JP5276821B2 - Resist composition and resist pattern forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resist composition which ensures a small change in resist pattern dimensions under variation of exposure energy and is excellent in mask reproducibility, and to provide a resist pattern forming method. <P>SOLUTION: The resist composition comprises: a base material component (A) of which solubility in an alkali developer changes by the action of an acid and an acid; generator component (B) which generates an acid upon exposure to light, wherein the acid generator component (B) comprises an acid generator (B1) having a cationic moiety represented by general formula (b'-1) [wherein two of R<SP>1"</SP>-R<SP>3"</SP>are each independently an alkyl group or an aryl group, the two may bond to each other to form a ring with the sulfur atom in the formula; and the balance is an alkyl group, an aryl group or -(R<SP>4'</SP>)-C(=O)-R<SP>5'</SP>, wherein R<SP>4'</SP>is a 1-5C alkylene group and R<SP>5'</SP>is an aryl group] and an acid generator (B2) having a cationic moiety containing a dibenzothiophene skeleton. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

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

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, and the resist film is selectively exposed to light such as light or an electron beam through a mask on which a predetermined pattern is formed. And a development process is performed to form a resist pattern having a predetermined shape on the resist film. A resist material in which the exposed portion changes to a property that dissolves in the developer is referred to as a positive type, and a resist material that changes to a property in which the exposed portion does not dissolve in the developer is referred to as a negative type.
In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has been rapidly progressing due to advances in lithography technology.
As a technique for miniaturization, the wavelength of an exposure light source is generally shortened. Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but at present, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has started. In addition, studies have been made on F ₂ excimer lasers, electron beams, EUV (extreme ultraviolet rays), X-rays, and the like having shorter wavelengths than these excimer lasers.

Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing a pattern with fine dimensions. As a resist material that satisfies such requirements, a chemically amplified resist containing a base resin whose solubility in an alkaline developer is changed by the action of an acid and an acid generator that generates an acid upon exposure is used. For example, a positive chemically amplified resist contains, as a base resin, a resin that increases solubility in an alkaline developer by the action of an acid and an acid generator. When the acid is generated, the exposed portion becomes soluble in the alkaline developer.
Up to now, as a base resin for chemically amplified resist, polyhydroxystyrene (PHS) having high transparency with respect to KrF excimer laser (248 nm) and a resin whose hydroxyl group is protected with an acid dissociable, dissolution inhibiting group (PHS resin) Has been used. However, since the PHS resin has an aromatic ring such as a benzene ring, the transparency to light having a wavelength shorter than 248 nm, for example, 193 nm, is not sufficient. For this reason, a chemically amplified resist having a PHS resin as a base resin component has drawbacks such as low resolution in a process using 193 nm light, for example.
Therefore, as a resist base resin currently used in ArF excimer laser lithography and the like, since it has excellent transparency near 193 nm, a resin (acrylic resin) having a structural unit derived from (meth) acrylic ester is used. System resin) is mainly used (see, for example, Patent Document 1).

  The “(meth) acrylic acid ester” means one or both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the α-position. “(Meth) acrylate” means one or both of an acrylate having a hydrogen atom bonded to the α-position and a methacrylate having a methyl group bonded to the α-position. “(Meth) acrylic acid” means one or both of acrylic acid having a hydrogen atom bonded to the α-position and methacrylic acid having a methyl group bonded to the α-position.

On the other hand, various acid generators used in chemically amplified resists have been proposed so far, such as onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, Diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators and the like are known. Currently, acid generators containing a triphenylsulfonium skeleton, a dinaphthyl monophenylsulfonium skeleton, and the like are used as the acid generator (see, for example, Patent Document 2).
JP 2003-241385 A Japanese Patent Laid-Open No. 2005-37888

In recent years, the miniaturization of resist patterns has further progressed, and conventional resist compositions are required to have higher resolution and improved various lithography properties than ever before.
For example, as one of them, an improvement in exposure margin (EL margin) is required in order to improve a process margin and the like during pattern formation.
The “EL margin” is a range of exposure amount that can form a resist pattern with a dimension within which a deviation from the target dimension is within a predetermined range when exposure is performed with varying exposure amount, that is, a resist pattern that is faithful to the mask pattern. This is the range of the exposure amount to be obtained. The larger the EL margin value, the smaller the change amount of the pattern size accompanying the variation in the exposure amount, and the better the process margin.
Also, the mask reproducibility when a resist pattern is formed is required to be improved as the pattern becomes finer.
One index indicating mask reproducibility is a mask error factor (MEF).
“MEF” is a parameter indicating how faithfully a mask pattern having a different line width and aperture can be reproduced with the same exposure amount when the pitch is fixed.

  The present invention has been made in view of the above circumstances, and the resist composition has a small change in resist pattern dimension when the exposure amount fluctuates (EL margin is large) and has excellent mask reproducibility (MEF). And a resist pattern forming method using the resist composition.

In order to achieve the above object, the present invention employs the following configuration.
Specifically, a first aspect of the present invention includes a base component which exhibits changed solubility in an alkali developing solution under action of acid (A), acid generator component that generates acid on exposure light (B) and nitrogen-containing organic compounds A resist composition containing (D) , wherein the acid generator component (B) includes an acid generator (B1) having a cation moiety represented by the following general formula (b′-1-0): following general formula (b'-5) with viewing contains an acid generating agent having a cation (B2) represented, the nitrogen-containing organic compound (D) is represented by the following formula (d-1) A resist composition comprising a nitrogen-containing organic compound .

［式中、Ｒ^１０”およびＲ^２０”はそれぞれ独立してアルキレン基であり；Ｒ^３０”は炭素数６〜２０の無置換のアリール基；該無置換のアリール基の水素原子の一部又は全部がアルキル基、アルコキシ基、アルコキシアルキルオキシ基、アルコキシカルボニルアルキルオキシ基、ハロゲン原子又は水酸基で置換された置換アリール基のいずれかであり、Ｒ^４０は水素原子又はアルキル基であり、Ｒ^４１はハロゲン原子、ハロゲン化アルキル基、アルキル基、アセチル基、カルボキシ基、又はヒドロキシアルキル基であり；Ｒ^４２およびＲ^４３はそれぞれ独立してハロゲン原子、ハロゲン化アルキル基、アルキル基、アセチル基、アルコキシ基、カルボキシ基、水酸基、又はヒドロキシアルキル基であり；ｎ_０〜ｎ_３はそれぞれ独立して０〜３の整数であり、ただし、ｎ_０＋ｎ_１は５以下である。］

［式中、Ｒ ^１ は下記一般式（Ｉ）で表される基である。ａは１〜３の整数である。ただし、式中のベンゼン環上に、置換基として炭素数１〜５のアルキル基をさらに有していてもよい。ｂは１〜３の整数である。Ｒ ^２ およびＲ ^３ は、それぞれ独立に、水素原子または炭素数１〜５のアルキル基である。］

［式中、Ｒ ^４ は、水素原子または炭素数１〜５のアルキル基である。Ｒ ^５ は、炭素数１〜５のアルキレン基である。ｃは、０または１である。］

[Wherein R ¹⁰ ″ and R ²⁰ ″ each independently represents an alkylene group ; R ³⁰ ″ represents an unsubstituted aryl group having 6 to 20 carbon atoms; a part of hydrogen atoms of the unsubstituted aryl group or all alkyl groups, alkoxy group, and a alkoxyalkyl group, an alkoxycarbonylalkyl group, or a substituted aryl group substituted by a halogen atom or a hydroxyl radical, R ⁴⁰ is a hydrogen atom or an alkyl radical, R ⁴¹ is a halogen atom, halogenated alkyl group, alkyl group, acetyl group, carboxy group, or hydroxyalkyl group; R ⁴² and R ⁴³ are each independently a halogen atom, halogenated alkyl group, alkyl group, acetyl group, An alkoxy group, a carboxy group, a hydroxyl group, or a hydroxyalkyl group; n _{0 to} n ₃ are each independently And n ₀ + n ₁ is 5 or less.]

[Wherein, R ¹ is a group represented by the following general formula (I). a is an integer of 1 to 3. However, you may further have a C1-C5 alkyl group as a substituent on the benzene ring in a formula. b is an integer of 1 to 3. R ² and R ³ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ]

[Wherein, R ⁴ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R ⁵ is an alkylene group having 1 to 5 carbon atoms. c is 0 or 1. ]

  According to a second aspect of the present invention, there is provided a step of forming a resist film on a support, a step of exposing the resist film, and an alkali development of the resist film using the resist composition of the first aspect. A resist pattern forming method including a step of forming a resist pattern.

In the present specification and claims, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified.
Further, the “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups unless otherwise specified.
The “lower alkyl group” is an alkyl group having 1 to 5 carbon atoms.
The “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
The “structural unit” means a monomer unit (monomer unit) constituting a polymer compound (polymer, copolymer).
“Exposure” is a concept including general irradiation of radiation.

  According to the present invention, a resist composition having a small change in resist pattern dimension when the exposure amount fluctuates (large EL margin) and excellent mask reproducibility (MEF), and a resist pattern using the resist composition A forming method can be provided.

≪Resist composition≫
The resist composition of the first aspect of the present invention generates a base component (A) (hereinafter referred to as component (A)) whose solubility in an alkaline developer is changed by the action of an acid, and an acid upon exposure. The acid generator component (B) (hereinafter referred to as the component (B)) is contained, and the component (B) is an acid generator (B1) having a cation moiety represented by the general formula (b′-1). And an acid generator (B2) having a cation moiety containing a dibenzothiophene skeleton.
When a resist film formed using such a resist composition is selectively exposed at the time of resist pattern formation, an acid is generated from the component (B), and the acid has a solubility in the alkaline developer of the component (A). Change. As a result, while the solubility of the exposed portion of the resist film in the alkaline developer changes, the unexposed portion does not change the solubility in the alkaline developer. In the case of the negative type, the unexposed part is dissolved and removed, and a resist pattern is formed.
The resist composition of the present invention may be a negative resist composition or a positive resist composition.

<(A) component>
As the component (A), organic compounds that are usually used as base material components for chemically amplified resists can be used singly or in combination of two or more.
Here, the “base material component” is an organic compound having a film forming ability, and an organic compound having a molecular weight of 500 or more is preferably used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved and a nano-level resist pattern is easily formed.
The organic compound having a molecular weight of 500 or more is largely classified into a low molecular weight organic compound having a molecular weight of 500 or more and less than 2000 (hereinafter referred to as a low molecular compound) and a high molecular weight resin having a molecular weight of 2000 or more (polymer material). Separated. As the low molecular weight compound, a non-polymer is usually used. In the case of a resin (polymer, copolymer), a polystyrene-reduced mass average molecular weight by GPC (gel permeation chromatography) is used as the “molecular weight”. Hereinafter, the term “resin” refers to a resin having a molecular weight of 2000 or more.
As the component (A), a resin whose alkali solubility is changed by the action of an acid can be used, and a low molecular weight material whose alkali solubility is changed by the action of an acid can also be used.

When the resist composition of the present invention is a negative resist composition, as the component (A), a base component that is soluble in an alkali developer is used, and a crosslinking agent is blended in the negative resist composition. .
In such a negative resist composition, when an acid is generated from the component (B) by exposure, the acid acts to cause crosslinking between the base material component and the crosslinking agent, resulting in poor solubility in an alkali developer. To do. Therefore, in the formation of a resist pattern, when a resist film obtained by applying the negative resist composition on a support is selectively exposed, the exposed portion turns into poorly soluble in an alkaline developer, while not yet exposed. Since the exposed portion remains soluble in the alkali developer and does not change, a resist pattern can be formed by alkali development.
As the component (A) of the negative resist composition, a resin that is soluble in an alkali developer (hereinafter referred to as an alkali-soluble resin) is usually used.
As the alkali-soluble resin, a resin having a unit derived from at least one selected from α- (hydroxyalkyl) acrylic acid or a lower alkyl ester of α- (hydroxyalkyl) acrylic acid is a good resist with little swelling. A pattern can be formed, which is preferable. Α- (Hydroxyalkyl) acrylic acid includes acrylic acid in which a hydrogen atom is bonded to the α-position carbon atom to which the carboxy group is bonded, and a hydroxyalkyl group (preferably having 1 carbon atom) in the α-position carbon atom. One or both of [alpha] -hydroxyalkylacrylic acids to which (5) hydroxyalkyl groups) are attached.
As the crosslinking agent, for example, it is usually preferable to use an amino crosslinking agent such as glycoluril having a methylol group or an alkoxymethyl group because a good resist pattern with less swelling can be formed. It is preferable that the compounding quantity of a crosslinking agent is 1-50 mass parts with respect to 100 mass parts of alkali-soluble resin.

When the resist composition of the present invention is a positive resist composition, the component (A) is a base component (A ′) (hereinafter referred to as (A ′)) whose solubility in an alkaline developer is increased by the action of an acid. Component)).
The component (A ′) is hardly soluble in an alkali developer before exposure. When an acid is generated from the component (B) by exposure, the solubility in the alkali developer is increased by the action of the acid. Therefore, in the formation of the resist pattern, when the resist film obtained by applying the positive resist composition on the support is selectively exposed, the exposed portion becomes insoluble to soluble in an alkaline developer. On the other hand, since the unexposed portion remains hardly soluble in alkali and remains unchanged, a resist pattern can be formed by alkali development.

In the resist composition of the present invention, the component (A) is preferably a base material component (A ′) whose solubility in an alkaline developer is increased by the action of an acid. That is, the resist composition of the present invention is preferably a positive resist composition.
The component (A ′) may be a resin component (A1) (hereinafter sometimes referred to as component (A1)) whose solubility in an alkaline developer is increased by the action of an acid. It may be a low molecular compound (A2) (hereinafter sometimes referred to as the component (A2)) whose solubility in a developer increases, or a mixture thereof.

[(A1) component]
As the component (A1), resin components (base resins) that are usually used as base components for chemically amplified resists can be used alone or in combination of two or more.
In the present invention, the component (A1) preferably contains a structural unit derived from an acrylate ester.
Here, in the present specification and claims, the “structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid esters” include those in which a hydrogen atom is bonded to the carbon atom at the α-position, and those in which a substituent (atom or group other than a hydrogen atom) is bonded to the carbon atom in the α-position. Include concepts. Examples of the substituent include a lower alkyl group and a halogenated lower alkyl group.
Note that the α-position (α-position carbon atom) of a structural unit derived from an acrylate ester means a carbon atom to which a carbonyl group is bonded, unless otherwise specified.
In the acrylate ester, as the lower alkyl group as a substituent at the α-position, specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, Examples include lower linear or branched alkyl groups such as isopentyl group and neopentyl group.
Specific examples of the halogenated lower alkyl group include groups in which part or all of the hydrogen atoms in the above-mentioned “lower alkyl group as a substituent at the α-position” are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
In the present invention, the α-position of the acrylate ester is preferably a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and is a hydrogen atom, a lower alkyl group or a fluorinated lower alkyl group. In view of industrial availability, a hydrogen atom or a methyl group is most preferable.

The component (A1) particularly preferably has a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.
In addition to the structural unit (a1), the component (A1) preferably further has a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group.
The component (A1) is a structural unit derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group in addition to the structural unit (a1) or in addition to the structural units (a1) and (a2) ( Preferably it has a3).

・ Structural unit (a1)
The acid dissociable, dissolution inhibiting group in the structural unit (a1) has an alkali dissolution inhibiting property that makes the entire component (A1) difficult to dissolve in an alkali developer before dissociation, and dissociates with an acid. This increases the solubility of the entire component in an alkaline developer, and those that have been proposed as acid dissociable, dissolution inhibiting groups for base resins for chemically amplified resists can be used. Generally, a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group in (meth) acrylic acid or the like; an acetal type acid dissociable, dissolution inhibiting group such as an alkoxyalkyl group is widely known. .

Here, the “tertiary alkyl ester” is an ester formed by replacing a hydrogen atom of a carboxy group with a chain or cyclic alkyl group, and the carbonyloxy group (—C (O)). A structure in which the tertiary carbon atom of the chain or cyclic alkyl group is bonded to the terminal oxygen atom of -O-). In this tertiary alkyl ester, when an acid acts, a bond is cut between an oxygen atom and a tertiary carbon atom.
The chain or cyclic alkyl group may have a substituent.
Hereinafter, a group that is acid dissociable by constituting a carboxy group and a tertiary alkyl ester is referred to as a “tertiary alkyl ester type acid dissociable, dissolution inhibiting group” for convenience.
Examples of the tertiary alkyl ester type acid dissociable, dissolution inhibiting group include an aliphatic branched acid dissociable, dissolution inhibiting group and an acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group.

“Aliphatic branched” means having a branched structure having no aromaticity.
The structure of the “aliphatic branched acid dissociable, dissolution inhibiting group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group.
The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated.
As the aliphatic branched acid dissociable, dissolution inhibiting group, a tertiary alkyl group having 4 to 8 carbon atoms is preferable, and specific examples include a tert-butyl group, a tert-pentyl group, and a tert-heptyl group. .

The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity.
The “aliphatic cyclic group” in the structural unit (a1) may or may not have a substituent. Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.
The basic ring structure excluding the substituent of the “aliphatic cyclic group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group.
The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated. The “aliphatic cyclic group” is preferably a polycyclic group.
Examples of the aliphatic cyclic group include monocycloalkanes, bicycloalkanes, tricycloalkanes, tetracycloalkanes that may or may not be substituted with a lower alkyl group, a fluorine atom or a fluorinated alkyl group. And groups obtained by removing one or more hydrogen atoms from a polycycloalkane. More specifically, monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane are exemplified. .

  Examples of the acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group include a group having a tertiary carbon atom on the ring skeleton of a cyclic alkyl group. Specifically, 2-methyl-2 -Adamantyl group, 2-ethyl-2-adamantyl group, etc. are mentioned. Alternatively, in the structural units represented by the following general formulas (a1 ″ -1) to (a1 ″ -6), an adamantyl group such as a group bonded to an oxygen atom of a carbonyloxy group (—C (O) —O—) An aliphatic cyclic group such as a cyclohexyl group, a cyclopentyl group, a norbornyl group, a tricyclodecanyl group, or a tetracyclododecanyl group, and a branched alkylene group having a tertiary carbon atom bonded thereto. Groups.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｒ^１５、Ｒ^１６はアルキル基（直鎖状、分岐鎖状のいずれでもよく、好ましくは炭素数１〜５である）を示す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; R ¹⁵ and R ^{16 each} represents an alkyl group (which may be linear or branched, and preferably has 1 to 5 carbon atoms. Is). ]

  In the general formulas (a1 ″ -1) to (a1 ″ -6), the lower alkyl group or halogenated lower alkyl group of R is a lower alkyl group or halogenated lower alkyl which may be bonded to the α-position of the acrylate ester. It is the same as the alkyl group.

The “acetal-type acid dissociable, dissolution inhibiting group” is generally bonded to an oxygen atom by substituting a hydrogen atom at the terminal of an alkali-soluble group such as a carboxy group or a hydroxyl group. When an acid is generated by exposure, the acid acts to break the bond between the acetal acid dissociable, dissolution inhibiting group and the oxygen atom to which the acetal acid dissociable, dissolution inhibiting group is bonded.
Examples of the acetal type acid dissociable, dissolution inhibiting group include a group represented by the following general formula (p1).

［式中、Ｒ^１’，Ｒ^２’はそれぞれ独立して水素原子または低級アルキル基を表し、ｎは０〜３の整数を表し、Ｙは低級アルキル基または脂肪族環式基を表す。］

[Wherein, R ¹ ′ and R ² ′ each independently represents a hydrogen atom or a lower alkyl group, n represents an integer of 0 to 3, and Y represents a lower alkyl group or an aliphatic cyclic group. ]

In the above formula, n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
Examples of the lower alkyl group for R ¹ ′ and R ² ′ include the same lower alkyl groups as those described above for R. A methyl group or an ethyl group is preferable, and a methyl group is most preferable.
In the present invention, it is preferable that at least one of R ¹ ′ and R ² ′ is a hydrogen atom. That is, the acid dissociable, dissolution inhibiting group (p1) is preferably a group represented by the following general formula (p1-1).

［式中、Ｒ^１’、ｎ、Ｙは上記と同様である。］

[Wherein R ¹ ′, n and Y are the same as described above. ]

Examples of the lower alkyl group for Y include the same lower alkyl groups as those described above for R.
The aliphatic cyclic group for Y can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups that have been proposed in a number of conventional ArF resists. For example, the above “aliphatic ring” Examples thereof are the same as those in the formula group.

  Examples of the acetal type acid dissociable, dissolution inhibiting group also include a group represented by the following general formula (p2).

［式中、Ｒ^１７、Ｒ^１８はそれぞれ独立して直鎖状もしくは分岐鎖状のアルキル基または水素原子であり、Ｒ^１９は直鎖状、分岐鎖状または環状のアルキル基である。または、Ｒ^１７およびＲ^１９がそれぞれ独立して直鎖状または分岐鎖状のアルキレン基であって、Ｒ^１７の末端とＲ^１９の末端とが結合して環を形成していてもよい。］

[Wherein, R ¹⁷ and R ¹⁸ each independently represent a linear or branched alkyl group or a hydrogen atom, and R ¹⁹ represents a linear, branched or cyclic alkyl group. Alternatively, R ¹⁷ and R ¹⁹ may be each independently a linear or branched alkylene group, and the end of R ^{17 and} the end of R ¹⁹ may be bonded to form a ring. ]

In R ¹⁷ and R ¹⁸ , the alkyl group preferably has 1 to 15 carbon atoms, may be linear or branched, and is preferably an ethyl group or a methyl group, and most preferably a methyl group. In particular, it is preferable that one of R ¹⁷ and R ¹⁸ is a hydrogen atom and the other is a methyl group.
R ¹⁹ is a linear, branched or cyclic alkyl group, and preferably has 1 to 15 carbon atoms, and may be any of linear, branched or cyclic.
When R ¹⁹ is linear or branched, it preferably has 1 to 5 carbon atoms, more preferably an ethyl group or a methyl group, and most preferably an ethyl group.
When R ¹⁹ is cyclic, it preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, one or more polycycloalkanes such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group. And the like, in which a hydrogen atom is removed. More specifically, monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane are exemplified. . Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
In the above formula, R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group (preferably an alkylene group having 1 to 5 carbon atoms), and the end of R ¹⁹ and R ^{19 17} ends may be bonded.
In this case, a cyclic group is formed by R ¹⁷ , R ¹⁹ , the oxygen atom to which R ¹⁹ is bonded, and the carbon atom to which the oxygen atom and R ¹⁷ are bonded. The cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

  As the structural unit (a1), one or more selected from the group consisting of structural units represented by the following general formula (a1-0-1) and structural units represented by the following general formula (a1-0-2): Is preferably used.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｘ^１は酸解離性溶解抑制基を示す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; and X ¹ represents an acid dissociable, dissolution inhibiting group. ]

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｘ^２は酸解離性溶解抑制基を示し；Ｙ^２はアルキレン基または脂肪族環式基を示す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; X ² represents an acid dissociable, dissolution inhibiting group; Y ² represents an alkylene group or an aliphatic cyclic group. ]

In general formula (a1-0-1), the lower alkyl group or halogenated lower alkyl group for R is the same as the lower alkyl group or halogenated lower alkyl group that may be bonded to the α-position of the acrylate ester. .
X ¹ is not particularly limited as long as it is an acid dissociable, dissolution inhibiting group, and examples thereof include the above-described tertiary alkyl ester type acid dissociable, dissolution inhibiting group and acetal type acid dissociable, dissolution inhibiting group. And tertiary alkyl ester type acid dissociable, dissolution inhibiting groups are preferred.

In general formula (a1-0-2), R is the same as defined above.
X ² is the same as X ¹ in formula (a1-0-1).
Y ² is preferably an alkylene group having 1 to 10 carbon atoms or a divalent aliphatic cyclic group, and a group in which two or more hydrogen atoms are removed is used as the aliphatic cyclic group. Except for the above, the same “aliphatic cyclic group” as described above can be used.
When Y ² is an alkylene group having 1 to 10 carbon atoms, it is more preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. .
When Y ² is a divalent aliphatic cyclic group, a group in which two or more hydrogen atoms have been removed from cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane, or tetracyclododecane is particularly preferable. .

  More specifically, examples of the structural unit (a1) include structural units represented by the following general formulas (a1-1) to (a1-4).

［式中、Ｘ’は第３級アルキルエステル型酸解離性溶解抑制基を表し、Ｙは炭素数１〜５の低級アルキル基、または脂肪族環式基を表し；ｎは０〜３の整数を表し；Ｙ^２はアルキレン基または脂肪族環式基を表し；Ｒは前記と同じであり、Ｒ^１’、Ｒ^２’はそれぞれ独立して水素原子または炭素数１〜５の低級アルキル基を表す。］

[Wherein, X ′ represents a tertiary alkyl ester type acid dissociable, dissolution inhibiting group, Y represents a lower alkyl group having 1 to 5 carbon atoms, or an aliphatic cyclic group; n represents an integer of 0 to 3] Y ² represents an alkylene group or an aliphatic cyclic group; R is the same as defined above, and R ¹ ′ and R ² ′ each independently represent a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms. Represent. ]

In the formula, X 'include the same tertiary alkyl ester-type acid dissociable, dissolution inhibiting groups as those described above for X ^{1.
R 1 ', R 2',} n, as the Y, respectively, ^{R 1} in the general formula listed in the description of "acetal-type acid dissociable, dissolution inhibiting group" described above ^{(p1) ', R 2'} , n, Y The same thing is mentioned.
The Y ^2, the same groups as those described above for ^{Y 2} in the general formula (a1-0-2).

  Specific examples of the structural units represented by the general formulas (a1-1) to (a1-4) are shown below.

Among the above, the structural unit represented by the general formula (a1-1) is preferable, and specifically, (a1-1-1) to (a1-1-6) and (a1-1-35) to (a1). More preferably, at least one selected from the group consisting of -1-41) is used.
Furthermore, as the structural unit (a1), in particular, those represented by the following general formula (a1-1-01) including the structural units of the formulas (a1-1-1) to (a1-1-4) The following general formula (a1-1-02) including the structural units of formulas (a1-1-35) to (a1-1-41) is also preferable.

（式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し、Ｒ^１１は低級アルキル基を示す。）

(In the formula, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹¹ represents a lower alkyl group.)

（式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し、Ｒ^１２は低級アルキル基を示す。ｈは１〜３の整数を表す。）

(In the formula, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, R ¹² represents a lower alkyl group, and h represents an integer of 1 to 3.)

In general formula (a1-1-01), R is the same as defined above.
The lower alkyl group for R ^{11 is the same as} the lower alkyl group for R, preferably a methyl group or an ethyl group, and most preferably a methyl group.
In general formula (a1-1-02), R is the same as defined above.
The lower alkyl group for R ^{12 is the same as} the lower alkyl group for R, preferably a methyl group or an ethyl group, and most preferably an ethyl group. h is preferably 1 or 2, and most preferably 2.

As the structural unit (a1), one type of structural unit may be used alone, or two or more types of structural units may be used in combination.
In the component (A1), the proportion of the structural unit (a1) is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, more preferably 25 to 50 mol%, based on all structural units constituting the component (A1). Is more preferable. By setting it to the lower limit value or more, a pattern can be easily obtained when the resist composition is used, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

・ Structural unit (a2)
The structural unit (a2) is a structural unit derived from an acrylate ester containing a lactone-containing cyclic group.
Here, the lactone-containing cyclic group refers to a cyclic group containing one ring (lactone ring) containing an —O—C (O) — structure. The lactone ring is counted as the first ring, and when it is only the lactone ring, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure.
When the component (A1) is used for forming a resist film, the lactone cyclic group of the structural unit (a2) increases the adhesion of the resist film to the substrate or has an affinity for a developer containing water. It is effective in raising.

As the structural unit (a2), any unit can be used without any particular limitation.
Specifically, examples of the lactone-containing monocyclic group include groups in which one hydrogen atom has been removed from γ-butyrolactone. Examples of the lactone-containing polycyclic group include groups in which one hydrogen atom has been removed from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring.
More specifically, examples of the structural unit (a2) include structural units represented by general formulas (a2-1) to (a2-5) shown below.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基であり；Ｒ’は水素原子、低級アルキル基、炭素数１〜５のアルコキシ基または−ＣＯＯＲ”であり；前記Ｒ”は水素原子、または炭素数１〜１５の直鎖状、分岐鎖状もしくは環状のアルキルキル基であり；ｍは０または１の整数であり；Ａ”は炭素数１〜５のアルキレン基または酸素原子である。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; R ′ represents a hydrogen atom, a lower alkyl group, an alkoxy group having 1 to 5 carbon atoms, or —COOR ″; A hydrogen atom or a linear, branched or cyclic alkylalkyl group having 1 to 15 carbon atoms; m is an integer of 0 or 1; A ″ is an alkylene group having 1 to 5 carbon atoms or an oxygen atom. is there.]

R in the general formulas (a2-1) to (a2-5) is the same as R in the structural unit (a1).
The lower alkyl group for R ′ is the same as the lower alkyl group for R in the structural unit (a1).
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms.
When R ″ is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a fluorine atom Or a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group More specifically, one or more hydrogen atoms are removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Group and the like.
In general formulas (a2-1) to (a2-5), R ′ is preferably a hydrogen atom in view of industrial availability.
Specific examples of the alkylene group of 1 to 5 carbon atoms for A ″ include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group.
Below, the specific structural unit of the said general formula (a2-1)-(a2-5) is illustrated.

  As the structural unit (a2), at least one selected from the group consisting of structural units represented by the general formulas (a2-1) to (a2-5) is preferable, and the general formulas (a2-1) to ( At least one selected from the group consisting of structural units represented by a2-3) is more preferred. Among them, chemical formulas (a2-1-1), (a2-1-2), (a2-2-1), (a2-2-2), (a2-3-1), (a2-3-2) ), (A2-3-9) and (a2-3-10), at least one selected from the group consisting of structural units represented by (a2-3-10) is preferred.

As the structural unit (a2), one type may be used alone, or two or more types may be used in combination.
In the component (A1), the proportion of the structural unit (a2) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, based on the total of all the structural units constituting the component (A1). 50 mol% is more preferable. By making it the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by making it the upper limit value or less, it is possible to balance with other structural units.

・ Structural unit (a3)
The structural unit (a3) is a structural unit derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.
When the component (A1) has the structural unit (a3), the hydrophilicity of the component (A1) is increased, the affinity with the developer is increased, the alkali solubility in the exposed area is improved, and the resolution is improved. Contributes to improvement.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom. A hydroxyl group is particularly preferable.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a polycyclic aliphatic hydrocarbon group (polycyclic group). It is done. As the polycyclic group, for example, a resin for a resist composition for ArF excimer laser can be appropriately selected from among many proposed ones. The polycyclic group preferably has 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom Is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like. Specific examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, there are groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane. Industrially preferable.

  The structural unit (a3) is derived from a hydroxyethyl ester of acrylic acid when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms. The structural unit is preferred. When the hydrocarbon group is a polycyclic group, the structural unit represented by the following formula (a3-1), the structural unit represented by the following formula (a3-2), and the following formula (a3-3) The structural unit is preferably mentioned.

（式中、Ｒは前記と同じであり、ｊは１〜３の整数であり、ｋは１〜３の整数であり、ｔ’は１〜３の整数であり、ｌは１〜５の整数であり、ｓは１〜３の整数である。）

(Wherein R is the same as above, j is an integer of 1 to 3, k is an integer of 1 to 3, t 'is an integer of 1 to 3, and l is an integer of 1 to 5) And s is an integer of 1 to 3.)

In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.
j is preferably 1, and a hydroxyl group bonded to the 3rd position of the adamantyl group is particularly preferred.
In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.
In formula (a3-3), t ′ is preferably 1. l is preferably 1. s is preferably 1. In these, a 2-norbornyl group or a 3-norbornyl group is preferably bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

As the structural unit (a3), one type may be used alone, or two or more types may be used in combination.
In the component (A1), the proportion of the structural unit (a3) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, and more preferably 5 to 25 mol% with respect to all the structural units constituting the component (A1). Is more preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (a3) can be sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

・ Structural unit (a4)
The component (A1) may contain other structural units (a4) other than the structural units (a1) to (a3) as long as the effects of the present invention are not impaired.
The structural unit (a4) is not particularly limited as long as it is another structural unit that is not classified into the structural units (a1) to (a3) described above, and is for ArF excimer laser and KrF excimer laser (preferably ArF excimer). A number of hitherto known materials can be used for resist resins such as lasers.
As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing an acid non-dissociable aliphatic polycyclic group is preferable. Examples of the polycyclic group include those exemplified in the case of the structural unit (a1), and for ArF excimer laser and KrF excimer laser (preferably for ArF excimer laser). A number of hitherto known materials can be used as the resin component of the resist composition.
In particular, at least one selected from a tricyclodecanyl group, an adamantyl group, a tetracyclododecanyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.
Specific examples of the structural unit (a4) include those represented by the following general formulas (a4-1) to (a4-5).

（式中、Ｒは前記と同じである。）

(In the formula, R is as defined above.)

  When the structural unit (a4) is contained in the component (A1), the proportion of the structural unit (a4) in the component (A1) is 1 to 30 with respect to the total of all the structural units constituting the component (A1). Mol% is preferable and 10 to 20 mol% is more preferable.

In the present invention, the component (A1) preferably contains a copolymer having the structural units (a1), (a2) and (a3). Examples of the copolymer include copolymers composed of the structural units (a1), (a2) and (a3), copolymers composed of the structural units (a1), (a2), (a3) and (a4). Can be mentioned.
As such a copolymer, for example, those containing three kinds of structural units represented by the following general formula (A1-11) are preferable.

［式（Ａ１−１１）中、Ｒは前記と同じであり、複数のＲはそれぞれ同じであっても異なっていてもよい。Ｒ^１０は低級アルキル基である。］

[In formula (A1-11), R is the same as defined above, and the plurality of R may be the same or different. R ¹⁰ is a lower alkyl group. ]

In formula (A1-11), the lower alkyl group for R ^{10 is the same as} the lower alkyl group for R, preferably a methyl group or an ethyl group, and most preferably a methyl group.

The component (A1) can be obtained by polymerizing a monomer for deriving each structural unit by a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN).
Further, for the component (A1), in the polymerization, a chain transfer agent such as HS—CH ₂ —CH ₂ —CH ₂ —C (CF ₃ ) ₂ —OH is used in combination, so that the terminal A —C (CF ₃ ) ₂ —OH group may be introduced into the. As described above, a copolymer introduced with a hydroxyalkyl group in which a part of hydrogen atoms of the alkyl group is substituted with a fluorine atom reduces development defects and LER (line edge roughness: uneven unevenness of line side walls). It is effective in reducing

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, preferably 2000 to 50000, more preferably 3000 to 30000, most preferably 5000 to 20000. preferable. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
Further, the dispersity (Mw / Mn) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5. In addition, Mn shows a number average molecular weight.

[(A2) component]
As the component (A2), a low molecular compound having a molecular weight of 500 or more and less than 2000 and having an acid dissociable, dissolution inhibiting group and a hydrophilic group as exemplified in the description of the component (A1) above is preferable. Specifically, a compound in which a part of hydrogen atoms of a hydroxyl group of a compound having a plurality of phenol skeletons is substituted with the acid dissociable, dissolution inhibiting group can be mentioned.
The component (A2) is, for example, a part of the hydrogen atom of the hydroxyl group of a low molecular weight phenol compound known as a sensitizer in a non-chemically amplified g-line or i-line resist or a heat resistance improver. Those substituted with a soluble dissolution inhibiting group are preferred and can be arbitrarily used.
Examples of such low molecular weight phenol compounds include bis (4-hydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, 2- (4-hydroxyphenyl) -2- (4′-hydroxyphenyl). ) Propane, 2- (2,3,4-trihydroxyphenyl) -2- (2 ′, 3 ′, 4′-trihydroxyphenyl) propane, tris (4-hydroxyphenyl) methane, bis (4-hydroxy-) 3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3, 4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyph Phenylmethane, bis (4-hydroxy-3-methylphenyl) -3,4-dihydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl- 4-hydroxy-6-methylphenyl) -3,4-dihydroxyphenylmethane, 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene, Examples include 2, 3, 4 nuclei of formalin condensates of phenols such as phenol, m-cresol, p-cresol or xylenol. Of course, it is not limited to these.
The acid dissociable, dissolution inhibiting group is not particularly limited, and examples thereof include those described above.

As the component (A), one type may be used alone, or two or more types may be used in combination.
In the resist composition of the present invention, the content of the component (A) may be adjusted according to the resist film thickness to be formed.

<(B) component>
In the resist composition of the present invention, the component (B) includes an acid generator (B1) (hereinafter referred to as the component (B1)) having a cation moiety represented by the following general formula (b′-1), and dibenzo. And an acid generator (B2) having a cation moiety containing a thiophene skeleton (hereinafter referred to as component (B2)).

［式（ｂ’−１）中、Ｒ^１”〜Ｒ^３”のうち、いずれか２つはそれぞれ独立してアルキル基又はアリール基であって、該２つが相互に結合して式中のイオウ原子と共に環を形成しており；Ｒ^１”〜Ｒ^３”のうち、残りの１つはアルキル基、アリール基、又は−（Ｒ^４’）−Ｃ（＝Ｏ）−Ｒ^５’である。ただし、Ｒ^４’は炭素数１〜５のアルキレン基であり、Ｒ^５’はアリール基である。］

[In the formula (b′-1), any two of R ¹ ″ to R ³ ″ are each independently an alkyl group or an aryl group, and the two are bonded to each other to form sulfur in the formula A ring is formed with the atoms; among R ¹ ″ to R ³ ″, the remaining one is an alkyl group, an aryl group, or — (R ⁴ ′) —C (═O) —R ⁵ ′. However, R < ⁴ '> is a C1-C5 alkylene group and R < ⁵ '> is an aryl group. ]

[Cation part of component (B1)]
In the present invention, the component (B1) is an acid generator having a cation moiety represented by the general formula (b′-1).
In the formula (b′-1), among R ¹ ″ to R ³ ″, the remaining one that is not used for forming a ring is an alkyl group, an aryl group, or — (R ⁴ ′) —C ( = O) -R ⁵ '.

When the remaining ^{one of} R ¹ ″ to R ³ ″ is an alkyl group, the alkyl group is not particularly limited, and examples thereof include linear, branched or cyclic alkyl groups having 1 to 10 carbon atoms. Can be mentioned. From the viewpoint of excellent resolution, the number of carbon atoms is preferably 1 to 5, and more preferably a linear alkyl group having 1 to 5 carbon atoms. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decanyl group. . Of these, a methyl group is the most preferable because it is excellent in resolution and can be synthesized at low cost.

When the remaining ^{one of} R ¹ ″ to R ³ ″ is an aryl group, the aryl group is not particularly limited and is, for example, an unsubstituted aryl group having 6 to 20 carbon atoms; a hydrogen atom of the unsubstituted aryl group Examples thereof include substituted aryl groups in which some or all of the atoms are substituted with alkyl groups, alkoxy groups, alkoxyalkyloxy groups, alkoxycarbonylalkyloxy groups, halogen atoms, hydroxyl groups, and the like.

  The unsubstituted aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.

The alkyl group in the substituted aryl group is preferably an alkyl group having 1 to 5 carbon atoms, particularly preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
The alkoxy group in the substituted aryl group is preferably an alkoxy group having 1 to 5 carbon atoms, and particularly preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group. preferable.
The halogen atom in the substituted aryl group is preferably a fluorine atom.

Examples of the alkoxyalkyloxy group in the substituted aryl group include, for example, a general formula: —O—C (R ⁴⁷ ) (R ⁴⁸ ) —O—R ⁴⁹ [wherein R ⁴⁷ and R ⁴⁸ are each independently a hydrogen atom or It is a linear or branched alkyl group, and R ⁴⁹ is an alkyl group. ] Is represented.
In R ⁴⁷ and R ⁴⁸ , the alkyl group preferably has 1 to 5 carbon atoms, may be linear or branched, and is preferably a methyl group or an ethyl group, and most preferably a methyl group.
At least one of R ⁴⁷ and R ⁴⁸ is preferably a hydrogen atom. In particular, it is more preferable that one is a hydrogen atom and the other is a hydrogen atom or a methyl group.
The alkyl group for R ⁴⁹ preferably has 1 to 15 carbon atoms and may be linear, branched or cyclic.
The linear or branched alkyl group for R ⁴⁹ preferably has 1 to 5 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group. Can be mentioned.
The cyclic alkyl group for R ⁴⁹ preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane which may or may not be substituted with an alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated alkyl group. And a group obtained by removing one or more hydrogen atoms from a polycycloalkane. Examples of the monocycloalkane include cyclopentane and cyclohexane. Examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Of these, a group in which one or more hydrogen atoms have been removed from adamantane is preferable.

Examples of the alkoxycarbonylalkyloxy group in the substituted aryl group include, for example, a general formula: —O—R ⁵⁰ —C (═O) —O—R ⁵¹ [wherein R ⁵⁰ is a linear or branched alkylene group. And R ⁵¹ is a tertiary alkyl group. ] Is represented.
The linear or branched alkylene group for R ⁵⁰ preferably has 1 to 5 carbon atoms, such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, or a 1,1-dimethylethylene group. Etc.
As the tertiary alkyl group for R ⁵¹ , 2-methyl-2-adamantyl group, 2-ethyl-2-adamantyl group, 1-methyl-1-cyclopentyl group, 1-ethyl-1-cyclopentyl group, 1-methyl -1-cyclohexyl group, 1-ethyl-1-cyclohexyl group, 1- (1-adamantyl) -1-methylethyl group, 1- (1-adamantyl) -1-methylpropyl group, 1- (1-adamantyl) -1-methylbutyl group, 1- (1-adamantyl) -1-methylpentyl group; 1- (1-cyclopentyl) -1-methylethyl group, 1- (1-cyclopentyl) -1-methylpropyl group, 1- (1-cyclopentyl) -1-methylbutyl group, 1- (1-cyclopentyl) -1-methylpentyl group; 1- (1-cyclohexyl) -1-methylethyl Group, 1- (1-cyclohexyl) -1-methylpropyl group, 1- (1-cyclohexyl) -1-methylbutyl group, 1- (1-cyclohexyl) -1-methylpentyl group, tert-butyl group, tert -Pentyl group, tert-hexyl group and the like.

Among the above, the remaining one aryl group in R ¹ ″ to R ³ ″ is preferably a phenyl group or a naphthyl group, and most preferably a phenyl group.

When the remaining ^{one of} R ¹ ″ to R ³ ″ is — (R ⁴ ′) —C (═O) —R ⁵ ′, R ⁴ ′ is an alkylene group having 1 to 5 carbon atoms, and R ⁵ ′ Is an aryl group.
Examples of the aryl group for R ⁵ ′ include the same groups as those exemplified in the case where the remaining one of R ¹ ″ to R ³ ″ is an aryl group.

Of the R ¹ ″ to R ³ ″, the remaining one is preferably an aryl group.

In the formula (b′-1), any two of R ¹ ″ to R ³ ″ are each independently an alkyl group or an aryl group, and the two are bonded to each other in the formula It forms a ring with sulfur atoms.
Specifically, a cation moiety represented by the following general formula (b′-1-0) is exemplified as the cation moiety of the component (B1).

［式（ｂ’−１−０）中、Ｒ^１０”およびＲ^２０”はそれぞれ独立してアルキレン基又はアリーレン基であり；Ｒ^３０”はアルキル基、アリール基、又は−（Ｒ^４０’）−Ｃ（＝Ｏ）−Ｒ^５０’である。ただし、Ｒ^４０’は炭素数１〜５のアルキレン基であり、Ｒ^５０’はアリール基である。］

[In Formula (b′-1-0), R ¹⁰ ″ and R ²⁰ ″ each independently represent an alkylene group or an arylene group; R ³⁰ ″ represents an alkyl group, an aryl group, or — (R ⁴⁰ ′) — C (═O) —R ⁵⁰ ′, wherein R ⁴⁰ ′ is an alkylene group having 1 to 5 carbon atoms, and R ⁵⁰ ′ is an aryl group.]

In the formula (b′-1-0), R ³⁰ ″ is the same as the remaining one of R ¹ ″ to R ³ ″ not used for ring formation in the formula (b′-1). Is mentioned.
In the formula (b′-1-0), examples of R ⁴⁰ ′ and R ⁵⁰ ′ include those similar to R ⁴ ′ and R ⁵ ′ in the formula (b′-1), respectively.

In the formula (b′-1-0), R ¹⁰ ″ and R ²⁰ ″ are the remaining 1 of R ¹ ″ to R ³ ″ not used for ring formation in the formula (b′-1). Examples thereof include groups in which one hydrogen atom has been further removed from the alkyl group and aryl group exemplified in the description of each. Specifically, the end of the alkylene group in which one hydrogen atom in the alkyl group is further removed, the end of the arylene group in which one hydrogen atom is further removed from the unsubstituted aryl group, and the aromatic hydrocarbon in the substituted aryl group The end of the divalent substituted aryl group from which one hydrogen atom is further removed from the nucleus, or the end of the divalent substituted aryl group from which one hydrogen atom in the substituent in the substituted aryl group is removed Combined to form a ring with the sulfur atom in the formula. Especially, it is preferable that R < ^{10 ''} > and R < ²⁰ >'' are alkylene groups, and these terminals couple | bond together and a ring is formed with the sulfur atom in a formula.
The ring formed by combining R ¹⁰ ″ and R ²⁰ ″ together with the sulfur atom in the formula is preferably a 3- to 10-membered ring including the sulfur atom, and is a 5- to 7-membered ring. Is particularly preferred.

Specific examples of the cation moiety represented by the formula (b′-1) include 1-phenyltetrahydrothiophenium, 1- (4-methylphenyl) tetrahydrothiophenium, 1- (3,5-dimethyl-4 -Hydroxyphenyl) tetrahydrothiophenium, 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium, 1- (4-ethoxynaphthalen-1-yl) tetrahydrothiophenium, 1- (4-n- Butoxynaphthalen-1-yl) tetrahydrothiophenium; 1-phenyltetrahydrothiopyranium, 1- (4-hydroxyphenyl) tetrahydrothiopyranium, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiopyra And 1- (4-methylphenyl) tetrahydrothiopyranium The
Moreover, the cation represented by the following general formula (b'-1-1) is also mentioned.

［式（ｂ’−１−１）中、Ｒ^９は置換基を有していてもよいフェニル基、ナフチル基又は炭素数１〜５のアルキル基である。ｕ”は１〜３の整数である。］

[In Formula (b′-1-1), R ⁹ represents a phenyl group, a naphthyl group, or an alkyl group having 1 to 5 carbon atoms which may have a substituent. u ″ is an integer of 1 to 3.]

In the formula (b′-1-1), the alkyl group for R ⁹ is particularly preferably a methyl group.
Examples of the substituent for R ⁹ include the same substituents as exemplified in the description of the substituted aryl group.
u ″ is most preferably 1 or 2.

[Cation part of component (B2)]
In the present invention, the component (B2) is an acid generator having a cation moiety containing a dibenzothiophene skeleton.
“Including a dibenzothiophene skeleton” means having a structure represented by the following general formula (b′-5-0). The structure (dibenzothiophene skeleton) may have a substituent.

  As the cation part of the component (B2), any cation part may be used as long as it contains a dibenzothiophene skeleton. Specifically, a cation part represented by the following general formula (b′-5) is preferable.

［式（ｂ’−５）中、Ｒ^４０は水素原子又はアルキル基であり、Ｒ^４１はハロゲン原子、ハロゲン化アルキル基、アルキル基、アセチル基、カルボキシ基、又はヒドロキシアルキル基であり、Ｒ^４２およびＲ^４３はそれぞれ独立してハロゲン原子、ハロゲン化アルキル基、アルキル基、アセチル基、アルコキシ基、カルボキシ基、水酸基、又はヒドロキシアルキル基であり；ｎ_０〜ｎ_３はそれぞれ独立して０〜３の整数であり、ただし、ｎ_０＋ｎ_１は５以下である。］

Wherein ^{(b'-5), R 40} is a hydrogen atom or an alkyl ^{group, R 41} is a halogen atom, a halogenated alkyl group, an alkyl group, an acetyl group, a carboxy group, or a hydroxyalkyl ^{group, R 42} And R ⁴³ are each independently a halogen atom, a halogenated alkyl group, an alkyl group, an acetyl group, an alkoxy group, a carboxy group, a hydroxyl group, or a hydroxyalkyl group; n _{0 to} n ₃ are each independently 0 to 3 Where n ₀ + n ₁ is 5 or less. ]

In the above formula (b′-5), in R ^{40 to} R ⁴³ , the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group, and a methyl group , Ethyl group, propyl group, isopropyl group, n-butyl group, or tert-butyl group is particularly preferable.
In R ⁴² and R ⁴³ , the alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a linear or branched alkoxy group, and particularly preferably a methoxy group or an ethoxy group.
In R ^{41 to} R ⁴³ , the hydroxyalkyl group is preferably a group in which one or more hydrogen atoms in the alkyl group are substituted with a hydroxy group, and examples thereof include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group. .
In R ^{41 to} R ⁴³ , examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom, and a fluorine atom is preferable.
In R ^{41 to} R ⁴³ , the halogenated alkyl group is preferably a halogenated alkyl group having 1 to 5 carbon atoms, and more preferably a halogenated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom. A trifluoromethyl group and a pentafluoroethyl group are particularly preferable.

If the sign _n 0 ~n ₃ attached to R ⁴⁰ to R ⁴³ represent an integer of 2 or more, plural ^R 40 ^{to R 43} may be the same, respectively, it may be different.

n ₀ is preferably 0 or 1, more preferably 0.
n ₁ is preferably 0 to 2, more preferably 0 or 1, and still more preferably 0.
n ₂ and n ₃ are preferably each independently 0 or 1, more preferably 0.
However, n ₀ + n ₁ is 5 or less.

[Anion part]
The anion part which (B1) component and (B2) component have is not restrict | limited in particular, What is known as an anion part of an onium salt type acid generator can be used suitably.
For example, an anion represented by the general formula “R ¹⁴ SO ₃ ^— (R ¹⁴ represents an optionally substituted alkyl group, halogenated alkyl group, aryl group, or alkenyl group)” is used. be able to.

In the general formula “R ¹⁴ SO ₃ ⁻ ”, R ¹⁴ represents an alkyl group, a halogenated alkyl group, an aryl group, or an alkenyl group which may have a substituent.

The alkyl group for R ¹⁴ may be linear, branched or cyclic.
The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
The cyclic alkyl group preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.

Examples of the halogenated alkyl group for R ¹⁴ include groups in which part or all of the hydrogen atoms of the linear, branched, or cyclic alkyl group have been substituted with halogen atoms. When the halogenated alkyl group has a smaller number of carbon atoms, the component (B1) or the component (B2) is more easily dispersed in the resist composition, which is effective in improving lithography properties such as EL margin and MEF.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
In the halogenated alkyl group, the ratio of the number of halogen atoms to the total number of halogen atoms and hydrogen atoms contained in the halogenated alkyl group (halogenation rate (%)) is preferably 10 to 100%. 50 to 100% is preferable, and 100% is most preferable. The higher the halogenation rate, the better the acid strength.

The aryl group for R ¹⁴ is preferably an aryl group having 6 to 20 carbon atoms.
The alkenyl group for R ¹⁴ is preferably an alkenyl group having 2 to 10 carbon atoms.

In R ¹⁴ , “may have a substituent” means a part of hydrogen atoms in the linear, branched or cyclic alkyl group, halogenated alkyl group, aryl group, or alkenyl group. Or it means that all may be substituted with a substituent (an atom or group other than a hydrogen atom).
The number of substituents in R ¹⁴ may be one or two or more.

Examples of the substituent include a halogen atom, a hetero atom, an alkyl group, and a group represented by R ⁶ —O— [wherein R ⁶ is a monovalent aromatic organic group or a monovalent aliphatic hydrocarbon group. Or a hydroxyalkyl group. ] Etc. are mentioned.
Examples of the halogen atom and alkyl group include the same groups as those described above for R ¹⁴ as the halogen atom and alkyl group in the halogenated alkyl group.
Examples of the hetero atom include an oxygen atom, a nitrogen atom, and a sulfur atom.

In the group represented by R ⁶ —O—, the monovalent aromatic organic group represented by R ⁶ includes a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, An aryl group such as a phenanthryl group obtained by removing one hydrogen atom from an aromatic hydrocarbon ring; a part of carbon atoms constituting the ring of the aryl group is a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom Substituted heteroaryl groups; arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group and the like.
The number of carbon atoms in the alkyl chain in the arylalkyl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.
These aryl groups, heteroaryl groups, and arylalkyl groups may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, an alkoxy group, a hydroxyl group, or a halogen atom. The alkyl group or halogenated alkyl group in the substituent preferably has 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. The halogenated alkyl group is preferably a fluorinated alkyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom, and a fluorine atom is preferable.
The monovalent aromatic organic group for R ⁶ is preferably an arylalkyl group, more preferably an arylmethyl group, and most preferably a naphthylmethyl group.

Examples of the monovalent aliphatic hydrocarbon group for R ⁶ include a linear, branched or cyclic monovalent saturated hydrocarbon group having 1 to 15 carbon atoms, or a linear chain having 2 to 5 carbon atoms. Or branched monovalent aliphatic unsaturated hydrocarbon group.
Examples of the linear monovalent saturated hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decanyl group.
Examples of the branched monovalent saturated hydrocarbon group include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1 -Ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like can be mentioned.
The cyclic monovalent saturated hydrocarbon group may be either a polycyclic group or a monocyclic group, for example, one from a polycycloalkane such as a monocycloalkane, a bicycloalkane, a tricycloalkane, or a tetracycloalkane. And a group in which a hydrogen atom is removed. More specifically, one hydrogen atom was removed from a monocycloalkane such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Group and the like.
Examples of the linear monovalent unsaturated hydrocarbon group include a vinyl group, a propenyl group (allyl group), and a butynyl group.
Examples of the branched monovalent unsaturated hydrocarbon group include a 1-methylpropenyl group and a 2-methylpropenyl group.
The number of carbon atoms of the monovalent aliphatic hydrocarbon group R ⁶ is 2 to 4 and most preferably 3.

The hydroxyalkyl group of R ⁶ is a group in which at least one hydrogen atom of a linear, branched or cyclic monovalent saturated hydrocarbon group is substituted with a hydroxyl group. Those in which one or two hydrogen atoms of a linear or branched monovalent saturated hydrocarbon group are substituted with a hydroxyl group are preferred. Specific examples include a hydroxymethyl group, a hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group, a 3-hydroxypropyl group, and a 2,3-dihydroxypropyl group.
Monovalent carbon number of the hydroxyalkyl group R ⁶ is preferably 1 to 10, more preferably 1 to 8, particularly preferably 1 to 6, 1 to 3 is most preferred.

Among the above, R ¹⁴ is preferably a halogenated alkyl group. That is, the anion moiety is preferably a halogenated alkyl sulfonate ion. And it is preferable that at least one anion part of (B1) component and (B2) component is a halogenated alkyl sulfonate ion.

  Moreover, the anion part which (B1) component or (B2) component has uses the anion represented by the following general formula (b'-3), the anion represented by the following general formula (b'-4), etc. You can also.

［式中、Ｘ”は、少なくとも１つの水素原子がフッ素原子で置換された炭素数２〜６のアルキレン基を表し；Ｙ”、Ｚ”は、それぞれ独立に、少なくとも１つの水素原子がフッ素原子で置換された炭素数１〜１０のアルキル基を表す。］

[Wherein X ″ represents an alkylene group having 2 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom; Y ″ and Z ″ each independently represent at least one hydrogen atom as a fluorine atom; Represents an alkyl group having 1 to 10 carbon atoms and substituted with

In the general formula (b′-3), X ″ is a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkylene group has 2 to 6 carbon atoms. Is preferable, 3 to 5 carbon atoms are more preferable, and 3 carbon atoms are most preferable.
In the general formula (b′-4), Y ″ and Z ″ each independently represent a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkyl group 1-10 are preferable, C1-C7 are more preferable, and C1-C3 is especially preferable.
The carbon number of the alkylene group of X ″ or the carbon number of the alkyl group of Y ″ and Z ″ is preferably as small as possible because the solubility in the resist solvent is good within the above carbon number range.
In addition, in the alkylene group of X ″ or the alkyl group of Y ″ and Z ″, as the number of hydrogen atoms substituted with fluorine atoms increases, the strength of the acid increases, and high-energy light or electron beam of 200 nm or less The ratio of fluorine atoms in the alkylene group or alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all. Are a perfluoroalkylene group or a perfluoroalkyl group in which a hydrogen atom is substituted with a fluorine atom.

In the resist composition of the present invention, preferred specific examples of the component (B1) include 1-phenyltetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate, or its nonafluorobutanesulfonate; 1- (4-methyl Phenyl) tetrahydrothiophenium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (4-hydroxyphenyl) tetrahydrothiophenium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, Heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (4-ethoxy Naphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, heptafluoropropane sulfonate or nonafluorobutanesulfonate; 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, Its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; tris of 1-phenyltetrahydrothiopyranium Fluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (4-hydroxyphenyl) tetrahydrothiopyranium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 5-dimethyl-4-hydroxyphenyl) tetrahydrothiopyranium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1- (2-methyl-4-hydroxyphenyl) tetrahydrothiopyranium trifluoromethanesulfonate , Its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1- (4-methylphenol Nyl) tetrahydrothiopyranium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate.
Moreover, the onium salt which replaced the anion part of these onium salts by methanesulfonate, n-propanesulfonate, n-butanesulfonate, and n-octanesulfonate can also be used.
Furthermore, the onium salt which uses the fluorinated alkyl (C1-C10 of this alkyl) sulfonate ion which has group represented by said R < ⁶ > -O- as an anion part is also mentioned. For example, an onium salt represented by the following chemical formula is preferable.

In the resist composition of the present invention, the (B2) component preferably has a cation part containing a dibenzothiophene skeleton, and the anion part represented by the general formula “R ¹⁴ SO ₃ ⁻ ” or the above A compound having the compound represented by the general formula (b′-3) is preferable.
Suitable specific examples of the component (B2) are exemplified below.

  In the present invention, it is most preferable to use the component (B1) and the component (B2) in combination.

In the component (B), as the component (B1) and the component (B2), one type may be used alone, or two or more types may be used in combination.
The total content of the component (B1) and the component (B2) in the component (B) is preferably 70% by mass or more, more preferably 80% by mass or more, and may be 100% by mass. . Especially, it is most preferable that it is 100 mass%. By being above the lower limit of the range, in resist pattern formation, changes in the resist pattern dimensions associated with fluctuations in exposure amount can be reduced (EL margin can be increased), and mask reproducibility (MEF) can be further improved. be able to.
Further, the ratio of the component (B1) to the total amount of the components (B1) and (B2) in the component (B) is not particularly limited, but is preferably 0.1 to 50% by mass, More preferably, it is 1-40 mass%, and it is most preferable that it is 5-35 mass%. By setting it as such a mixture ratio, a lithography characteristic improves.
And in the resist composition of this invention, it is preferable that the total content of (B1) component and (B2) component is 1-30 mass parts with respect to 100 mass parts of said (A) component, The amount is particularly preferably 20 parts by mass, and most preferably 7 to 18 parts by mass.
By being equal to or more than the lower limit of the range, it is possible to reduce the change in the resist pattern dimension accompanying the change in the exposure amount (increase the EL margin) and to further improve the mask reproducibility (MEF). On the other hand, storage stability will become favorable by being below an upper limit.

In the component (B), the acid generator (B3) (hereinafter referred to as the component (B3)) other than the component (B1) and the component (B2) is referred to as the component (B1) as long as the effects of the present invention are not impaired. ) Component and (B2) component may be used in combination.
The component (B3) is not particularly limited as long as it is other than the component (B1) and the component (B2), and those that have been proposed as acid generators for chemically amplified resists can be used.
Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, and poly (bissulfonyl) diazomethanes. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.

  As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) can be used.

［式中、Ｒ^１１”〜Ｒ^１３”，Ｒ^５”〜Ｒ^６”は、それぞれ独立に、アリール基またはアルキル基を表し；Ｒ^４”は、直鎖状、分岐鎖状または環状のアルキル基またはフッ素化アルキル基を表し；Ｒ^１１”〜Ｒ^１３”のうち少なくとも１つはアリール基を表し、Ｒ^５”〜Ｒ^６”のうち少なくとも１つはアリール基を表す。］

[Wherein R ¹¹ ″ to R ¹³ ″, R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group; R ⁴ ″ represents a linear, branched or cyclic alkyl group; Or a fluorinated alkyl group; at least one of R ¹¹ ″ to R ¹³ ″ represents an aryl group, and at least one of R ⁵ ″ to R ⁶ ″ represents an aryl group.]

In formula (b-1), R ¹¹ ″ to R ¹³ ″ each independently represents an aryl group or an alkyl group.
Further, at least one of R ¹¹ ″ to R ¹³ ″ represents an aryl group. Of R ¹¹ ″ to R ¹³ ″, two or more are preferably aryl groups, and most preferably R ¹¹ ″ to R ¹³ ″ are all aryl groups.
The aryl group for R ¹¹ ″ to R ¹³ ″ is not particularly limited, and is, for example, an aryl group having 6 to 20 carbon atoms, in which part or all of the hydrogen atoms are alkyl groups, alkoxy groups It may or may not be substituted with a group, a halogen atom, a hydroxyl group or the like. The aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.
The alkyl group that may be substituted for the hydrogen atom of the aryl group is preferably an alkyl group having 1 to 5 carbon atoms, and is a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Is most preferred.
As the alkoxy group that may be substituted for the hydrogen atom of the aryl group, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, Most preferred is a tert-butoxy group.
The alkoxy group that may be substituted for the hydrogen atom of the aryl group is preferably an alkoxy group having 1 to 5 carbon atoms, and most preferably a methoxy group or an ethoxy group.
The halogen atom that may be substituted for the hydrogen atom of the aryl group is preferably a fluorine atom.
The alkyl group for ^{R 11} "~R ^13", is not particularly limited, for example, linear C1-10, branched or cyclic alkyl group, and the like. It is preferable that it is C1-C5 from the point which is excellent in resolution. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decanyl group. A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost.
Of these, R ¹¹ ″ to R ¹³ ″ are most preferably a phenyl group or a naphthyl group.
In the compound represented by the general formula (b-1), any two of R ¹¹ ″ to R ¹³ ″ in the formula (b-1) are bonded to each other to form a ring together with the sulfur atom in the formula. Those having a cation moiety that forms are not included.

R ⁴ ″ represents a linear, branched or cyclic alkyl group or a fluorinated alkyl group.
The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
The cyclic alkyl group is a cyclic group as indicated by R ¹¹ ″, preferably having 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and more preferably 6 carbon atoms. Most preferably, it is -10.
The fluorinated alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
The fluorination rate of the fluorinated alkyl group (ratio of fluorine atoms in the alkyl group) is preferably 10 to 100%, more preferably 50 to 100%. Particularly, all the hydrogen atoms are substituted with fluorine atoms. A fluorinated alkyl group (perfluoroalkyl group) is preferable because the strength of the acid is increased.
R ⁴ ″ is most preferably a linear or cyclic alkyl group or a fluorinated alkyl group.

In formula (b-2), R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group. At least one of R ⁵ ″ to R ⁶ ″ represents an aryl group. It is preferable that all of R ⁵ ″ to R ⁶ ″ are aryl groups.
As the aryl group for R ⁵ ″ to R ⁶ ″, the same as the aryl groups for R ¹¹ ″ to R ¹³ ″ can be used.
Examples of the alkyl group for R ⁵ ″ to R ⁶ ″ include the same as the alkyl group for R ¹¹ ″ to R ¹³ ″.
Among these, it is most preferable that all of R ⁵ ″ to R ⁶ ″ are phenyl groups.
"As ^{R 4} in the formula (b-1)" ^{R 4} in the In the formula (b-2) include the same as.

Specific examples of the onium salt acid generators represented by the formulas (b-1) and (b-2) include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, bis (4-tert-butylphenyl) iodonium. Trifluoromethane sulfonate or nonafluorobutane sulfonate, triphenylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, tri (4-methylphenyl) sulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its Nonafluorobutanesulfonate, dimethyl (4-hydroxynaphthyl) sulfonium trifluoromethanesulfonate, its heptaful Lopropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of monophenyldimethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; trifluoromethanesulfonate of diphenylmonomethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate (4-methylphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, (4-methoxyphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate , Trifluoromethanesulfonate of tri (4-tert-butyl) phenylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of diphenyl (1- (4-methoxy) naphthyl) sulfonium, its heptafluoropropane Sulfonate or its nonafluorobutane sulfonate, di (1-naphthyl) phenylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate.
In addition, onium salts in which the anion portion of these onium salts is replaced with methanesulfonate, n-propanesulfonate, n-butanesulfonate, or n-octanesulfonate can also be used.

  Moreover, in the said general formula (b-1) or (b-2), the onium salt type acid which replaced the anion part with the anion part represented by the said general formula (b'-3) or (b'-4) A generator may also be used (the cation moiety is the same as the cation moiety in the compound represented by (b-1) or (b-2)).

  Moreover, the sulfonium salt which has a cation part represented with the following general formula (b'-6) can also be used as an onium salt type | system | group acid generator.

［式（ｂ’−６）中、Ｒ^４４〜Ｒ^４６はそれぞれ独立してアルキル基、アセチル基、アルコキシ基、カルボキシ基、水酸基またはヒドロキシアルキル基であり；ｎ_４およびｎ_５はそれぞれ独立して０〜３の整数であり、ｎ_６は０〜２の整数である。］

[In formula (b′-6), R ^{44 to} R ⁴⁶ are each independently an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxyl group or hydroxyalkyl group; n ₄ and n ₅ are each independently N is an integer of 0 to 3, and n ₆ is an integer of 0 to 2. ]

In R ⁴⁴ to R ^46, the alkyl group is preferably an alkyl group of 1 to 5 carbon atoms, more preferably an linear or branched alkyl group, a methyl group, an ethyl group, a propyl group, an isopropyl radical, n A butyl group or a tert-butyl group is particularly preferable.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a linear or branched alkoxy group, and particularly preferably a methoxy group or an ethoxy group.
The hydroxyalkyl group is preferably a group in which one or more hydrogen atoms in the alkyl group are substituted with a hydroxy group, and examples thereof include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.
When the symbols n _{4 to} n ₆ attached to R ^{44 to} R ⁴⁶ are integers of 2 or more, the plurality of R ^{44 to} R ⁴⁶ may be the same or different.
n ₄ is preferably 0 to 2, more preferably 0 or 1.
n ₅ is preferably 0 or 1, more preferably 0.
n ₆ is preferably 0 or 1, more preferably 1.

The anion part of the sulfonium salt having a cation part represented by the formula (b′-6) is not particularly limited, and may be the same as the anion part of the onium salt acid generators proposed so far. . Examples of the anion moiety include fluorinated alkyl sulfonate ions such as the anion moiety (R ⁴ ″ SO ₃ ⁻ ) of the onium salt acid generator represented by the general formula (b-1) or (b-2). An anion moiety represented by the above general formula (b′-3) or (b′-4), etc. Among these, a fluorinated alkyl sulfonate ion is preferable, and a fluorinated alkyl having 1 to 4 carbon atoms. A sulfonate ion is more preferable, and a linear perfluoroalkyl sulfonate ion having 1 to 4 carbon atoms is particularly preferable, and specific examples thereof include trifluoromethyl sulfonate ion, heptafluoro-n-propyl sulfonate ion, and nonafluoro. -N-butyl sulfonate ion etc. are mentioned.

  In this specification, the oxime sulfonate acid generator is a compound having at least one group represented by the following general formula (B-1), and has a property of generating an acid upon irradiation with radiation. is there. Such oxime sulfonate-based acid generators are frequently used for chemically amplified resist compositions, and can be arbitrarily selected and used.

（式（Ｂ−１）中、Ｒ^３１、Ｒ^３２はそれぞれ独立に有機基を表す。）

(In formula (B-1), R ³¹ and R ³² each independently represents an organic group.)

The organic groups of R ³¹ and R ³² are groups containing carbon atoms, and atoms other than carbon atoms (for example, hydrogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms (fluorine atoms, chlorine atoms, etc.), etc.) You may have.
As the organic group for R ^31, a linear, branched, or cyclic alkyl group or aryl group is preferable. These alkyl groups and aryl groups may have a substituent. There is no restriction | limiting in particular as this substituent, For example, a fluorine atom, a C1-C6 linear, branched or cyclic alkyl group etc. are mentioned. Here, “having a substituent” means that part or all of the hydrogen atoms of the alkyl group or aryl group are substituted with a substituent.
As an alkyl group, C1-C20 is preferable, C1-C10 is more preferable, C1-C8 is more preferable, C1-C6 is especially preferable, and C1-C4 is the most preferable. As the alkyl group, a partially or completely halogenated alkyl group (hereinafter sometimes referred to as a halogenated alkyl group) is particularly preferable. The partially halogenated alkyl group means an alkyl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated alkyl group means that all of the hydrogen atoms are halogen atoms. Means an alkyl group substituted with Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. That is, the halogenated alkyl group is preferably a fluorinated alkyl group.
The aryl group preferably has 4 to 20 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms. As the aryl group, a partially or completely halogenated aryl group is particularly preferable. The partially halogenated aryl group means an aryl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated aryl group means that all of the hydrogen atoms are halogen atoms. Means an aryl group substituted with.
R ³¹ is particularly preferably an alkyl group having 1 to 4 carbon atoms having no substituent or a fluorinated alkyl group having 1 to 4 carbon atoms.

As the organic group for R ^32, a linear, branched, or cyclic alkyl group, aryl group, or cyano group is preferable. As the alkyl group and aryl group for R ^32, the same alkyl groups and aryl groups as those described above for R ³¹ can be used.
R ³² is particularly preferably a cyano group, an alkyl group having 1 to 8 carbon atoms having no substituent, or a fluorinated alkyl group having 1 to 8 carbon atoms.

  More preferable examples of the oxime sulfonate-based acid generator include compounds represented by the following general formula (B-2) or (B-3).

［式（Ｂ−２）中、Ｒ^３３は、シアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３４はアリール基である。Ｒ^３５は置換基を有さないアルキル基またはハロゲン化アルキル基である。］

[In Formula (B-2), R ³³ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁴ is an aryl group. R ³⁵ represents an alkyl group having no substituent or a halogenated alkyl group. ]

［式（Ｂ−３）中、Ｒ^３６はシアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３７は２または３価の芳香族炭化水素基である。Ｒ^３８は置換基を有さないアルキル基またはハロゲン化アルキル基である。ｐ”は２または３である。］

[In Formula (B-3), R ³⁶ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁷ is a divalent or trivalent aromatic hydrocarbon group. ^R38 is an alkyl group having no substituent or a halogenated alkyl group. p ″ is 2 or 3.]

In the general formula (B-2), the alkyl group or halogenated alkyl group having no substituent of R ³³ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and carbon atoms. Numbers 1 to 6 are most preferable.
R ³³ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³³ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred.

As the aryl group of R ³⁴ , one hydrogen atom is removed from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, or a phenanthryl group. And a heteroaryl group in which a part of carbon atoms constituting the ring of these groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Among these, a fluorenyl group is preferable.
The aryl group of R ³⁴ may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, or an alkoxy group. The alkyl group or halogenated alkyl group in the substituent preferably has 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. The halogenated alkyl group is preferably a fluorinated alkyl group.

The alkyl group or halogenated alkyl group having no substituent of R ³⁵ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 6 carbon atoms.
R ³⁵ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³⁵ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred is the strength of the acid generated. Most preferably, it is a fully fluorinated alkyl group in which a hydrogen atom is 100% fluorine-substituted.

In the general formula (B-3), the alkyl group or halogenated alkyl group having no substituent for R ³⁶ is the same as the alkyl group or halogenated alkyl group having no substituent for R ^33. Is mentioned.
Examples of the divalent or trivalent aromatic hydrocarbon group for R ³⁷ include groups obtained by further removing one or two hydrogen atoms from the aryl group for R ³⁴ .
Examples of the alkyl group or halogenated alkyl group having no substituent of R ³⁸ include the same alkyl groups or halogenated alkyl groups as those having no substituent of R ³⁵ .
p ″ is preferably 2.

Specific examples of the oxime sulfonate acid generator include α- (p-toluenesulfonyloxyimino) -benzyl cyanide, α- (p-chlorobenzenesulfonyloxyimino) -benzyl cyanide, α- (4-nitrobenzenesulfonyloxy). Imino) -benzylcyanide, α- (4-nitro-2-trifluoromethylbenzenesulfonyloxyimino) -benzylcyanide, α- (benzenesulfonyloxyimino) -4-chlorobenzylcyanide, α- (benzenesulfonyl) Oxyimino) -2,4-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -2,6-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -4-methoxybenzyl cyanide, α- ( 2-Chlorobenzenesulfonyloxyimino) 4-methoxybenzylcyanide, α- (benzenesulfonyloxyimino) -thien-2-ylacetonitrile, α- (4-dodecylbenzenesulfonyloxyimino) -benzylcyanide, α-[(p-toluenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α-[(dodecylbenzenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α- (tosyloxyimino) -4-thienyl cyanide, α- (methylsulfonyloxyimino) -1-cyclo Pentenyl acetonitrile, α- (methylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -1-cycloheptenylacetonitrile, α- (methylsulfonyloxyimino) -1-cyclooctene Acetonitrile, α- (trifluoromethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -cyclohexylacetonitrile, α- (ethylsulfonyloxyimino) -ethylacetonitrile, α- (propyl Sulfonyloxyimino) -propylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclopentylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclohexylacetonitrile, α- (cyclohexylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- ( Ethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclope N-tenyl acetonitrile, α- (n-butylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (ethylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclohexenylacetonitrile , Α- (n-butylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -phenylacetonitrile, α- (methylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (trifluoro Methylsulfonyloxyimino) -phenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -p- Butoxy phenylacetonitrile, alpha-(propylsulfonyl oxyimino)-p-methylphenyl acetonitrile, alpha-like (methylsulfonyloxyimino)-p-bromophenyl acetonitrile.
Further, an oxime sulfonate-based acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014] [chemical formula 18] to [chemical formula 19]), pamphlet of International Publication No. 04/074242, An oxime sulfonate-based acid generator disclosed in Examples 1 to 40) on pages 65 to 85 can also be suitably used.
Moreover, the following can be illustrated as a suitable thing.

Among diazomethane acid generators, specific examples of bisalkyl or bisarylsulfonyldiazomethanes include bis (isopropylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, Examples include bis (cyclohexylsulfonyl) diazomethane, bis (2,4-dimethylphenylsulfonyl) diazomethane, and the like.
Further, diazomethane acid generators disclosed in JP-A-11-035551, JP-A-11-035552, and JP-A-11-035573 can also be suitably used.
Examples of poly (bissulfonyl) diazomethanes include 1,3-bis (phenylsulfonyldiazomethylsulfonyl) propane and 1,4-bis (phenylsulfonyldiazo) disclosed in JP-A-11-322707. Methylsulfonyl) butane, 1,6-bis (phenylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (phenylsulfonyldiazomethylsulfonyl) decane, 1,2-bis (cyclohexylsulfonyldiazomethylsulfonyl) ethane, 1,3 -Bis (cyclohexylsulfonyldiazomethylsulfonyl) propane, 1,6-bis (cyclohexylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (cyclohexylsulfonyldiazomethylsulfonyl) decane, etc. Door can be.

  As the component (B3), the acid generators mentioned as the component (B3) may be used alone, or two or more types may be used in combination.

  Content of (B) component in the resist composition of this invention is 0.5-30 mass parts with respect to 100 mass parts of (A) component, Preferably it is 1-20 mass parts. By setting it within the above range, pattern formation is sufficiently performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

<(D) component>
Since the resist composition of the present invention improves the resist pattern shape, the stability over time, and the like, it further contains a nitrogen-containing organic compound (D) (hereinafter referred to as “component (D)”) as an optional component. Is preferred.
Since a wide variety of components (D) have already been proposed, any known one may be used, and among them, cyclic amines, aliphatic amines, particularly secondary aliphatic amines and tertiary amines. Aliphatic amines are preferred. Here, the aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.

Examples of the aliphatic amine include amines (alkyl amines or alkyl alcohol amines) in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms. Specific examples thereof include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di-n-heptylamine, Dialkylamines such as di-n-octylamine and dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptyl Trialkylamines such as amine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n -Ok Noruamin, alkyl alcohol amines such as tri -n- octanol amine.
Among these, alkyl alcohol amines and trialkyl amines are preferable, and trialkyl amines are particularly preferable. Of the trialkylamines, tri-n-pentylamine is most preferred.

Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable. Specifically, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5. 4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane, and the like.

  Moreover, as (D) component, the nitrogen-containing organic compound represented by the following general formula (d-1) is also mentioned.

In formula (d-1), R ¹ is a group represented by the following general formula (I) (hereinafter referred to as group (I)).

In formula (I), R ⁴ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, Examples include lower linear or branched alkyl groups such as tert-butyl group, pentyl group, isopentyl group, and neopentyl group. The alkyl group for R ⁴ is preferably an alkyl group having 1 to 5 carbon atoms, and particularly preferably a methyl group.
R ⁵ is an alkylene group having 1 to 5 carbon atoms, and as the alkylene group, a linear or branched alkylene group having 1 to 5 carbon atoms is preferable, and a methylene group is particularly preferable.
c is 0 or 1. When c is 0, R ⁴ is preferably an alkyl group having 1 to 5 carbon atoms, preferably an alkyl group having 1 to 3 carbon atoms, and particularly preferably a methyl group. When c is 1, R ⁴ is preferably a hydrogen atom.

In formula (d-1), a is an integer of 1 to 3, preferably 1 or 2, and particularly preferably 1.
The bonding position of the group (I) to the benzene ring represented by the formula (d-1) is not particularly limited. When a is 1, that is, when one group (I) is bonded to the benzene ring, the bonding position of the group (I) is the para position of the bonding position of the carbonyl group adjacent to the benzene ring or The meta position is preferred, and the para position is particularly preferred.
When a is 2 or 3, that is, when a plurality of groups (I) are present, the plurality of groups (I) may be the same as or different from each other.

b is an integer of 1 to 3, 1 or 2 is preferable, and 1 is particularly preferable.
R ² and R ³ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and examples of the alkyl group include the same alkyl groups as those described above for R ⁴ .
In the present invention, R ² and R ³ are both preferably alkyl groups because they are excellent in the effects of the present invention. This is probably because the carbon atom to which R ² and R ³ are bonded is a tertiary carbon atom, so that the structure is changed by light during exposure, and the pKa is greatly increased compared to before exposure. Guessed.
At this time, the alkyl groups of R ² and R ³ may be the same or different.
The nitrogen-containing organic compound represented by the general formula (d-1) is particularly preferably a compound in which R ² and R ³ are alkyl groups having 1 to 5 carbon atoms and b is 1.

  The nitrogen-containing organic compound represented by the general formula (d-1) may further have a substituent on the benzene ring represented by the general formula (d-1). Here, “having a substituent” means that at least one hydrogen atom bonded to a carbon atom constituting the benzene ring is substituted with the substituent. As the substituent, an alkyl group is preferable, and an alkyl group having 1 to 5 carbon atoms is more preferable.

  Specific examples of the nitrogen-containing organic compound represented by the general formula (d-1) include, for example, nitrogen-containing organic compounds represented by the following chemical formulas (d-1-1) to (d-1-5). Can be mentioned. Among these, the nitrogen-containing organic compound represented by the formula (d-1-1), (d-1-2) or (d-1-3) is preferable.

(D) A component may be used independently and may be used in combination of 2 or more type.
In the present invention, it is particularly preferable to use the nitrogen-containing organic compound represented by the general formula (d-1) as the component (D).
(D) component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

<Optional component>
[(E) component]
The resist composition of the present invention comprises, as optional components, an organic carboxylic acid, a phosphorus oxo acid, and derivatives thereof for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, retention stability over time, and the like. At least one compound (E) selected from the group (hereinafter referred to as component (E)) can be contained.
As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.
Examples of phosphorus oxo acids and derivatives thereof include phosphoric acid, phosphonic acid, phosphinic acid and the like, and among these, phosphonic acid is particularly preferable.
Examples of the oxo acid derivative of phosphorus include esters in which the hydrogen atom of the oxo acid is substituted with a hydrocarbon group, and the hydrocarbon group includes an alkyl group having 1 to 5 carbon atoms and 6 to 6 carbon atoms. 15 aryl groups and the like.
Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.
Examples of phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid-di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.
Examples of the phosphinic acid derivatives include phosphinic acid esters such as phenylphosphinic acid.
(E) A component may be used individually by 1 type and may use 2 or more types together.
As the component (E), an organic carboxylic acid is preferable, and salicylic acid is particularly preferable.
(E) A component is used in the ratio of 0.01-5.0 mass parts per 100 mass parts of (A) component.

  The resist composition of the present invention further contains miscible additives as desired, for example, an additional resin for improving the performance of the resist film, a surfactant, a dissolution inhibitor, and a plasticizer for improving coatability. Stabilizers, colorants, antihalation agents, dyes, and the like can be added as appropriate.

[(S) component]
The resist composition of the present invention can be produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as (S) component).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution. Conventionally, any one of known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; Monohydric alcohols; compounds having an ester bond, such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, monomethyl ether, monoethyl of the polyhydric alcohols or compound having the ester bond Ether alkyl such as ether, monopropyl ether, monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having a propylene glycol monomethyl ether acetate (PGMEA) or propylene glycol monomethyl ether (PGME) among these]; cyclic ethers such as dioxane, methyl lactate, Esters such as ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, Aromatic organics such as dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene A solvent etc. can be mentioned.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Of these, PGMEA, PGME, and EL are preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is also preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be within the range.
More specifically, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. Moreover, when mix | blending PGME as a polar solvent, the mass ratio of PGMEA: PGME becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3.
In addition, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95: 5.
The amount of the component (S) used is not particularly limited, but it is a concentration that can be applied to a support such as a substrate, and is appropriately set according to the coating film thickness. The concentration is 2 to 20% by mass, preferably 5 to 15% by mass.

The resist composition of the present invention has the effect that the change in the resist pattern dimension when the exposure dose varies is small (EL margin is large) and the mask reproducibility (MEF) is excellent. The reason is not clear, but is presumed as follows.
In the resist composition of the present invention, an acid generator (B1) having a cation moiety represented by the general formula (b′-1), an acid generator (B2) having a cation moiety containing a dibenzothiophene skeleton, and The acid generator component (B) containing is contained.
The component (B2) is more transparent in light absorption in the exposure wavelength band (especially the ArF excimer laser wavelength band) than the acid generator having cation moiety such as triphenylsulfonium (TPS). It is highly probable. The component (B2) is also excellent in solubility in the organic solvent (S) used for dissolving various components of the resist, and can be distributed more uniformly in the resist film.
And by using this (B2) component together with the (B1) component having high acid generation efficiency, the acid generation efficiency can be increased while maintaining high transparency with respect to the exposure wavelength band. Thus, it is estimated that the above-described effects of the present invention can be obtained.

  In the present invention, lithography characteristics such as resist pattern shape, mask linearity, proximity effect, etc. are also good.

≪Resist pattern formation method≫
The resist pattern forming method of the second aspect of the present invention includes a step of forming a resist film on a support using the resist composition of the first aspect of the present invention, a step of exposing the resist film, and A step of developing the resist film to form a resist pattern.
The resist pattern forming method of the present invention can be performed, for example, as follows.
That is, first, the resist composition is coated on a support with a spinner or the like, and pre-baked (post-apply bake (PAB)) for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of 80 to 150 ° C. Then, after selectively exposing ArF excimer laser light through a desired mask pattern, for example, with an ArF exposure apparatus or the like, PEB (post-exposure heating) is performed for 40 to 120 seconds under a temperature condition of 80 to 150 ° C. Preferably, it is applied for 60 to 90 seconds. Next, this is developed with an alkali developer, for example, an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH), preferably rinsed with pure water and dried. In some cases, a baking process (post-bake) may be performed after the development process. In this way, a resist pattern faithful to the mask pattern can be obtained.

The support is not particularly limited, and a conventionally known one can be used, and examples thereof include a substrate for electronic components and a substrate on which a predetermined wiring pattern is formed. More specifically, a silicon substrate, a metal substrate such as copper, chromium, iron, and aluminum, a glass substrate, and the like can be given. As a material for the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used.
Further, the support may be a substrate in which an inorganic and / or organic film is provided on the above-described substrate. An inorganic antireflection film (inorganic BARC) is an example of the inorganic film. Examples of the organic film include an organic antireflection film (organic BARC).

The wavelength used for the exposure is not particularly limited, and ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. Can be done using radiation. The resist composition is effective for KrF excimer laser, ArF excimer laser, EB or EUV, and particularly effective for ArF excimer laser.

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.
<Base material component (A)>
In Comparative Examples 1 and 2 and Examples 1 to 4, the resin (A) -1 used as the component (A) is copolymerized by a known dropping polymerization method using the following monomers (1) to (3). I got it.

The structure of the obtained resin (A) -1 is summarized below.
In the formula, the number attached to the lower right of () indicates the ratio (mol%) of each constituent unit to the total of all constituent units constituting the resin. The proportion of each structural unit was calculated by carbon NMR. The results are shown in Table 1.
Moreover, GPC measurement was performed about obtained resin (A) -1, and the mass mean molecular weight (Mw) and dispersity (Mw / Mn) were calculated | required. The results are shown in Table 1.

(Examples 1-4, Comparative Examples 1-2).
<Preparation of resist composition>
Each component shown in Table 2 was mixed and dissolved to prepare a positive resist composition.

Each abbreviation in Table 2 has the following meaning. Moreover, the numerical value in [] is a compounding quantity (mass part).
(A) -1: the resin (A) -1.

(B) -1: a compound represented by the following chemical formula (B3-1).
(B) -2: a compound represented by the following chemical formula (B3-2).
(B) -3: A compound represented by the following chemical formula (B1-2) (1-phenyltetrahydrothiopyranium nonafluoro-n-butanesulfonate).
(B) -4: A compound represented by the following chemical formula (B1-1).
(B) -5: A compound represented by the following chemical formula (B2-3).
(B) -6: A compound represented by the following chemical formula (B2-4).

(D) -1: Triethylamine.
(D) -2: tri-n-pentylamine.
(D) -3: A nitrogen-containing organic compound represented by the following chemical formula (d-1-1).

(E) -1: salicylic acid.
(S) -1: γ-butyrolactone.
(S) -2: Mixed solvent of PGMEA / PGME = 6/4 (mass ratio).

<Evaluation of lithography properties>
A resist pattern was formed using the obtained positive resist composition, and an exposure dose (EL) margin and a mask error factor (MEF) were evaluated.

[Resist pattern formation]
ARC95 (trade name, manufactured by Brewer Science Co., Ltd.), an organic antireflective coating composition, is applied onto an 8-inch silicon wafer using a spinner, and baked on a hot plate at 205 ° C. for 60 seconds to dry. Thereby, an organic antireflection film having a thickness of 90 nm was formed.
Then, the positive resist composition obtained above is applied onto the organic antireflection film using a spinner, and pre-baked (PAB) is performed on a hot plate at 110 ° C. for 60 seconds. The resist film with a film thickness of 140 nm was formed by drying.
Next, an ArF excimer laser (193 nm) was applied to the mask pattern (halftone, transmittance 6%) using an ArF exposure apparatus NSR-S306 (manufactured by Nikon; NA (numerical aperture) = 0.78, σ = Di-pole Y). ) Selectively.
Thereafter, post-exposure heating (PEB) treatment was performed at 110 ° C. for 60 seconds, and a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution (trade name: NMD-3, Tokyo Ohka Kogyo Co., Ltd.) at 23 ° C. (Made by Co., Ltd.) was subjected to alkali development for 60 seconds, rinsed with pure water for 30 seconds, and then shaken and dried.
As a result, a line-and-space resist pattern (L / S pattern) having a line width of 65 nm and a pitch of 180 nm was formed in any positive resist composition.

[sensitivity]
In the above resist pattern formation, the optimum exposure dose Eop (mJ / cm ² ; sensitivity) at which a line-and-space L / S pattern with a line width of 65 nm and a pitch of 180 nm was formed was determined. The results are shown in Table 3.

[Exposure (EL) margin]
L / S patterns having a line width of 65 nm and a pitch of 180 nm as target dimensions were formed in the same manner as in [Registration pattern formation] described above, while changing the exposure amount.
At this time, an exposure amount when an L / S pattern having a target dimension (65 nm) within a range of ± 10% (that is, 58.5 to 71.5 nm) is formed is obtained, and an EL margin (unit: :%). The results are shown in Table 3.
EL margin (%) = (| E1-E2 | / Eop) × 100
E1: Exposure amount (mJ / cm ² ) when forming an L / S pattern having a line width of 58.5 nm.
E2: exposure amount (mJ / cm ² ) when forming an L / S pattern with a line width of 71.5 nm.

[Mask error factor (MEF)]
In the above Eop, L / S patterns with a pitch of 180 nm were formed using mask patterns with a target size of line width of 60 nm, 62.5 nm, 65 nm, 67.5 nm, and 70 nm, respectively. At this time, the slope of the straight line when the target size (nm) was plotted on the horizontal axis and the line width (nm) formed on the resist film using each mask pattern was plotted on the vertical axis was calculated as MEF. MEF (straight line) means that the closer the value is to 1, the better the mask reproducibility. The obtained results are shown in Table 3.

  As is clear from the results of Table 3, the positive resist compositions of Examples 1 to 4 according to the present invention have an EL margin equal to or greater than that of Comparative Examples 1 and 2. Since it is large and the MEF is a value closer to 1, it was confirmed that the change in the resist pattern dimension due to the change in the exposure amount was small and the mask reproducibility was excellent.

  Furthermore, when each resist pattern was formed using the positive resist composition of each example and the resist pattern shape, mask linearity, and proximity effect were evaluated, the positive resist compositions of Examples 1 to 4 according to the present invention were evaluated. As a result, the same results as those of the positive resist compositions of Comparative Examples 1 and 2 were obtained, and it was confirmed that all the lithography characteristics were not impaired.

Claims (7)

A resist composition containing a base component that exhibits a changed solubility in an alkali developing solution (A), 1 acid generator component that generates acid on exposure light (B) and nitrogen-containing organic compound (D) by the action of an acid And
The acid generator component (B) is represented by an acid generator (B1) having a cation moiety represented by the following general formula (b′-1-0) and the following general formula (b′-5). acid generator having a cation and (B2) seen including,
The nitrogen-containing organic compound (D) is a nitrogen-containing organic compound represented by the following general formula (d-1) .

[Wherein R ¹⁰ ″ and R ²⁰ ″ each independently represents an alkylene group ; R ³⁰ ″ represents an unsubstituted aryl group having 6 to 20 carbon atoms; a part of hydrogen atoms of the unsubstituted aryl group or all alkyl groups, alkoxy group, and a alkoxyalkyl group, an alkoxycarbonylalkyl group, or a substituted aryl group substituted by a halogen atom or a hydroxyl radical, R ⁴⁰ is a hydrogen atom or an alkyl radical, R ⁴¹ is a halogen atom, halogenated alkyl group, alkyl group, acetyl group, carboxy group, or hydroxyalkyl group; R ⁴² and R ⁴³ are each independently a halogen atom, halogenated alkyl group, alkyl group, acetyl group, An alkoxy group, a carboxy group, a hydroxyl group, or a hydroxyalkyl group; n _{0 to} n ₃ are each independently And n ₀ + n ₁ is 5 or less.]

[Wherein, R ¹ is a group represented by the following general formula (I). a is an integer of 1 to 3. However, you may further have a C1-C5 alkyl group as a substituent on the benzene ring in a formula. b is an integer of 1 to 3. R ² and R ³ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ]

[Wherein, R ⁴ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R ⁵ is an alkylene group having 1 to 5 carbon atoms. c is 0 or 1. ]   The resist composition according to claim 1, wherein the component (B1) in the acid generator component (B) is 0.1 to 50% by mass.   The resist composition according to claim 1 or 2, wherein the substrate component (A) is a substrate component (A ') whose solubility in an alkaline developer is increased by the action of an acid.   The resist composition according to claim 3, wherein the substrate component (A ') is a resin component (A1) and has a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.   The resist composition according to claim 4, wherein the resin component (A1) further has a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group.   The resist composition according to claim 4 or 5, wherein the resin component (A1) further has a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group. Using the resist composition according to any one of claims 1 to 6 forming a resist film on a substrate, the resist pattern wherein the step of exposing the resist film, and the resist film with an alkaline developer A resist pattern forming method including a step of forming a film.