JP2011190247A - Salt and resist composition - Google Patents

Abstract

【選択図】なしA salt for an acid generator of a resist composition capable of forming a pattern having excellent line edge roughness is provided.
A salt represented by formula (I). [In Formula (I), R ¹ and R ² each independently represent a fluorine atom or a C ₁ -C ₆ perfluoroalkyl group. X ¹ represents a divalent C _{1 to} C ₁₇ saturated hydrocarbon group, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, and the divalent saturated carbon group —CH ₂ — contained in the hydrogen group may be replaced by —O— or —CO—. Z ¹⁺ represents an organic counter ion. ]

[Selection figure] None

Description

  The present invention relates to a salt and a resist composition for an acid generator used for fine processing of semiconductors.

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

JP 2007-161707 A

  In the resist composition containing the conventional acid generator, the line edge roughness (LER) of the pattern obtained may not necessarily be satisfied.

［式（Ｉ）中、
Ｒ^１及びＲ^２は、互いに独立に、フッ素原子又はＣ₁〜Ｃ₆ペルフルオロアルキル基を表す。
Ｘ^１は、２価のＣ₁〜Ｃ₁₇飽和炭化水素基を表し、前記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、前記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。
Ｚ^{１ ＋}は、有機対イオンを表す。］ The present invention includes the following inventions.
[1] A salt represented by the formula (I).

[In the formula (I),
R ¹ and R ² each independently represent a fluorine atom or a C ₁ -C ₆ perfluoroalkyl group.
X ¹ represents a divalent C _{1 to} C ₁₇ saturated hydrocarbon group, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, and the divalent saturated carbon group —CH ₂ — contained in the hydrogen group may be replaced by —O— or —CO—.
Z ^{1 +} represents an organic counter ion. ]

[2] X ¹ represents a bond with * —CO—O—CH ₂ —CO— or —CH ₂ —O—CO—CH ₂ — (* represents —C (R ¹ ) (R ² ) —. The salt according to [1].

[3] The salt according to [1] or [2], wherein Z ^{1 +} is an arylsulfonium cation.

[4] An acid generator containing the salt according to any one of [1] to [3].

[5] A resist composition comprising the acid generator according to [4] and a resin.

[6] The resist composition according to [5], further comprising another acid generator different from the salt represented by the formula (I).

［式（Ｂ１）中、
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又はＣ₁〜Ｃ₆ペルフルオロアルキル基を表す。
Ｌ^b1は、単結合又は２価のＣ₁〜Ｃ₁₇飽和炭化水素基を表し、前記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Ｃ₁〜Ｃ_１８脂肪族炭化水素基又は置換基を有していてもよいＣ₃〜Ｃ_１８飽和環状炭化水素基を表し、前記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−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−で置き換わっていてもよい。
Ｚ⁺は、有機カチオンを表す。］ [7] The resist composition according to [6], wherein the other acid generator is an acid generator containing a salt represented by the formula (B1).

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C _{1 to} C ₆ perfluoroalkyl group.
L ^b1 represents a single bond or a divalent C _{1 to} C ₁₇ saturated hydrocarbon group, and —CH ₂ — contained in the divalent saturated hydrocarbon group is replaced by —O— or —CO—. Also good.
Y represents a C _{1 to} C ₁₈ aliphatic hydrocarbon group which may have a substituent or a C _{3 to} C ₁₈ saturated cyclic hydrocarbon group which may have a substituent, and the aliphatic hydrocarbon —CH ₂ — contained in the group and the saturated cyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z ⁺ represents an organic cation. ]

[8] The resist composition according to [7], wherein L ^b1 is * —CO—O— (* represents a bond with —C (Q ¹ ) (Q ² ) —).

[9] The resist composition according to [7] or [8], wherein Z ⁺ is a triarylsulfonium cation.

[10] Any of [5] to [9], wherein the resin has an acid labile group and is insoluble or hardly soluble in an alkaline aqueous solution and can be dissolved in an alkaline aqueous solution by the action of an acid. The resist composition as described.

[11] The resist composition according to any one of [5] to [10], which contains a basic compound.

[12] (1) A step of applying the resist composition according to any one of [5] to [11] on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer using an exposure machine;
(4) A step of heating the composition layer after exposure,
(5) a step of developing the heated composition layer using a developing device;
A method for producing a resist pattern including:

  According to the resist composition of the present invention, a pattern having excellent line edge roughness (LER) can be obtained.

［式（Ｉ）中、
Ｒ^１及びＲ^２は、互いに独立に、フッ素原子又はＣ₁〜Ｃ₆ペルフルオロアルキル基を表す。
Ｘ^１は、２価のＣ₁〜Ｃ₁₇飽和炭化水素基を表し、前記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、前記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。
Ｚ^{１ ＋}は、有機対イオンを表す。］ <Salt represented by formula (I) (hereinafter sometimes referred to as “salt (I)”. The same applies to other symbols)>
The salt of the present invention is represented by the formula (I).

[In the formula (I),
R ¹ and R ² each independently represent a fluorine atom or a C ₁ -C ₆ perfluoroalkyl group.
X ¹ represents a divalent C _{1 to} C ₁₇ saturated hydrocarbon group, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, and the divalent saturated carbon group —CH ₂ — contained in the hydrogen group may be replaced by —O— or —CO—.
Z ^{1 +} represents an organic counter ion. ]

R ¹ and R ² each independently represents a fluorine atom or a C _{1 to} C ₆ perfluoroalkyl group. Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. . R ¹ and R ² are each independently preferably a perfluoromethyl group or a fluorine atom, more preferably a fluorine atom.

X ¹ represents a divalent C _{1 to} C ₁₇ saturated hydrocarbon group. Examples of the divalent saturated hydrocarbon group include a linear alkanediyl group, a branched alkanediyl group, and a cyclic saturated hydrocarbon group.
Examples of the linear alkanediyl group include a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, and hexane-1,6-diyl. Group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1 , 12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1,17-diyl group Is mentioned.
The branched alkanediyl group, for example, the linearized alkanediyl group, C ₁ -C ₄ alkyl group (e.g. methyl group, an ethyl group, a propyl group, an isopropyl group, butyl group, sec- butyl group, tert-butyl group and the like).
Examples of the divalent cyclic saturated hydrocarbon group include a cycloalkanediyl group (for example, cyclohexanediyl group) and a divalent bridged cyclic hydrocarbon group (for example, adamantanediyl group).
X ¹ may be a combination of two or more of these groups.

—CH ₂ — in X ¹ may be replaced by —O— or —CO—. X ¹ is preferably a group represented by the formula (X1).

［式中、ｍｘは０又は１の整数を表す。
Ｘ^１１は、Ｃ₁〜Ｃ_1４飽和炭化水素基を表す。
＊は結合手を表す。］
式（Ｘ１）で表される基としては、式（Ｘ−１）で表される基及び式（Ｘ１−２）で表される基が挙げられ、より好ましくは式（Ｘ１−２）で表される基である。なお式（Ｘ１）、式（Ｘ１−１）又は式（Ｘ１−２）で表される基は、左側でＣ（Ｒ^１）（Ｒ^２）と結合し、右側で窒素原子と結合する。

[Wherein, mx represents an integer of 0 or 1.
X ¹¹ represents a C ₁ -C ₁₄ saturated hydrocarbon radicals.
* Represents a bond. ]
Examples of the group represented by the formula (X1) include a group represented by the formula (X-1) and a group represented by the formula (X1-2), and more preferably a group represented by the formula (X1-2). Group. Note that the group represented by the formula (X1), the formula (X1-1), or the formula (X1-2) is bonded to C (R ¹ ) (R ² ) on the left side and bonded to a nitrogen atom on the right side.

［式中、Ｘ^１１は、Ｃ₁〜Ｃ_1４飽和炭化水素基を表す。
＊は結合手を表す。］

[Wherein, X ¹¹ represents a C _{1 to} C ₁₄ saturated hydrocarbon group.
* Represents a bond. ]

X ¹¹ is preferably —CH ₂ —, — (CH ₂ ) ₂ —, — (CH ₂ ) ₄ —, — (CH ₂ ) ₈ —, — (CH ₂ ) ₁₂ —.
The saturated hydrocarbon group for X ¹ may be substituted with a fluorine atom.
Examples of the divalent group represented by the formula (X1-2) include the following.

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

Examples of Z ¹⁺ include onium cations such as sulfonium cations, iodonium cations, ammonium cations, benzothiazolium cations, and phosphonium cations. Among these, a sulfonium cation and an iodonium cation are preferable, and an arylsulfonium cation is more preferable.

Z ¹⁺ in the formula (I) is preferably represented by any one of the formulas (b2-1) to (b2-4).

In these formulas (b2-1) to (b2-4),
R ^{b4 to} R ^b6 each independently represent a C _{1 to} C ₃₀ aliphatic hydrocarbon group, a C _{3 to} C ₁₈ saturated cyclic hydrocarbon group, or a C _{6 to} C ₁₈ aromatic hydrocarbon group. The aliphatic hydrocarbon group may be substituted with a hydroxy group, a C _{1 to} C ₁₂ alkoxy group or a C _{6 to} C ₁₈ aromatic hydrocarbon group, and the saturated cyclic hydrocarbon group is a halogen atom, C ₂ -C ₄ acyl group or glycidyloxy group may be substituted with, the aromatic hydrocarbon group, a halogen atom, hydroxy group, C ₁ -C ₁₈ aliphatic hydrocarbon group, C ₃ -C ₁₈ saturated cyclic hydrocarbon hydrogen radical or C ₁ -C ₁₂ alkoxy group may be substituted.

R ^b7 and R ^b8 each independently represent a hydroxy group, a C _{1 to} C ₁₂ aliphatic hydrocarbon group or a C _{1 to} C ₁₂ alkoxy group.
m2 and n2 each independently represent an integer of 0 to 5.

R ^b9 and R ^b10 each independently represent a C _{1 to} C ₁₈ aliphatic hydrocarbon group or a C _{3 to} C ₁₈ saturated cyclic hydrocarbon group.
R ^b11 represents a hydrogen atom, a C _{1 to} C ₁₈ aliphatic hydrocarbon group, a C _{3 to} C ₁₈ saturated cyclic hydrocarbon group, or a C _{6 to} C ₁₈ aromatic hydrocarbon group.
The aliphatic hydrocarbon group for R ^{b9 to} R ^b11 is preferably C _{1 to} C ₁₂ , and the saturated cyclic hydrocarbon group is preferably C _{3 to} C ₁₈ , more preferably C _{4 to} C ₁₂ .
R ^b12 represents a C _{1 to} C ₁₂ aliphatic hydrocarbon group, a C _{3 to} C ₁₈ saturated cyclic hydrocarbon group, or a C _{6 to} C ₁₈ aromatic hydrocarbon group. The aromatic hydrocarbon group is substituted with C ₁ -C ₁₂ aliphatic hydrocarbon group, C ₁ -C ₁₂ alkoxy group, C ₃ -C ₁₈ saturated cyclic hydrocarbon group or a C ₁ -C ₁₂ alkylcarbonyloxy It may be.
R ^b9 and R ^b10 , and R ^b11 and R ^b12 may be independently bonded to each other to form a 3- to 12-membered ring (preferably a 3- to 7-membered ring), These rings —CH ₂ — may be replaced by —O—, —S— or —CO—.

R ^{b13 to} R ^b18 each independently represents a hydroxy group, a C _{1 to} C ₁₂ aliphatic hydrocarbon group or a C _{1 to} C ₁₂ alkoxy group.
L ^b11 represents -S- or -O-.
o2, p2, s2, and t2 each independently represents an integer of 0 to 5.
q2 and r2 each independently represents an integer of 0 to 4.
u2 represents 0 or 1.
When any of o2 to t2 is 2, any of the plurality of R ^{b13 to} R ^b18 may be the same as or different from each other.

  Examples of the alkylcarbonyloxy group include a methylcarbonyloxy group, an ethylcarbonyloxy group, an n-propylcarbonyloxy group, an isopropylcarbonyloxy group, an n-butylcarbonyloxy group, a sec-butylcarbonyloxy group, a tert-butylcarbonyloxy group, Examples thereof include a pentylcarbonyloxy group, a hexylcarbonyloxy group, an octylcarbonyloxy group, and a 2-ethylhexylcarbonyloxy group.

Preferred aliphatic hydrocarbon groups are methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, octyl and 2-ethylhexyl. It is.
Preferred saturated cyclic hydrocarbon groups are cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclodecyl group, 2-alkyl-2-adamantyl group, 1- (1-adamantyl) -1-alkyl group, And an isobornyl group.
Preferred aromatic hydrocarbon groups are phenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-cyclohexylphenyl group, 4-methoxyphenyl group, biphenylyl group, naphthyl group. It is.
Examples of the aliphatic hydrocarbon group (aralkyl group) whose substituent is an aromatic hydrocarbon group include a benzyl group.
Examples of the ring formed by R ^b9 and R ^b10 include a thiolane-1-ium ring (tetrahydrothiophenium ring), a thian-1-ium ring, and a 1,4-oxathian-4-ium ring.
^Examples of the ring formed by R ^b11 and R ^b12 include an oxocycloheptane ring, an oxocyclohexane ring, an oxonorbornane ring, and an oxoadamantane ring.

  Among the cations (b2-1) to (b2-4), the cation (b2-1) is preferable, the cation represented by the formula (b2-1-1) is more preferable, and the triphenylsulfonium cation (formula (b2) In (1-1), v2 = w2 = x2 = 0) is more preferable.

式（ｂ２−１−１）中、
Ｒ^b19〜Ｒ^b21は、それぞれ独立に、ハロゲン原子（より好ましくはフッ素原子）、ヒドロキシ基、Ｃ₁〜Ｃ_１８脂肪族炭化水素基、Ｃ₃〜Ｃ_１８飽和環状炭化水素基又はＣ₁〜Ｃ₁₂アルコキシ基を表す。
脂肪族炭化水素基は、好ましくはＣ_１〜Ｃ_１２であり、飽和環状炭化水素基は、好ましくはＣ_４〜Ｃ_１８である。
前記脂肪族炭化水素基は、ヒドロキシ基、Ｃ₁〜Ｃ₁₂アルコキシ基又はＣ₆〜Ｃ₁₈芳香族炭化水素基で置換されていてもよい。
前記飽和環状炭化水素基は、ハロゲン原子、Ｃ₂〜Ｃ₄アシル基又はグリシジルオキシ基で置換されていてもよい。
ｖ２〜ｘ２は、それぞれ独立に０〜５の整数（好ましくは０又は１）を表す。ｖ２〜ｘ２のいずれかが２以上のとき、それぞれ、複数のＲ^b19〜Ｒ^b21のいずれかは、互いに同一でも異なってもよい。
なかでも、Ｒ^b19〜Ｒ^b21は、それぞれ独立に、好ましくは、ハロゲン原子（より好ましくはフッ素原子）、ヒドロキシ基、Ｃ₁〜Ｃ₁₂アルキル基、又はＣ₁〜Ｃ₁₂アルコキシ基である。

In formula (b2-1-1),
R ^{b19 to} R ^b21 each independently represent a halogen atom (more preferably a fluorine atom), a hydroxy group, a C _{1 to} C ₁₈ aliphatic hydrocarbon group, a C _{3 to} C ₁₈ saturated cyclic hydrocarbon group, or a C _{1 to} C ₁₂ represents an alkoxy group.
The aliphatic hydrocarbon group is preferably C _{1 to} C ₁₂ , and the saturated cyclic hydrocarbon group is preferably C _{4 to} C ₁₈ .
The aliphatic hydrocarbon group, hydroxy group, may be substituted by C ₁ -C ₁₂ alkoxy or C ₆ -C ₁₈ aromatic hydrocarbon group.
The saturated cyclic hydrocarbon group may be substituted with a halogen atom, a C ₂ -C ₄ acyl group or a glycidyloxy group.
v2 to x2 each independently represents an integer of 0 to 5 (preferably 0 or 1). When any one of v2 to x2 is 2 or more, any one of the plurality of R ^{b19 to} R ^b21 may be the same as or different from each other.
Among these, R ^{b19 to} R ^b21 are preferably each independently a halogen atom (more preferably a fluorine atom), a hydroxy group, a C _{1 to} C ₁₂ alkyl group, or a C _{1 to} C ₁₂ alkoxy group.

Specific examples of the cation (b2-1-1) include the following.

Specific examples of the cation (b2-2) include the following.

Specific examples of the cation (b2-3) include the following.

Specific examples of the cation (b2-4) include the following.

The salt represented by the formula (I) is a combination of the above-mentioned anions and cations. Although the above-mentioned anion and cation can be combined arbitrarily, the salt represented below is preferable.

The salt represented by the formula (I) is, for example, the salt represented by the formula (IA) in which X ¹ is a group (—CO—) represented by the formula (X1-1). The salt represented by the formula (IA) can be obtained by reacting the salt represented by the formula (IA-2) with the compound represented by the formula (IA-2) in the presence of a catalyst. Examples of the solvent include acetonitrile. Examples of the catalyst include carbonyldiimidazole.
The salt represented by the formula (IA-1) can be synthesized by the method described in JP-A-2008-127367.
The compound represented by the formula (IA-2) is commercially available as 2,10-camphor sultam.

For example, a salt represented by the formula (IB) in which X ¹ is a group (—CO—O—X ¹¹ —CO—) represented by the formula (X1-2) is represented by the formula (IB-1). And a compound represented by the formula (IB-2) are reacted in the presence of a catalyst. Here, examples of the catalyst include potassium iodide and potassium carbonate. Examples of the solvent include dimethylformamide.
The salt represented by the formula (IB-1) can be synthesized by the method described in JP-A-2008-127367.

The salt represented by the formula (IB-2) can be obtained by reacting the compound represented by the formula (IB-3) with the compound represented by the formula (IB-4) in the presence of a base catalyst. . Here, sodium hydride etc. are mentioned as a catalyst. Examples of the solvent include toluene. Examples of the compound represented by the formula (IB-4) include chloroacetyl chloride.

  The acid generator of the present invention contains a salt represented by the formula (I). When used as an acid generator, the salt represented by the formula (I) may be used alone or in combination of two or more. The content of the salt represented by the formula (I) with respect to the total amount of the acid generator is preferably 5 parts by mass or more (more preferably 10 parts by mass or more), preferably 100 parts by mass with respect to 100 parts by mass of the acid generator. Or less.

  The resist composition of the present invention contains an acid generator containing a salt represented by the formula (I) and a resin, and further contains another acid generator.

  In the resist composition of the present invention, the content of the salt represented by the formula (I) is preferably 0.1 parts by mass or more (more preferably 0.5 parts by mass) with respect to 100 parts by mass of the resin (A). Or more, more preferably 1 part by mass or more), preferably 30 parts by mass or less (more preferably 20 parts by mass or less, more preferably 10 parts by mass or less).

<Other acid generators (hereinafter sometimes referred to as “acid generator (B)”)>
The acid generator (B) is classified into a nonionic type and an ionic type. Nonionic acid generators include organic halides, sulfonate esters (for example, 2-nitrobenzyl ester, aromatic sulfonate, oxime sulfonate, N-sulfonyloxyimide, N-sulfonyloxyimide, sulfonyloxyketone, DNQ 4- Sulfonate), sulfones (for example, disulfone, ketosulfone, sulfonyldiazomethane) and the like. The ionic acid generator is typically an onium salt containing an onium cation (for example, diazonium salt, phosphonium salt, sulfonium salt, iodonium salt). Examples of the anion of the onium salt include a sulfonate anion, a sulfonylimide anion, and a sulfonylmethide anion.

  Examples of the acid generator (B) include not only an acid generator (particularly a photoacid generator) used in the resist field, but also a photoinitiator for photocationic polymerization, a photodecolorant for dyes, or a photochromic agent. Known compounds that generate an acid by radiation (light) and mixtures thereof can also be used as appropriate. For example, JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, JP-A 63-163452, JP-A 62-153853, Acid can be obtained by radiation described in Japanese Utility Model Laid-Open No. 63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. The resulting compound can be used.

  The acid generator (B) is preferably a fluorine-containing acid generator, more preferably a sulfonate represented by the formula (B1).

［式（Ｂ１）中、
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又はＣ₁〜Ｃ₆ペルフルオロアルキル基を表す。
Ｌ^b1は、単結合又は２価のＣ₁〜Ｃ₁₇飽和炭化水素基を表し、前記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Ｃ₁〜Ｃ_１８脂肪族炭化水素基又は置換基を有していてもよいＣ₃〜Ｃ_１８飽和環状炭化水素基を表し、前記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−ＣＨ_２−は、−Ｏ−、−ＳＯ_２−又は−ＣＯ−で置き換わっていてもよい。
Ｚ⁺は、有機カチオンを表す。］

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C _{1 to} C ₆ perfluoroalkyl group.
L ^b1 represents a single bond or a divalent C _{1 to} C ₁₇ saturated hydrocarbon group, and —CH ₂ — contained in the divalent saturated hydrocarbon group is replaced by —O— or —CO—. Also good.
Y represents a C _{1 to} C ₁₈ aliphatic hydrocarbon group which may have a substituent or a C _{3 to} C ₁₈ saturated cyclic hydrocarbon group which may have a substituent, and the aliphatic hydrocarbon —CH ₂ — contained in the group and the saturated cyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z ⁺ represents an organic cation. ]

Examples of the perfluoroalkyl group include a perfluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluoro sec-butyl group, a perfluoro tert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. It is done.
In formula (B1), Q ¹ and Q ² are each independently preferably a perfluoromethyl group or a fluorine atom, more preferably a fluorine atom.

Examples of the divalent saturated hydrocarbon group include a linear alkylene group, a branched alkylene group, a monocyclic or polycyclic saturated cyclic hydrocarbon group, and a combination of two or more of these groups But you can.
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 alkylene groups such as 17-diyl group, methylidene group, ethylidene group, propylidene group, 2-propylidene group;
A straight-chain alkylene, an alkyl group (in particular, C ₁ -C ₄ alkyl group, e.g., methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec- butyl group, tert- butyl group, etc.) the side chain of For example, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group Branched alkylene such as 2-methyl-1,4-butylene group;
Monocyclic saturated cyclic hydrocarbon groups which are cycloalkylene groups such as 1,3-cyclobutylene group, 1,3-cyclopentylene group, 1,4-cyclohexylene group, 1,5-cyclooctylene group;
Examples thereof include polycyclic saturated cyclic hydrocarbon groups such as 1,4-norbornylene group, 2,5-norbornylene group, 1,5-adamantylene group, 2,6-adamantylene group and the like.

Examples of the group in which —CH ₂ — contained in the saturated hydrocarbon group of L ^b1 is replaced by —O— or —CO— include formula (b1-1) to formula (b1-6). L ^b1 is preferably any one of formulas (b1-1) to (b1-4), more preferably formula (b1-1) or formula (b1-2). Incidentally, the formula (b1-1) ~ formula (b1-6) are described together the left and right in the equation (B1), the left ^{C (Q 1) (Q 2} ) - bound to, the right side Combines with -Y. The same applies to specific examples of the following formulas (b1-1) to (b1-6).

式（ｂ１−１）〜式（ｂ１−６）中、
Ｌ^b2は、単結合又はＣ₁〜Ｃ₁₅アルキレン基を表す。
Ｌ^b3は、単結合又はＣ₁〜Ｃ₁₂アルキレン基を表す。
Ｌ^b4は、Ｃ₁〜Ｃ₁₃アルキレン基を表す。但しＬ^b3及びＬ^b4の炭素数上限は１３である。
Ｌ^b5は、Ｃ₁〜Ｃ₁₅アルキレン基を表す。
Ｌ^b6及びＬ^b7は、それぞれ独立に、Ｃ₁〜Ｃ₁₅アルキレン基を表す。但しＬ^b6及びＬ^b7の炭素数上限は１６である。
Ｌ^b8は、Ｃ₁〜Ｃ₁₄アルキレン基を表す。
Ｌ^b9及びＬ^b10は、それぞれ独立に、Ｃ₁〜Ｃ₁₁アルキレン基を表す。但しＬ^ｂ９及びＬ^ｂ１０の炭素数上限は１２である。
中でも、式（ｂ１−１）で表される２価の基が好ましく、Ｌ^b2が単結合又は−ＣＨ_２−である式（ｂ１−１）で表される２価の基がより好ましい。

In formula (b1-1) to formula (b1-6),
L ^b2 represents a single bond or a C _{1 to} C ₁₅ alkylene group.
L ^b3 represents a single bond or a C _{1 to} C ₁₂ alkylene group.
L ^b4 represents a C _{1 to} C ₁₃ alkylene group. However, the upper limit of the carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents a C _{1 to} C ₁₅ alkylene group.
L ^b6 and L ^b7 each independently represent a C _{1 to} C ₁₅ alkylene group. However, the upper limit of the carbon number of L ^b6 and L ^b7 is 16.
L ^b8 represents a C _{1 to} C ₁₄ alkylene group.
L ^b9 and L ^b10 each independently represent a C _{1 to} C ₁₁ alkylene group. However, the upper limit of the carbon number of L ^b9 and L ^b10 is 12.
Among these, a divalent group represented by the formula (b1-1) is preferable, and a divalent group represented by the formula (b1-1) in which L ^b2 is a single bond or —CH ₂ — is more preferable.

Examples of the divalent group represented by the formula (b1-1) include the following.

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

Examples of the divalent group represented by the formula (b1-3) include the following.

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

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

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

The saturated hydrocarbon group for L ^b1 may have a substituent. Examples of the substituent include a halogen atom, a hydroxy group, a carboxy group, a C _{6 to} C ₁₈ aromatic hydrocarbon group, a C _{7 to} C ₂₁ aralkyl group, a C _{2 to} C ₄ acyl group, and a glycidyloxy group. .
Examples of the aralkyl group include benzyl, phenethyl, phenylpropyl, trityl, naphthylmethyl group, naphthylethyl group, and the like.

Examples of the aliphatic hydrocarbon group of Y, C ₁ ~C ₆ alkyl group is preferable.
Examples of the substituent of the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group include a halogen atom (excluding a fluorine atom), a hydroxy group, an oxo group, a C _{1 to} C ₁₂ aliphatic hydrocarbon group, and a hydroxy group-containing C. ₁ -C ₁₂ aliphatic hydrocarbon group, C ₃ -C ₁₆ saturated cyclic hydrocarbon group, C ₁ -C ₁₂ alkoxy groups, C ₆ -C ₁₈ aromatic hydrocarbon group, C ₇ -C ₂₁ aralkyl group, C ₂ -C ₄ acyl group, glycidyloxy group, or _{- (CH 2) j2 -O-} CO-R b1 group (wherein, R ^b1 is, C ₁ -C ₁₆ aliphatic hydrocarbon group, C ₃ -C ₁₆ saturated cyclic Represents a hydrocarbon group or a C _{6 to} C ₁₈ aromatic hydrocarbon group, j2 represents an integer of 0 to 4, and the like. The aliphatic hydrocarbon group, saturated cyclic hydrocarbon group, aromatic hydrocarbon group, aralkyl group, and the like, which are substituents for Y, 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 hydroxyethyl 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, a cyclic ether group (—CH ₂ — is — O-, substituted groups), a saturated cyclic hydrocarbon group having an oxo group (-CH ₂ - is replaced by -CO- groups), sultone Hajime Tamaki (adjacent two -CH ₂ -, respectively, -O - or -SO ₂ - in the replaced groups) or lactone Hajime Tamaki (two adjacent -CH ₂ -, respectively, -O- or -CO- with replaced groups) and the like.

In particular, examples of the saturated cyclic hydrocarbon group for Y include groups represented by formulas (Y1) to (Y26).

  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 in which the — (CH ₂ ) _j2 —O—CO—R ^b1 group is substituted include the following.

  Y is preferably an adamantyl group which may have a substituent (for example, an oxo group or the like), more preferably an adamantyl group or an oxoadamantyl group.

Examples of the sulfonate anion in the salt represented by the formula (B1) include, for example, the following formulas (b1-1-1) to (b1-1-1-) in which the substituent L ^b1 is the formula (b1-1). The anion represented by 9) is preferred. In the following formulae, the definition of the substituent has the same meaning as described above, and the substituents R ^b2 and R ^b3 each independently represent a C _{1 to} C ₄ aliphatic hydrocarbon group (preferably a methyl group).

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 (b1-1) Examples of the sulfonate anion containing Y which is a hydrocarbon group and the divalent group represented by the formula (b1-1) 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 (b1-1), 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 (b1-1) 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 (b1-1) 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 (b1-1) include the following.

Examples of the sulfonate anion containing Y which is a lactone ring and the divalent group represented by the formula (b1-1) 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 (b1-1) include the following.

Examples of the sulfonate anion containing Y which is a sultone ring and the divalent group represented by the formula (b1-1) 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 (b1-2) Examples of the sulfonate anion containing Y which is a hydrocarbon group and the divalent group represented by the formula (b1-2) 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 (b1-2), 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 (b1-2) 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 (b1-2) include the following.

  Examples of the sulfonate anion containing Y which is a cyclic ether and the divalent group represented by the formula (b1-2) include the following.

  Examples of the sulfonate anion containing Y which is a lactone ring and the divalent group represented by the formula (b1-2) include the following.

  Examples of the sulfonate anion containing Y having an oxo group and the divalent group represented by the formula (b1-2) include the following.

  Examples of the sulfonate anion containing Y which is a sultone ring and the divalent group represented by the formula (b1-2) 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 (b1-3) Examples of the sulfonate anion containing the divalent group represented by the formula (b1-3) 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 (b1-3) 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 (b1-3) include the following: Things.

  Examples of the sulfonate anion containing Y having an oxo group and the divalent group represented by the formula (b1-3) 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 (b1-4) 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 (b1-4) 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 (b1-4) 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 (b1-4) include the following.

Among these, the following sulfonate anions having a divalent group represented by the formula (b1-1) are more preferable.

Next, the cation contained in the acid generator (B) will be described. Examples of the cation of the acid generator (B) include the same cation as Z ^{1+ of the} salt represented by the formula (I).

  The acid generator (B1) is a combination of the above-described sulfonate anion and organic cation. The above-mentioned anion and cation can be arbitrarily combined, but any one of anion (b1-1-1) to anion (b1-1-9) and a cation (b2-1-1), and an anion ( A combination of any one of b1-1-3) to (b1-1-5) and a cation (b2-3) is preferable.

  Preferred acid generators (B1) are those represented by formulas (B1-1) to (B1-17), and among these, acid generators (B1-1) and (B1) containing a triphenylsulfonium cation. -2), (B1-6), (B1-11), (B1-12), (B1-13) and (B1-14) are more preferred.

  The content of the acid generator (B) is preferably 1 part by mass or more (more preferably 3 parts by mass or more), preferably 30 parts by mass or less (more preferably) with respect to 100 parts by mass of the resin (A) described later. 25 parts by mass or less).

<Resin (hereinafter sometimes referred to as “resin (A)”)>
Resin (A) is a resin that becomes alkali-soluble by the action of an acid. A resin that becomes alkali-soluble by the action of an acid can be produced by polymerizing a monomer having an acid-labile group (hereinafter sometimes referred to as “monomer having an acid-labile group (a1)”), It becomes alkali-soluble by the action of acid. The phrase “becomes soluble in an alkali by the action of an acid” means “being insoluble or hardly soluble in an alkaline aqueous solution before contact with an acid, but soluble in an alkaline aqueous solution after contact with an acid”. . As the monomer (a1) having an acid labile group, one type may be used alone, or two or more types may be used in combination.

<Monomer (a1) having an acid labile group>
The term “acid-labile group” means a group that cleaves a leaving group upon contact with an acid to form a hydrophilic group (for example, a hydroxy group or a carboxy group). 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 (excluding a bridgehead carbon atom of a bridged cyclic hydrocarbon group) (ie, An ester bond having a tertiary alcohol residue). Hereinafter, the group represented by the formula (1) may be referred to as “acid-labile group (1)”.

式（１）中、Ｒ^a1〜Ｒ^a3は、それぞれ独立に、脂肪族炭化水素基又は飽和環状炭化水素基を表すか或いはＲ^a1及びＲ^a2は互いに結合して環を形成していてもよい。＊は結合手を表す（以下同じ）。

In formula (1), R ^{a1 to} R ^a3 each independently represents an aliphatic hydrocarbon group or a saturated cyclic hydrocarbon group, or R ^a1 and R ^a2 may be bonded to each other to form a ring. . * Represents a bond (same below).

式（１）では、飽和環状炭化水素基は、好ましくはＣ_３〜Ｃ_２０であり、より好ましくはＣ_３〜Ｃ_１２である。 The saturated cyclic hydrocarbon group may be monocyclic or polycyclic, for example, a cycloalkyl group (for example, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, a dimethylcyclohexyl group, a cycloheptyl group, Monocyclic saturated cyclic hydrocarbon groups such as cyclooctyl groups; groups obtained by hydrogenating condensed aromatic hydrocarbon groups (for example, hydronaphthyl groups), bridged cyclic hydrocarbon groups (for example, adamantyl groups, norbornyl) Group, methyl norbornyl group) and the like. 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.

In the formula (1), the saturated cyclic hydrocarbon group is preferably C _{3 to} C ₂₀ , more preferably C _{3 to} C ₁₂ .

Examples of the ring formed by combining R ^a1 and R ^a2 with each other include a saturated cyclic hydrocarbon group and an aromatic hydrocarbon group. Such rings are preferably _C 3 _{-C 20,} more preferably _C 3 _{-C 12.}

Examples of the acid labile group (1) include a 1,1-dialkylalkoxycarbonyl group (in the group (1), R ^{a1 to} R ^a3 are alkyl groups, preferably a tert-butoxycarbonyl group), 2-alkyl-2-adamantyloxycarbonyl 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- (1-adamantyl)- 1-alkylalkoxycarbonyl groups (in the formula (1), R ^a1 and R ^a2 are alkyl groups and R ^a3 is an adamantyl group) and the like.

  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 C _{5 to} C ₂₀ saturated cyclic hydrocarbon group 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 the (meth) acrylic monomers having the acid labile group (1) and the saturated cyclic hydrocarbon group, the acid labile group represented by the formula (a1-1) or the formula (a1-2) Monomers having are 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−を表し、ｋ１は１〜７の整数を表す。但しＬ^a1及びＬ^a2で列挙した−Ｏ−等は、それぞれ、左側で式（ａ１−１）及び式（ａ１−２）の−ＣＯ−と結合し、右側でアダマンチル基又はシクロへキシル基と結合することを意味する。
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、Ｃ₁〜Ｃ₈脂肪族炭化水素基又はＣ₃〜Ｃ₁₀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。

In formula (a1-1) and formula (a1-2),
L ^a1 and L ^a2 each independently represent —O— or —O— (CH ₂ ) _k1 —CO—O—, and k1 represents an integer of 1 to 7. However, —O— and the like enumerated for L ^a1 and L ^a2 are respectively bonded to —CO— of the formula (a1-1) and the formula (a1-2) on the left side, and to an adamantyl group or cyclohexyl group on the right side. Means to join.
R ^a4 and R ^a5 each independently represent a hydrogen atom or a methyl group.
R ^a6 and R ^a7 each independently represent a C _{1 to} C ₈ aliphatic hydrocarbon group or a C _{3 to} C ₁₀ saturated cyclic hydrocarbon group.
m1 represents the integer of 0-14.
n1 represents an integer of 0 to 10.

In the formula (a1-1) and the formula (a1-2), L ^a1 and L ^a2 are preferably, -O- or _{-O- (CH 2) f1 -CO-} O- and is (wherein f1 is 1 to 4), and more preferably -O-.
R ^a4 and R ^a5 are preferably methyl groups.
The aliphatic hydrocarbon group for R ^a6 and R ^a7 is preferably C ₆ or less. Saturated cyclic hydrocarbon group is preferably C ₈ or less, more preferably C 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.
k1 is preferably an integer of 1 to 4, more preferably 1.

  As a monomer (a1-1) which has an adamantyl group, the following are mentioned, for example. Among them, 2-methyl-2-adamantyl (meth) acrylate, 2-ethyl-2-adamantyl (meth) acrylate and 2-isopropyl-2-adamantyl (meth) acrylate are preferable, and those in the form of methacrylate are more preferable.

  As a monomer (a1-2) which has a cyclohexyl group, the following are mentioned, for example. Among these, 1-ethyl-1-cyclohexyl (meth) acrylate is preferable, and 1-ethyl-1-cyclohexyl methacrylate is more preferable.

  The content of the structural unit derived from the monomer represented by the formula (a1-1) or the formula (a1-2) in the resin is usually 10 to 95 mol%, preferably 15 to 90, in all units of the resin. It is 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 (a1-3) having an acid labile group has a bulky structure, the resolution of the resist can be improved. Furthermore, the monomer (a1-3) having an acid labile group can improve the resistance to dry etching of a 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、置換基（例えば、ヒドロキシ基）を有していてもよいＣ₁〜Ｃ₃脂肪族炭化水素基、カルボキシ基、シアノ基又はアルコキシカルボニル基（−ＣＯＯＲ^a13）を表し、Ｒ^a13は、Ｃ₁〜Ｃ₈脂肪族炭化水素基又はＣ₃〜Ｃ₈飽和環状炭化水素基を表し、前記脂肪族炭化水素基及び前記飽和環状炭化水素基の水素原子はヒドロキシ基で置換されていてもよく、前記脂肪族炭化水素基及び前記飽和環状炭化水素基の−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、Ｃ₁〜Ｃ₁₂脂肪族炭化水素基又はＣ₃〜Ｃ₁₂飽和環状炭化水素基を表すか、或いはＲ^a10及びＲ^a11は互いに結合して環を形成していてもよく、前記脂肪族炭化水素基及び前記飽和環状炭化水素基の水素原子はヒドロキシ基等で置換されていてもよく、前記脂肪族炭化水素基及び前記飽和環状炭化水素基の−ＣＨ_２−は−Ｏ−又は−ＣＯ−で置き換わっていてもよい。

In formula (a1-3),
R ^a9 represents a hydrogen atom, a C _{1 to} C ₃ aliphatic hydrocarbon group, a carboxy group, a cyano group or an alkoxycarbonyl group (—COOR ^a13 ) which may have a substituent (for example, a hydroxy group), R ^a13 represents a C _{1 to} C ₈ aliphatic hydrocarbon group or a C _{3 to} C ₈ saturated cyclic hydrocarbon group, and a hydrogen atom of the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group is substituted with a hydroxy group. And —CH ₂ — in the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group may be replaced by —O— or —CO—.
R ^{a10 to} R ^a12 each independently represent a C _{1 to} C ₁₂ aliphatic hydrocarbon group or a C _{3 to} C ₁₂ saturated cyclic hydrocarbon group, or R ^a10 and R ^a11 are bonded to each other to form a ring. The aliphatic hydrocarbon group and the hydrogen atom of the saturated cyclic hydrocarbon group may be substituted with a hydroxy group or the like, and —CH of the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group _2- 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 substituent for 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 (a1-3) having a norbornene ring include, for example, 5-norbornene-2-carboxylic acid-tert-butyl, 5-norbornene-2-carboxylic acid 1-cyclohexyl-1-methylethyl, 5-norbornene-2 -1-methylcyclohexyl carboxylate, 2-methyl-2-adamantyl 5-norbornene-2-carboxylate, 2-ethyl-2-adamantyl 5-norbornene-2-carboxylate, 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- (1-adap Pentyl) -1-methylethyl and the like.

  The content of the structural unit derived from the monomer represented by the formula (a1-3) in the resin is usually 10 to 95 mol%, preferably 15 to 90 mol%, more preferably in all units of the resin. Is 20 to 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Ｃ₁〜Ｃ₆アルキル基を表す。
Ｒ¹¹は、それぞれ独立に、ハロゲン原子、ヒドロキシ基、Ｃ₁〜Ｃ₆アルキル基、Ｃ₁〜Ｃ₆アルコキシ基、Ｃ₂〜Ｃ₄アシル基、Ｃ₂〜Ｃ₄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Ｃ₁〜Ｃ₁₂炭化水素基を表す。
Ｘ^ａ２は、単結合又は置換基を有していてもよい２価のＣ₁〜Ｃ₁₇飽和炭化水素基を表し、該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Ｃ₁〜Ｃ₆アルキル基を表す。
Ｙ^ａ３は、Ｃ₁〜Ｃ₁₂脂肪族炭化水素基、Ｃ₃〜Ｃ₁₈飽和環状炭化水素基又はＣ₆〜Ｃ₁₈芳香族炭化水素基であり、該脂肪族炭化水素基、飽和環状炭化水素基及び芳香族炭化水素基は、置換基を有していてもよい。］ Examples of the monomer having the acid labile group (1) and the carbon-carbon double bond include a monomer (a1-4) represented by the formula (a1-4).

[In the formula (a1-4),
R ¹⁰ represents a hydrogen atom, a halogen atom or a C ₁ -C ₆ alkyl group which may have a halogen atom.
R ¹¹ is independently a halogen atom, a hydroxy group, a C ₁ -C ₆ alkyl group, a C ₁ -C ₆ alkoxy group, a C ₂ -C ₄ acyl group, a C ₂ -C ₄ acyloxy group, an acryloyl group or a methacryloyl group. 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 represents a hydrogen atom or a C _{1 to} C ₁₂ hydrocarbon group.
X ^a2 represents a divalent C _{1 to} C ₁₇ saturated hydrocarbon group which may have a single bond or a substituent, and —CH ₂ — contained in the saturated hydrocarbon group represents —CO—, —O -, - S -, - SO 2 - or -N ^{(R c)} - it may be replaced by. R ^c represents a hydrogen atom or a C ₁ -C ₆ alkyl group.
Y ^a3 is a C _{1 to} C ₁₂ aliphatic hydrocarbon group, a C _{3 to} C ₁₈ saturated cyclic hydrocarbon group or a C _{6 to} C ₁₈ aromatic hydrocarbon group, and the aliphatic hydrocarbon group and saturated cyclic hydrocarbon The group and the aromatic hydrocarbon group may have a substituent. ]

Examples of the alkyl group that may have a halogen atom include a perfluoromethyl 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. Perfluorohexyl group, perchloromethyl group, perbromomethyl group, periodomethyl group and the like.
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. .
Examples of the acyl group include acetyl, propionyl, butyryl and the like.
Examples of the acyloxy group include acetyloxy, propionyloxy, butyryloxy and the like.
Examples of the hydrocarbon group include an aliphatic hydrocarbon group, a saturated cyclic hydrocarbon group, and an aromatic hydrocarbon group.
As aromatic hydrocarbon group, phenyl group, naphthyl group, anthranyl group, p-methylphenyl group, p-tert-butylphenyl group, p-adamantylphenyl group, tolyl group, xylyl group, cumenyl group, mesityl group, biphenyl Groups, anthryl groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.

In formula (a1-4), the alkyl groups of R ¹⁰ and R ¹¹ are preferably C _{1 to} C ₄ , more preferably C _{1 to} C ₂ , and particularly preferably a methyl group.
As the alkoxy group for R ¹¹ , C _{1 to} C ₂ are 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.
Examples of the group that may be substituted with the groups X ^a2 and Y ^a3 include a halogen atom, a hydroxy group, a C ₁ -C ₆ alkyl group, a C ₁ -C ₆ alkoxy group, a C ₂ -C ₄ acyl group, and a C ₂ -C ₄ acyloxy group, and the like. Of these, a hydroxy group is preferable.

  As a monomer (a1-4), the following monomers are mentioned, for example.

  The content of the structural unit derived from the monomer represented by the formula (a1-4) in the resin is usually 10 to 95 mol%, preferably 15 to 90 mol%, more preferably in all units of the resin. Is 20 to 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.

  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), high energy beam exposure such as electron beam or EUV light, the acid-stable monomer (a2) having a hydroxy group has an acid having a phenolic hydroxyl group which is a hydroxystyrene. It is preferable to use a stable monomer (a2-0). When using short wavelength ArF excimer laser exposure (193 nm) or the like, an acid stable monomer having a hydroxyadamantyl group represented by formula (a2-1) should be used as the acid stable monomer having a hydroxy group (a2). Is preferred. The acid-stable monomer (a2) having a hydroxy group may be used alone or in combination of two or more.

  Examples of the monomer (a2-0) having a phenolic hydroxyl group include styrene monomers such as p- or m-hydroxystyrene represented by the formula (a2-0).

［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Ｃ₁〜Ｃ₆アルキル基を表す。
Ｒ^９は、ハロゲン原子、ヒドロキシ基、Ｃ₁〜Ｃ₆アルキル基、Ｃ₁〜Ｃ₆アルコキシ基、Ｃ₂〜Ｃ₄アシル基、Ｃ₂〜Ｃ₄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は同一であっても異なってもよい。］

[In the formula (a2-0),
R ⁸ represents a C ₁ -C ₆ alkyl group which may have a hydrogen atom, a halogen atom or a halogen atom.
R ⁹ represents a halogen atom, a hydroxy group, a C ₁ -C ₆ alkyl group, a C ₁ -C ₆ alkoxy group, a C ₂ -C ₄ acyl group, a C ₂ -C ₄ acyloxy group, an acryloyl group or a methacryloyl group.
ma represents an integer of 0 to 4. When ma is an integer of 2 or more, the plurality of R ⁹ may be the same or different. ]

The alkyl group in R ^8, preferably C ₁ -C ₄ alkyl group, C ₁ -C more preferably ₂ alkyl group, a methyl group is particularly preferred.
Further, the alkoxy group is preferably a C ₁ -C ₄ alkoxy group, more preferably C ₁ -C ₂ alkoxy group, a methoxy group is particularly preferred.
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 hydroxyl group, the corresponding (meth) acrylic acid ester monomer, acetoxystyrene, and styrene are radically polymerized and then deacetylated with an acid. Can be obtained.
Examples of the monomer having a phenolic hydroxyl group include the following monomers.

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

  The content of the structural unit derived from the monomer represented by the formula (a2-0) in the resin is usually from 5 to 90 mol%, preferably from 10 to 85 mol%, more preferably in all units of the resin. Is 15 to 80 mol%.

  Examples of the acid stable monomer having a hydroxyadamantyl group include a monomer represented by the formula (a2-1).

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。
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。

In formula (a2-1),
L ^a3 represents —O— or —O— (CH ₂ ) _k2 —CO—O—,
k2 represents an integer of 1 to 7.
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-hydroxy-1-adamantyl (meth) acrylate, 3,5-dihydroxy-1-adamantyl (meth) acrylate, and 1- (3,5-dihydroxy-1-adamantyloxycarbonyl) methyl (meth) acrylate are Preferably, 3-hydroxy-1-adamantyl (meth) acrylate and 3,5-dihydroxy-1-adamantyl (meth) acrylate are more preferable, 3-hydroxy-1-adamantyl methacrylate and 3,5-dihydroxy-1-adamantyl methacrylate Is more preferable.

  The content of the structural unit derived from the monomer represented by the formula (a2-1) in the resin is usually 3 to 40 mol%, preferably 5 to 35 mol%, more preferably in all units of the resin. Is 5 to 30 mol%.

<Acid-stable monomer having a lactone ring (a3)>
The lactone ring possessed by the acid stable monomer (a3) may be, for example, a monocyclic ring such as a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, or a monocyclic lactone ring and another ring. 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。
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、Ｃ₁〜Ｃ₄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Ｃ₁〜Ｃ₄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.
R ^{a18 to} R ^a20 each independently represents a hydrogen atom or a methyl group.
R ^a21 represents a C _{1 to} C ₄ aliphatic hydrocarbon group.
p1 represents an integer of 0 to 5.
R ^a22 and R ^a23 each independently represent a carboxy group, a cyano group, or a C ₁ -C ₄ aliphatic hydrocarbon group.
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 the formula (a3-1) to the formula (a3-3), examples of L ^{a4 to} L ^a6 include those described for L ^a3 .
L ^{a4 to} L ^a6 are each independently preferably —O—, —O— (CH ₂ ) _d1 —CO—O— (wherein d1 is an integer of 1 to 4), more preferably -O-. However, —O— and the like enumerated in L ^{a4 to} L ^a6 mean that they are bonded to —CO— of the formula (a3-1) to the formula (a3-3) on the left side and to the lactone ring on the right side. To do.
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.

  As the acid stable monomer (a3-1) having a γ-butyrolactone ring, an acid labile monomer can also be exemplified. For example, the following are mentioned.

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

  As the acid stable monomer (a3-2) having a condensed ring of γ-butyrolactone ring and norbornane ring, an acid labile monomer can be exemplified. For example, the following are mentioned.

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

  An acid labile monomer can also be exemplified as the monomer (a3-3) having a condensed ring of γ-butyrolactone ring and cyclohexane ring. For example, the following are mentioned.

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.

  Content of the structural unit derived from the monomer represented by Formula (a3-1), Formula (a3-2), or Formula (a3-3) in the resin is usually 5 to 50 mol% in all units of the resin. Yes, preferably 10 to 45 mol%, more preferably 15 to 40 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、置換基（例えば、ヒドロキシ基）を有していてもよいＣ₁〜Ｃ₃脂肪族炭化水素基、シアノ基、カルボキシ基又はアルコキシカルボニル基（−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、Ｃ₁〜Ｃ_１８脂肪族炭化水素基又はＣ₃〜Ｃ_１８飽和環状炭化水素基を表し、脂肪族炭化水素基及び飽和環状炭化水素基の−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、３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 -C ₃ aliphatic hydrocarbon group, a cyano group, a carboxy group or an alkoxycarbonyl group (which may have a substituent (for example, a hydroxy group) ( -COOR ^a27 ) or R ^a25 and R ^a26 combine with each other to form -CO-O-CO-
R ^a27 represents a C _{1 to} C ₁₈ aliphatic hydrocarbon group or a C _{3 to} C ₁₈ saturated cyclic hydrocarbon group, and —CH ₂ — of the aliphatic hydrocarbon group and the saturated cyclic hydrocarbon group is —O— or It may be replaced by -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 substituent 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 is preferably C _{1 to} C ₈ , more preferably C _{1 to} C ₆ . The saturated cyclic hydrocarbon group is preferably C _{4 to} C ₁₈ , more preferably C _{4 to} C ₁₂ .
^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.

  Content of the structural unit derived from the monomer represented by Formula (a4-1), Formula (a4-2), or Formula (a4-3) in the resin is usually 2 to 40 mol% in all units of the resin. Yes, preferably 3-30 mol%, more preferably 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) and 50,000 or less (more preferably 30,000 or less).
It is preferable that content of resin (A) is 80 mass% or more 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 suitably 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, an amine). 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或いは芳香族炭化水素基を表す。但し前記脂肪族炭化水素基、前記飽和環状炭化水素基又は前記芳香族炭化水素基の水素原子は、ヒドロキシ基、アミノ基、又はＣ₁〜Ｃ₆アルコキシ基で置換されていてもよく、前記アミノ基は、Ｃ₁〜Ｃ₄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Ｃ_１〜Ｃ_６程度であり、前記飽和環状炭化水素基は、好ましくはＣ_５〜Ｃ_１０程度であり、前記芳香族炭化水素基は、好ましくはＣ_６〜Ｃ_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、或いはシクロアルキル基）、アルコキシ基、飽和環状炭化水素基或いは芳香族炭化水素基を表す。但し脂肪族炭化水素基、アルコキシ基、飽和環状炭化水素基及び芳香族炭化水素基の水素原子は、上記と同様の置換基を有していてもよい。
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Ｃ_１〜Ｃ_６程度である。

Here, Ar ^c1 represents an aromatic hydrocarbon group.
R ^c5 and R ^c6 each independently represent 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. However the aliphatic hydrocarbon group, a hydrogen atom of the saturated cyclic hydrocarbon group or the aromatic hydrocarbon group, hydroxy group, amino group, or a C ₁ -C ₆ alkoxy group may be substituted with the amino group may be substituted by C ₁ -C ₄ alkyl group.
The aliphatic hydrocarbon group is preferably about C _{1 to} C ₆ , the saturated cyclic hydrocarbon group is preferably about C _{5 to} C ₁₀ , and the aromatic hydrocarbon group is preferably C ₆ it is a ~C about _10.
R ^c7 represents an aliphatic hydrocarbon group (preferably an alkyl group or a cycloalkyl group), an alkoxy group, a saturated cyclic hydrocarbon group, or an aromatic hydrocarbon group. However, the hydrogen atom of an aliphatic hydrocarbon group, an alkoxy group, a saturated cyclic hydrocarbon group, and an aromatic hydrocarbon group may have a substituent similar to the 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 C ₁ -C _6.

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Ｃ_１〜Ｃ_６程度であり、飽和環状炭化水素基は、好ましくはＣ_３〜Ｃ_６程度であり、アルカノイル基は、好ましくはＣ_２〜Ｃ_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Ｃ_１〜Ｃ_６程度である。
Ｒ^c3は、Ｃ₁〜Ｃ₄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 is preferably about C _{1 to} C ₆ , the saturated cyclic hydrocarbon group is preferably about C _{3 to} C ₆ , and the alkanoyl group is preferably C _{2 to} C _6. Degree.
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 is preferably about C _{1 to} C ₆ .
R ^c3 represents a C ₁ -C ₄ alkyl group.

  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.

<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) The process of drying the composition after application | coating and forming 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 composition after application is dried to remove the solvent. The removal of the solvent is performed, for example, by evaporating the solvent using a heating device such as a hot plate or by using a decompression device to form a composition layer from which the solvent has been removed. 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. The exposure light source emits ultraviolet laser light such as KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), F ₂ laser (wavelength 157 nm), solid-state laser light source (YAG or semiconductor laser, etc.) Various types of laser beam can be used, such as those that convert the wavelength of the laser beam from) to radiate a harmonic laser beam in the far ultraviolet region or the vacuum ultraviolet region.

The composition layer after the exposure is subjected to heat treatment 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 is suitable as a resist composition for KrF excimer laser exposure, a resist composition for ArF excimer laser exposure, a resist composition for EB, or a resist composition for EUV exposure machines.

Hereinafter, the present invention will be described in detail by way of examples.
In Examples and Comparative Examples, “%” and “part” representing content and use amount are based on mass unless otherwise specified.
The weight average molecular weight is a value obtained by gel permeation chromatography (HLC-8120GPC, 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)

水素化ナトリウム１２．１６部、トルエン４００部及び式（ＩＩ−１）で表される化合物（商品名：２，１０−カンファースルタム、アルドリッチより購入）４１．４８部を仕込み、２３℃で３０分間攪拌した後、得られた混合物に式（ＩＩＩ−１）で表される化合物（商品名：クロロアセチルクロライド、東京化成より購入）２５．６９部を添加し、２３℃で２０時間攪拌した。得られた反応物にイオン交換水２００部及び酢酸エチル３００部を添加し、２３℃で３０分間攪拌した後、分液した。回収された有機層に、１Ｍ炭酸水素ナトリウム水溶液９２部を添加し、２３℃で３０分間攪拌した後、分液した。回収された有機層に、イオン交換水１８０部を添加し、２３℃で３０分間攪拌した後、分液した。この水洗を３回行った。得られた有機層を濃縮した後、メタノール１３０部を添加し、２３℃で３０分間攪拌した後、ろ過して、式（ＩＶ−１）で表される化合物２４．２１部を得た。 Example 1: [Synthesis of a salt represented by the formula (I-1)]

12.16 parts of sodium hydride, 400 parts of toluene, and 41.48 parts of a compound represented by the formula (II-1) (trade name: 2,10-camphor sultam, purchased from Aldrich) were charged at 30.degree. After stirring for 30 minutes, 25.69 parts of a compound represented by formula (III-1) (trade name: chloroacetyl chloride, purchased from Tokyo Kasei) were added to the resulting mixture, and the mixture was stirred at 23 ° C. for 20 hours. To the obtained reaction product, 200 parts of ion-exchanged water and 300 parts of ethyl acetate were added, stirred at 23 ° C. for 30 minutes, and then separated. To the collected organic layer, 92 parts of 1M aqueous sodium hydrogen carbonate solution was added, stirred at 23 ° C. for 30 minutes, and then separated. To the recovered organic layer, 180 parts of ion-exchanged water was added and stirred at 23 ° C. for 30 minutes, followed by liquid separation. This washing with water was performed three times. After concentrating the obtained organic layer, 130 parts of methanol was added and stirred at 23 ° C. for 30 minutes, followed by filtration to obtain 24.21 parts of a compound represented by the formula (IV-1).

式（Ｖ−１）で表される塩を、特開２００８−１２７３６７号公報に記載された方法で合成した。式（Ｖ−１）で表される塩４．９８部及びジメチルホルムアミド３０．０２部を仕込み、２３℃で３０分間攪拌した後、炭酸カルシウム１．５７部及びヨウ化カリウム０．４７部を仕込み、４０℃で３０分間攪拌した。得られた混合物に、式（ＩＶ−１）で表される化合物３．１５部を仕込み、４０℃で６時間攪拌した後、２３℃に冷却し、クロロホルム１７０部及び５％シュウ酸水溶液３２部を添加した。２３℃で３０分間攪拌した後、分液し、回収された有機層にイオン交換水６７部を仕込み、２３℃で３０分間攪拌した後、分液した。この水洗操作を３回繰り返した。得られた有機層に活性炭１．００部を仕込み、２３℃で３０分間攪拌した後、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１５．００部を添加して溶解した。これを濃縮し、酢酸エチル３７部を加えて攪拌し、上澄液を除去した。得られた残渣にｔｅｒｔ−ブチルメチルエーテル３７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、濃縮することにより、白色固体として、式（Ｉ−１）で表される塩３．０２部を得た。

The salt represented by the formula (V-1) was synthesized by the method described in JP 2008-127367 A. After charging 4.98 parts of the salt represented by the formula (V-1) and 30.02 parts of dimethylformamide and stirring at 23 ° C. for 30 minutes, 1.57 parts of calcium carbonate and 0.47 parts of potassium iodide were added. And stirred at 40 ° C. for 30 minutes. The resulting mixture was charged with 3.15 parts of the compound represented by formula (IV-1), stirred at 40 ° C. for 6 hours, cooled to 23 ° C., 170 parts of chloroform and 32 parts of 5% oxalic acid aqueous solution. Was added. After stirring at 23 ° C. for 30 minutes, liquid separation was performed, and 67 parts of ion-exchanged water was added to the collected organic layer. After stirring at 23 ° C. for 30 minutes, liquid separation was performed. This washing operation was repeated three times. The obtained organic layer was charged with 1.00 part of activated carbon, stirred at 23 ° C. for 30 minutes, and then filtered. The filtrate was concentrated, and 15.00 parts of acetonitrile was added and dissolved in the resulting concentrate. This was concentrated, 37 parts of ethyl acetate was added and stirred, and the supernatant was removed. To the obtained residue, 37 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed. The obtained residue was dissolved in chloroform and concentrated to obtain 3.02 parts of the salt represented by the formula (I-1) as a white solid.

MS (ESI (+) Spectrum): M ⁺ 263.1
MS (ESI (-) Spectrum): M ^- 430.0

リチウムアルミニウムハイドライド１０．４部、無水テトラヒドロフラン１２０部を仕込み２３℃で３０分間攪拌した。次いで、式（ＶＩ−２）で表される塩６２．２部を無水ＴＨＦ９００部に溶かした溶液を氷冷下で滴下し、２３℃で５時間攪拌した。反応マスに酢酸エチル５０．０部、６Ｎ塩酸５０．００部を添加、攪拌後、分液を行った。有機層を濃縮後、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（ＶＩＩ−２）で表される塩を８４．７部（純度６０％）を得た。
式（ＩＩＩ−２）で表される化合物１６．９１部、無水ＴＨＦ５００部を仕込み、２３℃で３０分間攪拌した。次いで、カルボニルジイミダゾール２８．９０部、無水ＴＨＦ５００部の混合溶液を２３℃で滴下し、２３℃で４時間攪拌した。得られた反応液を、式（ＶＩＩ−２）で表される塩６０．４０部（純度６０％）、無水ＴＨＦ５００部の混合液中に５４〜６０℃で、３０分間で滴下し、６０℃で１８時間加熱し、冷却後、ろ過した。得られたろ液を濃縮し、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（ＶＩＩＩ−２）で表される塩１５．４２部を得た。

水素化ナトリウム３．０４部、トルエン１００部及び式（ＩＩ−２）で表される化合物（商品名：２，１０−カンファースルタム、アルドリッチより購入）１０．３７部を仕込み、２３℃で３０分間攪拌した後、得られた混合物に式（ＶＩＩＩ−２）で表される化合物１４．８２部を添加し、２３℃で２０時間攪拌した。得られた反応物にイオン交換水５０部及び酢酸エチル１００部を添加し、２３℃で３０分間攪拌した後、分液した。回収された有機層を濃縮後、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（ＩＸ−２）で表される化合物１２．８６部を得た。

式（ＩＸ−２）で表される塩１２．１６部、クロロホルム３００部及びイオン交換水１００部を仕込み、２３℃で３０分間攪拌した。次いで、式（Ｘ−２）で表される塩８．３０部を加えて、２３℃で１２時間攪拌した後、分液を行った。有機層にイオン交換水１００部を添加、分液水洗を行った。この操作を３回行った。得られた有機層に活性炭３．００部を仕込み、２３℃で３０分間攪拌した後、ろ過した。ろ液を濃縮した後、得られた濃縮物に、アセトニトリル２００部を添加して溶解し、濃縮し、酢酸エチル２００部を加えて攪拌し、上澄液を除去した。得られた残渣にｔｅｒｔ−ブチルメチルエーテル２００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、濃縮した後、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（Ｉ−２）で表される塩５．８６部を得た。 Example 2: [Synthesis of salt represented by formula (I-2)]

10.4 parts of lithium aluminum hydride and 120 parts of anhydrous tetrahydrofuran were charged and stirred at 23 ° C. for 30 minutes. Next, a solution obtained by dissolving 62.2 parts of the salt represented by the formula (VI-2) in 900 parts of anhydrous THF was added dropwise under ice cooling, and the mixture was stirred at 23 ° C. for 5 hours. To the reaction mass, 50.0 parts of ethyl acetate and 50.00 parts of 6N hydrochloric acid were added, followed by liquid separation. After concentrating the organic layer, the column (Merck silica gel 60-200 mesh developing solvent: chloroform / methanol = 5/1) was collected to obtain 84.7 parts (purity 60) of the salt represented by the formula (VII-2). %).
16.91 parts of a compound represented by the formula (III-2) and 500 parts of anhydrous THF were charged and stirred at 23 ° C. for 30 minutes. Next, a mixed solution of 28.90 parts of carbonyldiimidazole and 500 parts of anhydrous THF was added dropwise at 23 ° C., and the mixture was stirred at 23 ° C. for 4 hours. The obtained reaction solution was dropped in a mixture of 60.40 parts (purity 60%) of the salt represented by the formula (VII-2) and 500 parts of anhydrous THF at 54 to 60 ° C. over 30 minutes, and 60 ° C. For 18 hours, cooled and filtered. The obtained filtrate was concentrated, and the concentrate was fractionated in a column (Merck silica gel 60-200 mesh developing solvent: chloroform / methanol = 5/1), whereby 15.42 salt represented by the formula (VIII-2). Got a part.

3.04 parts of sodium hydride, 100 parts of toluene and 10.37 parts of a compound represented by the formula (II-2) (trade name: 2,10-camphor sultam, purchased from Aldrich) were charged at 30 ° C. and 30 parts. After stirring for minutes, 14.82 parts of the compound represented by the formula (VIII-2) was added to the obtained mixture, and the mixture was stirred at 23 ° C. for 20 hours. To the obtained reaction product, 50 parts of ion-exchanged water and 100 parts of ethyl acetate were added, stirred at 23 ° C. for 30 minutes, and then separated. The collected organic layer is concentrated and then fractionated by a column (Merck silica gel 60-200 mesh developing solvent: chloroform / methanol = 5/1) to obtain 12.86 parts of the compound represented by the formula (IX-2). Obtained.

12.16 parts of a salt represented by the formula (IX-2), 300 parts of chloroform and 100 parts of ion-exchanged water were charged and stirred at 23 ° C. for 30 minutes. Next, 8.30 parts of the salt represented by the formula (X-2) was added and stirred at 23 ° C. for 12 hours, followed by liquid separation. 100 parts of ion-exchanged water was added to the organic layer, followed by liquid separation washing. This operation was performed three times. The obtained organic layer was charged with 3.00 parts of activated carbon, stirred at 23 ° C. for 30 minutes, and then filtered. After concentrating the filtrate, 200 parts of acetonitrile was added to the resulting concentrate to dissolve it, concentrated, 200 parts of ethyl acetate was added and stirred, and the supernatant was removed. To the obtained residue, 200 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed. The obtained residue was dissolved in chloroform and concentrated, and then the resulting concentrate was fractionated in a column (Merck silica gel 60-200 mesh developing solvent: chloroform / methanol = 5/1) to obtain the formula (I-2 ) Was obtained.

MS (ESI (+) Spectrum): M ⁺ 263.1
MS (ESI (-) Spectrum): M ^- 416.1

式（Ｖ−３）で表される塩５．４６部及びジメチルホルムアミド３０部を仕込み、２３℃で３０分間攪拌した後、炭酸カルシウム１．５７部及びヨウ化カリウム０．４７部を仕込み、４０℃で３０分間攪拌した。得られた混合物に、式（ＩＶ−１）で表される化合物３．１５部を仕込み、４０℃で６時間攪拌した後、２３℃に冷却し、クロロホルム１５０部及び５％シュウ酸水溶液３５部を添加した。２３℃で３０分間攪拌した後、分液し、回収された有機層にイオン交換水７５部を仕込み、２３℃で３０分間攪拌した後、分液した。この水洗操作を３回繰り返した。得られた有機層に活性炭１．００部を仕込み、２３℃で３０分間攪拌した後、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１５部を添加して溶解した。これを濃縮し、酢酸エチル４０部を加えて攪拌し、上澄液を除去した。得られた残渣にｔｅｒｔ−ブチルメチルエーテル４０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、濃縮することにより、式（Ｉ−３）で表される塩３．４８部を得た。 Example 3: [Synthesis of salt represented by formula (I-3)]

After charging 5.46 parts of the salt represented by the formula (V-3) and 30 parts of dimethylformamide and stirring at 23 ° C. for 30 minutes, 1.57 parts of calcium carbonate and 0.47 parts of potassium iodide were charged, 40 Stir at 30 ° C. for 30 minutes. The resulting mixture was charged with 3.15 parts of the compound represented by formula (IV-1), stirred at 40 ° C. for 6 hours, then cooled to 23 ° C., 150 parts of chloroform and 35 parts of 5% oxalic acid aqueous solution. Was added. After stirring at 23 ° C. for 30 minutes, liquid separation was performed, and 75 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, followed by liquid separation. This washing operation was repeated three times. The obtained organic layer was charged with 1.00 part of activated carbon, stirred at 23 ° C. for 30 minutes, and then filtered. The filtrate was concentrated, and 15 parts of acetonitrile was added to the resulting concentrate to dissolve it. This was concentrated, 40 parts of ethyl acetate was added and stirred, and the supernatant was removed. To the obtained residue, 40 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed. The obtained residue was dissolved in chloroform and concentrated to obtain 3.48 parts of the salt represented by the formula (I-3).

MS (ESI (+) Spectrum): M ⁺ 305.1
MS (ESI (-) Spectrum): M ^- 430.0

式（Ｖ−４）で表される塩５．１８部及びジメチルホルムアミド３０部を仕込み、２３℃で３０分間攪拌した後、炭酸カルシウム１．５７部及びヨウ化カリウム０．４７部を仕込み、４０℃で３０分間攪拌した。得られた混合物に、式（ＩＶ−１）で表される化合物３．１５部を仕込み、４０℃で６時間攪拌した後、２３℃に冷却し、クロロホルム１５０部及び５％シュウ酸水溶液３５部を添加した。２３℃で３０分間攪拌した後、分液し、回収された有機層にイオン交換水７５部を仕込み、２３℃で３０分間攪拌した後、分液した。この水洗操作を３回繰り返した。得られた有機層に活性炭１．００部を仕込み、２３℃で３０分間攪拌した後、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１５部を添加して溶解した。これを濃縮し、酢酸エチル４０部を加えて攪拌し、上澄液を除去した。得られた残渣にｔｅｒｔ−ブチルメチルエーテル４０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、濃縮することにより、式（Ｉ−４）で表される塩２．１４部を得た。 Example 4: [Synthesis of salt represented by formula (I-4)]

After charging 5.18 parts of the salt represented by the formula (V-4) and 30 parts of dimethylformamide and stirring at 23 ° C. for 30 minutes, 1.57 parts of calcium carbonate and 0.47 parts of potassium iodide were charged, 40 Stir at 30 ° C. for 30 minutes. The resulting mixture was charged with 3.15 parts of the compound represented by formula (IV-1), stirred at 40 ° C. for 6 hours, then cooled to 23 ° C., 150 parts of chloroform and 35 parts of 5% oxalic acid aqueous solution. Was added. After stirring at 23 ° C. for 30 minutes, liquid separation was performed, and 75 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, followed by liquid separation. This washing operation was repeated three times. The obtained organic layer was charged with 1.00 part of activated carbon, stirred at 23 ° C. for 30 minutes, and then filtered. The filtrate was concentrated, and 15 parts of acetonitrile was added to the resulting concentrate to dissolve it. This was concentrated, 40 parts of ethyl acetate was added and stirred, and the supernatant was removed. To the obtained residue, 40 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed. The obtained residue was dissolved in chloroform and concentrated to obtain 2.14 parts of the salt represented by the formula (I-4).

MS (ESI (+) Spectrum): M ⁺ 281.0
MS (ESI (-) Spectrum): M ^- 430.0

式（Ｖ−５）で表される塩４．３４部及びジメチルホルムアミド３０部を仕込み、２３℃で３０分間攪拌した後、炭酸カルシウム１．５７部及びヨウ化カリウム０．４７部を仕込み、４０℃で３０分間攪拌した。得られた混合物に、式（ＩＶ−１）で表される化合物３．１５部を仕込み、４０℃で６時間攪拌した後、２３℃に冷却し、クロロホルム１５０部及び５％シュウ酸水溶液３５部を添加した。２３℃で３０分間攪拌した後、分液し、回収された有機層にイオン交換水７５部を仕込み、２３℃で３０分間攪拌した後、分液した。この水洗操作を３回繰り返した。得られた有機層に活性炭１．００部を仕込み、２３℃で３０分間攪拌した後、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１５部を添加して溶解した。これを濃縮し、酢酸エチル４０部を加えて攪拌し、上澄液を除去した。得られた残渣にｔｅｒｔ−ブチルメチルエーテル４０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、濃縮することにより、式（Ｉ−５）で表される塩１．６４部を得た。 Example 5: [Synthesis of salt represented by formula (I-5)]

After charging 4.34 parts of the salt represented by the formula (V-5) and 30 parts of dimethylformamide and stirring at 23 ° C. for 30 minutes, 1.57 parts of calcium carbonate and 0.47 parts of potassium iodide were charged, 40 Stir at 30 ° C. for 30 minutes. The resulting mixture was charged with 3.15 parts of the compound represented by formula (IV-1), stirred at 40 ° C. for 6 hours, then cooled to 23 ° C., 150 parts of chloroform and 35 parts of 5% oxalic acid aqueous solution. Was added. After stirring at 23 ° C. for 30 minutes, liquid separation was performed, and 75 parts of ion-exchanged water was added to the collected organic layer, and the mixture was stirred at 23 ° C. for 30 minutes, followed by liquid separation. This washing operation was repeated three times. The obtained organic layer was charged with 1.00 part of activated carbon, stirred at 23 ° C. for 30 minutes, and then filtered. The filtrate was concentrated, and 15 parts of acetonitrile was added to the resulting concentrate to dissolve it. This was concentrated, 40 parts of ethyl acetate was added and stirred, and the supernatant was removed. To the obtained residue, 40 parts of tert-butyl methyl ether was added and stirred, and the supernatant was removed. The obtained residue was dissolved in chloroform and concentrated to obtain 1.64 parts of the salt represented by the formula (I-5).

MS (ESI (+) Spectrum): M ^<+> 207.1
MS (ESI (-) Spectrum): M ^- 430.0

〔樹脂Ａ１の合成〕
式（Ｄ）で表される化合物、式（Ｅ）で表される化合物、式（Ｂ）で表される化合物、式（Ｃ）で表される化合物及び式（Ｆ）で表される化合物を、モル比３０：１４：６：２０：３０の割合で仕込んだ。次いで、全モノマーの合計質量に対して、１．５質量倍のジオキサンを加えた。得られた混合物に、開始剤としてアゾビスイソブチロニトリルとアゾビス（２，４−ジメチルバレロニトリル）とを全モノマーの合計モル数に対して、それぞれ、１．００ｍｏｌ％と３．００ｍｏｌ％との割合で添加し、これを７３℃で約５時間加熱した。その後、反応液を、大量のメタノールと水との混合溶媒（４：１）に注いで沈殿させる操作を３回行うことにより精製し、重量平均分子量が約８．１×１０^３である共重合体を収率６５％で得た。この共重合体は、次式の構造単位を有するものであり、これを樹脂Ａ１とする。

〔樹脂Ａ２の合成〕
式（Ａ）で表される化合物、式（Ｂ）で表される化合物及び式（Ｃ）で表される化合物を、モル比５０：２５：２５の割合で仕込み、次いで、全モノマーの合計質量に対して、１．５質量倍のジオキサンを加えた。得られた混合物に、開始剤としてアゾビスイソブチロニトリルとアゾビス（２，４−ジメチルバレロニトリル）とを全モノマーの合計モル数に対して、それぞれ、１ｍｏｌ％と３ｍｏｌ％との割合で添加し、これを７７℃で約５時間加熱した。その後、反応液を、大量のメタノールと水との混合溶媒（３：１）に注いで沈殿させる操作を３回行うことにより精製し、重量平均分子量が約８．０×１０^３である共重合体を収率６０％で得た。この共重合体は、次式の構造単位を有するものであり、これを樹脂Ａ２とする。 The compounds used in the synthesis of the resin are shown below.

[Synthesis of Resin A1]
A compound represented by formula (D), a compound represented by formula (E), a compound represented by formula (B), a compound represented by formula (C), and a compound represented by formula (F) 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 73 ° C. for about 5 hours. Thereafter, the reaction solution is purified by performing the operation of pouring into a large amount of methanol / water mixed solvent (4: 1) and precipitating three times, and the weight average molecular weight is about 8.1 × 10 ^3. The coalescence was obtained with a yield of 65%. This copolymer has a structural unit of the following formula, and this is designated as resin A1.

[Synthesis of Resin A2]
The compound represented by the formula (A), the compound represented by the formula (B) and the compound represented by the formula (C) are charged at a molar ratio of 50:25:25, and then the total mass of all 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 77 ° C. for about 5 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 8.0 × 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.

  As shown in Table 1, a resist composition was prepared by filtering a mixture obtained by mixing and dissolving the following components through a fluororesin filter having a pore size of 0.2 μm.

Ｂ２：

Ｂ３：

<Resin>
A1: Resin A1
A2: Resin A2
<Acid generator>
I1: salt represented by formula (I-1) I2: salt represented by formula (I-2) I3: salt represented by formula (I-3) I4: represented by formula (I-4) Salt I5: salt B1: represented by formula (I-5)

B2:

B3:

<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

An organic antireflective coating composition [ARC-29; manufactured by Nissan Chemical Co., Ltd.] was applied onto a 12-inch silicon wafer and baked at 205 ° C. for 60 seconds to obtain a thickness of 780 mm. An organic antireflection film was formed. Next, the above resist composition was spin-coated on the organic antireflection film so that the film thickness after drying was 85 nm.
After applying the resist composition, the obtained silicon wafer was pre-baked (PB) for 60 seconds on a direct hot plate at the temperature described in the “PB” column of Table 1. Using the ArF excimer stepper for immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, 3/4 Annular XY polarized light] on the wafer on which the resist composition film is thus formed, the exposure amount is stepwise. The line and space pattern was subjected to immersion exposure.
After the exposure, post exposure bake (PEB) is performed on the hot plate at a temperature described in the “PEB” column of Table 1 for 60 seconds, and further with a 2.38 mass% tetramethylammonium hydroxide aqueous solution for 60 seconds. Paddle development was performed.

  In each resist film, the exposure amount at which the 50 nm line and space pattern becomes an exposure amount of 1: 1 was defined as the effective sensitivity.

  Line edge roughness evaluation (LER): The surface of the resist pattern after the lithography process is observed with a scanning electron microscope, and the contact width of the unevenness on the side wall of the resist pattern is 5 nm or less. And those exceeding 5 nm were evaluated as x. The results are shown in Table 2. The numerical value in the parenthesis indicates the touch width (nm) of the unevenness on the side wall of the resist pattern.

  According to the salt of the present invention, a pattern having excellent line edge roughness (LER) can be formed using a resist composition containing the salt.

Claims (12)

A salt represented by the formula (I).

[In the formula (I),
R ¹ and R ² each independently represent a fluorine atom or a C ₁ -C ₆ perfluoroalkyl group.
X ¹ represents a divalent C _{1 to} C ₁₇ saturated hydrocarbon group, and a hydrogen atom contained in the divalent saturated hydrocarbon group may be substituted with a fluorine atom, and the divalent saturated carbon group —CH ₂ — contained in the hydrogen group may be replaced by —O— or —CO—.
Z ^{1 +} represents an organic counter ion. ] X ¹ is * —CO—O—CH ₂ —CO— or —CH ₂ —O—CO—CH ₂ — (* represents a bond to —C (R ¹ ) (R ² ) —). The salt according to claim 1, wherein The salt according to claim 1 or 2, wherein Z ^{1 +} is an arylsulfonium cation.   The acid generator containing the salt in any one of Claims 1-3.   A resist composition comprising the acid generator according to claim 4 and a resin.   The resist composition according to claim 5, further comprising another acid generator different from the salt represented by formula (I). The resist composition according to claim 6, wherein the other acid generator is an acid generator containing a salt represented by the formula (B1).

[In the formula (B1),
Q ¹ and Q ² each independently represents a fluorine atom or a C _{1 to} C ₆ perfluoroalkyl group.
L ^b1 represents a single bond or a divalent C _{1 to} C ₁₇ saturated hydrocarbon group, and —CH ₂ — contained in the divalent saturated hydrocarbon group is replaced by —O— or —CO—. Also good.
Y represents a C _{1 to} C ₁₈ aliphatic hydrocarbon group which may have a substituent or a C _{3 to} C ₁₈ saturated cyclic hydrocarbon group which may have a substituent, and the aliphatic hydrocarbon —CH ₂ — contained in the group and the saturated cyclic hydrocarbon group may be replaced by —O—, —SO ₂ — or —CO—.
Z ⁺ represents an organic cation. ] The resist composition according to claim 7, wherein L ^b1 is * —CO—O— (* represents a bond with —C (Q ¹ ) (Q ² ) —). The resist composition according to claim 7 or 8, wherein Z ⁺ is a triarylsulfonium cation.   The resist composition according to any one of claims 5 to 9, wherein the resin is a resin having an acid labile group, insoluble or hardly soluble in an alkaline aqueous solution, and soluble in an alkaline aqueous solution by the action of an acid. .   The resist composition according to claim 5, comprising a basic compound. (1) The process of apply | coating the resist composition in any one of Claims 5-11 on a board | substrate,
(2) a step of drying 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 step of developing the heated composition layer using a developing device;
A method for producing a resist pattern including: