JP2012185482A - Resist composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist composition that can obtain a pattern having an excellent focus margin.SOLUTION: A resist composition comprises: an iodonium salt having an anion represented by formula (IA); an acrylic resin which has an acid-labile group, and is insoluble or sparingly soluble in an aqueous alkali solution and can dissolve in an aqueous alkali solution by an action of an acid; and an acid generator. In formula (IA), Rrepresents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms or an aralkyl group having 7 to 21 carbon atoms; Rrepresents an aliphatic hydrocarbon group having 7 to 12 carbon atoms, an alicyclic hydrocarbon group having 7 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms or aralkyl group having 7 to 21 carbon atoms; and Rand Rmay be bonded to form a C4-C20 nitrogen-containing ring with N.

Description

  The present invention relates to a resist composition and a pattern forming method.

  Patent Document 1 describes a resist composition containing bis (t-butylphenyl) iodonium cyclamate as an additive.

Japanese Patent Laid-Open No. 11-160861

  In conventional resist compositions, the focus margin (DOF) of the resulting pattern may not always be satisfactory.

［式（ＩＡ）中、
Ｒ^１は、水素原子、炭素数１〜１２の脂肪族炭化水素基、炭素数３〜２０の脂環式炭化水素基、炭素数６〜２０の芳香族炭化水素基又は炭素数７〜２１のアラルキル基を表し、該脂肪族炭化水素基、該脂環式炭化水素基、該芳香族炭化水素基及びアラルキル基に含まれる水素原子は、ヒドロキシル基、ニトリル基、フッ素原子、トリフルオロメチル基又はニトロ基で置換されていてもよく、該脂肪族炭化水素基に含まれる−ＣＨ_２−は−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
Ｒ^２は、炭素数７〜１２の脂肪族炭化水素基、炭素数７〜２０の脂環式炭化水素基、炭素数６〜２０の芳香族炭化水素基又は炭素数７〜２１のアラルキル基を表し、該脂肪族炭化水素基、該脂環式炭化水素基、該芳香族炭化水素基及びアラルキル基に含まれる水素原子は、ヒドロキシル基、ニトリル基、フッ素原子、トリフルオロメチル基又はニトロ基で置換されていてもよく、該脂肪族炭化水素基に含まれる−ＣＨ_２−は−Ｏ−又は−ＣＯ−で置き換わっていてもよい。
Ｒ^１及びＲ^２は互いに結合してＮとともに炭素数４〜２０の環を形成してもよい。］ The present invention includes the following inventions.
[1] An iodonium salt having an anion represented by the formula (IA), an acrylic having an acid labile group and insoluble or hardly soluble in an alkaline aqueous solution, and soluble in an alkaline aqueous solution by the action of an acid A resist composition comprising a resin and an acid generator.

[In the formula (IA),
R ¹ is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or 7 to 21 carbon atoms. Represents an aralkyl group, and the hydrogen atom contained in the aliphatic hydrocarbon group, the alicyclic hydrocarbon group, the aromatic hydrocarbon group and the aralkyl group is a hydroxyl group, a nitrile group, a fluorine atom, a trifluoromethyl group or It may be substituted with a nitro group, and —CH ₂ — contained in the aliphatic hydrocarbon group may be replaced with —O— or —CO—.
R ² represents an aliphatic hydrocarbon group having 7 to 12 carbon atoms, an alicyclic hydrocarbon group having 7 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 21 carbon atoms. And the hydrogen atom contained in the aliphatic hydrocarbon group, the alicyclic hydrocarbon group, the aromatic hydrocarbon group and the aralkyl group is a hydroxyl group, a nitrile group, a fluorine atom, a trifluoromethyl group or a nitro group. It may be substituted, and —CH ₂ — contained in the aliphatic hydrocarbon group may be replaced with —O— or —CO—.
R ¹ and R ² may combine with each other to form a ring having 4 to 20 carbon atoms together with N. ]

［式（ＩＢ）中、
Ｒ^３及びＲ^４は、それぞれ独立に、水酸基、ハロゲン原子、炭素数１〜１２のアルコキシ基、炭素数１〜３６の脂肪族炭化水素基、炭素数３〜３６の脂環式炭化水素基又は炭素数６〜１８の芳香族炭化水素基を表し、該脂肪族炭化水素基に含まれる水素原子は、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く、該脂環式炭化水素基に含まれる水素原子は、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く、該芳香族炭化水素基に含まれる水素原子は、ハロゲン原子、ヒドロキシ基、炭素数１〜３６の脂肪族炭化水素基、炭素数３〜３６の脂環式炭化水素基又は炭素数１〜１２のアルコキシ基で置換されていてもよい。
ｍｘ及びｍｙは、それぞれ独立に、０〜５の整数を表す。］ [2] The resist composition according to [1], wherein the iodonium salt having an anion represented by formula (IA) is an iodonium salt having a cation represented by formula (IB).

[In the formula (IB),
R ³ and R ⁴ are each independently a hydroxyl group, a halogen atom, an alkoxy group having 1 to 12 carbon atoms, an aliphatic hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or Represents an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aliphatic hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group, and the aromatic hydrocarbon The hydrogen atom contained in the group is substituted with a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. It may be.
mx and my each independently represent an integer of 0 to 5. ]

［式（Ｉ）中、
Ｒ^３、Ｒ^４、ｍｘ及びｍｚは、上記と同じ意味を表す。
Ｗ^１は、置換基を有していてもよい複素環を表す。］ [3] The resist composition according to [2], wherein the iodonium salt having an anion represented by formula (IA) is a salt represented by formula (I).

[In the formula (I),
R ³ , R ⁴ , mx, and mz represent the same meaning as described above.
W ¹ represents a heterocyclic ring which may have a substituent. ]

[4] The resist composition according to any one of [1] to [3], wherein the acrylic resin is a resin having a structural unit derived from a monomer having a lactone ring.

[5] (1) The process of apply | coating the resist composition in any one of [1]-[4] 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) 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 an excellent focus margin (DOF) can be obtained.

  The resist composition of the present invention has an iodonium salt having an anion represented by the formula (IA), an acid labile group, and is insoluble or hardly soluble in an alkaline aqueous solution. Acrylic resin that can be dissolved in an acid generator and an acid generator.

<Iodonium salt having an anion represented by formula (IA)>

  Examples of the aliphatic hydrocarbon group having 1 to 12 carbon atoms include methyl group (IR-1), ethyl group (IR-2), n-propyl group (IR-3), isopropyl group (IR-4), n- Butyl group (IR-5), sec-butyl group (IR-6), tert-butyl group (IR-7), n-pentyl group (IR-8), n-hexyl group (IR-9), heptyl group (IR-10), octyl group (IR-11), 2-ethylhexyl group (IR-12), nonyl group (IR-13), decyl group (IR-14), undecyl group (IR-15), dodecyl group (IR-16) and the like.

炭素数６〜２０の芳香族炭化水素基としては、例えば、フェニル基（ＩＲ−５１）、１−ナフチル基（ＩＲ−５２）、１−アントニル基（ＩＲ−５３）、ｐ−メチルフェニル基（ＩＲ−５４）、ｐ−ｔｅｒｔ−ブチルフェニル基（ＩＲ−５５）、ｐ−アダマンチルフェニル基（ＩＲ−５６）、２−ナフチル基（ＩＲ−５７）、２−アントニル基（ＩＲ−５８）、９−アントニル基（ＩＲ−５９）等が挙げられる。
炭素数７〜２１のアラルキル基としては、例えば、ベンジル基（ＩＲ−６１）、以下の基等が挙げられる。

Examples of the alicyclic hydrocarbon group having 3 to 20 carbon atoms include cyclopropyl group (IR-21), cyclobutyl group (IR-22), cyclopentyl group (IR-23), cyclohexyl group (IR-24), Cycloheptyl group (IR-25), cyclooctyl group (IR-26), cyclononyl group (IR-27), cyclodecyl group (IR-28), 1-norbornyl group (IR-29), 1-adamantyl group (IR -30), 2-adamantyl group (IR-31), 2-isobornyl group (IR-32), 2-norbornyl group (IR-39), groups shown below, and the like. * Represents a bond with N.

Examples of the aromatic hydrocarbon group having 6 to 20 carbon atoms include a phenyl group (IR-51), a 1-naphthyl group (IR-52), a 1-anthonyl group (IR-53), and a p-methylphenyl group ( IR-54), p-tert-butylphenyl group (IR-55), p-adamantylphenyl group (IR-56), 2-naphthyl group (IR-57), 2-anthonyl group (IR-58), 9 -Anthonyl group (IR-59) etc. are mentioned.
Examples of the aralkyl group having 7 to 21 carbon atoms include benzyl group (IR-61) and the following groups.

Examples of the aliphatic hydrocarbon group substituted with a hydroxyl group include the following groups.

Examples of the aliphatic hydrocarbon group substituted with a nitrile group include the following groups.

Examples of the aliphatic hydrocarbon group substituted with a fluorine atom include the following groups.

Examples of the aliphatic hydrocarbon group substituted with a nitro group include the following groups.

Examples of the alicyclic hydrocarbon group substituted with a hydroxyl group include the following groups.

Examples of the alicyclic hydrocarbon group substituted with a nitrile group include the following groups.

Examples of the alicyclic hydrocarbon group substituted with a fluorine atom include the following groups.

Examples of the alicyclic hydrocarbon group substituted with a nitro group include the following groups.

Examples of the aromatic hydrocarbon group substituted with a hydroxyl group include the following groups.

Examples of the aromatic hydrocarbon group substituted with a nitrile group include the following groups.

Examples of the aromatic hydrocarbon group substituted with a fluorine atom or a trifluoromethyl group include the following groups.

Examples of the aromatic hydrocarbon group substituted with a nitro group include the following groups.

Examples of the aralkyl group substituted with a hydroxyl group include the following groups.

Examples of the aralkyl group substituted with a nitrile group include the following groups.

Examples of the aralkyl group substituted with a fluorine atom include the following groups.

Examples of the aromatic hydrocarbon group substituted with a nitro group include the following groups.

Examples of the aliphatic hydrocarbon group in which —CH ₂ — is replaced by —O— include the following groups.

Examples of the aliphatic hydrocarbon group in which —CH ₂ — is replaced by —CO— include the following groups.

Examples of the aliphatic hydrocarbon group in which —CH ₂ — is replaced by —CO— and —O— include the following groups.

R ² is preferably an alicyclic hydrocarbon group having 3 to 20 carbon atoms, more preferably an adamantyl group.

［式（ＩＢ−Ｘ）中、
Ｗ^１は、置換基を有していてもよい複素環を表す。
＊はＳとの結合手を表す。］ When R ¹ and R ² are bonded to each other to form a ring with N, —NR ¹ R ² is preferably a group represented by the formula (IB-X), for example.

[In the formula (IB-X),
W ¹ represents a heterocyclic ring which may have a substituent.
* Represents a bond with S. ]

Examples of —NR ¹ R ² include the following groups. However, in the following formula, * represents a bond with S.

An iodonium salt refers to a salt composed of a cation and an anion having a positive charge on a divalent iodine atom.
As a cation which the iodonium salt which has an anion represented by a formula (IA) has, the cation represented by a formula (IB) is mentioned, for example.
Specific examples of the cation represented by the formula (IB) include the following.

  As the iodonium salt having an anion represented by the formula (IA), a salt represented by the formula (I) is preferable.

  Examples of the iodonium salt having an anion represented by the formula (IA) include the following iodonium salts. For example, “IR-1” in the table represents a group represented by the above formula (IR-1), and “IB-1” represents a cation represented by the above formula (IB-1). Represent. Further, “I-1” may be referred to as “a salt represented by the formula (I-1)”.

  Among the above-mentioned salts, Formula (I-1), Formula (I-2), Formula (I-216), Formula (I-228), Formula (I-301), Formula (I-305), Formula ( I-409) is preferred, and salts represented by formulas (I-1) and (I-216) are more preferred.

  A production method in the case where the iodonium salt having an anion represented by the formula (IA) has a cation represented by the formula (IB) is shown below.

［Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４、ｍｘ及びｍｙは上記と同じ意味を表す。
Ｘ^Ａ１＋はアンモニウムカチオンを表す。
Ｘ^Ｂ１―は、Ｃｌ^―、Ｂｒ^―及びＩ^―から選ばれるハロゲンアニオン、あるいは、アルキル硫酸イオン、硫酸イオン、カルボキシラートアニオン、アルコキシアニオン、水酸化物イオンを表す。］

[R ¹ , R ² , R ³ , R ⁴ , mx and my represent the same meaning as described above.
X ^{A1 +} represents an ammonium cation.
X ^B1- may, ^Cl -, Br ^- and I ^- halogen anion selected from or represent alkyl sulfate ion, sulfate ion, carboxylate anion, alkoxy anion, a hydroxide ion. ]

  By reacting an amine represented by the formula (IA-R1), a chlorosulfuric acid or a sulfate (such as triethylammonium sulfate), and a sulfur-containing compound selected from sulfur trioxide in a solvent under basic conditions, A salt represented by the formula (IA-R2) can be obtained. By stirring the obtained salt represented by the formula (IA-R2) and the salt represented by the formula (IB-R1) in a solvent, an iodonium salt having an anion represented by the formula (IA) is obtained. An iodonium salt having a cation represented by the formula (IB) can be obtained. Examples of the solvent include organic solvents such as chloroform, dichloroethane, dichloromethane, acetonitrile, dimethylformamide, and tetrahydrofuran. Examples of the base to be used include triethylamine, diazabicycloundecene, dimethylaminopyridine, pyridine and the like.

  The content of the iodonium salt having an anion represented by the formula (IA) is preferably 0.01 to 1.5 parts by mass with respect to 10 parts by mass of the resin of the composition, and 0.05 to 0.5 More preferably, it is a part.

<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.

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 alicyclic 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 3 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０〜３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 to 3. ]

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 alicyclic 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 and an acid-stable monomer (a3-1) having a condensed ring of a γ-butyrolactone ring and a norbornane ring are used. 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.
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.

<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 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).

［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 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 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 divalent saturated hydrocarbon group of L ^b1 is replaced by —O— or —CO— include formulas (b1-1) to (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２価の飽和炭化水素基を表す。
Ｌ^b3は、単結合又は炭素数１〜１２の２価の飽和炭化水素基を表す。
Ｌ^b4は、炭素数１〜１３の２価の飽和炭化水素基を表す。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２価の飽和炭化水素基を表す。
Ｌ^b6及びＬ^b7は、それぞれ独立に、炭素数１〜１５の２価の飽和炭化水素基を表す。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２価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２価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 divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b3 represents a single bond or a divalent saturated hydrocarbon group having 1 to 12 carbon atoms.
L ^b4 represents a divalent saturated hydrocarbon group having 1 to 13 carbon atoms. However, the upper limit of the carbon number of L ^b3 and L ^b4 is 13.
L ^b5 represents a divalent saturated hydrocarbon group having 1 to 15 carbon atoms.
L ^b6 and L ^b7 each independently represent a divalent saturated hydrocarbon group having 1 to 15 carbon atoms. However, the upper limit of the carbon number of L ^b6 and L ^b7 is 16.
L ^b8 represents a divalent saturated hydrocarbon group having 1 to 14 carbon atoms.
L ^b9 and L ^b10 each independently represent a divalent 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 of the alkyl group and the alicyclic hydrocarbon group include a halogen atom, a hydroxy group, an alkyl group having 1 to 12 carbon atoms, a hydroxy group-containing alkyl group having 1 to 12 carbon atoms, and 3 to 16 carbon atoms. An alicyclic hydrocarbon group, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an aralkyl group having 7 to 21 carbon atoms, an acyl group having 2 to 4 carbon atoms, a glycidyloxy 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 a group having 6 to 18 carbon atoms. Represents an aromatic hydrocarbon group, 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 here include an alkyl group, a halogen atom, and a hydroxy group.
Examples of the hydroxy group-containing alkyl group include a hydroxymethyl group and a hydroxyethyl group.

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, and 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 formula (B1) is preferably represented by any of formula (b2-1) to formula (b2-4).

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

R ^b7 and R ^b8 each independently represent a hydroxy group, an alkyl 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 alkyl group having 1 to 18 carbon atoms or an alicyclic hydrocarbon group having 3 to 18 carbon atoms.
R ^b11 represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms.
The alkyl group of R ^{b9 to} R ^b11 preferably has 1 to 12 carbon atoms, and the alicyclic hydrocarbon group preferably has 3 to 18 carbon atoms, more preferably 4 to 12 carbon atoms.
R ^b12 represents an alkyl group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The aromatic hydrocarbon group is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or an alkylcarbonyloxy group having 1 to 12 carbon atoms. May be substituted.
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 alkyl 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.

The alkyl group is preferably a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, octyl group and 2-ethylhexyl group. Is mentioned.
The alicyclic hydrocarbon group is preferably a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclodecyl group, a 2-alkyl-2-adamantyl group, or 1- (1-adamantyl) -1 -An alkyl group and an isobornyl group are mentioned.
The aromatic hydrocarbon group is preferably a phenyl group, a 4-methylphenyl group, a 4-ethylphenyl group, a 4-tert-butylphenyl group, a 4-cyclohexylphenyl group, a 4-methoxyphenyl group, or a biphenylyl group. And a naphthyl group.
Examples of the alkyl 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, and the cation represented by the formula (b2-1-1) is more preferable. Is a triphenylsulfonium cation (v2 = w2 = x2 = 0 in formula (b2-1-1)).

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のアルキル基、炭素数３〜１８の脂環式炭化水素基又は炭素数１〜１２のアルコキシ基を表す。
アルキル基は、好ましくは炭素数１〜１２であり、脂環式炭化水素基は、好ましくは炭素数４〜１８である。
前記アルキル基は、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。
前記脂環式炭化水素基は、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 alkyl group having 1 to 18 carbon atoms, an alicyclic hydrocarbon group having 3 to 18 carbon atoms, or 1 to 1 carbon atoms. 12 alkoxy groups are represented.
The alkyl group preferably has 1 to 12 carbon atoms, and the alicyclic hydrocarbon group preferably has 4 to 18 carbon atoms.
The alkyl 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 alicyclic 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 those described in JP2010-204646A.

  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.

  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 salt, 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>
This resist composition is obtained by mixing the resin (A), the acid generator (B) and the solvent (E), or
It can be prepared by mixing the resin (A), the acid generator (B), the basic compound (C) and the solvent (E). 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.

  Thus, after mixing resin (A), the acid generator (B) and the solvent (E), and each of the basic compound (C) or component (F) used as necessary, at a preferred content, The resist composition can be prepared by filtration 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) The process of apply | coating the resist composition of this invention 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.

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.

[Synthesis of a salt represented by the formula (I-1)]

  To a solution of 1.6 parts of a salt represented by the formula (I-1-a) (manufactured by Tokyo Chemical Industry Co., Ltd.) and 12.8 parts of chloroform was added 5.1 parts of a 10% aqueous sodium hydroxide solution. And stirred at room temperature for 1 hour. The aqueous layer of the reaction mixture was removed by liquid separation, and the organic layer was dried over magnesium sulfate. To the dried reaction mixture solution, 2.3 parts of triethylamine was added, cooled to −10 ° C., 1.1 parts of the compound represented by the formula (I-1-c) was added, and the mixture was stirred at room temperature for 1 hour. . To the reaction mixture, 3.0 parts of the salt represented by the formula (I-1-d) was added and stirred overnight. To the reaction mixture solution, 11 parts of ion exchange water was added and extracted with chloroform. The chloroform solution was concentrated under reduced pressure and recrystallized with a mixed solution of acetonitrile and 2-methoxy-2-methylpropane to obtain 2.9 parts of a salt represented by the formula (I-1).

^{MS (ESI (+) Spectrum)} : M + = 393.1 (C 20 H 26 I + = 393.1)
MS (ESI (−) Spectrum): M ⁻ = 230.1 (C ₁₀ H ₁₆ NO ₃ S ⁻ = 230.1)

[Synthesis of a salt represented by the formula (I-216)]

  3.8 parts of triethylamine is added to a solution of 2.0 parts of a compound represented by the formula (I-216-b) (manufactured by Tokyo Chemical Industry Co., Ltd.) and 20 parts of chloroform, and cooled to -10 ° C. After adding 1.84 parts of the compound represented by (I-216-c), the mixture was stirred at room temperature for 1 hour. To the reaction mixture solution, 5.0 parts of a salt represented by the formula (I-216-d) was added and stirred overnight. To the reaction mixture solution, 20 parts of ion exchange water was added and extracted with chloroform. The chloroform solution was concentrated under reduced pressure, a mixed solution of acetonitrile and 2-methoxy-2-methylpropane was added, the supernatant was removed by decantation, and the salt was dried, and the salt represented by the formula (I-216) 5. Two parts were obtained.

^{MS (ESI (+) Spectrum)} : M + = 393.1 (C 20 H 26 I + = 393.1)
MS (ESI (−) Spectrum): M ⁻ = 218.1 (C ₉ H ₁₆ NO ₃ S ⁻ = 218.1)

[Synthesis of a salt represented by the formula (I-409)]

  3.8 parts of triethylamine is added to a solution of 2.0 parts of a compound represented by the formula (I-216-b) (manufactured by Tokyo Chemical Industry Co., Ltd.) and 20 parts of chloroform, and cooled to -10 ° C. After adding 1.84 parts of the compound represented by (I-216-c), the mixture was stirred at room temperature for 1 hour. To the reaction mixture solution, 3.7 parts of the salt represented by the formula (I-409-d) was added and stirred overnight. To the reaction mixture solution, 20 parts of ion exchange water was added and extracted with chloroform. The chloroform solution was concentrated under reduced pressure, a mixed solution of acetonitrile and 2-methoxy-2-methylpropane was added, the supernatant was removed by decantation, dried, and the salt represented by the formula (I-409) 4. 1 part was obtained.

MS (ESI (+) Spectrum): M ⁺ = 281.0 (C ₁₂ H ₁₀ I ⁺ = 281.0)
MS (ESI (−) Spectrum): M ⁻ = 218.1 (C ₉ H ₁₆ NO ₃ S ⁻ = 218.1)

[Synthesis of a salt represented by the formula (I-301)]

  To a solution of 1.6 parts of the salt represented by the formula (I-301-a) (manufactured by Tokyo Chemical Industry Co., Ltd.) and 12.8 parts of chloroform, 5.1 parts of 10% aqueous sodium hydroxide solution was added. And stirred at room temperature for 1 hour. The aqueous layer of the reaction mixture was removed by liquid separation, and the organic layer was dried over magnesium sulfate. To the dried reaction mixture solution, 2.3 parts of triethylamine was added, cooled to −10 ° C., 1.1 parts of the compound represented by the formula (I-301-c) were added, and the mixture was stirred at room temperature for 1 hour. . To the reaction mixture solution, 2.2 parts of the salt represented by the formula (I-301-d) was added and stirred overnight. To the reaction mixture solution, 11 parts of ion exchange water was added and extracted with chloroform. The chloroform solution was concentrated under reduced pressure and recrystallized with a mixed solution of acetonitrile and 2-methoxy-2-methylpropane to obtain 2.5 parts of a salt represented by the formula (I-301).

MS (ESI (+) Spectrum): M ⁺ = 281.0 (C ₁₂ H ₁₀ I ⁺ = 281.0)
MS (ESI (−) Spectrum): M ⁻ = 230.1 (C ₁₀ H ₁₆ NO ₃ S ⁻ = 230.1)

[Synthesis of a salt represented by the formula (I-163)]

  3.8 parts of triethylamine is added to a solution of 2.5 parts of a compound represented by the formula (I-163-b) (manufactured by Tokyo Chemical Industry Co., Ltd.) and 20 parts of chloroform, and the formula (I-163-c) After adding 2.7 parts of the compound represented by the formula, the mixture was stirred at room temperature for 3 hours. To the reaction mixture solution, 6.0 parts of a salt represented by the formula (I-163-d) was added and stirred overnight. To the reaction mixture solution, 20 parts of ion exchange water was added and extracted with chloroform. 4. Concentrate the chloroform solution under reduced pressure, add a mixed solution of acetonitrile and 2-methoxy-2-methylpropane, remove the supernatant by decantation, dry the salt, and express the salt represented by the formula (I-163). 9 parts were obtained.

^{MS (ESI (+) Spectrum)} : M + = 393.1 (C 20 H 26 I + = 393.1)
MS (ESI (−) Spectrum): M ⁻ = 256.1 (C ₁₂ H ₁₈ NO ₃ S ⁻ = 256.1)

Synthesis of Resin A1 15.00 parts of the compound represented by Formula (M-1), 4.89 parts of the compound represented by Formula (M-2), and the compound represented by Formula (M-6) 11.12 parts, 8.81 parts of the compound represented by the formula (M-3) were charged (molar ratio 35: 12: 23: 30), and 1.5 wt. 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.

  As shown below, the resist composition was prepared by filtering the mixture obtained by mixing and melt | dissolving each component with the filter made from a fluororesin with the hole diameter of 0.2 micrometer.

＜樹脂＞
Ａ１：樹脂Ａ１
＜酸発生剤＞
Ｂ１：下記の酸発生剤

＜式（ＩＡ）で表されるアニオンを有するヨードニウム塩＞

II−１：ビス（ｔ−ブチルフェニル）ヨードニウムシクラメート
＜溶剤１＞
プロピレングリコールモノメチルエーテルアセテート ２２０．０部
２−ヘプタノン １０．０部
プロピレングリコールモノメチルエーテル ２０．０部
γ−ブチロラクトン ３．０部

<Resin>
A1: Resin A1
<Acid generator>
B1: The following acid generator

<Iodonium salt having an anion represented by formula (IA)>

II-1: Bis (t-butylphenyl) iodonium cyclamate <Solvent 1>
Propylene glycol monomethyl ether acetate 220.0 parts 2-heptanone 10.0 parts Propylene glycol monomethyl ether 20.0 parts γ-butyrolactone 3.0 parts

An organic antireflective coating composition [ARC29SR; manufactured by Nissan Chemical Co., Ltd.] is applied onto a 12-inch silicon wafer and baked at 205 ° C. for 60 seconds to provide an organic reflection having a thickness of 930 mm. A prevention film was formed. Subsequently, the resist composition was spin-coated on the organic antireflection film so that the film thickness after drying was 120 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 the table. ArF excimer scanner for immersion exposure [XT: 1900 Gi; manufactured by ASML, NA = 1.20, quadrupole on axis (σout / σin = 0.97 / 0.77), on the wafer thus formed with the resist composition film. The contact hole pattern was subjected to immersion exposure by changing the exposure amount stepwise using XY deflection.
After exposure, post exposure bake (PEB) is performed for 60 seconds on the hot plate at the temperature described in the “PEB” column of the table, and then paddles are further added for 60 seconds with an aqueous 2.38 mass% tetramethylammonium hydroxide solution. Developed.

  In each resist film, a hole mask of 160 nm with a pitch of 500 nm was used, and an exposure amount for forming a 140 nm hole pattern was defined as an effective sensitivity.

Depth of focus evaluation (DOF): Using a 160 nm Hole mask with a pitch of 500 nm, the focus margin at the effective sensitivity for forming a 140 nm hole pattern was evaluated. When the focus is shaken, the focus range in which the Hole diameter is 135 nm to 140 nm is defined as DOF. It can be said that the larger the DOF value, the better the focus margin.

  According to the resist composition of the present invention, a pattern having an excellent focus margin (DOF) can be obtained.

Claims (5)

An iodonium salt having an anion represented by the formula (IA), an acrylic resin having an acid labile group and insoluble or hardly soluble in an alkaline aqueous solution, and soluble in an alkaline aqueous solution by the action of an acid; A resist composition comprising an acid generator.

[In the formula (IA),
R ¹ is a hydrogen atom, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group having 3 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or 7 to 21 carbon atoms. Represents an aralkyl group, and the hydrogen atom contained in the aliphatic hydrocarbon group, the alicyclic hydrocarbon group, the aromatic hydrocarbon group and the aralkyl group is a hydroxyl group, a nitrile group, a fluorine atom, a trifluoromethyl group or It may be substituted with a nitro group, and —CH ₂ — contained in the aliphatic hydrocarbon group may be replaced with —O— or —CO—.
R ² represents an aliphatic hydrocarbon group having 7 to 12 carbon atoms, an alicyclic hydrocarbon group having 7 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 21 carbon atoms. And the hydrogen atom contained in the aliphatic hydrocarbon group, the alicyclic hydrocarbon group, the aromatic hydrocarbon group and the aralkyl group is a hydroxyl group, a nitrile group, a fluorine atom, a trifluoromethyl group or a nitro group. It may be substituted, and —CH ₂ — contained in the aliphatic hydrocarbon group may be replaced with —O— or —CO—.
R ¹ and R ² may combine with each other to form a ring having 4 to 20 carbon atoms together with N. ] The resist composition according to claim 1, wherein the iodonium salt having an anion represented by formula (IA) is an iodonium salt having a cation represented by formula (IB).

[In the formula (IB),
R ³ and R ⁴ are each independently a hydroxyl group, a halogen atom, an alkoxy group having 1 to 12 carbon atoms, an aliphatic hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or Represents an aromatic hydrocarbon group having 6 to 18 carbon atoms, and the hydrogen atom contained in the aliphatic hydrocarbon group is a hydroxy group, an alkoxy group having 1 to 12 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms. The hydrogen atom contained in the alicyclic hydrocarbon group may be substituted with a halogen atom, an acyl group having 2 to 4 carbon atoms, or a glycidyloxy group, and the aromatic hydrocarbon The hydrogen atom contained in the group is substituted with a halogen atom, a hydroxy group, an aliphatic hydrocarbon group having 1 to 36 carbon atoms, an alicyclic hydrocarbon group having 3 to 36 carbon atoms, or an alkoxy group having 1 to 12 carbon atoms. It may be.
mx and my each independently represent an integer of 0 to 5. ] 3. The resist composition according to claim 2, wherein the iodonium salt having an anion represented by the formula (IA) is a salt represented by the formula (I).

[In the formula (I),
R ³ , R ⁴ , mx, and mz represent the same meaning as described above.
W ¹ represents a heterocyclic ring which may have a substituent. ]   The resist composition according to claim 1, wherein the acrylic resin is a resin having a structural unit derived from a monomer having a lactone ring. (1) The process of apply | coating the resist composition in any one of Claims 1-4 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) a step of developing the heated composition layer using a developing device;
A method for producing a resist pattern including: