JP6282100B2 - Solvent development negative resist composition, resist pattern forming method - Google Patents

Description

  The present invention relates to a solvent development negative 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. Currently, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has been started. Further, studies have been made on electron beams 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).

JP 2009-025723 A

In the solvent development negative type process, since the exposed portion remains as a pattern, there are problems such as a decrease in the film thickness of the pattern and insufficient etching resistance compared to the alkali development process.
The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a solvent-developed negative resist composition and a resist pattern forming method that are less prone to film slippage and have excellent etching resistance.

A first aspect of the present invention is a solvent-developed negative resist composition that forms a negative resist pattern by development using an organic developer containing an organic solvent, and is soluble in an organic solvent by the action of an acid. There containing decreasing base component (a), said base component (a), configured to include an acid-decomposable group that exhibits increased polarity by the action of the structural unit (a14) and acids having an ether containing cyclic group polymer compounds containing units and (A1), a polymer compound having a structural unit containing an acid-decomposable group that exhibits increased polarity by the action of primary constituent unit containing an alcohol-based water acid groups (a13-1) and acid and (A2), have a, the structural unit (a14) is, solvent developing negatives, characterized in der Rukoto 40 mol% or less relative to the total of all the structural units that constitute the polymer compound (A1) Type resist composition
According to a second aspect of the present invention, there is provided a step of forming a resist film on a support using the solvent development negative resist composition of the first aspect, a step of exposing the resist film, and the resist film. And a solvent developing negative resist pattern forming method including a step of forming a negative resist pattern by developing with an organic developer containing an organic solvent .

  According to the present invention, it is possible to provide a solvent-developable negative resist composition and a resist pattern forming method that are less prone to film slippage and have excellent etching resistance.

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 the α-position carbon atom 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 containing a base component (A) whose solubility in an organic solvent is reduced by the action of an acid, and the base component (A) has an ether-containing cyclic group. The structural unit (a13-1) containing the polymer compound (A1) having the structural unit (a14) and a primary alcohol hydroxyl group, a secondary alcohol hydroxyl group, or a chain-like tertiary alcohol hydroxyl group, or the structural unit And a polymer compound (A2) having a structural unit (a13-2) in which a hydroxyl group in (a13-1) is protected with an acid-decomposable group.
In such a resist composition, when irradiated (exposed) with radiation, the solubility of the component (A) in the organic solvent is reduced by the action of an acid in the exposed portion. Therefore, in the formation of a resist pattern, when selective exposure is performed on a resist film obtained using the resist composition, the solubility of an exposed portion of the resist film in an organic developer containing the organic solvent However, since the solubility of the unexposed area in the organic developer does not change, negative development using the organic developer removes the unexposed area and forms a resist pattern. The

<Base component; component (A)>
In the present invention, the “base material component” means an organic compound having a film forming ability.
As the base material component, an organic compound having a molecular weight of 500 or more is usually used. When the molecular weight is 500 or more, it has a sufficient film forming ability and can easily form a nano-level resist pattern.
“Organic compounds having a molecular weight of 500 or more” 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. In the present specification and claims, “polymer compound” refers to a polymer having a molecular weight of 1000 or more.
In the case of a polymer compound, the “molecular weight” is a polystyrene-equivalent mass average molecular weight measured by GPC (gel permeation chromatography).
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 the present invention, the component (A) includes a polymer compound (A1) having a structural unit (a14) having an ether-containing cyclic group, a primary alcohol hydroxyl group, a secondary alcohol hydroxyl group, or a chain tertiary. Polymer unit (A2) having a structural unit (a13-2) in which a structural unit (a13-1) containing an alcoholic hydroxyl group or a hydroxyl group in the structural unit (a13-1) is protected with an acid-decomposable group And having.

[Polymer Compound (A1)]
(Structural unit (a14))
The resist composition of this invention contains the high molecular compound (A1) which has a structural unit (a14) in which the base material component (A) has an ether-containing cyclic group. In the present invention, the “ether-containing cyclic group” means a cyclic group containing a structure (cyclic ether) in which carbon of a cyclic hydrocarbon is substituted with oxygen. When the cyclic ether is counted as the first ring, the cyclic ether alone is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure.
As the structural unit (a14), any unit can be used without any particular limitation.
Specifically, the ether-containing cyclic group is a group obtained by removing one hydrogen atom from a 3- to 7-membered cyclic ether, for example, one hydrogen atom from a cyclic ether such as oxirane, oxetane, tetrahydrofuran, or tetrahydropyran. Excluded groups are mentioned. In the present invention, the “ether-containing cyclic group” is preferably an oxirane group-containing cyclic group or an oxetane group-containing cyclic group. Examples of the ether-containing polycyclic group include groups in which one hydrogen atom has been removed from a bicycloalkane, tricycloalkane, or tetracycloalkane having a cyclic ether.
The ether-containing cyclic group may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), —COOR ″, —OC (═O) R ″, a hydroxyalkyl group, a cyano group, and the like. Is mentioned.
The alkyl group as the substituent is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a hexyl group. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the group couple | bonded with the oxygen atom (-O-) to the alkyl group quoted as the alkyl group as the said substituent is mentioned.
Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group for the substituent include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.
Examples of the halogenated alkyl group as the substituent include a group in which part or all of the hydrogen atoms of the alkyl group mentioned as the alkyl group as the substituent are substituted with the halogen atom. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.
R ″ in —COOR ″ and —OC (═O) R ″ is a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms.
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. preferable.
When R ″ is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a fluorine atom Alternatively, one or more hydrogen atoms are removed from a polycycloalkane such as a monocycloalkane, bicycloalkane, tricycloalkane, or tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group. More specifically, one or more hydrogen atoms are removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane. Group.
The hydroxyalkyl group as the substituent is preferably one having 1 to 6 carbon atoms. Specifically, at least one of the hydrogen atoms of the alkyl group mentioned as the alkyl group as the substituent is substituted with a hydroxyl group. Group.
Specific examples include groups represented by any of the following formulas (arx4-r-1) to (arx4-r-5).

［式中、Ｒａ’^ｘ４１、Ｒａ’^ｘ４２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；
Ｒａ’^ｘ４２は互いに結合して橋かけ環構造を形成しても良い。ｑ’は０または１である。
ｓ’は０または１である。ｎ_ａｘ４１は０又は１である。＊は結合手である。］

[ ^Wherein , Ra ′ ^x41 and Ra ′ ^x42 each independently represent 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; R ″ is a hydrogen atom or an alkyl group;
Ra ′ ^x42 may be bonded to each other to form a bridged ring structure. q ′ is 0 or 1.
s ′ is 0 or 1. n _ax41 is 0 or 1. * Is a bond. ]

Ra ′ ^x41 and Ra ′ ^x42 each independently represent 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. is there.
The alkyl group in Ra ^'x41, Ra' ^x42, 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 Ra ^'x41, Ra' ^x42, preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the group couple | bonded with the oxygen atom (-O-) to the alkyl group quoted as the alkyl group as the said substituent is mentioned.
Examples of the halogen atom in Ra ′ ^x41 and Ra ′ ^x42 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 in Ra ′ ^x41 and Ra ′ ^x42 include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.
Examples of the halogenated alkyl group in Ra ′ ^x41 and Ra ′ ^x42 include groups in which some or all of the hydrogen atoms of the alkyl group mentioned as the alkyl group as the substituent are substituted with the halogen atom. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.
R ′ in —COOR ″ and —OC (═O) R ″ in Ra ′ ^x41 and Ra ′ ^x42 is a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms. is there.
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. preferable.
When R ″ is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a fluorine atom Alternatively, one or more hydrogen atoms are removed from a polycycloalkane such as a monocycloalkane, bicycloalkane, tricycloalkane, or tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group. More specifically, one or more hydrogen atoms are removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane. Group.
As the hydroxyalkyl group in Ra ′ ^x41 and Ra ′ ^x42 , those having 1 to 6 carbon atoms are preferable. Specifically, at least one of the hydrogen atoms of the alkyl group mentioned as the alkyl group as the substituent is And groups substituted with a hydroxyl group.
q ′ is 0 or 1. s ′ is 0 or 1. n _ax41 is 0 or 1.

  Specific examples of groups represented by any of formulas (arx4-r-1) to (arx4-r-5) are shown below. In the following formula, * is a bond.

  In the present invention, the structural unit (a14) is preferably a structural unit represented by the following formula (a14-1).

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり、Ｙａ^ｘ４１は単結合または２価の連結基であり、Ｒａ^ｘ４１は前記一般式（ａｘ４−ｒ−１）〜（ａｘ４−ｒ−５）のいずれかで表される基である。］

In the formula, R represents a hydrogen atom, a halogenated alkyl group of 1 to 5 alkyl group or a C1-5 ^{carbon, Ya x41} is a single bond or a divalent linking ^{group, Ra x41} is the general It is a group represented by any one of formulas (ax4-r-1) to (ax4-r-5). ]

Formula (a14-1) and R are a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group.
Examples of the alkyl group and halogenated alkyl group for R include the same alkyl groups and halogenated alkyl groups as mentioned for the α-position substituent in the description of the α-substituted acrylate ester. 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 most preferably a hydrogen atom or a methyl group.
The ^description of the single bond or divalent linking group of Ya ^x41 is the same as the description of Ya ^{21 in} the general formula (a2-1) described later.
Ra ^x41 is a group represented by any one of the general formulas (ax4-r-1) to (ax4-r-5).

  Specific examples of the structural unit represented by the general formula (a14-1) are shown below.

［式中、Ｒ、Ｒａ’^ｘ４１、Ｒａ’^ｘ４２、Ｙａ^ｘ４１、ｑ’、ｓ’、ｎ_ａｘ４１はそれぞれ前記同様である。］

[ ^Wherein , R, Ra ′ ^x41 , Ra ′ ^x42 , Ya ^x41 , q ′, s ′, and n _ax41 are the same as described above. ]

Specific examples of the structural unit represented by any one of the general formulas (a14-1-1) to (a14-1-5) 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 (a14) in the component (A1) is preferably 40 mol% or less, more preferably 30 mol% or less, and more preferably 5 to 25 mol% with respect to all the structural units constituting the component (A1). More preferably. It is thought that a crosslinking reaction advances efficiently by setting it as the said range.

  In the present invention, the polymer compound (A1) preferably has a structural unit (described below as “structural unit (a1)”) containing an acid-decomposable group whose polarity is increased by the 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 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 preferably has 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 is exemplified.
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 ~Ra' ⁹ is 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.
Moreover, it is preferable that the total carbon number of each alkyl group is 3-7, it is more preferable that it is 3-5, and it is most preferable that it is 3-4.

  The structural unit (a1) is a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and an acid whose polarity is increased by the action of an acid. 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, and two or more of the structural units may be used in combination.

［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), in the general formula (a1-1), the hydrocarbon group of Va ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon. It may be a 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.
Specific examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group having a ring in the structure, and the like.
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 is preferably one having 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 (A1) is preferably 20 to 80 mol%, more preferably 20 to 75 mol%, more preferably 25 to 70 mol%, based on all structural units constituting the component (A1). 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 polymer compound (A1) may further contain a structural unit (a2), a structural unit (a3), a structural unit (a5), or a structural unit (a9).

(Structural unit (a2))
The structural unit (a2) is a structural unit containing a lactone-containing cyclic group.
The lactone-containing cyclic group of the structural unit (a2) is effective in 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 lactone-containing cyclic group in the structure, the structural unit also corresponds to the structural unit (a2). However, such a structural unit is included in the structural unit (a1). Applicable and not applicable 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−、−ＣＯＮ（Ｒ’）−、−ＯＣＯ−、−ＣＯＮＨＣＯ−又は−ＣＯＮＨＣＳ−であり、Ｒ’は水素原子またはメチル基を示す。ただしＬａ^２１が−Ｏ−の場合、Ｙａ^２１は−ＣＯ−にはならない。Ｒａ^２１はラクトン含有環式基である。］

[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-, -CON (R ')-, -OCO-, -CONHCO- or -CONHCS-, wherein 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. ]

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.

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. An alkyl group, an alkoxy group or a halogen atom in Ra ′ ²¹ . , A halogenated alkyl group, —COOR ″, —OC (═O) R ″, and a hydroxyalkyl group, each having a divalent cyclic group in V ₀ ^a1 in the general formula (a0) Examples of the preferred substituent include the same alkyl groups, alkoxy groups, halogenated alkyl groups, —COOR ″, —OC (═O) R ″, and hydroxyalkyl groups.

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

  Among these, groups represented by the general formulas (a2-r-1) and (a2-r-2) are preferable, and the chemical formulas (r-lc-1-1) to (r-lc-1-7) are preferable. ) Or any one of (r-lc-2-1) to (r-lc-2-13) 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, it is possible to balance with other structural units, such as various kinds of DOF, CDU, etc. The lithography characteristics and pattern shape of the film are improved.

(Structural unit (a3))
The structural unit (a3) is a structural unit 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. In addition, it is considered that the solubility of the component (A) in the developer can be easily adjusted, and the sensitivity, resist pattern shape, and the like can be improved.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which part of hydrogen atoms of an alkyl group is substituted with a fluorine atom, and 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.
In terms of improving the sensitivity of the resist composition, it is preferable to have a structural unit represented by the formula (a3-1). On the other hand, it is preferable to have a structural unit represented by Formula (a3-2) or a structural unit represented by Formula (a3-3) in terms of improving the resist pattern shape.

［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 5 or 6 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%, more preferably 5 to 40 mol%, based on the total of all structural units constituting the resin component (A1). Preferably, 5 to 25 mol% is more preferable.
By setting the proportion of the structural unit (a3) to the lower limit value or more, the effect of including the structural unit (a3) can be sufficiently obtained, and by setting the proportion of the structural unit (a3) to the upper limit value or less, balance with other structural units can be obtained. It becomes easy.

(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 without being dissociated 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%.

(Structural unit (a5))
The structural unit (a5) is a structural unit represented by the general formula (a2-1), and Ra ²¹ in the general formula (a2-1) is a carbonate-containing cyclic group or —SO ₂ —. It is a structural unit that is a cyclic group.

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 in Ra ²¹ 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, —SO ₂ -containing cyclic groups are preferable, groups represented by the general formula (a5-r-1) are preferable, and the chemical formulas (r-sl-1-1) and (r-sl—) are preferable. The group of 1-18) is more preferable.

The structural unit (a5) contained in the component (A1) may be one type or two or more types.
When the component (A1) has the structural unit (a5), the proportion of the structural unit (a5) 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%. The effect by containing the structural unit (a5) can be sufficiently obtained by setting it to the lower limit value or more, and it can be balanced with other structural units by setting it to the upper limit value or less, and various kinds of DOF, CDU, etc. The lithography characteristics and pattern shape of the film are improved.

(Structural unit (a9))
In the present invention, the polymer compound (A1) is a structural unit represented by any one of the following general formulas (a9-1) to (a9-3).

［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^１は単結合または２価の連結基であり、Ｌａ^１、Ｌａ^２はそれぞれ独立に、−ＳＯ_２−又は−Ｃ（＝Ｏ）−であり（ただし、Ｌａ^２が−ＳＯ_２−のときＹａ^１は鎖状の２価の連結基である）。ｎ_１は０または１である。Ｒａ^１は、置換基を有していてもよい環式基、置換基を有していてもよい鎖状のアルキル基、又は置換基を有していてもよい鎖状のアルケニル基である。］

[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 ¹ is a single bond or a divalent linking group, La ¹ , La ² Are each independently —SO ₂ — or —C (═O) — (provided that when La ² is —SO ₂ —, Ya ¹ is a chain-like divalent linking group). n ₁ is 0 or 1. Ra ¹ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. ]

In general formulas (a9-1) to (a9-3), the description of R is the same as described above.
In the general formulas (a9-1) to (a9-3), Ya ¹ is a single bond or a divalent linking group, and is the same as described for Ya ^{21 in} the general formula (a2-1).
As the linking group of Ya ^{1 in} the general formula (a9-2), when La ² is —C (═O) —, —C (═O) O—Va ⁰¹ —, —C (═O) NH -Va ⁰¹ -is preferable.
Va ⁰¹ is an alkylene group or a cyclic aliphatic hydrocarbon group, and is preferably a (poly) cycloalkylene group.
When La ² is —SO ₂ —, a single bond, or —C (═O) O—Va ⁰¹ — (Va ⁰¹ is an alkylene group) is preferable. Further, when La ² is —SO ₂ —, it is preferable that Ya ¹ is a single bond and La ¹ is —C (═O) — (n ₁ is 1).
Ra ¹ is a cyclic group that may have a substituent, a chain alkyl group that may have a substituent, or a chain alkenyl group that may have a substituent, n ₁ and n ₂ are 0 or 1, and at least one is 1.

Examples of the cyclic group that may have a substituent, the chain-like alkyl group that may have a substituent, or the chain-like alkenyl group that may have a substituent in Ra ¹ include: In general formulas (b-1) to (b-3) to be described later, a cyclic group which may have a substituent in R ¹⁰¹ and R ^{104 to} R ¹⁰⁸ , and a chain which may have a substituent. And the same as the chain-like alkenyl group which may have a substituent.

In the present invention, examples of the cyclic group which may have a substituent in Ra ¹ include a monovalent alicyclic hydrocarbon group, an aryl group, an aralkyl group, and the like.
The monovalent alicyclic hydrocarbon group in Ra ¹ preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms, and may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon group, a group in which one or more hydrogen atoms have been removed from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 8 carbon atoms, and more preferably has 3 to 6 carbon atoms. Specific examples include cyclopropane, cyclobutane, cyclopentane, and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 20 carbon atoms, preferably 7 to 7 carbon atoms. 12 is more preferable. Specific examples include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
The aryl group in Ra ¹ preferably has 6 to 18 carbon atoms, more preferably has 6 to 10 carbon atoms, and specifically, a phenyl group is particularly preferable.
Aralkyl group in Ra ¹ are those in which the "aryl group for Ra ^1" alkylene group and the above C1-8 was bonded are preferred examples. More preferred is an aralkyl group in which an alkylene group having 1 to 6 carbon atoms and the above-mentioned “aryl group in Ra ¹ ” are bonded, and an aralkyl group in which an alkylene group having 1 to 4 carbon atoms and the above “aryl group in Ra ¹ ” are bonded. Is particularly preferred.
The hydrocarbon group in Ra ¹ is preferably such that part or all of the hydrogen atoms of the hydrocarbon group are substituted with fluorine atoms, and 30 to 100% of the hydrogen atoms of the hydrocarbon group are substituted with fluorine atoms. More preferably. Especially, it is especially preferable that it is the perfluoroalkyl group by which all the hydrogen atoms of the alkyl group mentioned above were substituted by the fluorine atom.

The hydrocarbon group in Ra ¹ may have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a halogen atom, an oxo group (═O), a hydroxyl group (—OH), an amino group (—NH ₂ ), —SO ₂ —NH _{2 and the} like. Moreover, a part of carbon atoms constituting the hydrocarbon group may be substituted with a substituent containing a hetero atom. Examples of the substituent containing a hetero atom include -O-, -NH-, -N =, -C (= O) -O-, -S-, -S (= O) _2- , -S (= O ) ₂ -O-.
In Ra ¹ , as the hydrocarbon group having a substituent, a lactone-containing cyclic group represented by each of the above general formulas (a2-r-1) to (a2-r-7), a general formula (a5-r) -SO ₂ -containing cyclic group represented by each of -1) to (a5-r-4); a substituted aryl group, a substituted (poly) cycloalkyl group, and a monovalent heterocyclic group represented by the following chemical formula Group and the like. In the following formula, * is a bond.

In the present invention, the chain alkyl group which may have a substituent in Ra ¹ preferably has 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, It may be linear or branched. Specifically, a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group and the like are preferable.
Examples of the fluorinated alkyl group for Ra ¹ include groups in which part or all of the above alkyl groups have been substituted with fluorine atoms.

Specific examples of the structural unit (a9) are shown below. R in the formula is the same as described above. R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

As the structural unit (a9) contained in the component (A1), 1 type of structural unit may be used, or 2 or more types may be used.
The proportion of the structural unit (a9) in the component (A1) is preferably 1 to 50 mol%, more preferably 5 to 45 mol%, based on the total of all structural units constituting the component (A1). 10 to 40 mol% is more preferable.
By setting the proportion of the structural unit (a9) to be equal to or higher than the lower limit value, lithography properties such as sensitivity and LWR are improved. Moreover, by making it into the upper limit value or less, it becomes easy to balance with other structural units, and a resist pattern having a good shape can be easily obtained.

  In the present invention, the component (A1) is preferably a polymer compound having the structural unit (a14) and the structural unit (a1), and further includes the structural unit (a14), the structural units (a2), and (a5). A polymer compound having one or more structural units selected from is more preferable. Examples of such a polymer compound include a polymer compound composed of the structural unit (a14) and a repeating structure of the structural units (a1) and (a2), the structural unit (a14), the structural units (a1), (a2) and (a5). ) Polymer compound having a repeating structure; polymer compound having a repeating unit of structural unit (a14) and structural units (a1), (a2), (a3) and (a5).

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography (GPC)) is not particularly limited, preferably 1000 to 50000, more preferably 1500 to 30000, 2000 to 2000 20000 is most preferred.
If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
The dispersity (Mw / Mn) is not particularly limited, but is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5. In addition, Mn shows a number average molecular weight.

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

As the component (A1), one type may be used alone, or two or more types may be used in combination.
The proportion of the component (A1) in the component (A) is preferably 5 to 75% by mass, more preferably 10 to 70% by mass, and still more preferably 20 to 60% by mass with respect to the total mass of the component (A). . By setting it as the said range, it is thought that it can carry out a crosslinking reaction efficiently with the high molecular compound (A2) mentioned later, reduces the film | membrane thinness of a pattern, and improves a lithography characteristic.

[Polymer Compound (A2)]
In the present invention, the polymer compound (A2) is a structural unit (a13-1) containing a primary alcohol hydroxyl group, a secondary alcohol hydroxyl group, or a chain tertiary alcohol hydroxyl group, or the structural unit (a13-). 1) It has a structural unit (a13-2) in which the hydroxyl group is protected with an acid-decomposable group.
(Structural unit (a13-1))
The structural unit (a13-1) is a structural unit containing a primary alcohol hydroxyl group, a secondary alcohol hydroxyl group, or a chain-like tertiary alcohol hydroxyl group.
Examples of the structural unit (a13-1) include structural units represented by any of the following general formulas (a13-1-1) to (a13-1-3).

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり、Ｙａ^１３は単結合又は２価の連結基であり、Ｙａ^１３’は炭素数１〜５のアルキル基であり、Ｘａ^１３は環状の炭化水素基であり、Ｒａ^１３、Ｒａ^１３’はそれぞれ炭素数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。Ｒａ^１３、Ｒａ^１３’は同一であっても異なっていてもよい。］

[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 ¹³ is a single bond or a divalent linking group, and Ya ^{13 ′} is carbon An alkyl group having 1 to 5 carbon atoms, Xa ¹³ is a cyclic hydrocarbon group, and Ra ¹³ and Ra ¹³ ′ are each an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms. . Ra ¹³ and Ra ¹³ ′ may be the same or different. ]

In the formula, the description of R is the same as described above.
The description of the single bond or divalent linking group of Ya ¹³ is the same as the description of Ya ^{21 in} the general formula (a2-1).
Ya ^{13 ′} is an alkyl group having 1 to 5 carbon atoms, and is preferably an unsubstituted alkyl group. The unsubstituted alkyl group may be linear, branched or cyclic, but is preferably a linear alkyl group.
Specific examples include a methylene group, an ethylene group, an n-propylene group, and an n-butylene group, and a methylene group or an ethylene group is preferable.
Xa ¹³ is a cyclic hydrocarbon group, and examples thereof include a monocyclic or polycyclic alicyclic hydrocarbon group. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a monocycloalkane. The monocycloalkane preferably has 3 to 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 preferably has 7 to 12 carbon atoms, specifically adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.
Ra ¹³ and Ra ¹³ ′ are each an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms. Ra ¹³ and Ra ¹³ ′ may be the same or different. Ra ¹³ and Ra ¹³ ′ are the same as those described for R.

  Specific examples of the structural unit (a13-1) are shown below. In the following formula, R is the same as described above.

As the structural unit (a13-1) contained in the component (A2), 1 type of structural unit may be used, or 2 or more types may be used.
The proportion of the structural unit (a13-1) in the component (A2) is preferably 1 to 50 mol%, and preferably 5 to 45 mol%, based on the total of all structural units constituting the component (A2). More preferably, 10-40 mol% is further more preferable.
By setting the proportion of the structural unit (a13-1) in the above range, it is considered that the film thickness of the pattern is reduced and the lithography characteristics are improved.

(Structural unit (a13-2))
The structural unit (a13-2) is a structural unit in which the hydroxyl group in the structural unit (a13-1) is protected with an acid-decomposable group.
More specifically, a group in which the hydroxyl group of the structural unit represented by any one of the general formulas (a13-1-1) to (a13-1-3) is protected with an acid-decomposable group, bicyclo [2 2.1] a group in which the hydroxyl group of heptane-2-methanol is protected with an acid-decomposable group, a group in which the hydroxyl group of acrylate ester is protected with an acid-decomposable group, or the following general formula (a13-2-1) The structural unit which has group represented by these is mentioned.

［式中、ｎはそれぞれ独立に０〜５の整数であり、Ｒａ^１３３、Ｒａ^１３２は炭素数１〜５のアルキル基である。］

Wherein, n is each independently an integer of ^{0~5, Ra 133,} Ra ¹³² is an alkyl group having 1 to 5 carbon atoms. ]

In formula (a13-2-1), examples of the alkyl group having 1 to 5 carbon atoms of Ra ¹³³ and Ra ¹³² include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, and the like. Or an ethyl group is preferable. n is an integer of 0-5 each independently.
As the acid-decomposable group for protecting a hydroxyl group in the structural unit (a13-2), an acid-dissociable group represented by the general formula (a1-r-1) (“acetal-type acid-dissociable group”) is preferable. .

  Specific examples of the structural unit (a13-2) are shown below. In the following formula, R is the same as described above.

As the structural unit (a13-1) or (a13-2) contained in the component (A2), 1 type of structural unit may be used, or 2 or more types may be used.
The proportion of the structural unit (a13-1) in the component (A2) is preferably 50 mol% or less, more preferably 45 mol% or less, more preferably 10 to 40 mol%, based on all structural units constituting the component (A2). More preferably.
The proportion of the structural unit (a13-2) in the component (A2) is preferably 65 mol% or less, more preferably 60 mol% or less, more preferably 20 to 50 mol%, based on all structural units constituting the component (A2). More preferably.
By setting the proportion of the structural unit (a13-1) or (a13-2) within the above range, it is considered that the film thickness of the pattern is reduced and the lithography properties are improved.

In the present invention, the polymer compound (A2) preferably has the structural unit (a1).
The proportion of the structural unit (a1) in the component (A2) is preferably 20 to 80 mol%, more preferably 20 to 75 mol%, more preferably 25 to 70 mol%, based on all structural units constituting the component (A2). 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 component (A2) is a polymer compound having the structural unit (a13-1) or (a13-2) and one or more structural units selected from the structural units (a2) and (a1). It is preferable. Examples of such a polymer compound include a polymer compound composed of the structural unit (a13-1) or (a13-2) and a repeating structure of the structural units (a1) and (a2), the structural unit (a13-1) or (a13). -2) and a repeating compound of the structural units (a1), (a2) and (a5); a repeating structure of the structural unit (a14) and the structural units (a1), (a2) and (a5) And the like.

(A2) A component may be used individually by 1 type and may use 2 or more types together.
The proportion of the component (A2) in the component (A) is preferably 5 to 90% by mass, more preferably 10 to 80% by mass, and still more preferably 20 to 60% by mass with respect to the total mass of the component (A). . By setting it within the above range, it is considered that the film slippage of the pattern is reduced and the lithography characteristics are improved.

In the present invention, since the substrate component (A) has the polymer compound (A1) and the polymer compound (A2), the film development of the pattern is difficult to occur, and the solvent development negative type having excellent etching resistance. It can be set as a resist composition. The reason is guessed as follows.
In the present invention, by using the polymer compound (A1) and the polymer compound (A2) in a mixed state, a crosslinking reaction occurs between the polymer compound (A1) and the polymer compound (A2) in the exposed portion. Therefore, it can be considered that it can contribute to an increase in the molecular weight of the exposed portion compared to the case where one kind of polymer compound is used.
Conventionally, a structural unit containing a hydroxyl group has not been generally adopted in a solvent-developable negative resist composition, but as a result of studies by the present inventors, a polymer compound having a structural unit containing a hydroxyl group. And a polymer compound having a structural unit having a crosslinkable ether-containing cyclic group were found to be hardly soluble in a developer due to a crosslinking reaction in an exposed area.
Furthermore, since the solvent-developed negative resist composition of the present invention can be made three-dimensional by a crosslinking reaction, it is presumed that it can be excellent in etching resistance.

<Acid generator component; (B) component>
The solvent-developed negative resist composition of the present invention preferably contains an acid generator component (B) (hereinafter referred to as (B) component) 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. Of these, it is preferable to use an onium salt acid generator.

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

［式中、Ｒ^１０１、Ｒ^１０４〜Ｒ^１０８はそれぞれ独立に置換基を有していてもよい環式基、置換基を有していてもよい鎖状のアルキル基、または置換基を有していてもよい鎖状のアルケニル基である。Ｒ^１０４、Ｒ^１０５は、相互に結合して環を形成していてもよい。Ｒ^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。］

[In the formula, each of R ¹⁰¹ and R ^{104 to} R ¹⁰⁸ 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, henocosyl 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 a group exemplified as the cyclic aliphatic hydrocarbon group in R ¹⁰¹ . Examples of the substituent include the same substituents that may be substituted for the cyclic aliphatic hydrocarbon group in R ¹⁰¹ .

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

R have a substituent in "which may chain substituted at ¹⁰¹ alkyl group, wherein preferably a group exemplified as chain alkyl group in R ¹⁰¹ .R" ¹⁰³ 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. Further, 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 of the formula (b1-1), and in particular, a sulfonium cation Or it is preferable that it is an iodonium cation, and the cation respectively represented by the following general formula (ca-1)-(ca-4) is especially 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 represent 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 solvent-developed negative resist composition of the present invention contains the component (B), the content of the component (B) is preferably 0.5 to 60 parts by mass with respect to 100 parts by mass of the component (A). -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.

<Basic compound component; (D) component>
In addition to the component (A) or the components (A) and (B), the resist composition of the present invention further includes an acid diffusion controller component (hereinafter also referred to as “component (D)”). You may contain.
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 decomposes 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 portion and lose acid diffusion controllability (basicity), and thus do not act as a quencher, and act as a quencher in an unexposed portion.

［式中、Ｒｄ^１〜Ｒｄ^４は置換基を有していてもよい環式基、置換基を有していてもよい鎖状のアルキル基、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 hydrocarbon group is preferred. The substituent that these groups may have is preferably a hydroxyl group, a fluorine atom or a fluorinated alkyl group.
The aromatic hydrocarbon group is more preferably 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.

-Cation part In formula (d1-1), Mm ⁺ is an m-valent organic cation.
The organic cation of M ^{m +} is not particularly limited, and examples thereof include those similar to the cations represented by the general formulas (ca-1) to (ca-4), respectively, and the 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 in Rd ⁴ include those similar to R ¹⁰¹ described above, 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) component and (d1-2) component is not specifically limited, It can manufacture by a well-known method.

  The content of the component (D1) is preferably 0.5 to 10.0 parts by mass and more preferably 0.5 to 8.0 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 it 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.

[(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.

[(E) component]
In the solvent-developed negative resist composition of the present invention, sensitivity deterioration is prevented (especially when an acid diffusion control agent component other than the above (D0) component is used), and the resist pattern shape and stability with time are improved. For this purpose, as an optional component, at least one compound (E) selected from the group consisting of organic carboxylic acids and phosphorus oxo acids and derivatives thereof (hereinafter referred to as component (E)) is included. Can do.
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.

[(S) component]
The solvent-developed negative resist composition of the present invention can be produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as (S) component).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution. Conventionally, any one of known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl-n-pentyl ketone (2-heptanone), methyl isopentyl ketone; ethylene glycol, diethylene glycol, propylene glycol, di- Polyhydric alcohols such as propylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, the polyhydric alcohols or compounds having the ester bond Monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having an ether bond such as propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) among these; cyclic ethers such as dioxane, , Methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, etc .; anisole, ethyl benzyl ether, cresyl methyl Ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene And aromatic organic solvents such as dimethyl sulfoxide (DMSO).
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Of these, PGMEA, PGME, γ-butyrolactone, and EL are preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is also preferable. The blending ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be within the range.
More specifically, when EL or cyclohexanone is blended as the polar solvent, the mass ratio of PGMEA: EL or cyclohexanone is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. . Moreover, when mix | blending PGME as a polar solvent, the mass ratio of PGMEA: PGME becomes like this. Preferably it is 1: 9-9: 1, More preferably, it is 2: 8-8: 2, More preferably, it is 3: 7-7: 3.
In addition, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95: 5.
(S) The usage-amount of a component is not specifically limited, It is a density | concentration which can be apply | coated to a board | substrate etc., and is suitably set according to a coating film thickness. Generally, it is used so that the solid content concentration of the resist composition is in the range of 1 to 20% by mass, preferably 2 to 15% by mass.

  The solvent-developed negative resist composition of the present invention further contains miscible additives as desired, for example, additional resins for improving the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, An antihalation agent, a dye, and the like can be appropriately added and contained.

  The solvent-developed negative resist composition of the present invention is excellent in residual film properties after development. The reason is not clear, but it is presumed as follows. The photodegradable quencher (D0) contained in the resist composition of the present invention generates an acid having a pKa of 2.0 or more upon exposure, and thus has a high quenching effect. It is presumed that the anion has an acid dissolution inhibiting effect and is excellent in the remaining film property.

≪Resist pattern formation method≫
More specifically, the resist pattern forming method of the present invention can be performed, for example, as follows.
First, the solvent-developed negative resist composition of the present invention is applied onto a support with a spinner or the like, and baking (post-apply bake (PAB)) treatment is performed, for example, at a temperature of 80 to 150 ° C. for 40 to 120 seconds. Preferably, it is applied for 60 to 90 seconds to form a resist film. Next, the resist film is exposed 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, or a mask pattern. After performing selective exposure by drawing or the like by direct irradiation with 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 Apply for ~ 90 seconds. The resist film is developed with an organic developer, and then preferably rinsed with a rinse containing an organic solvent and dried.
After the development process or the rinsing process, a process of removing the developer or the rinsing liquid adhering to the pattern with a supercritical fluid may be performed.
In some cases, a baking (post-baking) treatment may be performed after the development treatment, the rinsing treatment or the supercritical fluid treatment in order to remove the remaining organic solvent.

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 of forming a two-layer structure of an upper resist film and a lower organic film (two-layer resist method), and one or more intermediate layers between the upper resist film and the lower 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, and is particularly useful for ArF excimer laser, EB or EUV.

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

  The organic solvent contained in the organic solvent used for development is not particularly limited as long as it can dissolve the base component (A) (base component (A) before exposure), and is appropriately selected from known organic solvents. it can. Specific examples include ketone solvents, ester solvents, nitrile solvents, and the like. As the ester solvent, butyl acetate is preferred. As the ketone solvent, methyl amyl ketone (2-heptanone) is preferable.

  The ketone solvent is an organic solvent containing C—C (═O) —C in the structure. The ester solvent is an organic solvent containing C—C (═O) —O—C in the structure. The alcohol solvent is an organic solvent containing an alcoholic hydroxyl group in the structure, and “alcoholic hydroxyl group” means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. The amide solvent is an organic solvent containing an amide group in the structure. The ether solvent is an organic solvent containing C—O—C in the structure. Among organic solvents, there are organic solvents that contain multiple types of functional groups that characterize each of the above solvents in the structure, but in that case, any of the solvent types that contain the functional groups of the organic solvent is applicable. Shall. For example, diethylene glycol monomethyl ether corresponds to both alcohol solvents and ether solvents in the above classification. The hydrocarbon solvent is a hydrocarbon solvent made of hydrocarbon and having no substituent (a group or atom other than a hydrogen atom and a hydrocarbon group).

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

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

Examples of the nitrile solvent include acetonitrile, propionitryl, valeronitrile, butyronitryl and the like.
In the organic developer, a known surfactant can be blended as an additive as required.

  Development processing using an organic developer can be carried out by a known development method, for example, a method in which a support is immersed in the developer for a certain period of time (dip method), or a surface tension of the developer on the surface of the support. A method that swells and rests for a certain period of time (paddle method), a method of spraying developer on the surface of the support (spray method), and a developer coating nozzle that scans at a constant speed on a support that rotates at a constant speed. For example, there is a method of continuously applying the developer (dynamic dispensing method).

After the developing treatment, before the drying, a rinsing treatment can be performed using a rinsing liquid containing an organic solvent. By rinsing, a good pattern can be formed.
As the organic solvent used in the rinsing liquid, for example, organic solvents that are difficult to dissolve the resist pattern among the organic solvents mentioned as the organic solvent used in the organic developer can be used. Usually, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents is used. Among these, at least one selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents and amide solvents is preferable, and at least one selected from alcohol solvents and ester solvents is preferable. More preferred are alcohol solvents.
The alcohol solvent used for the rinse liquid is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched or cyclic. Specific examples include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and benzyl alcohol. It is done. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferable, and 1-hexanol or 2-hexanol is more preferable.
Any one of these organic solvents may be used alone, or two or more thereof may be mixed and used. Moreover, you may mix and use the organic solvent and water other than the above. However, in consideration of development characteristics, the blending amount of water in the rinsing liquid is preferably 30% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, more preferably 3% by mass or less based on the total amount of the rinsing liquid. Is particularly preferred.
A known additive can be blended in the organic developer as required. Examples of the additive include a surfactant. Examples of the surfactant include those described above, and nonionic surfactants are preferable, and fluorine-based surfactants or silicon-based surfactants are more preferable.
When the surfactant is blended, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and 0.01 to 0.5% by mass with respect to the total amount of the rinse liquid. % Is more preferable.
The rinsing treatment (washing treatment) using the rinsing liquid can be carried out by a known rinsing method. For example, the rinsing liquid is continuously applied onto a support rotating at a constant speed (rotary coating method). A method of immersing the support in a rinsing solution for a certain time (dip method), a method of spraying a rinsing solution on the surface of the support (spray method), and the like.

≪Etching process≫
The etching step is a step of etching the substrate using the pattern formed by the resist pattern forming method as a mask. In the present invention, the substrate may be etched using a pattern formed by the resist pattern forming method as a mask.
Although the etching method is not particularly limited, dry etching is preferable, and it is efficient to use oxygen (O ₂ ) plasma etching or etching using CF ₄ gas, CHF ₃ gas, Ar / CF ₄ gas. From the viewpoint, oxygen plasma etching is particularly preferable.
The dry etching conditions are not particularly limited, and can be appropriately determined according to the material of the pattern formed by the phase separation structure and the height from the substrate surface. For example, when oxygen plasma treatment is used, the pressure during the oxygen plasma treatment is preferably 1.33 to 66.5 Pa (10 to 50 mtorr), more preferably 13.3 to 26.6 Pa (100 to 200 mtorr). Moreover, 5-500W is preferable and the plasma output at the time of an oxygen plasma process has more preferable 5-50W. Further, the treatment time during the oxygen plasma treatment is preferably 1 to 100 seconds, and more preferably 2 to 60 seconds. The temperature of the oxygen plasma treatment is preferably -30 to 300 ° C, more preferably 0 to 100 ° C, and most preferably room temperature (5 to 40 ° C). The plasma apparatus used for the oxygen plasma treatment is not particularly limited, and for example, a PE-2000 plasma etcher (Plasma etcher) manufactured by South Bay Corporation (South Bay Technology, USA) can be used.
Since the solvent-developable negative resist composition of the present invention has low solubility in a developer due to crosslinking, film slippage can be reduced. For this reason, it is excellent in the etching resistance in an etching process.

  EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited to a following example.

[Example of polymer synthesis]
In a separable flask connected with a thermometer, a reflux tube, and a nitrogen introduction tube, 20.00 g (117.5 mmol) of compound (A1), 21.44 g (109.2 mmol) of compound (B2), 3.34 g (23 .5 mmol) of compound (D1) was dissolved in 67.18 g of methyl ethyl ketone (MEK). To this solution, 2.593 g (11.26 mmol) of dimethyl azobisisobutyrate (V-601) as a polymerization initiator was added and dissolved to prepare a dropping solution.
MEK23.75g was heated at 80 degreeC and the said dripping liquid was dripped over 4 hours in nitrogen atmosphere. After completion of dropping, the reaction solution was heated and stirred for 1 hour, and then the reaction solution was cooled to room temperature.
The obtained reaction polymerization liquid was dropped into a large amount of heptane (Hep) to precipitate a polymer, and the precipitated white powder was filtered off, washed with methanol and dried to obtain the target polymer 1 33.44 g of was obtained.
In the same manner, polymers 2 to 19 having the composition ratio shown in Table 1 were synthesized using the compounds shown below.
About these high molecular compounds, it calculated | required by the mass average molecular weight (Mw) and molecular weight dispersion degree (Mw / Mn) of standard polystyrene conversion calculated | required by GPC measurement, and the carbon 13 magnetic resonance spectrum (600 MHz, ¹³ C-NMR). The copolymer composition ratio (ratio (molar ratio) of each structural unit in the structural formula) is shown below.

In 100 parts by mass of each of the obtained polymer compounds 1 to 19, 6.0 parts by mass of the following compound (B) -1, 3.0 parts by mass of the following compound (B) -2, and the following polymer compound ( F) -1 is 1.5 parts by mass, salicylic acid is 0.5 parts by mass, γ-butyrolactone is 0.5 parts by mass, and solvent is 2500 parts by mass (mixed solvent of PGMEA / PGME / CH = 45/30/25). The negative resist composition (Examples 1-11, Comparative Examples 1-7) was prepared by mix | blending. However, Examples 6 to 11 are reference examples.

<Formation of negative resist pattern; Examples 1 to 11 and Comparative Examples 1 to 7>
An organic antireflective coating composition “ARC29A” (trade name, manufactured by Brewer Science) is applied onto a 12-inch silicon wafer using a spinner, and baked on a hot plate at 205 ° C. for 60 seconds to be dried. Thus, an organic antireflection film having a film thickness of 85 nm was formed.
Each of the negative resist compositions shown in Tables 2 to 3 is coated on the antireflection film, subjected to a pre-baking (PAB) treatment at 100 ° C. for 60 seconds on a hot plate, and then dried to form a resist having a thickness of 100 nm. A film was formed.
Next, an ArF exposure apparatus NSR-S609B (manufactured by Nikon; NA (numerical aperture) = 1.07, Crosssole 0.97 / 0.78 w / Polano, immersion medium: water) is applied to the resist film. ArF excimer laser (193 nm) was selectively irradiated.
Thereafter, PEB treatment was performed at 90 ° C. for 60 seconds.
Next, solvent development was carried out with butyl acetate at 23 ° C. for 13 seconds, followed by drying by shaking.
As a result, in each example, a line and space pattern (hereinafter referred to as “LS pattern”) arranged with a line width of 50 nm and a pitch of 100 nm was formed.

[EL evaluation]
The exposure amount when the line of the LS pattern was formed within the range of ± 5% (47.5 nm, 52.5 nm) of the target dimension was determined, and EL (unit:%) was determined by the following formula. The results are shown in Tables 2-3 as “5% EL”. Note that EL indicates that the larger the value, the smaller the change in pattern size that accompanies the variation in exposure.
EL (%) = (| E1-E2 | / Eop) × 100
In the above formula, E1 is an exposure amount when an LS pattern having a line width of 47.5 nm is formed (mJ / cm ² ), and E2 is an exposure amount when an LS pattern having a line width of 52.5 nm is formed ( mJ / cm ² ), Eop indicates the optimum exposure amount for forming an LS pattern having a line width of 50 nm and a pitch of 100 nm. Eop was determined by a conventional method.

[LWR (line width roughness) evaluation]
In the above LS pattern, the space width was measured at 400 locations in the longitudinal direction of the space with a length measurement SEM (scanning electron microscope, acceleration voltage 300 V, trade name: S-9380, manufactured by Hitachi High-Technologies Corporation). A triple value (3 s) of the standard deviation (s) was obtained, and a value averaged over 3 s at 400 locations was calculated as a scale indicating LWR. The results are shown in Tables 2-3.
A smaller value of 3s means that the roughness of the line width is smaller, and an LS pattern having a more uniform width is obtained.

[Evaluation of mask error factor (MEEF)]
According to the same procedure as the formation of the LS pattern, an LS pattern having a pitch of 100 nm was formed using mask patterns having a line pattern target size of 45 to 54 nm (1 nm increments, 10 points in total) at the same exposure amount. At this time, the slope of the straight line when the target size (nm) was plotted on the horizontal axis and the size (nm) of the line pattern formed on the resist film using each mask pattern was plotted on the vertical axis was calculated as MEEF. MEEF (straight line) means that the closer the value is to 1, the better the mask reproducibility. The results are shown in Tables 2-3.

[Resolution evaluation at low exposure]
Scanning electron microscope S-9380 (manufactured by Hitachi High-Technology Co., Ltd.) shows the minimum resolution dimension (nm) when the exposure dose is reduced from the optimum exposure dose Eop at which the LS pattern of 50 nm (pitch 100 nm) is formed. Was determined using. The results are shown in Tables 2-3 as “MinCD (nm)”.

[Evaluation of cross-sectional shape]
The LS pattern was observed with a length measurement SEM (scanning electron microscope, acceleration voltage 800 V, trade name: S-9220, manufactured by Hitachi, Ltd.). The results are shown in Tables 2 to 3 as “cross-sectional shapes”.

  As shown in the above results, a polymer containing a structural unit having a chain-like tertiary alcohol-based hydroxyl group, as compared with Comparative Example 1 using the polymer 16 containing a structural unit having a cyclic tertiary alcohol-based hydroxyl group. Since the polymer of the examples using the polymer had better reactivity, the crosslinking reaction was more likely to proceed, the dissolution contrast was increased by the increase in molecular weight, and various lithography properties were excellent.

≪Molecular weight change before and after exposure≫
For Examples 1 and 5 and Comparative Examples 1, 4, and 7, changes in molecular weight before and after exposure were measured by gel permeation chromatography (GPC).
[GPC measurement sample preparation method]
The resist compositions of Examples 1, 5, and Comparative Examples 1, 4, and 7 were applied on an 8-inch silicon substrate (hereinafter referred to as Bare Si), and pre-baked (PAB) at 100 ° C. for 60 seconds on a hot plate. ) A resist film having a film thickness of 100 nm was formed by performing treatment and drying.
Next, the entire surface of the resist film was exposed with an ArF exposure apparatus NSR-302 (manufactured by Nikon Corporation; NA (numerical aperture) = 0.60, σ0.75). Then, it was dried at 90 ° C. for 60 seconds.
Thereafter, the resist film was peeled off from the substrate, dissolved in a tetrahydrofuran solution, and measured by gel permeation chromatography (GPC).

  As shown in Table 4, it is presumed that the ratio of the intermolecular reaction to the intramolecular reaction before and after the exposure increased due to the polymer mixing, and the molecular weight further increased.

≪Dry etching evaluation≫
<Wafer preparation conditions>
On an 8-inch silicon substrate (hereinafter referred to as “Bare Si”), an organic antireflection film composition “ARC29A” (trade name, manufactured by Brewer Science Co., Ltd.) was applied using a spinner. An organic antireflection film having a thickness of 80 nm was formed by baking for 60 seconds and drying. The resist compositions of Examples 1 and 5 and Comparative Examples 1, 4, and 7 were applied, pre-baked (PAB) treatment at 110 ° C. for 60 seconds on a hot plate, and dried to obtain a resist having a film thickness of 100 nm. A film was formed.
Next, the entire surface of the resist film was exposed with an ArF exposure apparatus NSR-302 (manufactured by Nikon Corporation; NA (numerical aperture) = 0.60, σ0.75). The exposure amount was 30 mJ / cm ² . Then, it was dried at 90 ° C. for 60 seconds.
Next, solvent development was carried out with butyl acetate at 23 ° C. for 13 seconds, followed by drying by shaking.
Thereafter, post-baking was performed at 100 ° C. for 60 seconds.
<Dry etching evaluation conditions>
Next, dry etching (CF plasma etching) using plasma obtained from a fluorocarbon-based gas is performed on the resist film under the following conditions, the resist film etching rate is measured, and the resist film before and after etching is measured. From the difference in film thickness, the etch rate (etch rate (the thickness of the film etched per unit time)) was determined. The results are shown in Table 5.
[CF plasma etching]
Apparatus: High vacuum RIE apparatus (manufactured by Tokyo Ohka Kogyo Co., Ltd .; product name “TCE-3822”).
Gas: CF ₄
Output: 400W
Chamber pressure: 40Pa
Stage temperature: 40 ° C
Gas flow rate: 20 mL / min

  It is presumed that the etching rate was reduced by the three-dimensionalization by the crosslinking.

≪Residual film ratio after development≫
For Examples 1 and 5 and Comparative Examples 1, 4, and 7, the remaining film ratio after development was measured.
[Sample preparation for residual film measurement]
On an 8-inch silicon substrate (hereinafter referred to as “Bare Si”), an organic antireflection film composition “ARC29A” (trade name, manufactured by Brewer Science Co., Ltd.) was applied using a spinner. An organic antireflection film having a thickness of 80 nm was formed by baking for 60 seconds and drying. The resist compositions of Examples 1 and 5 and Comparative Examples 1, 4, and 7 were applied, pre-baked (PAB) treatment at 110 ° C. for 60 seconds on a hot plate, and dried to obtain a resist having a film thickness of 100 nm. A film was formed.
Next, the entire surface of the resist film was exposed with an ArF exposure apparatus NSR-302 (manufactured by Nikon Corporation; NA (numerical aperture) = 0.60, σ0.75). The exposure amount was the optimum exposure amount for each resist composition. Then, it was dried at 90 ° C. for 60 seconds.
Next, solvent development was carried out with butyl acetate at 23 ° C. for 13 seconds, followed by drying by shaking.
Thereafter, post-baking was performed at 100 ° C. for 60 seconds.
[Measurement of remaining film ratio]
From the film thickness (film thickness of the exposed area after solvent development) formed by using each resist composition in the above [Residual film measurement sample preparation method], the residual film ratio (unit:%) is obtained by the following formula. It was.
The results are shown in Table 6.
Residual film rate (%) = (FT2 / FT1) × 100
In the above formula, FT1 represents the resist film thickness (nm) before exposure, and FT2 represents the film thickness (nm) of the LS pattern.
The film thickness was measured with Nanospec 6100A (manufactured by Nanometrics).

As shown in the above results, cross-linking results in low solubility in the developer, and the cross-linked polymer can form a pattern with a small amount of deprotection (small amount of film slippage) compared to a normal polymer. all right. In addition, it was found that development film slippage was also suppressed by the crosslinked structure of the exposed portion.

Claims (3)

A solvent development negative resist composition for forming a negative resist pattern by development using an organic developer containing an organic solvent,
Containing a base material component (A) whose solubility in an organic solvent is reduced by the action of an acid ,
Said base component (A),
A polymer unit (A1) having a structural unit (a14) having an ether-containing cyclic group and a structural unit containing an acid-decomposable group whose polarity is increased by the action of an acid ;
Structural units containing a primary alcohol aqueous acid group (a13-1) and a polymer compound having a structural unit containing an acid-decomposable group that exhibits increased polarity by the action of an acid and (A2),
I have a,
The structural unit (a14) is the polymer compound solvent developing negative resist composition characterized in der Rukoto 40 mol% or less relative to the total of all structural units constituting the (A1).   The solvent-developed negative resist composition according to claim 1, wherein the ether-containing cyclic group is an oxirane-containing cyclic group or an oxetane-containing cyclic group. On a support, forming a resist film by using a solvent developing negative resist composition according to claim 1 or 2, conducting exposure of the resist film, and the resist film, an organic system comprising an organic solvent solvent developing negative resist pattern forming method comprising forming a negative resist pattern by developing with a developer.