JP6144875B2 - 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.

A technique (pattern formation technique) for forming a fine pattern on a substrate and processing the lower layer of the pattern by performing etching using the fine pattern as a mask is widely adopted in the manufacture of semiconductor elements and liquid crystal display elements. The fine pattern is usually made of an organic material, and is formed by a technique such as a lithography method or a nanoimprint method. For example, in a lithography method, a resist film is formed on a support such as a substrate using a resist material containing a base material component such as a resin, and the resist film is selected by radiation such as light or an electron beam. A step of forming a resist pattern having a predetermined shape on the resist film is performed by performing a general exposure and developing. And a semiconductor element etc. are manufactured through the process of processing a board | substrate by an etching using the said resist pattern as a mask.
The resist material is classified into a positive type and a negative type. A resist material whose solubility in an exposed portion of a developer is increased is called a positive type, and a resist material whose solubility in an exposed portion of a developer is reduced is called a negative type. .

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 solvent development negative process (for example, Patent Document 1).

JP 2009-025723 A

In the future, with further progress in lithography technology and further miniaturization of resist patterns, resist materials are expected to further improve various lithography properties such as CDU. In particular, the solvent development negative type process is more advantageous in the formation of trench patterns (isolated space patterns) and hole patterns than the alkali development process, and therefore a resist material that can improve lithography characteristics in the negative type development process is required. ing.
However, in the solvent development negative type process, the unexposed part dissolves in the developer and the exposed part remains to form a pattern part, so that the developer solubility of the resist material has a great influence on the lithography characteristics, and the patent In the conventional solvent-developable negative resist composition described in Document 1, there is still room for improvement in the developer resistance of the pattern portion (exposure portion) after development and the remaining film ratio.
The present invention has been made in view of the above circumstances, and in a solvent development negative type process using a developer containing an organic solvent, a resist pattern having excellent lithography characteristics and reduced film thickness reduction in a pattern portion. It is an object of the present invention to provide a negative resist composition capable of forming a film and a pattern forming method using the negative resist composition.

［式中、Ｒ’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；ｎ_ａ０１は０または１であり、ｎ_ａ０２は０〜２の整数である。］

［式中、Ｒ^８はフッ素化アルキル基である。Ｍ^ｍ＋はそれぞれ独立にｍ価の有機カチオンである。］

［式中、ｑ１〜ｑ２はそれぞれ独立に１〜５の整数であり、ｑ３は１〜１２の整数であり、ｔ３は１〜３の整数であり、ｒ１〜ｒ２はそれぞれ独立に０〜３の整数であり、ｇは１〜２０の整数であり、Ｒ^１０７は置換基であり、ｎ３〜ｎ６はそれぞれ独立に０または１であり、ｖ０、ｖ３〜ｖ６はそれぞれ独立に０〜３の整数であり、ｗ３〜ｗ６はそれぞれ独立に０〜３の整数であり、Ｑ”は炭素数１〜５のアルキレン基、−Ｏ−、−Ｓ−、−Ｏ−Ｒ^９４−または−Ｓ−Ｒ^９５−であり、Ｒ^９４およびＲ^９５はそれぞれ独立に炭素数１〜５のアルキレン基である。］
本発明の第二の態様は、前記第一の態様の溶剤現像ネガ型レジスト組成物を用いて支持体上にレジスト膜を形成する工程、前記レジスト膜を露光する工程、及び前記レジスト膜を、前記有機溶剤を含有する現像液を用いたネガ型現像によりパターニングしてレジストパターンを形成する工程、を含むことを特徴とするレジストパターン形成方法である。
In order to solve the above problems, the present invention employs the following configuration.
That is, one embodiment of the present invention includes a base material component (A) whose solubility in an organic solvent is reduced by the action of an acid, an acid generator component (B) that generates an acid upon exposure, and a basic compound component (D). A step of forming a resist film on a support using a resist composition containing, a step of exposing the resist film, and a patterning of the resist film by negative development using a developer containing the organic solvent A resist composition used for a resist pattern forming method including a step of forming a resist pattern, wherein the base material component (A) is a structural unit containing a 3- to 7-membered ether-containing cyclic group ( a resin component (A1) having a0), a structural unit (a1) containing an acid-decomposable group whose polarity is increased by the action of an acid, and a structural unit (a5) containing a —SO ₂ — containing cyclic group Contains The 3- to 7-membered ether-containing cyclic group is a group represented by any one of the following general formulas (a0-r-1) to (a0-r-5), and the basic compound component (D ) comprises a compound (d1) represented by the following general formula (d1), said acid generator component (B) is a compound represented by the following formula (b1) ~ (b3), one of (b6) ~ (b9) It is a solvent development negative resist composition characterized by including the compound which has an anion part represented by these.

[Wherein, each R ′ is independently 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; n _a01 is 0 or 1, and n _a02 is an integer of 0 to 2.]

Wherein, ^{R 8} is a fluorinated alkyl group. M ^{m +} is each independently an m-valent organic cation. ]

[Wherein, q1 to q2 are each independently an integer of 1 to 5, q3 is an integer of 1 to 12, t3 is an integer of 1 to 3, and r1 to r2 are each independently 0 to 3] G is an integer of 1 to 20, R ¹⁰⁷ is a substituent, n3 to n6 are each independently 0 or 1, and v0 and v3 to v6 are each independently an integer of 0 to 3. Each of w3 to w6 is independently an integer of 0 to 3, and Q ″ is an alkylene group having 1 to 5 carbon atoms, —O—, —S—, —O—R ⁹⁴ — or —S—R ⁹⁵ —. R ⁹⁴ and R ⁹⁵ are each independently an alkylene group having 1 to 5 carbon atoms.]
In the second aspect of the present invention, 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, A resist pattern forming method comprising a step of patterning by negative development using a developer containing the organic solvent to form a resist pattern.

In the present specification and claims, “aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity.
Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups.
The “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 that replaces 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, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydroxy group. An alkyl group etc. are mentioned. The α-position carbon atom of the acrylate ester is a carbon atom to which a carbonyl group is bonded unless otherwise specified.
Hereinafter, an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position is substituted with a substituent may be referred to as an α-substituted acrylate ester. Further, the acrylate ester and the α-substituted acrylate ester may be collectively referred to as “(α-substituted) acrylate ester”.
“A structural unit derived from hydroxystyrene or a hydroxystyrene derivative” means a structural unit formed by cleavage of an ethylenic double bond of hydroxystyrene or a hydroxystyrene derivative.
“Hydroxystyrene derivative” is a concept including those in which the hydrogen atom at the α-position of hydroxystyrene is substituted with another substituent such as an alkyl group or an alkyl halide group, and derivatives thereof. The derivatives include those in which the hydrogen atom at the α-position may be substituted with a substituent, the hydrogen atom of the hydroxyl group of hydroxystyrene substituted with an organic group, and the hydrogen atom at the α-position substituted with a substituent. Examples include those in which a substituent other than a hydroxyl group is bonded to a good benzene ring of hydroxystyrene. The α-position (α-position carbon atom) means a carbon atom to which a benzene ring is bonded unless otherwise specified.
Examples of the substituent for substituting the hydrogen atom at the α-position of hydroxystyrene include the same substituents as those mentioned as the substituent at the α-position in the α-substituted acrylic ester.
The “structural unit derived from vinyl benzoic acid or a vinyl benzoic acid derivative” means a structural unit configured by cleavage of an ethylenic double bond of vinyl benzoic acid or a vinyl benzoic acid derivative.
The “vinyl benzoic acid derivative” is a concept including a compound in which the hydrogen atom at the α-position of vinyl benzoic acid is substituted with another substituent such as an alkyl group or an alkyl halide group, and derivatives thereof. These derivatives include those obtained by substituting the hydrogen atom of the carboxy group of vinyl benzoic acid with an organic group, which may be substituted with a hydrogen atom at the α-position, and the hydrogen atom at the α-position with a substituent. Examples thereof include those in which a substituent other than a hydroxyl group and a carboxy group is bonded to the benzene ring of vinyl benzoic acid. The α-position (α-position carbon atom) means a carbon atom to which a benzene ring is bonded unless otherwise specified.
“Styrene” is a concept that includes styrene and those in which the α-position hydrogen atom of styrene is substituted with another substituent such as an alkyl group or a halogenated alkyl group.
“Structural unit derived from styrene” and “structural unit derived from styrene derivative” mean a structural unit formed by cleavage of an ethylenic double bond of styrene or a styrene derivative.
The alkyl group as a substituent at the α-position is preferably a linear or branched alkyl group, specifically, an alkyl group having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group). , N-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group) and the like.
Specific examples of the halogenated alkyl group as the substituent at the α-position include groups in which part or all of the hydrogen atoms of the above-mentioned “alkyl group as the substituent at the α-position” are substituted with a halogen atom. It is done. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
Specific examples of the hydroxyalkyl group as a substituent at the α-position include a group in which part or all of the hydrogen atoms of the “alkyl group as the substituent at the α-position” are substituted with a hydroxyl group. 1-5 are preferable and, as for the number of the hydroxyl groups in this hydroxyalkyl group, 1 is the most preferable.
“Exposure” is a concept including general irradiation of radiation.

  According to the present invention, in a solvent development negative type process using a developer containing an organic solvent, a negative type resist composition that is capable of forming a resist pattern that has excellent lithography properties and reduced film loss at the pattern portion, And the pattern formation method using this negative resist composition can be provided.

≪Resist composition≫
The solvent-developed negative resist composition of the first aspect of the present invention (hereinafter sometimes simply referred to as “resist composition”) is a base material component (A) whose solubility in organic solvents is reduced by the action of an acid. (Hereinafter referred to as “component (A)”), an acid generator component (B) that generates acid upon exposure (hereinafter referred to as “component (B)”), and a basic compound component (D) (hereinafter referred to as “component (A)”). , “(D) component”), a step of forming a resist film on a support using the resist composition, a step of exposing the resist film, and the resist film Is patterned by negative development using a developer containing the organic solvent to form a resist pattern, and used in a resist pattern forming method.
In such a resist composition, when radiation is irradiated (exposed), an acid is generated from the component (B) in the exposed area, and the solubility of the component (A) in the organic solvent decreases due to the action of the acid. 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).

[Resin component (A1)]
In the present invention, the component (A) includes at least a structural unit (a0) containing a 3- to 7-membered ether-containing cyclic group and a structural unit (a1) containing an acid-decomposable group whose polarity is increased by the action of an acid. And a resin component (A1) (hereinafter referred to as “component (A1)”).

In the component (A1) of the present invention, when an acid is generated from the component (B) by exposure, a part of the bond of the acid-decomposable group in the structural unit (a1) is cleaved as described later, so that The polarity of the component (A1) increases. This reduces the solubility in the organic developer containing the organic solvent in the exposed area, while maintaining the high solubility in the unexposed area without changing the solubility in the organic developer. A pattern can be formed by the dissolution contrast between the exposed portion and the exposed portion.
Furthermore, the component (A1) of the present invention, when an acid is generated from the component (B) by exposure, together with the increase in polarity, the ether-containing cyclic group in the structural unit (a0) is cleaved and polymerized with each other, As a result, the molecular weight of the component (A1) in the exposed area can be increased. This further reduces the solubility in the organic developer in the exposed area, while the solubility in the organic developer does not change in the unexposed area, further increasing the dissolution contrast between the unexposed area and the exposed area. It is possible to improve the lithography characteristics. In addition, since the (A1) component of the exposed portion polymerized by the action of the structural unit (a0) is superior in solvent resistance compared to the unpolymerized (A1) component, Residual film characteristics can be improved.

  The resist composition of the present invention is a solvent-developed negative resist composition. However, if the resist composition is used for alkali development, by increasing the polarity of the structural unit (a1) due to the action of an acid, While the solubility in the alkaline developer in the exposed area increases, the solubility in the alkaline developer in the unexposed area remains unchanged and maintains low solubility. At the same time, the increase in the molecular weight due to the structural unit (a0) reduces the solubility in the alkaline developer in the exposed area, while maintaining the low solubility without changing the solubility in the alkaline developer in the unexposed area. Will remain. Here, the change in the solubility of the exposed portion depends on the degree of action of the solubility increase by the structural unit (a1) and the solubility decrease by the structural unit (a0). It can vary depending on the situation. However, since the main controlling factor of the solubility is generally the molecular weight, it is considered that the solubility often decreases even in the exposed area. Therefore, if the resist composition of the present invention is used for alkali development, it is considered that a dissolution contrast cannot be obtained and a pattern cannot be formed.

In addition to the structural units (a0) and (a1), the component (A1) is further derived from the structural unit (a2) containing a lactone-containing cyclic group and the structural unit (a5) containing an SO ₂ -containing cyclic group. You may have at least 1 type of structural unit selected from the group which consists of.
The component (A1) may further have a structural unit (a3) containing a polar group-containing aliphatic hydrocarbon group.

(Structural unit (a0))
The structural unit (a0) is a structural unit containing a 3- to 7-membered ether-containing cyclic group.
Here, 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.

The structural unit (a0) is not particularly limited, and any unit can be used.
Specifically, as the ether-containing cyclic group, a group obtained by removing one hydrogen atom from a 3- to 7-membered cyclic ether, for example, 1 hydrogen atom from a cyclic ether such as epoxyethane, oxetane, tetrahydrofuran, tetrahydropyran, etc. Excluded groups are mentioned. 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.
More specifically, examples of the ether-containing cyclic group include groups represented by the following general formulas (a0-r-1) to (a0-r-5).

［式中、Ｒ’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；ｎ_ａ０１は０または１であり、ｎ_ａ０２は０〜２の整数である。］

[Wherein, each R ′ is independently 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; n _a01 is 0 or 1, and n _a02 is an integer of 0 to 2.]

In the formulas (a0-r-1) to (a0-r-5), an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, —COOR ″, —OC (═O) R ″, hydroxy of R ′ As the alkyl group, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, —COOR ″, —OC (═O) R ″, which are listed as substituents that the ether-containing cyclic group may have, respectively. , Hydroxyalkyl group, —COOR ″, —OC (═O) R ″ (where R ″ is the same as described above).
It is preferable that _na2 is 1-2.

  More specifically, examples of the structural unit (a0) include structural units represented by general formula (a0-1) shown below.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり、Ｒａ^０１はエーテル含有環式基であり、Ｙａ^０１は単結合または２価の連結基である。］

[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, Ra ⁰¹ is an ether-containing cyclic group, and Ya ⁰¹ is a single bond or a divalent group. The linking group of ]

In formula (a0-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.
Examples of the alkyl group and halogenated alkyl group for R are the same as the alkyl group and halogenated alkyl group mentioned as the substituent at the α-position. 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.

Ra ⁰¹ is the same as the ether-containing cyclic group mentioned above.
Ya ⁰¹ may be a single bond or a divalent linking group. The divalent linking group of Ya ⁰¹ 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.
More specific examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, and the like.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and still more preferably 1 to 5 carbon atoms.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group [—CH ₂ —], an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [ — (CH ₂ ) ₃ —], tetramethylene group [— (CH ₂ ) ₄ —], pentamethylene group [— (CH ₂ ) ₅ —] and the like can be mentioned.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ). _{2 -, - C (CH 3} ) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as - _{CH (CH 3) CH 2 -} , - CH (CH 3) CH (CH 3) -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - C (CH 2 CH _{3) 2} -CH ₂ - alkyl groups such _{as; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - alkyl trimethylene groups such as; -CH _(CH 3) _{CH 2 CH 2 CH 2 -,} - CH 2 CH (CH 3) CH 2 CH 2 - And the like alkyl alkylene group such as an alkyl tetramethylene group of. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The linear or branched aliphatic hydrocarbon group may or may not have a substituent (a group or atom other than a hydrogen atom) that replaces a hydrogen atom. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxo group (═O).

As the aliphatic hydrocarbon group containing a ring in the structure, a cyclic aliphatic hydrocarbon group which may contain a substituent containing a hetero atom in the ring structure (excluding two hydrogen atoms from the aliphatic hydrocarbon ring) Group), a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and the cyclic aliphatic hydrocarbon group is a linear or branched chain fatty acid. Group intervening in the middle of the group hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include those described above.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group may be polycyclic or monocyclic. As the monocyclic aliphatic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic aliphatic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, Examples include norbornane, isobornane, tricyclodecane, and tetracyclododecane.
The cyclic aliphatic hydrocarbon group may or may not have a substituent (a group or atom other than a hydrogen atom) that replaces a hydrogen atom. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxo group (═O).
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group. Most preferred is an ethoxy group.
Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.
In the cyclic aliphatic hydrocarbon group, a part of carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. As the substituent containing the hetero atom, —O—, —C (═O) —O—, —S—, —S (═O) ₂ —, and —S (═O) ₂ —O— are preferable.

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

(Divalent linking group containing a hetero atom)
The hetero atom in the “divalent linking group containing a hetero atom” in Ya ⁰¹ 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.
Examples of the divalent linking group containing a hetero atom include -O-, -C (= O) -O-, -C (= O)-, -O-C (= O) -O-, -C (= O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group, an acyl group, etc.), —S—, —S (═O) ₂ —, —S (═O) _{2 -O -, - NH-C} (= O) -, = N-, the formula ^{-Y A -O-Y B -,} - [Y A -C (= O) -O] m '-Y B - , —C (═O) —O—Y ^B — or —Y ^A —O—C (═O) —Y ^B —, wherein Y ^A and Y ^B are each independently a substituent. Is a divalent hydrocarbon group which may have, O is an oxygen atom, and m ′ is an integer of 0-3. ] Etc. are mentioned.
When Ya ⁰¹ is —NH—, H may be substituted with a substituent such as an alkyl group or an acyl group. The substituent (alkyl group, aryl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
Y ^A and Y ^B are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same groups as those described above as the “divalent hydrocarbon group which may have a substituent” in Ya ⁰¹ .
The Y ^A, preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, a linear alkylene group is more preferred, a methylene group or an ethylene group having 1 to 5 carbon atoms, especially preferable.
Y ^B is preferably a linear or branched aliphatic hydrocarbon group, 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 ^A —C (═O) —O] _{m ′} —Y ^B —, 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 ^A —C (═O) —O] _{m ′} —Y ^B — is represented by the formula —Y ^A —C (═O) —O—Y ^B —. 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.
As the divalent linking group containing a hetero atom, a linear group having an oxygen atom as a hetero atom, for example, a group containing an ether bond or an ester bond, is preferable, and the above formula —Y ^A —O—Y ^B —, ^A group represented by — [Y ^A —C (═O) —O] _{m ′} —Y ^B — or —Y ^A —O—C (═O) —Y ^B — is more preferable.

Among the above, the divalent linking group of Ya ⁰¹ is particularly a linear or branched alkylene group, a divalent alicyclic hydrocarbon group, or a divalent linking group containing a hetero atom. preferable. Among these, a linear or branched alkylene group or a divalent linking group containing an ester bond (—C (═O) —O—) is preferable.

  Specific examples of the structural unit represented by the general formula (a0-1) are shown below.

［式中、Ｒ、Ｙａ^０１、ｎ_ａ０１、ｎ_ａ０２はそれぞれ前記同様である。］

[Wherein, R, Ya ⁰¹ , n _a01 and n _a02 are the same as defined above. ]

Specific examples of the structural units represented by the general formulas (a0-1-1) to (a0-1-5) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

In the component (A1), as the structural unit (a0), one type may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a0) in the component (A1) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, based on the total of all structural units constituting the component (A1). 30 mol% is more preferable. By setting it to the lower limit value or more, lithography characteristics such as CDU and residual film characteristics can be improved, and by setting the upper limit value or less, it is possible to balance with other structural units.

(Structural unit (a1))
The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity is increased by the action of an acid.
The “acid-decomposable group” is an acid-decomposable group that can cleave at least part of bonds in the structure of the acid-decomposable group by the action of an acid.
Examples of the acid-decomposable group whose polarity increases by the action of an acid include a group that decomposes by the action of an acid to generate a polar group.
Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, a sulfo group (—SO ₃ H), and the like. Among these, a polar group containing —OH in the structure (hereinafter sometimes referred to as “OH-containing polar group”) is preferable, a carboxy group or a hydroxyl group is preferable, and a carboxy group is particularly preferable.
More specifically, examples of the acid-decomposable group include groups in which the polar group is protected with an acid-dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).
Here, “acid-dissociable group” means
(I) an acid-dissociable group capable of cleaving a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by the action of an acid, or
(Ii) a group capable of cleaving a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by further decarboxylation reaction after partial bond cleavage by the action of an acid ,
Both.
The acid-dissociable group constituting the acid-decomposable group must be a group having a lower polarity than the polar group generated by dissociation of the acid-dissociable group. Is dissociated, a polar group having a polarity higher than that of the acid dissociable group is generated to increase the polarity. As a result, the polarity of the entire component (A1) increases. As the polarity increases, the solubility in the developer changes relatively, and when the developer is an organic developer, the solubility decreases.

  The acid-dissociable group is not particularly limited, and those that have been proposed as acid-dissociable groups for base resins for chemically amplified resists can be used.

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

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

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

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 may be linear, branched or cyclic as the alkyl group.
The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and still more preferably 1 or 2. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.
The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group and the like, and isopropyl group is most preferable.
The cyclic alkyl group preferably has 3 to 20 carbon atoms, and more preferably 4 to 12 carbon atoms. Specific examples thereof include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Some of the carbon atoms constituting the ring of the cyclic alkyl group may be substituted with an etheric oxygen atom (—O—).
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).

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

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

In formula (a1-r-2), the hydrocarbon group of Ra ′ ^{4 to} Ra ′ ⁶ is preferably a linear, branched or cyclic alkyl group. The alkyl group is the same as Ra ′ ³ .
When Ra ′ ⁵ and Ra ′ ⁶ are bonded to each other to form a ring, the formed cyclic group may be a monocyclic group or a polycyclic group. Examples of the cyclic group include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. It is done.
Of the acid dissociable groups represented by the formula (a1-r-2), those composed of an alkyl group may be hereinafter referred to as “tertiary alkyl ester type acid dissociable groups” for convenience.

  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はアルキル基であり、Ｒａ’^８、Ｒａ’^９は互いに結合して環を形成してもよい。］

[Wherein, Ra ′ ^{7 to} Ra ′ ⁹ are alkyl groups, and Ra ′ ⁸ and Ra ′ ⁹ may be bonded to each other to form a ring. ]

In formula (a1-r-3), the alkyl groups of Ra ′ ^{7 to} Ra ′ ⁹ may be linear, branched or cyclic. The alkyl group is the same as Ra ′ ³ .
The ring formed by combining Ra ′ ⁸ and Ra ′ ⁹ is the same as the ring formed by combining Ra ′ ⁵ and Ra ′ ⁶ with each other.

  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.
Specific examples of the structural unit (a1) are shown below.

［式中、Ｒは前記同様であり、
Ｙａ^１〜Ｙａ^７はそれぞれ独立に２価の連結基であり、
ｎ_ａ１〜ｎ_ａ７はそれぞれ独立に０〜２の整数であり、
Ｒａ^１はアルキル基であり、Ｒａ^２は、当該Ｒａ^２が結合した炭素原子と共に脂肪族単環式基を形成する基であり、
Ｒａ^３、Ｒａ^４はそれぞれ独立に炭素数１〜８のアルキル基であり、Ｒａ^５はそれぞれ独立に置換基を有していていもよい鎖状の脂肪族炭化水素基又は脂肪族単環式基であり、
Ｒａ^６、Ｒａ^７はそれぞれ独立に、水素原子、炭素数１〜８の直鎖状又は分岐鎖状のアルキル基であり、
ｎ_ａ８〜ｎ_ａ９はそれぞれ独立に０〜２の整数である。
Ｒａ^８は分岐鎖状のアルキル基であり、Ｒａ^９はそれぞれ独立に、当該Ｒａ^９が結合した炭素原子と共に脂肪族多環式基を形成する基であり、
Ｒａ^１０は炭素数１〜５の直鎖状のアルキル基であり、
Ｒａ^１１それぞれ独立に脂肪族多環式基である。］

[Wherein R is as defined above,
Ya ^{1 to} Ya ⁷ are each independently a divalent linking group,
n _{a1 to} n _a7 are each independently an integer of 0 to 2,
Ra ¹ is an alkyl group, Ra ² is a group that forms an aliphatic monocyclic group together with the carbon atom to which Ra ² is bonded,
Ra ³ and Ra ⁴ are each independently an alkyl group having 1 to 8 carbon atoms, and Ra ⁵ is each independently a chained aliphatic hydrocarbon group or aliphatic monocyclic group which may have a substituent. And
Ra ⁶ and Ra ⁷ are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms,
n _{a8 to} n _a9 are each independently an integer of 0 to 2.
Ra ⁸ is a branched alkyl group, and Ra ⁹ is independently a group that forms an aliphatic polycyclic group together with the carbon atom to which the Ra ⁹ is bonded,
Ra ¹⁰ is a linear alkyl group having 1 to 5 carbon atoms,
Each of Ra ^{11 is} independently an aliphatic polycyclic group. ]

Examples of the divalent linking group of Ya ^{1 to} Ya ⁷ include the same divalent linking groups as those of Ya ⁰¹ , and include a linear or branched alkylene group, or a linear or branched chain. And a divalent linking group containing a hetero atom is preferable. A methylene group, an ethylene group, or a methylene group or an ethylene group, and —C (═O) —O— or —O—C A combination with (= O)-is preferred.
n _{a1 to} n _a7 are integers of 0 to 2, and 0 or 1 is preferable.

Examples of the alkyl group for Ra ¹ include the same groups as those for the Ra ′ ³ described above, and a methyl group, an ethyl group, or an isopropyl group is preferable.
Ra ^2. Examples of the aliphatic monocyclic group formed together with the carbon atom to which Ra ² is bonded, such as a group obtained by excluding one or more hydrogen atoms from a monocycloalkane. The monocycloalkane is preferably a 3- to 11-membered ring, more preferably a 3- to 8-membered ring, further preferably a 4- to 6-membered ring, and particularly preferably a 5- or 6-membered ring. In the monocycloalkane, a part of carbon atoms constituting the ring may or may not be substituted with an ether group (—O—).
Moreover, this monocycloalkane may have a C1-C5 alkyl group, a fluorine atom, or a C1-C5 fluorinated alkyl group as a substituent.
Examples of Ra ² constituting the aliphatic monocyclic group include a linear alkylene group in which an ether group (—O—) may be interposed between carbon atoms.

Ra ³ and Ra ^{4 are the same} as Ra ′ ^{4 to} Ra ′ ⁵ described above.
The aliphatic monocyclic group Ra ^2, is similar to the aliphatic monocyclic group formed together with the carbon atom to which the Ra ² is bonded.

As the linear or branched alkyl group of Ra ⁶ and Ra ^7, the linear or branched alkyl group mentioned for the alkyl group of Ra ′ ³ is preferable, and a methyl group or an ethyl group is preferable.
n _{a8 to} n _a8 are integers of 0 to 2, and 0 is preferable.

Examples of the branched alkyl group of Ra ⁸ include the same branched alkyl groups as those described for Ra ′ ³ above, and an isopropyl group is most preferable.
Ra ⁹ is, as the aliphatic polycyclic group formed together with the carbon atom to which Ra ⁹ is bonded, adamantane, norbornane, isobornane, tricyclodecane, one or more hydrogen atoms from a polycycloalkane such as tetracyclododecane Excluded groups and the like. Some of the carbon atoms constituting the ring of the cyclic alkyl group may be substituted with an etheric oxygen atom (—O—). Of these, a 2-adamantyl group is preferable.
Examples of the linear alkyl group for Ra ¹⁰ include the same linear alkyl groups as those described for Ra ′ ³ above, and a methyl group or an ethyl group is most preferable.
The aliphatic monocyclic group of Ra ^{11 is the same as} the aliphatic monocyclic group formed together with the carbon atom to which Ra ⁹ is bonded.

Specific examples of the formula (a1-1) include the following.
In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

  Specific examples of the formula (a1-2) include the following.

  Specific examples of the formula (a1-3) include the following.

  Specific examples of the formula (a1-4) include the following.

  Specific examples of the formula (a1-5) include the following.

  Specific examples of the formula (a1-6) include the following.

  Specific examples of the formula (a1-7) include the following.

  As the structural unit (a1), structural units represented by general formula (a1-21) or (a1-22) shown below are also preferred.

［式中、Ｒ、Ｒａ^６、Ｒａ^７は前記同様であり、Ｒａ^１２〜Ｒａ^１４は炭素数１〜５のアルキル基である。ｎ_ａ１０は０〜３の整数を表し、ｎ_ａ１１は１〜３の整数である。］
］

[Wherein, R, Ra ⁶ and Ra ⁷ are the same as defined above, and Ra ^{12 to} Ra ¹⁴ are alkyl groups having 1 to 5 carbon atoms. n _a10 represents an integer of 0 to 3, and n _a11 is an integer of 1 to 3. ]
]

  Specific examples of the formulas (a1-21) and (a1-21) include the following.

  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 it to the lower limit value or more, a pattern can be easily obtained when a solvent-developed negative resist composition is used, and the 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.

(Structural unit (a2) / Structural unit (a5))
The structural unit (a2) is a structural unit containing a lactone-containing cyclic group, and the structural unit (a5) is a structural unit containing a —SO ₂ — containing cyclic group. The —SO ₂ — containing cyclic group or lactone cyclic group of the structural units (a2) and (a5) increases the adhesion of the resist film to the substrate when the component (A1) is used for forming the resist film. It is effective. Moreover, it is effective in the alkali development process in that the affinity with a developer containing water such as an alkali developer is improved.

{Structural unit (a2)}
The “lactone-containing cyclic group” refers to a cyclic group containing a ring (lactone ring) containing —O—C (═O) — in the ring skeleton.
In the case where the structural units (a0) and (a1) contain a lactone-containing cyclic group in the structure, the structural unit also corresponds to the structural unit (a2). Such a structural unit is a structural unit. It corresponds to (a1) and does not correspond to the structural unit (a2).
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.
More specifically, examples of the lactone-containing cyclic group include groups represented by general formulas (a2-r-1) to (a2-r-7) shown below.

［式中、Ｒａ’^２１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり；Ｒ”は水素原子またはアルキル基であり；
Ａ”は酸素原子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, n ′ is an integer of 0 to 2, and m ′ is 0 or 1.]

As the Ra ′ ²¹ alkyl group, alkoxy group, halogen atom, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group, those described above as the substituent of the ether-containing cyclic group The same applies to R ″.

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.
s ″ is preferably an integer of 1 to 2.
Specific examples of cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7) are shown below. In addition, the wavy line in a formula shows a bond.

  The structural unit (a2) is not particularly limited as long as it has a lactone-containing cyclic group, and examples thereof include structural units represented by the following general formula (a2-1).

［式中、Ｒは前記同様であり、Ｖａ^２１は２価の炭化水素基であり、Ｌａ^２１は−Ｃ（＝Ｏ）−Ｏ−または−Ｏ−Ｃ（＝Ｏ）−結合であり、ｎ_ａ２１は０〜２であり、Ｒａ^２１は上記式（ａ２−ｒ−１）〜（ａ２−ｒ−７）で表されるラクトン含有環式基である。］

[Wherein, R is as defined above, Va ²¹ is a divalent hydrocarbon group, La ²¹ is a —C (═O) —O— or —O—C (═O) — bond, n _a21 is 0 to 2, and Ra ²¹ is a lactone-containing cyclic group represented by the above formulas (a2-r-1) to (a2-r-7). ]

In formula (a2-1), the divalent hydrocarbon group for Va ²¹ is not particularly limited, and examples thereof include the same divalent hydrocarbon groups as those described for Ya ⁰¹ . Among these, an alkylene group is preferable.
The alkylene group is preferably a linear or branched alkylene group. Specifically, the same as the linear alkylene group and the branched alkylene group mentioned as the aliphatic hydrocarbon group in Ya ⁰¹ can be given.
n _a21 is 0 to _{2, when n a21} is 2, ^{Va 21} and ^{La 21} may be different from each other.
More specifically, examples of the structural unit represented by the general formula (a2-1) include structural units represented by the following general formulas (a2-1-1) to (a2-1-3).

［式中、ＲおよびＲａ^２１はそれぞれ前記と同様であり、ｃ〜ｅはそれぞれ独立に１〜３の整数である。］

[Wherein, R and Ra ²¹ are the same as defined above, and c to e are each independently an integer of 1 to 3.] ]

{Structural unit (a5)}
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.
-SO ₂ - containing cyclic group, in particular, -O-SO ₂ - within the ring skeleton cyclic group containing, i.e. -O-SO ₂ - -O-S- medium is a part of the ring skeleton It is preferably a cyclic group containing a sultone ring to be formed.
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 an integer of 0 to 2.]

In general formulas (a5-r-1) to (a5-r-4), A ″ represents an oxygen atom (—O—) or a sulfur atom (—S—), and may have 1 to 5 carbon atoms. An alkylene group, an oxygen atom or a sulfur atom.
The alkylene group having 1 to 5 carbon atoms in A ″ is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group.
When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group in which —O— or —S— is interposed between the terminal or carbon atoms of the alkylene group, such as —O—CH _{2. -, - CH 2 -O-CH} 2 -, - S-CH 2 -, - CH 2 -S-CH 2 - , and the like.
A ″ is preferably an alkylene group having 1 to 5 carbon atoms or —O—, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.
Ra ′ ⁵¹ is the same as Ra ′ ²¹ .
Specific examples of cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4) are shown below. In the formula, “Ac” represents an acetyl group.

The structural unit (a5) is not particularly limited as long as it has a —SO ₂ — containing cyclic group, and is represented by the formula (a2-1) of the structural unit (a2). In the structural unit, a structural unit in which Ra ²¹ is replaced by the above-mentioned —SO ₂ -containing cyclic group is preferable, and is represented by the formulas (a2-1-1) to (a2-1-3) of the structural unit (a2). In the structural unit, a structural unit in which Ra ²¹ is replaced with the above-mentioned -SO ₂ -containing cyclic group is more preferable.

The component (A1) may contain one or more structural units (a2), may contain one or more structural units (a5), and may be a structural unit. (A2) and (a5) may be contained together.
When the component (A1) has one or more selected from the group consisting of the structural units (a2) and (a5), the proportion of the structural units (a2) and (a5) It is preferable that it is 1-80 mol% with respect to the sum total of a unit, It is more preferable that it is 10-70 mol%, It is more preferable that it is 10-65 mol%, 10-60 mol% is especially preferable. The effect by containing the structural units (a2) and (a5) can be sufficiently obtained by setting the lower limit value or more, and the balance with other structural units can be achieved by setting the lower limit value or less. Various lithography characteristics such as CDU and pattern shape are improved. The above ratio is the same when the component (A1) has any one of the structural units (that is, only the structural unit (a2) or (a5) only).

(Structural unit (a3))
The structural unit (a3) is a structural unit containing a polar group-containing aliphatic hydrocarbon group (excluding those corresponding to the structural units (a0), (a1), and (a2) described above).
When the component (A1) has the structural unit (a3), the hydrophilicity of the component (A) increases, which contributes to the improvement of resolution.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom. A hydroxyl group is particularly preferable.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a cyclic aliphatic hydrocarbon group (cyclic group). The cyclic group may be a monocyclic group or a polycyclic group. For example, a resin for a resist composition for an ArF excimer laser can be appropriately selected from those proposed. The cyclic group is preferably a polycyclic group, and more preferably 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom Is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like. Specific examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, there are groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane. Industrially preferable.

The structural unit (a3) is not particularly limited as long as it contains a polar group-containing aliphatic hydrocarbon group, and any structural unit can be used.
The structural unit (a3) is a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and includes a polar group-containing aliphatic hydrocarbon group A structural unit is preferred.
The structural unit (a3) is derived from a hydroxyethyl ester of acrylic acid when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms. When the hydrocarbon group is a polycyclic group, the structural unit represented by the following formula (a3-1), the structural unit represented by the formula (a3-2), the formula ( The structural unit represented by a3-3) is preferred.

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

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

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

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

As the structural unit (a3) contained in the component (A1), 1 type of structural unit may be used, or 2 or more types may be used.
In the component (A1), the proportion of the structural unit (a3) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, based on the total of all the structural units constituting the component (A1). 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.

The component (A1) may further have a structural unit (a4) containing an acid non-dissociable cyclic group as necessary. 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 contributes to the improvement in 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 polycyclic group is preferable. Examples of the polycyclic group include those exemplified in the case of the structural unit (a1), and for ArF excimer laser and KrF excimer laser (preferably for ArF excimer laser). A number of hitherto known materials can be used as the resin component of the resist composition.
In particular, at least one selected from a 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.
Moreover, as the structural unit (a4), a structural unit derived from an acrylate ester containing an acid non-dissociable aromatic group, a structural unit derived from styrene, a structural unit derived from hydroxystyrene, and the like are also preferable.
Specific examples of the structural unit (a4) include those having the following general formulas (a4-1) to (a4-6), vinyl (hydroxy) naphthalene, (hydroxy) naphthyl (meth) acrylate (hydroxy) benzyl ( A meth) acrylate etc. can be illustrated.

［式中、Ｒは前記と同じである。］

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

  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). 10 to 20 mol% is more preferable.

The component (A1) is a copolymer having at least the structural units (a0) and (a1).
Examples of such a copolymer include a copolymer composed of structural units (a0), (a1) and (a2); a copolymer composed of structural units (a0), (a1) and (a5); Copolymer consisting of units (a0), (a1) and (a3); copolymer consisting of structural units (a0), (a1), (a2) and (a3); structural units (a0), (a1) , (A2), (a5) and a copolymer comprising (a3); a copolymer comprising the structural units (a0), (a1), (a2), (a3) and (a4); a structural unit (a0) , (A1), (a5), a copolymer comprising (a3) and (a4), etc .; comprising structural units (a0), (a1), (a2), (a5), (a3) and (a4) A copolymer etc. can be illustrated.

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.

As the component (A1), one type may be used alone, or two or more types may be used in combination.
The proportion of the component (A1) in the component (A) is preferably 25% by mass or more, more preferably 50% by mass, further preferably 75% by mass, and 100% by mass with respect to the total mass of the component (A). May be. When the ratio is 25% by mass or more, lithography properties such as MEF, circularity, and roughness reduction are further improved.

The component (A) may contain a base material component (hereinafter referred to as “component (A2)”) whose polarity is increased by the action of an acid other than the component (A1) as long as the effects of the present invention are not impaired. Good.
Examples of the component (A2) include low molecular compounds having a molecular weight of 500 or more and less than 4000 and having an acid dissociable group and a hydrophilic group as exemplified in the description of the component (A1). Specific examples include those in which some or all of the hydrogen atoms of the hydroxyl group of the compound having a plurality of phenol skeletons are substituted with the acid dissociable group.
Examples of the low molecular weight compound include sensitizers in non-chemically amplified g-line and i-line resists, and some of the hydrogen atoms of the hydroxyl groups of low molecular weight phenol compounds known as heat resistance improvers. Those substituted with a dissociable group are preferred, and any of them can be used arbitrarily.
Examples of the low molecular weight phenol compound include bis (4-hydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, 2- (4-hydroxyphenyl) -2- (4′-hydroxyphenyl). ) Propane, 2- (2,3,4-trihydroxyphenyl) -2- (2 ′, 3 ′, 4′-trihydroxyphenyl) propane, tris (4-hydroxyphenyl) methane, bis (4-hydroxy-) 3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3, 4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxypheny Rumethane, bis (4-hydroxy-3-methylphenyl) -3,4-dihydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl- 4-hydroxy-6-methylphenyl) -3,4-dihydroxyphenylmethane, 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene, Examples include 2 to 6 nuclei of formalin condensates of phenols such as phenol, m-cresol, p-cresol and xylenol. Of course, it is not limited to these. In particular, a phenol compound having 2 to 6 triphenylmethane skeletons is preferable because of excellent resolution and line edge roughness (LWR). The acid dissociable group is not particularly limited, and examples thereof include those described above.

  In the resist composition used in the present invention, the content of the component (A) may be adjusted according to the resist film thickness to be formed.

<Acid generator component; (B) component>
The component (B) is an acid generator 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, poly (bissulfonyl) diazomethanes, and the like. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.
As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) can be used.

［式中、Ｒ^１０１は置換基を有していてもよい環式基、又は、置換基を有していてもよい鎖状のアルキル基若しくはアルケニル基であり
Ｙ^１０１は単結合または酸素原子を含む２価の連結基であり、
Ｖ^１０１は単結合、アルキレン基、またはフッ素化アルキレン基であり、
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り、
Ｒ^１０４、Ｒ^１０５は、それぞれ独立に、炭素数１〜１０のアルキル基またはフッ素化アルキル基であり、互いに結合して環を形成していてもよい。
Ｍ^ｍ＋はｍ価の有機カチオンである。］

[Wherein R ¹⁰¹ represents a cyclic group which may have a substituent, or a chain-like alkyl group or alkenyl group which may have a substituent, and Y ¹⁰¹ represents a single bond or an oxygen atom. A divalent linking group containing,
V ¹⁰¹ is a single bond, an alkylene group, or a fluorinated alkylene group,
R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms,
R ¹⁰⁴ and R ¹⁰⁵ are each independently an alkyl group having 1 to 10 carbon atoms or a fluorinated alkyl group, and may be bonded to each other to form a ring.
M ^{m +} is an m-valent organic cation. ]

{Anion part}
The cyclic group which may have a substituent of R ¹⁰¹ may be a cyclic aliphatic hydrocarbon group (aliphatic cyclic group), or an aromatic hydrocarbon group (aromatic cyclic group). It may be a heterocycle containing a heteroatom in the ring.
Examples of the cyclic aliphatic hydrocarbon group for R ¹⁰¹ include an aryl group obtained by removing one hydrogen atom from a monocycloalkane or polycycloalkane mentioned for the divalent aliphatic hydrocarbon group, and an adamantyl group and a norbornyl group are preferable.
Examples of the aromatic hydrocarbon group for R ¹⁰¹ include the aromatic hydrocarbon ring mentioned for the divalent aromatic hydrocarbon group, or an aryl group obtained by removing one hydrogen atom from an aromatic compound containing two or more aromatic rings. A phenyl group and a naphthyl group are preferred.
Specific examples of the heterocyclic ring for R ¹⁰¹ include: a lactone-containing cyclic group represented by the above general formulas (a2-r-1) to (a2-r-7);
The above mentioned general formula (a5-r-1) ~ (a5-r-4) with -SO ₂ represented - containing cyclic group,
・ Other heterocycles listed below.

The cyclic aliphatic hydrocarbon group, aromatic hydrocarbon group and heterocyclic ring of R ¹⁰¹ may have a substituent. Here, the hydrocarbon ring or heterocycle has a substituent means that part or all of the hydrogen atoms bonded to the ring structure of the hydrocarbon ring or heterocycle are substituted with atoms or groups other than hydrogen atoms. Say.
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), 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, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and a methoxy group. An ethoxy group is most preferred.
Examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
As the halogenated alkyl group as a substituent, a part of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, or the like A group in which all the halogen atoms are substituted is exemplified.

The chain alkyl group for R ¹⁰¹ may be either linear or branched.
The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group and the like.
The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, Examples include 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.

The alkenyl group for R ¹⁰¹ preferably has 2 to 10 carbon atoms, preferably 2 to 5, more preferably 2 to 4, and particularly preferably 3. For example, a vinyl group, a propenyl group (allyl group), a butynyl group, etc. are mentioned. Among the above, a propenyl group is particularly preferable.

Examples of the substituent in the chain alkyl group or alkenyl group of R ¹⁰¹ include, for example, the same alkoxy group, halogen atom, halogenated alkyl group, hydroxyl group, oxygen atom (═O), nitro as the substituent of the above cyclic group. Group, amino group; the above cyclic groups and the like.

In the present invention, R ¹⁰¹ is preferably a cyclic group which may have a substituent, and a group obtained by removing one or more hydrogen atoms from a phenyl group, a naphthyl group, or a polycycloalkane, lactone-containing cyclic groups represented by a2-r-1) to (a2-r-7), —SO ₂ — represented by general formulas (a5-r-1) to (a5-r-4) above Containing cyclic groups, etc. are preferred.

The divalent linking group containing an oxygen atom of Y ¹⁰¹ may contain an atom other than an oxygen atom. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, oxygen atoms, sulfur atoms, and nitrogen atoms.
Examples of the divalent linking group containing an oxygen atom include an oxygen atom (ether bond: —O—), an ester bond (—C (═O) —O—), and an amide bond (—C (═O) —NH. -), A carbonyl group (-C (= O)-), a non-hydrocarbon oxygen atom-containing linking group such as a carbonate bond (-O-C (= O) -O-); the non-hydrocarbon oxygen atom Examples include a combination of a containing linking group and an alkylene group. A sulfonyl group (—SO ₂ —) may be further linked to the combination.
Examples of the combination, for ^{example, -V 105 -O -, - V} 105 -O-C (= O) -, - C (= O) -O-V 105 -O-C (= O) -, - SO _2- O—V ¹⁰⁵ —O—C (═O) —, —V ¹⁰⁵ —SO ₂ —O—V ¹⁰⁶ —O—C (═O) — (wherein V ^{105 to} V ¹⁰⁶ are each independently alkylene. Group.) And the like.
The alkylene group for V ^{105 to} V ¹⁰⁶ is preferably a linear or branched alkylene group, and the alkylene group preferably has 1 to 12 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably 1 to 3 carbon atoms. preferable.
Examples of the alkylene group include the same alkylene groups as those described above for V ¹⁰³ and V ¹⁰⁴ .
Q ^′ is preferably a divalent linking group containing an ester bond or an ether bond, and among them, —V ¹⁰⁵ —O—, —V ¹⁰⁵ —O—C (═O) — or —C (═O) — O—V ¹⁰⁵ —O—C (═O) — is preferable.

^Examples of the alkylene group for V ¹⁰¹ include the same alkylene groups as those described above for V ¹⁰³ and V ^104, and preferably have 1 to 5 carbon atoms.
^Examples of the fluorinated alkylene group for V ¹⁰¹ include those in which part or all of the hydrogen atoms constituting the alkylene group for V ¹⁰³ and V ¹⁰⁴ are substituted with fluorine atoms. It is preferable that it is C1-C5, and 1-2 is more preferable.

Examples of the fluorinated alkyl group having 1 to 5 carbon atoms of R ¹⁰² include groups in which some or all of the hydrogen atoms constituting the alkyl group having 1 to 5 carbon atoms are substituted with fluorine atoms.

R ¹⁰⁴ and R ¹⁰⁵ are each independently an alkyl group having 1 to 10 carbon atoms or a fluorinated alkyl group, and may be bonded to each other to form a ring.
R ¹⁰⁴ and R ¹⁰⁵ are preferably linear or branched (fluorinated) alkyl groups. The (fluorinated) alkyl group has 1 to 10 carbon atoms, preferably 1 to 7 carbon atoms, and more preferably 1 to 3 carbon atoms. The number of carbon atoms of the (fluorinated) alkyl group of R ¹⁰⁴ and R ¹⁰⁵ is preferably as small as possible because of good solubility in a resist solvent within the above carbon number range.
Further, in the (fluorinated) 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 the transparency to high energy light and electron beams of 200 nm or less. This is preferable because of improved properties.
The proportion of fluorine atoms in the (fluorinated) alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are replaced with fluorine atoms. Perfluoroalkylene group or perfluoroalkyl group.

  Specific examples of the anion moiety represented by the formula (b-1) include anions represented by any of the following formulas (b1) to (b9).

［式中、ｑ１〜ｑ２はそれぞれ独立に１〜５の整数であり、ｑ３は１〜１２の整数であり、ｔ３は１〜３の整数であり、ｒ１〜ｒ２はそれぞれ独立に０〜３の整数であり、ｇは１〜２０の整数であり、Ｒ^１０７は置換基であり、ｎ１〜ｎ６はそれぞれ独立に０または１であり、ｖ０〜ｖ６はそれぞれ独立に０〜３の整数であり、ｗ１〜ｗ６はそれぞれ独立に０〜３の整数であり、Ｑ”は炭素数１〜５のアルキレン基、−Ｏ−、−Ｓ−、−Ｏ−Ｒ^９４−または−Ｓ−Ｒ^９５−であり、Ｒ^９４およびＲ^９５はそれぞれ独立に炭素数１〜５のアルキレン基であり、ｍは０または１の整数である。。］

[Wherein, q1 to q2 are each independently an integer of 1 to 5, q3 is an integer of 1 to 12, t3 is an integer of 1 to 3, and r1 to r2 are each independently 0 to 3] G is an integer of 1 to 20, R ¹⁰⁷ is a substituent, n1 to n6 are each independently 0 or 1, v0 to v6 are each independently an integer of 0 to 3, w1 to w6 are each independently an integer of 0 to 3, and Q ″ is an alkylene group having 1 to 5 carbon atoms, —O—, —S—, —O—R ⁹⁴ — or —S—R ⁹⁵ —. , R ⁹⁴ and R ⁹⁵ are each independently an alkylene group having 1 to 5 carbon atoms, and m is an integer of 0 or 1.]

In the formula, the alkylene group in Q ″, R ⁹⁴ and R ⁹⁵ is preferably a methylene group.
^Examples of the substituent for R ¹⁰⁷ include the same groups as those described above for R ¹⁰¹ , which may substitute a part of the hydrogen atoms bonded to the ring structure of the cyclic group.
Code (r1 and r2, W1 to W6) attached to R ¹⁰⁷ when is an integer of 2 or more, plural ^{by R 107} in the compound may be the same, respectively, it may be different.

{Cation part}
M ^{m +} is an m-valent organic cation.
The m-valent organic cation in M ^{m +} is not particularly limited. For example, an organic cation conventionally known as a cation moiety such as an onium-based acid generator of a resist composition can be used.
The m-valent organic cation is preferably a sulfonium cation or an iodonium cation, and those represented by the following general formulas (ca-1) to (ca-4) are particularly preferable.

［式中、Ｒ^２０１〜Ｒ^２０７、およびＲ^２１０〜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のいずれか２つ、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、
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 ^{210 to} R ²¹² each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent, and any one of 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,
L ²⁰¹ represents —C (═O) — or —C (═O) O—,
Y ²⁰¹ each independently represents an arylene group, an alkylene group or an alkenylene group,
x is 1 or 2, and W ²⁰¹ represents a (x + 1) -valent linking group. ]

As the aryl group in R ²⁰¹ to R ^207, and ^R 210 ^{to R 212,} include unsubstituted aryl group having 6 to 20 carbon atoms, a phenyl group, a naphthyl group.

The alkyl group in R ^{201 to} R ²⁰⁷ and R ^{210 to} R ²¹² is a chain / cyclic alkyl group, preferably having 1 to 30 carbon atoms.
The alkenyl group in R ^{201 to} R ²⁰⁷ and R ^{210 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, an oxo group (═O), a cyano group, an amino group, Examples include aryl groups and substituents represented by the following formulas (ca-r-1) to (ca-r-7).

［式中、Ｒ’^２０１はそれぞれ独立に、水素原子、炭素数１〜３０の炭化水素基である。］

[Wherein, R ′ ²⁰¹ each independently represents a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms. ]

The hydrocarbon group for R ′ ^{201 is the same as} the cyclic group which may have a substituent for R ^{101 and} the chain alkyl group and alkenyl group which may have a substituent.
^{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.

x is 1 or 2.
W ²⁰¹ is a (x + 1) valent, that is, a divalent or trivalent linking group.
Examples of the divalent linking group for W ²⁰¹ include the same divalent linking groups as those described above for Ya ⁰¹ , which may be linear, branched or cyclic, and cyclic. preferable. 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 a divalent linking group, a group in which a divalent linking group is further bonded to a divalent linking group, and the like. Examples of the divalent linking group include those similar to the divalent linking group of Ya ⁰¹ . The trivalent linking group in W ¹ is preferably a group in which three carbonyl groups are combined with an arylene group.

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

［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、Ｒｄ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, Rd is a hydrogen atom or a substituent, and the substituent is the same as the substituent that may be possessed by R ^{201 to} R ²⁰⁷ and R ^{210 to} R ²¹² . ]

As the organic cation in M ^{m +,} the organic cation represented by the formula (c-1) or (c-3) is preferable.

As the oxime sulfonate acid generator, an oxime sulfonate acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014], [Chem. 18] to [Chem. 19]), International Publication An oxime sulfonate-based acid generator disclosed in the pamphlet of No. 04/074242 (Examples 1 to 40 on pages 65 to 86) can be preferably used.
As the diazomethane acid generator, diazomethane acid generators disclosed in JP-A-11-035551, JP-A-11-035552, and JP-A-11-035573 can be suitably used.
Examples of poly (bissulfonyl) diazomethanes include 1,3-bis (phenylsulfonyldiazomethylsulfonyl) propane and 1,4-bis (phenylsulfonyldiazo) disclosed in JP-A-11-322707. Methylsulfonyl) butane, 1,6-bis (phenylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (phenylsulfonyldiazomethylsulfonyl) decane, 1,2-bis (cyclohexylsulfonyldiazomethylsulfonyl) ethane, 1,3 -Bis (cyclohexylsulfonyldiazomethylsulfonyl) propane, 1,6-bis (cyclohexylsulfonyldiazomethylsulfonyl) hexane, 1,10-bis (cyclohexylsulfonyldiazomethylsulfonyl) decane, etc. Door can be.

As the component (B), one type of acid generator described above may be used alone, or two or more types may be used in combination.
When the resist composition 1 of this invention contains (B) component, 0.5-60 mass parts is preferable with respect to 100 mass parts of (A ') component, and (B) component is 1-50. A mass part is more preferable, and 1-40 mass parts is still 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>
The component (D) is a basic compound component, and acts as an acid diffusion control agent, that is, a quencher that traps acid generated from the component (B) by exposure. In the present invention, the “basic compound” refers to a compound that is relatively basic with respect to the component (B).
(D) component in this invention contains the basic compound component (D1) (henceforth "(D1) component") which has a fluorine atom.

[(D1) component]
The component (D1) in the present invention is not particularly limited as long as it has a fluorine atom and is relatively basic with respect to the component (B). It is preferable to include a compound consisting of the following, more preferably a photoreactive quencher, a compound (d1) represented by the following general formula (d1) (hereinafter referred to as component (d1)), and the following general formula (d2). 1) selected from the group consisting of compound (d2) (hereinafter referred to as component (d2)) represented by formula (1) and compound (d3) (hereinafter referred to as component (d3)) represented by formula (d3) below. More preferably, it contains more than one compound.
The “photoreactive quencher” does not act as a quencher in the exposed part, but acts as a quencher in the unexposed part.

［式中、Ｒｄ^１は置換基を有していてもよいフッ素化アルキル基、又は置換基を有していてもよい炭化水素基であり、Ｒｄ^２は置換基を有していてもよい炭素数１〜３０の炭化水素基である。ただし、式（ｄ１）、（ｄ２）において、Ｒｄ^１又はＲｄ^２がフッ素原子を含まない場合、式中のＭ^ｍ＋がその置換基にフッ素原子を含む。また、式（ｄ２）において、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。Ｒｄ^３は有機基であり、Ｙｄ^１は直鎖状、分岐鎖状若しくは環状のアルキレン基又はアリーレン基であり、Ｒｄ^ｆ２はフッ素原子を含む炭化水素基である。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 is a fluorinated alkyl group which may have a substituent, or a hydrocarbon group which may have a substituent, and Rd ² is a carbon which may have a substituent. It is a hydrocarbon group of the number 1-30. However, in formulas (d1) and (d2), when Rd ¹ or Rd ² does not contain a fluorine atom, M ^{m +} in the formula contains a fluorine atom in the substituent. In the formula (d2), it is assumed that no fluorine atom is bonded to the carbon atom adjacent to the S atom. Rd ³ is an organic group, Yd ¹ is a linear, branched or cyclic alkylene group or an arylene group, and Rd ^f2 is a hydrocarbon group containing a fluorine atom. M ^{m +} is each independently an m-valent organic cation. ]

((D1) component)
Anion formula (d1), Rd ¹ which may have a substituent fluorinated alkyl group, or have a substituent is also optionally substituted hydrocarbon group.
The fluorinated alkyl group which may have a substituent of Rd ¹ may be linear or cyclic, but is preferably linear or branched.
1-11 are preferable, as for carbon number of a fluorinated alkyl group, 1-8 are more preferable, and 1-4 are more preferable. Specifically, for example, a part or all of a linear alkyl group such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, etc. Or a branched chain such as a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, or a 3-methylbutyl group. And a group in which some or all of the hydrogen atoms constituting the alkyl group are substituted with fluorine atoms.
The fluorinated alkyl group for Rd ¹ may contain an atom other than a fluorine atom. Examples of atoms other than fluorine atoms include oxygen atoms, carbon atoms, hydrogen atoms, oxygen atoms, sulfur atoms, and nitrogen atoms.
Among them, the fluorinated alkyl group for Rd ¹ is preferably a group in which some or all of the hydrogen atoms constituting the linear alkyl group are substituted with fluorine atoms. It is preferable that all the hydrogen atoms which comprise are the group (perfluoroalkyl group) substituted by the fluorine atom.

The hydrocarbon group which may have a substituent of Rd ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and has a substituent of R ^{101 in} the component (B). Examples thereof are the same as the cyclic group which may be substituted, the chain alkyl group which may have a substituent, and the alkenyl group.
Among them, the hydrocarbon group which may have a substituent of Rd ¹ is an aromatic hydrocarbon group which may have a substituent, or an aliphatic cyclic group which may have a substituent. A phenyl group or naphthyl group which may have a substituent; one or more hydrogen atoms are removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane. More preferably, it is a group.

Further, the hydrocarbon group which may have a substituent of Rd ¹ is preferably a linear, branched, or alicyclic alkyl group, or a fluorinated alkyl group.
The linear, branched or alicyclic alkyl group of Rd ¹ preferably has 1 to 10 carbon atoms, specifically, methyl group, ethyl group, propyl group, butyl group, pentyl group, Linear alkyl group such as hexyl group, heptyl group, octyl group, nonyl group, decyl group, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group A branched alkyl group such as 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, norbornyl group And alicyclic alkyl groups such as an adamantyl group.

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

In the cation partial formula (d1), M ^{m +} is an m-valent organic cation, which is the same as the cation in the component (B). Especially, it is preferable that they are a sulfonium cation or an iodonium cation, and the cation part represented by the said formula (ca-1-1)-(ca-1-57) is preferable.
However, in the component (d1), when Rd ¹ in the formula does not contain a fluorine atom, M ^{m +} contains a fluorine atom as a substituent. As M ^{m + in the} case of containing a fluorine atom, for example, a hydrogen atom constituting an aryl group or an alkyl group of R ^{201 to} R ²⁰⁷ and R ^{210 to} R ^{212 in} the formulas (ca-1) to (ca-4) And a cation moiety in which a part or all of them are substituted with a fluorine atom or a fluorinated alkyl group. Specifically, the above-described formulas (ca-1-29), (ca-1-33), (ca- 1-37) to (ca-1-39), cation moieties represented by (ca-1-40), and the like. Among these, (d1) as the component, it is preferred that Rd ¹ anion portion has a fluorine atom.
As the component (d1), one type may be used alone, or two or more types may be used in combination.

((D2) component)
Anion formula (d2), Rd ² is a hydrocarbon group of 1 to 30 carbon atoms which may have a substituent.
The hydrocarbon group having 1 to 30 carbon atoms which may have a substituent of Rd ² may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and the component (B) in the component (B) Examples are the same as the cyclic group which may have a substituent of R ^101, the chain alkyl group which may have a substituent, and the alkenyl group.
Among them, the hydrocarbon group which may have a substituent of Rd ² is preferably an aliphatic cyclic group which may have a substituent, such as adamantane, norbornane, isobornane, tricyclodecane, It is more preferably a group obtained by removing one or more hydrogen atoms from tetracyclododecane, camphor or the like (which may have a substituent).
The hydrocarbon group for Rd ² may have a substituent, and examples of the substituent include those similar to R ¹⁰¹ in the component (B). However, in Rd ² , the carbon adjacent to the S atom in SO ₃ ^— is not fluorine-substituted. Since SO ₃ ^— and a fluorine atom are not adjacent to each other, the anion of the component (d2) becomes an appropriate weak acid anion, and the quenching ability of the component (d2) is improved.
Preferred specific examples of the anion moiety of the component (d2) are shown below.

· Cation In formula (d2), ^{M m +} is the same as ^{M m +} in the formula (d1) in.
However, in the component (d2), when Rd ² in the formula does not contain a fluorine atom, M ^{m +} contains a fluorine atom as a substituent. M ^{m + in the} case of containing a fluorine atom is the same as that described above for the component (d1).
As the component (d2), one type may be used alone, or two or more types may be used in combination.

((D3) component)
During Anion formula (d3), Rd ³ is an organic group.
The organic group of Rd ³ is not particularly limited, but is an alkyl group, an alkoxy group, —O—C (═O) —C (Rd ³¹ ) ═CH ₂ (Rd ³¹ is a hydrogen atom, and has 1 to 5 carbon atoms. Or an alkyl group having 1 to 5 carbon atoms), or —O—C (═O) —Rd ³² (Rd ³² is a hydrocarbon group).
The alkyl group of Rd ³ 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 ³ may be substituted with a hydroxyl group, a cyano group or the like.
The alkoxy group of Rd ³ is preferably an alkoxy group having 1 to 5 carbon atoms. Specific examples of the alkoxy group having 1 to 5 carbon atoms include methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n- Examples include butoxy group and tert-butoxy group. Of these, a methoxy group and an ethoxy group are most preferable.

When Rd ³ is —O—C (═O) —C (Rd ³¹ ) ═CH ₂ , Rd ³¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. is there.
The alkyl group having 1 to 5 carbon atoms in Rd ³¹ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, n -Butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like can be mentioned.
The halogenated alkyl group for Rd ³¹ is a group in which part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
Rd ³¹ is preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a fluorinated alkyl group having 1 to 3 carbon atoms, and is most preferably a hydrogen atom or a methyl group in terms of industrial availability.

When Rd ³ is —O—C (═O) —Rd ³² , Rd ³² is a hydrocarbon group.
The hydrocarbon group for Rd ³² may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. Specific examples of the hydrocarbon group for Rd ³² include a cyclic group which may have a substituent for R ^{101 in} the component (B), a chain alkyl group which may have a substituent, and an alkenyl. The same thing as a group is mentioned.
Among them, the hydrocarbon group of Rd ³² includes an alicyclic group in which one or more hydrogen atoms are removed from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like. Aromatic groups such as phenyl group and naphthyl group are preferred. When Rd ³² is an alicyclic group, the resist composition is well dissolved in an organic solvent, so that the lithography properties are improved. In addition, when Rd ³² is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition has excellent light absorption efficiency, and good sensitivity and lithography characteristics.

Among these, as Rd ³ , —O—C (═O) —C (Rd ³¹ ′) ═CH ₂ (Rd ³¹ ′ is a hydrogen atom or a methyl group), or —O—C (═O ) -Rd ³² ′ (Rd ³² ′ is an aliphatic cyclic group).

In formula (d3), Yd ¹ represents a linear, branched or cyclic alkylene group or an arylene group.
Yd ¹ linear, the branched or cyclic alkylene group or arylene group, among the divalent linking group for the Ya ⁰¹ "linear or branched aliphatic hydrocarbon group", " Examples thereof include those similar to “cyclic aliphatic hydrocarbon group” and “aromatic hydrocarbon group”.
Among these, Yd ¹ is preferably an alkylene group, more preferably a linear or branched alkylene group, and even more preferably a methylene group or an ethylene group.

In formula (d3), Rd ^f2 is a hydrocarbon group containing a fluorine atom.
The hydrocarbon group containing a fluorine atom of Rd ^f2 is preferably a fluorinated alkyl group, and more preferably the same as the fluorinated alkyl group of Rd ^{1 in} the above formula (d1).
Preferred specific examples of the anion moiety of the component (d3) are shown below.

· Cation In formula (d3), ^{M m +} is the same as ^{M m +} in the formula (d1) in.
As the component (d3), one type may be used alone, or two or more types may be used in combination.

As the components (d1) to (d3), one type may be used alone, or two or more types may be used in combination.
The total content of the components (d1) to (d3) is preferably 0.5 to 10.0 parts by mass with respect to 100 parts by mass of the component (A), and 0.5 to 8.0 parts by mass. It is more preferable that it is 1.0 to 8.0 parts by mass. When it is at least the lower limit of the above range, particularly good lithography properties and resist pattern shape can be obtained. When the amount is not more than the upper limit of the above range, the sensitivity can be maintained satisfactorily and the throughput is excellent.

The production method of the component (d1) and the component (d2) is not particularly limited, and can be produced by a known method. In addition, the production method of the component (d3) is not particularly limited. For example, when Rd ³ in the formula (d3) is a group having an oxygen atom at the terminal bonded to Yd ¹ , the following general formula By reacting the compound (i-1) represented by the formula (i-1) with the compound (i-2) represented by the following general formula (i-2), the following general formula (i-3) And the compound (i-3) is reacted with Z ⁻ M ^{m +} (i-4) having the desired cation M ^{m +} to give a compound represented by the general formula (d3) The compound (d3) represented by these is manufactured.

［式中、Ｒｄ^３、Ｙｄ^１、Ｒｄ^ｆ１、Ｍ^ｍ＋は、それぞれ、前記一般式（ｄ３）中のＲｄ^３、Ｙｄ^３、Ｒｄ^ｆ１、Ｍ^ｍ＋と同じである。Ｒｄ^３ａはＲｄ^３から末端の酸素原子を除いた基であり、Ｚ⁻は対アニオンである。］

[Wherein, Rd ³ , Yd ¹ , Rd ^f1 and M ^{m +} are the same as Rd ³ , Yd ³ , Rd ^f1 and M ^{m + in the} general formula (d3), respectively. Rd ^3a is a group obtained by removing a terminal oxygen atom from Rd ³ , and Z ⁻ is a counter anion. ]

First, compound (i-1) and compound (i-2) are reacted to obtain compound (i-3).
In formula (i-1), Rd ³ is the same as described above, and Rd ^3a is a group obtained by removing a terminal oxygen atom from Rd ³ . In formula (i-2), Yd ¹ and Rd ^f1 are the same as described above.
As compound (i-1) and compound (i-2), commercially available compounds may be used or synthesized.
The method for obtaining compound (i-3) by reacting compound (i-1) with compound (i-2) is not particularly limited. For example, compound (i-) can be obtained in the presence of an appropriate acid catalyst. After reacting 2) and compound (i-1) in an organic solvent, the reaction mixture can be washed and recovered.

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

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

Next, the obtained compound (i-3) and the compound (i-4) are reacted to obtain the compound (d3).
In formula (i-4), M ^{m +} is the same as described above, and Z ⁻ is a counter anion.
The method of reacting compound (i-3) with compound (i-4) to obtain compound (d3) is not particularly limited. For example, compound (i-3) can be obtained in the presence of a suitable alkali metal hydroxide. -3) is dissolved in a suitable organic solvent and water, and the compound (i-4) is added and reacted by stirring.

The alkali metal hydroxide in the above reaction is not particularly limited, and examples thereof include sodium hydroxide, potassium hydroxide and the like, and the amount used is 0.3 to 1 mol per 1 mol of compound (i-3). About 3 mol is preferable.
Examples of the organic solvent in the above reaction include solvents such as dichloromethane, chloroform, and ethyl acetate, and the amount used is preferably 0.5 to 100 parts by mass with respect to compound (i-3). More preferably, it is 5-20 mass parts. A solvent may be used individually by 1 type and may use 2 or more types together.
The amount of compound (i-4) used in the above reaction is usually preferably about 0.5 to 5 mol, more preferably about 0.8 to 4 mol, relative to 1 mol of compound (i-3).

The reaction time in the above reaction varies depending on the reactivity between the compound (i-3) and the compound (i-4), the reaction temperature, etc., but is usually preferably 1 to 80 hours, more preferably 3 to 60 hours. .
The reaction temperature in the above reaction is preferably 20 ° C to 200 ° C, more preferably about 20 ° C to 150 ° C.
After completion of the reaction, the compound (d3) in the reaction solution may be isolated and purified. For isolation and purification, conventionally known methods can be used. For example, concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography, etc. can be used alone or in combination of two or more thereof. it can.

The structure of the compound (d3) obtained as described above has the following structure: ¹ H-nuclear magnetic resonance (NMR) spectrum method, ¹³ C-NMR spectrum method, ¹⁹ F-NMR spectrum method, infrared absorption (IR) spectrum method, mass It can be confirmed by a general organic analysis method such as analysis (MS) method, elemental analysis method or X-ray crystal diffraction method.

  In addition, as the component (D1) in the present invention, a basic compound containing a fluorine atom other than a compound composed of a cation part and an anion part can also be used. Such compounds include trifluoroethylamine, pentafluoropentylamine, heptafluorobutylamine, nonafluoropentylamine, pentafluoropyridine and the like.

  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 the amount is not more than the upper limit of the above range, the sensitivity can be maintained satisfactorily and the throughput is excellent.

[(D2) component]
(D) component may contain the other basic compound component (henceforth (D2) component) which does not correspond to the said (D1) component.
The component (D2) is particularly limited as long as it is a compound that is relatively basic with respect to the component (B), acts as an acid diffusion controller, and does not fall under the component (D1). It may be used arbitrarily from known ones. 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 roughness are further improved when a resist composition is used. Further, a better resist pattern shape can be obtained. When the amount is not more than the upper limit of the above range, the sensitivity can be maintained satisfactorily and the throughput is excellent.

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

[(F) component]
The resist composition of the present invention may contain a fluorine additive (hereinafter referred to as “component (F)”) in order to impart water repellency to the resist film. Examples of the component (F) include those described in JP 2010-002870 A, JP 2010-032994 A, JP 2010-277043 A, JP 2011-13569 A, and JP 2011-128226 A. These fluorine-containing polymer compounds can be used.
More specifically, examples of the component (F) include a polymer having a structural unit (f1) represented by the following formula (f1-1). Examples of such a polymer include a polymer consisting of only the structural unit (f1) (homopolymer); a copolymer of the structural unit represented by the following formula (f1) and the structural unit (a1); ), A copolymer of the structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1). Here, as the structural unit (a1) copolymerized with the structural unit represented by the following formula (f1), the structural unit represented by the formula (a1-1) (more preferably 1-ethyl-1 The structural unit represented by -cyclooctyl (meth) acrylate) or the structural unit represented by (a1-21) is preferable.

［式中、Ｒは前記同様であり、ａ１は１〜５の整数であり、Ｒ^２”はフッ素原子を含む有機基である。］

[Wherein, R is the same as defined above, a1 is an integer of 1 to 5, and R ² ″ is an organic group containing a fluorine atom.]

In formula (f1-1), R ^{2 ″} 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 is linear or branched. Examples include a group in which part or all of the hydrogen atoms of a chain alkyl group (preferably a linear alkyl group) are substituted with fluorine atoms.
Among these, R ^{2 ″} is preferably a group represented by “— (CH ₂ ) _o —CF ₃ ” (wherein o is an integer of 1 to 3).
In formula (f1-1), a1 is an integer of 1 to 5, preferably an integer of 1 to 3, and more preferably 1 or 2.
In formula (f1-1), R is the same as described above. R is preferably a hydrogen atom or a methyl group.
(F) As for the mass mean molecular weight (Mw) (polystyrene conversion reference | standard by a gel permeation chromatography), 1000-50000 are preferable, 5000-40000 are more preferable, and 10000-30000 are the most preferable. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
The dispersity (Mw / Mn) of the component (F) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5.

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

  The 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.

[(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, methyl isopentyl ketone, 2-heptanone; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol Polyhydric alcohols such as: ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, etc., compounds having an ester bond, monohydric ethers of the polyhydric alcohols or compounds having an ester bond , Monoalkyl ethers such as monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having an ether bond [in these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, and lactic acid Esters such as methyl, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, Diphenyl ether, dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, etc. An aromatic organic solvent, dimethyl sulfoxide (DMSO), etc. can be mentioned.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Of these, PGMEA, PGME, γ-butyrolactone, 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.

According to the resist composition of the present invention, it is possible to form a resist pattern excellent in lithography characteristics and residual film characteristics such as CDU in a solvent development negative type process using an organic developer.
The reason why the above effect is obtained is not clear, but the structural unit (a0) of the component (A1) of the present invention functions as a crosslinking component that undergoes ring-opening polymerization in the exposed portion, so that the film of the pattern portion by the developer is used. The decrease is considered to be reduced. In addition, the molecular weight of the component (A1) increases due to the polymerization of the structural unit (a0) in the exposed area, and the solubility in the developer decreases. On the other hand, in the unexposed area, the molecular weight changes and the solubility in the developer changes. Therefore, it is considered that the dissolution contrast between the exposed portion and the unexposed portion can be further improved, and the lithography characteristics are improved.
In addition, in the present invention, a group having a crosslinking ability is contained in the base material component as a structural unit (a0), so that a cross-linking agent component of a low molecular compound is added separately from the base material component. Thus, it is presumed that the diffusion of the group having crosslinking ability in the resist film can be appropriately controlled, and the lithography characteristics such as LWR and the pattern shape are improved.

Usually, since the acid generator is unevenly distributed near the surface of the resist film, the phenomenon that a part of the acid generated from the acid generator in the exposed area affects the unexposed area becomes prominent near the surface of the resist film. It was. In the solvent development negative type process, the exposed portion of the acid diffuses to the unexposed portion in the vicinity of the resist film surface layer, so that a part of the unexposed portion surface layer to be dissolved and removed is not removed. In some cases, the problem is that the line pattern is inferior, the shape of the line pattern is inversely tapered, or the like.
In the present invention, since the component (D1) contains a fluorine atom in its structure, the component (D1) is easily segregated near the surface layer in the resist film, and the component (D1) is an excess acid in the vicinity of the resist film surface layer. It is considered that good lithographic properties can be obtained by suppressing the diffusion of.

≪Resist pattern formation method≫
More specifically, the resist pattern forming method of the second aspect of the present invention can be performed, for example, as follows.
First, the solvent-developed negative resist composition is applied onto a support with a spinner or the like, and a baking (post-apply bake (PAB)) treatment is performed, for example, at a temperature of 80 to 150 ° C. for 40 to 120 seconds, preferably A resist film is formed by applying for 60 to 90 seconds. 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 having a two-layer structure of an upper layer resist film and a lower layer organic film (two layer resist method), and one or more intermediate layers between the upper layer resist film and the lower layer organic film And a method of forming a multilayer structure of three or more layers (metal thin film etc.) (three-layer resist method).

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

  Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.

[Example 1, Comparative Examples 1-3]
Each component shown in Table 1 was mixed and dissolved to prepare a solvent-developed negative resist composition.

Each abbreviation in Table 1 has the following meaning. Moreover, the numerical value in [] is a compounding quantity (mass part).
(A) -1: the following polymer compound (A) -1 [Mw = 10000, Mw / Mn = 1.61, 1 / m / n / o / p = 20/30/20/10/20 (molar ratio) ]].
(A) -2: the following polymer compound (A) -2 [Mw = 10000, Mw / Mn = 1.61, 1 / m / n / o = 25/35/25/15 (molar ratio)].
(B) -1: The following compound (B) -1.
(D) -1: The following compound (D) -1.
(D) -2: tri-n-pentylamine.
(D) -3: The following compound (D) -3.
(F) -1: The following polymer compound (F) -1.
(S) -1: Mixed solvent of PGMEA / cyclohexanone: 9/1 (mass ratio).

[Resist pattern formation and residual film characteristics evaluation]
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. As a result, an organic antireflection film having a thickness of 89 nm was formed.
Then, the resist composition of each example is applied onto the organic antireflection film using a spinner, prebaked (PAB) on a hot plate at 105 ° C. for 60 seconds, and dried. Thus, a resist film having a thickness of 100 nm was formed.
Next, ArF excimer was performed using an ArF immersion exposure apparatus NSR-S609B (Nikon Corporation; NA (numerical aperture) = 1.07, Cross pole (in / out = 0.97 / 0.78) with XY-Polarization). The laser was selectively irradiated through a halftone mask. Then, PEB treatment was performed at 85 ° C. for 60 seconds, development processing was further carried out with butyl acetate at 23 ° C. for 13 seconds, development treatment was further carried out with butyl acetate at 23 ° C. for 13 seconds, and drying was performed.
As a result, in each example, a 1: 2 line and space (LS) pattern having a space width of 50 nm and a pitch of 150 nm was formed on the resist film.
In the pattern portion of the 1: 2LS pattern formed as described above, the film thickness (nm) after development was measured, and the remaining film characteristics were evaluated. The results are also shown in Table 1.

[CDU evaluation]
A contact hole (CH) pattern in which holes with a hole diameter of 50 nm are arranged at equal intervals (pitch: 100 nm) was formed in the same manner as above except that the mask used was changed.
The CD of 100 holes in each of the formed CH patterns was measured, and a triple value (3σ) of the standard deviation (σ) calculated from the result was obtained. The results are also shown in Table 1.
3σ obtained in this way means that the smaller the value, the higher the CD uniformity of each hole formed in the resist film.

From the above results, it was confirmed that the resist composition of Example 1 according to the present invention was superior in CDR and remaining film ratio as compared with the resist compositions of Comparative Examples 1 to 3.

Claims (2)

Using a resist composition containing a base material component (A) whose solubility in an organic solvent is reduced by the action of an acid, an acid generator component (B) that generates acid upon exposure, and a basic compound component (D) A step of forming a resist film on a support, a step of exposing the resist film, and a step of patterning the resist film by negative development using a developer containing the organic solvent to form a resist pattern; A resist composition used for a resist pattern forming method comprising:
The base component (A) is a structural unit (a0) containing a 3- to 7-membered ether-containing cyclic group;
A resin component (A1) having a structural unit (a1) containing an acid-decomposable group whose polarity is increased by the action of an acid, and a structural unit (a5) containing a —SO ₂ — containing cyclic group ,
The 3- to 7-membered ether-containing cyclic group is a group represented by any one of the following general formulas (a0-r-1) to (a0-r-5),
The basic compound component (D) includes a compound (d1 ) represented by the following general formula (d1),
The solvent developing negative type wherein the acid generator component (B) contains a compound having an anion moiety represented by any of the following formulas (b1) to (b3) and (b6) to (b9) Resist composition.

[Wherein, each R ′ is independently 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; n _a01 is 0 or 1, and n _a02 is an integer of 0 to 2.]

Wherein, ^{R 8} is a fluorinated alkyl group. M ^{m +} is each independently an m-valent organic cation. ]

[Wherein, q1 to q2 are each independently an integer of 1 to 5, q3 is an integer of 1 to 12, t3 is an integer of 1 to 3, and r1 to r2 are each independently 0 to 3] G is an integer of 1 to 20, R ¹⁰⁷ is a substituent, n3 to n6 are each independently 0 or 1, and v0 and v3 to v6 are each independently an integer of 0 to 3. Each of w3 to w6 is independently an integer of 0 to 3, and Q ″ is an alkylene group having 1 to 5 carbon atoms, —O—, —S—, —O—R ⁹⁴ — or —S—R ⁹⁵ —. R ⁹⁴ and R ⁹⁵ are each independently an alkylene group having 1 to 5 carbon atoms.]   A step of forming a resist film on a support using the solvent-developed negative resist composition according to claim 1, a step of exposing the resist film, and a developing solution containing the organic solvent as the resist film. And a step of forming a resist pattern by patterning with the negative development used.