JP5990373B2 - Resist composition, resist pattern forming method, and polymer compound - Google Patents

Description

  The present invention relates to a resist composition, a resist pattern forming method, and a polymer compound useful as an additive for 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, but at present, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has started. Further, studies have been made on electron beams having shorter wavelengths (higher energy) than these excimer lasers, EUV (extreme ultraviolet rays), X-rays, and the like.
Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing a pattern with fine dimensions.
As a resist material satisfying such requirements, a chemically amplified resist composition containing a base material component whose solubility in an alkaline developer is changed by the action of an acid and an acid generator component that generates an acid upon exposure is used. It has been.

As a base material component used in the chemically amplified resist composition, a resin (base resin) is generally used.
For example, as a chemically amplified resist composition for forming a positive resist pattern in an alkali development process using an alkali developer as a developer, an acid generator component and solubility in an alkali developer due to the action of an acid are included. What contains the resin component which increases is 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. Therefore, by performing alkali development, a positive pattern in which an unexposed portion remains as a pattern is formed.
As the resin component, one that increases the polarity of the resin by the action of an acid is generally used. As the polarity increases, solubility in an alkaline developer increases while solubility in an organic solvent decreases. Therefore, when a solvent development process using an organic solvent-containing developer (organic developer) is applied instead of an alkali development process, the solubility in the organic developer is relatively reduced in the exposed area. In the solvent development process, the unexposed portion of the resist film is dissolved and removed by the organic developer, and a negative resist pattern is formed in which the exposed portion remains as a pattern. Such a solvent development process for forming a negative resist pattern is sometimes referred to as a negative development process (see, for example, Patent Document 1).

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

As one of the methods for further improving the resolution, exposure (immersion exposure) is performed by interposing a liquid (immersion medium) having a higher refractive index than air between the objective lens of the exposure machine and the sample. There is known a lithography method that performs so-called liquid immersion lithography (hereinafter sometimes referred to as “immersion exposure”). According to immersion exposure, even when a light source having the same exposure wavelength is used, the same high resolution as when using a light source with a shorter wavelength or using a high NA lens can be achieved, and the depth of focus can be reduced. There is no decline. Moreover, immersion exposure can be performed using an existing exposure apparatus. For this reason, immersion exposure has been widely used in recent years because it can realize the formation of a resist pattern with low cost, high resolution, and excellent depth of focus. Immersion exposure is effective in the formation of all pattern shapes, and can be combined with super-resolution techniques such as a phase shift method and a modified illumination method. Currently, as an immersion exposure technique, a technique mainly using an ArF excimer laser as a light source is being actively researched. As an immersion medium, water is mainly studied.
It has been proposed to add a compound containing a fluorine atom to a resist composition used for such immersion exposure. For example, Patent Document 3 discloses a fluorine-containing polymer compound having a structural unit having a fluorine atom and a structural unit derived from (meth) acrylic acid as a compound containing a fluorine atom to be added to the resist composition. ing.

JP 2009-025723 A JP 2003-241385 A JP 2011-13569 A

  In the above immersion exposure, in addition to normal lithography characteristics (sensitivity, resolution, etching resistance, etc.), a resist material having characteristics corresponding to the immersion exposure technique is required. For example, in immersion exposure, when the resist film and the immersion solvent come into contact with each other, elution of the substance in the resist film into the immersion solvent (substance elution) occurs. Substance elution causes phenomena such as alteration of the resist layer and change in the refractive index of the immersion solvent, thereby deteriorating the lithography properties. Since the amount of this substance elution is affected by the characteristics (for example, hydrophilicity / hydrophobicity) of the resist film surface, for example, the elution of the substance can be reduced by increasing the hydrophobicity of the resist film surface. In the case where the immersion medium is water, when immersion exposure is performed using a scanning immersion exposure machine as described in Non-Patent Document 1, the immersion medium follows the movement of the lens. Therefore, the water following ability to move is required. If the water followability is low, the exposure speed is lowered, and there is a concern that the productivity may be affected. This water followability is considered to be improved by increasing the hydrophobicity of the resist film.

Thus, it is considered that by increasing the hydrophobicity of the resist film surface, it is possible to solve problems peculiar to the immersion exposure technique such as reduction of substance elution and improvement of water followability.
However, even if the resist film is simply hydrophobized, there is an adverse effect on lithography characteristics and the like. For example, when the hydrophobicity of the resist film is increased, there is a problem that defects (defects) are likely to occur in the resist film after alkali development. In particular, when a pattern is formed using an alkali development process, defects are likely to occur in unexposed areas.
Here, “defect” refers to all defects detected when a developed resist pattern is observed from directly above, for example, by a surface defect observation apparatus (trade name “KLA”) manufactured by KLA Tencor. This defect is, for example, a defect due to adhesion of foreign matter or deposits on the resist pattern surface such as scum (resist residue), bubbles, dust, etc. after development, bridging between line patterns, filling of holes in contact hole patterns This refers to problems related to pattern shapes such as pattern irregularities and the like. In the resist composition described in Patent Document 3 and the like, the fluorine-containing polymer compound increases water repellency during exposure, and a hydrophilic group is formed during development to increase hydrophilicity and reduce defects. ing.
However, the conventional resist composition as described in Patent Document 3 has a problem that the effect of reducing the defect may not be sufficiently exhibited depending on the type of the developer used.

  The present invention has been made in view of the above circumstances, and is a resist composition capable of reducing the occurrence of defects, a resist pattern forming method using the resist composition, and a polymer useful as an additive for the resist composition. It is an object to provide a compound.

In order to solve the above problems, the present invention employs the following configuration.
That is, the first aspect of the present invention comprises a base component (A) whose solubility in a developer is changed by the action of an acid, an acid generator component (B) that generates an acid upon exposure, and a fluorine-containing compound component ( F) a resist composition, wherein the fluorine-containing compound component (F) includes a structural unit ( f1) represented by the following general formula (f1-1) and a structural unit (f2) containing a fluorine atom (Excluding the structural unit (f1)), and the base material component (A) includes a —SO ₂ — containing cyclic group, and is a carbon atom at the α-position. And a structural unit (a2 ^S ) derived from an acrylate ester optionally substituted with a substituent.

［式中、Ｒ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り、Ｒ ^１ は、直鎖状若しくは分岐鎖状の脂肪族炭化水素基、又は、ヘテロ原子を含む２価の連結基と、前記直鎖状若しくは分岐鎖状の脂肪族炭化水素基との組み合わせであって、前記ヘテロ原子を含む２価の連結基は、−Ｏ−、−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｏ）−、−Ｏ−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｏ）−ＮＨ−、−ＮＨ−（Ｈはアルキル基又はアシル基で置換されていてもよい。）、−Ｓ−、−Ｓ（＝Ｏ） _２ −又は−Ｓ（＝Ｏ） _２ −Ｏ−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, and R ¹ represents a linear or branched aliphatic hydrocarbon group, Or a combination of a divalent linking group containing a heteroatom and the linear or branched aliphatic hydrocarbon group, wherein the divalent linking group containing a heteroatom is -O-, —C (═O) —O—, —C (═O) —, —O—C (═O) —O—, —C (═O) —NH—, —NH— (H is an alkyl group or acyl) it may be substituted with a group), -. S -, - S (= O) 2 - or -S _{(= O)} is 2 -O-. ]

  According to a second aspect of the present invention, a resist film 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. It is a resist pattern formation method including the process of forming a pattern.

In the present specification and claims, “aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity.
Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in the alkoxy group.
The “alkylene group” includes linear, branched, and cyclic divalent saturated hydrocarbon groups unless otherwise specified.
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 present specification, acrylic acid and acrylic ester in which a hydrogen atom bonded to a carbon atom at the α-position is substituted with a substituent may be referred to as α-substituted acrylic acid and α-substituted acrylic ester, respectively. In addition, acrylic acid and α-substituted acrylic acid may be collectively referred to as “(α-substituted) acrylic acid”, and α-substituted acrylic acid ester may be collectively referred to as “(α-substituted) acrylic acid ester”.
Examples of the substituent bonded to the α-position carbon atom of the α-substituted acrylic acid or ester thereof include a halogen atom, an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, and a hydroxyalkyl group. It is done. 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.
Examples of the halogen atom as the α-position substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Specific examples of the alkyl group having 1 to 5 carbon atoms as the α-position substituent 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, Examples thereof include linear or branched alkyl groups such as isopentyl group and neopentyl group.
Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms as the α-position substituent include 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. Is mentioned. 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.
The hydroxyalkyl group as the α-position substituent is preferably a hydroxyalkyl group having 1 to 5 carbon atoms, specifically, a part or all of the hydrogen atoms of the above alkyl group having 1 to 5 carbon atoms. Examples thereof include a group substituted with a hydroxy group.
In the present invention, it is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms that is bonded to the α-position carbon atom of (α-substituted) acrylic acid or an ester thereof. It is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and is a hydrogen atom or a methyl group because of industrial availability. Most preferred.
An “organic group” is a group containing a carbon atom and has an atom other than a carbon atom (for example, a hydrogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom (fluorine atom, chlorine atom, etc.)). Also good.
The organic group of the (α-substituted) acrylate ester is not particularly limited. For example, the aromatic group, the polar conversion group, a characteristic group such as an acid-decomposable group to be described later, and a characteristic group including these characteristic groups in the structure. A containing group.
“Exposure” is a concept including general irradiation of radiation.

  ADVANTAGE OF THE INVENTION According to this invention, the resist composition which can reduce generation | occurrence | production of a defect, the resist pattern formation method using this resist composition, and a high molecular compound useful as this resist composition can be provided.

≪Resist composition≫
The resist composition according to the first aspect of the present invention comprises a base component (A) (hereinafter referred to as “component (A)”) whose solubility in a developing solution is changed by the action of an acid, and an acid generated by exposure. And an acid generator component (B) (hereinafter referred to as “component (B)”) and a fluorine-containing compound component (F) (hereinafter referred to as “component (F)”).
When a resist film formed using such a resist composition undergoes selective exposure at the time of resist pattern formation, an acid is generated from the component (B), and the acid changes the solubility of the component (A) in the developer. Let 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, the 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 resist composition 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), and a crosslinking agent component is further blended. Is done.
In such a resist composition, when an acid is generated from the component (B) by exposure, the acid acts to cause cross-linking between the base component and the cross-linking agent component, resulting in poor solubility in an alkali developer. . 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 turns into poorly soluble in an alkaline developer, while the unexposed portion Since it remains soluble in an alkali developer, the resist pattern can be formed by alkali development.
As the base component soluble in the alkali developer, a resin soluble in the 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 the base material component (A0) (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”), and is a low molecule whose polarity is increased by the action of an acid. 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 singly or in combination of two or more.
In the present invention, the component (A1) preferably has a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent.
In the resist composition of the present invention, in particular, the component (A1) is a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, It is preferable to have a structural unit (a1) containing an acid-decomposable group whose polarity is increased by the action of an acid.
In addition to the structural unit (a1), the component (A1) is a structural unit derived from an acrylate ester in which a hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. A structural unit derived from an acrylate ester containing an —SO ₂ — containing cyclic group and a hydrogen atom bonded to the carbon atom at the α-position, which may be substituted with a substituent, It is preferable to have at least one structural unit (a2) selected from the group consisting of structural units containing a containing cyclic group.
In addition to the structural unit (a1) or the structural units (a1) and (a2), the component (A1) further has a hydrogen atom bonded to the α-position carbon atom substituted with a substituent. The structural unit may be a structural unit derived from an acrylate ester which may be included and includes a structural unit (a3) containing a polar group-containing aliphatic hydrocarbon group.

(Structural unit (a1))
The structural unit (a1) is a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and the acid decomposition whose polarity is increased by the action of an acid A structural unit containing a sex group.
The “acid-decomposable group” is an acid-decomposable group capable of cleaving at least a part of the bond in the structure of the acid-decomposable group by the action of an acid generated from the component (B) upon exposure.
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, and a carboxy group or a hydroxyl group is more 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).
An “acid-dissociable group” is an acid dissociation in which at least a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group can be cleaved by the action of an acid generated from the component (B) upon exposure. It is a group having properties. 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, bicycloalkane, 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 an 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 an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, and the like, and an isopropyl group or a tert-butyl 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. Then, 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, and a carboxy group, a hydroxyl group, etc. 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^２１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 ²¹ represents an alkyl having 1 to 5 carbon atoms. Represents a group or an aliphatic cyclic group. ]

In the above formula, n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
Examples of the 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^２１は上記と同様である。］

[Wherein, R ¹ ′, n and Y ²¹ are the same as described above. ]

Examples of the alkyl group having 1 to 5 carbon atoms of Y ²¹ include the same as the alkyl group having 1 to 5 carbon atoms of R.
As the aliphatic cyclic group for Y ²¹ , it can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups that have been proposed in a number of conventional ArF resists. The same thing as a "cyclic group" can be illustrated.

  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 thereof 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^２２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 ²² represents a divalent linking group. Show. ]

In the general formula (a1-0-1), an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms represented by R is an alkyl group having 1 to 5 carbon atoms as a substituent at the α-position. Or it is the same as that of a C1-C5 halogenated alkyl group.
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).

Preferred examples of the divalent linking group for Y ²² include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like.
The term “having a substituent” for the hydrocarbon group means that part or all of the hydrogen atoms in the hydrocarbon group are substituted with groups or atoms other than hydrogen atoms.
The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity.
The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

Specific examples of the aliphatic hydrocarbon group in the hydrocarbon group for Y ²² include a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group having a ring in the structure. It is done.
The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, still more preferably 1 to 5, and most preferably 1 to 2.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group [—CH ₂ —], an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [ — (CH ₂ ) ₃ —], tetramethylene group [— (CH ₂ ) ₄ —], pentamethylene group [— (CH ₂ ) ₅ —] and the like can be mentioned.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ). _{2 -, - C (CH 3} ) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as - _{CH (CH 3) CH 2 -} , - CH (CH 3) CH (CH 3) -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - C (CH 2 CH _{3) 2} -CH ₂ - alkyl groups such _{as; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - alkyl trimethylene groups such as; -CH _(CH 3) _{CH 2 CH 2 CH 2 -,} - CH 2 CH (CH 3) CH 2 CH 2 - And the like alkyl alkylene group such as an alkyl tetramethylene group of. 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, an oxygen atom (= O), and the like.

Examples of the aliphatic hydrocarbon group including a ring in the structure 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 includes the chain described above. And a group that is bonded to the terminal of the chain-like aliphatic 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).

Examples of the aromatic hydrocarbon group in the hydrocarbon group of Y ²² include monovalent groups such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. A divalent aromatic hydrocarbon group obtained by removing one hydrogen atom from the nucleus of the aromatic hydrocarbon of the aromatic hydrocarbon group; a part of carbon atoms constituting the ring of the divalent aromatic hydrocarbon group Is an aromatic hydrocarbon group substituted with a hetero atom such as an oxygen atom, a sulfur atom or a nitrogen atom; benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthyl An arylalkyl group such as an ethyl group, and an aromatic hydrocarbon group obtained by removing one hydrogen atom from the nucleus of the aromatic hydrocarbon. The
The aromatic 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).

The hetero atom in the “divalent linking group containing a hetero atom” of Y ²² is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.
When Y ²² is a divalent linking group containing a heteroatom, examples of the divalent linking group containing a heteroatom 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 -, - A 1 -O ( oxygen ^{atom) -B 1 -, - [A} 1 -C (= O) -O] m - B ¹ —, —A ¹ —O—C (═O) —B ¹ — (A ¹ and B ¹ are each independently a divalent hydrocarbon group which may have a substituent) or And a combination of a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a hetero atom. Examples of the divalent hydrocarbon group which may have a substituent include those similar to the hydrocarbon group which may have a substituent described above, and may be linear, branched, or structural An aliphatic hydrocarbon group containing a ring therein is preferred.

When Y ²² 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 ²² is “A ¹ —O—B ¹ ”, A and B ¹ are each independently a divalent hydrocarbon group which may have a substituent.

The hydrocarbon group in A ¹ 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 ¹ may be saturated or unsaturated, and is usually preferably saturated.
Specific examples of the aliphatic hydrocarbon group for A ¹ include a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group having a ring in the structure. These are the same as above.
Among these, as A ¹ , a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 2 to 5 carbon atoms is further preferable, and an ethylene group is most preferable. .

Examples of the hydrocarbon group for B ¹ include the same divalent hydrocarbon groups as those described above for A.
B ¹ 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^２１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^２２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 ²¹ represents an alkyl group having 1 to 5 carbon atoms or an aliphatic cyclic group; n represents an integer of 0 to 3] Y ²² 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 21,} respectively, ^{R 1} in the general formula listed in the description of "acetal-type acid dissociable group" described above ^{(p1) ', R 2'} , n, Y 21 The same thing is mentioned.
The Y ^22, are the same as those for ^{Y 22} 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 (a1-1-1-) 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), formulas (a1-1-20) to (a1-1-23) and (a1-1-32) What is represented by the following general formula (a1-1-02) including the structural units, and the following general formula (a1-3) including the structural units of the formulas (a1-3-25) to (a1-3-26) -01), the following general formula (a1-3-02) including the structural units of formulas (a1-3-27) to (a1-3-28), or formula (a1-3-29) ) To (a1-3-30), and those represented by the following general formula (a1-3-03) including the structural units are also preferred.

[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のアルキル基を示し、Ｒ^１５’〜Ｒ^１６’は独立に炭素数１〜５のアルキル基を示し、Ｒ^Ｃは脂肪族環式基を示す。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, R ¹⁵ ′ to R ¹⁶ ′ independently represent an alkyl group having 1 to 5 carbon atoms, and R ^C represents an aliphatic cyclic group. 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^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 the same 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, more preferably an integer of 2 to 5, and most preferably 2.
Examples of the divalent linking group for Y ² ′ and Y ² ″ include the same groups as Y ²² in the general formula (a1-3).
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 for X ′ include the same groups as described above, preferably a tertiary alkyl ester-type acid-dissociable group, and a tertiary carbon atom on the ring skeleton of the cyclic alkyl group described above. Are more preferable, and among them, the groups represented by the general formulas (1-1) to (1-9) are 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), as the structural unit (a1), 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 (a1) is preferably from 5 to 90 mol%, more preferably from 10 to 85 mol%, more preferably from 15 to 80 mol%, based on all structural units constituting the component (A1). Is more preferable. By setting it to the lower limit value or more, a pattern can be easily obtained when the resist composition is used, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

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

-Structural unit (a2 ^S ):
The structural unit (a2 ^S ) is a structural unit derived from an acrylate ester containing a —SO ₂ — containing cyclic group and in which a hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. .
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. The ring containing —SO ₂ — in the ring skeleton is counted as the first ring, and when it is only the ring, it is a monocyclic group, and when it has another ring structure, it is a polycyclic group regardless of the structure. Called. 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 —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, and examples thereof include the same divalent linking group as Y ²² in formula (a1-0-2). 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 ²² can be given.
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 Y ²² in formula (a1-0-2).
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.
The linear or branched alkylene group, a divalent alicyclic hydrocarbon group, the divalent linking group containing a hetero atom, a linear or branched alkylene group of the Y ^22, annular And the same aliphatic 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.
Examples of the divalent linking group containing an oxygen atom, is preferably a divalent linking group containing an ether bond or an ester bond, the formula ^{-A 1 -O-B 1 -,} - [A 1 -C (= O) - O] _m —B ¹ — or —A ¹ —O—C (═O) —B ¹ — is more preferable.
Among these, a group represented by the formula —A ¹ —O—C (═O) —B ¹ — is preferable, and represented by — (CH ₂ ) _c1 —C (═O) —O— (CH ₂ ) _d1 —. Particularly preferred are the groups c1 is an integer of 1 to 5, and 1 or 2 is preferable. d1 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 in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and includes a lactone-containing cyclic group It is.
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. When only the lactone ring is present, 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’はそれぞれ独立にアルキル基、アルコキシ基、ハロゲン原子、ハロゲン化アルキル基、水酸基、酸素原子、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基、シアノ基であり、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 an alkyl group, an alkoxy group, a halogen atom, or a halogenated alkyl group. , A hydroxyl group, an oxygen atom, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group, a cyano group, R ″ is a hydrogen atom or an alkyl group; R ²⁹ is a single bond or a divalent linking group. 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; Is.]

R in the general formulas (a2-1) to (a2-5) is the same as R in the structural unit (a1).
The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group of R ′ each have a —SO ₂ — containing cyclic group. Alkyl groups, alkoxy groups, halogen atoms, halogenated alkyl groups, —COOR ″, —OC (═O) R ″, hydroxyalkyl groups, —COOR ″, —OC (═O) R, which may be enumerated as substituents. Examples thereof include “(R” is the same as above).
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 (a2-3) 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.

  When the component (A1) contains the structural unit (a2), the proportion of the structural unit (a2) in the component (A1) is 1 to 80 mol relative to the total of all the structural units constituting the component (A1). %, More preferably 10 to 75 mol%, still more preferably 10 to 70 mol%, and particularly preferably 10 to 65 mol%. 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 in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and includes a polar group-containing aliphatic hydrocarbon group It is a structural unit.
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, structural units represented by the following formulas (a3-1) to (a3-5) are 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の整数であり、ｊ１は０〜５の整数であり、ｊ２は１〜３の整数であり、ｊ３は０〜３の整数であり、Ｘ^３０は２価の連結基であり、Ｒ^４２、Ｒ^４３はそれぞれ独立に、水素原子、炭素数１〜１０のアルキル基、ＯＨ基、又は、置換基として少なくとも１つのＯＨ基を有する炭素数１〜１０のアルキル基であり、Ｒ^４２、Ｒ^４３のうち少なくとも一方はＯＨ基を含有する。]

[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] S is an integer of 1 to 3, j1 is an integer of 0 to 5, j2 is an integer of 1 to 3, j3 is an integer of 0 to 3, and X ³⁰ is a divalent linkage. Each of R ⁴² and R ⁴³ is independently a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an OH group, or an alkyl group having 1 to 10 carbon atoms having at least one OH group as a substituent. And at least one of R ⁴² and R ⁴³ contains an OH group. ]

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.

In formula (a3-4), j1 is an integer of 0 to 5, preferably an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 0.
j2 is an integer of 1 to 3, preferably 1 or 2, and more preferably 1. Among these, a structural unit in which j1 is 0 or 1, j2 is 1, and the hydroxy group is bonded to the 2-position of the adamantyl group is particularly preferable.
j3 is an integer of 0 to 3, preferably an integer of 0 to 2, and more preferably 0 or 1. When j3 is 0, j1 is preferably an integer of 1 to 5.

In formula (a3-5), X ³⁰ is a divalent linking group, and examples thereof include the same divalent linking groups as Y ²² in formula (a1-0-2). Among these, an alkylene group is preferable, and a methylene group or an ethylene group is particularly preferable.
In formula (a3-5), R ⁴² and R ⁴³ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an OH group, or a carbon atom having 1 to 10 carbon atoms having at least one OH group as a substituent. And at least one of R ⁴² and R ⁴³ contains an OH group.
The alkyl group having 1 to 10 carbon atoms of R ⁴² and R ⁴³ is preferably a chain alkyl group, and the chain alkyl group may be linear or branched.
Specific examples of the linear alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group.
Specific examples of the branched alkyl group include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, and 1-ethylbutyl. Group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.
Examples of the alkyl group having 1 to 10 carbon atoms and having at least one OH group as the substituent of ^{R 42,} R ^43, one or more of the hydrogen atoms of the alkyl group having 1 to 10 carbon atoms of the ^{R 42, R 43} is , Groups substituted by OH groups.
Among them, R ^42, R ⁴³ in the present invention preferably has either only OH groups, a combination of an alkyl group and the OH group is particularly preferred.

As the structural unit (a3), one type may be used alone, or two or more types may be used in combination.
When the component (A1) contains the structural unit (a3), the proportion of the structural unit (a3) in the component (A1) is 1 to 50 mol% with respect to all the structural units constituting the component (A1). It is preferably 3 to 45 mol%, more preferably 5 to 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, a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, which is an acid non-dissociable aliphatic group A structural unit containing a polycyclic group, a structural unit derived from a styrene monomer, a structural unit derived from a vinyl naphthalene monomer, or the like is preferable. Examples of the polycyclic group include those exemplified in the case of the structural unit (a1), and for ArF excimer laser and KrF excimer laser (preferably for ArF excimer laser). A number of hitherto known materials can be used as the resin component of the resist composition.
In particular, at least one selected from a tricyclodecanyl group, an adamantyl group, a tetracyclododecanyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.
Specific examples of the structural unit (a4) include those represented by the following general formulas (a4-1) to (a4-5).

［式中、Ｒは前記と同じである。］

[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 20 mol% with respect to the total of all the structural units constituting the component (A1). 15 mol% is more preferable and 1-10 mol% is further more preferable.

The component (A1) is preferably a copolymer having the structural unit (a1).
Examples of such a copolymer include a copolymer comprising the structural unit (a1) and the structural unit (a3); a copolymer comprising the structural units (a1) and (a2); the structural units (a1) and (a2). And a copolymer comprising (a3); a copolymer comprising the structural units (a1), (a2), (a3) and (a4).
In the present invention, the component (A1) preferably includes a combination of structural units represented by the following general formula (A1-11). In the following general formula, R, e, A ′, R ¹¹ , R ¹² , h, and j are the same as described above, and a plurality of R in the formula 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 1.0 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, effects such as lithography characteristics are improved.

[(A2) component]
As the component (A2), a low molecular compound having a molecular weight of 500 or more and less than 4000 and having an acid dissociable group and a hydrophilic group as exemplified in the description of the component (A1) above is preferable. 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, and those that have been proposed as acid generators for chemically amplified resists can be used. Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, poly (bissulfonyl) diazomethanes, and the like. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.
As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) can be used.

［式中、Ｒ^１”〜Ｒ^３”，Ｒ^５”〜Ｒ^６”はそれぞれ独立に置換基を有していてもよいアリール基、アルキル基又はアルケニル基を表す。式（ｂ−１）におけるＲ^１”〜Ｒ^３”のうち、いずれか二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い。Ｒ^４”は、置換基を有していてもよいアルキル基、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す。］

[Wherein, R ¹ ″ to R ³ ″ and R ⁵ ″ to R ⁶ ″ each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent. 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. R ⁴ ″ represents an alkyl group, a halogenated alkyl group, an aryl group, or an alkenyl group which may have a substituent.

In formula (b-1), R ¹ ″ to R ³ ″ each independently represents an aryl group, alkyl group or alkenyl group which may have a substituent. Any two of R ¹ ″ to R ³ ″ may be bonded to each other to form a ring together with the sulfur atom in the formula.
Moreover, it is preferable that at least one of R ¹ ″ to R ³ ″ is an aryl group, and two or more of R ¹ ″ to R ³ ″ since the lithography characteristics and the resist pattern shape are further improved. Is more preferably an aryl group, and it is particularly preferred that all of R ¹ ″ to R ³ ″ are aryl groups.

As the aryl group for R ¹ ″ to R ³ ″, an unsubstituted aryl group having 6 to 20 carbon atoms; some or all of the hydrogen atoms of the unsubstituted aryl group are alkyl groups, alkoxy groups, halogen atoms, hydroxyl groups , An oxo group (═O), an aryl group, an alkoxyalkyloxy group, an alkoxycarbonylalkyloxy group, —C (═O) —O—R ⁶ ′, —O—C (═O) —R ⁷ ′, —O And a substituted aryl group substituted with —R ⁸ ′ and the like. R ⁶ ′, R ⁷ ′ and R ⁸ ′ are each a linear, branched or cyclic saturated hydrocarbon group having 1 to 25 carbon atoms, or a C 2 to 5 carbon atoms. It is a linear or branched aliphatic unsaturated hydrocarbon group.
In R ¹ ″ to R ³ ″, the unsubstituted aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.
The alkyl group as a substituent in the substituted aryl group of R ¹ ″ to R ³ ″ 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. Most preferably.
As the alkoxy group as a substituent in the substituted 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, or a tert-butoxy group. Most preferably it is.
The halogen atom as a substituent in the substituted aryl group is preferably a fluorine atom.
Examples of the aryl group as a substituent in the substituted aryl group include the same aryl groups as those described above for R ¹ ″ to R ³ ″, preferably an aryl group having 6 to 20 carbon atoms, and an aryl group having 6 to 10 carbon atoms. Group is more preferable, and phenyl group and naphthyl group are more preferable.

As the alkoxyalkyloxy group in the substituted aryl group, for example,
General formula: -O-C ( ^R47 ) ( ^R48 ) -O- ^R49
[Wherein, R ⁴⁷ and R ⁴⁸ each independently represent a hydrogen atom or a linear or branched alkyl group, and R ⁴⁹ represents an alkyl group. ] Is represented.
In R ⁴⁷ and R ⁴⁸ , the alkyl group preferably has 1 to 5 carbon atoms, may be linear or branched, and is preferably an ethyl group or a methyl group, and most preferably a methyl group.
At least one of R ⁴⁷ and R ⁴⁸ is preferably a hydrogen atom. In particular, it is more preferable that one is a hydrogen atom and the other is a hydrogen atom or a methyl group.
The alkyl group for R ⁴⁹ preferably has 1 to 15 carbon atoms and may be linear, branched or cyclic.
The linear or branched alkyl group for R ⁴⁹ preferably has 1 to 5 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group. Can be mentioned.
The cyclic alkyl group for R ⁴⁹ preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane, etc., 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, etc. And a group obtained by removing one or more hydrogen atoms from the polycycloalkane. Examples of the monocycloalkane include cyclopentane and cyclohexane. Examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.

As the alkoxycarbonylalkyloxy group in the substituted aryl group, for example,
General formula: —O—R ⁵⁰ —C (═O) —O—R ⁵⁶
[Wherein, R ⁵⁰ represents a linear or branched alkylene group, and R ⁵⁶ represents a tertiary alkyl group. ] Is represented.
The linear or branched alkylene group for R ⁵⁰ preferably has 1 to 5 carbon atoms, such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, or a 1,1-dimethylethylene group. Etc.
As the tertiary alkyl group for R ⁵⁶ , 2-methyl-2-adamantyl group, 2-ethyl-2-adamantyl group, 1-methyl-1-cyclopentyl group, 1-ethyl-1-cyclopentyl group, 1-methyl -1-cyclohexyl group, 1-ethyl-1-cyclohexyl group, 1- (1-adamantyl) -1-methylethyl group, 1- (1-adamantyl) -1-methylpropyl group, 1- (1-adamantyl) -1-methylbutyl group, 1- (1-adamantyl) -1-methylpentyl group; 1- (1-cyclopentyl) -1-methylethyl group, 1- (1-cyclopentyl) -1-methylpropyl group, 1- (1-cyclopentyl) -1-methylbutyl group, 1- (1-cyclopentyl) -1-methylpentyl group; 1- (1-cyclohexyl) -1-methylethyl Group, 1- (1-cyclohexyl) -1-methylpropyl group, 1- (1-cyclohexyl) -1-methylbutyl group, 1- (1-cyclohexyl) -1-methylpentyl group, tert-butyl group, tert -Pentyl group, tert-hexyl group and the like.
Moreover, the general ^formula: the ^{R 56} in the -O-R 50 -C (= O ) -O-R 56, also include groups replaced by ^{R 56} '. R ⁵⁶ ′ is a hydrogen atom, an alkyl group, a fluorinated alkyl group, or an aliphatic cyclic group that may contain a hetero atom.
^Examples of the alkyl group for R ⁵⁶ ′ include the same alkyl groups as those described above for R ⁴⁹ .
^Examples of the fluorinated alkyl group for R ⁵⁶ ′ include groups in which some or all of the hydrogen atoms within the alkyl group for R ⁴⁹ have been substituted with fluorine atoms.
Examples of the aliphatic cyclic group which may contain a hetero atom in R ⁵⁶ ′ include an aliphatic cyclic group containing no hetero atom, an aliphatic cyclic group containing a hetero atom in the ring structure, and an aliphatic cyclic group. Examples include those in which a hydrogen atom in the group is substituted with a heteroatom.
Regarding R ⁵⁶ ′, the aliphatic cyclic group containing no hetero atom includes a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane, and the like. Can be mentioned. Examples of the monocycloalkane include cyclopentane and cyclohexane. Examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
Specific examples of the aliphatic cyclic group containing a hetero atom in the ring structure for R ⁵⁶ ′ include groups represented by the following formulas (L1) to (L6) and (S1) to (S4). It is done.
As for R ⁵⁶ ′, the hydrogen atom in the aliphatic cyclic group is specifically substituted with a hetero atom, specifically, the hydrogen atom in the aliphatic cyclic group is substituted with an oxygen atom (═O), etc. Is mentioned.

^{-C (= O) -O-R} 6 ', -O-C (= O) -R 7', 'R 6 ^{in' -O-R 8, R 7} ', R 8' are each carbon atoms 1 to 25 linear, branched or cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a linear or branched aliphatic unsaturated hydrocarbon group having 2 to 5 carbon atoms. .
The linear or branched saturated hydrocarbon group has 1 to 25 carbon atoms, preferably 1 to 15 carbon atoms, and more preferably 4 to 10 carbon atoms.
Examples of the linear saturated hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group.
Examples of the branched saturated hydrocarbon group excluding the tertiary alkyl group include, 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, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like can be mentioned.
The linear or branched saturated hydrocarbon group may have a substituent. Examples of the substituent include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), a cyano group, and a carboxy group.
As the alkoxy group as a substituent of the linear or branched saturated hydrocarbon 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 and a tert-butoxy group are preferable, and a methoxy group and an ethoxy group are most preferable.
Examples of the halogen atom as a substituent of the linear or branched saturated hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
As the halogenated alkyl group as a substituent of the linear or branched saturated hydrocarbon group, part or all of the hydrogen atoms of the linear or branched saturated hydrocarbon group are the halogen atoms. And a group substituted with.
The cyclic saturated hydrocarbon group having 3 to 20 carbon atoms in R ⁶ ′, R ⁷ ′, and R ⁸ ′ may be either a polycyclic group or a monocyclic group. A group in which one hydrogen atom has been removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, and the like. More specifically, one hydrogen atom was removed from a monocycloalkane such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Group and the like.
The cyclic saturated hydrocarbon group may have a substituent. For example, part of the carbon atoms constituting the ring of the cyclic alkyl group may be substituted with a heteroatom, or the hydrogen atom bonded to the ring of the cyclic alkyl group may be substituted with a substituent. Good.
Examples of the former include one or more hydrogen atoms from a heterocycloalkane in which a part of the carbon atoms constituting the ring of the monocycloalkane or polycycloalkane is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Examples include groups other than atoms. The ring structure may have an ester bond (—C (═O) —O—). Specifically, a lactone-containing monocyclic group such as a group obtained by removing one hydrogen atom from γ-butyrolactone, or a group obtained by removing one hydrogen atom from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring. And other lactone-containing polycyclic groups.
Examples of the substituent in the latter example include the same as those described above as the substituent that the linear or branched alkyl group may have, a lower alkyl group, and the like.
R ⁶ ′, R ⁷ ′, and R ⁸ ′ may be a combination of a linear or branched alkyl group and a cyclic alkyl group.
A combination of a linear or branched alkyl group and a cyclic alkyl group includes a group in which a cyclic alkyl group is bonded as a substituent to a linear or branched alkyl group, and a substituent to the cyclic alkyl group. And a group having a linear or branched alkyl group bonded thereto.
Examples of the linear aliphatic unsaturated hydrocarbon group for R ⁶ ′, R ⁷ ′, and R ⁸ ′ include a vinyl group, a propenyl group (allyl group), and a butynyl group.
Examples of the branched aliphatic unsaturated hydrocarbon group for R ⁶ ′, R ⁷ ′, and R ⁸ ′ include a 1-methylpropenyl group and a 2-methylpropenyl group.
The linear or branched aliphatic unsaturated hydrocarbon group may have a substituent. Examples of the substituent include the same ones as those exemplified as the substituent which the linear or branched alkyl group may have.
Among R ⁷ ′ and R ⁸ ′, among them, the lithography characteristics and the resist pattern shape are good, so that the linear or branched saturated hydrocarbon group having 1 to 15 carbon atoms, or the carbon number 3-20 cyclic saturated hydrocarbon groups are preferred.

The aryl groups for R ¹ ″ to R ³ ″ are each preferably a phenyl group or a naphthyl group.

Examples of the alkyl group for R ¹ ″ to R ³ ″ include a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms. Especially, 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.

As an alkenyl group of R < ¹ >"-R< ³ >", it is preferable that it is C2-C10, for example, 2-5 are more preferable, and 2-4 are more preferable. Specific examples include a vinyl group, a propenyl group (allyl group), a butynyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group.
The alkyl group and alkenyl group of R ¹ ″ to R ³ ″ are an alkyl group, an alkoxy group, a halogen atom, a hydroxyl group, an oxo group (═O), an aryl group, an alkoxyalkyloxy group, an alkoxycarbonylalkyloxy group, —C ( It may be a substituted alkyl group or a substituted alkenyl group substituted with —O) —O—R ⁶ ′, —O—C (═O) —R ⁷ ′, —O—R ⁸ ′ or the like. These substituents are the same as the substituents that the substituted aryl group may have.

When any two of R ¹ ″ to R ³ ″ are bonded to each other to form a ring together with the sulfur atom in the formula, it is preferable that a 3 to 10 membered ring including the sulfur atom is formed, It is particularly preferable to form a 5- to 7-membered ring.
When any two of R ¹ ″ to R ³ ″ are bonded to each other to form a ring together with the sulfur atom in the formula, the remaining one is preferably an aryl group. Examples of the aryl group include the same aryl groups as those described above for R ¹ ″ to R ³ ″.

  Specific examples of the cation moiety in the compound represented by the formula (b-1) include, for example, triphenylsulfonium, (3,5-dimethylphenyl) diphenylsulfonium, (4- (2-adamantoxymethyloxy)- 3,5-dimethylphenyl) diphenylsulfonium, (4- (2-adamantoxymethyloxy) phenyl) diphenylsulfonium, (4- (tert-butoxycarbonylmethyloxy) phenyl) diphenylsulfonium, (4- (tert-butoxycarbonyl) Methyloxy) -3,5-dimethylphenyl) diphenylsulfonium, (4- (2-methyl-2-adamantyloxycarbonylmethyloxy) phenyl) diphenylsulfonium, (4- (2-methyl-2-adamantyloxycarbonylmethyl) Xy) -3,5-dimethylphenyl) diphenylsulfonium, tri (4-methylphenyl) sulfonium, dimethyl (4-hydroxynaphthyl) sulfonium, monophenyldimethylsulfonium, diphenylmonomethylsulfonium, (4-methylphenyl) diphenylsulfonium, 4-methoxyphenyl) diphenylsulfonium, tri (4-tert-butyl) phenylsulfonium, diphenyl (1- (4-methoxy) naphthyl) sulfonium, di (1-naphthyl) phenylsulfonium, 1-phenyltetrahydrothiophenium, 1 -(4-Methylphenyl) tetrahydrothiophenium, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium, 1- (4-methoxynaphthalen-1-yl) Trahydrothiophenium, 1- (4-ethoxynaphthalen-1-yl) tetrahydrothiophenium, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium, 1-phenyltetrahydrothiopyranium, Examples include 1- (4-hydroxyphenyl) tetrahydrothiopyranium, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiopyranium, 1- (4-methylphenyl) tetrahydrothiopyranium, and the like.

  Specific examples of the cation moiety in the compound represented by the formula (b-1) include those shown below.

［式中、ｇ１は繰返し数を示し、１〜５の整数である。］

[Wherein g1 represents the number of repetitions and is an integer of 1 to 5. ]

［式中、ｇ２、ｇ３は繰返し数を示し、ｇ２は０〜２０の整数であり、ｇ３は０〜２０の整数である。］

[Wherein g2 and g3 represent the number of repetitions, g2 is an integer of 0 to 20, and g3 is an integer of 0 to 20. ]

In formula (b-1), 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 ″, “may have a substituent” 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 a halogen atom, a hetero atom, an alkyl group, a hydroxyl group, a formula: X ³ -Q ^1- [where Q ¹ is a divalent linking group containing an oxygen atom, and X ³ is a substituted group. It is a C3-C30 hydrocarbon group which may have a group. ] 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.

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

In the group represented by X ³ -Q ^1- , the hydrocarbon group for X ³ may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.
The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and most preferably 6 to 12. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aromatic hydrocarbon group include a hydrogen atom from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. Aryl groups such as aryl group, benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc., from which one is removed. The number of carbon atoms in the alkyl chain in the arylalkyl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.
The aromatic hydrocarbon group may have a substituent. For example, a part of carbon atoms constituting the aromatic ring of the aromatic hydrocarbon group may be substituted with a hetero atom, and the hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group is substituted with the substituent. May be.
Examples of the former include heteroaryl groups in which some of the carbon atoms constituting the ring of the aryl group are substituted with heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and aromatic hydrocarbons in the arylalkyl groups. Examples include heteroarylalkyl groups in which some of the carbon atoms constituting the ring are substituted with the above heteroatoms.
Examples of the substituent of the aromatic hydrocarbon group in the latter example include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
The alkyl group as a substituent of the aromatic hydrocarbon group is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. preferable.
The alkoxy group as a substituent of the aromatic hydrocarbon group is preferably an alkoxy group having 1 to 5 carbon atoms, and is a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, tert- A butoxy group is preferable, and a methoxy group and an ethoxy group are most preferable.
Examples of the halogen atom as a substituent for the aromatic hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent of the aromatic hydrocarbon group include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.

The aliphatic hydrocarbon group for X ³ 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 ³ , the aliphatic hydrocarbon group may be a group in which a part of carbon atoms constituting the aliphatic hydrocarbon group may be substituted with a substituent containing a hetero atom, and hydrogen constituting the aliphatic hydrocarbon group A part or all of the atoms may be substituted with a substituent containing a hetero atom.
The “heteroatom” in X ³ is not particularly limited as long as it is an atom other than a carbon atom and a hydrogen atom, and examples thereof include a halogen atom, an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom.
The substituent containing a hetero atom may be composed of only the hetero atom, or may be a group containing a group or atom other than the hetero atom.
Specific examples of the substituent for substituting a part of the carbon atom include —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O. —, —C (═O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group, an acyl group, etc.), —S—, —S (═O) ₂ —, — S (= O) ₂ —O— and the like can be mentioned. When the aliphatic hydrocarbon group is cyclic, these substituents may be included in the ring structure.
Specific examples of the substituent for substituting part or all of the hydrogen atoms include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), and a cyano group.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and a methoxy group or an ethoxy group. Is most preferred.
As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
As the halogenated alkyl group, a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc. And a group substituted with a halogen atom.

Examples of the aliphatic hydrocarbon group include a linear or branched saturated hydrocarbon group, a linear or branched monovalent unsaturated hydrocarbon group, or a cyclic aliphatic hydrocarbon group (aliphatic ring). Formula group) is preferred.
The linear saturated hydrocarbon group (alkyl group) preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, 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 —, wherein 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 aliphatic hydrocarbon group for X ³ .

In the present invention, X ³ is preferably a cyclic group which may have a substituent. The cyclic group may be an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a substituent. It is preferably an aliphatic cyclic group that may be used.
The aromatic hydrocarbon group is preferably a naphthyl group which may have a substituent or a phenyl group which may have a substituent.
As the aliphatic cyclic group which may have a substituent, a polycyclic aliphatic cyclic group which may have a substituent is preferable. The polycyclic aliphatic cyclic group is preferably a group obtained by removing one or more hydrogen atoms from the polycycloalkane, the above (L2) to (L6), (S3) to (S4), and the like.

In the present invention, R ⁴ ″ preferably has X ³ -Q ^1- as a substituent. In this case, R ⁴ ″ may be X ³ -Q ¹ -Y ^10- [wherein Q ¹ and X ^{1 3} is the same as above, and Y ¹⁰ 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 X ³ -Q ¹ -Y ^10- , the alkylene group for Y ¹⁰ 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 ^10, _{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 -, - _{CH 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 ¹⁰ 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, alkyl group or alkenyl group which may have a substituent.
Moreover, it is preferable that at least one of R ⁵ ″ to R ⁶ ″ is an aryl group because lithography characteristics and the resist pattern shape are further improved, and any of R ⁵ ″ to R ⁶ ″ is an aryl group. More preferably.
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 ″.
Examples of the alkenyl group for R ⁵ ″ to R ⁶ ″ include the same alkenyl groups for R ¹ ″ to R ³ ″.
Among these, it is most preferable that all of R ⁵ ″ to R ⁶ ″ are phenyl groups.
Specific examples of the cation moiety in the compound represented by the formula (b-2) include diphenyliodonium and bis (4-tert-butylphenyl) iodonium.
"The, ^{R 4} in the above formula (b-1)" ^{R 4} in the formula (b-2) include the same as.

  Specific examples of the onium salt acid generators represented by formulas (b-1) and (b-2) include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, bis (4-tert-butylphenyl) iodonium. Trifluoromethane sulfonate or nonafluorobutane sulfonate, triphenylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, tri (4-methylphenyl) sulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its Nonafluorobutanesulfonate, dimethyl (4-hydroxynaphthyl) sulfonium trifluoromethanesulfonate, its heptaful Lopropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of monophenyldimethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; trifluoromethanesulfonate of diphenylmonomethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate (4-methylphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, (4-methoxyphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate , Trifluoromethanesulfonate of tri (4-tert-butyl) phenylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of diphenyl (1- (4-methoxy) naphthyl) sulfonium, its heptafluoropropane Sulfonate or its nonafluorobutane sulfonate, di (1-naphthyl) phenyl sulphonium trifluoromethane sulphonate, its heptafluoropropane sulphonate or its nonafluorobutane sulphonate; 1-phenyltetrahydrothiophenium trifluoromethane sulphonate, its heptafluoropropane sulphonate Or nonafluorobutanesulfonate thereof; 1- (4-methylphenyl) ) Tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1- (4-ethoxynaphthalene-1- Yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonaflu 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1-phenyltetrahydrothiopyranium trifluoromethanesulfonate , Its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (4-hydroxyphenyl) tetrahydrothiopyranium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl -4-Hydroxyphenyl) tetrahydrothiopyranium trifluoromethanesulfonate, its heptafluoropropanes Honeto or nonafluorobutanesulfonate; 1- (4-methylphenyl) trifluoromethanesulfonate tetrahydrothiophenium Pila chloride, heptafluoropropane sulfonate or its nonafluorobutane sulfonate, and the like.

  Moreover, the onium salt which replaced the anion part of these onium salts by the anion part represented by either of following formula (b1)-(b9) can also be used.

［式中、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〜ｎ６はそれぞれ独立に０または１であり、ｖ０〜ｖ６はそれぞれ独立に０〜３の整数であり、ｗ１〜ｗ６はそれぞれ独立に０〜３の整数であり、Ｑ”は前記と同じである。］

[Wherein, 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 to r2 are each independently 0 to 3] G is an integer of 1 to 20, R ⁷ is a substituent, n1 to n6 are each independently 0 or 1, v0 to v6 are each independently an integer of 0 to 3, w1 to w6 are each independently an integer of 0 to 3, and Q ″ is the same as above.]

As the substituent of R ^7, the same as those mentioned as the substituent that the aliphatic hydrocarbon group may have and the substituent that the aromatic hydrocarbon group may have in the above X ³ Is mentioned.
Code (r1 and r2, W1 to W6) attached to R ⁷ when is an integer of 2 or more, a plurality of the ^{R 7} groups may be the same, respectively, 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, as an onium salt acid generator, a sulfonium salt having a cation represented by the following general formula (b-5) or (b-6) in the cation part can also be used.

［式中、Ｒ^８１〜Ｒ^８６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 ^{81 to} R ⁸⁶ 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 ^{81 to} R ⁸⁶ , 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 ^{81 to} R ⁸⁶ are integers of 2 or more, the plurality of R ^{81 to} R ⁸⁶ 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.

  Preferable examples of the cation represented by the formula (b-5) or the formula (b-6) include those shown below.

  Furthermore, the sulfonium salt which has the cation represented by the following general formula (b-7)-(b-9) in a cation part can also be used.

In formulas (b-7) to (b-9), u is an integer of 1 to 3, and 1 or 2 is most preferable.
In formula (b-7), R ^6a is an alkylene group that may have a substituent, and R ^6b has a hydrogen atom, an alkyl group that may have a substituent, or a substituent. It may be a phenyl group or a naphthyl group.
In Formula (b-8), R ^7a is an alkylene group which may have a substituent, and R ^7b is an alkyl group which may have a substituent, or an optionally substituted phenyl. Group or naphthyl group.
In formula (b-9), R ⁸ represents an alkyl group which may have a substituent, a phenyl group which may have a substituent, or a naphthyl group.

The alkylene group for R ^6a and R ^7a is preferably a linear or branched alkylene group. 1-12 are preferable, as for carbon number of this alkylene group, 1-5 are more preferable, 1-3 are more preferable, and 1 or 2 is especially preferable.
Examples of the substituent that the alkylene group may have include an alkoxy group, a halogen atom, a hydroxyl group, an oxo group (═O), a cyano group, an aryl group, an alkoxyalkyloxy group, an alkoxycarbonylalkyloxy group, —C ( ═O) —O—R ⁷ ″, —O—C (═O) —R ⁸ ″, —O—R ⁹ ″ and the like. Alkoxy group, halogen atom, aryl group, alkoxyalkyloxy group, alkoxycarbonyl As the alkyloxy group, —C (═O) —O—R ⁷ ″, —O—C (═O) —R ⁸ ″, —O—R ⁹ ″, R ¹ in the above formula (b-1) is used. In the description of “˜R ³ ”, the same as those described as the substituent that the substituted aryl group may have.
In the formula, as the alkyl group which may have a substituent in R ^6b , R ^7b , and R ^8, the substituted alkyl exemplified in the description of R ¹ ″ to R ³ ″ in the general formula (b-1). The same thing as a group is mentioned.
As the substituent that the phenyl group or naphthyl group in R ^6b , R ^7b , and R ⁸ may have, the substituted aryl described in the description of R ¹ ″ to R ³ ″ in the general formula (b-1). The thing similar to what was mentioned as a substituent which group may have is mentioned.
Preferable examples of the cation represented by the formula (b-7) or the formula (b-8) include those shown below. In the formula, R ^C represents a substituent (alkoxy group, alkoxyalkyloxy group, alkoxycarbonylalkyloxy group, halogen atom, hydroxyl group, oxo group (═O), aryl group exemplified in the description of the substituted aryl group. , —C (═O) —O—R ⁶ ′, —O—C (═O) —R ⁷ ′, —O—R ⁸ ′).

The anion part of the sulfonium salt having a cation represented by formulas (b-5) to (b-8) in the cation part is not particularly limited, and the anion part of the onium salt acid generators proposed so far It may be similar. Examples of the anion moiety include fluorinated alkyl sulfonate ions such as the anion moiety (R ⁴ ″ SO ₃ ⁻ ) of the onium salt acid generator represented by the general formula (b-1) or (b-2). An anion represented by the general formula (b-3) or (b-4), an anion represented by any one of the formulas (b1) to (b9), 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 (exposure) of radiation. It is what you have. 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 Nthenyl 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 18] to [Chemical 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.
When the resist composition of the present invention contains the component (B), it is preferable to use an onium salt acid generator having a fluorinated alkyl sulfonate ion as an anion as the component (B).
When the resist composition of the present invention contains the component (B), the content of the component (B) in the resist composition of the present invention is 0.5 to 50 parts by mass with respect to 100 parts by mass of the component (A). Preferably, 1-40 mass parts is more preferable. By setting it within the above range, pattern formation is sufficiently performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

<(F) component>
In the present invention, the component (F) is a fluorine-containing compound component and contains a polymer compound (F1) (hereinafter referred to as “(F1) component”).

[(F1) component]
The component (F1) is selected from the group consisting of the structural unit (f1-1) represented by the following general formula (f1-1) and the structural unit (f1-2) represented by the following general formula (f1-2) And at least one structural unit (f1) and a structural unit (f2) containing a fluorine atom (excluding the structural unit (f1)).

［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、又は炭素数１〜５のハロゲン化アルキル基であり、Ｒ^１、Ｒ^２はそれぞれ独立に２価の連結基であり、Ｒｆ^１はフッ素原子で置換されていてもよい炭素数１〜１０の直鎖状若しくは分岐鎖状の炭化水素基、又はフッ素原子で置換されていてもよい炭素数３〜２０の環含有炭化水素基である。］

[Wherein, R is independently 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 ¹ and R ² are each independently a divalent linking group. Rf ¹ is a linear or branched hydrocarbon group having 1 to 10 carbon atoms which may be substituted with a fluorine atom, or a ring having 3 to 20 carbon atoms which may be substituted with a fluorine atom It is a contained hydrocarbon group. ]

(Structural unit (f1))
The structural unit (f1) is selected from the group consisting of the structural unit (f1-1) represented by the formula (f1-1) and the structural unit (f1-2) represented by the formula (f1-2). It consists of at least one kind.

・ Structural unit (f1-1)
In formula (f1-1), 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. The alkyl group having 1 to 5 carbon atoms or the halogenated alkyl group having 1 to 5 carbon atoms in R is the same as described above.
In formula (f1-1), R ¹ is a divalent linking group, and examples thereof include the same divalent linking groups as Y ²² in formula (a0-1-2). Among them, the divalent linking group for R ¹ is preferably the above-mentioned “divalent linking group containing a heteroatom”; “a divalent hydrocarbon group optionally having substituent (s)” More preferably a combination with a divalent linking group containing a heteroatom; —C (═O) —O— or —C (═O) —NH— and a linear or branched fatty acid A combination with a group hydrocarbon group is more preferred; —C (═O) —O— or —C (═O) —NH— and a methylene group, —CH (CH ₃ ) — or —CH (CH ₂ CH _3); )-Is particularly preferred.

  Specific examples of the structural unit (f1-1) are shown below. In the following formula, R is the same as described above.

・ Structural unit (f1-2)
In the formula (f1-2), R is the same as described above.
In formula (f1-2), R ² is a divalent linking group, and examples thereof include the same divalent linking groups as Y ²² in formula (a0-1-2). Among these, the divalent linking group for R ² is preferably the above-mentioned “divalent linking group containing a heteroatom”; “a divalent hydrocarbon group which may have a substituent and a hetero group”. More preferably, it is a combination with a divalent linking group containing an atom; —C (═O) —O— or —C (═O) —NH— and a linear or branched aliphatic group More preferred is a combination with a hydrocarbon group; —C (═O) —O— or —C (═O) —NH— and a methylene group, —CH (CH ₃ ) — or —CH (CH ₂ CH ₃ ). The combination with-is particularly preferred.

In the formula (f1-2), Rf ¹ is a linear or branched hydrocarbon group having 1 to 10 carbon atoms which may be substituted with a fluorine atom, or carbon which may be substituted with a fluorine atom. It is a ring-containing hydrocarbon group of several 3-20.

The linear or branched hydrocarbon group of Rf ¹ has 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, and more preferably 1 to 3 carbon atoms. The linear or branched hydrocarbon group may be saturated or unsaturated, but is preferably a saturated hydrocarbon group.
Examples of the linear hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group.
Examples of the branched hydrocarbon group include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, Examples include 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.

The ring-containing hydrocarbon group of Rf ¹ has 3 to 20 carbon atoms, preferably 3 to 15 carbon atoms, and more preferably 5 to 12 carbon atoms.
The ring-containing hydrocarbon group of Rf ¹ is a cyclic aliphatic hydrocarbon group, an aromatic hydrocarbon, a cyclic aliphatic hydrocarbon group or an aromatic hydrocarbon group, and the above-mentioned “linear or branched chain” Combinations with “hydrocarbon groups” can be mentioned.

The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic group is preferably a group in which one hydrogen atom is removed from a C 3-8 monocycloalkane, and examples of the monocycloalkane include cyclopentane and cyclohexane. As the polycyclic group, a group in which one hydrogen atom is removed from a polycycloalkane having 7 to 20 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, tetra And cyclododecane.
Examples of the aromatic hydrocarbon group include a monovalent aromatic hydrocarbon group such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group; Aromatic hydrocarbon group in which a part of carbon atoms constituting the ring of the aromatic hydrocarbon group is substituted with a hetero atom such as oxygen atom, sulfur atom, nitrogen atom; benzyl group, phenethyl group, 1-naphthylmethyl group Arylalkyl groups such as 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, and the like.

These linear or branched hydrocarbon groups and ring-containing hydrocarbon groups are preferably substituted with fluorine atoms. It is preferable that 10% or more of the hydrogen atoms in the linear or branched hydrocarbon group or ring-containing hydrocarbon group are substituted with fluorine atoms, and more than 50% are substituted with fluorine atoms. Preferably, it may be a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms.
Moreover, these linear or branched hydrocarbon groups and ring-containing hydrocarbon groups may be substituted with a substituent other than a fluorine atom. Examples of the substituent other than the fluorine atom include a hydroxyl group, a chlorine atom, a bromine atom, an iodine atom, and an alkoxy group. The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, and examples thereof include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group.
In addition, the cyclic aliphatic hydrocarbon group or aromatic hydrocarbon group may be substituted with an alkyl group having 1 to 5 carbon atoms. The alkyl group having 1 to 5 carbon atoms is the same as the alkyl group having 1 to 5 carbon atoms as the α-position substituent described above.

  Specific examples of the structural unit (f1-2) are shown below. In the following formula, R is the same as described above.

As the structural unit (f1), one type selected from the group consisting of the structural unit (f1-1) and the structural unit (f1-2) may be used alone, or two or more types may be used in combination.
In the component (F1), the proportion of the structural unit (f1) is preferably from 1 to 70 mol%, more preferably from 1 to 60 mol%, more preferably from 5 to 50, based on the total of all structural units constituting the (F1) component. More preferred is mol%. By setting it to the above lower limit value or more, the resist film after development can be made hydrophilic favorably, and defects can be particularly preferably reduced. Moreover, by setting it as the said upper limit or more, each structural unit in (F1) component can be balanced.

(Structural unit (f2))
The structural unit (f2) is a structural unit containing a fluorine atom (excluding the structural unit (f1)). The structural unit (f2) is not particularly limited as long as it contains a fluorine atom in its structure, but is preferably a structural unit derived from a compound having an ethylenic double bond.

The “structural unit derived from a compound having an ethylenic double bond” means a structural unit having a structure in which an ethylenic double bond in a compound having an ethylenic double bond is cleaved to form a single bond.
Examples of the compound having an ethylenic double bond include acrylic acid or an ester thereof in which a hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, and a hydrogen atom bonded to the α-position carbon atom. Acrylamide or a derivative thereof optionally substituted with a substituent, a vinyl aromatic compound in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, a cycloolefin or a derivative thereof, a vinyl sulfonate, etc. Is mentioned.
Among these, a hydrogen atom bonded to the α-position carbon atom may be substituted with an acrylic acid or an ester thereof, and a hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. Acrylamide or a derivative thereof, and a vinyl aromatic compound in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent are preferable.

Examples of “acrylamide or a derivative thereof” include an acrylamide in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent (hereinafter sometimes referred to as (α-substituted) acrylamide), (α-substituted) acrylamide. Amino groups (compounds in which one or both of the terminal hydrogen atoms are substituted with a substituent, and the like).
Examples of the substituent that may be bonded to the α-position carbon atom of acrylamide or a derivative thereof are the same as those described as the substituent bonded to the α-position carbon atom of the α-substituted acrylate ester.
As the substituent that substitutes one or both of the hydrogen atoms at the amino group terminal of (α-substituted) acrylamide, an organic group is preferable. Although it does not specifically limit as this organic group, For example, the thing similar to the organic group which the said ((alpha) substituted) acrylate ester has is mentioned.
As the compound in which one or both of the hydrogen atoms at the terminal of the amino group of (α-substituted) acrylamide are substituted with a substituent, for example, —C (= bonded to the α-position carbon atom in the above (α-substituted) acrylate ester O) —O—, —C (═O) —N (R ^b ) — [wherein R ^b is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ] Are substituted.
In the formula, the alkyl group in R ^b is preferably linear or branched.

The “vinyl aromatic compound” is a compound having an aromatic ring and one vinyl group bonded to the aromatic ring, and examples thereof include styrene or a derivative thereof, vinyl naphthalene or a derivative thereof.
Examples of the substituent that may be bonded to the α-position carbon atom of the vinyl aromatic compound (the carbon atom bonded to the aromatic ring among the carbon atoms of the vinyl group) include the α-position carbon atom of the α-substituted acrylate ester. Examples thereof are the same as those listed as the substituents bonded to.
Hereinafter, a vinyl aromatic compound in which a hydrogen atom bonded to a carbon atom at the α-position is substituted with a substituent may be referred to as an (α-substituted) vinyl aromatic compound.

As “styrene or a derivative thereof”, a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, or a hydrogen atom bonded to a benzene ring may be substituted with a substituent other than a hydroxyl group. Good styrene (hereinafter, also referred to as (α-substituted) styrene), a hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, and a hydrogen atom bonded to the benzene ring is other than a hydroxyl group Hydroxystyrene which may be substituted with a substituent (hereinafter also referred to as (α-substituted) hydroxystyrene), (α-substituted) a compound in which the hydrogen atom of the hydroxyl group of hydroxystyrene is substituted with an organic group, The hydrogen atom bonded to the carbon atom may be substituted with a substituent, and the hydrogen atom bonded to the benzene ring may be substituted with a substituent other than a hydroxyl group and a carboxy group. Sulfonyl benzoic acid (hereinafter sometimes referred to (alpha-substituted) vinyl benzoic acid.), (Alpha-substituted) hydrogen atom of the carboxyl group of the vinyl benzoate compounds substituted with organic groups, and the like.
Hydroxystyrene is a compound in which one vinyl group and at least one hydroxyl group are bonded to a benzene ring. 1-3 are preferable and, as for the number of the hydroxyl groups couple | bonded with a benzene ring, 1 is especially preferable. The bonding position of the hydroxyl group in the benzene ring is not particularly limited. When the number of hydroxyl groups is one, the para 4-position of the vinyl group bonding position is preferred. When the number of hydroxyl groups is an integer of 2 or more, any bonding position can be combined.
Vinyl benzoic acid is a compound in which one vinyl group is bonded to the benzene ring of benzoic acid. The bonding position of the vinyl group in the benzene ring is not particularly limited.
The substituent other than the hydroxyl group and the carboxy group that may be bonded to the benzene ring of styrene or a derivative thereof is not particularly limited, and for example, a halogen atom, an alkyl group having 1 to 5 carbon atoms, Examples include halogenated alkyl groups. 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.
The organic group in the compound in which the hydrogen atom of the hydroxyl group of (α-substituted) hydroxystyrene is substituted with an organic group is not particularly limited. It is done.
The organic group in the compound in which the hydrogen atom of the carboxy group of (α-substituted) vinylbenzoic acid is substituted with an organic group is not particularly limited. Is mentioned.

As "vinyl naphthalene or a derivative thereof", the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and the hydrogen atom bonded to the naphthalene ring is substituted with a substituent other than a hydroxyl group. A good vinyl naphthalene (hereinafter sometimes referred to as (α-substituted) vinyl naphthalene), a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and a hydrogen atom bonded to the naphthalene ring is Vinyl (hydroxynaphthalene) optionally substituted with a substituent other than a hydroxyl group (hereinafter sometimes referred to as (α-substituted) vinyl (hydroxynaphthalene)), (α-substituted) hydrogen atom of hydroxyl group of vinyl (hydroxynaphthalene) Are compounds substituted with a substituent, and the like.
Vinyl (hydroxynaphthalene) is a compound in which one vinyl group and at least one hydroxyl group are bonded to a naphthalene ring. The vinyl group may be bonded to the 1-position of the naphthalene ring or may be bonded to the 2-position. 1-3 are preferable and, as for the number of the hydroxyl groups couple | bonded with a naphthalene ring, 1 is especially preferable. The bonding position of the hydroxyl group in the naphthalene ring is not particularly limited. In the case where a vinyl group is bonded to the 1-position or 2-position of the naphthalene ring, any one of the 5- to 8-positions of the naphthalene ring is preferable. In particular, when the number of hydroxyl groups is one, any one of 5 to 7 positions of the naphthalene ring is preferable, and 5 or 6 positions are preferable. When the number of hydroxyl groups is an integer of 2 or more, any bonding position can be combined.
Examples of the substituent which may be bonded to the naphthalene ring of vinyl naphthalene or a derivative thereof are the same as those described above as the substituent which may be bonded to the benzene ring of the (α-substituted) styrene.
The organic group in the compound in which the hydrogen atom of the hydroxyl group of (α-substituted) vinyl (hydroxynaphthalene) is substituted with an organic group is not particularly limited. For example, the same organic group as the (α-substituted) acrylic acid ester has Is mentioned.

  Among these, the structural unit (f2) is preferably a structural unit represented by the following formula (f2-1).

［式中、Ｒ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り、Ａは−Ｏ−又は−ＮＨ−であり、Ｘ^０は単結合又は２価の連結基であり、Ｒｆ^０は有機基であり、Ｘ^０、Ｒｆ^０の少なくともいずれか一方がフッ素原子を有し、ｖは０又は１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, A represents —O— or —NH—, and X ⁰ represents a single bond or It is a divalent linking group, Rf ⁰ is an organic group, at least one of X ⁰ and Rf ⁰ has a fluorine atom, and v is 0 or 1. ]

In formula (f2-1), 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. As the alkyl group having 1 to 5 carbon atoms and the halogenated alkyl group having 1 to 5 carbon atoms of R, the alkyl group having 1 to 5 carbon atoms and the halogenated group having 1 to 5 carbon atoms as the substituent at the α-position described above. It is the same as the alkyl group.
Among these, R is preferably a hydrogen atom or a methyl group.

In formula (f2-1), A is —O— or —NH—, and preferably —O—.
In formula (f2-1), v is 0 or 1. In the present invention, v = 0 means that —C (═O) —A— in the formula becomes a single bond.

In Formula (f2-1), X ⁰ is a single bond or a divalent linking group.
Examples of the divalent linking group for X ⁰ include a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a hetero atom. And a divalent hydrocarbon group which may have a substituent of Y ^{22 and} a divalent linking group containing a hetero atom. The divalent linking group of X ⁰ may or may not have an acid dissociable group in the structure. Examples of the acid dissociable group include the same groups as those exemplified in the structural unit (a1).

X ⁰ is preferably a single bond or a divalent linking group containing a hetero atom, and more preferably a single bond or a divalent linking group containing —C (═O) —O—.
More specifically, as the divalent linking group of X ⁰ when v is 0, a divalent aromatic hydrocarbon group which may have a substituent, and —O—C (═O) A combination with a divalent linking group containing-is preferred; a group in which one hydrogen atom is further removed from a phenyl group or naphthyl group which may have a substituent, and -O-C (= O)- A combination or a combination of these with a linear alkylene group is particularly preferred.
In addition, as the divalent linking group of X ⁰ when v is 1, a divalent hydrocarbon group which may have a substituent and a divalent group containing —C (═O) —O— are included. A combination with a linking group is preferable; a combination of an aliphatic hydrocarbon group or an aromatic hydrocarbon group which may have a substituent and —C (═O) —O— is more preferable. Moreover, the combination of these and an ether bond (-O-) is also preferable.
When X ⁰ is a divalent linking group, X ⁰ may or may not have a fluorine atom. When X ⁰ is a single bond, or when the divalent linking group of X ⁰ does not have a fluorine atom, the organic group of Rf ⁰ described later has a fluorine atom.

In formula (f2-1), Rf ⁰ is an organic group.
The organic group Rf ^0, even an organic group having a fluorine atom, or an organic group having no fluorine atom but, when the X ⁰ is a single bond or a divalent linking group for X ⁰ When does not have a fluorine atom, the organic group of Rf ⁰ has a fluorine atom. Here, the “organic group having a fluorine atom” refers to a group in which part or all of the hydrogen atoms in the organic group are substituted with fluorine atoms.
Preferred examples of the organic group for Rf ⁰ include a hydrocarbon group that may or may not have a fluorine atom, and may further have a substituent other than fluorine. . The hydrocarbon group that may have a fluorine atom or other substituent may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

Examples of the aliphatic hydrocarbon group represented by Rf ⁰ include linear, branched, or cyclic alkyl groups.
The linear or branched alkyl group preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, still more preferably 1 to 8 carbon atoms, and 1 carbon atom. Most preferred is ~ 5.
The cyclic alkyl group preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, still more preferably 6 to 10 carbon atoms, and 5 to 7 carbon atoms. Most preferred.

The aromatic hydrocarbon group represented by Rf ⁰ preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, most preferably 6 to 12 carbon atoms, and a phenyl group or a naphthyl group. Particularly preferred.

These alkyl groups and aromatic hydrocarbon groups are preferably substituted with fluorine atoms, and preferably 25% or more of the hydrogen atoms in the alkyl groups and aromatic hydrocarbon groups are substituted with fluorine atoms, It is more preferable that 50% or more is substituted with fluorine atoms, and a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms may be used.
Further, these alkyl groups and aromatic hydrocarbon groups may be substituted with other substituents other than fluorine atoms. Examples of the substituent other than the fluorine atom include a hydroxyl group, a chlorine atom, a bromine atom, an iodine atom, and an alkoxy group having 1 to 5 carbon atoms. In addition, the cyclic alkyl group or the aromatic hydrocarbon group may be substituted with an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, a hydroxyl group, or the like. As the alkyl group having 1 to 5 carbon atoms and the halogenated alkyl group having 1 to 5 carbon atoms, the alkyl group having 1 to 5 carbon atoms and the alkyl halide having 1 to 5 carbon atoms as the substituent at the α-position described above Group.

  Preferred specific examples of the structural unit represented by the formula (f2-1) include a structural unit (f2-11) represented by the following formula (f2-11) and a structure represented by the following formula (f2-12). A structural unit represented by the unit (f2-12), a structural unit (f2-13) represented by the following formula (f2-13), and a structural unit (f2-14) represented by the following formula (f2-14) Is mentioned.

［式中、Ｒｆ^１１〜Ｒｆ^１２はフッ素原子を有する有機基であり、Ａは前記同様であり、Ｘ^０１〜Ｘ^０２は２価の連結基であり、Ｒｆ^１３〜Ｒｆ^１４はフッ素原子を有していてもよい有機基である。Ｘ^０１又はＲｆ^１３の少なくとも一方、及び、Ｘ^０２又はＲｆ^１４の少なくとも一方はフッ素原子を有する。］

[Wherein Rf ^{11 to} Rf ¹² are organic groups having a fluorine atom, A is the same as described above, X ^{01 to} X ⁰² are divalent linking groups, and Rf ^{13 to} Rf ¹⁴ have a fluorine atom. It is an organic group that may be used. At least one of X ⁰¹ or Rf ¹³ and at least one of X ⁰² or Rf ¹⁴ have a fluorine atom. ]

In formula (f2-11), Rf ¹¹ is an organic group having a fluorine atom, and is preferably an aromatic hydrocarbon group having a fluorine atom. Examples of the aromatic hydrocarbon group having a fluorine atom include those in which part or all of the hydrogen atoms of the aromatic hydrocarbon group represented by Rf ⁰ are substituted with fluorine atoms.
In formula (f2-12), A is as defined above. Rf ¹² is an organic group having a fluorine atom, and is preferably a cyclic alkyl group having a fluorine atom or an aromatic hydrocarbon group having a fluorine atom. Examples of the cyclic alkyl group and aromatic hydrocarbon group having a fluorine atom include those in which part or all of the hydrogen atoms of the cyclic alkyl group and aromatic hydrocarbon group of Rf ⁰ are substituted with fluorine atoms. .

In the formula (f2-13), X ⁰¹ is a divalent linking group, and examples thereof include the same as X ⁰ described above.
Among these, X ⁰¹ is preferably a divalent aromatic hydrocarbon group which may have a substituent, and one hydrogen atom is further removed from a phenyl group or naphthyl group which may have a substituent. The group is particularly preferred.
As the substituent, a fluorine atom and an alkoxy group having 1 to 5 carbon atoms are preferable. When X ⁰¹ does not have a fluorine atom, Rf ¹³ has a fluorine atom.

In formula (f2-13), Rf ¹³ represents an organic group which may have a fluorine atom, and examples thereof include the same organic groups as those described above for Rf ⁰ . Rf ¹³ is preferably a linear or branched alkyl group which may have a fluorine atom, and preferably has 1 to 5 carbon atoms.

In formula (f2-14), A is as defined above. X ⁰² is a divalent linking group, and examples thereof include the same as X ⁰ described above.
Of these examples of X ^02, divalent may have a substituent aliphatic hydrocarbon group, an aromatic optionally substituted hydrocarbon group, an ether bond (-O-), an ester bond (—O—C (═O) —) or a combination thereof is preferred. The aliphatic hydrocarbon group may be a chain or a ring.
As the substituent, a fluorine atom, an alkoxy group having 1 to 5 carbon atoms, and an oxygen atom are preferable. When X ⁰² does not have a fluorine atom, Rf ¹⁴ has a fluorine atom.
In formula (f2-14), Rf ¹⁴ represents an organic group which may have a fluorine atom, and is the same as Rf ¹³ above.

In addition, if the resist pattern formation using the resist composition containing the component (F1) of the present invention is performed by alkali development, Rf ^{14 in} (f2-14) may be a base dissociable group. preferable. Rf ¹⁴ which is a base dissociable group is not particularly limited as long as Rf ¹⁴ is a hydrocarbon group or a hydrocarbon group which may have a substituent, but preferably has a fluorine atom.
In the present invention, the “base-dissociable group” is a group that exhibits decomposability (—O—Rf ¹⁴ is dissociated) by the action of an alkali developer. “Degradable with respect to alkali developer” means that it is decomposed by the action of an alkali developer (preferably at 23 ° C. by the action of a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution. This means that the solubility in an alkaline developer is increased. Specific examples include groups that decompose by the action of a base to generate polar groups. Examples of the polar group include a carboxy group, a hydroxyl group, and an amino group.
As described above, the structural unit (f2) changes from hydrophobic to hydrophilic before and after development, so that the scan followability at the time of immersion exposure is improved, and defects after exposure are reduced. Therefore, the resist composition of the present invention containing the structural unit (f2) containing a base dissociable group is useful as a resist composition for immersion exposure.

Specific examples of structural units represented by formulas (f2-11) to (f2-14) are shown below. In the formula, ^Rβ is a hydrogen atom or a methyl group.

  As the structural unit (f2), at least one selected from structural units (f2-11) to (f2-14) is preferable, and the structural unit (f2-2) or (f2-14) is particularly preferable.

As the structural unit (f2), one type may be used alone, or two or more types may be used in combination.
In the component (F1), the proportion of the structural unit (f2) is preferably from 30 to 99 mol%, more preferably from 40 to 99 mol%, more preferably from 50 to 95, based on the total of all structural units constituting the (F1) component. More preferred is mol%.
By setting the proportion of the structural unit (f2) in the component (F1) to be equal to or higher than the lower limit of the above range, the resist film surface can be made sufficiently water-repellent in resist pattern formation, and is excellent in immersion exposure. Pattern formation can be performed. By reducing the proportion of the structural unit (f2) in the component (F1) to be not more than the upper limit of the above range, defects can be reduced.

The component (F1) may have a structural unit other than the structural unit (f1) and the structural unit (f2) as long as the effects of the present invention are not impaired.
The structural unit is not particularly limited as long as it is copolymerizable with the structural unit (f1) and the structural unit (f2). And a structural unit (f3) containing an acid-decomposable group which is derived from an acrylate ester which may be prepared and which increases the polarity by the action of an acid.

(Structural unit (f3))
The structural unit (f3) is a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and the acid decomposition whose polarity is increased by the action of an acid A structural unit containing a sex group. As the structural unit (f3), the same structural units as those described above (a1) can be used.

When the component (F1) of the present invention contains the structural unit (f3), the acid-decomposable group in the structural unit (f3) is decomposed by the action of an acid in the exposed portion of the resist film (the acid dissociable group is When dissociated), a polar group is generated at the terminal of the structural unit (f3), and the solubility of the component (F1) in an alkali developer increases. Thereby, not only the component (A) which is the base resin but also the component (F), a dissolution contrast is obtained between the exposed portion and the unexposed portion. Furthermore, it is considered that a polar group is generated at the terminal of the structural unit (f3) in the exposed portion, whereby the resist film surface becomes hydrophilic and defects after development are suitably reduced.
Especially, since it shows hydrophilicity suitably, it is preferable that it is a structural unit which decomposes | disassembles as a structural unit (f3) by the effect | action of an acid and produces the carboxy group which is a polar group.
Further, as described above, since the component (F) is unevenly distributed on the resist film surface, before the decomposition of the acid-decomposable group (f3), hydrophobicity is imparted to the resist film surface so as to follow the scan during immersion exposure. Is thought to improve.

  Specifically, such a structural unit (f3) is preferably a structural unit represented by the above formula (a1-3-03), and most preferably a structural unit represented by the above formula (a1-3-22). .

As the structural unit (f3), one type may be used alone, or two or more types may be used in combination.
When the component (F1) contains the structural unit (f3), the proportion of the structural unit (f3) is preferably 1 to 50 mol% with respect to the total of all the structural units constituting the component (F1). 40 mol% is more preferable and 1-30 mol% is especially preferable. When the proportion of the structural unit (f3) is not less than the lower limit of the above range, the ability to reduce defects is further improved in forming a resist pattern. In addition, it is considered that the scan followability is improved. When the amount is not more than the upper limit of the above range, balance with other structural units can be achieved, and water repellency is improved.

  As the component (F1), a copolymer composed of the structural unit (f1-1) and the structural unit (f2-14); from the structural unit (f1-1), the structural unit (f2-14), and the structural unit (f3) A copolymer comprising the structural unit (f1-2) and the structural unit (f2-12); a copolymer comprising the structural unit (f1-2) and the structural unit (f2-14) being preferred. It can be illustrated.

As the component (F), one type of polymer compound (f1) may be used alone, or two or more types of polymer compounds (f1) may be used in combination.
The content of the component (F) is preferably 0.3 to 20 parts by mass, more preferably 0.3 to 10 parts by mass with respect to 100 parts by mass of the component (A), and 0.5 More preferably, it is -5 mass parts. By setting it within the above range, it is possible to balance the defect reduction ability with other lithography characteristics. By setting the above lower limit value or more, defects can be reduced particularly well. Further, by setting the range, it is possible to balance the defect reduction ability with other lithography characteristics.

  In the polymer compound (F1), a monomer that induces a desired structural unit is polymerized by a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate. Can be obtained.

The weight average molecular weight (Mw) of the component (F) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, preferably 1000 to 80000, more preferably 3000 to 60000, and most preferably 5000 to 50000. preferable. If it is less than or equal to the upper limit of this range, the resist film can be sufficiently segregated to the upper layer, and if it is more than or equal to the lower limit of this range, the solubility in the developer is appropriate and the defect is good.
Further, the dispersity (Mw / Mn) of the component (F) 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.

<Optional component>
[(D) component]
The resist composition of the present invention may contain a basic compound component (D) (hereinafter referred to as “component (D)”) as an optional component. In the present invention, the component (D) acts as an acid diffusion control agent, that is, a quencher that traps the acid generated from the component (B) by exposure. In the present invention, the “basic compound” refers to a compound that is relatively basic with respect to the component (B).
The component (D) in the present invention may be a basic compound (D1) (hereinafter referred to as “component (D1)”) composed of a cation moiety and an anion moiety, and does not correspond to the component (D1). It may be a basic compound (D2) (hereinafter referred to as “component (D2)”).

((D1) component)
In the present invention, as the component (D1), a compound (d1-1) represented by the following general formula (d1-1) (hereinafter referred to as “(d1-1) component”), the following general formula (d1) -2) (d1-2) (hereinafter referred to as “component (d1-2)”) and compound (d1-3) represented by the following general formula (d1-3) (hereinafter, It is preferable to contain one or more selected from the group consisting of “(d1-3) component”.

［式中、Ｒ^４は置換基を有していてもよい炭化水素基であり、Ｚ^２ｃは置換基を有していてもよい炭素数１〜３０の炭化水素基（ただし、Ｓに隣接する炭素にはフッ素原子は置換されていないものとする）であり、Ｒ^５は有機基であり、Ｙ^５は直鎖状、分岐鎖状若しくは環状のアルキレン基またはアリーレン基であり、Ｒｆ^３はフッ素原子を含む炭化水素基であり、Ｍ^＋はそれぞれ独立にスルホニウム又はヨードニウムカチオンである。］

[Wherein, R ⁴ is a hydrocarbon group which may have a substituent, and Z ^2c is a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent (however, adjacent to S R ⁵ is an organic group, Y ⁵ is a linear, branched or cyclic alkylene group or an arylene group, and Rf ³ is fluorine. It is a hydrocarbon group containing an atom, and each M ⁺ is independently a sulfonium or iodonium cation. ]

During · (d1-1) component Anion formula (d1-1), ^{R 4} is a hydrocarbon group which may have a substituent.
The hydrocarbon group which may have a substituent of R ⁴ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and the aliphatic hydrocarbon group of X ³ in component (B) Group and the same aromatic hydrocarbon group.
Among them, the hydrocarbon group which may have a substituent of R ⁴ is an aromatic hydrocarbon group which may have a substituent, or an aliphatic cyclic group which may have a substituent. A phenyl group or naphthyl group which may have a substituent; one or more hydrogen atoms are removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane. More preferably, it is a group.

In addition, the hydrocarbon group which may have a substituent for R ⁴ is preferably a linear or branched alkyl group or a fluorinated alkyl group.
The number of carbon atoms of the linear or branched alkyl group of R ⁴ is preferably 1 to 10, specifically, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, Linear alkyl group such as heptyl group, octyl group, nonyl group, decyl group, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3- Examples thereof include branched alkyl groups such as methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

The fluorinated alkyl group for R ⁴ may be linear or cyclic, but is preferably linear or branched.
1-11 are preferable, as for carbon number of a fluorinated alkyl group, 1-8 are more preferable, and 1-4 are more preferable. Specifically, for example, a part or all of a linear alkyl group such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, etc. Or a branched chain such as a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, or a 3-methylbutyl group. And a group in which some or all of the hydrogen atoms constituting the alkyl group are substituted with fluorine atoms.
Moreover, the fluorinated alkyl group for R ⁴ may contain an atom other than a fluorine atom. Examples of atoms other than fluorine atoms include oxygen atoms, carbon atoms, hydrogen atoms, oxygen atoms, sulfur atoms, and nitrogen atoms.
Among them, the fluorinated alkyl group for R ⁴ is preferably a group in which some or all of the hydrogen atoms constituting the linear alkyl group are substituted with fluorine atoms. It is preferable that all the hydrogen atoms which comprise are the group (perfluoroalkyl group) substituted by the fluorine atom.

  Preferred specific examples of the anion moiety of the component (d1-1) are shown below.

-Cation part In Formula (d1-1), M ^<+> is an organic cation.
Although it does not specifically limit as an organic cation of M ^<+> , For example, the thing similar to the cation part of the compound represented by the said Formula (b-1) or (b-2) is mentioned.
As the component (d1-1), one type may be used alone, or two or more types may be used in combination.

- (d1-2) in component Anion formula ^{(d1-2), Z 2c} is a hydrocarbon group of 1 to 30 carbon atoms which may have a substituent.
The hydrocarbon group having 1 to 30 carbon atoms which may have a substituent of Z ^2c may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and R in the component (B) Examples of the aliphatic hydrocarbon group and aromatic hydrocarbon group represented by X ³ described above as the substituent for ^{4 ″} are the same.
Among them, the hydrocarbon group which may have a substituent of Z ^2c is preferably an aliphatic cyclic group which may have a substituent, adamantane, norbornane, isobornane, tricyclodecane, It is more preferably a group obtained by removing one or more hydrogen atoms from tetracyclododecane, camphor or the like (which may have a substituent).
The hydrocarbon group for Z ^2c may have a substituent, and examples of the substituent include the same as X ³ in the component (B). However, in Z ^2c , the carbon adjacent to the S atom in SO ₃ ^— is not fluorine-substituted. Since SO ₃ ^— and a fluorine atom are not adjacent to each other, the anion of the component (d1-2) becomes an appropriate weak acid anion, and the quenching ability of the component (D) is improved.
Preferred specific examples of the anion moiety of the component (d1-2) are shown below.

During cation portion formula (d1-2), ^{M +} is the same as ^{M +} in the formula (d1-1) in.
As the component (d1-2), one type may be used alone, or two or more types may be used in combination.

During · (d1-3) component Anion formula (d1-3), ^{R 5} is an organic group.
The organic group for R ⁵ is not particularly limited, but is an alkyl group, an alkoxy group, —O—C (═O) —C (R ^C2 ) ═CH ₂ (R ^C2 is a hydrogen atom, a carbon number of 1 to 5 Or an alkyl group having 1 to 5 carbon atoms), or —O—C (═O) —R ^C3 (R ^C3 is a hydrocarbon group).
The alkyl group of R ⁵ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group. Tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. A part of hydrogen atoms of the alkyl group of R ² may be substituted with a hydroxyl group, a cyano group, or the like.
The alkoxy group of R ⁵ is preferably an alkoxy group having 1 to 5 carbon atoms. Specific examples of the alkoxy group having 1 to 5 carbon atoms include methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n- Examples include butoxy group and tert-butoxy group. Of these, a methoxy group and an ethoxy group are most preferable.

When R ⁵ 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 ⁵ 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 for X ^{3 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.

Among them, as R ⁵ , —O—C (═O) —C (R ^C2 ′) ═CH ₂ (R ^C2 ′ is a hydrogen atom or a methyl group), or —O—C (═O ) -R ^C3 ′ (R ^C3 ′ is an aliphatic cyclic group).

In formula (d1-3), Y ⁵ represents a linear, branched or cyclic alkylene group or an arylene group.
As the linear, branched or cyclic alkylene group or arylene group for Y ⁵ , among the divalent linking groups for Y ^{22 in} the above formula (a1-0-2), “linear or branched chain” And the same as the “cyclic aliphatic hydrocarbon group”, “cyclic aliphatic hydrocarbon group”, and “aromatic hydrocarbon group”.
Among these, Y ⁵ is preferably an alkylene group, more preferably a linear or branched alkylene group, and even more preferably a methylene group or an ethylene group.

In formula (d1-3), Rf ³ represents a hydrocarbon group containing a fluorine atom.
The hydrocarbon group containing a fluorine atom of Rf ³ is preferably a fluorinated alkyl group, and more preferably the same as the fluorinated alkyl group of R ⁴ above.
Preferred specific examples of the anion moiety of the component (d1-3) are shown below.

During cation portion formula (d1-3), ^{M +} is the same as ^{M +} in the formula (d1-1) in.
As the component (d1-3), one type may be used alone, or two or more types may be used in combination.

The component (D) may contain only one of the above components (d1-1) to (d1-3), or may contain two or more in combination. Especially, it is especially preferable to contain (d1-2) component.
The total content of the components (d1-1) to (d1-3) is preferably 0.5 to 10.0 parts by mass with respect to 100 parts by mass of the component (A), and 0.5 to 8 More preferably, it is 0.0 mass part, More preferably, it is 1.0-8.0 mass part, It is especially preferable that it is 2.5-5.5 mass part. When it is at least the lower limit of the above range, particularly good lithography properties and 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.

(Method for producing components (d1-1) to (d1-3))
The manufacturing method of the (d1-1) component and (d1-2) component in this invention is not specifically limited, It can manufacture by a well-known method.
Further, the method for producing the component (d1-3) is not particularly limited. For example, R ⁵ in the formula (d1-3) is a group having an oxygen atom at the terminal bonded to Y ^5. In this case, the following general formula is obtained by reacting the compound (i-1) represented by the following general formula (i-1) with the compound (i-2) represented by the following general formula (i-2). By obtaining the compound (i-3) represented by (i-3) and reacting the compound (i-3) with Z ⁻ M ⁺ (i-4) having a desired cation M ⁺ , A compound (d1-3) represented by the formula (d1-3) is produced.

［式中、Ｒ^５、Ｙ^５、Ｒｆ^３、Ｍ^＋は、それぞれ、前記一般式（ｄ１−３）中のＲ^５、Ｙ^５、Ｒｆ^３、Ｍ^＋と同じである。Ｒ^５ａはＲ^５から末端の酸素原子を除いた基であり、Ｚ⁻は対アニオンである。］

^{Wherein, R 5, Y 5, Rf} 3, M + , respectively, the general formula (d1-3) ^R 5 ^in, Y ^5, Rf 3, is the same as ^{M +.} R ^5a is a group obtained by removing a terminal oxygen atom from R ⁵ , and Z ⁻ is a counter anion. ]

First, compound (i-1) and compound (i-2) are reacted to obtain compound (i-3).
In formula (i-1), R ^5a is a group obtained by removing a terminal oxygen atom from R ⁵ . In formula (i-2), Y ⁵ and Rf ³ are the same as described above.
As compound (i-1) and compound (i-2), commercially available compounds may be used or synthesized.
The method for obtaining compound (i-3) by reacting compound (i-1) with compound (i-2) is not particularly limited. For example, compound (i- After reacting 2) and compound (i-1) in an organic solvent, the reaction mixture can be washed and recovered.

The acid catalyst in the said reaction is not specifically limited, For example, toluenesulfonic acid etc. are mentioned, The usage-amount is about 0.05-5 mol with respect to 1 mol of compounds (i-2).
The organic solvent in the above reaction may be any material that can dissolve the compound (i-1) and the compound (i-2) as raw materials, and specifically includes toluene and the like. It is preferable that it is 0.5-100 mass parts with respect to (i-1), and it is more preferable that it is 0.5-20 mass parts. A solvent may be used individually by 1 type and may use 2 or more types together.
The amount of compound (i-2) used in the above reaction is usually preferably about 0.5 to 5 mol, more preferably about 0.8 to 4 mol, per 1 mol of compound (i-1).

The reaction time in the above reaction varies depending on the reactivity between the compound (i-1) and the compound (i-2), the reaction temperature, etc., but is usually preferably 1 to 80 hours, more preferably 3 to 60 hours. .
The reaction temperature in the above reaction is preferably 20 ° C to 200 ° C, more preferably about 20 ° C to 150 ° C.

Next, the obtained compound (i-3) and the compound (i-4) are reacted to obtain the compound (d1-3).
In formula (i-4), M ⁺ is the same as described above, and Z ⁻ is a counter anion.
The method of reacting compound (i-3) and compound (i-4) to obtain compound (d1-3) is not particularly limited. For example, the compound is obtained in the presence of a suitable alkali metal hydroxide. It can be carried out by dissolving (i-3) in a suitable organic solvent and water, adding compound (i-4) and reacting with stirring.

The alkali metal hydroxide in the above reaction is not particularly limited, and examples thereof include sodium hydroxide, potassium hydroxide and the like. About 3 mol is preferable.
Examples of the organic solvent in the above reaction include solvents such as dichloromethane, chloroform, and ethyl acetate, and the amount used is preferably 0.5 to 100 parts by mass with respect to compound (i-3). More preferably, it is 5-20 mass parts. A solvent may be used individually by 1 type and may use 2 or more types together.
The amount of compound (i-4) used in the above reaction is usually preferably about 0.5 to 5 mol, more preferably about 0.8 to 4 mol, relative to 1 mol of compound (i-3).

The reaction time in the above reaction varies depending on the reactivity between the compound (i-3) and the compound (i-4), the reaction temperature, etc., but is usually preferably 1 to 80 hours, more preferably 3 to 60 hours. .
The reaction temperature in the above reaction is preferably 20 ° C to 200 ° C, more preferably about 20 ° C to 150 ° C.
After completion of the reaction, the compound (d1-3) in the reaction solution may be isolated and purified. For isolation and purification, conventionally known methods can be used. For example, concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography, etc. can be used alone or in combination of two or more thereof. it can.

The structure of the compound (d1-3) obtained as described above is as follows: ¹ H-nuclear magnetic resonance (NMR) spectrum method, ¹³ C-NMR spectrum method, ¹⁹ F-NMR spectrum method, infrared absorption (IR) spectrum method. It can be confirmed by a general organic analysis method such as mass spectrometry (MS) method, elemental analysis method, X-ray crystal diffraction method.

((D2) component)
The component (D2) is particularly limited as long as it is a compound that is relatively basic to the component (B), acts as an acid diffusion controller, and does not fall under the component (D1). It may be used arbitrarily from known ones. Examples thereof include amines such as aliphatic amines and aromatic amines, among which 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 amines (alkyl amines or alkyl alcohol amines) or cyclic amines in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms.
Specific examples 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} ethyl] amine, triethanolamine triacetate and the like, and triethanolamine triacetate is preferable.

  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.

(D2) A component may be used independently and may be used in combination of 2 or more type.
(D2) 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.

(D) A component may be used individually by 1 type and may be used in combination of 2 or more type.
When the resist composition of this invention contains (D) component, it is preferable that (D) component is 0.1-15 mass parts with respect to 100 mass parts of (A) component, 0.3- More preferably, it is 12 mass parts, and it is still more preferable that it is 0.5-12 mass parts. When it is at least the lower limit of the above range, lithography properties such as roughness are further improved when a positive resist composition is obtained. 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.

[(E) component]
The resist composition includes at least one selected from the group consisting of organic carboxylic acids and phosphorus oxo acids and derivatives thereof for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, retention time stability, and the like. (E) (hereinafter referred to as “component (E)”).
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 phosphinic acid derivatives include phenylphosphinic acid and phosphinic acid esters.
(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.

[(S) component]
The resist composition 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.
Furthermore, as the component (S), a mixed solvent of PGMEA and cyclohexanone is also preferable. In this case, the mixing ratio is preferably PGMEA: cyclohexanone = 95-5: 10-90.

According to the resist composition of the present invention, a resist pattern in which the occurrence of defects is reduced can be obtained. The reason why such an effect can be obtained is considered as follows.
In the resist composition of the present invention, when the structural unit (f1) in the component (F1) contains a polar group (—COOH, —SO ₂ NH ₂ ) at the terminal, the hydrophilicity of the formed resist film is increased. In particular, when rinsing with water after development in an alkali development process, components such as a base resin dissolved in an alkali developer are deposited and adhere to the surface of a highly hydrophobic resist pattern (occurrence of blob defects, etc.) Is considered to be suitably suppressed. In addition, the increase in hydrophilicity improves lithography properties such as resolution.
Furthermore, since the structural unit (f1) in the present invention contains R ¹ or R ² which is a divalent linking group between the main chain and the polar group, the side chain becomes a relatively long chain, It is presumed that the resist film after development is particularly well hydrophilized and the above effects can be obtained satisfactorily.

  Moreover, since the resist composition of this invention contains the structural unit (f2) containing a fluorine atom, (F) component is unevenly distributed near the surface of a resist film. As a result, the surface of the resist film formed using the resist composition of the present invention is given particularly good water repellency, and the scan followability during immersion exposure is improved.

≪Resist pattern formation method≫
The resist pattern forming method of the present invention includes a step of forming a resist film on a support using the resist composition of the present invention, a step of exposing the resist film, and developing the resist film to form a resist pattern. Forming.
The resist pattern forming method of the present invention can be performed, for example, as follows.
First, the resist composition is applied onto 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 under a temperature condition of 80 to 150 ° C. A film is formed. Next, the resist film is exposed through a mask (mask pattern) on which a predetermined pattern is formed or a mask pattern using an exposure apparatus such as an ArF exposure apparatus, an electron beam drawing apparatus, or an EUV exposure apparatus. After performing selective exposure by drawing or the like by direct irradiation with an electron beam (EB) not passing through, PEB (post-exposure heating) is applied for 40 to 120 seconds, preferably 60 to 90 seconds under a temperature condition of 80 to 150 ° C. .
Next, the resist film is developed.
The development treatment is performed using an alkaline developer in the case of an alkali development process, and using a developer (organic developer) containing an organic solvent in the case of a solvent development process.
A rinsing treatment is preferably performed after the development treatment. The rinse treatment is preferably a water rinse using pure water in the case of an alkali development process, and is preferably a rinse solution containing an organic solvent in the case of a solvent development process.
In the case of a solvent development process, after the development process or the rinse process, a process of removing the developer or rinse liquid adhering to the pattern with a supercritical fluid may be performed.
Drying is performed after development or rinsing. In some cases, a baking process (post-bake) may be performed after the development process. In this way, a resist 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, the immersion exposure is 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, exposure can be performed 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, a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms is particularly preferable. Specific examples of the perfluoroalkyl compound include a perfluoroalkyl ether compound and a perfluoroalkylamine compound.
More specifically, examples of the perfluoroalkyl ether compound include perfluoro (2-butyl-tetrahydrofuran) (boiling point: 102 ° C.). Examples of the perfluoroalkylamine compound include perfluorotributylamine ( Boiling point of 174 ° C.).
As the immersion medium, water is preferably used from the viewpoints of cost, safety, environmental problems, versatility, and the like.

Examples of the alkali developer used in the alkali development process include 0.1 to 10% by mass tetramethylammonium hydroxide (TMAH) aqueous solution.
The organic solvent contained in the organic developer used in the solvent development process 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. . Specifically, polar solvents such as ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents can be used.

In the present invention, it is also preferable to add a known additive to the developer used for the development treatment, if necessary. Examples of the additive include a surfactant. Although it does not specifically limit as surfactant, For example, a nonionic surfactant, an anionic surfactant, a cationic surfactant, and an amphoteric surfactant can be used, and a nonionic surfactant is especially preferable. Examples of nonionic surfactants include polyoxyethylene alkyl ethers and acetylenic nonionic surfactants.
When the surfactant is blended, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and 0.01 to 0.5% by mass with respect to the total amount of the developer. % Is more preferable.

The development treatment can be carried out by a known development method, for example, a method in which a support is immersed in a developer for a certain period of time (dip method), and the developer is raised on the surface of the support by surface tension and left stationary for a certain period of time. Method (Paddle method), Method of spraying developer on the surface of support (spray method), Continuous application of developer while scanning developer coating nozzle at constant speed on support rotating at constant speed And a method (dynamic dispensing method).
The rinse treatment (washing treatment) using the rinse liquid can be performed by a known rinse method. Examples of the method include a method of continuously applying a rinsing liquid on a support rotating at a constant speed (rotary coating method), a method of immersing the support in a rinsing liquid for a predetermined time (dip method), and the surface of the support. And a method of spraying a rinse liquid (spray method).

  The resist pattern forming method of the present invention can form a resist pattern with reduced occurrence of defects by using the resist composition of the present invention. Further, as described above, the resist composition of the present invention is suitable for both an alkali development process and a solvent development process, and is particularly suitable for an alkali development process using an alkali developer containing a surfactant.

≪Polymer compound≫
The polymer compound of the present invention is at least one structural unit selected from the group consisting of a structural unit represented by the following general formula (f1-1) and a structural unit represented by the following general formula (f1-2) (F1) and a structural unit (f2) containing a fluorine atom (excluding the structural unit (f1)).

［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、又は炭素数１〜５のハロゲン化アルキル基であり、Ｒ^１、Ｒ^２はそれぞれ独立に２価の連結基であり、Ｒｆ^１はフッ素原子で置換されていてもよい炭素数１〜１０の直鎖状若しくは分岐鎖状の炭化水素基、又はフッ素原子で置換されていてもよい炭素数３〜２０の環含有炭化水素基である。］

[Wherein, R is independently 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 ¹ and R ² are each independently a divalent linking group. Rf ¹ is a linear or branched hydrocarbon group having 1 to 10 carbon atoms which may be substituted with a fluorine atom, or a ring having 3 to 20 carbon atoms which may be substituted with a fluorine atom It is a contained hydrocarbon group. ]

  In the polymer compound of the present invention, the structural unit (f2) is preferably represented by the following general formula (f2-1).

［式中、Ｒ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り、Ａは−Ｏ−又は−ＮＨ−であり、Ｘ^０は単結合又は２価の連結基であり、Ｒｆ^０は有機基であり、Ｘ^０、Ｒｆ^０の少なくともいずれか一方がフッ素原子を有し、ｖは０又は１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, A represents —O— or —NH—, and X ⁰ represents a single bond or It is a divalent linking group, Rf ⁰ is an organic group, at least one of X ⁰ and Rf ⁰ has a fluorine atom, and v is 0 or 1. ]

The polymer compound of the present invention is the same as the component (F1) in the description of the resist composition according to the first aspect of the present invention, and each component in each structural unit and fluorine-containing compound component (F). About the content rate of a unit, it is the same as that of the above.
The polymer compound of the present invention is a novel compound useful as an additive for a resist composition, and can be suitably blended in a resist composition for immersion exposure.

(Method for producing polymer compound)
The polymer compound of the present invention is obtained by polymerizing a monomer for deriving a desired structural unit by a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate. Can be obtained. A commercially available monomer may be used, or the monomer may be synthesized by a known method.
The preferred mass average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer compound of the present invention are the same as those of the component (F1) described above.

The structure of the polymer compound of the present invention produced as described above includes ¹ H-nuclear magnetic resonance (NMR) spectrum method, ¹³ C-NMR spectrum method, ¹⁹ F-NMR spectrum method, infrared absorption (IR) spectrum. It can be confirmed by a general organic analysis method such as a method, a mass spectrometry (MS) method, an elemental analysis method or an X-ray crystal diffraction method.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.

[Polymer Synthesis Example 1: Synthesis of Polymer Compound 1]
In a separable flask connected with a thermometer, a reflux tube, and a nitrogen introduction tube, 23.09 g (101.70 mmol) of the compound (1), 6.64 g (25.43 mmol) of the compound (2), 38.09 g Dissolved in methyl ethyl ketone (MEK). To this solution, 2.42 mmol of dimethyl azobisisobutyrate (V-601) as a polymerization initiator was added and dissolved.
The resultant was dropwise added to 20.66 g of MEK heated to 80 ° C. in a nitrogen atmosphere over 4 hours. After completion of dropping, the reaction solution was heated and stirred for 1 hour, and then the reaction solution was cooled to room temperature.
The obtained reaction polymerization solution was dropped into a large amount of n-heptane, and a polymer was precipitated. The precipitated white powder was filtered off, washed with n-heptane, and dried. 22.5 g of molecular compound 1 was obtained.
With respect to this polymer compound 1, the weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 21,300, and the molecular weight dispersity (Mw / Mn) was 1.63.
The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) was 1 / m = 80.4 / 19. 6.

[Polymer synthesis examples 2 to 14: Production of polymer compounds 2 to 14]
The polymer compounds 2 to 14 were the same as the polymer synthesis example 1 except that the following monomers (1) to (8) for deriving structural units constituting each polymer compound were used in the molar ratio shown in Table 1. Manufactured. The mass average molecular weight (Mw) and molecular weight dispersion (Mw / Mn) of the obtained polymer compounds 2 to 14 are also shown in Table 1.

[Examples 1 to 10, Comparative Examples 1 to 4]
Each component shown in Table 2 was mixed and dissolved to prepare a resist composition.

Each abbreviation in Table 2 has the following meaning. Moreover, the numerical value in [] is a compounding quantity (mass part).
(A) -1: a polymer compound represented by the following formula (A) -1 (Mw = 5000, Mw / Mn = 5,500, l / m / n / o = 45/40/5/10 (mol) ratio)).
(B) -1: The following compound (B) -1.
(F) -1 to (F) -14: The above polymer compounds 1-14.
(D) -1: The following compound (D) -1.
(E) -1: salicylic acid.
(S) -1: PGMEA / PGME / cyclohexanone = 129/86/71 (mass ratio) mixed solvent.

  Using the obtained resist composition, a resist pattern was formed according to the following procedure, and the following evaluations were performed.

[Formation of resist pattern]
An organic antireflection film composition “ARC29A” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto a 12-inch silicon wafer using a spinner and baked on a hot plate at 205 ° C. for 60 seconds to be dried. Thereby, an organic antireflection film having a film thickness of 89 nm was formed.
Then, the resist composition of each example obtained above is applied onto the organic antireflection film using a spinner, and prebaked (PAB) treatment is performed on a hot plate at 80 ° C. for 60 seconds. By performing and drying, a resist film having a film thickness of 100 nm was formed.
Next, an immersion ArF exposure apparatus NSR-S609B (manufactured by Nikon Corporation; NA (numerical aperture) = 1.07, Annular (out-0.97 / In-0.78) w / XY-Pol. Immersion medium : Water), the resist film was selectively irradiated with an ArF excimer laser (193 nm).
Then, PEB treatment is performed at 80 ° C. for 60 seconds, and further developed at 23 ° C. with a 2.38 mass% TMAH aqueous solution (trade name: NMD-W, manufactured by Tokyo Ohka Kogyo Co., Ltd.) containing an acetylenic activator for 20 seconds. After that, the substrate was rinsed with pure water for 30 seconds, and then shaken and dried. Subsequently, post-baking was performed at 100 ° C. for 45 seconds.
The target size was a hole diameter (CD) of 100 nm and a pitch of 550 nm, and contact hole patterns were formed by the resist pattern forming method described above.

[Evaluation of development defects]
The contact hole pattern obtained as described above was observed using a surface defect observation apparatus KLA2371 (product name) manufactured by KLA Tencor. The number of development defects in the unexposed area per silicon wafer was measured. The results are shown in Table 3, with “◯” indicating that the number of development defects is less than 1000 and “×” indicating that the number of defects is 1000 or more.

[Evaluation of contact angle in resist film]
Next, each of the resist compositions of Examples 1 to 10 and Comparative Examples 1 to 4 was applied onto a 10-inch silicon wafer that had been subjected to hexamethyldisilazane (HMDS) treatment using a spinner, and on a hot plate. By prebaking at 80 ° C. for 60 seconds and drying, a resist film having a thickness of 90 nm was formed.
Water was dropped on the surface of the resist film (resist film before exposure), and contact angle was measured using DROP MASTER-700 (product name, manufactured by Kyowa Interface Science Co., Ltd.) (measurement of contact angle: 2 μL of water). This measured value was defined as “contact angle after application (°)”.
Next, with respect to each wafer after measuring the contact angle after coating, a 2.38 mass% TMAH aqueous solution (trade name: NMD-W, manufactured by Tokyo Ohka Kogyo Co., Ltd.) containing an acetylenic activator at 23 ° C. After developing for 30 seconds, and then rinsing with pure water for 15 seconds, shaking off and drying, the contact angles were measured in the same manner as described above. This measured value was defined as “contact angle after development (°)”.
These results are shown in Table 3.

From the above results, it was confirmed that the resist compositions of Examples 1 to 10 according to the present invention had a large difference between the contact angle after coating and the contact angle after development, and the development defects were reduced.
On the other hand, in Comparative Examples 1 to 4 using the polymer compounds 11 to 14, the post-development contact angle exceeded 60 °. Further, the resist films of Comparative Examples 1 to 4 were not sufficiently hydrophilic after development and had many development defects.

Claims (4)

A resist composition comprising a base component (A) whose solubility in a developing solution is changed by the action of an acid, an acid generator component (B) that generates an acid upon exposure, and a fluorine-containing compound component (F). ,
The fluorine-containing compound component (F) includes a structural unit ( f1) represented by the following general formula (f1-1) and a structural unit (f2) containing a fluorine atom (excluding the structural unit (f1)) A polymer compound (F1) having
The base component (A) includes a —SO ₂ -containing cyclic group, and is a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent ( resist composition characterized in that it has a a2 ^S).

[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 R ¹ represents a linear or branched aliphatic hydrocarbon group, Or a combination of a divalent linking group containing a heteroatom and the linear or branched aliphatic hydrocarbon group, wherein the divalent linking group containing a heteroatom is -O-, —C (═O) —O—, —C (═O) —, —O—C (═O) —O—, —C (═O) —NH—, —NH— (H is an alkyl group or acyl) it may be substituted with a group), -. S -, - S (= O) 2 - or -S _{(= O)} is 2 -O-. ] The resist composition according to claim 1, wherein the structural unit (f2) is represented by the following general formula (f2-1).

[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, A represents —O— or —NH—, and X ⁰ represents a single bond or It is a divalent linking group, Rf ⁰ is an organic group, at least one of X ⁰ and Rf ⁰ has a fluorine atom, and v is 0 or 1. ] The developer is a developer containing a surfactant,
The resist composition according to claim 1 or 2, wherein the base material component (A) is a base material component (A0) whose polarity is increased by the action of an acid.   A step of forming a resist film on the support using the resist composition according to any one of claims 1 to 3, a step of exposing the resist film, and developing the resist film to form a resist pattern A resist pattern forming method including a forming step.