JP2014102334A - Resist composition and method for forming resist pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist composition from which a resist pattern with more preferable lithographic characteristics can be formed, and to provide a method for forming a resist pattern using the resist composition.SOLUTION: The resist composition comprises: a base component (A) the solubility of which with a developing solution changes by an action of an acid; a sulfonium compound (B1) having a sulfonio group and an anion group expressed by general formula (b1-r-1) in one molecule; and a photo-degradable base (D1) that is decomposed by exposure to lose acid diffusion controllability. The method for forming a resist pattern is carried out by using the resist composition. In formula (b1-r-1), Yrepresents a divalent connecting group or a single bond; Lrepresents an ester bond or a single bond; Vrepresents a divalent hydrocarbon group having a fluorine atom; and n is 0 or 1.

Description

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

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 and developed to form a resist pattern having a predetermined shape on the resist film. The process to perform is performed. A resist material in which the exposed portion of the resist film 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.

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.
Conventionally, as a resist material satisfying such requirements, a chemically amplified resist composition containing a base material component whose solubility in a developing solution is changed by the action of an acid and an acid generator component that generates an acid upon exposure. Is used. For example, when the developer is an alkali developer (alkaline development process), the positive chemically amplified resist composition includes a resin component (base resin) whose solubility in an alkali developer is increased by the action of an acid, an acid Those containing a generator component are generally used. When a resist film formed using such a resist composition is selectively exposed at the time of resist pattern formation, an acid is generated from the acid generator component in the exposed portion, and the alkali developer of the base resin is generated by the action of the acid. And 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.
Here, as the base resin, a resin whose polarity is increased by the action of an acid is used, and the solubility in an alkali developer is increased while the solubility in an organic solvent is decreased. Therefore, when a 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. Thus, the 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 chemically amplified resist composition used in ArF excimer laser lithography and the like, it has a structural unit derived from (meth) acrylic acid ester in its main chain because of its excellent transparency near 193 nm. Resins (acrylic resins) 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.
Various acid generators used in chemically amplified resist compositions have been proposed so far, such as onium salt acid generators, oxime sulfonate acid generators, diazomethane acid generators. Nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like are known.
Recently, as the pattern becomes increasingly finer, a resin having an acid generating group that decomposes upon exposure to generate an acid has been proposed (see, for example, Patent Document 3).

JP 2009-025723 A JP 2003-241385 A JP 2006-045311 A

As the progress of lithography technology and the expansion of application fields proceed, the formation of resist patterns requires various improvements in lithography characteristics and resist pattern shapes.
However, the conventional resist compositions as described in Patent Documents 2 to 3 have not only high sensitivity and high resolution, but also lithography characteristics such as roughness reduction, mask reproducibility, and process margin. Improvement is necessary.
The present invention has been made in view of the above circumstances, and provides a resist composition that can form a resist pattern with better lithography characteristics, and a resist pattern forming method using the resist composition. And

  A first aspect of the present invention that solves the above problems is a base component (A) whose solubility in a developing solution is changed by the action of an acid, a sulfonio group and the following general formula (b1-r- A resist composition comprising a sulfonium compound (B1) having an anion group represented by 1) and a photodegradable base (D1) that is decomposed by exposure and loses acid diffusion controllability. .

［式中、Ｙ^１は２価の連結基又は単結合であり、Ｌ^１はエステル結合又は単結合であり、Ｖ^１はフッ素原子を有する２価の炭化水素基であり、ｎは０又は１である。］

[Wherein Y ¹ is a divalent linking group or a single bond, L ¹ is an ester bond or a single bond, V ¹ is a divalent hydrocarbon group having a fluorine atom, and n is 0 or 1 It is. ]

  According to a second aspect of the present invention, there is provided a step of forming a resist film on a support using the resist composition according to the first aspect of the present invention, a step of exposing the resist film, and developing the resist film Then, a resist pattern forming method comprising a step of forming a resist pattern.

  According to the resist composition and resist pattern forming method of the present invention, a resist pattern with better lithography properties can be formed.

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).
When it is described as “may have a substituent”, when a hydrogen atom (—H) is substituted with a monovalent group, and when a methylene group (—CH ₂ —) is substituted with a divalent group And both.
“Exposure” is a concept including general irradiation of radiation.

“A structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid 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.
In the acrylate ester, the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. The substituent (R ^α0 ) for substituting the hydrogen atom bonded to the α-position carbon atom is an atom or group other than a hydrogen atom, such as an alkyl group having 1 to 5 carbon atoms or a halogenated group having 1 to 5 carbon atoms. An alkyl group etc. are mentioned. In addition, itaconic acid diesters in which the substituent (R ^α0 ) is substituted with a substituent containing an ester bond, and α-hydroxyacrylic esters in which the substituent (R ^α0 ) is substituted with a hydroxyalkyl group or a group with a modified hydroxyl group thereof Shall be included. The α-position carbon atom of the acrylate ester is a carbon atom to which the carbonyl group of acrylic acid is bonded unless otherwise specified.
Hereinafter, an acrylate 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 an α-substituted acrylate ester. Further, the acrylate ester and the α-substituted acrylate ester may be collectively referred to as “(α-substituted) acrylate ester”.

“Structural unit derived from acrylamide” means a structural unit formed by cleavage of the ethylenic double bond of acrylamide.
In acrylamide, the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and one or both of the hydrogen atoms of the amino group of acrylamide may be substituted with a substituent. The α-position carbon atom of acrylamide is a carbon atom to which the carbonyl group of acrylamide is bonded unless otherwise specified.
Examples of the substituent for substituting the hydrogen atom bonded to the α-position carbon atom of acrylamide are the same as those described as the α-position substituent (substituent (R ^α0 )) in the α-substituted acrylic ester. Can be mentioned.

“A structural unit derived from hydroxystyrene or a hydroxystyrene derivative” means a structural unit formed by cleavage of an ethylenic double bond of hydroxystyrene or a hydroxystyrene derivative.
“Hydroxystyrene derivative” is a concept including those in which the hydrogen atom at the α-position of hydroxystyrene is substituted with another substituent such as an alkyl group or an alkyl halide group, and derivatives thereof. These derivatives include those obtained by substituting the hydrogen atom of the hydroxyl group of hydroxystyrene which may be substituted with a hydrogen atom at the α-position with an organic group; The thing etc. which the substituents other than a hydroxyl group couple | bonded with the benzene ring of good hydroxystyrene are mentioned. The α-position (α-position carbon atom) means a carbon atom to which a benzene ring is bonded unless otherwise specified.
Examples of the substituent for substituting the hydrogen atom at the α-position of hydroxystyrene include the same substituents as those mentioned as the substituent at the α-position in the α-substituted acrylic ester.

The “structural unit derived from vinyl benzoic acid or a vinyl benzoic acid derivative” means a structural unit configured by cleavage of an ethylenic double bond of vinyl benzoic acid or a vinyl benzoic acid derivative.
The “vinyl benzoic acid derivative” is a concept including a compound in which the hydrogen atom at the α-position of vinyl benzoic acid is substituted with another substituent such as an alkyl group or an alkyl halide group, and derivatives thereof. These derivatives include those in which the hydrogen atom at the carboxy group of vinyl benzoic acid, which may be substituted with a hydrogen atom at the α-position, is substituted with an organic group; the hydrogen atom at the α-position is substituted with a substituent. Examples thereof include those in which a substituent other than a hydroxyl group and a carboxy group is bonded to the benzene ring of vinyl benzoic acid. The α-position (α-position carbon atom) means a carbon atom to which a benzene ring is bonded unless otherwise specified.

“Styrene” is a concept that includes styrene and those in which the α-position hydrogen atom of styrene is substituted with another substituent such as an alkyl group or a halogenated alkyl group.
“Structural unit derived from styrene” and “structural unit derived from styrene derivative” mean a structural unit formed by cleavage of an ethylenic double bond of styrene or a styrene derivative.

The alkyl group as a substituent at the α-position is preferably a linear or branched alkyl group, specifically, an alkyl group having 1 to 5 carbon atoms (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.
Specific examples of the halogenated alkyl group as the substituent at the α-position include groups in which part or all of the hydrogen atoms of the above-mentioned “alkyl group as the substituent at the α-position” are substituted with a halogen atom. It is done. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
Specific examples of the hydroxyalkyl group as a substituent at the α-position include a group in which part or all of the hydrogen atoms of the “alkyl group as the substituent at the α-position” are substituted with a hydroxyl group. 1-5 are preferable and, as for the number of the hydroxyl groups in this hydroxyalkyl group, 1 is the most preferable.

≪Resist composition≫
The resist composition of the present invention comprises a base component (A) (hereinafter also referred to as “component (A)”) whose solubility in a developer is changed by the action of an acid, a sulfonio group and a general formula in one molecule. A sulfonium compound (B1) having an anion group represented by (b1-r-1) (hereinafter also referred to as “component (B1)”), and a photodegradable base that loses acid diffusion controllability by exposure to light ( D1) (hereinafter also referred to as “component (D1)”).
When a resist film is formed using such a resist composition and the resist film is selectively exposed, an acid is generated from the component (B1) in the exposed area, and the development of the component (A) is caused by the action of the acid. While the solubility in the liquid changes, the solubility of the component (A) in the developer does not change in the unexposed area, so that a difference in solubility in the developer occurs between the exposed area and the unexposed area. Therefore, when the resist film is developed, when the resist composition is positive, the exposed portion is dissolved and removed to form a positive resist pattern, and when the resist composition is negative, the unexposed portion is dissolved. This is removed to form a negative resist pattern.
In this specification, a resist composition in which an exposed portion is dissolved and removed to form a positive resist pattern is referred to as a positive resist composition, and a resist composition that forms a negative resist pattern in which an unexposed portion is dissolved and removed. Is referred to as a negative resist composition.
The resist composition of the present invention may be a positive resist composition or a negative resist composition.
In addition, the resist composition of the present invention may be used for an alkali development process using an alkali developer for development processing at the time of forming a resist pattern, and a developer (organic developer) containing an organic solvent is used for the development processing. It may be for the solvent development process used.

<Substrate component: (A) component>
In the present invention, the “base component” is an organic compound having a film forming ability, and preferably an organic compound having a molecular weight of 500 or more is used. When the molecular weight of the organic compound is 500 or more, the film forming ability is improved, and in addition, a nano-level resist pattern is easily formed.
Organic compounds used as the base material 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, the “low molecular compound” refers to a non-polymer having a molecular weight of 500 or more and less than 4000.
As the polymer, those having a molecular weight of 1000 or more are usually used. Hereinafter, the term “resin” refers to a polymer having a molecular weight of 1000 or more.
As the molecular weight of the polymer, a polystyrene-reduced mass average molecular weight by GPC (gel permeation chromatography) is used.
The component (A) may be a base material component whose solubility in a developing solution is changed by the action of an acid, a resin may be used, a low molecular compound may be used, or these may be used in combination.
Component (A) may have increased solubility in a developer due to the action of an acid, or may decrease solubility in a developer due to the action of an acid.

When the resist composition of the present invention is a “negative resist composition for alkali development process” that forms a negative resist pattern in an alkali development process, or “solvent development” that forms a positive resist pattern in a solvent development process In the case of “a positive resist composition for a process”, the component (A) is preferably a substrate component (A-2) (hereinafter referred to as “(A-2) component”) soluble in an alkali developer. In addition, a crosslinking agent component is blended. In such a resist composition, when an acid is generated from the component (B1) by exposure, the acid acts to cause crosslinking between the component (A-2) and the crosslinking agent component. Solubility decreases (solubility in organic developer increases). Therefore, in the formation of a resist pattern, when a resist film obtained by coating the resist composition on a support is selectively exposed, the exposed portion is hardly soluble in an alkali developer (to an organic developer). On the other hand, the unexposed area remains soluble (almost insoluble in the organic developer) while remaining undissolved in the alkaline developer, and a negative resist pattern is formed by developing with the alkaline developer. The At this time, a positive resist pattern is formed by developing with an organic developer.
As the component (A-2), a resin that is soluble in an alkali developer (hereinafter referred to as “alkali-soluble resin”) is 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. A resin having a unit derived from at least one selected from alkyl ester); a hydrogen atom bonded to a carbon atom at the α-position having a sulfonamide group, which is disclosed in US Pat. No. 6,949,325, is substituted with a substituent. Acrylic resin or polycycloolefin resin which may be contained; disclosed in US Pat. No. 6,949,325, Japanese Patent Application Laid-Open No. 2005-336452, and Japanese Patent Application Laid-Open No. 2006-317803, which contains a fluorinated alcohol and is in the α-position. The hydrogen atom bonded to the atom may be substituted with a substituent. Le resin; Japanese Patent disclosed in 2006-259582, JP-polycycloolefin resins having fluorinated alcohol is preferred because it can form a resist pattern with minimal swelling.
The α- (hydroxyalkyl) acrylic acid is a hydrogen atom bonded to the α-position carbon atom to which the carboxy group is bonded, among the acrylic acid in which the hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. One or both of acrylic acid having an atom bonded thereto and α-hydroxyalkylacrylic acid having a hydroxyalkyl group (preferably a hydroxyalkyl group having 1 to 5 carbon atoms) bonded to the α-position carbon atom are shown. .
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, and 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 “positive resist composition for an alkali development process” that forms a positive pattern in an alkali development process, or a “solvent development process that forms a negative resist pattern in a solvent development process In the case of “negative resist composition for use”, as the component (A), a base material component (A-1) (hereinafter referred to as “(A-1) component”) whose polarity is increased by the action of an acid is used. . By using the component (A-1), since the polarity of the base material component changes before and after exposure, a good development contrast can be obtained not only in the alkali development process but also in the solvent development process.
When an alkali development process is applied, the component (A-1) is hardly soluble in an alkali developer before exposure. When an acid is generated by exposure, the polarity is increased by the action of the acid, and the alkali development is performed. The solubility in the liquid is increased. 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 is formed by alkali development.
On the other hand, when a solvent development process is applied, the component (A-1) is highly soluble in an organic developer before exposure. When an acid is generated by exposure, the component (A-1) is highly polar due to the action of the acid. The solubility in an organic developer is reduced. 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 is formed.

  In the present invention, the component (A) is preferably the component (A-1).

[Polymer Compound (A1)]
When the component (A) is the component (A-1), the component (A-1) is a polymer compound (A1) having a structural unit (a1) containing an acid-decomposable group that increases in polarity by the action of an acid. (Hereinafter also referred to as “component (A1)”).
As the component (A1), in addition to the structural unit (a1), a component having a structural unit (a2) containing a lactone-containing cyclic group, an —SO ₂ -containing cyclic group, or a carbonate-containing cyclic group may be used. preferable.
Moreover, as the component (A1), in addition to the structural unit (a1), or in addition to the structural unit (a1) and the structural unit (a2), the structural unit (a3) containing a polar group-containing aliphatic hydrocarbon group However, it is preferable to use one having a structural unit (a1) or a structural unit (a2) that is not included in the structural unit (a2).

(Structural unit (a1))
The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity is increased by the action of an acid.
The “acid-decomposable group” is an acid-decomposable group that can cleave at least part of bonds in the structure of the acid-decomposable group by the action of an acid.
Examples of the acid-decomposable group whose polarity increases by the action of an acid include a group that decomposes by the action of an acid to generate a polar group.
Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, a sulfo group (—SO ₃ H), and the like. Among these, a polar group containing —OH in the structure (hereinafter sometimes referred to as “OH-containing polar group”) is preferable, a carboxy group or a hydroxyl group is more preferable, and a carboxy group is particularly preferable.
More specifically, examples of the acid-decomposable group include groups 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).
Here, the “acid-dissociable group” means (i) a group having acid-dissociable properties capable of cleaving a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by the action of an acid, Alternatively, (ii) after a partial bond is cleaved by the action of an acid, a further decarboxylation reaction occurs, whereby a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group is cleaved. Both of the resulting groups.
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. As the polarity increases, the solubility in the developer changes relatively. When the developer is an alkaline developer, the solubility increases. When the developer is an organic developer, the solubility increases. Decrease.

The acid-dissociable group is not particularly limited, and those that have been proposed as acid-dissociable groups for base resins for chemically amplified resists can be used.
Examples of the acid dissociable group that protects a carboxy group or a hydroxyl group among the polar groups include, for example, an acid dissociable group represented by the following general formula (a1-r-1) (hereinafter referred to as “acetal acid dissociable group”). May be included).

［式中、Ｒａ’^１、Ｒａ’^２は水素原子またはアルキル基であり、Ｒａ’^３は炭化水素基であって、Ｒａ’^３は、Ｒａ’^１、Ｒａ’^２のいずれかと結合して環を形成してもよい。］

[Wherein, Ra ′ ¹ and Ra ′ ² are a hydrogen atom or an alkyl group, Ra ′ ³ is a hydrocarbon group, and Ra ′ ³ is bonded to either Ra ′ ¹ or Ra ′ ² to form a ring. May be formed. ]

In formula (a1-r-1), at least one of Ra ′ ¹ and Ra ′ ² is preferably a hydrogen atom, and more preferably both are hydrogen atoms.
In the case where Ra ′ ¹ or Ra ′ ² is an alkyl group, the alkyl group is the alkyl group mentioned as the substituent that may be bonded to the α-position carbon atom in the description of the α-substituted acrylate ester. The same thing is mentioned, A C1-C5 alkyl group is preferable. Specifically, a linear or branched alkyl group is preferable. More specifically, 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 the like can be given. More preferred is a methyl group.

In formula (a1-r-1), examples of the Ra ′ ³ hydrocarbon group include a linear or branched alkyl group and a cyclic hydrocarbon group.
The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and still more preferably 1 or 2. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

  The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, and the like is preferably isopropyl group.

When Ra ′ ³ is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may be a polycyclic group or a monocyclic group.
The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane.
The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically, Adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

When the cyclic hydrocarbon group of Ra ′ ³ is an aromatic hydrocarbon group, the aromatic ring contained is specifically an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, phenanthrene; And aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specifically, the aromatic hydrocarbon group is a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group); a group in which one of the hydrogen atoms of the aryl group is substituted with an alkylene group (for example, Benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group and other arylalkyl groups). The alkylene group (the alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

When Ra ′ ³ is bonded to either Ra ′ ¹ or Ra ′ ² to form a ring, 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.

  Among the polar groups, examples of the acid dissociable group that protects the carboxy group include an acid dissociable group represented by the following general formula (a1-r-2). Of the acid dissociable groups represented by the following formula (a1-r-2), those composed of an alkyl group may be hereinafter referred to as “tertiary alkyl ester type acid dissociable groups” for convenience. .

［式中、Ｒａ’^４〜Ｒａ’^６はそれぞれ炭化水素基であって、Ｒａ’^５、Ｒａ’^６は互いに結合して環を形成してもよい。］

[Wherein, Ra ′ ^{4 to} Ra ′ ⁶ are each a hydrocarbon group, and Ra ′ ⁵ and Ra ′ ⁶ may be bonded to each other to form a ring. ]

As the hydrocarbon group for Ra ′ ^{4 to} Ra ′ ^6, the same groups as those described above for Ra ′ ³ can be mentioned.
Ra ′ ⁴ is preferably an alkyl group having 1 to 5 carbon atoms. When Ra ′ ⁵ and Ra ′ ⁶ are bonded to each other to form a ring, a group represented by general formula (a1-r2-1) shown below can be given. On the other hand, when Ra ′ ^{4 to} Ra ′ ⁶ are not bonded to each other and are independent hydrocarbon groups, groups represented by the following general formula (a1-r2-2) are exemplified.

［式中、Ｒａ’^１０は炭素数１〜１０のアルキル基、Ｒａ’^１１はＲａ’^１０が結合した炭素原子と共に脂肪族環式基を形成する基、Ｒａ’^１２〜Ｒａ’^１４は、それぞれ独立に炭化水素基を示す。］

[Wherein, Ra ′ ¹⁰ is an alkyl group having 1 to ¹⁰ carbon atoms, Ra ′ ¹¹ is a group that forms an aliphatic cyclic group together with a carbon atom to which Ra ′ ¹⁰ is bonded, and Ra ′ ^{12 to} Ra ′ ¹⁴ are Independently represents a hydrocarbon group. ]

Formula (a1-r2-1) in, Ra 'alkyl group having 1 to 10 carbon atoms ^10, Ra in formula (a1-r-1)' was mentioned as the linear or branched alkyl group of ³ Groups are preferred. In formula (a1-r2-1), an aliphatic cyclic group formed by Ra ′ ¹¹ together with the carbon atom to which Ra ′ ¹⁰ is bonded is a cyclic alkyl group of Ra ′ ³ in formula (a1-r-1). The groups mentioned are preferred.

In formula (a1-r2-2), Ra ′ ¹² and Ra ′ ¹⁴ are preferably each independently an alkyl group having 1 to 10 carbon atoms, and the alkyl group is represented by Ra in formula (a1-r-1). 'The group mentioned as a linear or branched alkyl group of ³ is more preferable, It is more preferable that it is a C1-C5 linear alkyl group, It is especially preferable that it is a methyl group or an ethyl group .
In formula (a1-r2-2), Ra ′ ¹³ is a linear, branched or cyclic alkyl group exemplified as the hydrocarbon group for Ra ′ ³ in formula (a1-r-1). Is preferred. Among these, a group exemplified as the cyclic alkyl group for Ra ′ ³ is more preferable.

  Specific examples of the group represented by the formula (a1-r2-1) are given below. In addition, in this specification, * mark in a formula shows a bond.

  Specific examples of the group represented by the formula (a1-r2-2) are given below.

  Examples of the acid dissociable group for protecting the hydroxyl group among the polar groups include an acid dissociable group represented by the following general formula (a1-r-3) (hereinafter referred to as “tertiary alkyloxycarbonyl acid dissociable group for convenience”). ”).

［式中、Ｒａ’^７〜Ｒａ’^９はそれぞれアルキル基である。］

[Wherein, Ra ′ ^{7 to} Ra ′ ⁹ each represents an alkyl group. ]

In formula (a1-r-3), Ra ′ ^{7 to} Ra ′ ⁹ are each preferably an alkyl group having 1 to 5 carbon atoms, and more preferably 1 to 3 groups.
Moreover, it is preferable that the total carbon number of each alkyl group is 3-7, it is more preferable that it is 3-5, and it is most preferable that it is 3-4.

  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 an acid whose polarity is increased by the action of an acid. Structural unit containing a decomposable group; a structural unit derived from acrylamide and containing an acid-decomposable group whose polarity is increased by the action of an acid; a hydroxyl group of a structural unit derived from hydroxystyrene or a hydroxystyrene derivative A structural unit in which at least a part of the hydrogen atoms in is protected by a substituent containing the acid-decomposable group; a hydrogen atom in —C (═O) —OH of a structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative And a structural unit in which at least a part of the group is protected by a substituent containing the acid-decomposable group.

Among the above, the structural unit (a1) is preferably 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.
Preferable specific examples of the structural unit (a1) include structural units represented by the following general formula (a1-1) or (a1-2).

［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る。Ｖａ^１はエーテル結合を有していてもよい２価の炭化水素基であり、ｎ_ａ１は０〜２であり、Ｒａ^１は上記式（ａ１−ｒ−１）又は（ａ１−ｒ−２）で表される酸解離性基である。Ｗａ^１はｎ_ａ２＋１価の炭化水素基であり、ｎ_ａ２は１〜３であり、Ｒａ^２は上記式（ａ１−ｒ−１）又は（ａ１−ｒ−３）で表される酸解離性基である。］

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Va ¹ is a divalent hydrocarbon group which may have an ether bond, n _a1 is 0 to 2, and Ra ¹ is the above formula (a1-r-1) or (a1-r-2) It is an acid dissociable group represented by. Wa ¹ is a n _a2 +1 valent hydrocarbon group, n _a2 is 1 to 3, and Ra ² is an acid dissociation property represented by the above formula (a1-r-1) or (a1-r-3). It is a group. ]

In the formula (a1-1), the alkyl group having 1 to 5 carbon atoms of R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically a methyl group or an ethyl group. Propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. The halogenated alkyl group having 1 to 5 carbon atoms 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 halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and is most preferably a hydrogen atom or a methyl group in terms of industrial availability.

The hydrocarbon group for Va 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 as a divalent hydrocarbon group in Va ¹ may be saturated or unsaturated, and is usually preferably saturated.
More specific examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group having a ring in the structure, and the like.
Va ¹ may have an ether bond (—O—) between carbon atoms of the divalent hydrocarbon group. One or two or more ether bonds may be present in Va ¹ .

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, more preferably 1 to 4, and most preferably 1 to 3.
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.

Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and an alicyclic hydrocarbon group that is linear or branched. Examples thereof include a group bonded to the end of a chain aliphatic hydrocarbon group and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those described above.
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 a polycyclic group or a monocyclic group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane.
The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring.
The aromatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, and 6 to 6 carbon atoms. 15 is particularly preferred and 6-10 is most preferred. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aromatic ring possessed by the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; some of the carbon atoms constituting the aromatic hydrocarbon ring are heterogeneous. Aromatic heterocycles substituted with atoms. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specifically, the aromatic hydrocarbon group is a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group) A group in which one of the hydrogen atoms is substituted with an alkylene group (for example, arylalkyl groups such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.) And a group obtained by further removing one hydrogen atom from the aryl group. The alkylene group (the alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

In the formula (a1-2), the n _a2 +1 valent hydrocarbon group in Wa ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity, may be saturated or unsaturated, and is usually preferably saturated. Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group including a ring in the structure, or a linear or branched aliphatic hydrocarbon group. Examples thereof include a combination of an aliphatic hydrocarbon group containing a ring in the structure.
The n _a2 +1 valence is preferably 2 to 4, and more preferably 2 or 3.

Specific examples of the structural unit represented by the formula (a1-1) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

  Specific examples of the structural unit represented by the formula (a1-2) are shown below.

As the structural unit (a1) contained in the component (A1), 1 type of structural unit may be used, or 2 or more types may be used.
The proportion of the structural unit (a1) in the component (A1) is preferably from 10 to 80 mol%, more preferably from 15 to 75 mol%, more preferably from 20 to 70 mol%, based on all structural units constituting the component (A1). Is more preferable.
By setting the proportion of the structural unit (a1) to the lower limit value or more, a resist pattern can be easily obtained, and lithography properties such as sensitivity, resolution, and LWR are also improved. In addition, by setting 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 including a lactone-containing cyclic group, an —SO ₂ -containing cyclic group, or a carbonate-containing cyclic group.
The lactone-containing cyclic group, —SO ₂ — containing cyclic group or carbonate-containing cyclic group of the structural unit (a2) can be used to adhere the resist film to the substrate when the component (A1) is used for forming the resist film. It is effective in enhancing the sex.
In addition, when the structural unit (a1) includes a lactone-containing cyclic group, an —SO ₂ -containing cyclic group, or a carbonate-containing cyclic group in the structure, the structural unit is also included in the structural unit (a2). Although applicable, such a structural unit corresponds to the structural unit (a1) and does not correspond to the structural unit (a2).

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-containing cyclic group in the structural unit (a2) is not particularly limited, and any lactone-containing cyclic group can be used. Specific examples include groups represented by general formulas (a2-r-1) to (a2-r-7) shown below.

［式中、Ｒａ’^２１はそれぞれ独立に水素原子、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、−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り；Ａ”は酸素原子（−Ｏ−）もしくは硫黄原子（−Ｓ−）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、ｎ’は０〜２の整数であり、ｍ’は０または１である。］

[Wherein, Ra ′ ²¹ each independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group. Yes; R ″ is a hydrogen atom or an alkyl group; A ″ is an alkylene group having 1 to 5 carbon atoms, oxygen atom or sulfur which may contain an oxygen atom (—O—) or a sulfur atom (—S—). An atom, n ′ is an integer of 0 to 2, and m ′ is 0 or 1. ]

In the general formula (a2-r-1) ~ (a2-r-7), the alkyl group in Ra ^'21, 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 in the ra ^'21, preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, groups of the the Ra 'group and an oxygen atom mentioned as the alkyl group in ²¹ (-O-) are linked and the like.
Examples of the halogen atom in Ra ′ ²¹ 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 ^21, the Ra' Ra part or all of the hydrogen atoms of the alkyl group in ²¹ can be mentioned it has been substituted with the aforementioned halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

In —COOR ″ and —OC (═O) R ″ in Ra ′ ²¹ , R ″ is a hydrogen atom or an alkyl group.
The alkyl group for R ″ may be linear, branched or cyclic, and preferably has 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 in Ra ′ ²¹ is preferably one having 1 to 6 carbon atoms, and specifically, a group in which at least one hydrogen atom of the alkyl group in Ra ′ ²¹ is substituted with a hydroxyl group can be mentioned. .

In the general formulas (a2-r-2), (a2-r-3), and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A ″ is linear or branched. An alkylene group is preferable, and examples include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, etc. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include the terminal of the alkylene group or carbon. between atoms -O- or -S- can be mentioned a group intervening, for example, _{-O-CH 2 -, - CH} 2 -O-CH 2 -, - S-CH 2 -, - CH 2 -S-CH _As A ″, an alkylene group having 1 to 5 carbon atoms or —O— is preferable, an alkylene group having 1 to 5 carbon atoms is more preferable, and a methylene group is most preferable.

  Specific examples of groups represented by general formulas (a2-r-1) to (a2-r-7) are given below.

The “—SO ₂ -containing cyclic group” refers to a cyclic group containing a ring containing —SO ₂ — in the ring skeleton, specifically, the sulfur atom (S) in —SO ₂ — is It is a cyclic group that forms 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 a monocyclic group or a polycyclic group.
-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 A cyclic group containing a sultone ring to be formed is preferable.
More specifically, examples of the —SO ₂ -containing cyclic group include groups represented by general formulas (a5-r-1) to (a5-r-4) shown below.

［式中、Ｒａ’^５１はそれぞれ独立に水素原子、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、−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、ｎ’は０〜２の整数である。］

[Wherein, Ra ′ ⁵¹ independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group. Yes; R ″ is a hydrogen atom or an alkyl group; 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, and n ′ is 0 to 2 Is an integer. ]

In general formulas (a5-r-1) to (a5-r-4), A ″ represents the general formulas (a2-r-2), (a2-r-3), and (a2-r-5). Same as A ″ in the middle.
As the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group in Ra ′ ^51, the general formulas (a2-r-1) to ( a2-r-7) as in the same as those exemplified in the description of the Ra ^'21 of the like.
Specific examples of groups represented by general formulas (a5-r-1) to (a5-r-4) are given below. “Ac” in the formula represents an acetyl group.

The “carbonate-containing cyclic group” refers to a cyclic group containing a ring (carbonate ring) containing —O—C (═O) —O— in the ring skeleton. When the carbonate ring is counted as the first ring, the carbonate ring alone is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure. The carbonate-containing cyclic group may be a monocyclic group or a polycyclic group.
Any carbonate ring-containing cyclic group can be used without any particular limitation. Specific examples include groups represented by the following general formulas (ax3-r-1) to (ax3-r-3).

［式中、Ｒａ’^ｘ３１はそれぞれ独立に水素原子、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、−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ｑ’は０または１である。］

[ ^Wherein , Ra ′ ^x31 each independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group. Yes; R ″ is a hydrogen atom or an alkyl group; 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, and q ′ is 0 or 1. is there. ]

In the general formulas (ax3-r-1) to (ax3-r-3), A ″ represents the general formulas (a2-r-2), (a2-r-3), (a2-r-5). Same as A ″ in the middle.
As the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group in Ra ′ ³¹ , the above general formulas (a2-r-1) to ( a2-r-7) as in the same as those exemplified in the description of the Ra ^'21 of the like.
Specific examples of groups represented by general formulas (ax3-r-1) to (ax3-r-3) are given below.

As the structural unit (a2), 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 is preferable.
The structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

［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る。Ｙａ^２１は単結合または２価の連結基である。Ｌａ^２１は−Ｏ−、−ＣＯＯ−、−ＣＯＮ（Ｒ’）−、−ＯＣＯ−、−ＣＯＮＨＣＯ−又は−ＣＯＮＨＣＳ−であり、Ｒ’は水素原子またはメチル基を示す。ただしＬａ^２１が−Ｏ−の場合、Ｙａ^２１は−ＣＯ−にはならない。Ｒａ^２１はラクトン含有環式基、カーボネート含有環式基、又は−ＳＯ_２−含有環式基である。］

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Ya ²¹ is a single bond or a divalent linking group. La ²¹ represents —O—, —COO—, —CON (R ′) —, —OCO—, —CONHCO— or —CONHCS—, and R ′ represents a hydrogen atom or a methyl group. However, when La ²¹ is —O—, Ya ²¹ is not —CO—. Ra ²¹ is a lactone-containing cyclic group, a carbonate-containing cyclic group, or an —SO ₂ -containing cyclic group. ]

In formula (a2-1), R is the same as described above.
The divalent linking group of Ya ²¹ is not particularly limited, and preferred examples thereof include a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a hetero atom.

In Ya ²¹ , the hydrocarbon group as the divalent linking 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.
Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, and the like.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, more preferably 1 to 4, and most preferably 1 to 3.
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 linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and a carbonyl group.

As the aliphatic hydrocarbon group containing a ring in the structure, a cyclic aliphatic hydrocarbon group which may contain a substituent containing a hetero atom in the ring structure (excluding two hydrogen atoms from the aliphatic hydrocarbon ring) Group), a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and the cyclic aliphatic hydrocarbon group is a linear or branched chain fatty acid. Group intervening in the middle of the group hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those described above.
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. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and a carbonyl group.
The alkyl group as the substituent 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.
The alkoxy group as the substituent 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. Most preferred is an ethoxy group.
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 as the substituent include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.
In the cyclic aliphatic hydrocarbon group, a part of carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. As the substituent containing the hetero atom, —O—, —C (═O) —O—, —S—, —S (═O) ₂ —, and —S (═O) ₂ —O— are preferable.

The aromatic hydrocarbon group as a divalent hydrocarbon group is a hydrocarbon group having at least one aromatic ring.
The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. It is preferable that carbon number of an aromatic ring is 5-30, 5-20 are more preferable, 6-15 are more preferable, and 6-12 are especially preferable. However, the carbon number does not include the carbon number in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which a part of carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms, and the like. Can be mentioned. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, the aromatic hydrocarbon group is a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); an aromatic compound containing two or more aromatic rings A group obtained by removing two hydrogen atoms from (for example, biphenyl, fluorene, etc.); 1 of the hydrogen atoms of a group (aryl group or heteroaryl group) obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring A group substituted with an alkylene group (for example, an aryl group in an arylalkyl group such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.) A group in which one atom is further removed). The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

In the aromatic hydrocarbon group, a hydrogen atom of the aromatic hydrocarbon group may be substituted with a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group.
The alkyl group as the substituent 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.
Examples of the alkoxy group, the halogen atom and the halogenated alkyl group as the substituent include those exemplified as the substituent for substituting the hydrogen atom of the cyclic aliphatic hydrocarbon group.

When Ya ²¹ is a divalent linking group containing a hetero atom, preferred examples of the linking group include —O—, —C (═O) —O—, —C (═O) —, —O—. C (═O) —O—, —C (═O) —NH—, —NH—, —NH—C (═NH) — (H may be substituted with a substituent such as an alkyl group or an acyl group) _{good), -. S -, -} S (= O) 2 -, - S (= O) 2 -O-, the formula ^{-Y 21 -O-Y 22 -,} - Y 21 -O -, - Y 21 _{^{-C (= O) -O -,}} - [Y 21 -C (= O) -O] m "-Y 22 -, - Y 21 -O-C (= O) -Y 22 - or ^{-Y 21} - A group represented by S (═O) ₂ —O—Y ²² —, wherein Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent; Is an oxygen atom and m ″ is 0 It is an integer of ~ 3. ] Etc. are mentioned.
The divalent linking group containing a hetero atom is -C (= O) -NH-, -C (= O) -NH-C (= O)-, -NH-, -NH-C (= NH). In the case of-, the H may be substituted with a substituent such as an alkyl group or acyl. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
Formula ^{-Y 21 -O-Y 22 -,} - Y 21 -O -, - Y 21 -C (= O) -O -, - [Y 21 -C (= O) -O] m "-Y 22 —, —Y ²¹ —O—C (═O) —Y ²² — or —Y ²¹ —S (═O) ₂ —O—Y ²² —, wherein Y ²¹ and Y ²² are each independently a substituent. As the divalent hydrocarbon group, the divalent hydrocarbon group mentioned in the description of the divalent linking group (divalent optionally having substituents) may be used. And the same hydrocarbon groups as those described above.
Y ²¹ is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group. preferable.
Y ²² is preferably a linear or branched aliphatic hydrocarbon group, and more preferably a methylene group, an ethylene 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.
In the group represented by the formula — [Y ²¹ —C (═O) —O] _{m ″} —Y ²² —, m ″ is an integer of 0 to 3, preferably an integer of 0 to 2, Or 1 is more preferable, and 1 is particularly preferable. That is, the group represented by the formula — [Y ²¹ —C (═O) —O] _{m ″} —Y ²² — is represented by the formula —Y ²¹ —C (═O) —O—Y ²² —. Especially preferred are groups represented by the formula — (CH ₂ ) _{a ′} —C (═O) —O— (CH ₂ ) _{b ′} —, wherein a ′ is 1 to It is an integer of 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, more preferably 1 or 2, and most preferably 1. b ′ is an integer of 1 to 10, and 1 to 8 An integer of 1 is preferable, an integer of 1 to 5 is more preferable, 1 or 2 is more preferable, and 1 is most preferable.

Ya ²¹ is preferably a single bond, an ester bond [—C (═O) —O—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof. .

In the formula (a2-1), Ra ²¹ is a lactone-containing cyclic group, an —SO ₂ -containing cyclic group, or a carbonate-containing cyclic group.
The lactone-containing cyclic group, -SO ₂ -containing cyclic group, and carbonate-containing cyclic group in Ra ²¹ are each represented by the general formulas (a2-r-1) to (a2-r-7) described above. Groups represented by general formulas (a5-r-1) to (a5-r-4), groups represented by general formulas (ax3-r-1) to (ax3-r-3), respectively. Are preferable.
Among these, a lactone-containing cyclic group or an —SO ₂ -containing cyclic group is preferable, and each is represented by the general formula (a2-r-1), (a2-r-2), or (a5-r-1). Groups are more preferred. Specifically, the chemical formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-13), (r- Any group represented by sl-1-1) and (r-sl-1-18) is more preferred.

As the structural unit (a2) contained in the component (A1), 1 type of structural unit may be used, or 2 or more types may be used.
When the component (A1) has the structural unit (a2), the proportion of the structural unit (a2) is preferably 1 to 80 mol% with respect to the total of all the structural units constituting the component (A1). It is more preferably 10 to 70 mol%, further preferably 10 to 65 mol%, particularly preferably 10 to 60 mol%.
By setting the proportion of the structural unit (a2) to be equal to or higher than the lower limit value, the effect of containing the structural unit (a2) can be sufficiently obtained, and by setting the ratio to the upper limit value or less, a balance with other structural units is obtained. And various lithographic properties and pattern shapes are good.

(Structural unit (a3))
The structural unit (a3) is a structural unit containing a polar group-containing aliphatic hydrocarbon group (excluding those corresponding to either the structural unit (a1) or the structural unit (a2) described above).
It is considered that when the component (A1) has the structural unit (a3), the hydrophilicity of the component (A) is increased and the resolution is improved.

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 cyclic aliphatic hydrocarbon group (cyclic group). The cyclic group may be a monocyclic group or a polycyclic group. For example, a resin for a resist composition for an ArF excimer laser can be appropriately selected from those proposed. The cyclic group is preferably a polycyclic group, and more preferably 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 not particularly limited as long as it contains a polar group-containing aliphatic hydrocarbon group, and any structural unit can be used.
The structural unit (a3) 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, and includes a polar group-containing aliphatic hydrocarbon group. Containing units are preferred.
The structural unit (a3) is derived from a hydroxyethyl ester of acrylic acid when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms. When the hydrocarbon group is a polycyclic group, the structural unit represented by the following formula (a3-1), the structural unit represented by the formula (a3-2), the formula ( The structural unit represented by a3-3) is preferred.

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

[Wherein, R is the same as above, j is an integer of 1 to 3, k is an integer of 1 to 3, t ′ is an integer of 1 to 3, and l is an integer of 1 to 5] And s is an integer of 1 to 3. ]

In formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group is bonded to the 3-position of the adamantyl group.
j is preferably 1, and a hydroxyl group bonded to the 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.

The structural unit (a3) contained in the component (A1) may be one type or two or more types.
When the component (A1) has the structural unit (a3), it is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, based on the total of all structural units constituting the component (A1). 5-30 mol% is more preferable.
By setting the proportion of the structural unit (a3) to the lower limit value or more, the effect of including the structural unit (a3) can be sufficiently obtained, and by setting the proportion of the structural unit (a3) to the upper limit value or less, balance with other structural units can be obtained. It becomes easy.

(Other structural units)
In addition to the structural units (a1) to (a3), the component (A1) may further include other structural units that do not correspond to these structural units.
The other structural unit is not particularly limited as long as it is a structural unit not classified into the structural units described above. Resin resins for ArF excimer laser, KrF excimer laser (preferably for ArF excimer laser), etc. A number of hitherto known compounds can be used, and examples include the structural unit (a4) shown below.

Structural unit (a4):
The structural unit (a4) is a structural unit containing an acid non-dissociable aliphatic cyclic group.
When the component (A1) has the structural unit (a4), the dry etching resistance of the formed resist pattern is improved. Moreover, the hydrophobicity of (A) component increases. The improvement in hydrophobicity is thought to contribute to the improvement of resolution, resist pattern shape, etc., particularly in the case of organic solvent development.
The “acid non-dissociable cyclic group” in the structural unit (a4) is such that the acid acts when an acid is generated in the resist composition by exposure (when an acid is generated from the component (B1)). However, the cyclic group remains in the structural unit as it is without dissociating.
As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing a non-acid-dissociable aliphatic cyclic group is preferable. Examples of the cyclic group include those similar to those exemplified for the structural unit (a1), for ArF excimer laser, for KrF excimer laser (preferably for ArF excimer laser), etc. 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 tricyclodecyl group, an adamantyl group, a tetracyclododecyl 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 structural units represented by general formulas (a4-1) to (a4-7) shown below.

［式中、Ｒ^αは前記と同じである。］

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

The structural unit (a4) contained in the component (A1) may be one type or two or more types.
When the component (A1) has the structural unit (a4), the proportion of the structural unit (a4) is preferably 1 to 30 mol% with respect to the total of all the structural units constituting the component (A1). 3-20 mol% is more preferable.
By making the proportion of the structural unit (a4) equal to or higher than the lower limit value, the effect of including the structural unit (a4) can be sufficiently obtained, and by making the proportion lower than the upper limit value, a balance with other structural units can be obtained. It becomes easy.

In the resist composition of the present invention, the component (A1) is preferably a polymer having at least the structural unit (a1), and is selected from the structural unit (a2) and the structural unit (a3) in addition to the structural unit (a1). More preferably, the copolymer has one or more structural units.
Examples of such a copolymer include a copolymer having a repeating structure of the structural units (a1) and (a2), a copolymer having a repeating structure of the structural units (a1) and (a3); a structural unit (a1), ( a copolymer having a repeating structure of a2) and (a3); a copolymer having a repeating structure of structural units (a1), (a2), (a3) and (a4).

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography (GPC)) is not particularly limited, preferably 1000 to 50000, more preferably 1500 to 30000, 2000 to 2000 20000 is most preferred. 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.
The dispersity (Mw / Mn) is not particularly limited, but is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5. Mn represents a number average molecular weight.

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

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, lithography characteristics such as mask reproducibility (MEEF), roundness (Circularity), roughness reduction, and depth of focus (DOF) characteristics are further improved.

The resist composition of the present invention contains, as the component (A-1), a base material component (hereinafter referred to as “component (A2)”) that does not correspond to the component (A1) and whose polarity is increased by the action of an acid. May be.
The component (A2) is not particularly limited, and many conventionally known base components for chemically amplified resist compositions (for example, for ArF excimer laser, for KrF excimer laser (preferably ArF excimer laser) For example, base resins and low molecular compounds). (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.
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.

<Sulphonium Compound: Component (B1)>
In the resist composition of the present invention, the component (B1) is a sulfonium compound having a sulfonio group and an anion group represented by the following general formula (b1-r-1) in one molecule. This component (B1) is an acid generator component that generates an acid upon exposure.

［式中、Ｙ^１は２価の連結基又は単結合であり、Ｌ^１はエステル結合又は単結合であり、Ｖ^１はフッ素原子を有する２価の炭化水素基であり、ｎは０又は１である。］

[Wherein Y ¹ is a divalent linking group or a single bond, L ¹ is an ester bond or a single bond, V ¹ is a divalent hydrocarbon group having a fluorine atom, and n is 0 or 1 It is. ]

{Anionic group}
In formula (b1-r-1), Y ¹ represents a divalent linking group or a single bond.
Examples of the divalent linking group for Y ¹ include those similar to Ya ²¹ in formula (a2-1), which includes a divalent hydrocarbon group which may have a substituent and a hetero atom. A divalent linking group is preferable, and a divalent hydrocarbon group which may have a substituent is more preferable.
In Y ¹ , the divalent hydrocarbon group which may have a substituent is preferably an alkylene group having 1 to 10 carbon atoms, and particularly preferably an alkylene group having 1 to 5 carbon atoms.
In Y ¹ , examples of the divalent linking group containing a hetero atom include —Y ²¹ —O—Y ²² —, — [Y ²¹ —C (═O) —O] _{m ′} —Y ²² — ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m ′ is an integer of 0 to 3). The divalent hydrocarbon group for Y ²¹ and Y ²² is the same as that described in the description of the divalent linking group for Ya ²¹ (the divalent hydrocarbon group which may have a substituent). Can be mentioned.

The ester bond in L ¹ represents either one of —C (═O) —O— and —O—C (═O) —.

As the divalent hydrocarbon group for V ¹ , 2 exemplified in the description of Ya ²¹ (divalent hydrocarbon group optionally having substituents) in General Formula (a2-1) above. The thing similar to a valent hydrocarbon group is mentioned. V ¹ is a divalent hydrocarbon group in which at least one hydrogen atom of the hydrocarbon group is substituted with a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms such as a trifluoromethyl group. More preferred.
For example, when the hydrocarbon group is an aliphatic hydrocarbon group, it is an alkylene group having 1 to 10, preferably 1 to 5 carbon atoms, and a hydrogen atom in the alkylene group portion having 1 to 3 carbon atoms on the SO ₃ ^- side. A group in which at least one of is substituted with a fluorine atom or a trifluoromethyl group, or a group in which at least one of the hydrogen atoms of a (poly) cycloalkylalkylene group having 7 to 20 carbon atoms is substituted with a fluorine atom or a trifluoromethyl group Is mentioned. The (poly) cycloalkyl portion is the same as the cyclic aliphatic hydrocarbon group of Ya ²¹ (divalent alicyclic hydrocarbon group), and the alkylene portion preferably has 1 to 3 carbon atoms. . The substitution position of the fluorine atom or the trifluoromethyl group is more preferably the alkylene moiety and the SO ₃ ⁻ side.
When the hydrocarbon group is an aromatic hydrocarbon group, 2,3,5,6-tetrafluorophenylene group, 3,5-difluoro-1,4-phenylene group, 2-trifluoromethyl-1,4 An arylene group substituted with a fluorine atom or a trifluoromethyl group such as a -phenylene group or a 3-trifluoromethyl-1,4-phenylene group;
Among them, V ¹ is an alkylene group having 1 to 10 carbon atoms, which is a fluoromethylene group or a difluoromethylene group next to the sulfur atom (S) of the —SO ₃ ^— group, or (poly) cycloalkyl having 7 to 20 carbon atoms. An alkylene group is particularly preferred.

n is 0 or 1, and when n = 0, it is preferable that L ¹ is not a single bond and Y ¹ is not a single bond. When n = 1, when L ¹ is not a single bond, Y ¹ is preferably not a single bond. By including an ester bond in the anion group represented by the general formula (b1-r-1), for example, compatibility with the component (A) is improved and lithography properties are further improved.

  The anionic group represented by the general formula (b1-r-1) is particularly preferably an anionic group represented by the following general formula (b1-r-1-01).

［式中、Ｙ^１は２価の連結基または単結合であり、Ｌ^１はエステル結合または単結合であり、Ｖ^１１はフッ素原子を有していてもよい炭素数１〜１０のアルキレン基又は単結合である。ただし、Ｌ^１が単結合であるときｎ＝１である。ｑは１または２である。］

[Wherein Y ¹ represents a divalent linking group or a single bond, L ¹ represents an ester bond or a single bond, and V ¹¹ represents an alkylene group having 1 to 10 carbon atoms which may have a fluorine atom, or It is a single bond. However, n = 1 when L ¹ is a single bond. q is 1 or 2. ]

The divalent linking group of Y ¹ is the same as ^{Y 1} in the formula (b1-r-1) in.
Ester bond of L ¹ is the same as ^{L 1} in the general formula (b1-r-1) in.
The alkylene group having 1 to 10 carbon atoms which may have a fluorine atom in V ¹¹ may be linear, branched or cyclic. The linear alkylene group preferably has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms, and still more preferably a methylene group or an ethylene group. As a branched alkylene group, C2-C5 is preferable and 2-3 is more preferable. The cyclic alkylene group may be monocyclic or polycyclic, and is preferably a cyclopentylene group, a cyclohexylene group, a norbornylene group, or an adamantylene group.
V ¹¹ is preferably an alkylene group not substituted with a fluorine atom. When a part of the hydrogen atoms of the alkylene group constituting V ¹¹ is substituted with a fluorine atom, the fluorine atom is preferably bonded to a carbon atom close to the — (CF ₂ ) q-group.
n is 0 or 1, and when n = 0, it is preferable that L ¹ is not a single bond and Y ¹ is not a single bond. When n = 1, when L ¹ is not a single bond, Y ¹ is preferably not a single bond.
q is preferably 1.

  Specific examples of the anion group represented by the general formula (b1-r-1) are shown below.

{Sulfonio group}
The sulfonio group of the component (B1) is a group represented by the following general formula (b1-0).

［式中、Ｒ^１１〜Ｒ^２１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、置換基を有していてもよいアルキル基または置換基を有していてもよいアルケニル基を表し、Ｒ^１１〜Ｒ^２１が相互に結合して式中の硫黄原子と共に環を形成していてもよい。Ｒ^１１〜Ｒ^２１のうちいずれか１つは、置換基として前記一般式（ｂ１−ｒ−１）で表されるアニオン基を有するアリール基、該アニオン基を有するアルキル基または該アニオン基を有するアルケニル基であってもよいし、そうでなくてもよい。＊は結合手を示す。］

[Wherein, R ^{11 to} R ²¹ each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. , R ^{11 to} R ²¹ may be bonded to each other to form a ring together with the sulfur atom in the formula. Any one of R ^{11 to} R ²¹ has an aryl group having an anion group represented by the general formula (b1-r-1) as a substituent, an alkyl group having the anion group, or the anion group. An alkenyl group may or may not be. * Indicates a bond. ]

Any one of R ^{11 to} R ²¹ is an aryl group having an anion group represented by the general formula (b1-r-1) as a substituent, and is represented by the general formula (b1-r-1). In the case of an alkyl group having an anion group or an alkenyl group having an anion group represented by the general formula (b1-r-1), the bond (*) may have an aryl group which may have a substituent. , An alkyl group which may have a substituent, or an alkenyl group which may have a substituent is bonded.
Any one of R ^{11 to} R ²¹ is an aryl group having an anion group represented by the general formula (b1-r-1) as a substituent, and is represented by the general formula (b1-r-1). When it is not an alkyl group having an anion group or an alkenyl group having an anion group represented by the general formula (b1-r-1), a bond (*) is bonded to the general formula (*) via a linking group. It is preferable that an anion group represented by b1-r-1) is bonded. More preferably, the bond (*) is an aryl group having an anion group represented by the general formula (b1-r-1) as a substituent, or the general formula (b1-r-1). An alkyl group having an anion group or an alkenyl group having an anion group represented by the general formula (b1-r-1) is bonded.
The aryl group, alkyl group or alkenyl group is the same as the aryl group, alkyl group or alkenyl group in the following general formulas (b1-1) and (b1-2).

  Specific examples of the sulfonium compound of the component (B1) include compounds represented by the following general formula (b1-1) or (b1-2), and are represented by the following general formula (b1-1). More preferably, the compound is

［式中、Ｒ^１〜Ｒ^３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、置換基を有していてもよいアルキル基、又は置換基を有していてもよいアルケニル基を表し、Ｒ^１〜Ｒ^３のうち、いずれか２つが相互に結合して式中の硫黄原子と共に環を形成していてもよい。但し、Ｒ^１〜Ｒ^３のうち、少なくとも１つは、置換基として前記一般式（ｂ１−ｒ−１）で表されるアニオン基を有するアリール基、一般式（ｂ１−ｒ−１）で表されるアニオン基を有するアルキル基、又は一般式（ｂ１−ｒ−１）で表されるアニオン基を有するアルケニル基である。］

[Wherein R ^{1 to} R ³ each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. And 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. However, at least one of R ^{1 to} R ³ is an aryl group having an anion group represented by the general formula (b1-r-1) as a substituent, and represented by the general formula (b1-r-1). Or an alkenyl group having an anion group represented by formula (b1-r-1). ]

［式中、Ｒ^４〜Ｒ^７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、置換基を有していてもよいアルキル基または置換基を有していてもよいアルケニル基を表し、Ｒ^４〜Ｒ^５は相互に結合して式中のイオウ原子と共に環を形成していてもよく、Ｒ^６〜Ｒ^７は相互に結合して式中のイオウ原子と共に環を形成していてもよい。また、一分子内に、置換基として（ｘ＋１）個の前記一般式（ｂ１−ｒ−１）で表されるアニオン基を有するアリール基、前記一般式（ｂ１−ｒ−１）で表されるアニオン基を有するアルキル基または前記一般式（ｂ１−ｒ−１）で表されるアニオン基を有するアルケニル基を有する。ｘは１または２であり、Ｗ^２は（ｘ＋１）価の連結基を表す。］

[Wherein, R ^{4 to} R ⁷ each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. R ^{4 to} R ⁵ may be bonded to each other to form a ring together with the sulfur atom in the formula, and R ^{6 to} R ⁷ may be bonded to each other to form a ring together with the sulfur atom in the formula Also good. In addition, (x + 1) aryl groups having an anion group represented by the above general formula (b1-r-1) as a substituent in one molecule, represented by the above general formula (b1-r-1) An alkyl group having an anion group or an alkenyl group having an anion group represented by formula (b1-r-1). x is 1 or 2, and W ² represents a (x + 1) -valent linking group. ]

In general formulas (b1-1) and (b1-2), examples of the aryl group in R ^{1 to} R ³ and R ^{4 to} R ⁷ include an unsubstituted aryl group having 6 to 20 carbon atoms, a phenyl group, A naphthyl group is preferred.
The alkyl group in R ^{1 to} R ³ and R ^{4 to} R ⁷ is a chain or cyclic alkyl group, preferably having 1 to 30 carbon atoms.
The alkenyl group in R ^{1 to} R ³ and R ^{4 to} R ⁷ preferably has 2 to 10 carbon atoms.
Examples of the substituent that R ^{1 to} R ³ and R ^{4 to} R ⁷ may have include, for example, an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and the following general groups. And groups represented by formulas (ca-r-1) to (ca-r-7), respectively. Among these, an alkyl group having 1 to 5 carbon atoms and a group represented by the general formula (ca-r-1) (particularly an alkoxy group having 1 to 5 carbon atoms) are preferable.

［式中、Ｒ’^２０１はそれぞれ独立に、水素原子、置換基を有していてもよい環式基、鎖状のアルキル基、または鎖状のアルケニル基である。］

[Wherein, R ′ ²⁰¹ each independently represents a hydrogen atom, an optionally substituted cyclic group, a chain alkyl group, or a chain alkenyl group. ]

R ′ ²⁰¹ may each independently have a hydrogen atom, a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. A chain alkenyl group.
The cyclic group for R ′ ²⁰¹ is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.
The aromatic hydrocarbon group in R ′ ²⁰¹ is an aryl group obtained by removing one hydrogen atom from an aromatic hydrocarbon ring mentioned in the divalent aromatic hydrocarbon group or an aromatic compound containing two or more aromatic rings. And a phenyl group and a naphthyl group are preferable.
Examples of the cyclic aliphatic hydrocarbon group for R ′ ²⁰¹ include groups in which one hydrogen atom has been removed from the monocycloalkane or polycycloalkane mentioned for the divalent aliphatic hydrocarbon group, and include an adamantyl group and a norbornyl group. Is preferred.
Further, the cyclic group in R ′ ²⁰¹ may contain a hetero atom such as a heterocycle, and specifically, in the general formulas (a2-r-1) to (a2-r-7), respectively. Lactone-containing cyclic groups represented by formulas, —SO ₂ -containing cyclic groups represented by the above general formulas (a5-r-1) to (a5-r-4), and other heterocyclic groups shown below. Can be mentioned.

Examples of the substituent in the cyclic group of R ′ ²⁰¹ include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), and a nitro group.
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
The alkoxy group as a substituent 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, a methoxy group, An ethoxy group is particularly preferred.
Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
The halogenated alkyl group as a substituent is a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group or the like. Is a group substituted with the halogen atom.

The chain alkyl group for R ′ ²⁰¹ may be either linear or branched, and the linear alkyl group preferably has 1 to 20 carbon atoms, and preferably 1 to 15 carbon atoms. More preferred is 1-10. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group and the like.
The branched 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.

The chain alkenyl group for R ′ ²⁰¹ preferably has 2 to 10 carbon atoms, more preferably 2 to 5, further preferably 2 to 4, and particularly preferably 3. For example, a vinyl group, a propenyl group (allyl group), a butynyl group, etc. are mentioned. Examples of the branched monovalent unsaturated hydrocarbon group include a 1-methylpropenyl group and a 2-methylpropenyl group. Among the above, the chain alkenyl group is particularly preferably a propenyl group.
Examples of the substituent in the chain alkyl group or alkenyl group of R ′ ²⁰¹ include, for example, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), a nitro group, an amino group, and the above R ′ ^201. And the like, and the like.

Among these, R ′ ²⁰¹ is preferably a cyclic group which may have a substituent, more preferably a cyclic hydrocarbon group, and 1 from phenyl group, naphthyl group and polycycloalkane. Groups other than one or more hydrogen atoms, lactone-containing cyclic groups represented by the above formulas (a2-r-1) to (a2-r-7), and the above general formulas (a5-r-1) to ( a5-r-4) with -SO ₂ represented respectively - containing cyclic group is particularly preferred.

When any two of R ^{1 to} R ³ , R ^{4 to} R ^5, or R ^{6 to} R ⁷ are bonded to each other to form a ring together with the sulfur atom in the formula, these are a sulfur atom, an oxygen atom , and hetero atoms such as nitrogen atom, a carbonyl _{group, -SO -, - SO 2 -} , - SO 3 -, - COO -, - CONH- , or -N _(R N) - (wherein _{R N} is 1 to carbon atoms Or a functional group such as 5).
As a ring to be formed, one ring containing a sulfur atom in the ring skeleton in the formula, including a sulfur atom, is preferably a 3- to 10-membered ring, particularly preferably a 5- to 7-membered ring. Specific examples of the ring formed include, for example, thiophene ring, thiazole ring, benzothiophene ring, thianthrene ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, thianthrene ring, phenoxathiin ring, tetrahydro A thiophenium ring, a tetrahydrothiopyranium ring, etc. are mentioned.

In the formula (b1-2), x is 1 or 2.
W ² is a (x + 1) valence, that is, a divalent or trivalent linking group.
The divalent linking group in W ² is preferably a divalent hydrocarbon group which may have a substituent, and examples thereof include the same hydrocarbon groups as Ya ²¹ in the general formula (a2-1).
The divalent linking group in W ² may be linear, branched or cyclic, and is preferably cyclic. Of these, an arylene group, a carbonyl group, and a group in which carbonyl groups are bonded to both ends of the arylene group are preferable. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferable.
Examples of the trivalent linking group in W ² include a group obtained by removing one hydrogen atom from the divalent linking group, and a group in which one hydrogen atom of the divalent linking group is substituted with the divalent linking group. Etc. The trivalent linking group for W ² is preferably a group in which three carbonyl groups are bonded to an arylene group.

  Specific examples of the component (B1) represented by the general formula (b1-1) are shown below. In the following formula, an anion group represented by the general formula (b1-r-1) is bonded to *.

［式中、Ｒ”^２０１は水素原子又は置換基であって、置換基としては前記Ｒ^１〜Ｒ^３およびＲ^４〜Ｒ^７が有していてもよい置換基として挙げたものと同様のものが挙げられる。］

[Wherein, R ″ ²⁰¹ is a hydrogen atom or a substituent, and the substituents are the same as those mentioned as the substituents that R ^{1 to} R ³ and R ^{4 to} R ⁷ may have. Can be mentioned.]

  Specific examples of the component (B1) represented by the general formula (b1-2) are shown below. In the following formula, an anion group represented by the general formula (b1-r-1) is bonded to *.

(B1) A component may be used individually by 1 type and may be used in combination of 2 or more type.
0.5-50 mass parts is preferable with respect to 100 mass parts of (A) component, as for content of (B1) component in a resist composition, 1-40 mass parts is more preferable, and 1-30 mass parts is further. preferable.
When the content of the component (B1) in the resist composition is equal to or more than the preferable lower limit, when the resist composition is used, lithography characteristics such as roughness reduction and mask reproducibility are further improved. Moreover, it becomes easy to obtain a resist pattern having a good shape. It is preferable for the content of the component (B1) to be equal to or less than the preferable upper limit because a uniform solution is easily obtained and the storage stability is improved.

<Photodegradable base: (D1) component>
In the resist composition of the present invention, the component (D1) is a photodegradable base that is decomposed by exposure and loses acid diffusion controllability.
The component (D1) is not particularly limited as long as it is decomposed by exposure and loses acid diffusion controllability, and is a compound represented by the following general formula (d1-1) (hereinafter referred to as “(d1-1) component”). ), A compound represented by the general formula (d1-2) (hereinafter referred to as “(d1-2) component”), a compound represented by the general formula (d1-3) (hereinafter referred to as “(d1-3)”. ) Component ”and one or more compounds selected from the group consisting of compounds represented by formula (d1-4) (hereinafter referred to as“ (d1-4) component ”) are preferred.
The components (d1-1) to (d1-4) are decomposed in the exposed portion and lose acid diffusion controllability (basicity), and thus do not act as a quencher, and act as a quencher in an unexposed portion.

［式中、Ｒｄ^１〜Ｒｄ^４は置換基を有していてもよい環式基、置換基を有していてもよい鎖状のアルキル基、又は置換基を有していてもよい鎖状のアルケニル基である。但し、式（ｄ１−２）中のＲｄ^２における、Ｓ原子に隣接する炭素原子にはフッ素原子は結合していないものとする。Ｙｄ^１は単結合又は２価の連結基である。Ｒｄ^５は露光により酸を発生するアニオン部位を有する基である。Ｒｄ^６は水素原子、又は露光により酸を発生するアニオン部位を有さない置換基である。Ｗ^１はプロトンアクセプター性を有する窒素原子をｆ個含むｚ価の官能基であり；ｆは１以上の整数、ｚ＝ｘ＋ｙであり、かつ、ｆ≦ｘ≦ｚであり、ｘは１以上の整数、ｙは０以上の整数、ｚは１以上の整数である。ｍは１以上の整数であって、Ｍ^ｍ＋はそれぞれ独立にｍ価の有機カチオンである。］

[Wherein Rd ^{1 to} Rd ⁴ are a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain which may have a substituent. Of the alkenyl group. However, a fluorine atom is not bonded to a carbon atom adjacent to the S atom in Rd ² in the formula (d1-2). Yd ¹ is a single bond or a divalent linking group. Rd ⁵ is a group having an anion moiety that generates an acid upon exposure. Rd ⁶ is a hydrogen atom or a substituent having no anion moiety that generates an acid upon exposure. W ¹ is a z-valent functional group containing f nitrogen atoms having proton acceptor properties; f is an integer of 1 or more, z = x + y, and f ≦ x ≦ z, and x is 1 or more , Y is an integer of 0 or more, and z is an integer of 1 or more. m is an integer of 1 or more, and M ^{m +} is each independently an m-valent organic cation. ]

{(D1-1) component}
During Anion formula (d1-1), Rd ¹ is has an optionally substituted cyclic group which may have a substituent chain alkyl group or a substituted group, And a chain alkenyl group which may be the same as R ¹⁰¹ in formula (b-1) described later.
Among these, Rd ¹ may have an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a substituent. A chain alkyl group is preferred. The substituent that these groups may have is preferably a hydroxyl group, a fluorine atom or a fluorinated alkyl group.
As the aromatic hydrocarbon group, a phenyl group or a naphthyl group is more preferable.
The aliphatic cyclic group is more preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane.
The chain alkyl group preferably has 1 to 10 carbon atoms, specifically, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, Linear alkyl groups such as nonyl and decyl; 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylbutyl A branched alkyl group such as a group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group.

When the chain alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the fluorinated alkyl group preferably has 1 to 11 carbon atoms, more preferably 1 to 8 carbon atoms. ~ 4 is more preferred. The fluorinated alkyl group may contain an atom other than a fluorine atom. Examples of atoms other than fluorine atoms include oxygen atoms, carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms.
Rd ¹ is preferably a fluorinated alkyl group in which some or all of the hydrogen atoms constituting the linear alkyl group are substituted by fluorine atoms, and the hydrogen atom constituting the linear alkyl group It is preferable that all are fluorinated alkyl groups (linear perfluoroalkyl groups) substituted with fluorine atoms.

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

-Cation part In formula (d1-1), Mm ⁺ is an m-valent organic cation.
The organic cation of M ^{m +} is not particularly limited, and is preferably an m-valent onium cation, more preferably a sulfonium cation or an iodonium cation, and the following general formulas (ca-1) to (ca -4) is particularly preferable.

［式中、Ｒ^２０１〜Ｒ^２０７、およびＲ^２１１〜Ｒ^２１２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、アルキル基またはアルケニル基を表し、Ｒ^２０１〜Ｒ^２０３、Ｒ^２０６〜Ｒ^２０７、Ｒ^２１１〜Ｒ^２１２は、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^２０８〜Ｒ^２０９はそれぞれ独立に水素原子または炭素数１〜５のアルキル基を表し、Ｒ^２１０は置換基を有していてもよいアリール基、アルキル基、アルケニル基、又は−ＳＯ_２−含有環式基であり、Ｌ^２０１は−Ｃ（＝Ｏ）−または−Ｃ（＝Ｏ）−Ｏ−を表し、Ｙ^２０１は、それぞれ独立に、アリーレン基、アルキレン基またはアルケニレン基を表し、ｘは１または２であり、Ｗ^２０１は（ｘ＋１）価の連結基を表す。］

[Wherein, R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent, and R ^{201 to} R ²⁰³ , R ²⁰⁶ to R ²⁰⁷ and R ^{211 to} R ²¹² may be bonded to each other to form a ring together with the sulfur atom in the formula. R ^{208 to} R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ²¹⁰ is an aryl group, alkyl group, alkenyl group, or —SO ₂ — containing an optionally substituted substituent. A cyclic group, L ²⁰¹ represents —C (═O) — or —C (═O) —O—, Y ²⁰¹ each independently represents an arylene group, an alkylene group or an alkenylene group, and x represents 1 or 2 and W ²⁰¹ represents a (x + 1) -valent linking group. ]

Examples of the aryl group in R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² include an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferable.
The alkyl group in R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² is a chain or cyclic alkyl group and preferably has 1 to 30 carbon atoms.
The alkenyl group in R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² preferably has 2 to 10 carbon atoms.
Examples of the substituent that R ^{201 to} R ²⁰⁷ and R ^{210 to} R ²¹² may have include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and the above-mentioned substituents. Groups represented by formulas (ca-r-1) to (ca-r-7), respectively.

^{R 201 ~R 203, R 206 ~R} 207, R 211 ~R 212 , when bonded to each other to form a ring with the sulfur atom, a sulfur atom, an oxygen atom, or a hetero atom such as nitrogen atom, carbonyl _{group, -SO -, - SO 2 -} , - SO 3 -, - COO -, - CONH- , or -N _(R N) - (. the _{R N} is an alkyl group having 1 to 5 carbon atoms), etc. You may couple | bond through the functional group of. As the ring to be formed, one ring containing a sulfur atom in the ring skeleton in the formula is preferably a 3- to 10-membered ring, particularly a 5- to 7-membered ring, including the sulfur atom. preferable. Specific examples of the ring formed include, for example, thiophene ring, thiazole ring, benzothiophene ring, thianthrene ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, thianthrene ring, phenoxathiin ring, tetrahydro A thiophenium ring, a tetrahydrothiopyranium ring, etc. are mentioned.

R ^{208 to} R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and a hydrogen atom or an alkyl group having 1 to 3 carbon atoms is preferable. A ring may be formed.

R ²¹⁰ may have an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a substituent. -SO ₂ - containing cyclic group.
The aryl group in R ^210, include unsubstituted aryl group having 6 to 20 carbon atoms, a phenyl group, a naphthyl group.
The alkyl group for R ²¹⁰ is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.
The alkenyl group for R ²¹⁰ preferably has 2 to 10 carbon atoms.
The —SO ₂ — containing cyclic group which may have a substituent in R ²¹⁰ is the same as the “—SO ₂ — containing cyclic group” of Ra ²¹ in the general formula (a2-1) described above. And the group represented by the above general formula (a5-r-1) is preferable.

Y ²⁰¹ each independently represents an arylene group, an alkylene group or an alkenylene group.
Examples of the arylene group for Y ²⁰¹ include a group in which one hydrogen atom has been removed from the aryl group exemplified as the aromatic hydrocarbon group for R ¹⁰¹ in formula (b-1) described later.
Examples of the alkylene group and alkenylene group for Y ²⁰¹ include the same aliphatic hydrocarbon groups as the divalent hydrocarbon group for Va ¹ in the general formula (a1-1).

In the formula (ca-4), x is the same as x in the formula (b1-2).
W ²⁰¹ is a (x + 1) valent, that is, a divalent or trivalent linking group.
The divalent linking group in W ²⁰¹ is preferably a divalent hydrocarbon group which may have a substituent, and examples thereof include the same hydrocarbon groups as Ya ²¹ in the above general formula (a2-1). . The divalent linking group in W ²⁰¹ may be linear, branched or cyclic, and is preferably cyclic. Of these, a group in which two carbonyl groups are combined at both ends of the arylene group is preferable. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferable.
^Examples of the trivalent linking group in W ²⁰¹ include a group obtained by removing one hydrogen atom from the divalent linking group in W ²⁰¹ , a group in which the divalent linking group is further bonded to the divalent linking group, and the like. Can be mentioned. The trivalent linking group in W ²⁰¹ is preferably a group in which two carbonyl groups are bonded to an arylene group.

  Specific examples of suitable cations represented by the formula (ca-1) include cations represented by the following formulas (ca-1-1) to (ca-1-67), respectively.

［式中、ｇ１、ｇ２、ｇ３は繰返し数を示し、ｇ１は１〜５の整数であり、ｇ２は０〜２０の整数であり、ｇ３は０〜２０の整数である。］

[Wherein, g1, g2, and g3 represent the number of repetitions, g1 is an integer of 1 to 5, g2 is an integer of 0 to 20, and g3 is an integer of 0 to 20. ]

［式中、Ｒ”^２０１は水素原子又は置換基であって、置換基としては前記Ｒ^２０１〜Ｒ^２０７、およびＲ^２１０〜Ｒ^２１２が有していてもよい置換基として挙げたものと同様である。］

[Wherein R ″ ²⁰¹ is a hydrogen atom or a substituent, and the substituent is the same as the substituents that R ^{201 to} R ²⁰⁷ and R ^{210 to} R ²¹² may have. is there.]

  Specific examples of suitable cations represented by the formula (ca-2) include diphenyliodonium cation and bis (4-tert-butylphenyl) iodonium cation.

  Specific examples of suitable cations represented by the formula (ca-3) include cations represented by the following formulas (ca-3-1) to (ca-3-6).

  Specific examples of suitable cations represented by the formula (ca-4) include cations represented by the following formulas (ca-4-1) to (ca-4-2).

Among them, the cation part [(M ^{m +} ) _{1 / m} ] is preferably the same as the cation represented by the general formulas (ca-1) to (ca-4), The cation represented by the general formula (ca-1) is more preferable, and the cations represented by the formulas (ca-1-1) to (ca-1-67) are more preferable.
As the component (d1-1), one type may be used alone, or two or more types may be used in combination.

{(D1-2) component}
· During anion formula (d1-2), Rd ² is has an optionally substituted cyclic group which may have a substituent chain alkyl group or a substituted group, And a chain alkenyl group which may be the same as R ¹⁰¹ in formula (b-1) described later.
However, a fluorine atom is not bonded to a carbon atom adjacent to the S atom in Rd ² (not fluorine-substituted). Thereby, the anion of (d1-2) component turns into a moderate weak acid anion, and the quenching ability as (D1) component improves.
Rd ² is preferably an aliphatic cyclic group which may have a substituent, and a group in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane or the like. (It may have a substituent); it is more preferably a group obtained by removing one or more hydrogen atoms from camphor or the like.
The hydrocarbon group of Rd ² may have a substituent, and examples of the substituent include a hydrocarbon group (aromatic hydrocarbon group, aliphatic hydrocarbon group) in Rd ¹ of the formula (d1-1). The same thing as the substituent which may have is mentioned.

  Preferred specific examples of the anion moiety of the component (d1-2) are shown below.

-Cation part In formula (d1-2), Mm ⁺ is an m-valent organic cation, and is the same as Mm ⁺ in formula (d1-1).
As the component (d1-2), one type may be used alone, or two or more types may be used in combination.

{(D1-3) component}
During Anion formula (d1-3), Rd ³ is have an optionally substituted cyclic group which may have a substituent chain alkyl group or a substituted group, A chain alkenyl group which may be the same as R ^{101 in} the formula (b-1) described later, and includes a cyclic group containing a fluorine atom, a chain alkyl group, or a chain alkenyl group. It is preferable that Among them, a fluorinated alkyl group is preferable, and the same as the fluorinated alkyl group for Rd ¹ is more preferable.

In formula (d1-3), Rd ⁴ may have a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. Examples of the chain alkenyl group include those similar to R ^{101 in} the formula (b-1) described later.
Among these, an alkyl group, an alkoxy group, an alkenyl group, or a cyclic group which may have a substituent is preferable.
The alkyl group in Rd ⁴ 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 the hydrogen atoms of the alkyl group of Rd ⁴ may be substituted with a hydroxyl group, a cyano group, or the like.
The alkoxy group in Rd ⁴ 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 preferable.

Examples of the alkenyl group for Rd ⁴ include the same as those for R ^{101 in} the formula (b-1) described later, and a vinyl group, a propenyl group (allyl group), a 1-methylpropenyl group, and a 2-methylpropenyl group are preferable. . These groups may further have, as a substituent, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms.

Examples of the cyclic group in Rd ⁴ include those similar to R ¹⁰¹ in formula (b-1) described later, and cycloalkanes such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. An alicyclic group in which one or more hydrogen atoms have been removed, or an aromatic group such as a phenyl group or a naphthyl group is preferred. When Rd ⁴ is an alicyclic group, the resist composition is well dissolved in an organic solvent, whereby the lithography properties are improved. In addition, when Rd ⁴ is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition is excellent in light absorption efficiency, and sensitivity and lithography characteristics are good.

In formula (d1-3), Yd ¹ represents a single bond or a divalent linking group.
The divalent linking group in Yd ¹ is not particularly limited, but may be a divalent hydrocarbon group (aliphatic hydrocarbon group or aromatic hydrocarbon group) which may have a substituent, or a hetero atom containing 2 Valent linking groups and the like. Each of these includes a divalent hydrocarbon group which may have a substituent and a hetero atom which are mentioned in the description of the divalent linking group of Ya ²¹ in the formula (a2-1). The thing similar to a valent coupling group is mentioned.
Yd ¹ is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. The alkylene group is preferably a linear or branched alkylene group, and more preferably a methylene group or an ethylene group.

  Preferred specific examples of the anion moiety of the component (d1-3) are shown below.

-Cation part In formula (d1-3), Mm ⁺ is an m-valent organic cation, and is the same as Mm ⁺ in formula (d1-1).
As the component (d1-3), one type may be used alone, or two or more types may be used in combination.

{(D1-4) component}
· During anion formula (d1-4), Rd ⁵ is a group having anionic sites that generates acid upon exposure.
The site that generates an acid by exposure means a site that can generate or release a proton by exposure.
The group having an anion moiety capable of generating or releasing a proton upon exposure is preferably a group containing a sulfonate anion, a carbanion, a carboxylate anion, an imide anion, or a sulfonylmethide anion. The groups represented by (r-an-1) to (r-an-3) are more preferable.

［式中、Ｖａ’^６１はフッ素原子を有する２価の炭化水素基であり、Ｌａ’^６１〜Ｌａ’^６２は−ＳＯ_２−であり、Ｌａ’^６３〜Ｌａ’^６５は−ＳＯ_２−または単結合であり、Ｒａ’^６１〜Ｒａ’^６３はそれぞれ独立に炭化水素基である。］

[Wherein, Va ′ ⁶¹ represents a divalent hydrocarbon group having a fluorine atom, La ′ ^{61 to} La ′ ⁶² represent —SO ₂ —, and La ′ ^{63 to} La ′ ⁶⁵ represent —SO ₂ — or a single group. A bond, and Ra ′ ^{61 to} Ra ′ ⁶³ are each independently a hydrocarbon group. ]

The divalent hydrocarbon group for Va ′ ⁶¹ is preferably a group exemplified as the divalent hydrocarbon group for Ya ²¹ in formula (a2-1), and is an alkylene group having 1 to 5 carbon atoms. Is more preferable, and a methylene group or an ethylene group is more preferable.
In the hydrocarbon group in Va ′ ⁶¹ , part or all of the hydrogen atoms of the hydrocarbon group are substituted with fluorine atoms, and 30 to 100% of the hydrogen atoms of the hydrocarbon group are substituted with fluorine atoms. It is more preferable. Among these, a (per) fluoroalkylene group in which part or all of the hydrogen atoms of the alkylene group exemplified as the divalent hydrocarbon group of Ya ²¹ is substituted with a fluorine atom is particularly preferable.

As the hydrocarbon group in Ra ′ ^{61 to} Ra ′ ^63, one of the two bonds of the group exemplified as the divalent hydrocarbon group in Ya ²¹ in the general formula (a2-1) is used as one bond. A monovalent hydrocarbon group having a hydrogen atom bonded thereto can be exemplified. It is preferable that part or all of the hydrogen atoms of the hydrocarbon group constituting Ra ′ ^{61 to} Ra ′ ⁶³ are substituted with fluorine atoms, and 30 to 100% of the hydrogen atoms of the hydrocarbon groups are substituted with fluorine atoms. More preferably. Among them, perfluoroalkyl in which all of the hydrogen atoms bonded to a group having a monovalent alkyl group as an alkylene group having 1 to 10 carbon atoms exemplified as the divalent hydrocarbon group of Ya ²¹ is substituted with a fluorine atom. Particularly preferred is a group.

  Specific examples of the groups represented by the formulas (r-an-1) to (r-an-3) are shown below.

In the component (d1-4), the number of anion sites that generate an acid upon exposure is preferably 1 or more, preferably 1 to 5, more preferably 1 to 3 than the number of nitrogen atoms having proton acceptor properties. More preferably, 1 or 2 more is more preferable.
When the number of the anion sites is larger than the number of nitrogen atoms in the above numerical range, an acid is generated when the compound is sufficiently exposed, and an acid is not easily generated by insufficient exposure, or the acid is in the resist film. Since it is difficult to diffuse, the contrast of the acid generation density between the exposed portion and the unexposed portion is increased. As a result, a sufficient difference can be generated in the developability between the exposed portion and the unexposed portion of the resist film, and lithography characteristics such as roughness reduction and mask reproducibility become more excellent. Further, in the unexposed area, the nitrogen atom having proton acceptor properties can function as an acid quencher, so that unnecessary acid that has diffused in the unexposed area is trapped. Is even better.

Among them, Rd ^5, the anion site (anionic group) is preferred to have one, and more preferably a group represented by the formula (r-an-1).

In formula (d1-4), Rd ⁶ is a hydrogen atom or a substituent that does not have an anion moiety that generates an acid upon exposure.
The substituent is preferably an organic group, and more preferably an optionally substituted hydrocarbon group having 1 to 20 carbon atoms. The hydrocarbon group may be linear, branched or cyclic, and may be either an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

In formula (d1-4), W ¹ is a z-valent functional group containing f nitrogen atoms having proton acceptor properties.
The “nitrogen atom having proton acceptor properties” refers to trapping a proton released by decomposing a part of the intramolecular structure by exposure or a proton released around the component (d1-4) by exposure ( It means a nitrogen atom having a loan pair (unshared electron pair) capable of accepting and binding.
The nitrogen atom in the component (d1-4) may be any as long as it has a loan pair capable of trapping protons, and includes, for example, structures represented by the following formulas (y1) to (y5), respectively. The constituting nitrogen atom is preferred.
On the other hand, examples of the nitrogen atom having no proton acceptor property include nitrogen atoms constituting imides and amides. Usually, the nitrogen atom constituting the imide or amide resonates with the double bond of the carbonyl group, so that the loan pair possessed by the nitrogen atom hardly traps protons.

Examples of the functional group containing a nitrogen atom having proton acceptor properties include those containing at least one of structures represented by the following formulas (y1) to (y5). Here, the structure in which the carbon atom constituting the structure represented by the formula (y4) forms a double bond with a nitrogen atom not shown in the formula (y4) is the same as the structure represented by the formula (y3). In this case, the structure is a structure represented by the formula (y3).
“*” In each formula means a bond, preferably bonded to a hydrogen atom, carbon atom, nitrogen atom or oxygen atom, more preferably bonded to a carbon atom or nitrogen atom, It is more preferable to combine with.

As an example of a functional group including one structure represented by the formula (y1), the following formulas (y1-1-1) to (y1-1-4), (y1-2), and (y1-3) And the group represented.
However, for the groups represented by formulas (y1-2) and (y1-3), any hydrogen atom constituting the ring skeleton is removed, and the carbon atom to which the hydrogen atom is bonded is You may have a bond. However, the description of the bond on the ring skeleton of each formula is omitted.

［式中、ｌは１又は２である。］

[In the formula, l is 1 or 2. ]

  Examples of the functional group including two or more structures represented by the formula (y1) include groups represented by the following formulas (y1-4) to (y1-6), respectively.

In the above formula, V ′ ¹ independently represents a linear, branched or cyclic alkylene group, preferably a linear or branched alkylene group having 1 to 10 carbon atoms, A linear alkylene group having 1 to 5 carbon atoms is more preferable, and a linear alkylene group having 2 to 3 carbon atoms is more preferable.
Specific examples of the functional group containing two or more structures represented by the formula (y1) include the following formula (y1-4-1), formula (y1-4-2), formula (y1-5-1), And groups represented by formula (y1-6-1). However, for the group represented by the formula (y1-4-2), the description of the bond on the ring skeleton is omitted.

As an example of a functional group including one or two structures represented by the formula (y2) and a functional group including one structure represented by each of the formulas (y3) to (y5), the following formula (y2 -1) to (y2-5), and formulas (y3-1) to (y3-3), formulas (y4-1), (y4-2), and formulas (y5-1) And groups represented respectively by
Note that the following formula (y2-3) is an example of a functional group including one structure each represented by the formula (y2) and the formula (y4). However, the description of the bond on the ring skeleton of each formula is omitted.

W ¹ is preferably a functional group containing at least one structure represented by each of the formulas (y1) to (y5), and the formulas (y1-1-1) to (y1-1-4). ), (Y1-2) to (y1-6), formula (1-4-1), formula (y1-4-2), formula (y1-5-1), formula (y1-6-1), Represented by formulas (y2-1) to (y2-5), formulas (y3-1) to (y3-3), formulas (y4-1), (y4-2) or formulas (y5-1). Those containing at least one functional group are more preferred.

Z representing the valence of W ¹ and the number f of nitrogen atoms having proton acceptor properties included in W ¹ are the integers of 1 or more and z = x + y in the formula (d1-4), And it has the relationship of f <= x <= z, x is an integer greater than or equal to 1, y is an integer greater than or equal to 0, and z is an integer greater than or equal to 1.
Here, x is preferably 1 to 6, more preferably 1 to 4, and particularly preferably 1 or 2.
Also, f is preferably equal to x or 1 to 2 less; more preferably equal to x or 1 less.
Moreover, y is preferably 0 or 1.

-Cation part In formula (d1-4), Mm ⁺ is an m-valent organic cation, and is the same as Mm ⁺ in formula (d1-1).
As the component (d1-4), one type may be used alone, or two or more types may be used in combination.

Since the component (d1-4) has a function of generating an acid by exposure and a function of trapping an unnecessary acid in the same molecule, the generation of the acid and the trap of the acid are within the resist film. It is considered that lithography characteristics such as roughness reduction and mask reproducibility are improved by being easily generated uniformly.
In addition, it is thought that the nitrogen atom which has proton acceptor property will reduce or lose | disappear the proton acceptor property by trapping the proton released | emitted by exposure, or the group containing this nitrogen atom will change into an acidic group. .

  Among the compounds represented by the general formula (d1-4), a compound represented by the following general formula (d1-4-0) is preferable.

［式中、Ｙ^１、Ｙ^２はそれぞれ独立に単結合または２価の連結基であり、Ｒ^３は前記式（ｒ−ａｎ−１）〜（ｒ−ａｎ−３）でそれぞれ表される基である。Ｒｄ^６，ｘ，ｙは前記式（ｄ１−４）中のＲｄ^６，ｘ，ｙと同じである。］

[Wherein Y ¹ and Y ² are each independently a single bond or a divalent linking group, and R ³ is a group represented by the above formulas (r-an-1) to (r-an-3), respectively. It is. Rd ^6, x, y are the same as ^Rd 6, x, y in the formula (D1-4) in. ]

In the formula (d1-4-0), Y ¹ and Y ² each independently represent a single bond or a divalent linking group. Examples of the divalent linking group include those similar to Ya ²¹ in the formula (a2-1), and a divalent linking group containing a hetero atom is preferable. A divalent aliphatic hydrocarbon group, a linking group containing an oxygen atom (—O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O—) Etc.) or a linking group obtained by combining these. However, the case where oxygen atoms are adjacently bonded to each other in “—Y ¹ —O—” and “—O—Y ² —” is excluded.
In the formula (d1-4-0), Y ¹ and Y ² are each a single bond, a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, —C (═O) —, or these. A combined linking group is preferred.
In the formula (d1-4-0), R ³ is preferably a group represented by the formula (r-an-1).

  Preferred examples of the anion moiety of the compound represented by the formula (d1-4) include anions represented by the following formulas (d1-4-1) to (d1-4-13).

［式中、Ｙ^２及びＲ^３は前記と同様であり、ｊｏは１〜４の整数であり、ｎ_１及びｎ_２はそれぞれ独立に１〜６の整数であり、ｌｏは１〜２の整数であり、Ｒ^４は水素原子又は炭素数１〜１０の炭化水素基である。］

[Wherein Y ² and R ³ are the same as defined above, jo is an integer of 1 to 4, n ₁ and n ₂ are each independently an integer of 1 to 6, and lo is an integer of 1 to 2] And R ⁴ is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. ]

Y ² is preferably a single bond, one exemplified as the divalent hydrocarbon group of Ya ²¹ or a group in which the divalent hydrocarbon group and an ester bond are combined, and as the divalent hydrocarbon group, Is more preferably a C 1-5 alkylene group, and even more preferably a methylene group or an ethylene group.
R ³ is preferably a group represented by the formula (r-an-1).
The counter cation of R ³ is preferably independently a monovalent organic cation, and more preferably the same as the cations represented by the general formulas (ca-1) to (ca-4), respectively. Preferably, the cations represented by the formulas (ca-1-1) to (ca-1-67) are more preferable.

As the component (D1), only one of the above components (d1-1) to (d1-4) may be used, or two or more may be used in combination.
The content of the component (D1) is preferably 0.5 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, and 1 to 8 parts by mass with respect to 100 parts by mass of the component (A). More preferably, it is a part.
When the content of the component (D1) is equal to or more than the preferable lower limit value, it is easy to obtain a resist pattern having good lithography characteristics and a good shape, particularly roughness reduction and mask reproducibility. On the other hand, when it is not more than the upper limit value, the sensitivity can be maintained well and the throughput is also excellent.

(Production method of component (D1))
The manufacturing method of said (d1-1) component, (d1-2) component, (d1-4) component is not specifically limited, It can manufacture by a well-known method.
Moreover, the manufacturing method of (d1-3) component is not specifically limited, For example, it manufactures similarly to the method of US2012-0149916 gazette.

In the resist composition of the present invention, the mixing ratio of the component (B1) and the component (D1) is preferably 0.05 to 20 in terms of a molar ratio represented by the component (B1) / (D1). More preferably, it is 0.1-10, It is further more preferable that it is 0.2-5, It is especially preferable that it is 0.2-3.
When the (B1) component / (D1) component is at least the preferred lower limit value, the sensitivity can be maintained satisfactorily and a better pattern shape can be easily obtained during resist pattern formation. On the other hand, when the (B1) component / (D1) component is less than or equal to the preferable upper limit value, lithography properties such as roughness are further improved.

<Other ingredients>
The resist composition of the present invention may further contain other components in addition to the components (A), (B1) and (D1) described above.

[Acid generator component: (B2) component]
In the resist composition of the present invention, an acid generator component (hereinafter referred to as “component (B2)”) other than the component (B1) and the component (D1) may be used in combination.
The component (B2) 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, and diazomethanes such as poly (bissulfonyl) diazomethanes. Examples include an acid generator, a nitrobenzyl sulfonate acid generator, an imino sulfonate acid generator, and a disulfone acid generator. Of these, it is preferable to use an onium salt acid generator.

  Examples of the onium salt-based acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as “(b-1) component”) and a general formula (b-2). A compound (hereinafter also referred to as “(b-2) component”) or a compound represented by the general formula (b-3) (hereinafter also referred to as “(b-3) component”) can be used.

［式中、Ｒ^１０１、Ｒ^１０４〜Ｒ^１０８はそれぞれ独立に置換基を有していてもよい環式基、置換基を有していてもよい鎖状のアルキル基、または置換基を有していてもよい鎖状のアルケニル基である。Ｒ^１０４、Ｒ^１０５は、相互に結合して環を形成していてもよい。Ｒ^１０２はフッ素原子または炭素数１〜５のフッ素化アルキル基である。Ｙ^１０１は単結合または酸素原子を含む２価の連結基である。Ｖ^１０１〜Ｖ^１０３はそれぞれ独立に単結合、アルキレン基、またはフッ素化アルキレン基である。Ｌ^１０１〜Ｌ^１０２はそれぞれ独立に単結合または酸素原子である。Ｌ^１０３〜Ｌ^１０５はそれぞれ独立に単結合、−ＣＯ−又は−ＳＯ_２−である。ｍは１以上の整数であって、Ｍ’^ｍ＋はｍ価のオニウムカチオンである。］

[Wherein, R ¹⁰¹ and R ^{104 to} R ¹⁰⁸ each independently has a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. A chain alkenyl group which may be present. R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring. R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom. V ^{101 to} V ¹⁰³ are each independently a single bond, an alkylene group, or a fluorinated alkylene group. L ^{101 to} L ¹⁰² are each independently a single bond or an oxygen atom. L ^{103 to} L ¹⁰⁵ are each independently a single bond, —CO— or —SO ₂ —. m is an integer of 1 or more, and M ′ ^{m +} is an m-valent onium cation. ]

{Anion part}.
-Anion moiety of component (b-1) In formula (b-1), R ¹⁰¹ represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, Alternatively, a chain alkenyl group which may have a substituent.

(Cyclic group which may have a substituent)
The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic 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.

The aromatic hydrocarbon group for R ¹⁰¹ is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, further preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aromatic ring of the aromatic hydrocarbon group in R ¹⁰¹ include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or a part of carbon atoms constituting these aromatic rings substituted with a heteroatom. An aromatic heterocyclic ring is mentioned. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom.
Specifically, the aromatic hydrocarbon group in R ¹⁰¹ is a group obtained by removing one hydrogen atom from the aromatic ring (aryl group: for example, phenyl group, naphthyl group, etc.), and one of the hydrogen atoms of the aromatic ring is alkylene. And a group substituted with a group (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.). The alkylene group (the alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

Examples of the cyclic aliphatic hydrocarbon group for R ¹⁰¹ include an aliphatic hydrocarbon group containing a ring in the structure.
As the aliphatic hydrocarbon group containing a ring in this structure, an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring), an alicyclic hydrocarbon group is linear or branched Examples thereof include a group bonded to the end of a chain aliphatic hydrocarbon group and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group.
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 a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group in which one or more hydrogen atoms have been removed from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms. Adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.
Among these, the cyclic aliphatic hydrocarbon group for R ¹⁰¹ is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane or polycycloalkane, and more preferably a group obtained by removing one hydrogen atom from a polycycloalkane. An adamantyl group and a norbornyl group are particularly preferable, and an adamantyl group is most preferable.

The linear or branched aliphatic hydrocarbon group that may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and 1 to 4 carbon atoms. Is more preferable, and 1-3 are most preferable.
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.

In addition, the cyclic hydrocarbon group for R ¹⁰¹ may contain a hetero atom such as a heterocyclic ring. Specifically, the lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), and the general formulas (a5-r-1) to (a5-r- -SO 2 respectively represented by 4) _- containing cyclic group, heterocyclic group listed other less like.

Examples of the substituent in the cyclic hydrocarbon group of R ¹⁰¹ include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group.
The alkyl group as a substituent 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.
The alkoxy group as a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group. Most preferred is an ethoxy group.
Examples of the halogen atom as a substituent 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, a part or all of hydrogen atoms such as an alkyl group having 1 to 5 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, and the like And a group substituted with a halogen atom.
The carbonyl group as a substituent is a group that substitutes a methylene group (—CH ₂ —) constituting a cyclic hydrocarbon group.

(A chain alkyl group which may have a substituent)
The chain alkyl group for R ¹⁰¹ may be either linear or branched.
The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group and the like.
The branched 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.

(Chain-like alkenyl group which may have a substituent)
The chain alkenyl group for R ¹⁰¹ may be either linear or branched, preferably has 2 to 10 carbon atoms, more preferably 2 to 5, still more preferably 2 to 4, more preferably 3 Is particularly preferred. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched alkenyl group include 1-methylvinyl group, 2-methylvinyl group, 1-methylpropenyl group, 2-methylpropenyl group and the like.
Among the above, the chain alkenyl group is more preferably a vinyl group or a propenyl group, and particularly preferably a vinyl group.

Examples of the substituent in the chain alkyl group or alkenyl group of R ¹⁰¹ include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and the cyclic group in R ¹⁰¹ described above. Can be mentioned.

Among these, R ¹⁰¹ is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, a phenyl group, a naphthyl group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and lactones represented by the above formulas (a2-r-1) to (a2-r-7), respectively. The containing cyclic group, the —SO ₂ -containing cyclic group represented by the general formulas (a5-r-1) to (a5-r-4), respectively, and the like are preferable.

In formula (b-1), Y ¹⁰¹ represents a single bond or a divalent linking group containing an oxygen atom.
When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, Y ¹⁰¹ may contain an atom other than an oxygen atom. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen 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 oxycarbonyl group (—O—C (═O). )-), Amide bond (—C (═O) —NH—), carbonyl group (—C (═O) —), carbonate bond (—O—C (═O) —O—), etc. A combination of a non-hydrocarbon oxygen atom-containing linking group and an alkylene group; and the like. A sulfonyl group (—SO ₂ —) may be further linked to the combination. Examples of the combination include linking groups represented by the following formulas (y-al-1) to (y-al-7), respectively.

［式中、Ｖ’^１０１は単結合または炭素数１〜５のアルキレン基であり、Ｖ’^１０２は炭素数１〜３０の２価の飽和炭化水素基である。］

[Wherein, V ′ ¹⁰¹ is a single bond or an alkylene group having 1 to 5 carbon atoms, and V ′ ¹⁰² is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms. ]

The divalent saturated hydrocarbon group for V ′ ¹⁰² is preferably an alkylene group having 1 to 30 carbon atoms.

The alkylene group for V ′ ¹⁰¹ and V ′ ¹⁰² may be a linear alkylene group or a branched alkylene group, and a linear alkylene group is preferred.
Specific examples of the alkylene group in V ′ ¹⁰¹ and V ′ ¹⁰² 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 Groups [—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 alkyl groups such as, trimethylene group (n- propylene _{group) [- CH 2 CH 2 CH} 2 -]; - CH (CH 3) CH 2 CH 2 -, - CH 2 CH (CH 3) CH ₂ - and the like alkyl trimethylene group; tetramethylene _{[-CH 2 CH 2 CH 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.
Moreover, some methylene groups in the alkylene group in V ′ ¹⁰¹ or V ′ ¹⁰² may be substituted with a C 5-10 divalent aliphatic cyclic group. The aliphatic cyclic group is preferably a divalent group obtained by further removing one hydrogen atom from the cyclic aliphatic hydrocarbon group of Ra ′ ^{3 in} the formula (a1-r-1). 1,5-adamantylene group or 2,6-adamantylene group is more preferable.

Y ¹⁰¹ is preferably a divalent linking group containing an ester bond or an ether bond, and linking groups represented by the above formulas (y-al-1) to (y-al-5) are preferred.

In formula (b-1), V ¹⁰¹ represents a single bond, an alkylene group, or a fluorinated alkylene group. The alkylene group and fluorinated alkylene group for V ¹⁰¹ preferably have 1 to 4 carbon atoms. ^Examples of the fluorinated alkylene group for V ¹⁰¹ include groups in which some or all of the hydrogen atoms of the alkylene group for V ¹⁰¹ have been substituted with fluorine atoms. Among ^{them, V 101} is preferably a single bond, or a fluorinated alkylene group having 1 to 4 carbon atoms.

In formula (b-1), R ¹⁰² represents a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. R ¹⁰² is preferably a fluorine atom or a C 1-5 perfluoroalkyl group, and more preferably a fluorine atom.

(B-1) Specific examples of the anion moiety of the component, for example, if the Y ¹⁰¹ is a single bond, fluorinated alkyl sulfonate anions such as trifluoromethane sulfonate anion or perfluorobutane sulfonate anion can be exemplified; Y ¹⁰¹ is In the case of a divalent linking group containing an oxygen atom, anions represented by any one of the following formulas (an-1) to (an-3) can be mentioned.

［式中、Ｒ”^１０１は、置換基を有していてもよい脂肪族環式基、前記式（ｒ−ｈｒ−１）〜（ｒ−ｈｒ−９）でそれぞれ表される基、又は置換基を有していてもよい鎖状のアルキル基であり；Ｒ”^１０２は、置換基を有していてもよい脂肪族環式基、前記式（ａ２−ｒ−１）〜（ａ２−ｒ−７）でそれぞれ表されるラクトン含有環式基、又は前記一般式（ａ５−ｒ−１）〜（ａ５−ｒ−４）でそれぞれ表される−ＳＯ_２−含有環式基であり；Ｒ”^１０３は、置換基を有していてもよい芳香族環式基、置換基を有していてもよい脂肪族環式基、又は置換基を有していてもよい鎖状のアルケニル基であり；ｖ”はそれぞれ独立に０〜３の整数であり、ｑ”はそれぞれ独立に１〜２０の整数であり、ｔ”は１〜３の整数であり、ｎ”は０または１である。］

[Wherein R ″ ¹⁰¹ represents an aliphatic cyclic group which may have a substituent, a group represented by each of the above formulas (r-hr-1) to (r-hr-9), or a substituent. A chain-like alkyl group which may have a group; R ″ ¹⁰² represents an aliphatic cyclic group which may have a substituent, the above formulas (a2-r-1) to (a2-r); lactone-containing cyclic group represented respectively by -7), or the formula (a5-r-1) ~ (a5-r-4) with -SO ₂ respectively represented - be-containing cyclic group; R ¹⁰³ is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent. Yes; v ″ is independently an integer of 0 to 3, q ″ is independently an integer of 1 to 20, t ″ is an integer of 1 to 3, and n ″ is 0 or 1 a is.]

The aliphatic cyclic group which may have a substituent of R ″ ¹⁰¹ , R ″ ¹⁰² and R ″ ¹⁰³ is preferably a group exemplified as the cyclic aliphatic hydrocarbon group in R ¹⁰¹ . Examples of the substituent include the same substituents that may be substituted for the cyclic aliphatic hydrocarbon group in R ¹⁰¹ .

The aromatic cyclic group which may have a substituent in R ″ ¹⁰³ is preferably the group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in R ¹⁰¹ . , R ¹⁰¹ and the same substituents that may be substituted for the aromatic hydrocarbon group.

The chain alkyl group which may have a substituent in R ″ ¹⁰¹ is preferably the group exemplified as the chain alkyl group in R ^101. The chain in R ″ ¹⁰³ has a substituent. The good chain alkenyl group is preferably the group exemplified as the chain alkenyl group in R ¹⁰¹ .

-Anion part of component (b-2) In formula (b-2), R ¹⁰⁴ and R ¹⁰⁵ may each independently have a cyclic group which may have a substituent or a substituent. Examples thereof include a good chain alkyl group or a chain alkenyl group which may have a substituent, and examples thereof include the same as those described above for R ¹⁰¹ in formula (b-1). However, R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring.
R ¹⁰⁴ and R ¹⁰⁵ are preferably a chain alkyl group which may have a substituent, and are a linear or branched alkyl group, or a linear or branched fluorinated alkyl group. It is more preferable.
The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and still more preferably 1 to 3 carbon atoms. The carbon number of the chain alkyl group of R ¹⁰⁴ and R ¹⁰⁵ is preferably as small as possible for reasons such as good solubility in a resist solvent within the above carbon number range. In addition, in the chain alkyl group of R ¹⁰⁴ and R ^105, the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, and against high-energy light and electron beams of 200 nm or less Since transparency improves, it is preferable. The proportion of fluorine atoms in the chain 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. Perfluoroalkyl group.
In formula (b-2), V ¹⁰² and V ¹⁰³ are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and each of them is the same as V ¹⁰¹ in formula (b-1). Can be mentioned.
In formula (b-2), L ^{101 to} L ¹⁰² each independently represents a single bond or an oxygen atom.

-Anion part of (b-3) component In formula (b-3), R < ¹⁰⁶ > -R < ¹⁰⁸ > may have the cyclic group which may have a substituent, and a substituent each independently. Examples thereof include a good chain alkyl group or a chain alkenyl group which may have a substituent, and examples thereof include the same as those described above for R ¹⁰¹ in formula (b-1).
L ^{103 to} L ¹⁰⁵ are each independently a single bond, —CO— or —SO ₂ —.

{Cation part}
In formulas (b-1), (b-2), and (b-3), M ′ ^{m +} is an m-valent onium cation, and a sulfonium cation and an iodonium cation are preferable.
Specifically, the general formulas (ca-1) to (ca-4) exemplified in the description of M ^{m +} (m-valent organic cation) in the formulas (d1-1) to (d1-4). And organic cations represented respectively by

As the component (B2), one type of acid generator described above may be used alone, or two or more types may be used in combination.
When the resist composition of the present invention contains the component (B2), the content of the component (B2) is preferably 50 parts by mass or less, and 0.5 to 50 parts by mass with respect to 100 parts by mass of the component (A). More preferred is 1 to 20 parts by mass.
By forming the content of the component (B2) within the above range, pattern formation is sufficiently performed. Moreover, when each component of a resist composition is melt | dissolved in the organic solvent, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

[Acid diffusion controller component: (D2) component]
The resist composition of the present invention may be used in combination with an acid diffusion controller component (hereinafter referred to as “(D2) component”) other than the component (D1) described above.
The component (D2) is not particularly limited as long as it functions as an acid diffusion controller and does not correspond to the component (D1), and any known component may be used. Of these, aliphatic amines, and particularly, secondary aliphatic amines and tertiary aliphatic amines are preferable.
An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
Examples of the aliphatic amine include an amine (alkyl amine or alkyl alcohol amine) or a cyclic amine in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms.
Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di- -Dialkylamines such as n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine , Trialkylamines such as tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, Li isopropanolamine, di -n- octanol amines, alkyl alcohol amines tri -n- octanol amine. Among these, a trialkylamine having 5 to 10 carbon atoms is 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.

As the component (D2), an aromatic amine may be used.
Examples of the aromatic amine include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine and the like.

(D2) A component may be used independently and may be used in combination of 2 or more type.
When the resist composition of this invention contains (D2) component, 10 mass parts or less are preferable with respect to 100 mass parts of (A) component, and, as for content of (D2) component, 0.01-5 mass parts is preferable. More preferred. By setting the content in the above range, the resist pattern shape, the stability over time, and the like are improved.

[(E) component]
The resist composition of the present invention comprises, as optional components, an organic carboxylic acid, a phosphorus oxo acid, and derivatives thereof for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, retention stability over time, and the like. At least one compound (E) selected from the group (hereinafter referred to as “component (E)”) can be contained.
As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.
Examples of phosphorus oxo acids 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 phosphinic acid esters and phenylphosphinic acid.
(E) A component may be used individually by 1 type and may use 2 or more types together.
(E) A component is normally used in 0.01-5 mass parts with respect to 100 mass parts of (A) component.

[(F) component]
The resist composition of the present invention may contain a fluorine additive (hereinafter referred to as “component (F)”) in order to impart water repellency to the resist film.
Examples of the component (F) include those described in JP 2010-002870 A, JP 2010-032994 A, JP 2010-277043 A, JP 2011-13569 A, and JP 2011-128226 A. These fluorine-containing polymer compounds can be used.
More specifically, examples of the component (F) include a polymer having a structural unit (f1) represented by the following formula (f1-1). Examples of the polymer include a polymer (homopolymer) composed only of the structural unit (f1) represented by the following formula (f1-1); a copolymer of the structural unit (f1) and the structural unit (a1). A copolymer of the structural unit (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1). Here, the structural unit (a1) copolymerized with the structural unit (f1) is preferably a structural unit derived from 1-ethyl-1-cyclooctyl (meth) acrylate.

［式中、Ｒは前記と同様であり、Ｒｆ^１０２およびＲｆ^１０３はそれぞれ独立して水素原子、ハロゲン原子、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を表し、Ｒｆ^１０２およびＲｆ^１０３は同じであっても異なっていてもよい。ｎｆ^１は１〜５の整数であり、Ｒｆ^１０１はフッ素原子を含む有機基である。］

[Wherein, R is as defined above, and Rf ¹⁰² and Rf ¹⁰³ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. , Rf ¹⁰² and Rf ¹⁰³ may be the same or different. nf ¹ is an integer of ¹ to 5, and Rf ¹⁰¹ is an organic group containing a fluorine atom. ]

In formula (f1-1), R bonded to the α-position carbon atom is the same as described above. R is preferably a hydrogen atom or a methyl group.
In formula (f1-1), examples of the halogen atom for Rf ¹⁰² and Rf ¹⁰³ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. Examples of the alkyl group having 1 to 5 carbon atoms of Rf ¹⁰² and Rf ¹⁰³ include the same as the alkyl group having 1 to 5 carbon atoms of R, and a methyl group or an ethyl group is preferable. Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms of Rf ¹⁰² and Rf ¹⁰³ 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. Can be 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 inter alia ^{Rf 102} and ^{Rf 103,} a hydrogen atom, a fluorine atom, or an alkyl group of 1 to 5 carbon atoms is preferable, a hydrogen atom, a fluorine atom, a methyl group or an ethyl group, preferred.
In formula (f1-1), nf ¹ is an integer of ¹ to 5, preferably an integer of 1 to 3, and more preferably 1 or 2.

In formula (f1-1), Rf ¹⁰¹ is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom.
The hydrocarbon group containing a fluorine atom may be linear, branched or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms. The carbon number of 1 to 10 is particularly preferable.
The hydrocarbon group containing a fluorine atom preferably has 25% or more of the hydrogen atoms in the hydrocarbon group fluorinated, more preferably 50% or more fluorinated, and 60% or more. Fluorination is particularly preferable because the hydrophobicity of the resist film during immersion exposure is increased.
Among ^these, as ^{Rf 101,} particularly preferably a fluorinated hydrocarbon group having 1 to 5 carbon atoms, a trifluoromethyl _{group, -CH 2 -CF 3, -CH 2} -CF 2 -CF 3, -CH (CF 3 ) ₂ , —CH ₂ —CH ₂ —CF ₃ , —CH ₂ —CH ₂ —CF ₂ —CF ₂ —CF ₂ —CF ₃ are most preferred.

(F) As for the mass mean molecular weight (Mw) (polystyrene conversion reference | standard by a gel permeation chromatography), 1000-50000 are preferable, 5000-40000 are more preferable, and 10000-30000 are the most 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.
The dispersity (Mw / Mn) of the component (F) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5.

(F) A component may be used individually by 1 type and may use 2 or more types together.
(F) A component is used in the ratio of 0.5-10 mass parts with respect to 100 mass parts of (A) component.

  The resist composition of the present invention further contains, if desired, miscible additives such as additional resins for improving the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents, A dye or the like can be appropriately added and contained.

[(S) component]
The resist composition of the present invention can be produced by dissolving a resist material in an organic solvent (hereinafter sometimes referred to as “(S) component”).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution. Conventionally, any one of known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, 2-heptanone; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol Polyhydric alcohols such as: ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate and the like compounds having an ester bond, the polyhydric alcohols or monomethyl ether of the compound having an ester bond , Monoalkyl ethers such as monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having an ether bond [in these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, and lactic acid Esters such as methyl, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, Diphenyl ether, dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, etc. An aromatic organic solvent, dimethyl sulfoxide (DMSO), etc. can be mentioned.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Of these, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is also preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be within the range.
More specifically, when EL or cyclohexanone is blended as the polar solvent, the mass ratio of PGMEA: EL or cyclohexanone 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. Furthermore, a mixed solvent of PGMEA, PGME, and cyclohexanone is also preferable.
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.
(S) The usage-amount of a component is not specifically limited, It is a density | concentration which can be apply | coated to a board | substrate etc., and is suitably set according to a coating film thickness. Generally, it is used so that the solid content concentration of the resist composition is in the range of 1 to 20% by mass, preferably 2 to 15% by mass.

According to the resist composition of the present invention described above, a resist pattern with better lithography characteristics can be formed.
In the resist composition of the present invention, together with the base material component (A), a sulfonium compound (B1) having a cation moiety and an anion moiety in one molecule, and photodegradability that decomposes upon exposure and loses acid diffusion controllability. And a base (D1). The component (D1) acts as a quencher (acid diffusion control agent) that traps acid generated by exposure from the component (B1) in the unexposed portion of the resist film. In the formation of the resist pattern, the (B1) component and the (D1) component synergistically act to increase the dissolution contrast between the exposed and unexposed portions of the resist film. improves.

≪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 according to the present invention is applied onto a support with a spinner or the like, and a baking (post-apply bake (PAB)) treatment is performed, for example, at a temperature of 80 to 150 ° C. for 40 to 120 seconds, preferably Is applied for 60 to 90 seconds to form a resist film.
Next, exposure or a mask pattern is performed on the resist film through a mask (mask pattern) on which a predetermined pattern is formed 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 of an electron beam without passing through, baking (post-exposure baking (PEB)) treatment is performed, for example, at a temperature of 80 to 150 ° C. for 40 to 120 seconds, preferably 60 to Apply for 90 seconds.
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 organic films such as an organic antireflection film (organic BARC) and a lower organic film in a multilayer resist method.
Here, the multilayer resist method is a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate, and the resist pattern formed on the upper resist film is used as a mask. This is a method of patterning a lower organic film, and it is said that a pattern with a high aspect ratio can be formed. That is, according to the multilayer resist method, the required thickness can be secured by the lower organic film, so that the resist film can be thinned and a fine pattern with a high aspect ratio can be formed.
In the multilayer resist method, basically, a method having a two-layer structure of an upper layer resist film and a lower layer organic film (two layer resist method), and one or more intermediate layers between the upper layer resist film and the lower layer organic film And a method of forming a multilayer structure of three or more layers (metal thin film etc.) (three-layer resist method).

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

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

Examples of the alkali developer used for the development treatment in the alkali development process include a 0.1 to 10% by mass tetramethylammonium hydroxide (TMAH) aqueous solution.
The organic solvent contained in the organic developer used for the development process in the solvent development process is not particularly limited as long as it can dissolve the component (A) (component (A) before exposure). It can be selected as appropriate. Specific examples include ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, ether solvents, and other polar solvents, hydrocarbon solvents, and the like.
The ketone solvent is an organic solvent containing C—C (═O) —C in the structure. The ester solvent is an organic solvent containing C—C (═O) —O—C in the structure. The alcohol solvent is an organic solvent containing an alcoholic hydroxyl group in the structure, and “alcoholic hydroxyl group” means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. A nitrile solvent is an organic solvent containing a nitrile group in its structure. The amide solvent is an organic solvent containing an amide group in the structure. The ether solvent is an organic solvent containing C—O—C in the structure.
Among organic solvents, there are organic solvents that contain multiple types of functional groups that characterize each of the above solvents in the structure, but in that case, any of the solvent types that contain the functional groups of the organic solvent is applicable. Shall. For example, diethylene glycol monomethyl ether shall correspond to both of the alcohol solvent and the ether solvent in the above classification.
The hydrocarbon solvent is a hydrocarbon solvent made of a hydrocarbon which may be halogenated and having no substituent other than 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 preferable.
Among the above, the organic solvent contained in the organic developer is preferably a polar solvent, and is preferably a ketone solvent, an ester solvent, a nitrile solvent, or the like.

Specific examples of each solvent include ketone solvents such as 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutylketone, cyclohexanone, Methylcyclohexanone, phenylacetone, methylethylketone, methylisobutylketone, acetylacetone, acetonylacetone, ionone, diacetylalcohol, acetylcarbinol, acetophenone, methylnaphthylketone, isophorone, propylene carbonate, γ-butyrolactone, methylamylketone (2- Heptanone) and the like.
As the ketone solvent, methyl amyl ketone (2-heptanone) is preferable.

Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono Propyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene Recall monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl acetate, propylene glycol monomethyl ether acetate, Propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate, 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxy Nethyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, pyrubin Methyl acid, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, 2-hydroxypropionate Examples include ethyl acid, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, and propyl-3-methoxypropionate.
As the ester solvent, butyl acetate is preferred.

  Examples of the nitrile solvent include acetonitrile, propionitryl, valeronitrile, butyronitryl and the like.

A known additive can be blended in the organic developer as required. Examples of the additive include a surfactant. The surfactant is not particularly limited. For example, ionic or nonionic fluorine-based and / or silicon-based surfactants can be used. As the surfactant, a nonionic surfactant is preferable, and a fluorine-based surfactant or a silicon-based surfactant is more preferable.
When the surfactant is blended, the blending amount is usually 0.001 to 5% by weight, preferably 0.005 to 2% by weight, and 0.01 to 0.00% with respect to the total amount of the organic developer. 5 mass% is more preferable.

  The development process can be performed 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), a developer is raised on the surface of the support by surface tension, and is left for a certain period of time. (Paddle method), spraying developer on the surface of the support (spray method), coating the developer while scanning the developer coating nozzle at a constant speed on the support rotating at a constant speed The method to continue (dynamic dispensing method) etc. are mentioned.

As the organic solvent contained in the rinsing liquid used for the rinsing process after the development process in the solvent developing process, for example, an organic solvent that is difficult to dissolve the resist pattern is selected as appropriate from the organic solvents used as the organic solvent used in the organic developer. Can be used. Usually, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents is used. Among these, at least one selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents and amide solvents is preferable, and at least one selected from alcohol solvents and ester solvents is preferable. More preferred are alcohol solvents.
The alcohol solvent used for the rinse liquid is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched or cyclic. Specific examples include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and benzyl alcohol. It is done. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferable, and 1-hexanol or 2-hexanol is more preferable.
Any one of these organic solvents may be used alone, or two or more thereof may be mixed and used. Moreover, you may mix and use the organic solvent and water other than the above. However, in consideration of development characteristics, the blending amount of water in the rinsing liquid is preferably 30% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, more preferably 3% by mass or less based on the total amount of the rinsing liquid. Is particularly preferred.
A well-known additive can be mix | blended with a rinse liquid as needed. Examples of the additive include a surfactant. Examples of the surfactant are the same as those described above, and a nonionic surfactant is preferable, and a fluorine-based surfactant or a silicon-based surfactant is more preferable.
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 rinse liquid. % Is more preferable.

  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).

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

<Synthesis example of sulfonium compound>
In a three-necked flask under a nitrogen atmosphere, 6.0 g of compound (1), 2.00 g of compound (2), 0.103 g of N, N-dimethylaminopyridine, and 10 g of dichloromethane were added, and 10 ° C. Stirred below. Thereto was added 0.97 g of compound (3) while maintaining the temperature of 10 ° C., and the mixture was stirred at 10 ° C. or lower for 0.5 hours, heated to 25 ° C. and stirred for 12 hours. Thereafter, the reaction solution was washed with 10 g of a 1% by mass hydrochloric acid aqueous solution and washed with 10 g of water four times. After washing, the mixture was added dropwise to 100 g of hexane with stirring, stirred for 30 minutes, and then filtered. The obtained powder was dried to obtain 1.3 g of Compound (B1) -2.
The obtained compound (B1) -2 was subjected to NMR measurement, and the structure was identified from the following results.
¹ H NMR (DMSO, 400 MHz): 7.63-7.82 (m, 10H, Ph), 4.67-4.79 (m, 4H, CH ₂ + CH ₂ ), 2.33 (s, 6H, _{CH 3), 1.31 (s,} 18H, tBu)
¹⁹ F NMR (DMSO, 376 MHz): −111.1

<Preparation of resist composition>
(Examples 1-12, Comparative Examples 1-2, Reference Example 1)
The resist composition of each example was prepared by mixing and dissolving each component shown in Table 1.

In Table 1, each abbreviation has the following meaning. The numerical value in [] is a compounding amount (part by mass).
(A) -1: a polymer compound represented by the following chemical formula (A) -1. The mass average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 6500, and the molecular weight dispersity (Mw / Mn) is 1.68. The copolymer composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) is 1 / m / n = 47/33/20. In the analysis by NMR, the internal standard of ¹³ C-NMR is tetramethylsilane (TMS).
(B1) -1: A compound represented by the following chemical formula (B1) -1.
(B1) -2: A compound represented by the following chemical formula (B1) -2.
(B2) -1: A compound represented by the following chemical formula (B2) -1.
(B2) -2: A compound represented by the following chemical formula (B2) -2.
(D1) -1 to (D1) -5: Compounds represented by the following chemical formulas (D1) -1 to (D1) -5, respectively. In addition, the mixing ratio of the component (B1) and the component (D1) is a molar ratio represented by the component (B1) / the component (D1). Examples 1 to 10 are 2.3, and Examples 11 to 12 are 3.5.
(D2) -1: tri-n-pentylamine.
(E) -1: salicylic acid.
(F) -1: A fluorine-containing polymer compound represented by the following chemical formula (F) -1. The weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement is 17000, and the molecular weight dispersity (Mw / Mn) is 1.32. The copolymer composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) is 1 / m / n = 70/20/10.
(S) -1: γ-butyrolactone.
(S) -2: mixed solvent of propylene glycol monomethyl ether acetate / propylene glycol monomethyl ether / cyclohexanone = 45/30/25 (mass ratio).

<Evaluation>
[Formation of resist pattern]
An organic antireflective coating composition “ARC95” (trade name, manufactured by Brewer Science) is applied onto a 12-inch silicon wafer using a spinner, baked on a hot plate at 205 ° C. for 60 seconds, and dried. Thereby, an organic antireflection film having a thickness of 90 nm was formed.
The resist composition of each example was applied onto the antireflection film using a spinner, prebaked (PAB) at 110 ° C. for 60 seconds on a hot plate, and dried to obtain a film thickness of 90 nm. The resist film was formed.
Next, an immersion ArF exposure apparatus NSR-S609B [manufactured by Nikon; NA (numerical aperture) = 1.07, Dipole (in / out = 0.78 / 0.97) with Polano, An immersion medium: water] was selectively irradiated with an ArF excimer laser (193 nm) through a photomask.
Thereafter, a post-exposure bake (PEB) treatment was performed at 95 ° C. for 60 seconds.
Next, alkali development is performed for 10 seconds with a 2.38 mass% TMAH aqueous solution (trade name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23 ° C., and then water rinse for 30 seconds using pure water. Then, it was shaken and dried.
As a result, in each example, a 1: 1 line and space (LS) pattern having a line width of 50 nm and a pitch of 100 nm was formed.
The optimum exposure dose EOP (mJ / cm ² ) at which such an LS pattern is formed was determined. The results are shown in Table 2.

[Evaluation of LWR (Line Width Roughness)]
In the LS pattern formed by EOP, 400 line widths were measured in the longitudinal direction of the line with a length measurement SEM (scanning electron microscope, acceleration voltage 800 V, trade name: S-9380, manufactured by Hitachi High-Technologies Corporation). From the results, the standard deviation (s) 3 times (3 s) (unit: nm) was calculated as 3 s, which is a measure of LWR. The results are shown in Table 2 as “LWR (nm)”.
The smaller the value of 3s, the smaller the roughness of the line width, which means that an LS pattern with a more uniform width was obtained.

[Evaluation of LER (Line Edge Roughness)]
With respect to the LS pattern having a line width of 50 nm and a pitch of 100 nm formed in [Formation of resist pattern], 3σ, which is a measure indicating LER, was obtained.
“3σ” is a standard deviation obtained by measuring 400 line positions in the longitudinal direction of the line with a scanning electron microscope (acceleration voltage 800 V, trade name: S-9380, manufactured by Hitachi High-Technologies Corporation). A triple value (3σ) (unit: nm) of (σ) is shown.
The smaller the value of 3σ, the smaller the roughness of the line side wall, which means that an LS pattern with a more uniform width was obtained. The results are shown in Table 2 as “LER (nm)”.

[Evaluation of mask reproducibility]
In accordance with the same procedure as [Formation of resist pattern], an LS pattern with a pitch of 100 nm was formed using mask patterns with a line width target size of 45 to 54 nm (1 nm increments, 10 points in total) at the same exposure amount. .
At that time, the slope of the straight line was calculated when the target size (nm) was plotted on the horizontal axis and the line width (nm) of the LS pattern actually formed on the resist film using each mask pattern was plotted on the vertical axis. The value of the slope of this straight line is shown in Table 2 as “MEEF”.
The closer the slope of the straight line is to 1, the better the mask reproducibility.

[Evaluation of depth of focus (DOF) characteristics]
In the above EOP, the focus is appropriately shifted up and down to form a resist pattern in the same manner as in [Registration of resist pattern], and the LS pattern has a target dimension ± 5% (ie, 47.5 to 52.5 nm). The depth of focus (DOF, unit: nm) that can be formed within the range of the rate was determined. The results are shown in Table 2 as “5% DOF (nm)”.
Note that “DOF” refers to a depth of focus range in which a resist pattern can be formed with a dimension within which a deviation with respect to a target dimension is within a predetermined range when the focus is shifted up and down at the same exposure amount, that is, a mask. This is the range in which a resist pattern faithful to the pattern can be obtained, and the larger the value, the better.

  From the results shown in Table 2, the resist compositions of Examples 1 to 5 to which the present invention was applied were compared to the resist compositions of Comparative Examples 1 and 2, and the Examples 6 to 12 to which the present invention was applied. It was confirmed that the resist composition was superior in lithography characteristics such as roughness reduction, mask reproducibility, and depth of focus width characteristics, respectively, as compared with the resist compositions of Comparative Example 1 and Reference Example 1.

Claims (5)

A base component (A) whose solubility in a developer is changed by the action of an acid;
In one molecule, a sulfonium compound (B1) having a sulfonio group and an anion group represented by the following general formula (b1-r-1);
A photodegradable base (D1) that decomposes upon exposure and loses acid diffusion controllability,
A resist composition comprising:

[Wherein Y ¹ is a divalent linking group or a single bond, L ¹ is an ester bond or a single bond, V ¹ is a divalent hydrocarbon group having a fluorine atom, and n is 0 or 1 It is. ] The photodegradable base (D1) is a compound represented by the following general formula (d1-1), a compound represented by the general formula (d1-2), a compound represented by the general formula (d1-3) And a resist composition according to claim 1, which is one or more compounds selected from the group consisting of compounds represented by formula (d1-4).

[Wherein Rd ^{1 to} Rd ⁴ are a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain which may have a substituent. Of the alkenyl group. However, a fluorine atom is not bonded to a carbon atom adjacent to the S atom in Rd ² in the formula (d1-2). Yd ¹ is a single bond or a divalent linking group. Rd ⁵ is a group having an anion moiety that generates an acid upon exposure. Rd ⁶ is a hydrogen atom or a substituent having no anion moiety that generates an acid upon exposure. W ¹ is a z-valent functional group containing f nitrogen atoms having proton acceptor properties; f is an integer of 1 or more, z = x + y, and f ≦ x ≦ z, and x is 1 or more , Y is an integer of 0 or more, and z is an integer of 1 or more. m is an integer of 1 or more, and M ^{m +} is each independently an m-valent organic cation. ] The resist composition according to claim 1 or 2, wherein the sulfonium compound (B1) is a compound represented by the following general formula (b1-1).

[Wherein R ^{1 to} R ³ each independently represents an aryl group which may have a substituent, an alkyl group which may have a substituent, or an alkenyl group which may have a substituent. And 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. However, at least one of R ^{1 to} R ³ is an aryl group having an anion group represented by the general formula (b1-r-1) as a substituent, and represented by the general formula (b1-r-1). Or an alkenyl group having an anion group represented by formula (b1-r-1). ]   The said base material component (A) contains the high molecular compound (A1) which has a structural unit (a1) containing the acid-decomposable group which polarity increases by the effect | action of an acid. The resist composition as described.   A step of forming a resist film on the support using the resist composition according to any one of claims 1 to 4, a step of exposing the resist film, and developing the resist film to form a resist pattern A resist pattern forming method including a forming step.