JP5297875B2 - Resist composition, method for forming resist pattern, and method for producing resist composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide: a resist composition having excellent application properties to a support; a method for forming a resist pattern; and a method for producing the resist composition. <P>SOLUTION: The resist composition is prepared by dissolving a base component (A) whose solubility with an alkali developing solution changes by the action of an acid and an acid generator component (B) generating an acid by exposure into an organic solvent (S). The organic solvent (S) contains 1-butoxy-2-propanol and 2-butoxy-1-propanol excluding a solvent prepared by mixing 1-butoxy-2-propanol and 2-butoxy-1-propanol, in which the proportion of the 2-butoxy-1-propnaol is &ge;1.5 parts by mass based on 100 parts by mass of the 1-butoxy-2-propanol. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

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

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

  Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing a pattern with fine dimensions. As a resist material that satisfies these requirements, a chemically amplified resist obtained by dissolving, in an organic solvent, a base resin whose solubility in an alkaline developer is changed by the action of an acid and an acid generator component that generates an acid upon exposure. Is used. For example, a positive chemically amplified resist is formed by dissolving a resin whose solubility in an alkali developer increases by the action of an acid as a base resin and an acid generator component in an organic solvent. When an acid is generated from the acid generator by exposure, the exposed portion becomes soluble in an alkali developer.

Up to now, as a base resin for chemically amplified resist, polyhydroxystyrene (PHS) having high transparency with respect to KrF excimer laser (248 nm) and a resin whose hydroxyl group is protected with an acid dissociable, dissolution inhibiting group (PHS resin) Has been used. However, since the PHS resin has an aromatic ring such as a benzene ring, the transparency to light having a wavelength shorter than 248 nm, for example, 193 nm, is not sufficient. For this reason, a chemically amplified resist having a PHS resin as a base resin component has drawbacks such as low resolution in a process using 193 nm light, for example.
Therefore, as a resist base resin currently used in ArF excimer laser lithography and the like, since it has excellent transparency near 193 nm, a resin (acrylic resin) having a structural unit derived from (meth) acrylic ester is used. Resin) is mainly used (for example, see Patent Document 1).

  In addition, as a resist used in ArF excimer laser lithography and the like, the acrylic resin is made of propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), cyclohexanone (CH), 2-heptanone, ethyl lactate ( A resist composition dissolved in an organic solvent such as EL) is often used.

On the other hand, in recent years, as the resist pattern has been further miniaturized, a double patterning process has been proposed in which a resist pattern is formed by performing patterning twice or more as one of lithography techniques for further improving the resolution. (For example, see Non-Patent Documents 1 and 2).
According to this double patterning process, for example, the first resist pattern is formed on the support by patterning using the first resist composition, and then the support is formed with the first resist pattern. Further, by patterning using the second resist composition, a resist pattern having a higher resolution than the resist pattern formed by one patterning can be formed.

However, in the double patterning process, the first resist pattern is easily affected when the second resist composition is applied. That is, for example, a part or the whole of the first resist pattern is dissolved by the solvent of the second resist composition, film loss or the like occurs, and the resist pattern shape is damaged, or the first resist pattern and the second resist pattern There are problems that the resist composition dissolves, so-called mixing occurs, and a good resist pattern cannot be formed.
Such a problem can be solved by using, as the second resist composition, a resist composition using an organic solvent in which the first resist pattern is difficult to dissolve. Therefore, conventionally, as the second resist composition, when a positive resist composition is used as the first resist composition, the compatibility with the positive resist composition is low and the solubility of the resist material is low. A negative resist composition using an organic solvent such as a good alcoholic organic solvent is mainly used.

JP 2003-241385 A

Proceedings of SPIE, 5256, 985-994 (2003). Proceedings of SPIE, 6153, 615301-1-19 (2006).

On the other hand, when a positive resist composition is used as the second resist composition in the same manner as the first resist composition, when the conventional positive resist composition is directly applied on the first resist pattern, The resist pattern is dissolved. Therefore, it is necessary to protect the first resist pattern using a freezing agent or the like, and there are problems that the number of processes is increased and workability is inferior compared with the case of using a negative resist composition.
As a countermeasure against such a problem, a method in which a positive resist composition using an alcohol-based organic solvent is used as the second resist composition can be considered.

Further, in order to perform fine patterning with high accuracy, it is also important to make the film thickness uniform when forming a resist film on a support.
However, in a conventional resist composition using an alcohol-based organic solvent as the organic solvent, the spread to the support surface is poor compared to a resist composition using, for example, a mixed solvent of PGMEA and PGME as the organic solvent. Therefore, there is a problem that it is necessary to make the rotation time of the coating apparatus longer than in the past, or stripe-shaped coating marks (striations, wavy marks, etc.) are formed on the resist film. According to the study by the present inventors, it has been confirmed that the coating trace causes a non-uniform thickness of the resist film.

  This invention is made | formed in view of the said situation, Comprising: It makes it a subject to provide the resist composition excellent in the applicability | paintability to a support body, the resist pattern formation method, and the manufacturing method of a resist composition.

  In order to solve the above problems, the present invention employs the following configuration.

  That is, in the first aspect of the present invention, a base component (A) whose solubility in an alkaline developer is changed by the action of an acid and an acid generator component (B) that generates an acid upon exposure to an organic solvent ( The organic solvent (S) contains 1-butoxy-2-propanol and 2-butoxy-1-propanol (however, 1-butoxy-2-propanol). And 2-butoxy-1-propanol), and the ratio of 2-butoxy-1-propanol is 1 with respect to 100 parts by mass of 1-butoxy-2-propanol. It is a resist composition characterized by being 5 parts by mass or more.

  According to a second aspect of the present invention, a resist composition is coated on a support to form a first resist film, the first resist film is selectively exposed, alkali-developed and subjected to alkali development. A step of forming one resist pattern, a step of applying the resist composition of the first aspect on the support on which the first resist pattern is formed, and forming a second resist film; And a step of selectively exposing the second resist film and performing alkali development to form a resist pattern.

  A third aspect of the present invention is a method for producing the resist composition of the first aspect, wherein the substrate component (A) and the acid generator component (B) are combined with the organic solvent (S). It is a manufacturing method of the resist composition melt | dissolved in this.

In the present specification and claims, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified.
Further, the “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups unless otherwise specified.
The “lower alkyl group” is an alkyl group having 1 to 5 carbon atoms.
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.
“Aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity.
“Structural unit” means a monomer unit (monomer unit) constituting a polymer compound (polymer, copolymer).
“Exposure” is a concept including general irradiation of radiation.

“(Meth) acrylic acid” means one or both of acrylic acid having a hydrogen atom bonded to the α-position and methacrylic acid having a methyl group bonded to the α-position.
“(Meth) acrylic acid ester” means one or both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the α-position. “(Meth) acrylate” means one or both of an acrylate having a hydrogen atom bonded to the α-position and a methacrylate having a methyl group bonded to the α-position.

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

≪Resist composition≫
The resist composition according to the first aspect of the present invention comprises a base component (A) (hereinafter referred to as “component (A)”) whose solubility in an alkali developer is changed by the action of an acid, and an acid upon exposure. The generated acid generator component (B) (hereinafter referred to as “component (B)”) is dissolved in an organic solvent (S).
When a resist film formed using such a resist composition is selectively exposed at the time of resist pattern formation, an acid is generated from the component (B), and the acid has a solubility in the alkaline developer of the component (A). Change. As a result, while the solubility of the exposed portion of the resist film in the alkali developer changes, the solubility of the unexposed portion in the alkali developer does not change. However, in the case of the negative type, the unexposed portion is dissolved and removed to form a resist pattern.
The resist composition of the present invention preferably further contains a nitrogen-containing organic compound component (D).
The resist composition of the present invention may be a negative resist composition or a positive resist composition.

<(A) component>
As the component (A), organic compounds that are usually used as base material components for chemically amplified resists can be used singly or in combination of two or more.
Here, the “base material component” is an organic compound having a film forming ability, and an organic compound having a molecular weight of 500 or more is preferably used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved and a nano-level resist pattern is easily formed.
The organic compound having a molecular weight of 500 or more includes a low molecular weight organic compound having a molecular weight of 500 to less than 2000 (hereinafter referred to as “low molecular compound”) and a high molecular weight resin having a molecular weight of 1000 or more (polymer material). Broadly divided. As the low molecular weight compound, a non-polymer is usually used. In the case of a resin (polymer, copolymer), a polystyrene-reduced mass average molecular weight by GPC (gel permeation chromatography) is used as the “molecular weight”. Hereinafter, the term “resin” simply means a resin having a molecular weight of 1000 or more.
As the component (A), a resin component whose solubility in an alkali developer is changed by the action of an acid can be used, and a low molecular compound component whose solubility in an alkali developer is changed by the action of an acid can also be used. .

When the resist composition of the present invention is a “negative resist composition”, a base component that is soluble in an alkali developer is used as the component (A), and the negative resist composition further includes a crosslinking agent component. Is blended.
In such a negative resist composition, when an acid is generated from the component (B) by exposure, the acid acts to cause cross-linking between the base component and the cross-linking agent component, resulting in poor solubility in an alkali developer. Change. Therefore, in the formation of a resist pattern, when a resist film obtained by applying the negative resist composition on a support is selectively exposed, the exposed portion turns into poorly soluble in an alkali developer, while Since the exposed portion remains soluble in the alkali developer and does not change, a resist pattern can be formed by alkali development.
As the component (A) of the negative resist composition, a resin that is soluble in an alkali developer (hereinafter referred to as “alkali-soluble resin”) is usually used.
Examples of the alkali-soluble resin include a resin having a unit derived from at least one selected from α- (hydroxyalkyl) acrylic acid or a lower alkyl ester of α- (hydroxyalkyl) acrylic acid, and JP-A-2005-336442. Alternatively, a resin having a fluorinated alcohol disclosed in JP-A-2006-259582 is preferable because it can form a good resist pattern with little swelling. Α- (Hydroxyalkyl) acrylic acid includes acrylic acid in which a hydrogen atom is bonded to the α-position carbon atom to which the carboxy group is bonded, and a hydroxyalkyl group (preferably having 1 carbon atom) in the α-position carbon atom. One or both of [alpha] -hydroxyalkylacrylic acids to which (5) hydroxyalkyl groups) are attached.
As the crosslinking agent component, for example, it is usually preferable to use an amino crosslinking agent such as glycoluril having a methylol group or an alkoxymethyl group because a good resist pattern with less swelling can be formed. It is preferable that the compounding quantity of a crosslinking agent component is 1-50 mass parts with respect to 100 mass parts of alkali-soluble resin.

When the resist composition of the present invention is a “positive resist composition”, the component (A) is a base material component (hereinafter referred to as “(A0) component”) whose solubility in an alkaline developer is increased by the action of an acid. .) Is used.
The component (A0) is hardly soluble in an alkali developer before exposure, and when an acid is generated from the component (B) upon exposure, the solubility in the alkali developer is increased by the action of the acid. Therefore, in the formation of the resist pattern, when the resist film obtained by applying the positive resist composition on the support is selectively exposed, the exposed portion changes from poorly soluble to soluble in an alkaline developer. On the other hand, since the unexposed portion remains hardly soluble in alkali and does not change, a resist pattern can be formed by alkali development.

In the resist composition of the present invention, the component (A) is preferably a base material component ((A0) component) whose solubility in an alkaline developer is increased by the action of an acid. That is, the resist composition of the present invention is preferably a positive resist composition.
The component (A0) may be a resin component (A1) (hereinafter sometimes referred to as “component (A1)”) whose solubility in an alkaline developer is increased by the action of an acid. It may be a low molecular compound component (A2) (hereinafter sometimes referred to as “component (A2)”) that increases the solubility in a developer, or a mixture thereof.
Especially, it is preferable that (A1) component is included as this (A0) component.

[(A1) component]
As the component (A1), resin components (base resins) that are usually used as base components for chemically amplified resists can be used singly or in combination of two or more.
In the present invention, the component (A1) preferably has a structural unit derived from an acrylate ester.
Here, in the present specification and claims, the “structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid esters” include those in which a hydrogen atom is bonded to the carbon atom at the α-position, and those in which a substituent (atom or group other than a hydrogen atom) is bonded to the carbon atom in the α-position. Include concepts. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms and a halogenated alkyl group having 1 to 5 carbon atoms.
Note that the α-position (α-position carbon atom) of a structural unit derived from an acrylate ester means a carbon atom to which a carbonyl group is bonded, unless otherwise specified.
In the acrylic ester, the alkyl group having 1 to 5 carbon atoms as the substituent at the α-position, specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl And a lower linear or branched alkyl group such as a group, a pentyl group, an isopentyl group and a neopentyl group.
Further, as the halogenated alkyl group having 1 to 5 carbon atoms, specifically, a part or all of the hydrogen atoms in the above-mentioned “alkyl group having 1 to 5 carbon atoms as a substituent at the α-position” are substituted with halogen atoms. Group. 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.
In the present invention, the α-position of the acrylate ester is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. It is more preferably a C 1-5 alkyl group or a C 1-5 fluorinated alkyl group, and most preferably a hydrogen atom or a methyl group in terms of industrial availability.

In the resist composition of the present invention, it is particularly preferable that the component (A1) has a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.
In addition to the structural unit (a1), the component (A1) preferably further has a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group.
In addition to the structural unit (a1) or the structural units (a1) and (a2), the component (A1) is further a structural unit (a5) represented by the general formula (a5-1) described later. ).
In addition to the structural unit (a1), the component (A1) includes the structural units (a1) and (a2), the structural units (a1) and (a5), or the structural unit (a1). In addition to (a2) and (a5), it is preferable to further have a structural unit (a6) represented by the general formula (a6-1) described later.

(Structural unit (a1))
The structural unit (a1) is a structural unit derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.
The acid dissociable, dissolution inhibiting group in the structural unit (a1) has an alkali dissolution inhibiting property that makes the entire component (A1) difficult to dissolve in an alkali developer before dissociation, and dissociates with an acid. This increases the solubility of the entire component in an alkaline developer, and those that have been proposed as acid dissociable, dissolution inhibiting groups for base resins for chemically amplified resists can be used.
In general, a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group in (meth) acrylic acid or the like; an acetal-type acid dissociable, dissolution inhibiting group such as an alkoxyalkyl group is widely known. .

Here, the “tertiary alkyl ester” is an ester formed by replacing a hydrogen atom of a carboxy group with a chain or cyclic alkyl group, and the carbonyloxy group (—C (O)). A structure in which the tertiary carbon atom of the chain or cyclic alkyl group is bonded to the terminal oxygen atom of -O-). In this tertiary alkyl ester, when an acid acts, a bond is cut between an oxygen atom and a tertiary carbon atom.
The chain or cyclic alkyl group may have a substituent.
Hereinafter, a group that is acid dissociable by constituting a carboxy group and a tertiary alkyl ester is referred to as a “tertiary alkyl ester type acid dissociable, dissolution inhibiting group” for convenience.
Examples of the tertiary alkyl ester type acid dissociable, dissolution inhibiting group include an aliphatic branched acid dissociable, dissolution inhibiting group and an acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group.

Here, the term “aliphatic branched” in the claims and the specification means having a branched structure having no aromaticity.
The structure of the “aliphatic branched acid dissociable, dissolution inhibiting group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group.
The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated.
As the aliphatic branched acid dissociable, dissolution inhibiting group, a tertiary alkyl group having 4 to 8 carbon atoms is preferable, and specific examples include a tert-butyl group, a tert-pentyl group, and a tert-heptyl group. .

The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity.
The “aliphatic cyclic group” in the structural unit (a1) may or may not have a substituent. Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms, a lower alkoxy group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O) and the like.
The basic ring structure excluding the substituent of the “aliphatic cyclic group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group.
The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated. The “aliphatic cyclic group” is preferably a polycyclic group.
Examples of the aliphatic cyclic group include a monocycloalkane which may or may not be substituted with a lower alkyl group, a fluorine atom or a fluorinated alkyl group; a bicycloalkane, a tricycloalkane, or a tetracycloalkane. And a group obtained by removing one or more hydrogen atoms from a polycycloalkane. More specifically, monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane are exemplified. .

  Examples of the acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group include a group having a tertiary carbon atom on the ring skeleton of a cyclic alkyl group. Specifically, 2-methyl-2 -Adamantyl group, 2-ethyl-2-adamantyl group, etc. are mentioned. Alternatively, in the structural units represented by the following general formulas (a1 ″ -1) to (a1 ″ -6), an adamantyl group such as a group bonded to an oxygen atom of a carbonyloxy group (—C (O) —O—) A group having an aliphatic cyclic group such as a cyclohexyl group, a cyclopentyl group, a norbornyl group, a tricyclodecyl group, or a tetracyclododecyl group and a branched alkylene group having a tertiary carbon atom bonded thereto. Can be mentioned.

［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を示し；Ｒ^１５、Ｒ^１６はアルキル基（直鎖状、分岐鎖状のいずれでもよく、好ましくは炭素数１〜５である）を示す。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; R ¹⁵ and R ¹⁶ represent an alkyl group (either linear or branched); Or preferably 1 to 5 carbon atoms). ]

  In the general formulas (a1 ″ -1) to (a1 ″ -6), the alkyl group or the halogenated alkyl group of R is an alkyl group having 1 to 5 carbon atoms which may be bonded to the α-position of the acrylate ester or The same as the halogenated alkyl group having 1 to 5 carbon atoms.

The “acetal acid dissociable, dissolution inhibiting group” is generally bonded to an oxygen atom by substituting a hydrogen atom at the terminal of an alkali-soluble group such as a carboxy group or a hydroxyl group. When an acid is generated by exposure, the acid acts to break the bond between the acetal acid dissociable, dissolution inhibiting group and the oxygen atom to which the acetal acid dissociable, dissolution inhibiting group is bonded.
Examples of the acetal type acid dissociable, dissolution inhibiting group include a group represented by the following general formula (p1).

［式中、Ｒ^１’，Ｒ^２’はそれぞれ独立して水素原子または炭素数１〜５のアルキル基を表し、ｎは０〜３の整数を表し、Ｙは炭素数１〜５のアルキル基または脂肪族環式基を表す。］

[Wherein, R ¹ 'and R ² ' each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, n represents an integer of 0 to 3, and Y represents an alkyl group having 1 to 5 carbon atoms. Or represents an aliphatic cyclic group. ]

In the above formula, n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
Examples of the alkyl group having 1 to 5 carbon atoms of R ¹ ′ and R ² ′ include those similar to the alkyl group having 1 to 5 carbon atoms of R, preferably a methyl group or an ethyl group, and most preferably a methyl group. preferable.
In the present invention, it is preferable that at least one of R ¹ ′ and R ² ′ is a hydrogen atom. That is, the group represented by the general formula (p1) is preferably a group represented by the following general formula (p1-1).

［式中、Ｒ^１’、ｎ、Ｙは上記と同様である。］

[Wherein R ¹ ′, n and Y are the same as described above. ]

Examples of the alkyl group having 1 to 5 carbon atoms of Y include the same as the alkyl group having 1 to 5 carbon atoms of R.
The aliphatic cyclic group for Y can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups that have been proposed in a number of conventional ArF resists. For example, the above “aliphatic ring” Examples thereof are the same as those in the formula group.

  Examples of the acetal type acid dissociable, dissolution inhibiting group also include a group represented by the following general formula (p2).

［式中、Ｒ^１７、Ｒ^１８はそれぞれ独立して直鎖状または分岐鎖状のアルキル基または水素原子であり、Ｒ^１９は直鎖状、分岐鎖状または環状のアルキル基である。または、Ｒ^１７およびＲ^１９がそれぞれ独立に直鎖状または分岐鎖状のアルキレン基であって、Ｒ^１７の末端とＲ^１９の末端とが結合して環を形成していてもよい。］

[Wherein, R ¹⁷ and R ¹⁸ each independently represent a linear or branched alkyl group or a hydrogen atom, and R ¹⁹ represents a linear, branched or cyclic alkyl group. Alternatively, R ¹⁷ and R ¹⁹ may be each independently a linear or branched alkylene group, and the end of R ^{17 and} the end of R ¹⁹ may be bonded to form a ring. ]

In R ¹⁷ and R ¹⁸ , the alkyl group preferably has 1 to 15 carbon atoms, may be linear or branched, and is preferably an ethyl group or a methyl group, and most preferably a methyl group. In particular, it is preferable that one of R ¹⁷ and R ¹⁸ is a hydrogen atom and the other is a methyl group.
R ¹⁹ is a linear, branched or cyclic alkyl group, preferably having 1 to 15 carbon atoms, and may be any of linear, branched or cyclic.
When R ¹⁹ is linear or branched, it preferably has 1 to 5 carbon atoms, more preferably an ethyl group or a methyl group, and most preferably an ethyl group.
When R ¹⁹ is cyclic, it preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, one or more polycycloalkanes such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group, are included. Examples include a group excluding a hydrogen atom. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
In the above formula, R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group (preferably an alkylene group having 1 to 5 carbon atoms), and the end of R ^{19 and} the end of R ¹⁷ And may be combined.
In this case, a cyclic group is formed by R ¹⁷ , R ¹⁹ , the oxygen atom to which R ¹⁹ is bonded, and the carbon atom to which the oxygen atom and R ¹⁷ are bonded. The cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

  As the structural unit (a1), one or more selected from the group consisting of structural units represented by the following general formula (a1-0-1) and structural units represented by the following general formula (a1-0-2): Is preferably used.

［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を示し；Ｘ^１は酸解離性溶解抑制基を示す。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; X ¹ represents an acid dissociable, dissolution inhibiting group. ]

［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を示し；Ｘ^２は酸解離性溶解抑制基を示し；Ｙ^２は２価の連結基を示す。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; X ² represents an acid dissociable, dissolution inhibiting group; Y ² represents a divalent group. A linking group is shown. ]

In general formula (a1-0-1), the alkyl group or halogenated alkyl group represented by R is an alkyl group having 1 to 5 carbon atoms or 1 to 5 carbon atoms which may be bonded to the α-position of the acrylate ester. The same as the halogenated alkyl group.
X ¹ is not particularly limited as long as it is an acid dissociable, dissolution inhibiting group, and examples thereof include the above-described tertiary alkyl ester type acid dissociable, dissolution inhibiting group and acetal type acid dissociable, dissolution inhibiting group. And tertiary alkyl ester type acid dissociable, dissolution inhibiting groups are preferred.

In general formula (a1-0-2), R is the same as defined above.
X ² is the same as X ¹ in formula (a1-0-1).

Examples of the divalent linking group for Y ² include an alkylene group, a divalent aliphatic cyclic group, and a divalent linking group containing a hetero atom.
As the aliphatic cyclic group, those similar to the explanation of the “aliphatic cyclic group” can be used except that a group in which two or more hydrogen atoms are removed is used.
When Y ² is an alkylene group, it is preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms, and 1 to 3 carbon atoms. Most preferably it is.
When Y ² is a divalent aliphatic cyclic group, a group in which two or more hydrogen atoms have been removed from cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane, or tetracyclododecane is particularly preferable. .
When Y ² is a divalent linking group containing a hetero atom, examples of the divalent linking group containing a hetero atom include —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O—, —C (═O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group or an acyl group), —S—. , —S (═O) ₂ —, —S (═O) ₂ —O—, “—AO (oxygen atom) —B— (wherein A and B each independently have a substituent) A divalent hydrocarbon group that may be present.) ”And the like.

When Y ² is —NH—, the substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and more preferably 1 to 5 carbon atoms. It is particularly preferred that
When Y ² is “A—O—B”, A and B are each independently a divalent hydrocarbon group which may have a substituent.
The hydrocarbon group having “substituent” means that part or all of the hydrogen atoms in the hydrocarbon group are substituted with groups or atoms other than hydrogen atoms.

  The hydrocarbon group in A may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity.

The aliphatic hydrocarbon group for A may be saturated or unsaturated, and is usually preferably saturated.
Specific examples of the aliphatic hydrocarbon group for A include a linear or branched aliphatic hydrocarbon group, and an aliphatic hydrocarbon group containing a ring in the structure.

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

Examples of the aliphatic hydrocarbon group containing a ring include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and the cyclic aliphatic hydrocarbon group described above as a chain-like aliphatic group. And a group bonded to the terminal of the aromatic hydrocarbon group or interposed in the middle of the chain-like aliphatic hydrocarbon group.
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 the monocyclic group, a group in which two hydrogen atoms have been removed from a monocycloalkane having 3 to 6 carbon atoms is preferable, and examples of the monocycloalkane include cyclopentane and cyclohexane.
As the polycyclic group, a group in which two hydrogen atoms are removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, tetra And cyclododecane.
The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (= O).

  A is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 2 to 5 carbon atoms, and most preferably an ethylene group.

Examples of the hydrocarbon group for B include the same divalent hydrocarbon groups as those described above for A.
B is preferably a linear or branched aliphatic hydrocarbon group, particularly preferably a methylene group or an alkylmethylene group.
The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.

  More specifically, examples of the structural unit (a1) include structural units represented by the following general formulas (a1-1) to (a1-4).

［式中、Ｘ’は第３級アルキルエステル型酸解離性溶解抑制基を表し、Ｙは炭素数１〜５のアルキル基又は脂肪族環式基を表し；ｎは０〜３の整数を表し；Ｙ^２は２価の連結基を表し；Ｒは前記と同じであり、Ｒ^１’、Ｒ^２’はそれぞれ独立して水素原子又は炭素数１〜５のアルキル基を表す。］

[Wherein, X ′ represents a tertiary alkyl ester type acid dissociable, dissolution inhibiting group, Y represents an alkyl group having 1 to 5 carbon atoms or an aliphatic cyclic group, and n represents an integer of 0 to 3] Y ² represents a divalent linking group; R is the same as defined above; R ¹ ′ and R ² ′ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; ]

In the formula, X 'include the same tertiary alkyl ester-type acid dissociable, dissolution inhibiting groups as those described above for X ^{1.
R 1 ', R 2',} n, as the Y, respectively, ^{R 1} in the general formula listed in the description of "acetal-type acid dissociable, dissolution inhibiting group" described above ^{(p1) ', R 2'} , n, Y The same thing is mentioned.
The Y ^2, the same groups as those described above for ^{Y 2} in the general formula (a1-0-2).

Specific examples of the structural units represented by the general formulas (a1-1) to (a1-4) are shown below.
In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

As the structural unit (a1), one type may be used alone, or two or more types may be used in combination.
Among these, the structural unit represented by the general formula (a1-1) or (a1-3) is preferable, and specifically, the formulas (a1-1-1) to (a1-1-4) and (a1- It is more preferable to use at least one selected from the group consisting of structural units represented by 1-20) to (a1-1-23) and (a1-3-25) to (a1-3-28). .
Furthermore, the structural unit (a1) is represented by the following general formula (a1-1-01) that includes the structural units represented by the formula (a1-1-1) to the formula (a1-1-3). The following general formula (a1) including structural units represented by formulas (a1-1-16) to (a1-1-17) and formulas (a1-1-20) to (a1-1-23) Represented by the following general formula (a1-3-01) including structural units represented by formulas (a1-3-25) to (a1-3-26): And those represented by the following general formula (a1-3-02) including the structural units represented by formulas (a1-3-27) to (a1-3-28) are also preferable.

（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を示し、Ｒ^１１は炭素数１〜５のアルキル基を示す。）

(In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and R ¹¹ represents an alkyl group having 1 to 5 carbon atoms.)

（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を示し、Ｒ^１２は炭素数１〜５のアルキル基を示す。ｎ’は１〜６の整数を表す。）

(In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, R ¹² represents an alkyl group having 1 to 5 carbon atoms. Represents an integer of 6.)

In general formula (a1-1-01), R is the same as defined above.
Alkyl group of 1 to 5 carbon atoms for R ¹¹ is the same as the alkyl group having 1 to 5 carbon atoms for R, a methyl group or an ethyl group is preferred.

In general formula (a1-1-02), R is the same as defined above.
The alkyl group having 1 to 5 carbon atoms of R ¹² is the same as the alkyl group having 1 to 5 carbon atoms in R, preferably a methyl group or an ethyl group, and most preferably an ethyl group.
n ′ is preferably 1 or 2.

（式中、Ｒは水素原子、炭素数１〜５のアルキル基、又は炭素数１〜５のハロゲン化アルキル基を示し；Ｒ^１４は炭素数１〜５のアルキル基であり、Ｒ^１３は水素原子またはメチル基であり、ａ７は１〜１０の整数である。）

(In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; R ¹⁴ represents an alkyl group having 1 to 5 carbon atoms, and R ¹³ represents hydrogen. An atom or a methyl group, and a7 is an integer of 1 to 10.)

（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を示し；Ｒ^１４は炭素数１〜５のアルキル基であり、Ｒ^１３は水素原子またはメチル基であり、ａ７は１〜１０の整数であり、ｎ’は１〜６の整数である。）

(In the formula, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; R ¹⁴ represents an alkyl group having 1 to 5 carbon atoms, and R ¹³ represents hydrogen. An atom or a methyl group, a7 is an integer of 1 to 10, and n ′ is an integer of 1 to 6.)

In the general formula (a1-3-01) or (a1-3-02), R is the same as described above.
R ¹³ is preferably a hydrogen atom.
Alkyl group of 1 to 5 carbon atoms for R ¹⁴ is the same as the alkyl group having 1 to 5 carbon atoms for R, a methyl group or an ethyl group is preferred.
a7 is preferably an integer of 1 to 8, particularly preferably an integer of 2 to 5, and most preferably 2.
n ′ is the same as above, and is preferably 1 or 2.

  In the component (A1), the proportion of the structural unit (a1) is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, with respect to the total of all structural units constituting the component (A1). More preferred is mol%. By setting it to the lower limit value or more, a pattern can be easily obtained when the resist composition is used, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

(Structural unit (a2))
The structural unit (a2) is a structural unit derived from an acrylate ester containing a lactone-containing cyclic group.
Here, the lactone-containing cyclic group refers to a cyclic group containing one ring (lactone ring) containing an —O—C (O) — structure. The lactone ring is counted as the first ring, and when it is only the lactone ring, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure.
When the component (A1) is used for forming a resist film, the lactone cyclic group of the structural unit (a2) increases the adhesion of the resist film to the substrate or has an affinity for a developer containing water. It is effective in raising.

As the structural unit (a2), any unit can be used without any particular limitation.
Specifically, as the lactone-containing monocyclic group, a group in which one hydrogen atom is removed from a 4- to 6-membered ring lactone, for example, a group in which one hydrogen atom is removed from β-propionolactone, or γ-butyrolactone. Examples thereof include a group in which one hydrogen atom has been removed, and a group in which one hydrogen atom has been removed from δ-valerolactone. Examples of the lactone-containing polycyclic group include groups in which one hydrogen atom has been removed from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring.

  More specifically, examples of the structural unit (a2) include structural units represented by general formulas (a2-1) to (a2-5) 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り；Ｒ’はそれぞれ独立に水素原子、炭素数１〜５のアルキル基、炭素数１〜５のアルコキシ基または−ＣＯＯＲ”であり、Ｒ”は水素原子またはアルキル基であり；Ｒ^２９は単結合または２価の連結基であり、ｓ”は０または１〜２の整数であり；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；ｍは０又は１の整数である。］

[Wherein, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; R ′ is independently a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, An alkoxy group having 1 to 5 carbon atoms or —COOR ″, R ″ is a hydrogen atom or an alkyl group; R ²⁹ is a single bond or a divalent linking group, and s ″ is 0 or an integer of 1 to 2 A ″ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom; m is an integer of 0 or 1; ]

R in the general formulas (a2-1) to (a2-5) is the same as R in the structural unit (a1). Of these, R is preferably a hydrogen atom or a methyl group.
Examples of the alkyl group having 1 to 5 carbon atoms of R ′ include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group.
Examples of the alkoxy group having 1 to 5 carbon atoms of R ′ include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group.
R ′ is preferably a hydrogen atom in view of industrial availability.
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, and more preferably 1 to 5 carbon atoms.
When R ″ is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a fluorine atom Or a monocycloalkane which may or may not be substituted with a fluorinated alkyl group; a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as a bicycloalkane, tricycloalkane or tetracycloalkane Specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Etc.
A ″ is preferably an alkylene group having 1 to 5 carbon atoms or —O—, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.
R ²⁹ is a single bond or a divalent linking group. The divalent linking group is the same as the divalent linking group described for Y ² in the general formula (a1-0-2), and among them, an alkylene group and an ester bond (—C (═O ) -O-) or a combination thereof. The alkylene group as the divalent linking group for R ²⁹ is more preferably a linear or branched alkylene group. Specifically, the same as the linear alkylene group and the branched alkylene group mentioned as the aliphatic hydrocarbon group for A in Y ² can be used.
s ″ is preferably an integer of 1 to 2.
Specific examples of the structural units represented by the general formulas (a2-1) to (a2-5) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

In the component (A1), as the structural unit (a2), one type of structural unit may be used, or two or more types may be used in combination.
As the structural unit (a2), at least one selected from the group consisting of structural units represented by the general formulas (a2-1) to (a2-5) is preferable, and the general formulas (a2-1) to ( At least one selected from the group consisting of structural units represented by a2-3) is more preferred. Among them, chemical formulas (a2-1-1), (a2-1-2), (a2-2-1), (a2-2-7), (a2-3-1) and (a2-3-5) It is preferable to use at least one selected from the group consisting of structural units represented by

  The proportion of the structural unit (a2) in the component (A1) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, with respect to the total of all structural units constituting the component (A1). 50 mol% is more preferable. By making it the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by making it the upper limit value or less, it is possible to balance with other structural units.

(Structural unit (a5))
The structural unit (a5) is a structural unit represented by the following general formula (a5-1).

［式（ａ５−１）中、Ｒは水素原子、炭素数１〜５のアルキル基、又は炭素数１〜５のハロゲン化アルキル基であり；Ｙ^１は置換基を有していてもよい脂肪族炭化水素基であり、Ｚは１価の有機基であり；ａは１〜３の整数であり、ｂは０〜２の整数であり、かつ、ａ＋ｂ＝１〜３であり；ｃ、ｄ、ｅはそれぞれ独立して０〜３の整数である。］

[In formula (a5-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; Y ¹ may have a substituent. A hydrocarbon group, Z is a monovalent organic group; a is an integer of 1 to 3, b is an integer of 0 to 2, and a + b = 1 to 3; c, d , E are each independently an integer of 0-3. ]

  In general formula (a5-1), the same as R in the structural unit (a1). Of these, R is preferably a hydrogen atom or a methyl group.

In general formula (a5-1), Y ¹ represents an aliphatic hydrocarbon group which may have a substituent.
The aliphatic hydrocarbon group for Y ¹ may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear, branched or cyclic.
Here, in the present specification and claims, the “aliphatic hydrocarbon group” indicates an aliphatic hydrocarbon group having no aromaticity.
Further, “may have a substituent” means that a part of carbon atoms constituting the aliphatic hydrocarbon group may be substituted with a substituent containing a hetero atom, and the aliphatic hydrocarbon It means that part or all of the hydrogen atoms constituting the group may be substituted with a substituent containing a hetero atom.
The “heteroatom” in Y ¹ is not particularly limited as long as it is an atom other than a carbon atom and a hydrogen atom, and examples thereof include a halogen atom, an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom.
The substituent containing a hetero atom may consist of only the hetero atom, or may be a group containing the hetero atom and a group or atom other than the hetero atom. Specifically, for example, —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O—, —C (═O) —NH—, -NH- (H is an alkyl group, may be substituted with a substituent such as an acyl _{group), - S -, - S} (= O) 2 -, - S (= O) 2 -O- and the like can be mentioned It is done. When the aliphatic hydrocarbon group is cyclic, these substituents may be included in the ring structure.
Specific examples of the substituent for substituting part or all of the hydrogen atoms constituting the aliphatic hydrocarbon group include, for example, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (= O), cyano Group, alkyl group and the like.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group, and a methoxy group or an ethoxy group. Is most preferred.
As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
As the halogenated alkyl group, a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc. And a group substituted with a halogen atom.
As said alkyl group, a C1-C5 alkyl group (lower alkyl group), for example, a methyl group, an ethyl group, a propyl group, n-butyl group, a tert-butyl group etc. are mentioned.

When Y ¹ is a linear or branched aliphatic hydrocarbon group, the carbon number is preferably 1 to 10, more preferably 1 to 5, and most preferably 1 to 3. Specifically, a chain alkylene group is preferable.

When Y ¹ is a cyclic aliphatic hydrocarbon group (aliphatic cyclic group), the structure of the basic ring (aliphatic ring) excluding the substituent of the aliphatic cyclic group is a ring composed of carbon and hydrogen. It is not limited to being a (hydrocarbon ring), and a hetero atom such as an oxygen atom may be included in the structure of the ring (aliphatic ring). The “hydrocarbon ring” may be either saturated or unsaturated, but is usually preferably saturated.
The aliphatic cyclic group may be either a polycyclic group or a monocyclic group. Examples of the aliphatic cyclic group include a monocycloalkane which may or may not be substituted with a lower alkyl group, a fluorine atom or a fluorinated alkyl group; a bicycloalkane, a tricycloalkane, or a tetracycloalkane. Groups obtained by removing two or more hydrogen atoms from polycycloalkanes and the like. More specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing two or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. .
Examples of the aliphatic cyclic group include two or more hydrogen atoms from tetrahydrofuran or tetrahydropyran which may or may not be substituted with a lower alkyl group, a fluorine atom or a fluorinated alkyl group. Examples include groups other than.
The aliphatic cyclic group in the structural unit (a5) is preferably a polycyclic group, and particularly preferably a group obtained by removing two or more hydrogen atoms from adamantane.

In the general formula (a5-1), Z is a monovalent organic group.
Here, in the present specification and claims, the “organic group” means a group containing a carbon atom, and an atom other than a carbon atom (for example, a hydrogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom ( A fluorine atom, a chlorine atom, etc.).
Examples of the organic group represented by Z include an aliphatic hydrocarbon group which may have a substituent, an aromatic hydrocarbon group which may have a substituent, and a formula -Q ⁵ -R ^5. Group (wherein Q ⁵ is a divalent linking group, and R ⁵ is an aliphatic hydrocarbon group which may have a substituent or an aromatic hydrocarbon group which may have a substituent). Is mentioned.

  In the organic group of Z, the aliphatic hydrocarbon group is, for example, a linear, branched or cyclic saturated hydrocarbon group having 1 to 20 carbon atoms, or a linear or branched chain having 2 to 20 carbon atoms. And an aliphatic unsaturated hydrocarbon group.

Examples of the linear saturated hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group.
Examples of the branched saturated hydrocarbon group include 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-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.

The linear or branched alkyl group may have a substituent. Examples of the substituent include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), a cyano group, and a carboxy group.
As the alkoxy group as a substituent of the linear or branched alkyl group, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n- A butoxy group and a tert-butoxy group are preferable, and a methoxy group and an ethoxy group are most preferable.
Examples of the halogen atom as a substituent of the linear or branched alkyl group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
The halogenated alkyl group as a substituent for the aromatic group is a hydrogen atom of an alkyl group having 1 to 5 carbon atoms (preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc.). Examples thereof include a group in which part or all of the atoms are substituted with the halogen atom.

The cyclic saturated hydrocarbon group may be either a polycyclic group or a monocyclic group, and examples thereof include a cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, such as monocycloalkane; bicycloalkane, tricyclo And groups obtained by removing one hydrogen atom from polycycloalkane such as alkane and tetracycloalkane. More specifically, one hydrogen atom was removed from a monocycloalkane such as cyclopentane, cyclohexane, cycloheptane, and cyclooctane, and a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Group and the like.
The cyclic alkyl group may have a substituent. For example, part of the carbon atoms constituting the ring of the cyclic alkyl group may be substituted with a heteroatom, or the hydrogen atom bonded to the ring of the cyclic alkyl group may be substituted with a substituent. Good.
Examples of the former include one or more hydrogen atoms from a heterocycloalkane in which a part of the carbon atoms constituting the ring of the monocycloalkane or polycycloalkane is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Examples include groups other than atoms. The ring structure may have an ester bond (—C (═O) —O—). Specifically, a lactone-containing monocyclic group such as a group obtained by removing one hydrogen atom from γ-butyrolactone, or a group obtained by removing one hydrogen atom from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring. And other lactone-containing polycyclic groups.
Examples of the substituent in the latter example include the same as those exemplified as the substituent that the linear or branched alkyl group may have, an alkyl group having 1 to 5 carbon atoms, and the like.

Examples of the linear unsaturated hydrocarbon group include a vinyl group, a propenyl group (allyl group), and a butynyl group.
Examples of the branched unsaturated hydrocarbon group include a 1-methylpropenyl group and a 2-methylpropenyl group.
The linear or branched unsaturated hydrocarbon group may have a substituent. Examples of the substituent include the same ones as those exemplified as the substituent which the linear or branched alkyl group may have.

In the organic group of Z, the aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and most preferably 6 to 12. However, the carbon number does not include the carbon number in the substituent.
The aromatic organic group may have an aromatic hydrocarbon ring in which the ring skeleton of the aromatic ring is composed only of carbon atoms, and the aromatic ring group includes aromatic atoms containing hetero atoms other than carbon atoms. It may have a heterocyclic ring.
Specific examples of the aromatic hydrocarbon group include a hydrogen atom from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. A heteroaryl group in which a part of carbon atoms constituting the ring of these aryl groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom; a benzyl group, a phenethyl group, 1 -Arylalkyl groups such as naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, and the like. The alkyl chain in the arylalkyl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2, and particularly preferably 1.
The aromatic hydrocarbon group may have a substituent. For example, a part of carbon atoms constituting the aromatic ring of the aromatic hydrocarbon group may be substituted with a hetero atom, and the hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group is substituted with the substituent. May be.
Examples of the former include a heteroaryl group in which a part of carbon atoms constituting the ring of the aryl group is substituted with a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, or a carbon constituting the ring of the arylalkyl group. Examples include heteroarylalkyl groups in which a part of the atoms is substituted with the heteroatom.
Examples of the substituent of the aromatic group in the latter example include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), and an acetyl group.
Examples of the alkyl group, alkoxy group, halogen atom, and halogenated alkyl group as the substituent of the aromatic group include those mentioned as the substituent that the linear or branched alkyl group may have. The same thing and a C1-C5 alkyl group are mentioned.

In the group represented by the formula -Q ⁵ -R ⁵ , Q ⁵ is a divalent linking group, and R ⁵ has an aliphatic hydrocarbon group or a substituent which may have a substituent. An aromatic hydrocarbon group that may be present.
Examples of the divalent linking group for Q ⁵ include the same groups as those exemplified in the description of Y ² in the above formula (a1-0-2).
R ⁵ may be the same as those exemplified in the description of the aliphatic hydrocarbon group and aromatic hydrocarbon group in Z above.

Among the above, the organic group of Z is a group containing an aliphatic hydrocarbon group which may have a substituent since the solubility in an organic solvent is further improved when a resist composition is formed. Preferably, the group represented by the formula -Q ⁵ -R ⁸ ′ (wherein Q ⁵ is a divalent linking group, and R ⁸ ′ is an aliphatic carbon which may have a substituent. It is more preferably a hydrogen group. Specifically, a tertiary alkyl group-containing group or an alkoxyalkyl group is preferable.

(Tertiary alkyl group-containing group)
Here, in the present specification and claims, the “tertiary alkyl group” refers to an alkyl group having a tertiary carbon atom. As described above, the “alkyl group” represents a monovalent saturated hydrocarbon group, and includes a chain (straight chain or branched chain) alkyl group and an alkyl group having a cyclic structure.
The “tertiary alkyl group-containing group” refers to a group containing a tertiary alkyl group in its structure. The tertiary alkyl group-containing group may be composed only of a tertiary alkyl group, or may be composed of a tertiary alkyl group and another atom or group other than the tertiary alkyl group. .
Examples of the “atom or group other than the tertiary alkyl group” that constitutes the tertiary alkyl group-containing group together with the tertiary alkyl group include a carbonyloxy group, a carbonyl group, an alkylene group, an oxygen atom, and the like. .

Examples of the tertiary alkyl group-containing group for Z include a tertiary alkyl group-containing group having no cyclic structure, a tertiary alkyl group-containing group having a cyclic structure, and the like.
The tertiary alkyl group-containing group having no cyclic structure is a group containing a branched tertiary alkyl group as the tertiary alkyl group and having no cyclic structure in the structure.
Examples of the branched tertiary alkyl group include groups represented by the following general formula (I).

In formula (I), R ^{21 to} R ²³ are each independently a linear or branched alkyl group. 1-5 are preferable and, as for carbon number of this alkyl group, 1-3 are more preferable.
Moreover, it is preferable that the total carbon number of group represented by general formula (I) is 4-7, it is more preferable that it is 4-6, and it is most preferable that it is 4-5.
Preferred examples of the group represented by the general formula (I) include a tert-butyl group and a tert-pentyl group, and a tert-butyl group is more preferable.

Examples of the tertiary alkyl group-containing group that does not have a cyclic structure include the above-described branched tertiary alkyl group; the above-described branched tertiary alkyl group is a linear or branched alkylene group A tertiary alkyl group-containing chain alkyl group bonded to the above; a tertiary alkyloxycarbonyl group having the branched tertiary alkyl group described above as the tertiary alkyl group; And tertiary alkyloxycarbonylalkyl groups having a branched tertiary alkyl group.
The alkylene group in the tertiary alkyl group-containing chain alkyl group is preferably an alkylene group having 1 to 5 carbon atoms, more preferably an alkylene group having 1 to 4 carbon atoms, and further preferably an alkylene group having 2 to 2 carbon atoms.
Examples of the chain-like tertiary alkyloxycarbonyl group include a group represented by the following general formula (II). ^R 21 ^{to R 23} in the formula (II) is the same as ^R 21 ^{to R 23} in general formula (I). The chain-like tertiary alkyloxycarbonyl group is preferably a tert-butyloxycarbonyl group (t-boc) or a tert-pentyloxycarbonyl group.

Examples of the chain-like tertiary alkyloxycarbonylalkyl group include a group represented by the following general formula (III). ^R 21 ^{to R 23} in the formula (III) are the same as ^R 21 ^{to R 23} in general formula (I). f is an integer of 1 to 3, and 1 or 2 is preferable. As the chain-like tertiary alkyloxycarbonylalkyl group, a tert-butyloxycarbonylmethyl group and a tert-butyloxycarbonylethyl group are preferable.
Of these, the tertiary alkyl group-containing group having no cyclic structure is preferably a tertiary alkyloxycarbonyl group or a tertiary alkyloxycarbonylalkyl group, more preferably a tertiary alkyloxycarbonyl group. A tert-butyloxycarbonyl group (t-boc) is most preferred.

The tertiary alkyl group-containing group having a cyclic structure is a group having a tertiary carbon atom and a cyclic structure in the structure.
In the tertiary alkyl group-containing group having a cyclic structure, the cyclic structure preferably has 4 to 12 carbon atoms, more preferably 5 to 10 carbon atoms, and more preferably 6 to 10 carbon atoms constituting the ring. Most preferred. Examples of the cyclic structure include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane. Preferable examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

Examples of the tertiary alkyl group-containing group having a cyclic structure include a group having the following group (1) or (2) as a tertiary alkyl group.
(1) A group in which a linear or branched alkyl group is bonded to a carbon atom constituting a ring of a cyclic alkyl group (cycloalkyl group), and the carbon atom is a tertiary carbon atom.
(2) A group in which an alkylene group having a tertiary carbon atom (branched alkylene group) is bonded to the carbon atom constituting the ring of the cycloalkyl group.

The linear or branched alkyl group in the group (1) preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms. .
Examples of the group (1) include a 2-methyl-2-adamantyl group, a 2-ethyl-2-adamantyl group, a 1-methyl-1-cycloalkyl group, and a 1-ethyl-1-cycloalkyl group.

In the above (2), the cycloalkyl group to which the branched alkylene group is bonded may have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= O), and the like.
Examples of the group (2) include groups represented by the following chemical formula (IV).

In the formula (IV), R ²⁴ is a cycloalkyl group which may or may not have a substituent. Examples of the substituent that the cycloalkyl group may have include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (═O).
R ²⁵ and R ²⁶ are each independently a linear or branched alkyl group, and the alkyl group is the same as the alkyl group of R ^{21 to} R ²³ in the formula (I). Can be mentioned.

(Alkoxyalkyl group)
Examples of the alkoxyalkyl group for Z include groups represented by the following general formula (V).

In the formula, R ⁴¹ is a linear, branched or cyclic alkyl group.
When R ⁴¹ is linear or branched, it preferably has 1 to 5 carbon atoms, more preferably an ethyl group or a methyl group, and most preferably an ethyl group.
When R ⁴¹ is cyclic, it preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. For example, one or more hydrogen atoms from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group And the like except for. More specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. . Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
^R42 is a linear or branched alkylene group. The alkylene group preferably has 1 to 5 carbon atoms, more preferably 1 to 3 carbon atoms, and still more preferably 1 to 2 carbon atoms.
As the alkoxyalkyl group for Z, a group represented by the following general formula (VI) is particularly preferable.

In the formula (VI), R ⁴¹ is the same as described above, and R ⁴³ and R ⁴⁴ are each independently a linear or branched alkyl group or a hydrogen atom.
In R ⁴³ and R ⁴⁴ , the alkyl group preferably has 1 to 15 carbon atoms, may be linear or branched, and is preferably an ethyl group or a methyl group, and most preferably a methyl group. In particular, it is preferable that one of R ⁴³ and R ⁴⁴ is a hydrogen atom and the other is a methyl group.

  Among these, as Z, a tertiary alkyl group-containing group is preferable, a group represented by the general formula (II) is more preferable, and a tert-butyloxycarbonyl group (t-boc) is most preferable.

In the general formula (a5-1), a is an integer of 1 to 3, b is an integer of 0 to 2, and a + b = 1 to 3.
a is preferably 1.
b is preferably 0.
a + b is preferably 1.
c is an integer of 0 to 3, preferably 0 or 1, and more preferably 0.
d is an integer of 0 to 3, preferably 0 or 1, and more preferably 0.
e is an integer of 0 to 3, preferably 0 or 1, and more preferably 0.

  As the structural unit (a5), a structural unit represented by general formula (a5-1-1) or (a5-1-2) shown below is particularly desirable.

［式中、Ｒ，Ｚ，ｂ，ｃ，ｄ，ｅはそれぞれ前記と同じである。］

[Wherein R, Z, b, c, d and e are the same as defined above. ]

［式中、Ｒ，Ｚ，ａ，ｂ，ｃ，ｄ，ｅはそれぞれ前記と同じである。ｃ”は１〜３の整数である。］

[Wherein R, Z, a, b, c, d and e are the same as defined above. c ″ is an integer of 1 to 3.]

In the formula (a5-1-2), c ″ is an integer of 1 to 3, preferably 1 or 2, and more preferably 1.
When c in the formula (a5-1-2) is 0, the oxygen atom at the terminal of the carbonyloxy group (—C (═O) —O—) of the acrylate ester is bonded to the oxygen atom in the cyclic group. It is preferable that it is not bonded to the carbon atom. That is, when c is 0, there are two or more carbon atoms between the terminal oxygen atom and the oxygen atom in the cyclic group (the number of carbon atoms is 1 (that is, acetal bond and It is preferable that the above is excluded).

  The monomer for deriving the structural unit (a5) is, for example, a compound represented by the following general formula (a5-1 ′) (an acrylate ester containing an aliphatic cyclic group having 1 to 3 alcoholic hydroxyl groups). It can be synthesized by protecting a part or all of the hydroxyl groups with an organic group (preferably a tertiary alkyl group-containing group or an alkoxyalkyl group) using a known method.

［式中、Ｒ，Ｙ^１，ａ，ｂ，ｃ，ｄ，ｅはそれぞれ前記と同じである。］

[Wherein, R, Y ¹ , a, b, c, d, and e are the same as defined above. ]

As the structural unit (a5), one type of structural unit may be used alone, or two or more types of structural units may be used in combination.
The proportion of the structural unit (a5) in the component (A1) is preferably 1 to 45 mol%, and preferably 5 to 45 mol%, based on the total of all structural units constituting the component (A1). More preferably, it is more preferably 5 to 40 mol%, and most preferably 5 to 35 mol%. By setting it to the lower limit value or more, solubility in an organic solvent is improved, and when it is equal to or lower than the upper limit value, the balance with other structural units is good.

(Structural unit (a6))
The structural unit (a6) is a structural unit represented by the following general formula (a6-1).

［式（ａ６−１）中、Ｒは水素原子、炭素数１〜５のアルキル基、又は炭素数１〜５のハロゲン化アルキル基であり；Ｙ^３はアルキレン基又は脂肪族環式基であり；ｇ、ｈはそれぞれ独立して０〜３の整数であり；ｉは１〜３の整数である。］

[In Formula (a6-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; Y ³ is an alkylene group or an aliphatic cyclic group; G and h are each independently an integer of 0 to 3; i is an integer of 1 to 3; ]

In general formula (a6-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. R is the same as R in the structural unit (a1). Of these, R is preferably a hydrogen atom or a methyl group.
Y ³ is an alkylene group or an aliphatic cyclic group.
Examples of the alkylene group for Y ³ include alkylene groups having 1 to 10 carbon atoms.
Examples of the aliphatic cyclic group for Y ³ include the same aliphatic cyclic groups exemplified in the description of Y ¹ in the formula (a5-1). Y ³ preferably has the same basic ring (aliphatic ring) structure as Y ¹ .
g is an integer of 0 to 3, preferably 0 or 1, and more preferably 0.
h is an integer of 0 to 3, preferably 0 or 1, and more preferably 0.
i is an integer of ˜3, preferably 1.

As the structural unit (a6), a structural unit represented by general formula (a6-1-1) shown below is particularly preferable. Among them, one of i — (CH ₂ ) _h —OH is represented by 1- It is preferably bonded to the 3-position of the adamantyl group.

［式中、Ｒ，ｇ，ｈ，ｉはそれぞれ前記と同じである。］

[Wherein R, g, h and i are the same as defined above. ]

As the structural unit (a6), one type may be used alone, or two or more types may be used in combination.
The proportion of the structural unit (a6) in the component (A1) is preferably 1 to 40 mol%, and preferably 1 to 35 mol%, based on the total of all structural units constituting the component (A1). More preferably, it is more preferably 5 to 30 mol%, and most preferably 5 to 25 mol%. By setting it to the lower limit value or more, the rectangular shape of the cross-sectional shape is high, and a resist pattern having a good shape can be formed.

(Other structural units)
The component (A1) may contain other structural units other than the structural units (a1), (a2), (a5) and (a6) as long as the effects of the present invention are not impaired.
Such other structural unit is not particularly limited as long as it is a structural unit not classified into the above-mentioned structural units (a1), (a2), (a5) and (a6). For ArF excimer laser, KrF excimer laser A number of hitherto known materials that can be used for resist resins such as those for use can be used.
Examples of the other structural unit include a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group, and an acrylate ester containing an acid non-dissociable aliphatic polycyclic group. And the structural unit (a4).

Structural Unit (a3) The structural unit (a3) is a structural unit derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group. However, the structural unit (a3) does not include the structural unit (a5) and the structural unit (a6) described above.
When the component (A1) has the structural unit (a3), the hydrophilicity of the component (A) is increased, the affinity with the developer is increased, the alkali solubility in the exposed area is improved, and the resolution is improved. Contributes to improvement.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a cyclic aliphatic hydrocarbon group (cyclic group). The cyclic group may be a monocyclic group or a polycyclic group. For example, a resin for a resist composition for an ArF excimer laser can be appropriately selected from those proposed. The cyclic group is preferably a polycyclic group, and more preferably 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom Is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane and the like. Specific examples include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, there are groups in which two or more hydrogen atoms have been removed from adamantane, groups in which two or more hydrogen atoms have been removed from norbornane, and groups in which two or more hydrogen atoms have been removed from tetracyclododecane. Industrially preferable.

  The structural unit (a3) is derived from a hydroxyethyl ester of acrylic acid when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms. When the hydrocarbon group is a polycyclic group, the structural unit represented by the following formula (a3-1) and the structural unit represented by the formula (a3-2) are preferred. As mentioned.

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

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

  In formula (a3-1), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.

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

As the structural unit (a3), one type may be used alone, or two or more types may be used in combination.
In the component (A1), the proportion of the structural unit (a3) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, based on the total of all structural units constituting the component (A1). 5 to 25 mol% is more preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (a3) can be sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

Structural Unit (a4) The structural unit (a4) is a structural unit derived from an acrylate ester containing a non-acid-dissociable aliphatic polycyclic group.
Examples of the polycyclic group include those exemplified in the case of the structural unit (a1), and for ArF excimer laser and KrF excimer laser (preferably for ArF excimer laser). A number of hitherto known materials can be used as the resin component of the resist composition.
In particular, at least one selected from a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.
Specific examples of the structural unit (a4) include those represented by the following general formulas (a4-1) to (a4-5).

（式中、Ｒは前記と同じである。）

(In the formula, R is as defined above.)

  When the structural unit (a4) is contained in the component (A1), the structural unit (a4) is preferably contained in an amount of 1 to 30 mol% based on the total of all the structural units constituting the component (A1). 10 to 20 mol% is more preferable.

In the present invention, the component (A1) is preferably a copolymer having the structural unit (a1). Examples of the copolymer include the structural units (a1) and (a2). Copolymer, copolymer having structural units (a1) and (a5), copolymer having structural units (a1), (a2) and (a5), structural units (a1) and (a6) A copolymer having structural units (a1), (a2) and (a6), a copolymer having structural units (a1), (a5) and (a6), and a structural unit (a1). ), (A2), (a5) and (a6).
Specific examples of the component (A1) include copolymers composed of the structural units (a1), (a2), (a5), and (a6).

In the component (A0), the component (A1) may be used alone or in combination of two or more.
In the present invention, as the component (A1), those containing the following combinations of structural units are particularly preferable.

［式（Ａ１−１１）中、Ｒは上記と同じであり、複数のＲは相互に同じであっても異なっていてもよい。Ｒ^１１は式（ａ１−１−０１）におけるＲ^１１と同じである。Ｒ^２１〜Ｒ^２３は上記式（ＩＩ）におけるＲ^２１〜Ｒ^２３とそれぞれ同じであり、ｅは上記式（ａ５−１）におけるｅと同じである。］

[In Formula (A1-11), R is the same as above, and the plurality of R may be the same or different from each other. R ¹¹ is the same as ^{R 11} in formula (a1-1-01). R ^{21 to} R ²³ are the same as R ^{21 to} R ²³ in the formula (II), respectively, and e is the same as e in the formula (a5-1). ]

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

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, preferably 1000 to 50000, more preferably 1500 to 30000, and most preferably 2000 to 20000. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
Further, the dispersity (Mw / Mn) of the component (A1) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5. “Mn” represents a number average molecular weight.

[(A2) component]
As the component (A2), a low molecular compound having a molecular weight of 500 or more and less than 2000 and having an acid dissociable, dissolution inhibiting group and a hydrophilic group as exemplified in the description of the component (A1) above is preferable. Specifically, a compound in which a part of hydrogen atoms of a hydroxyl group of a compound having a plurality of phenol skeletons is substituted with the acid dissociable, dissolution inhibiting group can be mentioned.
The component (A2) is, for example, a part of the hydrogen atom of the hydroxyl group of a low molecular weight phenol compound known as a sensitizer in a non-chemically amplified g-line or i-line resist or a heat resistance improver. Those substituted with a soluble dissolution inhibiting group are preferred and can be arbitrarily used.
Examples of such low molecular weight phenol compounds include bis (4-hydroxyphenyl) methane, bis (2,3,4-trihydroxyphenyl) methane, 2- (4-hydroxyphenyl) -2- (4′-hydroxyphenyl). ) Propane, 2- (2,3,4-trihydroxyphenyl) -2- (2 ′, 3 ′, 4′-trihydroxyphenyl) propane, tris (4-hydroxyphenyl) methane, bis (4-hydroxy-) 3,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -2-hydroxyphenylmethane, bis (4-hydroxy-3,5-dimethylphenyl) -3, 4-dihydroxyphenylmethane, bis (4-hydroxy-2,5-dimethylphenyl) -3,4-dihydroxyph Phenylmethane, bis (4-hydroxy-3-methylphenyl) -3,4-dihydroxyphenylmethane, bis (3-cyclohexyl-4-hydroxy-6-methylphenyl) -4-hydroxyphenylmethane, bis (3-cyclohexyl- 4-hydroxy-6-methylphenyl) -3,4-dihydroxyphenylmethane, 1- [1- (4-hydroxyphenyl) isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene, Examples include 2, 3, 4 nuclei of formalin condensates of phenols such as phenol, m-cresol, p-cresol or xylenol. Of course, it is not limited to these.
The acid dissociable, dissolution inhibiting group is not particularly limited, and examples thereof include those described above.

  In the component (A0), 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 invention, the content of the component (A) may be adjusted according to the resist film thickness to be formed.

<(B) component>
In the present invention, the component (B) is not particularly limited, and those that have been proposed as acid generators for chemically amplified resists can be used.
Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, poly (bissulfonyl) diazomethanes, and the like. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.
As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) can be used.

［式中、Ｒ^１”〜Ｒ^３”，Ｒ^５”〜Ｒ^６”は、それぞれ独立に、アリール基またはアルキル基を表し；式（ｂ−１）におけるＲ^１”〜Ｒ^３”のうち、いずれか２つが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く；Ｒ^４”は、置換基を有していてもよいアルキル基、ハロゲン化アルキル基、アリール基、またはアルケニル基を表し；Ｒ^１”〜Ｒ^３”のうち少なくとも１つはアリール基を表し、Ｒ^５”〜Ｒ^６”のうち少なくとも１つはアリール基を表す。］

[Wherein, R ¹ ″ to R ³ ″ and R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group; among R ¹ ″ to R ³ ″ in formula (b-1), Any two may be bonded to each other to form a ring together with the sulfur atom in the formula; R ⁴ ″ may be an optionally substituted alkyl group, halogenated alkyl group, aryl group, or alkenyl group; And at least one of R ¹ ″ to R ³ ″ represents an aryl group, and at least one of R ⁵ ″ to R ⁶ ″ represents an aryl group.]

In formula (b-1), R ¹ ″ to R ³ ″ each independently represents an aryl group or an alkyl group. In addition, any two of R ¹ ″ to R ³ ″ in formula (b-1) may be bonded to each other to form a ring together with the sulfur atom in the formula.
Further, at least one of R ¹ ″ to R ³ ″ represents an aryl group. Of R ¹ ″ to R ³ ″, two or more are preferably aryl groups, and most preferably all R ¹ ″ to R ³ ″ are aryl groups.

The aryl group for R ¹ ″ to R ³ ″ is not particularly limited, and is, for example, an aryl group having 6 to 20 carbon atoms, in which part or all of the hydrogen atoms are alkyl groups, alkoxy groups It may be substituted with a group, a halogen atom, a hydroxyl group or the like, or may not be substituted.
The aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.
The alkyl group that may be substituted for the hydrogen atom of the aryl group is preferably an alkyl group having 1 to 5 carbon atoms, and is a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Is most preferred.
As the alkoxy group that may be substituted for the hydrogen atom of the aryl group, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, A tert-butoxy group is preferable, and a methoxy group and an ethoxy group are most preferable.
The halogen atom that may be substituted with the hydrogen atom of the aryl group is preferably a fluorine atom.

The alkyl group for R 1 ^{"~R 3",} is not particularly limited, for example, linear C1-10, branched or cyclic alkyl group, and the like. It is preferable that it is C1-C5 from the point which is excellent in resolution. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decyl group. A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost.

When any two of R ¹ ″ to R ³ ″ in the formula (b-1) are bonded to each other to form a ring together with the sulfur atom in the formula, a 3 to 10 membered ring including the sulfur atom is formed. It is preferable that a 5- to 7-membered ring is formed.
When any two of R ¹ ″ to R ³ ″ in formula (b-1) are bonded to each other to form a ring together with the sulfur atom in the formula, the remaining one may be an aryl group preferable. Examples of the aryl group include the same aryl groups as those described above for R ¹ ″ to R ³ ″.

Preferable examples of the cation moiety of the compound represented by the formula (b-1) include cation moieties represented by the following formulas (I-1-1) to (I-1-10). Among these, those having a triphenylmethane skeleton such as a cation moiety represented by formulas (I-1-1) to (I-1-8) are preferable.
In the following formulas (I-1-9) to (I-1-10), R ⁹ and R ¹⁰ are each independently a phenyl group, naphthyl group or carbon number 1 to 5 which may have a substituent. An alkyl group, an alkoxy group, and a hydroxyl group.
u is an integer of 1 to 3, and 1 or 2 is most preferable.

R ⁴ ″ represents an alkyl group, a halogenated alkyl group, an aryl group, or an alkenyl group which may have a substituent.
The alkyl group for R ⁴ ″ may be linear, branched or cyclic.
The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
The cyclic alkyl group preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.
Examples of the halogenated alkyl group for R ⁴ ″ include groups in which part or all of the hydrogen atoms of the linear, branched, or cyclic alkyl group have been substituted with halogen atoms. A fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
In the halogenated alkyl group, the ratio of the number of halogen atoms to the total number of halogen atoms and hydrogen atoms contained in the halogenated alkyl group (halogenation rate (%)) is preferably 10 to 100%. 50 to 100% is preferable, and 100% is most preferable. The higher the halogenation rate, the better the acid strength.
The aryl group for R ⁴ ″ is preferably an aryl group having 6 to 20 carbon atoms.
The alkenyl group in R ⁴ ″ is preferably an alkenyl group having 2 to 10 carbon atoms.
In the above R ⁴ ″, “optionally substituted” means one of hydrogen atoms in the linear, branched or cyclic alkyl group, halogenated alkyl group, aryl group, or alkenyl group. It means that part or all may be substituted with a substituent (an atom or group other than a hydrogen atom).
The number of substituents in R ⁴ ″ may be one, or two or more.

Examples of the substituent include a halogen atom, a hetero atom, an alkyl group, and a formula: XQ ^1- [wherein Q ¹ is a divalent linking group containing an oxygen atom, and X has a substituent. And a hydrocarbon group having 3 to 30 carbon atoms. ] Etc. which are represented by these.
Examples of the halogen atom and alkyl group include the same groups as those described as the halogen atom and alkyl group in the halogenated alkyl group in R ⁴ ″.
Examples of the hetero atom include an oxygen atom, a nitrogen atom, and a sulfur atom.

X-Q 1 ^- In the group represented by, Q ¹ represents a divalent linking group containing an oxygen atom.
Q ¹ may contain an atom other than an oxygen atom. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, oxygen atoms, sulfur atoms, and nitrogen atoms.
Examples of the divalent linking group containing an oxygen atom include an oxygen atom (ether bond; —O—), an ester bond (—C (═O) —O—), and an amide bond (—C (═O) —NH. -), A carbonyl group (-C (= O)-), a non-hydrocarbon oxygen atom-containing linking group such as a carbonate bond (-O-C (= O) -O-); the non-hydrocarbon oxygen atom Examples include a combination of a containing linking group and an alkylene group.
Examples of the combination include —R ⁹¹ —O—, —R ⁹² —O—C (═O) —, —C (═O) —O—R ⁹³ —O—C (═O) — , R ^{91 to} R ⁹³ are each independently an alkylene group.) And the like.
The alkylene group for R ^{91 to} R ⁹³ is preferably a linear or branched alkylene group, and the alkylene group preferably has 1 to 12 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably 1 to 3 carbon atoms. preferable.
Specific examples of the alkylene group include a methylene group [—CH ₂ —]; —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ) ₂ —, —C ( _{CH 3) (CH 2 CH 3} ) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as ethylene 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 ) CH ₂ — and the like. Alkylethylene groups; trimethylene groups (n-propylene groups) [—CH ₂ CH ₂ CH ₂ —]; alkyls such as —CH (CH ₃ ) CH ₂ CH ₂ — and —CH ₂ CH (CH ₃ ) CH ₂ — trimethylene; tetramethylene group _[-CH 2 _CH 2 C _{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.
Q ¹ is preferably a divalent linking group containing an ester bond or an ether bond, and in particular, —R ⁹¹ —O—, —R ⁹² —O—C (═O) — or —C (═O) — O—R ⁹³ —O—C (═O) — is preferred.

In the group represented by XQ ^1- , the hydrocarbon group of X may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.

The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and most preferably 6 to 12. However, the carbon number does not include the carbon number in the substituent.
Specific examples of the aromatic hydrocarbon group include a hydrogen atom from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. Aryl groups such as aryl group, benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc., from which one is removed. The number of carbon atoms in the alkyl chain in the arylalkyl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

The aromatic hydrocarbon group may have a substituent. For example, a part of carbon atoms constituting the aromatic ring of the aromatic hydrocarbon group may be substituted with a hetero atom, and the hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group is substituted with the substituent. May be.
Examples of the former include heteroaryl groups in which some of the carbon atoms constituting the ring of the aryl group are substituted with heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and aromatic hydrocarbons in the arylalkyl groups. Examples include heteroarylalkyl groups in which some of the carbon atoms constituting the ring are substituted with the above heteroatoms.
Examples of the substituent of the aromatic hydrocarbon group in the latter example include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
The alkyl group as a substituent of the aromatic hydrocarbon group is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. preferable.
The alkoxy group as a substituent of the aromatic hydrocarbon group is preferably an alkoxy group having 1 to 5 carbon atoms, and is a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, tert- A butoxy group is preferable, and a methoxy group and an ethoxy group are most preferable.
Examples of the halogen atom as a substituent for the aromatic hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent of the aromatic hydrocarbon group include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.

The aliphatic hydrocarbon group for X may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear, branched or cyclic.
In X, the aliphatic hydrocarbon group may have a part of the carbon atoms constituting the aliphatic hydrocarbon group substituted by a substituent containing a hetero atom, and the hydrogen atom constituting the aliphatic hydrocarbon group May be substituted with a substituent containing a hetero atom.
The “heteroatom” in X is not particularly limited as long as it is an atom other than a carbon atom and a hydrogen atom, and examples thereof include a halogen atom, an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom.
The substituent containing a hetero atom may be composed of only the hetero atom, or may be a group containing a group or atom other than the hetero atom.
Specific examples of the substituent for substituting a part of the carbon atom include —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O. —, —C (═O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group, an acyl group, etc.), —S—, —S (═O) ₂ —, — S (= O) ₂ —O— and the like can be mentioned. When the aliphatic hydrocarbon group is cyclic, these substituents may be included in the ring structure.
Specific examples of the substituent for substituting part or all of the hydrogen atoms include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), and a cyano group.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group, and a methoxy group or an ethoxy group. Is most preferred.
As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
As the halogenated alkyl group, a part or all of hydrogen atoms of an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc. And a group substituted with a halogen atom.

Examples of the aliphatic hydrocarbon group include a linear or branched saturated hydrocarbon group, a linear or branched monovalent unsaturated hydrocarbon group, or a cyclic aliphatic hydrocarbon group (aliphatic ring). Formula group) is preferred.
The linear saturated hydrocarbon group (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, decyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group and the like.
The branched saturated hydrocarbon group (alkyl group) preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, Examples include 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.

As an unsaturated hydrocarbon group, it is preferable that carbon number is 2-10, 2-5 are preferable, 2-4 are preferable, and 3 is especially preferable. Examples of the linear monovalent unsaturated hydrocarbon group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched monovalent unsaturated hydrocarbon group include a 1-methylpropenyl group and a 2-methylpropenyl group.
Among the above, the unsaturated hydrocarbon group is particularly preferably a propenyl group.

The aliphatic cyclic group may be a monocyclic group or a polycyclic group. The number of carbon atoms is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12.
Specifically, for example, a group in which one or more hydrogen atoms are removed from a monocycloalkane; a group in which one or more hydrogen atoms are removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, etc. Can be mentioned. More specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; one or more polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples include a group excluding a hydrogen atom.
When the aliphatic cyclic group does not contain a substituent containing a hetero atom in the ring structure, the aliphatic cyclic group is preferably a polycyclic group, and one or more hydrogen atoms from the polycycloalkane are substituted. Excluded groups are preferred, and most preferred are groups in which one or more hydrogen atoms have been removed from adamantane.
When the aliphatic cyclic group includes a substituent containing a hetero atom in the ring structure, examples of the substituent containing a hetero atom include —O—, —C (═O) —O—, —S—. , —S (═O) ₂ — and —S (═O) ₂ —O— are preferable. Specific examples of the aliphatic cyclic group include groups represented by the following formulas (L1) to (L5) and (S1) to (S4).

［式中、Ｑ”は炭素数１〜５のアルキレン基、−Ｏ−、−Ｓ−、−Ｏ−Ｒ^９４−または−Ｓ−Ｒ^９５−であり、Ｒ^９４およびＲ^９５はそれぞれ独立に炭素数１〜５のアルキレン基であり、ｍは０または１の整数である。］

[Wherein, Q ″ is an alkylene group having 1 to 5 carbon atoms, —O—, —S—, —O—R ⁹⁴ — or —S—R ⁹⁵ —, and R ⁹⁴ and R ⁹⁵ are each independently carbon. An alkylene group of 1 to 5 and m is an integer of 0 or 1.]

In the formula, examples of the alkylene group for Q ″, R ⁹⁴ and R ⁹⁵ include the same alkylene groups as those described above for R ^{91 to} R ⁹³ .
In these aliphatic cyclic groups, a part of hydrogen atoms bonded to carbon atoms constituting the ring structure may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
As said alkyl group, a C1-C5 alkyl group is preferable, and it is especially preferable that they are a methyl group, an ethyl group, a propyl group, n-butyl group, and a tert- butyl group.
Examples of the alkoxy group and the halogen atom are the same as those exemplified as the substituent for substituting part or all of the hydrogen atoms.

Among the above, X is preferably a cyclic group which may have a substituent. The cyclic group may be an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a substituent. It is preferably an aliphatic cyclic group that may be used.
The aromatic hydrocarbon group is preferably a naphthyl group which may have a substituent or a phenyl group which may have a substituent.
As the aliphatic cyclic group which may have a substituent, a polycyclic aliphatic cyclic group which may have a substituent is preferable. Examples of the polycyclic aliphatic cyclic group include groups obtained by removing one or more hydrogen atoms from the polycycloalkane, groups represented by the above (L2) to (L5) and (S3) to (S4). Etc. are preferred.

Further, in the present invention, X preferably has a polar site because lithography characteristics and resist pattern shape are further improved.
As what has a polar site | part, the carbon atom which comprises the aliphatic cyclic group of X mentioned above, for example, the substituent in which a hetero atom contains, ie, -O-, -C (= O) -O-. , —C (═O) —, —O—C (═O) —O—, —C (═O) —NH—, —NH— (H is substituted with a substituent such as an alkyl group or an acyl group) may _{be), - S -, - S} (= O) 2 -, - S (= O) 2 -O- , etc., in include those substituted.

In the present invention, ^{R 4} ", ^{X-Q 1} - as a substituent preferably has the case, ^{R 4."} The, ^X-Q 1 -Y ⁴ - in [wherein, ^{Q 1} and X are the Y ⁴ is an optionally substituted alkylene group having 1 to 4 carbon atoms or an optionally substituted fluorinated alkylene group having 1 to 4 carbon atoms. ] Is preferable.
^X-Q 1 -Y ⁴ - In the group represented by, as the alkylene group for ^{Y 4,} include the same ones having 1 to 4 carbon atoms of the alkylene group mentioned in the ^{Q 1.}
Examples of the fluorinated alkylene group for Y ⁴ include groups in which some or all of the hydrogen atoms of the alkylene group have been substituted with fluorine atoms.
As Y ^4, _{specifically, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF (CF 2 CF 3) -, _{-C (CF 3) 2 -,} - CF 2 CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF ₃ ) —, —C (CF ₃ ) ₂ CF ₂ —, —CF (CF ₂ CF ₃ ) CF ₂ —, —CF (CF ₂ CF ₂ CF ₃ ) —, —C (CF ₃ ) (CF _{2 CF 3) -; - CHF} -, - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -, - CH (CF 3) CH 2 -, - CH (CF 2 _{CF 3) -, - C (} CH 3) (CF 3) -, - CH 2 CH 2 CH 2 CF 2 -, - C H ₂ CH ₂ CF ₂ CF ₂ —, —CH (CF ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CF ₃ ) CH ₂ —, —CH (CF ₃ ) CH (CF ₃ ) —, —C ( _{CF 3) 2 CH 2 -;} - CH 2 -, - CH 2 CH 2 -, - CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 -, - CH (CH 2 CH 3) -, - _{C (CH 3) 2 -,} - CH 2 CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 -, - CH (CH 3) CH _{(CH 3) -, - C} (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - CH (CH 2 CH 2 CH 3) -, - C (CH 3) (CH 2 CH ₃ ) — and the like.

Y ⁴ is preferably a fluorinated alkylene group, and particularly preferably a fluorinated alkylene group in which the carbon atom bonded to the adjacent sulfur atom is fluorinated. Examples of such fluorinated alkylene _{group, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF 2 CF 2 CF 2 CF 2 _{-, - CF (CF 3)} CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF 3) -, - C (CF 3) 2 CF 2 -, _{-CF (CF 2 CF 3) CF} 2 -; - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -; - CH 2 CH 2 CH 2 CF 2 -, - CH ₂ CH ₂ CF ₂ CF ₂ —, —CH ₂ CF ₂ CF ₂ CF ₂ — and the like can be mentioned.
Of _{these, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, or _CH 2 _CF 2 CF ₂ - is _{preferable, -CF 2 -, - CF 2} CF 2 - or -CF ₂ CF ₂ CF ₂ - is more preferable, -CF ₂ - is particularly preferred.

The alkylene group or fluorinated alkylene group may have a substituent. An alkylene group or a fluorinated alkylene group has a “substituent” means that part or all of the hydrogen atom or fluorine atom in the alkylene group or fluorinated alkylene group is substituted with an atom or group other than a hydrogen atom and a fluorine atom. Means that
Examples of the substituent that the alkylene group or fluorinated alkylene group may have include an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a hydroxyl group.

In the formula (b-2), R ⁵ ″ to R ⁶ ″ each independently represents an aryl group or an alkyl group. At least one of R ⁵ ″ to R ⁶ ″ represents an aryl group. It is preferable that all of R ⁵ ″ to R ⁶ ″ are aryl groups.
As the aryl group for R ⁵ ″ to R ⁶ ″, the same as the aryl groups for R ¹ ″ to R ³ ″ can be used.
Examples of the alkyl group for R ⁵ ″ to R ⁶ ″ include the same as the alkyl group for R ¹ ″ to R ³ ″.
Among these, it is most preferable that R ⁵ ″ to R ⁶ ″ are all phenyl groups.
"The, ^{R 4} in the above formula (b-1)" ^{R 4} in the In the formula (b-2) include the same as.

  Specific examples of the onium salt acid generators represented by formulas (b-1) and (b-2) include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, bis (4-tert-butylphenyl) iodonium. Trifluoromethane sulfonate or nonafluorobutane sulfonate, triphenylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, tri (4-methylphenyl) sulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its Nonafluorobutanesulfonate, dimethyl (4-hydroxynaphthyl) sulfonium trifluoromethanesulfonate, its heptaful Lopropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of monophenyldimethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; trifluoromethanesulfonate of diphenylmonomethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate (4-methylphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, (4-methoxyphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate , Trifluoromethanesulfonate of tri (4-tert-butyl) phenylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of diphenyl (1- (4-methoxy) naphthyl) sulfonium, its heptafluoropropane Sulfonate or its nonafluorobutane sulfonate, di (1-naphthyl) phenyl sulphonium trifluoromethane sulphonate, its heptafluoropropane sulphonate or its nonafluorobutane sulphonate; 1-phenyltetrahydrothiophenium trifluoromethane sulphonate, its heptafluoropropane sulphonate Or nonafluorobutanesulfonate thereof; 1- (4-methylphenyl) ) Tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1- (4-ethoxynaphthalene-1- Yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonaflu 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1-phenyltetrahydrothiopyranium trifluoromethanesulfonate , Its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (4-hydroxyphenyl) tetrahydrothiopyranium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl -4-Hydroxyphenyl) tetrahydrothiopyranium trifluoromethanesulfonate, its heptafluoropropanes Honeto or nonafluorobutanesulfonate; 1- (4-methylphenyl) trifluoromethanesulfonate tetrahydrothiophenium Pila chloride, heptafluoropropane sulfonate or its nonafluorobutane sulfonate, and the like.

  In addition, the anion portion of these onium salts may be substituted with methanesulfonate, n-propanesulfonate, n-butanesulfonate, n-octanesulfonate, 1-adamantansulfonate, 2-norbornanesulfonate, or the like; d-camphor-10-sulfonate Further, onium salts substituted with sulfonates such as benzenesulfonate, perfluorobenzenesulfonate, and p-toluenesulfonate can also be used.

  Moreover, the onium salt which replaced the anion part of these onium salts by the anion represented by either of following formula (b1)-(b8) can also be used.

［式中、ｐは１〜３の整数であり、ｑ１〜ｑ２はそれぞれ独立に１〜５の整数であり、ｑ３は１〜１２の整数であり、ｔ３は１〜３の整数であり、ｒ１〜ｒ２はそれぞれ独立に０〜３の整数であり、ｊは１〜２０の整数であり、Ｒ^７は置換基であり、ｍ１〜ｍ５はそれぞれ独立に０または１であり、ｖ０〜ｖ５はそれぞれ独立に０〜３の整数であり、ｗ１〜ｗ５はそれぞれ独立に０〜３の整数であり、Ｑ”は前記と同じである。］

[Wherein p is an integer of 1 to 3, q1 to q2 are each independently an integer of 1 to 5, q3 is an integer of 1 to 12, t3 is an integer of 1 to 3, and r1 ~ R2 are each independently an integer of 0 to 3, j is an integer of 1 to 20, R ⁷ is a substituent, m1 to m5 are each independently 0 or 1, and v0 to v5 are each Each independently represents an integer of 0 to 3, w1 to w5 are each independently an integer of 0 to 3, and Q ″ is the same as defined above.]

Examples of the substituent for R ⁷ are the same as those described above as the substituent that the aliphatic hydrocarbon group may have and the substituent that the aromatic hydrocarbon group may have in X. Can be mentioned.
Code (r1 and r2, w1 to w5) attached to R ⁷ when is an integer of 2 or more, a plurality of the ^{R 7} groups may be the same, respectively, may be different.

As the onium salt-based acid generator, in the general formula (b-1) or (b-2), the anion moiety ^(R 4 "SO ₃ ^-) of the following general formula (b-3) or (b- An onium salt acid generator substituted with the anion represented by 4) can also be used (the cation moiety is the same as the cation moiety in the formula (b-1) or (b-2)).

［式中、Ｘ”は、少なくとも１つの水素原子がフッ素原子で置換された炭素数２〜６のアルキレン基を表し；Ｙ”、Ｚ”は、それぞれ独立に、少なくとも１つの水素原子がフッ素原子で置換された炭素数１〜１０のアルキル基を表す。］

[Wherein X ″ represents an alkylene group having 2 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom; Y ″ and Z ″ each independently represent at least one hydrogen atom as a fluorine atom; Represents an alkyl group having 1 to 10 carbon atoms and substituted with

X ″ is a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkylene group has 2 to 6 carbon atoms, preferably 3 to 5 carbon atoms, Most preferably, it has 3 carbon atoms.
Y ″ and Z ″ are each independently a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkyl group has 1 to 10 carbon atoms, preferably Has 1 to 7 carbon atoms, more preferably 1 to 3 carbon atoms.
The carbon number of the alkylene group of X ″ or the carbon number of the alkyl group of Y ″ and Z ″ is preferably as small as possible because the solubility in the resist solvent is good within the above carbon number range.
In addition, in the alkylene group of X ″ or the alkyl group of Y ″ and Z ″, as the number of hydrogen atoms substituted with fluorine atoms increases, the strength of the acid increases, and high-energy light or electron beam of 200 nm or less This is preferable because the transparency to the surface is improved.
The proportion of fluorine atoms in the alkylene group or alkyl group, that is, the fluorination rate is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are substituted with fluorine atoms. A perfluoroalkylene group or a perfluoroalkyl group.

As the onium salt-based acid generator, in the general formula (b-1) or (b-2), anion ^{- a, R a -COO (R 4 "} SO 3) - [ wherein, ^{R a} Is an alkyl group or a fluorinated alkyl group.] An onium salt-based acid generator substituted with a cation moiety can also be used (the cation moiety is the same as the cation moiety in the formula (b-1) or (b-2)).
In the above formula, as R ^{a, the same} as R ⁴ ″ can be mentioned.
Specific examples of the “R ^a —COO ⁻ ” include trifluoroacetate ions, acetate ions, 1-adamantanecarboxylate ions and the like.

  Moreover, the sulfonium salt which has a cation part represented by the following general formula (b-5) or (b-6) can also be used as an onium salt type | system | group acid generator.

［式中、Ｒ^８１〜Ｒ^８６はそれぞれ独立してアルキル基、アセチル基、アルコキシ基、カルボキシ基、水酸基またはヒドロキシアルキル基であり；ｎ_１〜ｎ_５はそれぞれ独立して０〜３の整数であり、ｎ_６は０〜２の整数である。］

[Wherein R ^{81 to} R ⁸⁶ are each independently an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxyl group or hydroxyalkyl group; n _{1 to} n ₅ are each independently an integer of 0 to 3; There, _{n 6} is an integer of 0-2. ]

In R ^{81 to} R ⁸⁶ , the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group, and a methyl group, an ethyl group, a propyl group, an isopropyl group, n A butyl group or a tert-butyl group is particularly preferable.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a linear or branched alkoxy group, and particularly preferably a methoxy group or an ethoxy group.
The hydroxyalkyl group is preferably a group in which one or more hydrogen atoms in the alkyl group are substituted with a hydroxy group, and examples thereof include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.
When the symbols n _{1 to} n ₆ attached to R ^{81 to} R ⁸⁶ are integers of 2 or more, the plurality of R ^{81 to} R ⁸⁶ may be the same or different.
n ₁ is preferably 0 to 2, more preferably 0 or 1, and still more preferably 0.
n ₂ and n ₃ are preferably each independently 0 or 1, more preferably 0.
n ₄ is preferably 0 to 2, more preferably 0 or 1.
n ₅ is preferably 0 or 1, more preferably 0.
n ₆ is preferably 0 or 1, more preferably 1.

The anion part of the sulfonium salt having a cation part represented by the formula (b-5) or (b-6) is not particularly limited, and is the same as the anion part of the onium salt acid generators proposed so far. It may be a thing. Examples of the anion moiety include fluorinated alkyl sulfonate ions such as the anion moiety (R ⁴ ″ SO ₃ ⁻ ) of the onium salt acid generator represented by the general formula (b-1) or (b-2). An anion represented by the above general formula (b-3) or (b-4).

  In this specification, the oxime sulfonate acid generator is a compound having at least one group represented by the following general formula (B-1), and has a property of generating an acid upon irradiation (exposure) of radiation. It is what you have. Such oxime sulfonate-based acid generators are frequently used for chemically amplified resist compositions, and can be arbitrarily selected and used.

（式（Ｂ−１）中、Ｒ^３１、Ｒ^３２はそれぞれ独立に有機基を表す。）

(In formula (B-1), R ³¹ and R ³² each independently represents an organic group.)

The organic groups of R ³¹ and R ³² are groups containing carbon atoms, and atoms other than carbon atoms (for example, hydrogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms (fluorine atoms, chlorine atoms, etc.), etc.) You may have.
As the organic group for R ^31, a linear, branched, or cyclic alkyl group or aryl group is preferable. These alkyl groups and aryl groups may have a substituent. There is no restriction | limiting in particular as this substituent, For example, a fluorine atom, a C1-C6 linear, branched or cyclic alkyl group etc. are mentioned. Here, “having a substituent” means that part or all of the hydrogen atoms of the alkyl group or aryl group are substituted with a substituent.
As an alkyl group, C1-C20 is preferable, C1-C10 is more preferable, C1-C8 is more preferable, C1-C6 is especially preferable, and C1-C4 is the most preferable. As the alkyl group, a partially or completely halogenated alkyl group (hereinafter sometimes referred to as a halogenated alkyl group) is particularly preferable. The partially halogenated alkyl group means an alkyl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated alkyl group means that all of the hydrogen atoms are halogen atoms. Means an alkyl group substituted with 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. That is, the halogenated alkyl group is preferably a fluorinated alkyl group.
The aryl group preferably has 4 to 20 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms. As the aryl group, a partially or completely halogenated aryl group is particularly preferable. The partially halogenated aryl group means an aryl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated aryl group means that all of the hydrogen atoms are halogen atoms. Means an aryl group substituted with.
R ³¹ is particularly preferably an alkyl group having 1 to 4 carbon atoms having no substituent or a fluorinated alkyl group having 1 to 4 carbon atoms.
As the organic group for R ^32, a linear, branched, or cyclic alkyl group, aryl group, or cyano group is preferable. As the alkyl group and aryl group for R ^32, the same alkyl groups and aryl groups as those described above for R ³¹ can be used.
R ³² is particularly preferably a cyano group, an alkyl group having 1 to 8 carbon atoms having no substituent, or a fluorinated alkyl group having 1 to 8 carbon atoms.

  More preferable examples of the oxime sulfonate-based acid generator include compounds represented by the following general formula (B-2) or (B-3).

［式（Ｂ−２）中、Ｒ^３３は、シアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３４はアリール基である。Ｒ^３５は置換基を有さないアルキル基またはハロゲン化アルキル基である。］

[In Formula (B-2), R ³³ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁴ is an aryl group. R ³⁵ represents an alkyl group having no substituent or a halogenated alkyl group. ]

［式（Ｂ−３）中、Ｒ^３６はシアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３７は２または３価の芳香族炭化水素基である。Ｒ^３８は置換基を有さないアルキル基またはハロゲン化アルキル基である。ｐ”は２または３である。］

[In Formula (B-3), R ³⁶ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁷ is a divalent or trivalent aromatic hydrocarbon group. ^R38 is an alkyl group having no substituent or a halogenated alkyl group. p ″ is 2 or 3.]

In the general formula (B-2), the alkyl group or halogenated alkyl group having no substituent of R ³³ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and carbon atoms. Numbers 1 to 6 are most preferable.
R ³³ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³³ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred.
As the aryl group of R ³⁴ , one hydrogen atom is removed from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, or a phenanthryl group. And a heteroaryl group in which a part of carbon atoms constituting the ring of these groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Among these, a fluorenyl group is preferable.
The aryl group of R ³⁴ may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, or an alkoxy group. The alkyl group or halogenated alkyl group in the substituent preferably has 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. The halogenated alkyl group is preferably a fluorinated alkyl group.
The alkyl group or halogenated alkyl group having no substituent for R ³⁵ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 6 carbon atoms.
R ³⁵ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³⁵ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred is the strength of the acid generated. Most preferably, it is a fully fluorinated alkyl group in which a hydrogen atom is 100% fluorine-substituted.

In the general formula (B-3), the alkyl group or halogenated alkyl group having no substituent for R ³⁶ is the same as the alkyl group or halogenated alkyl group having no substituent for R ^33. Is mentioned.
Examples of the divalent or trivalent aromatic hydrocarbon group for R ³⁷ include groups obtained by further removing one or two hydrogen atoms from the aryl group for R ³⁴ .
Examples of the alkyl group or halogenated alkyl group having no substituent of R ³⁸ include the same alkyl groups or halogenated alkyl groups as those having no substituent of R ³⁵ .
p ″ is preferably 2.

Specific examples of the oxime sulfonate acid generator include α- (p-toluenesulfonyloxyimino) -benzyl cyanide, α- (p-chlorobenzenesulfonyloxyimino) -benzyl cyanide, α- (4-nitrobenzenesulfonyloxy). Imino) -benzylcyanide, α- (4-nitro-2-trifluoromethylbenzenesulfonyloxyimino) -benzylcyanide, α- (benzenesulfonyloxyimino) -4-chlorobenzylcyanide, α- (benzenesulfonyl) Oxyimino) -2,4-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -2,6-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -4-methoxybenzyl cyanide, α- ( 2-Chlorobenzenesulfonyloxyimino) 4-methoxybenzylcyanide, α- (benzenesulfonyloxyimino) -thien-2-ylacetonitrile, α- (4-dodecylbenzenesulfonyloxyimino) -benzylcyanide, α-[(p-toluenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α-[(dodecylbenzenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α- (tosyloxyimino) -4-thienyl cyanide, α- (methylsulfonyloxyimino) -1-cyclo Pentenyl acetonitrile, α- (methylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -1-cycloheptenylacetonitrile, α- (methylsulfonyloxyimino) -1-cyclooctene Acetonitrile, α- (trifluoromethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -cyclohexylacetonitrile, α- (ethylsulfonyloxyimino) -ethylacetonitrile, α- (propyl Sulfonyloxyimino) -propylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclopentylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclohexylacetonitrile, α- (cyclohexylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- ( Ethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclope N-tenyl acetonitrile, α- (n-butylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (ethylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclohexenylacetonitrile , Α- (n-butylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -phenylacetonitrile, α- (methylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (trifluoro Methylsulfonyloxyimino) -phenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -p- Butoxy phenylacetonitrile, alpha-(propylsulfonyl oxyimino)-p-methylphenyl acetonitrile, alpha-like (methylsulfonyloxyimino)-p-bromophenyl acetonitrile.
Further, an oxime sulfonate-based acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014] [chemical formula 18] to [chemical formula 19]), pamphlet of International Publication No. 04/074242, An oxime sulfonate-based acid generator disclosed in Examples 1 to 40) on pages 65 to 85 can also be suitably used.
Moreover, the following can be illustrated as a suitable thing.

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

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.
In the present invention, it is preferable to use an onium salt acid generator having a fluorinated alkyl sulfonate ion as an anion as the component (B).
0.5-50 mass parts is preferable with respect to 100 mass parts of (A) component, and, as for content of (B) component in the resist composition of this invention, 1-40 mass parts is more preferable. By setting it within the above range, pattern formation is sufficiently performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

<(S) component>
In the resist composition of the present invention, the organic solvent (S) (hereinafter referred to as “(S) component”) contains 1-butoxy-2-propanol and 2-butoxy-1-propanol (provided that 1-butoxy is used). 2-butoxy-2-propanol and a mixture prepared by mixing 2-butoxy-1-propanol), and the proportion of 2-butoxy-1-propanol is 100 parts by mass of 1-butoxy-2-propanol. Is 1.5 parts by mass or more.
Hereinafter, 1-butoxy-2-propanol may be represented as “1-BP” and 2-butoxy-1-propanol as “2-BP”.

  The component (S) contains 1-butoxy-2-propanol and 2-butoxy-1-propanol. However, (S) component in this invention remove | excludes what was prepared by mixing 1-butoxy-2-propanol and 2-butoxy-1-propanol.

In the claims and in the present specification, “prepared by mixing 1-butoxy-2-propanol and 2-butoxy-1-propanol” means, for example, 1-BP and 2-BP. Mixture; 1-BP and a mixture of 1-BP and 2-BP; 2-BP and a mixture of 1-BP and 2-BP; 1-BP and 2- It shall include a mixture of a mixture with BP.
The 1-BP, 2-BP, and the mixture of 1-BP and 2-BP may each contain other organic solvents.

In the component (S), the total ratio of 1-butoxy-2-propanol and 2-butoxy-1-propanol is preferably 97% by mass or more, more preferably 98% by mass or more, and 99% by mass. % Or more is more preferable, and may be 100% by mass.
When the total ratio of 1-BP and 2-BP is 97% by mass or more, particularly 99% by mass or more, the coating property to the support is further improved when a resist composition is obtained. Moreover, in the double patterning application, the dissolution of the first resist pattern is suppressed by using it as the organic solvent of the second resist composition during the second patterning. In addition, since the solubility of the component (A) in the component (S) is improved, options for the polymer compound used as the component (A) are widened, which contributes to the improvement of lithographic properties. This point is also effective for double patterning applications.

In the resist composition of the present invention, the ratio of 2-butoxy-1-propanol in the component (S) is 1.5 parts by mass or more with respect to 100 parts by mass of 1-butoxy-2-propanol, and 2 masses. The upper limit value is preferably 900 parts by mass or less, more preferably 500 parts by mass or less, and preferably 20 parts by mass or less. More preferably, it is particularly preferably 15 parts by mass or less, and most preferably 10 parts by mass or less.
When the ratio of 2-BP is 1.5 parts by mass or more with respect to 100 parts by mass of 1-BP, the resist composition has excellent coating properties. In particular, striation, wavy traces of the resist film (flow of rippling liquid), peeling of the resist film from the support, and the like can be suppressed. Moreover, the solubility with respect to the organic solvent of the compounding component in a resist composition improves. On the other hand, the solubility with respect to the organic solvent of the compounding component in a resist composition improves that an upper limit is 900 mass parts or less. Furthermore, defects can be suppressed.

The component (S) may be anything other than “prepared by mixing 1-butoxy-2-propanol and 2-butoxy-1-propanol”. For example, 1-BP and 2- It is preferable that at least a part of 1-BP is removed from an organic solvent containing BP so that the ratio of 2-BP is 1.5 parts by mass or more with respect to 100 parts by mass of 1-BP. Can be mentioned.
Specifically, it was prepared by removing a part of 1-BP from butoxypropanol containing 1-BP and 2-BP by distillation, and the ratio of 2-BP was 1-BP100. What is 1.5 mass parts or more with respect to a mass part is mentioned.
The distillation method is not particularly limited, and a known distillation method can be used.

The component (S) can be used in combination with an organic solvent other than 1-butoxy-2-propanol and 2-butoxy-1-propanol as long as the effects of the present invention are not impaired.
Examples of organic solvents other than 1-butoxy-2-propanol and 2-butoxy-1-propanol include alcohol-based organic solvents other than 1-butoxy-2-propanol and 2-butoxy-1-propanol (hereinafter referred to as “(S1 ) Component ”), ether-based organic solvents having no hydroxyl group (hereinafter referred to as“ (S2) component ”), and organic solvents other than these (hereinafter referred to as“ (S3) component ”).

[(S1) component]
The component (S1) is an alcoholic organic solvent excluding 1-butoxy-2-propanol and 2-butoxy-1-propanol.
In the present specification, the “alcohol-based organic solvent” refers to a compound in which at least one hydrogen atom of an aliphatic hydrocarbon is substituted with a hydroxyl group and is a liquid at normal temperature and normal pressure. The structure of the main chain constituting the aliphatic hydrocarbon may be a chain structure, may be a cyclic structure, may have a cyclic structure in the chain structure, The chain structure may contain an ether bond.
“Monohydric alcohol” means an alcohol molecule having one hydroxy group. “Boiling point” refers to the normal boiling point measured under normal pressure.

Specifically, as the component (S1), those having a chain structure are n-hexanol (boiling point 157.1 ° C.), 2-heptanol (boiling point 160.4 ° C.), 3-heptanol (boiling point 156.2 ° C.), 1 -Heptanol (boiling point 176 ° C), 5-methyl-1-hexanol (boiling point 167 ° C), 6-methyl-2-heptanol (boiling point 171 ° C), 1-octanol (boiling point 196 ° C) 2-octanol (boiling point 179 ° C) 3-octanol (boiling point 175 ° C.), 4-octanol (boiling point 175 ° C.), 2-ethyl-1-hexanol (boiling point 185 ° C.), 2- (2-butoxyethoxy) ethanol (boiling point 231 ° C.),
n-pentyl alcohol (boiling point 138.0 ° C.), s-pentyl alcohol (boiling point 119.3 ° C.), t-pentyl alcohol (101.8 ° C.), isopentyl alcohol (boiling point 130.8 ° C.), isobutanol (isobutyl) (Also called alcohol or 2-methyl-1-propanol) (boiling point 108 ° C.), isopropyl alcohol (boiling point 82.3 ° C.), 2-ethylbutanol (boiling point 147 ° C.), neopentyl alcohol (boiling point 114 ° C.), n- Butanol (boiling point 117.7 ° C), s-butanol (boiling point 99.5 ° C), t-butanol (boiling point 82.5 ° C), 1-propanol (boiling point 97.2 ° C), n-hexanol (boiling point 157.1) ° C), 2-methyl-1-butanol (boiling point 128.0 ° C), 2-methyl-2-butanol (boiling point 112.0 ° C), 4 Such as monohydric alcohols such as methyl-2-pentanol (boiling point 132 ° C.) and the like.
As the component (S1), specifically, those having a cyclic structure include cyclopentanemethanol (boiling point 162 ° C.), 1-cyclopentylethanol (boiling point 167 ° C.), cyclohexanol (boiling point 160 ° C.), cyclohexanemethanol (CM; Boiling point 183 ° C), cyclohexaneethanol (boiling point 205 ° C), 1,2,3,6-tetrahydrobenzyl alcohol (boiling point 191 ° C), exo-norbornol (boiling point 176 ° C), 2-methylcyclohexanol (boiling point 165 ° C) And monohydric alcohols such as cycloheptanol (boiling point 185 ° C.), 3,5-dimethylcyclohexanol (boiling point 185 ° C.), and benzyl alcohol (boiling point 204 ° C.).

Among these, as the component (S1), an alcoholic organic solvent having a boiling point of 150 ° C or higher is preferable, an alcoholic organic solvent having a boiling point of 155 ° C or higher is more preferable, and an alcoholic organic solvent having a temperature of 155 to 250 ° C is particularly preferable.
When the boiling point is 150 ° C. or higher, the solubility of the component (A) in the component (S) containing the component (S1) is improved. Further, when the lower limit value is 150 ° C. or more and the upper limit value is 250 ° C. or less, the resist composition has excellent coating properties (wetting properties) on the support. Moreover, since it is excellent in the solubility of (A) component, the choice of the high molecular compound used as (A) component spreads, and it contributes to the improvement of a litho characteristic. Such a point is also effective in double patterning applications.

Examples of the alcohol-based organic solvent having a boiling point of 150 ° C. or higher include monohydric alcohols and dihydric alcohols, monohydric alcohols are preferable, and primary or secondary monohydric alcohols are more preferable. Furthermore, as the alcoholic organic solvent having a boiling point of 150 ° C. or higher, one having a cyclic structure having 5 or more carbon atoms (more preferably 7 or more carbon atoms) or 5 or more carbon atoms (more preferably 7 carbon atoms) is used. The chain structure described above is preferred. The cyclic structure or chain structure may include an ether bond in the structure.
For a chain structure having 5 or more carbon atoms (more preferably 7 or more carbon atoms), the longest main chain containing —OH is more preferably 5 or more carbon atoms. The main chain may contain an ether bond in its structure.
A particularly preferred alcoholic organic solvent having a boiling point of 150 ° C. or higher is a monohydric alcohol having a chain structure having 5 or more (more preferably 7 or more) carbon atoms.

[(S2) component]
The component (S2) is an ether organic solvent having no hydroxyl group.
In this specification, the “ether-based organic solvent having no hydroxyl group” means that it has no hydroxyl group, has an ether bond (C—O—C) in its structure, and is liquid at room temperature and normal pressure. Refers to a compound.
Among the components (S2), those having neither a hydroxyl group nor a carbonyl group are more preferable.
(S2) As a component, the compound represented with the following general formula (s1'-1) is mentioned as a suitable thing.
R ⁷⁰ —O—R ⁷¹ (s1′-1)
[Wherein, R ⁷⁰ and R ⁷¹ are each independently a hydrocarbon group. Alternatively, R ⁷⁰ and R ⁷¹ may be bonded to form a ring. -O- represents an ether bond. ]

In the formula (s1′-1), examples of the hydrocarbon group for R ⁷⁰ and R ⁷¹ include an alkyl group and an aryl group, and an alkyl group is preferable. Among ^them, it is preferable that any of R ^{70, R 71} is an alkyl ^group, more preferably a a ^{pair of R 70} and ^{R 71} are the same alkyl group.
As each of the alkyl groups of R ^70, R ^71, not particularly limited, for example, straight, branched or cyclic alkyl group, and the like. In the alkyl group, part or all of the hydrogen atoms may or may not be substituted with a halogen atom or the like.
The alkyl group preferably has 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms, because the coating properties of the resist composition are good. Specific examples include an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, an isopentyl group, a cyclopentyl group, and a hexyl group, and an n-butyl group and an isopentyl group are particularly preferable. .
The halogen atom that may be substituted for the hydrogen atom of the alkyl group is preferably a fluorine atom.

Each aryl group for R ⁷⁰ and R ⁷¹ is not particularly limited, and is, for example, an aryl group having 6 to 12 carbon atoms, in which part or all of the hydrogen atoms are alkyl groups, alkoxy groups, It may or may not be substituted with a halogen atom or the like.
The aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specifically, a phenyl group, a benzyl group, a naphthyl group, etc. are mentioned, for example.
The alkyl group that may be substituted for the hydrogen atom of the aryl group is preferably an alkyl group having 1 to 5 carbon atoms, and is a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. Is more preferable.
As the alkoxy group which may substitute the hydrogen atom of the said aryl group, a C1-C5 alkoxy group is preferable and a methoxy group and an ethoxy group are more preferable.
The halogen atom that may be substituted for the hydrogen atom of the aryl group is preferably a fluorine atom.

In the formula (s1′-1), R ⁷⁰ and R ⁷¹ may be bonded to form a ring.
R ⁷⁰ and R ⁷¹ are each independently a linear or branched alkylene group (preferably an alkylene group having 1 to 10 carbon atoms), and the end of R ⁷⁰ is bonded to the end of R ⁷¹ To form a ring. In addition, the carbon atom of the alkylene group may be substituted with an oxygen atom.
Specific examples of the ether organic solvent include 1,8-cineol, tetrahydrofuran, dioxane and the like.

  The boiling point (under normal pressure) of the component (S2) is preferably 30 to 300 ° C, more preferably 100 to 200 ° C, and further preferably 140 to 180 ° C. By being equal to or higher than the lower limit of the temperature range, the component (S) is less likely to evaporate during spin coating at the time of applying the resist composition of the present invention, so that coating unevenness is suppressed and coatability is improved. On the other hand, by being below the upper limit, the (S) component is sufficiently removed from the resist film by pre-baking, and the resist film formability is improved. Moreover, when the temperature is within this range, the effect of reducing the film thickness of the resist pattern and the stability of the composition during storage are further improved. Moreover, it is preferable also from a viewpoint of the heating temperature of a PAB process or a PEB process.

Specific examples of the component (S2) include 1,8-cineol (boiling point 176 ° C.), dibutyl ether (boiling point 142 ° C.), diisopentyl ether (boiling point 171 ° C.), dioxane (boiling point 101 ° C.), anisole (boiling point). 155 ° C.), ethyl benzyl ether (boiling point 189 ° C.), diphenyl ether (boiling point 259 ° C.), dibenzyl ether (boiling point 297 ° C.), phenetol (boiling point 170 ° C.), butyl phenyl ether, tetrahydrofuran (boiling point 66 ° C.), ethyl propyl ether (Boiling point 63 ° C.), diisopropyl ether (boiling point 69 ° C.), dihexyl ether (boiling point 226 ° C.), dipropyl ether (boiling point 91 ° C.), cresyl methyl ether and the like.
Among these, as the component (S2), a cyclic or chain ether-based organic solvent is preferable because the film pattern reduction effect of the resist pattern is good, and among them, 1,8-cineol, dibutyl ether and diiso At least one selected from the group consisting of pentyl ether is preferred.

[(S3) component]
The component (S3) is an organic solvent other than 1-butoxy-2-propanol, 2-butoxy-1-propanol, the (S1) component, and the (S2) component.
As the component (S3), any component can be used as long as it can dissolve the resist material to be used to form a uniform solution. Conventionally, any one of known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
By further using the component (S3) in combination, the solubility and other characteristics of the component (A) and the component (B) can be adjusted.

  Examples of the component (S3) include lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; ethylene glycol, diethylene glycol, propylene glycol , Polyhydric alcohols such as dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate, the polyhydric alcohols or the ester bond Monoalkyl ether or monophenyl such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether of the compound Polyhydric alcohol derivatives [Among these, such a compound having an ether bond such as ether, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME) are preferable. ] Esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; ethylbenzene, diethylbenzene, pentylbenzene, isopropyl Aromatic organic solvents such as benzene, toluene, xylene, cymene and mesitylene, dimethyl sulfoxide (DMSO) and the like can be mentioned.

  In the resist composition of the present invention, the amount of the component (S) used is not particularly limited, but it is a concentration that can be applied to a substrate or the like and is appropriately set according to the coating film thickness. It is used so that the solid content concentration of the composition is preferably in the range of 0.5 to 20% by mass, more preferably 1 to 15% by mass.

  The dissolution of the resist material in the component (S) can be performed, for example, by simply mixing and stirring each of the above components by a conventional method, and if necessary, a disperser such as a dissolver, a homogenizer, or a three roll mill. May be dispersed and mixed. Moreover, after mixing, you may further filter using a mesh, a membrane filter, etc.

<Optional component>
[(D) component]
The resist composition of the present invention can contain a nitrogen-containing organic compound component (D) (hereinafter referred to as “component (D)”) as an optional component.
The component (D) is not particularly limited as long as it acts as an acid diffusion control agent, that is, a quencher that traps the acid generated from the component (B) by exposure, and a wide variety of components have already been proposed. Therefore, it may be used arbitrarily from known ones, and among them, aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are preferred.
An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
Examples of the aliphatic amine include an amine (alkyl amine or alkyl alcohol amine) or a cyclic amine in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms.
Specific examples of alkylamines and alkyl alcohol amines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di- -Dialkylamines such as n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine , Trialkylamines such as tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, Li isopropanolamine, di -n- octanol amines, alkyl alcohol amines tri -n- octanol amine. Among these, a trialkylamine having 5 to 10 carbon atoms is more preferable, and tri-n-octylamine is most preferable.
Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable. Specifically, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5. 4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane, and the like.

These may be used alone or in combination of two or more.
In the present invention, it is preferable to use a trialkylamine having 5 to 10 carbon atoms as the component (D).
(D) component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component. By setting the content in the above range, the resist pattern shape, the stability over time, and the like are improved.

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

  The resist composition of the present invention further contains miscible additives as desired, for example, an additional resin for improving the performance of the resist film, a surfactant, a dissolution inhibitor, and a plasticizer for improving coatability. Stabilizers, colorants, antihalation agents, dyes, and the like can be added as appropriate.

  The resist composition of the present invention described above is excellent in applicability to a support. Further, according to the resist composition of the present invention, the coating property to the support is excellent, the spread to the support surface is excellent, the variation in the film thickness within the support surface is small, and the film thickness uniformity of the resist film is also good. It is good. Furthermore, the wettability when applied on the support, the film formability when a resist film is formed on the support are good, the coating unevenness is small, and the occurrence of striation is suppressed.

The reason why such an effect is obtained is not clear, but is estimated as follows.
The resist composition of the present invention contains 1-butoxy-2-propanol and 2-butoxy-1-propanol as the organic solvent (S) (provided that 1-butoxy-2-propanol and 2-butoxy-1 are included). -Except for those prepared by mixing with propanol), and the ratio of 2-butoxy-1-propanol is 1.5 parts by mass or more with respect to 100 parts by mass of 1-butoxy-2-propanol. Some are used.
In contrast, in a resist composition using an organic solvent in which the ratio of 2-butoxy-1-propanol is less than 1.5 parts by mass with respect to 100 parts by mass of 1-butoxy-2-propanol, The applicability to the support is poor and the same effect as the resist composition of the present invention cannot be obtained. This is because the resist composition of the present invention using an organic solvent having a 2-BP ratio of 1.5 parts by mass or more and a resist using an organic solvent having a 2-BP ratio of less than 1.5 parts by mass. When the surface tension in the composition was measured, a difference was found in the value of the surface tension between the two (examples described later), and thus the difference in surface tension is considered as one of the factors.

On the other hand, those prepared by mixing 1-butoxy-2-propanol and 2-butoxy-1-propanol, such as those having a high proportion of 2-butoxy-1-propanol, and 2-butoxy-1-propanol In a resist composition using an organic solvent prepared by mixing an organic solvent containing almost no benzene, the ratio of 2-butoxy-1-propanol in the organic solvent prepared by mixing is 1-butoxy- Even if it is 1.5 mass parts or more with respect to 100 mass parts of 2-propanol, the applicability | paintability to a support body is bad and the effect similar to the resist composition of this invention is not acquired.
This is due to the fact that even if a mixture with a high proportion of 2-butoxy-1-propanol and a mixture containing almost no 2-butoxy-1-propanol are mixed, they do not mix sufficiently uniformly. Presumed to be something.
Therefore, the resist composition of the present invention is clearly different from a resist composition using an organic solvent prepared by mixing 1-butoxy-2-propanol and 2-butoxy-1-propanol.

  In addition, in the resist composition using the organic solvent prepared by mixing, even if a stabilizer (for example, dibutylhydroxytoluene) or a surfactant that suppresses the degradation of the organic solvent with time is added, The applicability remains poor, and the same effect as the resist composition of the present invention cannot be obtained.

Moreover, the resist composition of this invention can form the resist pattern by double patterning, without melt | dissolving the 1st resist pattern formed using the 1st resist composition in the double patterning process.
That is, the resist composition of the present invention is
A step of applying a first resist composition on a support to form a first resist film, and selectively exposing the first resist film and developing the first resist pattern to form a first resist pattern A step of applying a second resist composition on the support on which the first resist pattern has been formed to form a second resist film, and selectively selecting the second resist film. In the resist pattern forming method including the steps of exposing to light and developing with alkali to form a resist pattern, the resist composition is preferably used as the second resist composition.
The description of each step in the resist pattern forming method is the same as the description of each step in the resist pattern forming method of the present invention described later.
As described above, the resist composition of the present invention is also suitable as a resist composition for a double patterning process, and can be finely patterned with high accuracy and useful.

≪Resist pattern formation method≫
In the resist pattern forming method of the present invention, a resist composition (hereinafter sometimes referred to as “first resist composition”) is applied on a support to form a first resist film (hereinafter referred to as “film”). Forming step (1) "), a step of selectively exposing the first resist film and developing with alkali to form a first resist pattern (hereinafter referred to as" patterning step (1) "). The step of applying the resist composition of the present invention on the support on which the first resist pattern is formed to form a second resist film (hereinafter referred to as “film forming step (2)”). And a step of selectively exposing the second resist film and forming a resist pattern by alkali development (hereinafter referred to as “patterning step (2)”).
Hereinafter, each step will be described in more detail.

[Film Formation Step (1)]
The support is not particularly limited, and a conventionally known one can be used, and examples thereof include a substrate for electronic components and a substrate on which a predetermined wiring pattern is formed. More specifically, a silicon substrate, a metal substrate such as copper, chromium, iron, and aluminum, a glass substrate, and the like can be given. As a material for the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used.
Further, the support may be a substrate in which an inorganic and / or organic film is provided on the above-described substrate. An inorganic antireflection film (inorganic BARC) is an example of the inorganic film. Examples of the organic film include an organic antireflection film (organic BARC) and a lower layer film in a multilayer resist method. In particular, it is preferable to provide an organic film because a pattern with a high aspect ratio can be formed on the substrate, which is useful in manufacturing semiconductors.
Here, the multilayer resist method is a method in which at least one organic film (lower film) and at least one resist film are provided on a substrate, and the lower layer is patterned using the resist pattern formed on the upper resist film as a mask. It is said that a high aspect ratio pattern can be formed. In the multilayer resist method, basically, a method having a two-layer structure of an upper layer resist film and a lower layer film, and one or more intermediate layers (metal thin film, etc.) are provided between these resist film and lower layer film. It is divided into a method of providing a multilayer structure of three or more layers provided. According to the multilayer resist method, by securing a required thickness with the lower layer film, the resist film can be thinned and a fine pattern with a high aspect ratio can be formed.
The inorganic film can be formed, for example, by applying an inorganic antireflective film composition such as a silicon-based material on a substrate and baking it.
The organic film is formed by, for example, applying an organic film forming material in which a resin component or the like constituting the film is dissolved in an organic solvent to a substrate with a spinner or the like, preferably 200 to 300 ° C., preferably 30 to 300 seconds, More preferably, it can be formed by baking under heating conditions of 60 to 180 seconds.

A method for forming a first resist film by applying a first resist composition (described later) on a support is not particularly limited, and a conventionally known method can be used.
Specifically, for example, a chemically amplified resist composition is applied as a first resist composition by using a conventionally known method such as using a spinner on a support, and a temperature condition of 80 to 150 ° C. The first resist film can be formed by performing a baking treatment (pre-baking) for 40 to 120 seconds, preferably 60 to 90 seconds, and volatilizing the organic solvent.
The thickness of the first resist film is preferably 50 to 500 nm, more preferably 50 to 450 nm. By setting it within this range, there are effects that a resist pattern can be formed with high resolution and sufficient resistance to etching can be obtained.

[Patterning process (1)]
Next, the first resist film is selectively exposed and alkali-developed to form a first resist pattern.
Specifically, for example, the first resist film formed as described above is selectively exposed through a photomask, preferably subjected to post-exposure heating (PEB) treatment, alkali development, and first development. A resist pattern is formed.

The wavelength used for the exposure is not particularly limited, and includes KrF excimer laser, ArF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. Can be done using radiation.
As the photomask, for example, a binary mask (Binary-Mask) in which the transmittance of the light shielding portion is 0% or a halftone phase shift mask (HT-Mask) in which the transmittance of the light shielding portion is 6% can be used.
The binary mask is generally formed by forming a chromium film, a chromium oxide film or the like as a light shielding portion on a quartz glass substrate.
As the halftone phase shift mask, generally, a quartz glass substrate on which a MoSi (molybdenum silicide) film, a chromium film, a chromium oxide film, a silicon oxynitride film, or the like is formed as a light shielding portion is used. .
Note that selective exposure may be performed by exposure without using a photomask, for example, drawing by EB or the like.

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

The PEB treatment is performed at a baking temperature that changes (increases or decreases) the solubility of the first resist film in the alkaline developer.
That is, the first resist film, for example, a resist film made of a chemically amplified resist composition is subjected to PEB treatment after exposure, whereby the acid generated from the acid generator component is diffused in the resist film, The change (increase / decrease) in the solubility of the resist film in the alkali developer by the action of the acid proceeds.
Specifically, for example, after the first resist film is selectively exposed through a photomask on which a predetermined pattern is formed, PEB (post-exposure heating) is performed at 40 to 120 under a temperature condition of 80 to 150 ° C. For 2 seconds, preferably 60-90 seconds.

After the PEB treatment, alkali development is performed to form a first resist pattern.
The alkali development can be carried out by a known method using an aqueous alkali solution, for example, an aqueous tetramethylammonium hydroxide (TMAH) solution having a concentration of 0.1 to 10% by mass. By such alkali development, the exposed portion (positive type) or the unexposed portion (negative type) of the first resist film is removed, and a first resist pattern is formed.
After the alkali development, a rinse treatment with water or the like may be performed.
Further, after the alkali development, a baking process (post-bake) may be further performed. Post baking is usually performed under conditions of about 100 ° C. (because it is performed for the purpose of removing water after alkali development and rinsing), and the processing time is preferably 30 to 90 seconds.

[Film Formation Step (2)]
Next, the resist composition of the present invention is applied on the support on which the first resist pattern is formed to form a second resist film. For example, when the first resist pattern is a line-and-space resist pattern (hereinafter referred to as “LS pattern”), the second resist film is filled so as to fill a space portion between the plurality of resist patterns in the LS pattern. Like the first resist film, can be formed by a conventionally known method.
The film thickness of the second resist film is preferably at least the same as or higher than the height of the first resist pattern. That is, when the support is viewed from the second resist film side, the surface is preferably flat.

[Patterning process (2)]
Next, the second resist film is selectively exposed and alkali developed to form a resist pattern.
Specifically, for example, the second resist film is selectively exposed through a photomask at a position different from the position where the plurality of resist patterns are formed, subjected to PEB treatment, and subjected to alkali development to form a resist. Form a pattern.
As a result, when the resist composition of the present invention is positive, the exposed portion of the second resist film is removed, and when the resist composition of the present invention is negative, the unexposed portion is removed, and the LS pattern is removed. In the method, a plurality of new resist patterns are respectively formed between the plurality of resist patterns. As a result, a resist pattern including a plurality of resist patterns and a plurality of resist patterns newly formed on the second resist film is formed on the support.
Here, in the present invention, except for the case where it completely coincides with the first resist pattern, all are “positions different from the position where the first resist pattern is formed”, and there are no overlaps and some Including duplicate cases.
In the present invention, for example, when finally forming a line-and-space resist pattern, the position where the first resist pattern is formed and the position where selective exposure is performed in the patterning step (2) do not overlap at all. Is preferred. Thereby, a narrow pitch pattern in which the pattern interval (pitch) is narrower than the first resist pattern formed in the patterning step (1) can be formed.

The selective exposure of the second resist film can be performed, for example, by slightly shifting the exposure position of the photomask used in the patterning step (1). At this time, a photomask different from the photomask used in the patterning step (1) may be used.
The position of the resist pattern formed from the second resist film may not overlap at all with the position of the first resist pattern, and may partially overlap with the position of the first resist pattern. It is preferable that the position of the resist pattern formed from the second resist film and the position of the first resist pattern do not overlap at all. Thus, a narrow pitch resist pattern having a pattern interval (pitch) narrower than that of the first resist pattern formed in the patterning step (1) is obtained.

For example, in the case of forming a line-and-space resist pattern, for example, in the patterning step (1), a line-and-space resist pattern using a line-and-space photomask in which a plurality of lines are arranged at a constant pitch is used. In the patterning step (2), the position of the photomask is changed and a line pattern is formed at an intermediate position between the line pattern and the line pattern formed in the patterning step (1). A line and space resist pattern (dense pattern) having a narrower pitch than the formed line and space resist pattern (sparse pattern) is formed.
The “sparse pattern” is preferably a line and space pattern having a line width: space width = 1: 2 or larger in the line and space resist pattern.

After exposure, PEB processing is performed.
The PEB process can be performed by the same method as the PEB process in the patterning step (1).
After the PEB treatment, alkali development of the second resist film is performed. The alkali development can be carried out by a known method using an aqueous alkali solution, for example, an aqueous tetramethylammonium hydroxide (TMAH) solution having a concentration of 0.1 to 10% by mass. By such alkali development, when the resist composition of the present invention is positive, the exposed portion of the second resist film is removed, and when the resist composition of the present invention is negative, the unexposed portion is removed, respectively. Is formed.
After the alkali development, a rinse treatment with water or the like may be performed.
Further, after the alkali development, a baking process (post-bake) may be further performed. Post baking is usually performed under conditions of about 100 ° C. (because it is performed for the purpose of removing water after alkali development and rinsing), and the processing time is preferably 30 to 90 seconds.

In the resist pattern forming method of the present invention, since the dense line and space pattern with a narrow pitch can be easily formed, the first resist pattern is preferably a line and space resist pattern.
Specifically, for example, after forming a line and space pattern (sparse pattern) having a line width of 100 nm and a line width: space width = 1: 3, the photomask is translated by 200 nm in a direction perpendicular to the line direction. Then, a line and space pattern having a line width of 100 nm and a line width: space width = 1: 3 is formed. As a result, a line and space pattern (dense pattern) having a line width of 100 nm and a line width: space width = 1: 1 can be formed.
Further, the photomask used in the patterning step (1) is rotated or moved, or a photomask different from the photomask used in the patterning step (1) (for example, a line-and-space photomask or patterning in the patterning step (1)). By using a hole photomask or the like in step (2), a fine resist pattern and / or resist patterns having various shapes can be formed. Furthermore, exposure and development are performed in a positional relationship orthogonal to the first line and space resist pattern obtained in the patterning step (1), that is, by performing cross-line patterning, a hole shape or a lattice shape is obtained. A resist pattern can also be formed.

  In the resist pattern forming method of the present invention, after the patterning step (2), the same operations as the above-described film forming step (2) and patterning step (2) may be repeated a plurality of times. That is, the resist composition of the present invention is applied to the support on which the resist pattern is formed in the patterning step (2) to form a resist film, the resist film is selectively exposed, and alkali-developed. The operation for forming the resist pattern may be performed a plurality of times. Thereby, a denser pattern with a narrower pitch or a pattern with a complicated shape can be formed.

In the resist pattern forming method of the present invention, after the patterning step (2), the support may be etched using the formed resist pattern as a mask. Thus, a semiconductor device etc. can be manufactured by etching a support body.
A known method can be used as the etching method. For example, the etching of the organic film (resist pattern, organic antireflection film, etc.) is preferably dry etching. In particular, oxygen plasma etching or etching using CF ₄ gas or CHF ₃ gas is preferable, and oxygen plasma etching is particularly preferable.
Etching of the substrate and the inorganic antireflection film is preferably performed using a halogen gas, more preferably using a fluorocarbon gas, and particularly preferably using a CF ₄ gas or a CHF ₃ gas.

(First resist composition)
In the above-described film forming step (1), the first resist composition for forming the first resist film is not particularly limited, and is preferably a chemically amplified resist composition.
The chemically amplified resist composition may be a chemically amplified positive resist composition, a chemically amplified negative resist composition, or a chemically amplified positive resist composition. It is preferable.

-Chemically amplified positive resist composition The chemically amplified positive resist composition is not particularly limited, and from among positive resist compositions that have been proposed in a number of conventional ArF resists, It can be appropriately selected and used according to the exposure light source to be used, lithography characteristics and the like.
Such a chemically amplified positive resist composition includes a base material component ((A0) component) whose solubility in an alkaline developer is increased by the action of an acid, and an acid generator component ((B) that generates an acid upon exposure. ) Component) is generally dissolved in an organic solvent.

The component (A0) may be a resin component ((A1) component) whose solubility in an alkaline developer is increased by the action of an acid, and a low molecular compound whose solubility in an alkali developer is increased by the action of an acid. It may be a component (component (A2)) or a mixture thereof.
Especially, it is preferable that (A1) component is included as this (A0) component.

The component (A1) in such a chemically amplified positive resist composition preferably has a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.
In addition to the structural unit (a1), the component (A1) preferably further has a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group.
The component (A1) is derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group in addition to the structural unit (a1) or in addition to the structural units (a1) and (a2). The structural unit (a3) or the structural unit (a6) represented by the general formula (a6-1) is preferably included.
In addition to the structural unit (a1), the component (A1) includes structural units other than the structural units (a2), (a3), and (a6), for example, non-acid dissociable aliphatic polycyclic groups. You may have the structural unit (a4) induced | guided | derived from an acrylate ester.
The structural units (a1) to (a4) and (a6) are the same as the structural units (a1) to (a4) and (a6) in the component (A1) of the resist composition of the present invention described above.

In the component (A1), the proportion of the structural unit (a1) is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, with respect to the total of all structural units constituting the component (A1). More preferred is mol%. By setting it to the lower limit value or more, a pattern can be easily obtained when the resist composition is used, and by setting it to the upper limit value or less, it is possible to balance with other structural units.
The proportion of the structural unit (a2) in the component (A1) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, with respect to the total of all structural units constituting the component (A1). 50 mol% is more preferable. By making it the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by making it the upper limit value or less, it is possible to balance with other structural units.
In the component (A1), the proportion of the structural unit (a3) or (a6) is preferably 5 to 50 mol%, and preferably 5 to 40 mol based on the total of all the structural units constituting the component (A1). % Is more preferable, and 5 to 25 mol% is more preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (a3) or (a6) is sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units.
When the structural unit (a4) is contained in the component (A1), the structural unit (a4) is preferably contained in an amount of 1 to 30 mol% based on the total of all the structural units constituting the component (A1). 10 to 20 mol% is more preferable.

In such a chemically amplified positive resist composition, the component (A1) is preferably a copolymer having the structural unit (a1). Examples of the copolymer include the structural unit (a1) and the structural unit (a2). ), A copolymer comprising the structural unit (a1) and the structural unit (a3), a copolymer comprising the structural unit (a1) and the structural unit (a6); a structural unit (a1), a structural unit ( copolymer comprising a2) and structural unit (a3); copolymer comprising structural unit (a1), structural unit (a2), structural unit (a3) and structural unit (a4); structural unit (a1), structural unit Examples include a copolymer composed of the unit (a2) and the structural unit (a6); a copolymer composed of the structural unit (a1), the structural unit (a2), the structural unit (a6), and the structural unit (a4).
In the component (A0), the component (A1) may be used alone or in combination of two or more.
In such a chemically amplified positive resist composition, the component (A1) preferably includes a combination of structural units such as the following general formula (A1-21).

［式（Ａ１−２１）中、Ｒは上記と同じであり、複数のＲは相互に同じであっても異なっていてもよい。Ｒ^２０は上記式（ａ１−１−０１）におけるＲ^１１と同様である。］

[In formula (A1-21), R is the same as defined above, and the plurality of R may be the same as or different from each other. R ²⁰ is the same as R ¹¹ in formula (a1-1-01). ]

The component (A1) can be obtained by polymerizing a monomer for deriving each structural unit by a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN).
Further, for the component (A1), in the polymerization, a chain transfer agent such as HS—CH ₂ —CH ₂ —CH ₂ —C (CF ₃ ) ₂ —OH is used in combination, so that the terminal A —C (CF ₃ ) ₂ —OH group may be introduced into the. Thus, a copolymer into which a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group are substituted with fluorine atoms is effective in reducing LWR. Further, it is effective for reducing development defects and LER (line edge roughness: uneven unevenness of line side walls).

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but is preferably 1000 to 50000, more preferably 1500 to 30000, and most preferably 2000 to 20000. preferable. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
Further, the dispersity (Mw / number average molecular weight (Mn)) is not particularly limited, and is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and 1.2 to 2. 5 is most preferred.

Examples of the component (A2) and the component (B) in the chemically amplified positive resist composition include the same components as the components (A2) and (B) in the resist composition of the present invention. The organic solvent is preferably the same as the component (S3) in the resist composition of the present invention.
In addition, the chemical amplification type positive resist composition preferably further contains a nitrogen-containing organic compound component (D) as an optional component, and includes a group consisting of organic carboxylic acid, phosphorus oxo acid and derivatives thereof. At least one compound (E) selected from can also be contained. Examples of the component (D) and the component (E) are the same as the component (D) and the component (E) in the resist composition of the present invention.
In addition, the chemical amplification type positive resist composition further includes a miscible additive as desired, for example, an additional resin for improving the performance of the resist film, a surfactant for improving the coating property, A dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent, a dye, and the like can be appropriately added and contained.

Chemically Amplified Negative Resist Composition The chemically amplified negative resist composition includes a resin (alkali-soluble resin) component (A ′) (hereinafter referred to as “(A ′) component”) that is soluble in an alkali developer. ), An acid generator component (B ′) that generates an acid upon exposure (hereinafter referred to as “(B ′) component”) and a crosslinking agent component (C ′) (hereinafter referred to as “(C ′) component”). Is generally dissolved in an organic solvent (S ′) (hereinafter referred to as “component (S ′)”).
In such a negative resist composition, when an acid is generated from the component (B ′) by exposure, cross-linking occurs between the component (A ′) and the component (C ′) by the action of the acid, so that an alkaline developer is formed. On the other hand, it changes from soluble to insoluble in an alkaline developer. Therefore, in the formation of a resist pattern, when the resist film obtained by applying the negative resist composition on a support such as a substrate is selectively exposed, the exposed portion becomes insoluble in an alkaline developer. On the other hand, since the unexposed portion remains soluble in the alkali developer and does not change, alkali development can be performed.
There is no restriction | limiting in particular as this negative resist composition, According to an exposure light source, a lithography characteristic, etc., it can select and use suitably from well-known negative resist compositions.

<(A ') component>
As the component (A ′), an exposure light source used at the time of resist pattern formation is proposed as an alkali-soluble resin such as a conventional chemically amplified negative resist composition for KrF and an ArF negative resist composition. Depending on the type, it can be appropriately selected. Specific examples include novolak resins having a hydrophilic group (hydroxyl group, carboxy group, etc.), PHS resins, and acrylic resins. Any of these may be used alone or in combination of two or more.
As the component (A ′) in the negative resist composition that may be used in the present invention, a fluorinated hydroxyalkyl group (for example, a group represented by the general formula (a1′-1-1) described later) is used. An alkali-soluble resin is preferable.
As a preferable example of the component (A ′), specifically, for example, a resin (A1 ′) having a structural unit (a1 ′) having an aliphatic cyclic group having a fluorinated hydroxyalkyl group in the main chain. Can be mentioned.
Moreover, as a suitable thing of (A ') components other than resin (A1'), the structural unit containing the aliphatic cyclic group which has a fluorinated hydroxyalkyl group, for example, Preferably, it contains a hydroxyl group further Resin (A2) having a structural unit derived from an acrylate ester containing an aliphatic cyclic group and / or a structural unit not having a cyclic structure and derived from acrylic acid having an alcoholic hydroxyl group in the side chain ').

[Resin (A1 ′)]
The resin (A1 ′) includes a structural unit (a1 ′) having an aliphatic cyclic group having a fluorinated hydroxyalkyl group in the main chain.
In addition to the structural unit (a1 ′), the resin (A1 ′) preferably further includes a structural unit (a2 ′) having a hydroxyalkyl group.

・ Structural unit (a1 ′)
In the structural unit (a1 ′), “aliphatic cyclic group having a fluorinated hydroxyalkyl group” means that a fluorinated hydroxyalkyl group is bonded to a carbon atom constituting a ring of the aliphatic cyclic group. Means the group.
Further, “having an aliphatic cyclic group in the main chain” means that at least one, preferably two or more carbon atoms on the ring of the aliphatic cyclic group have a main chain of the resin (A1 ′). It means to compose.
In the present invention, when the component (A ′) contains the resin (A1 ′) having the structural unit (a1 ′), the solubility in an alkali developer is increased, and the resist pattern shape and line width roughness (LWR) are increased. Lithographic properties such as are improved. Further, by having an aliphatic cyclic group (for example, a structure of norbornane or tetracyclododecane) in the main chain, the carbon density is increased and the etching resistance is also improved.

Here, the “fluorinated hydroxyalkyl group” is a hydroxyalkyl group in which part of the hydrogen atoms of the alkyl group is substituted with a hydroxy group, and part or all of the remaining hydrogen atoms in the hydroxyalkyl group are It is substituted by a fluorine atom.
In the fluorinated hydroxyalkyl group, the hydrogen atom of the hydroxy group is easily released by fluorination.
In the fluorinated hydroxyalkyl group, the alkyl group is preferably a linear or branched alkyl group. Although carbon number of this alkyl group is not specifically limited, 1-20 are preferable, 4-16 are more preferable, and it is most preferable that it is 4-12.
The number of hydroxy groups in the fluorinated hydroxyalkyl group is not particularly limited, but is preferably one.

The fluorinated hydroxyalkyl group is a group in which a fluorinated alkyl group and / or a fluorine atom is bonded to the carbon atom to which the hydroxy group is bonded (here, the α-position carbon atom of the hydroxyalkyl group). Is preferred.
Here, in the fluorinated alkyl group bonded to the α-position, it is preferable that all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms. Further, the alkyl group of the fluorinated alkyl group is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and more preferably 1 carbon atom.

The aliphatic cyclic group in the “aliphatic cyclic group having a fluorinated hydroxyalkyl group” may be a monocyclic group or a polycyclic group. In the structural unit (a1 ′), the aliphatic cyclic group is preferably polycyclic because it is excellent in etching resistance and the like.
An aliphatic cyclic group is a hydrocarbon group consisting of carbon and hydrogen (alicyclic group), and heterocycles in which some of the carbon atoms constituting the ring of the alicyclic group are oxygen atoms, nitrogen atoms, sulfur atoms, etc. Heterocyclic groups and the like substituted with atoms are included. These aliphatic cyclic groups may have a substituent, and examples of the substituent include an alkyl group having 1 to 5 carbon atoms.
Here, “having a substituent” means that part or all of the hydrogen atoms bonded to the carbon atoms constituting the ring of the aliphatic cyclic group are substituted with a substituent (atom or group other than a hydrogen atom). Means that In the present invention, the alicyclic group is preferable as the aliphatic cyclic group.
The aliphatic cyclic group may be either saturated or unsaturated, but is preferably saturated because it is highly transparent to ArF excimer laser and the like, and has excellent resolution and depth of focus (DOF). .
It is preferable that carbon number of an aliphatic cyclic group is 5-15.
Specific examples of the aliphatic cyclic group include the following.
Examples of the monocyclic group include groups in which two or more hydrogen atoms have been removed from a cycloalkane. More specifically, a group in which two or more hydrogen atoms have been removed from cyclopentane or cyclohexane can be mentioned, and a group in which two or more hydrogen atoms have been removed from cyclohexane is preferred.
Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane, or the like. More specifically, a group in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane can be used.
Such an aliphatic cyclic group can be appropriately selected and used from among many proposed resins for photoresist compositions for ArF excimer laser processes, for example.
Among these, a group obtained by removing two or more hydrogen atoms from cyclohexane, adamantane, norbornane, or tetracyclododecane is preferable because it is easily available from an industrial viewpoint.
Among these exemplified alicyclic groups, a group obtained by removing three hydrogen atoms from norbornane or tetracyclododecane is preferable, as in the structural unit (a1′-1) described later, and in particular, three hydrogen atoms from norbornane. Groups other than are preferred.

  Preferred examples of the structural unit (a1 ′) include structural units (a1′-1) represented by general formula (a1′-1) shown below. By including the structural unit (a1′-1), solubility in an alkali developer is particularly improved. Also, lithography properties such as resolution are improved.

［式中、Ｚ’はフッ素化されたヒドロキシアルキル基であり、ｒは０または１である。］

[In the formula, Z ′ represents a fluorinated hydroxyalkyl group, and r is 0 or 1. ]

In the formula (a1′-1), r is 0 or 1, and is preferably 0 because it is easily available industrially.
In the formula (a1′-1), examples of the “fluorinated hydroxyalkyl group” represented by Z ′ are the same as those described above.
Among these, Z ′ is preferably a group represented by the following general formula (a1′-1-1) because the resist pattern shape is excellent and line edge roughness (LER) is reduced. “Line edge roughness (LER)” refers to uneven unevenness on the side wall of a line.

［式中、Ｒ^１１”，Ｒ^１２”はそれぞれ独立して水素原子または炭素数１〜５のアルキル基であり、ｍ”，ｎ”はそれぞれ独立して１〜５の整数であり、ｑは１〜５の整数である。］

[Wherein R ¹¹ ″ and R ¹² ″ are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, m ″ and n ″ are each independently an integer of 1 to 5, and q is It is an integer of 1-5. ]

In formula (a1′-1-1), R ¹¹ ″ and R ¹² ″ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.
The alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, Examples include a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like, and a methyl group is preferable.
Among these, it is preferable that R ¹¹ ″ and R ¹² ″ are both hydrogen atoms.
q is an integer of 1 to 5, more preferably an integer of 1 to 3, and most preferably 1.
m ″ and n ″ are each independently an integer of 1 to 5, more preferably an integer of 1 to 3. In particular, m ″ and n ″ are preferably 1 because of excellent synthesis.

As the structural unit (a1 ′), one type or a mixture of two or more types can be used.
In the resin (A1 ′), the proportion of the structural unit (a1 ′) is preferably 50 to 90 mol% and more preferably 55 to 90 mol% with respect to the total of all the structural units constituting the resin (A1 ′). 60 to 80 mol% is more preferable. The effect by containing a structural unit (a1 ') improves by being more than the lower limit of the said range, and a balance with another structural unit becomes favorable by being below an upper limit.

・ Structural unit (a2 ′)
The resin (A1 ′) preferably further contains a structural unit (a2 ′) having a hydroxyalkyl group in addition to the structural unit (a1 ′).
In the present invention, when the component (A ′) contains the resin (A1 ′) having such a structural unit (a2 ′), the solubility in an alkali developer is improved. In addition, the crosslinkability with the component (C ′) is increased, the difference in solubility (contrast) in the alkaline developer between the exposed part and the unexposed part is increased, and the negative resist composition functions more fully. Can do.
Examples of the structural unit (a2 ′) include a structural unit (a210 ′) having an aliphatic cyclic group having a hydroxyalkyl group in the main chain, and a structural unit derived from an acrylate ester having a hydroxyl group-containing alkyl group ( a220 ′) and the like are preferably used.
These structural units (a2 ′) can be used alone or in combination of two or more.

..Structural unit (a210 ')
In the present invention, the structural unit (a210 ′) is a structural unit having an aliphatic cyclic group having a hydroxyalkyl group in the main chain.
As the structural unit (a210 ′), in the “fluorinated hydroxyalkyl group” of the structural unit (a1 ′), a non-fluorinated hydroxyalkyl group, that is, a part of hydrogen atoms of the alkyl group is a hydroxy group. The structural unit similar to the structural unit (a1 ′) is preferable except that the remaining hydrogen atom in the substituted hydroxyalkyl group is not substituted with a fluorine atom.
Preferred examples of the structural unit (a210 ′) include structural units (a2′-1) represented by general formula (a2′-1) shown below. By including the structural unit (a2′-1), lithography characteristics such as a resist pattern shape and line width roughness (LWR) are improved. In addition, good contrast is easily obtained and etching resistance is improved.

［式中、Ｒ^１３”，Ｒ^１４”はそれぞれ独立して水素原子又は炭素数１〜５のアルキル基であり、Ｙ’は水素原子またはヒドロキシアルキル基であり、ｒは０または１であり、ｇ”は１〜３の整数である。］

[Wherein R ¹³ ″ and R ¹⁴ ″ each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, Y ′ represents a hydrogen atom or a hydroxyalkyl group, and r is 0 or 1. g ″ is an integer of 1 to 3.]

The structural unit (a2′-1) represented by the general formula (a2′-1) is a structural unit having a norbornane or tetracyclododecane structure having a hydroxyalkyl group in the main chain.
In formula (a2′-1), R ¹³ ″ and R ¹⁴ ″ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. Examples of this alkyl group include the same alkyl groups represented by R ¹¹ ″ and R ¹² ″ in the formula (a1′-1-1). Among these, it is preferable that R ¹³ ″ and R ¹⁴ ″ are both hydrogen atoms.
Y ′ is a hydrogen atom or a hydroxyalkyl group.
The hydroxyalkyl group is preferably a linear or branched hydroxyalkyl group having 10 or less carbon atoms, more preferably a linear or branched hydroxyalkyl group having 8 or less carbon atoms, and further preferably Is a linear lower hydroxyalkyl group having 1 to 3 carbon atoms.
The number of hydroxyl groups and the bonding position in the hydroxyalkyl group are not particularly limited, but are usually one and preferably bonded to the terminal of the alkyl group.
Y ′ is particularly preferably a hydrogen atom.
r is 0 or 1, and 0 is preferable.
g ″ is an integer of 1 to 3, preferably 1 or 2, and most preferably 1.

  Specific examples of the structural unit (a2′-1) include structural units represented by the following chemical formulas (a2′-1-1) to (a2′-1-7).

Among these, the above chemical formulas (a2′-1-1), (a2′-1-2), and (a2′-1-3) are preferable.
As the structural unit (a210 ′), one type or a mixture of two or more types can be used.
In the resin (A1 ′), the proportion of the structural unit (a210 ′) is preferably 10 to 50 mol% and more preferably 15 to 50 mol% with respect to the total of all the structural units constituting the resin (A1 ′). 20 to 45 mol% is more preferable. By being more than the lower limit of the above range, the effect of containing the structural unit (a210 ′) such that alkali solubility is improved and good contrast is easily obtained is improved. On the other hand, the balance with other structural units becomes favorable by being below an upper limit.

..Structural unit (a220 ')
The structural unit (a220 ′) is a structural unit derived from an acrylate ester having a hydroxyl group-containing alkyl group.
Hydroxyl group-containing alkyl groups can be broadly classified into hydroxyl group-containing cyclic alkyl groups and hydroxyl group-containing chain alkyl groups.

In the case where the structural unit (a220 ′) is a structural unit having a hydroxyl group-containing cyclic alkyl group (hereinafter abbreviated as the structural unit (a221 ′)), the swelling suppression effect of the resist pattern is enhanced.
Also, the resolution is improved. Furthermore, good contrast and etching resistance are easily obtained.
The structural unit (a221 ′) is exemplified in the description of “structural unit (a22 ′) derived from an acrylate ester containing a hydroxyl group-containing aliphatic cyclic group” constituting the resin (A2 ′) described later, for example. Among the structural units, an aliphatic cyclic group is a saturated hydrocarbon group. Among them, the substituent bonded to the α-position of the acrylate ester is more preferably a fluorine atom or a fluorinated alkyl group, particularly preferably a fluorinated alkyl group, and a trifluoromethyl group (—CF ₃ ) is most preferred.

In the case where the structural unit (a220 ′) is a structural unit having a hydroxyl group-containing chain alkyl group (hereinafter abbreviated as “structural unit (a222 ′)”), the hydrophilicity of the entire component (A ′) is increased and an alkali developer. Solubility increases with respect to and improves resolution. Further, the controllability of the crosslinking reaction during the formation of the resist pattern becomes good, and the pattern shape and resolution are improved. Further, the film density tends to be improved, whereby the film loss during etching can be suppressed and the heat resistance tends to be improved.
As the structural unit (a222 ′), for example, “structural unit (a23 derived from acrylic acid having no cyclic structure and having an alcoholic hydroxyl group in the side chain) constituting the resin (A2 ′) described later. Among the structural units exemplified in the description of “)”, those having a hydroxyalkyl group are exemplified. Among them, those having a hydroxyalkyl group in the ester portion of the acrylate ester are preferable, and among them, the substituent bonded to the α-position of the acrylate ester is more preferably a fluorine atom or a fluorinated alkyl group, Those that are fluorinated alkyl groups are particularly preferred, and those that are trifluoromethyl groups (—CF ₃ ) are most preferred.

As the structural unit (a220 ′), one type or a mixture of two or more types can be used.
10-80 mol% is preferable with respect to the sum total of all the structural units which comprise resin (A1 ') in resin (A1'), and the ratio of structural unit (a220 ') is more preferable 15-60 mol%. 20 to 55 mol% is more preferable. The effect by containing a structural unit (a220 ') is acquired by being more than the lower limit of the said range, and a balance with another structural unit becomes favorable by being below an upper limit.

When the structural unit (a220 ′) includes both the structural unit (a221 ′) and the structural unit (a222 ′), the mixing ratio of both is a molar ratio, and the structural unit (a221 ′): structural unit (a222) ') = 9: 1 to 1: 9 is preferable, 8: 2 to 2: 8 is more preferable, and 6: 4 to 7: 3 is more preferable.
A good exposure margin can be obtained by blending the structural unit (a221 ′) and the structural unit (a222 ′) in a balanced manner at the mixing ratio. Moreover, a moderate contrast is obtained and the resolution is improved. Furthermore, etching resistance is also improved.

Other structural units In the negative resist composition used in the present invention, the resin (A1 ′) is a conventional chemically amplified resist composition as a structural unit other than the structural units (a1 ′) and (a2 ′). A structural unit used in a known component (A ′) for physical use can be appropriately used.
In the present invention, the resin (A1 ′) is preferably a resin mainly composed of the structural unit (a1 ′) and the structural unit (a2 ′).
Here, the “main component” means that the total of the structural unit (a1 ′) and the structural unit (a2 ′) is 70 mol% or more with respect to the total of all the structural units constituting the resin (A1 ′). Means 80% by mole or more. Among them, a resin composed of the structural unit (a1 ′) and the structural unit (a2 ′) is preferable.

  In the present invention, the combination of the structural unit (a1 ′) and the structural unit (a2 ′) in the resin (A1 ′) is preferably a combination of the structural unit (a1 ′) and the structural unit (a210 ′). Examples of the combination include the following chemical formulas (A1′-1) to (A1′-4).

The mass average molecular weight (Mw; polystyrene-converted value by gel permeation chromatography) of the resin (A1 ′) is preferably 1000 to 10,000, more preferably 2000 to 10,000, and further preferably 3000 to 6000. , 3000 to 5000 is particularly preferable. A favorable contrast can be obtained by being more than the lower limit of the said range, and swelling of a resist pattern can be suppressed by being below an upper limit. As a result, the resolution is improved. Further, since the swelling of the pattern can be suppressed, the effect of improving the depth of focus (DOF) characteristic and the effect of suppressing the line edge roughness (LER) can be obtained. Moreover, it is preferable to make the said mass mean molecular weight into this range from the point that the swelling inhibitory effect of a resist pattern is also high. When the mass average molecular weight is lower within this range, good characteristics tend to be obtained.
The dispersity (Mw / Mn) is preferably 1.0 to 5.0, and more preferably 1.0 to 2.5.

When the resin (A1 ′) is used in the component (A ′), one or more of the resins (A1 ′) can be mixed and used.
When the resin (A1 ′) is used, the ratio of the resin (A1 ′) contained in the component (A ′) is preferably 70% by mass or more, more preferably 80% by mass or more, and 100% by mass. % Is most preferred.

[Resin (A2 ′)]
The resin (A2 ′) has a structural unit (a21 ′) containing an aliphatic cyclic group having a fluorinated hydroxyalkyl group.
In addition to the structural unit (a21 ′), the resin (A2 ′) preferably further includes a structural unit (a22 ′) derived from an acrylate ester containing a hydroxyl group-containing aliphatic cyclic group.
In addition to the structural unit (a21 ′) or the structural unit (a21 ′) and the structural unit (a22 ′), the resin (A2 ′) preferably further does not have a cyclic structure. And a structural unit (a23 ′) derived from acrylic acid having an alcoholic hydroxyl group in the side chain.

・ Structural unit (a21 ′)
The structural unit (a21 ′) is a structural unit containing an aliphatic cyclic group having a fluorinated hydroxyalkyl group. By including the structural unit (a21 ′), the solubility in the antkari developer is improved. Moreover, swelling of the resist is suppressed, and lithography properties such as pattern shape and LWR are improved.

The aliphatic cyclic group having a fluorinated hydroxyalkyl group is the same as that of the structural unit (a1 ′), and the aliphatic cyclic group (the state before the fluorinated hydroxyalkyl group is bonded). Among them, a group in which two hydrogen atoms have been removed from cyclohexane, adamantane, norbornane, or tetracyclododecane is preferred because it is easily available in the industry.
Of these exemplified monocyclic groups and polycyclic groups, groups in which two hydrogen atoms have been removed from norbornane are particularly preferred.

  The structural unit (a21 ′) is preferably a structural unit derived from acrylic acid, and in particular, an oxygen atom (—O—) of a carbonyloxy group [—C (═O) —O—] of an acrylate ester. And a structure in which the aliphatic cyclic group is bonded to each other (a structure in which a hydrogen atom of a carboxy group of acrylic acid is substituted with the aliphatic cyclic group).

  More specifically, the structural unit (a21 ′) is preferably a structural unit represented by the following general formula (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を示し；ｙ、ｔ、ｘはそれぞれ独立して１〜５の整数である。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; y, t, and x are each independently an integer of 1 to 5; ]

In the formula (1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.
Examples of the alkyl group of R include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group, and a methyl group is preferable. .
The halogenated alkyl group for R is a group in which one or more hydrogen atoms of an alkyl group having 5 or less carbon atoms are substituted with a halogen atom. Specific examples of the alkyl group in the halogenated alkyl group are the same as described above. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. The hydrogen atom substituted with a halogen atom may be a part or all of the hydrogen atoms constituting the alkyl group.
In the present invention, R is preferably a hydrogen atom or an alkyl group, and more preferably a hydrogen atom or a methyl group in terms of industrial availability.

y is each independently an integer of 1 to 5, preferably an integer of 1 to 3, and 1 is most preferable.
t is an integer of 1 to 5, preferably an integer of 1 to 3, and 1 is most preferable.
x is an integer of 1 to 3, preferably an integer of 1 to 2, and 1 is most preferable.
In the structural unit represented by the general formula (1), it is preferable that a 2-norbornyl group or a 3-norbornyl group is bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

As the structural unit (a21 ′), one type or a mixture of two or more types can be used.
In the resin (A2 ′), the proportion of the structural unit (a21 ′) is preferably 10 to 90 mol% and more preferably 20 to 90 mol% with respect to the total of all the structural units constituting the resin (A2 ′). 40 to 90 mol% is particularly preferable, and 45 to 85 mol% is most preferable. The effect by containing a structural unit (a21 ') is acquired by being more than the lower limit of the said range, and a balance with another structural unit is favorable by being below an upper limit.

・ Structural unit (a22 ′)
The resin (A2 ′) preferably has a structural unit (a22 ′) derived from an acrylate ester containing a hydroxyl group-containing aliphatic cyclic group in addition to the structural unit (a21 ′). When the resin (A2 ′) having such a structural unit (a22 ′) is added to the negative resist composition, the hydroxyl group (alcoholic hydroxyl group) of the structural unit (a22 ′) is an acid generated from the component (B ′). By the action, it reacts with the component (C ′), whereby the resin (A2 ′) changes from a soluble property to an insoluble property in an alkaline developer.

A “hydroxyl group-containing aliphatic cyclic group” is a group in which a hydroxyl group is bonded to an aliphatic cyclic group.
The number of hydroxyl groups bonded to the aliphatic cyclic group is preferably 1 to 3, more preferably 1.
The aliphatic cyclic group may be monocyclic or polycyclic, but is preferably a polycyclic group. Moreover, it is preferable that it is an alicyclic hydrocarbon group. Moreover, it is preferable that it is saturated. Moreover, it is preferable that carbon number of an aliphatic cyclic group is 5-15.
Specific examples of the aliphatic cyclic group (the state before the hydroxyl group is bonded) include those similar to the aliphatic cyclic group of the structural unit (a21 ′).
As the aliphatic cyclic group of the structural unit (a22 ′), among them, a cyclohexyl group, an adamantyl group, a norbornyl group, and a tetracyclododecyl group are preferable because they are easily available industrially. Among these, a cyclohexyl group and an adamantyl group are preferable, and an adamantyl group is particularly preferable.
In addition to the hydroxyl group, a linear or branched alkyl group having 1 to 4 carbon atoms may be bonded to the aliphatic cyclic group.

In the structural unit (a22 ′), the hydroxyl group-containing aliphatic cyclic group is preferably bonded to the ester group (—C (═O) —O—) of the acrylate ester.
In this case, in the structural unit (a22 ′), other substituents may be bonded to the α-position (α-position carbon atom) of the acrylate ester instead of the hydrogen atom. Preferred examples of the substituent include an alkyl group and a halogenated alkyl group.
These descriptions are the same as the description of R in the general formula (1) of the structural unit (a21 ′), and among those capable of bonding to the α-position, a preferable one is a hydrogen atom or an alkyl group, In particular, a hydrogen atom or a methyl group is more preferable, and a hydrogen atom is most preferable.

  As a specific example of the structural unit (a22 ′), for example, a structural unit represented by the following general formula (2) is preferable.

［式中、Ｒは前記と同じであり；Ｒ^７”は水素原子、アルキル基、または炭素数１〜５のアルコキシ基であり；ｒ’は１〜３の整数である。］

[Wherein, R is as defined above; R ⁷ ″ is a hydrogen atom, an alkyl group, or an alkoxy group having 1 to 5 carbon atoms; r ′ is an integer of 1 to 3]

In the formula (2), R is the same as the description of R in the general formula (1).
The alkyl group for R ⁷ ″ is preferably an alkyl group having 1 to 5 carbon atoms, and is the same as the alkyl group for R ⁷ .
In the general formula (2), R and R ⁷ ″ are most preferably a hydrogen atom.
r ′ is an integer of 1 to 3, and is preferably 1.
The bonding position of the hydroxyl group is not particularly limited, but is preferably bonded to the 3rd position of the adamantyl group.

As the structural unit (a22 ′), one type or a mixture of two or more types can be used.
In the resin (A2 ′), the proportion of the structural unit (a22 ′) is preferably 10 to 70 mol%, more preferably 10 to 50 mol%, based on the total of all the structural units constituting the resin (A2 ′). 20-40 mol% is more preferable. The effect by containing a structural unit (a22 ') is acquired by being more than the lower limit of the said range, and a balance with another structural unit is favorable by being below an upper limit.

・ Structural unit (a23 ′)
In addition to the structural unit (a21 ′) or the structural unit (a21 ′) and the structural unit (a22 ′), the resin (A2 ′) further has no cyclic structure and has a side chain. It is preferable to have a structural unit (a23 ′) derived from acrylic acid having an alcoholic hydroxyl group.
When the resin (A2 ′) containing the structural unit (a23 ′) is blended with the negative resist composition, the alcoholic hydroxyl group of the structural unit (a23 ′), together with the hydroxyl group of the structural unit (a22 ′), (B ′) It reacts with the component (C ′) by the action of an acid generated from the component. Therefore, the resin (A2 ′) easily changes from a soluble property to an insoluble property with respect to an alkaline developer, and an effect of improving lithography properties such as resolution can be obtained. Moreover, film loss can be suppressed. Moreover, the controllability of the crosslinking reaction during pattern formation is improved. Furthermore, the film density tends to improve. Thereby, there exists a tendency for heat resistance to improve. Furthermore, etching resistance is also improved.

In the structural unit (a23 ′), “having no cyclic structure” means having no aliphatic cyclic group or aromatic group.
The structural unit (a23 ′) is clearly distinguished from the structural unit (a22 ′) by not having a cyclic structure.
Examples of the structural unit having an alcoholic hydroxyl group in the side chain include a structural unit having a hydroxyalkyl group.
Examples of the hydroxyalkyl group include those similar to the hydroxyalkyl group in the “fluorinated hydroxyalkyl group” of the structural unit (a21 ′).
For example, the hydroxyalkyl group may be directly bonded to the α-position carbon atom of the main chain (the portion where the ethylenic double bond of acrylic acid is cleaved), or may be substituted with the hydrogen atom of the carboxy group of acrylic acid. You may comprise ester.
In the structural unit (a23 ′), it is preferable that at least one or both of them be present.
When a hydroxyalkyl group is not bonded to the α-position, an alkyl group or a halogenated alkyl group may be bonded to the α-position carbon atom instead of a hydrogen atom. About these, it is the same as that of description of R in General formula (1).

  As the structural unit (23 ′), structural unit (a23 ′) represented by general formula (3) shown below is preferred.

［式中、Ｒ^８”は水素原子、アルキル基、ハロゲン化アルキル基またはヒドロキシアルキル基であり、Ｒ^９”は、水素原子、アルキル基、またはヒドロキシアルキル基であり、かつ、Ｒ^８”、Ｒ^９”の少なくとも一方はヒドロキシアルキル基である。］

[Wherein R ⁸ ″ represents a hydrogen atom, an alkyl group, a halogenated alkyl group, or a hydroxyalkyl group, R ⁹ ″ represents a hydrogen atom, an alkyl group, or a hydroxyalkyl group, and R ⁸ ″, R ^At least one of ⁹ "is a hydroxyalkyl group. ]

The hydroxyalkyl group in R ⁸ ″ is preferably a hydroxyalkyl group having 10 or less carbon atoms, desirably a linear or branched chain, and more preferably a hydroxyalkyl group having 2 to 8 carbon atoms. And most preferably a hydroxymethyl group or a hydroxyethyl group.
The number of hydroxyl groups and the bonding position are not particularly limited, but are usually one and preferably bonded to the terminal of the alkyl group.
The alkyl group for R ⁸ ″ is preferably an alkyl group having 10 or less carbon atoms, more preferably an alkyl group having 2 to 8 carbon atoms, and most preferably an ethyl group or a methyl group.
The halogenated alkyl group for R ⁸ ″ is preferably a group in which part or all of the hydrogen atoms in an alkyl group having 5 or less carbon atoms (preferably an ethyl group or a methyl group) 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 the alkyl group and hydroxyalkyl group for R ⁹ ″, the same alkyl groups and hydroxyalkyl groups as described for R ⁸ ″ can be used.

As the structural unit represented by the general formula (3), specifically, a structural unit derived from (α-hydroxyalkyl) acrylic acid (however, a structural unit derived from an acrylate ester is not included here). ), Structural units derived from (α-hydroxyalkyl) acrylic acid alkyl esters, and structural units derived from (α-alkyl) acrylic acid hydroxyalkyl esters.
Among these, when the structural unit (a23 ′) includes a structural unit derived from (α-hydroxyalkyl) acrylic acid alkyl ester, it is preferable from the viewpoint of improving the film density, and among them, (α-hydroxymethyl)- Structural units derived from acrylic acid ethyl ester or (α-hydroxymethyl) -acrylic acid methyl ester are preferred.
Moreover, when the structural unit (a23 ′) includes a structural unit derived from (α-alkyl) acrylic acid hydroxyalkyl ester, it is preferable in terms of crosslinking efficiency. Among them, a structural unit derived from α-methyl-acrylic acid hydroxyethyl ester or α-methyl-acrylic acid hydroxymethyl ester is preferable.

As the structural unit (a23 ′), one type or a mixture of two or more types can be used.
In the resin (A2 ′), the proportion of the structural unit (a23 ′) is preferably 5 to 50 mol% and more preferably 5 to 40 mol% with respect to the total of all the structural units constituting the resin (A2 ′). 5 to 30 mol% is particularly preferable, and 10 to 25 mol% is most preferable. The effect by containing a structural unit (a23 ') is acquired by being more than the lower limit of the said range, and a balance with another structural unit becomes favorable by being below an upper limit.

-Other structural unit Resin (A2 ') may have another structural unit which can be copolymerized as structural units other than said each structural unit (a21')-(a23 ').
As such a constitutional unit, a constitutional unit conventionally used for a known resin component for a chemically amplified resist composition can be used. For example, it is derived from an acrylate ester containing a lactone-containing monocyclic or polycyclic group. And a structural unit (a24 ′).
As the structural unit (a24 ′), the same structural units as those exemplified in the description of the structural unit (a2) in the component (A) of the resist composition can be given.

As the structural unit (a24 ′), one type or a mixture of two or more types can be used.
When the structural unit (a24 ′) is contained in the resin (A2 ′), the proportion of the structural unit (a24 ′) in the resin (A2 ′) is based on the total of all the structural units constituting the resin (A2 ′). 10 to 70 mol% is preferable, 10 to 40 mol% is more preferable, and 10 to 25 mol% is most preferable. The effect by containing a structural unit (a24 ') is acquired by being more than the lower limit of the said range, and a balance with another structural unit becomes favorable by being below an upper limit.

The resin (A2 ′) is particularly preferably a resin mainly composed of the structural units (a21 ′) to (a23 ′).
Here, the “main component” means that the total of the structural units (a21 ′) to (a23 ′) occupies 50 mol% or more, preferably 70 mol% or more, more preferably 80 mol%. That's it. Most preferably, it is 100 mol%. That is, the resin (A2 ′) is most preferably a resin composed of the structural unit (a21 ′), the structural unit (a22 ′), and the structural unit (a23 ′).

The mass average molecular weight (Mw; polystyrene conversion value by gel permeation chromatography) of the resin (A2 ′) is preferably 1000 to 30000, more preferably 2000 to 10000, and further preferably 3000 to 8000. By setting it within this range, a good dissolution rate in an alkaline developer can be obtained, which is preferable from the viewpoint of high resolution. When the mass average molecular weight is lower within this range, good characteristics tend to be obtained.
Moreover, 1.0-5.0 are preferable and, as for dispersity (Mw / Mn), 1.0-2.5 are more preferable.

In the component (A ′), when the resin (A2 ′) is used, one or more of the resins (A2 ′) can be mixed and used.
When the resin (A2 ′) is used, the ratio of the resin (A2 ′) contained in the component (A ′) is preferably 50% by mass or more, more preferably 70% by mass or more, and 80% by mass. % Or more is particularly preferable, and 100% by mass is most preferable.

The component (A ′) such as the resin (A1 ′) and the resin (A2 ′) is, for example, a method of radical polymerization of a monomer that derives each structural unit by a conventional method, a method described in International Publication No. 2004/076495, etc. Can be synthesized.
In addition to the resin (A1 ′) and the resin (A2 ′), the component (A ′) includes other polymer compounds (hydroxystyrene resin, novolak resin, acrylic resin) used in conventional negative resist compositions. Etc.) can also be used.

  The content of the (A ′) component in the negative resist composition may be adjusted according to the resist film thickness to be formed.

<(B ′) component>
The acid generator component (B ′) is not particularly limited, and any conventionally known acid generator for chemically amplified resists can be appropriately selected and used.
Examples of the component (B ′) are the same as those exemplified in the description of the component (B) of the resist composition.
As the component (B ′), one type of acid generator may be used alone, or two or more types may be used in combination.
The content of the component (B ′) in the negative resist composition of the present invention is preferably 0.5 to 50 parts by mass and more preferably 1 to 40 parts by mass with respect to 100 parts by mass of the component (A ′). By setting it within the above range, pattern formation is sufficiently performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

<(C ′) component>
The crosslinking agent component (C ′) is not particularly limited, and can be arbitrarily selected from the crosslinking agents used in the chemically amplified negative resist compositions known so far.
Specifically, for example, 2,3-dihydroxy-5-hydroxymethylnorbornane, 2-hydroxy-5,6-bis (hydroxymethyl) norbornane, cyclohexanedimethanol, 3,4,8 (or 9) -trihydroxytri Aliphatic cyclic carbonization having a hydroxyl group or a hydroxyalkyl group or both such as cyclodecane, 2-methyl-2-adamantanol, 1,4-dioxane-2,3-diol, 1,3,5-trihydroxycyclohexane Examples thereof include hydrogen and oxygen-containing derivatives thereof.

In addition, amino group-containing compounds such as melamine, acetoguanamine, benzoguanamine, urea, ethylene urea, propylene urea, glycoluril are reacted with formaldehyde or formaldehyde and lower alcohol, and the hydrogen atom of the amino group is hydroxymethyl group or lower alkoxymethyl. And a compound substituted with a group and a compound having an epoxy group.
Of these, those using melamine are melamine-based crosslinking agents, those using urea are urea-based crosslinking agents, those using alkylene ureas such as ethylene urea and propylene urea are alkylene urea-based crosslinking agents, and glycoluril is used. What was used was a glycoluril-based crosslinking agent, and what used an epoxy group-containing compound was called an epoxy-based crosslinking agent.
The component (C ′) is preferably at least one selected from the group consisting of melamine crosslinking agents, urea crosslinking agents, alkylene urea crosslinking agents, glycoluril crosslinking agents, and epoxy crosslinking agents, A glycoluril-based crosslinking agent is particularly preferable.

  Melamine-based crosslinking agents include compounds in which melamine and formaldehyde are reacted to replace the amino group hydrogen atom with a hydroxymethyl group, and melamine, formaldehyde and lower alcohol are reacted to convert the amino group hydrogen atom into a lower alkoxy group. Examples include compounds substituted with a methyl group. Specific examples include hexamethoxymethyl melamine, hexaethoxymethyl melamine, hexapropoxymethyl melamine, hexabutoxybutyl melamine, and the like, among which hexamethoxymethyl melamine is preferable.

  Urea-based crosslinking agents include compounds in which urea and formaldehyde are reacted to replace amino group hydrogen atoms with hydroxymethyl groups, and urea, formaldehyde and lower alcohols are reacted to convert amino group hydrogen atoms into lower alkoxy groups. Examples include compounds substituted with a methyl group. Specific examples include bismethoxymethylurea, bisethoxymethylurea, bispropoxymethylurea, bisbutoxymethylurea, etc. Among them, bismethoxymethylurea is preferable.

  As an alkylene urea type crosslinking agent, the compound represented, for example by the following general formula (c1'-1) is mentioned.

［式中のＲ^５’とＲ^６’はそれぞれ独立に水酸基又は低級アルコキシ基であり、Ｒ^３’とＲ^４’はそれぞれ独立に水素原子、水酸基又は低級アルコキシ基であり、ｖは０又は１〜２の整数である。］

[In the formula, R ⁵ ′ and R ⁶ ′ are each independently a hydroxyl group or a lower alkoxy group, R ³ ′ and R ⁴ ′ are each independently a hydrogen atom, a hydroxyl group or a lower alkoxy group, and v is 0 or 1 It is an integer of ~ 2. ]

When R ⁵ ′ and R ⁶ ′ are lower alkoxy groups, they are preferably alkoxy groups having 1 to 4 carbon atoms, and may be linear or branched. R ⁵ ′ and R ⁶ ′ may be the same or different from each other. More preferably, they are the same.
When R ³ ′ and R ⁴ ′ are lower alkoxy groups, they are preferably alkoxy groups having 1 to 4 carbon atoms, and may be linear or branched. R ³ ′ and R ⁴ ′ may be the same or different from each other. More preferably, they are the same.
v is 0 or an integer of 1 to 2, preferably 0 or 1.
As the alkylene urea crosslinking agent, a compound in which v is 0 (ethylene urea crosslinking agent) and / or a compound in which v is 1 (propylene urea crosslinking agent) are particularly preferable.

  The compound represented by the general formula (c1′-1) can be obtained by a condensation reaction between alkylene urea and formalin, and by reacting this product with a lower alcohol.

  Specific examples of the alkylene urea crosslinking agent include, for example, mono and / or dihydroxymethylated ethylene urea, mono and / or dimethoxymethylated ethylene urea, mono and / or diethoxymethylated ethylene urea, mono and / or dipropoxy Ethylene urea-based crosslinking agents such as methylated ethylene urea, mono and / or dibutoxymethylated ethylene urea; mono and / or dihydroxymethylated propylene urea, mono and / or dimethoxymethylated propylene urea, mono and / or diethoxymethyl Propylene urea-based crosslinkers such as propylene urea, mono and / or dipropoxymethylated propylene urea, mono and / or dibutoxymethylated propylene urea; 1,3-di (methoxymethyl) 4,5-dihydroxy-2- Imidazolidinone, 1,3-di (Metoki Like, etc.) -4,5-dimethoxy-2-imidazolidinone.

Examples of the glycoluril-based crosslinking agent include glycoluril derivatives in which the N position is substituted with one or both of a hydroxyalkyl group and an alkoxyalkyl group having 1 to 4 carbon atoms. Such a glycoluril derivative can be obtained by a condensation reaction between glycoluril and formalin and by reacting this product with a lower alcohol.
Specific examples of the glycoluril-based crosslinking agent include, for example, mono, di, tri and / or tetrahydroxymethylated glycoluril, mono, di, tri and / or tetramethoxymethylated glycoluril, mono, di, tri and / or Examples include tetraethoxymethylated glycoluril, mono, di, tri and / or tetrapropoxymethylated glycoluril, mono, di, tri and / or tetrabutoxymethylated glycoluril.

The epoxy-based crosslinking agent is not particularly limited as long as it has an epoxy group, and can be arbitrarily selected and used. Among them, those having two or more epoxy groups are preferable. By having two or more epoxy groups, crosslinking reactivity is improved.
The number of epoxy groups is preferably 2 or more, more preferably 2 to 4, and most preferably 2.
The following are suitable as the epoxy-based crosslinking agent.

As the component (C ′), one type may be used alone, or two or more types may be used in combination.
The content of the component (C ′) is preferably 1 to 50 parts by mass, more preferably 3 to 30 parts by mass, and further preferably 3 to 15 parts by mass with respect to 100 parts by mass of the component (A ′). 5 to 10 parts by mass is most preferable. When the content of the component (C ′) is at least the lower limit value, crosslinking formation proceeds sufficiently and a good resist pattern with little swelling is obtained. Moreover, when it is less than or equal to this upper limit value, the storage stability of the resist coating solution is good and the deterioration of sensitivity over time is suppressed.

<Optional component>
[(D ′) component]
The negative resist composition further contains a nitrogen-containing organic compound component (D ′) (hereinafter referred to as “(D ′) component”) as an optional component in order to improve the resist pattern shape, stability with time, and the like. It is preferable to contain.
Examples of the component (D ′) include those exemplified in the description of the component (D) of the resist composition.
As the component (D ′), one type may be used alone, or two or more types may be used in combination.
The component (D ′) is usually used in the range of 0.01 to 5.0 parts by mass with respect to 100 parts by mass of the component (A ′).

[(E ′) component]
The negative resist composition includes, as an optional component, from the group consisting of organic carboxylic acids and phosphorus oxoacids and derivatives thereof for the purpose of preventing sensitivity deterioration, improving the resist pattern shape, stability over time, etc. At least one compound (E ′) selected (hereinafter referred to as “component (E ′)”) can be contained.
Examples of the component (E ′) include those exemplified in the description of the component (E) of the resist composition.
As the component (E ′), one type may be used alone, or two or more types may be used in combination.
The component (E ′) is usually used at a ratio of 0.01 to 5.0 parts by mass with respect to 100 parts by mass of the component (A ′).

  The negative resist composition further includes miscible additives as desired, for example, additional resins for improving the performance of the resist film, surfactants for improving coatability, dissolution inhibitors, plasticizers, Stabilizers, colorants, antihalation agents, dyes, and the like can be added as appropriate.

[(S ′) component]
Examples of the component (S ′) include those exemplified in the description of the component (S) of the resist composition.
(S ') A component may be used individually by 1 type and may use 2 or more types.
The amount of component (S ′) used is not particularly limited, and the amount of the negative resist composition used is a liquid having a concentration that can be applied onto the support on which the first resist pattern is formed.

According to the resist pattern forming method of the present invention described above, it is difficult to be affected by the second patterning in the double patterning process.
Further, the resist pattern forming method of the present invention can stably form a resist pattern having a small dimensional change before and after the second patterning, a high resolution, and a good shape. Furthermore, according to the resist pattern forming method of the present invention, it is not necessary to use a freezing agent or the like, and workability is improved.

<< Method for producing resist composition >>
The method for producing a resist composition of the present invention is a method for producing the resist composition of the present invention, wherein the substrate component (A) and the acid generator component (B) are combined with the organic solvent (S). It is a method to dissolve in.
In the method for producing a resist composition of the present invention, the organic solvent (S) is an organic solvent containing 1-butoxy-2-propanol and 2-butoxy-1-propanol. It is preferable that at least a part of is removed by distillation.
By preparing the organic solvent (S) by distillation, the ratio of 2-butoxy-1-propanol to 1-butoxy-2-propanol can be easily controlled, and the resist composition has excellent coatability on the support. Can be prepared.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.

<Synthesis of resin component (A1)>
In this example, the resin (A1-11-1) of the resin component (A1) used as the base component (A) was synthesized with reference to the synthesis example described in JP-A-2008-003540.
The mass average molecular weight (Mw) and dispersity (Mw / Mn) of this resin were determined on the basis of polystyrene conversion by gel permeation chromatography (GPC).
Moreover, the ratio (mol%) of the structural unit induced | guided | derived from each monomer in resin was computed by carbon NMR.

［Ｍｗ７０００，Ｍｗ／Ｍｎ１．６４，ａ１／ａ２／ａ６／ａ５＝４５／２５／１５／１５］

[Mw7000, Mw / Mn1.64, a1 / a2 / a6 / a5 = 45/25/15/15]

<Synthesis of Acid Generator Component (B)>
In this example, the acid generator (1) used as the acid generator component (B) was synthesized based on the synthesis example described in JP-A-2009-019028.

<Preparation of resin solution and resist composition>
(Example 1, Comparative Examples 1-3)
A resin solution was prepared by mixing and dissolving the components shown in Table 1.
Further, a positive resist composition was prepared by mixing and dissolving the components shown in Table 2.
In Tables 1 and 2, “-” indicates that it is not blended.

  In Tables 1 and 2, each abbreviation indicates the following, and the numerical value in [] is the blending amount (part by mass).

(A) -1: the resin (A1-11-1).
(B) -1: The acid generator (1).
(D) -1: tri-n-pentylamine.
(E) -1: salicylic acid.
Add-1: Dibutylhydroxytoluene (BHT).
Add-2: Fluorine-based surfactant (trade name: XR-104, manufactured by Dainippon Ink & Chemicals, Inc.).

  (S) -1: A part of 1-butoxy-2-propanol was removed by distillation from an organic solvent (manufactured by Dow Chemical Co.) containing 1-butoxy-2-propanol and 2-butoxy-1-propanol. Hontoru (hereinafter referred to as “Hontoru (1)”). The ratio of 2-butoxy-1-propanol is 2.6 parts by mass with respect to 100 parts by mass of 1-butoxy-2-propanol, and the ratio of 2-butoxy-1-propanol in the main distillate (1) is 2. .6% by mass.

  (S) -2: The main distillate obtained by removing a part of 1-butoxy-2-propanol from (S) -1 by distillation (hereinafter referred to as “the main distillate (2)”). The ratio of 2-butoxy-1-propanol is 0.1 part by mass with respect to 100 parts by mass of 1-butoxy-2-propanol, and the ratio of 2-butoxy-1-propanol in the main distillate (2) is 0. .1% by mass.

  (S) -3: A main distillation in which a part of 1-butoxy-2-propanol was removed from (S) -1 by distillation (hereinafter referred to as “main distillation (3)”). The ratio of 2-butoxy-1-propanol is 0.1 part by mass with respect to 100 parts by mass of 1-butoxy-2-propanol, and the ratio of 2-butoxy-1-propanol in the main distillate (3) is 0. .1% by mass.

(S) -4: First distillation in which a part of 1-butoxy-2-propanol was removed from (S) -1 by distillation. The ratio of 2-butoxy-1-propanol is 0.10 parts by mass with respect to 100 parts by mass of 1-butoxy-2-propanol, and the ratio of 2-butoxy-1-propanol in the initial distillation is 0.1 mass. What is%.
(S) -5: A main distillation in which a part of 1-butoxy-2-propanol was removed from (S) -1 by distillation (hereinafter referred to as “main distillation (4)”). The ratio of 2-butoxy-1-propanol is 1.0 part by mass with respect to 100 parts by mass of 1-butoxy-2-propanol, and the ratio of 2-butoxy-1-propanol in the main distillate (4) is 1. 0.0% by mass.
(S) -6: Residue obtained by removing a part of 1-butoxy-2-propanol from (S) -1 by distillation (kamazan: organic solvent remaining without evaporation). The ratio of 2-butoxy-1-propanol is 11 parts by mass with respect to 100 parts by mass of 1-butoxy-2-propanol, and the ratio of 2-butoxy-1-propanol in the residue is 10% by mass .

(S) -7: (S) -4 / (S) -6 = 100/12 (mass ratio) mixed organic solvent (1). The ratio of 2-butoxy-1-propanol is 1.2 parts by mass with respect to 100 parts by mass of 1-butoxy-2-propanol, and the ratio of 2-butoxy-1-propanol in the mixed organic solvent (1) is What is 1.2% by mass.
(S) -8: (S) -4 / (S) -6 = 100/24 (mass ratio) mixed organic solvent (2). The ratio of 2-butoxy-1-propanol is 2.1 parts by mass with respect to 100 parts by mass of 1-butoxy-2-propanol, and the ratio of 2-butoxy-1-propanol in the mixed organic solvent (2) is What is 2.0% by mass.
(S) -9: (S) -4 / (S) -6 = 100/32 (mass ratio) mixed organic solvent (3). The ratio of 2-butoxy-1-propanol is 2.6 parts by mass with respect to 100 parts by mass of 1-butoxy-2-propanol, and the ratio of 2-butoxy-1-propanol in the mixed organic solvent (3) is What is 2.5 mass%.
(S) -10: (S) -4 / (S) -6 = 100/42 (mass ratio) mixed organic solvent (4). The ratio of 2-butoxy-1-propanol is 3.1 parts by mass with respect to 100 parts by mass of 1-butoxy-2-propanol, and the ratio of 2-butoxy-1-propanol in the mixed organic solvent (4) is What is 3.0 mass%.

(S) -11: (S) -1 / (S) -3 = 1/2 (mass ratio) mixed organic solvent (5). The ratio of 2-butoxy-1-propanol is 0.94 parts by mass with respect to 100 parts by mass of 1-butoxy-2-propanol, and the ratio of 2-butoxy-1-propanol in the mixed organic solvent (5) is What is 0.93 mass%.
(S) -12: (S) -1 / (S) -3 = 2/1 (mass ratio) mixed organic solvent (6). The ratio of 2-butoxy-1-propanol is 1.8 parts by mass with respect to 100 parts by mass of 1-butoxy-2-propanol, and the ratio of 2-butoxy-1-propanol in the mixed organic solvent (6) is What is 1.8% by mass.

<Evaluation of applicability to support>
[Formation of resist film]
The resin solution or resist composition obtained above is applied onto an 8-inch silicon wafer (disc-shaped) using a coating apparatus TEL ACT12 (product name, manufactured by Tokyo Electron Ltd.), baked, and dried. As a result, a resist film having a thickness of 90 nm was formed.
Specifically, as a coating method, while rotating the silicon wafer at a rotation speed of 1500 rpm and a rotation time of 25 seconds, 10 mL of a resin solution or a resist composition is supplied from the nozzle of the coating apparatus near the center of the silicon wafer. The solution was dropped to form a coating film on the entire surface of the silicon wafer.
Next, the coating film was dried at a hot plate temperature of 90 ° C. for 60 seconds to form a resist film having a thickness of 90 nm.

[Evaluation of coatability on support]
The surface of the formed resist film was observed under a sodium lamp, and the applicability to the support was evaluated according to the following criteria. The results are shown in Tables 5-12.
◯: No striations or wavy traces (flow of undulating liquid) was observed, and the film was uniformly formed on the silicon wafer surface with a uniform film thickness.
Δ: Formation of striations or wavy marks was observed.
X: The formation of striations or wavy marks was greatly recognized.

From the results of Table 5, an organic solvent prepared by distillation so that the ratio of 2-butoxy-1-propanol to 2.7 parts by mass (1.5 parts by mass or more) with respect to 100 parts by mass of 1-butoxy-2-propanol was used. It turns out that the resin liquid-1 which is excellent in the applicability | paintability to a support body.
On the other hand, the ratio of 2-butoxy-1-propanol to 0.10 parts by mass (less than 1.5 parts by mass) with respect to 100 parts by mass of 1-butoxy-2-propanol was prepared by distillation. However, it can be seen that Resin liquids 2 to 4 using a high-purity organic solvent have poor applicability to the support.

From the results of Table 6, it was confirmed that the resist composition of Example 1 using an organic solvent that was excellent in the application property to the support in the resin liquid was excellent in the application property to the support.
On the other hand, it was confirmed that the resist composition of Comparative Example 1 using an organic solvent that had a poor coating property on the support in the resin solution had a poor coating property on the support.

The reason why the results of Table 6 were obtained is not clear, but when the surface tension of the resist composition was measured, the resist composition of Example 1 using (S) -1 was 26.7 (unit: mN / m). Since the resist composition of Comparative Example 1 using m) and (S) -3 was 25.0 (unit: mN / m), it can be attributed to the difference in surface tension.
Here, the “surface tension” indicates a value measured by a drop type automatic surface tension meter TVT2 (manufactured by LAUDA).

From the results in Table 7, the higher the ratio of 2-butoxy-1-propanol to 100 parts by mass of 1-butoxy-2-propanol in the organic solvent prepared by distillation, the better the coating property to the support. I understand.
From the result of Resin Liquid-5, when the ratio of 2-butoxy-1-propanol with respect to 100 parts by mass of 1-butoxy-2-propanol is 1.0 part by mass, the applicability to the support is still insufficient. I understand.

From the results of Tables 8 to 9, a resin solution using an organic solvent prepared by mixing a mixture having a high proportion of 2-butoxy-1-propanol and a mixture containing almost no 2-butoxy-1-propanol 7-12, even if the ratio of 2-butoxy-1-propanol to 100 parts by mass of 1-butoxy-2-propanol exceeds 1.0 part by mass, It was confirmed that the applicability was poor.
That is, the one prepared by mixing 1-butoxy-2-propanol and 2-butoxy-1-propanol has a coating property to the support even if the proportion of 2-butoxy-1-propanol is increased. I know it ’s bad.

  The reason why the results of Tables 8 to 9 are obtained is not clear, but even if a mixture having a high proportion of 2-butoxy-1-propanol and a mixture containing almost no 2-butoxy-1-propanol are mixed, It is conceivable that the surface tensions of 1-butoxy-2-propanol and 2-butoxy-1-propanol were different from each other, so that they did not mix sufficiently uniformly.

  From the results of Table 10, it was confirmed that the resin liquids 13 to 15 to which BHT (dibutylhydroxytoluene) was added had poor applicability to the support as in the case of the resin liquid-3, and the effect of the addition of BHT was recognized. I can't understand.

  From the results of Table 11, it was confirmed that the resin liquids 16 to 17 to which the surfactant (XR-104: manufactured by Dainippon Ink & Chemicals, Inc.) was added had poor applicability to the support, similar to the resin liquid-3. It can be seen that the effect of adding the surfactant is not recognized.

  From the results of Table 12, it was confirmed that the resist compositions of Comparative Examples 2 to 3 to which the surfactant was added had poor applicability to the support as in the resist composition of Comparative Example 1. It can be seen that the effect of addition of the surfactant is not recognized.

  From the above results, the organic solvent (S) in the present invention, that is, 1-butoxy-2-propanol and 2-butoxy-1-propanol (including 1-butoxy-2-propanol and 2-butoxy-1) was included. -Except for those prepared by mixing with propanol), and the ratio of 2-butoxy-1-propanol is 1.5 parts by mass or more with respect to 100 parts by mass of 1-butoxy-2-propanol. It was confirmed that a resist composition obtained by dissolving the base material component (A) and the acid generator component (B) in the present invention was excellent in applicability to a support.

Claims (11)

A resist composition obtained by dissolving a base component (A) whose solubility in an alkali developer is changed by the action of an acid and an acid generator component (B) that generates an acid upon exposure in an organic solvent (S). There,
The organic solvent (S) contains 1-butoxy-2-propanol and 2-butoxy-1-propanol (provided by mixing 1-butoxy-2-propanol and 2-butoxy-1-propanol) And a ratio of the 2-butoxy-1-propanol is 1.5 parts by mass or more with respect to 100 parts by mass of the 1-butoxy-2-propanol. object. A step of applying a first resist composition on a support to form a first resist film, and selectively exposing the first resist film and developing the first resist pattern to form a first resist pattern A step of applying a second resist composition on the support on which the first resist pattern has been formed to form a second resist film, and selectively selecting the second resist film. And a resist pattern forming method including a step of forming a resist pattern by exposing to alkali and developing,
The resist composition according to claim 1, which is a resist composition used as the second resist composition.   The resist composition according to claim 1 or 2, wherein the substrate component (A) contains a resin component (A1) whose solubility in an alkaline developer is increased by the action of an acid.   The resist composition according to claim 3, wherein the resin component (A1) has a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.   The resist composition according to claim 4, wherein the resin component (A1) further has a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group. The resist composition according to claim 4 or 5, wherein the resin component (A1) further comprises a structural unit (a5) represented by the following general formula (a5-1).

[In formula (a5-1), R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; Y ¹ may have a substituent. A hydrocarbon group, Z is a monovalent organic group; a is an integer of 1 to 3, b is an integer of 0 to 2, and a + b = 1 to 3; c, d , E are each independently an integer of 0-3. ] The resist composition according to any one of claims 4 to 6, wherein the resin component (A1) further has a structural unit (a6) represented by the following general formula (a6-1).

[In Formula (a6-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms; Y ³ is an alkylene group or an aliphatic cyclic group; G and h are each independently an integer of 0 to 3; i is an integer of 1 to 3; ]   Furthermore, the resist composition as described in any one of Claims 1-7 formed by melt | dissolving a nitrogen-containing organic compound component (D).   A step of applying a resist composition on a support to form a first resist film; a step of selectively exposing the first resist film and performing alkali development to form a first resist pattern; Applying the resist composition according to any one of claims 1 to 8 to form a second resist film on the support on which the first resist pattern is formed; And a step of selectively exposing the second resist film and performing alkali development to form a resist pattern. A method for producing the resist composition according to claim 1,
The manufacturing method of the resist composition which melt | dissolves the said base material component (A) and the said acid generator component (B) in the said organic solvent (S).   The organic solvent (S) is obtained by distilling at least a part of 1-butoxy-2-propanol from an organic solvent containing 1-butoxy-2-propanol and 2-butoxy-1-propanol. The manufacturing method of the resist composition of Claim 10.