JP5422213B2 - Positive resist composition and resist pattern forming method - Google Patents

Description

  The present invention relates to a positive resist composition and a resist pattern forming method using the positive 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 satisfying such requirements, a chemically amplified resist composition containing a base material component 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. ing.
For example, as a positive chemically amplified resist composition, a composition containing a resin component (base resin) whose solubility in an alkaline developer is increased by the action of an acid and an acid generator component is generally used. Yes. When such a resist film formed using the resist composition is selectively exposed at the time of forming the resist pattern, an acid is generated from the acid generator in the exposed portion, and the alkali developer of the resin component is generated by the action of the acid. As a result, the exposed area becomes soluble in an alkaline developer.
Currently, as a resist base resin used in ArF excimer laser lithography and the like, a resin having a constitutional unit derived from (meth) acrylic acid ester (acrylic resin) because of its excellent transparency near 193 nm Etc. are generally used (see, for example, Patent Documents 1 and 2). Here, “(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. “(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.
At present, as a base resin for a chemically amplified resist, a resin containing a plurality of structural units is used in order to improve lithography properties and the like. For example, in the case of the positive type, it usually contains a structural unit having an acid dissociable, dissolution inhibiting group that is dissociated by the action of an acid generated from an acid generator, and further has a structural unit having a polar group such as a hydroxyl group, a lactone structure. The thing containing the structural unit which has is used. Among these, the structural unit having a lactone structure is generally considered to contribute to the improvement of lithography properties by improving the adhesion of the resist film to the substrate and improving the affinity with an alkali developer.
Here, depending on the type of substrate (especially in the case of a silicon-containing (inorganic) underlayer film), the acid generated from the acid generator is deactivated at the interface between the resist film and the substrate, and the solubility contrast in the alkali developer There is a problem (bad substrate matching) that cannot be sufficiently obtained. In order to solve this problem, a method of improving the components of the silicon-containing underlayer film has been used (see Patent Document 3). However, in the case of improving the resist composition components, not only the substrate matching is improved, but also good There were difficulties in maintaining and improving lithography properties.

JP 2003-241385 A JP 2006-016379 A JP 2007-037157 A

In the future, there is a demand for new materials that can be used for lithography applications as further advancement of lithography technology and expansion of application fields are expected. For example, as the pattern becomes finer, the resist material is required to improve various lithography characteristics. For example, when the rectangular shape of the cross-sectional shape of the resist pattern is low or the LWR (line width roughness) is large, there is a risk of adversely affecting the formation of fine semiconductor elements. LWR is a phenomenon in which when a resist pattern is formed using a resist composition, the pattern surface is roughened (roughness) and the line width of the line pattern becomes non-uniform.
Therefore, the improvement of the resist pattern shape and LWR becomes more important as the pattern becomes finer. In addition, good matching between the resist material and the substrate of the semiconductor element is an important characteristic that serves as a basis for improving various lithography characteristics.
The present invention has been made in view of the above circumstances, and provides a positive resist composition and a resist pattern forming method that can form a resist pattern having a good shape, a low LWR, and a good matching with a substrate. The task is to do.

［式中、Ｒ^８１は水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり、Ｒ^８２は酸素原子を有していてもよい炭素数２〜１２の２価の脂肪族炭化水素基である。］

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり、Ｒ ^２１ は直鎖状または分岐鎖状のアルキル基であり、Ｒ ^２２ は、当該Ｒ ^２２ が結合した炭素原子と共に脂肪族単環式基を形成する基である。］
前記第二実施形態は、酸の作用によりアルカリ現像液に対する溶解性が増大する基材成分（Ａ）、および露光により酸を発生する酸発生剤成分（Ｂ）を含有するポジ型レジスト組成物であって、前記基材成分（Ａ）が、下記一般式（ａ０−１）で表される構成単位（ａ０）、酸解離性溶解抑制基を含むアクリル酸エステルから誘導される構成単位（ａ１）を少なくとも２種、およびラクトン含有環式基を含むアクリル酸エステルから誘導される構成単位（ａ２）を有する高分子化合物（Ａ１）を含有し、
前記高分子化合物（Ａ１）が、前記構成単位（ａ１）の１種として、前記構成単位（ａ１）として、下記一般式（ａ１−０−１３）で表される構成単位（ａ１−０−１３）を有することを特徴とするポジ型レジスト組成物である。

［式中、Ｒ ^１ は水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり、Ａは２価の連結基であり、Ｂは２価の連結基であり、Ｒ ^２ は酸解離性溶解抑制基である。］ In order to achieve the above object, the present invention employs the following configuration.
That is, the first aspect of the present invention is a positive resist composition according to the following first and second embodiments.
The first embodiment is a positive resist composition containing a base component (A) whose solubility in an alkaline developer is increased by the action of an acid, and an acid generator component (B) that generates an acid upon exposure. And the said base-material component (A) is the structural unit (a1) induced | guided | derived from the acrylate ester containing the structural unit (a0) represented by the following general formula (a0-1), and an acid dissociable, dissolution inhibiting group. A polymer compound (A1) having a structural unit (a2) derived from an acrylate ester containing at least two kinds of lactones and a lactone-containing cyclic group ,
The polymeric compound (A1) is, as a kind of the structural unit (a1), and characterized in that have a structural unit (a1-0-11) represented by the following general formula (a1-0-11) This is a positive resist composition.

[Wherein, R ⁸¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and R ⁸² has 2 to 12 carbon atoms which may have an oxygen atom. It is a divalent aliphatic hydrocarbon group. ]

Wherein R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, R ²¹ is a linear or branched alkyl group, and R ²² is , R ²² is a group that forms an aliphatic monocyclic group together with the carbon atom to which R ²² is bonded. ]
The second embodiment is a positive resist composition containing a base component (A) whose solubility in an alkaline developer is increased by the action of an acid and an acid generator component (B) that generates an acid upon exposure. And the said base-material component (A) is the structural unit (a1) induced | guided | derived from the acrylate ester containing the structural unit (a0) represented by the following general formula (a0-1), and an acid dissociable, dissolution inhibiting group. A polymer compound (A1) having a structural unit (a2) derived from an acrylate ester containing at least two kinds of lactones and a lactone-containing cyclic group,
The polymer compound (A1) is a structural unit (a1-0-13) represented by the following general formula (a1-0-13) as the structural unit (a1) as one type of the structural unit (a1). And a positive resist composition.

[Wherein, R ¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, A is a divalent linking group, and B is a divalent linking group. R ² is an acid dissociable, dissolution inhibiting group. ]

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

In the present specification and claims, “aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity.
Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups.
Unless otherwise specified, the “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups. The same applies to the alkyl group in the alkoxy group.
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.
“Fluorinated alkyl group” or “fluorinated alkylene group” refers to a group in which part or all of the hydrogen atoms of an alkyl group or alkylene group are substituted with fluorine atoms.
“Structural unit” means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).
“A 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 bonded to the α-position carbon atom include an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, and a hydroxyalkyl group. Hereinafter, the alkyl group having 1 to 5 carbon atoms and the halogenated alkyl group having 1 to 5 carbon atoms may be referred to as a lower alkyl group and a halogenated lower alkyl group, respectively. The α-position carbon atom of the acrylate ester is a carbon atom to which a carbonyl group is bonded unless otherwise specified.
“Exposure” is a concept including general irradiation of radiation.

  According to the present invention, it is possible to provide a positive resist composition and a resist pattern forming method that can form a resist pattern with a good shape and a small LWR and have a good matching with the substrate.

≪Positive resist composition≫
The positive resist composition of the present invention (hereinafter sometimes referred to simply as “resist composition”) is a base component (A) (hereinafter referred to as “component (A)”) whose solubility in an alkaline developer is increased by the action of an acid. And an acid generator component (B) (hereinafter referred to as component (B)) that generates an acid upon irradiation with radiation.
In such a positive resist composition, when radiation is irradiated (exposed), an acid is generated from the component (B), and the solubility of the component (A) in an alkaline developer is increased by the action of the acid. Therefore, in the formation of the resist pattern, when selective exposure is performed on the resist film obtained using the positive resist composition, the solubility of the resist film in the alkaline developer in the exposed portion increases. Since the solubility of the unexposed portion in the alkaline developer does not change, a resist pattern can be formed by performing alkali development.
Here, the “base material component” is an organic compound having a film forming ability. As the substrate component, 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.
“Organic compounds having a molecular weight of 500 or more” used as the base component are roughly classified into non-polymers and polymers.
As the non-polymer, those having a molecular weight of 500 or more and less than 4000 are usually used. Hereinafter, a nonpolymer having a molecular weight of 500 or more and less than 4000 is referred to as a low molecular compound.
As the polymer, those having a molecular weight of 2000 or more are usually used. Hereinafter, a polymer having a molecular weight of 2000 or more is referred to as a polymer compound. In the case of a polymer compound, the “molecular weight” is a polystyrene-reduced mass average molecular weight measured by GPC (gel permeation chromatography). Hereinafter, the polymer compound may be simply referred to as “resin”.

<(A) component>
[Polymer Compound (A1)]
In the present invention, the polymer compound (A1) (hereinafter referred to as the component (A1)) is an acrylic acid containing the structural unit (a0) represented by the general formula (a0-1) and an acid dissociable, dissolution inhibiting group. The structural unit (a2) derived from an acrylate ester containing at least two structural units (a1) derived from an ester and a lactone-containing cyclic group.
Furthermore, in the present invention, the component (A1) is an acryl containing a polar group-containing aliphatic hydrocarbon group in addition to the structural unit (a0), the structural unit (a1), and the structural unit (a2). It is preferable to have a structural unit (a3) derived from an acid ester.

<Structural unit (a0)>
In formula (a0-1), R ⁸¹ represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.
The alkyl group having 1 to 5 carbon atoms of R ⁸¹ is preferably a linear or branched alkyl group, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, or an isobutyl group. Tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like.
The halogenated alkyl group having 1 to 5 carbon atoms of R ⁸¹ is a group in which part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with a halogen atom. 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.
R ⁸¹ is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and is most preferably a hydrogen atom or a methyl group in terms of industrial availability.

In formula (a0-1), R ⁸² represents a C 2-12 divalent aliphatic hydrocarbon group which may have an oxygen atom.
Divalent aliphatic hydrocarbon group having 2 to 12 carbon atoms R ⁸² may be contain an oxygen atom, it may not include.
The divalent aliphatic hydrocarbon group includes “oxygen atom” means that part or all of the hydrogen atoms in the divalent aliphatic hydrocarbon group and / or the divalent aliphatic hydrocarbon group It means that a part of carbon atoms is substituted with an oxygen atom.
Here, the divalent aliphatic hydrocarbon group means a divalent hydrocarbon group having no aromaticity.
The divalent aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.
The divalent aliphatic hydrocarbon group may be a divalent aliphatic hydrocarbon group having a substituent. The “having a substituent” means that part or all of the hydrogen atoms in the divalent aliphatic hydrocarbon group are substituted with groups or atoms other than hydrogen atoms.

More specifically, examples of the divalent aliphatic hydrocarbon group include a linear or branched divalent aliphatic hydrocarbon group, a divalent aliphatic hydrocarbon group having a ring in the structure, and the like. Can be mentioned.
The linear or branched divalent aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 2 to 8, and most preferably 3 to 6.

As the linear divalent aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [— (CH ₂ ) ₃ -], tetramethylene group _{[- (CH 2) 4 -} ], a pentamethylene group _{[- (CH 2) 5 -} ], hexamethylene group _{[- (CH 2) 6 -} ] and the like.

As the branched divalent aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C ( _{CH 3) 2 -, - C} (CH 3) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - and the like alkyl methylene _{group; -CH (CH 3) CH 2} -, - CH (CH 3) CH (CH 3) -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - C Alkylethylene groups such as (CH ₂ CH ₃ ) ₂ —CH ₂ —; alkyl trimethylene groups such as —CH (CH ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CH ₃ ) CH ₂ —; _{CH 3) CH 2 CH 2 CH} 2 -, - CH 2 CH (CH 3) CH 2 CH Examples thereof include alkylalkylene groups such as an alkyltetramethylene group such as _2- . The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

  The linear or branched divalent aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include 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, and among them, an oxygen atom (═O) is preferable.

The divalent aliphatic hydrocarbon group containing a ring in the structure includes a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and the cyclic aliphatic hydrocarbon group. Examples thereof include a group bonded to the terminal of the chain divalent aliphatic hydrocarbon group described above or interposed in the middle of the chain divalent aliphatic hydrocarbon group.
The cyclic aliphatic hydrocarbon group preferably has 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic group, a group in which two hydrogen atoms have been removed from a monocycloalkane having 3 to 6 carbon atoms is preferable, and examples of the monocycloalkane include cyclopentane and cyclohexane. As the polycyclic group, a group in which two hydrogen atoms are removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, tetra And cyclododecane.
The cyclic aliphatic hydrocarbon group 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.

Specific examples of the divalent aliphatic hydrocarbon group containing an oxygen atom include —O—, —C (═O) —, —O—C (═O) —, —C (═O) —O—. , Carbonate bond (—O—C (═O) —O—), —S (═O) ₂ —, —S (═O) ₂ —O—, —NH—C (═O) —, etc. Bonded to the end of a chain-like divalent aliphatic hydrocarbon group, interposed in the middle of the chain-like divalent aliphatic hydrocarbon group, or constitutes a ring skeleton of the above-mentioned cyclic aliphatic hydrocarbon group And a group that substitutes for the carbon atom.

In the present invention, the divalent aliphatic hydrocarbon group having 2 to 12 carbon atoms which may have an oxygen atom of R ⁸² is preferably an alkylene group or a divalent aliphatic hydrocarbon group containing an oxygen atom. . Among these, a divalent aliphatic hydrocarbon group containing an oxygen atom is particularly preferable.
When ^R82 is an alkylene group, the alkylene group preferably has 2 to 10 carbon atoms, and most preferably has 2 to 6 carbon atoms. Specific examples include the same linear alkylene groups and branched alkylene groups as mentioned above.

When ^R82 is a divalent aliphatic hydrocarbon group containing an oxygen atom, preferred examples thereof include a group represented by the formula -AO-, a group represented by the formula -AO-B-, Examples include a group represented by the formula-[A-C (= O) -O] _m -B-, a group represented by the formula-[A-O-C (= O)] _m -B-, and the like. Among these, a group represented by the formula-[A-O-C (= O)] _m -B- is most preferable. Here, A and B are each independently a divalent aliphatic hydrocarbon group, and m is an integer of 1 to 3.

Examples of the divalent aliphatic hydrocarbon group for A and B, include the same as those of the divalent aliphatic hydrocarbon group for R ⁸² above.
The A is preferably a linear or branched divalent aliphatic hydrocarbon group, more preferably a linear or branched alkylene group, and a linear or branched chain having 2 to 6 carbon atoms. An alkylene group is more preferred, an ethylene group or an alkylethylene group is particularly preferred, and an ethylene group is most preferred.
The alkyl group in the alkylethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.

The B is preferably a linear or branched divalent aliphatic hydrocarbon group, more preferably a linear or branched alkylene group, and a linear or branched chain having 2 to 6 carbon atoms. An alkylene group is more preferred, an ethylene group or an alkylethylene group is particularly preferred, and an ethylene group is most preferred.
The alkyl group in the alkylethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.
In the group represented by the formula — [A—O—C (═O)] _m —B—, m is an integer of 1 to 3, more preferably 1 or 2, and most preferably 1.

  In the present invention, the structural unit (a0) is particularly preferably a structural unit represented by the following general formula (a0-1-11).

［式中、Ｒ^８１は前記と同じであり、ａ”およびｂ”は１〜３の整数である。］

[Wherein R ⁸¹ is the same as defined above, and a ″ and b ″ are integers of 1 to 3. ]

In general formula (a0-1-11), a ″ is an integer of 1 to 3, and preferably 2.
In general formula (a0-1-11), b ″ is an integer of 1 to 3, and preferably 2.

As the structural unit (a0), one type may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a0) in the component (A1) is determined when the resist pattern is formed using the positive resist composition containing the component (A1). (Roughness), excellent matching to the substrate, and the like, so that it is preferably 1 mol% or more, more preferably 5 to 30 mol%, more preferably 5 to 25 mol% with respect to all structural units constituting the component (A1) Is more preferable, and 5 to 20 mol% is most preferable.

<Structural unit (a1)>
The structural unit (a1) is a structural unit derived from an acrylate ester not containing the structural unit (a0) and containing an acid dissociable, dissolution inhibiting group. Here, “the structural unit (a1) does not correspond to the structural unit (a0)” is a structural unit corresponding to the structural unit (a0), and includes a structure containing an acid dissociable, dissolution inhibiting group in the structure. The unit indicates that it does not correspond to the structural unit (a1).
As the acid dissociable, dissolution inhibiting group in the structural unit (a1), those proposed so far as the acid dissociable, dissolution inhibiting group of the base resin for chemically amplified resist can be used. In general, 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. . 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.
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.
Here, “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.
Examples of the aliphatic branched acid dissociable, dissolution inhibiting group include a group represented by -C (R ⁷¹ ) (R ⁷² ) (R ⁷³ ). ^Wherein, R 71 ^{to R 73} each independently represents a linear alkyl group of 1 to 5 carbon atoms. The group represented by —C (R ⁷¹ ) (R ⁷² ) (R ⁷³ ) preferably has 4 to 8 carbon atoms, specifically a tert-butyl group or a 2-methyl-2-butyl group. , 2-methyl-2-pentyl group, 3-methyl-3-pentyl group and the like. A tert-butyl group is particularly preferable.

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 lower alkoxy 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 a group in which one or more hydrogen atoms have been removed from a monocycloalkane which may or may not be substituted with a lower alkyl group, a fluorine atom or a fluorinated alkyl group. , Groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as bicycloalkane, tricycloalkane, and tetracycloalkane. More specifically, a group obtained by removing one or more hydrogen atoms from a monocycloalkane such as cyclopentane or cyclohexane, or one or more polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. And a group in which a hydrogen atom is removed. Further, a part of the carbon atoms constituting the ring of a group obtained by removing one or more hydrogen atoms from these monocycloalkanes or a group obtained by removing one or more hydrogen atoms from polycycloalkanes are etheric oxygen atoms (- O-) may be substituted.
Examples of the acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group include (i) a group having a tertiary carbon atom on the ring skeleton of a monovalent aliphatic cyclic group; (ii) a monovalent A group having an aliphatic cyclic group and a branched alkylene having a tertiary carbon atom bonded thereto; and the like.
(I) Specific examples of the group having a tertiary carbon atom on the ring skeleton of the monovalent aliphatic cyclic group are represented by the following general formulas (1-1) to (1-9). Groups and the like.
(Ii) Specific examples of the group having a monovalent aliphatic cyclic group and a branched alkylene group having a tertiary carbon atom bonded thereto include, for example, the following general formulas (2-1) to (2-1) And the group represented by (2-6).

［式中、Ｒ^１４はアルキル基であり、ｇは０〜８の整数である。］

[Wherein, R ¹⁴ represents an alkyl group, and g represents an integer of 0 to 8. ]

［式中、Ｒ^１５およびＲ^１６は、それぞれ独立してアルキル基である。］

[Wherein, R ¹⁵ and R ¹⁶ each independently represents an alkyl group. ]

The alkyl group for R ¹⁴ is preferably a linear or branched alkyl group.
The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and still more preferably 1 or 2. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.
The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group and the like, and isopropyl group is most preferable.
g is preferably an integer of 0 to 3, more preferably an integer of 1 to 3, and still more preferably 1 or 2.
Examples of the alkyl group for R ^{15 to} R ¹⁶ include the same alkyl groups as those for R ¹⁴ .
In the formulas (1-1) to (1-9) and the formulas (2-1) to (2-6), a part of the carbon atoms constituting the ring is an etheric oxygen atom (—O—). May be substituted.
In formulas (1-1) to (1-9) and (2-1) to (2-6), a hydrogen atom bonded to a carbon atom constituting the ring may be substituted with a substituent. Examples of the substituent include a lower alkyl group, a fluorine atom, and a fluorinated alkyl group.

The “acetal 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 formula (p1), 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 ⁸¹ , preferably a methyl group or an ethyl group, and most preferably a methyl group.
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は上記と同じである。］

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

As the lower alkyl group for Y, the same as the lower alkyl groups for R ⁸¹ above can be mentioned.
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若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、分岐鎖状若しくは環状のアルキル基である。または、Ｒ^１７およびＲ^１９がそれぞれ独立に直鎖状若しく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 represents 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, preferably having 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. Specific examples include 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. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
In the formula (p2), 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 is The terminal of R ¹⁷ 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.

  Specific examples of the acetal type acid dissociable, dissolution inhibiting group include groups represented by the following formulas (p3-1) to (p3-12).

［式中、Ｒ^１３は水素原子またはメチル基であり、ｇは前記と同じである。］

[Wherein, R ¹³ represents a hydrogen atom or a methyl group, and g is the same as defined above. ]

  More specifically, examples of the structural unit (a1) include structural units represented by general formula (a1-0-1) shown below, structural units represented by general formula (a1-0-2) shown below, and the like. .

［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；Ｘ^１は酸解離性溶解抑制基であり；Ｙ^２は２価の連結基であり；Ｘ^２は酸解離性溶解抑制基である。］

[Wherein, R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; X ¹ is an acid dissociable, dissolution inhibiting group; Y ² is a divalent linking group; X ² is acid dissociable] It is a dissolution inhibiting group. ]

In general formula (a1-0-1), the lower alkyl group for R is the same as the lower alkyl group for R ⁸¹ in general formula (a0-1).
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).

Examples of the divalent linking group for Y ² include an alkylene group, a divalent aliphatic cyclic group, and a divalent linking group containing a hetero atom.
As the aliphatic cyclic group, those similar to the explanation of the “aliphatic cyclic group” can be used except that a group in which two or more hydrogen atoms are removed is used.
When Y ² is an alkylene group, it is preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms, and 1 to 3 carbon atoms. Most preferably it is.
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. .
When Y ² is a divalent linking group containing a hetero atom, examples of the divalent linking group containing a hetero atom include —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O—, —C (═O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group or an acyl group), —S—. , —S (═O) ₂ —, —S (═O) ₂ —O—, “—AO (oxygen atom) —B— (wherein A and B each independently have a substituent) A divalent hydrocarbon group that may be present.) ”And the like.

When Y ² is —NH—, the substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and more preferably 1 to 5 carbon atoms. It is particularly preferred that
When Y ² is “A—O—B”, A and B are each independently a divalent hydrocarbon group which may have a substituent.
The hydrocarbon group having “substituent” means that part or all of the hydrogen atoms in the hydrocarbon group are substituted with groups or atoms other than hydrogen atoms.

  The hydrocarbon group in A may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity.

The aliphatic hydrocarbon group for A may be saturated or unsaturated, and is usually preferably saturated.
Specific examples of the aliphatic hydrocarbon group for A include a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group containing a ring in the structure.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, still more preferably 2 to 5, and most preferably 2.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group, an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [— (CH ₂ ) ₃ -], tetramethylene group _{[- (CH 2) 4 -} ], a pentamethylene group _{[- (CH 2) 5 -} ] , and the like.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ). _{2 -, - C (CH 3} ) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as - Alkylethylene groups such as CH (CH ₃ ) CH ₂ —, —CH (CH ₃ ) CH (CH ₃ ) —, —C (CH ₃ ) ₂ CH ₂ —, —CH (CH ₂ CH ₃ ) CH ₂ —; Alkyl trimethylene groups such as —CH (CH ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CH ₃ ) CH ₂ —; —CH (CH ₃ ) CH ₂ CH ₂ CH ₂ —, —CH ₂ CH (CH _{3) CH} 2 CH ₂ - alkyl, such as alkyl tetramethylene group such as Such as an alkylene group, and the like. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The chain-like aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include 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.

Examples of the aliphatic hydrocarbon group containing a ring include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and the cyclic aliphatic hydrocarbon group described above as a chain-like aliphatic group. And a group bonded to the terminal of the aromatic hydrocarbon group or interposed in the middle of the chain-like aliphatic hydrocarbon group.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic group, a group in which two hydrogen atoms have been removed from a monocycloalkane having 3 to 6 carbon atoms is preferable, and examples of the monocycloalkane include cyclopentane and cyclohexane.
As the polycyclic group, a group in which two hydrogen atoms are removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, tetra And cyclododecane.
The cyclic aliphatic hydrocarbon group 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.

  A is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 2 to 5 carbon atoms, and most preferably an ethylene group.

Examples of the hydrocarbon group for B include the same divalent hydrocarbon groups as those described above for A.
B is preferably a linear or branched aliphatic hydrocarbon group, particularly preferably a methylene group or an alkylmethylene group.
The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.

  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２価の連結基を表し；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 a divalent linking group; R is the same as defined above; R ¹ ′ and R ² ′ each independently represent a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms. ]

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.
In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

As the structural unit (a1) in the present invention, at least two types may be used, and three or more types may be used in combination. By having at least two types, in the formation of a resist pattern containing the component (A1), lithography properties such as resolution are further improved.
In the present invention, the structural unit (a1-0-11) represented by the following general formula (a1-0-11) as the structural unit (a1), particularly from the point of excellent lithography properties such as PEB margin, It preferably has at least one selected from the group consisting of structural units (a1-0-12) represented by the structural units represented by general formula (a1-0-12) shown below and has 2 or more types. It is more preferable.
In this case, the at least two structural units (a1) are a structural unit represented by the general formula (a1-0-11) and a structural unit represented by the following general formula (a1-0-12). It may be comprised only from what is selected from the group which consists of the structural unit represented (a1-0-12), At least 1 sort (s) of these structural units, and the structural unit (a1) which does not correspond to these For example, a combination with a structural unit (a1-0-13) represented by general formula (a1-0-13) described later is preferable from the viewpoint of lithography properties such as resolution.
Note that the PEB margin means that a desired resist pattern size can be stably formed without depending on the temperature change even if there is a slight deviation in the temperature during PEB when forming a resist pattern.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり、Ｒ^２１は直鎖状または分岐鎖状のアルキル基であり、Ｒ^２２は、当該Ｒ^２２が結合した炭素原子と共に脂肪族単環式基を形成する基であり、Ｒ^２３は直鎖状または分岐鎖状のアルキル基であり、Ｒ^２４は、当該Ｒ^２４が結合した炭素原子と共に脂肪族単環式基を形成する基であり、前記Ｒ^２２と前記Ｒ^２４とは互いに異なる。］

Wherein R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, R ²¹ is a linear or branched alkyl group, and R ²² is , R ²² is a group that forms an aliphatic monocyclic group together with the carbon atom to which R ²² is bonded, R ²³ is a linear or branched alkyl group, and R ²⁴ is a carbon to which R ²⁴ is bonded. It is a group that forms an aliphatic monocyclic group together with atoms, and R ²² and R ²⁴ are different from each other. ]

In each formula, the description of R is the same as described above.
In formula (a1-0-11), examples of the alkyl group for R ²¹ include the same alkyl groups as those described above for R ¹⁴ in formulas (1-1) to (1-9). Group is preferred, and ethyl group is most preferred.
R ²² is, the aliphatic monocyclic group formed together with the carbon atom to which R ²² is bonded, the same aliphatic cyclic groups as those in the tertiary alkyl ester-type acid dissociable, monocyclic The thing similar to what is a formula group is mentioned. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane is preferably a 3-11 membered ring, more preferably a 3-8 membered ring, still more preferably a 4-6 membered ring, particularly preferably a 5 or 6 membered ring, and a 6 membered ring. Is most preferred.
In the monocycloalkane, a part of carbon atoms constituting the ring may or may not be substituted with an etheric oxygen atom (—O—).
The monocycloalkane may have a lower alkyl group, a fluorine atom or a fluorinated alkyl group as a substituent.
Examples of R ²² constituting the aliphatic monocyclic group include a linear alkylene group in which an etheric oxygen atom (—O—) may be interposed between carbon atoms.

Specific examples of the structural unit represented by the formula (a1-0-11) include structural units represented by the formulas (a1-1-16) to (a1-1-23). Among these, the following formula (a1−16) including structural units represented by formulas (a1-1-16) to (a1-1-17) and (a1-1-20) to (a1-1-23) The structural unit represented by 1-02) is preferred.
In the formula, h is preferably 1 or 2, and most preferably 2.

（式中、Ｒ、Ｒ^２１はそれぞれ前記と同じであり、ｈは１〜３の整数である。）

(In the formula, R and R ²¹ are the same as defined above, respectively, and h is an integer of 1 to 3.)

In formula (a1-0-12), as the linear or branched alkyl group for R ²³ , the linear or branched alkyl group for R ²¹ in formula (a1-0-11) is used. The thing similar to what was mentioned by said is mentioned, An ethyl group or a methyl group is preferable, and a methyl group is the most preferable.
In formula ^{(a1-0-12), R 24 is,} the aliphatic monocyclic group formed together with the carbon atom ^{to which R 24} is bonded, the formula (a1-0-11) aliphatic ^{R 22} in the single The thing similar to what was mentioned by the cyclic group is mentioned, A 5- or 6-membered ring is preferable and a 5-membered ring is the most preferable.

Specific examples of the structural unit represented by the formula (a1-0-12) include structural units represented by the formulas (a1-1-16) to (a1-1-23). Among these, the above formula (a1- The structural unit represented by 1-02) is preferred.
In the formula, h is preferably 1 or 2, and most preferably 1.

In the present invention, R ²² and R ²⁴ form different aliphatic monocyclic groups. When the positive resist composition of the present invention contains (A1) component having two different aliphatic monocyclic groups, the resolution, shape and LWR of the resist pattern are improved, Also, the PEB margin can be made wider. Here, the PEB margin means that even when there is a slight deviation in the temperature during PEB when forming a resist pattern, the desired resist pattern size can be stably formed without depending on the temperature change.

  In the present invention, particularly from the viewpoint of resolution, the structural unit (a1) is selected from the group consisting of structural units (a1-0-13) represented by the following general formula (a1-0-13). It is preferable to have at least one selected.

［式中、Ｒ^１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、Ａ_０１は２価の連結基であり、Ｂ_０１は２価の連結基であり、Ｒ^２は酸解離性溶解抑制基である。］

[Wherein, R ¹ is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, A ₀₁ is a divalent linking group, B ₀₁ is a divalent linking group, and R ² is an acid-dissociable group. It is a dissolution inhibiting group. ]

In formula (a1-0-13), R ¹ is the same as R.
Examples of the divalent linking group for A ₀₁ include a divalent hydrocarbon group which may have a substituent and a divalent group containing a hetero atom.
The hydrocarbon group having “substituent” means that part or all of the hydrogen atoms in the hydrocarbon group are substituted with groups or atoms other than hydrogen atoms.
The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
The aliphatic hydrocarbon group for A ₀₁ may be saturated or unsaturated, and is usually preferably saturated.

More specifically, examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, and the like.
The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, still more preferably 1 to 5, and most preferably 1 to 2.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group [—CH ₂ —], an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [ — (CH ₂ ) ₃ —], tetramethylene group [— (CH ₂ ) ₄ —], pentamethylene group [— (CH ₂ ) ₅ —] and the like can be mentioned.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ). _{2 -, - C (CH 3} ) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as - _{CH (CH 3) CH 2 -} , - CH (CH 3) CH (CH 3) -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - CH (CH 2 Alkylethylene groups such as CH ₃ ) CH ₂ —; alkyltrimethylene groups such as —CH (CH ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CH ₃ ) CH ₂ —; —CH (CH ₃ ) CH _{2 CH 2 CH 2 -, - CH} 2 CH (CH 3) CH 2 CH 2 - , etc. And alkyl alkylene groups such as Le Kill tetramethylene group. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The chain-like aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include 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.

Examples of the aliphatic hydrocarbon group containing a ring include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and the cyclic aliphatic hydrocarbon group described above as a chain-like aliphatic group. And a group bonded to the terminal of the aromatic hydrocarbon group or interposed in the middle of the chain-like aliphatic hydrocarbon group.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic group, a group in which two hydrogen atoms have been removed from a monocycloalkane having 3 to 6 carbon atoms is preferable, and examples of the monocycloalkane include cyclopentane and cyclohexane. As the polycyclic group, a group in which two hydrogen atoms are removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, tetra And cyclododecane.
The cyclic aliphatic hydrocarbon group 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 “heteroatom” in the divalent group containing a heteroatom is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.
Examples of the divalent group containing a hetero atom include —O—, —C (═O) —, —C (═O) —O—, —NH—, —NR ⁰⁴ (R ⁰⁴ is an alkyl group) — , —NH—C (═O) —, ═N—, a combination of at least one of these and the divalent hydrocarbon group, and the like.

A ₀₁ is preferably a divalent hydrocarbon group which may have a substituent, more preferably a linear aliphatic hydrocarbon group, and still more preferably a linear alkylene group. Among these, a linear alkylene group having 1 to 5 carbon atoms is preferable, and a methylene group and an ethylene group are most preferable.

_Examples of the divalent linking group for B ₀₁ include the same divalent linking groups as those described above for A.
B ₀₁ is preferably a divalent hydrocarbon group which may have a substituent, more preferably a linear aliphatic hydrocarbon group, and even more preferably a linear alkylene group. Among these, a linear alkylene group having 1 to 5 carbon atoms is preferable, and a methylene group and an ethylene group are most preferable.

R ² 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.

  As the structural unit represented by the formula (a1-0-13), preferred are structural units represented by the following general formula (a1-0-13-1) or (a1-0-13-2). preferable. Among these, the structural unit represented by the formula (a1-0-13-1) is preferable, and the structural units represented by the formulas (a1-3-29) to (a1-3-30) are particularly preferable.

［式中、ＲおよびＲ^１４はそれぞれ前記と同じであり、Ｒ^２０は水素原子またはメチル基であり、ａは１〜１０の整数であり、ｂは１〜１０の整数であり、ｔは０〜３の整数である。］

[Wherein, R and R ¹⁴ are the same as defined above, R ²⁰ is a hydrogen atom or a methyl group, a is an integer of 1 to 10, b is an integer of 1 to 10, and t is 0. It is an integer of ~ 3. ]

a is preferably an integer of 1 to 5, and 1 or 2 is particularly preferable.
b is preferably an integer of 1 to 5, and 1 or 2 is particularly preferable.
t is preferably an integer of 1 to 3, and 1 or 2 is particularly preferable.

  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. By setting it as the above range, lithography properties such as LWR and resist pattern shape are further improved.

<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, as the lactone-containing monocyclic group, a group in which one hydrogen atom is removed from a 4- to 6-membered ring lactone, for example, a group in which one hydrogen atom is removed from β-propionolactone, or γ-butyrolactone. Examples thereof include a group in which one hydrogen atom has been removed, and a group in which one hydrogen atom has been removed from δ-valerolactone. 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’はそれぞれ独立に水素原子、炭素数１〜５のアルキル基、炭素数１〜５のアルコキシ基または−ＣＯＯＲ”であり、Ｒ”は水素原子またはアルキル基であり；Ｒ^２９は単結合または２価の連結基であり、ｓ”は０または１〜２の整数であり；Ａ”は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子であり；ｍは０または１の整数である。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; R ′ each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, or —COOR; R "is a hydrogen atom or an alkyl group; R ²⁹ is a single bond or a divalent linking group; s" is 0 or an integer of 1 to 2; A "is an oxygen atom or a sulfur atom. An alkylene group having 1 to 5 carbon atoms, an oxygen atom or a sulfur atom, and m is an integer of 0 or 1. ]

R in the general formulas (a2-1) to (a2-5) is the same as R in the structural unit (a1).
Examples of the alkyl group having 1 to 5 carbon atoms of R ′ include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group.
Examples of the alkoxy group having 1 to 5 carbon atoms of R ′ include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group.
R ′ is preferably a hydrogen atom in view of industrial availability.
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 Specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Etc.
As A ″, an alkylene group having 1 to 5 carbon atoms or —O— is preferable, and —O— is most preferable.
R ²⁹ is a single bond or a divalent linking group. The divalent linking group is the same as the divalent linking group described for Y ² in the general formula (a1-0-2), and among them, an alkylene group and an ester bond (—C (═O ) -O-) or a combination thereof. The alkylene group as the divalent linking group for R ²⁹ is more preferably a linear or branched alkylene group. Specifically, the same as the linear alkylene group and the branched alkylene group mentioned as the aliphatic hydrocarbon group for A in Y ² can be used.
s ″ is preferably an integer of 1 to 2.
Specific examples of the structural units represented by the general formulas (a2-1) to (a2-5) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

In the component (A1), as the structural unit (a2), one type may be used alone, or two or more types may be used in combination.
In the present invention, the component (A1) is preferably at least one selected from the group consisting of structural units represented by the general formulas (a2-1) to (a2-5) as the structural unit (a2). At least one selected from the group consisting of structural units represented by general formulas (a2-1) to (a2-3) is more preferable. Among them, chemical formulas (a2-1-1), (a2-2-1), (a2-2-7), (a2-3-1), (a2-3-5), chemical formula (a2-2-2-), It is preferable to use at least one selected from the group consisting of structural units represented by 12) to (a2-2-17), and represented by chemical formula (a2-1-1) and chemical formula (a2-2-14) Most preferably, at least one selected from the group consisting of the structural units represented is used.

  The proportion of the structural unit (a2) in the component (A1) is such that the resist film formed using the positive resist composition containing the component (A1) adheres to a support such as a substrate, and the developer. From the standpoint of excellent affinity and the like, it is preferably from 5 to 70 mol%, more preferably from 10 to 65 mol%, further preferably from 20 to 65 mol%, based on all structural units constituting the component (A1). Preferably, 20 to 45 mol% is most preferable. By setting it as the above range, the adhesion property of the resist composition to the substrate and the lithography properties such as LWR and resist pattern shape are further improved.

<Structural unit (a3)>
In the present invention, the component (A1) is an acrylic ester containing a polar group-containing aliphatic hydrocarbon group in addition to the structural unit (a0), the structural unit (a1), and the structural unit (a2). It is preferable to have a derived structural unit (a3).
When the component (A1) has the structural unit (a3), the hydrophilicity of the component (A) 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.
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 monocyclic or polycyclic aliphatic hydrocarbon group (cyclic group). ). As the formula group, for example, a resin for a resist composition for ArF excimer laser can be appropriately selected and used from among many proposed groups. The cyclic group preferably has 5 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. When the hydrocarbon group is a polycyclic group, a structural unit represented by the following formula (a3-1), a structural unit represented by (a3-2), (a3-3) ) Is preferable.

（式中、Ｒは前記に同じであり、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. These preferably have a 2-norbornyl group or a 3-norbornyl group 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.
The proportion of the structural unit (a3) in the component (A1) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, based on all structural units constituting the component (A1). More preferred is ˜25 mol%.

<Other structural units>
The component (A1) may contain other structural units (hereinafter referred to as structural unit (a4)) other than the structural units (a0) 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 (a0) to (a3) described above. 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 a non-acid-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) is preferably 1 to 30 mol% with respect to the total of all the structural units constituting the component (A1). -20 mol% is more preferable.

  The proportion of the component (A1) in the component (A) is preferably 25% by mass or more, more preferably 50% by mass, further preferably 75% by mass, and 100% by mass with respect to the total mass of the component (A). May be. When the ratio is 25% by mass or more, effects such as lithography characteristics are improved.

  In the component (A), as the copolymer (A1), one type may be used alone, or two or more types may be used in combination.

  In the present invention, the copolymer (A1) is preferably one containing a combination of structural units such as the following formulas (A1-11) to (A1-15).

［式中、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。ａ”、ｂ”は１〜３の整数であり；Ｒ^１０’、Ｒ^１１’は低級アルキル基である。］

[Wherein, R is the same as defined above, and a plurality of R may be the same or different. a ″ and b ″ are integers of 1 to 3; R ^{10 ′} and R ^{11 ′} are lower alkyl groups. ]

［式中、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。ａ”、ｂ”、ｃ”は前記と同じであり；Ａ”は前記と同じであり、Ｒ^１０’、Ｒ^１１’は低級アルキル基である。］

[Wherein, R is the same as defined above, and a plurality of R may be the same or different. a ″, b ″ and c ″ are the same as above; A ″ is the same as above, and R ^{10 ′} and R ^{11 ′} are lower alkyl groups. ]

［式中、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。ａ”、ｂ”は前記と同じであり；Ｒ^１１は前記と同じであり；Ｒ^２１は前記と同じであり；ｈは前記と同じである。］

[Wherein, R is the same as defined above, and a plurality of R may be the same or different. a ″, b ″ are the same as above; R ¹¹ is the same as above; R ²¹ is the same as above; h is the same as above. ]

［式中、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。ａ”、ｂ”は前記と同じであり；ａ、ｂは前記と同様であり、Ｒ^１４は前記と同じであり；Ｒ^２１は前記と同じであり；ｈは前記と同じである。］

[Wherein, R is the same as defined above, and a plurality of R may be the same or different. a ″ and b ″ are the same as above; a and b are the same as above; R ¹⁴ is the same as above; R ²¹ is the same as above; h is the same as above. ]

［式中、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。ａ”、ｂ”は１〜３の整数であり；Ｒ^１０’、Ｒ^１１’は低級アルキル基である。］

[Wherein, R is the same as defined above, and a plurality of R may be the same or different. a ″ and b ″ are integers of 1 to 3; R ^{10 ′} and R ^{11 ′} are lower alkyl groups. ]

［式中、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。ａ”、ｂ”は１〜３の整数であり；Ｒ^１０’、Ｒ^１１’は低級アルキル基である。］

[Wherein, R is the same as defined above, and a plurality of R may be the same or different. a ″ and b ″ are integers of 1 to 3; R ^{10 ′} and R ^{11 ′} are lower alkyl groups. ]

［式中、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。ａ”、ｂ”は１〜３の整数であり；Ｒ^１０’、Ｒ^１１’は低級アルキル基である。］

[Wherein, R is the same as defined above, and a plurality of R may be the same or different. a ″ and b ″ are integers of 1 to 3; R ^{10 ′} and R ^{11 ′} are lower alkyl groups. ]

［式中、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。ａ”、ｂ”は前記と同じである。］

[Wherein, R is the same as defined above, and a plurality of R may be the same or different. a ″ and b ″ are the same as described above. ]

In formula (A1-11), formula (A1-12), and formula (A1-15) to formula (A1-17), the lower alkyl group for R ^{10 ′ is} the same as the lower alkyl group for R, and Group or ethyl group is preferred, and ethyl group is most preferred.
In formula (A1-11), formula (A1-12), and formula (A1-15) to formula (A1-17), the lower alkyl group for R ^{11 ′ is} the same as the lower alkyl group for R, and Group or ethyl group is preferred, and methyl group is most preferred.

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
A commercially available monomer may be used as the monomer for deriving each structural unit, or the monomer may be synthesized using a known method.

  For example, the monomer for deriving the structural unit (a1-0-13) includes a compound (I) represented by the following general formula (I).

［式中、Ｒ^１、Ａ_０１、Ｂ_０１、Ｒ^２はそれぞれ前記と同じである。］

[Wherein, R ¹ , A ₀₁ , B ₀₁ and R ² are the same as defined above. ]

Compound (I) is not particularly limited, and can be produced using a conventionally known method.
For example, compound (I) can be produced by the production method (1) shown below.
Production method (1): a compound represented by the following general formula (I-1) (hereinafter referred to as compound (I-1)) and a compound represented by the following general formula (I-2) (hereinafter referred to as compound) (I-2)) is reacted to obtain a compound represented by the following general formula (I-3) (hereinafter referred to as compound (I-3)) (hereinafter referred to as the first step). And compound (I-3) and a compound represented by the following general formula (I-4) (hereinafter referred to as compound (I-4)) to obtain compound (I) (hereinafter referred to as “compound”). A manufacturing method including the second step).

［式中、Ｒ^１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、Ａ_０１は２価の連結基であり、Ｂ_０１は２価の連結基であり、Ｒ^２は酸解離性溶解抑制基であり、Ｘ^１１およびＸ^１２はそれぞれ独立してハロゲン原子である。］

[Wherein, R ¹ is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, A ₀₁ is a divalent linking group, B ₀₁ is a divalent linking group, and R ² is an acid-dissociable group. It is a dissolution inhibiting group, and X ¹¹ and X ¹² are each independently a halogen atom. ]

^{_{R 1, A 01, B 01}} , R 2 in the formula (I-1) ~ (I -4) , respectively, ^R 1 in the general formula _{(I), A 01, B} 01, the same as ^{R 2} It is.
X ¹¹ and X ¹² are each independently a halogen atom. Examples of the halogen atom include a bromine atom, a chlorine atom, an iodine atom, and a fluorine atom.
As the halogen atom for X ¹¹ or X ¹² , a chlorine atom or a bromine atom is preferable because of excellent reactivity.

"First step"
Compound (I-1) and compound (I-2) can be reacted by a known method. For example, the method of making compound (I-1) and compound (I-2) contact in reaction solvent in presence of a base is mentioned. This method can be carried out, for example, by adding compound (I-2) to a solution in which compound (I-1) is dissolved in a reaction solvent in the presence of a base.
As compound (I-1) and compound (I-2), commercially available compounds may be used or synthesized.
Examples of the compound (I-2) include 2-methyl-2-adamantyloxycarbonylmethyl chloride, 2-ethyl-2-adamantyloxycarbonylmethyl chloride, 1-methyl-1-cyclohexyloxycarbonylmethyl chloride, 1-ethyl-1 -Cyclohexyloxycarbonylmethyl chloride, 1-methyl-1-cyclopentyloxycarbonylmethyl chloride, 1-ethyl-1-cyclopentyloxycarbonylmethyl chloride and the like.
Any reaction solvent may be used as long as it can dissolve the starting compounds (I-1) and (I-2). Specifically, tetrahydrofuran (THF), acetone, dimethylformamide (DMF), dimethylacetamide , Dimethyl sulfoxide (DMSO), acetonitrile and the like.
Examples of the base include inorganic bases such as sodium hydride and K ₂ CO ₃ ; organic bases such as triethylamine, 4-dimethylaminopyridine (DMAP) and pyridine. In the first step, K ₂ CO ₃ is particularly preferably used.
The amount of compound (I-2) added is preferably about 1 to 100 moles, more preferably 1 to 50 moles, with respect to compound (I-1).
0-50 degreeC is preferable and, as for reaction temperature, 5-40 degreeC is more preferable.
The reaction time varies depending on the reactivity and reaction temperature of the compound (I-1) and the compound (I-2), but usually 1 to 24 hours are preferable, and 3 to 12 hours are more preferable.

  After completion of the reaction, the reaction solution may be used in the next step as it is, or the compound (I-3) in the reaction solution may be isolated and purified. For isolation and purification, conventionally known methods can be used. For example, concentration, solvent extraction, crystallization, recrystallization, chromatography and the like can be used alone or in combination of two or more.

"Second step"
The method for reacting compound (I-3) with compound (I-4) is not particularly limited. For example, the presence of a base in the solution in which compound (I-3) obtained in the first step is dissolved Below, the method of adding a compound (I-4) is mentioned.
As the solution in which the compound (I-3) is dissolved, the reaction solution obtained in the first step may be used as it is, and the compound (I-3) isolated and purified from the reaction solution is dissolved in the reaction solvent. A solution may be used.
Any reaction solvent may be used as long as it can dissolve the raw material compound (I-3), and examples thereof include the same reaction solvents as those mentioned in the first step.
Examples of the base include the same bases as those mentioned in the first step. In the first step, triethylamine is particularly preferably used.
The amount of compound (I-4) to be added is preferably about 1 to 2 moles, more preferably 1 to 1.5 moles, relative to compound (I-3).
The reaction temperature is preferably 0 to 50 ° C, more preferably 5 to 40 ° C, and most preferably a reaction at room temperature.
The reaction time varies depending on the reactivity of the compounds (I-3) and (I-4), the reaction temperature, and the like, but usually 1 to 24 hours are preferable, and 3 to 12 hours are more preferable.

After completion of the reaction, the compound (I) in the reaction solution may be isolated and purified. For isolation and purification, conventionally known methods can be used. For example, concentration, solvent extraction, crystallization, recrystallization, chromatography and the like can be used alone or in combination of two or more.
The structure of the compound obtained in the above step is as follows: ¹ H-nuclear magnetic resonance (NMR) spectrum method, ¹³ C-NMR spectrum method, ¹⁹ F-NMR spectrum method, infrared absorption (IR) spectrum method, mass spectrometry (MS) method. It can be confirmed by general organic analysis methods such as elemental analysis and X-ray crystal diffraction.

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but is preferably 2000 to 50000, more preferably 3000 to 30000, and 5000 to 20000. Most preferred. If it is smaller than the upper limit of this range, there is sufficient solubility in a resist solvent to be used as a resist, and if it is larger than 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.

In the resist composition of the present invention, as the component (A), a base material component (hereinafter referred to as the component (A2)) that does not correspond to the component (A1) and whose solubility in an alkaline developer is increased by the action of an acid. You may contain.
The component (A2) is not particularly limited, and many conventionally known base components for chemically amplified positive resist compositions (for example, for ArF excimer laser, for KrF excimer laser (preferably ArF) A base resin such as for excimer laser) may be arbitrarily selected and used. For example, the base resin for ArF excimer laser includes a resin having the structural unit (a1) as an essential structural unit and optionally further including the structural units (a2) to (a4).
(A2) A component may be used individually by 1 type and may be used in combination of 2 or more type.

  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>
The component (B) is not particularly limited, 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, poly (bissulfonyl) diazomethanes, and the like. 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^１”〜Ｒ^３”，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；式（ｂ−１）におけるＲ^１”〜Ｒ^３”のうち、いずれか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もよく；Ｒ^４”は、置換基を有していても良いアルキル基、ハロゲン化アルキル基、アリール基、またはアルケニル基を表し；Ｒ^１”〜Ｒ^３”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 ¹ ″ to R ³ ″ and R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group; among R ¹ ″ to R ³ ″ in formula (b-1), Any two may be bonded to each other to form a ring together with the sulfur atom in the formula; R ⁴ ″ may be an optionally substituted alkyl group, halogenated alkyl group, aryl group, or alkenyl group; And at least one of R ¹ ″ to R ³ ″ represents an aryl group, and at least one of R ⁵ ″ to R ⁶ ″ represents an aryl group.]

In formula (b-1), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group. In addition, any two of R ¹ ″ to R ³ ″ in formula (b-1) may be bonded to each other to form a ring together with the sulfur atom in the formula.
Further, at least one of R ¹ ″ to R ³ ″ represents an aryl group. Of R ¹ ″ to R ³ ″, two or more are preferably aryl groups, and most preferably all R ¹ ″ to R ³ ″ are aryl groups.

The aryl group for R ¹ ″ to R ³ ″ 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, A tert-butoxy group is preferable, and a methoxy group and an ethoxy group are most preferable.
The halogen atom that may be substituted with the hydrogen atom of the aryl group is preferably a fluorine atom.

The alkyl group for R 1 ^{"~R 3",} 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.

When any two of R ¹ ″ to R ³ ″ in the formula (b-1) are bonded to each other to form a ring together with the sulfur atom in the formula, a 3 to 10 membered ring including the sulfur atom is formed. It is preferable that a 5- to 7-membered ring is formed.
When any two of R ¹ ″ to R ³ ″ in formula (b-1) are bonded to each other to form a ring together with the sulfur atom in the formula, the remaining one may be an aryl group preferable. Examples of the aryl group include the same aryl groups as R ¹ ″ to R ³ ″.

Preferable examples of the cation moiety of the compound represented by the formula (b-1) include cation moieties represented by the following formulas (I-1-1) to (I-1-10). Among these, those having a triphenylsulfonium skeleton such as a cation moiety represented by formulas (I-1-1) to (I-1-8) are preferable.
In the following formulas (I-1-9) to (I-1-10), R ⁹ and R ¹⁰ are each independently a phenyl group, naphthyl group or carbon number 1 to 5 which may have a substituent. An alkyl group, an alkoxy group, and a hydroxyl group.
u is an integer of 1 to 3, and 1 or 2 is most preferable.

R ⁴ ″ 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 ⁴ ″ 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 ⁴ ″ 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. A fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, 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 ⁴ ″ is preferably an aryl group having 6 to 20 carbon atoms.
The alkenyl group in R ⁴ ″ is preferably an alkenyl group having 2 to 10 carbon atoms.
In the above R ⁴ ″, “optionally substituted” means one of hydrogen atoms in the linear, branched or cyclic alkyl group, halogenated alkyl group, aryl group, or alkenyl group. It means that part or all may be substituted with a substituent (an atom or group other than a hydrogen atom).
The number of substituents in R ⁴ ″ may be one or two or more.

Examples of the substituent include, for example, a halogen atom, a hetero atom, an alkyl group, a formula: XQ ^1- [where Q ¹ is a divalent linking group containing an oxygen atom, and X has a substituent. And a hydrocarbon group having 3 to 30 carbon atoms. ] Etc. which are represented by these.
Examples of the halogen atom and alkyl group include the same groups as those described above for R ⁴ ″ 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.

X-Q 1 ^- In the group represented by, Q ¹ represents a divalent linking group containing an oxygen atom.
Q ¹ may contain an atom other than an oxygen atom. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, oxygen atoms, sulfur atoms, and nitrogen atoms.
Examples of the divalent linking group containing an oxygen atom include an oxygen atom (ether bond; —O—), an ester bond (—C (═O) —O—), and an amide bond (—C (═O) —NH. -), A carbonyl group (-C (= O)-), a non-hydrocarbon oxygen atom-containing linking group such as a carbonate bond (-O-C (= O) -O-); the non-hydrocarbon oxygen atom Examples include a combination of a containing linking group and an alkylene group.
Examples of the combination include —R ⁹¹ —O—, —R ⁹² —O—C (═O) —, —C (═O) —O—R ⁹³ —O—C (═O) — , R ^{91 to} R ⁹³ are each independently an alkylene group.) And the like.
The alkylene group for R ^{91 to} R ⁹³ is preferably a linear or branched alkylene group, and the alkylene group preferably has 1 to 12 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably 1 to 3 carbon atoms. preferable.
Specific examples of the alkylene group include a methylene group [—CH ₂ —]; —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ) ₂ —, —C ( _{CH 3) (CH 2 CH 3} ) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as ethylene group _[-CH 2 CH _2— ]; —CH (CH ₃ ) CH ₂ —, —CH (CH ₃ ) CH (CH ₃ ) —, —C (CH ₃ ) ₂ CH ₂ —, —CH (CH ₂ CH ₃ ) CH ₂ — and the like. Alkylethylene groups; trimethylene groups (n-propylene groups) [—CH ₂ CH ₂ CH ₂ —]; alkyls such as —CH (CH ₃ ) CH ₂ CH ₂ — and —CH ₂ CH (CH ₃ ) CH ₂ — trimethylene; tetramethylene group _[-CH 2 _CH 2 C _{2 CH 2 -]; - CH} (CH 3) CH 2 CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 CH 2 - alkyl tetramethylene group and the like; pentamethylene group _[-CH 2 _CH 2 CH ₂ CH ₂ CH ₂ —] and the like.
Q ¹ is preferably a divalent linking group containing an ester bond or an ether bond, and in particular, —R ⁹¹ —O—, —R ⁹² —O—C (═O) — or —C (═O) — O—R ⁹³ —O—C (═O) — is preferred.

In the group represented by XQ ^1- , the hydrocarbon group of X may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.
The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and most preferably 6 to 12. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aromatic hydrocarbon group include a hydrogen atom from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. Aryl groups such as aryl group, benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc., from which one is removed. 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.
The aromatic hydrocarbon group may have a substituent. For example, a part of carbon atoms constituting the aromatic ring of the aromatic hydrocarbon group may be substituted with a hetero atom, and the hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group is substituted with the substituent. May be.
Examples of the former include heteroaryl groups in which some of the carbon atoms constituting the ring of the aryl group are substituted with heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and aromatic hydrocarbons in the arylalkyl groups. Examples include heteroarylalkyl groups in which some of the carbon atoms constituting the ring are substituted with the above heteroatoms.
Examples of the substituent of the aromatic hydrocarbon group in the latter example include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
The alkyl group as a substituent of the aromatic hydrocarbon group is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. preferable.
The alkoxy group as a substituent of the aromatic hydrocarbon group is preferably an alkoxy group having 1 to 5 carbon atoms, and is a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, tert- A butoxy group is preferable, and a methoxy group and an ethoxy group are most preferable.
Examples of the halogen atom as a substituent for the aromatic hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent of the aromatic hydrocarbon group include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.

The aliphatic hydrocarbon group for X may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear, branched or cyclic.
In X, the aliphatic hydrocarbon group may have a part of the carbon atoms constituting the aliphatic hydrocarbon group substituted by a substituent containing a hetero atom, and the hydrogen atom constituting the aliphatic hydrocarbon group May be substituted with a substituent containing a hetero atom.
The “heteroatom” in X is not particularly limited as long as it is an atom other than a carbon atom and a hydrogen atom, and examples thereof include a halogen atom, an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom.
The substituent containing a hetero atom may be composed of only the hetero atom, or may be a group containing a group or atom other than the hetero atom.
Specific examples of the substituent for substituting a part of the carbon atom include —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O. —, —C (═O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group, an acyl group, etc.), —S—, —S (═O) ₂ —, — S (= O) ₂ —O— and the like can be mentioned. When the aliphatic hydrocarbon group is cyclic, these substituents may be included in the ring structure.
Specific examples of the substituent for substituting part or all of the hydrogen atoms include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), and a cyano group.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group, and a methoxy group or an ethoxy group. Is most preferred.
As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
As the halogenated alkyl group, a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc. And a group substituted with a halogen atom.

Examples of the aliphatic hydrocarbon group include a linear or branched saturated hydrocarbon group, a linear or branched monovalent unsaturated hydrocarbon group, or a cyclic aliphatic hydrocarbon group (aliphatic ring). Formula group) is preferred.
The linear saturated hydrocarbon group (alkyl group) preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group and the like.
The branched saturated hydrocarbon group (alkyl group) preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, Examples include 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.

As an unsaturated hydrocarbon group, it is preferable that carbon number is 2-10, 2-5 are preferable, 2-4 are preferable, and 3 is especially preferable. 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.
Among the above, the unsaturated hydrocarbon group is particularly preferably a propenyl group.

The aliphatic cyclic group may be a monocyclic group or a polycyclic group. The number of carbon atoms is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12.
Specifically, for example, a group in which one or more hydrogen atoms are removed from a monocycloalkane; a group in which one or more hydrogen atoms are removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, etc. Can be mentioned. More specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; one or more polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples include a group excluding a hydrogen atom.
When the aliphatic cyclic group does not contain a substituent containing a hetero atom in the ring structure, the aliphatic cyclic group is preferably a polycyclic group, and one or more hydrogen atoms from the polycycloalkane are substituted. Excluded groups are preferred, and most preferred are groups in which one or more hydrogen atoms have been removed from adamantane.
When the aliphatic cyclic group includes a substituent containing a hetero atom in the ring structure, examples of the substituent containing a hetero atom include —O—, —C (═O) —O—, —S—. , —S (═O) ₂ — and —S (═O) ₂ —O— are preferable. Specific examples of the aliphatic cyclic group include the following formulas (L1) to (L5), (S1) to (S4), and the like.

［式中、Ｑ”は炭素数１〜５のアルキレン基、−Ｏ−、−Ｓ−、−Ｏ−Ｒ^９４−または−Ｓ−Ｒ^９５−であり、Ｒ^９４およびＲ^９５はそれぞれ独立に炭素数１〜５のアルキレン基であり、ｍは０または１の整数である。］

[Wherein, Q ″ is an alkylene group having 1 to 5 carbon atoms, —O—, —S—, —O—R ⁹⁴ — or —S—R ⁹⁵ —, and R ⁹⁴ and R ⁹⁵ are each independently carbon. An alkylene group of 1 to 5 and m is an integer of 0 or 1.]

In the formula, examples of the alkylene group for Q ″, R ⁹⁴ and R ⁹⁵ include the same alkylene groups as those described above for R ^{91 to} R ⁹³ .
In these aliphatic cyclic groups, a part of hydrogen atoms bonded to carbon atoms constituting the ring structure may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
As said alkyl group, a C1-C5 alkyl group is preferable, and it is especially preferable that they are a methyl group, an ethyl group, a propyl group, n-butyl group, and a tert- butyl group.
Examples of the alkoxy group and the halogen atom are the same as those exemplified as the substituent for substituting part or all of the hydrogen atoms.

In the present invention, X is preferably a cyclic group which may have a substituent. The cyclic group may be an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a substituent. It is preferably an aliphatic cyclic group that may be used.
The aromatic hydrocarbon group is preferably a naphthyl group which may have a substituent or a phenyl group which may have a substituent.
As the aliphatic cyclic group which may have a substituent, a polycyclic aliphatic cyclic group which may have a substituent is preferable. The polycyclic aliphatic cyclic group is preferably a group obtained by removing one or more hydrogen atoms from the polycycloalkane, the above (L2) to (L5), (S3) to (S4), and the like.

In the present invention, ^{R 4} "is ^{X-Q 1} - as a substituent when having, ^{R 4"} as ^{the, X-Q 1 -Y 1 -} [ wherein, ^{Q 1} and X are as defined above, Y ¹ is an alkylene group having 1 to 4 carbon atoms which may have a substituent or a fluorinated alkylene group having 1 to 4 carbon atoms which may have a substituent. ] Is preferable.
In the group represented by XQ ¹ -Y ^1- , the alkylene group for Y ¹ includes the same alkylene groups as those described above for Q ¹ having 1 to 4 carbon atoms.
Examples of the fluorinated alkylene group include groups in which part or all of the hydrogen atoms of the alkylene group have been substituted with fluorine atoms.
As Y ^1, _{specifically, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF (CF 2 CF 3) -, _{-C (CF 3) 2 -,} - CF 2 CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF ₃ ) —, —C (CF ₃ ) ₂ CF ₂ —, —CF (CF ₂ CF ₃ ) CF ₂ —, —CF (CF ₂ CF ₂ CF ₃ ) —, —C (CF ₃ ) (CF _{2 CF 3) -; - CHF} -, - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -, - CH (CF 3) CH 2 -, - CH (CF 2 _{CF 3) -, - C (} CH 3) (CF 3) -, - CH 2 CH 2 CH 2 CF 2 -, - C H ₂ CH ₂ CF ₂ CF ₂ —, —CH (CF ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CF ₃ ) CH ₂ —, —CH (CF ₃ ) CH (CF ₃ ) —, —C ( _{CF 3) 2 CH 2 -;} - CH 2 -, - CH 2 CH 2 -, - CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 -, - CH (CH 2 CH 3) -, - _{C (CH 3) 2 -,} - CH 2 CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 -, - CH (CH 3) CH _{(CH 3) -, - C} (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - CH (CH 2 CH 2 CH 3) -, - C (CH 3) (CH 2 CH ₃ ) — and the like.

Y ¹ is preferably a fluorinated alkylene group, and particularly preferably a fluorinated alkylene group in which the carbon atom bonded to the adjacent sulfur atom is fluorinated. Examples of such fluorinated alkylene _{group, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF 2 CF 2 CF 2 CF 2 _{-, - CF (CF 3)} CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF 3) -, - C (CF 3) 2 CF 2 -, _{-CF (CF 2 CF 3) CF} 2 -; - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -; - CH 2 CH 2 CH 2 CF 2 -, - CH ₂ CH ₂ CF ₂ CF ₂ —, —CH ₂ CF ₂ CF ₂ CF ₂ — and the like can be mentioned.
Of _{these, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, or chromatography _CH 2 CF ₂ - is _{preferable, -CF 2 -, - CF 2} CF 2 -, or -CH ₂ CF ₂ - is more preferable, _{-CH 2} CF 2 - is particularly preferred.

The alkylene group or fluorinated alkylene group may have a substituent. An alkylene group or a fluorinated alkylene group has a “substituent” means that part or all of the hydrogen atom or fluorine atom in the alkylene group or fluorinated alkylene group is substituted with an atom or group other than a hydrogen atom and a fluorine atom. Means that
Examples of the substituent that the alkylene group or fluorinated alkylene group may have include an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a hydroxyl 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 ¹ ″ to R ³ ″ can be used.
Examples of the alkyl group for R ⁵ ″ to R ⁶ ″ include the same as the alkyl group for R ¹ ″ to R ³ ″.
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 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) phenyl sulphonium trifluoromethane sulphonate, its heptafluoropropane sulphonate or its nonafluorobutane sulphonate; 1-phenyltetrahydrothiophenium trifluoromethane sulphonate, its heptafluoropropane sulphonate Or nonafluorobutanesulfonate thereof; 1- (4-methylphenyl) ) Tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1- (4-ethoxynaphthalene-1- Yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonaflu 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1-phenyltetrahydrothiopyranium trifluoromethanesulfonate , Its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (4-hydroxyphenyl) tetrahydrothiopyranium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl -4-Hydroxyphenyl) tetrahydrothiopyranium trifluoromethanesulfonate, its heptafluoropropanes Honeto or nonafluorobutanesulfonate; 1- (4-methylphenyl) trifluoromethanesulfonate tetrahydrothiophenium Pila chloride, heptafluoropropane sulfonate or its nonafluorobutane sulfonate, and the like.
Moreover, the onium salt which replaced the anion part of these onium salts with alkyl sulfonates, such as methanesulfonate, n-propanesulfonate, n-butanesulfonate, n-octanesulfonate, can also be used.
Moreover, the onium salt which replaced the anion part of these onium salts by the anion part represented by either of following formula (b1)-(b8) can also be used.

［式中、ｐはそれぞれ独立に１〜３の整数であり、ｑ１〜ｑ３はそれぞれ独立に１〜５の整数であり、ｒ０は０〜３の整数であり、ｇは１〜２０の整数であり、Ｒ^７は置換基であり、ｎ１〜ｎ５はそれぞれ独立に０または１であり、ｖ１〜ｖ５はそれぞれ独立に０〜３の整数であり、ｗ１〜ｗ６はそれぞれ独立に０〜３の整数であり、Ｑ”は前記と同じである。］

[In the formula, p is each independently an integer of 1 to 3, q1 to q3 are each independently an integer of 1 to 5, r0 is an integer of 0 to 3, and g is an integer of 1 to 20. Yes, R ⁷ is a substituent, n1 to n5 are each independently 0 or 1, v1 to v5 are each independently an integer of 0 to 3, and w1 to w6 are each independently an integer of 0 to 3. And Q ″ is the same as above.]

Examples of the substituent for R ⁷ are the same as those described above as the substituent that the aliphatic hydrocarbon group may have and the substituent that the aromatic hydrocarbon group may have in X. Can be mentioned.
Code (r1, W1 to W6) attached to R ⁷ when is an integer of 2 or more, a plurality of the R ⁷ groups may be the same, respectively, it may be different.

  Moreover, as an onium salt type | system | group acid generator, in the said general formula (b-1) or (b-2), an anion part is represented by the following general formula (b-3) or (b-4). An onium salt-based acid generator replaced with can also be used (the cation moiety is the same as (b-1) or (b-2)).

［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

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, preferably 3 to 5 carbon atoms, Most preferably, it has 3 carbon atoms.
Y ″ and Z ″ are each independently a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkyl group has 1 to 10 carbon atoms, preferably Has 1 to 7 carbon atoms, more preferably 1 to 3 carbon atoms.
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.

  Moreover, the sulfonium salt which has a cation part represented by the following general formula (b-5) or (b-6) can also be used as an onium salt type | system | group acid generator.

［式中、Ｒ^４１〜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_１〜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。］

[Wherein R ^{41 to} R ⁴⁶ are each independently an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxyl group or hydroxyalkyl group; n _{1 to} n ₅ are each independently an integer of 0 to 3; There, _{n 6} is an integer of 0-2. ]

In R ^{41 to} R ⁴⁶ , 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, an ethyl group, a propyl group, an isopropyl group, 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 _{1 to} n ₆ attached to R ^{41 to} R ⁴⁶ are integers of 2 or more, the plurality of R ^{41 to} R ⁴⁶ may be the same or different.
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.
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-5) or (b-6) is not particularly limited, and is the same as the anion part of the onium salt acid generators proposed so far. It may be a thing. 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). The anion part represented by the general formula (b-3) or (b-4) and the like.

  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 heteroaryl groups in which some of the carbon atoms constituting the ring of these groups are substituted with heteroatoms such as oxygen, sulfur, and nitrogen atoms. 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 for 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]), WO2004 / 074242A2 (pages 65 to 85). The oxime sulfonate acid generators disclosed in Examples 1 to 40) of No. 1 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.

(B) As a component, these acid generators may be used individually by 1 type, and may be used in combination of 2 or more type.
In the present invention, it is preferable to use an onium salt acid generator having a fluorinated alkyl sulfonate ion as an anion as the component (B).
The content of the component (B) in the positive resist composition of the present invention is preferably 0.5 to 50 parts by mass and more preferably 1 to 40 parts by mass with respect to 100 parts by mass of the component (A). 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.

<Optional component>
The positive resist composition of the present invention may further contain a nitrogen-containing organic compound (D) (hereinafter referred to as “component (D)”) as an optional component.
The component (D) is not particularly limited as long as it acts as an acid diffusion controller, that is, a quencher that traps the acid generated from the component (B) by exposure, and a wide variety of components have already been proposed. Therefore, any known one may be used, and aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are particularly preferable. Here, the aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 20 carbon atoms.
Examples of the aliphatic amine include an amine (alkylamine or alkyl alcohol amine) or a cyclic amine in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 20 or less carbon atoms. .
Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di- -Dialkylamines such as n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-hexylamine, tri-n-pentylamine , Tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, tri-n-dodecylamine, etc .; diethanolamine, triethanolamine, diisopropanolamine Triisopropanolamine, di -n- octanol amine, tri -n- octanol amine, stearyl diethanolamine, alkyl alcohol amines such as lauryl diethanolamine. Among these, trialkylamine and / or alkyl alcohol amine are preferable.
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.
Examples of the aromatic amine include aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, diphenylamine, triphenylamine, and tribenzylamine.
Other aliphatic amines include tris (2-methoxymethoxyethyl) amine, tris {2- (2-methoxyethoxy) ethyl} amine, tris {2- (2-methoxyethoxymethoxy) ethyl} amine, tris {2 -(1-methoxyethoxy) ethyl} amine, tris {2- (1-ethoxyethoxy) ethyl} amine, tris {2- (1-ethoxypropoxy) ethyl} amine, tris [2- {2- (2-hydroxy Ethoxy) ethoxy} ethylamine and the like.
These may be used alone or in combination of two or more.
(D) component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component. By setting the content in the above range, the resist pattern shape, the stability over time, and the like are improved.

The positive resist composition of the present invention includes, as optional components, organic carboxylic acids, phosphorus oxoacids and derivatives thereof for the purpose of preventing sensitivity deterioration, improving the resist pattern shape, retention stability over time, etc. At least one compound (E) selected from the group consisting of (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.
(E) A component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

  The positive resist composition of the present invention further contains miscible additives as desired, for example, additional resins for improving the performance of the resist film, surfactants for improving coating properties, dissolution inhibitors, Plasticizers, stabilizers, colorants, antihalation agents, dyes, and the like can be added and contained as appropriate.

The positive 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, 2-heptanone;
Polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol;
Compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, monomethyl ether, monoethyl ether, monopropyl of the polyhydric alcohols or the compound having an ester bond Derivatives of polyhydric alcohols such as ethers, monoalkyl ethers such as monobutyl ether or compounds having an ether bond such as monophenyl ether [in these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME) Is preferred];
Cyclic ethers such as dioxane and esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate;
Aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, etc. be able to.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (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 is a concentration that can be applied to a substrate or the like and is appropriately set according to the coating film thickness. In general, the solid content concentration of the resist composition is 0. .5 to 20% by mass, preferably 1 to 15% by mass.

The positive resist composition of the present invention is a novel one that has not been known so far.
The positive resist composition of the present invention has good matching with the substrate, the resist pattern shape to be formed (for example, high rectangularity when line and space is formed, less tailing), and LWR (Line width roughness) is also good.
Here, “bottoming” means that when a resist pattern is formed using a positive resist composition, a part of the resist film in the exposed portion remains undissolved at the substrate interface, and the resist is formed. This is a phenomenon that the cross-sectional shape of the pattern becomes a skirt shape. The problem of tailing tends to occur particularly when a substrate in which the surface in contact with the resist film is made of a silicon-containing material, that is, a so-called hard mask is used. LWR is a phenomenon in which the line width of a line pattern becomes non-uniform when a resist pattern is formed using a resist composition, and the improvement becomes more important as the pattern becomes finer.
The reason why the above effect can be obtained is presumed as follows.
In the structural unit (a0), since the side chain having an alkali-soluble carboxyl group (—COOH) is relatively long, the side chain of the other structural unit of the component (A1) acts effectively without being buried in the side chain. It is possible. That is, since the carboxyl group of the structural unit (a0) is easily located on the surface of the polymer molecule composed of the component (A1), the alkaline developer of the component (A1) in the exposed area during development after exposure. Even if the acid generated from the acid generator is deactivated at the interface between the resist film and the substrate and the deprotection reaction in the component (A1) is inadequate, there is no tailing. Pattern can be obtained. Further, in combination with at least two kinds of structural units (a1), the structural unit (a0) has a relatively long side chain, so that in addition to the above-mentioned good developer solubility, the LWR has high resolution. It is considered that a resist pattern having a smaller shape and a better shape can be formed.
In addition, since the resist composition of the present invention has at least two structural units (a1), resolution and lithography properties (EL margin, LWR, etc.) can be improved. The reason is that the dissociation energies of the acid dissociation inhibiting groups in the at least two kinds of structural units (a1) are different from each other, and the contrast and the lithography characteristics with sufficient solubility in the alkali developer between the exposed area and the unexposed area. It is conceivable that the balance can be adjusted.
Here, when at least one of the at least two structural units (a1) is an acid dissociable, dissolution inhibiting group containing an aliphatic monocyclic group, the PEB margin can be improved. The reason for this is that if the acid dissociability-inhibiting group in (a1) is an aliphatic monocyclic group, the low nuclei generated after dissociation with an acid are more likely to volatilize, and the Tg (glass It is presumed that the variation of the transition temperature is reduced, and it is considered that the dimension and shape of the formed pattern are less affected by heat.
Further, when at least one of the at least two structural units (a1) has the structural unit (a1-0-13), the tip of a relatively long side chain of the structural unit (a1-0-13) Since there is an acid dissociable, dissolution inhibiting group, it can interact with the component (B) in particular, and the distribution of the component (B) in the resist film can be made more uniform. Can be formed.
In addition, since the resist composition of the present invention has the structural unit (a2), the adhesion of the resist film to a support such as a substrate becomes better, and when the cyclic group is bulky, etching resistance is obtained. It is conceivable that will be further improved.

≪Resist pattern formation method≫
The resist pattern forming method of the present invention comprises a step of forming a resist film on a support using the positive resist composition of the present invention, a step of exposing the resist film, and developing the resist film to form a resist. Forming a pattern.
The resist pattern forming method of the present invention can be performed, for example, as follows.
That is, first, the positive resist composition of the present invention is applied onto a support with a spinner or the like, and pre-baked (post-apply bake (PAB)) for 40 to 120 seconds under a temperature condition of 80 to 150 ° C., preferably For 60 to 90 seconds, using an exposure apparatus such as an ArF exposure apparatus, an electron beam drawing apparatus, or an EUV exposure apparatus, exposure through a mask pattern, or drawing by direct irradiation of an electron beam without using a mask pattern, etc. Then, PEB (post-exposure heating) is applied for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of 80 to 150 ° C. Subsequently, this is developed using 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, particularly ArF excimer laser.

The exposure method of the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be immersion exposure (Liquid Immersion Lithography).
In immersion exposure, the space between the resist film and the lens at the lowest position of the exposure apparatus is previously filled with a solvent (immersion medium) having a refractive index larger than that of air, and exposure (immersion exposure) is performed in that state. It is an exposure method.
As the immersion medium, a solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film to be exposed is preferable. The refractive index of such a solvent is not particularly limited as long as it is within the above range.
Examples of the solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film include water, a fluorine-based inert liquid, a silicon-based solvent, and a hydrocarbon-based solvent.
Specific examples of the fluorine-based inert liquid include a fluorine-based compound such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , and C ₅ H ₃ F ₇ as a main component. Examples thereof include liquids, and those having a boiling point of 70 to 180 ° C are preferable, and those having a boiling point of 80 to 160 ° C are more preferable. It is preferable that the fluorine-based inert liquid has a boiling point in the above range since the medium used for immersion can be removed by a simple method after the exposure is completed.
As the fluorine-based inert liquid, a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms is particularly preferable. Specific examples of the perfluoroalkyl compound include a perfluoroalkyl ether compound and a perfluoroalkylamine compound.
More specifically, examples of the perfluoroalkyl ether compound include perfluoro (2-butyl-tetrahydrofuran) (boiling point: 102 ° C.). Examples of the perfluoroalkylamine compound include perfluorotributylamine ( Boiling point of 174 ° C.).
As the immersion medium, water is preferably used from the viewpoints of cost, safety, environmental problems, versatility, and the like.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.
In this example, the unit represented by the chemical formula (1) is referred to as “compound (1)”, and the same applies to compounds represented by other formulas.

[Synthesis Example 1]
<Synthesis of 2- (2- (2-methyl-2-adamantyloxy) -2-oxoethoxy) -2-oxoethanol>
A 2 L three-necked flask equipped with a thermometer, a condenser and a stirrer was charged with 37.6 g (494 mmol) of glycolic acid, 700 mL of DMF, 86.5 g (626 mmol) of potassium carbonate, and 28.3 g (170 mmol) of potassium iodide at room temperature. For 30 minutes. Then, 300 mL of dimethylformamide in 100 g (412 mmol) of 2-methyl-2-adamantyl chloroacetate was slowly added. The temperature was raised to 40 ° C. and stirred for 4 hours. After completion of the reaction, 2000 mL of diethyl ether was added and filtered, and the resulting solution was washed 3 times with 500 mL of distilled water. Crystallization was performed using a mixed solution of toluene (300 mL) and heptane (200 mL) to obtain 78 g (yield 67%, GC purity 99%) of the target product as a colorless solid.

The instrumental analysis results of the obtained compound were as follows.
¹ H-NMR: 1.59 (d, 2H, J = 12.5 Hz), 1.64 (s, 3H), 1.71 to 1.99 (m, 10H), 2.29 (m, 2H) 2.63 (t, 1H, J = 5.2 Hz), 4.29 (d, 2H, J = 5.2 Hz), 4.67 (s, 2H).
¹³ C-NMR: 22.35, 26.56, 27.26, 32.97, 34.54, 36.29, 38.05, 60.54, 61.50, 89.87, 165.97, 172 .81.
GC-MS: 282 (M ⁺ , 0.02%), 165 (0.09%), 149 (40%), 148 (100%), 133 (22%), 117 (2.57%), 89 (0.40%).
From the above results, it was confirmed that the obtained compound was 2- (2- (2-methyl-2-adamantyloxy) -2-oxoethoxy) -2-oxoethanol.

[Synthesis Example 2]
<Synthesis of 2- (2- (2-methyl-2-adamantyloxy) -2-oxoethoxy) -2-oxoethyl methacrylate (Compound 13)>
To a 2 L three-necked flask equipped with a thermometer, a condenser and a stirrer was added 165 g (584 mmol) of 2- (2- (2-methyl-2-adamantyloxy) -2-oxoethoxy) -2-oxoethanol, 2000 mL of THF, Triethylamine 105 mL (754 mmol) and p-methoxyphenol 0.165 g (1000 ppm) were added and dissolved. After dissolution, 62.7 mL (648 mmol) of methacryloyl chloride was slowly added in an ice bath, warmed to room temperature, and stirred for 3 hours. After completion of the reaction, 1000 mL of diethyl ether was added and washed 5 times with 200 mL of distilled water. The extract was concentrated to obtain 198 g (yield 97%, GC purity 99%) of the target product as a colorless liquid.

The instrumental analysis result of the obtained compound 13 was as follows.
¹ H-NMR: 1.58 (d, J = 12.5 Hz, 2H), 1.63 (s, 3H), 1.71 to 1.89 (m, 8H), 1.98 (s, 3H) , 2.00 (m, 2H), 2.30 (m, 2H), 4.62 (s, 2H), 4.80 (s, 2H), 5.66 (m, 1H), 6.23 ( m, 1H).
¹³ C-NMR: 18.04, 22.15, 26.42, 27.14, 32.82, 34.38, 36.11, 37.92, 60.44, 61.28, 89.42, 126 79, 135.18, 165.61, 166.30, 167.20.
GC-MS: 350 (M ⁺ , 1.4%), 206 (0.13%), 149 (47%), 148 (100%), 133 (20%), 69 (37%).

[Polymer synthesis example 1]
In a three-necked flask connected with a thermometer and a reflux tube, 17.81 g (77.36 mmol) of compound (1), 23.45 g (137.79 mmol) of compound (6), 23.25 g (118.45 mmol) Compound (3), 30.5 g (87.03 mmol) of Compound (13) and 14.85 g (62.86 mmol) of Compound (5) were dissolved in 175 g of methyl ethyl ketone (MEK). To this solution, 24 mmol of dimethyl azobisisobutyrate (V-601) as a polymerization initiator was added and dissolved. The resultant was dropwise added to 96 g of MEK heated to 78 ° C. in a nitrogen atmosphere over 3 hours. After completion of dropping, the reaction solution was heated and stirred for 4 hours, and then the reaction solution was cooled to room temperature. The obtained reaction polymerization solution was dropped into a large amount of normal (n-) heptane, and the polymer was precipitated. The precipitated white powder was filtered, washed with a mixed solvent of n-heptane / isopropyl alcohol, and dried. As a result, g of polymer compound 1 as the target product was obtained.
About this high molecular compound 1, the mass mean molecular weight (Mw) of standard polystyrene conversion calculated | required by GPC measurement was 7000, and molecular weight dispersion degree (Mw / Mn) was 1.6. The copolymer composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by carbon 13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) is 1 / m / n / o / p = It was 15/30/25/15/15.

The following polymer compounds 2 to 14 are prepared from the monomers (1), (6), (3), (5) and the following monomers (2), (4), (7) to (11), in a predetermined molar ratio. Using these combinations, the compounds were appropriately synthesized under the same reaction conditions as in Polymer Synthesis Example 1.

［モル比：ｌ／ｍ／ｎ／ｏ／ｐ＝１０／３０／２５／２５／１０］

[Molar ratio: 1 / m / n / o / p = 10/30/25/25/10]

［モル比：ｌ／ｍ／ｎ／ｏ／ｐ＝１０／３０／２５／２５／１０］

[Molar ratio: 1 / m / n / o / p = 10/30/25/25/10]

［モル比：ｌ／ｍ／ｎ／ｏ＝１０／４０／２５／２５］

[Molar ratio: 1 / m / n / o = 10/40/25/25]

［モル比：ｌ／ｍ／ｎ／ｏ／ｐ＝１０／３０／２５／２５／１０］

[Molar ratio: 1 / m / n / o / p = 10/30/25/25/10]

［モル比：ｌ／ｍ／ｎ／ｏ／ｐ／ｑ＝１０／３０／２５／２５／１０］

[Molar ratio: 1 / m / n / o / p / q = 10/30/25/25/10]

［モル比：ｌ／ｍ／ｎ／ｏ＝１０／３６／３６／１８］

[Molar ratio: 1 / m / n / o = 10/36/36/18]

［モル比：ｌ／ｍ／ｎ／ｏ／ｐ＝１０／３０／２５／２５／１０］

[Molar ratio: 1 / m / n / o / p = 10/30/25/25/10]

［モル比：ｌ／ｍ／ｎ／ｏ／ｐ＝１０／３０／１０／２５／２５］

[Molar ratio: 1 / m / n / o / p = 10/30/10/25/25]

［モル比：ｌ／ｍ／ｎ／ｏ／ｐ＝１０／３０／２５／２５／１０］

[Molar ratio: 1 / m / n / o / p = 10/30/25/25/10]

［モル比：ｌ／ｍ／ｎ／ｏ／ｐ＝１０／３０／２５／２５／１０］

[Molar ratio: 1 / m / n / o / p = 10/30/25/25/10]

［モル比：ｌ／ｍ／ｎ／ｏ／ｐ＝１０／３０／２５／２５／１０］

[Molar ratio: 1 / m / n / o / p = 10/30/25/25/10]

［モル比：ｌ／ｍ／ｎ／ｏ／ｐ＝１０／３０／２５／２５／１０］

[Molar ratio: 1 / m / n / o / p = 10/30/25/25/10]

［モル比：ｌ／ｍ／ｎ／ｏ／ｐ＝１０／３０／２５／２５／１０］

[Molar ratio: 1 / m / n / o / p = 10/30/25/25/10]

<Synthesis Example of Compound (B-1)>
5.87 g of the following compound (B-1-a), 41.85 g of dichloromethane, and 20.93 g of pure water were added to a beaker, and 4.16 g of the following compound (B-1-b) was added thereto, and 1 at room temperature. Stir for hours. Thereafter, the reaction solution was separated, and the organic phase was further washed with dilute hydrochloric acid and water. The obtained organic phase was added dropwise to 249.0 g of n-hexane to obtain 6.70 g of the target compound (B-1) as a white powder.

This compound (B-1) was analyzed by NMR.
¹ H-NMR (DMSO-d6, 400 MHz):
δ (ppm) = 1.7-1-1.97 (m, 30H, Ad + CH ₃ ), 2.21 (s, 2H, Ad), 2.31 (s, 6H, Ar—CH ₃ ), 4.54 ( _{s, 2H, OCH 2),} 4.59 (s, 2H, CF 2 CH 2), 7.61 (s, 2H, Ar), 7.72-7.83 (m, 10H, Ar).
¹⁹ F-NMR (DMSO-d6, 376 MHz): δ (ppm) = − 111.3.
From the results of the above analysis, it was confirmed that the compound (B-1) had a structure represented by the chemical formula (B-1).

<Synthesis Example of Compound (5 ′)>
[Synthesis Step 1; Synthesis Example of Compound (4 ′)]
(I) To 192.1 g of methyl fluorosulfonyl (difluoro) acetate and 480 g of pure water, 440 g of a 30% by mass aqueous sodium hydroxide solution was added dropwise while maintaining the temperature at 10 ° C. or lower in an ice bath. After dropping, the mixture was refluxed at 100 ° C. for 3 hours, cooled, and neutralized with 10 mass% hydrochloric acid. The obtained solution was added dropwise to 9074 g of acetone, and the precipitate was filtered and dried to obtain 257.6 g of compound (1 ′) as a white solid (purity: 80.7%, yield: 94.5%). It was.

  (Ii) 56.2 g of the compound (1 ′) and 562.2 g of acetonitrile were charged, 77.4 g of p-toluenesulfonic acid monohydrate was added, and the mixture was refluxed at 110 ° C. for 3 hours. Then, it filtered and the filtrate was concentrated and dried. To the obtained solid, 900 g of t-butyl methyl ether (TBME) was added and stirred. Thereafter, the mixture was filtered, and the filtrate was dried to obtain 25.7 g of compound (2 ′) as a white solid (purity: 91.0%, yield: 52.0%).

  (Iii) 5.00 g of compound (2 ′) (purity: 91.0%), 4.80 g of sultone-OH (3 ′) and 25.0 g of toluene are charged, and 0.935 g of p-toluenesulfonic acid monohydrate Was added and refluxed at 110 ° C. for 26 hours. Then, it filtered, 25.0g of toluene was added to the residue, it stirred at room temperature for 10 minutes, and the process of performing filtration was repeated twice, and white powder was obtained. The white powder was dried in vacuo overnight. The next day, 5 g of acetone was added to the white powder and stirred at room temperature for 15 minutes, followed by filtration. The obtained filtrate was slowly added dropwise to 25.0 g of TBME and 25.0 g of methylene chloride, and the precipitated solid was recovered by filtration. -By drying, 5.89 g (purity: 98.4%, yield: 68.1%) of the compound (4 ′) was obtained as a white powder.

The compound (4 ′) was analyzed by ¹ H-NMR and ¹⁹ F-NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) 1.73-2.49 (m, 4H, Ha, Hb), 2.49 (m, 1H, Hc), 3.34 (m, 1H, Hd), 3.88 (t, 1H, He), 4.66 (t, 1H, Hf), 4.78 (m, 1H, Hg)
¹⁹ F-NMR (DMSO-d6, 400 MHz): δ (ppm) -107.7 (m, 2F, Fa) (however, the peak of hexafluorobenzene was set to −160 ppm)
From the results shown above, it was confirmed that the compound (4 ′) had a structure shown below.

[Synthesis Step 2; Synthesis Example of Compound (B-3)]
(Iv) 3.21 g of the compound (4 ′) is dissolved in 32.1 g of pure water, 3.72 g of 4-methyltriphenylsulfonium bromide is added, 32.1 g of methylene chloride is added, and the mixture is stirred at room temperature for 1 hour. went. Thereafter, the organic layer was taken out by liquid separation. The organic layer was washed 3 times with a 1% by mass aqueous HCl solution and then 4 times with pure water, and the organic layer was concentrated to give 4.94 g of compound (5 ′) as a white solid (purity: 98.8%). Yield: 86.8%).

The compound (5 ′) was analyzed by ¹ H-NMR and ¹⁹ F-NMR.
¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) 1.74-2.21 (m, 4H, Ha, Hb), 2.41 (t, 3H, Hh), 2.58 (m, 1H, Hc), 3.47 (m, 1H, Hd), 3.87 (t, 1h, He), 4.66 (t, 1H, Hf), 4.78 (m, 1H, Hg), 7 .58 (m, 2H, Hi), 7.64-7.84 (m, 12H, Hj),
¹⁹ F-NMR (DMSO-d6, 400 MHz): δ (ppm) −107.6 (m, 2F, Fa), where the peak of hexafluorobenzene was −160 ppm.
From the results shown above, it was confirmed that the compound (5 ′) had a structure shown below.

[Examples 1-15, Comparative Examples 1-6]
Each component shown in Table 1 was mixed and dissolved to prepare a positive resist composition.

In Table 1, the numerical values in [] indicate the blending amount (parts by mass). Moreover, the symbol in Table 2 shows the following, respectively.
(A) -1: The polymer compound 1.
(A) -2: The polymer compound 2.
(A) -3: The polymer compound 3.
(A) -4: The polymer compound 4.
(A) -5: The polymer compound 5.
(A) -6: The polymer compound 6.
(A) -7: The polymer compound 7.
(A) -8: The polymer compound 8.
(A) -9: The polymer compound 9.
(A) -10: The polymer compound 10.
(A) -11: The polymer compound 11.
(A) -12: The polymer compound 12.
(A) -13: the polymer compound 13.
(A) -14: the polymer compound 14.
(B) -1: Compound represented by the chemical formula (B-1).
(B) -2: Compound represented by the chemical formula (5 ′).
(B) -3: A compound represented by the following chemical formula (B).
(D) -1: tri-n-pentylamine (E) -1: salicylic acid.
(S) -1: PGMEA / PGME = 6/4 (mass ratio) mixed solvent.
(S) -2: γ-butyrolactone.

The following evaluation was performed about each obtained positive resist composition.
[Formation of resist pattern]
An antireflection film composition “TBLM730” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied onto an 8-inch silicon wafer using a spinner, and baked on a hot plate at 250 ° C. for 90 seconds to form an antireflection film. Then, a silicon-containing antireflection film composition “TSRC-013” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied onto the antireflection film on an 8-inch silicon wafer using a spinner, The plate was baked at 250 ° C. for 90 seconds to form a silicon-containing antireflection film having a thickness of 45 nm.
On the inorganic antireflection film, the positive resist compositions of Examples 1 to 13 and Comparative Examples 1 to 9 obtained above were applied using a spinner, respectively, and the temperatures listed in Table 2 on the hot plate. A pre-baking (PAB) process was performed for 60 seconds at, and the resist film having a thickness of 120 nm was formed by drying.
Next, an ArF excimer laser (193 nm) is applied to the resist film by using an ArF exposure apparatus NSR-S302 (manufactured by Nikon; NA (numerical aperture) = 0.60, 2/3 annular illumination) with a mask pattern ( 6% halftone), respectively.
Then, a post-exposure heating (PEB) treatment was performed for 60 seconds at the temperature shown in Table 2, and a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution NMD-3 (trade name, Tokyo Ohka Kogyo Co., Ltd.) at 23 ° C. Developed by Alkali Co., Ltd. for 30 seconds, rinsed with pure water for 30 seconds, and then shaken and dried.
As a result, in each example, a line-and-space resist pattern (hereinafter referred to as an L / S pattern) having a line width of 130 nm and a pitch of 260 nm was formed. Further, in the above resist pattern formation, the optimum exposure dose Eop (mJ / cm ² ; sensitivity) for forming an L / S pattern with a line width of 130 nm and a pitch of 260 nm was determined. The results are shown in Table 2.

[Shape evaluation]
The shape of the L / S pattern having a line width of 130 nm and a pitch of 260 nm formed by Eop was observed with a side length SEM and a cross-section SEM, and evaluated according to the following criteria. The results are shown in Table 2.
(Criteria)
(Double-circle): It is a favorable shape without skirting and the rectangularity of the cross-sectional shape of a resist pattern is also high.
○: Good shape without skirting, but the top portion is slightly rounded and the rectangularity is slightly low.
(Triangle | delta): The top part of the cross-sectional shape of a resist pattern is tinged, skirting is also seen, and rectangularity is low.

[LWR evaluation]
With respect to the L / S pattern having a line width of 130 nm and a pitch of 260 nm formed by the above Eop, the line width is changed to the longitudinal direction of the line by a length measurement SEM (scanning electron microscope, trade name: S-9220, manufactured by Hitachi, Ltd.). 5 points were measured, and from the results, the standard deviation (s) three times the value (3 s) was calculated as a scale (nm) indicating LWR. The smaller the value of 3s, the smaller the roughness of the line width, which means that a more uniform width L / S pattern was obtained. The results are shown in Table 2.
Of the resist patterns of Comparative Examples 1 to 9, the LWR was not calculated for patterns with a large tail.

  As shown in Table 2, each of the resist compositions of Examples 1 to 13 according to the present invention has a smaller LWR and a shape of the formed resist pattern as compared with the resist compositions of Comparative Examples 1 to 9. It was excellent. It is clear that the substrate matching of the resist film using the resist composition according to the present invention is good because the shape is a good shape without skirting.

Claims (7)

A positive resist composition comprising a base component (A) whose solubility in an alkaline developer is increased by the action of an acid, and an acid generator component (B) that generates an acid upon exposure,
The base material component (A) includes at least two structural units (a0) represented by the following general formula (a0-1) and structural units (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group. A polymer compound (A1) having a structural unit (a2) derived from a seed and an acrylate ester containing a lactone-containing cyclic group ,
The polymeric compound (A1) is, as a kind of the structural unit (a1), and characterized in that have a structural unit (a1-0-11) represented by the following general formula (a1-0-11) A positive resist composition.

[Wherein, R ⁸¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and R ⁸² has 2 to 12 carbon atoms which may have an oxygen atom. It is a divalent aliphatic hydrocarbon group. ]

Wherein R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, R ²¹ is a linear or branched alkyl group, and R ²² is , R ²² is a group that forms an aliphatic monocyclic group together with the carbon atom to which R ²² is bonded. ] The polymer compound (A1) includes, as the structural unit (a1), a structural unit (a1-0-11) represented by the following general formula (a1-0-11), and a general formula (a1-0- The positive resist composition according to claim 1, having a structural unit (a1-0-12) represented by 12).

Wherein R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, R ²¹ is a linear or branched alkyl group, and R ²² is , R ²² is a group that forms an aliphatic monocyclic group together with the carbon atom to which R ²² is bonded, R ²³ is a linear or branched alkyl group, and R ²⁴ is a carbon to which R ²⁴ is bonded. It is a group that forms an aliphatic monocyclic group together with atoms, and R ²² and R ²⁴ are different from each other. ] A positive resist composition comprising a base component (A) whose solubility in an alkaline developer is increased by the action of an acid, and an acid generator component (B) that generates an acid upon exposure,
The base material component (A) includes at least two structural units (a0) represented by the following general formula (a0-1) and structural units (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group. A polymer compound (A1) having a structural unit (a2) derived from a seed and an acrylate ester containing a lactone-containing cyclic group,
The polymer compound (A1) has a structural unit (a1-0-13) represented by the following general formula (a1-0-13) as the structural unit (a1). Composition.

[Wherein, R ⁸¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and R ⁸² has 2 to 12 carbon atoms which may have an oxygen atom. It is a divalent aliphatic hydrocarbon group. ]

[Wherein, R ¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, A is a divalent linking group, and B is a divalent linking group. R ² is an acid dissociable, dissolution inhibiting group. ] The polymeric compound (A1) is, as the structural unit (a1), according to claim 1 or 2 having the structural unit represented by the following general formula (a1-0-13) (a1-0-13) Positive resist composition.

[Wherein, R ¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, A is a divalent linking group, and B is a divalent linking group. R ² is an acid dissociable, dissolution inhibiting group. ] The positive type according to any one of claims 1 to 4, wherein the polymer compound (A1) further has a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group. Resist composition. The positive resist composition as described in any one of Claims 1-5 containing a nitrogen-containing organic compound (D). A step of forming a resist film on a support using the positive resist composition according to any one of claims 1 to 6, a step of exposing the resist film, and an alkali developing of the resist film to form a resist A resist pattern forming method including a step of forming a pattern.