JP2012031145A - Salt, acid generator, resist composition, and production method of resist pattern - Google Patents

Abstract

［式中、Ｒ^１は、置換基を有していてもよい飽和炭化水素基又は芳香族炭化水素基；Ｒ^２〜Ｒ^９は、それぞれ独立に、水素原子、ハロゲン原子、ヒドロキシ基、アルキル基又はアルコキシ基；Ｒ¹⁰及びＲ¹¹は、それぞれ独立に、フッ素原子又はペルフルオロアルキル基；Ｌ^１は、単結合又は２価の飽和炭化水素基；Ｙは、置換基を有していてもよい脂肪族炭化水素基又は置換基を有していてもよい飽和環状炭化水素基を表す。］
【選択図】なしAn object of the present invention is to provide a salt excellent in exposure margin (EL) and mask error factor (MEF) at the time of forming a resist pattern, an acid generator containing the salt, and a resist composition containing the acid generator.
A salt represented by formula (I), an acid generator containing the salt, and a resist composition containing the acid generator.

[Wherein, R ¹ represents a saturated hydrocarbon group or aromatic hydrocarbon group which may have a substituent; R ^{2 to} R ⁹ each independently represents a hydrogen atom, a halogen atom, a hydroxy group, or an alkyl group; Or an alkoxy group; R ¹⁰ and R ¹¹ are each independently a fluorine atom or a perfluoroalkyl group; L ¹ is a single bond or a divalent saturated hydrocarbon group; Y is an optionally substituted aliphatic group; Represents a saturated cyclic hydrocarbon group which may have an aromatic hydrocarbon group or a substituent. ]
[Selection figure] 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 salt represented by the formula (X1) and a resist composition containing this salt as an acid generator.

JP 2003-149800 A

  Conventional resist compositions containing a salt as an acid generator may not always satisfy the exposure margin (EL) and mask error factor (MEF) when forming a resist pattern.

［式（Ｉ）中、Ｒ^１は、炭素数１〜１２の飽和炭化水素基又は炭素数６〜１４の芳香族炭化水素基を表し、該飽和炭化水素基及び該芳香族炭化水素基に含まれる水素原子は、ヒドロキシ基、ハロゲン原子又は炭素数１〜６のアルキル基で置換されていてもよい。
Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５、Ｒ^６、Ｒ^７、Ｒ^８及びＲ^９は、それぞれ独立に、水素原子、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基又は炭素数１〜６のアルコキシ基を表す。
Ｒ¹⁰及びＲ¹¹は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^１は、単結合又は２価の炭素数１〜１７の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子はフッ素原子で置換されていてもよく、該２価の飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
Ｙは、置換基を有していてもよい炭素数１〜１８の脂肪族炭化水素基又は置換基を有していてもよい炭素数３〜１８の飽和環状炭化水素基を表し、該脂肪族炭化水素基及び該飽和環状炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−で置き換わっていてもよい。］ The present invention includes the following inventions.
[1] A salt represented by the formula (I).

[In Formula (I), R ¹ represents a saturated hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 14 carbon atoms, and is included in the saturated hydrocarbon group and the aromatic hydrocarbon group. The hydrogen atom to be substituted may be substituted with a hydroxy group, a halogen atom or an alkyl group having 1 to 6 carbon atoms.
R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ are each independently a hydrogen atom, a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms or a carbon number of 1 Represents an alkoxy group of -6.
R ¹⁰ and R ¹¹ each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ¹ represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, and the divalent —CH ₂ — contained in the saturated hydrocarbon group may be replaced by —O— or —CO—.
Y represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent or a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the aliphatic group —CH ₂ — contained in the hydrocarbon group and the saturated cyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—. ]

[2] L ¹ is * —CO—O— (CH ₂ ) _n — (* represents a bond with —C (R ¹⁰ ) (R ¹¹ ) —, and n represents 0 or 1). A salt of [1].
[3] An acid generator containing the salt of [1] or [2].
[4] The acid generator according to [3] and a resin, wherein the resin has an acid labile group and is insoluble or hardly soluble in an alkaline aqueous solution. A resist composition, which is a resin that can be dissolved in
[5] The resist composition according to [4], further including a basic compound.
[6] The resist composition according to [4] or [5], further including a solvent.

[7] (1) A step of applying the resist composition of [6] on a substrate,
(2) a step of removing the solvent from the composition after coating to form a composition layer;
(3) a step of exposing the composition layer using an exposure machine;
(4) A step of heating the composition layer after exposure,
(5) A method for producing a resist pattern, comprising a step of developing the heated composition layer using a developing device.

  According to the salt of the present invention, a resist composition containing the salt is excellent in exposure margin (EL) and mask error factor (MEF) when forming a resist pattern.

In this specification, unless otherwise specified, specific chemical substituents described later can be applied to any chemical structural formula having the same substituents while appropriately selecting the number of carbon atoms. Those which can take any of linear, branched or cyclic are included unless otherwise specified, and in the same group, linear, branched and / or cyclic partial structures are mixed. It may be. When stereoisomers exist, all of those stereoisomers are included.
Further, "(meth) acrylic monomer" means at least one monomer having a structure of "CH ₂ = CH-CO-" or _{"CH 2 = C (CH 3)} -CO- ". Similarly, “(meth) acrylate” and “(meth) acrylic acid” mean “at least one of acrylate and methacrylate” and “at least one of acrylic acid and methacrylic acid”, respectively.

［式（Ｉ）中、Ｒ^１は、炭素数１〜１２の飽和炭化水素基又は炭素数６〜１４の芳香族炭化水素基を表し、該飽和炭化水素基及び該芳香族炭化水素基に含まれる水素原子は、ヒドロキシ基、ハロゲン原子又は炭素数１〜６のアルキル基で置換されていてもよい。
Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５、Ｒ^６、Ｒ^７、Ｒ^８及びＲ^９は、それぞれ独立に、水素原子、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基又は炭素数１〜６のアルコキシ基を表す。
Ｒ¹⁰及びＲ¹¹は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^１は、単結合又は炭素数１〜１７の２価の飽和炭化水素基を表し、該２価の飽和炭化水素基に含まれる水素原子はフッ素原子で置換されていてもよく、該２価の飽和炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
Ｙは、置換基を有していてもよい炭素数１〜１８の脂肪族炭化水素基又は置換基を有していてもよい炭素数３〜１８の飽和環状炭化水素基を表し、該脂肪族炭化水素基及び該飽和環状炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−で置き換わっていてもよい。］ <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 Formula (I), R ¹ represents a saturated hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 14 carbon atoms, and is included in the saturated hydrocarbon group and the aromatic hydrocarbon group. The hydrogen atom to be substituted may be substituted with a hydroxy group, a halogen atom or an alkyl group having 1 to 6 carbon atoms.
R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ are each independently a hydrogen atom, a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms or a carbon number of 1 Represents an alkoxy group of -6.
R ¹⁰ and R ¹¹ each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ¹ represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, and the divalent —CH ₂ — contained in the saturated hydrocarbon group may be replaced by —O— or —CO—.
Y represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent or a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the aliphatic group —CH ₂ — contained in the hydrocarbon group and the saturated cyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—. ]

Examples of the saturated hydrocarbon group for R ¹ include an aliphatic hydrocarbon group and a saturated cyclic hydrocarbon group.
Examples of the aliphatic hydrocarbon group include methyl group, ethyl group, n-propyl group, 1-methylethyl group (isopropyl group), n-butyl group, 1,1-dimethylethyl group (tert-butyl group), 2, 2-dimethylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1,2-dimethylpropyl group, 2,2-dimethylpropyl group, 1-ethylpropyl group, n-pentyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, n-hexyl group, 1-propylbutyl group, pentyl group, 1-methylpentyl group, 1,4-dimethylhexyl group, heptyl group, 1-methylheptyl group, octyl group, etc. Of the alkyl group.
The saturated cyclic hydrocarbon group may be monocyclic or polycyclic. Examples thereof include monocyclic saturated cyclic hydrocarbon groups such as a cycloalkyl group (for example, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, and a cyclooctyl group). Polycyclic saturation such as groups obtained by hydrogenating condensed aromatic hydrocarbon groups (for example, hydronaphthyl group) and bridged cyclic hydrocarbon groups (for example, adamantyl group, norbornyl group, methylnorbornyl group) A cyclic hydrocarbon group is mentioned. Further, a group in which a bridging ring (for example, norbornane ring) and a single ring (for example, cycloheptane ring, cyclohexane ring) or polycyclic (for example, decahydronaphthalene ring) or a bridging ring are condensed as described below. Groups; groups in which these are combined (methylcyclohexyl group, dimethylcyclohexyl group, methylnorbornyl group) and the like.

Examples of the aromatic hydrocarbon group for R ¹ include a phenyl group, a naphthyl group, a p-methylphenyl group, a p-ethylphenyl group, a p-tert-butylphenyl group, a p-cyclohexylphenyl group, and a p-methoxyphenyl group. P-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl group, anthryl group, phenanthryl group, 2,6-diethylphenyl group, aryl group such as 2-methyl-6-ethylphenyl, etc. Can be mentioned.
Examples of halogen atoms such as R ¹ include fluorine, chlorine, bromine and iodine atoms.
Examples of the alkoxy group such as R ² include methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, n-pentoxy group, and n-hexoxy group. Etc.

Examples of the perfluoroalkyl group represented by R ¹⁰ and R ¹¹ include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, and a perfluoropentyl group. And perfluorohexyl group.
In the salt represented by the formula (I), the perfluoroalkyl groups of R ¹⁰ and R ¹¹ are each independently preferably a trifluoromethyl group or a fluorine atom, more preferably a fluorine atom.

Examples of the divalent saturated hydrocarbon group for L ¹ include a linear alkanediyl group, a branched alkanediyl group, a monocyclic or polycyclic saturated cyclic hydrocarbon group, and two of these groups. A combination of the above may also be used.
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 , Dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1, Linear alkanediyl groups such as 17-diyl group, ethane-1,1-diyl group, propane-1,1-diyl group, propane-2,2-diyl group;
An alkyl group (particularly an alkyl group having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group); For example, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl A branched alkanediyl group such as a 2-methylbutane-1,4-diyl group;
Cyclobutane-1,3-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,2-diyl group, 1-methylcyclohexane-1,2-diyl group, cyclohexane-1,4-diyl group, cyclo A monocyclic saturated cyclic hydrocarbon group which is a cycloalkanediyl group such as an octane-1,2-diyl group or a cyclooctane-1,5-diyl group;
A polycyclic group such as norbornane-2,3-diyl group, norbornane-1,4-diyl group, norbornane-2,5-diyl group, adamantane-1,5-diyl group, adamantane-2,6-diyl group, etc. Saturated cyclic hydrocarbon group etc. are mentioned.
In addition, the divalent saturated hydrocarbon group may be a bond obtained by removing any one hydrogen atom from the above-described monovalent saturated cyclic hydrocarbon group.

Examples of the group in which —CH ₂ — in the divalent saturated hydrocarbon group of L ¹ is replaced by —O— or —CO— include groups represented by formula (L1-1) to formula (L1-6), for example. Is mentioned. L ¹ is preferably a group represented by formula (L1-1) to formula (L1-4) or formula (L1-6), more preferably formula (L1-1), formula (L1-2) or formula. A group represented by (L1-6), more preferably a group represented by formula (L1-1) or formula (L1-6). Incidentally, the formula (L1-1) ~ formula (L1-6) has its left and right are described in conjunction in formula (I), and the left ^{C (R 10) (R 11} ) - bound to, the right side Combine with Y. The same applies to specific examples of the following formulas (L1-1) to (L1-6).

式（Ｌ１−１）〜式（Ｌ１−６）中、
Ｌ^b2は、単結合又は炭素数１〜１５の２価の飽和炭化水素基を表す。
Ｌ^b3は、単結合又は炭素数１〜１２の２価の飽和炭化水素基を表す。
Ｌ^b4は、炭素数１〜１３の２価の飽和炭化水素基を表す。
Ｌ^b5は、炭素数１〜１５の２価の飽和炭化水素基を表す。
Ｌ^b6及びＬ^b7は、それぞれ独立に、炭素数１〜１５の２価の飽和炭化水素基を表す。
Ｌ^b8は、炭素数１〜１４の２価の飽和炭化水素基を表す。
Ｌ^b9及びＬ^b1１は、それぞれ独立に、単結合又は炭素数１〜１１の２価の飽和炭化水素基を表す。
Ｌ^b1０は、炭素数１〜１１の２価の飽和炭化水素基を表す。
中でも、式（Ｌ１−１）で表される２価の基、式（Ｌ１−２）で表される２価の基及び式（Ｌ１−６）で表される２価の基が好ましい。
Ｌ^b2は、単結合又は−ＣＨ_２−であることが好ましい。
Ｌ^b３は、単結合又は−ＣＨ_２−であることが好ましい。
Ｌ^b４は、炭素数１〜６のアルカンジイル基、炭素数６〜１１の２価の飽和環状炭化水素基又は飽和環状炭化水素基とアルカンジイル基とを組み合わせた炭素数７〜１１の２価の基であることが好ましく、−ＣＨ_２−又はアダマンタンジイル基であることがより好ましい。
Ｌ^b9は、単結合又は炭素数１〜６の２価の飽和炭化水素基であることが好ましく、単結合又は−ＣＨ_２−であることがより好ましい。
Ｌ^b１０は、炭素数６〜１１の２価の飽和環状炭化水素基又は飽和環状炭化水素基とアルカンジイル基とを組み合わせた炭素数７〜１１の２価の基であることが好ましく、

であることがより好ましい。
Ｌ^b１１は、単結合又は−ＣＨ_２−であることが好ましい。

In formula (L1-1) to formula (L1-6),
L ^b2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b4 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms.
L ^b5 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b6 and L ^b7 each independently represent a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b8 represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms.
L ^b9 and L ^b11 each independently represent a single bond or a divalent saturated hydrocarbon group having 1 to 11 carbon atoms.
L ^b10 represents a divalent saturated hydrocarbon group having 1 to 11 carbon atoms.
Among these, a divalent group represented by the formula (L1-1), a divalent group represented by the formula (L1-2), and a divalent group represented by the formula (L1-6) are preferable.
L ^b2 is preferably a single bond or —CH ₂ —.
L ^b3 is preferably a single bond or —CH ₂ —.
L ^b4 is an alkanediyl group having 1 to 6 carbon atoms, a divalent saturated cyclic hydrocarbon group having 6 to 11 carbon atoms, or a divalent group having 7 to 11 carbon atoms in which a saturated cyclic hydrocarbon group and an alkanediyl group are combined. And is more preferably —CH ₂ — or an adamantanediyl group.
L ^b9 is preferably a single bond or a divalent saturated hydrocarbon group having 1 to 6 carbon atoms, and more preferably a single bond or —CH ₂ —.
L ^b10 is preferably a divalent saturated cyclic hydrocarbon group having 6 to 11 carbon atoms or a divalent group having 7 to 11 carbon atoms in which a saturated cyclic hydrocarbon group and an alkanediyl group are combined,

It is more preferable that
L ^b11 is preferably a single bond or —CH ₂ —.

Examples of the divalent group represented by the formula (L1-1) include the following.

Examples of the divalent group represented by the formula (L1-2) include the following.

Examples of the divalent group represented by the formula (L1-3) include the following.

Examples of the divalent group represented by the formula (L1-4) include the following.

Examples of the divalent group represented by the formula (L1-5) include the following.

Examples of the divalent group represented by the formula (L1-6) include the following.

Examples of the substituent for the aliphatic hydrocarbon group and saturated cyclic hydrocarbon group in Y include, for example, a halogen atom (excluding a fluorine atom), a hydroxy group, an oxo group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, hydroxy Group-containing C1-C12 aliphatic hydrocarbon group, C3-C16 saturated cyclic hydrocarbon group, C1-C12 alkoxy group, C6-C18 aromatic hydrocarbon group, C7 aralkyl group to 21, an acyl group having 2 to 4 carbon atoms, glycidyloxy group or a _{- (CH 2) j2 -O-} CO-R b1 group (wherein, R ^b1 is an aliphatic C1-16 hydrocarbon Represents a hydrogen group, a saturated cyclic hydrocarbon group having 3 to 16 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, j2 represents an integer of 0 to 4). These substituents such as an aliphatic hydrocarbon group, a saturated cyclic hydrocarbon group, an aromatic hydrocarbon group, and an aralkyl group may further have a substituent. Examples of the substituent include an alkyl group, a halogen atom, a hydroxy group, and an oxo group.
Examples of the hydroxy group-containing aliphatic hydrocarbon group include a hydroxymethyl group and a 2-hydroxyethyl group.
Examples of the aralkyl group include benzyl group, phenethyl group, phenylpropyl group, trityl group, naphthylmethyl group, naphthylethyl group and the like.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.

Examples of the group in which —CH ₂ — in the aliphatic hydrocarbon group and saturated cyclic hydrocarbon group of Y is replaced by —O—, —SO ₂ — or —CO— include, for example,
An ether bond or a cyclic ether group (a group in which —CH ₂ — is replaced by —O—),
A saturated cyclic hydrocarbon group having an oxo group (a group in which —CH ₂ — is replaced by —CO—),
Sultone ring groups (groups in which two adjacent —CH ₂ — are replaced by —O— and —SO ₂ —, respectively) and lactone ring groups (two adjacent —CH ₂ — are each in —O— and —CO, respectively). A group replaced with-) and the like.
Specific examples include groups represented by the following formula (Y12) to formula (Y26).

As the aliphatic hydrocarbon group for Y, an alkyl group having 1 to 6 carbon atoms is preferable.
Examples of the saturated cyclic hydrocarbon group for Y include groups represented by formulas (Y1) to (Y11).

  Especially, it is preferably a group represented by any one of formulas (Y1) to (Y19), more preferably represented by formula (Y11), formula (Y14), formula (Y15) or formula (Y19). And more preferably a group represented by formula (Y11) or formula (Y14).

Examples of Y, which is a saturated cyclic hydrocarbon group substituted with an aliphatic hydrocarbon group, include the following.

  Examples of Y that is a saturated cyclic hydrocarbon group substituted with a hydroxy group or a hydroxy group-containing aliphatic hydrocarbon group include the following.

  Examples of Y, which is a saturated cyclic hydrocarbon group substituted with an aromatic hydrocarbon group, include the following.

Examples of Y that is a saturated cyclic hydrocarbon group substituted by — (CH ₂ ) _j2 —O—CO—R ^b1 group include the following.

  Among them, Y is preferably a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent (for example, a hydroxy group, an oxo group, etc.), and more preferably has a substituent. A cyclohexyl group which may be substituted or an adamantyl group which may have a substituent, and more preferably a cyclohexyl group, an adamantyl group, a hydroxyadamantyl group or an oxoadamantyl group.

Sulphonate anion containing Y which is an aliphatic hydrocarbon group or an unsubstituted saturated cyclic hydrocarbon group and a divalent group represented by the formula (L1-1), and saturated saturated aliphatic hydrocarbon group Examples of the sulfonate anion containing Y which is a cyclic hydrocarbon group and the divalent group represented by the formula (L1-1) include the following.

As the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with — (CH ₂ ) _j2 —O—CO—R ^b1 group and a divalent group represented by the formula (L1-1), For example, the following are mentioned.

Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with a hydroxy group or a hydroxy group-containing aliphatic hydrocarbon group and a divalent group represented by the formula (L1-1) include the following: Things.

  Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with an aromatic hydrocarbon group or an aralkyl group and a divalent group represented by the formula (L1-1) include the following. It is done.

Examples of the sulfonate anion containing Y which is a cyclic ether and the divalent group represented by the formula (L1-1) include the following.

Examples of the sulfonate anion containing Y which is a lactone ring and the divalent group represented by the formula (L1-1) include the following.

  Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon having an oxo group and a divalent group represented by the formula (L1-1) include the following.

Examples of the sulfonate anion containing Y which is a sultone ring and the divalent group represented by the formula (L1-1) include the following.

Saturated cyclic substituted with a sulfonate anion or an aliphatic hydrocarbon group containing Y which is an aliphatic hydrocarbon group or an unsubstituted saturated cyclic hydrocarbon group and a divalent group represented by the formula (L1-2) Examples of the sulfonate anion containing Y which is a hydrocarbon group and the divalent group represented by the formula (L1-2) include the following.

As the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with — (CH ₂ ) _j2 —O—CO—R ^b1 group and a divalent group represented by the formula (L1-2), For example, the following are mentioned.

Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with a hydroxy group or a hydroxy group-containing aliphatic hydrocarbon group and a divalent group represented by the formula (L1-2) include the following: Things.

Examples of the sulfonate anion containing Y, which is a saturated cyclic hydrocarbon group substituted with an aromatic hydrocarbon group, and a divalent group represented by the formula (L1-2) include the following.

Examples of the sulfonate anion containing Y which is a cyclic ether and the divalent group represented by the formula (L1-2) include the following.

Examples of the sulfonate anion containing Y which is a lactone ring and the divalent group represented by the formula (L1-2) include the following.

Examples of the sulfonate anion containing Y having an oxo group and the divalent group represented by the formula (L1-2) include the following.

Examples of the sulfonate anion containing Y which is a sultone ring and a divalent group represented by the formula (L1-2) include the following.

Y which is an aliphatic hydrocarbon group or a saturated cyclic hydrocarbon group substituted with a sulfonate anion or an aliphatic hydrocarbon group containing an unsubstituted Y and a divalent group represented by the formula (L1-3) Examples of the sulfonate anion containing the divalent group represented by the formula (L1-3) include the following.

Examples of the sulfonate anion containing Y, which is a saturated cyclic hydrocarbon group substituted with an alkoxy group, and a divalent group represented by the formula (L1-3) include the following.

Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with a hydroxy group or a hydroxy group-containing aliphatic hydrocarbon group and a divalent group represented by the formula (L1-3) include the following: Things.

Examples of the sulfonate anion containing Y having an oxo group and the divalent group represented by the formula (L1-3) include the following.

Examples of the sulfonate anion containing Y, which is a saturated cyclic hydrocarbon group substituted with an aliphatic hydrocarbon group, and a divalent group represented by the formula (L1-4) include the following.

Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with an alkoxy group and a divalent group represented by the formula (L1-4) include the following.

Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group substituted with a hydroxy group or a hydroxy group-containing aliphatic hydrocarbon group and a divalent group represented by the formula (L1-4) include the following: Things.

Examples of the sulfonate anion containing Y which is a saturated cyclic hydrocarbon group having an oxo group and a divalent group represented by the formula (L1-4) include the following.

Examples of the sulfonate anion containing Y, which is a saturated cyclic hydrocarbon group substituted with a hydroxy group, and a divalent group represented by the formula (b1-5) include the following.

Examples of the sulfonate anion containing Y, which is a saturated cyclic hydrocarbon group substituted with a hydroxy group, and a divalent group represented by the formula (b1-6) include the following.

Examples of the sulfonate anion in the salt represented by the formula (I) include the following formulas (L1-1-1) to (L1-1-9) in which L ¹ is the formula (L1-1). An anion represented by formula (L1-6-1) or formula (L1-6-2), wherein L ¹ is formula (L1-6), is preferred. In the following formulae, the substituents R ^b2 and R ^b3 each independently represent an aliphatic hydrocarbon group having 1 to 4 carbon atoms (preferably a methyl group). R ¹⁰ , R ¹¹ and L ^b2 represent the same meaning as described above.

Specifically, the following sulfonate anions having a divalent group represented by the formula (L1-1) or a divalent group represented by the formula (L1-6) are more preferable.

Examples of the salt represented by the formula (I) include the following salts.

溶剤としては、クロロホルム等が挙げられる。
式（Ｉ−ｂ）で表される塩としては、特開第２００８−２０９９１７号公報に記載された方法によって製造することができる。 The salt (I) can be produced by a method known in the art.
For example, the salt represented by the formula (I) can be obtained by reacting the compound represented by the formula (Ia) and the salt represented by the formula (Ib) in a solvent.

Examples of the solvent include chloroform.
The salt represented by the formula (Ib) can be produced by the method described in JP 2008-209917 A.

溶剤としては、アセトニトリル等が挙げられる。
式（Ｉ−ｃ）で表される化合物としては、フェノチアジン等が挙げられる。
式（Ｉ−ｄ）で表される化合物としては、ヨウ化メチル等が挙げられる。 The salt represented by the formula (Ia) is obtained by combining a compound represented by the formula (Ic) and a compound represented by the formula (Id) in a solvent in the presence of silver oxide and methanesulfonic acid. It can obtain by making it react.

Examples of the solvent include acetonitrile.
Examples of the compound represented by the formula (Ic) include phenothiazine.
Examples of the compound represented by the formula (Id) include methyl iodide.

<Acid generator>
The acid generator of the present invention contains a salt (I). When using salt (I) as an acid generator, you may use it individually or in combination of 2 or more types. The acid generator of the present invention further comprises a known salt other than the salt (I), a salt comprising a cation and a known anion contained in the salt (I), and an anion and a known cation contained in the salt (I). The salt which consists of, etc. may be included.

<Resist composition>
The resist composition of the present invention includes the acid generator and a resin described above. The resist composition preferably further contains a basic compound. Further, this resist composition preferably further contains a solvent.
<Resin (hereinafter sometimes referred to as “resin (A)”)>
The resin (A) is a resin having an acid labile group and insoluble or hardly soluble in an alkaline aqueous solution, and can be dissolved in an alkaline aqueous solution by the action of an acid. “Can be dissolved in an alkaline aqueous solution by the action of an acid” means “insoluble or hardly soluble in an alkaline aqueous solution before contact with an acid but becomes soluble in an alkaline aqueous solution after contact with an acid”. To do.
A resin that can be dissolved in an alkaline aqueous solution by the action of an acid is produced by polymerizing a monomer having an acid-labile group (hereinafter sometimes referred to as “monomer having an acid-labile group (a1)”). be able to. The monomer (a1) having an acid labile group may be used alone or in combination of two or more.

<Monomer (a1) having an acid labile group>
The “acid-labile group” means a group that cleaves a leaving group to form a hydrophilic group (for example, a carboxy group or a hydroxy group) upon contact with an acid. Examples of the acid labile group include an alkoxycarbonyl group represented by the formula (1) in which —O— is bonded to a tertiary carbon atom. In addition, the acid-labile group in the case where the hydrophilic group is a hydroxy group is represented by the formula (2) in which the hydrogen atom of the hydroxy group is replaced with an organic residue and becomes a group containing an acetal structure. Things. Hereinafter, the group represented by formula (1) or formula (2) may be referred to as “acid-labile group (1)”.

式（１）中、Ｒ^a1〜Ｒ^a3は、それぞれ独立に、炭素数１〜８の脂肪族炭化水素基又は炭素数３〜２０の飽和環状炭化水素基を表すか、或いはＲ^a1及びＲ^a2は互いに結合して炭素数３〜２０の環を形成する。＊は結合手を表す（以下同じ）。

In formula (1), R ^{a1 to} R ^a3 each independently represent an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 20 carbon atoms, or R ^a1 and R ^a2 Combine with each other to form a ring having 3 to 20 carbon atoms. * Represents a bond (same below).

式（１）では、Ｒ^a1及びＲ^a2は互いに結合して形成する環は、好ましくは炭素数３〜１２である。
また、飽和環状炭化水素基は、好ましくは炭素数３〜１６である。 When R ^a1 and R ^a2 are bonded to each other to form a ring, examples of the —C (R ^a1 ) (R ^a2 ) (R ^a3 ) group include the following groups.

In the formula (1), the ring formed by combining R ^a1 and R ^a2 with each other preferably has 3 to 12 carbon atoms.
The saturated cyclic hydrocarbon group preferably has 3 to 16 carbon atoms.

Examples of the group having a carboxylic acid ester include a group having a (meth) acrylic acid ester, a norbornene carboxylic acid ester, a tricyclodecene carboxylic acid ester, and a tetracyclodecene carboxylic acid ester.
Examples of the acid labile group (1) include:
1,1-dialkylalkoxycarbonyl group (in the formula (1), R ^{a1 to} R ^a3 are alkyl groups, preferably tert-butoxycarbonyl group),
2-alkyladamantan-2-yloxycarbonyl group (in the formula (1), R ^a1 , R ^a2 and a carbon atom form an adamantyl group and R ^a3 is an alkyl group) and 1- (adamantane-1- Yl) -1-alkylalkoxycarbonyl group (in the formula (1), R ^a1 and R ^a2 are alkyl groups, and R ^a3 is an adamantyl group).

式（２）中、Ｒ^b1及びＲ^b2は、それぞれ独立に、水素原子又は炭素数１〜１２の炭化水素基を表し、Ｒ^b3は、炭素数１〜２０の炭化水素基を表すか、あるいは、Ｒ^b2及びＲ^b3は互いに結合して、それらが各々結合する炭素原子及び酸素原子とともに炭素数３〜２０の環を形成する。Ｒ^b2及びＲ^b3は互いに結合して形成される環又は該炭化水素基が−ＣＨ_２−を有する場合、該−ＣＨ_２−は、−Ｏ−、−Ｓ−又は−ＣＯ−で置き換わっていてもよい。＊は結合手を表す。

In formula (2), R ^b1 and R ^b2 each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^b3 represents a hydrocarbon group having 1 to 20 carbon atoms, or , R ^b2 and R ^b3 are bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom and the oxygen atom to which they are bonded. When R ^b2 and R ^b3 are a ring formed by bonding to each other or the hydrocarbon group has —CH ₂ —, the —CH ₂ — is replaced by —O—, —S— or —CO—. Also good. * Represents a bond.

Examples of the hydrocarbon group of R ^{b1 to} R ^b3 include an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. Here, the alicyclic hydrocarbon group is the same as that described as the group of R ^{a1 to} R ^a3 .
^Examples of the ring formed by combining R ^b2 and R ^b3 with each other include the same ring formed by combining R ^a1 and R ^a2 with each other.
At least one of R ^{b1 to} R ^b2 is preferably a hydrogen atom.

Examples of the acid labile group (2) include the following groups.

  The monomer (a1) having an acid labile group is preferably a monomer having an acid labile group (1) and a carbon-carbon double bond, more preferably an acid labile group (1). (Meth) acrylic monomer having

  Among the (meth) acrylic monomers having the acid-labile group (1), those having a saturated cyclic hydrocarbon group having 5 to 20 carbon atoms are preferred. If a resin obtained by polymerizing the monomer (a1) having a bulky structure such as a saturated cyclic hydrocarbon group is used, the resolution of the resist can be improved.

  Among (meth) acrylic monomers having an acid labile group (1) and a saturated cyclic hydrocarbon group, a monomer represented by the formula (a1-1) or a monomer represented by the formula (a1-2) Is preferred. These may be used alone or in combination of two or more.

［式（ａ１−１）及び式（ａ１−２）中、
Ｌ^a1及びＬ^a2は、それぞれ独立に、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k1−ＣＯ−Ｏ−を表す。
ｋ１は１〜７の整数を表す。＊は−ＣＯ−との結合手を表す。
Ｒ^a4及びＲ^a5は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a6及びＲ^a7は、それぞれ独立に、炭素数１〜８の脂肪族炭化水素基又は炭素数３〜１０の飽和環状炭化水素基を表す。
ｍ１は０〜１４の整数を表す。
ｎ１は０〜１０の整数を表す。
ｎ２は０又は１の整数を表す。］

[In Formula (a1-1) and Formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or ^* —O— (CH ₂ ) _k1 —CO—O—.
k1 represents an integer of 1 to 7. * Represents a bond with -CO-.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 10 carbon atoms.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.
n2 represents an integer of 0 or 1. ]

L ^a1 and L ^a2 are preferably —O— or ^* —O— (CH ₂ ) _f1 —CO—O— (wherein f1 represents an integer of 1 to 4), more preferably —O—. It is. k1 is preferably an integer of 1 to 4, more preferably 1.
R ^a4 and R ^a5 are preferably methyl groups.
The aliphatic hydrocarbon group represented by R ^a6 and R ^a7 preferably has 6 or less carbon atoms. The saturated cyclic hydrocarbon group preferably has 8 or less carbon atoms, more preferably 6 or less.
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.

  Examples of the monomer represented by the formula (a1-1) include the following. Among them, 2-methyladamantan-2-yl (meth) acrylate, 2-ethyladamantan-2-yl (meth) acrylate and 2-isopropyl-adamantan-2-yl (meth) acrylate are preferable, and 2-methyladamantan-2 More preferred are -yl methacrylate, 2-ethyladamantan-2-yl methacrylate and 2-isopropyladamantan-2-yl methacrylate.

  Examples of the monomer represented by the formula (a1-2) include the following. Among these, 1-ethylcyclohexane-1-yl (meth) acrylate is preferable, and 1-ethylcyclohexane-1-yl methacrylate is more preferable.

  When the resin (A) includes a structural unit derived from the monomer represented by the formula (a1-1) and / or the monomer represented by the formula (a1-2), the total content thereof is the resin (A). It is 10-95 mol% normally with respect to all the structural units of, Preferably it is 15-90 mol%, More preferably, it is 20-85 mol%.

  Examples of the monomer having an acid labile group (1) and a carbon-carbon double bond include a monomer having a norbornene ring represented by the formula (a1-3). Since the resin having a structural unit derived from the monomer represented by the formula (a1-3) has a bulky structure, the resolution of the resist can be improved. Furthermore, the monomer represented by the formula (a1-3) can improve the dry etching resistance of the resist by introducing a rigid norbornane ring into the main chain of the resin.

［式（ａ１−３）中、
Ｒ^a9は、水素原子、ヒドロキシ基を有していてもよい炭素数１〜３の脂肪族炭化水素基、カルボキシ基、シアノ基又は−ＣＯＯＲ^a13を表す。
Ｒ^a13は、炭素数１〜８の脂肪族炭化水素基又は炭素数３〜２０の飽和環状炭化水素基を表し、該脂肪族炭化水素基及び該飽和環状炭化水素基に含まれる水素原子はヒドロキシ基で置換されていてもよく、該脂肪族炭化水素基及び該飽和環状炭化水素基に含まれる−ＣＨ_２−は−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
Ｒ^a10〜Ｒ^a12は、それぞれ独立に、炭素数１〜１２の脂肪族炭化水素基又は炭素数３〜２０の飽和環状炭化水素基を表すか、或いはＲ^a10及びＲ^a11は互いに結合して炭素数３〜２０の環を形成し、該脂肪族炭化水素基及び前記飽和環状炭化水素基に含まれる水素原子はヒドロキシ基等で置換されていてもよく、該脂肪族炭化水素基及び該飽和環状炭化水素基に含まれる−ＣＨ_２−は−Ｏ−又は−ＣＯ−で置き換わっていてもよい。］

[In the formula (a1-3),
R ^a9 represents a hydrogen atom, a C 1-3 aliphatic hydrocarbon group which may have a hydroxy group, a carboxy group, a cyano group or —COOR ^a13 .
R ^a13 represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 20 carbon atoms, and the hydrogen atom contained in the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group is hydroxy. It may be substituted with a group, and —CH ₂ — contained in the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group may be replaced with —O— or —CO—.
R ^{a10 to} R ^a12 each independently represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 20 carbon atoms, or R ^a10 and R ^a11 are bonded to each other to form carbon. A hydrogen atom contained in the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group may be substituted with a hydroxy group, the aliphatic hydrocarbon group and the saturated cyclic group; —CH ₂ — contained in the hydrocarbon group may be replaced by —O— or —CO—. ]

  Here, examples of the alkoxycarbonyl group include groups in which a carbonyl group is bonded to an alkoxy group such as a methoxycarbonyl group or an ethoxycarbonyl group.

Examples of the aliphatic hydrocarbon group which may have a hydroxy group of R ^a9 include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, and a 2-hydroxyethyl group.
^Examples of R ^a13 include a methyl group, an ethyl group, a propyl group, a 2-oxo-oxolan-3-yl group, and a 2-oxo-oxolan-4-yl group.
Examples of R ^{a10 to} R ^a12 include a methyl group, an ethyl group, a cyclohexyl group, a methylcyclohexyl group, a hydroxycyclohexyl group, an oxocyclohexyl group, and an adamantyl group.
Examples of the ring formed by R ^a10 , R ^a11 and the carbon to which they are bonded include saturated cyclic hydrocarbon groups, and specific examples include a cyclohexyl group and an adamantyl group.

  Examples of the monomer represented by the formula (a1-3) include tert-butyl 5-norbornene-2-carboxylate, 1-cyclohexyl-1-methylethyl 5-norbornene-2-carboxylate, and 5-norbornene-2. -Carboxylic acid 1-methylcyclohexyl, 5-norbornene-2-carboxylic acid 2-methyladamantan-2-yl, 5-norbornene-2-carboxylic acid 2-ethyladamantan-2-yl, 5-norbornene-2-carboxylic acid 1- (4-methylcyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1- (4-hydroxycyclohexyl) -1-methylethyl, 5-norbornene-2-carboxylic acid 1-methyl-1- (4-Oxocyclohexyl) ethyl, 5-norbornene-2-carboxylic acid 1- (adamantane) 1-yl) -1-methylethyl and the like.

  When the resin (A) includes a structural unit derived from the monomer represented by the formula (a1-3), the content thereof is usually 10 to 95 mol% with respect to all the structural units of the resin (A). , Preferably it is 15-90 mol%, More preferably, it is 20-85 mol%.

［式（ａ１−４）中、
Ｒ¹⁰は、水素原子、ハロゲン原子又はハロゲン原子を有してもよい炭素数１〜６のアルキル基を表す。
Ｒ¹¹は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、炭素数２〜４のアシルオキシ基、アクリロイル基又はメタクリロイル基を表す。
ｌａは０〜４の整数を表す。ｌａが２以上の整数である場合、複数のＲ¹¹は同一であっても異なってもよい。
Ｒ¹²及びＲ¹³はそれぞれ独立に、水素原子又は炭素数１〜１２の炭化水素基を表す。
Ｘ^ａ２は、単結合又は２価の炭素数１〜１７の飽和炭化水素基を表し、前記飽和炭化水素基に含まれるに含まれる水素原子はハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基又は炭素数２〜４のアシルオキシ基で置換されていてもよく、前記飽和炭化水素基に含まれる−ＣＨ_２−は−ＣＯ−、−Ｏ−、−Ｓ−、−ＳＯ_２−又は−Ｎ（Ｒ^ｃ）−で置き換わっていてもよい。Ｒ^ｃは、水素原子又は炭素数１〜６のアルキル基を表す。
Ｙ^ａ３は、炭素数１〜１２の脂肪族炭化水素基、炭素数３〜１８の飽和環状炭化水素基又は炭素数６〜１８の芳香族炭化水素基であり、前記脂肪族炭化水素基、飽和環状炭化水素基及び芳香族炭化水素基に含まれるに含まれる水素原子はハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基又は炭素数２〜４のアシルオキシ基で置換されていてもよい。］ Examples of the monomer having an acid labile group (1) and a carbon-carbon double bond include monomers represented by the formula (a1-4).

[In the formula (a1-4),
R ¹⁰ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ¹¹ 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 acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyl group, or methacryloyl. Represents a group.
la represents an integer of 0 to 4. When la is an integer of 2 or more, the plurality of R ¹¹ may be the same or different.
R ¹² and R ¹³ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms.
X ^a2 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and the hydrogen atom contained in the saturated hydrocarbon group is a halogen atom, a hydroxy group, or an alkyl group having 1 to 6 carbon atoms. Group, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, or an acyloxy group having 2 to 4 carbon atoms, and —CH ₂ — contained in the saturated hydrocarbon group is — CO—, —O—, —S—, —SO ₂ — or —N (R ^c ) — may be substituted. R ^c represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
Y ^a3 is an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the aliphatic hydrocarbon group, saturated The hydrogen atom contained in the cyclic hydrocarbon group and the aromatic hydrocarbon group 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, or an acyl having 2 to 4 carbon atoms. Group or an acyloxy group having 2 to 4 carbon atoms may be substituted. ]

Examples of the alkyl group which may have a halogen atom include a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, and a perfluoropentyl group. Group, perfluorohexyl group, perchloromethyl group, perbromomethyl group, periodiomethyl group and the like.
Examples of the acyl group include an acetyl group, a propionyl group, and a butyryl group.
Examples of the acyloxy group include an acetyloxy group, a propionyloxy group, and a butyryloxy group.
Examples of the hydrocarbon group include an aliphatic hydrocarbon group, a saturated cyclic hydrocarbon group, and an aromatic hydrocarbon group.

The alkyl group for R ¹⁰ and R ¹¹ preferably has 1 to 4 carbon atoms, more preferably 1 or 2 carbon atoms, and particularly preferably a methyl group.
As the alkoxy group for R ¹¹ , C 1 or 2 is more preferable, and a methoxy group is particularly preferable.
Examples of the hydrocarbon group for R ¹² and R ¹³ include isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group, 2-ethylhexyl group, cyclohexyl group, adamantyl group, A 2-alkyl-2-adamantyl group, a 1- (1-adamantyl) -1-alkyl group, an isobornyl group, and the like are preferable.
The substituent that X ^a2 and Y ^a3 may have is preferably a hydroxy group.

Examples of the monomer represented by the formula (a1-4) include the following monomers.

  When the resin (A) includes a structural unit derived from the monomer represented by the formula (a1-4), the content is usually 10 to 95 mol% with respect to all the structural units of the resin (A). , Preferably it is 15-90 mol%, More preferably, it is 20-85 mol%.

<Other acid labile monomers>
Furthermore, other monomers that derive other structural units having an acid labile group and a carbon-carbon double bond in the molecule may be used.
Examples of such a monomer include the following monomers.

  When the resin (A) has a structural unit derived from another acid labile monomer, the content thereof is usually 10 to 95 mol% with respect to the total structural unit of the resin (A), preferably 15 It is -90 mol%, More preferably, it is 20-85 mol%.

The resin (A) is preferably a co-polymerization of a monomer (a1) having an acid labile group and a monomer having no acid labile group (hereinafter sometimes referred to as “acid stable monomer”). It is a coalescence. An acid stable monomer may be used individually by 1 type, and may use 2 or more types together.
When the resin (A) is a copolymer of a monomer (a1) having an acid labile group and an acid stable monomer, the structural units derived from the monomer (a1) having an acid labile group are all Preferably it is 10-80 mol% with respect to 100 mol% of structural units, More preferably, it is 20-60 mol%. Further, the structural unit derived from the monomer having an adamantyl group (particularly the monomer (a1-1) having an acid labile group) is converted to 15 mol per 100 mol% of the monomer (a1) having an acid labile group. It is preferable to set it as mol% or more. When the ratio of the monomer having an adamantyl group increases, the dry etching resistance of the resist is improved.

<Acid stable monomer>
As the acid stable monomer, those having a hydroxy group or a lactone ring are preferred. Derived from an acid stable monomer having a hydroxy group (hereinafter referred to as “acid stable monomer having a hydroxy group (a2)”) or an acid stable monomer having a lactone ring (hereinafter referred to as “acid stable monomer having a lactone ring (a3)”) If a resin having a structural unit to be used is used, the resolution of the resist and the adhesion to the substrate can be improved.

<Acid-stable monomer having a hydroxy group (a2)>
When the resist composition is used for KrF excimer laser exposure (248 nm), irradiation with high energy rays such as an electron beam or EUV light, a phenolic hydroxy group which is a hydroxystyrene as an acid-stable monomer (a2) having a hydroxy group It is preferable to use an acid-stable monomer (a2-0) having When used for short wavelength ArF excimer laser exposure (193 nm) or the like, an acid stable monomer having a hydroxyadamantyl group represented by formula (a2-1) is used as the acid stable monomer (a2) having a hydroxy group. It is preferable. The acid-stable monomer (a2) having a hydroxy group may be used alone or in combination of two or more.

［式（ａ２−０）中、
Ｒ^８は、水素原子、ハロゲン原子又はハロゲン原子を有してもよい炭素数１〜６のアルキル基を表す。
Ｒ^９は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、炭素数２〜４のアシルオキシ基、アクリロイル基又はメタクリロイル基を表す。
ｍａは０〜４の整数を表す。ｍａが２以上の整数である場合、複数のＲ^９は互いに同一であっても異なってもよい。］ Examples of the monomer (a2-0) having a phenolic hydroxy group include styrene monomers such as p- or m-hydroxystyrene represented by the formula (a2-0).

[In the formula (a2-0),
R ⁸ represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ⁹ 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 acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyl group, or methacryloyl. Represents a group.
ma represents an integer of 0 to 4. When ma is an integer greater than or equal to 2, several R < ⁹ > may mutually be same or different. ]

Examples of the alkyl group for R ⁸ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group. An alkyl group having 1 to 4 carbon atoms is preferable, an alkyl group having 1 or 2 carbon atoms is more preferable, and a methyl group is particularly preferable.
Examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, an n-pentoxy group, and an n-hexoxy group. , An alkoxy group having 1 to 4 carbon atoms is preferable, an alkoxy group having 1 or 2 carbon atoms is more preferable, and a methoxy group is particularly preferable.
ma is preferably 0 to 2, more preferably 0 or 1, and particularly preferably 0.

When obtaining a copolymer resin having a structural unit derived from a monomer having such a phenolic hydroxy group, acetyloxystyrenes corresponding to those obtained by replacing the phenolic hydroxy group with an acetyloxy group and a monomer to be copolymerized are used. After radical polymerization, it can be obtained by deacetylation with an acid.
Examples of the monomer having a phenolic hydroxy group include the following monomers.

  Of the above monomers, 4-hydroxystyrene or 4-hydroxy-α-methylstyrene is particularly preferred.

  When the resin (A) includes a structural unit derived from the monomer represented by the formula (a2-0), the content is usually 5 to 90 mol% with respect to all the structural units of the resin (A). , Preferably it is 10-85 mol%, More preferably, it is 15-80 mol%.

式（ａ２−１）中、
Ｌ^a3は、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k2−ＣＯ−Ｏ−を表し、
ｋ２は１〜７の整数を表す。＊は−ＣＯ−との結合手を表す。
Ｒ^a14は、水素原子又はメチル基を表す。
Ｒ^a15及びＲ^a16は、それぞれ独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０〜１０の整数を表す。 Examples of the acid stable monomer having a hydroxyadamantyl group include a monomer represented by the formula (a2-1).

In formula (a2-1),
L ^a3 represents —O— or ^* —O— (CH ₂ ) _k2 —CO—O—,
k2 represents an integer of 1 to 7. * Represents a bond with -CO-.
R ^a14 represents a hydrogen atom or a methyl group.
R ^a15 and R ^a16 each independently represent a hydrogen atom, a methyl group or a hydroxy group.
o1 represents an integer of 0 to 10.

In the formula (a2-1), L ^a3 is preferably, -O -, - O- (CH 2) f1 -CO-O- and is (wherein f1 is an integer from 1 to 4), more preferably 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 an acid stable monomer (a2-1) which has a hydroxyadamantyl group, the following are mentioned, for example. Among them, 3-hydroxyadamantan-1-yl (meth) acrylate, 3,5-dihydroxyadamantan-1-yl (meth) acrylate and (meth) acrylic acid 1- (3,5-dihydroxyadamantan-1-yloxycarbonyl ) Methyl is preferred, 3-hydroxyadamantan-1-yl (meth) acrylate and 3,5-dihydroxyadamantan-1-yl (meth) acrylate are more preferred, 3-hydroxyadamantan-1-yl methacrylate and 3,5- More preferred is dihydroxyadamantan-1-yl methacrylate.

  When the resin (A) includes a structural unit derived from the monomer represented by the formula (a2-1), the content is usually 3 to 40 mol% with respect to all the structural units of the resin (A). , Preferably it is 5-35 mol%, More preferably, it is 5-30 mol%, More preferably, it is 5-20 mol%.

<Acid-stable monomer having a lactone ring (a3)>
The lactone ring possessed by the acid stable monomer (a3) may be, for example, a monocycle such as a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, and a monocyclic lactone ring and other rings The condensed ring may be used. Among these lactone rings, a γ-butyrolactone ring and a condensed ring of a γ-butyrolactone ring and another ring are preferable.

  The acid-stable monomer (a3) having a lactone ring is preferably represented by the formula (a3-1), the formula (a3-2) or the formula (a3-3). These 1 type may be used independently and may use 2 or more types together.

式（ａ３−１）〜式（ａ３−３）中、
Ｌ^a4〜Ｌ^a6は、それぞれ独立に、−Ｏ−又は^＊−Ｏ−（ＣＨ₂）_k3−ＣＯ−Ｏ−を表す。
ｋ３は１〜７の整数を表す。＊は−ＣＯ−との結合手を表す。
Ｒ^a18〜Ｒ^a20は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a21は、炭素数１〜４の脂肪族炭化水素基を表す。
ｐ１は０〜５の整数を表す。
Ｒ^a22及びＲ^a23は、それぞれ独立に、カルボキシ基、シアノ基又は炭素数１〜４の脂肪族炭化水素基を表す。
ｑ１及びｒ１は、それぞれ独立に０〜３の整数を表す。ｐ１、ｑ１又はｒ１が２以上のとき、それぞれ、複数のＲ^a21、Ｒ^a22又はＲ^a23は、互いに同一でも異なってもよい。

In formula (a3-1) to formula (a3-3),
L ^{a4 to} L ^a6 each independently represent —O— or ^* —O— (CH ₂ ) _k3 —CO—O—.
k3 represents an integer of 1 to 7. * Represents a bond with -CO-.
R ^{a18 to} R ^a20 each independently represents a hydrogen atom or a methyl group.
R ^a21 represents an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
p1 represents an integer of 0 to 5.
R ^a22 and R ^a23 each independently represent a carboxy group, a cyano group, or an aliphatic hydrocarbon group having 1 to 4 carbon atoms.
q1 and r1 each independently represents an integer of 0 to 3. When p1, q1 or r1 is 2 or more, a plurality of R ^a21 , R ^a22 or R ^a23 may be the same as or different from each other.

In Formula (a3-1) to Formula (a3-3), L ^{a4 to} La ⁶ are each independently preferably —O— or ^* —O— (CH ₂ ) _d1 —CO—O— ( The d1 is an integer of 1 to 4, and more preferably —O—.
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 to r1 are each independently preferably 0 to 2, more preferably 0 or 1.

Examples of the acid stable monomer (a3-1) having a γ-butyrolactone ring include the following.

  Examples of the acid stable monomer (a3-2) having a condensed ring of γ-butyrolactone ring and norbornane ring include the following.

Examples of the acid stable monomer (a3-3) having a condensed ring of γ-butyrolactone ring and cyclohexane ring include the following.

Among acid-stable monomers (a3) having a lactone ring, (meth) acrylic acid (5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-2-yl, (meth) acrylic Acid tetrahydro-2-oxo-3-furyl, 2- (5-oxo-4-oxatricyclo [4.2.1.0 ^3,7 ] nonan-2-yloxy) -2-oxoethyl (meth) acrylate Are preferred, and those in the form of methacrylate are more preferred.

  When the resin (A) includes a structural unit derived from the monomer represented by the formula (a3-1), the formula (a3-2) or the formula (a3-3), the content thereof is the total of the resin (A). It is 5-50 mol% normally with respect to a structural unit, Preferably it is 10-45 mol%, More preferably, it is 15-40 mol%. Moreover, when resin (A) contains the structural unit derived from the acid stable monomer (a3) which has a lactone ring, the total content is 5-60 mol% normally in all the units of resin (A), Preferably it is 15-55 mol%.

<Other acid stable monomers (a4)>
Examples of the other acid stable monomer (a4) include maleic anhydride represented by formula (a4-1), itaconic anhydride represented by formula (a4-2), and formula (a4-3). And acid-stable monomers having a norbornene ring.

式（ａ４−３）中、
Ｒ^a25及びＲ^a26は、それぞれ独立に、水素原子、ヒドロキシ基を有していてもよい炭素数１〜３の脂肪族炭化水素基、シアノ基、カルボキシ基又は−ＣＯＯＲ^a27を表すか、或いはＲ^a25及びＲ^a26は互いに結合して−ＣＯ−Ｏ−ＣＯ−を形成し、
Ｒ^a27は、炭素数１〜１８の脂肪族炭化水素基又は炭素数３〜１８の飽和環状炭化水素基を表し、該脂肪族炭化水素基及び該飽和環状炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−又は−ＣＯ−で置き換わっていてもよい。但し−ＣＯＯＲ^a27が酸不安定基となるものは除く（即ちＲ^a27は、第三級炭素原子が−Ｏ−と結合するものを含まない）。

In formula (a4-3),
R ^a25 and R ^a26 each independently represent a hydrogen atom, a C 1-3 aliphatic hydrocarbon group ^optionally having a hydroxy group, a cyano group, a carboxy group, or —COOR ^a27 , or R a ^a25 and R ^a26 combine with each other to form -CO-O-CO-;
R ^a27 represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, and —CH ₂ — contained in the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group. May be replaced by -O- or -CO-. However, those in which —COOR ^a27 is an acid labile group are excluded (that is, R ^a27 does not include those in which a tertiary carbon atom is bonded to —O—).

^Examples of the aliphatic hydrocarbon group which may have a hydroxyl group for R ^a25 and R ^a26 include a methyl group, an ethyl group, a propyl group, a hydroxymethyl group, and a 2-hydroxyethyl group.
The aliphatic hydrocarbon group for R ^a27 preferably has 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms. The saturated cyclic hydrocarbon group preferably has 4 to 18 carbon atoms, more preferably 4 to 12 carbon atoms.
^Examples of R ^a27 include a methyl group, an ethyl group, a propyl group, a 2-oxo-oxolan-3-yl group, and a 2-oxo-oxolan-4-yl group.

  Examples of the acid-stable monomer (a4-3) having a norbornene ring include 2-norbornene, 2-hydroxy-5-norbornene, 5-norbornene-2-carboxylic acid, methyl 5-norbornene-2-carboxylate, 5- Examples include norbornene-2-carboxylic acid 2-hydroxy-1-ethyl, 5-norbornene-2-methanol, and 5-norbornene-2,3-dicarboxylic acid anhydride.

  When the resin (A) includes a structural unit derived from the monomer represented by the formula (a4-1), the formula (a4-2), or the formula (a4-3), the content thereof is all of the resin (A). It is 2-40 mol% normally with respect to a structural unit, Preferably it is 3-30 mol%, More preferably, it is 5-20 mol%.

  A preferred resin (A) is a copolymer obtained by polymerizing at least a monomer (a1) having an acid labile group, an acid stable monomer (a2) having a hydroxy group, and / or an acid stable monomer (a3) having a lactone ring. It is a polymer. In this preferred copolymer, the monomer (a1) having an acid labile group is more preferably at least one of a monomer (a1-1) having an adamantyl group and a monomer (a1-2) having a cyclohexyl group. A species (more preferably a monomer (a1-1) having an adamantyl group), and an acid stable monomer (a2) having a hydroxy group, preferably an acid stable monomer (a2-1) having a hydroxyadamantyl group, and a lactone The acid-stable monomer (a3) having a ring is more preferably an acid-stable monomer (a3-1) having a γ-butyrolactone ring and an acid-stable monomer (a3-2) having a condensed ring of a γ-butyrolactone ring and a norbornane ring At least one of the following. Resin (A) can be manufactured by a well-known polymerization method (for example, radical polymerization method).

The weight average molecular weight of the resin (A) is preferably 2,500 or more (more preferably 3,000 or more, more preferably 3,500 or more), 50,000 or less (more preferably 30,000 or less, and further preferably Is 10,000 or less).
It is preferable that content of resin (A) is 80 to 99 mass% in solid content of a composition.
In the present specification, the “solid content in the composition” means the total of resist composition components excluding the solvent (E) described later. The solid content in the composition and the content of the resin (A) relative thereto can be measured by a known analysis means such as liquid chromatography or gas chromatography.

<Basic compound (hereinafter sometimes referred to as “basic compound (C)”)>
The resist composition of the present invention preferably contains a basic compound (C).
The content of the basic compound (C) is preferably about 0.01 to 1% by mass based on the solid content of the resist composition.

  The basic compound (C) is preferably a basic nitrogen-containing organic compound (for example, amine and ammonium salt). The amine may be an aliphatic amine or an aromatic amine. As the aliphatic amine, any of primary amine, secondary amine and tertiary amine can be used. The aromatic amine may be any of an amino group bonded to an aromatic ring such as aniline and a heteroaromatic amine such as pyridine. Preferable basic compound (C) includes an aromatic amine represented by the formula (C2), particularly an aniline represented by the formula (C2-1).

ここで、Ａｒ^c1は、芳香族炭化水素基を表す。
Ｒ^c5及びＲ^c6は、それぞれ独立に、水素原子、脂肪族炭化水素基（好ましくはアルキル基又はシクロアルキル基）、飽和環状炭化水素基又は芳香族炭化水素基を表す。前記脂肪族炭化水素基、該飽和環状炭化水素基又は該芳香族炭化水素基に含まれる水素原子は、ヒドロキシ基、アミノ基又は炭素数１〜６のアルコキシ基で置換されていてもよく、該アミノ基は、炭素数１〜４のアルキル基で置換されていてもよい。
前記脂肪族炭化水素基は、好ましくは炭素数１〜６程度であり、前記飽和環状炭化水素基は、好ましくは炭素数５〜１０程度であり、前記芳香族炭化水素基は、好ましくは炭素数６〜１０程度である。
Ｒ^c7は、脂肪族炭化水素基（好ましくはアルキル基）、アルコキシ基、飽和環状炭化水素基（好ましくはシクロアルキル基）又は芳香族炭化水素基を表す。該脂肪族炭化水素基、該アルコキシ基、該飽和環状炭化水素基及び該芳香族炭化水素基に含まれる水素原子は、上記と同様の置換基で置換されていてもよい。
ｍ３は０〜３の整数を表す。ｍ３が２以上のとき、複数のＲ^c7は、互いに同一でも異なってもよい。
Ｒ^c7の脂肪族炭化水素基、飽和環状炭化水素基及び芳香族炭化水素基の好ましい炭素数は、上記と同じであり、Ｒ^c7のアルコキシ基は、好ましくは炭素数１〜６程度である。

Here, Ar ^c1 represents an aromatic hydrocarbon group.
R ^c5 and R ^c6 each independently represents a hydrogen atom, an aliphatic hydrocarbon group (preferably an alkyl group or a cycloalkyl group), a saturated cyclic hydrocarbon group or an aromatic hydrocarbon group. The hydrogen atom contained in the aliphatic hydrocarbon group, the saturated cyclic hydrocarbon group or the aromatic hydrocarbon group may be substituted with a hydroxy group, an amino group or an alkoxy group having 1 to 6 carbon atoms, The amino group may be substituted with an alkyl group having 1 to 4 carbon atoms.
The aliphatic hydrocarbon group preferably has about 1 to 6 carbon atoms, the saturated cyclic hydrocarbon group preferably has about 5 to 10 carbon atoms, and the aromatic hydrocarbon group preferably has about carbon atoms. It is about 6-10.
R ^c7 represents an aliphatic hydrocarbon group (preferably an alkyl group), an alkoxy group, a saturated cyclic hydrocarbon group (preferably a cycloalkyl group) or an aromatic hydrocarbon group. Hydrogen atoms contained in the aliphatic hydrocarbon group, the alkoxy group, the saturated cyclic hydrocarbon group, and the aromatic hydrocarbon group may be substituted with the same substituents as described above.
m3 represents an integer of 0 to 3. When m3 is 2 or more, the plurality of R ^c7 may be the same as or different from each other.
Aliphatic hydrocarbon group R ^c7, preferable number of carbon atoms of the saturated cyclic hydrocarbon group and the aromatic hydrocarbon group are the same as above, an alkoxy group of R ^c7 is independently in, preferably about 1 to 6 carbon atoms.

Examples of the aromatic amine (C2) include 1-naphthylamine and 2-naphthylamine.
Examples of aniline (C2-1) include aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N-dimethylaniline, diphenylamine and the like.
Of these, diisopropylaniline (particularly 2,6-diisopropylaniline) is preferable.

ここで、
Ｒ^c8は、上記Ｒ^c7で説明したいずれかの基を表す。
窒素原子と結合するＲ^c9、Ｒ^c10、Ｒ^c11〜Ｒ^c14、Ｒ^c16〜Ｒ^c19及びＲ^c22は、それぞれ独立に、Ｒ^c5及びＲ^c6で説明したいずれかの基を表す。
芳香族炭素と結合するＲ^c20、Ｒ^c21、Ｒ^c23〜Ｒ^c28は、それぞれ独立に、Ｒ^c7で説明したいずれかの基を表す。
ｏ３〜ｕ３は、それぞれ独立に０〜３の整数を表す。ｏ３〜ｕ３のいずれかが２以上であるとき、それぞれ、複数のＲ^c20〜Ｒ^c28のいずれかは互いに同一でも異なってもよい。
Ｒ^c15は、脂肪族炭化水素基、飽和環状炭化水素基又はアルカノイル基を表す。
ｎ３は０〜８の整数を表す。ｎ３が２以上のとき、複数のＲ^c15は、互いに同一でも異なってもよい。
Ｒ^c15の脂肪族炭化水素基は、好ましくは炭素数１〜６程度であり、飽和環状炭化水素基は、好ましくは炭素数３〜６程度である。
アルカノイル基としては、アセチル基、２−メチルアセチル基、２，２−ジメチルアセチル基、プロピオニル基、ブチリル基、イソブチリル基、ペンタノイル基、２，２−ジメチルプロピオニル基等が挙げられ、好ましくは炭素数２〜６程度である。
Ｌ^c1及びＬ^c2は、それぞれ独立に、２価の脂肪族炭化水素基（好ましくはアルキレン基）、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｃ（＝ＮＲ^c3）−、−Ｓ−、−Ｓ−Ｓ−又はこれらの組合せを表す。前記２価の脂肪族炭化水素基は、好ましくは炭素数１〜６程度である。
Ｒ^c3は、炭素数１〜４のアルキル基を表す。 Examples of the basic compound (C) include compounds represented by the formulas (C3) to (C11).

here,
R ^c8 represents any of the groups described for R ^c7 above.
R ^c9 , R ^c10 , R ^{c11 to} R ^c14 , R ^{c16 to} R ^c19 and R ^c22 bonded to the nitrogen atom each independently represent any of the groups described for R ^c5 and R ^c6 .
R ^c20 , R ^c21 and R ^{c23 to} R ^c28 bonded to the aromatic carbon each independently represents any of the groups described for R ^c7 .
o3 to u3 each independently represents an integer of 0 to 3. When any of o3 to u3 is 2 or more, any of the plurality of R ^{c20 to} R ^c28 may be the same as or different from each other.
R ^c15 represents an aliphatic hydrocarbon group, a saturated cyclic hydrocarbon group or an alkanoyl group.
n3 represents an integer of 0 to 8. When n3 is 2 or more, the plurality of R ^c15 may be the same as or different from each other.
The aliphatic hydrocarbon group for R ^c15 preferably has about 1 to 6 carbon atoms, and the saturated cyclic hydrocarbon group preferably has about 3 to 6 carbon atoms.
Examples of the alkanoyl group include an acetyl group, a 2-methylacetyl group, a 2,2-dimethylacetyl group, a propionyl group, a butyryl group, an isobutyryl group, a pentanoyl group, and a 2,2-dimethylpropionyl group. It is about 2-6.
L ^c1 and L ^c2 are each independently a divalent aliphatic hydrocarbon group (preferably an alkylene group), —CO—, —C (═NH) —, —C (═NR ^c3 ) —, —S—. , -SS- or a combination thereof. The divalent aliphatic hydrocarbon group preferably has about 1 to 6 carbon atoms.
R ^c3 represents an alkyl group having 1 to 4 carbon atoms.

  Examples of the compound (C3) include hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, Tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctyl Amine, methyl dinonyl amine, methyl didecyl amine, ethyl dibutyl amine, ethyl dipentyl amine, ethyl di Silamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine ethylenediamine, tetramethylenediamine, hexamethylene Examples include diamine, 4,4′-diamino-1,2-diphenylethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, and the like.

Examples of the compound (C4) include piperazine.
Examples of the compound (C5) include morpholine.
Examples of the compound (C6) include piperidine and hindered amine compounds having a piperidine skeleton described in JP-A No. 11-52575.
Examples of the compound (C7) include 2,2′-methylenebisaniline.
Examples of the compound (C8) include imidazole and 4-methylimidazole.
Examples of the compound (C9) include pyridine and 4-methylpyridine.
Examples of the compound (C10) include 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene, and 1,2-di. (4-pyridyl) ethene, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) ethane, di (2-pyridyl) ketone, 4,4′-dipyridyl sulfide, 4, 4'-dipyridyl disulfide, 2,2'-dipyridylamine, 2,2'-dipicolylamine and the like can be mentioned.
Examples of the compound (C11) include bipyridine.

  As ammonium salts, tetramethylammonium hydroxide, tetraisopropylammonium hydroxide, tetrabutylammonium hydroxide, tetrahexylammonium hydroxide, tetraoctylammonium hydroxide, phenyltrimethylammonium hydroxide, 3- (trifluoromethyl) phenyltrimethyl Examples include ammonium hydroxide, tetra-n-butylammonium salicylate, choline, and the like.

<Solvent (sometimes referred to as "solvent (E)")
The resist composition of the present invention may contain the solvent (E) in an amount of 90% by mass or more in the composition. The resist composition of the present invention containing the solvent (E) is suitable for producing a thin film resist. The content of the solvent (E) is 90% by mass or more (preferably 92% by mass or more, more preferably 94% by mass or more) and 99.9% by mass or less (preferably 99% by mass or less) in the composition.
The content of the solvent (E) can be measured by a known analysis means such as liquid chromatography or gas chromatography.

  Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and And esters such as ethyl pyruvate; ketones such as acetone, methyl isobutyl ketone, 2-heptanone and cyclohexanone; cyclic esters such as γ-butyrolactone; A solvent (E) may be used individually by 1 type, and may use 2 or more types together.

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

<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises:
(1) The process of apply | coating the resist composition of this invention mentioned above on a board | substrate,
(2) a step of removing the solvent from the composition after coating to form a composition layer;
(3) a step of exposing the composition layer using an exposure machine;
(4) A step of heating the composition layer after exposure,
(5) The process which develops the composition layer after a heating using a image development apparatus is included.

  Application of the resist composition onto the substrate can be performed by a commonly used apparatus such as a spin coater.

The removal of the solvent is performed, for example, by evaporating the solvent using a heating device such as a hot plate (so-called pre-baking) or by using a decompression device to form a composition layer from which the solvent has been removed. The As for the temperature in this case, about 50-200 degreeC is illustrated, for example. The pressure is exemplified by about 1 to 1.0 × 10 ⁵ Pa.

The obtained composition layer is exposed using an exposure machine. The exposure machine may be an immersion exposure machine. At this time, exposure is usually performed through a mask corresponding to a required pattern. 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.) can be used such as those that convert the wavelength of the laser light from the above and radiate the harmonic laser light in the far ultraviolet region or the vacuum ultraviolet region. Further, the exposure machine may irradiate an electron beam or extreme ultraviolet light (EUV).

The composition layer after exposure is subjected to heat treatment (so-called post-exposure baking) for promoting the deprotection group reaction. As heating temperature, it is about 50-200 degreeC normally, Preferably it is about 70-150 degreeC.
The heated composition layer is usually developed using an alkali developer using a developing device.
The alkaline developer used here 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).
After development, it is preferable to rinse with ultrapure water to remove water 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, It is suitable as a chemically amplified photoresist composition.

Hereinafter, the present invention will be described in detail by way of examples. In the examples,% and parts representing the content and the amount used are based on mass unless otherwise specified.
In the following examples, the structure of the compound was confirmed by mass spectrometry (LC; Agilent 1100 type, MASS; Agilent LC / MSD type).
The weight average molecular weight is a value determined by gel permeation chromatography (HLC-8120GPC type manufactured by Tosoh Corporation, three columns are “TSKgel Multipore HXL-M”, and the solvent is tetrahydrofuran) using polystyrene as a standard product.
Column: TSKgel Multipore H _XL -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)

酸化銀２．９１部及びアセトニトリル５．８１部を仕込み、２３℃で３０分間攪拌した。その後、メタンスルホン酸２．４１部及びアセトニトリル４．８２部の溶液を３０分かけて添加した。２３℃で３０分間攪拌後、式（Ｂ１−ａ）で表される化合物５．００部及びアセトニトリル１０．００部の溶液を仕込み、さらに、式（Ｂ１−ｂ）で表される化合物３．５６部を仕込み、２３℃で１５時間攪拌し、ろ過した。回収された濾液を濃縮し、ｔｅｒｔ−ブチルメチルエーテル２８．０２部を加えて２３℃で３０分間攪拌した。上澄み液を除き、その後、濃縮し、更にアセトニトリル５０部を加えて２３℃で３０分間攪拌し、濃縮することにより、式（Ｂ１−ｃ）で表される塩５．１２部を得た。 Example 1: Synthesis of a salt represented by the formula (B1)

2.91 parts of silver oxide and 5.81 parts of acetonitrile were charged and stirred at 23 ° C. for 30 minutes. Thereafter, a solution of 2.41 parts of methanesulfonic acid and 4.82 parts of acetonitrile was added over 30 minutes. After stirring at 23 ° C. for 30 minutes, a solution of 5.00 parts of the compound represented by the formula (B1-a) and 10.00 parts of acetonitrile was charged, and further a compound 3.56 represented by the formula (B1-b) Parts were charged, stirred at 23 ° C. for 15 hours, and filtered. The collected filtrate was concentrated, 28.02 parts of tert-butyl methyl ether was added, and the mixture was stirred at 23 ° C. for 30 minutes. The supernatant was removed, then concentrated, 50 parts of acetonitrile was further added, and the mixture was stirred at 23 ° C. for 30 minutes and concentrated to obtain 5.12 parts of the salt represented by the formula (B1-c).

特開第２００８−２０９９１７号公報に記載された方法によって得られた式（Ｂ１−ｄ）で表される化合物３．９０部及びクロロホルム５８．７５部を仕込み、２３℃で３０分間攪拌した。その後、式（Ｂ１−ｃ）で表される化合物４．１０部及びイオン交換水５６．６２部を仕込み、２３℃で１５時間攪拌した。得られた反応マスに、２８％アンモニア水溶液３．００部を加えて２３℃で３０分間攪拌し、分液した。回収された有機層に、イオン交換水２９．３７部を仕込み２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を３回行った。回収された有機層に、活性炭０．６７部を添加し、２３℃で３０分間攪拌し、ろ過した。回収された濾液を濃縮し、ｔｅｒｔ−ブチルメチルエーテル２５．８３部を加えて２３℃で３０分間攪拌した。上澄み液を除き、濃縮し、更にアセトニトリル２０部を加えて２３℃で３０分間攪拌し、濃縮した。得られた濃縮物に、酢酸エチル２８．８０部を加えて２３℃で３０分間攪拌し、濃縮した。得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル４５．７５部を加えて２３℃で３０分間攪拌した。上澄み液を除き、濃縮し、更にアセトニトリル２０部を加えて２３℃で３０分間攪拌し、濃縮することにより、式（Ｂ１）で表される塩４．１０部を得た。

3.90 parts of a compound represented by the formula (B1-d) obtained by the method described in JP-A-2008-209917 and 58.75 parts of chloroform were charged and stirred at 23 ° C. for 30 minutes. Thereafter, 4.10 parts of the compound represented by the formula (B1-c) and 56.62 parts of ion-exchanged water were charged and stirred at 23 ° C. for 15 hours. To the obtained reaction mass, 3.00 parts of a 28% aqueous ammonia solution was added and stirred at 23 ° C. for 30 minutes for liquid separation. The recovered organic layer was charged with 29.37 parts of ion-exchanged water, stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. This washing operation was performed three times. To the collected organic layer, 0.67 parts of activated carbon was added, stirred at 23 ° C. for 30 minutes, and filtered. The collected filtrate was concentrated, 25.83 parts of tert-butyl methyl ether was added, and the mixture was stirred at 23 ° C. for 30 minutes. The supernatant was removed and concentrated, and 20 parts of acetonitrile was further added, and the mixture was stirred at 23 ° C. for 30 minutes and concentrated. To the obtained concentrate, 28.80 parts of ethyl acetate was added, stirred at 23 ° C. for 30 minutes, and concentrated. To the obtained residue, 45.75 parts of tert-butyl methyl ether was added and stirred at 23 ° C. for 30 minutes. The supernatant was removed, the mixture was concentrated, 20 parts of acetonitrile was further added, and the mixture was stirred at 23 ° C. for 30 minutes and concentrated to obtain 4.10 parts of the salt represented by the formula (B1).

Identification of the salt represented by the formula (B1);
MS (ESI (+) Spectrum): M ⁺ 214.1
MS (ESI (−) Spectrum): M ⁻ 271.1

特開第２００８−２０９９１７号公報に記載された方法によって得られた式（Ｂ１−ｄ）で表される化合物３．９０部及びクロロホルム５８．７５部を仕込み、２３℃で３０分間攪拌した。その後、式（Ｂ２−ａ）で表される化合物５．３４部及びイオン交換水７３．７４部を仕込み、２３℃で１５時間攪拌した。得られた反応マスに、２８％アンモニア水溶液３．００部を加えて２３℃で３０分間攪拌し、分液した。回収された有機層に、イオン交換水３８．４２部を仕込み２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を３回行った。回収された有機層に、活性炭０．８２部を添加し、２３℃で３０分間攪拌し、ろ過した。回収された濾液を濃縮し、ｔｅｒｔ−ブチルメチルエーテル３２．２４部を加えて２３℃で３０分間攪拌した。上澄み液を除き、濃縮し、更にアセトニトリル２０部を加えて２３℃で３０分間攪拌し、濃縮した。得られた濃縮物に、酢酸エチル２８．９８部を加えて２３℃で３０分間攪拌し、濃縮した。得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル５０．０８部を加えて２３℃で３０分間攪拌した。上澄み液を除き、濃縮し、更にアセトニトリル２０．０９部を加えて２３℃で３０分間攪拌した。その後、濃縮することにより、式（Ｂ２）で表される塩４．２８部を得た。 Example 2: Synthesis of a salt represented by the formula (B2)

3.90 parts of a compound represented by the formula (B1-d) obtained by the method described in JP-A-2008-209917 and 58.75 parts of chloroform were charged and stirred at 23 ° C. for 30 minutes. Thereafter, 5.34 parts of the compound represented by the formula (B2-a) and 73.74 parts of ion-exchanged water were charged and stirred at 23 ° C. for 15 hours. To the obtained reaction mass, 3.00 parts of a 28% aqueous ammonia solution was added and stirred at 23 ° C. for 30 minutes for liquid separation. The recovered organic layer was charged with 38.42 parts of ion-exchanged water, stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. This washing operation was performed three times. To the collected organic layer, 0.82 part of activated carbon was added, stirred at 23 ° C. for 30 minutes, and filtered. The collected filtrate was concentrated, 32.24 parts of tert-butyl methyl ether was added, and the mixture was stirred at 23 ° C. for 30 minutes. The supernatant was removed and concentrated, and 20 parts of acetonitrile was further added, and the mixture was stirred at 23 ° C. for 30 minutes and concentrated. To the obtained concentrate, 28.98 parts of ethyl acetate was added, stirred at 23 ° C. for 30 minutes, and concentrated. To the obtained residue, 50.08 parts of tert-butyl methyl ether was added and stirred at 23 ° C. for 30 minutes. The supernatant was removed, the mixture was concentrated, and 20.09 parts of acetonitrile was further added, followed by stirring at 23 ° C. for 30 minutes. Then, 4.28 parts of salt represented by Formula (B2) was obtained by concentrating.

Identification of the salt represented by the formula (B2);
MS (ESI (+) Spectrum): M ⁺ 276.1
MS (ESI (−) Spectrum): M ⁻ 271.1

特開第２００６−２５７０７８号公報に記載された方法によって得られた式（Ｂ３−ｄ）で表される化合物４．８０部及びクロロホルム７２．３１部を仕込み、２３℃で３０分間攪拌した。その後、式（Ｂ２−ａ）で表される化合物５．３４部及びイオン交換水７３．７４部を仕込み、２３℃で１５時間攪拌した。得られた反応マスに、２８％アンモニア水溶液３．００部を加えて２３℃で３０分間攪拌し、分液した。回収された有機層に、イオン交換水４０部を仕込み２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を３回行った。回収された有機層に、活性炭１．００部を添加し、２３℃で３０分間攪拌し、ろ過した。回収された濾液を濃縮し、ｔｅｒｔ−ブチルメチルエーテル３５部を加えて２３℃で３０分間攪拌した。上澄み液を除き、濃縮し、更にアセトニトリル１５部を加えて２３℃で３０分間攪拌し、濃縮した。得られた濃縮物に、酢酸エチル３０部を加えて２３℃で３０分間攪拌し、濃縮した。得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル５０部を加えて２３℃で３０分間攪拌した。上澄み液を除き、濃縮し、更にアセトニトリル２０部を加えて２３℃で３０分間攪拌した。その後、濃縮することにより、式（Ｂ３）で表される塩３．２２部を得た。 Example 3: Synthesis of a salt represented by the formula (B3)

4.80 parts of the compound represented by the formula (B3-d) obtained by the method described in JP-A-2006-257078 and 72.31 parts of chloroform were charged and stirred at 23 ° C. for 30 minutes. Thereafter, 5.34 parts of the compound represented by the formula (B2-a) and 73.74 parts of ion-exchanged water were charged and stirred at 23 ° C. for 15 hours. To the obtained reaction mass, 3.00 parts of a 28% aqueous ammonia solution was added and stirred at 23 ° C. for 30 minutes for liquid separation. The recovered organic layer was charged with 40 parts of ion exchange water, stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. This washing operation was performed three times. To the collected organic layer, 1.00 part of activated carbon was added, stirred at 23 ° C. for 30 minutes, and filtered. The collected filtrate was concentrated, 35 parts of tert-butyl methyl ether was added, and the mixture was stirred at 23 ° C. for 30 minutes. The supernatant was removed and concentrated, and 15 parts of acetonitrile was further added, followed by stirring at 23 ° C. for 30 minutes and concentration. To the obtained concentrate, 30 parts of ethyl acetate was added, stirred at 23 ° C. for 30 minutes, and concentrated. To the obtained residue, 50 parts of tert-butyl methyl ether was added and stirred at 23 ° C. for 30 minutes. The supernatant was removed, the mixture was concentrated, 20 parts of acetonitrile was further added, and the mixture was stirred at 23 ° C. for 30 minutes. Then, 3.22 parts of salt represented by Formula (B3) was obtained by concentrating.

Identification of the salt represented by the formula (B3);
MS (ESI (+) Spectrum): M ⁺ 276.1
MS (ESI (-) Spectrum): M ^- 339.1

特開第２００６−２５７０７８号公報に記載された方法によって得られた式（Ｂ３−ｄ）で表される化合物４．８０部及びクロロホルム７２．３１部を仕込み、２３℃で３０分間攪拌した。その後、式（Ｂ１−ｃ）で表される化合物４．１０部及びイオン交換水５６．６２部を仕込み、２３℃で１５時間攪拌した。得られた反応マスに、２８％アンモニア水溶液３．００部を加えて２３℃で３０分間攪拌し、分液した。回収された有機層に、イオン交換水３０部を仕込み２３℃で３０分間攪拌し、分液することにより有機層を回収した。この水洗の操作を３回行った。回収された有機層に、活性炭１．００部を添加し、２３℃で３０分間攪拌し、ろ過した。回収された濾液を濃縮し、ｔｅｒｔ−ブチルメチルエーテル３０部を加えて２３℃で３０分間攪拌した。上澄み液を除き、濃縮し、更にアセトニトリル２０部を加えて２３℃で３０分間攪拌し、濃縮した。得られた濃縮物に、酢酸エチル３０部を加えて２３℃で３０分間攪拌し、濃縮した。得られた残渣に、ｔｅｒｔ−ブチルメチルエーテル５０部を加えて２３℃で３０分間攪拌した。上澄み液を除き、濃縮し、更にアセトニトリル２０部を加えて２３℃で３０分間攪拌し、濃縮することにより、式（Ｂ４）で表される塩２．８１部を得た。 Example 4: Synthesis of salt represented by formula (B4)

4.80 parts of the compound represented by the formula (B3-d) obtained by the method described in JP-A-2006-257078 and 72.31 parts of chloroform were charged and stirred at 23 ° C. for 30 minutes. Thereafter, 4.10 parts of the compound represented by the formula (B1-c) and 56.62 parts of ion-exchanged water were charged and stirred at 23 ° C. for 15 hours. To the obtained reaction mass, 3.00 parts of a 28% aqueous ammonia solution was added and stirred at 23 ° C. for 30 minutes for liquid separation. To the recovered organic layer, 30 parts of ion-exchanged water was charged, stirred at 23 ° C. for 30 minutes, and separated to recover the organic layer. This washing operation was performed three times. To the collected organic layer, 1.00 part of activated carbon was added, stirred at 23 ° C. for 30 minutes, and filtered. The collected filtrate was concentrated, 30 parts of tert-butyl methyl ether was added, and the mixture was stirred at 23 ° C. for 30 minutes. The supernatant was removed and concentrated, and 20 parts of acetonitrile was further added, and the mixture was stirred at 23 ° C. for 30 minutes and concentrated. To the obtained concentrate, 30 parts of ethyl acetate was added, stirred at 23 ° C. for 30 minutes, and concentrated. To the obtained residue, 50 parts of tert-butyl methyl ether was added and stirred at 23 ° C. for 30 minutes. The supernatant was removed, the mixture was concentrated, 20 parts of acetonitrile was further added, and the mixture was stirred at 23 ° C. for 30 minutes and concentrated to obtain 2.81 parts of the salt represented by the formula (B4).

Identification of the salt represented by the formula (B4);
MS (ESI (+) Spectrum): M ⁺ 214.1
MS (ESI (-) Spectrum): M ^- 339.1

式（Ｂ３）で表される塩３．０８部及びアセトニトリル１５．００部を仕込み、２３℃で３０分間攪拌した。その後、式（Ｂ５−ａ）で表される化合物０．８５部を添加し、６０℃で１時間攪拌した。得られた反応溶液をろ過し、回収されたろ液を濃縮した。得られた濃縮物に、クロロホルム２０部及びイオン交換水１０部を加え、２３℃で３０分間攪拌した。その後、静置し、分液して有機層を得た。得られた有機層に、イオン交換水１０部を加え、２３℃で３０分間攪拌した。この水洗の操作をさらに３回行った。得られた有機層に活性炭０．５０部を仕込み、２３℃で３０分間攪拌し、ろ過した。ろ液を濃縮することにより、式（Ｂ５−ｂ）で表される塩２．８９部を得た。 Example 5: Synthesis of salt represented by formula (B5)

A salt represented by the formula (B3) (3.08 parts) and acetonitrile (15.00 parts) were charged, and the mixture was stirred at 23 ° C. for 30 minutes. Thereafter, 0.85 part of a compound represented by the formula (B5-a) was added and stirred at 60 ° C. for 1 hour. The obtained reaction solution was filtered, and the collected filtrate was concentrated. To the obtained concentrate, 20 parts of chloroform and 10 parts of ion-exchanged water were added and stirred at 23 ° C. for 30 minutes. Then, it left still and liquid-separated and obtained the organic layer. To the obtained organic layer, 10 parts of ion-exchanged water was added and stirred at 23 ° C. for 30 minutes. This washing operation was further performed 3 times. The obtained organic layer was charged with 0.50 part of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated to obtain 2.89 parts of the salt represented by the formula (B5-b).

式（Ｂ５−ｂ）で表される化合物２．５５部、ジメチルホルムアミド２０．００部及び式（Ｂ５−ｃ）で表される化合物０．６９部を仕込み、２３℃で３０分間攪拌し、炭酸カリウム０．０５部を仕込み、２３℃で２時間攪拌した。得られた反応物に、クロロホルム３０部及びイオン交換水１０部を仕込み、攪拌、分液を行った。水洗を６回行った。得られた有機層に活性炭０．６０部を仕込み、２３℃で３０分間攪拌し、ろ過した。ろ液を濃縮し、得られた濃縮物に、アセトニトリル１０部を添加して溶解し、濃縮した。その後、これに、ｔｅｒｔ−ブチルメチルエーテル３０部を加えて攪拌し、上澄液を除去した。得られた残渣をクロロホルムに溶解し、濃縮した。得られた濃縮物をカラム（メルク シリカゲル６０−２００メッシュ 展開溶媒：クロロホルム／メタノール＝５／１）分取することにより、式（Ｂ５）で表される塩１．１２部を得た。

Charge 2.55 parts of the compound represented by the formula (B5-b), 20.00 parts of dimethylformamide and 0.69 parts of the compound represented by the formula (B5-c), and stir at 23 ° C. for 30 minutes. 0.05 part of potassium was charged and stirred at 23 ° C. for 2 hours. To the obtained reaction product, 30 parts of chloroform and 10 parts of ion-exchanged water were added, followed by stirring and liquid separation. Water washing was performed 6 times. The obtained organic layer was charged with 0.60 part of activated carbon, stirred at 23 ° C. for 30 minutes, and filtered. The filtrate was concentrated, and 10 parts of acetonitrile was added to the resulting concentrate to dissolve and concentrate. Thereafter, 30 parts of tert-butyl methyl ether was added thereto and stirred, and the supernatant was removed. The obtained residue was dissolved in chloroform and concentrated. The resulting concentrate was fractionated in a column (Merck silica gel 60-200 mesh developing solvent: chloroform / methanol = 5/1) to obtain 1.12 parts of the salt represented by the formula (B5).

Identification of the salt represented by the formula (B5);
MS (ESI (+) Spectrum): M ⁺ 276.1
MS (ESI (-) Spectrum): M ^- 547.2

The monomers used in the resin synthesis are shown below.

[Synthesis of Resin A1]
A monomer represented by formula (A), a monomer represented by formula (E), a monomer represented by formula (B), a monomer represented by formula (C) and a monomer represented by formula (D) The molar ratio was 30: 14: 6: 20: 30. Subsequently, 1.5 mass times dioxane was added with respect to the total mass of all the monomers. Into the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were respectively added to 1.00 mol% and 3.00 mol% with respect to the total number of moles of all monomers. And heated at 75 ° C. for about 5 hours. Thereafter, the reaction solution is purified by pouring it into a large amount of methanol / water mixed solvent (4: 1) and precipitating three times, and the weight average molecular weight is about 7.2 × 10 ^3. The coalescence was obtained with a yield of 78%. This copolymer has a structural unit of the following formula, and this is designated as resin A1.

[Synthesis of Resin A2]
The monomer represented by the formula (A), the monomer represented by the formula (B) and the monomer represented by the formula (C) are charged in a molar ratio of 50:25:25, and then the total mass of all the monomers. 1.5 times by mass of dioxane was added. To the obtained mixture, azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators in proportions of 1 mol% and 3 mol%, respectively, with respect to the total number of moles of all monomers. This was heated at 80 ° C. for about 8 hours. Thereafter, the reaction solution is purified by pouring it into a large amount of methanol / water mixed solvent (3: 1) and precipitating three times, and the weight average molecular weight is about 9.2 × 10 ^3. The coalescence was obtained in 60% yield. This copolymer has a structural unit of the following formula, and this is designated as resin A2.

(Preparation of resist composition)
As shown in Table 1, the resist composition was prepared by filtering the mixture obtained by mixing and dissolving each component with a fluororesin filter having a pore diameter of 0.2 μm.

<Resin>
Resins A1 to A2
Resin A3: having a structural unit of the following formula

Ｂ２：式（Ｂ２）で表される塩

Ｂ３：式（Ｂ３）で表される塩

Ｂ４：式（Ｂ４）で表される塩

Ｂ５：式（Ｂ５）で表される塩

Ｘ１：式（Ｘ１）で表される塩

Ｘ２：式（Ｘ２）で表される塩

<Acid generator>
B1: Salt represented by the formula (B1)

B2: salt represented by formula (B2)

B3: salt represented by the formula (B3)

B4: salt represented by formula (B4)

B5: salt represented by the formula (B5)

X1: Salt represented by the formula (X1)

X2: salt represented by the formula (X2)

<Basic compound: Quencher>
C1: 2,6-Diisopropylaniline <Solvent>
Propylene glycol monomethyl ether acetate 265 parts 2-heptanone 20.0 parts Propylene glycol monomethyl ether 20.0 parts γ-butyrolactone 3.5 parts

[Evaluation of resist composition]
An organic antireflective coating composition [ARC-29; manufactured by Nissan Chemical Industries, Ltd.] was applied onto a 12-inch silicon wafer and baked at 205 ° C. for 60 seconds to obtain a thickness of 78 nm. An organic antireflection film was formed. Next, the resist composition was spin-coated on the organic antireflection film so that the film thickness after drying (pre-baking) was 110 nm.
The obtained silicon wafer was pre-baked (PB) for 60 seconds on the direct hot plate at the temperature described in the “PB” column of Table 1. An ArF excimer laser stepper for immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, 2-poles on axis illumination (σout = 0.97, σin) = 0.77, Y-polarized light], the line and space pattern was subjected to immersion exposure by changing the exposure amount in stages, and ultrapure water was used as the immersion medium.
After the exposure, post-exposure baking (PEB) was performed on the hot plate at the temperature described in the “PEB” column of Table 1 for 60 seconds.
Further, paddle development was performed for 60 seconds with an aqueous 2.38 mass% tetramethylammonium hydroxide solution to obtain a resist pattern.

  In forming a resist pattern from each resist composition, the exposure amount at which the line width of a 50 nm line-and-space pattern was 1: 1 was defined as effective sensitivity.

Exposure margin evaluation (EL): The exposure amount is plotted on the horizontal axis and the line width of a 50 nm line pattern formed at the exposure amount is plotted on the vertical axis in the exposure range of effective sensitivity ± 10%.
The absolute value of the slope of the regression line obtained from the plot is
What is 1.1 nm / (mJ / cm ² ) or less, ◎,
The one below 1.3 nm / (mJ / cm ² ) ○
More than 1.3 nm / (mJ / cm ² ) and 1.5 nm / (mJ / cm ² ) or less Δ
What exceeded 1.5 nm / (mJ / cm < ² >) was set as x.

Mask error factor evaluation (MEF): Line patterns were formed using masks with mask sizes of 48 nm, 50 nm, and 52 nm (pitch are both 100 nm) in effective sensitivity. The mask size is plotted on the horizontal axis, and the line widths of line patterns formed using masks of each mask size are plotted on the vertical axis. When the slope of the regression line obtained from the plot is 2.3 or less,
○ less than 2.5
Δ over 2.5 and under 3.0
What exceeded 3.0 was set as x.
These results are shown in Table 2.

  According to the salt of the present invention, a resist composition containing the salt is excellent in exposure margin (EL) and mask error factor (MEF) when forming a resist pattern.

Claims (7)

A salt represented by the formula (I).

[In Formula (I), R ¹ represents a saturated hydrocarbon group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 14 carbon atoms, and is included in the saturated hydrocarbon group and the aromatic hydrocarbon group. The hydrogen atom to be substituted may be substituted with a hydroxy group, a halogen atom or an alkyl group having 1 to 6 carbon atoms.
R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ are each independently a hydrogen atom, a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms or a carbon number of 1 Represents an alkoxy group of -6.
R ¹⁰ and R ¹¹ each independently represents a fluorine atom or a C 1-6 perfluoroalkyl group.
L ¹ represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, and the divalent —CH ₂ — contained in the saturated hydrocarbon group may be replaced by —O— or —CO—.
Y represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms which may have a substituent or a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the aliphatic group —CH ₂ — contained in the hydrocarbon group and the saturated cyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—. ] L ¹ is * —CO—O— (CH ₂ ) _n — (* represents a bond with —C (R ¹⁰ ) (R ¹¹ ) —, and n represents 0 or 1). 1. The salt according to 1.   The acid generator containing the salt of Claim 1 or 2.   A resin comprising an acid generator according to claim 3 and a resin, wherein the resin has an acid labile group and is insoluble or hardly soluble in an alkaline aqueous solution, and is dissolved in the alkaline aqueous solution by the action of the acid. A resist composition which is a resin to be obtained.   The resist composition according to claim 4, further comprising a basic compound.   Furthermore, the resist composition of Claim 4 or 5 containing a solvent. (1) The process of apply | coating the resist composition of Claim 6 on a board | substrate,
(2) a step of removing the solvent from the composition after coating to form a composition layer;
(3) a step of exposing the composition layer using an exposure machine;
(4) A step of heating the composition layer after exposure,
(5) A method for producing a resist pattern, comprising a step of developing the heated composition layer using a developing device.