JP5124255B2 - Resist composition and resist pattern forming method - Google Patents

Description

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

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, and the resist film is selectively exposed to light such as light or an electron beam through a mask on which a predetermined pattern is formed. And a development process is performed to form a resist pattern having a predetermined shape on the resist film.
A resist material in which the exposed portion changes to a property that dissolves in the developer is referred to as a positive type, and a resist material that changes to a property in which the exposed portion does not dissolve in the developer is referred to as a negative type.
In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has been rapidly progressing due to advances in lithography technology.
As a technique for miniaturization, the wavelength of an exposure light source is generally shortened. Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but at present, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has started. Further, studies have been made on 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 patterns with fine dimensions.
As a resist material satisfying 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 forming the resist pattern, 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 having a constitutional unit derived from (meth) acrylic acid ester (acrylic resin) 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.
JP 2003-241385 A

In recent years, the miniaturization of resist patterns has further progressed, and the demand for high resolution has further increased for conventional resist compositions. For example, in the formation of a resist pattern for a hole pattern, there is an increasing demand for the formation of a resist pattern having a good hole circularity and a good shape.
This invention is made | formed in view of the said situation, Comprising: It makes it a subject to provide the resist composition which can form a resist pattern of a favorable shape, and the resist pattern formation method using this resist composition.

In order to achieve the above object, the present invention employs the following configuration.
That is, the first aspect of the present invention includes a base material 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 the following general formula: represented by (d1-1-0), and a resist composition characterized by containing a nitrogen-containing organic compound molecular weight of 200 or more.

［式（ｄ１−１−０）中、Ｒ ^４ は疎水基であって、置換基を有していてもよい炭素数５〜５０のアルキル基であり、Ｒ ^５ およびＲ ^６ はそれぞれ独立して置換基を有していてもよい炭素数１〜３０のアルキレン基である。］

[In the formula (d1-1-0) , R ⁴ is a hydrophobic group and is an optionally substituted alkyl group having 5 to 50 carbon atoms, and R ⁵ and R ⁶ are each independently It is a C1-C30 alkylene 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, a step of exposing the resist film, and an alkali development of the resist film using the resist composition of the first aspect. A resist pattern forming method including a step of forming a resist pattern.

In the present specification and claims, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified.
Further, the “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups unless otherwise specified.
The “lower alkyl group” is an alkyl group having 1 to 5 carbon atoms.
The “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with a halogen atom, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
“Aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity.
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, it is possible to provide a resist composition capable of forming a resist pattern having a good shape and a resist pattern forming method using the resist composition.

≪Resist composition≫
The resist composition according to the first aspect of the present invention generates a base 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. An acid generator component (B) (hereinafter referred to as the component (B)) and a nitrogen-containing organic compound (D1) represented by the general formula (d1) and having a molecular weight of 200 or more are contained.
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 unexposed portion does not change the solubility in the alkaline developer. In the case of the negative type, the unexposed part is dissolved and removed, and a resist pattern is formed.
The resist composition of the present invention may be a negative resist composition or a positive resist composition.

<(A) component>
As the component (A), organic compounds that are usually used as base material components for chemically amplified resists can be used singly or in combination of two or more.
Here, the “base material component” is an organic compound having a film forming ability, and an organic compound having a molecular weight of 500 or more is preferably used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved and a nano-level resist pattern is easily formed.
The organic compound having a molecular weight of 500 or more is largely classified into a low molecular weight organic compound having a molecular weight of 500 or more and less than 2000 (hereinafter referred to as a low molecular compound) and a high molecular weight resin having a molecular weight of 2000 or more (polymer material). Separated. 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, as the component (A), a base component that is soluble in an alkali developer is used, and a crosslinking agent is blended in the negative resist composition. .
In such a negative resist composition, when an acid is generated from the component (B) by exposure, the acid acts to cause cross-linking between the base component and the cross-linking agent, 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 an alkali-soluble resin) is usually used.
As the alkali-soluble resin, 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 is a good resist with little swelling. A pattern can be formed, which is preferable. 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 component (A ′) (hereinafter referred to as (A ′)) whose solubility in an alkaline developer is increased by the action of an acid. Component)).
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 base material component (A ′) 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 (A2) (hereinafter sometimes referred to as component (A2)) that increases the solubility in a 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 alone or in combination of two or more.
In the present invention, the component (A1) preferably contains a structural unit derived from an acrylate ester.
Here, in the present specification and claims, the “structural unit derived from an acrylate ester” means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester.
“Acrylic acid esters” include those in which a hydrogen atom is bonded to the carbon atom at the α-position, and those in which a substituent (atom or group other than a hydrogen atom) is bonded to the carbon atom in the α-position. Include concepts. Examples of the substituent include 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 part or all of the hydrogen atoms in 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.

The component (A1) particularly preferably has a structural unit (a1) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.
In addition to the structural unit (a1), the component (A1) preferably further has a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group.
The component (A1) is derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group in addition to the structural unit (a1) or in addition to the structural units (a1) and (a2). It is preferable to have a unit (a3).

・ Structural unit (a1)
The acid dissociable, dissolution inhibiting group in the structural unit (a1) has an alkali dissolution inhibiting property that makes the entire component (A1) difficult to dissolve in an alkali developer before dissociation, and dissociates with an acid. This increases the solubility of the entire component in an alkaline developer, and those that have been proposed as acid dissociable, dissolution inhibiting groups for base resins for chemically amplified resists can be used. Generally, 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.

“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 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 that 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 specifically, monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane are exemplified. .

  Examples of the acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group include a group having a tertiary carbon atom on the ring skeleton of a cyclic alkyl group. Specifically, 2-methyl-2 -Adamantyl group, 2-ethyl-2-adamantyl group, etc. are mentioned. Alternatively, in the structural units represented by the following general formulas (a1 ″ -1) to (a1 ″ -6), an adamantyl group such as a group bonded to an oxygen atom of a carbonyloxy group (—C (O) —O—) 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 that have been proposed in a number of conventional ArF resists. For example, the above “aliphatic ring” Examples thereof are the same as those in the formula group.

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

［式中、Ｒ^１７、Ｒ^１８はそれぞれ独立して直鎖状もしく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がそれぞれ独立して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, and preferably has 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. More specifically, monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane are exemplified. . 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 ^{19 17} ends may be bonded.
In this case, a cyclic group is formed by R ¹⁷ , R ¹⁹ , the oxygen atom to which R ¹⁹ is bonded, and the carbon atom to which the oxygen atom and R ¹⁷ are bonded. The cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

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

［式中、Ｒは水素原子、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はアルキレン基、２価の脂肪族環式基又は「Ａ−Ｏ−Ｂ」（ただし、Ａは置換基を有していてもよい炭素数１以上の２価の炭化水素基であり、Ｂは置換基を有していてもよい炭素数１以上の２価の炭化水素基である。）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 an alkylene group, a divalent aliphatic cyclic group or “A —O—B ”(where A is a divalent hydrocarbon group having 1 or more carbon atoms which may have a substituent, and B is 2 having 1 or more carbon atoms which may have a substituent. Is a valent hydrocarbon 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).

Y ² represents an alkylene group, a divalent aliphatic cyclic group, or the “A-O-B”.
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—O—B”, A is a divalent hydrocarbon group having 1 or more carbon atoms which may have a substituent, and B has a substituent. Or a divalent hydrocarbon group having 1 or more carbon atoms.
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 may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity.

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

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8, still more preferably 2 to 5, and most preferably 2.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. Specifically, a methylene group, an ethylene group [— (CH ₂ ) ₂ —], a trimethylene group [— (CH ₂ ) ₃ -], tetramethylene group _{[- (CH 2) 4 -} ], a pentamethylene group _{[- (CH 2) 5 -} ] , and the like.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ). _{2 -, - C (CH 3} ) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as - _{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, an oxygen atom (═O), and the like.

Examples of the aliphatic hydrocarbon group containing a ring include a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and the cyclic aliphatic hydrocarbon group described above as a chain-like aliphatic group. And a group bonded to the terminal of the aromatic hydrocarbon group or interposed in the middle of the chain-like aliphatic hydrocarbon group.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic group, a group in which two hydrogen atoms have been removed from a monocycloalkane having 3 to 6 carbon atoms is preferable, and examples of the monocycloalkane include cyclopentane and cyclohexane.
As the polycyclic group, a group in which two hydrogen atoms are removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, tetra And cyclododecane.
The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include 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 an ethylene group.

Examples of the hydrocarbon group for B include the same divalent hydrocarbon groups having 2 or more carbon atoms as those described above for A and a methylene group that may have a substituent. Examples of the substituent that the methylene group may have include the same substituents as those exemplified as the substituent that the chain aliphatic hydrocarbon group may have.
B is preferably a linear or branched aliphatic hydrocarbon group, particularly preferably a methylene group or an alkylmethylene group.
The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.

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

［式中、Ｘ’は第３級アルキルエステル型酸解離性溶解抑制基を表し、Ｙは炭素数１〜５の低級アルキル基、または脂肪族環式基を表し；ｎは０〜３の整数を表し；Ｙ^２はアルキレン基、脂肪族環式基又は「Ａ−Ｏ−Ｂ」（ただし、Ａ、Ｂは前記と同じである。）を表し；Ｒは前記と同じであり、Ｒ^１’、Ｒ^２’はそれぞれ独立して水素原子または炭素数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 represents an alkylene group, an aliphatic cyclic group, or “A—O—B” (where A and B are the same as above); R is the same as above, and R ¹ ′ , R ² ′ each independently represents 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.

Among the above, the structural unit represented by the general formula (a1-1) or (a1-3) is preferable, and specifically, (a1-1-1) to (a1-1-6), (a1-1) It is more preferable to use at least one selected from the group consisting of -35) to (a1-1-41) and (a1-3-49) to (a1-3-56).
Furthermore, as the structural unit (a1), those represented by the following general formula (a1-1-01) that include structural units of the formula (a1-1-1) to the formula (a1-1-4), What is represented by the following general formula (a1-1-02) including the structural units of formulas (a1-1-35) to (a1-1-41), formulas (a1-3-49) to (a1- 3-52) represented by the following general formula (a1-3-01) including the structural units, or the following structural units of the formulas (a1-3-53) to (a1-3-56) What is represented by general formula (a1-3-02) 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１〜３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 3.)

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, preferably a methyl group or an ethyl group, and most preferably 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０〜３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 0 to 3.)

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

As the structural unit (a1), one type of structural unit may be used alone, or two or more types of structural units may be used in combination.
In the component (A1), the proportion of the structural unit (a1) is preferably 10 to 80 mol%, more preferably 20 to 70 mol%, more preferably 25 to 50 mol%, based on all structural units constituting the component (A1). Is more preferable. By setting it to the lower limit value or more, a pattern can be easily obtained when 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 structural unit represented by the general formula (a1-3-01) and a monomer that derives the structural unit represented by the general formula (a1-3-02) (hereinafter collectively referred to as “monomer W”). Can be produced, for example, by the first production method shown below.

First manufacturing method:
In the presence of a base, the compound represented by the following general formula (I-2) is added to the solution in which the compound represented by the following general formula (I-1) is dissolved in the reaction solvent, and the reaction is performed. After obtaining a compound represented by general formula (I-3) (hereinafter referred to as compound (I-3)), a solution in which compound (I-3) is dissolved is represented by the following general formula (I-4). The monomer W is obtained by adding and reacting the represented compound in the presence of a base.
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 (I-1) and (I-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は置換基を有していてもよい炭素数２以上の２価の炭化水素基であり、Ｂは置換基を有していてもよい炭素数１以上の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。］

[Wherein, R represents a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; A represents a divalent hydrocarbon group having 2 or more carbon atoms which may have a substituent, and B represents a substituent. X ² is an acid dissociable, dissolution inhibiting group, X ¹⁰ and X ¹² are each independently a hydroxyl group or a halogen atom. , X ¹⁰ and X ¹² are a hydroxyl group, the other is a halogen atom, and X ¹¹ is a halogen atom. ]

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 and particularly preferably a bromine atom because of excellent reactivity.

・ 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 γ-butyrolactone. 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 ″; A hydrogen atom or a linear, branched or cyclic alkylalkyl 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 have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group More specifically, one or more hydrogen atoms are removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Group and the like.
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.

  As the structural unit (a2), at least one selected from the group consisting of structural units represented by the general formulas (a2-1) to (a2-5) is preferable, and the general formulas (a2-1) to ( At least one selected from the group consisting of structural units represented by a2-3) is more preferred. Among them, chemical formulas (a2-1-1), (a2-1-2), (a2-2-1), (a2-2-2), (a2-2-9), (a2-2-10) ), (A2-3-1), (a2-3-2), (a2-3-9) and (a2-3-10), and at least one selected from the group consisting of structural units represented by More preferably, at least one selected from the group consisting of structural units represented by (a2-1-1), (a2-1-2), (a2-2-1) and (a2-2-2) Is particularly preferred.

As the structural unit (a2), one type may be used alone, or two or more types may be used in combination.
In the component (A1), the proportion of the structural unit (a2) is preferably 5 to 60 mol%, more preferably 10 to 50 mol%, based on the total of all the structural units constituting the component (A1). 50 mol% is more preferable. By making it the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by making it the upper limit value or less, it is possible to balance with other structural units.

・ Structural unit (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 (A1) is increased, the affinity with the developer is increased, the alkali solubility in the exposed area is improved, and the resolution is improved. Contributes to improvement.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom. A hydroxyl group is particularly preferable.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a 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. The structural unit is preferred. 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 (a3-3) The structural unit is preferably mentioned.

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

(Wherein R is the same as above, j is an integer of 1 to 3, k is an integer of 1 to 3, t 'is an integer of 1 to 3, and l is an integer of 1 to 5) And s is an integer of 1 to 3.)

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

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

・ Structural unit (a4)
The component (A1) may contain other structural units (a4) other than the structural units (a1) to (a3) as long as the effects of the present invention are not impaired.
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. 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。）

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

  When the structural unit (a4) is contained in the component (A1), the proportion of the structural unit (a4) in the component (A1) is 1 to 30 with respect to the total of all the structural units constituting the component (A1). Mol% is preferable and 10 to 20 mol% is more preferable.

In the present invention, the component (A1) preferably contains a copolymer having the structural units (a1), (a2) and (a3). Examples of the copolymer include copolymers composed of the structural units (a1), (a2) and (a3), copolymers composed of the structural units (a1), (a2), (a3) and (a4). Can be mentioned.
As such a copolymer, for example, those containing three types of structural units represented by the following general formulas (A1-11) to (A1-13) are preferable.

［式（Ａ１−１１）中、Ｒ、Ａ”、ａ、Ｒ^１３、Ｒ^１４はそれぞれ前記と同じである。複数のＲはそれぞれ同じであっても異なっていてもよい。］

[In formula (A1-11), R, A ″, a, R ¹³ and R ¹⁴ are the same as defined above. The plurality of R may be the same or different.

^A in formula ^{(A1-11), R 13, R} 14 are each, ^a in the general formula (a1-3-01), is the same as R ^{13, R 14.}
a is preferably an integer of 2 to 5, and most preferably 2.
R ¹³ is preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.
R ¹⁴ is preferably a methyl group or an ethyl group, and most preferably a methyl group.
A ″ in the formula (A1-11) is the same as A ″ in the general formula (a2-2), and A ″ is preferably an oxygen atom, a methylene group, or an ethylene group.
R is the same as R mentioned in the structural units (a1), (a2), (a3) and the like, and a plurality of R may be the same or different.

［式（Ａ１−１２）中、Ｒは前記と同じであり、複数のＲはそれぞれ同じであっても異なっていてもよい。Ｒ^１０は低級アルキル基である。］

[In formula (A1-12), R is the same as defined above, and the plurality of R may be the same or different. R ¹⁰ is a lower alkyl group. ]

In formula (A1-12), the lower alkyl group for R ^{10 is the same as} the lower alkyl group for R, preferably a methyl group or an ethyl group, and most preferably an ethyl group.

［式（Ａ１−１３）中、Ｒ、Ａ”は前記と同じであり、複数のＲはそれぞれ同じであっても異なっていてもよい。Ｒ^２０は低級アルキル基である。］

[In Formula (A1-13), R and A ″ are the same as defined above, and the plurality of R may be the same or different. R ²⁰ is a lower alkyl group.]

In formula (A1-13), the lower alkyl group for R ^{20 is the same as} the lower alkyl group for R, preferably a methyl group or an ethyl group, and most preferably an ethyl group.

In the resist composition of the present invention, among the copolymers containing the three structural units represented by the general formulas (A1-11) to (A1-13), three kinds represented by the general formula (A1-11) are used. Is particularly preferable as a combination with the nitrogen-containing organic compound (D1).
When a copolymer containing three types of structural units represented by general formula (A1-11) and the nitrogen-containing organic compound (D1) are used in combination, a resist pattern having a better shape is formed.

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

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, preferably 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.

As the component (A), one type may be used alone, or two or more types may be used in combination.
In the resist composition of the present 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 an onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) can be used.

［式中、Ｒ^１”〜Ｒ^３”，Ｒ^５”〜Ｒ^６”は、それぞれ独立に、アリール基またはアルキル基を表し；式（ｂ−１）におけるＲ^１”〜Ｒ^３”のうち、いずれか２つが相互に結合して式中のイオウ原子と共に環を形成してもよく；Ｒ^４”は、置換基を有していてもよいアルキル基、ハロゲン化アルキル基、アリール基、またはアルケニル基を表し；Ｒ^１”〜Ｒ^３”のうち少なくとも１つはアリール基を表し、Ｒ^５”〜Ｒ^６”のうち少なくとも１つはアリール基を表す。］

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

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

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

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

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

R ⁴ ″ represents an alkyl group, a halogenated alkyl group, an aryl group, or an alkenyl group which may have a substituent.
The alkyl group for R ⁴ ″ may be linear, branched or cyclic.
The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
The cyclic alkyl group preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.

Examples of the halogenated alkyl group for R ⁴ ″ include groups in which part or all of the hydrogen atoms of the linear, branched, or cyclic alkyl group have been substituted with halogen atoms.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
In the halogenated alkyl group, the ratio of the number of halogen atoms to the total number of halogen atoms and hydrogen atoms contained in the halogenated alkyl group (halogenation rate (%)) is preferably 10 to 100%. 50 to 100% is preferable, and 100% is most preferable. The higher the halogenation rate, the better the acid strength.

The aryl group for R ⁴ ″ is preferably an aryl group having 6 to 20 carbon atoms.
The alkenyl group in R ⁴ ″ is preferably an alkenyl group having 2 to 10 carbon atoms.

In the above R ⁴ ″, “optionally substituted” means that the hydrogen atom in the linear, branched, or cyclic alkyl group, halogenated alkyl group, aryl group, or alkenyl group is It means that part or all may be substituted with a substituent (an atom or group other than a hydrogen atom).
The number of substituents in R ⁴ ″ may be one, or two or more.

  Examples of the substituent include a halogen atom, a hetero atom, an alkyl group, and a group represented by the following general formula (b-7).

［式（ｂ−７）中、Ｒ^７”は１価の芳香族有機基、ヘテロ原子を含んでいてもよい１価の脂肪族炭化水素基、またはヒドロキシアルキル基であり；ｂは０または１である。］

[In the formula (b-7), R ⁷ ″ is a monovalent aromatic organic group, a monovalent aliphatic hydrocarbon group which may contain a hetero atom, or a hydroxyalkyl group; b is 0 or 1 Is.]

Examples of the halogen atom and alkyl group in the substituent include the same groups as those described above for R ⁴ ″ as the halogen atom and alkyl group in the halogenated alkyl group.
Examples of the hetero atom include an oxygen atom, a nitrogen atom, and a sulfur atom.

In the group represented by the general formula (b-7), examples of the monovalent aromatic organic group represented by R ⁷ ″ include a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group. ), Aryl groups such as phenanthryl groups, etc., wherein one hydrogen atom is removed from the aromatic hydrocarbon ring; some of the carbon atoms constituting the ring of these aryl groups are oxygen atoms, sulfur atoms, nitrogen atoms, etc. Heteroaryl groups substituted with heteroatoms; arylalkyl groups such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl and the like.
The number of carbon atoms in the alkyl chain in the arylalkyl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.
These aryl groups, heteroaryl groups, and arylalkyl groups may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, an alkoxy group, a hydroxyl group, or a halogen atom. 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. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom, and a fluorine atom is preferable.
The monovalent aromatic organic group for R ⁷ ″ is preferably an arylalkyl group, more preferably an arylmethyl group, and most preferably a naphthylmethyl group.

Examples of the aliphatic hydrocarbon group of the monovalent aliphatic hydrocarbon group which may contain a hetero atom of R ⁷ ″ include, for example, a linear, branched or cyclic monovalent monovalent hydrocarbon having 1 to 15 carbon atoms. Examples thereof include a saturated hydrocarbon group or a linear or branched monovalent aliphatic unsaturated hydrocarbon group having 2 to 5 carbon atoms.
As the monovalent aliphatic hydrocarbon group containing a hetero atom, it suffices if the structure contains a hetero atom. For example, an oxygen atom, a nitrogen atom, a sulfur atom, or an ester bond (—C (═O) Examples of the aliphatic hydrocarbon group include O-).
In the aliphatic hydrocarbon group, examples of the linear monovalent saturated hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, and a nonyl group. And a decanyl group.
Examples of the branched monovalent saturated hydrocarbon group include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1 -Ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like can be mentioned.
The cyclic monovalent saturated hydrocarbon group may be either a polycyclic group or a monocyclic group, for example, one from a polycycloalkane such as a monocycloalkane, a bicycloalkane, a tricycloalkane, or a tetracycloalkane. And a group in which a hydrogen atom is removed. More specifically, one hydrogen atom was removed from a monocycloalkane such as cyclopentane, cyclohexane, cycloheptane, cyclooctane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Group and the like.
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.
The carbon number of the monovalent aliphatic hydrocarbon group for R ⁷ ″ is preferably 2 to 4, and particularly preferably 3.

The hydroxyalkyl group for R ⁷ ″ is one in which at least one hydrogen atom of a linear, branched, or cyclic monovalent saturated hydrocarbon group is substituted with a hydroxyl group. A monovalent saturated hydrocarbon group in which one or two hydrogen atoms are substituted with a hydroxyl group is preferable, specifically, a hydroxymethyl group, a hydroxyethyl group, a 1-hydroxypropyl group, a 2-hydroxypropyl group, A 3-hydroxypropyl group, a 2,3-dihydroxypropyl group, etc. are mentioned.
1-10 are preferable, as for carbon number of the monovalent | monohydric hydroxyalkyl group of R < ⁷ >'', 1-8 are more preferable, 1-6 are especially preferable, and 1-3 are the most preferable.

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 R ⁵ ″ to R ⁶ ″ are all phenyl groups.
"The, ^{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 formulas (b-1) and (b-2) include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, bis (4-tert-butylphenyl) iodonium. Trifluoromethane sulfonate or nonafluorobutane sulfonate, triphenylsulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, tri (4-methylphenyl) sulfonium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its Nonafluorobutanesulfonate, dimethyl (4-hydroxynaphthyl) sulfonium trifluoromethanesulfonate, its heptaful Lopropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of monophenyldimethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; trifluoromethanesulfonate of diphenylmonomethylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate (4-methylphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, (4-methoxyphenyl) diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate , Trifluoromethanesulfonate of tri (4-tert-butyl) phenylsulfonium, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, trifluoromethanesulfonate of diphenyl (1- (4-methoxy) naphthyl) sulfonium, its heptafluoropropane Sulfonate or its nonafluorobutane sulfonate, di (1-naphthyl) phenyl sulphonium trifluoromethane sulphonate, its heptafluoropropane sulphonate or its nonafluorobutane sulphonate; 1-phenyltetrahydrothiophenium trifluoromethane sulphonate, its heptafluoropropane sulphonate Or nonafluorobutanesulfonate thereof; 1- (4-methylphenyl) ) Tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropane sulfonate 1- (4-methoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1- (4-ethoxynaphthalene-1- Yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonaflu 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate; 1-phenyltetrahydrothiopyranium trifluoromethanesulfonate , Its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (4-hydroxyphenyl) tetrahydrothiopyranium trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1- (3,5-dimethyl -4-Hydroxyphenyl) tetrahydrothiopyranium trifluoromethanesulfonate, its heptafluoropropanes Honeto or nonafluorobutanesulfonate; 1- (4-methylphenyl) trifluoromethanesulfonate tetrahydrothiophenium Pila chloride, heptafluoropropane sulfonate or its nonafluorobutane sulfonate, and the like.
Moreover, the onium salt which replaced the anion part of these onium salts by methanesulfonate, n-propanesulfonate, n-butanesulfonate, and n-octanesulfonate can also be used.
Furthermore, the onium salt which uses the fluorinated alkyl (C1-C10 of this alkyl) sulfonate ion which has group represented by the said general formula (b-7) as an anion part is also mentioned. For example, an onium salt represented by the following chemical formula is preferable.

  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 and substituted with

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

  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 codes 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). And an anion moiety represented by the general formula (b-3) or (b-4), an anion moiety represented by the general formula (b-7), and the like.

  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), the alkyl group or halogenated alkyl group having no substituent of R ³³ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and carbon atoms. Numbers 1 to 6 are most preferable.
R ³³ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³³ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred.

As the aryl group of R ³⁴ , one hydrogen atom is removed from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, or a phenanthryl group. And a heteroaryl group in which a part of carbon atoms constituting the ring of these groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Of 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 as those having no substituent of R ³⁵ .
p ″ is preferably 2.

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

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

(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, as the component (B), it is preferable to use an onium salt acid generator having a fluorinated alkyl sulfonate ion which may have a substituent as an anion part.
0.5-30 mass parts is preferable with respect to 100 mass parts of (A) component, and, as for content of (B) component in the resist composition of this invention, 1-10 mass parts is more preferable. By setting it within the above range, pattern formation is sufficiently performed. Moreover, since a uniform solution is obtained and storage stability becomes favorable, it is preferable.

<(D1) component>
The resist composition of the present invention contains a nitrogen-containing organic compound (D1) (hereinafter referred to as (D1) component) represented by the following general formula (d1) and having a molecular weight of 200 or more.

［式（ｄ１）中、Ｒ^１〜Ｒ^３はそれぞれ独立して置換基を有していてもよい炭化水素基であって、Ｒ^１〜Ｒ^３のうち少なくとも１つが極性基含有炭化水素基であり、かつ、Ｒ^１〜Ｒ^３のうち少なくとも１つが疎水基である。ただし、Ｒ^１〜Ｒ^３のいずれか２つが相互に結合して式中の窒素原子と共に環を形成してもよい。］

[In formula (d1), R ^{1 to} R ³ are each independently a hydrocarbon group optionally having a substituent, and at least one of R ^{1 to} R ³ is a polar group-containing hydrocarbon group. And at least one of R ^{1 to} R ³ is a hydrophobic group. However, any two of R ^{1 to} R ³ may be bonded to each other to form a ring together with the nitrogen atom in the formula. ]

The molecular weight of the component (D1) is 200 or more, preferably 220 or more, and more preferably 300 or more. When the molecular weight of the component (D1) is 200 or more, a resist pattern having a good shape is easily formed.
The upper limit is preferably 1000 or less, more preferably 800 or less, and even more preferably 700 or less. When the molecular weight is 1000 or less, solubility in a resist solvent (such as an organic solvent (S) described later) is improved.

In formula (d1), R ^{1 to} R ³ are each independently a hydrocarbon group which may have a substituent, and at least one of R ^{1 to} R ³ is a polar group-containing hydrocarbon group. And at least one of R ^{1 to} R ³ is a hydrophobic group.

In the hydrocarbon group which may have a substituent, the hydrocarbon group “has a substituent” means that part or all of the hydrogen atoms in the hydrocarbon group are substituted with groups or atoms other than hydrogen atoms. Means that
The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity.
Examples of the substituent include a halogen atom, a halogenated lower alkyl group having 1 to 5 carbon atoms substituted with a halogen atom, a polar group, or a group containing a polar group.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group include groups in which some or all of the hydrogen atoms in the alkyl group have been substituted with halogen atoms, with fluorinated alkyl groups being particularly preferred.

In the polar group or the group containing a polar group, preferred specific examples of the polar group include an ether group (—O—), an ester group, a hydroxy group (—OH), and a carbonyl group (—C (═O) — ), A carboxy group (—COOH), an oxygen atom (═O), a cyano group (—CN), a lactone ring, an amino group (—NH ₂ ), and an amide group (—NHC (═O) —).
A group containing a polar group (hereinafter referred to as polar group-containing substituent) refers to a group or atom containing a polar group in its structure.
For example, the component (D1) includes a compound containing a moiety represented by the following formula.

  Examples of the polar group-containing substituent include an alkyloxy group, a hydroxyalkyloxy group, an alkyloxyalkyloxy group, an alkyloxycarbonyloxy group, an alkoxycarbonylalkyloxy group, and an alkyloxycarbonyl group.

The aliphatic hydrocarbon group in R ^{1 to} R ³ may be saturated or unsaturated, and is usually preferably saturated.
1-50 are preferable, as for carbon number of an aliphatic hydrocarbon group, it is more preferable that it is 2-50, and it is further more preferable that it is 3-50.
Examples of the aliphatic hydrocarbon group include a linear, branched or cyclic monovalent saturated hydrocarbon group; a linear or branched monovalent aliphatic unsaturated hydrocarbon group.

Examples of the linear monovalent saturated hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decanyl group, an undecyl group, and a dodecyl group. Group, tridecyl group, isotridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group and the like.
Examples of the branched monovalent saturated hydrocarbon group include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1 -Ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like can be mentioned.
Examples of the cyclic monovalent saturated hydrocarbon group include a cyclic saturated hydrocarbon group (a group obtained by removing two hydrogen atoms from a saturated hydrocarbon ring), or the above-described chain saturated hydrocarbon group. Examples thereof include a group bonded to the terminal of a hydrogen group or interposed in the middle of a chain-like aliphatic hydrocarbon group. The cyclic saturated hydrocarbon group may be either a polycyclic group or a monocyclic group. For example, a single hydrogen atom is obtained from a polycycloalkane such as a monocycloalkane, a bicycloalkane, a tricycloalkane, or a tetracycloalkane. Excluded groups and the like. More specifically, one hydrogen atom was removed from a monocycloalkane such as cyclopentane, cyclohexane, cycloheptane, cyclooctane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Group and the like.

Examples of the linear monovalent aliphatic unsaturated hydrocarbon group include a propenyl group (allyl group) and a butynyl group.
Examples of the branched monovalent aliphatic unsaturated hydrocarbon group include a 1-methylpropenyl group and a 2-methylpropenyl group.

Examples of the aromatic hydrocarbon group in R ^{1 to} R ³ include aromatic hydrocarbon groups such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, and a phenanthryl group. An aryl group in which one hydrogen atom is removed from the ring; a heteroaryl group in which a part of carbon atoms constituting the ring of these aryl groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom; a benzyl group; Examples thereof include arylalkyl groups such as phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group and 2-naphthylethyl group.
The number of carbon atoms in the alkyl chain in the arylalkyl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.
These aryl groups, heteroaryl groups, and arylalkyl groups may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, an alkoxy group, a hydroxyl group, or a halogen atom.
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. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom, and a fluorine atom is preferable.

In the formula (d1), at least one of R ^{1 to} R ³ is a polar group-containing hydrocarbon group, and at least one of R ^{1 to} R ³ is a hydrophobic group. Thereby, the effect of the present invention can be obtained.
In the polar group-containing hydrocarbon group, the polar group may be present at any position in the hydrocarbon group. For example, the polar group may be present at the end of the hydrocarbon group, and hydrogen in the middle of the hydrocarbon chain. A part of the atoms may be substituted and may be present in the middle of the hydrocarbon group, or may be present as a linking group between the carbon atoms constituting the hydrocarbon chain of the hydrocarbon group. Examples of the linking group include an ether group (—O—), an ester group, a carbonyl group (—C (═O) —), an amide group (—NHC (═O) —), and the like.
Further, the polar group present in the hydrocarbon group may be one or plural, and preferably one is present.
Examples of the polar group-containing hydrocarbon group include those in which the terminal of the aliphatic hydrocarbon group or the aromatic hydrocarbon group or a hydrogen atom in the middle thereof is substituted by the polar group or the polar group-containing substituent; And the like in which the polar group is present as a linking group in the middle of the hydrocarbon chain of the aliphatic hydrocarbon group.

  Examples of the hydrophobic group include, for example, the above aliphatic hydrocarbon group, aromatic hydrocarbon group, aliphatic hydrocarbon group to which a halogen atom or a halogenated lower alkyl group is bonded, and aromatic to which a halogen atom or a halogenated lower alkyl group is bonded. Group hydrocarbon group.

However, in the formula (d1), any two of R ^{1 to} R ³ may be bonded to each other to form a ring together with the nitrogen atom in the formula. In this case, a cyclic group is formed by any two of R ^{1 to} R ³ and the nitrogen atom in the formula.
In such a case, the polar group-containing hydrocarbon group may constitute part or all of the cyclic group, in which case the polar group or polar group-containing substituent forms part of the main chain of the ring. It may be bonded to a carbon atom constituting the ring as a substituent.
As the cyclic group, a 4- to 7-membered ring including a nitrogen atom in the formula is preferable, and a 4- to 6-membered ring is more preferable.
For example, the component (D1) includes a compound containing a moiety represented by the following formula.

Among these, as the component (D1), since the effect of the present invention is better, two of R ^{1 to} R ³ in the general formula (d1) are polar group-containing hydrocarbon groups. In addition, a nitrogen-containing organic compound (D1-1) (hereinafter referred to as the component (D1-1)) in which the remaining one is a hydrophobic group is preferable.
Among those contained in the component (D1-1), a nitrogen-containing organic compound represented by the following general formula (d1-1-0) is most preferable because the effect of the present invention is particularly good.

［式（ｄ１−１−０）中、Ｒ^４は置換基を有していてもよい炭素数５〜５０のアルキル基であり、Ｒ^５およびＲ^６はそれぞれ独立して置換基を有していてもよい炭素数１〜３０のアルキレン基である。］

[In the formula (d1-1-0), R ⁴ is an optionally substituted alkyl group having 5 to 50 carbon atoms, and R ⁵ and R ⁶ each independently have a substituent. The alkylene group may have 1 to 30 carbon atoms. ]

In formula (d1-1-0), R ⁴ represents an alkyl group having 5 to 50 carbon atoms which may have a substituent.
Examples of the substituent include those similar to the substituents exemplified in the description of R ¹ to R ^3.
In the alkyl group of R ^4, preferably 5 to 50 carbon atoms, more preferably 5 to 45 carbon atoms, more preferably 5 to 40 carbon atoms, is 10 to 20 carbon atoms It is particularly preferable that the number of carbon atoms is 15-20. When the number is 5 or more, the resolution is improved, and when the number is 50 or less, the solubility in a resist solvent (such as an organic solvent (S) described later) is improved.

In formula (d1-1-0), R ⁵ and R ⁶ are each independently an alkylene group having 1 to 30 carbon atoms which may have a substituent.
Examples of the substituent include those similar to the substituents exemplified in the description of R ¹ to R ^3.
The alkylene groups for R ⁵ and R ⁶ each independently preferably have 1 to 30 carbon atoms, more preferably 1 to 25 carbon atoms, and still more preferably 1 to 20 carbon atoms. When the number is 1 or more, the resolution and roundness are improved, and when the number is 30 or less, the solubility in a resist solvent (such as an organic solvent (S) described later) is improved.

  Specific examples suitable as the component (D1) are shown below.

In the resist composition of the present invention, as the component (D1), one type may be used alone, or two or more types may be used in combination.
The content ratio of the component (D1) in the resist composition of the present invention is preferably 0.01 to 5 parts by mass, and 0.01 to 3 parts by mass with respect to 100 parts by mass of the component (A). Particularly preferred is 0.02 to 2.5 parts by mass. By being more than the lower limit of the range, a better resist pattern can be formed. On the other hand, storage stability will become favorable by being below an upper limit.

<Optional component>
[(D2) component]
In the resist composition of the present invention, a nitrogen-containing organic compound (D2) other than the component (D1) (hereinafter referred to as the component (D2)) is added to the resist pattern shape and the drawing within a range not impairing the effects of the present invention. Since the stability over time is improved, it can be further contained as an optional component.
Since a wide variety of the component (D2) has already been proposed, any component other than the component (D1) may be used from known ones, among which cyclic amines, aliphatic amines, Secondary aliphatic amines and tertiary aliphatic amines are preferred. Here, the aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.

Examples of the aliphatic amine include amines (alkyl amines or alkyl alcohol amines) in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms. Specific examples thereof include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, 1-adamantanamine; diethylamine, di-n-propylamine, di- dialkylamines such as n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, Trialkylamines such as tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, tri-n-dodecylamine, dicyclohexylmethylamine; diethanolamine, triethanolamine, diisopropaline Ruamin, triisopropanolamine, di -n- octanol amine, tri -n- octanol amine, diethylethanolamine, and the like alkyl alcohol amines such as diethyl propanolamine.
Other examples include tris (2- (2-methoxyethoxy) ethyl) amine.
Among these, alkyl alcohol amines and trialkyl amines are preferable, and trialkyl amines are particularly preferable. Of the trialkylamines, tri-n-pentylamine is most preferred.

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.

As the component (D2), the nitrogen-containing organic compounds mentioned as the component (D2) may be used alone, or two or more kinds may be used in combination.
Content of (D2) component in the resist composition of this invention 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 an organic carboxylic acid, a phosphorus oxo acid, and derivatives thereof as optional components for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, retention stability over time, etc. 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 and derivatives thereof include phosphoric acid, phosphonic acid, phosphinic acid and the like, and among these, phosphonic acid is particularly preferable.
Examples of the oxo acid derivative of phosphorus include esters in which the hydrogen atom of the oxo acid is substituted with a hydrocarbon group, and the hydrocarbon group includes an alkyl group having 1 to 5 carbon atoms and 6 to 6 carbon atoms. 15 aryl groups and the like.
Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.
Examples of phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid-di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.
Examples of the phosphinic acid derivatives include phosphinic acid esters such as phenylphosphinic acid.
(E) A component may be used individually by 1 type and may use 2 or more types together.
As the component (E), an organic carboxylic acid is preferable, and salicylic acid is particularly preferable.
(E) A component is used in the ratio of 0.01-5.0 mass parts per 100 mass parts of (A) component.

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

[(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, PGMEA, 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 the component (S) used is not particularly limited, but it is a concentration that can be applied to a support such as a substrate, and is appropriately set according to the coating film thickness. The concentration is 2 to 20% by mass, preferably 5 to 15% by mass.

The resist composition of the present invention has an effect that a resist pattern having a good shape can be formed. In forming the hole pattern, a resist pattern with high roundness can be formed. The reason is not clear, but is presumed as follows.
In the resist composition of the present invention, a nitrogen-containing organic compound (D1) having a molecular weight of 200 or more and having a polar group-containing hydrocarbon group and a hydrophobic group is used.
Since the component (D1) has a molecular weight of 200 or more, it is difficult to evaporate out of the resist film during pre-baking in forming a resist pattern. In addition, the component (D1) tends to be uniformly distributed because diffusion in the resist film is moderately suppressed by the interaction between the polar group in the polar group-containing hydrocarbon group and other compounding components.
By these, since the diffusion of the acid generated from the component (B) by exposure is effectively suppressed, it is presumed that a resist pattern having a good shape can be formed.

Moreover, according to the resist composition of the present invention, a resist pattern having a good shape can be formed even if the baking temperature for forming the resist pattern is set to a low value.
In addition, according to the resist composition of the present invention, it is possible to suppress film loss in forming a hole pattern and to form a resist pattern with high perpendicularity. When “film reduction” occurs, the shape of the cross section of the hole pattern is not rectangular, and the TOP portion of the hole is rounded.

≪Resist pattern formation method≫
The resist pattern forming method of the second aspect of the present invention includes a step of forming a resist film on a support using the resist composition of 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 is more effective for KrF excimer laser, ArF excimer laser, EB, or EUV, and is 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, as described above, the portion between the lens, which has been conventionally filled with an inert gas such as air or nitrogen, and the resist film on the wafer is refracted larger than the refractive index of air. The exposure is performed in a state filled with a solvent having a high rate (immersion medium).
More specifically, the immersion exposure is a solvent (immersion medium) having a refractive index larger than the refractive index of air between the resist film obtained as described above and the lowermost lens of the exposure apparatus. And in that state, exposure 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 fluorine-based inert liquid include a fluorine-based compound such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , and C ₅ H ₃ F ₇ as a main component. Examples thereof include liquids, and those having a boiling point of 70 to 180 ° C are preferable, and those having a boiling point of 80 to 160 ° C are more preferable. It is preferable that the fluorine-based inert liquid has a boiling point in the above range since the medium used for immersion can be removed by a simple method after the exposure is completed.
As the fluorine-based inert liquid, a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms is particularly preferable. Specific examples of the perfluoroalkyl compound include a perfluoroalkyl ether compound and a perfluoroalkylamine compound.
More specifically, examples of the perfluoroalkyl ether compound include perfluoro (2-butyl-tetrahydrofuran) (boiling point 102 ° C.). Examples of the perfluoroalkylamine compound include perfluorotributylamine ( Boiling point of 174 ° C.).

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

<Base material component (A)>
In Examples 1-21 and Comparative Examples 1-15, the resin (A) -1 to resin (A) -4 used as the component (A) are known by using the following monomers (i) to (vi). Each was obtained by copolymerization by the dropping polymerization method.

[Synthesis Example 1: Synthesis of Resin (A) -1]
(Synthesis of monomer (ii))
Into a 1 L three-necked flask, 4.8 g of sodium hydride (NaH) was added, while maintaining at 0 ° C. in an ice bath, 300 g of tetrahydrofuran (THF) was added, and 124 g of compound (1) was further added with stirring. Stir for 10 minutes. Thereafter, 30 g of the compound (2) was added with stirring and reacted for 12 hours. After completion of the reaction, the reaction solution was subjected to suction filtration, and THF was removed from the collected filtrate by concentration under reduced pressure. Thereafter, water and ethyl acetate were added to the concentrate for extraction, and the resulting ethyl acetate solution was concentrated under reduced pressure and purified by column chromatography (SiO ₂ , heptane: ethyl acetate = 8: 2), and the fractions were reduced in pressure. Concentration and further drying under reduced pressure gave 12 g of compound (3).

About the obtained compound (3), < ¹ > H-NMR was measured. The results are shown below.
¹ H-NMR (solvent: CDCl ₃ , 400 MHz): δ (ppm) = 4.09 (s, 2H (H ^a )), 3.75 (t, 2H (H ^b )), 3.68 (t, ^{2H (H c)), 3.03} (brs, 2H (H d)), 1.51-2.35 (m, 17H (H e)).
From the results described above, it was confirmed that the compound (3) had a structure shown below.

Next, 5 g of the compound (3), 3.04 g of triethylamine (Et ₃ N) and 10 g of THF were added to a 300 mL three-necked flask and stirred for 10 minutes. Thereafter, 2.09 g of the compound (4) and 10 g of THF were added and reacted at room temperature for 12 hours. After completion of the reaction, the reaction solution was subjected to suction filtration, and THF was removed from the collected filtrate by concentration under reduced pressure. Thereafter, water and ethyl acetate were added to the concentrated solution for extraction. The obtained ethyl acetate solution was purified by column chromatography (SiO ₂ , heptane: ethyl acetate = 8: 2), the fraction was concentrated under reduced pressure, and further dried under reduced pressure to obtain 4.9 g of compound (5). .

About the obtained compound (5), < ¹ > H-NMR was measured. The results are shown below.
¹ H-NMR (solvent: CDCl ₃ , 400 MHz): δ (ppm) = 6.15 (s, 1H (H ^a )), 5.58 (s, 1 H (H ^b )), 4.35 (t, ^{2H (H c)), 4.08} (s, 2H (H d)), 3.80 (t, 2H (H e)), 1.51-2.35 (m, 20H (H f)).
From the results shown above, it was confirmed that the compound (5) had a structure shown below.

(Synthesis of Resin (A) -1)
6.19 g of the monomer (i), 10.00 g of the monomer (ii), and 3.51 g of the monomer (iii) were dissolved in 78.8 g of methyl ethyl ketone. To this solution, 0.01 mmol of V-601 (polymerization initiator) manufactured by Wako Pure Chemical Industries, Ltd. was added and dissolved. This was added dropwise to 32.83 g of methyl ethyl ketone heated to 75 ° C. in a nitrogen atmosphere over 6 hours. After completion of dropping, the reaction solution was heated and stirred for 1 hour, and then the reaction solution was cooled to room temperature. Thereafter, the operation of dropping the reaction solution into a large amount of methanol / water mixed solution and precipitating the reaction product was repeated three times. The reaction product thus obtained was dried under reduced pressure at room temperature to obtain a white powder.

Let the obtained reaction product be a high molecular compound (1). Its structural formula is shown below.
As a result of measuring the carbon 13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR) at 600 MHz for this polymer compound (1), the polymer composition (ratio (molar ratio) of each structural unit in the structural formula) was l /M/n=40.4/39.1/20.5.
Moreover, the standard polystyrene conversion mass mean molecular weight calculated | required by GPC measurement was 8700, and dispersion degree was 2.18. From this result, the obtained polymer compound (1) is a copolymer of the monomer (i), the monomer (ii), and the monomer (iii), that is, the resin (A) -1. Was confirmed.

[Synthesis Example 2: Synthesis of Resins (A) -2 to (A) -4]
In Examples 2 to 20, the resin (A) -2, the resin (A) -3, and the resin (A) -4 used as the component (A) are the same as the monomers (i), (iii) to (vi). And copolymerized by a known dropping polymerization method.
GPC measurement was performed on the obtained resins (A) -2 to (A) -4, and the mass average molecular weight (Mw) and the dispersity (Mw / Mn) were determined.
The structures of resins (A) -2 to (A) -4 are shown below. In the formula, the number attached to the lower right of () indicates the ratio (mol%) of each structural unit to the total of all the structural units constituting each resin. The proportion of each structural unit was calculated by carbon NMR.

［Ｍｗ１００００、Ｍｗ／Ｍｎ１．７］

[Mw10000, Mw / Mn1.7]

［Ｍｗ１００００、Ｍｗ／Ｍｎ１．９］

[Mw10000, Mw / Mn1.9]

［Ｍｗ７０００、Ｍｗ／Ｍｎ１．８］

[Mw7000, Mw / Mn1.8]

<Preparation of resist composition>
The components shown in Tables 1 to 4 were mixed and dissolved to prepare a positive resist composition.

In Tables 1 to 4, each abbreviation indicates the following, and the numerical value in [] is the blending amount (part by mass).
(A) -1: the resin (A) -1.
(A) -2: Resin (A) -2.
(A) -3: the resin (A) -3.
(A) -4: The resin (A) -4.
(B) -1: An acid generator represented by the following chemical formula (b-1-1).
(B) -2: Triphenylsulfonium heptafluoro-n-propanesulfonate.

  The acid generator (B) -1 represented by the chemical formula (b-1-1) is prepared by dissolving 6.99 g of triphenylsulfonium bromide in 125 ml of pure water, and adding 2-naphthylmethyloxytetrafluoroethane to the solution. 5.50 g of lithium salt of sulfonic acid was added and stirred for 19 hours at room temperature, then 125 g of dichloromethane was added and stirred, the organic phase was separated and taken out, and the organic phase was washed with 40 ml of pure water. Thereafter, liquid separation was performed, the organic phase was taken out, and the taken out organic phase was concentrated and then dried.

(D) -1: tri-n-pentylamine (molecular weight 227.43).
(D) -2: Triethanolamine (molecular weight 149.19).
(D) -3: tri-n-octylamine (molecular weight 353.67).
(D) -4: Nitrogen-containing organic compound (stearyl diethanolamine) represented by the following chemical formula (d1-1-1) (molecular weight 357.61).
(D) -5: tri-n-butylamine (TBA) (molecular weight 185.35).
(D) -6: triisopropanolamine (molecular weight 191.27).
(D) -7: Diethylethanolamine (molecular weight 117.19).
(D) -8: Diethylpropanolamine (molecular weight 131.22).
(D) -9: Tris [2- (2-methoxyethoxy) ethyl] amine (molecular weight 323.43).
(D) -10: Dicyclohexylmethylamine (molecular weight 195.34).
(D) -11: 1-adamantanamine (molecular weight 151.25).
(S) -1: PGMEA / PGME = 6/4 (mass ratio) mixed solvent.

<Evaluation of resist pattern shape>
About the obtained positive resist composition, a resist pattern was formed according to the following procedure, and the lithography characteristics were evaluated.

(Example 1, Comparative Examples 1-4)
[Resolution and sensitivity]
An organic antireflection film composition “ARC29” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto an 8-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 82 nm was formed. Then, on the antireflection film, the positive resist compositions of Example 1 and Comparative Examples 1 to 4 obtained above were respectively applied using a spinner, and the conditions were 100 ° C. and 60 seconds on a hot plate. The resist film having a film thickness of 120 nm was formed by performing pre-baking (PAB) treatment and drying.
Next, an ArF excimer laser (193 nm) is applied to the resist film by an ArF exposure apparatus NSR-S302 (Nikon Corporation; NA (numerical aperture) = 0.60, 2/3 annular illumination) with a mask pattern (6 % Halftone).
Then, PEB treatment is performed at 100 ° C. for 60 seconds, and further, alkali development is performed with a 2.38 mass% TMAH aqueous solution at 23 ° C. for 30 seconds, and then rinsed with pure water for 30 seconds and shaken off. Drying was performed.
As a result, in each example, a resist pattern of a contact hole pattern in which holes with a hole diameter of 130 nm were arranged at equal intervals (pitch 260 nm) was formed on the resist film.
At this time, the optimum exposure dose Eop (mJ / cm ² ; sensitivity) for forming a contact hole pattern having a diameter of 130 nm and a pitch of 260 nm was determined. The results are shown in Table 5.

(Examples 2-9)
[Resolution and sensitivity]
An organic antireflection film composition “ARC29” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto an 8-inch silicon wafer using a spinner, and baked on a hot plate at 205 ° C. for 60 seconds to be dried. Thereby, an organic antireflection film having a film thickness of 89 nm was formed. Then, the positive resist compositions of Examples 2 to 9 obtained above were applied onto the antireflection film using a spinner, and prebaked (PAB) at 90 ° C. for 60 seconds on a hot plate. ) A resist film having a thickness of 120 nm was formed by performing treatment and drying.
Next, a protective film-forming coating solution “TSRC-002” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied onto the resist film using a spinner and heated at 90 ° C. for 60 seconds. A top coat having a thickness of 29 nm was formed.
Next, an immersion ArF exposure apparatus NSR-S609B (manufactured by Nikon; NA (numerical aperture) = 1.07, 2/3 annular illumination, reduction magnification 1/4) is applied to the resist film on which the top coat is formed. The ArF excimer laser (193 nm) was selectively irradiated through the mask pattern (6% halftone) with a double immersion medium: water.
Next, the top coat is removed using a protective film removing solution “TS-Remover-S” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.), and then subjected to PEB treatment at 95 ° C. for 60 seconds, and further to 23 ° C. Then, it is alkali-developed with a 2.38 mass% TMAH aqueous solution NMD-W (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) for 30 seconds, rinsed with pure water for 25 seconds, and then shaken and dried. It was.
As a result, in each example, a resist pattern of a contact hole pattern in which holes with a hole diameter of 70 nm were arranged at equal intervals (pitch 150 nm) was formed on the resist film.
At this time, the optimum exposure dose Eop (mJ / cm ² ; sensitivity) for forming a contact hole pattern having a diameter of 70 nm and a pitch of 150 nm was determined. The results are shown in Table 5.

(Examples 10 to 20)
[Resolution and sensitivity]
An organic antireflection film composition “ARC29” (trade name, manufactured by Brewer Science Co., Ltd.) is applied onto an 8-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 82 nm was formed. Then, the positive resist compositions of Examples 10 to 20 obtained above were applied onto the antireflection film using a spinner, and prebaked (PAB) on a hot plate at 90 ° C. for 60 seconds. ) A resist film having a thickness of 120 nm was formed by performing treatment and drying.
Next, an ArF excimer laser (193 nm) is applied to the resist film by an ArF exposure apparatus NSR-S302 (Nikon Corporation; NA (numerical aperture) = 0.60, 2/3 annular illumination) with a mask pattern (6 % Halftone).
Then, PEB treatment was performed at 90 ° C. for 60 seconds, and further alkali development was performed at 23 ° C. with a 2.38 mass% TMAH aqueous solution NMD-3 (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) for 30 seconds. Thereafter, water rinsing was performed using pure water for 30 seconds, followed by drying by shaking.
As a result, in each example, a resist pattern of a contact hole pattern in which holes with a hole diameter of 130 nm were arranged at equal intervals (pitch 260 nm) was formed on the resist film.
At this time, the optimum exposure dose Eop (mJ / cm ² ; sensitivity) for forming a contact hole pattern having a diameter of 130 nm and a pitch of 260 nm was determined. The results are shown in Table 5.

(Example 21, Comparative Examples 5 to 15)
[Resolution and sensitivity]
[Resolution / sensitivity] in Example 21 and Comparative Examples 5 to 15 is the same as that of Example 21 and Comparative Examples 1 to 4 in Example 21 and Comparative Examples 1 to 4. A contact hole pattern in which holes having a hole diameter of 130 nm are arranged at equal intervals (pitch 260 nm) was formed by the same resist pattern forming method except that the type resist composition was used.
At this time, the optimum exposure dose Eop (mJ / cm ² ; sensitivity) for forming a contact hole resist pattern having a diameter of 130 nm and a pitch of 260 nm was determined. The results are shown in Table 6.

[Evaluation of roundness]
As described above, the contact hole patterns formed by the respective resist pattern forming methods were observed from above using a scanning electron microscope SEM, and the roundness of the hole patterns was evaluated according to the following criteria. The results are shown in Tables 5 and 6.
A: The roundness is very high (no irregularities were seen on the circumference of the hole pattern observed from above, and the shape was very good).
○: High roundness (although some irregularities are seen on the circumference of the hole pattern observed from above, the overall shape was highly round).
(Triangle | delta): The roundness is low (many unevenness | corrugations were seen in the circumference part of the hole pattern observed from the sky).

[Evaluation of film reduction]
Using the positive resist compositions of Example 21 and Comparative Examples 5 to 15, the cross section of the contact hole pattern formed by the resist pattern forming method in the above [Resolution / Sensitivity] was measured using a scanning electron microscope SEM. And the presence or absence of film loss was evaluated according to the following criteria. The results are shown in Table 6.
○: The film is not reduced.
X: The film is reduced.

As is clear from the above results, the positive resist composition of Example 1 containing the nitrogen-containing organic compound (D1) according to the present invention is different from Comparative Example 1 and the present invention not containing the (D1) component. Compared to any of the positive resist compositions of Comparative Examples 2 to 4 containing a nitrogen-containing organic compound, the roundness of the hole pattern is very high, confirming that a resist pattern with a better shape can be formed. did it.
Moreover, also about the positive resist composition of Examples 2-20 containing the nitrogen-containing organic compound (D1) based on this invention, since the roundness of a hole pattern is high, it can form a resist pattern of a favorable shape. Was confirmed.

Moreover, from the evaluation results of Comparative Example 2 and Comparative Example 4, it was confirmed that the molecular weight of the component (D) increases and the roundness of the resist pattern tends to improve.
Furthermore, from comparison between Example 1 and Comparative Example 4 containing the component (D) having substantially the same molecular weight, the circularity of the resist pattern is very high by including a hydroxy group (polar group) in the molecule. It was confirmed that a resist pattern having a good shape could be formed.

Further, the positive resist composition of Example 21 containing the nitrogen-containing organic compound (D1) according to the present invention has a higher roundness of the hole pattern than the positive resist compositions of Comparative Examples 5 to 15. Thus, it was confirmed that a resist pattern having a good shape could be formed.
Furthermore, it was confirmed that the positive resist composition of Example 21 was able to form a resist pattern with high verticality in addition to the high roundness of the hole pattern and the ability to suppress film loss.
In addition, although the positive resist compositions of Comparative Examples 5, 11, and 12 suppressed film thickness reduction, they were inferior in the verticality of the hole pattern, and the shape was worse than that of the positive resist composition of Example 21.

Claims (6)

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
Represented by the following general formula (d1-1-0), and the resist composition characterized by containing a nitrogen-containing organic compound is a molecular weight of 200 or more.

[In the formula (d1-1-0) , R ⁴ is a hydrophobic group and is an optionally substituted alkyl group having 5 to 50 carbon atoms, and R ⁵ and R ⁶ are each independently It is a C1-C30 alkylene group which may have a substituent . ] It said base component (A), the resist composition according to claim 1 Symbol placing by the action of an acid is a base component which exhibits increased solubility in an alkali developing solution (A '). 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 resin component (A1) further has a structural unit (a2) derived from an acrylate ester containing a lactone-containing cyclic group. The resist composition according to claim 3 or 4, wherein the resin component (A1) further has a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group. Using the resist composition according to any one of claims 1 to 5 , a step of forming a resist film on a support, a step of exposing the resist film, and a resist pattern by alkali-developing the resist film A resist pattern forming method including a step of forming a film.