JP6515140B2 - Resist composition and method for forming resist pattern - Google Patents

Description

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

A technique (pattern forming technique) of processing a lower layer of a pattern by forming a fine pattern on a substrate and performing etching using this 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 the lithography method, a resist film is formed on a support such as a substrate using a resist material containing a base component such as a resin, and the resist film is selected by radiation such as light or electron beam. The step of forming a resist pattern of a predetermined shape on the resist film is carried out by performing a selective exposure and a development treatment. Then, a semiconductor element or the like is manufactured through the process of processing the substrate by etching using the resist pattern as a mask.
The resist material is divided into a positive type and a negative type, and the solubility of the exposed portion in the developer is increased. The resist material is referred to as a positive type. The resist material in which the exposed portion is reduced in the developer is referred to as a negative. .
As the developer, an aqueous alkaline solution (alkaline developer) such as an aqueous solution of tetramethyl ammonium hydroxide (TMAH) is usually used. In addition, organic solvents such as aromatic solvents, aliphatic hydrocarbon solvents, ether solvents, ketone solvents, ester solvents, amide solvents, alcohol solvents and the like are also used as a developer.

In recent years, with the advance of lithography technology, miniaturization of patterns is rapidly advancing.
Generally as a method of refinement | miniaturization, shortening of the wavelength (exposure) of the exposure light source is performed. Specifically, conventionally, ultraviolet rays represented by g-line and i-line have been used, but at present, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has been started. Also, studies are being made on EB (electron beam), EUV (extreme ultraviolet), X-ray, etc., which have a shorter wavelength (high energy) than these excimer lasers.
With the shortening of the wavelength of the exposure light source, the resist material is required to improve the lithography characteristics such as the sensitivity to the exposure light source and the resolution capable of reproducing the pattern of fine dimensions. Chemically amplified resist compositions are known as resist materials satisfying such requirements.
As the chemically amplified resist composition, generally used is one containing a base component whose solubility in a developer changes due to the action of an acid, and an acid generator component which generates an acid upon exposure to light. There is. For example, when the developing solution is an alkaline developing solution (alkali developing process), a base component having an increased solubility in the alkaline developing solution by the action of an acid is used.
Heretofore, resins (base resins) have been mainly used as base components of chemically amplified resist compositions. At present, as a base resin of a chemically amplified resist composition used in ArF excimer laser lithography and the like, it has a structural unit derived from (meth) acrylic acid ester in the main chain because it has excellent transparency at around 193 nm. Resin (acrylic resin) is the mainstream.

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

  The base resin of the chemical amplification resist composition generally has plural types of structural units in order to improve the lithography properties and the like. For example, a structural unit having a lactone structure, a structural unit having a polar group such as a hydroxyl group, etc. may be used together with a structural unit having an acid degradable group which is decomposed by the action of an acid generated from an acid generator to generate an alkali soluble group. (See, for example, Patent Document 1). When the base resin is an acrylic resin, generally, as the acid decomposable group, the carboxy group in (meth) acrylic acid etc. is protected by an acid dissociable group such as a tertiary alkyl group or an acetal group The thing is used.

  The positive developing process, which is a combination of a positive chemically amplified resist composition, that is, a chemically amplified resist composition in which the solubility in an alkali developer increases with exposure, and an alkaline developer, is a negative chemically amplified resist process. As compared with a negative development process in which a resist composition and an alkali developer are combined, there are advantages such as the ability to simplify the structure of the photomask and the excellent characteristics of the formed pattern. Therefore, at present, a positive development process in which a positive chemically amplified resist composition and an alkali developer are combined is mainly used for forming a fine pattern.

In recent years, with the further progress of lithography technology and the expansion of application fields, etc., improvement of various lithography properties is further demanded for the positive development process.
In the case of applying the positive development process, when the resist film obtained by applying the chemically amplified resist composition on a support is selectively exposed, the exposed portion of the resist film is degraded by the acid decomposition in the base resin. While the basic group is decomposed by the action of the acid generated from the acid generator etc. and turns from being poorly soluble to soluble in the alkaline developer, the unexposed area of the resist film remains poorly soluble in alkali, so By developing with a developer, dissolution contrast can be provided between the exposed portion and the unexposed portion, and a positive resist pattern can be formed.
However, if a more fine pattern (isolated trench pattern, fine and dense contact hole pattern, etc.) is to be formed by applying the positive development process, the optical part of the exposed part of the resist film, particularly in the film thickness direction, Regions of weak strength are generated, and the resolution of the resist pattern is likely to be reduced.

In order to form such a fine pattern as described above, a method in which a region having weak optical strength is selectively dissolved and removed to form a resist pattern (negative resist pattern) is useful. As a method of forming a negative resist pattern using a chemically amplified resist composition used in the mainstream positive developing process, a negative developing process combined with a developer containing an organic solvent (organic developer) Are known (see, for example, Patent Documents 2 and 3).
In the case of applying the negative development process, when the resist film obtained by applying the chemically amplified resist composition on a support is selectively exposed, the exposed portion of the resist film is degraded by the acid decomposition in the base resin. The organic group is decomposed by the action of the acid generated from the acid generator etc. and turns from soluble to insoluble in the organic developer while the unexposed area of the resist film remains soluble. By developing with a developer, dissolution contrast can be provided between the exposed portion and the unexposed portion, and a negative resist pattern can be formed.

Unexamined-Japanese-Patent No. 2003-241385 JP, 2011-191727, A JP 2012-073565 A

With the ever-increasing performance and miniaturization of electronic devices, further improvement in lithography characteristics and resist pattern shape is required for pattern formation in the manufacture of semiconductor devices and the like. However, conventionally, in the lithography method, it is particularly difficult to achieve both in-plane uniformity (CDU) of pattern dimensions and depth of focus (DOF) characteristics.
The present invention has been made in view of the above circumstances, and an object thereof is to improve the lithography characteristics and the resist pattern shape.

In order to solve the above-mentioned subject, the present invention adopted the following composition.
That is, a first aspect of the present invention is a resist composition which generates an acid upon exposure and whose solubility in a developer changes by the action of the acid, and is represented by the following general formula (a0-1) Structural unit (a0) and, among the acid-degradable groups whose polarity is increased by the action of an acid, a group containing a monocyclic group or a structural unit (a1) containing a chain group, and the action of an acid Among the acid-degradable groups that increase, a structural unit (a1 ′) containing a group containing a polycyclic group, a structural unit (a2) containing a lactone-containing monocyclic group, and a —SO ₂ — containing cyclic group And a polymer compound (A1) having a structural unit (a5) containing the above, and the ratio of the structural unit (a1) to the total of all structural units constituting the polymer compound (A1) is the structural unit It is a resist composition characterized by having a ratio of (a1 ') or more.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基である。Ｒ^１はラクトン含有多環式基である。Ｒ^２及びＲ^３はそれぞれ独立に水素原子又は炭素数１〜５のアルキル基である。Ｌ^１はエステル結合である。ｎ_１は１〜３の整数である。］

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. R ¹ is a lactone-containing polycyclic group. R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. L ¹ is an ester bond. n ₁ is an integer of ₁ to 3; ]

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

  The resist composition and the method for forming a resist pattern according to the present invention can form a resist pattern excellent in lithography properties and shape.

In the present specification and claims, “aliphatic” is a concept relative to an aromatic and is defined to mean a group, a compound or the like having no aromaticity.
The term "alkyl group" is intended to include linear, branched and cyclic monovalent saturated hydrocarbon groups, unless otherwise specified. The same applies to the alkyl group in the alkoxy group.
The "alkylene group" is intended to include a linear, branched and cyclic divalent saturated hydrocarbon group unless otherwise specified.
The “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
The "fluorinated alkyl group" or "fluorinated alkylene group" refers to a group in which part or all of the hydrogen atoms of the alkyl group or the alkylene group are substituted with a fluorine atom.
The "constituent unit" means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).
When it is described that "it may have a substituent", when substituting a hydrogen atom (-H) with a monovalent group and when substituting a methylene group (-CH _2- ) with a divalent group And both.
"Exposure" is a concept that includes general radiation irradiation.

The “constituent unit derived from acrylic acid ester” means a constitutional unit formed by cleavage of the ethylenic double bond of acrylic acid ester.
The “acrylic 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 acrylic ester, the hydrogen atom bonded to the carbon atom at the α-position may be substituted by a substituent. The substituent (R ^α0 ) for substituting the hydrogen atom bonded to the carbon atom at the α-position is an atom or a group other than a hydrogen atom, and is, for example, an alkyl group of 1 to 5 carbon atoms, or a halogenation of 1 to 5 carbon atoms An alkyl group etc. are mentioned. Further, itaconic acid diesters in which the substituent (R ^α0 ) is substituted with a substituent containing an ester bond, and α hydroxy acrylic esters in which the substituent (R ^α0 ) is substituted with a hydroxyalkyl group or a group modified with a hydroxyl group thereof Shall be included. In addition, the carbon atom of alpha-position of acrylic acid ester is a carbon atom which the carbonyl group of acrylic acid has couple | bonded, unless there is particular notice.
Hereinafter, an acrylic acid 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 acrylic acid ester. Moreover, an acrylic ester and an alpha substituted acrylic ester may be included and it may be called "(alpha substituted) acrylic ester."

The “constituent unit derived from acrylamide” means a constituent unit formed by cleavage of the ethylenic double bond of acrylamide.
In the acrylamide, the hydrogen atom bonded to the carbon atom at the α position may be substituted by a substituent, and one or both of the hydrogen atoms of the amino group of acrylamide may be substituted by a substituent. The carbon atom at the α-position of acrylamide is a carbon atom to which a carbonyl group of acrylamide is bonded unless otherwise specified.
As the substituent for substituting the hydrogen atom bonded to the carbon atom at the α-position of acrylamide, those similar to the ones mentioned as the substituent at the α-position (substituent (R ^α0 )) in the above-mentioned α-substituted acrylic acid ester It can be mentioned.

The “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.
The term "hydroxystyrene derivative" is a concept including those in which a hydrogen atom at the alpha position of hydroxystyrene is substituted with another substituent such as an alkyl group or a halogenated alkyl group, and derivatives thereof. As their derivatives, those in which the hydrogen atom of hydroxystyrene which may be substituted with a hydrogen atom at the α position is substituted with an organic group; even if the hydrogen atom at the α position is substituted by a substituent A compound in which a substituent other than a hydroxyl group is bonded to the benzene ring of good hydroxystyrene, and the like can be mentioned. The alpha position (carbon atom at the alpha position) of hydroxystyrene refers to the carbon atom to which the benzene ring is bonded unless otherwise noted.
As a substituent which substitutes the hydrogen atom of alpha position of hydroxystyrene, the thing similar to what was mentioned as a substituent of alpha position in the above-mentioned alpha substitution acrylic acid ester is mentioned.

The “constituent unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative” means a constitutional unit formed by cleavage of an ethylenic double bond of vinylbenzoic acid or a vinylbenzoic acid derivative.
The "vinyl benzoic acid derivative" is a concept including those in which the hydrogen atom at the α-position of vinyl benzoic acid is substituted with an alkyl group, another substituent such as a halogenated alkyl group, and derivatives thereof. As their derivatives, those in which the hydrogen atom at the α-position is substituted with an organic group and the hydrogen atom of the carboxy group of vinyl benzoic acid which may be substituted with a substituent; the hydrogen atom at the α-position is substituted with a substituent And the like in which a substituent other than a hydroxyl group and a carboxy group is bonded to the benzene ring of vinyl benzoic acid which may be mentioned. In addition, the alpha position (carbon atom of alpha position) of vinyl benzoic acid means the carbon atom which the benzene ring has couple | bonded, unless there is particular notice.

"Styrene" is a concept including styrene and those in which a hydrogen atom at the alpha position of styrene is substituted with another substituent such as an alkyl group or a halogenated alkyl group.
The “structural unit derived from styrene” and the “structural unit derived from a 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, and specifically, an alkyl group having 1 to 5 carbon atoms (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.
In addition, specific examples of the halogenated alkyl group as a substituent at the α-position include groups in which part or all of the hydrogen atoms of the above “alkyl group as a substituent at the α-position” are substituted with a halogen atom Be 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.
Further, specific examples of the hydroxyalkyl group as a substituent at the α-position include groups in which part or all of the hydrogen atoms of the above-mentioned “alkyl group as a substituent at the α-position” are substituted with a hydroxyl group. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1 to 5, and most preferably 1.

«Resist composition»
The resist composition according to the first aspect of the present invention is a resist composition which generates an acid upon exposure to light and whose solubility in a developer changes due to the action of the acid, and which dissolves in the developer due to the action of an acid. As a base material component (A) (hereinafter also referred to as “component (A)”) in which is changed, the polymer compound (A1) (hereinafter also referred to as “component (A1) component”) described later is contained.
When a resist film is formed using this resist composition and selective exposure is performed on the resist film, an acid is generated at the exposed portion of the resist film, and the developer of component (A) is generated by the action of the acid. Since the solubility of the component (A) does not change in the unexposed area of the resist film while the solubility in the area of the resist film changes, the difference in solubility in the developer between the exposed area and the unexposed area is It occurs. Therefore, when the resist film is developed, the exposed portion is dissolved and removed to form a positive resist pattern when the resist composition is positive, and the unexposed portion is dissolved when the resist composition is negative. It is removed to form a negative resist pattern.
In the present specification, a resist composition in which an exposed part is dissolved and removed to form a positive resist pattern is called a positive resist composition, and a non-exposed part is dissolved and removed to form a negative resist pattern. Is referred to as a negative resist composition.
The resist composition of this embodiment may be a positive resist composition or a negative resist composition.
Further, the resist composition of the present embodiment may be for an alkaline development process using an alkaline developer for development processing at the time of resist pattern formation, and the development processing may be a developer (organic developer) containing an organic solvent. It may be for the solvent development process used.

The resist composition of this embodiment has an acid generating ability to generate an acid upon exposure, and the component (A) may generate an acid upon exposure, and the additive compounded separately from the component (A) The components may generate an acid upon exposure.
Specifically, the resist composition of this embodiment is
(1) may contain an acid generator component (B) (hereinafter referred to as "component (B)") which generates an acid upon exposure to light;
(2) The component (A) may be a component that generates an acid upon exposure to light;
(3) The component (A) may be a component that generates an acid upon exposure to light, and may further contain a component (B).
That is, in the case of the above (2) and (3), the component (A) becomes “a base component which generates an acid upon exposure and whose solubility in a developer changes by the action of the acid”. When the component (A) generates an acid upon exposure and the solubility in a developer changes by the action of the acid, the component (A1) described later generates an acid upon exposure, and It is preferable that it is a polymer compound whose solubility in a developer changes by the action of an acid. As such a polymer compound, a resin having a structural unit that generates an acid upon exposure can be used. Known structural units can be used as structural units that generate an acid upon exposure.
The resist composition of this aspect is preferably the one in the case of the above (1).

<(A) component>
In the present invention, the “base component” is an organic compound having film forming ability, preferably an organic compound having a molecular weight of 500 or more. When the molecular weight of the organic compound is 500 or more, the film forming ability is improved, and in addition, it is easy to form a nano-level resist pattern.
Organic compounds used as a base component are roughly classified into non-polymers and polymers.
As the non-polymer, one having a molecular weight of 500 or more and less than 4,000 is usually used. Hereinafter, the term "low molecular weight compound" refers to a non-polymer having a molecular weight of 500 or more and less than 4,000.
As the polymer, one having a molecular weight of 1,000 or more is usually used. Hereinafter, the term "resin" or "polymer compound" refers to a polymer having a molecular weight of 1,000 or more.
As a molecular weight of a polymer, the mass mean molecular weight of polystyrene conversion by GPC (gel permeation chromatography) shall be used.
As the component (A) used in the resist composition of this embodiment, at least the component (A1) is used, and another polymer compound and / or low molecular weight compound may be used in combination with the component (A1).

[(A1) component]
The component (A1) is a structural unit (a0) represented by the general formula (a0-1) and a group containing a monocyclic group among acid decomposable groups whose polarity is increased by the action of an acid, or a chain And a structural unit (a1 ′) containing a group containing a polycyclic group among acid decomposable groups whose polarity is increased by the action of an acid, and a lactone-containing monocyclic group And a structural unit (a2).
When a resist film formed using a resist composition containing the component (A1) is exposed, the structural unit (a1) and the structural unit (a1 ′) are at least partially contained in the structure by the action of an acid. The bond is cleaved and the polarity is increased. Therefore, the resist composition of the present embodiment becomes positive in the alkali development process and becomes negative in the solvent development process. The polarity of the component (A1) changes before and after exposure. Therefore, by using the component (A1), it is possible to obtain good development contrast not only in the alkali development process but also in the solvent development process.
That is, when an alkali development process is applied, the component (A1) is poorly soluble in an alkali developer before exposure, and when an acid is generated by exposure, the polarity is increased by the action of the acid, and the alkali developer is produced. The solubility to Therefore, in the formation of a resist pattern, when the resist film obtained by applying the resist composition on a support is selectively exposed, the exposed portion changes from being poorly soluble to soluble in an alkaline developer. Since the unexposed area does not change as it is poorly soluble in alkali, a positive resist pattern can be formed by alkali development.
On the other hand, when a solvent development process is applied, the component (A1) has high solubility in an organic developing solution before exposure, and when an acid is generated by exposure, the action of the acid makes the polarity high and the organic type The solubility in the developer decreases. Therefore, in the formation of a resist pattern, when the resist film obtained by applying the resist composition on a support is selectively exposed, the exposed portion changes from soluble to hardly soluble in organic developer. On the other hand, since the unexposed area remains soluble, the development with the organic developing solution makes it possible to provide a contrast between the exposed area and the unexposed area, thereby forming a negative resist pattern.

(Constituent unit (a0))
The structural unit (a0) is a structural unit represented by general formula (a0-1) shown below.
The structural unit (a0) has a lactone-containing polycyclic group (R ¹ ) in its side chain. The lactone-containing polycyclic group (R ¹ ) is effective in enhancing the adhesion of the resist film to the support when the component (A1) is used to form a resist film.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基である。Ｒ^１はラクトン含有多環式基である。Ｒ^２及びＲ^３はそれぞれ独立に水素原子又は炭素数１〜５のアルキル基である。Ｌ^１はエステル結合である。ｎ_１は１〜３の整数である。］

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. R ¹ is a lactone-containing polycyclic group. R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. L ¹ is an ester bond. n ₁ is an integer of ₁ to 3; ]

R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group in said Formula (a0-1).
The alkyl group having 1 to 5 carbon atoms of R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, methyl group, ethyl group, propyl group, isopropyl group, n- A butyl group, an isobutyl group, a tert- butyl group, a pentyl group, an isopentyl group, a neopentyl group etc. are mentioned. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with 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.
As R, a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a fluorinated alkyl group of 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is particularly preferable in terms of industrial availability.

In said formula (a0-1), R < ¹ > is a lactone containing polycyclic group.
"A lactone containing polycyclic group" shows the polycyclic group containing the ring (lactone ring) containing -OC (= O)-in the ring frame | skeleton. The lactone ring is counted as the first ring, and the case having another ring structure is referred to as a polycyclic group regardless of the structure.
The lactone-containing polycyclic group in the structural unit (a0) is not particularly limited, and any group can be used. Specifically, groups represented by general formulas (a2-r-1) to (a2-r-6) shown below can be mentioned.
In the present specification, “*” in the chemical formula indicates that it is a bond.

［式中、Ｒａ’^２１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ_０”、−ＯＣ（＝Ｏ）Ｒ_０”、ヒドロキシアルキル基またはシアノ基であり；Ｒ_０”は水素原子、アルキル基又はラクトン含有多環式基であり；Ａ”は酸素原子（−Ｏ−）もしくは硫黄原子（−Ｓ−）を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子であり、ｍ’は０または１である。］

Wherein, Ra ^'21 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, hydroxyl _{group, -COOR 0 ", -OC (=} O) R 0", a hydroxyalkyl group or cyano R _{0 ′} ′ is a hydrogen atom, an alkyl group or a lactone-containing polycyclic group; A ′ ′ is an oxygen atom (—O—) or a sulfur atom (—S—); And an alkylene group of 5 to 5, an oxygen atom or a sulfur atom, and m 'is 0 or 1. ]

In the general formula (a2-r-1) ~ (a2-r-6), the alkyl group in Ra ^'21, preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group and the like can be mentioned. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
The alkoxy group in the ra ^'21, preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, groups of the the Ra 'group and an oxygen atom mentioned as the alkyl group in ²¹ (-O-) are linked and the like.
As the halogen atom in ra ^'21, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a fluorine atom is preferable.
'Examples of the halogenated alkyl group for ^21, the Ra' Ra part or all of the hydrogen atoms of the alkyl group in ²¹ can be mentioned it has been substituted with the aforementioned halogen atoms. The halogenated alkyl group is preferably a fluorinated alkyl group, particularly preferably a perfluoroalkyl group.

As for —COOR ₀ ′ ′ and —OC (= O) R ₀ ′ ′ in Ra ′ ²¹ , R ₀ ′ ′ is a hydrogen atom, an alkyl group or a lactone-containing polycyclic group.
The alkyl group for R _{0 ′} ′ may be linear, branched or cyclic, and preferably has 1 to 15 carbon atoms.
When R _{0 ′} ′ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and is a methyl group or an ethyl group Particularly preferred.
When R _{0 ′} ′ 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. Groups obtained by removing one or more hydrogen atoms from a monocycloalkane which may or may not be substituted with an atom or a fluorinated alkyl group; polycyclo such as bicycloalkane, tricycloalkane, tetracycloalkane and the like Examples include groups in which one or more hydrogen atoms have been removed from alkanes, etc. More specifically, groups in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane, cyclohexane, etc .; adamantane, norbornane, isobornane, Groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as tricyclodecane and tetracyclododecane It is.
Examples of the lactone-containing polycyclic group in R _{0 ′} ′ include groups represented by the general formulas (a2-r-1) to (a2-r-6).

The hydroxyalkyl group in Ra ′ ²¹ is preferably one having 1 to 6 carbon atoms, and specific examples include a group in which at least one of the hydrogen atoms of the alkyl group in Ra ′ ²¹ is substituted with a hydroxyl group .

In the above general formulas (a2-r-1), (a2-r-2) and (a2-r-4), as the alkylene group having 1 to 5 carbon atoms in A ′ ′, a linear or branched chain is preferred. An alkylene group is preferable, and examples thereof include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, etc. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include the terminal or carbon of the alkylene group. between atoms -O- or -S- can be mentioned a group intervening, for example, _{-O-CH 2 -, - CH} 2 -O-CH 2 -, - S-CH 2 -, - CH 2 -S-CH _2- "etc. is mentioned. As A", a C1-C5 alkylene group or -O- is preferable, a C1-C5 alkylene group is more preferable, and a methylene group is the most preferable.

  Specific examples of the groups represented by general formulas (a2-r-1) to (a2-r-6) will be given below.

Among the above, as the lactone-containing polycyclic group for R ¹ , a group represented by the formula (a2-r-1), a group represented by the formula (a2-r-5), and the formula (a2) The group represented by -r-6) is preferable. Among them, in terms of in-plane uniformity (CDU) of pattern dimensions, depth of focus (DOF) characteristics, and mask reproducibility (MEEF) in a resist pattern to be formed, it is represented by the above formula (a2-r-5). Are more preferred.
Among the groups represented by the formula (a2-r-1), the group represented by the chemical formula (r-lc-1-1) is particularly preferable.
Among the groups represented by the formula (a2-r-5), the group represented by the chemical formula (r-lc-5-1) is particularly preferable.
Among the groups represented by the formula (a2-r-6), the group represented by the chemical formula (r-lc-6-1) is particularly preferable.

R < ² > and R < ³ > are respectively independently a hydrogen atom or a C1-C5 alkyl group in said Formula (a0-1).
At least one of R ² and R ³ is preferably a hydrogen atom, and more preferably both are a hydrogen atom.
As an alkyl group in R ² and R ³ , a linear or branched alkyl group is preferably mentioned. More 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 can be mentioned, and methyl group or ethyl group is More preferred is methyl group.

In formula (a0-1), L ¹ is an ester bond.
As ester bond in L ¹ , —C (CO) —O—, —O—C (= O) —, —O—S (= O) ₂ —, —S (= O) ₂ —O—, etc. And —C (= O) —O— and —O—C (= O) — are preferable.
It is particularly preferable that the terminal group “-L ¹ -R ¹ ” in the formula (a0-1) is —C (= O) —O—R ¹ .

In the formula (a0-1), n ₁ is an integer of ₁ to 3, preferably 1 or 2, and particularly preferably 1.

Specific examples of the structural unit (a0-1) are shown below. In each of the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

The structural unit (a0) of the component (A1) may be of one type or of two or more types.
The proportion of the structural unit (a0) is preferably 1 to 40 mol%, more preferably 5 to 30 mol%, based on the total of all the structural units constituting the component (A1), and 7 to 7 It is more preferable that it is 25 mol%, and 10 to 20 mol% is especially preferable.
By setting the ratio of the structural unit (a0) to the preferable lower limit value or more, various lithography properties and pattern shapes become better. In particular, both in-plane uniformity (CDU) of pattern dimensions and depth of focus (DOF) characteristics are improved. On the other hand, by setting the content to the preferable upper limit value or less, it becomes easy to balance with other constituent units.

(Constituent unit (a1), constituent unit (a1 ′))
The structural unit (a1) is a structural unit containing a group containing a monocyclic group or a chain group among acid-degradable groups whose polarity is increased by the action of an acid.
The structural unit (a1 ′) is a structural unit including a group containing a polycyclic group among acid-degradable groups whose polarity is increased by the action of an acid.
In the present invention, the term "acid-degradable group" refers to a group having acid-degradability capable of cleaving at least a part of bonds in the structure by the action of an acid.
Examples of the acid-degradable group whose polarity is increased by the action of an acid include, for example, a group which is decomposed by the action of an acid to generate a polar group.
Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, a sulfo group _(-SO 3 H) and the like. Among these, a polar group containing -OH in the structure (hereinafter sometimes referred to as "OH-containing polar group") is preferable, a carboxy group or a hydroxyl group is more preferable, and a carboxy group is particularly preferable.
More specifically, examples of the acid-degradable group include groups in which the polar group is protected by an acid dissociative group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected by an acid dissociative group).
Here, the “acid dissociable group” is (i) a group having an acid dissociability that can cleave the bond between the acid dissociable group and the atom adjacent to the acid dissociable group by the action of an acid; Or (ii) after a partial bond is cleaved by the action of an acid, a decarboxylation reaction is further caused to cleave the bond between the acid dissociable group and the atom adjacent to the acid dissociable group It refers to both of the obtained groups.
The acid dissociable group constituting the acid decomposable group is required to be a group having a polarity lower than that of the polar group generated by the dissociation of the acid dissociable group, whereby the acid dissociable group is formed by the action of an acid. When dissociates, 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) is increased. The increase in polarity relatively changes the solubility in the developer, the solubility increases when the developer is an alkaline developer, and the solubility when the developer is an organic developer. Decrease.

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

  As an acid dissociative group which protects a carboxy group or a hydroxyl group among the said polar groups, the acid dissociative group (following "acetal type acid dissociative group") represented with the following general formula (a1-r-1) is mentioned, for example May be mentioned).

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

[Wherein, Ra ′ ¹ and Ra ′ ² are a hydrogen atom or an alkyl group, and Ra ′ ³ is a hydrocarbon group which may have a substituent, and Ra ′ ³ is Ra ′ ¹ or Ra It may be combined with any of ² to form a ring. ]

In formula (a1-r-1), at least one of Ra ′ ¹ and Ra ′ ² is preferably a hydrogen atom, and more preferably both are a hydrogen atom.
When Ra ′ ¹ or Ra ′ ² is an alkyl group, examples of the alkyl group include the alkyl groups mentioned as the substituent which may be bonded to the carbon atom at the α position in the description of the α-substituted acrylic acid ester. The same thing is mentioned, and a C1-C5 alkyl group is preferable. Specifically, a linear or branched alkyl group is preferably mentioned. More 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 can be mentioned, and methyl group or ethyl group is More preferred is methyl group.

Wherein (a1-r-1), the hydrocarbon group of Ra ^'3, linear or branched alkyl group, or, cyclic hydrocarbon groups.
The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and still more preferably 1 or 2 carbon atoms. Specifically, methyl group, ethyl group, n-propyl group, n-butyl group, n-pentyl group and the like can be mentioned. 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. Specifically, an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, a 2,2-dimethylbutyl group and the like can be mentioned, with preference given to an isopropyl group.

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

When the cyclic hydrocarbon group of Ra ′ ³ is an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.
The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. The carbon number of the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene and phenanthrene; and aromatic heterocyclic rings in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom It can be mentioned. Examples of the hetero atom in the aromatic heterocycle 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.
Specific examples of the aromatic hydrocarbon group in ra ^'3, the aromatic hydrocarbon ring or one hydrogen atom from an aromatic heterocyclic group formed by removing (aryl or heteroaryl group); two or more aromatic rings A group obtained by removing one hydrogen atom from an aromatic compound (eg, biphenyl, fluorene etc.) containing; a group in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocycle is substituted with an alkylene group (eg, a benzyl group And arylalkyl groups such as phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group and the like) and the like. It is preferable that carbon number of the alkylene group couple | bonded with the said aromatic hydrocarbon ring or aromatic heterocycle is 1-4, It is more preferable that it is 1-2, It is especially preferable that it is 1.

The “optionally having a substituent” in the above Ra ′ ³ means that part or all of the hydrogen atoms in the linear or branched alkyl group or the cyclic hydrocarbon group have a substituent It means that it may be substituted by other atoms or groups other than a hydrogen atom.
The number of substituents in Ra ′ ³ may be one or two or more.
As said substituent, a halogen atom, a hetero atom, an alkyl group, ester bond, an oxo group (= O) etc. are mentioned, for example.
As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, A fluorine atom is preferable.
Examples of the hetero atom include an oxygen atom, a nitrogen atom, and a sulfur atom.
As said alkyl group, a C1-C6 alkyl group is preferable. The alkyl group is preferably linear or branched. Specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group and the like can be mentioned. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.
The ester bond as a substituent (when a methylene group (-CH _2- ) is substituted with a divalent group) in Ra ′ ³ is , -OS (= O) _2- , -S (= O) _2- O- and the like.

When Ra ′ ³ combines with any of Ra ′ ¹ and Ra ′ ² to form a ring, the cyclic group is preferably a 4 to 7-membered ring, more preferably a 4 to 6-membered ring. Specific examples of the cyclic group include tetrahydropyranyl group, tetrahydrofuranyl group and the like.

  As an acid dissociative group which protects a carboxy group among the said polar groups, the acid dissociative group represented by the following general formula (a1-r-2) is mentioned, for example. Among the acid dissociable groups represented by the following formula (a1-r-2), those composed of alkyl groups may be hereinafter referred to as “tertiary alkyl ester type acid dissociable groups” for convenience. .

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

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

Examples of the hydrocarbon group Ra ^'4 ~Ra' ^6, the same as the Ra ^'3 and the like.
Ra ^'4 is preferably an alkyl group having 1 to 5 carbon atoms. If Ra and ^'5 and Ra' ⁶ are bonded to each other to form a ring, preferably a group represented by the following general formula (a1-r2-1). On the other hand, when Ra ′ ^{4 to} Ra ′ ⁶ do not bind to each other and are independent hydrocarbon groups, groups represented by general formula (a1-r2-2) shown below are preferable.

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

Wherein, Ra ^'10 is an alkyl group having 1 to 10 carbon atoms, Ra' ¹¹ is a group which forms an aliphatic cyclic group together with the carbon atom to which Ra ^'10 is bonded. Ra ^'12 ~Ra' ¹⁴ each independently represent a hydrocarbon group. ]

In Formula (a1-r2-1), the C1-C10 alkyl group of Ra ′ ¹⁰ is exemplified as the linear or branched alkyl group of Ra ′ ³ in Formula (a1-r-1) Groups are preferred. In the formula (a1-r2-1), the aliphatic cyclic group formed by Ra ′ ¹¹ together with the carbon atom to which Ra ′ ¹⁰ is bonded may have a substituent, and the formula (a1-r-1) The groups (monocyclic aliphatic hydrocarbon groups and polycyclic aliphatic hydrocarbon groups) listed as the cyclic aliphatic hydrocarbon groups of Ra ′ ^{3 in} the above are preferable. The Ra ^'11 is Ra' aliphatic cyclic group substituents which may be possessed of forming together with the carbon atom ^{to which 10} is bonded are the same as those of the substituent in the Ra ^'3.
As the monocyclic aliphatic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable, and among these, one having 3 to 6 carbon atoms of the monocycloalkane is more preferable, Particular preference is given to cyclopentyl or cyclohexyl, with cyclopentyl being most preferred.
The polycyclic aliphatic hydrocarbon group is particularly preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and most preferably an adamantyl group.

Wherein (a1-r2-2), it is preferable that Ra is ^'12 and Ra' ¹⁴ each independently represents an alkyl group having 1 to 10 carbon atoms, the alkyl group, Ra in formula (a1-r-1) The group mentioned as the linear or branched alkyl group of ' ³ is more preferable, a C1-C5 linear alkyl group is more preferable, and a methyl group or an ethyl group is particularly preferable. .
In the formula (a1-r2-2), Ra ′ ¹³ is a linear or branched alkyl group exemplified as the hydrocarbon group of Ra ′ ³ in the formula (a1-r-1), or cyclic It is preferably a hydrocarbon group. Among cyclic hydrocarbon groups, the groups (monocyclic aliphatic hydrocarbon groups and polycyclic aliphatic hydrocarbon groups) listed as the cyclic aliphatic hydrocarbon groups of Ra ′ ³ are more preferable A polycyclic aliphatic hydrocarbon group is more preferable, a group obtained by removing one hydrogen atom from a polycycloalkane is particularly preferable, and an adamantyl group is most preferable.

  As the acid dissociable group for protecting the hydroxyl group among the polar groups, for example, an acid dissociable group represented by the following general formula (a1-r-3) (hereinafter, for convenience, “tertiary alkyloxycarbonyl acid dissociable group” There is a case where

［式中、Ｒａ’^７〜Ｒａ’^９はそれぞれアルキル基である。］

Wherein, Ra ^'7 ~Ra' ⁹ are each an alkyl group. ]

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

Structural unit (a1): among acid-decomposable groups whose polarity is increased by the action of an acid, a group containing a monocyclic group or a structural unit containing a chain group acid-decomposable group in the structural unit (a1) Is a group containing a monocyclic group or a chain group.
The “group containing a monocyclic group” includes an acid-decomposable group consisting of a monocyclic group, and an acid-decomposable group formed by combining a monocyclic group and another group. Examples of the “acid-degradable group formed by combining a monocyclic group and another group” include, for example, an acid-degradable group formed by combining a monocyclic group and a chain group.
When the acid-degradable group in the structural unit (a1) is a "chain group", the acid-degradable group is a group consisting only of chains.
Specific examples of the acid-degradable group in the structural unit (a1) are given below.

Among the above, the acid decomposable group in the structural unit (a1) includes a monocyclic group from the viewpoint of the high residual film ratio of the resist film exposed portion in the formation of a negative resist pattern by a solvent development process. A group is preferable, and an acid decomposable group represented by a formula (r-pr-s8) is preferable among them.
Further, from the viewpoint of resolution in the resist pattern to be formed, a chain group is preferable, and among them, the acid decomposable represented by either the formula (r-pr-c3) or the formula (r-pr-c4) A group is preferred, and an acid-degradable group represented by the formula (r-pr-c4) is particularly preferred.

  The structural unit (a1) is a structural unit derived from an acrylic acid 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. Constituent unit containing degradable group; Constituent unit derived from acrylamide, containing acid-degradable group whose polarity is increased by the action of acid; hydroxyl group of constituent unit derived from hydroxystyrene or hydroxystyrene derivative A structural unit in which at least a part of hydrogen atoms in the above is protected by a substituent containing the acid-degradable group; a hydrogen atom in -C (= O) -OH of a structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative The structural unit etc. which were protected by the substituent in which at least one part of these contained the said acid-degradable group were mentioned.

Among the above, as the structural unit (a1), a structural unit derived from an acrylic acid ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent is preferable.
Preferred specific examples of the structural unit (a1) include structural units represented by general formulas (a1-1) to (a1-3) shown below.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基である。Ｖａ^１はエーテル結合を有していてもよい２価の炭化水素基であり、ｎ_ａ１は０〜２であり、Ｒａ^１及びＲａ^３は、それぞれ上記式（ａ１−ｒ−１）又は（ａ１−ｒ−２）で表される酸解離性基であって、単環式基を含む基、又は鎖状の基である。Ｗａ^１はｎ_ａ２＋１価の炭化水素基であり、ｎ_ａ２は１〜３であり、Ｒａ^２は上記式（ａ１−ｒ−１）又は（ａ１−ｒ−３）で表される酸解離性基であって、単環式基を含む基、又は鎖状の基である。Ｗａ^２はｎ_ａ３＋１価の炭化水素基であり、ｎ_ａ３は１〜３であり、Ｖａ^２はエーテル結合、ウレタン結合又はアミド結合を有していてもよい２価の炭化水素基である。］

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

In the formulas (a1-1) to (a1-3), R is the same as R in the formula (a0-1) described above.
In the formula (a1-1), the divalent hydrocarbon group of Va ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group as a bivalent hydrocarbon group in Va ¹ may be saturated or unsaturated, and is usually preferably saturated.
More specific examples of the aliphatic hydrocarbon group in Va ¹ include linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups containing a ring in the structure.
As the Va ^1, it may have an ether bond (-O-) between carbon atoms of the divalent hydrocarbon group. One or two or more ether bonds may be present in Va ¹ .

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.
As a linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [-CH _2- ], an ethylene group [-(CH ₂ ) _2- ], a trimethylene group [ _{- (CH 2) 3 -]} , a tetramethylene group _{[- (CH 2) 4 -} ], a pentamethylene group _{[- (CH 2) 5 -} ] , and the like.
As the branched aliphatic hydrocarbon group, preferably a branched chain alkylene group, _{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 An alkylethylene group such as CH ₃ ) ₂ -CH _2- ; an alkyltrimethylene group such as -CH (CH ₃ ) CH ₂ CH _2- , -CH ₂ CH (CH ₃ ) CH _2-, etc .; -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. As an alkyl group in an alkyl alkylene group, a C1-C5 linear alkyl group is preferable.

As an aliphatic hydrocarbon group which contains a ring in the said structure, alicyclic hydrocarbon group (The group which remove | eliminated two hydrogen atoms from the aliphatic hydrocarbon ring), and an alicyclic hydrocarbon group are linear or branched Examples thereof include a group bonded to the end of a linear aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group intervenes in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as the linear or branched aliphatic hydrocarbon group in the above Va ¹ .
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As a monocyclic alicyclic 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 include cyclopentane, cyclohexane and the like. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferable, and as the polycycloalkane, one having 7 to 12 carbon atoms is preferable, and specifically, adamantane , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

The aromatic hydrocarbon group in Va ¹ is a hydrocarbon group having at least one aromatic ring. The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. The carbon number of the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene and phenanthrene; and aromatic heterocyclic rings in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom It can be mentioned. Examples of the hetero atom in the aromatic heterocycle 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 as the aromatic hydrocarbon group, a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); aromatic compound containing two or more aromatic rings A group obtained by removing two hydrogen atoms from (eg, biphenyl, fluorene etc.); one hydrogen atom of a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) Hydrogen atom from an arylalkyl group such as a benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc. And the like) and the like. It is preferable that carbon number of the alkylene group couple | bonded with the said aryl group or heteroaryl group is 1-4, It is more preferable that it is 1-2, It is especially preferable that it is 1.

In the formula (a1-2), the n _a2 + 1-valent hydrocarbon group in Wa ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity, which may be saturated or unsaturated, and is preferably saturated. As the aliphatic hydrocarbon group, a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, or a linear or branched aliphatic hydrocarbon group The group which combined the aliphatic hydrocarbon group containing a ring in a structure is mentioned. As said aromatic hydrocarbon group, the group containing the aromatic hydrocarbon ring or aromatic heterocycle illustrated in the description about said Va ¹ is mentioned.
The n _a2 +1 valence is preferably 2 to 4 and more preferably 2 or 3.

In the formula (a1-3), the n _a3 +1 monovalent hydrocarbon group in Wa ² may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and n _a2 in Wa ¹ The same as the monovalent hydrocarbon group can be mentioned.
The n _a3 +1 valence is preferably 2 to 4 and more preferably 2 or 3.
Examples of the divalent hydrocarbon group in Va ² include the same ones as the divalent hydrocarbon group in Va ¹ above.

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

The structural unit (a1) contained in the component (A1) may be one type or two or more types.
The proportion of the structural unit (a1) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, with respect to the total of all the structural units constituting the component (A1), and 15 to 15 mol%. It is more preferable that it is 45 mol%, and 20 to 40 mol% is especially preferable.
By setting the ratio of the structural unit (a1) to the preferable lower limit value or more, in particular, both in-plane uniformity (CDU) of pattern dimension and depth of focus (DOF) characteristics are improved in resist pattern formation. On the other hand, by setting the content to the preferable upper limit value or less, it becomes easy to balance with other constituent units.

Structural unit (a1 ′): Of the acid degradable groups whose polarity is increased by the action of an acid, a structural unit containing a group containing a polycyclic group The acid degradable group in the structural unit (a1 ′) is a polycyclic ring It is a group containing a formula group.
The “group containing a polycyclic group” includes an acid-decomposable group consisting of a polycyclic group, and an acid-decomposable group formed by combining a polycyclic group and another group. Examples of the “acid-degradable group formed by combining a polycyclic group and another group” include, for example, an acid-degradable group formed by combining a polycyclic group and a chain group.
Specific examples of the acid-degradable group in the structural unit (a1 ′) are given below.

  Among the above, as the acid decomposable group in the structural unit (a1 ′), an acid decomposable group formed by combining a polycyclic group with a group other than this is preferable from the viewpoint of depth of focus (DOF), An acid-degradable group formed by combining a polycyclic group and a chain group is more preferable. Among them, an acid-degradable group represented by the formula (r-pr-cm 2) is particularly preferable.

  The structural unit (a1 ′) is a structural unit derived from an acrylic acid ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and the polarity is increased by the action of acid A structural unit containing an acid degradable group; a structural unit derived from acrylamide and containing an acid degradable group whose polarity is increased by the action of an acid; a structural unit derived from hydroxystyrene or a hydroxystyrene derivative A constituent unit in which at least a part of hydrogen atoms in a hydroxyl group is protected by a substituent containing the acid decomposable group; a hydrogen in —C (= O) —OH of a constituent unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative The structural unit etc. which were protected by the substituent in which at least one part of the atom contains the said acid-degradable group are mentioned.

Among the above, as the structural unit (a1 ′), structural units derived from an acrylic acid ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent are preferable.
As a preferable specific example of this structural unit (a1 ′), in the structural units represented by the above general formula (a1-1) or general formula (a1-3), Ra ¹ and Ra ³ are each independently selected from the above an acid dissociable group represented by a1-r-1) or (a1-r-2), which is a group containing a polycyclic group; a structure represented by the above general formula (a1-2) In the unit, examples thereof include an acid dissociable group represented by the above formula (a1-r-1) or (a1-r-3) in which Ra ² is a group containing a polycyclic group.

The specific example of a structural unit (a1 ') is shown below. In each of the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

The structural unit (a1 ′) of the component (A1) may be one type or two or more types.
The proportion of the structural unit (a1 ′) is preferably 3 to 40 mol%, more preferably 5 to 35 mol%, based on the total of all the structural units constituting the component (A1). It is more preferable that it is -25 mol%, and 10-20 mol% is especially preferable.
By setting the ratio of the structural unit (a1 ′) to the preferable lower limit value or more, in particular, both in-plane uniformity (CDU) of pattern dimension and depth of focus (DOF) characteristics are improved in resist pattern formation. On the other hand, by setting the content to the preferable upper limit value or less, it becomes easy to balance with other constituent units.

(Constituent unit (a2))
The structural unit (a2) is a structural unit containing a lactone-containing monocyclic group.
The lactone-containing monocyclic group of the structural unit (a2) is effective in enhancing the adhesion of the resist film to the support when the component (A1) is used to form the resist film.
When the structural unit (a1) or the structural unit (a1 ′) is a structural unit containing a lactone-containing monocyclic group in the structure, the structural unit also corresponds to the structural unit (a2), Such a structural unit corresponds to the structural unit (a1) or the structural unit (a1 ′), and does not correspond to the structural unit (a2).
"A lactone containing monocyclic group" shows the cyclic group which consists only of the ring (lactone ring) which contains -OC (= O)-in ring structure.
The lactone-containing monocyclic group in the structural unit (a2) is not particularly limited and any arbitrary one can be used. Specifically, groups represented by general formula (a2-r-7) shown below can be mentioned.

［式中、複数のＲａ’^２１１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_２”、−ＯＣ（＝Ｏ）Ｒ_２”、ヒドロキシアルキル基またはシアノ基であり；Ｒ_２”は水素原子、アルキル基又はラクトン含有単環式基であり；ｎ’は０〜２の整数である。］

[Wherein, each of a plurality of Ra ′ ²¹¹ independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR ₂ ′ ′, —OC (= O) R ₂ ′ ′, a hydroxyalkyl group Or R _{2 ′} ′ is a hydrogen atom, an alkyl group or a lactone-containing monocyclic group; n ′ is an integer of 0 to 2

In the formula (a2-r-7), the alkyl group, the alkoxy group, the halogen atom, the halogenated alkyl group, and the hydroxyalkyl group in Ra ′ ²¹¹ are the same as those in the formula (a2-r-1) And the same as the alkyl group, the alkoxy group, the halogen atom, the halogenated alkyl group and the hydroxyalkyl group for Ra ′ ²¹ in the above.
Ra '-COOR ₂ in ²¹¹ for _{", -OC (= O) R} 2", the alkyl group of _{R 2} ", the formula (a2-r-1) ~ (a2-r-6) in ra' ²¹ Are the same as the alkyl group of R ₀ ′ ′ in
As a lactone containing monocyclic group in R < _{2 '} >, the group represented by said general formula (a2-r-7) is mentioned.
n 'is an integer of 0 to 2, preferably 0 or 1, and more preferably 1.

  Specific examples of the group represented by general formula (a2-r-7) will be given below.

As the structural unit (a2), a structural unit derived from an acrylic acid ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted by a substituent is particularly preferable.
The structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

［式中、Ｒは水素原子、炭素数１〜５のアルキル基又は炭素数１〜５のハロゲン化アルキル基である。Ｙａ^２１は単結合または２価の連結基である。Ｌａ^２１は−Ｏ−、−ＣＯＯ−、−ＣＯＮ（Ｒ’）−、−ＯＣＯ−、−ＣＯＮＨＣＯ−又は−ＣＯＮＨＣＳ−であり、Ｒ’は水素原子またはメチル基を示す。ただしＬａ^２１が−Ｏ−の場合、Ｙａ^２１は−ＣＯ−にはならない。Ｒａ^２１はラクトン含有単環式基である。］

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

In the formula (a2-1), R is the same as R in the formula (a0-1) described above.
Ya ²¹ is a single bond or a divalent linking group.
The divalent linking group for Ya ²¹ is not particularly limited, and preferred examples thereof include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like.

Divalent hydrocarbon group which may have a substituent:
In Ya ²¹ , the divalent hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
The aliphatic hydrocarbon group as a bivalent hydrocarbon group in Ya ²¹ means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.
Examples of the aliphatic hydrocarbon group include linear or branched aliphatic hydrocarbon groups, and aliphatic hydrocarbon groups having a ring in the structure.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.
As a linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [-CH _2- ], an ethylene group [-(CH ₂ ) _2- ], a trimethylene group [ _{- (CH 2) 3 -]} , a tetramethylene group _{[- (CH 2) 4 -} ], a pentamethylene group _{[- (CH 2) 5 -} ] , and the like.
As the branched aliphatic hydrocarbon group, preferably a branched chain alkylene group, _{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 An alkylethylene group such as CH ₃ ) ₂ -CH _2- ; an alkyltrimethylene group such as -CH (CH ₃ ) CH ₂ CH _2- , -CH ₂ CH (CH ₃ ) CH _2-, etc .; -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. As an alkyl group in an alkyl alkylene group, a C1-C5 linear alkyl group is preferable.
The linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group of 1 to 5 carbon atoms substituted with a fluorine atom, and a carbonyl group.

As the aliphatic hydrocarbon group containing a ring in the above structure, a cyclic aliphatic hydrocarbon group which may contain a substituent containing a hetero atom in the ring structure (2 hydrogen atoms are removed from an 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 fatty acid And the like interposed in the middle of the group hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as described above.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As a 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 include cyclopentane, cyclohexane and the like. The polycyclic aliphatic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and as the polycycloalkane, one having 7 to 12 carbon atoms is preferable, and specifically, adamantane, And norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group and the like.
The alkyl group as the substituent is preferably an alkyl group having a carbon number of 1 to 5, and particularly 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 a carbon number of 1 to 5, and is preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group, methoxy Groups and ethoxy groups are particularly preferred.
As a halogen atom as the said substituent, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, A fluorine atom is preferable.
As a halogenated alkyl group as said substituent, the group by which one part or all part of the hydrogen atom of the said alkyl group was substituted by the said halogen atom is mentioned.
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. The substituent containing a hetero atom, -O -, - C (= O) -O -, - S -, - S (= O) 2 -, - S (= O) 2 -O- are preferred.

The aromatic hydrocarbon group as a divalent hydrocarbon group in Ya ²¹ is a hydrocarbon group having at least one aromatic ring.
The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. The carbon number of the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. 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; and aromatic heterocyclic rings in which a part of carbon atoms constituting the aromatic hydrocarbon ring is substituted with a hetero atom It can be mentioned. Examples of the hetero atom in the aromatic heterocycle 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 as the aromatic hydrocarbon group, a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); aromatic compound containing two or more aromatic rings A group obtained by removing two hydrogen atoms from (eg, biphenyl, fluorene etc.); one hydrogen atom of a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or heteroaryl group) Hydrogen atom from an arylalkyl group such as a benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc. And the like) and the like. It is preferable that carbon number of the alkylene group couple | bonded with the said aryl group or heteroaryl group is 1-4, It is more preferable that it is 1-2, It is especially preferable that it is 1.

In the aromatic hydrocarbon group, the hydrogen atom of the aromatic hydrocarbon group may be substituted by a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be substituted by a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group and the like.
The alkyl group as the substituent is preferably an alkyl group having a carbon number of 1 to 5, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group.
As the alkoxy group, the halogen atom and the halogenated alkyl group as the substituent, those exemplified as the substituent for substituting the hydrogen atom of the cyclic aliphatic hydrocarbon group can be mentioned.

Divalent linking group containing a heteroatom:
When Ya ²¹ is a divalent linking group containing a hetero atom, preferred as the linking group are —O—, —C (= O) —O—, —C (= O) —, —O— C (= O) -O-, -C (= O) -NH-, -C (= O) -NH-C (= O)-, -NH-, -NH-C (= NH)-(H may) be substituted with a substituent such as an alkyl group, an acyl group _{- S -, - S (=} O) 2 -, - S (= O) 2 -O-, the formula ^-Y 21 -O ^{-Y 22 -, - Y 21 -O} -, - Y 21 -C (= O) -O -, - [Y 21 -C (= O) -O] m "-Y 22 -, - Y 21 -O A group represented by —C (= O) —Y ²² — or —Y ²¹ —S (= O) ₂ —O—Y ²² [wherein, each of Y ²¹ and Y ²² independently has a substituent A divalent hydrocarbon group that may be And O is an oxygen atom, and m ′ ′ is an integer of 0 to 3. Etc.
The divalent linking group containing a heteroatom is -C (= O) -NH-, -C (= O) -NH-C (= O)-, -NH-, -NH-C (= NH) In the case of-, the H may be substituted by a substituent such as an alkyl group or an acyl group. The substituent (such as an alkyl group or an acyl group) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
Formula ^{-Y 21 -O-Y 22 -,} - Y 21 -O -, - Y 21 -C (= O) -O -, - [Y 21 -C (= O) -O] m "-Y 22 ^{-, - Y 21 -O-C} (= O) -Y 22 - or _{^{-Y 21 -S (= O) 2}} -O-Y 22 - ^{in, Y 21} and ^{Y 22} are each independently a substituent The divalent hydrocarbon group may have one or more substituents described above as the divalent linking group (a divalent hydrocarbon group which may have a substituent). And the same as the above.
As Y ²¹ , a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or an ethylene group is particularly preferable preferable.
As Y ²² , a linear or branched aliphatic hydrocarbon group is preferable, and a methylene group, an ethylene group or an alkylmethylene group is more preferable. The alkyl group in the alkylmethylene group is preferably a linear alkyl group of 1 to 5 carbon atoms, more preferably a linear alkyl group of 1 to 3 carbon atoms, and most preferably a methyl group.
Formula _{^{- [Y 21 -C (= O}} ) -O] m "-Y 22 - In the group represented by, m" is an integer of 0 to 3, preferably an integer of 0 to 2, 0 Or 1 is more preferable, and 1 is particularly preferable. In other words, the formula ^- Examples of the group represented by the formula ^{-Y 21 -C (= O) -O} -Y 22 - - [Y 21 -C (= O) -O] m "-Y 22 represented by group is particularly preferred among them, the formula _{-. (CH 2) a '} -C (= O) -O- (CH 2) b' -. in the group represented by the formula in the formula, a 'is 1 It is an integer of 10, an integer of 1 to 8 is preferable, an integer of 1 to 5 is more preferable, 1 or 2 is more preferable, and 1 is most preferable b ′ is an integer of 1 to 10, 1 to 8 The integer of is preferable, the integer of 1-5 is more preferable, 1 or 2 is more preferable, 1 is most preferable.

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

In the formula (a2-1), Ra ²¹ is a lactone-containing monocyclic group, and a group represented by general formula (a2-r-7) described above is preferably mentioned. Specifically, groups represented by the chemical formulas (r-lc-7-1) to (r-lc-7-7) can be mentioned, and in particular, it is possible to use the chemical formula (r-lc-7-1) The group represented and the group represented by said chemical formula (r-lc-7-2) are preferable.

The structural unit (a2) contained in the component (A1) may be one type or two or more types.
The proportion of the structural unit (a2) is preferably 5 to 70 mol%, more preferably 10 to 60 mol%, with respect to the total of all structural units constituting the component (A1) It is more preferable that it is 55 mol%, and 20 to 45 mol% is especially preferable.
By setting the ratio of the structural unit (a2) to the preferable lower limit value or more, various lithography properties and pattern shapes become better. In particular, both in-plane uniformity (CDU) of pattern dimensions and depth of focus (DOF) characteristics are improved. On the other hand, by setting the content to the preferable upper limit value or less, it becomes easy to balance with other constituent units.

(Other units)
In addition to the structural unit (a0), the structural unit (a1), the structural unit (a1 ′) and the structural unit (a2), the component (A1) further includes other structural units that do not fall under these structural units. You may have.
The other structural unit is not particularly limited as long as it is a structural unit not classified into the above-mentioned structural unit, and a resin for resists such as for ArF excimer laser and KrF excimer laser (preferably for ArF excimer laser) A large number of what is conventionally known as being used for can be used.
Among them, the component (A1) further includes a —SO ₂ — containing cyclic group in addition to the structural unit (a0), the structural unit (a1), the structural unit (a1 ′) and the structural unit (a2) Preference is also given to those having units (a5).
Moreover, as another structural unit, a structural unit (a13) containing a carbonate-containing cyclic group, a structural unit (a3) containing a polar group-containing aliphatic hydrocarbon group, and an acid non-dissociative aliphatic cyclic group The structural unit (a4), a structural unit that generates an acid upon exposure, and the like can be mentioned.

Constitutional unit (a5):
The structural unit (a5) is a structural unit containing a —SO ₂ -containing cyclic group.
The —SO ₂ — containing cyclic group of the structural unit (a5) is effective in enhancing the adhesion of the resist film to the substrate when the component (A1) is used to form a resist film.
Incidentally, the structural unit (a1) or structural unit (a1 ') is -SO 2 within the structure _- when a structural unit containing an containing cyclic group, the structural unit corresponding to the structural unit (a5) However, such a structural unit corresponds to the structural unit (a1) or the structural unit (a1 ′) and does not correspond to the structural unit (a5).
And _- "-SO 2 containing cyclic group", -SO 2 _- within the ring skeleton thereof shows a cyclic group containing a ring containing, in particular, -SO 2 _- sulfur atom (S) is in It is a cyclic group that forms a 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 in the case of only this ring, it is a monocyclic group, and in the case of having another ring structure, a polycyclic group regardless of its structure It is called. The —SO ₂ -containing cyclic group may be a monocyclic group or a polycyclic group.
The -SO ₂ -containing cyclic group is, in particular, a cyclic group containing -O-SO ₂ -in its ring skeleton, ie -O-S- in -O-SO ₂ -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 general formulas (a5-r-1) to (a5-r-4) shown below.

［式中、Ｒａ’^５１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ_５”、−ＯＣ（＝Ｏ）Ｒ_５”、ヒドロキシアルキル基またはシアノ基であり；Ｒ_５”は水素原子又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 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, hydroxyl _{group, -COOR 5 ", -OC (=} O) R 5", a hydroxyalkyl group or cyano R _{5 ′} ′ is a hydrogen atom or an alkyl group; A ′ ′ is an oxygen atom or an alkylene group having 1 to 5 carbon atoms which may contain a sulfur atom, an oxygen atom or a sulfur atom, and n ′ is a group It is an integer of 0-2. ]

In the general formulas (a5-r-1) to (a5-r-4), A ′ ′ represents the general formulas (a2-r-1), (a2-r-2) and (a2-r-4). It is the same as A "in.
As the alkyl group, the alkoxy group, the halogen atom, the halogenated alkyl group, and the hydroxyalkyl group in Ra ′ ^51, an alkyl in Ra ′ ²¹ in the general formulas (a2-r-1) to (a2-r-6), respectively, The same groups as in the group, alkoxy group, halogen atom, halogenated alkyl group and hydroxyalkyl group can be mentioned.
Ra '-COOR ₅ in ⁵¹ for _{", -OC (= O) R} 5", the alkyl group for _{R 5} ", the formula (a2-r-1) ~ (a2-r-6) in ra' ²¹ Are the same as the alkyl group of R ₀ ′ ′ in
n 'is an integer of 0 to 2, preferably 0 or 1, and more preferably 1.

  Specific examples of the groups represented by general formulas (a5-r-1) to (a5-r-4) will be given below. "Ac" in a formula shows an acetyl group.

Among the above, as the -SO ₂ -containing cyclic group, a group represented by the general formula (a5-r-1) is preferable, and in particular, a group represented by the chemical formula (r-sl-1-1) And groups each represented by the aforementioned chemical formula (r-sl-1-18) are preferable.

As the structural unit (a5), structural units derived from an acrylic acid ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted by a substituent are particularly preferable.
As a preferable specific example of the structural unit (a5), in the structural unit represented by the above general formula (a2-1), Ra ²¹ is a group represented by the above general formula (a5-r-1) And the structural unit represented by the following general formula (a5-1) is more preferable.

［式中、Ｒは、前記と同様である。Ｒａ^５１は上記一般式（ａ５−ｒ−１）で表される基である。Ｒａ^５２及びＲａ^５３はそれぞれ独立に水素原子又は炭素数１〜５のアルキル基である。ｎａ_５１は１〜３の整数である。］

[Wherein, R is as defined above. Ra ⁵¹ is a group represented by the above general formula (a5-r-1). Ra ⁵² and Ra ⁵³ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. na ₅₁ is an integer of 1 to 3; ]

As an alkyl group of Ra ⁵² and Ra ⁵³ in said Formula (a5-1), it is the same as the alkyl group in said R. Among them, ^{Ra 52} and ^{Ra 53, when Ra 52} and ^{Ra 53} are both hydrogen atoms, or, if only one of ^{Ra 52} and ^{Ra 53} is an alkyl group (particularly preferably methyl group) .
It is preferable that na ₅₁ is 1 or 2.

The structural unit (a5) contained in the component (A1) may be one type or two or more types.
When the component (A1) has the structural unit (a5), the proportion of the structural unit (a5) is preferably 1 to 50 mol% with respect to the total of all structural units constituting the component (A1), The amount is more preferably 3 to 40 mol%, further preferably 5 to 30 mol%, and particularly preferably 10 to 25 mol%.
By setting the ratio of the structural unit (a5) to the preferable lower limit value or more, the resolution in forming a resist pattern is further enhanced. On the other hand, by setting the content to the preferable upper limit value or less, it becomes easy to balance with other constituent units.

Constitutional unit (a13):
The structural unit (a13) is a structural unit containing a carbonate-containing cyclic group.
The “carbonate-containing cyclic group” refers to a cyclic group containing a ring (carbonate ring) containing —O—C (−O) —O— in the ring skeleton thereof. The carbonate ring is counted as the first ring, and when it has only a carbonate ring, it is a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of its structure. The carbonate-containing cyclic group may be a monocyclic group or a polycyclic group.
The carbonate ring-containing cyclic group is not particularly limited, and any group can be used. Specifically, groups represented by the following general formulas (ax3-r-1) to (ax3-r-3) can be mentioned.

［式中、Ｒａ’^ｘ３１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ_１３”、−ＯＣ（＝Ｏ）Ｒ_１３”、ヒドロキシアルキル基またはシアノ基であり；Ｒ_１３”は水素原子又はアルキル基であり；Ａ”は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子であり、ｐ’は０〜３の整数であり、ｑ’は０または１である。］

[ ^Wherein , each of Ra ' ^{x 31} independently represents a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR ₁₃ ", -OC (= O) R ₁₃ ", a hydroxyalkyl group or cyano R _{13 ′} ′ is a hydrogen atom or an alkyl group; A ′ ′ is an oxygen atom or an alkylene group having 1 to 5 carbon atoms which may contain a sulfur atom, an oxygen atom or a sulfur atom, and p ′ is a group It is an integer of 0 to 3, and q 'is 0 or 1. ]

In the general formulas (ax3-r-1) to (ax3-r-3), A ′ ′ represents the general formulas (a2-r-1), (a2-r-2) and (a2-r-4). It is the same as A "in.
Ra 'alkyl group in ^x31, alkoxy group, halogen atom, halogenated alkyl group, a hydroxyalkyl group, each of the general formulas (a2-r-1) ~ (a2-r-6) in the Ra' alkyl in ²¹ The same groups as in the group, alkoxy group, halogen atom, halogenated alkyl group and hydroxyalkyl group can be mentioned.
The alkyl group represented by R ₁₃ ′ ′ in —COOR ₁₃ ′ ′ and —OC (= O) R ₁₃ ′ ′ in Ra ′ ^{x 31} is preferably an Ra ′ ^{21 in the} formulas (a2-r-1) to (a2-r-6) Are the same as the alkyl group of R ₀ ′ ′ in
p 'is an integer of 0 to 3, preferably 1 to 3, and more preferably 1 or 2.

  Specific examples of the groups represented by general formulas (ax3-r-1) to (ax3-r-3) will be given below.

As the structural unit (a13), structural units derived from an acrylic acid ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted by a substituent are particularly preferable.
As a preferable specific example of the structural unit (a13), in the structural unit represented by the general formula (a2-1), Ra ²¹ is a group represented by the general formulas (ax3-r-1) to (ax3-r-3) What is group represented by either of is mentioned.

The structural unit (a13) contained in the component (A1) may be one type or two or more types.
When the component (A1) has the structural unit (a13), the proportion of the structural unit (a13) is preferably 1 to 50 mol% with respect to the total of all structural units constituting the component (A1), The amount is more preferably 3 to 40 mol%, further preferably 5 to 30 mol%, and particularly preferably 10 to 25 mol%.
By setting the ratio of the structural unit (a13) to the preferable lower limit value or more, the resolution in forming a resist pattern is further enhanced. On the other hand, by setting the content to the preferable upper limit value or less, it becomes easy to balance with other constituent units.

Constitutional unit (a3):
The structural unit (a3) is a structural unit containing a polar group-containing aliphatic hydrocarbon group (however, the above-mentioned structural unit (a0), structural unit (a1), structural unit (a1 ′), structural unit (a2), structural unit Excluding the unit (a5) or the unit (a13).
When the component (A1) has the structural unit (a3), the hydrophilicity of the component (A) is enhanced, which contributes to the improvement of the 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 the alkyl group is substituted with a fluorine atom, with a hydroxyl group being particularly preferable.
As an aliphatic hydrocarbon group, a C1-C10 linear or branched hydrocarbon group (preferably alkylene group) and cyclic aliphatic hydrocarbon group (cyclic group) are mentioned. The cyclic group may be a monocyclic group or a polycyclic group. For example, in the resin for a resist composition for ArF excimer laser, it can be appropriately selected and used from those proposed in large numbers. The cyclic group is preferably a polycyclic group, and more preferably 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylic acid 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 preferred. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from a bicycloalkane, tricycloalkane, tetracycloalkane or the like. Specific examples thereof 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, groups in which two or more hydrogen atoms are removed from adamantane, groups in which two or more hydrogen atoms are removed from norbornane, and groups in which two or more hydrogen atoms are removed from tetracyclododecane are Industrially preferred.

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 acrylic acid ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and a polar group-containing aliphatic hydrocarbon group Constituent units are preferred.
As the structural unit (a3), 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, it is derived from hydroxyethyl ester of acrylic acid Structural unit is preferable, and when the hydrocarbon group is a polycyclic group, a structural unit represented by the following formula (a3-1), a structural unit represented by the formula (a3-2), a formula ( The structural unit represented by a3-3) is mentioned as a preferable thing.

［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 as defined above, j is an integer of 1 to 3, k is an integer of 1 to 3, t 'is an integer of 1 to 3, and l is an integer of 1 to 5] And s is an integer of 1 to 3. ]

In the formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group be bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group be bonded to the 3rd position of the adamantyl group.
j is preferably 1, and particularly preferably, 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 5- or 6-position of the norbornyl group.

  In formula (a3-3), t ′ is preferably 1. l is preferably 1. s is preferably 1. As for these, it is preferable that 2- norbornyl group or 3- norbornyl group is couple | bonded with the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5 or 6 position of the norbornyl group.

The structural unit (a3) that the component (A1) has may be one type or two or more types.
When the component (A1) has a structural unit (a3), the proportion of the structural unit (a3) is preferably 1 to 40 mol% with respect to the total of all structural units constituting the component (A1), It is more preferable that it is 2-30 mol%, It is further more preferable that it is 5-25 mol%, 10-20 mol% is especially preferable.
By setting the ratio of the structural unit (a3) to the preferable lower limit value or more, the resolution in forming a resist pattern is further enhanced. On the other hand, by setting the content to the preferable upper limit value or less, it becomes easy to balance with other constituent units.

Constitutional unit (a4):
The structural unit (a4) is a structural unit containing a non-acid dissociable, aliphatic cyclic group.
When the component (A1) has the structural unit (a4), the dry etching resistance of the formed resist pattern is improved. In addition, the hydrophobicity of the component (A) is enhanced. The improvement of the hydrophobicity contributes to the improvement of the resolution, the resist pattern shape and the like particularly in the case of the solvent development process.
The “non-acid dissociable cyclic group” in the structural unit (a4) is an acid when generated in the resist composition upon exposure (for example, when an acid is generated from the component (B) described later), the acid It is a cyclic group which remains as it is in the structural unit without dissociation even if.
As the structural unit (a4), for example, a structural unit derived from an acrylic acid ester containing a non-acid dissociable aliphatic cyclic group is preferable. As the cyclic group, many groups conventionally known as those used for resin components of resist compositions such as for ArF excimer laser and for KrF excimer laser (preferably for ArF excimer laser) can be used. .
Particularly, at least one selected from a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group is preferable from the viewpoint of industrial availability and the like. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.
Specific examples of the structural unit (a4) include structural units represented by general formulas (a4-1) to (a4-7) shown below.

［式中、Ｒ^αは前記と同じである。］

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

The structural unit (a4) contained in the component (A1) may be one type or two or more types.
When the component (A1) has a structural unit (a4), the proportion of the structural unit (a4) is preferably 1 to 40 mol% with respect to the total of all structural units constituting the component (A1), It is more preferable that it is 5-20 mol%.
By setting the ratio of the structural unit (a4) to the preferable lower limit value or more, the effect by containing the structural unit (a4) can be sufficiently obtained, while by setting the ratio to the preferable upper limit value or less, other structural units and Makes it easy to balance

The resist composition of this embodiment contains a polymer compound (A1) having at least a structural unit (a0), a structural unit (a1), a structural unit (a1 ′) and a structural unit (a2).
Specifically as the component (A1), repeating of the structural unit (a0), the structural unit (a1), the structural unit (a1 '), the structural unit (a2), the structural unit (a5) and the structural unit (a3) A polymer compound having a structure, a polymer compound having a repeating structure of a structural unit (a0), a structural unit (a1), a structural unit (a1 ′), a structural unit (a2) and a structural unit (a3), a structural unit (a) A high molecular compound etc. which consist of repeating structure of a0), a structural unit (a1), a structural unit (a1 '), and a structural unit (a2) can be illustrated.

In addition, as a preferable combination of the structural unit (a1) and the structural unit (a1 ′) in the component (A1), both the structural unit (a1) and the structural unit (a1 ′) have the above formula (a1-1) a structural unit represented in, as Ra ¹ in the structural unit (a1) is a group represented by the formula (a1-r-2), Ra 1 in the structural unit (a1 ') is the formula A combination of the group represented by (a1-r-1) with (the former); the structural unit (a1) and the structural unit (a1 ′) are each represented by the formula (a1-1) And Ra ¹ in the structural unit (a1) is a group represented by the above formula (a1-r-2), and Ra ¹ in the structural unit (a1 ′) is the above formula (a1−r−) A combination of the group represented by 2) and the group (the latter) can be exemplified.
Furthermore, as a specific example of the latter, the structural unit (a1) and the structural unit (a1 ′) are both structural units represented by the above formula (a1-1), and Ra ¹ in the structural unit (a1) is the above A combination of a group represented by the formula (a1-r2-1) and a group represented by the formula (a1-r2-2), wherein Ra ¹ in the structural unit (a1 ′) is a group represented by the formula (a1-r2-2); The structural unit (a1) and the structural unit (a1 ′) are both structural units represented by the above formula (a1-1), and Ra ¹ in the structural unit (a1) is the above formula (a1-r2-2) And combinations of those in which the structural unit (a1 ′) has Ra ¹ of the group represented by the above formula (a1-r2-2), and the like. Preferred examples of the acid dissociable group in each combination are as described above.

In addition, in the resist composition of the present embodiment, the ratio of the structural unit (a1) to the total of all the structural units constituting the polymer compound (A1) is not less than the ratio of the structural unit (a1 ′) . This results in better lithographic properties and pattern shapes. In particular, both in-plane uniformity (CDU) of pattern dimensions and depth of focus (DOF) characteristics are improved.
The mixing ratio of the structural unit (a1) to the structural unit (a1 ′) [(a1) / (a1 ′)] is (a1) / (a1 ′) = 50/50 to 90/10 in molar ratio Is preferable, and 50/50 to 80/20 is particularly preferable.
In addition, the total proportion of the structural unit (a1) and the structural unit (a1 ′) is preferably 25 mol% or more, 30 mol% with respect to the total of all the structural units constituting the component (A1). The content is more preferably 30 to 80 mol%, and particularly preferably 30 to 50 mol%.
By setting the ratio of the total of the structural unit (a1) and the structural unit (a1 ′) to a preferable lower limit value or more, the effects of the present invention can be more easily obtained. On the other hand, by setting the content to the preferable upper limit value or less, it becomes easy to balance with other constituent units.
In the resist composition of this aspect, the total proportion of the structural unit (a1) and the structural unit (a1 ′) is at least 25 mol%, and the mixture ratio of the two is (a1)> (a1 ′). Is particularly preferred.

In the resist composition of the present embodiment, the ratio of the structural unit (a2) to the total of all the structural units constituting the polymer compound (A1) is higher than the ratio of the structural unit (a0) preferable. By having the structural unit (a2), the solubility in organic solvents is enhanced. For this reason, when the ratio of the structural unit (a2) is higher than the ratio of the structural unit (a0), this contributes to the improvement of the resolution particularly in the negative development process.
The mixing ratio [(a2) / (a0)] of the structural unit (a2) to the structural unit (a0) is preferably (a2) / (a0) = 50/50 to 90/10 in molar ratio 55/45 to 90/10, and more preferably 60/40 to 80/20.
In addition, the total proportion of the structural unit (a0) and the structural unit (a2) is preferably 20 mol% or more, preferably 30 mol% or more, based on the total of all structural units constituting the component (A1). Is more preferably 30 to 70 mol%, and particularly preferably 30 to 50 mol%.
By setting the ratio of the total of the structural unit (a0) and the structural unit (a2) to a preferable lower limit value or more, the effects of the present invention can be obtained more easily. On the other hand, by setting the content to the preferable upper limit value or less, it becomes easy to balance with other constituent units.
In the resist composition of this embodiment, the total proportion of the structural unit (a0) and the structural unit (a2) is at least 20 mol%, and the mixture ratio of the both is (a2)> (a0), among others Is particularly preferred.

The mass average molecular weight (Mw) (based on polystyrene conversion by gel permeation chromatography (GPC)) of the component (A1) is not particularly limited, and 1000 to 50000 is preferable, 1500 to 30000 is more preferable, and 2000 to 2000. 20000 is most preferred.
When the Mw of the component (A1) is less than the preferable upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and when it is not less than the preferable lower limit of this range, dry etching resistance or The resist pattern cross-sectional shape is good.
The dispersion degree (Mw / Mn) of the component (A1) is not particularly limited, and is preferably 1.0 to 5.0, more preferably 1.0 to 4.0, and most preferably 1.0 to 3.0. . 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 or more, further preferably 75% by mass or more, and 100% by mass, based on the total mass of the component (A). It may be When the proportion is 25% by mass or more, a resist pattern having a good shape is easily formed, in particular, excellent in various lithography properties such as in-plane uniformity (CDU) of pattern dimension and depth of focus (DOF) characteristics. Become.

The resist composition of this embodiment does not correspond to the component (A1) as the component (A), and a base component (hereinafter referred to as "component (A2)") whose solubility in a developer changes due to the action of an acid. You may use together.
The component (A2) is not particularly limited, and many components conventionally known as base components for chemically amplified resist compositions (for example, for ArF excimer laser, KrF excimer laser (preferably ArF excimer laser) And the like, and may be selected from arbitrary base resins. As the component (A2), one type may be used alone, or two or more types may be used in combination.

In the resist composition of the present embodiment, as the component (A), one type may be used alone, or two or more types may be used in combination.
In the resist composition of the present embodiment, the content of the component (A) may be adjusted according to the thickness of the resist film to be formed.

<Other ingredients>
The resist composition of the present embodiment may further contain other components other than the component (A) in addition to the component (A) described above. Examples of other components include the following components (B), (D), (E), (F), and (S).

[(B) component: acid generator component]
The resist composition of this embodiment may further contain an acid generator component (hereinafter referred to as "component (B)") in addition to the component (A).
The component (B) is not particularly limited, and those which have been proposed as acid generators for chemically amplified resists can be used.
Examples of such an acid generator include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, bisalkyl or bisarylsulfonyldiazomethanes, and diazomethanes such as poly (bissulfonyl) diazomethanes. There are various types such as an acid generator, a nitrobenzyl sulfonate-based acid generator, an iminosulfonate-based acid generator, and a disulfone-based acid generator. Among them, it is preferable to use an onium salt-based acid generator.

  As the onium salt-based acid generator, for example, a compound represented by the following general formula (b-1) (hereinafter also referred to as “component (b-1)”), a compound represented by general formula (b-2) It is possible to use a compound (hereinafter also referred to as “component (b-2)”) or a compound represented by general formula (b-3) (hereinafter also referred to as “component (b-3)”).

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

[Wherein, R ¹⁰¹ and R ^{104 to} R ¹⁰⁸ each independently have a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a substituent] It is a chain-like alkenyl group which may be R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring. R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom. V ^{101 to} V ¹⁰³ each independently represent a single bond, an alkylene group or a fluorinated alkylene group. L ^{101 to} L ¹⁰² each independently represent a single bond or an oxygen atom. L ^{103 to} L ¹⁰⁵ are each independently a single bond, -CO- or -SO _2- . m is an integer of 1 or more, and M ' ^{m +} is an m-valent onium cation. ]

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

Cyclic group which may have a substituent:
The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. In addition, the aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

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

The cyclic aliphatic hydrocarbon group in R ¹⁰¹ includes aliphatic hydrocarbon groups containing a ring in the structure.
As the aliphatic hydrocarbon group containing a ring in this structure, an alicyclic hydrocarbon group (a group obtained by removing one hydrogen atom from an aliphatic hydrocarbon ring) and an alicyclic hydrocarbon group having a linear or branched chain Examples thereof include a group bonded to the end of a linear aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group intervenes in the middle of a linear or branched aliphatic hydrocarbon group.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As a monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane is preferably one having 3 to 6 carbon atoms, and specific examples include cyclopentane, cyclohexane and the like. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from polycycloalkane is preferable, and as the polycycloalkane, one having 7 to 30 carbon atoms is preferable. Among them, as the polycycloalkane, a polycycloalkane having a bridged ring type polycyclic skeleton such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like; a condensed ring system such as a cyclic group having a steroid skeleton More preferred are polycycloalkanes having a polycyclic skeleton of
In the present specification, the "steroid skeleton" means a skeleton (st) represented by the following chemical formula in which three six-membered rings and one five-membered ring are connected.

Among them, as the cyclic aliphatic hydrocarbon group for R ¹⁰¹ , a group obtained by removing one or more hydrogen atoms from a monocycloalkane or polycycloalkane is preferable, and a group obtained by removing one hydrogen atom from a polycycloalkane is more preferable. An adamantyl group and a norbornyl group are particularly preferable, and an adamantyl group is most preferable.

The linear or branched aliphatic hydrocarbon group which may be bonded to an alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and 1 to 4 carbon atoms. Are more preferred, and 1 to 3 are most preferred.
As a linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specifically, a methylene group [-CH _2- ], an ethylene group [-(CH ₂ ) _2- ], a trimethylene group [ _{- (CH 2) 3 -]} , a tetramethylene group _{[- (CH 2) 4 -} ], a pentamethylene group _{[- (CH 2) 5 -} ] , and the like.
As the branched aliphatic hydrocarbon group, preferably a branched chain alkylene group, _{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 An alkylethylene group such as CH ₃ ) ₂ -CH _2- ; an alkyltrimethylene group such as -CH (CH ₃ ) CH ₂ CH _2- , -CH ₂ CH (CH ₃ ) CH _2-, etc .; -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. As an alkyl group in an alkyl alkylene group, a C1-C5 linear alkyl group is preferable.

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

As a substituent in the cyclic group of R ¹⁰¹ , for example, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group and the like can be mentioned.
As an alkyl group as a substituent, a C1-C5 alkyl group is preferable and a methyl group, an ethyl group, a propyl group, n-butyl group, and a tert- butyl group are the most preferable.
As an alkoxy group as a substituent, a C1-C5 alkoxy group is preferable, and a methoxy group, an ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, tert-butoxy group is more preferable, and methoxy is preferable. And ethoxy groups are most preferred.
As a halogen atom as a substituent, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, A fluorine atom is preferable.
As a halogenated alkyl group as a substituent, a part or all of hydrogen atoms, such as an alkyl group having 1 to 5 carbon atoms, such as methyl group, ethyl group, propyl group, n-butyl group, tert-butyl group, etc. The group substituted by the halogen atom is mentioned.
Carbonyl group as a substituent, a methylene group constituting the cyclic hydrocarbon group - a group substituting (-CH _2).

Chain-like alkyl group which may have a substituent:
The linear alkyl group of R ¹⁰¹ may be 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, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl Groups, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, henicosyl 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, 1-methyl pentyl group, 2-methyl pentyl group, 3-methyl pentyl group, 4-methyl pentyl group etc. are mentioned.

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

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

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

In formula (b-1), Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom.
When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, the Y ¹⁰¹ may contain an atom other than the oxygen atom. As an atom other than an oxygen atom, a carbon atom, a hydrogen atom, a sulfur atom, a nitrogen atom etc. are mentioned, for example.
Examples of the divalent linking group containing an oxygen atom include an oxygen atom (ether bond: -O-), an ester bond (-C (= O) -O-), an oxycarbonyl group (-O-C (= O Non-hydrocarbons such as)-), amide bond (-C (= O) -NH-), carbonyl group (-C (= O)-), carbonate bond (-O-C (= O) -O-) etc And oxygen atom-containing linking groups of the system; combinations of such non-hydrocarbon oxygen atom-containing linking groups and alkylene groups, and the like. A sulfonyl group (—SO ₂ —) may be further linked to this combination. As a bivalent coupling group containing this oxygen atom, the coupling group represented, for example by the following general formula (y-al-1)-(y-al-7) is mentioned, for example.

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

[In Formula, V ' ¹⁰¹ is a single bond or a C1-C5 alkylene group, V' ¹⁰² is a C1-C30 bivalent saturated hydrocarbon group. ]

The divalent saturated hydrocarbon group in V ′ ¹⁰² is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and an alkylene group having 1 to 5 carbon atoms It is further preferred that

The alkylene group in V ′ ¹⁰¹ and V ′ ¹⁰² may be a linear alkylene group or a branched alkylene group, and a linear alkylene group is preferable.
Specific examples of the alkylene group as V ′ ¹⁰¹ and V ′ ¹⁰² include methylene group [—CH ₂ —]; —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, and —C (CH ₃ ). _{2 -, - C (CH 3} ) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as ethylene group _{[-CH 2 CH 2 -];} - CH (CH 3) CH 2 -, - CH (CH 3) CH (CH 3) -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH ₃ ) alkyl ethylene group such as CH _2- ; trimethylene group (n-propylene group) [-CH ₂ CH ₂ CH _2- ]; -CH (CH ₃ ) CH ₂ CH _2- , -CH ₂ CH (CH ₃ ) CH ₂ - and the like alkyl trimethylene group; tetramethylene _{[-CH 2 CH 2 CH 2 CH} 2 -]; - CH (CH 3) CH 2 CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 CH 2 - alkyl tetramethylene group and the like; pentamethylene group _{[-CH 2 CH 2 CH 2 CH} 2 CH 2 -] , and the like.
Moreover, a part of methylene group in the said alkylene group in V ' ¹⁰¹ or V' ¹⁰² may be substituted by the C5-C10 bivalent aliphatic cyclic group. The aliphatic cyclic group is a cyclic aliphatic hydrocarbon group of Ra ′ ^{3 in} the formula (a1-r-1) (a monocyclic aliphatic hydrocarbon group or a polycyclic aliphatic hydrocarbon group) ) Is preferably a divalent group in which one hydrogen atom is further removed, and more preferably a cyclohexylene group, a 1,5-adamantylene group or a 2,6-adamantylene group.

As Y ¹⁰¹ , a divalent linking group containing an ester bond or a divalent linking group containing an ether bond is preferable, and is represented by the above formulas (y-al-1) to (y-al-5) respectively. A linking group is more preferred.

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

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

(B-1) Specific examples of the anion moiety of the component, for example, if the Y ¹⁰¹ is a single bond, fluorinated alkyl sulfonate anions such as trifluoromethane sulfonate anion or perfluorobutane sulfonate anion can be exemplified; Y ¹⁰¹ is When it is a bivalent coupling group containing an oxygen atom, the anion represented by either of following formula (an-1)-(an-3) is mentioned.

［式中、Ｒ”^１０１は、置換基を有していてもよい脂肪族環式基、前記式（ｒ−ｈｒ−１）〜（ｒ−ｈｒ−６）でそれぞれ表される基、又は置換基を有していてもよい鎖状のアルキル基であり；Ｒ”^１０２は、置換基を有していてもよい脂肪族環式基、前記一般式（ａ２−ｒ−１）〜（ａ２−ｒ−７）でそれぞれ表されるラクトン含有環式基、又は前記一般式（ａ５−ｒ−１）〜（ａ５−ｒ−４）でそれぞれ表される−ＳＯ_２−含有環式基であり；Ｒ”^１０３は、置換基を有していてもよい芳香族環式基、置換基を有していてもよい脂肪族環式基、又は置換基を有していてもよい鎖状のアルケニル基であり；ｖ”はそれぞれ独立に０〜３の整数であり、ｑ”はそれぞれ独立に１〜２０の整数であり、ｔ”は１〜３の整数であり、ｎ”は０または１である。］

[Wherein, R ′ ′ ¹⁰¹ is an aliphatic cyclic group which may have a substituent, a group represented by any of the above formulas (r-hr-1) to (r-hr-6), or a substituted group R ′ ′ ¹⁰² is an aliphatic cyclic group which may have a substituent, and the above-described general formulas (a2-r-1) to (a2-). a lactone-containing cyclic group represented by r-7) or a —SO ₂ — containing cyclic group represented by the general formulas (a5-r-1) to (a5-r-4), respectively; R ′ ′ ¹⁰³ is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain-like alkenyl group which may have a substituent V ′ ′ is each independently an integer of 0 to 3; q ′ ′ is each independently an integer of 1 to 20; t ′ ′ is an integer of 1 to 3; n ′ ′ is 0 The other is 1.]

The aliphatic cyclic group which may have a substituent of R ′ ′ ¹⁰¹ , R ′ ′ ¹⁰² and R ′ ′ ¹⁰³ is preferably the group exemplified as the cyclic aliphatic hydrocarbon group for R ¹⁰¹ above. Examples of the substituent include those similar to the substituents which may substitute the cyclic aliphatic hydrocarbon group for R ¹⁰¹ .

The aromatic cyclic group which may have a substituent in R ′ ¹⁰³ is preferably the group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in R ¹⁰¹ described above. And the same as the substituent which may substitute the aromatic hydrocarbon group in R ¹⁰¹ .

R have a substituent in "which may chain substituted at ¹⁰¹ alkyl group, wherein preferably a group exemplified as chain alkyl group in R ¹⁰¹ .R" ¹⁰³ The chain-like alkenyl group is also preferably the group exemplified as the chain-like alkenyl group in R ¹⁰¹ above.

-Anion part of component (b-2) In formula (b-2), each of R ¹⁰⁴ and R ¹⁰⁵ independently has a cyclic group which may have a substituent, or a substituent. A good chained alkyl group or a chained alkenyl group which may have a substituent, each of which is similar to R ¹⁰¹ in formula (b-1). However, R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring.
R ¹⁰⁴ and R ¹⁰⁵ each are preferably a linear alkyl group which may have a substituent, and is a linear or branched alkyl group or a linear or branched fluorinated alkyl group Is more preferred.
It is preferable that carbon number of this chain | strand-shaped alkyl group is 1-10, More preferably, it is C1-C7, More preferably, it is C1-C3. The carbon number of the linear alkyl group of R ¹⁰⁴ and R ¹⁰⁵ is preferably as small as possible because the solubility in a resist solvent is also good within the above-mentioned range of carbon numbers. Further, in the chain alkyl group of R ¹⁰⁴ and R ^105, the greater the number of hydrogen atoms substituted by fluorine atoms, the stronger the acid strength, and the high energy light and electron beams of 200 nm or less. It is preferable because the transparency is improved. The proportion of fluorine atoms in the linear alkyl group, ie, the fluorination ratio, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are substituted by fluorine atoms. Perfluoroalkyl group.
In formula (b-2), each of V ¹⁰² and V ¹⁰³ independently represents a single bond, an alkylene group, or a fluorinated alkylene group, and each of them is the same as V ¹⁰¹ in formula (b-1) It can be mentioned.
In formula (b-2), L ¹⁰¹ and L ¹⁰² each independently represent a single bond or an oxygen atom.

-Anion part of component (b-3) In formula (b-3), each of R ^{106 to} R ¹⁰⁸ independently has a cyclic group which may have a substituent, and a substituent A good chained alkyl group or a chained alkenyl group which may have a substituent, each of which is the same as R ¹⁰¹ in formula (b-1).
L ^{103 to} L ¹⁰⁵ are each independently a single bond, -CO- or -SO _2- .

{Cation part}
In formulas (b-1), (b-2) and (b-3), m is an integer of 1 or more, M ' ^{m +} is an m-valent onium cation, and a sulfonium cation and an iodonium cation are preferable Particularly preferred are organic cations which are mentioned and represented by the following general formulas (ca-1) to (ca-4).

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

[Wherein, R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² each independently represent an aryl group which may have a substituent, an alkyl group or an alkenyl group, and R ^{201 to} R ²⁰³ and R ²⁰⁶ to R ²⁰⁷ and R ^{211 to} R ²¹² may be mutually bonded to form a ring with the sulfur atom in the formula. R ^{208 to} R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and R ²¹⁰ represents an aryl group which may have a substituent, an alkyl group which may have a substituent, It is an alkenyl group which may have a substituent or a -SO ₂ -containing cyclic group which may have a substituent, and L ²⁰¹ is -C (= O)-or -C (= O) Y ²⁰¹ represents each independently an arylene group, an alkylene group or an alkenylene group, x represents 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 211 ^{to R 212,} include unsubstituted aryl group having 6 to 20 carbon atoms, a phenyl group, a naphthyl group.
The alkyl group of R ²⁰¹ to R ^207, and ^R 211 ^{to R 212,} a chain or cyclic alkyl group, preferably from 1 to 30 carbon atoms.
The alkenyl group in R ²⁰¹ to R ^207, and ^R 211 ^{to R 212,} preferably has 2 to 10 carbon atoms.
Examples of the substituent which R ^{201 to} R ²⁰⁷ and R ^{210 to} R ²¹² may have include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, Groups represented by formulas (ca-r-1) to (ca-r-7) can be mentioned.

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

[Wherein, R ′ ²⁰¹ each independently has a hydrogen atom, a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent It may be a chain-like alkenyl group. ]

The cyclic group which may have a substituent of R ′ ^201, the chain-like alkyl group which may have a substituent, or the chain-like alkenyl group which may have a substituent is formula (b-1) except that include those similar to the R ¹⁰¹ in, the foregoing as may have a substituent group cyclic group or optionally substituted chain alkyl group The same acid dissociable group represented by the formula (a1-r-2) can also be mentioned.

When R ^{201 to} R ²⁰³ , R ^{206 to} R ²⁰⁷ and R ^{211 to} R ²¹² are mutually bonded to form a ring with the sulfur atom in the formula, a hetero atom such as a sulfur atom, an oxygen atom or a 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. May be bonded via a functional group of As the ring to be formed, one ring containing a sulfur atom in the formula in its ring skeleton is preferably a 3- to 10-membered ring, including a sulfur atom, and particularly preferably a 5- to 7-membered ring 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, tetrahydrofuran Thiophenium rings, tetrahydrothiopyranium rings and the like can be mentioned.

R ^{208 to} R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and when it is an alkyl group, they are mutually bonded It may form a ring.

R ²¹⁰ may have an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a substituent -SO ₂ - containing cyclic group.
As an aryl group in R ^210, a C6-C20 unsubstituted aryl group is mentioned, A phenyl group and a naphthyl group are preferable.
The alkyl group in R ²¹⁰ is preferably a linear or cyclic alkyl group having 1 to 30 carbon atoms.
The alkenyl group in R ²¹⁰ preferably has 2 to 10 carbon atoms.
^Examples of the —SO ₂ -containing cyclic group which may have a substituent in R ²¹⁰ include the same ones as the above-mentioned “—SO ₂ -containing cyclic group”, and among these, a general formula The group represented by a5-r-1) is preferable.

Each Y ²⁰¹ independently represents an arylene group, an alkylene group or an alkenylene group.
The arylene group in Y ²⁰¹ includes a group in which one hydrogen atom is removed from the aryl group exemplified as the aromatic hydrocarbon group in R ¹⁰¹ in the above-mentioned formula (b-1).
Examples of the alkylene group and the alkenylene group in Y ²⁰¹ include a group in which one hydrogen atom is removed from the group exemplified as the chained alkyl group and the chained alkenyl group in R ¹⁰¹ in the above formula (b-1) .

In the formula (ca-4), x is 1 or 2.
W ²⁰¹ is a (x + 1) valent, ie, a divalent or trivalent linking group.
The divalent linking group in W ²⁰¹ is preferably a divalent hydrocarbon group which may have a substituent, and has a substituent similar to Ya ²¹ in the general formula (a2-1) described above And optionally substituted divalent hydrocarbon groups. The divalent linking group in W ²⁰¹ may be linear, branched or cyclic, and is preferably cyclic. Among them, a group in which two carbonyl groups are combined at both ends of an arylene group is preferable. As an arylene group, a phenylene group, a naphthylene group, etc. are mentioned, A phenylene group is especially preferable.
^Examples of the trivalent linking group in W ²⁰¹ include a group obtained by removing one hydrogen atom from the divalent linking group in W ²⁰¹ , a group in which the divalent linking group is further bonded to the divalent linking group, and the like. It can be mentioned. The trivalent linking group in W ²⁰¹ is preferably a group in which two carbonyl groups are bonded to an arylene group.

  Specifically as a suitable cation represented by said Formula (ca-1), the cation respectively represented by following formula (ca-1-1)-(ca-1-67) is mentioned.

［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。］

[In formula, g1, g2, g3 shows repetition number, g1 is an integer of 1-5, g2 is an integer of 0-20, g3 is an integer of 0-20. ]

［式中、Ｒ”^２０１は水素原子又は置換基であって、該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。］

[In the Formula, R ′ ′ ²⁰¹ is a hydrogen atom or a substituent, and the substituent is the same as the substituent described above as an example of the substituent that R ^{201 to} R ²⁰⁷ and R ^{210 to} R ²¹² may have. It is

  Specifically as a suitable cation represented by said Formula (ca-2), a diphenyl iodonium cation, a bis (4-tert- butylphenyl) iodonium cation, etc. are mentioned.

  Specifically as a suitable cation represented by said Formula (ca-3), the cation respectively represented by following formula (ca-3-1)-(ca-3-6) is mentioned.

  Specifically as a suitable cation represented by said Formula (ca-4), the cation respectively represented by following formula (ca-4-1)-(ca-4-2) is mentioned.

Among the above, the cation moiety [(M ′ ^{m +} ) _{1 / m 2} ] is preferably a cation represented by general formula (ca-1), and is represented by formulas (ca-1-1) to (ca-1-67) The cation respectively represented is more preferable.

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 contains the component (B), the content of the component (B) is preferably 0.5 to 60 parts by mass, more preferably 1 to 50 parts by mass with respect to 100 parts by mass of the component (A). 1 to 40 parts by mass is more preferable.
By setting the content of the component (B) in the above range, pattern formation is sufficiently performed. Moreover, when each component of the resist composition is dissolved in an organic solvent, a uniform solution is easily obtained, and the storage stability as the resist composition becomes good, which is preferable.

[(D) component: acid diffusion control agent component]
In the resist composition of this embodiment, in addition to the component (A), or to the components (A) and (B), an acid diffusion controller component (hereinafter referred to as "component (D)") is further added. You may contain. The component (D) acts as a quencher (acid diffusion control agent) which traps an acid generated by exposure in the resist composition.
The component (D) may be a photodisintegrable base (D1) (hereinafter referred to as “component (D1)”) which is decomposed by exposure to lose acid diffusion controllability, and does not fall under the component (D1). It may be a nitrogen organic compound (D2) (hereinafter referred to as "component (D2)").

Component (D1) By using the resist composition containing the component (D1), it is possible to improve the contrast between the exposed area and the unexposed area when forming a resist pattern.
The component (D1) is not particularly limited as long as it decomposes by exposure and loses acid diffusion controllability, and a compound represented by the following general formula (d1-1) (hereinafter "component (d1-1)") A compound represented by the following general formula (d1-2) (hereinafter referred to as "(d1-2) component") and a compound represented by the following general formula (d1-3) (hereinafter referred to as "(d1- 3) One or more types of compounds selected from the group consisting of components.
The components (d1-1) to (d1-3) do not act as a quencher because they decompose and lose acid diffusion controllability (basicity) in the exposed portion of the resist film, but act as a quencher in the unexposed portion. Do.

［式中、Ｒｄ^１〜Ｒｄ^４は置換基を有していてもよい環式基、置換基を有していてもよい鎖状のアルキル基、又は置換基を有していてもよい鎖状のアルケニル基である。但し、式（ｄ１−２）中のＲｄ^２における、Ｓ原子に隣接する炭素原子にはフッ素原子は結合していないものとする。Ｙｄ^１は単結合又は２価の連結基である。ｍは１以上の整数であって、Ｍ^ｍ＋はそれぞれ独立にｍ価の有機カチオンである。］

[Wherein, Rd ^{1 to} Rd ⁴ each represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain which may have a substituent] Alkenyl group of However, it is assumed that a fluorine atom is not bonded to the carbon atom adjacent to the S atom in Rd ² in the formula (d1-2). Yd ¹ is a single bond or a divalent linking group. m is an integer of 1 or more, and M ^{m +} is independently an m-valent organic cation. ]

{(D1-1) ingredients}
·· Anion moiety In the formula (d1-1), Rd ¹ has a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a substituent It may be a chain-like alkenyl group, and examples thereof include the same as R ¹⁰¹ in the formula (b-1).
Among these, Rd ¹ may have an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a substituent. A linear alkyl group is preferred. Examples of the substituent which these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, and the general formulas (a2-r-1) to (a2-r-). The lactone containing cyclic group respectively represented by 7), ether bond, ester bond, or these combination is mentioned. When it contains an ether bond or an ester bond as a substituent, it may be via an alkylene group, and the substituent in this case is represented by the above formulas (y-al-1) to (y-al-5). A linking group is preferred.
The aromatic hydrocarbon group is more preferably a phenyl group or a naphthyl group.
The aliphatic cyclic group is more preferably a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane.
The chain alkyl group preferably has 1 to 10 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, Linear alkyl group such as nonyl group and decyl group; 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl And branched alkyl groups such as 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.

When the chained alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the carbon number of the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and 1 To 4 is more preferable. The fluorinated alkyl group may contain an atom other than a fluorine atom. As an atom other than a fluorine atom, an oxygen atom, a sulfur atom, a nitrogen atom etc. are mentioned, for example.
Rd ¹ is preferably a fluorinated alkyl group in which a part or all of the hydrogen atoms constituting the linear alkyl group are substituted by a fluorine atom, and one of the hydrogen atoms constituting the linear alkyl group is preferred. Particularly preferred is a fluorinated alkyl group (a linear perfluoroalkyl group) which is all substituted with a fluorine atom.

  The preferable specific example of the anion part of a (d1-1) component is shown below.

.. Cation part In formula (d1-1), M ^{m +} is an m-valent organic cation.
As the organic cation of M ^{m +} , those similar to the cations respectively represented by the general formulas (ca-1) to (ca-4) are preferably exemplified, and are represented by the general formula (ca-1) The cation is more preferable, and the cation represented by each of the formulas (ca-1-1) to (ca-1-67) is more preferable.
As the component (d1-1), one type may be used alone, or two or more types may be used in combination.

{(D1-2) ingredients}
·· Anion moiety In the formula (d1-2), Rd ² has a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a substituent It may be a chained alkenyl group which may be substituted, and examples thereof include the same ones as R ¹⁰¹ in the formula (b-1).
However, a fluorine atom is not bonded to the carbon atom adjacent to the S atom in Rd ² (not substituted with fluorine). As a result, the anion of the (d1-2) component becomes an appropriate weak acid anion, and the quenching ability as the (D) component is improved.
Rd ² is preferably a chain-like alkyl group which may have a substituent or an aliphatic cyclic group which may have a substituent. The chain alkyl group preferably has 1 to 10 carbon atoms, and more preferably 3 to 10 carbon atoms. As an aliphatic cyclic group, a group obtained by removing one or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane or the like (which may have a substituent); 1 from camphor etc. It is more preferable that it is the group except the above hydrogen atom.
The hydrocarbon group of Rd ² may have a substituent, and examples of the substituent include a hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, and the like in Rd ¹ of the formula (d1-1). The same substituents as those which the chain alkyl group may have may be mentioned.

  The preferable specific example of the anion part of (d1-2) component is shown below.

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

{(D1-3) ingredients}
·· Anion moiety In the formula (d1-3), Rd ³ has a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a substituent A cyclic alkenyl group, which may be the same as R ¹⁰¹ in the formula (b-1), and may be a cyclic group containing a fluorine atom, a linear alkyl group, or a linear alkenyl group Is preferred. Among them, a fluorinated alkyl group is preferable, and the same fluorinated alkyl group as Rd ¹ is more preferable.

In formula (d1-3), Rd ⁴ may have a cyclic group which may have a substituent, a chained alkyl group which may have a substituent, or a substituent. It is a chain | strand-shaped alkenyl group and the thing similar to R ^{101 in} said Formula (b-1) is mentioned.
Among them, an alkyl group which may have a substituent, an alkoxy group, an alkenyl group and a cyclic group are preferable.
The alkyl group in Rd ⁴ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group And tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. A part of the hydrogen atoms of the alkyl group of Rd ⁴ may be substituted with a hydroxyl group, a cyano group or the like.
The alkoxy group in Rd ⁴ is preferably an alkoxy group having 1 to 5 carbon atoms, and as the alkoxy group having 1 to 5 carbon atoms, specifically, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, n- Examples include butoxy and tert-butoxy. Among these, methoxy and ethoxy are preferable.

The alkenyl group in Rd ⁴ includes the same as R ¹⁰¹ in the above formula (b-1), and a vinyl group, propenyl group (allyl group), 1-methylpropenyl group, and 2-methylpropenyl group are preferable. These groups may further have, as a substituent, an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms.

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

In formula (d1-3), Yd ¹ is a single bond or a divalent linking group.
The divalent linking group in Y d ¹ is not particularly limited, and may be a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent, a hetero atom And the like. These are each a divalent hydrocarbon group which may have a substituent, which is mentioned in the description of the divalent linking group of Ya ²¹ in the formula (a2-1), and a hetero atom The same one as the linking group of valence can be mentioned.
As Yd ¹ , a carbonyl group, an ester bond, an amide bond, an alkylene group or a combination thereof is preferable. The alkylene group is more preferably a linear or branched alkylene group, and still more preferably a methylene group or an ethylene group.

  The preferable specific example of the anion part of (d1-3) component is shown below.

... Cation Part In Formula (d1-3), M ^{m +} is an m-valent organic cation, and is the same as M ^{m +} in Formula (d1-1).
As the component (d1-3), one type may be used alone, or two or more types may be used in combination.

As the component (D1), any one of the components (d1-1) to (d1-3) may be used alone, or two or more thereof may be used in combination.
When the resist composition contains the component (D1), the content of the component (D1) is preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the component (A), and 0.5 to 10 parts by mass. The amount is more preferably 8 parts by mass, further preferably 1 to 8 parts by mass.
When the content of the component (D1) is equal to or more than the preferable lower limit value, particularly favorable lithography characteristics and a resist pattern shape are easily obtained. On the other hand, when it is below the upper limit value, the sensitivity can be favorably maintained and the throughput is also excellent.

Method of producing the component (D1):
The manufacturing method of said (d1-1) component and (d1-2) component is not specifically limited, It can manufacture by a well-known method.
Moreover, the manufacturing method of (d1-3) component is not specifically limited, For example, it manufactures similarly to the method as described in US2012-0149916.

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

The cyclic amine includes, for example, a heterocyclic compound 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 aliphatic monocyclic amines include piperidine, piperazine and the like.
The aliphatic polycyclic amine preferably has 6 to 10 carbon atoms, and 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, etc. are mentioned, and triethanolamine triacetate is preferable.

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

The component (D2) may be used alone or in combination of two or more.
When the resist composition contains the component (D2), the component (D2) is used usually in the range of 0.01 to 5 parts by mass with respect to 100 parts by mass of the component (A). By setting it in the above-mentioned range, the resist pattern shape, the stability over time of placing, etc. are improved.

[(E) Component: at least one compound selected from the group consisting of an organic carboxylic acid and an oxo acid of phosphorus and a derivative thereof]
The resist composition of this embodiment comprises an organic carboxylic acid and an oxo acid of phosphorus and a derivative thereof as an optional component for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, storage stability over time, etc. At least one compound (E) (hereinafter referred to as “component (E)”) selected from the group 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 preferable.
Examples of phosphorus oxo acids include phosphoric acid, phosphonic acid and phosphinic acid. Among these, phosphonic acid is particularly preferable.
Examples of derivatives of oxo acids of phosphorus include esters in which a hydrogen atom of the above oxo acid is substituted with a hydrocarbon group, and examples of the hydrocarbon group include alkyl groups having 1 to 5 carbon atoms and 6 to 6 carbon atoms. 15 aryl groups and the like can be mentioned.
Examples of derivatives of phosphoric acid include phosphoric acid di-n-butyl ester, phosphoric acid esters such as phosphoric acid diphenyl ester, and the like.
Examples of derivatives of phosphonic acid include phosphonic acid dimethyl ester, phosphonic acid di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, phosphonic acid esters such as phosphonic acid dibenzyl ester, and the like.
Examples of phosphinic acid derivatives include phosphinic acid esters and phenylphosphinic acid.
As the component (E), one type may be used alone, or two or more types may be used in combination.
When the resist composition contains the component (E), the component (E) is used usually in the range of 0.01 to 5 parts by weight with respect to 100 parts by weight of the component (A).

[(F) component: fluorine additive component]
The resist composition of this embodiment may contain a fluorine additive component (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-A-2010-002870, JP-A-2010-032994, JP-A-2010-277043, JP-A-2011-13569, and JP-A-2011-128226. The fluorine-containing polymer compound of can be used.
More specific examples of the component (F) include polymers having a structural unit (f1) represented by the following formula (f1-1). As the polymer, a polymer (homopolymer) consisting only of a structural unit (f1) represented by the following formula (f1-1): a copolymer of the structural unit (f1) and the structural unit (a1) A copolymer of the structural unit (f1) and the structural unit (a1 ′); the structural unit (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1) It is preferably a copolymer. Here, as the structural unit (a1) to be copolymerized with the structural unit (f1), a structural unit derived from 1-ethyl-1-cyclooctyl (meth) acrylate is preferable.

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

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

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

In Formula (f1-1), Rf ¹⁰¹ is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom.
The hydrocarbon group containing a fluorine atom may be linear, branched or cyclic, and preferably has 1 to 20 carbon atoms, and more preferably 1 to 15 carbon atoms. And 1 to 10 carbon atoms are particularly preferred.
Moreover, as for the hydrocarbon group containing a fluorine atom, it is preferable that 25% or more of the hydrogen atoms in the said hydrocarbon group are fluorinated, It is more preferable that 50% or more is fluorinated, 60% or more Fluorination is particularly preferable because the hydrophobicity of the resist film at the time of immersion exposure is increased.
Among them, a fluorinated hydrocarbon group having 1 to 5 carbon atoms is more preferable as Rf ¹⁰¹ , and a trifluoromethyl group, -CH ₂ -CF ₃ , -CH ₂ -CF ₂ -CF ₃ , -CH (CF _{3 ) 2, -CH 2 -CH 2 -CF} 3, is _{-CH 2 -CH 2 -CF 2 -CF 2} -CF 2 -CF 3 particularly preferred.

1000-50000 are preferable, as for the mass mean molecular weight (Mw) (the polystyrene conversion standard by gel permeation chromatography) of (F) component, 5000-40000 are more preferable, and 10000-30000 are the most preferable. When it is below the upper limit of this range, it has sufficient solubility in a solvent for resist to be used as a resist, and when it is above the lower limit of this range, its dry etching resistance and resist pattern cross-sectional shape are good. .
The dispersion degree (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.

As the component (F), one type may be used alone, or two or more types may be used in combination.
When the resist composition contains the component (F), the component (F) is usually used in a proportion of 0.5 to 10 parts by mass with respect to 100 parts by mass of the component (A).

  In the resist composition of the present embodiment, additives which are optionally miscible, for example, an additional resin for improving the performance of the resist film, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent, Dyes and the like can be appropriately added and contained.

[(S) component: organic solvent component]
The resist composition of this embodiment can be produced by dissolving a resist material in an organic solvent component (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, and any component can be appropriately selected from conventionally known solvents for chemically amplified resist compositions. It can be selected and used.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, 2-heptanone, etc .; ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol and the like Compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate, monomethyl ether of the polyhydric alcohol or the compound having the ester bond, monoethyl ether Ethers such as mono alkyl ethers such as ether, monopropyl ether and monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having a complex [in these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME) are preferable]; cyclic ethers such as dioxane; methyl lactate Esters such as ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate and ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether Aromatic compounds such as dibenzyl ether, phenetole, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene and mesitylene Solvents, dimethyl sulfoxide (DMSO) and the like can be mentioned.
The component (S) may be used alone or as a mixed solvent of two or more.
Among them, PGMEA, PGME, γ-butyrolactone, EL and cyclohexanone are preferable.
Moreover, the mixed solvent which mixed PGMEA and the polar solvent is also preferable. The compounding ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, etc., but is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. It is preferable to be in the range.
More specifically, in the case of blending EL or cyclohexanone as a 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 1: 9-9: 1, More preferably, 2: 8-8: 2, More preferably, 3: 7-7: It is three. Furthermore, mixed solvents of PGMEA, PGME and cyclohexanone are also preferable.
In addition, as the component (S), mixed solvents of at least one selected from PGMEA and EL and γ-butyrolactone are also preferable. In this case, the mass ratio of the former and the latter is preferably 70:30 to 95: 5 as the mixing ratio.
The amount of the component (S) to be used is not particularly limited, and is a concentration that can be applied to a substrate or the like, and is appropriately set according to the applied film thickness. In general, the (S) component is used so that the solid content concentration of the resist composition is in the range of 1 to 20% by mass, preferably 2 to 15% by mass.

The resist composition of the present invention described above contains a polymer compound (A1) having four specific structural units.
Specifically, the component (A1) is a constituent unit containing different lactone-containing cyclic groups, that is, a constituent unit (a0) having a long side chain and a lactone-containing polycyclic group at its terminal, and a lactone It has a structural unit (a2) containing a containing monocyclic group. In addition, the component (A1) includes constituent units containing different acid-degradable groups, that is, a constituent unit containing a monocyclic group or a constituent unit (a1) containing a chain group, and a polycyclic group And a structural unit (a1 ′) containing a group. Furthermore, as for the constituent unit containing these acid-decomposable groups, the ratio of the constituent unit (a1) to the total of all constituent units constituting the component (A1) is not less than the proportion of the constituent unit (a1 ′).
By using the resist composition containing the component (A1), the effect of the combination of the four specific structural units and the balance effect of the mixing ratio of the structural unit (a1) to the structural unit (a1 ′) are obtained. By being exhibited, it is possible to form a resist pattern having excellent lithography characteristics and a good shape. In particular, it is possible to achieve both in-plane uniformity (CDU) of pattern dimensions and depth of focus (DOF) characteristics, which have been difficult until now.

«Method for forming resist pattern»
The method for forming a resist pattern according to the second aspect of the present invention comprises the steps of: forming a resist film on a support using the resist composition according to the first aspect of the present invention; exposing the resist film; The process of developing the resist film after the said exposure, and forming a resist pattern is included.
The resist pattern formation method of this aspect can be performed, for example, as follows.
First, the resist composition of the first aspect is applied onto a support by a spinner or the like, and baking (post applied bake (PAB)) treatment is carried out, for example, at a temperature condition of 80 to 150 ° C. for 40 to 120 seconds. Preferably, it is applied for 60 to 90 seconds to form a resist film.
Next, the resist film is exposed through a mask (mask pattern) on which a predetermined pattern is formed, using an exposure apparatus such as, for example, an ArF exposure apparatus, an electron beam writing apparatus, or an EUV exposure apparatus, or a mask pattern Selective exposure by drawing etc. by direct irradiation of the electron beam not through Thereafter, a baking (post-exposure baking (PEB)) treatment is performed, for example, at a temperature condition of 80 to 150 ° C. for 40 to 120 seconds, preferably 60 to 90 seconds.
Next, the resist film after the exposure and baking (PEB) is developed. The development processing is performed using an alkaline developer in the case of an alkali development process and using a developer (organic developer) containing an organic solvent in the case of a solvent development process.
In the method for forming a resist pattern according to this aspect, a finer pattern (isolated trench pattern, fine and dense contact hole pattern, etc.) is formed by forming a resist pattern by patterning by negative development using an organic developer. Even when forming, it is easy to obtain a pattern of high resolution. In addition, the resist pattern to be formed has excellent lithography properties and a good shape, and in particular, it is easy to achieve both in-plane uniformity (CDU) of pattern dimensions and depth of focus (DOF) characteristics.
After the development process, a rinse process is preferably performed. In the case of the alkali development process, water rinse using pure water is preferable, and in the case of the solvent development process, it is preferable to use a rinse solution containing an organic solvent.
In the case of the solvent development process, after the development process or rinse process, a process of removing the developer or rinse solution adhering on the pattern with a supercritical fluid may be performed.
After development processing or rinse processing, drying is performed. Further, in some cases, a bake treatment (post bake) may be performed after the development treatment. Thus, a resist pattern can be obtained.

The support is not particularly limited, and conventionally known ones can be used, and examples thereof include a substrate for an electronic component, and a substrate on which a predetermined wiring pattern is formed. More specifically, a silicon wafer, a metal substrate such as copper, chromium, iron, aluminum or the like, a glass substrate, etc. may be mentioned. As a material of the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used.
In addition, as the support, an inorganic and / or organic film may be provided on the substrate as described above. Examples of inorganic films include inorganic antireflective films (inorganic BARCs). Examples of the organic film include organic films such as an organic antireflective film (organic BARC) and a lower organic film in a multilayer resist method.
Here, in the multilayer resist method, at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate, and a resist pattern formed on the upper resist film is used as a mask. It is a method of patterning the lower organic film, and is said to be able to form a pattern with a high aspect ratio. That is, according to the multilayer resist method, since the required thickness can be secured by the lower layer organic film, the resist film can be thinned, and a fine pattern having a high aspect ratio can be formed.
In the multilayer resist method, basically, a method of forming a two-layer structure of an upper resist film and a lower organic film (bilayer resist method), and one or more intermediate layers between the upper resist film and the lower organic film It is divided into the method (three-layer resist method) of forming a multilayer structure of three or more layers provided with a metal thin film etc.).

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

The exposure method of the resist film may be a normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be a liquid immersion exposure (Liquid Immersion Lithography).
In immersion exposure, the space between the resist film and the lowermost lens 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 which is 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 the 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, a hydrocarbon-based solvent and the like.
Specific examples of the fluorine-based inert liquid include fluorine-based compounds 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 main components. A liquid etc. are mentioned, The thing of 70-180 degreeC of boiling points is preferable, and the thing of 80-160 degreeC is 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 completion of exposure.
As the fluorine-based inert liquid, particularly preferred is a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms. Specific examples of perfluoroalkyl compounds include perfluoroalkyl ether compounds and perfluoroalkylamine compounds.
Furthermore, specifically, as the perfluoroalkylether compound, perfluoro (2-butyl-tetrahydrofuran) (boiling point 102 ° C.) can be mentioned, and as the perfluoroalkylamine compound, perfluorotributylamine ( Boiling point 174 ° C.) can be mentioned.
Water is preferably used as the immersion medium from the viewpoints of cost, safety, environmental problems, versatility and the like.

As an alkali developing solution used for image development process by an alkali developing process, 0.1-10 mass% tetramethyl ammonium hydroxide (TMAH) aqueous solution is mentioned, for example.
The organic solvent contained in the organic developer used for development in the solvent development process may be any solvent which can dissolve the component (A1) (component (A1) before exposure), and among known organic solvents It can be selected appropriately. Specifically, polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, ether solvents, hydrocarbon solvents and the like can be mentioned.
The ketone solvent is an organic solvent containing C—C (= O) —C in the structure. An ester solvent is an organic solvent which contains C-C (= O) -O-C in a structure. The alcohol-based solvent is an organic solvent containing an alcoholic hydroxyl group in the structure, and the "alcoholic hydroxyl group" means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group. The nitrile solvent is an organic solvent containing a nitrile group in the structure. An 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, an organic solvent containing a plurality of functional groups characterizing each of the above-mentioned solvents in the structure is also present, in which case it corresponds to any solvent type containing a functional group possessed by the organic solvent. It shall be. For example, diethylene glycol monomethyl ether corresponds to any of alcohol solvents and ether solvents in the above classification.
The hydrocarbon-based solvent is a hydrocarbon solvent composed of an optionally halogenated hydrocarbon and having no substituent other than a halogen atom. As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned, A fluorine atom is preferable.
Among the above, the organic solvent contained in the organic developer is preferably a polar solvent, and is preferably a ketone solvent, an ester solvent, a nitrile solvent or the like. Specific examples of each solvent are shown below.

Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone And methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methylnaphthyl ketone, isophorone, propylene carbonate, γ-butyrolactone, methyl amyl ketone (2-heptanone) and the like.
As a ketone solvent, methyl amyl ketone (2-heptanone) is preferable.

As ester solvents, for example, methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, methoxyethyl acetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono acid 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 Nthyl acetate, 4-methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, pyruvine 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 And ethyl acid, methyl 3-methoxy propionate, ethyl 3-methoxy propionate, ethyl 3-ethoxy propionate, propyl 3-methoxy propionate and the like.
As an ester solvent, butyl acetate is preferable.

  Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, butyronitryl and the like.

Known additives can be blended into the organic developer as required. Examples of the additive include surfactants. The surfactant is not particularly limited, and for example, an ionic or non-ionic fluorine-based and / or silicon-based surfactant can be used. The surfactant is preferably a nonionic surfactant, more preferably a fluorine-based surfactant or a silicon-based surfactant.
When mix | blending surfactant, the compounding quantity is 0.001-5 mass% normally with respect to whole quantity of an organic type developing solution, 0.005-2 mass% is preferable, and 0.01-0. 5 mass% is more preferable.

  The development processing can be carried out by a known development method, for example, a method of immersing the support in a developer for a fixed time (dip method), a developer is raised on the surface of the support by surface tension and rested for a fixed time Method (paddle method), method of spraying the developer on the surface of the support (spray method), coating the developer while scanning the developer coating nozzle at a constant speed on the support rotating at a constant speed The following method may be mentioned (dynamic dispensing method).

As the organic solvent contained in the rinse solution used for the rinse treatment after development processing in the solvent development process, for example, among the organic solvents listed as the organic solvent used for the organic developer, one that does not easily dissolve the resist pattern is appropriately selected 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 More preferred are alcohol solvents.
The alcohol solvent used for the rinse solution is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched or cyclic. Specifically, 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, benzyl alcohol etc. Be Among these, 1-hexanol, 2-heptanol and 2-hexanol are preferable, and 1-hexanol and 2-hexanol are more preferable.
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 with the organic solvent and water other than the above. However, in consideration of the development characteristics, the blending amount of water in the rinse solution is preferably 30% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, and 3% by mass with respect to the total amount of rinse solution. The following are particularly preferred.
A well-known additive can be mix | blended with a rinse agent as needed. Examples of the additive include surfactants. Examples of the surfactant include the same as those described above, preferably a nonionic surfactant, and more preferably a fluorine-based surfactant or a silicon-based surfactant.
When mix | blending surfactant, the compounding quantity is normally 0.001-5 mass% with respect to the whole quantity of rinse solution, 0.005-2 mass% is preferable, and 0.01-0.5 mass is preferable. % Is more preferable.

  The rinse process (washing process) using the rinse liquid can be implemented by the well-known rinse method. The method includes, for example, a method of continuously applying a rinse solution on a support rotating at a constant speed (rotation coating method), a method of immersing a support in a rinse solution for a certain time (dip method), a support surface And a method of spraying a rinse liquid (spray method).

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited by these examples.
In the analysis by NMR, the internal standard of ¹³ C-NMR is tetramethylsilane (TMS).
Further, in this example, for example, the monomer represented by the chemical formula (1) is described as “monomer (1)”, and the same applies to monomers represented by other chemical formulas.

<Manufacture of polymer compound>
(Production Example 1 of Polymer Compound)
In a separable flask connected to a thermometer, a reflux tube and a nitrogen inlet tube, put 138.90 g of a mixed solvent of propylene glycol monomethyl ether acetate (PM) and methyl ethyl ketone (MEK) (PGMEA / MEK = 50/50 mass ratio) It was heated to 80.degree.
Separately, 25.00 g (146.9 mmol) of the monomer (21), 14.50 g (47.02 mmol) of the monomer (01), 15.46 g (46.52 mmol) of the monomer (51), 15.44 g (55.86 mmol) of monomer (1′1), 32.46 g (165.36 mmol) of monomer (11) and 11.40 g (48.24 mmol) of monomer (31) are mixed solvent (PGMEA / It dissolves in 140.82 g of MEK = 50/50 mass ratio), and further, 7.16 g (31.10 mmol) of dimethyl azobisisobutyrate (V601) as a polymerization initiator and 3000 ppm with respect to 0.0464 g of triethylamine (monomer (51) (By mass) were added and dissolved.
The monomer mixed solution was dropped into the mixed solvent heated to 80 ° C. in a nitrogen atmosphere over 4 hours. After completion of the dropwise addition, the reaction solution was heated and stirred for 2 hours, and then the reaction solution was cooled to room temperature.
The resulting reaction polymerization solution is dropped into a large amount of heptane / ethyl acetate to precipitate a polymer, and the precipitated white powder is washed with a large amount of heptane / ethyl acetate and dried to obtain the desired product. 92.3g (yield 80.8%) of high molecular compound A-2 which is is obtained.
The weight average molecular weight (Mw) of standard polystyrene conversion calculated | required by GPC measurement about this high molecular compound A-2 was 8200, and molecular weight dispersion degree (Mw / Mn) was 1.75. In addition, the copolymerization composition ratio (ratio of each structural unit in the polymer compound (molar ratio)) determined by carbon 13 nuclear magnetic resonance spectrum (600 MHz ¹³ C-NMR) is 1 / m / n / o / p It was / q = 3/1/1/1/1/3.

(Production Examples 2 to 23 of Polymer Compound)
The polymer compounds A-1 and A-3 to A-23 were prepared in the same manner as in Production Example 1 except that the following monomers providing the constituent units constituting each polymer compound were used at a predetermined molar ratio. Manufactured.
Copolymer composition ratio (ratio of constituent units in polymer compound (molar ratio) of the obtained polymer compounds A-1 and A-3 to A-23 determined by ¹³ C-NMR for the polymer compounds ), Standard polystyrene equivalent mass average molecular weight (Mw) and molecular weight dispersion degree (Mw / Mn) determined by GPC measurement are also shown in Table 1.

<Preparation of Resist Composition>
(Examples 1 to 14, Comparative Examples 1 to 9>
The resist composition of each example was prepared by mixing and dissolving the components shown in Table 2. However, Example 3, Example 5, Example 8, Example 13, and Example 14 are reference examples.

Each abbreviation in Table 2 has the following meaning. The numerical values in [] are compounding amounts (parts by mass).
(A) -1 to (A) -23: the above-mentioned polymer compounds A-1 to A-23.
(B) -1: An acid generator comprising a compound represented by the following chemical formula (B) -1.
(B) -2: an acid generator comprising a compound represented by the following chemical formula (B) -2.
(D) -1: An acid diffusion control agent comprising a compound represented by the following chemical formula (D) -1.
(E) -1: salicylic acid.
(F) -1: a fluorine-containing polymer represented by the following chemical formula (F) -1. The weight average molecular weight (Mw) of standard polystyrene conversion determined by GPC measurement is 23100, and the molecular weight distribution (Mw / Mn) is 1.78. ^The copolymer composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by ¹³ C-NMR is l / m = 77/23.
(S) -1: γ-butyrolactone.
(S) -2: propylene glycol monomethyl ether acetate.
(S) -3: propylene glycol monomethyl ether.
(S) -4: cyclohexanone.

<Formation of resist pattern>
An organic antireflective film having a thickness of 150 nm was formed on a 12-inch silicon wafer, and then an inorganic antireflective film having a thickness of 35 nm was laminated on the organic antireflective film.
The resist composition of each example is applied onto the inorganic antireflective film using a spinner, prebaked (PAB) at 60 ° C. for 60 seconds on a hot plate, and dried. A 100 nm thick resist film was formed.
Next, for the resist film, an immersion ArF exposure apparatus NSR-S609B [manufactured by Nikon; NA (numerical aperture) = 1.07, Annular (0.97 / 0.78) with Y-Polarization, immersion] Medium: Water] was selectively applied to the ArF excimer laser (193 nm) through a photomask (6% halftone).
Thereafter, a post exposure bake (PEB) process was performed at 85 ° C. for 60 seconds.
Subsequently, solvent development was performed for 13 seconds with butyl acetate at 23 ° C., and shake-off and drying were performed.
As a result, in any of the examples, contact hole patterns (hereinafter referred to as "CH patterns") were formed in which holes of 55 nm in diameter were arranged at equal intervals (pitch 110 nm).

[Evaluation of in-plane uniformity (CDU) of pattern dimensions]
The 100 holes in the above CH pattern are observed from the sky above the CH pattern by a length measurement SEM (scanning electron microscope, accelerating voltage 300 V, trade name: S-9380, manufactured by Hitachi High-Technologies Corporation), and each hole is The diameter (nm) was measured. Then, a triple value (3σ) of the standard deviation (σ) calculated from the measurement result was determined. The results are shown in Table 3 as "CDU (nm)".
The smaller the value of 3σ determined in this manner, the higher the uniformity (CD) uniformity of the plurality of holes formed in the resist film.

[Evaluation of the minimum dimension value]
When the CH pattern is formed by appropriately changing the exposure amount (mJ / cm ² ) and the focal point, the smallest dimension of the resolved CH pattern is measured by a length measurement SEM (scanning electron microscope, acceleration voltage 300 V, trade name: S -9380, manufactured by Hitachi High-Technologies Corporation). The results are shown in Table 3 as "Min Hole (nm)".

[Evaluation of depth of focus (DOF)]
At the optimum exposure dose (Eop (mJ / cm ² )) at which the CH pattern is formed in the above <Formation of a resist pattern>, the focal point is shifted up and down appropriately to form a CH pattern in the same manner as the above <Formation of a resist pattern> did. At this time, the depth of focus (DOF, unit: μm) that the CH pattern can form within the dimensional change rate range of target dimension ± 5% (that is, 52.25 to 57.75 nm) was determined. The results are shown in Table 3.

[Evaluation of mask reproducibility]
In Eop (mJ / cm ² ), a CH pattern was formed in the same manner as in <Formation of Resist Pattern> except that photomasks with different target sizes were used. At this time, while the pitch was fixed at 110 nm, the hole diameter was changed in 1 nm steps within the range of 55 nm ± 5 nm, with the target size of the photomask fixed.
The hole diameter (nm) of each hole of the total of 11 CH patterns formed was plotted on the vertical axis, and the hole diameter (nm) on the target size was plotted on the horizontal axis. The slope of the straight line at this time was calculated as "MEEF". The results are shown in Table 3.
MEEF means that the closer the value is to 1, the better the mask reproducibility.

[Evaluation of pattern height]
The height (nm) of the CH pattern formed by the above <Formation of Resist Pattern> was measured using a wafer shape / characteristic measurement apparatus (trade name: SCD-XT, manufactured by KLA Tencor Corporation). The results are shown in Table 3.

From the evaluation results shown in Table 3, the resist patterns formed using the resist compositions of Examples 1 to 12 to which the present invention is applied use the resist compositions of Comparative Examples 1 to 6 outside the scope of the present invention. It can be confirmed that the lithography characteristics are excellent and the shape is good compared to the formed resist pattern. Moreover, the resist pattern formed using the resist composition of Examples 13-14 to which this invention is applied is a resist pattern formed using the resist composition of Comparative Examples 7-9 besides the range of this invention. In comparison, it can be confirmed that the lithography properties are excellent and the shape is good.
In addition, it can be seen that resist patterns formed using the resist compositions of Examples 1 to 14 are excellent in both in-plane uniformity (CDU) of pattern dimension and depth of focus (DOF) characteristics.

Claims (4)

A resist composition which generates an acid upon exposure and whose solubility in a developer changes by the action of the acid,
The structural unit (a0) represented by the following general formula (a0-1),
Among the acid-degradable groups whose polarity is increased by the action of an acid, a structural unit (a1) containing a group containing a monocyclic group or a group consisting of only a chain;
Among the acid-degradable groups whose polarity is increased by the action of an acid, a constituent unit (a1 ′) containing a group containing a polycyclic group,
A structural unit (a2) containing a lactone-containing monocyclic group,
A structural unit (a5) containing a —SO ₂ -containing cyclic group,
Containing a polymer compound (A1) having
The structural unit (a1 ′) contains an acid decomposable group which is decomposed by the action of an acid to generate a carboxy group, and the acid decomposable group is represented by the following general formula (a1-r2-2). Group which is protected by an acid dissociable group,
A resist composition wherein the ratio of the structural unit (a1) to the total of all the structural units constituting the polymer compound (A1) is equal to or more than the ratio of the structural unit (a1 ′).

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. R ¹ is a lactone-containing polycyclic group. R ² and R ³ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. L ¹ is an ester bond. n ₁ is an integer of ₁ to 3; ]

Wherein, Ra ^'12 and Ra' ¹⁴ are each independently an alkyl group having 1 to 10 carbon atoms. Ra ^'13 is a polycyclic aliphatic hydrocarbon group. ]   The resist composition according to claim 1, wherein the ratio of the structural unit (a2) to the total of all the structural units constituting the polymer compound (A1) is higher than the ratio of the structural unit (a0).   A step of forming a resist film on a support using the resist composition according to claim 1, a step of exposing the resist film, and a step of developing a resist film after the exposure to form a resist pattern And a method of forming a resist pattern.   4. The resist according to claim 3, wherein the step of developing the resist film after the exposure to form a resist pattern is a step of forming a resist pattern by patterning by negative development using a developer containing an organic solvent. Pattern formation method.