JP6228796B2 - Resist composition and resist pattern forming method - Google Patents

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

Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing a pattern with fine dimensions.
Conventionally, as a resist material satisfying such requirements, there is 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. It 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 polarity of the base resin increases due to the action of the acid. Thus, the exposed portion becomes soluble in the alkaline developer. Therefore, by performing alkali development, a positive pattern in which an unexposed portion remains as a pattern is formed. On the other hand, when a solvent development process using a developer containing an organic solvent (organic developer) is applied, the solubility in the organic developer is relatively lowered when the polarity of the base resin is increased. The unexposed portion is dissolved and removed by the organic developer, and a negative resist pattern is formed in which the exposed portion remains as a pattern. Such a solvent development process for forming a negative resist pattern is sometimes referred to as a negative development process (Patent Document 1).

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

JP 2009-025723 A JP 2003-241385 A

In the future, with further advancement of lithography technology and further miniaturization of resist patterns, resist materials are required to improve various lithography characteristics.
However, the conventional resist compositions as described in Patent Documents 1 and 2 still have room for improvement in coating properties and the like.

In the future, there is a demand for new materials that can be used for lithography applications as further progress in lithography technology and expansion of application fields progress.
An object of the present invention is to provide a resist composition excellent in applicability and solubility in a resist solvent, and a resist pattern forming method using the resist composition.

A first aspect of the present invention is a resist composition that generates an acid upon exposure and changes its solubility in a developing solution by the action of an acid, and a substrate whose solubility in a developing solution changes by the action of an acid A resist composition comprising a component (A) and an organic solvent component (S), wherein the organic solvent component (S) contains an organic solvent (S1) composed of N, N, 2-trimethylpropionamide. It is a thing.

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

  ADVANTAGE OF THE INVENTION According to this invention, the resist composition excellent in applicability | paintability and the solubility to a resist solvent, and a resist pattern formation method can be provided.

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 “alkylene group” includes linear, branched, and cyclic divalent saturated hydrocarbon groups unless otherwise specified. The same applies to the alkyl group in the alkoxy group.
The “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
“Fluorinated alkyl group” or “fluorinated alkylene group” refers to a group in which part or all of the hydrogen atoms of an alkyl group or alkylene group are substituted with fluorine atoms.
“Structural unit” means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).
“A structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid 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 ^α ) 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. Examples thereof include an alkyl group and a hydroxyalkyl group. The α-position carbon atom of the acrylate ester is a carbon atom to which a carbonyl group 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”.
“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. The derivatives include those in which the hydrogen atom at the α-position may be substituted with a substituent, the hydrogen atom of the hydroxyl group of hydroxystyrene substituted with an organic group, and the hydrogen atom at the α-position substituted with a substituent. Examples include those in which a substituent other than a hydroxyl group is bonded to a good benzene ring of hydroxystyrene. 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 obtained by substituting the hydrogen atom of the carboxy group of vinyl benzoic acid with an organic group, which may be substituted with a hydrogen atom at the α-position, and the hydrogen atom at the α-position 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.
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 Including both.
“Exposure” is a concept including general irradiation of radiation.

≪Resist composition≫
The resist composition of the present invention is a resist composition that generates an acid upon exposure and changes its solubility in a developer by the action of an acid, and is a base material component that changes its solubility in a developer by the action of an acid ( A) (hereinafter also referred to as “component (A)”) and an organic solvent (S1) (organic solvent component (S) (hereinafter referred to as “(S)”) composed of the compound (s-1) represented by the general formula (1). ) Component "))).
When a resist film is formed using such a resist composition and the resist film is selectively exposed, an acid is generated in the exposed portion, and the action of the acid causes the solubility of the component (A) in the developer. On the other hand, since the solubility of the component (A) in the developer does not change in the unexposed area, 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.

The resist composition of the present invention has an acid generating ability to generate an acid upon exposure, and the component (A) may generate an acid upon exposure, and is an additive added separately from the component (A). The component may generate an acid upon exposure.
Specifically, the resist composition of the present invention comprises:
(1) It may contain an acid generator component (B) that generates an acid upon exposure (hereinafter referred to as “component (B)”);
(2) The component (A) may be a component that generates an acid upon exposure;
(3) The component (A) is a component that generates an acid upon exposure, and may further contain a component (B).
That is, in the case of the above (2) and (3), the component (A) is a “base material component that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid”. When the component (A) is a base material component that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid, the component (A1) described later generates an acid upon exposure, and A polymer compound whose solubility in a developing solution is changed by the action of an acid is preferable. As such a polymer compound, a resin having a structural unit that generates an acid upon exposure can be used. A well-known thing can be used as a structural unit which generate | occur | produces an acid by exposure.
The resist composition of the present invention is particularly preferably the case (1) above.

<(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 weight average molecular weight by GPC (gel permeation chromatography) is used.
As the component (A), 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.
In the present invention, the component (A) may generate an acid upon exposure.

  In this invention, it is preferable that a base material component (A) contains the resin component (A1) which has the structural unit (a1) containing the acid-decomposable group which polarity increases by the effect | action of an acid.

(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 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, “acid-dissociable group” means
(I) an acid-dissociable group 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, or
(Ii) a group capable of cleaving a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by further decarboxylation reaction after partial bond cleavage by the action of an acid ,
Both.
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, and when the developer is an organic developer, the solubility decreases.

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.
Among the polar groups, examples of the acid dissociable group that protects a carboxy group or a hydroxyl group include an acid dissociable group represented by the following general formula (a1-r-1) (hereinafter referred to as “acetal acid dissociable for convenience”). Group ”).

［式中、Ｒａ’^１、Ｒａ’^２は水素原子またはアルキル基、Ｒａ’^３は炭化水素基、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 hydrogen atoms or alkyl groups, Ra ′ ³ is a hydrocarbon group, and Ra ′ ³ may be bonded to either Ra ′ ¹ or Ra ′ ² to form a ring. Good. ]

In formula (a1-r-1), Ra ′ ¹ and Ra ′ ² are exemplified as substituents that may be bonded to the α-position carbon atom in the description of the α-substituted acrylate ester described above. Examples thereof include the same as the alkyl group, preferably a methyl group or an ethyl group, and most preferably a methyl group.

The hydrocarbon group for Ra ′ ³ is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms; a linear or branched alkyl group is preferable, specifically , Methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, 1,1-dimethylethyl group, 1,1-diethylpropyl group 2,2-dimethylpropyl group, 2,2, -dimethylbutyl group and the like can be mentioned.

When Ra ′ ³ is a cyclic hydrocarbon group, it may be aliphatic or aromatic, may be polycyclic, or may be monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane preferably has 3 to 8 carbon atoms, and specific examples include cyclopentane, cyclohexane and cyclooctane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

In the case of an aromatic hydrocarbon group, specific examples of the aromatic ring contained include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, phenanthrene; carbon atoms constituting the aromatic hydrocarbon ring. An aromatic heterocycle partially substituted with a heteroatom; and the like. 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, arylalkyl group such as 2-naphthylethyl group); and the like. The alkylene group (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) (the following formula (a1-r-2) Among the acid dissociable groups represented by), those composed of an alkyl group may hereinafter be referred to as “tertiary alkyl ester type acid dissociable groups” for convenience).

［式中、Ｒａ’^４〜Ｒａ’^６は炭化水素基であり、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 hydrocarbon groups, 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. In the case where 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. ]

In formula (a1-r2-1), the alkyl group of the alkyl group having 1 to ¹⁰ carbon atoms of Ra ′ ¹⁰ is a linear or branched alkyl group of Ra ′ ³ in formula (a1-r-1) The groups mentioned as are preferred. Wherein (a1-r2-1), Ra 'aliphatic cyclic ^{group 11} is configured, Ra in formula (a1-r-1)' group listed as a cyclic alkyl group of ³ is 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 formula (a1-r2-1) are given below. In the following formula, “*” indicates a bond.

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

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

［式中、Ｒａ’^７〜Ｒａ’^９はアルキル基を示す。］

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

In formula (a1-r-3), Ra ′ ^{7 to} Ra ′ ⁹ are preferably an alkyl group having 1 to 5 carbon atoms, and more preferably 1 to 3 groups.
The total carbon number of each alkyl group is preferably 3-7, more preferably 3-5, and most preferably 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. A structural unit containing a decomposable group; a structural unit in which at least a part of hydrogen atoms in the hydroxyl group of a structural unit derived from hydroxystyrene or a hydroxystyrene derivative is protected by a substituent containing the acid-decomposable group; vinylbenzoic acid or Examples include a structural unit in which at least a part of hydrogen atoms in —C (═O) —OH of a structural unit derived from a vinylbenzoic acid derivative 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.
As the structural unit (a1), structural units represented by any of the following general formulas (a1-1) to (a1-3) are preferable.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基である。Ｖａ^１はエーテル結合、ウレタン結合、又はアミド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）〜（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である。
Ｒａ^２は上記式（ａ１−ｒ−１）または（ａ１−ｒ−３）で表される酸解離性基である。
Ｗａ^２はｎ_ａ３＋１価の炭化水素基であり、ｎ_ａ３は１〜３であり、
Ｖａ^２はエーテル結合、ウレタン結合、又はアミド結合を有していてもよい２価の炭化水素基であり、
Ｒａ^３は上記式（ａ１−ｒ−１）〜（ａ１−ｒ−２）で表される酸解離性基である。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va ¹ is a divalent hydrocarbon group which may have an ether bond, a urethane bond, or an amide bond, _na1 is 0 to 2,
Ra ¹ is an acid dissociable group represented by the above formulas (a1-r-1) to (a1-r-2).
Wa ¹ is n _a2 +1 valent hydrocarbon group, and n _a2 is 1 to 3.
Ra ² is an acid dissociable group represented by the above formula (a1-r-1) or (a1-r-3).
Wa ² is _n a3 +1 monovalent hydrocarbon _{group, n a3} is 1 to 3,
Va ² is a divalent hydrocarbon group which may have an ether bond, a urethane bond, or an amide bond,
Ra ³ is an acid dissociable group represented by the above formulas (a1-r-1) to (a1-r-2). ]

In the general formulas (a1-1) to (a1-3), the alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, Examples thereof 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, and a neopentyl group. 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.
In the general formula (a1-1), 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 containing a ring in the structure, and the like.
Examples of Va ¹ include those in which the divalent hydrocarbon group is bonded through an ether bond, a urethane bond, or an amide bond.

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 polycyclic or monocyclic. 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 preferable, and 6 to 10 is most preferable. 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; and the like. 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) ) In which one of the hydrogen atoms is substituted with an alkylene group (for example, arylalkyl such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.) Group in which one hydrogen atom is further removed from the aryl group in the group); and the like. The alkylene group (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. It includes a group formed by combining an aliphatic hydrocarbon group in the structure containing a ring, and specific examples thereof include the same groups as Va ¹ of the aforementioned formula (a1-1).
The n _a2 +1 valence is preferably 2 to 4, and more preferably 2 or 3.

In the formula (a1-3), the n _a3 +1 valent hydrocarbon group in Wa ² 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. It includes a group formed by combining an aliphatic hydrocarbon group in the structure containing a ring, and specific examples thereof include the same groups as Va ¹ of the aforementioned formula (a1-1).
The n _a3 +1 valence is preferably 2 to 4, and more preferably 2 or 3.
In the formula (a1-3), Va ² includes the same group as Va ^{1 in the} formula (a1-1).

  As the formula (a1-2), a structural unit represented by general formula (a1-2-01) shown below is particularly desirable.

In formula (a1-2-01), Ra ² is an acid dissociable group represented by the above formula (a1-r-1) or (a1-r-3). n _a2 is an integer of 1 to 3, preferably 1 or 2, and more preferably 1. c is an integer of 0 to 3, preferably 0 or 1, and more preferably 1. R is the same as described above.
Specific examples of the above formulas (a1-1) and (a1-2) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

  The proportion of the structural unit (a1) in the component (A) is preferably 10 to 80 mol%, more preferably 10 to 75 mol%, more preferably 10 to 70 mol%, based on all structural units constituting the component (A). Is more preferable. By setting the lower limit value or more, lithography properties such as sensitivity, resolution, and LWR are also improved. Moreover, the balance with another structural unit can be taken by making it below an upper limit.

In the present invention, the base component (A) further includes a structural unit (a2) containing a lactone-containing cyclic group, a carbonate-containing cyclic group, or an —SO ₂ -containing cyclic group, and a polar group-containing aliphatic hydrocarbon. The resin component (A1) having a structural unit (a3) containing a group and a structural unit (a4) containing an acid non-dissociable cyclic group may be contained.

(Structural unit (a2))
The structural unit (a2) is a structural unit including a lactone-containing cyclic group, a carbonate-containing cyclic group, or an —SO ₂ -containing cyclic group.
The lactone-containing cyclic group or carbonate-containing cyclic group of the structural unit (a2) is effective in improving the adhesion of the resist film to the substrate when the component (A1) is used for forming the resist film. is there.
In addition, when the structural unit (a1) includes a lactone-containing cyclic group or a carbonate-containing cyclic group in the structure, the structural unit also corresponds to the structural unit (a2). It corresponds to the structural unit (a1) and does not correspond to the structural unit (a2).
The —SO ₂ — containing cyclic group of the structural unit (a2) is effective for enhancing the adhesion of the resist film to the substrate when the component (A1) is used for forming the resist film.
In addition, when the structural unit (a1) includes a —SO ₂ — containing cyclic group in the structure, the structural unit also corresponds to the structural unit (a2). It corresponds to a1) and does not correspond to the structural unit (a2).

  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り、Ｙａ^２１は単結合または２価の連結基であり、Ｌａ^２１は−Ｏ−、−ＣＯＯ−、−ＯＣＯ−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。］

[Wherein, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, Ya ²¹ is a single bond or a divalent linking group, and La ²¹ is —O -, -COO-, -OCO-, 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. ]

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.

(Divalent hydrocarbon group which may have a substituent)
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. Specifically, the above-described formula (a1- The group illustrated by Va ¹ in 1) is mentioned.

  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.
Specific examples of the cyclic aliphatic hydrocarbon group include the groups exemplified for Va ¹ in the above formula (a1-1).
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.

Specific examples of the aromatic hydrocarbon group as the divalent hydrocarbon group include groups exemplified by Va ¹ in the above formula (a1-1).
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.

(Divalent linking group containing a hetero atom)
The hetero atom in the divalent linking group containing a hetero atom is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.

When Ya ²¹ is a divalent linking group containing a hetero atom, preferred examples of the linking group include —O—, —C (═O) —O—, —C (═O) —, and —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). _{.), - S -, -} S (= O) 2 -, - S (= O) 2 -O-, the formula ^{-Y 21 -O-Y 22 -,} - Y 21 -O -, - Y 21 - C (═O) —O—, —C (═O) —O—Y ²¹ , — [Y ²¹ —C (═O) —O] _{m ′} —Y ²² — or —Y ²¹ —O—C (= O) a group represented by —Y ²² —, wherein Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, m 'is an integer of 0-3. ] Etc. are mentioned.
When the divalent linking group containing a hetero atom is —C (═O) —NH—, —NH—, —NH—C (═NH) —, H is a substituent such as an alkyl group or acyl. May be substituted. 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 -, - C (= O) -O-Y 21 -, - [Y 21 -C (═O) —O] _{m ′} —Y ²² — or —Y ²¹ —O—C (═O) —Y ²² —, wherein Y ²¹ and Y ²² each independently have a substituent. It is also a good divalent hydrocarbon group. Examples of the divalent hydrocarbon group include those similar to the “divalent hydrocarbon group optionally having substituent (s)” mentioned in the description of the divalent linking group.
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 —. The group is particularly preferred. Among these, a group represented by the formula — (CH ₂ ) _{a ′} —C (═O) —O— (CH ₂ ) _{b ′} — is preferable. In the formula, a ′ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, further preferably 1 or 2, and most preferably 1. b ′ is an integer of 1 to 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.

Ya ²¹ in the present invention is a single bond, an ester bond [—C (═O) —O—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof. It is preferable.

In the formula (a2-1), Ra ²¹ is a lactone-containing cyclic group, a carbonate-containing cyclic group, or an —SO ₂ -containing cyclic group.

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.
Any lactone-containing cyclic group can be used without any particular limitation. Specific examples include groups represented by the following general formulas (a2-r-1) to (a2-r-7). Hereinafter, “*” represents a bond.

［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 which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, and n ′ is 0 to 2 And m ′ is 0 or 1. ]

In general formulas (a2-r-1) to (a2-r-7), A ″ represents an oxygen atom (—O—) or a sulfur atom (—S—), and may have 1 to 5 carbon atoms. The alkylene group having 1 to 5 carbon atoms in A ″ is preferably a linear or branched alkylene group, a methylene group, an ethylene group, an n-propylene group, An isopropylene group etc. are mentioned. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group in which —O— or —S— is interposed between the terminal or carbon atoms of the alkylene group, such as —O—CH _{2. -, - CH 2 -O-CH} 2 -, - S-CH 2 -, - CH 2 -S-CH 2 - , and the like. A ″ is preferably an alkylene group having 1 to 5 carbon atoms or —O—, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.

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 any hydrogen atom, alkyl group, lactone-containing cyclic group, carbonate-containing cyclic group, or —SO ₂ -containing cyclic group. It is.
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 Or a group obtained by removing one or more hydrogen atoms from a monocycloalkane which may or may not be substituted with a fluorinated alkyl group; a polycycloalkane such as a bicycloalkane, tricycloalkane or tetracycloalkane A group in which one or more hydrogen atoms are removed from a monocycloalkane such as cyclopentane, cyclohexane, etc .; more specifically, a group in which one or more hydrogen atoms are removed; adamantane, norbornane, isobornane, tri Examples include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as cyclodecane or tetracyclododecane. That.
Examples of the lactone-containing cyclic group for R ″ include the same groups as those represented by general formulas (a2-r-1) to (a2-r-7).
The carbonate-containing cyclic group for R ″ is the same as the carbonate-containing cyclic group described later, and specifically, groups represented by general formulas (ax3-r-1) to (ax3-r-3), respectively. Is mentioned.
The —SO ₂ — containing cyclic group in R ″ is the same as the later-described —SO ₂ — containing cyclic group, and specifically, is represented by the general formulas (a5-r-1) to (a5-r-4) And groups represented respectively by

As the hydroxyalkyl group in Ra ′ ²¹ , those having 1 to 6 carbon atoms are preferable, and specific examples include a group in which at least one hydrogen atom of the alkyl group in Ra ′ ²¹ is substituted with a hydroxyl group. .
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 monocyclic or polycyclic.
The —SO ₂ — containing cyclic group as the cyclic hydrocarbon group in R ¹ is particularly a cyclic group containing —O—SO ₂ — in its ring skeleton, that is, —O— in —O—SO ₂ —. -S- is preferably a cyclic group containing a sultone ring that forms part of the ring skeleton. More specifically, examples of the —SO ₂ -containing cyclic group include groups represented by the following general formulas (a5-r-1) to (a5-r-4).

［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 the general formulas (a5-r-1) to (a5-r-4), A ″ is the same as A ″ in the general formulas (a2-r-1) to (a2-r-7). As the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group in Ra ′ ⁵¹ , the above general formulas (a2-r-1) to (a2 The same as Ra ′ ²¹ in −r-7).

  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.

As the —SO ₂ — containing cyclic group, among the above, a group represented by the general formula (a5-r-1) is preferable, and the chemical formulas (r-sl-1-1) and (r-sl— It is more preferable to use at least one selected from the group consisting of groups represented by any one of 1-18), (r-sl-3-1) and (r-sl-4-1), The group represented by (r-sl-1-1) is most preferable.

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.
The carbonate ring-containing cyclic group as the cyclic hydrocarbon group for R ¹ is not particularly limited, and any one can be used. 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ｐ’は０〜３の整数であり、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 p ′ is 0 to 3 It is an integer and q ′ is 0 or 1. ]

In the general formulas (ax3-r-1) to (ax3-r-3), A ″ is the same as A ″ in the general formula (a2-r-1).
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.

Among these, a lactone-containing cyclic group or a —SO ₂ — containing cyclic group is preferable, and is represented by the general formula (a2-r-1), (a2-r-2), or (a5-r-1). The groups represented by the chemical formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-13), (r- Any of the groups (sl-1-1) and (r-sl-1-18) is more preferable.

The structural unit (a2) contained in the component (A1) may be one type or two or more types.
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 5 to 70 mol%, further preferably 10 to 65 mol%, and particularly preferably 10 to 60 mol%. By setting it to the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by setting it to the upper limit value or less, balance with other structural units can be achieved. The lithography characteristics and pattern shape of the film are improved.

(Structural unit (a3))
The structural unit (a3) is a structural unit containing a polar group-containing aliphatic hydrocarbon group (except for those corresponding to the structural units (a1) and (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 carbon atom at the α-position may be substituted with a substituent, and includes a polar group-containing aliphatic hydrocarbon group A structural unit is 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 it is particularly preferred that the hydroxyl group is bonded to the 3-position of the adamantyl group.

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

As the structural unit (a3) contained in the component (A1), 1 type of structural unit may be used, or 2 or more types may be used.
In the component (A1), the proportion of the structural unit (a3) is preferably 5 to 50 mol%, and 5 to 40 mol% with respect to the total of all the structural units constituting the substrate component (A1). More preferably, 5-25 mol% is further 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.

(Structural unit (a4))
The structural unit (a4) is a structural unit containing an acid non-dissociable 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 (A1) 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 a ring that remains in the structural unit as it is without dissociation even when the acid acts when an acid is generated from the component (B) by exposure. Formula group.
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 those having the structures of the following general formulas (a4-1) to (a4-7).

［式中、Ｒ^αは、水素原子、メチル基またはトリフルオロメチル基を示す。］

[Wherein, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group. ]

As the structural unit (a4) contained in the component (A1), 1 type of structural unit may be used, or 2 or more types may be used.
When the structural unit (a4) is contained in the component (A1), the proportion of the structural unit (a4) is preferably 1 to 30 mol% with respect to the total of all the structural units constituting the component (A1). More preferably, it is 10-20 mol%.

  The component (A1) is preferably a copolymer having the structural unit (a1). The copolymer having the structural unit (a1) is preferably a copolymer having either (a2) or (a3), and the structural units (a1), (a2) and (a3) More preferably, it is a copolymer. Moreover, in this invention, it is preferable to have 2 or more types of structural units (a1), and to include 2 or more types of further structural units (a2).

In the present invention, the weight average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, preferably 1000 to 50000, more preferably 1500 to 30000, 2000 ˜20,000 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.
Further, the dispersity (Mw / Mn) of the component (A1) is not particularly limited, and is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and 1.2 to 2 .5 is most preferred. In addition, Mn shows a number average molecular weight.

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 substrate component (A) is preferably 25% by mass or more, more preferably 50% by mass, further preferably 75% by mass, based on the total mass of the substrate component (A). It may be mass%. When the ratio is 25% by mass or more, lithography properties such as MEF, circularity, and roughness reduction are further improved.

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.

[(S) component]
(S1) Component The resist composition of the present invention contains an organic solvent component (S) (hereinafter sometimes referred to as “(S) component”), and the organic solvent component (S) is represented by the following general formula (1). The organic solvent (S1) (henceforth (S1) component) consisting of the compound (s-1) represented by these is contained. The resist composition of the present invention is produced by dissolving each component in the component (S).

［式中、Ｒ^１は、水素原子又は水酸基を表し、Ｒ^２、Ｒ^３は、それぞれ独立に水素原子又は炭素数１〜３のアルキル基を表し、Ｒ^４、Ｒ^５は、それぞれ独立に炭素数１〜３のアルキル基を表す。］

[Wherein, R ¹ represents a hydrogen atom or a hydroxyl group, R ² and R ³ each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ⁴ and R ⁵ each independently represent carbon. The alkyl group of number 1-3 is represented. ]

In formula (1), R ¹ represents a hydrogen atom or a hydroxyl group.
In formula (1), R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Examples of the alkyl group having 1 to ³ carbon atoms in R ² and R ³ include a methyl group, an ethyl group, a propyl group, and an isopropyl group, and a methyl group or an ethyl group is preferable.
In formula (1), R ⁴ and R ⁵ are each independently an alkyl group having 1 to 3 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, and an isopropyl group, and are a methyl group or an ethyl group. Is preferred.

  Specific examples of the compound represented by formula (1) are shown below.

As the component (S1), one type may be used alone, or two or more types may be used in combination.
The component (S) may be composed only of the component (S1), and has an organic solvent (S2) that does not correspond to the component (S1) (hereinafter referred to as “(S2) component”). There may be. The component (S2) will be described later. Especially, it is preferable that (S) component of this invention consists of (S1) component and (S2) component.
When (S) component of this invention contains (S2) component, it is preferable that the ratio of (S1) component in (S) component is 5-80 mass%, and is 10-70 mass%. Is more preferable, and it is especially preferable that it is 15-60 mass%. By containing 5% by mass or more of the component (S1), the affinity with the highly polar functional group in the component (B) is improved, and the applicability of the resist composition to the support is particularly good. it can.

[(S2) component]
(S) component of this invention may contain the organic solvent component (S2) (henceforth (S2) component) which does not correspond to the said (S1) component.
As the component (S2), any component that does not correspond to the component (S1) and that can dissolve each component to be used to form a uniform solution may be used. Any one or two or more of them can be appropriately selected and used.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; many such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol Monohydric alcohols; compounds having an ester bond, such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, monomethyl ether, monoethyl of the polyhydric alcohols or compound having the ester bond Ether alkyl such as ether, monopropyl ether, monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having a propylene glycol monomethyl ether acetate (PGMEA) or propylene glycol monomethyl ether (PGME) among these]; cyclic ethers such as dioxane, methyl lactate, Esters such as ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, Aromatic organics such as dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene A solvent etc. can be mentioned.
(S2) A component may be used independently and may be used as 2 or more types of mixed solvents.
Of these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), cyclohexanone, and EL are preferable, and PGMEA, PGME, and cyclohexanone are more 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. For example, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. Moreover, when mix | blending PGME as a polar solvent, the mass ratio of PGMEA: PGME becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3. In addition, when cyclohexanone is blended as a polar solvent, the mass ratio of PGMEA: cyclohexanone is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2, and still more preferably 3: 7 to 7: 3.
When (S) component contains (S2) component, it is preferable that the ratio of (S2) component in (S) component is 20-95 mass% with respect to the total mass of (S) component, 30 More preferably, it is -90 mass%, and it is especially preferable that it is 40-85 mass%. By setting it within the above range, coating defects of the resist composition are particularly reduced.

The resist composition of the present invention preferably contains an acid generator component (B) that generates an acid upon exposure.
The component (B) is not particularly limited, and those that have been proposed as acid generators for chemically amplified resists can be used.
Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, 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. Among these, it is preferable to use a diazomethane acid generator or an onium salt acid generator.

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

  The diazomethane acid generator is preferably a compound represented by the following general formula (b-8).

［式中、Ｒｂ^１、Ｒｂ^２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アルキル基、置換基を有していてもよい鎖状アルケニル基である。］

[Wherein, Rb ¹ and Rb ² each independently have a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. It is a chain alkenyl group. ]

In the formula (b-8), a cyclic group which may have a substituent of Rb ¹ or Rb ^2, a chain alkyl group which may have a substituent, or a substituent. The chain alkenyl group is a cyclic group which may have a substituent in R ¹⁰¹ in the general formula (b-1) described later, a chain alkyl group which may have a substituent, or a substituent. This is the same as the chain alkenyl group which may have a group.

  Especially, the compound represented by the following (b-8-1) or (b-9-1) is preferable.

  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^１０６〜Ｒ^１０７のいずれか２つは、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’^ｍ＋はｍ価の有機カチオンである。］

[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. Any two of R ^{106 to} R ¹⁰⁷ 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 ′ ^{m +} is an m-valent organic 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.
The aromatic hydrocarbon group for R ¹⁰¹ is the aromatic hydrocarbon ring mentioned for the divalent aromatic hydrocarbon group for Va ¹ in the formula (a1-1), or an aromatic compound containing two or more aromatic rings. Examples include an aryl group in which one hydrogen atom is removed, and a phenyl group and a naphthyl group are preferable.
The cyclic aliphatic hydrocarbon group for R ¹⁰¹ is a group obtained by removing one hydrogen atom from the monocycloalkane or polycycloalkane mentioned as the divalent aliphatic hydrocarbon group for Va ¹ in the formula (a1-1). Is mentioned. Among the polycycloalkanes, in particular, polycycloalkanes having a polycyclic skeleton having a bridged ring system such as an adamantyl group and norbornyl group, and polycycloalkanes having a polycyclic skeleton having a condensed ring system such as a cyclic group having a steroid skeleton Is more preferable. The steroid skeleton in the present specification means a skeleton (st) shown below in which three six-membered rings and one five-membered ring are connected.

In addition, the cyclic hydrocarbon group in R ¹⁰¹ may contain a hetero atom such as a heterocycle, and is specifically represented by the general formulas (a2-r-1) to (a2-r-7). include-containing cyclic group, a heterocyclic group mentioned for other less - lactone-containing cyclic group, -SO ₂ respectively represented by the general formula (a5-r-1) ~ (a5-r-4) to be It is done.

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.

(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 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 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.

As a specific example of the anion part of the component (b-1), for example,
When Y ¹⁰¹ is a single bond, fluorinated alkyl sulfonate anions such as trifluoromethane sulfonate anion and perfluorobutane sulfonate anion can be mentioned; when Y ¹⁰¹ is a divalent linking group containing an oxygen atom, the following formula (an An anion represented by any one of (-1) to (an-3).

［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−６）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”^１０１は、フッ素化アルキレン基であり；Ｌ”^１０１は、−Ｃ（＝Ｏ）−又は−ＳＯ_２−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、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-6), 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. ^{There; V "101} is an fluorinated alkylene ^{group; L" 101} is, -C (= O) - or -SO ₂ - a and; v "0 to 3 are each independently Is an integer, q "are each independently an integer of 1 to 20, n" is 0 or 1. ]

The aliphatic cyclic group which may have a substituent of R ″ ¹⁰¹ , R ″ ¹⁰² and R ″ ¹⁰³ is preferably the 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 . V ″ ¹⁰¹ is preferably a fluorinated alkylene group having 1 to 3 carbon atoms, and particularly preferably —CF ₂ —, —CF ₂ CF ₂ —, —CHFCF ₂ —, —CF (CF ₃ ) CF ₂ —. , —CH (CF ₃ ) CF ₂ —.

-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 the formulas (b-1), (b-2), and (b-3), M ′ ^{m +} is an m-valent organic cation other than the cation in the compound (B11), and in particular, a sulfonium cation or an iodonium cation. The cations represented by the following general formulas (ca-1) to (ca-4) are 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 an arylthio group. And groups represented by the following formulas (ca-r-1) to (ca-r-7).
The aryl group in the arylthio group as a substituent is the same as that described for R ¹⁰¹ , and specifically includes a phenylthio group or a biphenylthio group.

［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. ]

The cyclic group which may have a substituent of R ′ ^201, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent are as described above. In addition to the same groups as those described above for R ^{101 in} formula (b-1), a cyclic group which may have a substituent or a chain alkyl group which may have a substituent may have the above formula ( Examples thereof include the same acid dissociable groups represented by a1-r-2).

^{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 represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and when formed into an alkyl group, they are bonded to each other to form 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). The group represented by the 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 the above formula (b-1).
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 1 or 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 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-1-63), 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-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).

As the component (B), 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 this invention contains (B) component, 0.5-60 mass parts is preferable with respect to 100 mass parts of (A) component, and, as for content of (B) component, 1-50 mass parts Is more preferable, and 1-40 mass parts is further more preferable. By forming the content of the component (B) 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; component (D)>
In addition to the components (A) and (B), the resist composition of the present invention may further contain an acid diffusion controller component (hereinafter also referred to as “component (D)”).
The component (D) acts as a quencher (acid diffusion controller) that traps acid generated by exposure from the component (B) and the like.
The component (D) in the present invention may be a photodegradable base (D1) (hereinafter referred to as “(D1) component”) that is decomposed by exposure and loses acid diffusion controllability. A non-corresponding nitrogen-containing organic compound (D2) (hereinafter referred to as “component (D2)”) may be used.

[(D1) component]
By forming the resist composition containing the component (D1), the contrast between the exposed portion and the non-exposed portion can be improved when forming a resist pattern.
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 following general formula (d1-2) (hereinafter referred to as “(d1-2) component”) and a compound represented by the following general formula (d1-3) (hereinafter referred to as “(d1- One or more compounds selected from the group consisting of “3) component”) are preferred.
The components (d1-1) to (d1-3) are decomposed in the exposed part and lose acid diffusion controllability (basicity), and therefore do not act as a quencher, and act as a quencher in an unexposed part.

［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、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。ただし、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、または２価の連結基である。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. M ^{m +} is each independently an m-valent organic cation. ]

{(D1-1) component}
During Anion formula (d1-1), Rd ¹ is have an optionally substituted cyclic group which may have a substituent chain alkyl group or a substituted group, Or a similar chain alkenyl group to the same as R ¹⁰¹ .
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 substituents that these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom or a fluorinated alkyl group, and the above general formulas (a2-r-1) to (a2-r-7). ) -Containing cyclic groups, ether bonds, ester bonds, or combinations thereof. When an ether bond or an ester bond is included as a substituent, an alkylene group may be interposed, and a linking group represented by each of the following formulas (y-al-1) to (y-al-5) is preferable.
The aromatic hydrocarbon group is more preferably an aryl group such as a phenyl group or a naphthyl group.
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.
As the chain hydrocarbon group, a chain alkyl group is preferable. The chain alkyl group preferably has 1 to 10 carbon atoms, and specifically includes a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a nonyl group. A linear alkyl group such as a group or decyl group; 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group And branched chain alkyl groups such as 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, and the like.

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. The fluorinated alkyl group, which is more preferably ˜4, 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.

In the cation partial formula (d1-1), M ^{m +} is an m-valent organic cation (excluding the cation in the compound (D0) as in M ′ ^{m +} described later).
The organic cation of M ^{m +} is not particularly limited, and examples thereof include those similar to the cations represented by the following general formulas (ca-1) to (ca-4), respectively, and the following formula (ca-1- Cations represented by 1) to (ca-1-63) are 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, A chain alkenyl group which may be the same as R ¹⁰¹ .
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 of (D) 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 that may be the same as R ^101, and is preferably a cyclic group containing a fluorine atom, a chain alkyl group, or a chain alkenyl group. 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 .
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 groups as those described above for R ^101, 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 for Rd ⁴ include the same groups as those described above for R ^101, and one or more hydrogen atoms are removed from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. An alicyclic group 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. These may be the same as those exemplified in the description of the divalent linking group of Ya ²¹ in the formula (a2-1).
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.

As the component (D1), only one of the above components (d1-1) to (d1-3) 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, with respect to 100 parts by mass of the component (A). More preferably, it is part by mass.
When the content of the component (D1) is not less than the preferable lower limit value, particularly good lithography characteristics and a resist pattern shape can be obtained. 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.

  The manufacturing method of said (d1-1)-(d1-3) component is not specifically limited, It can manufacture by a well-known method.

  The content of the component (D1) is preferably 0.5 to 15.0 parts by mass and more preferably 0.5 to 10.0 parts by mass with respect to 100 parts by mass of the component (A). 1.0 to 8.0 parts by mass is even more preferable. When it is at least the lower limit of the above range, particularly good lithography properties and resist pattern shape can be obtained. When the amount is not more than the upper limit of the above range, the sensitivity can be maintained satisfactorily and the throughput is excellent.

((D2) component)
(D) component may contain the nitrogen-containing organic compound component (henceforth (D2) component) which does not correspond to the said (D1) component.
The component (D2) is not particularly limited as long as it functions as an acid diffusion control agent and does not correspond to the component (D1), and any known component may be used. Of these, aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are preferred.
An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
Examples of the aliphatic amine include an amine (alkyl amine or alkyl alcohol amine) or a cyclic amine in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms.
Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di- -Dialkylamines such as n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine , Trialkylamines such as tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, Li isopropanolamine, di -n- octanol amines, alkyl alcohol amines tri -n- octanol amine. Among these, a trialkylamine having 5 to 10 carbon atoms is more preferable, and tri-n-pentylamine or tri-n-octylamine is particularly preferable.

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

  Other aliphatic amines include tris (2-methoxymethoxyethyl) amine, tris {2- (2-methoxyethoxy) ethyl} amine, tris {2- (2-methoxyethoxymethoxy) ethyl} amine, tris {2 -(1-methoxyethoxy) ethyl} amine, tris {2- (1-ethoxyethoxy) ethyl} amine, tris {2- (1-ethoxypropoxy) ethyl} amine, tris [2- {2- (2-hydroxy Ethoxy) ethoxy} ethyl] amine, triethanolamine triacetate and the like, and triethanolamine triacetate is preferable.

As the component (D2), an aromatic amine may be used.
Aromatic amines include aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, diphenylamine, triphenylamine, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxy. And carbonylpyrrolidine.

(D2) A component may be used independently and may be used in combination of 2 or more type.
(D2) A component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component. By setting the content in the above range, the resist pattern shape, the stability over time, and the like are improved.

(D) A component may be used individually by 1 type and may be used in combination of 2 or more type.
When the resist composition of this invention contains (D) component, it is preferable that (D) component is 0.1-15 mass parts with respect to 100 mass parts of (A) component, 0.3- More preferably, it is 12 mass parts, and it is still more preferable that it is 0.5-12 mass parts. When it is at least the lower limit of the above range, lithography properties such as LWR are further improved when a resist composition is used. Further, a better resist pattern shape can be obtained. When the amount is not more than the upper limit of the above range, the sensitivity can be maintained satisfactorily and the throughput is excellent.

<Optional component>
[(E) component]
The resist composition of the present invention comprises, as optional components, an organic carboxylic acid, a phosphorus oxo acid, and derivatives thereof for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, retention stability over time, and the like. At least one compound (E) selected from the group (hereinafter referred to as component (E)) can be contained.
As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.
Examples of phosphorus oxo acids 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 0.01-5.0 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 JP 2010-002870 A, JP 2010-032994 A, JP 2010-277043 A, JP 2011-13569 A, and JP 2011-128226 A. The described fluorine-containing polymer compound 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). As the polymer, a polymer (homopolymer) consisting only of the structural unit (f1) represented by the following formula (f1-1); a structural unit (f1) represented by the following formula (f1-1); A copolymer with the structural unit (a1); a structural unit (f1) represented by the following formula (f1-1); a structural unit derived from acrylic acid or methacrylic acid; and the structural unit (a1) It is preferable that it is a copolymer. Here, as the structural unit (a1) copolymerized with the structural unit (f1) represented by the following formula (f1-1), 1-ethyl-1-cyclooctyl (meth) acrylate or the formula (a1) -2-01) is preferred.

［式中、Ｒは前記同様であり、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 the same 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 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 methyl _{group, -CH 2 -CF 3, -CH 2} -CF 2 -CF 3, -CH (CF 3) 2 _{, -CH} 2 _-CH 2 _-CF 3, and most preferably _{-CH 2 -CH 2 -CF 2 -CF 2} -CF 2 -CF 3.

(F) As for the weight average 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.

The resist composition of the present invention has excellent coating properties and solubility in a resist solvent. The reason why such an effect is obtained is not clear, but is presumed as follows.
In the resist composition of the present invention, the organic solvent component (S) contains a component (S1) composed of a compound represented by the general formula (1).
Compared with the component (S2), the component (S1) has a higher affinity with the polar part of the highly polar acid generator component (B), which is hardly soluble in an organic solvent, and the solubility of the resist composition is improved. As a result, it is thought that it leads to the improvement of lithography characteristics.

≪Resist pattern formation method≫
The resist pattern forming method according to the second aspect of the present invention includes a step of forming a resist film on a support using the resist composition of the present invention, a step of exposing the resist film, and the resist film. And developing to form a resist pattern.
The resist pattern forming method of the present invention can be performed, for example, as follows.
First, the resist composition of 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 60. A resist film is formed by applying for 90 seconds.
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 the exposure is not particularly limited, and ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. Can be done using radiation. The resist composition is highly useful for KrF excimer laser, 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 in 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. Specifically, polar solvents such as ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents can be used.
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.
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. 0% 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.

  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 more concretely, this invention is not limited to a following example.

<Solubility Evaluation: Test Examples 1-4, Reference Examples 1-4>
The solubility evaluation of the various acid generator (B) components in the various organic solvents (S1) and (S2) was visually performed. The results are shown in Table 1. The solid content of the component (B) with respect to the component (S) was 10% by mass, and the mixture was stirred for 5 minutes by underwater ultrasonic waves.
○: Completely dissolved.
○ ': almost melted, melts over time
Δ: almost dissolved, dissolved when the concentration is diluted.
Δ ×: not substantially dissolved.
X: Insoluble or cloudy.

In Table 1, each abbreviation indicates the following.
(B) -1: An acid generator represented by the following chemical formula (B) -1.
(B) -2: An acid generator represented by the following chemical formula (B) -2.
(B) -3: An acid generator represented by the following chemical formula (B) -3.
(B) -4: An acid generator represented by the following chemical formula (B) -4.
(B) -5: An acid generator represented by the following chemical formula (B) -5.
(B) -6: An acid generator represented by the following chemical formula (B) -6.
(B) -7: An acid generator represented by the following chemical formula (B) -7.
(B) -8: An acid generator represented by the following chemical formula (B) -8.
(B) -9: An acid generator represented by the following chemical formula (B) -9.
(S1) -1: N, N, 2-trimethylpropionamide.
(S1) -2: A compound represented by the following chemical formula (S1) -2.
(S1) -3: A compound represented by the following chemical formula (S1) -3.
(S1) -4: A compound represented by the following chemical formula (S1) -4.
(S2) -1: PGMEA.
(S2) -2: PGME.
(S2) -3: Anisole.
(S2) -4: Cyclohexanone.

  From the above results, N, N, 2-trimethylpropionamide (Test Example 1) which is (S1) -1 of (S1) component according to the present invention is an onium salt-based acid generator (B) -1 to ( B) It was confirmed that the solubility in -7 was high.

<Solubility and applicability evaluation: Test Examples 2 to 5, Reference Example 5>
The solubility evaluation of the resin (A) -1 as the component (A) in the component (S) with a different mixing ratio was performed. The results are shown in Table 2. The solid content of (A) -1 with respect to the component (S) was 10% by mass, and was stirred for 5 minutes with ultrasonic waves in water to evaluate the solubility. For Test Examples 2 to 5 and Reference Example 5, the resist composition was applied using a coater and evaluated for coatability.

  Moreover, each symbol (S2) -1, (S1) -1: It is the same as the above, and resin (A) -1 shows the following.

  From the above results, (S1) -1 (N, N, 2-trimethylpropionamide) relating to the component (S1) is excellent in the solubility of the resin regardless of the mixing ratio with the other solvent component (S2). It was confirmed that the property was also good.

<Adjustment of resist composition>
[Examples 1 to 4, Comparative Examples 1 to 6]
A resist composition was prepared by mixing and dissolving the components shown in Table 3.

In Table 3, the numerical value in [] of (A) component-(S) component is a compounding quantity (mass part). Moreover, each abbreviation shows the following, respectively.
(A) -1: The resin component (A) -1.
(B) -2: The acid generator (B) -2.
(B) -6: The acid generator (B) -6.
(S1) -1: the solvent component (S1) -1.
(S2) -1: the solvent component (S2) -1.
(S2) -2: the solvent component (S2) -2.
(S2) -3: the solvent component (S2) -3.
(S2) -4: The solvent component (S2) -4.
(S2) -5: γ-butyrolactone.
(E) -1: salicylic acid.

<Solubility and applicability evaluation: Examples 1 to 4, Comparative Examples 1 to 6>
About Examples 1-4 and Comparative Examples 1-6, it stirred for 5 minutes with the ultrasonic wave in water, and the solubility evaluation was performed. The results are shown in Table 4. Moreover, about Examples 1-4 and Comparative Examples 1-6, the resist composition was apply | coated using the coater and the applicability | paintability was evaluated.

  As shown in the above results, the resist composition of the present invention was excellent in solubility and coatability.

Claims (5)

A resist composition that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid,
Containing a base material component (A) whose solubility in a developer is changed by the action of an acid, and an organic solvent component (S);
The organic solvent component (S) contains an organic solvent (S1) composed of N, N, 2-trimethylpropionamide .   The resist composition according to claim 1, comprising an acid generator component (B) that generates an acid upon exposure.   The resist composition according to claim 1 or 2, wherein the substrate component (A) contains a resin component (A1) whose polarity is increased by the action of an acid.   Content of the said organic solvent (S1) is 5-80 mass% in the said organic solvent component (S), The resist composition of any one of Claims 1-3.   A step of forming a resist film on the support using the resist composition according to any one of claims 1 to 5, 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.