JP5903840B2 - Salt and resist composition - Google Patents

Description

  The present invention relates to a salt and a resist composition.

Patent Document 1 includes 2-ethyl-2-adamantyl methacrylate, 3-hydroxy-1-adamantyl methacrylate, methacrylic acid = 2 (5-oxo-4-oxatricyclo [4.2.1.03]. 7] Nonan-2-yloxy) -2-oxoethyl and a resin comprising structural units derived from α-methacryloyloxy-γ-butyrolactone, triphenylsulfonium = 4-oxoadamantan-1-yl-oxycarbonyl (difluoro) ) A resist composition comprising an acid generator composed of methanesulfonate, a quencher composed of 2,6-diisopropylaniline, and a solvent is described.
Patent Document 2 describes a resist composition comprising a resin, a photoacid generator, a compound represented by the following formula, a solvent, and a surfactant.

JP 2008-170983 A JP 2009-199021 A

  Conventional resist compositions may not always satisfy the line width roughness (LWR) of the resulting pattern.

［式（Ｉ）中、
Ｒ^１、Ｒ^２及びＲ^３は、それぞれ独立に、水素原子又は炭素数１〜１２の炭化水素を表すか、Ｒ^２及びＲ^３は互いに結合して炭素原子とともに炭素数３〜２０の環を形成し、該炭化水素基及び該環に含まれる水素原子は、ヒドロキシ基で置換されていてもよく、該炭化水素基及び該環に含まれる−ＣＨ_２−は−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
Ｒ^４及びＲ^５は、それぞれ独立に、水素原子、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｘ^１は、２価の炭素数１〜１７の炭化水素基を表し、前記２価の炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−Ｓ−又は−ＣＯ−で置き換わっていてもよい。また、前記２価の炭化水素基に含まれる水素原子は、−ＯＨで置き換わっていてもよい。
Ｒ^６は、水素原子又は炭素数１〜１２の炭化水素を表す。
Ａ^＋は、有機カチオンを表す。］ The present invention includes the following inventions.
[1] A salt represented by the formula (I).

[In the formula (I),
R ¹ , R ² and R ³ each independently represent a hydrogen atom or a hydrocarbon having 1 to 12 carbon atoms, or R ² and R ³ are bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom. And the hydrogen atom contained in the hydrocarbon group and the ring may be substituted with a hydroxy group, and —CH ₂ — contained in the hydrocarbon group and the ring may be —O— or —CO—. It may be replaced.
R ⁴ and R ⁵ each independently represent a hydrogen atom, a fluorine atom, or a C 1-6 perfluoroalkyl group.
X ¹ represents a divalent hydrocarbon group having 1 to 17 carbon atoms, and —CH ₂ — contained in the divalent hydrocarbon group is replaced by —O—, —S— or —CO—. Also good. The hydrogen atom contained in the divalent hydrocarbon group may be replaced with -OH.
R ⁶ represents a hydrogen atom or a hydrocarbon having 1 to 12 carbon atoms.
A ⁺ represents an organic cation. ]

[2] The salt according to [1], wherein R ¹ is an ethyl group, and R ² and R ³ are methyl groups.

[3] X ¹ represents ^* —CO—O— (CH ₂ ) _k1 —O—CO— (CH ₂ ) _k2 — ( ^* represents a bond with C (R ⁴ ) (R ⁵ ), and k1 and k2 represents each independently an integer of 1 to 6.) The salt according to [1] or [2].

[4] The salt according to any one of [1] to [3], wherein A ⁺ is a triarylsulfonium cation.

[5] A resist composition comprising the salt according to any one of [1] to [4] and a resin.

[6] The resist composition according to [5], 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.

[7] The resist composition according to [5] or [6], further comprising an acid generator.

[8] The resist composition according to any one of [5] to [7], further containing a basic compound.

[9] (1) A step of applying the resist composition according to any one of [5] to [8] 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, and (5) a step of developing the heated composition layer using a developing device,
A method for producing a resist pattern including:

  According to the salt of the present invention, a pattern having excellent line width roughness (LWR) can be obtained from a resist composition containing the salt.

［式（Ｉ）中、
Ｒ^１、Ｒ^２及びＲ^３は、それぞれ独立に、水素原子又は炭素数１〜１２の炭化水素を表すか、Ｒ^２及びＲ^３は互いに結合して炭素原子とともに炭素数３〜２０の環を形成し、該炭化水素基及び該環に含まれる水素原子は、ヒドロキシ基で置換されていてもよく、該炭化水素基及び該環に含まれる−ＣＨ_２−は−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
Ｒ^４及びＲ^５は、それぞれ独立に、水素原子、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｘ^１は、２価の炭素数１〜１７の炭化水素基を表し、前記２価の炭化水素基に含まれる−ＣＨ_２−は、−Ｏ−、−Ｓ−又は−ＣＯ−で置き換わっていてもよい。また、前記２価の炭化水素基に含まれる水素原子は、−ＯＨで置き換わっていてもよい。
Ｒ^６は、水素原子又は炭素数１〜１２の炭化水素を表す。
Ａ^＋は、有機カチオンを表す。］ The salt of the present invention is represented by the formula (I).

[In the formula (I),
R ¹ , R ² and R ³ each independently represent a hydrogen atom or a hydrocarbon having 1 to 12 carbon atoms, or R ² and R ³ are bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom. And the hydrogen atom contained in the hydrocarbon group and the ring may be substituted with a hydroxy group, and —CH ₂ — contained in the hydrocarbon group and the ring may be —O— or —CO—. It may be replaced.
R ⁴ and R ⁵ each independently represent a hydrogen atom, a fluorine atom, or a C 1-6 perfluoroalkyl group.
X ¹ represents a divalent hydrocarbon group having 1 to 17 carbon atoms, and —CH ₂ — contained in the divalent hydrocarbon group is replaced by —O—, —S— or —CO—. Also good. The hydrogen atom contained in the divalent hydrocarbon group may be replaced with -OH.
R ⁶ represents a hydrogen atom or a hydrocarbon having 1 to 12 carbon atoms.
A ⁺ represents an organic cation. ]

［式（ＩＡａ）中、Ｒ^１〜Ｒ^３は、上記と同じ意味を表す。＊は、Ｎとの結合手を表す。］ The group represented by the formula (IAa) contained in the salt represented by the formula (I) will be described.

[In Formula (IAa), R ^{1 to} R ³ represent the same meaning as described above. * Represents a bond with N. ]

  Examples of the hydrocarbon group having 1 to 12 carbon atoms include an alkyl group having 1 to 12 carbon atoms and an aralkyl group having 7 to 12 carbon atoms.

  Examples of the alkyl group having 1 to 12 carbon atoms include methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, and n-pentyl. Group, i-pentyl group, t-pentyl group, neopentyl group, 1-methylbutyl group, 2-methylbutyl group, 1,2-dimethylpropyl group, 1-ethylpropyl group, n-hexyl group, 1-methylpentyl group, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, (ethyl) pentyl, (methyl) hexyl, (ethyl) hexyl, (propyl) ) Hexyl group, 1,1-dimethylhexyl group and the like.

［＊は、結合手を表す。］ Examples of the aralkyl group having 7 to 12 carbon atoms include groups shown below.

[* Represents a bond. ]

Examples of the ring having 3 to 20 carbon atoms which R ² and R ³ are bonded to each other and formed together with the carbon atom include saturated hydrocarbon rings having 3 to 12 carbon atoms and aromatic rings having 6 to 20 carbon atoms. Includes the following rings.

—CH ₂ — contained in the ring may be replaced by —O— or —CO—. A hydrogen atom contained in the ring may be substituted with -OH. Examples of such a ring include the rings shown below.

Examples of the group represented by the formula (IAa) include groups represented by the formula (IAa-1) to the formula (IAa-29), and the group represented by the formula (IA-2) (R ¹ is ethyl). Group in which R ² and R ³ are methyl groups). * Represents the same meaning as in formula (IAa).

R ⁴ and R ⁵ each independently represent a hydrogen atom, a fluorine atom, or a C 1-6 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. . Q ¹ and Q ² are each independently preferably a perfluoromethyl group or a fluorine atom, more preferably a fluorine atom.

X ¹ represents a divalent hydrocarbon group having 1 to 17 carbon atoms. Examples of the divalent hydrocarbon group include a linear alkylene group, a branched alkylene group, and a cyclic hydrocarbon group.
Examples of the linear alkylene 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 a 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, etc. Is mentioned.
Examples of the branched alkylene group include an alkyl group having 1 to 4 carbon atoms (for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, tert-butyl group and the like).
Examples of the divalent cyclic 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—. The hydrogen atom contained in the divalent hydrocarbon group may be replaced with -OH. X ¹ is preferably represented by the formula (X1-A) to the formula (X1-F), more preferably the formula (X1-F). Note that the groups represented by the formulas (X1-A) to (X1-F) are bonded to C (R ⁴ ) (R ⁵ ) on the left side and bonded to a nitrogen atom on the right side.
Of the groups represented by the formula (X1-F), ^* —CO—O— (CH ₂ ) _k1 —O—CO— (CH ₂ ) _k2 — ( ^* represents C (R ⁴ ) (R ⁵ ). And k1 and k2 each independently represent an integer of 1 to 6).

［Ｘ^１１は、単結合又は炭素数１〜１５の炭化水素基を表す。
Ｘ^１２は、炭素数１〜１４の炭化水素基を表す。
Ｘ^１３、Ｘ^１５、Ｘ^１６及びＸ^１７は、それぞれ独立に、炭素数１〜１３の炭化水素基を表す。
Ｘ^１４及びＸ^１８は、それぞれ独立に、単結合又は炭素数１〜１２の炭化水素基を表す。
Ｘ^１１〜Ｘ^１８における炭化水素基に含まれる−ＣＨ_２−は、−Ｓ−で置き換わっていてもよい。］

[X ¹¹ represents a single bond or a hydrocarbon group having 1 to 15 carbon atoms.
X ¹² represents a hydrocarbon group having 1 to 14 carbon atoms.
X ¹³ , X ¹⁵ , X ¹⁶ and X ¹⁷ each independently represent a hydrocarbon group having 1 to 13 carbon atoms.
X ¹⁴ and X ¹⁸ each independently represent a single bond or a hydrocarbon group having 1 to 12 carbon atoms.
—CH ₂ — contained in the hydrocarbon group for X ^{11 to} X ¹⁸ may be replaced by —S—. ]

X ¹¹ , X ¹⁴ , X ¹⁶ and X ¹⁸ are a single bond, —CH ₂ —, — (CH ₂ ) ₂ —, — (CH ₂ ) ₄ —, — (CH ₂ ) ₈ —, — (CH ₂ ). _12- is preferred.
X ¹² , X ¹³ , X ¹⁵ , X ¹⁶ and X ¹⁷ are —CH ₂ —, — (CH ₂ ) ₂ —, — (CH ₂ ) ₄ —, — (CH ₂ ) ₈ —, — (CH ₂ ). _12- is preferred.

Examples of the divalent group represented by the formula (X1-B) include the following.

Examples of the divalent group represented by the formula (X1-C) include the following.

Examples of the divalent group represented by the formula (X1-D) include the following.

Examples of the divalent group represented by the formula (X1-E) include the following.

Examples of the divalent group represented by the formula (X1-F) include the following.

Preferred examples of the anion part (IA) of the salt represented by the formula (I) include the following anions.

Examples of A ⁺ 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.

A ⁺ is preferably represented by any one of formulas (b2-1) to (b2-4).

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

R ^b7 and R ^b8 each independently represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
m2 and n2 each independently represent an integer of 0 to 5.

R ^b9 and R ^b10 each independently represent an aliphatic hydrocarbon group having 1 to 18 carbon atoms or a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms.
R ^b11 represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
The aliphatic hydrocarbon group of R ^{b9 to} R ^b11 preferably has 1 to 12 carbon atoms, and the saturated cyclic hydrocarbon group preferably has 3 to 18 carbon atoms, more preferably 4 to 12 carbon atoms.
R ^b12 represents an aliphatic hydrocarbon group having 1 to 12 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The aromatic hydrocarbon group is an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, or an alkylcarbonyloxy having 1 to 12 carbon atoms. It may be substituted with a group.
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 represent a hydroxy group, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms.
L ^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、炭素数１〜１８の脂肪族炭化水素基、炭素数３〜１８の飽和環状炭化水素基又は炭素数１〜１２のアルコキシ基を表す。
脂肪族炭化水素基は、好ましくは炭素数１〜１２であり、飽和環状炭化水素基は、好ましくは炭素数４〜１８である。
前記脂肪族炭化水素基は、ヒドロキシ基、炭素数１〜１２のアルコキシ基又は炭素数６〜１８の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、炭素数２〜４の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、炭素数１〜１２のアルキル基、又は炭素数１〜１２の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, an aliphatic hydrocarbon group having 1 to 18 carbon atoms, a saturated cyclic hydrocarbon group having 3 to 18 carbon atoms, or a carbon number. 1 to 12 alkoxy groups are represented.
The aliphatic hydrocarbon group preferably has 1 to 12 carbon atoms, and the saturated cyclic hydrocarbon group preferably has 4 to 18 carbon atoms.
The aliphatic hydrocarbon group may be substituted with a hydroxy group, an alkoxy group having 1 to 12 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
The saturated cyclic hydrocarbon group may be substituted with a halogen atom, an acyl group having 2 to 4 carbon atoms, 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 them, R ^{b19 to} R ^b21 are preferably each independently a halogen atom (more preferably a fluorine atom), a hydroxy group, an alkyl group having 1 to 12 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. .

Specific examples of the cation include triarylsulfonium cations described in formulas (IB-1) to (IB-21), sulfonium cations of formulas (IC-31) to (IC-72), and JP2010-204646A. And the triarylsulfonium salts described in formulas (IB-1) to (IB-21) are preferred, and in particular, formula (IB-1), formula (IB-2) and formula ( More preferred is IB-10).

  Examples of the salt represented by the formula (I) include salts composed of anions and cations shown in the following table.

  Among the above-mentioned salts, Formula (I-1), Formula (I-21), Formula (I-22), Formula (I-29), Formula (I-33), Formula (I-53), Formula ( I-58), formula (I-62), formula (I-68), and salt represented by formula (I-104), respectively, are preferred, and formula (I-1), formula (I-21), formula (I I-33) and salts represented by formula (I-104) are more preferred.

［式（Ｉ−Ａ）中、Ｒ^１〜Ｒ^６、Ｘ^１７、Ｘ^１８及びＡ^＋は、それぞれ上記と同じ意味を表す。］ A method for producing the salt represented by the formula (I) is shown below.
Among the salts represented by the formula (I), the production method of the salt represented by the formula (IA) is shown below.

[In formula (IA), R ^{1 to} R ⁶ , X ¹⁷ , X ¹⁸ and A ⁺ each represent the same meaning as described above. ]

［Ｒ^１〜Ｒ^６、Ｘ^１７、Ｘ^１８及びＡ^＋は、それぞれ上記と同じ意味を表す。
Ｘ^ｈは塩素原子、臭素原子又はヨウ素原子を表す。］ By reacting a salt represented by the formula (IAa) with a compound represented by the formula (IAb) in a solvent under a basic condition, the salt is represented by the formula (IA). Can be obtained. Examples of the solvent include organic solvents such as acetonitrile, dimethylformamide, and tetrahydrofuran. Examples of the base to be used include inorganic salts such as potassium carbonate, sodium carbonate and sodium hydride, and triethylamine, DBU, dimethylaminopyridine, pyridine and the like.
The salt represented by the formula (IAa) can be synthesized, for example, by the method described in JP-A-2008-13551.

[R ^{1 to} R ⁶ , X ¹⁷ , X ¹⁸ and A ⁺ each have the same meaning as described above.
X ^h represents a chlorine atom, a bromine atom or an iodine atom. ]

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

The resist composition of the present invention contains a salt represented by the formula (I). The resist composition of the present invention further comprises a resin having an acid labile group and insoluble or hardly soluble in an alkaline aqueous solution, which can be dissolved in an alkaline aqueous solution by the action of an acid, an acid generator, a base It is preferable to contain an ionic compound.
The content of the salt represented by the formula (I) is preferably about 0.01 to 20% by mass, more preferably about 0.1 to 10% by mass, based on the solid content of the resist composition. Especially preferably, it is about 1-7 mass%. 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, for example, by a known analysis means such as liquid chromatography or gas chromatography.

<Resin (hereinafter sometimes referred to as “resin (A)”)>
The resin (A) is a resin having an acid labile group and insoluble or hardly soluble in an alkaline aqueous solution, and can be dissolved in an alkaline aqueous solution by the action of an acid. Resin (A) 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 melted. “Can be dissolved in an alkaline aqueous solution by the action of an acid” means that “it is insoluble or hardly soluble in an alkaline aqueous solution before contact with an acid, but becomes soluble in an alkaline aqueous solution after contact with an acid”. means. 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 a group represented by the formula (1) and a group represented by the formula (2).

［式（１）中、Ｒ^a1〜Ｒ^a3は、それぞれ独立に、炭素数１〜８のアルキル基又は炭素数３〜２０の脂環式炭化水素基を表すか、Ｒ^a1及びＲ^a2は互いに結合して炭素数２〜２０の２価の炭化水素基を形成する。＊は結合手を表す。］

［式（２）中、Ｒ^ａ1’及びＲ^ａ２’は、それぞれ独立に、水素原子又は炭素数１〜１２の炭化水素基を表し、Ｒ^ａ３’は、炭素数１〜２０の炭化水素基を表すか、Ｒ^ａ２’及びＲ^ａ３’は互いに結合して炭素数２〜２０の２価の炭化水素基を形成し、前記炭化水素基及び２価の基に含まれる−ＣＨ_２−は、−Ｏ―又は―Ｓ−で置き換わってもよい。

In Expression (1), R ^a1 ~R ^a3 each independently represent a cycloaliphatic hydrocarbon radical of the alkyl group or 3 to 20 carbon atoms having 1 to 8 carbon atoms, R ^a1 and R ^a2 are each Bonding to form a divalent hydrocarbon group having 2 to 20 carbon atoms. * Represents a bond. ]

[In Formula (2), R ^{a1 ′} and R ^{a2 ′} each independently represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and R ^{a3 ′} represents a hydrocarbon group having 1 to 20 carbon atoms. R ^{a2 ′} and R ^{a3 ′} are bonded to each other to form a divalent hydrocarbon group having 2 to 20 carbon atoms, and —CH ₂ — contained in the hydrocarbon group and the divalent group is — O- or -S- may be substituted.

式（１）では、脂環式炭化水素基の炭素数は、好ましくは炭素数１〜１６である。 Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group.
The alicyclic hydrocarbon group may be monocyclic or polycyclic. Examples of the monocyclic alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, and dimethylcyclohexane. Examples thereof include a cycloalkyl group such as a hexyl group, a cycloheptyl group, and a cyclooctyl group. Examples of the polycyclic saturated hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, methylnorbornyl group, and the following groups.

In the formula (1), the alicyclic hydrocarbon group preferably has 1 to 16 carbon atoms.

In the case where R ^a1 and R ^a2 are bonded to each other to form a divalent hydrocarbon group, examples of the —C (R ^a1 ) (R ^a2 ) (R ^a3 ) group include the following groups. The carbon number of the divalent hydrocarbon group is preferably 3 to 12 carbon atoms.

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

Examples of the hydrocarbon group include an alkyl group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group.
Aromatic hydrocarbon groups include phenyl, naphthyl, anthonyl, p-methylphenyl, p-tert-butylphenyl, p-adamantylphenyl, tolyl, xylyl, cumenyl, mesityl, biphenyl Groups, anthryl groups, phenanthryl groups, 2,6-diethylphenyl groups, aryl groups such as 2-methyl-6-ethylphenyl, and the like.

Preferably, at least one of R ^{a1 ′} and R ^{a2 ′} is a hydrogen atom.

Specific examples of the group represented by the formula (2) include the following groups.

  The monomer (a1) having an acid labile group is preferably a monomer having an acid labile group and a carbon-carbon double bond, more preferably a (meth) acryl having an acid labile group. Monomer.

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

  As the (meth) acrylic monomer having an acid labile group and an alicyclic hydrocarbon group, a monomer represented by the formula (a1-1) or a monomer represented by the formula (a1-2) is preferably used. Can be mentioned. 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の整数を表し、＊は−ＣＯ−との結合手を表す。
Ｒ^a4及びＲ^a5は、それぞれ独立に、水素原子又はメチル基を表す。
Ｒ^a6及びＲ^a7は、それぞれ独立に、炭素数１〜８のアルキル基又は炭素数３〜１０の脂環式炭化水素基を表す。
ｍ１は０〜１４の整数を表す。
ｎ１は０〜１０の整数を表す。
ｎ２は０又は１の整数を表す。］

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

ｍ１は、好ましくは０〜３の整数、より好ましくは０又は１である。
ｎ１は、好ましくは０〜３の整数、より好ましくは０又は１である。 L ^a1 and L ^a2 are preferably —O— or ^* —O— (CH ₂ ) _k1 —CO—O—, more preferably —O—. k1 is preferably an integer of 1 to 4, more preferably 1.
R ^a4 and R ^a5 are preferably methyl groups.
^Examples of the alkyl group for R ^a6 and R ^a7 include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, and an octyl group. The alkyl group for R ^a6 and R ^a7 preferably has 6 or less carbon atoms. The alicyclic hydrocarbon group preferably has 8 or less carbon atoms, more preferably 6 or less.
The alicyclic hydrocarbon group for R ^a6 and R ^a7 may be monocyclic or polycyclic, and examples of the monocyclic alicyclic hydrocarbon group include a cyclopentyl group, a cyclohexyl group, Examples thereof include cycloalkyl groups such as methylcyclohexyl group, dimethylcyclohexyl group, cycloheptyl group, and cyclooctyl group. Examples of the polycyclic saturated hydrocarbon group include decahydronaphthyl group, adamantyl group, norbornyl group, methylnorbornyl group, and the following groups.

m1 is preferably an integer of 0 to 3, more preferably 0 or 1.
n1 is preferably an integer of 0 to 3, more preferably 0 or 1.

Examples of the monomer represented by the formula (a1-1) include monomers described in JP 2010-204646 A. Monomers represented by the following formulas (a1-1-1) to (a1-1-6) are preferred, and monomers represented by the following formulas (a1-1-1) to (a1-1-3) are more preferred. .

Examples of the monomer represented by the formula (a1-2) include 1-ethyl-1-cyclopentyl (meth) acrylate, 1-ethyl-1-cyclohexyl (meth) acrylate, 1-ethyl-1-cycloheptyl (meta ) Acrylate, 1-methyl-1-cyclopentyl (meth) acrylate, 1-isopropyl-1-cyclopentyl (meth) acrylate, and the like. Monomers represented by the following formulas (a1-2-1) to (a1-2-6) are preferred, and monomers represented by the following formulas (a1-2-3) to (a1-2-4) are more preferred. A monomer represented by the following formula (a1-2-3) is more preferable.

  The content of the structural unit derived from the monomer represented by the formula (a1-1) or the monomer represented by the formula (a1-2) in the resin is usually 10 to 95 mol% in all the units of the resin, Preferably it is 15-90 mol%, More preferably, it is 20-85 mol%.

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

  As an acid stable monomer, Preferably, the monomer which has a hydroxyl group or a lactone ring is mentioned. 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 is preferably a phenolic hydroxyl group which is a hydroxystyrene. An acid stable monomer (a2-0) having When using short-wavelength ArF excimer laser exposure (193 nm) or the like, the acid-stable monomer (a2) having a hydroxy group is preferably an acid-stable monomer having a hydroxyadamantyl group represented by the formula (a2-1). use. 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^a30は、水素原子、ハロゲン原子又はハロゲン原子を有してもよい炭素数１〜６のアルキル基を表す。
Ｒ^a31は、ハロゲン原子、ヒドロキシ基、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数２〜４のアシル基、炭素数２〜４のアシルオキシ基、アクリロイル基又はメタクリロイル基を表す。
ｍａは０〜４の整数を表す。ｍａが２以上の整数である場合、複数のＲ^a31は同一であっても異なってもよい。］

[In the formula (a2-0),
R ^a30 represents a hydrogen atom, a halogen atom or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.
R ^a31 is a halogen atom, a hydroxy group, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an acyl group having 2 to 4 carbon atoms, an acyloxy group having 2 to 4 carbon atoms, an acryloyl group, or methacryloyl. Represents a group.
ma represents an integer of 0 to 4. When ma is an integer of 2 or more, the plurality of R ^a31 may be the same or different. ]

^Examples of the alkyl group in R ^a30 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, and an n-hexyl group. Preferably, it is a C1-C4 alkyl group, More preferably, it is a C1-C2 alkyl group, Most preferably, it is a methyl group.
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. , Preferably, it is a C1-C4 alkoxy group, More preferably, it is a C1-C2 alkoxy group, Most preferably, it is a methoxy group.
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.
As a monomer which has a phenolic hydroxyl group, the monomer described in Unexamined-Japanese-Patent No. 2010-204634 is mentioned, for example. Monomers represented by the following formulas (a2-0-1) and (a2-0-2) are preferred. When manufacturing resin (A), what protected the phenolic hydroxyl group in these with the suitable protective group can also be used.

  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。＊は−ＣＯ−との結合手を表す。
Ｒ^a14は、水素原子又はメチル基を表す。
Ｒ^a15及びＲ^a16は、それぞれ独立に、水素原子、メチル基又はヒドロキシ基を表す。
ｏ１は、０〜１０の整数を表す。

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

In the formula (a2-1), L ^a3 is preferably, -O -, - O- (CH 2) f1 -CO-O- and is (wherein f1 is an integer from 1 to 4), more preferably Is —O—.
R ^a14 is preferably a methyl group.
R ^a15 is preferably a hydrogen atom.
R ^a16 is preferably a hydrogen atom or a hydroxy group.
o1 is preferably an integer of 0 to 3, more preferably 0 or 1.

As an acid stable monomer (a2-1) which has a hydroxyadamantyl group, the monomer described in Unexamined-Japanese-Patent No. 2010-204646 is mentioned, for example. Monomers represented by the following formulas (a2-1-1) to (a2-1-6) are preferred, and monomers represented by the following formulas (a2-1-1) to (a2-1-4) are more preferred. A monomer represented by the following formula (a2-1-1) or (a2-1-3) 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 monocycle such as a β-propiolactone ring, γ-butyrolactone ring, or δ-valerolactone ring, and a monocyclic lactone ring and other rings The condensed ring may be used. Among these lactone rings, a γ-butyrolactone ring or a condensed ring of γ-butyrolactone ring and another ring is preferable.

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

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

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

In 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— or ^* —O— (CH ₂ ) _k3 —CO—O—, more preferably —O—. k3 is preferably an integer of 1 to 4, more preferably 1.
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) having a lactone ring include monomers described in JP 2010-204646 A. In the following formulas (a3-1-1) to (a3-1-4), (a3-2-1) to (a3-2-4), (a3-3-1) to (a3-3-4) Monomers represented by the following formulas (a3-1-1) to (a3-1-2) and (a3-2-3) to (a3-2-4) are more preferred, A monomer represented by formula (a3-1-1) or (a3-2-3) is more preferable.

  The content of the structural unit derived from the acid-stable monomer (a3) having a lactone ring in the resin is usually 5 to 50 mol%, preferably 10 to 45 mol%, more preferably, in all units of the resin. 15 to 40 mol%.

<Other monomer (a4)>
The resin may have a structural unit derived from another known monomer (a4) other than the above-mentioned monomers.

  Preferably, the resin (A) polymerizes at least the monomer (a1) having an acid labile group, the acid stable monomer (a2) having a hydroxy group, and / or the acid stable monomer (a3) having a lactone ring. Copolymer. In the 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. (More preferably, the monomer (a1-1) having an adamantyl group), and the acid-stable monomer (a2) having a hydroxy group is preferably an acid-stable monomer (a2-1) having a hydroxyadamantyl group, and a lactone ring More preferably, the acid-stable monomer (a3) having a γ-butyrolactone ring is an acid-stable monomer (a3-1) and an acid-stable monomer (a3-2) having a condensed ring of a γ-butyrolactone ring and a norbornane ring. At least one. 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).
The content of the resin (A) is preferably 80% by mass or more in the solid content of the composition.

<Acid generator (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 JP-A 63-26653, JP-A 55-164824, JP-A 62-69263, JP-A 63-146038, JP-A 63-163452, JP-A-62-153853, JP-A-63-146029, U.S. Pat. No. 3,779,778, U.S. Pat. No. 3,849,137, German Patent 3914407, European Patent 126,712. The compound which generate | occur | produces an acid by the radiation as described in No. etc. can be used.

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

［式（Ｂ１）中、
Ｑ¹及びＱ²は、それぞれ独立に、フッ素原子又は炭素数１〜６のペルフルオロアルキル基を表す。
Ｌ^b1は、単結合又は２価の炭素数１〜１７の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炭素数１〜１８のアルキル基又は置換基を有していてもよい炭素数３〜１８の脂環式炭化水素基を表し、前記アルキル基及び前記脂環式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 1-6 perfluoroalkyl group.
L ^b1 represents a single bond or a divalent saturated hydrocarbon group having 1 to 17 carbon atoms, and —CH ₂ — contained in the divalent saturated hydrocarbon group is replaced by —O— or —CO—. May be.
Y represents an alkyl group having 1 to 18 carbon atoms which may have a substituent or an alicyclic hydrocarbon group having 3 to 18 carbon atoms which may have a substituent, and the alkyl group and the above —CH ₂ — contained in the alicyclic 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 perfluorosec-butyl group, a perfluorotert-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 alicyclic hydrocarbon group, and a combination of two or more of these groups. It may be a thing.
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;
On the side of an alkyl group (particularly an alkyl group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, a tert-butyl group) Having a chain, 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 alicyclic 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 alicyclic 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、単結合又は炭素数１〜１５の飽和炭化水素基を表す。
Ｌ^b3は、単結合又は炭素数１〜１２の飽和炭化水素基を表す。
Ｌ^b4は、炭素数１〜１３の飽和炭化水素基を表す。但しＬ^b3及びＬ^b4の炭素数上限は１３である。
Ｌ^b5は、炭素数１〜１５の飽和炭化水素基を表す。
Ｌ^b6及びＬ^b7は、それぞれ独立に、炭素数１〜１５の飽和炭化水素基を表す。但しＬ^b6及びＬ^b7の炭素数上限は１６である。
Ｌ^b8は、炭素数１〜１４の飽和炭化水素基を表す。
Ｌ^b9及びＬ^b10は、それぞれ独立に、炭素数１〜１１の飽和炭化水素基を表す。但しＬ^ｂ９及びＬ^ｂ１０の炭素数上限は１２である。
中でも、好ましくは式（ｂ１−１）で表される２価の基であり、より好ましくは、Ｌ^b2が単結合又は−ＣＨ_２−である式（ｂ１−１）で表される２価の基である。

In formula (b1-1) to formula (b1-6),
L ^b2 represents a single bond or a saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b3 represents a single bond or a saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b4 represents a saturated hydrocarbon group having 1 to 13 carbon atoms. However, the upper limit of the carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents a saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b6 and L ^b7 each independently represent a saturated hydrocarbon group having 1 to 15 carbon atoms. However, the upper limit of the carbon number of L ^b6 and L ^b7 is 16.
L ^b8 represents a saturated hydrocarbon group having 1 to 14 carbon atoms.
L ^b9 and L ^b10 each independently represent a saturated hydrocarbon group having 1 to 11 carbon atoms. However, the upper limit of the carbon number of L ^b9 and L ^b10 is 12.
Among them, 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. It is a group.

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.

As an alkyl group of Y, Preferably, a C1-C6 alkyl group is mentioned.
Examples of the substituent for the alkyl group and the alicyclic hydrocarbon group include a halogen atom, a hydroxy group, an oxo group, an alkyl group having 1 to 12 carbon atoms, a hydroxy group-containing alkyl group having 1 to 12 carbon atoms, and 3 carbon atoms. -16 alicyclic hydrocarbon group, C1-C12 alkoxy group, C6-C18 aromatic hydrocarbon group, C7-C21 aralkyl group, C2-C4 acyl group, glycidyl An oxy group or — (CH ₂ ) _j2 —O—CO—R ^b1 group (wherein R ^b1 is an alkyl group having 1 to 16 carbon atoms, an alicyclic hydrocarbon group having 3 to 16 carbon atoms, or 6 carbon atoms) Represents an aromatic hydrocarbon group of ˜18.j2 represents an integer of 0 to 4.) and the like. The alkyl group, alicyclic 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 alkyl group include a hydroxymethyl group and a hydroxyethyl group.
Examples of the group in which —CH ₂ — in the alkyl group and alicyclic hydrocarbon group of Y is replaced by —O—, —SO ₂ — or —CO— include, for example, a cyclic ether group (—CH ₂ — is —O—). ), An alicyclic hydrocarbon group having an oxo group (a group in which —CH ₂ — is replaced by —CO—), and a sultone ring group (two adjacent —CH ₂ — are each represented by —O— Or a group substituted by —SO ₂ —) or a lactone ring group (a group in which two adjacent —CH ₂ — are each replaced by —O— or —CO—).

In particular, examples of the alicyclic 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 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.

The sulfonate anion in the salt represented by the formula (B1) is preferably an anion represented by the formula (b1-1-1) to the formula (b1-1-1-9). 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 an alkyl group having 1 to 4 carbon atoms (preferably a methyl group).
Specific examples of the sulfonate anion in the salt represented by the formula (B1) include the anions described in JP 2010-204646 A.

  The cation contained in the acid generator (B) includes an onium cation, such as a sulfonium cation, an iodonium cation, an ammonium cation, a benzothiazolium cation, and a phosphonium cation, and preferably a sulfonium cation or an iodonium cation, More preferred is an arylsulfonium cation.

Z ⁺ in the formula (B1) is preferably represented by any of the formulas (b2-1) to (b2-4) described above.

  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, and preferably a combination of any one of anion (b1-1-1) to anion (b1-1-9) and cation (b2-1-1), and A combination of any one of anions (b1-1-3) to (b1-1-5) and a cation (b2-3) may be mentioned.

  The acid generator (B1) is preferably a salt represented by the formula (B1-1) to the formula (B1-17), and more preferably an acid generator (B1-) containing a triphenylsulfonium cation. 1), (B1-2), (B1-6), (B1-11), (B1-12), (B1-13) and (B1-14).

  The content of the acid generator (B) in the resin (A) is preferably 1% by mass or more (more preferably 3% by mass or more), preferably 30% by mass or less (more preferably 25% by mass or less). .

<Basic compound (hereinafter sometimes referred to as “basic compound (C)”)>
The resist composition of the present invention preferably contains a basic compound (C). The basic compound (C) acts as a quencher. However, the basic compound (C) is different from the salt represented by the formula (I).

  The basic compound (C) is preferably a basic nitrogen-containing organic compound, and examples thereof include amines and ammonium salts. Examples of amines include aliphatic amines and aromatic amines. Aliphatic amines include primary amines, secondary amines and tertiary amines. The basic compound (C) is preferably a compound represented by the formula (C1) to a compound represented by the formula (C8), more preferably a compound represented by the formula (C1-1). It is done.

［式（Ｃ１）中、Ｒ^c1、Ｒ^c2及びＲ^c3は、それぞれ独立に、水素原子、炭素数１〜６のアルキル基、炭素数５〜１０の脂環式炭化水素基又は炭素数６〜１０の芳香族炭化水素基を表し、該アルキル基及び該脂環式炭化水素基に含まれる水素原子は、ヒドロキシ基、アミノ基又は炭素数１〜６のアルコキシ基で置換されていてもよく、該芳香族炭化水素基に含まれる水素原子は、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数５〜１０の脂環式炭化水素又は炭素数６〜１０の芳香族炭化水素基で置換されていてもよい。］

[In formula (C1), R ^c1 , R ^c2 and R ^c3 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 5 to 10 carbon atoms, or 6 to 6 carbon atoms. 10 represents an aromatic hydrocarbon group, and the hydrogen atom contained in the alkyl group and the alicyclic hydrocarbon group may be substituted with a hydroxy group, an amino group or an alkoxy group having 1 to 6 carbon atoms, The hydrogen atom contained in the aromatic hydrocarbon group is an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alicyclic hydrocarbon having 5 to 10 carbon atoms, or an aromatic group having 6 to 10 carbon atoms. It may be substituted with a group hydrocarbon group. ]

［式（Ｃ１−１）中、Ｒ^c2及びＲ^c3は、上記と同じ意味を表す。
Ｒ^c4は、炭素数１〜６のアルキル基、炭素数１〜６のアルコキシ基、炭素数５〜１０の脂環式炭化水素又は炭素数６〜１０の芳香族炭化水素基を表す。
ｍ３は０〜３の整数を表し、ｍ３が２以上のとき、複数のＲ^c4は、互いに同一でも異なってもよい。］

[In Formula (C1-1), R ^c2 and R ^c3 represent the same meaning as described above.
R ^c4 represents an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alicyclic hydrocarbon having 5 to 10 carbon atoms, or an aromatic hydrocarbon group having 6 to 10 carbon atoms.
m3 represents an integer of 0 to 3, and when m3 is 2 or more, a plurality of R ^{c4 s} may be the same as or different from each other. ]

［式（Ｃ２）、式（Ｃ３）及び式（Ｃ４）中、Ｒ^c5、Ｒ^c6、Ｒ^c7及びＲ^c8は、それぞれ独立に、Ｒ^c1と同じ意味を表す。
Ｒ^c9は、炭素数１〜６のアルキル基、炭素数３〜６の脂環式炭化水素基又は炭素数２〜６のアルカノイル基を表す。
ｎ３は０〜８の整数を表し、ｎ３が２以上のとき、複数のＲ^c9は、互いに同一でも異なってもよい。］

[In Formula (C2), Formula (C3) and Formula (C4), R ^c5 , R ^c6 , R ^c7 and R ^c8 each independently represent the same meaning as R ^c1 .
R ^c9 represents an alkyl group having 1 to 6 carbon atoms, an alicyclic hydrocarbon group having 3 to 6 carbon atoms, or an alkanoyl group having 2 to 6 carbon atoms.
n3 represents an integer of 0 to 8, and when n3 is 2 or more, the plurality of R ^c9 may be the same as or different from each other. ]

［式（Ｃ５）及び式（Ｃ６）中、Ｒ^c10、Ｒ^c11、Ｒ^c12、Ｒ^c13及びＲ^c16は、それぞれ独立に、Ｒ^c1と同じ意味を表す。
Ｒ^c14、Ｒ^c15及びＲ^c17は、それぞれ独立に、Ｒ^c4と同じ意味を表す。
ｏ３及びｐ３は、それぞれ独立に０〜３の整数を表し、ｏ３又はｐ３が２以上であるとき、それぞれ、複数のＲ^c14及びＲ^c15は互いに同一でも異なってもよい。
Ｌ^c1は、炭素数１〜６のアルキレン基、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｓ−又はこれらを組合せた２価の基を表す。］

[In Formula (C5) and Formula (C6), R ^c10 , R ^c11 , R ^c12 , R ^c13 and R ^c16 each independently represent the same meaning as R ^c1 .
R ^c14 , R ^c15 and R ^c17 each independently represent the same meaning as R ^c4 .
o3 and p3 each independently represent an integer of 0 to 3, and when o3 or p3 is 2 or more, the plurality of R ^c14 and R ^c15 may be the same as or different from each other.
L ^c1 represents a C 1-6 alkylene group, —CO—, —C (═NH) —, —S—, or a divalent group obtained by combining these. ]

［式（Ｃ７）及び式（Ｃ８）中、Ｒ^c18、Ｒ^c19及びＲ^c20は、それぞれ独立に、Ｒ^c4と同じ意味を表す。
ｑ３、ｒ３及びｓ３は、それぞれ独立に０〜３の整数を表し、ｑ３、ｒ３及びｓ３が２以上であるとき、それぞれ、複数のＲ^c18、Ｒ^c19及びＲ^c20は互いに同一でも異なってもよい。
Ｌ^c2は、単結合又は炭素数１〜６のアルキレン基、−ＣＯ−、−Ｃ（＝ＮＨ）−、−Ｓ−又はこれらを組合せた２価の基を表す。］

Wherein (C7) and formula ^{(C8), R c18, R} c19 and R ^c20 in each occurrence independently represent the same meaning as R ^c4.
q3, r3 and s3 each independently represent an integer of 0 to 3, q3, when r3 and s3 is 2 or more, each of a plurality of R ^c18, R ^c19 and R ^{c 20} may be the same or different from each other .
L ^c2 represents a single bond or an alkylene group having 1 to 6 carbon atoms, —CO—, —C (═NH) —, —S—, or a divalent group obtained by combining these. ]

  Examples of the compound represented by the formula (C1) include 1-naphthylamine, 2-naphthylamine, aniline, diisopropylaniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, N-methylaniline, N, N- Dimethylaniline, diphenylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, triethylamine, trimethylamine, tripropylamine, tributylamine, tri Pentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyl Hexylamine, methyldicyclohexylamine, methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonyl Amine, ethyldidecylamine, dicyclohexylmethylamine, tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diamino-1,2-diphenyl Examples include ethane, 4,4′-diamino-3,3′-dimethyldiphenylmethane, 4,4′-diamino-3,3′-diethyldiphenylmethane, and preferably diisopropyl Ruanirin. Particularly preferred include 2,6-diisopropylaniline.

Examples of the compound represented by the formula (C2) include piperazine.
Examples of the compound represented by the formula (C3) include morpholine.
Examples of the compound represented by the formula (C4) include piperidine and hindered amine compounds having a piperidine skeleton described in JP-A No. 11-52575.
Examples of the compound represented by the formula (C5) include 2,2′-methylenebisaniline.
Examples of the compound represented by the formula (C6) include imidazole and 4-methylimidazole.
Examples of the compound represented by the formula (C7) include pyridine and 4-methylpyridine.
Examples of the compound represented by the formula (C8) include 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1,2-di (2-pyridyl) ethene, 1, 2-di (4-pyridyl) ethene, 1,3-di (4-pyridyl) propane, 1,2-di (4-pyridyloxy) ethane, di (2-pyridyl) ketone, 4,4′-dipyridyl sulfide 4,4′-dipyridyl disulfide, 2,2′-dipyridylamine, 2,2′-dipiconylamine, bipyridine and the like.

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

  The content of the basic compound (C) is preferably about 0.01 to 5% by mass, more preferably about 0.01 to 3% by mass, and particularly preferably based on the solid content of the resist composition. It is about 0.01-1 mass%.

<Solvent (sometimes referred to as "solvent (E)")
The resist composition of the present invention may contain a solvent (E). The content of the solvent (E) is, for example, 90% by mass or more in the resist composition, preferably 92% by mass or more, more preferably 94% by mass or more, for example 99.9% by mass or less, preferably 99% by mass or less. It is.
The content rate of a solvent (E) can be measured by well-known analysis means, such as a liquid chromatography or a gas chromatography, for example.

  Examples of the solvent (E) include glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate and propylene glycol monomethyl ether acetate; glycol ethers such as propylene glycol monomethyl ether; ethyl lactate, butyl acetate, amyl acetate and 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.

<This resist composition and its preparation method>
The resist composition is prepared by mixing a salt represented by the formula (I), a resin (A), an acid generator (B), a solvent (E), or the like, or a salt represented by the formula (I). , Resin (A), acid generator (B), basic compound (C), solvent (E) and the like can be mixed. In such mixing, the mixing order is arbitrary and is not particularly limited. The temperature at the time of mixing can select an appropriate temperature range from the range of 10-40 degreeC according to the kind etc. of resin, the solubility with respect to solvent (E), such as resin. An appropriate mixing time can be selected from 0.5 to 24 hours depending on the mixing temperature. The mixing means is not particularly limited, and stirring and mixing can be used.

  After mixing, the resist composition can be prepared by filtering using a filter having a pore size of about 0.2 μm.

<Method for producing resist pattern>
The method for producing a resist pattern of the present invention comprises:
(1) A step of applying the resist composition of the present invention on a substrate,
(2) The process of drying the composition after application | coating and forming a composition layer,
(3) a step of exposing the composition layer using an exposure machine;
(4) a step of heating the composition layer after exposure, and (5) a step of developing the heated composition layer using a developing device.

  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.

EXAMPLES Next, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited by these Examples.
In Examples and Comparative Examples, “%” and “part” representing the content or amount used are based on mass unless otherwise specified.
Further, the weight average molecular weight is a value obtained by gel permeation chromatography (HLC-8120GPC type manufactured by Tosoh Corporation, column is TSKgel Multipore HXL-M3, solvent is tetrahydrofuran) using polystyrene as a standard product.
The structure of the compound was confirmed by NMR (GX-270 type or EX-270 type; manufactured by JEOL), mass spectrometry (LC; Agilent 1100 type, MASS; Agilent LC / MSD type or LC / MSD TOF type). did.

Example 1
Synthesis of salt represented by formula (I-1)

A salt represented by the formula (I-1-a) was synthesized by the method described in JP 2010-1000083.
To a solution of 2.5 parts of the compound represented by the formula (I-1-b) and 10 parts of dimethylformamide, 0.66 part of potassium carbonate and 0.2 part of potassium iodide are added, Stir for hours. To the reaction mixture solution, 3.5 parts of the salt represented by the formula (I-1-a) was added and stirred at 60 ° C. for 2 hours. The reaction mixture was cooled to room temperature, then added to a solution of 12 parts of a 5% aqueous oxalic acid solution, and extracted with 173 parts of chloroform. The extracted organic layer was washed with ion exchange water and then concentrated under reduced pressure. The obtained residue was recrystallized with a mixed solution of acetonitrile and 2-methoxy-2-methylpropane to obtain 3.0 parts of a salt represented by the formula (I-1).

MS (ESI (+) Spectrum): M ⁺ = 263.1 (C ₁₈ H ₁₅ S ⁺ = 263.1)
MS (ESI (−) Spectrum): M ⁻ = 446.1 (C ₁₆ H ₂₆ F ₂ NO ₉ S ⁻ = 446.1)

Example 2
Synthesis of salt represented by formula (I-33)

A salt represented by the formula (I-33-a) was synthesized by the method described in JP 2010-1000083.
To a solution of 2.6 parts of the compound represented by the formula (I-33-b) and 10 parts of dimethylformamide, 0.69 part of potassium carbonate and 0.21 part of potassium iodide are added, and 1 at 40 ° C. Stir for hours. To the reaction mixture solution, 4.0 parts of the salt represented by the formula (I-33-a) was added and stirred at 60 ° C. for 2 hours. The reaction mixture was cooled to room temperature, then added to a solution of 13 parts of a 5% aqueous oxalic acid solution, and extracted with 184 parts of chloroform. The extracted organic layer was washed with ion exchange water and then concentrated under reduced pressure. The obtained residue was recrystallized from a mixed solution of acetonitrile and 2-methoxy-2-methylpropane to obtain 3.0 parts of the salt represented by the formula (I-33).

MS (ESI (+) Spectrum): M ⁺ = 263.1 (C ₁₈ H ₁₅ S ⁺ = 263.1)
MS (ESI (−) Spectrum): M ⁻ = 474.1 (C ₁₈ H ₃₀ F ₂ NO ₉ S ⁻ = 474.1)

Example 3
Synthesis of salt represented by formula (I-21)

A salt represented by the formula (I-21-a) was synthesized by the method described in JP 2010-1000083.
To a solution of 2.0 parts of the compound represented by the formula (I-21-b) and 8 parts of dimethylformamide, 0.69 parts of potassium carbonate and 0.21 parts of potassium iodide are added, and 1 at 40 ° C. Stir for hours. To the reaction mixture solution, 4.0 parts of the salt represented by the formula (I-21-a) was added and stirred at 60 ° C. for 2 hours. The reaction mixture was cooled to room temperature, then added to a solution of 13 parts of a 5% aqueous oxalic acid solution, and extracted with 184 parts of chloroform. The extracted organic layer was washed with ion exchange water and then concentrated under reduced pressure. The obtained residue was recrystallized with a mixed solution of acetonitrile and 2-methoxy-2-methylpropane to obtain 3.3 parts of a salt represented by the formula (I-21).

MS (ESI (+) Spectrum): M ⁺ = 263.1 (C ₁₈ H ₁₅ S ⁺ = 263.1)
MS (ESI (−) Spectrum): M ⁻ = 418.1 (C ₁₄ H ₂₂ F ₂ NO ₉ S ⁻ = 418.1)
Example 4
Synthesis of salt represented by formula (I-104)

A salt represented by the formula (I-104-a) was synthesized by the method described in JP 2010-1000083.
To a solution of 1.8 parts of the compound represented by formula (I-104-b) and 9.3 parts of dimethylformamide, 0.69 parts of potassium carbonate and 0.21 parts of potassium iodide are added, and 40 ° C. For 1 hour. To the reaction mixture solution, 4.0 parts of a salt represented by the formula (I-104-a) was added and stirred at 60 ° C. for 2 hours. The reaction mixture was cooled to room temperature, then added to a solution of 13 parts of a 5% aqueous oxalic acid solution, and extracted with 184 parts of chloroform. The extracted organic layer was washed with ion exchange water and then concentrated under reduced pressure. The obtained residue was recrystallized from a mixed solution of acetonitrile and 2-methoxy-2-methylpropane to obtain 3.1 parts of a salt represented by the formula (I-104).

MS (ESI (+) Spectrum): M ⁺ = 263.1 (C ₁₈ H ₁₅ S ⁺ = 263.1)
MS (ESI (−) Spectrum): M ⁻ = 418.1 (C ₁₅ H ₂₄ F ₂ NO ₁₀ S ⁻ = 448.1)

Synthesis of Resin A1 15.00 parts of the monomer represented by the formula (M-1), 4.89 parts of the monomer represented by the formula (M-2), and the monomer represented by the formula (M-6) 11.12 parts, 8.81 parts of the monomer represented by the formula (M-3) are charged (molar ratio 35: 12: 23: 30), and 1.5 weight times dioxane of the total monomer amount is added to the solution. did. 1 mol% and 3 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) as initiators were added to the total monomer amount, respectively, and heated at 77 ° C. for about 5 hours. Thereafter, the reaction solution was purified by pouring it into a mixed solvent of a large amount of methanol and water and precipitating three times to obtain a copolymer having a weight average molecular weight of about 8.1 × 10 ^{3 in} a yield of 78%. Got in. This copolymer has each structural unit of the following formula, and this is designated as resin A1.

Synthesis of Resin A2 130.00 parts of the monomer represented by the formula (M-1), 61.65 parts of the monomer represented by the formula (M-4), and the monomer represented by the formula (M-2) 49.48 g, 178.13 parts of the monomer represented by the formula (M-3) were charged (molar ratio 25: 15: 10: 50), and 1.5 times the total amount of dioxane was added to form a solution. . Thereto, 0.7 mol% and 2.1 mol% of azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile) were added as initiators with respect to the total amount of monomers, respectively, and heated at 75 ° C. for about 5 hours. . Thereafter, the reaction solution was purified by pouring it into a large amount of a mixed solvent of methanol and water and precipitating three times to obtain 347.2 parts of a copolymer having a weight average molecular weight of about 1.1 × 10 ⁴ . (Yield 82%). This copolymer has each structural unit of the following formula, and this is designated as resin A2.

  A mixture obtained by mixing and dissolving the components shown in Table 4 was filtered through a fluororesin filter having a pore size of 0.2 μm to prepare a resist composition. In the table, “-” indicates that the content is 0.

<Resin>
A1: Resin A1
A2: Resin A2

Ｂ２：式（Ｂ１−３）で表される酸発生剤

<Acid generator>
<Acid generator>
B1: Acid generator represented by formula (B1-6)

B2: Acid generator represented by formula (B1-3)

Ｉ−３３：式（Ｉ−３３）で表される塩

Ｉ−２１：式（Ｉ−２１）で表される塩

Ｉ−１０４：式（Ｉ−１０４）で表される塩

<Salt represented by formula (I)>
I-1: salt represented by formula (I-1)

I-33: salt represented by formula (I-33)

I-21: a salt represented by the formula (I-21)

I-104: a salt represented by the formula (I-104)

<Basic compound: Quencher>
C1: 2,6-diisopropylaniline C2: compound represented by the formula (C2)

<Solvent>
E1:
Propylene glycol monomethyl ether acetate 280.0 parts 2-heptanone 20.0 parts Propylene glycol monomethyl ether 20.0 parts γ-butyrolactone 3.0 parts

An organic antireflection coating composition [ARC-29SR-309; 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. A 93 nm organic antireflection coating was formed.
Next, the above resist composition was spin-coated on the organic antireflection film so that the film thickness after drying was 80 nm.
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 4. The obtained wafer was exposed using an ArF excimer scanner for immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.35, Dipole35, σout / in = 0.97 / 0.77, Y deflection]. The line and space pattern was subjected to immersion exposure by changing the amount stepwise.
After the exposure, post-exposure baking (PEB) was performed for 60 seconds on a hot plate at the temperature described in the “PEB” column of Table 4, and then with an aqueous 2.38 mass% tetramethylammonium hydroxide solution for 60 seconds. Paddle development was performed.

  In each resist film, the exposure amount at which the 40 nm line-and-space pattern becomes an exposure amount of 1: 1 was defined as the effective sensitivity.

Line width roughness evaluation (LWR): The resist pattern line width after the lithography process was observed with a scanning electron microscope, and the resist pattern line width variation (3σ) was less than 4.5 nm. The thing of 5 nm or more was set as x. The results are shown in Table 5.

  According to the salt of the present invention, a pattern having excellent line width roughness (LWR) can be obtained from a resist composition containing the salt.

Claims (9)

A salt represented by the formula (I).

[In the formula (I),
R ^1, R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, hydrogen atoms contained in the alkyl group may be substituted with a hydroxy group, said alkyl —CH ₂ — contained in the group may be replaced by —O— or —CO—.
R ⁴ and R ⁵ each independently represent a hydrogen atom, a fluorine atom, or a C 1-6 perfluoroalkyl group.
X ¹ represents a group represented by the formula (X1-F).

X ¹⁷ represents a hydrocarbon group having 1 to 12 carbon atoms.
X ¹⁸ represents a single bond or a hydrocarbon group having 1 to 12 carbon atoms, —CH ₂ — contained in the hydrocarbon group may be replaced by —S—, and hydrogen contained in the hydrocarbon group The atom may be substituted with a hydroxy group.
R ⁶ represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms.
A ⁺ represents a sulfonium cation . ] The salt according to claim 1, wherein R ¹ is an ethyl group, and R ² and R ³ are methyl groups. X ¹ represents ^* —CO—O— (CH ₂ ) _k1 —O—CO— (CH ₂ ) _k2 — ( ^* represents a bond with C (R ⁴ ) (R ⁵ ), and k1 and k2 are The salt according to claim 1 or 2, wherein each independently represents an integer of 1 to 6. The salt according to any one of claims 1 to 3, wherein A ⁺ is a triarylsulfonium cation.   The resist composition containing the salt and resin in any one of Claims 1-4.   6. The resist composition according to claim 5, 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.   Furthermore, the resist composition of Claim 5 or 6 containing an acid generator.   Furthermore, the resist composition in any one of Claims 5-7 containing a basic compound. (1) The process of apply | coating the resist composition in any one of Claims 5-8 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, and (5) a step of developing the heated composition layer using a developing device,
A method for producing a resist pattern including: