to form a non-aromatic hydrocarbon ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded.
ma and na each independently represents 0 or 1, and at least one of ma and na represents 1.
* Represents a binding site. ]
[In formula (2), R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms. 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 —CH ₂ 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.
* Represents a binding site. ]

^Examples of the alkyl group in R ^a1 , R ^a2 and R ^a3 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
The alicyclic hydrocarbon group in R ^a1 , R ^a2 and R ^a3 may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include cycloalkyl groups such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic alicyclic hydrocarbon group include a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following group (* represents a binding site). Carbon number of the alicyclic hydrocarbon group of R ^a1 , R ^a2 and R ^a3 is preferably 3 to 16.
Examples of the group in which an alkyl group and an alicyclic hydrocarbon group are combined include, for example, methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group, cyclohexylmethyl group, adamantylmethyl group, adamantyldimethyl group, norbornyl An ethyl group etc. are mentioned.
Preferably, ma is 0 and na is 1.
Examples of —C (R ^a1 ) (R ^a2 ) (R ^a3 ) in the case where R ^a1 and R ^a2 are bonded to each other to form a non-aromatic hydrocarbon ring include the following rings. The non-aromatic hydrocarbon ring preferably has 3 to 12 carbon atoms. * Represents a binding site to -O-.

Examples of the hydrocarbon group in R ^{a1 ′} , R ^{a2 ′} and R ^{a3 ′} include an alkyl group, an alicyclic hydrocarbon group, an aromatic hydrocarbon group, and a group formed by combining these.
Examples of the alkyl group and the alicyclic hydrocarbon group include the same groups as those described for R ^a1 , R ^a2 and R ^a3 .
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-described alkyl group and alicyclic hydrocarbon group are combined (for example, a cycloalkylalkyl group), an aralkyl group such as a benzyl group, and an aromatic hydrocarbon group having an alkyl group (p-methyl). Phenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), alicyclic hydrocarbon group And aromatic hydrocarbon groups (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cycloalkyl groups such as phenylcyclohexyl group, and the like.
When R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a heterocyclic ring together with the carbon atom to which they are bonded and X, —C (R ^{a1 ′} ) (R ^{a3 ′} ) —X—R ^{a2 ′} Of the ring. * Represents a binding site.
Of R ^{a1 ′} and R ^{a2 ′} , at least one is preferably a hydrogen atom.
na ′ is preferably 0.

Examples of the group (1) include the following groups.
In the formula (1), R ^a1 , R ^a2 and R ^a3 are alkyl groups, and ma = 0 and na = 1. As the group, a tert-butoxycarbonyl group is preferable.
In formula (1), R ^a1 and R ^a2 together with the carbon atom to which they are bonded form an adamantyl group, R ^a3 is an alkyl group, ma = 0 and na = 1 .
In the formula (1), R ^a1 and R ^a2 are each independently an alkyl group, R ^a3 is an adamantyl group, ma = 0, and na = 1.
Specific examples of the group (1) include the following groups. * Represents a binding site.

Specific examples of the group (2) include the following groups. * Represents a binding site.

  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.

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

The structural unit derived from the (meth) acrylic monomer having the group (1) is preferably a structural unit represented by the 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 structural unit (a1- 2) in some cases). These may be used alone or in combination of two or more.
[In Formula (a1-0), Formula (a1-1) and Formula (a1-2),
L ^a01 , L ^a1 and L ^a2 each independently represent —O— or * —O— (CH ₂ ) _k1 —CO—O—, k1 represents any integer of 1 to 7, and * represents It represents a binding site to —CO—.
R ^a01 , R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a02 , R ^a03 and R ^a04 each independently ^represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a combination thereof.
R ^a6 and R ^a7 each independently represent an alkyl group having 1 to 8 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or a group formed by combining these.
m1 represents an integer of 0 to 14.
n1 represents any integer of 0 to 10.
n1 ′ represents any integer of 0 to 3. ]

R ^a01 , R ^a4 and R ^a5 are preferably methyl groups.
L ^a01 , L ^a1 and L ^a2 are preferably an oxygen atom or * —O— (CH ₂ ) _k01 —CO—O— (where k01 is preferably an integer of 1 to 4, more preferably Is 1.), more preferably an oxygen atom.
Examples of the alkyl group, alicyclic hydrocarbon group, and a combination thereof in R ^a02 , R ^a03 , R ^a04 , R ^a6, and R ^a7 include the groups listed as R ^a1 , R ^a2, and R ^a3 in formula (1). The same group is mentioned.
The carbon number of the alkyl group in R ^a02 , R ^a03 and R ^a04 is preferably 1 to 6, more preferably a methyl group or an ethyl group, and still more preferably a methyl group.
The carbon number of the alkyl group in R ^a6 and R ^a7 is preferably 1 to 6, more preferably a methyl group, an ethyl group, or an isopropyl group, and still more preferably an ethyl group or an isopropyl group.
Carbon number of the alicyclic hydrocarbon group of R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 is preferably 5 to 12, more preferably 5 to 10.
The group in which the alkyl group and the alicyclic hydrocarbon group are combined preferably has a total carbon number of 18 or less in combination of the alkyl group and the alicyclic hydrocarbon group.
R ^a02 and R ^a03 are preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group or an ethyl 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 preferably an alkyl group having 1 to 6 carbon atoms, more preferably a methyl group, an ethyl group, or an isopropyl group, and still more preferably an ethyl group or an isopropyl group.
m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 ′ is preferably 0 or 1.

As the structural unit (a1-0), for example, R ^a01 in the structural unit represented by any of the formulas (a1-0-1) to (a1-0-12) and the structural unit (a1-0) Examples include a structural unit in which a corresponding methyl group is replaced with a hydrogen atom, and a structural unit represented by any one of formulas (a1-0-1) to (a1-0-10) is preferable.

As a structural unit (a1-1), the structural unit derived from the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Especially, the methyl group corresponding to R ^a4 in the structural unit represented by any one of the formulas (a1-1-1) to (a1-1-4) and the structural unit (a1-1) was replaced with a hydrogen atom. A structural unit is preferable, and a structural unit represented by any one of formulas (a1-1-1) to (a1-1-4) is more preferable.

The structural unit (a1-2) corresponds to the structural unit represented by any one of the formulas (a1-2-1) to (a1-2-6) and R ^a5 in the structural unit (a1-2). Examples include a structural unit in which a methyl group is replaced with a hydrogen atom, and the formula (a1-2-2), the formula (a1-2-5), and the formula (a1-2-6) are preferable.

  When the resin (A) includes the structural unit (a1-0) and / or the structural unit (a1-1) and / or the structural unit (a1-2), the total content thereof is the total structure of the resin (A). It is 10-95 mol% normally with respect to a unit, Preferably it is 15-90 mol%, More preferably, it is 20-85 mol%, More preferably, it is 25-70 mol%, More preferably 30 to 65 mol%.

Examples of the structural unit having the group (2) in the structural unit (a1) include a structural unit represented by the formula (a1-4) (hereinafter sometimes referred to as “structural unit (a1-4)”). .
[In the formula (a1-4),
R ^a32 represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a33 is 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 alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, acryloyl An oxy group or a methacryloyloxy group is represented.
la represents an integer of 0 to 4. When la is 2 or more, the plurality of R ^a33 may be the same as or different from each other.
R ^a34 and R ^a35 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, R ^a36 may represent a hydrocarbon group having 1 to 20 carbon atoms, R ^a35 and R ^a36 are bonded to each other Together with —C—O— to which they are bonded to form a divalent hydrocarbon group having 2 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group and the divalent hydrocarbon group is — O- or -S- may be substituted. ]

^Examples of the alkyl group in R ^a32 and R ^a33 include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, and a hexyl group. The alkyl group is preferably an alkyl group having 1 to 4 carbon atoms, more preferably a methyl group or an ethyl group, and further preferably a methyl group.
Examples of the halogen atom in R ^a32 and R ^a33 include a fluorine atom, a chlorine atom, and a bromine atom.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1 , 2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 1,1,2,2,3,3 , 4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl group, etc. Is mentioned.
Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a pentyloxy group, and a hexyloxy group. Especially, a C1-C4 alkoxy group is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is further more preferable.
Examples of the alkylcarbonyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the alkylcarbonyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group.
As the hydrocarbon group for R ^a34, R ^a35 and R ^a36, an alkyl group, an alicyclic hydrocarbon group, aromatic hydrocarbon group, and include groups formed by combining these, alkyl groups and alicyclic hydrocarbon groups Examples thereof include the same groups as the alkyl group and the alicyclic hydrocarbon group in R ^a02 , R ^a03 , R ^a04 , R ^a6 and R ^a7 .
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-described alkyl group and alicyclic hydrocarbon group are combined (for example, a cycloalkylalkyl group), an aralkyl group such as a benzyl group, and an aromatic hydrocarbon group having an alkyl group (p-methyl). Phenyl group, p-tert-butylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, 2,6-diethylphenyl group, 2-methyl-6-ethylphenyl group, etc.), alicyclic hydrocarbon group And aromatic hydrocarbon groups (p-cyclohexylphenyl group, p-adamantylphenyl group, etc.), aryl-cyclohexyl groups such as phenylcyclohexyl group, and the like. In particular, as R ^a36 , 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 Is mentioned.

In formula (a1-4), R ^a32 is preferably a hydrogen atom.
R ^a33 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.
As la, 0 or 1 is preferable, and 0 is more preferable.
R ^a34 is preferably a hydrogen atom.
R ^a35 is preferably an alkyl group having 1 to 12 carbon atoms or an alicyclic hydrocarbon group, more preferably a methyl group or an ethyl group.
The hydrocarbon group for R ^a36 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 combination thereof. It is a group to be formed, more preferably an alkyl group having 1 to 18 carbon atoms, an alicyclic aliphatic hydrocarbon group having 3 to 18 carbon atoms, or an aralkyl group having 7 to 18 carbon atoms. The alkyl group and alicyclic hydrocarbon group in R ^a36 are preferably unsubstituted. The aromatic hydrocarbon group for R ^a36 is preferably an aromatic ring having an aryloxy group having 6 to 10 carbon atoms.
^{-OC (R a34) (R a35} ) -O-R a36 in the structural unit (a1-4) is desorbed by contact with an acid (e.g. p- toluenesulfonic acid) to form a hydroxy group.

As a structural unit (a1-4), the structural unit derived from the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Preferably, hydrogen atom corresponding to ^{R a32} in equation (a1-4-1) represented respectively to Formula (a1-4-8) structural units and structural units (a1-4) is replaced by a methyl group structure And more preferably, structural units represented by formula (a1-4-1) to formula (a1-4-5) and formula (a1-4-10), respectively.

  When resin (A) contains a structural unit (a1-4), it is preferable that the content rate is 10-95 mol% with respect to the sum total of all the structural units of resin (A), 15-90 It is more preferably mol%, more preferably 20 to 85 mol%, still more preferably 20 to 70 mol%, still more preferably 20 to 60 mol%.

Examples of the structural unit derived from the (meth) acrylic monomer having the group (2) include a structural unit represented by the formula (a1-5) (hereinafter sometimes referred to as “structural unit (a1-5)”). It is done.
In formula (a1-5),
R ^a8 represents a C 1-6 alkyl group optionally having a halogen atom, a hydrogen atom or a halogen atom.
Z ^a1 represents a single bond or * — (CH ₂ ) _h3 —CO—L ⁵⁴ —, h3 represents any integer of 1 to 4, and * represents a binding site to L ⁵¹ .
L ⁵¹ , L ⁵² , L ⁵³ and L ⁵⁴ each independently represent —O— or —S—.
s1 represents any integer of 1 to 3.
s1 ′ represents any integer of 0 to 3.

Examples of the halogen atom include a fluorine atom and a chlorine atom, and a fluorine atom is preferable.
Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, fluoromethyl and trifluoro A methyl group is mentioned.
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.
Of L ⁵² and L ⁵³ , one is preferably —O— and the other is preferably —S—.
s1 is preferably 1.
s1 ′ is preferably an integer of 0 to 2.
Z ^a1 is preferably a single bond or * —CH ₂ —CO—O—.

As a structural unit (a1-5), the structural unit derived from the monomer described in Unexamined-Japanese-Patent No. 2010-611117 is mentioned, for example. Among these, structural units each represented by formula (a1-5-1) to formula (a1-5-4) are preferable, and are represented by formula (a1-5-1) or formula (a1-5-2). A structural unit is more preferable.

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

In addition, examples of the structural unit (a1) include the following structural units.

  When the resin (A) includes structural units such as (a1-3-1) to (a1-3-7), the content is 10 to 10% with respect to all the structural units of the resin (A). 95 mol% is preferable, 15-90 mol% is more preferable, 20-85 mol% is further more preferable, 20-70 mol% is still more preferable, 20-60 mol% is especially preferable.

<Structural unit (s)>
The structural unit (s) is derived from a monomer having no acid labile group (hereinafter sometimes referred to as “monomer (s)”). As the monomer for deriving the structural unit (s), a monomer having no acid labile group known in the resist field can be used.
The structural unit (s) preferably has a hydroxy group or a lactone ring. A structure having a hydroxy group and having no acid labile group (hereinafter sometimes referred to as “structural unit (a2)”) and / or a lactone ring and having no acid labile group If a resin having a unit (hereinafter sometimes referred to as “structural unit (a3)”) is used in the resist composition of the present invention, the resolution of the resist pattern and the adhesion to the substrate can be improved.

<Structural unit (a2)>
The hydroxy group contained in the structural unit (a2) may be an alcoholic hydroxy group or a phenolic hydroxy group.
When a resist pattern is produced from the resist composition of the present invention, when a high energy beam such as a KrF excimer laser (248 nm), an electron beam or EUV (ultra-ultraviolet light) is used as an exposure light source, the structural unit (a2) It is preferable to use the structural unit (a2) having a phenolic hydroxy group. In the case of using an ArF excimer laser (193 nm) or the like, the structural unit (a2) having an alcoholic hydroxy group is preferable as the structural unit (a2), and the structural unit (a2-1) described later is more used. preferable. As a structural unit (a2), 1 type may be included independently and 2 or more types may be included.

Examples of the structural unit having a phenolic hydroxy group in the structural unit (a2) include a structural unit represented by the formula (a2-A) (hereinafter sometimes referred to as “structural unit (a2-A)”).
[In the formula (a2-A),
R ^a50 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a51 is 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 alkylcarbonyl group having 2 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 4 carbon atoms, acryloyl An oxy group or a methacryloyloxy group is represented.
A ^a50 represents a single bond or * —X ^a51 — (A ^a52 —X ^a52 ) _nb —, and * represents a bonding site to the carbon atom to which —R ^a50 is bonded.
A ^a52 each independently represents an alkanediyl group having 1 to 6 carbon atoms.
X ^a51 and X ^a52 each independently represent —O—, ^—CO —O— or —O—CO—.
nb represents 0 or 1.
mb represents an integer of 0 to 4. When mb is any integer of 2 or more, the plurality of ^Ra51s may be the same as or different from each other. ]

^Examples of the halogen atom for R ^a50 include a fluorine atom, a chlorine atom and a bromine atom.
^Examples of the alkyl group having 1 to 6 carbon atoms which may have a halogen atom in R ^a50 include a trifluoromethyl group, a difluoromethyl group, a methyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 2,2,3,3 4,4,4-heptafluorobutyl group, 1,1,2,2,3,3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4 5,5,5-nonafluoropentyl group, pentyl group, hexyl group and perfluorohexyl group.
R ^a50 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and even more preferably a hydrogen atom or a methyl group.
^Examples of the alkyl group for R ^a51 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.
^Examples of the alkoxy group for R ^a51 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. A C1-C4 alkoxy group is preferable, a methoxy group or an ethoxy group is more preferable, and a methoxy group is more preferable.
^Examples of the alkylcarbonyl group for R ^a51 include an acetyl group, a propionyl group, and a butyryl group.
^Examples of the alkylcarbonyloxy group for R ^a51 include an acetyloxy group, a propionyloxy group, and a butyryloxy group.
R ^a51 is preferably a methyl group.

* —X ^a51 — (A ^a52 —X ^a52 ) _nb — includes * ^—O— , * —CO—O—, * ^—O — ^CO— , * —CO—O—A ^a52 —CO—O—, * —O—CO—A ^a52 —O—, * —O—A ^a52 —CO—O—, * —CO—O—A ^a52 —O— ^CO— , * —O—CO—A ^a52 —O—CO -. Of these, * —CO—O—, * —CO—O—A ^a52 —CO—O— or * —O—A ^a52 —CO—O— is preferable.

Examples of alkanediyl groups include methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane- 1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group and 2 -Methylbutane-1,4-diyl group etc. are mentioned.
A ^a52 is preferably a methylene group or an ethylene group.

A ^a50 is preferably a single bond, * —CO—O— or * —CO—O—A ^a52 —CO—O—, and is preferably a single bond, * —CO—O— or * —CO—O—CH. _2- CO-O- is more preferable, and a single bond or * -CO-O- is more preferable.

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

  Examples of the structural unit (a2-A) include structural units derived from monomers described in JP2010-204634A and JP2012-12577A.

As the structural unit (a2-A), structural units represented by formula (a2-2-1) to formula (a2-2-6) and formula (a2-2-1) to formula (a2-2-2) In the structural unit represented by 6), a structural unit in which a methyl group corresponding to R ^a50 in the structural unit (a2-A) is replaced with a hydrogen atom can be mentioned. The structural unit (a2-A) is represented by the structural unit represented by the formula (a2-2-1), the structural unit represented by the formula (a2-2-3), and the formula (a2-2-6). A structural unit represented by formula (a2-2-1), a structural unit represented by formula (a2-2-3) or a structural unit represented by formula (a2-2-6), A structural unit in which a methyl group corresponding to R ^a50 in the structural unit (a2-A) is replaced with a hydrogen atom is preferable.

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 based on all structural units. It is 10-70 mol%, More preferably, it is 15-65 mol%, More preferably, it is 20-65 mol%.
The structural unit (a2-A) can be included in the resin (A) by, for example, polymerization using the structural unit (a1-4) and then treating with an acid such as p-toluenesulfonic acid. Moreover, after superposing | polymerizing using acetoxy styrene etc., a structural unit (a2-A) can be included in resin (A) by processing with alkalis, such as tetramethylammonium hydroxide.

Examples of the structural unit having an alcoholic hydroxy group in the structural unit (a2) include a structural unit represented by the formula (a2-1) (hereinafter sometimes referred to as “structural unit (a2-1)”).
In formula (a2-1),
L ^a3 represents —O— or * —O— (CH ₂ ) _k2 —CO—O—,
k2 represents any integer of 1 to 7. * Represents a binding site to -CO-.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group.
o1 represents an integer of 0 to 10.

In the formula (a2-1), L ^a3 is preferably —O—, —O— (CH ₂ ) _f1 —CO—O— (wherein f1 represents an integer of 1 to 4). More preferably, it is —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, more preferably 0 or 1.

As a structural unit (a2-1), the structural unit derived from the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. A structural unit represented by any one of formula (a2-1-1) to formula (a2-1-6) is preferred, and any one of formula (a2-1-1) to formula (a2-1-4) The structural unit represented is more preferable, and the structural unit represented by the formula (a2-1-1) or the formula (a2-1-3) is more preferable.

  When resin (A) contains a structural unit (a2-1), the content rate is 1-45 mol% normally with respect to all the structural units of resin (A), Preferably it is 1-40 mol%. Yes, more preferably 1 to 35 mol%, still more preferably 2 to 20 mol%, and even more preferably 2 to 10 mol%.

<Structural unit (a3)>
The lactone ring of the structural unit (a3) may be a monocycle such as a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, or a condensed ring of a monocyclic lactone ring and another ring. But you can. Preferably, a γ-butyrolactone ring, an adamantanelactone ring, or a bridged ring containing a γ-butyrolactone ring structure (for example, a structural unit represented by the following formula (a3-2)) is used.

The structural unit (a3) is preferably a structural unit represented by the formula (a3-1), the formula (a3-2), the formula (a3-3), or the formula (a3-4). One of these may be contained alone, or two or more thereof may be contained.
[In Formula (a3-1), Formula (a3-2), Formula (a3-3) and Formula (a3-4),
L ^a4 , L ^a5 and L ^a6 are each independently represented by —O— or * —O— (CH ₂ ) _k3 —CO—O— (k3 represents any integer of 1 to 7). Represents a group.
L ^a7 represents —O—, * —O—L ^a8 —O—, * —O—L ^a8 —CO—O—, * —O—L ^a8 —CO—O—L ^a9 —CO—O— or *. —O—L ^a8 —O—CO—L ^a9 —O— is represented.
L ^a8 and L ^a9 each independently represent an alkanediyl group having 1 to 6 carbon atoms.
* Represents a binding site with a carbonyl group.
R ^a18 , R ^a19 and R ^a20 each independently represent a hydrogen atom or a methyl group.
R ^a24 represents a C 1-6 alkyl group ^optionally having a halogen atom, a hydrogen atom, or a halogen atom.
X ^a3 represents —CH ₂ — or an oxygen atom.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
R ^a22 , R ^a23 and R ^a25 each independently represent a carboxy group, a cyano group or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents any integer of 0 to 5.
q1 represents any integer of 0 to 3.
r1 represents any integer of 0 to 3.
w1 represents an integer of 0 to 8.
When p1, q1, r1 and / or w1 is 2 or more, a plurality of R ^a21 , R ^a22 , R ^a23 and / or R ^a25 may be the same as or different from each other. ]

Examples of the aliphatic hydrocarbon group in R ^a21 , R ^a22 , R ^a23 and R ^a25 include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group and tert-butyl group. It is done.
Examples of the halogen atom for R ^a24 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
^Examples of the alkyl group in R ^a24 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 have 1 to 4 carbon atoms. And more preferably a methyl group or an ethyl group.
Examples of the alkyl group having a halogen atom in R ^a24 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 perfluoro group. A hexyl group, a trichloromethyl group, a tribromomethyl group, a triiodomethyl group, etc. are mentioned.

^Examples of the alkanediyl group in ^La8 and ^La9 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, and a pentane-1,5. -Diyl group, hexane-1,6-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1, 4-diyl group, 2-methylbutane-1,4-diyl group, etc. are mentioned.

In the formula (a3-1) to the formula (a3-3), L ^{a4 to} L ^a6 are each independently, preferably —O— or * —O— (CH ₂ ) _k3 —CO—O—, Is a group of any one of 1 to 4, more preferably —O— and * —O—CH ₂ —CO—O—, still more preferably an oxygen atom.
R ^{a18 to} R ^a21 are preferably methyl groups.
R ^a22 and R ^a23 are each independently preferably a carboxy group, a cyano group or a methyl group.
p1, q1 and r1 are each independently preferably an integer of 0 to 2, more preferably 0 or 1.

In formula (a3-4), R ^a24 is preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom, a methyl group or an ethyl group, and still more preferably a hydrogen atom or a methyl group. It is.
R ^a25 is preferably a carboxy group, a cyano group, or a methyl group.
L ^a7 is preferably —O— or * —O—L ^a8 —CO—O—, more preferably —O—, —O—CH ₂ —CO—O— or —O—C ₂ H ₄ —. 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) ′.
(Wherein R ^a24 and L ^a7 represent the same meaning as described above.)

As the structural unit (a3), a monomer derived from JP2010-204646, a monomer described in JP2000-122294A, a structure derived from a monomer described in JP2012-41274A Units are listed. As the structural unit (a3), the formula (a3-1-1), the formula (a3-1-2), the formula (a3-2-1), the formula (a3-2-2), the formula (a3-3) 1), a structural unit represented by any one of formula (a3-3-2) and formula (a3-4-1) to formula (a3-4-12), and the structural unit represented by formula (a3-1) ) To a structural unit in which a methyl group corresponding to R ^a18 , R ^a19 , R ^a20 and R ^a24 in formula (a3-4) is replaced with a hydrogen atom.
When the resin (A) includes the structural unit (a3), the total content is usually 5 to 70 mol%, preferably 10 to 65 mol%, based on all the structural units of the resin (A). More preferably, it is 10-60 mol%.
Moreover, the content rate of a structural unit (a3-1), a structural unit (a3-2), a structural unit (a3-3), or a structural unit (a3-4) is respectively with respect to all the structural units of resin (A). 5 to 60 mol% is preferable, 5 to 50 mol% is more preferable, and 10 to 50 mol% is more preferable.

<Structural unit (a4)>
Examples of the structural unit (a4) include the following structural units.
[In the formula (a4),
R ⁴¹ represents a hydrogen atom or a methyl group.
R ⁴² represents a saturated hydrocarbon group having a halogen atom having 1 to 24 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced with —O— or —CO. ]
Saturated hydrocarbon groups represented by R ⁴² is a chain saturated hydrocarbon group and monocyclic or polycyclic alicyclic saturated hydrocarbon group, and, and a group formed by combining these.

The chain saturated hydrocarbon group includes methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl. Is mentioned. Monocyclic or polycyclic alicyclic saturated hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl; decahydronaphthyl, adamantyl, norbornyl, and the following Examples thereof include polycyclic alicyclic saturated hydrocarbon groups such as a group (* represents a bonding site).
Examples of the group formed by the combination include a group formed by combining one or more alkyl groups or one or more alkanediyl groups and one or more alicyclic saturated hydrocarbon groups, and -alkanediyl group Examples include -alicyclic saturated hydrocarbon group, -alicyclic saturated hydrocarbon group-alkyl group, -alkanediyl group-alicyclic saturated hydrocarbon group-alkyl group, and the like.

The structural unit (a4) is at least selected from the group consisting of formula (a4-0), formula (a4-1), formula (a4-2), formula (a4-3), and formula (a4-4). A structural unit represented by one is mentioned.
[In the 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. ]

As the alkanediyl group in L ^4a, a linear alkanediyl group such as a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, an ethane-1,1-diyl group, Examples include branched alkanediyl groups such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group. It is done.

As the perfluoroalkanediyl group in L ^3a , 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, perfluorobutane-1,4-diyl group, perfluorobutane-2,2-diyl group, perfluorobutane-1,2-diyl group, perfluoropentane-1,5-diyl group, perfluoropentane-2,2 -Diyl group, perfluoropentane-3,3-diyl group, perfluorohexane-1,6-diyl group, perfluorohexane-2,2-diyl group, perfluorohexane-3,3-diyl group, perfluoroheptane-1,7 -Diyl group, perfluorohept -2,2-diyl group, perfluoroheptane-3,4-diyl group, perfluoroheptane-4,4-diyl group, perfluorooctane-1,8-diyl group, perfluorooctane-2,2-diyl group, perfluoro Examples include an octane-3,3-diyl group and a perfluorooctane-4,4-diyl group.
^Examples of the perfluorocycloalkanediyl group in L ^3a include a perfluorocyclohexanediyl group, a perfluorocyclopentanediyl group, a perfluorocycloheptanediyl group, and a perfluoroadamantanediyl group.

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 C 1-6 perfluoroalkanediyl group, more preferably a C 1-3 perfluoroalkanediyl group.

As the structural unit (a4-0), a structural unit in which a methyl group corresponding to R ⁵⁴ in the structural unit shown below and the structural unit (a4-0) in the structural unit shown below is replaced with a hydrogen atom can be mentioned.

[In the formula (a4-1),
R ^a41 represents a hydrogen atom or a methyl group.
R ^a42 represents a C1-C20 saturated hydrocarbon group which may have a substituent, and —CH ₂ — contained in the saturated hydrocarbon group is replaced by —O— or —CO—. May be.
A ^a41 represents an ^optionally substituted alkanediyl group having 1 to 6 carbon atoms or a group represented by the formula (a-g1). However, at least one of A ^a41 and R ^a42 has a halogen atom (preferably a fluorine atom) as a substituent.
[In the formula (a-g1),
s represents 0 or 1.
A ^a42 and A ^a44 each independently represent a ^C 1-5 divalent saturated hydrocarbon group which may have a substituent.
A ^a43 represents a single bond or a divalent saturated hydrocarbon group having 1 to 5 carbon atoms which may have a substituent.
X ^a41 and X ^a42 each independently represent —O—, —CO—, ^—CO —O— or —O—CO—.
However, the total number of carbon atoms of A ^a42 , A ^a43 , A ^a44 , X ^a41 and X ^a42 is 7 or less. ]
* Is a binding site, and * on the right side is a binding site with -O-CO- ^Ra42 . ]

^Examples of the saturated hydrocarbon group for R ^a42 include a chain hydrocarbon group, a monocyclic or polycyclic alicyclic hydrocarbon group, and a group formed by combining these.

The chain hydrocarbon group includes methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl. Can be mentioned. Examples of the monocyclic or polycyclic alicyclic hydrocarbon group include a cycloalkyl group such as a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, and a cyclooctyl group; a decahydronaphthyl group, an adamantyl group, a norbornyl group, and the following groups: And polycyclic alicyclic hydrocarbon groups such as (* represents a bond).
Examples of the group formed by the combination include a group formed by combining one or more alkyl groups or one or more alkanediyl groups and one or more alicyclic hydrocarbon groups, -alkanediyl group- An alicyclic hydrocarbon group, -alicyclic hydrocarbon group-alkyl group, -alkanediyl group-alicyclic hydrocarbon group-alkyl group and the like can be mentioned.

^Examples of the substituent that R ^a42 may have include at least one selected from the group consisting of a halogen atom and a group represented by formula (a-g3). As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned, Preferably it is a fluorine atom.
[In the formula (a-g3),
X ^a43 represents an oxygen atom, a carbonyl group, * ^—O —CO— or * —CO—O— (* represents a bonding site with R ^a42 ).
A ^a45 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a halogen atom.
* Represents a binding site. ]
However, in R ^a42 —X ^a43 —A ^a45 , when R ^a42 does not have a halogen atom, A ^a45 represents a C ^1-17 saturated hydrocarbon group having at least one halogen atom.

The saturated hydrocarbon group for A ^a45 includes methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, dodecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl. Alkyl groups such as groups;
Monocyclic alicyclic hydrocarbon groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl; and decahydronaphthyl, adamantyl, norbornyl, and the following groups (* represents a bond) And polycyclic alicyclic hydrocarbon groups.

R ^a42 is preferably a saturated hydrocarbon group which may have a halogen atom, more preferably an alkyl group having a halogen atom and / or a saturated hydrocarbon group having a group represented by the formula (a-g3).
When R ^a42 is a saturated hydrocarbon group having a halogen atom, it is preferably a saturated hydrocarbon group having a fluorine atom, more preferably a perfluoroalkyl group or a perfluorocycloalkyl group, still more preferably 1 to 1 carbon atoms. 6 perfluoroalkyl group, particularly preferably a C 1-3 perfluoroalkyl group. 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.
When R ^a42 is a saturated hydrocarbon group having a group represented by the formula (a-g3), including the number of carbons contained in the group represented by the formula (a-g3), the total carbon of R ^a42 The number is preferably 15 or less, and more preferably 12 or less. When it has a group represented by the formula (a-g3) as a substituent, the number is preferably 1.

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

1-6 are preferable and, as for carbon number of the saturated hydrocarbon group of ^Aa46 , 1-3 are more preferable.
The carbon number of the saturated hydrocarbon group for A ^a47 is preferably 4 to 15, more preferably 5 to 12, and A ^a47 is more preferably a cyclohexyl group or an adamantyl group.

A preferable structure of the group represented by the formula (a-g2) is the following structure (* is a bonding site with a carbonyl group).

As the alkanediyl group in ^Aa41 , 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 Linear alkanediyl group such as propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,2-diyl group, 1-methylbutane-1,4-diyl group, Examples include branched alkanediyl groups such as 2-methylbutane-1,4-diyl group.
^Examples of the substituent in the alkanediyl group represented by A ^a41 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 still more preferably an ethylene group.

The divalent saturated hydrocarbon group represented by A ^a42 , A ^a43 and A ^{a44 in} the group represented by the formula (a-g1) includes a linear or branched alkanediyl group and a monocyclic divalent alicyclic group. Examples thereof include a saturated hydrocarbon group and a divalent saturated hydrocarbon group formed by combining an alkanediyl group and a divalent alicyclic saturated hydrocarbon group. Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, 1-methylpropane-1,3-diyl group, Examples include 2-methylpropane-1,3-diyl group and 2-methylpropane-1,2-diyl group.
^Examples of the substituent of the divalent saturated hydrocarbon group represented by A ^a42 , A ^a43 and A ^a44 include a hydroxy group and an alkoxy group having 1 to 6 carbon atoms.
s is preferably 0.

In the group represented by the formula (a-g1), ^{examples of the} group in which X ^a42 is —O—, ^—CO— , ^—CO —O—, or —O—CO— include the following groups. In the following examples, * and ** each represent a binding site, and ** is a binding site with —O—CO—R ^a42 .

As the structural unit represented by the formula (a4-1), a methyl group corresponding to R ^a41 in the structural unit shown below and the structural unit represented by the formula (a4-1) in the following structural unit is a hydrogen atom. Examples include structural units that have been replaced.

As the structural unit represented by the formula (a4-1), a structural unit represented by the formula (a4-2) is preferable.
[In the 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 —CH ₂ — contained in the alkanediyl group may be replaced with —O— or —CO—.
R ^f6 represents a saturated hydrocarbon group having 1 to 20 carbon atoms.
However, the upper limit of the total number of carbon atoms of L ⁴⁴ and R ^f6 are 21. ]

Alkanediyl group having 1 to 6 carbon atoms L ⁴⁴ include the same groups as those exemplified in A ^a41.
Examples of the saturated hydrocarbon group for R ^f6 include the same groups as those exemplified for R ^a42 .
As a C1-C6 alkanediyl group in L < ⁴⁴ >, a C2-C4 alkanediyl group is preferable and an ethylene group is more preferable.

Examples of the structural unit represented by formula (a4-2) include structural units represented by formula (a4-1-1) to formula (a4-1-11), respectively. A structural unit in which a methyl group corresponding to R ^f5 in the structural unit (a4-2) is replaced with a hydrogen atom is also exemplified as the structural unit represented by the formula (a4-2).

[In the 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 C 1-18 divalent saturated hydrocarbon group which may have a fluorine atom.
X ^f12 represents * —O—CO— or * —CO—O— (* represents a binding site with A ^f13 ).
A ^f14 represents a saturated hydrocarbon group having 1 to 17 carbon atoms which may have a fluorine atom.
However, at least one of A ^f13 and A ^f14 has a fluorine atom, and the upper limit of the total carbon number of L ⁵ , A ^f13 and A ^f14 is 20. ]

As the alkanediyl group for L ^5, the same groups as those exemplified for the alkanediyl group of A ^a41 can be mentioned.

The divalent saturated hydrocarbon group which may have a fluorine atom in A ^f13 preferably has a divalent chain saturated hydrocarbon group which may have a fluorine atom and a fluorine atom. A divalent alicyclic saturated hydrocarbon group, more preferably a perfluoroalkanediyl group.
Examples of the divalent chain saturated hydrocarbon group which may have a fluorine atom include alkanediyl groups such as methylene group, ethylene group, propanediyl group, butanediyl group and pentanediyl group; difluoromethylene group, perfluoroethylene group, Examples thereof include perfluoroalkanediyl groups such as perfluoropropanediyl group, perfluorobutanediyl group and perfluoropentanediyl group.
The divalent alicyclic saturated hydrocarbon group which may have a fluorine atom may be 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.

As the saturated hydrocarbon group for A ^{f14 and} the saturated hydrocarbon group which may have a fluorine atom, the same groups as those exemplified for R ^a42 can be mentioned. Among them, trifluoromethyl group, difluoromethyl group, methyl group, perfluoroethyl group, 2,2,2-trifluoroethyl group, 1,1,2,2-tetrafluoroethyl group, ethyl group, perfluoropropyl group, 2,2,3,3,3-pentafluoropropyl group, propyl group, perfluorobutyl group, 2,2,3,3,4,4,4-heptafluorobutyl group, 1,1,2,2,3 , 3,4,4-octafluorobutyl group, butyl group, perfluoropentyl group, 2,2,3,3,4,4,5,5,5-nonafluoropentyl group, pentyl group, hexyl group, perfluorohexyl Group, heptyl group, perfluoroheptyl group, octyl group, perfluorooctyl group and other fluorinated alkyl groups, cyclopropylmethyl group, cyclopropyl group, cyclobutyl group Rumechiru group, a cyclopentyl group, a cyclohexyl group, perfluorocyclohexyl group, an adamantyl group, adamantylmethyl group, adamantyl dimethyl group, norbornyl group, norbornylmethyl group, perfluoro adamantyl group, a perfluoroalkyl adamantylmethyl group and the like are preferable.

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

Examples of the structural unit represented by formula (a4-3) include structural units represented by formula (a4-1′-1) to formula (a4-1′-11), respectively. A structural unit in which a methyl group corresponding to R ^f7 in the structural unit (a4-3) is replaced with a hydrogen atom is also exemplified as the structural unit represented by the formula (a4-3).

Examples of the structural unit (a4) include a structural unit represented by the formula (a4-4).
[In the formula (a4-4),
R ^f21 represents a hydrogen atom or a methyl group.
A ^f21 represents — (CH ₂ ) _j1 —, — (CH ₂ ) _j2 —O— (CH ₂ ) _j3 — or — (CH ₂ ) _j4 —CO—O— (CH ₂ ) _j5 —.
j1 to j5 each independently represents an integer of 1 to 6.
R ^f22 represents a C 1-10 saturated hydrocarbon group having a fluorine atom. ]

^Examples of the saturated hydrocarbon group for R ^f22 include the same saturated hydrocarbon groups represented by R ^a42 . R ^f22 is preferably a ^C 1-10 alkyl group having a fluorine atom or a C 1-10 alicyclic saturated hydrocarbon group having a fluorine atom, and a C 1-10 alkyl group having a fluorine atom. More preferably, a C1-C6 alkyl group which has a fluorine atom is still more preferable.

In formula (A4-4), as the _{^{A f21, - (CH 2)}} j1 - , more preferably an ethylene group or a methylene group, more preferably a methylene group.

As the structural unit represented by the formula (a4-4), for example, in the following structural unit and the structural unit represented by the following formula, a methyl group corresponding to R ^f21 in the structural unit (a4-4) is hydrogen. Examples include structural units replaced by atoms.

  When the resin (A) has a structural unit (a4), the content is preferably 1 to 20 mol%, more preferably 2 to 15 mol%, based on all structural units of the resin (A). More preferably, it is 10 mol%.

<Structural unit (a5)>
Examples of the non-elimination hydrocarbon group that the structural unit (a5) has include a group having a linear, branched, or cyclic hydrocarbon group. Among these, the structural unit (a5) is preferably a group having an alicyclic hydrocarbon group.
As a structural unit (a5), the structural unit represented by a formula (a5-1) is mentioned, for example.
[In the formula (a5-1),
R ⁵¹ represents a hydrogen atom or a methyl group.
R ⁵² represents an alicyclic hydrocarbon group having 3 to 18 carbon atoms, and 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 —CH ₂ — contained in the saturated hydrocarbon group may be replaced by —O— or —CO—. . ]

The alicyclic hydrocarbon group for R ⁵² may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the polycyclic alicyclic hydrocarbon group include an adamantyl group and a norbornyl group.
Examples of the aliphatic hydrocarbon group having 1 to 8 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2 -Alkyl groups, such as an ethylhexyl group, are mentioned.
Examples of the alicyclic hydrocarbon group having a substituent include a 3-hydroxyadamantyl group and 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.

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

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

L ^x1 is preferably a C 1-8 divalent aliphatic saturated hydrocarbon group, more preferably a methylene group or an ethylene group.
L ^x2 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond.
L ^x3 is preferably a C 1-8 divalent aliphatic saturated hydrocarbon group.
L ^x4 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x5 is preferably a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group.
L ^x6 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a methylene group or an ethylene group.
L ^x7 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms.
L ^x8 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group.
L ^x9 is preferably a single bond or a divalent aliphatic saturated hydrocarbon group having 1 to 8 carbon atoms, more preferably a single bond or a methylene group.
W ^x1 is preferably a divalent alicyclic saturated hydrocarbon group having 3 to 10 carbon atoms, more preferably a cyclohexanediyl group or an adamantanediyl group.

As group represented by a formula (L1-1), the bivalent group shown below is mentioned, for example.

As group represented by a formula (L1-2), the bivalent group shown below is mentioned, for example.

As group represented by a formula (L1-3), the bivalent group shown below is mentioned, for example.

As group represented by a formula (L1-4), the bivalent group shown below is mentioned, for example.

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

Examples of the structural unit (a5-1) include structural units in which a methyl group corresponding to R ⁵¹ in the structural unit shown below and the structural unit (a5-1) in the structural unit shown below is replaced with a hydrogen atom.
When the resin (A) has the structural unit (a5), the content is preferably 1 to 30 mol%, more preferably 2 to 20 mol%, based on all structural units of the resin (A). More preferred is ˜15 mol%.

<Structural unit (II)>
The resin (A) may further contain a structural unit that decomposes upon exposure to generate an acid (hereinafter sometimes referred to as “structural unit (II)”. As the structural unit (II), Specifically, the structural unit described in JP-A-2016-79235 can be mentioned, and the structural unit having a sulfonate group or a carboxylate group and an organic cation in the side chain, or the structural unit having a sulfonio group and an organic anion in the side chain It is preferable that

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 the formula (II-2-A ′).
[In the formula (II-2-A ′)
X ^III3 represents a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced by —O—, —S— or —CO—. The hydrogen atom contained in the saturated hydrocarbon group may be replaced with 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 with a fluorine atom or a perfluoroalkyl group having 1 to 6 carbon atoms.
RA ^- represents a sulfonate or carboxylate groups.
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.
ZA ⁺ represents an organic cation. ]

Examples of the halogen atom represented by R ^III3 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
As the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R ^III3 , an alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R ^a8 and The same can be mentioned.
Examples of the alkanediyl group having 1 to 8 carbon atoms represented by A ^x1 include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, and a pentane-1,5-diyl group. Hexane-1,6-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, pentane-2, 4-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, etc. Can be mentioned.

Examples of the divalent saturated hydrocarbon group having 1 to 18 carbon atoms represented by ^XIII3 include a linear or branched alkanediyl group, a monocyclic or polycyclic divalent alicyclic saturated hydrocarbon group. These may be combined.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, propane-1,2-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1 , 6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group , Linear alkanediyl groups such as dodecane-1,12-diyl group; butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group Branched alkanediyl groups such as pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group; cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1 , 4-diyl group, Cycloalkanediyl group such as looctane-1,5-diyl group; norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group Bivalent polycyclic alicyclic saturated hydrocarbon groups and the like.

Examples of the group in which —CH ₂ — contained in the saturated hydrocarbon group is replaced by —O—, —S—, or —CO— include divalent groups represented by formula (X1) to formula (X53), for example. Can be mentioned. However, the number of carbon atoms before —CH ₂ — contained in the saturated hydrocarbon group is replaced with —O—, —S—, or —CO— is 17 or less. In the following formulas, * and ** represent the binding site, and * represents a binding site with A ^x1.

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.

Examples of the organic cation represented by ZA ⁺ include the same cation Z ⁺ in the salt (I).

The structural unit represented by the formula (II-2-A ′) is preferably a structural unit represented by the formula (II-2-A).
[In formula (II-2-A), R ^III3 , X ^III3 and ZA ⁺ represent the same meaning as described above.
z represents an integer of 0 to 6.
R ^III2 and R ^III4 each independently represent a hydrogen atom, a fluorine atom or a C 1-6 perfluoroalkyl group, and when z is 2 or more, the plurality of R ^III2 and R ^III4 are the same as each other It may be different or different.
Q ^a and Q ^b each independently represent a fluorine atom or a C 1-6 perfluoroalkyl group. ]

^{Examples of} the C 1-6 perfluoroalkyl group represented by R ^III2 , R ^III4 , Q ^a and Q ^b include the same as the C 1-6 perfluoroalkyl group represented by Q ^b1 described above. .

The structural unit represented by the formula (II-2-A) is preferably a structural unit represented by the formula (II-2-A-1).
[In the formula (II-2-A-1)
R ^III2 , R ^III3 , R ^III4 , Q ^a , Q ^b , z and ZA ⁺ represent the same meaning as described above.
R ^III5 represents a saturated hydrocarbon group having 1 to 12 carbon atoms.
X ^I2 represents a divalent saturated hydrocarbon group having 1 to 11 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group may be replaced by —O—, —S— or —CO—. The hydrogen atom contained in the saturated hydrocarbon group may be substituted with a halogen atom or a hydroxy group. ]

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

As the structural unit represented by the formula (II-2-A-1), a structural unit represented by the formula (II-2-A-2) is preferable.
[In Formula (II-2-A-2), R ^III3 , R ^III5 and ZA ⁺ represent the same meaning as described above.
m and n each independently represents 1 or 2. ]

Examples of the structural unit represented by the formula (II-2-A ′) include the following structural units and the structural units described in International Publication No. 2012/050015. ZA ⁺ represents an organic cation.

The structural unit having a sulfonio group and an organic anion in the side chain is preferably a structural unit represented by the formula (II-1-1).
[In the formula (II-1-1),
A ^II1 represents a single bond or a divalent linking group.
R ^II1 represents a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.
R ^II2 and R ^II3 each independently represent a hydrocarbon group having 1 to 18 carbon atoms, and R ^II2 and R ^II3 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded.
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. ]
Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by R ^II1 include a phenylene group and a naphthylene group.
Examples of the hydrocarbon group represented by R ^II2 and R ^II3 include the same hydrocarbon groups represented by R ³ .
Examples of the halogen atom represented by R ^II4 include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
As the alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R ^II4 , an alkyl group having 1 to 6 carbon atoms which may have a halogen atom represented by R ^a8 ; The same can be mentioned.
Examples of the divalent linking group represented by A ^II1 include a divalent saturated hydrocarbon group having 1 to 18 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group is: -O-, -S- or -CO- may be substituted. Specifically, the same thing as a C1-C18 bivalent saturated hydrocarbon group represented by ^XIII3 is mentioned.

Examples of the structural unit containing a cation in formula (II-1-1) include the structural units represented below.

A ^- The organic anion represented by a sulfonic acid anion, sulfonyl imide anion, methide anion and a carboxylate anion, and the like. A ^- organic anion represented by the sulfonate anion are preferable, and as a sulfonate anion, more preferably an anion contained in the salt represented by the formula (B1) to above.

A ^- The sulfonyl imide anions represented by, the following may be mentioned.

Examples of the sulfonylmethide anion include the following.

Examples of the carboxylate anion include the following.

Examples of the structural unit represented by the formula (II-1-1) include the structural units represented below.

  When the structural unit (II) is contained in the resin (A), the content of the structural unit (II) is preferably 1 to 20 mol% with respect to the total structural units of the resin (A). Preferably it is 2-15 mol%, More preferably, it is 3-10 mol%.

  The resin (A) may have a structural unit other than the above-described structural unit, and examples of such a structural unit include structural units well known in the art.

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 a group consisting of the structural unit (a1-0), the structural unit (a1-1) and the structural unit (a1-2) (preferably the structural unit having a cyclohexyl group and a cyclopentyl group). And 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 the formula (a2-1). The structural unit (a3) is preferably a group consisting of a structural unit represented by the formula (a3-1), a structural unit represented by the formula (a3-2), and a structural unit represented by the formula (a3-4). Is at least one selected from
Each structural unit constituting the resin (A) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer that derives these structural units. be able to. The content rate of each structural unit which resin (A) has can be adjusted with the usage-amount of the monomer used for superposition | polymerization.
The weight average molecular weight of the resin (A) is preferably 2,000 or more (more preferably 2,500 or more, more preferably 3,000 or more), 50,000 or less (more preferably 30,000 or less, further preferably 15,000 or less). In the present specification, the weight average molecular weight is a value obtained by gel permeation chromatography under the conditions described in Examples.

<Resin other than resin (A)>
Examples of the resin other than the resin (A) include a resin containing the structural unit (a4) or the structural unit (a5) (hereinafter sometimes referred to as the resin (X)).
Among them, the resin (X) is preferably a resin containing the structural unit (a4).
In the resin (X), the content of the structural unit (a4) is preferably 30 mol% or more, more preferably 40 mol% or more with respect to the total of all the structural units of the resin (X). More preferably, it is 45 mol% or more.
Examples of the structural unit that the resin (X) may further include a structural unit derived from the structural unit (a1), the structural unit (a2), the structural unit (a3), and other known monomers. Especially, it is preferable that resin (X) is resin which consists only of structural unit (a4) and / or structural unit (a5), and it is more preferable that it is resin which consists only of structural unit (a4).
Each structural unit constituting the resin (X) may be used alone or in combination of two or more, and is produced by a known polymerization method (for example, radical polymerization method) using a monomer that derives these structural units. can do. The content rate of each structural unit which resin (X) has can be adjusted with the usage-amount of the monomer used for superposition | 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 means for measuring the weight average molecular weight of the resin (X) is the same as that for the resin (A).
When the resist composition of this invention contains resin (X), the content is 1-2500 mass parts (more preferably 1-1000 mass parts) normally with respect to 100 mass parts of resin (A). is there.
Moreover, when a resist composition contains resin (X), the content becomes like this. Preferably it is 1-60 mass parts with respect to 100 mass parts of resin (A), More preferably, it is 1-50 mass parts. More preferably, it is 1-40 mass parts, More preferably, it is 1-30 mass parts, More preferably, it is 1-8 mass parts.

  The content of the resin (A) in the resist composition is preferably 80% by mass to 99% by mass and more preferably 90% by mass to 99% by mass with respect to the solid content of the resist composition. Moreover, when resin (X) is included, it is preferable that the total content rate of resin (A) and resin (X) is 80 to 99 mass% with respect to solid content of a resist composition. 90 mass% or more and 99 mass% or less are more preferable. In the present specification, the “solid content of the resist composition” means the total of components excluding the solvent (E) described later from the total amount of the resist composition. The solid content of the resist composition and the resin content relative thereto can be measured by a known analysis means such as liquid chromatography or gas chromatography.

<Solvent (E)>
The content of the solvent (E) is usually 90% by mass or more and 99.9% by mass or less, preferably 92% by mass or more and 99% by mass or less, more preferably 94% by mass or more and 99% by mass in the resist composition. % Or less. The content rate of a solvent (E) can be measured by well-known analysis means, such as a liquid chromatography or a gas chromatography, for example.
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; ethyl lactate, butyl acetate, amyl acetate and ethyl pyruvate Esters such as acetone, methyl isobutyl ketone, ketones such as 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; and the like. One kind of the solvent (E) may be used alone, or two or more kinds may be used.

<Quencher (C)>
Examples of the quencher (C) include a basic nitrogen-containing organic compound and a salt that generates an acid having a lower acidity than the acid generated from the acid generator (B). The content of the quencher (C) is preferably about 0.01 to 5% by mass based on the solid content of the resist composition.
Examples of the basic nitrogen-containing organic compound include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines.
Examples of the amine include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N-dimethylaniline, diphenylamine, hexylamine, Heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, tri Heptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, Rudicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyl Didecylamine, 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-methyli Dazole, pyridine, 4-methylpyridine, 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene, 1,2-di (4-pyridyl) ethene, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) ethane, di (2-pyridyl) ketone, 4,4′-dipyridyl sulfide, 4, 4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipicolylamine, bipyridine and the like are preferable, and aromatic amines such as diisopropylaniline are preferable, and 2,6-diisopropyl is more preferable. Aniline is mentioned.

As ammonium salts, tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3- (trifluoromethyl) phenyltrimethyl Ammonium hydroxide, tetra-n-butylammonium salicylate, choline and the like can be mentioned.
The acidity in a salt that generates an acid having a lower acidity than the acid generated from the acid generator (B) is indicated by an acid dissociation constant (pKa). The salt that generates an acid having a lower acidity than the acid generated from the acid generator (B) is a salt in which the acid dissociation constant of the acid generated from the salt is usually -3 <pKa, preferably -1 < A salt having a pKa <7, more preferably a salt having a 0 <pKa <5.
Examples of the salt that generates an acid having a lower acidity than the acid generated from the acid generator (B) include a salt represented by the following formula and a salt represented by the formula (D) described in JP-A-2015-147926. (Hereinafter, also referred to as “weak acid inner salt (D)”), JP 2012-229206 A, JP 2012-6908 A, JP 2012-72109 A, JP 2011-39502 A. And salts described in JP-A-2011-191745. The salt that generates an acid having a weaker acidity than the acid generated from the acid generator (B) is preferably a weak acid inner salt (D).

Examples of the weak acid inner salt (D) include the following salts.
When the resist composition contains the quencher (C), the content of the quencher (C) is usually 0.01 to 5% by mass in the solid content of the resist composition, preferably 0.01 to 3% by mass.

<Other ingredients>
The resist composition of the present invention may contain components other than the above components (hereinafter sometimes referred to as “other components (F)”) as necessary. The other component (F) is not particularly limited, and additives known in the resist field, such as sensitizers, dissolution inhibitors, surfactants, stabilizers, dyes and the like can be used.

<Preparation of resist composition>
The resist composition of the present invention comprises a salt (I) and a resin (A), and if necessary, an acid generator (B), a resin other than the resin (A), a solvent (E), and a quencher (C). And other components (F) can be mixed. The mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select an appropriate temperature from 10-40 degreeC according to the kind etc. of resin etc., the solubility with respect to solvents (E), such as resin. An appropriate 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 each component, it is preferable to filter using a filter having a pore size of about 0.003 to 0.2 μm.

<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises:
(1) A step of applying the resist composition of the present invention on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer;
(4) a step of heating the composition layer after exposure, and (5) a step of developing the composition layer after heating.
The resist composition can be applied onto the substrate by a commonly used apparatus such as a spin coater. Examples of the substrate include an inorganic substrate such as a silicon wafer. Before applying the resist composition, the substrate may be washed, or an antireflection film or the like may be formed on the substrate.
By drying the composition after coating, the solvent is removed and a composition layer is formed. Drying is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking), or using a decompression device. The heating temperature is preferably 50 to 200 ° C., and the heating time is preferably 10 to 180 seconds. Moreover, it is preferable that the pressure at the time of drying under reduced pressure is about 1-1.0 * 10 < ⁵ > Pa.
The obtained composition layer is usually exposed using an exposure machine. The exposure machine may be an immersion exposure machine. Exposure light sources include those that emit laser light in the ultraviolet region such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ excimer laser (wavelength 157 nm), solid-state laser light source (YAG or semiconductor laser) Etc.) Using various lasers such as those that convert wavelength of laser light from the laser and emit harmonic laser light in the far-ultraviolet region or vacuum ultraviolet region, those that irradiate electron beams or extreme ultraviolet light (EUV), etc. Can do. In this specification, the irradiation of these radiations may be collectively referred to as “exposure”. At the time of exposure, exposure is usually performed through a mask corresponding to a required 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 heat treatment (so-called post-exposure baking) in order to promote the deprotection reaction in the acid labile group. The heating temperature is usually about 50 to 200 ° C, preferably about 70 to 150 ° C.
The heated composition layer is usually developed using a developer using a developing device. Examples of the developing method include a dipping method, a paddle method, a spray method, and a dynamic dispensing method. The development temperature is preferably 5 to 60 ° C., for example, and the development time is preferably 5 to 300 seconds, for example. A positive resist pattern or a negative resist pattern can be produced by selecting the type of developer as follows.
When producing a positive resist pattern from the resist composition of the present invention, an alkaline developer is used as the developer. The alkaline developer may be various alkaline aqueous solutions used in this field. Examples thereof include an aqueous solution of tetramethylammonium hydroxide and (2-hydroxyethyl) trimethylammonium hydroxide (commonly called choline). The alkali developer may contain a surfactant.
It is preferable to wash the resist pattern with ultrapure water after development, and then remove the water remaining on the substrate and the pattern.
In the case of producing a negative resist pattern from the resist composition of the present invention, a developer containing an organic solvent as a developer (hereinafter sometimes referred to as “organic developer”) is used.
Organic solvents contained in the organic developer include ketone solvents such as 2-hexanone and 2-heptanone; glycol ether ester solvents such as propylene glycol monomethyl ether acetate; ester solvents such as butyl acetate; glycols such as propylene glycol monomethyl ether Examples include ether solvents; amide solvents such as N, N-dimethylacetamide; aromatic hydrocarbon solvents such as anisole.
In the organic developer, the content of the organic solvent is preferably 90% by mass or more and 100% by mass or less, more preferably 95% by mass or more and 100% by mass or less, and still more preferably only the organic solvent.
Among them, the organic developer is preferably a developer containing butyl acetate and / or 2-heptanone. In the organic developer, the total content of butyl acetate and 2-heptanone is preferably 50% by mass to 100% by mass, more preferably 90% by mass to 100% by mass, and substantially butyl acetate and / or 2 -More preferred is heptanone alone.
The organic developer may contain a surfactant. The organic developer may contain a trace amount of water.
At the time of development, the development may be stopped by substituting a solvent of a different type from the organic developer.
It is preferable to wash the developed resist pattern with a rinse solution. The rinsing liquid is not particularly limited as long as it does not dissolve the resist pattern, and a solution containing a general organic solvent can be used, and an alcohol solvent or an ester solvent is preferable.
After the cleaning, it is preferable to remove the rinse solution remaining on the substrate and the pattern.

<Application>
The resist composition of the present invention includes a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for electron beam (EB) exposure, or a resist composition for EUV exposure, particularly ArF. It is suitable as a resist composition for excimer laser exposure and is useful for fine processing of semiconductors.

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

Example 1: Synthesis of a salt represented by the formula (I-1)
3.40 parts of the salt represented by the formula (I-1-a) and 12.20 parts of acetonitrile were mixed and stirred at 23 ° C. for 30 minutes. To the obtained mixture, 1.98 parts of the compound represented by the formula (I-1-b) was added, and the mixture was further stirred at 50 ° C. for 2 hours. To the obtained reaction mixture, 3.05 parts of the compound represented by the formula (I-1-c) was added, and the mixture was further stirred at 50 ° C. for 4 hours, and then cooled to 23 ° C. To the obtained reaction mixture, 40 parts of chloroform and 10 parts of 5% oxalic acid aqueous solution were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out an organic layer. To the obtained organic layer, 20 parts of ion-exchanged water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 5 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 the supernatant was removed and concentrated to give the formula (I-1 ) Was obtained.
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (−) Spectrum): M ⁻ 419.1

Example 2: Synthesis of a salt represented by the formula (I-2)
3.40 parts of the salt represented by the formula (I-1-a) and 12.20 parts of acetonitrile were mixed and stirred at 23 ° C. for 30 minutes. To the obtained mixture, 1.98 parts of the compound represented by the formula (I-1-b) was added, and the mixture was further stirred at 50 ° C. for 2 hours. To the obtained reaction mixture, 3.42 parts of the compound represented by the formula (I-2-c) was added, and the mixture was further stirred at 50 ° C. for 4 hours, and then cooled to 23 ° C. To the obtained reaction mixture, 40 parts of chloroform and 10 parts of 5% oxalic acid aqueous solution were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out an organic layer. To the obtained organic layer, 20 parts of ion-exchanged water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 5 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 the supernatant was removed and concentrated to give a compound of formula (I-2 ) Was obtained.
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (−) Spectrum): M ^- 451.1

Example 3: Synthesis of salt represented by formula (I-141)
4.78 parts of the salt represented by the formula (I-141-a) and 12.20 parts of acetonitrile were mixed and stirred at 23 ° C. for 30 minutes. To the obtained mixture, 1.98 parts of the compound represented by the formula (I-1-b) was added, and the mixture was further stirred at 50 ° C. for 2 hours. To the obtained reaction mixture, 3.05 parts of the compound represented by the formula (I-1-c) was added, and the mixture was further stirred at 50 ° C. for 4 hours, and then cooled to 23 ° C. To the obtained reaction mixture, 40 parts of chloroform and 10 parts of 5% oxalic acid aqueous solution were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out an organic layer. To the obtained organic layer, 20 parts of ion-exchanged water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 5 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 the supernatant was removed and concentrated to give the formula (I-141 ) Was obtained.
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (−) Spectrum): M ^- 597.2

Example 4: Synthesis of salt represented by formula (I-142)
4.78 parts of the salt represented by the formula (I-141-a) and 12.20 parts of acetonitrile were mixed and stirred at 23 ° C. for 30 minutes. To the obtained mixture, 1.98 parts of the compound represented by the formula (I-1-b) was added, and the mixture was further stirred at 50 ° C. for 2 hours. To the obtained reaction mixture, 3.42 parts of the compound represented by the formula (I-2-c) was added, and the mixture was further stirred at 50 ° C. for 4 hours, and then cooled to 23 ° C. To the obtained reaction mixture, 40 parts of chloroform and 10 parts of 5% oxalic acid aqueous solution were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out an organic layer. To the obtained organic layer, 20 parts of ion-exchanged water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out the organic layer. This washing operation was repeated 5 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 the supernatant was removed and concentrated to give a compound of formula (I-142 ) Was obtained.
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (−) Spectrum): M ^- 629.2

Example 5: Synthesis of salt represented by formula (I-17)
0.20 part of a compound represented by the formula (I-17-a) and 10 parts of acetonitrile were mixed and stirred at 23 ° C. for 30 minutes. To the obtained mixture, 0.16 part of the compound represented by the formula (I-1-b) was added, and the mixture was further stirred at 50 ° C. for 2 hours. To the obtained reaction mixture, 0.68 part of the salt represented by the formula (I-1) was added, and the mixture was further stirred at 50 ° C. for 4 hours, and then cooled to 23 ° C. To the obtained reaction mixture, 20 parts of chloroform and 10 parts of 5% oxalic acid aqueous solution were added and stirred at 23 ° C. for 30 minutes, followed by liquid separation to take out an organic layer. After adding 10 parts of ion-exchanged water to the obtained organic layer and stirring for 30 minutes at 23 ° C., the solution was separated to take out the organic layer. This washing operation was repeated 5 times. After concentrating the obtained organic layer, 10 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 the supernatant was removed and concentrated to give the formula (I-17). ) Was obtained.
MASS (ESI (+) Spectrum): M ⁺ 263.1
MASS (ESI (−) Spectrum): M ^- 597.2

Synthesis of Resin The compound (monomer) used for the synthesis of the resin (A) is shown below. Hereinafter, these compounds are referred to as “monomer (a1-1-3)” or the like according to the formula number.

Synthesis Example 1: Synthesis of Resin A1 As the monomer, monomer (a1-1-3), monomer (a1-2-5), monomer (a2-1-3) and monomer (a3-4-2) were used. The molar ratio [monomer (a1-1-3): monomer (a1-2-9): monomer (a2-1-3): monomer (a3-4-2)] is 45: 14: 2.5: 38. The resulting mixture was mixed with propylene glycol monomethyl ether acetate having a mass ratio of 1.5 times the total monomer amount to obtain a solution. To this solution, 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and these were heated at 73 ° C. for about 5 hours. did. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate the resin, and this resin was filtered. The obtained resin was again dissolved in propylene glycol monomethyl ether acetate, and the resulting solution was poured into a methanol / water mixed solvent to precipitate the resin, followed by reprecipitation operation of filtering the resin twice. Resin A1 having a molecular weight of 7.6 × 10 ³ was obtained in a yield of 68%. This resin A1 has the following structural units.

Synthesis Example 2: Synthesis of Resin X1 Monomer (a5-1-1) and monomer (a4-0-12) were used as monomers, and the molar ratio [monomer (a5-1-1): monomer (a4-0-) 12)] was 50:50, and methyl isobutyl ketone 1.2 mass times the total monomer amount was added to obtain a solution. To this solution, 3 mol% of azobis (2,4-dimethylvaleronitrile) as an initiator was added based on the total amount of monomers, and heated at 70 ° C. for about 5 hours. The obtained reaction mixture was poured into a large amount of methanol / water mixed solvent to precipitate a resin, and this resin was filtered to obtain a resin X1 having a weight average molecular weight of 1.0 × 10 ^{4 in} a yield of 91%. This resin X1 has the following structural units.

<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.

<Resin>
A1, X1: Resin A1, Resin X1
<Salt (I)>
I-1: Salt represented by formula (I-1) I-2: Salt represented by formula (I-2) I-17: Salt represented by formula (I-17) I-141: Formula Salt represented by (I-141) I-142: Salt represented by formula (I-142) <Acid generator>
B1-21: a salt represented by the formula (B1-21) (synthesized according to Examples in JP 2012-224611 A)
B1-22: a salt represented by the formula (B1-22) (synthesized according to Examples in JP 2012-224611 A)
IX-1: a salt represented by the formula (IX-1) (synthesized according to Examples in Japanese Patent Application Laid-Open No. 2014-040405)
<Quencher (C)>
D1: (Tokyo Chemical Industry Co., Ltd.)
<Solvent>
Propylene glycol monomethyl ether acetate 265 parts Propylene glycol monomethyl ether 20 parts 2-heptanone 20 parts γ-butyrolactone 3.5 parts

<Manufacture of resist pattern and its evaluation>
An organic antireflective coating composition (ARC-29; manufactured by Nissan Chemical Co., Ltd.) is applied to a silicon wafer and baked at 205 ° C. for 60 seconds to form an organic reflective film having a thickness of 78 nm on the wafer. A prevention film was formed. Next, on the organic antireflection film, the above resist composition was applied (spin coated) so that the film thickness after drying was 85 nm. After coating, the silicon wafer was pre-baked on a direct hot plate at the temperature described in the “PB” column of Table 2 for 60 seconds to form a composition layer. ArF excimer stepper for immersion exposure (XT: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light) on a silicon wafer on which the composition layer is formed, and a contact hole pattern (hole pitch 90 nm) Using a mask for forming a hole diameter of 55 nm), the exposure amount was changed stepwise. Note that ultrapure water was used as the immersion medium.
After the exposure, post-exposure baking was performed for 60 seconds on the hot plate at the temperature described in the “PEB” column of Table 2. Next, the composition layer on the silicon wafer is developed by using a butyl acetate (manufactured by Tokyo Chemical Industry Co., Ltd.) as a developing solution by a dynamic dispensing method at 23 ° C. for 20 seconds, thereby forming a negative resist pattern. Manufactured.

  In the resist pattern obtained after development, the exposure amount at which the hole diameter formed using the mask was 45 nm was defined as the effective sensitivity.

<Evaluation of mask error factor (MEF)>
In terms of effective sensitivity, a resist pattern was formed using masks having mask hole diameters (hole diameters of light transmitting portions of the mask) of 57 nm, 56 nm, 55 nm, 54 nm, and 53 nm (all hole pitches were 90 nm). The slope of the regression line when the mask hole diameter was plotted on the horizontal axis and the hole diameter of the resist pattern formed (transferred) on the substrate by exposure was plotted on the vertical axis was calculated as the MEF value.
The results are shown in Table 3. Numerical values in parentheses indicate MEF values.

  Since the resist composition containing the salt of the present invention can produce a resist pattern with a good mask error factor (MEF), it is suitable for fine processing of semiconductors.

Claims (7)

A salt represented by the formula (I).
[In the formula (I),
Q ¹ and Q ² each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
R ¹ and R ² each independently represents a hydrogen atom, a fluorine atom, or a C 1-6 perfluoroalkyl group.
z represents an integer of 0 to 6, and when z is 2 or more, the plurality of R ¹ and R ² may be the same as or different from each other.
X ¹ represents * —CO—O—, * —O—CO—, * —O—CO—O— or * —O—, and * represents C (R ¹ ) (R ² ) or C (Q ¹ ) Represents the binding site with (Q ² ).
L ¹ represents a divalent hydrocarbon group having 1 to 36 carbon atoms which may have a single bond or a substituent, and —CH ₂ — contained in the hydrocarbon group is —O— or —S. -, - CO- or -SO ₂ - may be replaced to.
R ³ and R ⁴ represent a group represented by the formula (1a) or a group represented by the formula (2a).
[In Formula (1a), R ^aa1 , R ^aa2 and R ^aa3 each independently represent an alkyl group having 1 to 8 carbon atoms, or R ^aa1 and R ^aa2 are bonded to each other together with the carbon atom to which they are bonded. A non-aromatic hydrocarbon ring having 3 to 20 carbon atoms is formed.
* Represents a binding site. ]
[In Formula (2a), R ^{aa1 ′} and R ^{aa2 ′} each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, R ^{aa3 ′} represents an alkyl group having 1 to 8 carbon atoms, —CH ₂ — contained in the alkyl group may be replaced by —O— or —S—.
^Xc represents an oxygen atom or a sulfur atom.
* Represents a binding site. ]
R ⁵ represents a hydrogen atom or an optionally substituted hydrocarbon group having 1 to 36 carbon atoms, and —CH ₂ — contained in the hydrocarbon group is —O—, —S—, — CO— or —SO ₂ — may be substituted.
Z ⁺ represents an organic cation. ] L ¹ is a single bond, a divalent alicyclic hydrocarbon group or an alkanediyl group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms (the alkanediyl group and the alicyclic hydrocarbon). The salt according to claim 1, wherein —CH ₂ — contained in the group is a group in combination with —O—, —S—, —CO— or —SO ₂ —. R ⁵ is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a group formed by combining an alkanediyl group having 1 to 6 carbon atoms and an alicyclic hydrocarbon group having 3 to 18 carbon atoms (the alkyl group, alkanediyl group). The —CH ₂ — contained in the group and the alicyclic hydrocarbon group may be replaced by —O—, —S—, —CO— or —SO ₂ —). .   The acid generator containing the salt in any one of Claims 1-3.   A resist composition comprising the acid generator according to claim 4 and a resin having an acid labile group.   6. The resist composition according to claim 5, further comprising a salt that generates an acid having a lower acidity than an acid generated from the acid generator. (1) The process of apply | coating the resist composition of Claim 5 or 6 on a board | substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer;
(4) A method for producing a resist pattern, comprising: a step of heating the composition layer after exposure; and (5) a step of developing the composition layer after heating.