JP2010037215A - Resist composition, method for forming resist pattern, new compound, and photobase generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resist composition improving lithographic characteristics and forming a resist pattern of an excellent shape, a method for forming a resist pattern, a photobase generator for use in the resist composition, and a new compound useful as the photobase generator. <P>SOLUTION: The resist composition comprising a base material component that changes its solubility to an alkali developer by the action of an acid, an acid generator component that generates an acid upon exposure to light, and a photobase generator component (F) that generates an alkali upon exposure to light, is characterized in that the photobase generator component (F) contains a photobase generator (F1) comprised of a compound represented by formula (f1) [in the formula, R and R" each represents a hydrogen atom or a 1-30C hydrocarbon group that may contain a substituent (provided that R and R" are bound to each other to form a ring in case R and R" both are 1-30C hydrocarbon groups that may contain a substituent); and R' represents an aryl group that may contain a substituent, or an alicyclic group]. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a resist composition, a method for forming a resist pattern using the resist composition, a novel compound useful as a photobase generator for the resist composition, and a photobase generator.

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 wavelength of an exposure light source is generally shortened. Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but now mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has started. In addition, studies have been made on F ₂ excimer lasers, electron beams, EUV (extreme ultraviolet rays), X-rays, and the like having shorter wavelengths than these excimer lasers.

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 such requirements, a chemically amplified resist composition containing a base material component whose solubility in an alkaline developer is changed by the action of an acid and an acid generator that generates an acid upon exposure is used. ing.
For example, as a positive chemically amplified resist composition, a composition containing a resin component (base resin) whose solubility in an alkaline developer is increased by the action of an acid and an acid generator component is generally used. Yes. When such a resist film formed using the resist composition is selectively exposed at the time of resist pattern formation, an acid is generated from the acid generator in the exposed portion, and the alkali developer of the resin component is generated by the action of the acid. As a result, the exposed area becomes soluble in an alkaline developer.
Currently, as a resist base resin used in ArF excimer laser lithography and the like, a resin (acrylic resin) having a structural unit derived from (meth) acrylic acid ester in its main chain because of its excellent transparency near 193 nm ) And the like are generally used (see, for example, Patent Document 1).
Here, “(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.

As the acid generator used in the chemically amplified resist composition, various types have been proposed so far, for example, onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, Diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators and the like are known.
Currently, an onium salt acid generator having an onium ion such as triphenylsulfonium in the cation portion is used as the acid generator. The anion moiety of the onium salt acid generator is generally an alkyl sulfonate ion or a fluorinated alkyl sulfonate ion in which part or all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms (for example, Patent Documents). 2).
JP 2003-241385 A JP-A-2005-37888

In the future, with further advancement of lithography technology and further miniaturization of resist patterns, there is an increasing demand for resist materials with high resolution.
However, in the conventional resist composition, as a result of the increase or decrease in the amount of light hitting the exposed portion due to changes in the mask size (hole diameter in the hole pattern or line width in the line and space pattern) used in forming the resist pattern, Since the amount of acid generated from the acid generator therein varies, there is a problem that the pattern shape collapses when forming a fine pattern with a narrow pitch, for example, a hole pattern having a hole diameter of about 100 nm or less. Therefore, in the conventional resist composition, for example, in the formation of a resist pattern of a contact hole pattern, lithography characteristics such as a mask error factor (MEF) are improved, and a resist pattern having a good hole roundness can be formed. There is an increasing need. The MEF is a parameter indicating how faithfully a mask pattern having a different size can be reproduced when the mask size is changed with the same exposure amount and a fixed pitch.
The present invention has been made in view of the above circumstances, and has improved lithography characteristics and can form a resist pattern with a good shape, a resist pattern forming method, and the resist composition. It is an object of the present invention to provide a novel photobase generator and a novel compound useful as the photobase generator.

The present inventors propose the following means in order to solve the above problems.
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, an acid generator component (B) that generates an acid by exposure, and a base by exposure. A resist composition containing a generated photobase generator component (F), wherein the photobase generator component (F) comprises a compound represented by the following general formula (f1): A resist composition comprising:

［式中、ＲおよびR”は、水素原子または置換基を有していても良い炭素数１〜３０の炭化水素基であり（ただし、RおよびＲ”がともに置換基を有していても良い炭素数１〜３０の炭化水素基である場合は、互いに結合して環を形成するものとし）；Ｒ’は置換基を有していても良いアリール基または脂肪族環式基である。］

[Wherein, R and R ″ are a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent (provided that both R and R ″ may have a substituent) When they are good hydrocarbon groups having 1 to 30 carbon atoms, they are bonded to each other to form a ring); R ′ is an aryl group or an aliphatic cyclic group which may have a substituent. ]

  According to a second aspect of the present invention, there is provided a step of forming a resist film on a support using the resist composition of the first aspect, a step of exposing the resist film, and an alkali development of the resist film. A resist pattern forming method including a step of forming a resist pattern.

  A third aspect of the present invention is a compound represented by the following general formula (f1).

［式中、RおよびＲ”は、水素原子または置換基を有していても良い炭素数１〜３０の炭化水素基であり（ただし、RおよびＲ”がともに置換基を有していても良い炭素数１〜３０の炭化水素基である場合は、互いに結合して環を形成するものとし）；Ｒ’は置換基を有していても良いアリール基または脂肪族環式基である。］

[Wherein, R and R ″ are a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent (provided that both R and R ″ may have a substituent) When they are good hydrocarbon groups having 1 to 30 carbon atoms, they are bonded to each other to form a ring); R ′ is an aryl group or an aliphatic cyclic group which may have a substituent. ]

  A fourth aspect of the present invention is a photobase generator comprising the compound of the third aspect.

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.
The “structural unit” means a monomer unit (monomer unit) constituting a polymer compound (polymer, copolymer).
“Exposure” is a concept including general irradiation of radiation.

  According to the present invention, as a resist composition and a resist pattern forming method capable of forming a resist pattern having a good shape with improved lithography characteristics, a photobase generator for the resist composition, and the photobase generator Novel compounds that are useful can be provided.

≪Resist composition≫
The resist composition according to the first aspect of the present invention comprises a base material component (A) whose solubility in an alkaline developer is changed by the action of an acid (hereinafter referred to as “component (A)”), and an acid upon exposure. It contains an acid generator component (B) that is generated (hereinafter referred to as “component (B)”).
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 alkaline developer changes, the solubility of the unexposed portion in the alkaline 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 may be a negative resist composition or a positive resist composition.
In addition to these components (A) and (B), the resist composition of the present invention further contains a photobase generator component (F) (hereinafter referred to as “component (F)”) that generates a base upon exposure. To do.
Hereinafter, each component will be described.

<(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 or more and less than 2000 (hereinafter referred to as “low molecular compound”) and a high molecular weight resin having a molecular weight of 2000 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” refers to a resin having a molecular weight of 2000 or more.
As the component (A), a resin whose alkali solubility is changed by the action of an acid can be used, and a low molecular weight material whose alkali solubility 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. Blended.
In such a negative resist composition, when an acid is generated from the component (B) by exposure, the acid acts to cause crosslinking between the base material component and the crosslinking agent, resulting in poor solubility in an alkali developer. To do. 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 alkaline developer, while not yet exposed. 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, 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 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 “(A ′) component”) whose solubility in an alkaline developer is increased by the action of an acid. Is used).
The component (A ′) is hardly soluble in an alkali developer before exposure. When an acid is generated from the component (B) by 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 becomes insoluble 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 substrate component ((A ′) 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 (A ′) 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 an alkali developer, or a mixture thereof.

[(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 not only acrylic acid esters in which a hydrogen atom is bonded to the α-position carbon atom, but also those in which a substituent (an atom or group other than a hydrogen atom) is bonded to the α-position carbon atom. Include concepts. Examples of the substituent include a lower alkyl group and a halogenated lower alkyl group.
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 acrylate ester, as the lower alkyl group as a substituent at the α-position, specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, Examples include lower linear or branched alkyl groups such as isopentyl group and neopentyl group.
Specific examples of the halogenated lower alkyl group include groups in which some or all of the hydrogen atoms of the above-mentioned “lower alkyl group as a substituent at the α-position” are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
In the present invention, the α-position of the acrylate ester is preferably a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and is a hydrogen atom, a lower alkyl group or a fluorinated lower alkyl group. In view of industrial availability, a hydrogen atom or a methyl group is most preferable.

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.
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). It is preferable to have a structural unit (a3).

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. It increases the solubility of the entire component in an alkaline developer, and those proposed so far 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, in the present specification, “aliphatic” is a relative concept with respect to aromatics, and is defined to mean a group, a compound, or the like that does not have aromaticity.
“Aliphatic branched” 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 monocycloalkanes, bicycloalkanes, tricycloalkanes, tetracycloalkanes which may or may not be substituted with a lower alkyl group, a fluorine atom or a fluorinated alkyl group. And groups obtained by removing one or more hydrogen atoms from a polycycloalkane. 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. .

  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—) An aliphatic cyclic group such as a cyclohexyl group, a cyclopentyl group, a norbornyl group, a tricyclodecanyl group, or a tetracyclododecanyl group, and a branched alkylene group having a tertiary carbon atom bonded thereto. Groups.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；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, a lower alkyl group or a halogenated lower alkyl group; R ¹⁵ and R ^{16 each} represents an alkyl group (which may be linear or branched, and preferably has 1 to 5 carbon atoms. Is). ]

  In the general formulas (a1 ″ -1) to (a1 ″ -6), the lower alkyl group or halogenated lower alkyl group of R is a lower alkyl group or halogenated lower alkyl which may be bonded to the α-position of the acrylate ester. It is the same as the alkyl group.

The “acetal-type 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低級アルキル基を表し、ｎは０〜３の整数を表し、Ｙは低級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 a lower alkyl group, n represents an integer of 0 to 3, and Y represents a lower alkyl group or 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 lower alkyl group for R ¹ ′ and R ² ′ include the same lower alkyl groups as those described above for R. A methyl group or an ethyl group is preferable, and a methyl group is most 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 acid dissociable, dissolution inhibiting group (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 lower alkyl group for Y include the same lower alkyl groups as those described above for R.
The aliphatic cyclic group for Y can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups conventionally proposed in a number of ArF resists and the like. 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. And the like, in which a hydrogen atom is removed. 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 R ¹⁷ The end of each may be bonded.
In this case, the R ^17, R ^19, the oxygen atom to which R ¹⁹ is bonded, the cyclic group is formed by the carbon atom having the oxygen atom and R ¹⁷ are bonded. The cyclic group is preferably a 4-7 membered ring, and more preferably a 4-6 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、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｘ^１は酸解離性溶解抑制基を示す。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; and X ¹ represents an acid dissociable, dissolution inhibiting group. ]

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；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, a lower alkyl group or a halogenated lower alkyl group; X ² represents an acid dissociable, dissolution inhibiting group; Y ² represents a divalent linking group. ]

In general formula (a1-0-1), the lower alkyl group or halogenated lower alkyl group for R is the same as the lower alkyl group or halogenated lower alkyl group that may be bonded to the α-position of the acrylate ester. .
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, a divalent linking group containing a hetero atom, or a combination thereof.
As the aliphatic cyclic group, those similar to the description 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 -, - NR 04 - (R 04 is an alkyl group, an acyl group, etc.), - NH-C (= O) -, = N _{-, - S -, - S} (= O) 2 -, - S (= O) 2 -O -, "- A-O (oxygen atom) -B- (However, A and B are each independently substituted A divalent hydrocarbon group which may have a group.) ”And the like.

In —NR ⁰⁴ — of Y ² , R ⁰⁴ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
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, and 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 - _{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 Alkylethylene groups such as CH ₃ ) CH ₂ —; alkyltrimethylene 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 - , etc. And alkyl alkylene groups such as Le Kill tetramethylene group. 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 lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxygen atom (= O).

Examples of the aliphatic hydrocarbon group including a ring in the structure 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 includes the chain described above. And a group that is bonded to the terminal of the chain-like aliphatic hydrocarbon group or intervenes 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 a lower alkyl 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.

  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 a methylene group or 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.

The divalent linking group for Y ² is more preferably an alkylene group, a divalent aliphatic cyclic group, or a divalent linking group containing an alkylene group and a hetero atom, and a divalent linking group containing an alkylene group and a hetero atom. The group is particularly preferred.

  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の低級アルキル基、または脂肪族環式基を表し；ｎは０〜３の整数を表し；Ｙ^２は２価の連結基であり；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または炭素数１〜５の低級アルキル基を表す。］

[Wherein, X ′ represents a tertiary alkyl ester type acid dissociable, dissolution inhibiting group, Y represents a lower alkyl group having 1 to 5 carbon atoms, or an aliphatic cyclic group; n represents an integer of 0 to 3] Y ² is a divalent linking group; R is the same as defined above; R ¹ ′ and R ² ′ each independently represent a hydrogen atom or a lower 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 above formula, 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 general formula (a1-1) or (a1-3) is preferable, and specifically, (a1-1-1) to (a1-1-4), (a1-1-1-) It is more preferable to use at least one selected from the group consisting of 20) to (a1-1-23) and (a1-3-25) to (a1-3-30).
Furthermore, as the structural unit (a1), those represented by the following general formula (a1-1-01) including particularly the structural units of the formula (a1-1-1) to the formula (a1-1-3), In the following general formula (a1-1-02) including the structural units of formulas (a1-1-16) to (a1-1-17) and formulas (a1-1-20) to (a1-1-23) What is represented, what is represented by the following general formula (a1-3-01) including the structural units of the formulas (a1-3-25) to (a1-3-26), and the formula (a1-3-27) ) To (a1-3-28) and those represented by the following general formula (a1-3-02) or the structures of formulas (a1-3-29) to (a1-3-30) What is represented with the following general formula (a1-3-03) which includes a unit is also preferable.

（式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し、Ｒ^１１は低級アルキル基を示す。）

(In the formula, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹¹ represents a lower alkyl group.)

（式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し、Ｒ^１２は低級アルキル基を示す。ｈは１〜６の整数を表す。）

(In the formula, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, R ¹² represents a lower alkyl group, and h represents an integer of 1 to 6.)

In general formula (a1-1-01), R is the same as defined above. The lower alkyl group for R ^{11 is the same as} the lower alkyl group for R, and is preferably a methyl group or an ethyl group.

In general formula (a1-1-02), R is the same as defined above. The lower alkyl group for R ^{12 is the same as} the lower alkyl group for R, preferably a methyl group or an ethyl group, and most preferably an ethyl group. h is preferably 1 or 2, and most preferably 2.

（式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｒ^１４は低級アルキル基であり、Ｒ^１３は水素原子またはメチル基であり、ａは１〜１０の整数である。）

Wherein R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; R ¹⁴ represents a lower alkyl group, R ¹³ represents a hydrogen atom or a methyl group, and a represents an integer of 1 to 10. .)

（式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｒ^１４は低級アルキル基であり、Ｒ^１３は水素原子またはメチル基であり、ａは１〜１０の整数であり、ｎ’は１〜６の整数である。）

Wherein R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; R ¹⁴ represents a lower alkyl group, R ¹³ represents a hydrogen atom or a methyl group, and a represents an integer of 1 to 10. , N ′ is an integer of 1 to 6.)

（式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基を示し；Ｒ^１４は低級アルキル基であり、Ｒ^１３は水素原子またはメチル基であり、ａは１〜１０の整数である。）

Wherein R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; R ¹⁴ represents a lower alkyl group, R ¹³ represents a hydrogen atom or a methyl group, and a represents an integer of 1 to 10. .)

In the general formulas (a1-3-01) to (a1-3-03), R is the same as described above.
R ¹³ is preferably a hydrogen atom.
The lower alkyl group for R ^{14 is the same as} the lower alkyl group for R, and is preferably a methyl group, an ethyl group, or an isopropyl group.
In the general formula (a1-3-01) or (a1-3-02), a is preferably an integer of 1 to 8, particularly preferably an integer of 2 to 5, and most preferably 2.
In the general formula (a1-3-03), a is preferably an integer of 1 to 8, particularly preferably an integer of 1 to 5, and most preferably 1.

  In the copolymer (A1), the proportion of the structural unit (a1) is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, based on all the structural units constituting the copolymer (A1). More preferred is ˜70 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.

In the component (A1), the proportion of the structural unit represented by the general formula (a1-1-01) or the general formula (a1-1-02) is based on the total of all the structural units constituting the component (A1). 10-80 mol% is preferable, 15-70 mol% is more preferable, 15-50 mol% is further more preferable. 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.
In the component (A1), the proportion of the structural units represented by general formulas (a1-3-01) to (a1-3-03) is 5 to 5 with respect to the total of all the structural units constituting the component (A1). 50 mol% is preferable, 5-30 mol% is more preferable, and 5-25 mol% is still more preferable. 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 monomers for deriving the structural units represented by the general formulas (a1-3-01) to (a1-3-03) (hereinafter collectively referred to as “monomer W”) are produced by, for example, the production method shown below. can do.

Monomer W Production Method:
In the presence of a base, a compound represented by the following general formula (X-1) (hereinafter referred to as “compound (X-1)”) dissolved in a reaction solvent is represented by the following general formula (X-2). And a compound represented by the following general formula (X-3) (hereinafter referred to as “compound (X-3)”) by adding and reacting the compound (hereinafter referred to as “compound (X-2)”). Then, the compound represented by the following general formula (X-4) is added to the solution in which the compound (X-3) is dissolved in the presence of a base and reacted, whereby the monomer W is obtained. .
Compound (X-2) can be obtained, for example, by reacting X ¹¹ —B—C (═O) —OH with X ² —H. Further, instead of the compound (X-2), X ¹¹ —B—C (═O) —OH and X ² —H may be used separately.
Examples of the base include inorganic bases such as sodium hydride, K ₂ CO ₃ and Cs ₂ CO ₃ ; organic bases such as triethylamine, 4-dimethylaminopyridine (DMAP) and pyridine.
Any reaction solvent may be used as long as it can dissolve the starting compounds (X-1) and (X-2). Specifically, tetrahydrofuran (THF), acetone, dimethylformamide (DMF), dimethylacetamide , Dimethyl sulfoxide (DMSO), acetonitrile and the like.

［式中、Ｒは水素原子、低級アルキル基またはハロゲン化低級アルキル基であり；ＡおよびＢはそれぞれ独立して置換基を有していてもよい２価の炭化水素基であり、Ｘ^２は酸解離性溶解抑制基であり、Ｘ^１０およびＸ^１２はそれぞれ独立して水酸基またはハロゲン原子であって、Ｘ^１０およびＸ^１２のいずれか一方が水酸基であり、他方がハロゲン原子であり、Ｘ^１１はハロゲン原子である。ｕは０又は１である。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; A and B each independently represent a divalent hydrocarbon group which may have a substituent, and X ² represents An acid dissociable, dissolution inhibiting group, X ¹⁰ and X ¹² are each independently a hydroxyl group or a halogen atom, and one of X ¹⁰ and X ¹² is a hydroxyl group, the other is a halogen atom, and X ¹¹ Is a halogen atom. u is 0 or 1. ]

In the above formula, R, X ² , A, and B are all the same as described above.
Examples of the halogen atom in X ¹⁰ , X ¹¹ and X ¹² include a bromine atom, a chlorine atom, an iodine atom and a fluorine atom.
The halogen atom for X ¹⁰ or X ¹² is preferably a chlorine atom or a bromine atom because of excellent reactivity.
X ¹¹ is preferably a bromine atom or a chlorine atom because of excellent reactivity.
The manufacturing method of the monomer W indicates a manufacturing method of each monomer that derives the structural unit represented by the general formula (a1-3-01) or (a1-3-02) when u = 0, In the case of = 1, the manufacturing method of each monomer which derives the structural unit represented by the general formula (a1-3-03) is shown.

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. When only the lactone ring is present, it is called a monocyclic group. 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, examples of the lactone-containing monocyclic group include groups in which one hydrogen atom has been removed from a monocyclic lactone such as γ-butyrolactone and mevalonic lactone. 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、低級アルキル基またはハロゲン化低級アルキル基であり；Ｒ’は水素原子、低級アルキル基、炭素数１〜５のアルコキシ基または−ＣＯＯＲ”であり、前記Ｒ”は水素原子、または炭素数１〜１５の直鎖状、分岐鎖状もしくは環状のアルキル基であり；ｍは０または１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る。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; R ′ represents a hydrogen atom, a lower alkyl group, an alkoxy group having 1 to 5 carbon atoms, or —COOR ″, and R ″ represents A hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms; m is an integer of 0 or 1; A ″ is a carbon which may contain an oxygen atom or a sulfur atom. It is an alkylene group of formulas 1 to 5, an oxygen atom or a sulfur atom.]

R in the general formulas (a2-1) to (a2-5) is the same as R in the structural unit (a1).
The lower alkyl group for R ′ is the same as the lower alkyl group for R in the structural unit (a1).
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 group in which one or more hydrogen atoms are removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group 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.
In general formulas (a2-1) to (a2-5), R ′ is preferably a hydrogen atom in view of industrial availability.
Specific examples of the alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or sulfur atom of A ″ include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, —O—CH ₂ —. _{, -CH 2 -O-CH 2 -} , - S-CH 2 -, - CH 2 -S-CH 2 - , and the like.
Below, the specific structural unit of the said general formula (a2-1)-(a2-5) is illustrated.

In the above formula, R ^α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

In the copolymer (A1), as the structural unit (a2), one type of structural unit may be used alone, 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 (a2) -3) At least 1 sort (s) selected from the group which consists of a structural unit represented by 3) is more preferable. Among these, from structural units represented by chemical formulas (a2-1-1), (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

  5-60 mol% is preferable with respect to the sum total of all the structural units which comprise a copolymer (A1), and the ratio of the structural unit (a2) in a copolymer (A1) is 10-50 mol% more. Preferably, 20-50 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 (a3) The structural unit (a3) is a structural unit derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.
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 part of the hydrogen atoms of the alkyl group is substituted with a fluorine atom. A hydroxyl group is particularly preferred.
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 polycyclic aliphatic hydrocarbon group (polycyclic group). It is done. As the polycyclic group, for example, a resin for a resist composition for ArF excimer laser can be appropriately selected from among many proposed ones. The polycyclic group preferably has 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), the structural unit represented by the following formula (a3-2), and the following formula The structural unit represented by (a3-3) and the structural unit represented by the following formula (a3-4) are preferred.

［式中、Ｒは前記と同じであり、ｊは１〜３の整数であり、ｋは１〜３の整数であり、ｔ’は１〜３の整数であり、ｌは１〜５の整数であり、ｓは１〜３の整数であり、ｄは１〜３の整数であり、ｅは０または１である。］

[Wherein, R is the same as defined above, j is an integer of 1 to 3, k is an integer of 1 to 3, t ′ is an integer of 1 to 3, and l is an integer of 1 to 5] S is an integer of 1 to 3, d is an integer of 1 to 3, and e is 0 or 1. ]

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

  In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.

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

In formula (a3-4), d is preferably 1 or 2, and more preferably 1. The bonding position of the hydroxyl group is not particularly limited, and when d is 1, the 2nd position is preferable because it is readily available and inexpensive. When d is 2 or 3, arbitrary substitution positions can be combined.
In formula (a3-4), e is preferably 1.

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

-About structural unit (a4) (A1) component may contain other structural units (a4) other than the said structural units (a1)-(a3) in the range which does not impair the effect of this invention.
The structural unit (a4) is not particularly limited as long as it is another structural unit that is not classified into the structural units (a1) to (a3) described above, and is for ArF excimer laser and KrF excimer laser (preferably ArF excimer). A number of hitherto known materials can be used for resist resins such as lasers.
As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing a non-acid-dissociable aliphatic polycyclic group is preferable. Examples of the polycyclic group include those exemplified in the case of the structural unit (a1), and for ArF excimer laser and KrF excimer laser (preferably for ArF excimer laser). A number of hitherto known materials can be used as the resin component of the resist composition.
In particular, at least one selected from a tricyclodecanyl group, an adamantyl group, a tetracyclododecanyl 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。］

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

  When the structural unit (a4) is contained in the component (A1), the proportion of the structural unit (a4) is preferably 1 to 30 mol% with respect to the total of all the structural units constituting the component (A1). 20 mol% is more preferable.

  In the present invention, the copolymer (A1) is a copolymer having the structural units (a1), (a2) and (a3), and examples of the copolymer include the structural units (a1), ( Examples thereof include a copolymer comprising a2) and (a3), a copolymer comprising the structural units (a1), (a2), (a3) and (a4).

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

In general formula (A1-11), R is the same as defined above, and the plurality of R may be the same or different. R ¹¹ , R ¹⁴ , a and b are all the same as described above.

In the formula (A1-11), the lower alkyl group for R ¹¹ is most preferably an ethyl group or an isopropyl group.
The lower alkyl group for R ¹⁴ is preferably a methyl group or an ethyl group, and most preferably a methyl group.
a is an integer of 1 to 10, 1 or 2 is particularly preferable, and 1 is most preferable.
b is an integer of 1 to 10, 1 or 2 is particularly preferable, and 1 is most preferable.

The component (A1) is obtained by polymerizing a monomer that derives each structural unit by a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate. be able to.
Further, for the component (A1), in the polymerization, a chain transfer agent such as HS—CH ₂ —CH ₂ —CH ₂ —C (CF ₃ ) ₂ —OH is used in combination, so that the terminal A —C (CF ₃ ) ₂ —OH group may be introduced into the. As described above, a copolymer into which a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom is introduced has reduced 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 2000 to 50000, more preferably 3000 to 30000, most preferably 5000 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 / Mn) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5. In addition, Mn shows 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.

(A) A component may be used individually by 1 type and may use 2 or more types together.
Among the above, the component (A) preferably contains the component (A1).
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>
The component (B) is not particularly limited, and those that have been proposed as acid generators for chemically amplified resists can be used. Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, and poly (bissulfonyl) diazomethanes. 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、直鎖状、分岐鎖状または環状のアルキル基またはフッ素化アルキル基を表し；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 together to form a ring with the sulfur atom in the formula; R ⁴ ″ represents a linear, branched or cyclic alkyl group or a fluorinated alkyl group; R ¹ At least one of “˜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 of 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 or alkoxy. It may or may not be substituted with a group, a halogen atom, a hydroxyl group 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. 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, ethyl group, propyl group, n-butyl group, or 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, Most preferred is a tert-butoxy group.
The alkoxy group that may be substituted with a hydrogen atom of the aryl group is preferably an alkoxy group having 1 to 5 carbon atoms, and most preferably a methoxy group or an ethoxy group.
The halogen atom that may substitute 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 decanyl group. A methyl group is preferable because it is excellent in resolution and can be synthesized at low cost.
Among these, R ¹ ″ to R ³ ″ are most preferably a phenyl group or a naphthyl group, respectively.

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, 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 are the same as the aryl groups of R ¹ ″ to R ³ ″.

R ⁴ ″ represents a linear, branched or cyclic alkyl group or a fluorinated alkyl group.
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 is a cyclic group as indicated by R ¹ ″ and preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and more preferably 6 carbon atoms. Most preferably, it is -10.
The fluorinated 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 fluorination rate of the fluorinated alkyl group (ratio of fluorine atoms in the alkyl group) is preferably 10 to 100%, more preferably 50 to 100%. Particularly, all the hydrogen atoms are substituted with fluorine atoms. A fluorinated alkyl group (perfluoroalkyl group) is preferable because the strength of the acid is increased.
R ⁴ ″ is most preferably a linear or cyclic alkyl group or a fluorinated alkyl group.

In 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 all of R ⁵ ″ to R ⁶ ″ are phenyl groups.
"As ^{R 4} in the 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 the formulas (b-1) and (b-2) include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, bis (4-tert-butylphenyl) iodonium. Trifluoromethanesulfonate or nonafluorobutanesulfonate, triphenylsulfonium trifluoromethanesulfonate, heptafluoropropanesulfonate or nonafluorobutanesulfonate, tri (4-methylphenyl) sulfonium trifluoromethanesulfonate, heptafluoropropanesulfonate or the same 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) phenylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1-phenyltetrahydrothiophenium trifluoromethane sulfonate, its heptafluoropropane sulfonate 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, onium salts in which the anion portion of these onium salts is replaced with methanesulfonate, n-propanesulfonate, n-butanesulfonate, or n-octanesulfonate can also be used.

  In addition, in the general formula (b-1) or (b-2), an onium salt-based acid generator in which the anion moiety is replaced with an anion moiety represented by the following general formula (b-3) or (b-4). Can also be used (the cation moiety is the same as (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 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, 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 ″, the strength of the acid increases as the number of hydrogen atoms substituted with fluorine atoms increases, and high-energy light or electron beam of 200 nm or less The ratio 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. Are a perfluoroalkylene group or a perfluoroalkyl group in which a hydrogen atom is substituted with a fluorine atom.

  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^４１〜Ｒ^４６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 ^{41 to} R ⁴⁶ 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 ^{41 to} R ⁴⁶ , 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 ^{41 to} R ⁴⁶ are integers of 2 or more, the plurality of R ^{41 to} R ⁴⁶ 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 moiety represented by the above general formula (b-3) or (b-4), etc. Among these, a fluorinated alkylsulfonic acid ion is preferable, and a fluorinated alkylsulfonic acid having 1 to 4 carbon atoms. Ion is more preferable, and linear perfluoroalkylsulfonic acid ions having 1 to 4 carbon atoms are particularly preferable, and specific examples thereof include trifluoromethylsulfonic acid ions, heptafluoro-n-propylsulfonic acid ions, and nonafluoro-n. -Butyl sulfonate ion etc. are mentioned.

  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 with radiation. is there. 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), alkyl or halogenated alkyl group having no substituent group for R ³³ preferably has 1 to 10 carbon atoms, 1 to 8 carbon atoms, more preferably, carbon 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 of 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 having no substituent as R ³⁵ described above.
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.
Also, an oxime sulfonate-based acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014] [chemical formula 18] to [chemical formula 19]), WO 2004 / 074242A2 (pages 65 to 85). The oxime sulfonate acid generators disclosed in Examples 1 to 40) of No. 1 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.

(B) As a component, these acid generators may be used individually by 1 type, and may be used in combination of 2 or more type.
In the present invention, it is particularly preferable to use an onium salt having a fluorinated alkyl sulfonate ion as an anion as the component (B).
The content of the component (B) in the resist composition is preferably 0.5 to 60 parts by mass, 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.

<(F) component>
The resist composition of the present invention contains a photobase generator component (F) “hereinafter referred to as component (F)” that generates a base upon exposure, and the component (F) is represented by the following general formula (f1). A base generator (F1) (hereinafter referred to as “component (F1)”) comprising the compound represented.

［式中、ＲおよびR”は、水素原子または置換基を有していても良い炭素数１〜３０の炭化水素基であり（ただし、RおよびＲ”がともに置換基を有していても良い炭素数１〜３０の炭化水素基である場合は、互いに結合して環を形成するものとし）；Ｒ’は置換基を有していても良いアリール基または脂肪族環式基である。］

[Wherein, R and R ″ are a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent (provided that both R and R ″ may have a substituent) When they are good hydrocarbon groups having 1 to 30 carbon atoms, they are bonded to each other to form a ring); R ′ is an aryl group or an aliphatic cyclic group which may have a substituent. ]

  When the component (F) contains the component (F1), the resist composition of the present invention is used to form a resist pattern of, for example, a contact hole pattern, and lithography characteristics such as a mask error factor (MEF). As a result, a resist pattern with good roundness of holes can be formed.

In said general formula (f1), R is a C1-C30 hydrocarbon group which may have a hydrogen atom or a substituent.
The hydrocarbon group having 1 to 30 carbon atoms which may have an R substituent 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, particularly 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. Examples include 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 3, and particularly preferably 1 to 2.
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 and 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 a substituent of the aromatic hydrocarbon group include an alkyl group having 1 to 5 carbon atoms, such as an alkyl group such as a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group. And a group in which part or all of the hydrogen atoms are substituted with the halogen atoms.

The aliphatic hydrocarbon group for R in the general formula (f1) may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear, branched or cyclic.
In R in the general formula (f1), the aliphatic hydrocarbon group may be substituted with a substituent containing a hetero atom in a part of carbon atoms constituting the aliphatic hydrocarbon group. A part or all of the hydrogen atoms constituting the hydrocarbon group may be substituted with a substituent containing a hetero atom.
The “heteroatom” in R in the general formula (f1) 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 only of 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 carbon atoms include, 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. When the aliphatic hydrocarbon group is cyclic, these substituents may be included in the ring structure.
Specific examples of the substituent that substitutes 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, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group and the like.
The branched 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 cyclic aliphatic hydrocarbon group (aliphatic cyclic group) in R in the general formula (f1) is an aliphatic cyclic group having 3 to 30 carbon atoms which may have a substituent.
In R in the general formula (f1), the aliphatic cyclic group may be substituted with a substituent containing a hetero atom in a part of carbon atoms constituting the aliphatic cyclic group. A part or all of the hydrogen atoms constituting the cyclic group may be substituted with a substituent containing a hetero atom.
The “heteroatom” in R in the general formula (f1) 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 only of 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 carbon atoms include, for example, —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— and the like. These substituents may be contained 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.

The aliphatic cyclic group may be a monocyclic group or a polycyclic group. The number of carbon atoms is 3 to 30, preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12.
Specifically, for example, a group in which one or more hydrogen atoms have been removed from a monocycloalkane; a group in which one or more hydrogen atoms have been 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; 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 groups obtained by removing one or more hydrogen atoms from adamantane are most preferred.
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 the following formulas (L1) to (L5), (S1) to (S4), and the like.

［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 —, wherein 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.]

Wherein, Q ", the alkylene group in R ⁹⁴ and R ^95, preferably a linear or branched alkylene group, the carbon number of the alkylene group is 1-5, is 1-3 It is 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 —, Alkylethylene groups such as —CH (CH ₂ CH ₃ ) CH ₂ —; trimethylene group (n-propylene group) [—CH ₂ CH ₂ CH ₂ —]; —CH (CH ₃ ) CH ₂ CH ₂ —, —CH _{2 CH (CH 3) CH 2} - alkyl trimethylene group and the like; Toramechiren group _{[-CH 2 CH 2 CH 2 CH} 2 -]; - CH (CH 3) CH 2 CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 CH 2 - alkyl tetramethylene group and the like; penta And methylene group [—CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ —] and the like.

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).
The alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, particularly preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or 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.

  In the present invention, the aliphatic cyclic group which may have a substituent of R in the general formula (f1) is a polycyclic aliphatic cyclic group which may have a substituent. Is preferred. The polycyclic aliphatic cyclic group is preferably a group obtained by removing one or more hydrogen atoms from the polycycloalkane, the above (L2) to (L5), (S3) to (S4), and the like.

When R in the general formula (f1) is an optionally substituted hydrocarbon group having 1 to 30 carbon atoms, it may form a ring with an adjacent carbon atom. The ring formed may be monocyclic or polycyclic. The number of carbon atoms is preferably 5-30 (including bonded carbon atoms), more preferably 5-20.
Specifically, among the cyclic aliphatic hydrocarbon groups (aliphatic cyclic groups) in R described above (assuming that the bonded carbon atoms are also part of the ring), an aliphatic cyclic group having 5 to 30 carbon atoms. Groups.

In the present invention, R in the general formula (f1) is preferably a hydrogen atom or 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 aromatic hydrocarbon group that may be used.
As the aliphatic cyclic group which may have a substituent, a polycyclic aliphatic cyclic group which may have a substituent is preferable. The polycyclic aliphatic cyclic group is preferably a group obtained by removing one or more hydrogen atoms from the polycycloalkane, the above (L2) to (L5), (S3) to (S4), and the like.
As the aromatic hydrocarbon group which may have a substituent, a naphthyl group which may have a substituent or a phenyl group which may have a substituent is more preferable.
In the present invention, R in the general formula (f1) is most preferably a hydrogen atom.

Examples of the aryl group in R ′ in the general formula (f1) include those obtained by removing the arylalkyl group from those exemplified as the aromatic hydrocarbon group in R of the general formula (f1). The aryl group for R ′ is more preferably a phenyl group.
The aliphatic cyclic group for R ′ in the general formula (f1) is the same as the aliphatic cyclic group for R in the general formula (f1). The aliphatic cyclic group for R ′ is preferably an aliphatic polycyclic group, more preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and particularly preferably one or more groups from adamantane. A group excluding a hydrogen atom.
Examples of the substituent that the aromatic hydrocarbon group or aliphatic cyclic group of R ′ may have include the same substituents as those described for R in the general formula (f1).

Examples of R ″ in the general formula (f1) include the same as R in the general formula (f1).
In the present invention, R ″ in the general formula (f1) is preferably a cyclic group which may have a substituent. The cyclic group may have an aromatic which may have a substituent. It may be an aromatic hydrocarbon group, an aliphatic cyclic group that may have a substituent, or an aromatic hydrocarbon group that 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. The polycyclic aliphatic cyclic group is preferably a group obtained by removing one or more hydrogen atoms from the polycycloalkane, the above (L2) to (L5), (S3) to (S4), and the like.
In the present invention, R ″ in the general formula (f1) is more preferably a naphthyl group which may have a substituent or a phenyl group which may have a substituent, and may have a substituent. A good phenyl group is most preferred.

In the present invention, when R and R ″ in the general formula (f1) are both a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent, they are bonded to each other to form a ring. The ring formed may be monocyclic or polycyclic. The number of carbon atoms, including the carbon atom to which R and R ″ are bonded in general formula (f1), is preferably 5 to 30, and preferably 5 to 20. More preferred.
Specifically, the carbon atom to which R and R ″ are bonded in the general formula (f1) is also considered to be a part of the formed ring, and the cyclic aliphatic hydrocarbon group (aliphatic group in R described above). Aliphatic cyclic group having 5 to 30 carbon atoms.

Specific examples of the base generator (F1) comprising the compound represented by the general formula (f1) are given below.
These may be used alone or in combination of two or more.

In the component (F), a photobase generator (F2) other than the component (F1) (hereinafter referred to as “component (F2)”) may be used in combination with the component (F1).
The component (F2) is not particularly limited as long as it is other than the component (F1), and those conventionally proposed as photobase generators for chemically amplified resists can be used.
Examples of such a photobase generator include triphenylsulfonium compounds, triphenylmethanol; photoactive carbamates such as benzyl carbamate and benzoin carbamate; o-carbamoylhydroxylamide, o-carbamoyloxime, aromatic sulfonamide, alpha- Amides such as lactam and N- (2-allylethynyl) amide; oxime esters, α-aminoacetophenone, cobalt complexes and the like, and those described in JP-A 2007-279493 are known.

  (F) As for content of a component, 0.05-20 mass parts is preferable with respect to 100 mass parts of (A) component, 0.05-15 mass parts is more preferable, and 0.1-10 mass parts is the most. preferable. (F) The effect of this invention improves because content of a component is more than a lower limit. On the other hand, by being below the upper limit, it is possible to balance the amount of acid generated from the component (B).

<Optional component>
[(D) component]
Since the resist composition of the present invention improves the resist pattern shape, the stability over time, and the like, a nitrogen-containing organic compound component (D) (hereinafter referred to as “component (D)”) is further added as an optional component. It is preferable to contain.
Since a wide variety of components (D) have already been proposed, any known one may be used. Among them, aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are used. preferable. Here, the aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 20 carbon atoms.
Examples of the aliphatic amine include an amine (alkylamine 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 20 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-hexylamine, tri-n-pentylamine , Tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, tri-n-dodecylamine, and the like; diethanolamine, triethanolamine, diisopropanolamine Triisopropanolamine, di -n- octanol amine, tri -n- octanol amine, lauryl diethanolamine, alkyl alcohol amines such as stearyl diethanolamine. Among these, a C5-C10 trialkylamine and alkyl alcohol amine are preferable, and tri-n-pentylamine, diethanolamine, and stearyl diethanolamine are particularly preferable.
Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable. Specifically, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5. 4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane, and the like.
Examples of the aromatic amine include aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, diphenylamine, triphenylamine, and tribenzylamine.
Other aliphatic amines include tris (2-methoxymethoxyethyl) amine, tris {2- (2-methoxyethoxy) ethyl} amine, tris {2- (2-methoxyethoxymethoxy) ethyl} amine, tris {2 -(1-methoxyethoxy) ethyl} amine, tris {2- (1-ethoxyethoxy) ethyl} amine, tris {2- (1-ethoxypropoxy) ethyl} amine, tris [2- {2- (2-hydroxy Ethoxy) ethoxy} ethylamine and the like.
These may be used alone or in combination of two or more.
(D) component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

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

  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.

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

The resist composition of the present invention described above is a novel one that has not been known so far.
According to the resist composition of the present invention, for example, in resist pattern formation of a contact hole pattern, lithography characteristics such as a mask error factor (MEF) are improved, and a resist pattern with good hole roundness can be formed. The reason why such an effect is obtained is not certain but is presumed as follows.
The resist composition of the present invention contains a photobase generator (F1) that generates a base upon exposure. In the resist pattern formation using the resist composition, even if the amount of acid generated from the acid generator changes due to the change in exposure amount, the amount of base generated from the component (F1) is the same as that of the acid generator component. Depending on the exposure amount (if the exposure amount increases, the amount of acid / base generated from each of the components (B) and (F) increases, and decreases if the exposure amount decreases) Therefore, it is considered that the acid diffusing into the resist film is controlled to an appropriate amount. From the above, it is presumed that the resist composition of the present invention has an effect that the lithography characteristics are improved and a resist pattern having a good shape can be formed.

≪Resist pattern formation method≫
The resist pattern forming method according to the second aspect of the present invention includes a step of forming a resist film on a support using the resist composition according to the first aspect of the present invention, a step of exposing the resist film, And a step of alkali developing the resist film to form a resist pattern.
The resist pattern forming method of the present invention can be performed, for example, as follows.
That is, first, the resist composition is coated on a support with a spinner or the like, and pre-baked (post-apply bake (PAB)) for 40 to 120 seconds, preferably 60 to 90 seconds, at a temperature of 80 to 150 ° C. Then, after selectively exposing ArF excimer laser light through a desired mask pattern, for example, with an ArF exposure apparatus or the like, PEB (post-exposure heating) is performed for 40 to 120 seconds under a temperature condition of 80 to 150 ° C. Preferably, it is applied for 60 to 90 seconds. Subsequently, this is alkali-development-processed using alkaline developing solution, for example, 0.1-10 mass% tetramethylammonium hydroxide (TMAH) aqueous solution, Preferably, water rinse is carried out using a pure water, and it dries. In some cases, a baking treatment (post-baking) may be performed after the alkali development treatment. In this way, a resist pattern faithful to the mask pattern can be obtained.

The support is not particularly limited, and a conventionally known one can be used, and examples thereof include a substrate for electronic components and a substrate on which a predetermined wiring pattern is formed. More specifically, a silicon substrate, a metal substrate such as copper, chromium, iron, and aluminum, a glass substrate, and the like can be given. As a material for the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used.
Further, the support may be a substrate in which an inorganic and / or organic film is provided on the above-described substrate. An inorganic antireflection film (inorganic BARC) is an example of the inorganic film. Examples of the organic film include an organic antireflection film (organic BARC).

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

The exposure of the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be immersion exposure.
In immersion exposure, at the time of exposure, a solvent (having a refractive index larger than the refractive index of air) is formed between a lens and a resist film on the wafer, which is conventionally filled with an inert gas such as air or nitrogen. Exposure is performed in a state filled with the 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 can be performed through a desired mask pattern (immersion exposure).
As the immersion medium, a solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film 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 fluorinated inert liquid include fluorinated compounds such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , and C ₅ H ₃ F ₇ as main components. 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.).

In the resist pattern forming method including the immersion exposure step, the resist composition according to the first aspect of the present invention can be suitably used as a resist composition for immersion exposure, and good lithography characteristics can be obtained. Moreover, in the resist pattern forming method including the step of forming a three-layer resist laminate, the resist composition of the present invention can be suitably used as a positive resist composition for forming an upper resist film, and has good lithography characteristics. can get.
Furthermore, the resist composition of the present invention can also be applied to the double exposure method and the double patterning method.

≪Compound≫
The compound which is the third aspect of the present invention is a compound represented by the above general formula (f1).
The description of the compound of the present invention is the same as the description of the photobase generator (F1) contained in the component (F) of the resist composition according to the first aspect of the present invention.

≪Photobase generator≫
The photobase generator which is the 4th aspect of this invention consists of a compound represented by the said general formula (f1).
The photobase generator is useful as a photobase generator for chemically amplified resist compositions, for example, the photobase generator component (F) of the resist composition according to the first aspect of the present invention.

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

[Production Example 1 (Synthesis of polymer compounds (1) and (2))]
[Synthesis Example 1] (Synthesis of 2- (2- (2-methyl-2-adamantyloxy) -2-oxoethoxy) -2-oxoethanol)
A 2 L three-necked flask equipped with a thermometer, a condenser and a stirrer was charged with 37.6 g (494 mmol) of glycolic acid, 700 mL of DMF, 86.5 g (626 mmol) of potassium carbonate, and 28.3 g (170 mmol) of potassium iodide at room temperature. For 30 minutes. Then, 300 mL of dimethylformamide in 100 g (412 mmol) of 2-methyl-2-adamantyl chloroacetate was slowly added. The temperature was raised to 40 ° C. and stirred for 4 hours. After completion of the reaction, 2000 mL of diethyl ether was added and filtered, and the resulting solution was washed 3 times with 500 mL of distilled water. Crystallization was performed using a mixed solution of toluene (300 mL) and heptane (200 mL) to obtain 78 g (yield 67%, GC purity 99%) of the target product as a colorless solid.

The instrumental analysis results of the obtained compound were as follows.
¹ H-NMR: 1.59 (d, 2H, J = 12.5 Hz), 1.64 (s, 3H), 1.71 to 1.99 (m, 10H), 2.29 (m, 2H) 2.63 (t, 1H, J = 5.2 Hz), 4.29 (d, 2H, J = 5.2 Hz), 4.67 (s, 2H).
¹³ C-NMR: 22.35, 26.56, 27.26, 32.97, 34.54, 36.29, 38.05, 60.54, 61.50, 89.87, 165.97, 172 .81.
GC-MS: 282 (M +, 0.02%), 165 (0.09%), 149 (40%), 148 (100%), 133 (22%), 117 (2.57%), 89 ( 0.40%).
From the above results, it was confirmed that the obtained compound was 2- (2- (2-methyl-2-adamantyloxy) -2-oxoethoxy) -2-oxoethanol.

[Synthesis Example 2] (Synthesis of 2- (2- (2-methyl-2-adamantyloxy) -2-oxoethoxy) -2-oxoethyl methacrylate (Compound 3))
To a 2 L three-necked flask equipped with a thermometer, a condenser and a stirrer was added 165 g (584 mmol) of 2- (2- (2-methyl-2-adamantyloxy) -2-oxoethoxy) -2-oxoethanol, 2000 mL of THF, Triethylamine 105 mL (754 mmol) and p-methoxyphenol 0.165 g (1000 ppm) were added and dissolved. After dissolution, 62.7 mL (648 mmol) of methacryloyl chloride was slowly added in an ice bath, warmed to room temperature, and stirred for 3 hours. After completion of the reaction, 1000 mL of diethyl ether was added and washed 5 times with 200 mL of distilled water. The extract was concentrated to obtain 198 g (yield 97%, GC purity 99%) of the target product as a colorless liquid.

The instrumental analysis results of the obtained compound 3 were as follows.
¹ H-NMR: 1.58 (d, J = 12.5 Hz, 2H), 1.63 (s, 3H), 1.71 to 1.89 (m, 8H), 1.98 (s, 3H) , 2.00 (m, 2H), 2.30 (m, 2H), 4.62 (s, 2H), 4.80 (s, 2H), 5.66 (m, 1H), 6.23 ( m, 1H).
¹³ C-NMR: 18.04, 22.15, 26.42, 27.14, 32.82, 34.38, 36.11, 37.92, 60.44, 61.28, 89.42, 126 79, 135.18, 165.61, 166.30, 167.20.
GC-MS: 350 (M +, 1.4%), 206 (0.13%), 149 (47%), 148 (100%), 133 (20%), 69 (37%).

[Synthesis Example 3] (Synthesis of polymer compound (1))
3.11 g (18.28 mmol) of [Compound 1], 16.00 g (45.71 mmol) of [Compound 2], 6.40 g (18.28 mmol) of [Compound 3], 1.73 g (7.31 mmol) [Compound 4] was dissolved in 108.96 g of methyl ethyl ketone. To this solution, 3.1 mmol of dimethyl azobisisobutyrate (V-601) as a polymerization initiator was added and dissolved. This reaction solution was added dropwise to 45.40 g of methyl ethyl ketone heated to 75 ° C. over 6 hours under a nitrogen atmosphere.
After completion of dropping, the reaction solution was heated and stirred for 1 hour, and then the reaction solution was cooled to room temperature.
The obtained reaction polymerization liquid is concentrated under reduced pressure, then dropped into a large amount of methanol / water mixed solution, and an operation for precipitating the polymer is performed. The precipitated polymer compound is filtered, washed, and dried to obtain the target product. 15 g of polymer compound (A) -3 was obtained.
About this high molecular compound, the mass mean molecular weight (Mw) of standard polystyrene conversion calculated | required by GPC measurement was 7,100, and dispersion degree (Mw / Mn) was 1.59.
The copolymer composition ratio (ratio of each structural unit in the structural formula (molar ratio)) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — 13C-NMR) was 1 / m / n / o = 24.9 / 31. It was 0.9 / 28.7 / 14.5.

[Synthesis Example 4 (Synthesis of Polymer Compound (2))]
In a 500 mL beaker, 5.10 g (30 mmol) of the following [Compound 1], 17.38 g (70 mmol) of the following [Compound 5], 7.00 g (20 mmol) of [Compound 3], 5.67 g (24 mmol) of the following [Compound 4] was added and dissolved in 55.13 g of methyl ethyl ketone. To this solution, 4.0 mmol of dimethyl azobisisobutyrate (V-601) as a polymerization initiator was added and dissolved. This reaction solution was added dropwise to 30.62 g of methyl ethyl ketone heated to 75 ° C. in a separable flask over 6 hours in a nitrogen atmosphere. After completion of dropping, the reaction solution was heated and stirred for 1 hour, and then the reaction solution was cooled to room temperature. The obtained reaction polymerization solution is concentrated under reduced pressure, then dropped into a large amount of methanol / water mixed solution, and the reaction product (copolymer) is precipitated. The precipitated reaction product is filtered, washed and dried. As a result, 15 g of the target polymer compound (2) was obtained.
With respect to this polymer compound (2), the weight average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement was 8,200, and the dispersity (Mw / Mn) was 1.75.
The copolymer composition ratio (ratio of each structural unit in the above structural formula (molar ratio)) determined by carbon 13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) at 600 MHz is 1 / m / n / o = 25.3 / 35.3 / 14.8 / 24.6.

[Synthesis Example 5] (Synthesis of polymer compound (3))
7.77 g (45.71 mmol) of [Compound 1], 31.14 g (118.85 mmol) of [Compound 2], 16.00 g (45.71 mmol) of [Compound 3], 4.32 g (18.28 mmol) [Compound 4] was dissolved in 236.92 g of methyl ethyl ketone. To this solution, 13.71 mmol of dimethyl azobisisobutyrate (V-601) as a polymerization initiator was added and dissolved. This reaction solution was added dropwise to 98.72 g of methyl ethyl ketone heated to 75 ° C. over 6 hours under a nitrogen atmosphere.
After completion of dropping, the reaction solution was heated and stirred for 1 hour, and then the reaction solution was cooled to room temperature.
The obtained reaction polymerization liquid is concentrated under reduced pressure, then dropped into a large amount of methanol / water mixed solution, and an operation for precipitating the polymer is performed. The precipitated polymer compound is filtered, washed, and dried to obtain the target product. 20 g of the polymer compound (3) was obtained.
With respect to this polymer compound (3), the standard polystyrene equivalent weight average molecular weight (Mw) determined by GPC measurement was 7,000, and the dispersity (Mw / Mn) was 1.51.
The copolymer composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by carbon-13 nuclear magnetic resonance spectrum (600 MHz — 13C-NMR) is 1 / m / n / o = 30/40/20. / 10.

[Production Example 2 (Synthesis of photobase generator)]
[Synthesis Example 6 (Synthesis of Compound A)]
Compound (I) 5.34g and THF 36.54g were stirred at 10 degreeC, 5.80g of triethylamines were added there, and it stirred for 5 minutes. Thereto was added a mixture of 11.38 g of compound (II) with 19.30 g of THF while keeping the temperature within 10 ° C. of the system. After stirring for 20 hours, the mixture was filtered, and the filtrate was concentrated and dried. The dried product was dissolved in 62.5 g of dichloromethane, and the organic layer was washed once with 62.5 g of 1% HCl aqueous solution, once with NaOH aqueous solution, and four times with pure water. The organic layer was concentrated and dried, and then dispersed and washed with 37.5 g of hexane to obtain 6.79 g of compound (A) (yield 54%).
The obtained compound was analyzed by NMR.
¹ H-NMR (DMSO, 400 MHz): δ (ppm) = 8.66 (s, 1H, N═C—H), 7.73 (d, 2H, Ar), 7.45-7.54 ( m, 3H, Ar), 2.00 (s, 3H, Ad), 1.92 (s, 6H, Ad), 1.69 (s, 6H, Ad).
From the results described above, it was confirmed that the compound (A) had a structure shown below.

[Synthesis Example 7 (Synthesis of Compound IV)]
6.72 g of compound (I) and 48.23 g of THF were stirred at 10 ° C., 7.86 g of triethylamine was added thereto, and the mixture was stirred for 5 minutes. Thereto, 9.36 g of compound (III) mixed with 18.72 g of THF was added while keeping the system at 10 ° C. or lower. After stirring for 20 hours, the reaction solution was concentrated and dried. The dried product was dissolved in 62.5 g of dichloromethane, and the organic layer was washed twice with 62.5 g of 1% HCl aqueous solution, twice with NaOH aqueous solution, and four times with pure water. The organic layer was concentrated and dried, then dissolved in 18.60 g of THF, dropped into 234.5 g of hexane, and the precipitated solid was collected by filtration to obtain 8.20 g of compound (IV) (yield 66%). Obtained.
The obtained compound was analyzed by NMR.
¹ H-NMR (DMSO, 400 MHz): δ (ppm) = 8.89 (s, 1H, N = C—H), 8.06 (d, 2H, Ar), 7.81 (d, 2H, Ar), 7.70 (t, 1H, Ar), 7.48-7.58 (m, 5H, Ar).
From the results described above, it was confirmed that the compound (IV) had a structure shown below.

[Examples 1-3, Comparative Examples 1-2]
Each component shown in Table 1 was mixed and dissolved to prepare a positive resist composition.

In Table 1, the numerical values in [] indicate the blending amount (parts by mass). Moreover, the symbol in Table 1 shows the following, respectively.
(A) -1: the polymer compound (1).
(A) -2: the polymer compound (2).
(A) -3: The polymer compound (3).
(B) -1: The following compound (B).
(F) -1: Compound (A).
(F) -2: Compound (IV).
(D) -1: Tree n-pentylamine.
(D) -2: Diethanolamine.
(E) -1: salicylic acid.
(S) -1: PGMEA / PGME = 6/4 (mass ratio) mixed solvent.

Using the obtained resist composition, a resist pattern was formed by the following procedure, and the lithography characteristics were evaluated.
[Resolution and sensitivity]
An organic antireflection film composition “ARC29” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto a 12-inch silicon wafer using a spinner, and baked on a hot plate at 205 ° C. for 60 seconds to be dried. Thus, an organic antireflection film having a film thickness of 85 nm was formed. Then, the resist compositions of Examples 1 to 3 and Comparative Examples 1 and 2 obtained above were applied onto the organic antireflection film using a spinner, and the hot resist was applied at 90 ° C. for 60 seconds. A pre-bake (PAB) treatment was performed under the conditions described above and dried to form a resist film having a thickness of 120 nm.
Next, Table 1 shows an ArF excimer laser (193 nm) with respect to the resist film using an ArF exposure apparatus NSR-S308F (manufactured by Nikon; NA (numerical aperture) = 0.92, 2/3 annular illumination). Irradiation was selectively performed through a mask pattern (6% halftone) using a contact hole pattern having a target size (hole diameter (nm) / pitch (nm)) as a target.
Thereafter, PEB treatment was performed for 60 seconds under each PEB temperature condition shown in Table 1, and further, 20% with a 2.38 mass% TMAH aqueous solution NMD-W (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) at 23 ° C. The film was alkali-developed under the conditions of seconds, rinsed with pure water for 15 seconds, and then shaken and dried.
As a result, contact hole patterns (hereinafter referred to as C / H patterns) having the hole diameters and pitches shown in Table 1 were formed in each resist composition.
Table 1 shows the optimum exposure amount Eop (mJ / cm ² ), the roundness of the hole, and the mask error factor (MEF).

[Evaluation of roundness]
Each contact hole pattern formed above was observed from above using a scanning electron microscope (SEM), and the roundness of the hole pattern was evaluated according to the following criteria. The results are also shown in Table 1.
A: The hole pattern as a whole has a high roundness (less irregularities on the circumference of the hole pattern observed from above), and has a particularly good shape.
○: The hole pattern as a whole has a high roundness (less irregularities on the circumference of the hole pattern observed from above) and a good shape.

[Evaluation of mask error factor (MEF)]
The mask error factor (MEF) in the dense CH pattern having a hole diameter of 85 nm was evaluated.
At the above Eop, using a mask pattern having a hole diameter size of 92 to 100 nm (2 nm interval, 5 points), a dense CH pattern having a pitch of 131 nm or 135 nm was formed.
At this time, the slope of the straight line when the target size (nm) was plotted on the horizontal axis and the aperture (nm) of the hole pattern formed on the resist film using each mask pattern was plotted on the vertical axis was calculated as MEF. The results are shown in Table 5.
MEF (straight line) means that the closer the value is to 1, the better the mask reproducibility.
From the above results, by using the resist composition of the present invention, for example, when forming a fine pattern with a narrow pitch of 100 nm or less such as a C / H pattern with a hole diameter of 85 nm, a pitch of 131 nm or a pitch of 135 nm. It was confirmed that the roundness of the film and the mask error factor (MEF) can be improved.
Therefore, according to the resist composition containing the compound according to the present invention as a photobase generator and the resist pattern forming method using the resist composition, lithography characteristics can be improved and a resist pattern having a good shape can be formed. Was confirmed.

Claims (9)

A base component (A) whose solubility in an alkaline developer is changed by the action of an acid, an acid generator component (B) that generates an acid upon exposure, and a photobase generator component (F) that generates a base upon exposure. A resist composition containing:
The photobase generator component (F) is represented by the following general formula (f1)

[Wherein, R and R ″ are a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent (provided that both R and R ″ may have a substituent) When they are good hydrocarbon groups having 1 to 30 carbon atoms, they are bonded to each other to form a ring); R ′ is an aryl group or an aliphatic cyclic group which may have a substituent. ]
The resist composition characterized by including the photobase generator (F1) which consists of a compound represented by these.   The resist composition according to claim 1, wherein the base component (A) is a base component whose solubility in an alkali developer is increased by the action of an acid.   The resist composition according to claim 2, wherein the substrate component (A) is a resin component (A1) and has a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.   The resist composition according to claim 3, wherein the substrate component (A) further comprises a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group.   The resist composition according to claim 3 or 4, wherein the substrate component (A) further comprises a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group.   The resist composition as described in any one of Claims 1-5 containing a nitrogen-containing organic compound (D).   A step of forming a resist film on a support using the resist composition according to any one of claims 1 to 6, a step of exposing the resist film, and an alkali development of the resist film to form a resist pattern A resist pattern forming method including a forming step. The compound represented by the following general formula (f1).

[Wherein, R and R ″ are a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent (provided that both R and R ″ may have a substituent) When they are good hydrocarbon groups having 1 to 30 carbon atoms, they are bonded to each other to form a ring); R ′ is an aryl group or an aliphatic cyclic group which may have a substituent. ]   A photobase generator comprising the compound according to claim 8.