JP2012108447A - Resist composition and resist pattern forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist composition excellent in resolution as well as lithographic characteristics such as pattern features and LER (line edge roughness), and to provide a method for forming a resist pattern.SOLUTION: The resist composition comprises: a base component (A) of which the solubility with respect to a developing solution varies by an effect of an acid; a nitrogen-containing organic compound component (C) containing a compound (C1) expressed by formula (c1); and an acid generator component (B) that generates an acid by exposure (excluding the compound (C1)). The acid generator component (B) is included by 10 to 60 parts by mass with respect to 100 parts by mass of the base component (A), and the compound (C1) is included by 1 to 15 mol% with respect to the sum of the compound (C1) and the acid generator component (B). In formula (c1), Rrepresents a hydroxyl group, alkoxy group, cyano group, -O-C(=O)-C(R)=CHor -O-C(=O)-R; Yrepresents a divalent aliphatic hydrocarbon group; Rrepresents a hydrogen atom, fluorine atom, alkyl group or fluorinated alkyl group; p represents 1 to 10; and Arepresents an organic cation.

Description

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

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, and the resist film is selectively exposed to light such as light or an electron beam through a mask on which a predetermined pattern is formed. And a development process is performed to form a resist pattern having a predetermined shape on the resist film.
A resist material in which the exposed portion changes to a property that dissolves in the developer is referred to as a positive type, and a resist material that changes to a property in which the exposed portion does not dissolve in the developer is referred to as a negative type.
In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has been rapidly progressing due to advances in lithography technology.
As a technique for miniaturization, the exposure light source is generally shortened in wavelength (increased energy). Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used. Currently, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has been started. Further, studies have been made on electron beams (EB), EUV (extreme ultraviolet rays), X-rays, and the like having shorter wavelengths (higher energy) 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 a developing solution is changed by the action of an acid and an acid generator component that generates an acid upon exposure is used. ing.
For example, when the developer is an alkali developer (alkaline development process), the positive chemically amplified resist composition includes a resin component (base resin) whose solubility in an alkali developer is increased by the action of an acid, an acid Those containing a generator component are generally used. When a resist film formed using such a resist composition is selectively exposed at the time of resist pattern formation, an acid is generated from the acid generator component 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. Then, a positive pattern in which an unexposed portion remains as a pattern is formed. Here, as the base resin, a resin whose polarity is increased by the action of an acid is used, and the solubility in an alkali developer is increased while the solubility in an organic solvent is decreased. Therefore, when a process using a developer containing an organic solvent (organic developer) (hereinafter sometimes referred to as a solvent development process or a negative development process) is applied instead of an alkali development process, Therefore, in the solvent development process, the unexposed portion of the resist film is dissolved and removed by the organic developer, and the exposed portion remains as a pattern in the solvent development process. Is formed. For example, Patent Document 1 proposes a negative development process.

  At present, as a base resin of a resist composition used in ArF excimer laser lithography and the like, a resin (acrylic resin) having a structural unit derived from a (meth) acrylate ester in its main chain because of its excellent transparency near 193 nm And the like are generally used (see, for example, Patent Document 2).

Various acid generators used in chemically amplified resist compositions have been proposed so far, for example, onium salt acid generators, oxime sulfonate acid generators, diazomethane acid generators. Nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like are known. Among these, as an onium salt acid generator, an iodonium salt having an iodonium ion as a cation and a sulfonium salt having a sulfonium ion as a cation have been conventionally used.
In recent years, resist pattern formation using EB or EUV as an exposure light source has been attempted with the goal of forming a fine pattern of several tens of nanometers. In particular, lithography by EUV has a reaction mechanism different from that of lithography using other exposure light sources, and therefore development of a resist material corresponding to EUV is required.
Further, as the resist pattern dimension becomes smaller as described above, it is very important that the resist composition has high sensitivity to the exposure light source. Therefore, as a chemically amplified resist composition using EUV or the like as an exposure light source, a composition containing a large amount of an acid generator is disclosed (for example, see Patent Document 3).

Further, in the chemically amplified resist composition, in addition to the base resin and the acid generator, a nitrogen-containing organic compound such as an alkylamine or an alkyl alcohol amine is blended. The nitrogen-containing organic compound acts as a quencher that traps the acid generated from the acid generator, and contributes to improvement of lithography properties, resist pattern shape, and the like.
In particular, tertiary amines are widely used as nitrogen-containing organic compounds, and also in Patent Document 3, tertiary amines are used as acid diffusion control agents and basic compounds.

JP 2008-292975 A JP 2003-241385 A JP 2007-58159 A

In the future, with further advancement of lithography technology and further miniaturization of resist patterns, further improvements in various lithography characteristics and pattern shapes are desired for resist materials. Lithographic characteristics that are desired to be improved include, for example, line edge roughness (LER) and EL margin.
In lithography using EUV as an exposure light source, attempts have been made to increase the sensitivity by using a large amount of an acid generator as in Patent Document 3 described above, but when a large amount of acid generator is used, the resolution is Although obtained, there was room for improvement in terms of lithography characteristics such as pattern shape and LER.
The present invention has been made in view of the above circumstances, and is a resist composition excellent in resolution and excellent in lithography properties such as a pattern shape and LER, and a resist pattern forming method using the resist composition It is an issue to provide.

In order to solve the above problems, the present invention employs the following configuration.
That is, the first aspect of the present invention is a nitrogen-containing organic compound containing a base component (A) whose solubility in a developer is changed by the action of an acid, and a compound (C1) represented by the following general formula (c1) A resist composition containing a component (C) and an acid generator component (B) that generates acid upon exposure (excluding the compound (C1)), and 100 parts by mass of the base component (A) On the other hand, the content rate of the said acid generator component (B) is 10-60 mass parts, and with respect to the sum total of the said compound (C1) and the said acid generator component (B) of the said compound (C1). The resist composition is characterized in that the content is 1 to 15 mol%.

［式中、Ｒ^Ｃ１は水酸基、アルコキシ基、シアノ基、−Ｏ−Ｃ（＝Ｏ）−Ｃ（Ｒ^Ｃ２）＝ＣＨ_２（Ｒ^Ｃ２は水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基である）、または−Ｏ−Ｃ（＝Ｏ）−Ｒ^Ｃ３（Ｒ^Ｃ３は炭化水素基である）であり、Ｙ^１は２価の脂肪族炭化水素基であり、Ｒ^１は水素原子、フッ素原子、アルキル基又はフッ素化アルキル基である。ｐは１〜１０の整数を表す。Ａ^＋は有機カチオンを表す。］

[Wherein R ^C1 represents a hydroxyl group, an alkoxy group, a cyano group, —O—C (═O) —C (R ^C2 ) ═CH ₂ (R ^C2 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a carbon number. 1 to 5 halogenated alkyl groups), or —O—C (═O) —R ^C3 (R ^C3 is a hydrocarbon group), and Y ¹ is a divalent aliphatic hydrocarbon group. , R ¹ is a hydrogen atom, a fluorine atom, an alkyl group or a fluorinated alkyl group. p represents an integer of 1 to 10. A ⁺ represents an organic cation. ]

  In a second aspect of the present invention, a resist pattern is formed on a support using the resist composition of the first aspect, the resist film is exposed, and the resist film is developed to form a resist pattern. It is a resist pattern formation method including the process of forming.

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.
The “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified.
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).
“Acrylic acid ester” is a compound in which the hydrogen atom at the carboxy group terminal of acrylic acid (CH ₂ ═CH—COOH) is substituted with an organic group.
“A structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
In the “acrylate ester in which an atom other than a hydrogen atom or a substituent may be bonded to a carbon atom at the α-position”, examples of the atom other than a hydrogen atom include a halogen atom, and the substituent includes 1 carbon atom. -5 alkyl groups, C1-C5 halogenated alkyl groups, hydroxyalkyl groups, and the like. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Note that the α-position (α-position carbon atom) of a structural unit derived from an acrylate ester means a carbon atom to which a carbonyl group is bonded, unless otherwise specified.
Specific examples of the alkyl group having 1 to 5 carbon atoms in the substituent which may be bonded to the α-position carbon atom include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, Examples thereof include linear or branched alkyl groups such as tert-butyl group, pentyl group, isopentyl group, and neopentyl group.
Further, as the halogenated alkyl group having 1 to 5 carbon atoms in the substituent, a part or all of the hydrogen atoms in the above-mentioned “alkyl group having 1 to 5 carbon atoms in the substituent” are halogen atoms. And a 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.
Specific examples of the hydroxyalkyl group in the substituent include groups in which part or all of the hydrogen atoms in the above-mentioned “alkyl group having 1 to 5 carbon atoms in the substituent” are substituted with a hydroxy group. .
In the present invention, the bond to the carbon atom at the α-position is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. It is more preferably a C 1-5 alkyl group or a C 1-5 fluorinated alkyl group, and most preferably a hydrogen atom or a methyl group in terms of industrial availability.
“Hydroxystyrene derivative” is a concept including hydroxystyrene and those in which the hydrogen atom at the α-position of hydroxystyrene is substituted with a substituent such as an alkyl group or a halogenated alkyl group, and derivatives thereof. The α-position carbon atom of hydroxystyrene is a carbon atom to which a benzene ring is bonded unless otherwise specified.
“A structural unit derived from a hydroxystyrene derivative” means a structural unit formed by cleavage of an ethylenic double bond of a hydroxystyrene derivative.
“Styrene” has a concept including styrene and those in which the hydrogen atom at the α-position of styrene is substituted with another substituent such as an alkyl group.
“Structural unit derived from styrene” means a structural unit formed by cleavage of an ethylenic double bond of styrene. In styrene, the hydrogen atom of the phenyl group may be substituted with a substituent such as an alkyl group having 1 to 5 carbon atoms.
“Exposure” is a concept including general irradiation of radiation.

  According to the present invention, it is possible to provide a resist composition excellent in resolution and excellent in lithography properties such as pattern shape and LER, and a resist pattern forming method using the resist composition.

≪Resist composition≫
The resist composition according to the first aspect of the present invention comprises a substrate component (A) whose solubility in a developer is changed by the action of an acid (hereinafter referred to as “component (A)”), the general formula (c1). A nitrogen-containing organic compound component (C) (hereinafter referred to as “component (C)”) containing a compound (C1) represented by formula (1), and an acid generator component (B) that generates an acid upon exposure (hereinafter referred to as “(B ) Component ”)).
When a resist film formed using such a resist composition is selectively exposed at the time of forming a resist pattern, the solubility of the component (A) in the developing solution is caused by the acid from the component (B) (or the compound (C1)). To change. As a result, while the solubility of the exposed portion of the resist film in the developer changes, the unexposed portion does not change the solubility in the developer, so by developing, the exposed portion in the case of a positive pattern, In the case of a negative pattern, unexposed portions are dissolved and removed to form a resist pattern.
The resist composition of the present invention may be a negative resist composition or a positive resist composition.
In this specification, a resist composition that forms a positive pattern in which an exposed portion is dissolved and removed is referred to as a positive resist composition, and a resist composition that forms a negative pattern in which an unexposed portion is dissolved and removed is referred to as a negative. This is referred to as a type resist composition.

<(A) component>
As the component (A), organic compounds that are usually used as base material components for chemically amplified resists can be used singly or in combination of two or more.
Here, the “base material component” is an organic compound having a film forming ability, and an organic compound having a molecular weight of 500 or more is preferably used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved and a nano-level resist pattern is easily formed.
“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 1000 or more are usually used. Hereinafter, a polymer having a molecular weight of 1000 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”.
As the component (A), a resin component whose solubility in a developer is changed by the action of an acid can be used, and a low molecular compound component whose solubility in a developer is changed by the action of an acid can also be used.

When the resist composition of the present invention is a “negative resist composition for an alkali development process” that forms a negative pattern in an alkali development process, a base component that is soluble in an alkali developer is used as the component (A). Furthermore, a crosslinking agent component is blended.
In such a negative resist composition for an alkali development process, when an acid is generated from the component (B) by exposure, the acid acts to cause crosslinking between the base material component and the crosslinking agent component. Changes to slightly soluble. Therefore, in the formation of a resist pattern, when a resist film obtained by applying the negative resist composition on a support is selectively exposed, the exposed portion turns into poorly soluble in an alkaline developer, while not yet exposed. Since the exposed portion remains soluble in the alkali developer and does not change, a resist pattern can be formed by alkali development.
As the component (A) of the negative resist composition for an alkali development process, a resin that is soluble in an alkali developer (hereinafter referred to as “alkali-soluble resin”) is usually used.
Examples of the alkali-soluble resin include α- (hydroxyalkyl) acrylic acid or α- (hydroxyalkyl) acrylic acid alkyl ester (preferably having 1 to 5 carbon atoms) disclosed in, for example, JP-A-2000-206694. Resin having a unit derived from at least one selected from alkyl ester); disclosed in US Pat. No. 6,949,325, an atom other than a hydrogen atom or a substituent is bonded to the α-position carbon atom having a sulfonamide group Acrylic resin or polycycloolefin resin which may be used; containing a fluorinated alcohol disclosed in US Pat. An atom other than a hydrogen atom or a substituent may be bonded to the carbon atom. Acrylic resin; disclosed in Japanese 2006-259582 discloses, polycycloolefin resins having fluorinated alcohol, with minimal swelling can formation of a satisfactory resist pattern.
In addition, the α- (hydroxyalkyl) acrylic acid is an α-position carbon atom to which a carboxy group is bonded among acrylic acids in which an atom other than a hydrogen atom or a substituent may be bonded to the α-position carbon atom. One or both of acrylic acid to which a hydrogen atom is bonded and α-hydroxyalkyl acrylic acid in which a hydroxyalkyl group (preferably a hydroxyalkyl group having 1 to 5 carbon atoms) is bonded to the α-position carbon atom Show.
As the crosslinking agent component, for example, it is usually preferable to use an amino crosslinking agent such as glycoluril having a methylol group or an alkoxymethyl group, a melamine crosslinking agent, or the like because a good resist pattern with less swelling can be formed. It is preferable that the compounding quantity of a crosslinking agent component is 1-50 mass parts with respect to 100 mass parts of alkali-soluble resin.

When the resist composition of the present invention is a resist composition that forms a positive pattern in an alkali development process and a negative pattern in a solvent development process, the component (A) has increased polarity due to the action of an acid. It is preferable to use a base material component (hereinafter referred to as “(A0) component”). By using the component (A0), the polarity of the base material component changes before and after exposure, so that good development contrast can be obtained not only in the alkali development process but also in the solvent development process.
When the alkali development process is applied, the component (A0) is hardly soluble in an alkali developer before exposure, and when acid is generated from the component (B) by exposure, the polarity increases due to the action of the acid. As a result, the solubility in an alkali developer increases. Therefore, in the formation of a resist pattern, when a resist film obtained by applying the resist composition on a support is selectively exposed, the exposed portion changes from slightly soluble to soluble in an alkaline developer. Since the unexposed portion remains hardly soluble in alkali and does not change, a positive pattern can be formed by alkali development.
In addition, when a solvent development process is applied, the component (A0) is highly soluble in an organic developer before exposure, and when an acid is generated from the component (B) by exposure, the action of the acid As a result, the polarity becomes higher and the solubility in an organic developer decreases. Therefore, in the formation of the resist pattern, when the resist film obtained by applying the resist composition on the support is selectively exposed, the exposed portion changes from soluble to poorly soluble in an organic developer. On the other hand, since the unexposed portion remains soluble and does not change, by developing with an organic developer, a contrast can be provided between the exposed portion and the unexposed portion, and a negative pattern can be formed.

In the resist composition of the present invention, the component (A) is preferably a base material component ((A0) component) whose polarity is increased by the action of an acid. That is, the resist composition of the present invention is preferably a chemically amplified resist composition that becomes positive in the alkali development process and negative in the solvent development process.
The component (A0) may be a resin component (A1) whose polarity is increased by the action of an acid (hereinafter sometimes referred to as “(A1) component”). It may be a compound component (A2) (hereinafter sometimes referred to as “component (A2)”) or a mixture thereof.

[(A1) component]
As the component (A1), resin components (base resins) that are usually used as base components for chemically amplified resists can be used alone or in combination of two or more.
The component (A1) in the present invention preferably has a structural unit (a0) containing an acid-decomposable group whose polarity is increased by the action of an acid. The structural unit (a0) is a structural unit derived from an acrylate ester in which an atom other than a hydrogen atom or a substituent may be bonded to a carbon atom at the α-position, and its polarity is increased by the action of an acid. A structural unit (a1) containing an acid-decomposable group, or a structural unit derived from a hydroxystyrene derivative, the structural unit (a11) containing an acid-decomposable group whose polarity is increased by the action of an acid. preferable. The component (A1) may include both the structural units (a1) and (a11), or may be either one.
In the resist composition of the present invention, it is particularly preferable that the component (A1) has the structural unit (a1).
In addition to the structural unit (a1), the component (A1) further contains a —SO ₂ — containing cyclic group, and an atom other than a hydrogen atom or a substituent may be bonded to the α-position carbon atom. A structural unit derived from a good acrylate ester, and a structural unit derived from an acrylate ester containing a lactone-containing cyclic group, and an atom other than a hydrogen atom or a substituent may be bonded to the α-position carbon atom It is preferable to have at least one structural unit (a2) selected from the group consisting of
In addition to the structural unit (a1) or in addition to the structural units (a1) and (a2), the component (A1) further includes a polar group-containing aliphatic hydrocarbon group, and the α-position carbon atom It is preferable to have a structural unit (a3) derived from an acrylate ester to which an atom other than a hydrogen atom or a substituent may be bonded.

(Structural unit (a1))
The structural unit (a1) is a structural unit derived from an acrylate ester in which an atom other than a hydrogen atom or a substituent may be bonded to a carbon atom at the α-position, and an acid whose polarity is increased by the action of an acid. A structural unit containing a degradable group.
An “acid-decomposable group” is an acid that can cleave at least some of the bonds in the structure of the acid-decomposable group by the action of an acid (such as an acid generated from the component (B) or the compound (C1) upon exposure). It is a group having decomposability.
Examples of the acid-decomposable group whose polarity increases by the action of an acid include a group that decomposes by the action of an acid to generate a polar group.
Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, a sulfo group (—SO ₃ H), and the like. Among these, a polar group containing —OH in the structure (hereinafter sometimes referred to as OH-containing polar group) is preferable, a carboxy group or a hydroxyl group is preferable, and a carboxy group is particularly preferable.
More specifically, examples of the acid-decomposable group include a group in which the polar group is protected with an acid-dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).
“Acid-dissociable group” means that at least a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group is cleaved by the action of an acid (such as an acid generated from the component (B) by exposure). It is a group having acid dissociation ability. The acid-dissociable group constituting the acid-decomposable group must be a group having a lower polarity than the polar group generated by dissociation of the acid-dissociable group. Is dissociated, a polar group having a polarity higher than that of the acid dissociable group is generated to increase the polarity. As a result, the polarity of the entire component (A1) increases. Due to the increase in polarity, the solubility in an alkaline developer is relatively increased if an alkali development process is applied. On the other hand, if a solvent development process is applied, the solubility in an organic developer containing an organic solvent is reduced.

  As the acid dissociable group in the structural unit (a1), those proposed so far as the acid dissociable group of the base resin for a 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 group such as an alkoxyalkyl group is widely known.

Here, the “tertiary alkyl ester” is an ester formed by replacing a hydrogen atom of a carboxy group with a chain or cyclic alkyl group, and the carbonyloxy group (—C (═O ) -O-) shows a structure in which the tertiary carbon atom of the chain-like or cyclic alkyl group is bonded to the terminal oxygen atom. In this tertiary alkyl ester, when an acid acts, a bond is cut between an oxygen atom and a tertiary carbon atom to form a carboxy group, thereby increasing the polarity of the component (A1).
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 group” for convenience.
Examples of the tertiary alkyl ester type acid dissociable group include an aliphatic branched acid dissociable group and an acid dissociable group containing an aliphatic cyclic group.

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

The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity.
The “aliphatic cyclic group” in the structural unit (a1) may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like. Is mentioned.
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 monocycloalkane, a bicycloalkane, and a tricyclo which may or may not be substituted with an alkyl group having 1 to 5 carbon atoms, a fluorine atom, or a fluorinated alkyl group. Examples thereof include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as alkane or tetracycloalkane. More specifically, monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane are exemplified. .

Examples of the acid-dissociable group containing an aliphatic cyclic group include a group having a tertiary carbon atom on the ring skeleton of a cyclic alkyl group. Examples thereof include 2-methyl-2-adamantyl group and 2-ethyl-2-adamantyl group such as those represented by 1) to (1-9).
As the aliphatic branched acid dissociable group, adamantyl group, cyclohexyl group, cyclopentyl group, norbornyl group, tricyclodecyl group as shown in the following general formulas (2-1) to (2-6) And a group having an aliphatic cyclic group such as a tetracyclododecyl group and a branched alkylene group having a tertiary carbon atom bonded thereto.

［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、Ｒ^１６はそれぞれ独立してアルキル基（直鎖状、分岐鎖状のいずれでもよく、好ましくは炭素数１〜５である）を示す。］

[Wherein, R ¹⁵ and R ¹⁶ each independently represents an alkyl group (which may be linear or branched, and preferably has 1 to 5 carbon atoms). ]

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 (2-1) to (2-6), a part of the carbon atoms constituting the ring is substituted with an etheric oxygen atom (—O—). May be.
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 an alkyl group having 1 to 5 carbon atoms, a fluorine atom, and a fluorinated alkyl group.

The “acetal-type acid dissociable group” is generally bonded to an oxygen atom by substituting a hydrogen atom at the terminal of an OH-containing polar group such as a carboxy group or a hydroxyl group. When an acid is generated by exposure, this acid acts to break the bond between the acetal type acid dissociable group and the oxygen atom to which the acetal type acid dissociable group is bonded. By forming the OH-containing polar group, the polarity of the component (A1) is increased.
Examples of the acetal type acid dissociable 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炭素数１〜５のアルキル基を表し、ｎは０〜３の整数を表し、Ｙは炭素数１〜５の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 an alkyl group having 1 to 5 carbon atoms, n represents an integer of 0 to 3, and Y represents an alkyl group having 1 to 5 carbon atoms. Or represents an aliphatic cyclic group. ]

In the above formula, n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
Examples of the alkyl group having 1 to 5 carbon atoms of R ¹ ′ and R ² ′ include those similar to the alkyl group having 1 to 5 carbon atoms of R, preferably a methyl group or an ethyl group, and most preferably a methyl group. preferable.
In the present invention, it is preferable that at least one of R ¹ ′ and R ² ′ is a hydrogen atom. That is, the acid dissociable group (p1) is preferably a group represented by the following general formula (p1-1).

［式中、Ｒ^１’、ｎ、Ｙは上記と同様である。］

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

Examples of the alkyl group having 1 to 5 carbon atoms of Y include the same as the alkyl group having 1 to 5 carbon atoms of R.
The aliphatic cyclic group for Y can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups that have been proposed in a number of conventional ArF resists, for example, the “aliphatic ring” described above. Examples thereof are the same as those in the formula group.

  Examples of the acetal type acid dissociable 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または分岐鎖状のアルキル基または水素原子であり、Ｒ^１９は直鎖状、分岐鎖状または環状のアルキル基である。または、Ｒ^１７およびＲ^１９がそれぞれ独立に直鎖状または分岐鎖状のアルキレン基であって、Ｒ^１７の末端とＲ^１９の末端とが結合して環を形成していてもよい。］

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

In R ¹⁷ and R ¹⁸ , the alkyl group preferably has 1 to 15 carbon atoms, may be linear or branched, and is preferably an ethyl group or a methyl group, and most preferably a methyl group. In particular, it is preferable that one of R ¹⁷ and R ¹⁸ is a hydrogen atom and the other is a methyl group.
R ¹⁹ is a linear, branched or cyclic alkyl group, 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, are included. Examples include a group excluding a hydrogen atom. 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 above formula, R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group (preferably an alkylene group having 1 to 5 carbon atoms), and the end of R ¹⁹ and R ¹⁷ The terminal may be bonded.
In this case, a cyclic group is formed by R ¹⁷ , R ¹⁹ , the oxygen atom to which R ¹⁹ is bonded, and the carbon atom to which the oxygen atom and R ¹⁷ are bonded. The cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

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

［式中、Ｒは水素原子、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を示し、Ｘ^１は酸解離性基を示す。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and X ¹ represents an acid dissociable group. ]

［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を示し、Ｘ^２は酸解離性基を示し、Ｙ^２は２価の連結基を示す。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, X ² represents an acid dissociable group, and Y ² represents a divalent linking group. Show. ]

In the general formula (a1-0-1), the alkyl group having 1 to 5 carbon atoms or the halogenated alkyl group having 1 to 5 carbon atoms represented by R is a substituent which may be bonded to the carbon atom at the α-position. It is the same as the alkyl group having 1 to 5 carbon atoms or the halogenated alkyl group having 1 to 5 carbon atoms.
X ¹ is not particularly limited as long as it is an acid dissociable group, and examples thereof include the above-described tertiary alkyl ester type acid dissociable groups, acetal type acid dissociable groups, and the like. An ester type acid dissociable group is 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) And a combination of an alkylene group and a divalent linking group containing a hetero atom.

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 alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (═O).

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 that is bonded to the terminal of the aromatic hydrocarbon group or intervenes 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 an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (= O).

  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基を表し、Ｙは炭素数１〜５のアルキル基、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のアルキル基を表す。］

[Wherein, X ′ represents a tertiary alkyl ester-type acid dissociable group, Y represents an 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 an alkyl group having 1 to 5 carbon atoms. ]

In the formula, X 'include the same tertiary alkyl ester-type acid dissociable groups 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 group" described above ^{(p1) ', R 2'} , n, similarly to the Y Can be 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), one type may be used alone, or two or more types may be used in combination.
Among these, the structural unit represented by general formula (a1-1), (a1-2) or (a1-3) is preferable, and specifically, (a1-1-1) to (a1-1-4). , (A1-1-20) to (a1-1-23), (a1-2-1) to (a1-2-24) and (a1-3-25) to (a1-3-28) It is more preferable to use at least one selected from the group.
Furthermore, as the structural unit (a1), in particular, the following general formula (a1-1) including structural units of the formulas (a1-1-1) to (a1-1-3) and (a1-1-26) −01), formulas (a1-1-16) to (a1-1-17) and formulas (a1-1-20) to (a1-1-23) The following general formula (A) containing the structural unit represented by formula (a1-1-02), formula (a1-2-3), formula (a1-2-6) and formula (a1-2-14) a1-2-01), a compound represented by the following general formula (a1-3-01) including the structural units of formulas (a1-3-25) to (a1-3-26), The following general formula (a1-3-02) including the structural units of formulas (a1-3-27) to (a1-3-28) or formulas (a1-3-29) to Those represented by even preferred by the following general formula which includes the structural units a1-3-30) (a1-3-03).

[式中、Ｒはそれぞれ独立に水素原子、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を示し、Ｒ^１１は炭素数１〜５のアルキル基を示す。Ｒ^１２は炭素数１〜７のアルキル基を示す。ｈは１〜６の整数を表す。]

[Wherein, R independently represents 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 ¹¹ represents an alkyl group having 1 to 5 carbon atoms. R ¹² represents an alkyl group having 1 to 7 carbon atoms. h represents an integer of 1 to 6. ]

In general formula (a1-1-01), R is the same as defined above. The alkyl group having 1 to 5 carbon atoms of R ¹¹ is the same as the alkyl group having 1 to 5 carbon atoms in R, and is preferably a methyl group, an ethyl group, or an isopropyl group.

In general formula (a1-1-02), R is the same as defined above. The alkyl group having 1 to 5 carbon atoms of R ¹² is the same as the alkyl group having 1 to 5 carbon atoms in R, and is preferably a methyl group, an ethyl group, or an isopropyl group. h is preferably 1 or 2, and most preferably 2.

[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を示し、Ｒ^１３は水素原子またはメチル基であり、Ｒ^８は水素原子または炭素数１〜５のアルキル基であり、ｃは０〜３の整数である。]

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, R ¹³ represents a hydrogen atom or a methyl group, and R ⁸ represents a hydrogen atom or a carbon number. 1 to 5 alkyl groups, and c is an integer of 0 to 3. ]

In general formula (a1-2-01), R is the same as described above. The alkyl group having 1 to 5 carbon atoms of R ⁸ is the same as the alkyl group having 1 to 5 carbon atoms in R, and is preferably a methyl group, an ethyl group, or an isopropyl group, and R ⁸ is a hydrogen atom, a methyl group or the like. , An ethyl group, or an isopropyl group is preferable. c is preferably 0 to 2, and more preferably 0 or 1.

[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を示し；Ｒ^１４は前記同様であり、Ｒ^１３は水素原子またはメチル基であり、ａは１〜１０の整数である。]

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ¹⁴ is the same as described above; R ¹³ is a hydrogen atom or a methyl group; a is an integer of 1-10. ]

[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を示し；Ｒ^１４は前記同様であり、Ｒ^１３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、ｎ’は１〜６の整数である。]

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ¹⁴ is the same as described above; R ¹³ is a hydrogen atom or a methyl group; a is an integer of 1 to 10, and n ′ is an integer of 1 to 6. ]

［式中、Ｒは前記と同じであり、Ｙ^２’およびＹ^２”はそれぞれ独立して２価の連結基であり、Ｘ’は酸解離性基であり、ｎは０〜３の整数である。］

[Wherein, R is as defined above, Y ² ′ and Y ² ″ are each independently a divalent linking group, X ′ is an acid-dissociable group, and n is an integer of 0 to 3] is there.]

In the general formulas (a1-3-01) to (a1-3-03), R is the same as described above.
R ¹³ is preferably a hydrogen atom.
n ′ is preferably 1 or 2, and most preferably 2.
a is preferably an integer of 1 to 8, particularly preferably an integer of 2 to 5, and most preferably 2.
As the divalent linking group for Y ² ′ and Y ² ″, the same groups as those described above for Y ² in formula (a1-3) can be given.
Y ² ′ 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.
Y ² ″ 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. A linear alkylene group of 1 to 5 is preferable, and a methylene group and an ethylene group are most preferable.
Examples of the acid dissociable group in X ′ include the same groups as described above, and are preferably tertiary alkyl ester-type acid dissociable groups, and the ring skeleton of the above-described (i) monovalent aliphatic cyclic group A group having a tertiary carbon atom is more preferable, and among them, a group represented by the general formula (1-1) is preferable.
n is an integer of 0 to 3, and n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 1.

  In the component (A1), the proportion of the structural unit (a1) is preferably from 5 to 80 mol%, more preferably from 10 to 80 mol%, more preferably from 15 to 75 mol%, based on all structural units constituting the component (A1). Is more preferable. By setting it to the lower limit value or more, a pattern can be easily obtained when the resist composition is used, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

(Structural unit (a11))
The structural unit (a11) is a structural unit derived from a hydroxystyrene derivative and includes an acid-decomposable group that increases in polarity by the action of an acid. Examples of the acid-decomposable group in the structural unit (a11) include the same groups as those described above for the structural unit (a1).
Examples of the acid-decomposable group include a group in which the —OH hydrogen atom of the phenolic hydroxyl group in the structural unit (a11) is replaced by an acetal acid dissociable group; —OH of the phenolic hydroxyl group in the structural unit (a11) Through a linking group such as —C (═O) O— or (—Y ² —C (═O) —O—) in the above formula (a1-0-2). And a group substituted with a secondary alkyl ester-type acid-dissociable group or an acetal-type acid-dissociable group.
In the component (A1), the proportion of the structural unit (a11) is preferably from 5 to 80 mol%, more preferably from 10 to 80 mol%, more preferably from 15 to 75 mol%, based on all structural units constituting the component (A1). Is more preferable. By setting it to the lower limit value or more, a pattern can be easily obtained when the resist composition is used, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

(Structural unit (a2))
The structural unit (a2) includes a —SO ₂ -containing cyclic group, and is derived from an acrylate ester in which an atom other than a hydrogen atom or a substituent may be bonded to the α-position carbon atom (hereinafter referred to as “structural unit”). , A structural unit (a2 ^S )), and a structural unit derived from an acrylate ester which may have a lactone-containing cyclic group and an atom other than a hydrogen atom or a substituent bonded to the α-position carbon atom. It is at least one structural unit selected from the group consisting of (hereinafter referred to as structural unit (a2 ^L )).
The structural unit (a2) contains a —SO ₂ — containing cyclic group or a lactone cyclic group, whereby a resist film formed using the positive resist composition containing the component (A1) is applied to the substrate. It contributes to the improvement of lithography properties by increasing the adhesion and increasing the affinity with a developer containing water (particularly in the case of an alkali development process).

-Structural unit (a2 ^S ):
The structural unit (a2 ^S ) is a structural unit derived from an acrylate ester containing an —SO ₂ -containing cyclic group and having an atom other than a hydrogen atom or a substituent bonded to the α-position carbon atom. is there.
Here, -SO ₂ - and containing cyclic group, -SO ₂ - within the ring skeleton thereof shows a cyclic group containing a ring containing, in particular, -SO ₂ - in the sulfur atom (S) Are cyclic groups that form part of the ring skeleton of the cyclic group. A ring containing —SO ₂ — in the ring skeleton is counted as one ring, and if it is only the ring, it is a monocyclic group, and if it has another ring structure, it is polycyclic regardless of the structure It is called a group. The —SO ₂ — containing cyclic group may be monocyclic or polycyclic.
-SO ₂ - containing cyclic group, in particular, -O-SO ₂ - within the ring skeleton cyclic group containing, i.e. -O-SO ₂ - -O-S- medium is a part of the ring skeleton It is preferably a cyclic group containing a sultone ring to be formed.
The —SO ₂ — containing cyclic group preferably has 3 to 30 carbon atoms, preferably 4 to 20 carbon atoms, more preferably 4 to 15 carbon atoms, and particularly preferably 4 to 12 carbon atoms. . However, the carbon number is the number of carbon atoms constituting the ring skeleton, and does not include the carbon number in the substituent.
The —SO ₂ — containing cyclic group may be an —SO ₂ — containing aliphatic cyclic group or an —SO ₂ — containing aromatic cyclic group. Preferably -SO ₂ - containing aliphatic cyclic group.
The —SO ₂ -containing aliphatic cyclic group includes at least a hydrogen atom from an aliphatic hydrocarbon ring in which a part of carbon atoms constituting the ring skeleton is substituted with —SO ₂ — or —O—SO ₂ —. One group is excluded. More specifically, a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring in which —CH ₂ — constituting the ring skeleton is substituted with —SO ₂ —, —CH ₂ — constituting the ring And a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring in which CH ₂ — is substituted with —O—SO ₂ —.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms are removed from a monocycloalkane having 3 to 6 carbon atoms. Examples of the monocycloalkane include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon group, a group in which two hydrogen atoms have been removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane. , Tricyclodecane, tetracyclododecane and the like.

The —SO ₂ — containing cyclic group may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), —COOR ″, —OC (═O) R ″, a hydroxyalkyl group, a cyano group and the like. Is mentioned.
The alkyl group as the substituent is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a hexyl group. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the group couple | bonded with the oxygen atom (-O-) to the alkyl group quoted as the alkyl group as the said substituent is mentioned.
Examples of the halogen atom as the substituent 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 for the substituent include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.
Examples of the halogenated alkyl group as the substituent include a group in which part or all of the hydrogen atoms of the alkyl group mentioned as the alkyl group as the substituent are substituted with the halogen atom. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.
R ″ in the —COOR ″ and —OC (═O) R ″ is a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms.
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. preferable.
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 Alternatively, one or more hydrogen atoms are removed from a polycycloalkane such as a monocycloalkane, bicycloalkane, tricycloalkane, or tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group. More specifically, one or more hydrogen atoms are removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Group.
The hydroxyalkyl group as the substituent is preferably one having 1 to 6 carbon atoms. Specifically, at least one of the hydrogen atoms of the alkyl group mentioned as the alkyl group as the substituent is substituted with a hydroxyl group. Group.
More specifically, examples of the —SO ₂ -containing cyclic group include groups represented by the following general formulas (3-1) to (3-4).

［式中、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、ｚは０〜２の整数であり、Ｒ^２７はアルキル基、アルコキシ基、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり、Ｒ”は水素原子またはアルキル基である。］

[In the formula, A ′ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, z is an integer of 0 to 2, and R ²⁷ is an alkyl group. , An alkoxy group, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group, and R ″ is a hydrogen atom or an alkyl group.]

In the general formulas (3-1) to (3-4), A ′ represents an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (—O—) or a sulfur atom (—S—), An oxygen atom or a sulfur atom.
The alkylene group having 1 to 5 carbon atoms in A ′ is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group.
When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group in which —O— or —S— is interposed between the terminal or carbon atoms of the alkylene group, such as —O—CH _{2. -, - CH 2 -O-CH} 2 -, - S-CH 2 -, - CH 2 -S-CH 2 - , and the like.
A ′ is preferably an alkylene group having 1 to 5 carbon atoms or —O—, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.
z may be any of 0 to 2, and is most preferably 0.
When z is 2, the plurality of R ²⁷ may be the same or different.
As the alkyl group, alkoxy group, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group in R ²⁷ , the —SO ₂ — containing cyclic group has the above-mentioned, respectively. And the same alkyl groups, alkoxy groups, halogenated alkyl groups, —COOR ″, —OC (═O) R ″, and hydroxyalkyl groups as those which may be substituted.
Below, the specific cyclic group represented by the said general formula (3-1)-(3-4) is illustrated. In the formula, “Ac” represents an acetyl group.

Among the above, the —SO ₂ -containing cyclic group is preferably a group represented by the general formula (3-1), and the chemical formulas (3-1-1), (3-1-18), ( It is more preferable to use at least one selected from the group consisting of groups represented by any of 3-3-1) and (3-4-1), and represented by the chemical formula (3-1-1). Are most preferred.

More specifically, examples of the structural unit (a2 ^S ) include structural units represented by general formula (a2-0) shown below.

［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^２８は−ＳＯ_２−含有環式基であり、Ｒ^２９は単結合または２価の連結基である。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, R ²⁸ represents a —SO ₂ — containing cyclic group, and R ²⁹ represents a single bond. Or it is a bivalent coupling group. ]

In formula (a2-0), R is the same as defined above.
R ²⁸ is the same as the —SO ₂ — containing cyclic group mentioned above.
R ²⁹ may be a single bond or a divalent linking group. Since it is excellent in the effect of this invention, it is preferable that it is a bivalent coupling group.
The divalent linking group for R ²⁹ is not particularly limited. For example, as the divalent linking group for Y ² in the general formula (a1-0-2) mentioned in the description of the structural unit (a1). The thing similar to what was mentioned is mentioned. Among these, those containing an alkylene group or an ester bond (—C (═O) —O—) are preferable.
The alkylene group is 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 Y ² can be used.
As the divalent linking group containing an ester bond, in particular, the general formula: —R ³⁰ —C (═O) —O— [wherein R ³⁰ is a divalent linking group. ] Is preferable. That is, the structural unit (a2 ^S ) is preferably a structural unit represented by the following general formula (a2-0-1).

［式中、ＲおよびＲ^２８はそれぞれ前記と同様であり、Ｒ^３０は２価の連結基である。］

[Wherein, R and R ²⁸ are the same as defined above, and R ³⁰ is a divalent linking group. ]

R ³⁰ is not particularly limited, and examples thereof include those similar to the divalent linking group of R ²⁹ in formula (a2-0).
The divalent linking group for R ³⁰ is preferably a linear or branched alkylene group, a divalent alicyclic hydrocarbon group, or a divalent linking group containing a hetero atom.
Examples of the linear or branched alkylene group, divalent alicyclic hydrocarbon group, and divalent linking group containing a hetero atom include the linear or branched chain mentioned as preferred in X described later. Examples thereof include the same alkylene groups, divalent alicyclic hydrocarbon groups, and divalent linking groups containing a hetero atom.
Among these, a linear or branched alkylene group or a divalent linking group containing an oxygen atom as a hetero atom is preferable.
As the linear alkylene group, a methylene group or an ethylene group is preferable, and a methylene group is particularly preferable.
As the branched alkylene group, an alkylmethylene group or an alkylethylene group is preferable, and —CH (CH ₃ ) —, —C (CH ₃ ) ₂ — or —C (CH ₃ ) ₂ CH ₂ — is particularly preferable.
The divalent linking group containing an oxygen atom is preferably a divalent linking group containing an ether bond or an ester bond, and the above formulas -A-O-B-,-[A-C (= O) -O] _m A group represented by —B— or —A—O—C (═O) —B— is more preferable.
Among them, preferred is a group represented by the formula -A-O-C (= O ) -B-, - represented by _{- (CH 2) c -C (} = O) -O- (CH 2) d The group is particularly preferred. c is an integer of 1 to 5, and 1 or 2 is preferable. d is an integer of 1-5, and 1 or 2 is preferable.

As the structural unit (a2 ^S ), a structural unit represented by general formula (a0-1-11) or (a0-1-12) shown below is particularly preferable, and represented by formula (a0-1-12). A structural unit is more preferable.

［式中、Ｒ、Ａ’、Ｒ^２７、ｚおよびＲ^３０はそれぞれ前記と同じである。］

[Wherein, R, A ′, R ²⁷ , z and R ³⁰ are the same as defined above. ]

In formula (a0-1-11), A ′ is preferably a methylene group, an oxygen atom (—O—) or a sulfur atom (—S—).
R ³⁰ is preferably a linear or branched alkylene group or a divalent linking group containing an oxygen atom. As the linear or branched alkylene group and the divalent linking group containing an oxygen atom in R ^30, the linear or branched alkylene group mentioned above and a divalent linking group containing an oxygen atom are mentioned. Examples are the same as the linking group.
As the structural unit represented by the formula (a0-1-12), a structural unit represented by the following general formula (a0-1-12a) or (a0-1-12b) is particularly preferable.

［式中、ＲおよびＡ’はそれぞれ前記と同じであり、ｃ〜ｅはそれぞれ独立に１〜３の整数である。］

[Wherein, R and A ′ are the same as defined above, and c to e are each independently an integer of 1 to 3.] ]

-Structural unit (a2 ^L ):
The structural unit (a2 ^L ) is a structural unit derived from an acrylate ester that contains a lactone-containing cyclic group and may have an atom or substituent other than a hydrogen atom bonded to the α-position carbon atom.
Here, the lactone-containing cyclic group refers to a cyclic group containing a ring (lactone ring) containing —O—C (O) — in the ring skeleton. 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. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.
The lactone cyclic group in the structural unit (a2 ^L ) is not particularly limited, and any one can be used. Specifically, the lactone-containing monocyclic group is a group obtained by removing one hydrogen atom from a 4- to 6-membered ring lactone, such as a group obtained by removing one hydrogen atom 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.
Examples of the structural unit (a2 ^L ) include those obtained by substituting R ²⁸ in the general formula (a2-0) with a lactone-containing cyclic group, and more specifically, the following general formula (a2- The structural unit represented by 1)-(a2-5) is mentioned.

［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’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０〜２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である。］

[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 ′ is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, carbon An alkoxy group of 1 to 5 or —COOR ″, R ″ is a hydrogen atom or an alkyl group; R ²⁹ is a single bond or a divalent linking group, and s ″ is an integer of 0 to 2; A ″ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom; m is 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.
The alkyl group in R ″ may be linear, branched or cyclic.
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.
Examples of A ″ include the same as A ′ in the general formula (3-1). A ″ represents an alkylene group having 1 to 5 carbon atoms, an oxygen atom (—O—) or a sulfur atom (— S-) is preferable, and an alkylene group having 1 to 5 carbon atoms or -O- is more preferable. The alkylene group having 1 to 5 carbon atoms is more preferably a methylene group or dimethylmethylene group, and most preferably a methylene group.
R ²⁹ is the same as ^{R 29} in the aforementioned general formula (a2-0).
In formula (a2-1), s ″ is preferably 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.

As the structural unit (a2 ^L ), at least one selected from the group consisting of structural units represented by the general formulas (a2-1) to (a2-5) is preferable, and the general formula (a2-1) to More preferably, at least one selected from the group consisting of structural units represented by (a2-3) is selected from the group consisting of structural units represented by the general formula (a2-1) or (a2-2) Particularly preferred is at least one of the above.
Among them, the formulas (a2-1-1), (a2-1-2), (a2-2-1), (a2-2-7), (a2-2-12), (a2-2-2-) 14), (a2-3-1), at least one selected from the group consisting of structural units represented by (a2-3-5) is preferred.

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. For example, as the structural unit (a2), only the structural unit (a2 ^S ) may be used, or only the structural unit (a2 ^L ) may be used, or they may be used in combination. As the structural unit (a2 ^S ) or the structural unit (a2 ^L ), one type may be used alone, or two or more types may be used in combination.
In the present invention, it is particularly preferable to have at least the structural unit (a2 ^S ) as the structural unit (a2) because the effects of the present invention are excellent.

  In the component (A1), the proportion of the structural unit (a2) is preferably 1 to 80 mol%, and preferably 10 to 70 mol%, based on the total of all structural units constituting the component (A1). Is more preferable, it is more preferable that it is 10-65 mol%, and 10-60 mol% is especially preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units, such as various kinds of DOF, CDU, etc. The lithography characteristics and pattern shape of the film are improved.

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

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

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

[Wherein, R is as defined 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 3-position of the adamantyl group is particularly preferred.

  In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.

  In formula (a3-3), t ′ is preferably 1. l is preferably 1. s is preferably 1. In these, a 2-norbornyl group or a 3-norbornyl group is preferably bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

As the structural unit (a3), one type may be used alone, or two or more types may be used in combination.
In the component (A1), the proportion of the structural unit (a3) is preferably 1 to 50 mol%, more preferably 3 to 45 mol%, based on all structural units constituting the component (A1). More preferred is ˜40 mol%. By setting it to the lower limit value or more, the effect of containing the structural unit (a3) can be sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

(Other structural units)
The component (A1) may contain other structural units (hereinafter referred to as structural unit (a4)) other than the structural units (a1) to (a3) as long as the effects of the present invention are not impaired.
The structural unit (a4) is not particularly limited as long as it is another structural unit that is not classified into the structural units (a1) to (a3) described above. A number of hitherto known materials can be used for resist resins such as lasers.
As the structural unit (a4), for example, an acid non-dissociable aliphatic polycyclic group is included, which is derived from an acrylate ester in which an atom other than a hydrogen atom or a substituent may be bonded to the α-position carbon atom. And a structural unit derived from a hydroxystyrene derivative, a structural unit derived from styrene, a structural unit derived from a vinylnaphthalene monomer, and the like. 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。］

[Wherein, R is the same as defined above. ]

As the structural unit (a4), one type may be used alone, or two or more types may be used in combination.
When the structural unit (a4) is contained in the component (A1), the proportion of the structural unit (a4) is preferably 1 to 90 mol% with respect to the total of all the structural units constituting the component (A1). 85 mol% is more preferable, and 1 to 80 mol% is more preferable.

The component (A1) is preferably a copolymer having the structural unit (a1).
Examples of such a copolymer include: a copolymer composed of structural units (a1), (a2) and (a3); a copolymer composed of structural units (a1) and (a4); a structural unit (a1), ( Examples thereof include a copolymer comprising a2), (a3) and (a4).
In the present invention, the component (A1) preferably includes a combination of structural units represented by the following general formulas (A1-11) to (A1-14). In the following general formula, R, R ²⁹ , s ″, R ¹³ , c, R ⁸ , j, e, A ′, R ¹¹ , R ¹² , h are the same as described above, and a plurality of Rs in the formula are Each may be the same or different.

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, preferably 1000 to 50000, more preferably 1500 to 30000, most preferably 2500 to 20000. preferable. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
Further, the dispersity (Mw / Mn) of the component (A1) is not particularly limited, and is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and 1.2 to 2 .5 is most preferred.
In addition, Mn shows a number average molecular weight.

In the component (A), as the component (A1), one type may be used alone, or two or more types may be used in combination.
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, the effects such as lithography characteristics are improved.

[(A2) component]
The component (A2) is preferably a low molecular compound having a molecular weight of 500 or more and less than 2500 and having an acid dissociable group and a hydrophilic group as exemplified in the description of the component (A1). Specific examples include those in which some of the hydrogen atoms of the hydroxyl group of the compound having a plurality of phenol skeletons are substituted with the acid dissociable group.
The component (A2) is, for example, a part of the hydrogen atom of the hydroxyl group of a low molecular weight phenol compound known as a sensitizer in a non-chemically amplified g-line or i-line resist or a heat resistance improver. Those substituted with a functional group are preferred and can be arbitrarily used.
Examples of such low molecular weight phenol compounds include bis (4-hydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, 2- (4-hydroxyphenyl) -2- (4′-hydroxyphenyl). ) Propane, 2- (2,3,4-trihydroxyphenyl) -2- (2 ′, 3 ′, 4′-trihydroxyphenyl) propane, tris (4-hydroxyphenyl) methane, bis (4-hydroxy-) 3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3, 4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyph Phenylmethane, bis (4-hydroxy-3-methylphenyl) -3,4-dihydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl- 4-hydroxy-6-methylphenyl) -3,4-dihydroxyphenylmethane, 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene, Examples include 2 to 6 nuclei of formalin condensates of phenols such as phenol, m-cresol, p-cresol and xylenol. Of course, it is not limited to these. In particular, a phenol compound having 2 to 6 triphenylmethane skeletons is preferable because of excellent resolution and LWR.
The acid dissociable group is not particularly limited, and examples thereof include those described above.
(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, as the component (A), one type may be used alone, or two or more types may be used in combination.
Among the above, the component (A) preferably contains the component (A1).
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 as long as it does not correspond to the compound (C1) to be described later, and what has been proposed as an acid generator for a chemically amplified resist can be used. Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, and poly (bissulfonyl) diazomethanes. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.
As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) can be used.

［式中、Ｒ^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 for 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 decyl 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 those described above for 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-1-11). Among these, those having a triphenylmethane skeleton such as a cation moiety represented by formulas (I-1-1) to (I-1-8) are preferable. Further, those having a dinaphthyl skeleton such as a cation moiety represented by the formula (I-1-9) are also preferred.
In the following formulas (I-1-10) to (I-1-11), 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 in 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 among them, —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 carbon atoms, still more preferably 5 to 20, particularly 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, for example, 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, decyl 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 has one or more hydrogen atoms from the polycycloalkane. 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 (L6), (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, (L2) to (L6), (S3) to (S4), and the like.

In the present invention, ^{R 4} ", ^{X-Q 1} - as a substituent preferably has the case, ^{R 4."} The, ^{X-Q 1} -Y 1 - in the Formula, ^{Q 1} and X are the Y ¹ is an optionally substituted alkylene group having 1 to 4 carbon atoms or an optionally substituted fluorinated alkylene group having 1 to 4 carbon atoms. ] 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 _CH 2 _CF 2 CF ₂ - is _{preferable, -CF 2 -, - CF 2} CF 2 - or -CF ₂ CF ₂ CF ₂ - is more preferable, -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 R ⁵ ″ to R ⁶ ″ are all phenyl groups.
"The, ^{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.
In addition, the anion part of these onium salts is an alkyl sulfonate such as methanesulfonate, n-propanesulfonate, n-butanesulfonate, n-octanesulfonate, 1-adamantanesulfonate, 2-norbornanesulfonate, d-camphor-10-sulfonate, An onium salt substituted with an aromatic sulfonate such as benzene sulfonate, perfluorobenzene sulfonate, or p-toluene sulfonate 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１〜３の整数であり、ｑ１〜ｑ２はそれぞれ独立に１〜５の整数であり、ｑ３は１〜１２の整数であり、ｔ３は１〜３の整数であり、ｒ１〜ｒ２はそれぞれ独立に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、ｖ０〜ｖ５はそれぞれ独立に０〜３の整数であり、ｗ１〜ｗ５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。］

[Wherein p is an integer of 1 to 3, q1 to q2 are each independently an integer of 1 to 5, q3 is an integer of 1 to 12, t3 is an integer of 1 to 3, and r1 ~ R2 is each independently an integer of 0 to 3, g is an integer of 1 to 20, R ⁷ is a substituent, n1 to n5 are each independently 0 or 1, and v0 to v5 are each Each independently represents an integer of 0 to 3, w1 to w5 are each independently an integer of 0 to 3, and Q ″ is the same as defined above.]

Examples of the substituent for R ⁷ include the same substituents 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 and r2, w1 to w5) attached to R ⁷ when is an integer of 2 or more, a plurality of the ^{R 7} groups may be the same, respectively, 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 This is preferable because the transparency to the surface is improved.
The proportion 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 hydrogen atoms are substituted with fluorine atoms. A perfluoroalkylene group or a perfluoroalkyl group.

  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 a heteroaryl group in which a part of carbon atoms constituting the ring of these groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Among these, a fluorenyl group is preferable.
The aryl group of R ³⁴ may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, or an alkoxy group. The alkyl group or halogenated alkyl group in the substituent preferably has 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. The halogenated alkyl group is preferably a fluorinated alkyl group.
The alkyl group or halogenated alkyl group having no substituent of R ³⁵ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 6 carbon atoms.
R ³⁵ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³⁵ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred is the strength of the acid generated. Most preferably, it is a fully fluorinated alkyl group in which a hydrogen atom is 100% fluorine-substituted.

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

Specific examples of the oxime sulfonate acid generator include α- (p-toluenesulfonyloxyimino) -benzyl cyanide, α- (p-chlorobenzenesulfonyloxyimino) -benzyl cyanide, α- (4-nitrobenzenesulfonyloxy). Imino) -benzylcyanide, α- (4-nitro-2-trifluoromethylbenzenesulfonyloxyimino) -benzylcyanide, α- (benzenesulfonyloxyimino) -4-chlorobenzylcyanide, α- (benzenesulfonyl) Oxyimino) -2,4-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -2,6-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -4-methoxybenzyl cyanide, α- ( 2-Chlorobenzenesulfonyloxyimino) 4-methoxybenzylcyanide, α- (benzenesulfonyloxyimino) -thien-2-ylacetonitrile, α- (4-dodecylbenzenesulfonyloxyimino) -benzylcyanide, α-[(p-toluenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α-[(dodecylbenzenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α- (tosyloxyimino) -4-thienyl cyanide, α- (methylsulfonyloxyimino) -1-cyclo Pentenyl acetonitrile, α- (methylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -1-cycloheptenylacetonitrile, α- (methylsulfonyloxyimino) -1-cyclooctene Acetonitrile, α- (trifluoromethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -cyclohexylacetonitrile, α- (ethylsulfonyloxyimino) -ethylacetonitrile, α- (propyl Sulfonyloxyimino) -propylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclopentylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclohexylacetonitrile, α- (cyclohexylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- ( Ethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclope N-tenyl acetonitrile, α- (n-butylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (ethylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclohexenylacetonitrile , Α- (n-butylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -phenylacetonitrile, α- (methylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (trifluoro Methylsulfonyloxyimino) -phenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -p- Butoxy phenylacetonitrile, alpha-(propylsulfonyl oxyimino)-p-methylphenyl acetonitrile, alpha-like (methylsulfonyloxyimino)-p-bromophenyl acetonitrile.
Further, an oxime sulfonate-based acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014] [chemical formula 18] to [chemical formula 19]), pamphlet of International Publication No. 04/074242, An oxime sulfonate-based acid generator disclosed in Examples 1 to 40) on pages 65 to 86 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, as the component (B), it is preferable to use a fluorinated alkyl sulfonate ion or an onium salt acid generator having an anion moiety represented by the above formula (b-3) as an anion.
Content of (B) component in the positive resist composition of this invention is 10-60 mass parts with respect to 100 mass parts of (A) component, Comprising: 10-50 mass parts is preferable, 12-40 mass parts Is more preferable. By setting it as the above range, even when EUV or EB is used as an exposure light source, sufficient sensitivity can be obtained and pattern formation can be performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

<(C) component>
In the present invention, the component (C) includes a compound (C1) represented by the following general formula (c1) (hereinafter referred to as “component (C1)”). In the present invention, the component (C) acts as an acid diffusion control agent, that is, a quencher that traps the acid generated from the component (B) by exposure.
In addition, the component (C) of the present invention may include a nitrogen-containing organic compound component (C2) (hereinafter referred to as “(C2) component”) that does not correspond to the component (C1).

［式中、Ｒ^Ｃ１は水酸基、アルコキシ基、シアノ基、−Ｏ−Ｃ（＝Ｏ）−Ｃ（Ｒ^Ｃ２）＝ＣＨ_２（Ｒ^Ｃ２は水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基である）、または−Ｏ−Ｃ（＝Ｏ）−Ｒ^Ｃ３（Ｒ^Ｃ３は炭化水素基である）であり、Ｙ^１は２価の脂肪族炭化水素基であり、Ｒ^１は水素原子、フッ素原子、アルキル基又はフッ素化アルキル基である。ｐは１〜１０の整数を表す。Ａ^＋は有機カチオンを表す。］

[Wherein R ^C1 represents a hydroxyl group, an alkoxy group, a cyano group, —O—C (═O) —C (R ^C2 ) ═CH ₂ (R ^C2 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a carbon number. 1 to 5 halogenated alkyl groups), or —O—C (═O) —R ^C3 (R ^C3 is a hydrocarbon group), and Y ¹ is a divalent aliphatic hydrocarbon group. , R ¹ is a hydrogen atom, a fluorine atom, an alkyl group or a fluorinated alkyl group. p represents an integer of 1 to 10. A ⁺ represents an organic cation. ]

[(C1) component]
(C1) component is a compound which consists of an anion part and a cation part represented by the said Formula (c1).
In formula (c1), R ^C1 represents a hydroxyl group, an alkoxy group, a cyano group, —O—C (═O) —C (R ^C2 ) ═CH ₂ (R ^C2 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or A halogenated alkyl group having 1 to 5 carbon atoms), or —O—C (═O) —R ^C3 (R ^C3 is a hydrocarbon group). When EUV or EB is used as the exposure light source, it is preferable that R ^C1 has a hydroxyl group because the decomposition reaction in the exposed area is promoted.
The alkoxy group of R ^C1 is preferably an alkoxy group having 1 to 5 carbon atoms. Specific examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n- Examples include butoxy group and tert-butoxy group. Of these, a methoxy group and an ethoxy group are most preferable.

When R ^C1 is —O—C (═O) —C (R ^C2 ) ═CH ₂ , R ^C2 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. is there.
The alkyl group having 1 to 5 carbon atoms in R ^C2 is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, n -Butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like can be mentioned.
The halogenated alkyl group in R ^C2 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 ^C2 is preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a fluorinated alkyl group having 1 to 3 carbon atoms, and is most preferably a hydrogen atom or a methyl group from the viewpoint of industrial availability.

When R ^C1 is —O—C (═O) —R ^C3 , R ^C3 is a hydrocarbon group.
The hydrocarbon group for R ^C3 may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. Specific examples of the hydrocarbon group for R ^C3 include the same hydrocarbon groups as those described above for the substituent for R ^{4 ″ in} the component (B).
Among them, as the hydrocarbon group for R ^C3 , an alicyclic group in which one or more hydrogen atoms are removed from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like, or Aromatic groups such as phenyl group and naphthyl group are preferred. When R ^C3 is an alicyclic group, the resist composition is well dissolved in an organic solvent, so that the lithography properties are improved. Further, when R ^C3 is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition is excellent in light absorption efficiency, and sensitivity and lithography characteristics are good.

In formula (c1), Y ¹ is a divalent aliphatic hydrocarbon group, and an alkylene group and a divalent aliphatic cyclic group are preferred.
The alkylene group for Y ¹ preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms, and 2 to 3 carbon atoms. Is most preferred.

In the divalent aliphatic cyclic group for Y ¹ , the “aliphatic cyclic group” may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (= O). Etc.
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” may be either a monocyclic group or a polycyclic group, and is preferably a polycyclic group.
Examples of the aliphatic cyclic group include monocycloalkanes that may or may not be substituted with the above substituents; two from cyclocycloalkanes such as bicycloalkanes, tricycloalkanes, and tetracycloalkanes. Examples include groups in which the above hydrogen atoms have been removed. More specifically, a group in which two or more hydrogen atoms are removed from a monocycloalkane such as cyclopentane or cyclohexane; two or more groups from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples include a group excluding a hydrogen atom.

In the formula (c1), R ¹ is a hydrogen atom, a fluorine atom, an alkyl group or a fluorinated alkyl group. In particular, when R ¹ is a fluorine atom or a fluorinated alkyl group, the strength (acidity) of the acid generated from the (C1) component by exposure increases (although it is weak), and the acid generated from the (B) component by exposure This is preferable because the balance between the ease of salt exchange and the ease of maintaining the counter cation in the component (C1) before exposure is improved.

The alkyl group for R ¹ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
The fluorinated alkyl group for R ^1, include those in which a part or all of the hydrogen atoms in the alkyl group in R ¹ of the is substituted with a fluorine atom.
The fluorination rate of the fluorinated alkyl group (ratio of the number of fluorine atoms to the total number of fluorine atoms and hydrogen atoms (%)) is preferably 50 to 100%, more preferably 80 to 100%, and more preferably 85 to 100%. Is more preferable.

Any of the alkyl group or the fluorinated alkyl group in R ¹ may have a substituent. Examples of the substituent include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
The alkoxy group of the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group. A group and an ethoxy group are particularly preferred.
Examples of the halogen atom for the substituent include a chlorine atom, a bromine atom, and an iodine atom.
Examples of the halogenated alkyl group of the substituent include groups in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with the halogen atoms (chlorine atom, bromine atom, iodine atom, etc.). .

In formula (c1), p represents an integer of 1 to 10. Especially, it is more preferable that p is an integer of 1-4, and it is especially preferable that it is 1-2.
In the case where p is an integer of 1 to 4 and R ¹ is not a fluorinated alkyl group, the skeleton of “R ¹ — (CF ₂ ) _p —SO ₂ —” is, for example, a perfluoroalkyl having 6 to 10 carbon atoms Although the chain is hardly decomposable, the degradability is good, and the handleability considering bioaccumulation is further improved. Further, it is preferable because it is easily distributed uniformly in the resist film.

In the formula (c1), A ⁺ represents an organic cation.
The organic cation of A ⁺ is not particularly limited, and any conventionally known cation moiety such as an onium salt acid generator can be used as appropriate.
Specifically, the organic cation part of the compounds represented by the formulas (b-1) to (b-2) and the organic cation represented by the formulas (b-5) to (b-6) are preferable. Can be used.
In the present invention, as A ⁺ , the organic cation part of the compound represented by the formula (b-1) or the organic cation represented by (b-5) is preferable, and the formula (I-1-1) is particularly preferable. ) To (I-1-8) are preferred, and organic cation having a triphenyl skeleton such as organic cations represented by the formulas (I-1-1) to (I-1-8) More preferably.

  The component (C1) is a compound represented by the following formulas (c1-1) to (c1-3) because lithography characteristics such as roughness and the resist pattern shape are better when a resist composition is used. It is particularly preferred.

［式中、Ｒ^１”〜Ｒ^３”、Ｒ^１、ｐはそれぞれ前記と同じである。ｑは１〜１０の整数である。Ｒ^０は水素原子又はメチル基であり、Ｒ^Ｃ３０は脂環式基又は芳香族基である。］

[Wherein, R ¹ ″ to R ³ ″, R ¹ and p are the same as defined above. q is an integer of 1-10. R ⁰ is a hydrogen atom or a methyl group, and R ^C30 is an alicyclic group or an aromatic group. ]

In the above formula, q is preferably an integer of 1 to 6, more preferably an integer of 1 to 4, more preferably an integer of 1 to 3, and most preferably 2.
In the above formula, the alicyclic group and aromatic group of R ^C30 are the same as the alicyclic group and aromatic group of R ^C3 .

As the component (C1), one type may be used alone, or two or more types may be used in combination.
In the positive resist composition of the present invention, the content ratio of the (C1) component with respect to the total of the (C1) component and the (B) component is 1 to 15 mol% and 2 to 13 mol%. Is preferable, and it is more preferable that it is 3-12 mol%.
By setting it to be equal to or higher than the lower limit of the above range, acid diffusion control by the component (C1) is suitably performed, and lithography properties such as sensitivity and roughness are improved. Moreover, by setting it as below the upper limit of the said range, a sensitivity can be maintained favorable and it can be set as the resist composition excellent also in the throughput.
The component (C1) is preferably 0.5 to 10.0 parts by mass, more preferably 0.5 to 5.0 parts by mass with respect to 100 parts by mass of the component (A). More preferably, it is 0.8-4.0 mass parts. When the positive resist composition is above the lower limit of the above range, the lithography properties such as roughness are further improved in combination with the component (A1). Further, a better resist pattern shape can be obtained. When the amount is not more than the upper limit of the above range, the sensitivity can be maintained satisfactorily and the throughput is excellent.

[(C2) component]
The component (C2) is a nitrogen-containing organic compound component (C2) that does not correspond to the component (C1).
The component (C2) is not particularly limited as long as it functions as an acid diffusion controller and does not correspond to the component (C1), and any known component may be used. Of these, aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are preferred.
An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
Examples of the aliphatic amine include an amine (alkyl amine 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 12 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-pentylamine, tri-n-hexylamine , Trialkylamines such as tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, Li isopropanolamine, di -n- octanol amines, alkyl alcohol amines tri -n- octanol amine. Among these, a trialkylamine having 5 to 10 carbon atoms is more preferable, and tri-n-pentylamine or tri-n-octylamine is particularly 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.

  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, triethanolamine triacetate and the like, and triethanolamine triacetate is preferable.

Moreover, you may use an aromatic amine as (C2) component.
Aromatic amines include aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, diphenylamine, triphenylamine, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxy. And carbonylpyrrolidine.

(C2) A component may be used independently and may be used in combination of 2 or more type.
(C2) A 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.

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

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

[(S) component]
The resist composition of the present invention can be produced by dissolving the components blended in the resist composition in an organic solvent (hereinafter 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.
(S) component is, for example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, 2-heptanone; ethylene glycol, diethylene glycol, propylene glycol, Polyhydric alcohols such as dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, the polyhydric alcohols or compounds having the ester bond Monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, or monophenyl ether Derivatives of polyhydric alcohols such as compounds having an ether bond such as propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) among these; cyclic ethers such as dioxane, , Methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, etc .; anisole, ethyl benzyl ether, cresyl methyl Ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene An aromatic organic solvent such as

(S) A component may be used independently and may be used as 2 or more types of mixed solvents.
Of these, γ-butyrolactone, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), and ethyl lactate (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, and is preferably in the range of 1: 9 to 9: 1. 2: 8 to 8: A range of 2 is more preferable.
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, 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 0.00. It is used in a range of 5 to 20% by mass, preferably 1 to 15% by mass.

  The dissolution of the component to be blended in the resist composition into the component (S) can be performed, for example, by simply mixing and stirring the above-described components by a usual method. If necessary, a dissolver, a homogenizer, 3 You may disperse and mix using dispersers, such as this roll mill. Moreover, after mixing, you may further filter using a mesh, a membrane filter, etc.

According to the resist composition of the present invention, it is possible to form a resist pattern excellent in resolution and excellent in lithography properties such as pattern shape and LER. Further, since the resist composition of the present invention is highly sensitive to an exposure light source such as EUV, a fine pattern can be formed even when EUV or the like is used. The reason why such an effect is obtained is presumed as follows.
The resist composition of the present invention contains a component (C1). Therefore, in the unexposed part, the anion part in the component (C1) is salt-exchanged with the strong acid generated from the component (B) in the exposed part by exposure to suppress the diffusion of the strong acid generated from the component (B). It functions as a quencher.
The component (C1) of the present invention also functions as a photoacid generator that decomposes upon exposure and generates a weak acid. Therefore, the acid is generated not only from the component (B) but also from the component (C1) in the exposed area (therefore, the component (C1) loses its function as a quencher after photolysis), so that the component (B), etc. It is surmised that the generation of acid and the deprotection reaction are accelerated, the contrast between the exposed part and the unexposed part is increased, and a resist pattern having a more excellent shape and lithography characteristics can be obtained.
Furthermore, the resist composition of the present invention contains a large amount of the component (B) and includes the component (C1) at a specific blending ratio with respect to the component (B), so that it can be used for an exposure light source such as EUV. It is considered that the sensitivity can be obtained and a pattern can be obtained.

≪Resist pattern formation method≫
The resist pattern forming method according to the second aspect of the present invention includes a step of forming a resist film on a support using the resist composition according to the first aspect of the present invention, a step of exposing the resist film, And a step of developing the resist film to form a resist pattern.
The resist pattern forming method of the present invention can be performed, for example, as follows.
That is, first, the resist composition is coated on a support with a spinner or the like, and pre-baked (post-apply bake (PAB)) for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of 80 to 150 ° C. Then, after selectively exposing an electron beam (EB) through a desired mask pattern by an electron beam drawing machine or the like, PEB (post-exposure heating) is 40 to 120 at a temperature of 80 to 150 ° C. Second, preferably 60-90 seconds. Next, this is developed.
In the case of an alkali development process, an alkali development treatment is performed using an alkali developer, for example, a 0.1 to 10% by mass tetramethylammonium hydroxide (TMAH) aqueous solution.
In the case of a solvent development process, development processing is performed using an organic solvent. The organic solvent is not particularly limited as long as it can dissolve the component (A) (component (A) before exposure), and can be appropriately selected from known organic solvents. Specific examples include ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, and other polar solvents, hydrocarbon solvents, and the like, with ester solvents being preferred. As the ester solvent, butyl acetate is preferred.
A rinsing treatment is preferably performed after the development treatment. In the case of an alkali development process, water rinsing using pure water is preferable. In the case of the solvent development process, it is preferable to use a rinse solution containing the organic solvent mentioned above.
Thereafter, drying is performed. 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 of the present invention is more effective for KrF excimer laser, ArF excimer laser, EB or EUV, and particularly effective for ArF excimer laser.

The exposure 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.
In immersion exposure, at the time of exposure, a solvent (having a refractive index larger than the refractive index of air) is formed between a lens and a resist film on the wafer, which is conventionally filled with an inert gas such as air or nitrogen. Exposure is performed in a state filled with the immersion medium.
More specifically, in the immersion exposure, a solvent (immersion medium) having a refractive index larger than the refractive index of air between the resist film obtained as described above and the lowermost lens of the exposure apparatus. And in that state, it can be carried out by exposing through a desired mask pattern (immersion exposure).
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 exposed by the immersion exposure 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, n is particularly preferably a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms. 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.

[Examples 1 to 27, Comparative Examples 1 to 11]
The components shown in Tables 1 to 4 were mixed and dissolved to prepare a positive resist composition.

Each abbreviation in Tables 1 to 4 has the following meaning. Moreover, the numerical value in [] is a compounding quantity (part by mass), and the numerical value in <> is the number of moles.
(A) -1 to (A) -5: the following polymer compounds (A) -1 to (A) -5.
(B) -1 to (B) -4: The following compounds (B) -1 to (B) -4.
(C1) -1: The following compound (C1) -1.
(C1) -2: The following compound (C1) -2 obtained by the following synthesis method.
(C1) -3: The following compound (C1) -3.
(C2) -1: tri-n-octylamine.
(E) -1: salicylic acid.
(S) -1: γ-butyrolactone.
(S) -2: Mixed solvent of PGMEA / PGME / cyclohexanone = 2205/1960/1225 (mass ratio).
(S) -3: PGMEA / PGME = 6/4 (mass ratio) mixed solvent.

The synthesis example of the compound represented by the following (C1) -2 is shown below. In the analysis by NMR, the chemical shift reference material of ¹ H-NMR is tetramethylsilane (TMS), and the chemical shift reference material of ¹⁹ F-NMR is trichlorofluoromethane (however, the peak of hexafluorobenzene is -162.2 ppm).

[Synthesis Example 1: Synthesis of N- [2- (adamantan-1-ylcarbonyloxy) ethyl] trifluoromethanesulfonamide]
In a glass flask equipped with a thermometer and a condenser, 100 g (0.52 mol) of trifluoromethanesulfonic acid amide ethanol, 108.6 g (0.54 mol) of 1-adamantanecarboxylic acid, p-toluenesulfonic acid (0.1 mol), and toluene 500 g was added and dehydration was performed under reflux using a Dean-Stark type dehydrator. After refluxing for 9 hours, about 9 ml of water could be removed. This reaction solution is dissolved in 500 g of ethyl acetate and washed twice with a saturated sodium hydrogen carbonate solution, once with 1N HCl, and once with a saturated saline solution. The organic phase was dried over sodium sulfate, the solvent was distilled off under reduced pressure, and then recrystallized in hexane to give 140 g of N- [2- (adamantan-1-ylcarbonyloxy) ethyl] trifluoromethanesulfonamide (yield 75%, 99% purity) was obtained.

[Physical analysis of N- [2- (adamantan-1-ylcarbonyloxy) ethyl] trifluoromethanesulfonamide)
The N- [2- (adamantan-1-ylcarbonyloxy) ethyl] trifluoromethanesulfonamide) was analyzed by NMR.
¹ H NMR (measurement solvent: deuterated chloroform, reference material: tetramethylsilane); δ = 5.43-5.35 (brs, 1H), 4.20 (t, 2H, J = 5.2 Hz), 3. 53 (td, 2H, J = 5.2 Hz), 2.08-1.98 (brs, 3H), 1.91-1.87 (brs, 6H), 1.75-1.67 (brs, 6H) ).
¹⁹ F NMR (measurement solvent: deuterated chloroform, reference material: trichlorofluoromethane); δ = −77.8 (s, 3F).
From the results of the above analysis, it was confirmed that the obtained compound was N- [2- (adamantan-1-ylcarbonyloxy) ethyl] trifluoromethanesulfonamide represented by the following formula (i).

[Synthesis Example 2: Synthesis of triphenylsulfonium N- [2- (adamantan-1-ylcarbonyloxy) ethyl] trifluoromethanesulfonamide]
To a 3 L reactor, 240 g (0.63 mol) of N- [2- (adamantan-1-ylcarbonyloxy) ethyl] trifluoromethanesulfonamide obtained in Synthesis Example 1 above, 800 mL of water and 800 mL of chloroform were added, and While maintaining the temperature at 0 ° C., 240% (0.68 mol) of 11% NaOH was slowly added dropwise and stirred for 30 minutes. After adding 244 g (0.71 mol) of triphenylsulfonium bromide and stirring at room temperature for 15 hours, liquid separation was performed, and the obtained organic layer was washed with 800 mL of water four times and concentrated under reduced pressure. The obtained yellow oily substance was dissolved in acetonitrile and recrystallized in IPE to obtain 360 g of triphenylsulfonium N- [2- (adamantan-1-ylcarbonyloxy) ethyl] trifluoromethanesulfonamide. At this time, the purity was 99% and the yield was 87%.

[Physical analysis of triphenylsulfonium N- [2- (adamantan-1-ylcarbonyloxy) ethyl] trifluoromethanesulfonamide]
The triphenylsulfonium N- [2- (adamantan-1-ylcarbonyloxy) ethyl] trifluoromethanesulfonamide was analyzed by NMR.
¹ H NMR (measurement solvent: heavy DMSO, reference material: tetramethylsilane); δ = 7.88-7.76 (m, 15H; Ph ₃ S ⁺ ), 3.85 (t, 2H), 3.02 (T, 2H), 2.08-1.98 (brs, 3H), 1.91-1.87 (brs, 6H), 1.75-1.67 (brs, 6H).
¹⁹ F NMR (measuring solvent: heavy DMSO, reference material: trichlorofluoromethane); δ = −75.5 (s, 3F).
From the results of the above analysis, it was confirmed that the obtained compound was triphenylsulfonium N- [2- (adamantan-1-ylcarbonyloxy) ethyl] trifluoromethanesulfonamide shown in the following (C1) -2.

［Ｍｗ＝８０００、Ｍｗ／Ｍｎ＝１．９１、ｌ／ｍ／ｎ＝３８．７／３８．２／２３．１（モル比）］

[Mw = 8000, Mw / Mn = 1.91, 1 / m / n = 38.7 / 38.2 / 23.1 (molar ratio)]

［Ｍｗ＝７４００、Ｍｗ／Ｍｎ＝２．２９、ｌ／ｍ／ｎ／ｏ＝３４．５／２１．７／３０．５／１３．３（モル比）］

[Mw = 7400, Mw / Mn = 2.29, 1 / m / n / o = 34.5 / 21.7 / 30.5 / 13.3 (molar ratio)]

［Ｍｗ＝８３００、Ｍｗ／Ｍｎ＝１．９６、ｌ／ｍ／ｎ＝３１／５７／１２（モル比）］

[Mw = 8300, Mw / Mn = 1.96, 1 / m / n = 31/57/12 (molar ratio)]

［Ｍｗ＝７４００、Ｍｗ／Ｍｎ＝１．８３、ｌ／ｍ／ｎ／ｏ／ｐ＝３６．２／２１．２／１５．９／１４．６／１２．０（モル比）］

[Mw = 7400, Mw / Mn = 1.83, 1 / m / n / o / p = 36.2 / 21.2 / 15.9 / 14.6 / 12.0 (molar ratio)]

［Ｍｗ＝８０００、Ｍｗ／Ｍｎ＝１．８６、ｌ／ｍ＝７０．１／２９．９（モル比）］

[Mw = 8000, Mw / Mn = 1.86, 1 / m = 70.1 / 29.9 (molar ratio)]

<Formation of resist pattern> [Sensitivity]
The resolution was evaluated using the obtained positive resist composition.
The positive resist composition of each example was uniformly applied using a spinner on an 8-inch silicon substrate subjected to hexamethyldisilazane (HMDS) treatment at 90 ° C. for 36 seconds, and the temperatures shown in Table 5 were obtained. A resist film (film thickness 60 nm) was formed by performing a baking process (PAB) for 60 seconds.
The resist film was drawn (exposed) using an electron beam drawing machine HL-800D (VSB) (manufactured by Hitachi Ltd.) at an acceleration voltage of 70 kV and an exposure dose of 75 μC / cm ² or less. Moreover, the baking process (PEB) for 60 second was performed at the temperature shown in Table 5, and also the 2.38 mass% aqueous solution (brand name: NMD-3, Tokyo Ohka) of tetramethylammonium hydroxide (TMAH) at 23 degreeC. Development was performed for 30 seconds using Kogyo Co., Ltd., followed by rinsing with pure water for 15 seconds, followed by shake-off drying.
As a result, Comparative Examples 6 to 11 did not resolve, but in any example except Comparative Examples 6 to 11, the resist film had a 1: 1 space space and line (space width 100 nm, pitch 200 nm). S / L) pattern was formed. In addition, the optimum exposure amount Eop (μC / cm ² ) at this time, that is, the sensitivity of the formed pattern was obtained. The results are shown in Table 5.

[Pattern shape evaluation]
The cross-sectional shape of the pattern formed at the optimum exposure amount Eop at which the 100 nm 1: 1 S / L pattern is formed is observed using a scanning electron microscope (trade name: S-4700, manufactured by Hitachi, Ltd.) The shape was evaluated according to the following criteria. The results are shown in Table 5.
○: The rectangularity is high and good.
X: Top-round shape and low rectangularity.

[Resolution]
The limiting resolution (nm) in the above Eop was determined using a scanning electron microscope S-9220 (manufactured by Hitachi). The results are shown in Table 5 with ◯ for those resolved at 50 nm and x for those not resolved at 50 nm (patterns that could not be completely removed). The following LER and EL margin were examined in an example in which the resolution result was ◯.

[Line edge roughness (LER)]
The dimensional variation for each line of the S / L pattern was evaluated.
Specifically, the line width of 16 lines was measured with a length measuring SEM (scanning electron microscope, acceleration voltage 800 V, trade name: S-9220, manufactured by Hitachi, Ltd.), and the standard deviation calculated from the results was measured. The triple value (3s) of (s) was determined.
3s obtained in this way means that the smaller the value is, the smaller the roughness is, and an S / L pattern having a uniform width is obtained.

[Evaluation of exposure margin (EL margin)]
With the above Eop, the exposure amount when the line of the S / L pattern is formed within the range of ± 10% (90 nm to 110 nm) of the target dimension (line width 100 nm) is obtained, and the EL margin (unit:%) is obtained by the following equation. ) The results are shown in Table 5.
EL margin (%) = (| E1-E2 | / EOP) × 100
E1: Exposure amount when a S / L pattern having a space width of 90 nm is formed (μC / cm ² )
E2: exposure amount (μC / cm ² ) when an S / L pattern having a space width of 110 nm was formed
Note that the larger the value of the EL margin, the smaller the change amount of the pattern size accompanying the change in the exposure amount.

  From the results of Table 5, the resist compositions of Examples 1 to 27 have better lithography properties such as resolution, LWR, and EL margin, and pattern shapes than the resist compositions of Comparative Examples 1 to 11. Was confirmed.

Claims (5)

A base component (A) whose solubility in a developing solution is changed by the action of an acid,
The nitrogen-containing organic compound component (C) containing the compound (C1) represented by the following general formula (c1), and the acid generator component (B) that generates an acid upon exposure (excluding the compound (C1)) A resist composition comprising:
The content ratio of the acid generator component (B) is 10 to 60 parts by mass with respect to 100 parts by mass of the base material component (A).
The resist composition, wherein a content ratio of the compound (C1) is 1 to 15 mol% with respect to a total of the compound (C1) and the acid generator component (B).

[Wherein R ^C1 represents a hydroxyl group, an alkoxy group, a cyano group, —O—C (═O) —C (R ^C2 ) ═CH ₂ (R ^C2 represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a carbon number. 1 to 5 halogenated alkyl groups), or —O—C (═O) —R ^C3 (R ^C3 is a hydrocarbon group), and Y ¹ is a divalent aliphatic hydrocarbon group. , R ¹ is a hydrogen atom, a fluorine atom, an alkyl group or a fluorinated alkyl group. p represents an integer of 1 to 10. A ⁺ represents an organic cation. ]   The resist composition according to claim 1, wherein the base material component (A) is a base material component (A0) whose polarity is increased by the action of an acid.   The base component (A0) is a structural unit derived from an acrylate ester in which an atom other than a hydrogen atom or a substituent may be bonded to a carbon atom at the α-position, and the polarity is increased by the action of an acid. The resist composition according to claim 2, comprising a resin component (A1) having a structural unit (a1) containing an acid-decomposable group.   The resist composition according to any one of claims 1 to 3, wherein the nitrogen-containing organic compound component (C) further includes a nitrogen-containing organic compound component (C2) that does not correspond to the compound (C1).   A step of forming a resist film on a support using the resist composition according to any one of claims 1 to 4, a step of exposing the resist film, and developing the resist film to form a resist pattern A resist pattern forming method including the step of: