KR102612639B1 - Resist composition and method of forming resist pattern - Google Patents

Abstract

(Assignment) Resist composition and resist pattern formation method.
(Solution means) Base component (A) whose solubility in an alkaline developer changes due to the action of acid, acid generator component (B) which generates acid upon exposure, solvent (S), and 0.2 to 10 mass of total solids. A resist composition containing a polymer (F) having a structural unit represented by the following formula (f1) in %, wherein the solvent (S) is propylene carbonate, propylene glycol monomethyl ether acetate (PGMEA), and propylene glycol monomethyl ether (PGME). A resist composition comprising, and the amount of propylene carbonate in the total solvent is 0.1 to 3% by mass.
Equation (f1)

(In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and L ₁ and L ₂ are the same or different from each other and have a single bond, a carbonyl group, an ether bond, or an ester bond. It is a hydrocarbon group optionally having 1 to 10 carbon atoms, x is 0 or 1, m is an integer of 1 to 20, n represents an integer of 1 to 2m+1, p is an integer of 1 to 20, and q is Represents an integer of 1 to 2p.)

Description

Resist composition and resist pattern forming method {RESIST COMPOSITION AND METHOD OF FORMING RESIST PATTERN}

The present invention relates to resist compositions and methods for forming resist patterns.

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, the resist film is selectively exposed to radiation such as light or electron beam through a mask on which a predetermined pattern is formed, and development is performed. By performing this, a process of forming a resist pattern of a predetermined shape on the resist film is carried out.

A resist material whose exposed portion changes in the property of being soluble in the developer is called a positive type, and a resist material whose exposed portion changes to a property of being insoluble in the developer is called a negative type.

Recently, in the manufacture of semiconductor devices and liquid crystal display devices, patterns have been rapidly refined due to advances in lithography technology.

As a technique for miniaturization, shortening the wavelength (higher energy) of the exposure light source is generally implemented. Specifically, conventionally, ultraviolet rays represented by g-rays and i-rays have been used, but currently, mass production of semiconductor devices using KrF excimer lasers and ArF excimer lasers has been started. In addition, electron beams with shorter wavelengths (higher energy) than these excimer lasers, EUV (extreme ultraviolet rays), and X-rays are also being examined.

In the liquid immersion exposure process, when exposing using a scan-type liquid immersion exposure machine, if the liquid immersion liquid does not move as the lens moves, the exposure speed may decrease, which may affect productivity. For this reason, it is desirable for the resist film to have a high receding contact angle with respect to the immersion liquid.

Accordingly, studies have been conducted to improve the receding contact angle for the immersion liquid during liquid immersion exposure. For example, Patent Document 1 discloses a resist composition that improves the receding contact angle by employing gamma-butyl lactone (GBL) and alkyl carbonate.

Japanese Patent Publication No. 2010-102329

However, in the invention described in Patent Document 1, etc., there was a problem that the edge shape formed by EBR (Edge bread removal) was rough due to the large amount of GBL or propylene carbonate.

The present invention has been made in consideration of the above circumstances, and by employing a resist composition containing a mixed solvent containing a small amount of propylene carbonate and a specific fluorinated polymer, a high receding contact angle can be obtained and an excellent resist can be obtained with an excellent edge shape. The object is to provide a composition and a method of forming a resist pattern using the resist composition.

The first aspect of the present invention is a base component (A) whose solubility in an alkaline developer changes due to the action of an acid, an acid generator component (B) that generates an acid upon exposure, a solvent (S), and total solids. A resist composition containing 0.2 to 10% by mass of a polymer (F) having a structural unit represented by the following formula (f1),

The solvent (S) is a resist composition containing propylene carbonate, propylene glycol monomethyl ether acetate (PGMEA), and propylene glycol monomethyl ether (PGME), and the amount of propylene carbonate in the total solvent is 0.1 to 3% by mass.

[Formula 1]

Equation (f1)

(In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and L ₁ and L ₂ are the same or different from each other and have a single bond, a carbonyl group, an ether bond, or an ester bond. It is a hydrocarbon group optionally having 1 to 10 carbon atoms, x is 0 or 1, m is an integer of 1 to 20, n represents an integer of 1 to 2m+1, p is an integer of 1 to 20, and q is Represents an integer of 1 to 2p.)

A second aspect of the present invention includes a process of forming a resist film on a support using the resist composition of the first aspect of the invention, exposing the resist film, and developing the resist film to form a resist pattern. A resist pattern forming method comprising:

According to the present invention, it is possible to provide a resist composition with excellent lithographic properties and a method of forming a resist pattern using the resist composition.

In this specification and the claims, “aliphatic” is a relative concept to aromatic, and is defined to mean a group, compound, etc. without aromaticity.

Unless otherwise specified, “alkyl group” includes linear, branched, and cyclic monovalent saturated hydrocarbon groups.

Unless otherwise specified, “alkylene group” includes straight-chain, branched-chain, and cyclic divalent saturated hydrocarbon groups. The alkyl group in the alkoxy group is the same.

A “halogenated alkyl group” is a group in which some or all of the hydrogen atoms of an alkyl group are replaced with halogen atoms, and examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

“Fluorinated alkyl group” or “fluorinated alkylene group” refers to a group in which some or all of the hydrogen atoms of an alkyl group or alkylene group are replaced with fluorine atoms.

“Structural unit” means a monomer unit (monomer unit) constituting a high molecular compound (resin, polymer, copolymer).

“Constitutive unit derived from acrylic acid ester” means a structural unit formed by cleavage of the ethylenic double bond of acrylic acid ester.

“Acrylic acid ester” is a compound in which the hydrogen atom at the terminal carboxyl group of acrylic acid (CH2=CH-COOH) is replaced with an organic group.

In the acrylic acid ester, the hydrogen atom bonded to the carbon atom at the α position may be substituted with a substituent. The substituent (Rα) that replaces the hydrogen atom bonded to the carbon atom at the α position is an atom or group other than a hydrogen atom, such as an alkyl group with 1 to 5 carbon atoms, a halogenated alkyl group with 1 to 5 carbon atoms, or a hydroxyalkyl group. I can hear it. Additionally, the carbon atom at the α position of the acrylic acid ester refers to the carbon atom to which the carbonyl group is bonded, unless otherwise specified.

Hereinafter, acrylic acid ester in which the hydrogen atom bonded to the carbon atom at the α position is replaced with a substituent may be referred to as α-substituted acrylic acid ester. In addition, acrylic acid ester and α-substituted acrylic acid ester are sometimes collectively referred to as “(α-substituted) acrylic acid ester.”

“Structural unit derived from a hydroxystyrene derivative” means a structural unit formed by cleavage of the ethylenic double bond of hydroxystyrene or a hydroxystyrene derivative.

“Hydroxystyrene derivatives” is a concept that includes those in which the hydrogen atom at the α position of hydroxystyrene is replaced by other substituents such as an alkyl group and a halogenated alkyl group, as well as derivatives thereof. Their derivatives include those in which the hydrogen atom of the hydroxyl group of hydroxystyrene, in which the hydrogen atom in the α position may be substituted with a substituent, is substituted with an organic group, and those in which the hydrogen atom in the α position is optionally substituted with a substituent in the benzene ring of hydroxystyrene with a hydroxyl group. Substituents other than those bonded together may be mentioned. Additionally, the α position (carbon atom at the α position) refers to the carbon atom to which the benzene ring is bonded, unless otherwise specified.

Substituents that replace the hydrogen atom at the α position of hydroxystyrene include the same substituents as those exemplified as the substituents at the α position in the α-substituted acrylic acid ester.

“Constitutive unit derived from vinylbenzoic acid or vinylbenzoic acid derivative” means a structural unit formed by cleavage of the ethylenic double bond of vinylbenzoic acid or vinylbenzoic acid derivative.

“Vinylbenzoic acid derivatives” is a concept that includes those in which the hydrogen atom at the α position of vinylbenzoic acid is replaced by other substituents such as an alkyl group and a halogenated alkyl group, as well as derivatives thereof. Their derivatives include those in which the hydrogen atom of the carboxyl group of vinylbenzoic acid, where the hydrogen atom at the α position may be substituted with a substituent, is substituted with an organic group, and those in which the hydrogen atom at the α position is optionally substituted with a substituent, in which the hydrogen atom of the carboxyl group is substituted with an organic group, and those in which the hydrogen atom at the α position is optionally substituted with a substituent, in which the hydrogen atom of the carboxyl group is replaced with an organic group, and those in which the hydrogen atom at the α position is optionally substituted with a substituent, have a hydroxyl group and a carboxyl group in the benzene ring. Substituents other than those bonded together may be mentioned. Additionally, the α position (carbon atom at the α position) refers to the carbon atom to which the benzene ring is bonded, unless otherwise specified.

“Styrene derivative” means that the hydrogen atom at the α position of styrene is substituted with another substituent such as an alkyl group or halogenated alkyl group.

“Structural unit derived from styrene” and “structural unit derived from styrene derivative” mean a structural unit formed by cleavage of the ethylenic double bond of styrene or a styrene derivative.

The alkyl group as the substituent at the α position is preferably a linear or branched alkyl group, and specifically, an alkyl group having 1 to 5 carbon atoms (methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl). , tert-butyl group, pentyl group, isopentyl group, neopentyl group), etc.

In addition, the halogenated alkyl group as the substituent at the α position specifically includes a group in which part or all of the hydrogen atoms of the above-mentioned “alkyl group as the substituent at the α position” are replaced 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.

Moreover, the hydroxyalkyl group as the substituent at the α position specifically includes a group in which part or all of the hydrogen atoms of the above-mentioned “alkyl group as the substituent at the α position” are substituted with hydroxyl groups. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1 to 5, and 1 is most preferable.

When it is stated that “it may have a substituent,” it includes both the case of replacing the hydrogen atom (-H) with a monovalent group and the case of replacing the methylene group (-CH2-) with a divalent group.

“Exposure” is a concept that includes the overall irradiation of radiation.

≪Resist composition≫

The first aspect of the present invention is a base component (A) whose solubility in an alkaline developer changes due to the action of an acid, an acid generator component (B) that generates an acid upon exposure, a solvent (S), and total solids. A resist composition containing 0.2 to 10% by mass of a polymer (F) having a structural unit represented by the following formula (f1), wherein the solvent (S) is propylene carbonate, propylene glycol monomethyl ether acetate (PGMEA), and propylene glycol monomethyl. It is a resist composition containing ether (PGME), and the amount of propylene carbonate in the total solvent is 0.1 to 3% by mass.

[Formula 2]

Equation (f1)

(In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and L ₁ and L ₂ are the same or different from each other and have a single bond, a carbonyl group, an ether bond, or an ester bond. It is a hydrocarbon group optionally having 1 to 10 carbon atoms, x is 0 or 1, m is an integer of 1 to 20, n represents an integer of 1 to 2m+1, p is an integer of 1 to 20, and q is Represents an integer of 1 to 2p.)

In the present invention, the resist composition contains a base component (A) (hereinafter also referred to as “component (A)”) whose solubility in a developer changes due to the action of an acid.

When a resist film is formed using such a resist composition and selective exposure is performed on the resist film, acid is generated in the exposed area, and the solubility of component (A) in the developer solution changes due to the action of the acid. Since the solubility of component (A) in the developer does not change in the exposed area, a difference in solubility in the developer occurs between the exposed and unexposed areas. Therefore, when the resist film is developed, if the resist composition is a positive type, the exposed portion is dissolved and removed to form a positive resist pattern, and if the resist composition is a negative type, the unexposed portion is dissolved and removed to form a negative resist pattern. is formed

In this specification, a resist composition in which exposed areas are dissolved and removed to form a positive resist pattern is referred to as a positive resist composition, and a resist composition in which unexposed areas are dissolved and removed to form a negative resist pattern is referred to as a negative resist composition.

In the present invention, the resist composition may be a positive resist composition or a negative resist composition.

In addition, in the present invention, the resist composition may be used for an alkaline development process using an alkaline developer for the development process when forming a resist pattern, or for a solvent development process using a developer containing an organic solvent (organic developer) for the development treatment. Although it may be for a solvent development process, it is preferable that it is for a solvent development process.

The resist composition used to form a resist pattern has an acid-generating ability to generate acid upon exposure. Component (A) may generate acid upon exposure, and an additive component is blended separately from component (A). Acid may be generated through this exposure.

Specifically, in the present invention, the resist composition is:

(1) It may contain an acid generator component (B) that generates acid upon exposure (hereinafter referred to as “component (B)”);

(2) The component (A) may be a component that generates acid upon exposure;

(3) The component (A) is a component that generates acid upon exposure, and may further contain the component (B).

That is, in the cases of (2) and (3) above, component (A) is a “base component that generates acid upon exposure and whose solubility in the developer changes due to the action of the acid.” When the component (A) is a base component that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, the component (A1) described later generates an acid upon exposure and also the action of the acid. It is preferable that it is a polymer compound whose solubility in the developer changes depending on the condition. As such a polymer compound, a resin having a structural unit that generates acid upon exposure can be used. Known structural units that generate acid upon exposure can be used.

In the present invention, it is particularly preferable that the resist composition is in the case of (1) above.

<(A) component>

In the present invention, the “base component” is an organic compound having film-forming ability, and preferably an organic compound with a molecular weight of 500 or more is used. When the molecular weight of the organic compound is 500 or more, the film forming ability is improved, and in addition, it is easy to form a nano-level photosensitive resin pattern.

Organic compounds used as base components are broadly divided into non-polymers and polymers.

As a non-polymer, those having a molecular weight of 500 to 4000 are usually used. Hereinafter, when referred to as a “low molecular compound”, it refers to a non-polymer having a molecular weight of 500 or more and less than 4000.

As a polymer, a polymer having a molecular weight of 1000 or more is usually used. Hereinafter, when referred to as “resin”, it refers to a polymer with a molecular weight of 1000 or more.

As the molecular weight of the polymer, the mass average molecular weight calculated in terms of polystyrene by GPC (gel permeation chromatography) is used.

As the component (A), a resin may be used, a low molecular compound may be used, or these may be used in combination.

The component (A) has increased solubility in the developer due to the action of acid.

Additionally, in the present invention, component (A) may be one that generates acid upon exposure.

In the present invention, component (A) is a structural unit containing an acid-decomposable group whose polarity increases by the action of an acid (hereinafter sometimes referred to as “structural unit (a1)”) and a -SO2- containing cyclic group. , a structural unit containing a lactone-containing cyclic group, a carbonate-containing cyclic group, or a heterocyclic group other than these (hereinafter sometimes referred to as “structural unit (a2)”), a structural unit containing a polar group-containing aliphatic hydrocarbon group (hereinafter, It is preferable to contain a polymer compound (A1) having a "structural unit (a3)" in some cases.

(Constitutive unit (a1))

The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity increases due to the action of an acid.

An “acid-decomposable group” is a group having acid-decomposability in which at least a portion of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid.

Examples of acid-decomposable groups whose polarity increases by the action of an acid include groups that decompose by the action of an acid to produce a polar group.

Examples of polar groups include carboxyl group, hydroxyl group, amino group, and sulfo group (-SO3H). Among these, a sulfo group or a polar group containing -OH in the structure (hereinafter sometimes referred to as "OH-containing polar group") is preferable, a sulfo group, a carboxyl group, or a hydroxyl group is preferable, and a carboxyl group or a hydroxyl group is especially preferable.

More specifically, the acid-decomposable group includes a group in which the above-described polar group is protected by an acid-dissociable group (for example, a group in which the hydrogen atom of an OH-containing polar group is protected by an acid-dissociable group).

Here, “mountain dissociation penis” means,

(i) a group having an acid dissociable property in which the bond between the acid dissociable group and an atom adjacent to the acid dissociable group can be cleaved by the action of an acid, or,

(ii) a group in which a bond between the acid dissociable group and an atom adjacent to the acid dissociable group can be cleaved by further decarboxylation reaction occurring after some of the bonds are cleaved by the action of an acid;

refers to both sides.

The acid dissociable group constituting the acid dissociable group must be a group with a lower polarity than the polar group generated by dissociation of the acid dissociable group. Therefore, when the acid dissociable group is dissociated by the action of the acid, it is necessary to be a group less polar than the acid dissociable group. A highly polar group is created and polarity increases. As a result, the polarity of the entire component (A1) increases. As polarity increases, the solubility in the developer relatively changes, and when the developer is an organic developer, the solubility decreases.

There is no particular limitation on the acid dissociable group, and any acid dissociable group that has been proposed so far as an acid dissociable group in base resins for chemically amplified resists can be used.

Among the above polar groups, the acid dissociable group that protects the carboxyl group or the hydroxyl group is, for example, an acid dissociable group represented by the following general formula (a1-r-1) (hereinafter, for convenience, it is referred to as an “acetal-type acid dissociable group”) ) can be mentioned.

[Formula 3]

… (a1-r-1)

[In the formula, Ra' ¹ and Ra' ² are a hydrogen atom or an alkyl group, Ra' ³ is a hydrocarbon group, and Ra' ³ may be combined with any of Ra' ¹ and Ra' ² to form a ring. * means combined hand.]

In formula (a1-r-1), the alkyl groups of Ra' ¹ and Ra' ² include the same alkyl groups exemplified as substituents that may be bonded to the carbon atom at the α position in the description of the α-substituted acrylic acid ester. A methyl group or an ethyl group is preferred, and a methyl group is most preferred.

As the hydrocarbon group for Ra' ³ , an alkyl group with 1 to 20 carbon atoms is preferable, and an alkyl group with 1 to 10 carbon atoms is more preferable; A straight-chain or branched-chain alkyl group is preferable, and specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neophene. Tyl group, 1,1-dimethylethyl group, 1,1-diethylpropyl group, 2,2-dimethylpropyl group, 2,2-dimethylbutyl group, etc. are mentioned.

When Ra' ³ is a cyclic hydrocarbon group, it may be aliphatic or aromatic, and may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 8 carbon atoms, and specific examples include cyclopentane, cyclohexane, and cyclooctane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, norbornane, and isocarbon group. Bornane, tricyclodecane, tetracyclododecane, etc. can be mentioned.

When it is an aromatic hydrocarbon group, specific examples of aromatic rings included include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; an aromatic heterocycle in which some of the carbon atoms constituting the aromatic hydrocarbon ring are replaced with heteroatoms; etc. can be mentioned. Hetero atoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms.

Specifically, the aromatic hydrocarbon group includes a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group); A group in which one of the hydrogen atoms of the aryl group is replaced with an alkylene group (e.g., benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc. arylalkyl group) ; etc. can be mentioned. The carbon number of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and especially preferably 1.

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

Among the above polar groups, examples of the acid dissociable group that protects the carboxyl group include an acid dissociable group represented by the following general formula (a1-r-2) (acids represented by the following formula (a1-r-2) Among the dissociable groups, those composed of an alkyl group may hereinafter be referred to as “tertiary alkyl ester type acid dissociable groups” for convenience.

[Formula 4]

… (a1-r-2)

[In the formula, Ra' ⁴ to Ra' ⁶ are hydrocarbon groups, and Ra' ⁵ and Ra' ⁶ may be combined with each other to form a ring. * means combined hand.]

Hydrocarbon groups of Ra' ⁴ to Ra' ⁶ include the same hydrocarbon groups as Ra' ³ above. Ra' ⁴ is preferably an alkyl group having 1 to 5 carbon atoms. When Ra' ⁵ and Ra' ⁶ combine with each other to form a ring, a group represented by the following general formula (a1-r2-1) may be included.

On the other hand, when Ra' ⁴ to Ra' ⁶ are not bonded to each other and are independent hydrocarbon groups, groups represented by the following general formula (a1-r2-2) can be mentioned.

[Formula 5]

(a1-r2-1) (a1-r2-2)

[In the formula, Ra' ¹⁰ is an alkyl group having 1 to 10 carbon atoms, Ra' ¹¹ is a group that forms an aliphatic cyclic group with the carbon atom to which Ra' ¹⁰ is bonded, and Ra' ¹² to Ra' ¹⁴ each independently represent a hydrocarbon group. . * means combined hand.]

In formula (a1-r2-1), the alkyl group of the alkyl group having 1 to 10 carbon atoms of Ra' ¹⁰ is exemplified as the straight-chain or branched alkyl group of Ra' ³ in formula (a1-r-1). Gi is preferable. In formula (a1-r2-1), the aliphatic cyclic group constituted by Ra' ¹¹ is preferably the group exemplified as the cyclic alkyl group of Ra' ³ in formula (a1-r-1).

In the formula (a1-r2-2), Ra' ¹² and Ra' ¹⁴ are each independently preferably an alkyl group having 1 to 10 carbon atoms, and the alkyl group is represented by Ra' ³ in the formula (a1-r-1). The groups exemplified as straight-chain or branched alkyl groups are more preferable, more preferably straight-chain alkyl groups having 1 to 5 carbon atoms, and particularly preferably methyl or ethyl groups.

In formula (a1-r2-2), Ra' ¹³ is preferably a straight-chain, branched-chain or cyclic alkyl group exemplified by the hydrocarbon group of Ra' ³ in formula (a1-r-1). . Among these, the group exemplified as the cyclic alkyl group of Ra' ³ is more preferable.

Specific examples of the above formula (a1-r2-1) are given below. In the formulas below, “*” represents a bond.

[Formula 6]

Specific examples of the above formula (a1-r2-2) are given below.

[Formula 7]

In addition, examples of the acid dissociable group that protects the hydroxyl group among the polar groups include an acid dissociable group represented by the following general formula (a1-r-3) (hereinafter referred to as a “tertiary alkyloxycarbonyl acid dissociable group” for convenience) There are cases where it is said).

[Formula 8]

… (a1-r-3)

[In the formula, Ra' ⁷ to Ra' ⁹ represent an alkyl group. * means combined hand.]

In formula (a1-r-3), Ra' ⁷ to Ra' ⁹ are preferably an alkyl group having 1 to 5 carbon atoms, and more preferably 1 to 3 carbon atoms.

Moreover, the total carbon number of each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

The structural unit (a1) is a structural unit derived from an acrylic acid ester in which the hydrogen atom bonded to the carbon atom at the α position may be substituted with a substituent, and contains an acid-decomposable group whose polarity increases by the action of an acid; A structural unit derived from hydroxystyrene or a hydroxystyrene derivative in which at least part of the hydrogen atoms in the hydroxyl group of the structural unit is protected by a substituent containing the acid-decomposable group; Examples include structural units derived from vinylbenzoic acid or vinylbenzoic acid derivatives in which at least part of the hydrogen atom in -C(=O)-OH is protected by a substituent containing the acid-decomposable group.

As the structural unit (a1), among the above, a structural unit derived from an acrylic acid ester in which the hydrogen atom bonded to the carbon atom at the α position may be substituted with a substituent is preferable.

As the structural unit (a1), a structural unit represented by the following general formula (a1-1) or (a1-2) is preferable.

[Formula 9]

[Wherein, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va ¹ is a divalent hydrocarbon group that may have an ether bond, a urethane bond, or an amide bond, n _a1 is 0 to 2, and Ra ¹ is one of the above formulas (a1-r-1) to (a1-r-2) It is an acid dissociative group represented by . Wa ¹ is a hydrocarbon group with n _a2 + 1 valence, n _a2 is 1 to 3, and Ra ² is an acid dissociable group represented by the above formula (a1-r-1) or (a1-r-3).]

In the general formula (a1-1), the alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, methyl group, ethyl group, propyl group, isopropyl group, n -butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. A halogenated alkyl group having 1 to 5 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are replaced 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.

R is preferably a hydrogen atom, an alkyl group with 1 to 5 carbon atoms, or a fluorinated alkyl group with 1 to 5 carbon atoms, and most preferably a hydrogen atom or a methyl group because it is industrially easy to obtain.

The hydrocarbon group of Va ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. An aliphatic hydrocarbon group refers to a hydrocarbon group that does not have aromaticity. The aliphatic hydrocarbon group as the divalent hydrocarbon group in Va1 may be saturated or unsaturated, and is usually preferably saturated.

More specifically, the aliphatic hydrocarbon group includes linear or branched aliphatic hydrocarbon groups, aliphatic hydrocarbon groups containing a ring in the structure, and the like.

Additionally, Va ¹ may include a divalent hydrocarbon group bonded to an ether bond, a urethane bond, or an amide bond.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, further preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.

The straight-chain aliphatic hydrocarbon group is preferably a straight-chain alkylene group, and specifically, a methylene group [-CH ₂ -], an ethylene group [-(CH ₂ ) _2- ], and a trimethylene group [-(CH _2). ) ₃ -], tetramethylene group [-(CH ₂ ) ₄ -], pentamethylene group [-(CH ₂ ) ₅ -], etc.

The branched aliphatic hydrocarbon group is preferably a branched alkylene group, specifically -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C. Alkylmethylene groups such as (CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, and -C(CH ₂ CH ₃ ) ₂ -; -CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH ₃ )-, -C(CH ₃ ) ₂ CH ₂ -, -CH(CH ₂ CH ₃ )CH ₂ -, -C(CH Alkylethylene groups such as ₂ CH ₃ ) ₂ -CH ₂ - ; Alkyltrimethylene groups such as -CH(CH ₃ )CH ₂ CH ₂ - and -CH ₂ CH(CH ₃ )CH ₂ -; Alkyl alkylene groups such as alkyl tetramethylene groups such as -CH(CH ₃ )CH ₂ CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ CH ₂ -, etc. are mentioned. The alkyl group in the alkyalkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

The aliphatic hydrocarbon group containing a ring in the above structure includes an alicyclic hydrocarbon group (a group in which two hydrogen atoms are removed from the aliphatic hydrocarbon ring), and a group in which the alicyclic hydrocarbon group is bonded to the terminal of a straight-chain or branched aliphatic hydrocarbon group. , a group in which an alicyclic hydrocarbon group is interposed between a straight-chain or branched-chain aliphatic hydrocarbon group, and the like. Examples of the straight-chain or branched-chain aliphatic hydrocarbon group include the same ones as above.

The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.

The alicyclic hydrocarbon group may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, and isocarbon group. Bornane, tricyclodecane, tetracyclododecane, etc. can be mentioned.

An aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring.

The aromatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, further preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and 6 ~10 is most preferable. However, the carbon number shall not include the carbon number in the substituent.

Specific examples of the aromatic ring possessed by the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; an aromatic heterocycle in which some of the carbon atoms constituting the aromatic hydrocarbon ring are replaced with heteroatoms; etc. can be mentioned. Hetero atoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms.

Specifically, the aromatic hydrocarbon group is a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); A group in which one hydrogen atom of the aromatic hydrocarbon ring (aryl group) is replaced with an alkylene group (e.g., benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group) , a group obtained by removing one hydrogen atom from an aryl group in an arylalkyl group such as a 1-naphthylethyl group or a 2-naphthylethyl group); etc. can be mentioned. The carbon number of the alkylene group (alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and especially preferably 1.

In the above formula (a1-2), the n _a2 + 1 valent hydrocarbon group in Wa ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group refers to a hydrocarbon group that does not have aromaticity, and may be saturated or unsaturated, and is usually preferably saturated. The aliphatic hydrocarbon group includes a straight-chain or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, or a combination of a straight-chain or branched aliphatic hydrocarbon group with a ring-containing aliphatic hydrocarbon group in the structure. One group can be mentioned, and specifically, the same group as Va ¹ of the above-mentioned formula (a1-1) can be mentioned.

The n _a2 +1 value is preferably 2 to 4, and more preferably 2 or 3.

As the above formula (a1-2), a structural unit represented by the following general formula (a1-2-01) is particularly preferable.

[Formula 10]

In formula (a1-2-01), Ra ² is an acid dissociable group represented by the formula (a1-r-1) or (a1-r-3). n _a2 is an integer of 1 to 3, preferably 1 or 2, and more preferably 1. c is an integer of 0 to 3, preferably 0 or 1, and more preferably 1. R is the same as above.

Specific examples of the above formulas (a1-1) and (a1-2) are shown below. In each formula below, R ^α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[Formula 11]

[Formula 12]

[Formula 13]

[Formula 14]

[Formula 15]

The proportion of the structural unit (a1) in component (A) is preferably 20 to 80 mol%, more preferably 20 to 75 mol%, and 25 to 70 mol% relative to the total structural units constituting component (A). It is more desirable. By exceeding the lower limit, lithography characteristics such as sensitivity, resolution, and LWR are also improved. Also, by setting it below the upper limit, it is possible to achieve balance with other structural units.

(Constitutive unit (a2))

In the present invention, the base component preferably contains a structural unit (a2) having a -SO ₂ --containing cyclic group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a heterocyclic group other than these.

When component (A) is used to form a resist film, the -SO ₂ --containing cyclic group, lactone-containing cyclic group, carbonate-containing cyclic group, or heterocyclic group other than these in the structural unit (a2) has an effect on the substrate of the resist film. It is effective in increasing adhesion.

In addition, when the structural unit (a1) described later contains in its structure an -SO ₂ -containing cyclic group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a heterocyclic group other than these, the structural unit is a structural unit. Although it also corresponds to (a2), this structural unit is assumed to correspond to structural unit (a1) and not to structural unit (a2).

The structural unit (a2) is preferably a structural unit represented by the following general formula (a2-1).

[Formula 16]

[Wherein, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, Ya ²¹ is a single bond or a divalent linking group, and La ²¹ is -O-, -COO-, -CON( R')-, -OCO-, -CONHCO- or -CONHCS-, and R' represents a hydrogen atom or a methyl group. However, when La ²¹ is -O-, Ya ²¹ does not become -CO-. Ra ²¹ is a -SO ₂ --containing cyclic group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a heterocyclic group other than these.]

The divalent linking group for Ya ²¹ is not particularly limited, but preferable examples include a divalent hydrocarbon group that may have a substituent, a divalent linking group containing a hetero atom, and the like.

(Divalent hydrocarbon group which may have a substituent)

The hydrocarbon group as the divalent linking group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

An aliphatic hydrocarbon group refers to a hydrocarbon group that does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.

The aliphatic hydrocarbon group includes linear or branched aliphatic hydrocarbon groups or aliphatic hydrocarbon groups containing a ring in the structure, and specifically, Va ¹ in the above formula (a1-1) Examples include:

The linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and a carbonyl group.

The aliphatic hydrocarbon group containing a ring in the above structure may include a substituent containing a hetero atom in the ring structure, and may be a cyclic aliphatic hydrocarbon group (a group in which two hydrogen atoms are removed from an aliphatic hydrocarbon ring), an electrocyclic group, etc. Examples include groups in which an aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and groups in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the straight-chain or branched-chain aliphatic hydrocarbon group include the same ones as above.

The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.

Specific examples of the cyclic aliphatic hydrocarbon group include the group exemplified by Va1 in the above-mentioned formula (a1-1).

The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and a carbonyl group.

The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.

The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, tert-butoxy group, and methoxy group. , ethoxy group is most preferred.

Halogen atoms as the substituent include fluorine atom, chlorine atom, bromine atom, iodine atom, etc., and fluorine atom is preferable.

Examples of the halogenated alkyl group as the substituent include groups in which part or all of the hydrogen atoms of the alkyl group are replaced with the halogen atoms.

In the cyclic aliphatic hydrocarbon group, some of the carbon atoms constituting the ring structure may be substituted with a substituent containing a hetero atom. As the substituent containing the hetero atom, -O-, -C(=O)-O-, -S-, -S(=O) ₂ -, -S(=O) ₂ -O- are preferable. .

Specific examples of the aromatic hydrocarbon group as the divalent hydrocarbon group include the group exemplified by Va1 in the above-mentioned formula (a1-1).

The hydrogen atom of the aromatic hydrocarbon group may be substituted with a substituent. For example, the hydrogen atom bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyl group.

The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.

Examples of the alkoxy group, halogen atom, and halogenated alkyl group as the substituent include those exemplified as substituents that replace the hydrogen atom of the cyclic aliphatic hydrocarbon group.

(Divalent linking group containing a hetero atom)

The hetero atom in the divalent linking group containing a hetero atom is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.

When Ya ²¹ is a divalent linking group containing a hetero atom, preferred linking groups include -O-, -C(=O)-O-, -C(=O)-, -OC(=O)- O-, -C(=O)-NH-, -NH-, -NH-C(= NH)- (H may be substituted with a substituent such as an alkyl group or acyl group), -S-, -S( =O) ₂ -, -S(=O) ₂ -O-, general formula -Y ²¹ -OY ²² -, -Y ²¹ -O-, -Y ²¹ -C(=O)-O-, -C( =O)-OY ²¹ -, -[Y ²¹ -C(=O)-O] _m' -Y ²² - or -Y ²¹ -OC(=O)-Y ²² - A group represented by [Formula, Y ²¹ and Y ²² is each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m' is an integer of 0 to 3.].

When the divalent linking group containing the hetero atom is -C(=O)-NH-, -NH-, -NH-C(=NH)-, H may be substituted with a substituent such as an alkyl group or acyl group. do. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and especially preferably 1 to 5 carbon atoms.

Formula -Y ²¹ -OY ²² -, -Y ²¹ -O-, -Y ²¹ -C(=O)-O-, -C(=O)-OY ²¹ -, -[Y ²¹ -C(=O) -O] _m' -Y ²² - or -Y ²¹ -OC(=O)-Y ²² -, where Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include those similar to the “divalent hydrocarbon group which may have a substituent” exemplified in the description of the divalent linking group above.

As Y ²¹ , a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 1 to 5 carbon atoms is still more preferable, and a methylene group or an ethylene group is particularly preferable.

As Y ²² , a linear or branched aliphatic hydrocarbon group is preferable, and a methylene group, an ethylene group, or an alkylmethylene group is more preferable. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.

In the group represented by the formula -[Y ²¹ -C(=O)-O] _m' -Y ²² -, m' is an integer of 0 to 3, preferably an integer of 0 to 2, and more preferably 0 or 1. And 1 is particularly preferable. In short, as the group represented by the formula -[Y ²¹ -C(=O)-O] _m' -Y ²² -, the group represented by the formula -Y ²¹ -C(=O)-OY ²² - is particularly preferable. Among them, a group represented by the formula -(CH ₂ ) _a' -C(=O)-O-(CH ₂ ) _b' - is preferable. In the formula, a' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably 1 to 5, more preferably 1 or 2, and most preferably 1. b' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably 1 to 5, more preferably 1 or 2, and most preferably 1.

In the present invention, Ya ²¹ is a single bond, an ester bond [-C(=O)-O-], an ether bond (-O-), a straight chain or branched alkylene group, or a combination thereof. desirable.

In the above formula (a2-1), Ra ²¹ is an -SO ₂ --containing cyclic group, a lactone-containing cyclic group, a heterocyclic group, or a carbonate-containing cyclic group.

“-SO ₂ --containing cyclic group” refers to a cyclic group containing a ring containing -SO ₂ - in its ring skeleton, and specifically, the sulfur atom (S) in -SO ₂ - is a cyclic group. It is a cyclic group that forms part of the ring skeleton. In the ring skeleton, the ring containing -SO ₂ - is counted as the first ring. If it is only that ring, it is called a monocyclic group, and if it also has another ring structure, it is called a polycyclic group regardless of the structure. The -SO ₂ --containing cyclic group may be monocyclic or polycyclic.

The -SO ₂ --containing cyclic group is, in particular, a cyclic group containing -O-SO ₂ - in its ring skeleton, that is, a sultone in which -OS- in -O-SO ₂ - forms a part of the ring skeleton. It is preferable that it is a cyclic group containing a ring. As the -SO ₂ --containing cyclic group, more specifically, groups each represented by the following general formulas (a5-r-1) to (a5-r-4) can be mentioned.

[Formula 17]

[In the formula, Ra' ⁵¹ is each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group; R" is a hydrogen atom or an alkyl group; A" is an alkylene group with 1 to 5 carbon atoms that may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, and n' is an integer from 0 to 2.]

In the general formulas (a5-r-1) to (a5-r-4), A" is the same as A" in the general formulas (a2-r-1) to (a2-r-7) described later. The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group for Ra' ⁵¹ have general formulas (a2-r-1) to (a2) described later. It is the same as Ra' ²¹ in -r-7).

Specific examples of groups each represented by general formulas (a5-r-1) to (a5-r-4) are given below. “Ac” in the formula represents an acetyl group.

[Formula 18]

[Formula 19]

[Formula 20]

In the present invention, when the structural unit (a2) contains an -SO ₂ --containing cyclic group, the logP value of the acrylic acid ester monomer containing an -SO ₂ --containing cyclic group is not particularly limited as long as it is less than 1.2, but among the above, The group represented by the above general formula (a5-r-1) is preferred, and the above formulas (r-sl-1-1), (r-sl-1-18), (r-sl-3-1) and (r It is more preferable to use at least one member selected from the group consisting of groups represented by any of -sl-4-1), and the group represented by the above formula (r-sl-1-1) is most preferable.

“Lactone-containing cyclic group” refers to a cyclic group containing a ring (lactone ring) containing -O-C(=O)- in its ring skeleton. The lactone ring is counted as the first ring. If it is only a lactone ring, it is called a monocyclic group. If it has another ring structure, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.

There is no particular limitation on the lactone-containing cyclic group, and any group can be used. Specifically, groups each represented by the following general formulas (a2-r-1) to (a2-r-7) can be mentioned. Hereinafter, “*” represents a bond.

[Formula 21]

[In the formula, Ra' ²¹ is each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group; R" is a hydrogen atom or an alkyl group; A" is an alkylene group with 1 to 5 carbon atoms that may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, n' is an integer from 0 to 2, and m' is It is 0 or 1.]

In the general formulas (a2-r-1) to (a2-r-7), A" is an alkylene group having 1 to 5 carbon atoms that may contain an oxygen atom (-O-) or a sulfur atom (-S-). , an oxygen atom or a sulfur atom. The alkylene group having 1 to 5 carbon atoms in A" is preferably a straight-chain or branched-chain alkylene group, and includes methylene group, ethylene group, n-propylene group, and isopropylene group. etc. can be mentioned. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples include a group in which -O- or -S- is interposed between the ends of the alkylene group or carbon atoms, for example -O -CH ₂ -, -CH ₂ -O-CH ₂ -, -S-CH ₂ -, -CH ₂ -S-CH ₂ -, and the like. A" is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group. Ra' ²¹ is each independently an alkyl group, an alkoxy group, It is a halogen atom, a halogenated alkyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group.

The alkyl group for Ra' ²¹ is preferably an alkyl group having 1 to 5 carbon atoms.

The alkoxy group for Ra' ²¹ is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, a group in which an oxygen atom (-O-) is linked to the alkyl group exemplified as the alkyl group for Ra' ²¹ above can be mentioned.

The halogen atom in Ra' ²¹ includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is preferable.

Examples of the halogenated alkyl group at Ra' ²¹ include groups in which some or all of the hydrogen atoms of the alkyl group at Ra' ²¹ are replaced with the halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

Specific examples of groups each represented by general formulas (a2-r-1) to (a2-r-7) are given below.

[Formula 22]

In the present invention, the structural unit (a2) is preferably a group represented by the above general formula (a2-r-1) or (a2-r-2), respectively, and has the above general formula (r-lc-1-1) or ( The groups each represented by r-lc-2-7) are more preferable.

“Carbonate-containing cyclic group” refers to a cyclic group containing a ring (carbonate ring) containing -O-C(=O)-O- in its ring skeleton. The carbonate ring is counted as the first ring. If it is only a carbonate ring, it is called a monocyclic group. If it has another ring structure, it is called a polycyclic group regardless of the structure. The carbonate-containing cyclic group may be a monocyclic group or a polycyclic group.

There is no particular limitation on the carbonate ring-containing cyclic group as the cyclic hydrocarbon group for R ¹ , and any one can be used. Specifically, groups represented by the following general formulas (ax3-r-1) to (ax3-r-3) can be mentioned.

[Formula 23]

[In the ^formula , Ra' is a hydrogen atom or an alkyl group; A" is an alkylene group of 1 to 5 carbon atoms that may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, and q' is 0 or 1.]

A" in the general formulas (ax3-r-1) to (ax3-r-3) and A" are the same as A" in the general formula (a2-r-1).

The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group for Ra' ³¹ are respectively represented by the above general formulas (a2-r-1) to (a2). The same examples as those exemplified in the description of Ra' ²¹ in -r-7) can be given.

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

[Formula 24]

“Heterocyclic group” refers to a cyclic group containing one or more atoms other than carbon in addition to carbon, and includes heterocyclic groups exemplified by (r-hr-1) to (r-hr-16) below, respectively. , nitrogen-containing heterocycles, etc. Examples of the nitrogen-containing heterocyclic group include cycloalkyl groups having 3 to 8 carbon atoms which may be substituted with one or two oxo groups. Preferred examples of the cycloalkyl group include 2,5-dioxopyrrolidine and 2,6-dioxopiperidine.

[Formula 25]

The number of structural units (a2) contained in component (A1) may be one or two or more, but two or more types are preferable.

When the component (A1) has a structural unit (a2), the proportion of the structural unit (a2) is preferably 1 to 80 mol%, and is 5 to 70 mol% relative to the total of all structural units constituting the component (A). It is more preferable that it is mol%, it is still more preferable that it is 10-65 mol%, and 10-60 mol% is especially preferable. By setting it above the lower limit, the effect of containing the structural unit (a2) is sufficiently obtained, and by setting it below the upper limit, it is possible to achieve balance with other structural units, and various lithography characteristics and pattern shapes become good.

(Constitutive unit (a3))

The structural unit (a3) is a structural unit containing a polar group-containing aliphatic hydrocarbon group (however, those corresponding to the structural units (a1) and (a2) described above are excluded).

It is thought that when component (A1) has the structural unit (a3), the hydrophilicity of component (A) increases and contributes to improvement of resolution.

The polar group includes a hydroxyl group, a cyano group, a carboxyl group, and a hydroxyalkyl group in which part of the hydrogen atoms of the alkyl group are replaced with fluorine atoms, and a hydroxyl group is particularly preferable.

Examples of the aliphatic hydrocarbon group include linear or branched hydrocarbon groups having 1 to 10 carbon atoms (preferably alkylene groups) and cyclic aliphatic hydrocarbon groups (cyclic groups). The cyclic group may be a monocyclic group or a polycyclic group. For example, in a resin for a resist composition for an ArF excimer laser, it can be appropriately selected and used from among many proposed groups. The cyclic group is preferably a polycyclic group, and more preferably has 7 to 30 carbon atoms.

Among them, structural units derived from an acrylic acid ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a portion of the hydrogen atoms of the hydroxyl group, cyano group, carboxyl group, or alkyl group are substituted with fluorine atoms are more preferable. Examples of the polycyclic group include groups obtained by removing two or more hydrogen atoms from bicycloalkanes, tricycloalkanes, tetracycloalkanes, etc. Specifically, groups obtained by removing two or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane can be mentioned. Among these polycyclic groups, groups obtained by removing two or more hydrogen atoms from adamantane, groups obtained by removing two or more hydrogen atoms from norbornane, and groups obtained by removing two or more hydrogen atoms from tetracyclododecane are industrially preferable.

The structural unit (a3) is not particularly limited and any unit can be used as long as it contains an aliphatic hydrocarbon group containing a polar group.

The structural unit (a3) is preferably a structural unit derived from an acrylic acid ester in which the hydrogen atom bonded to the carbon atom at the α position may be substituted with a substituent and containing a polar group-containing aliphatic hydrocarbon group.

As the structural unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, a structural unit derived from hydroxyethyl ester of acrylic acid is preferable, When the hydrocarbon group is a polycyclic group, preferred structural units include the structural unit represented by the following formula (a3-1), the structural unit represented by the formula (a3-2), and the structural unit represented by the formula (a3-3).

[Formula 26]

[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, l is an integer of 1 to 5, and s is It is an integer from 1 to 3.]

In formula (a3-1), j is preferably 1 or 2, and is 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 3rd position of the adamantyl group.

j is preferably 1, and in particular, it is preferable that the hydroxyl group is bonded to the 3rd position of the adamantyl group.

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

In formula (a3-3), t' is preferably 1. l is preferably 1. s is preferably 1. These preferably have a 2-norbornyl group or a 3-norbornyl group bonded to the terminal of the carboxyl group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5 or 6 position of the norbornyl group.

The number of structural units (a3) contained in the component (A1) may be one, and two or more types may be sufficient as them.

Among the components (A1), the proportion of the structural unit (a3) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, relative to the total of all structural units constituting the resin component (A1). 5 to 25 mol% is more preferable.

By setting the ratio of the structural unit (a3) to the lower limit or more, the effect of containing the structural unit (a3) is sufficiently obtained, and by setting it to the upper limit or less, it becomes easy to maintain a balance with other structural units.

Component (A1) may have the following structural unit (a4) in addition to the structural units (a1), (a2), and (a3).

(Constitutive unit (a4))

The structural unit (a4) is a structural unit containing an acid non-dissociable cyclic group. When the component (A1) has the structural unit (a4), the dry etching resistance of the formed resist pattern is improved. Additionally, the hydrophobicity of component (A1) increases. It is believed that improvement in hydrophobicity contributes to improvement in resolution, resist pattern shape, etc., especially in the case of organic solvent development.

The “acid non-dissociable cyclic group” in the structural unit (a4) is a cyclic group that remains in the structural unit without being dissociated even when the acid acts on it when an acid is generated from the component (B), which will be described later, by exposure to light.

The structural unit (a4) is preferably, for example, a structural unit derived from an acrylic acid ester containing an acid-non-dissociable aliphatic cyclic group. The cyclic group may, for example, be the same as that exemplified in the case of the structural unit (a1) described above, and may be used in resists such as those for ArF excimer lasers and KrF excimer lasers (preferably for ArF excimer lasers). A number of those conventionally known for use in the resin component of the composition can be used.

In particular, at least one type selected from tricyclodecyl group, adamantyl group, tetracyclododecyl group, isobornyl group, and norbornyl group is preferable because it is easy to obtain industrially. 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 having structures of the following general formulas (a4-1) to (a4-7).

[Formula 27]

[Wherein, R ^α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.]

The number of structural units (a4) contained in the component (A1) may be one, or two or more types may be used.

When the structural unit (a4) is contained in the (A1) component, the proportion of the structural unit (a4) is preferably 1 to 30 mol%, 10 to 20 mol%, relative to the total of all structural units constituting the (A1) component. It is more preferable that it is mol%.

The (A1) component is preferably a copolymer having (a1), (a2), and (a3).

Component (A1) can be obtained by polymerizing the monomers from which each structural unit is derived, for example, by known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate. .

In _{addition ,} in component (A1), _{during the} polymerization, _-C ( CF ₃ ) ₂ -OH group may be introduced. In this way, a copolymer into which a hydroxyalkyl group is introduced, in which some of the hydrogen atoms of the alkyl group are replaced with fluorine atoms, is effective in reducing development defects and reducing LER (line edge roughness: uneven unevenness of the line side wall).

In the present invention, the weight average molecular weight (Mw) of component (A1) (based on polystyrene conversion by gel permeation chromatography) is not particularly limited, and is preferably 1000 to 50000, more preferably 1500 to 30000, 2000 to 20000 is most preferable. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent for use as a resist, and if it is above the lower limit of this range, the dry etching resistance and cross-sectional shape of the resist pattern are good.

(A1) Component may be used individually by 1 type, or may use 2 or more types together.

The ratio of component (A1) in base component (A) is preferably 25% by mass or more, more preferably 50% by mass, further preferably 75% by mass, and 100% by mass relative to the total mass of base component (A). You can continue. When the ratio is 25% by mass or more, lithography characteristics are further improved.

In this invention, component (A) may be used individually by 1 type, or may be used in combination of 2 or more types.

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

<Acid generator component; (B) Ingredient>

In the present invention, the resist composition contains an acid generator component (B) (hereinafter referred to as component (B)) that generates acid upon exposure. The component (B) is not particularly limited, and any of the acid generators proposed so far for chemically amplified resists can be used.

Such acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, bisalkyl or bisarylsulfonyldiazomethanes, and poly(bissulfonyl)diazomethane. There are various types of acid generators, such as diazomethane-based acid generators, nitrobenzylsulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators. Among them, it is preferable to use an onium salt-based acid generator.

Examples of onium salt-based acid generators include compounds represented by the following general formula (b-1) (hereinafter also referred to as “component (b-1)”) and compounds represented by general formula (b-2) (hereinafter referred to as “( (also referred to as “b-2) component”), or a compound represented by general formula (b-3) (hereinafter also referred to as “(b-3) component”) can be used.

[Formula 28]

[In the formula, R ¹⁰¹ , R ¹⁰⁴ to R ¹⁰⁸ each independently represent a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring. Any two of R ¹⁰⁶ to R ¹⁰⁷ may be bonded to each other to form a ring. R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom. V ¹⁰¹ to V ¹⁰³ are each independently a single bond, an alkylene group, or a fluorinated alkylene group. L ¹⁰¹ to L ¹⁰² are each independently a single bond or an oxygen atom. L ¹⁰³ to L ¹⁰⁵ are each independently a single bond, -CO- or -SO ₂ -. M' ^m+ is an m-valent organic cation.]

{Anionbu}

·(b-1) Anionic part of component

In formula (b-1), R ¹⁰¹ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent.

(Cyclic group that may have a substituent at R ¹⁰¹ )

The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.

The aromatic hydrocarbon group for R ¹⁰¹ is an aromatic hydrocarbon ring exemplified by the divalent aromatic hydrocarbon group for Va ¹ in the formula (a1-1) above, or one hydrogen atom from an aromatic compound containing two or more aromatic rings. Examples of the removed aryl group include phenyl group and naphthyl group.

The cyclic aliphatic hydrocarbon group for R ¹⁰¹ includes groups obtained by removing one hydrogen atom from the monocycloalkane or polycycloalkane exemplified by the divalent aliphatic hydrocarbon group for Va ¹ in the above formula (a1-1). and adamantyl group and norbornyl group are preferred.

In addition, the cyclic hydrocarbon group for R ¹⁰¹ may contain a hetero atom such as a heterocyclic ring, and specifically, contains lactones each represented by the general formulas (a2-r-1) to (a2-r-7) above. Cyclic groups, -SO ₂ -containing cyclic groups each represented by the general formulas (a5-r-1) to (a5-r-4) above, and others (r-hr-1) to (r-hr-16) below. and heterocyclic groups exemplified by .

[Formula 29]

Examples of the substituent in the cyclic hydrocarbon group of R101 include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, and a nitro group.

The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.

As the alkoxy group as a substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, and tert-butoxy group are more preferable, and methoxy group is more preferable. , ethoxy group is most preferred.

Halogen atoms as substituents include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, with fluorine atoms being preferred.

Halogenated alkyl groups as substituents include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups in which some or all of the hydrogen atoms are replaced with the halogen atoms. .

(Chain-type alkyl group that may have a substituent at R ¹⁰¹ )

The chain alkyl group for R ¹⁰¹ may be either linear or branched.

The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group. , tetradecyl group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, henicosyl group, docosyl group, etc.

The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2 -Ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group, etc. are mentioned.

(Chain-type alkenyl group that may have a substituent at R ¹⁰¹ )

The chain alkenyl group for R ¹⁰¹ may be linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, and even more preferably 2 to 4 carbon atoms. 3 is particularly preferable. Examples of straight-chain alkenyl groups include vinyl group, propenyl group (allyl group), and butynyl group. Examples of branched chain alkenyl groups include 1-methylpropenyl group and 2-methylpropenyl group.

As the chain alkenyl group, among the above, propenyl group is particularly preferable.

Substituents for the chain alkyl or alkenyl group of R ¹⁰¹ include, for example, an alkoxy group, halogen atom, halogenated alkyl group, hydroxyl group, carbonyl group, nitro group, amino group, and the cyclic group for R ¹⁰¹ . You can.

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

In formula (b-1), Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom.

When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, Y ¹⁰¹ may contain an atom other than an oxygen atom. Atoms other than oxygen atoms include, for example, carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms.

Examples of the divalent linking group containing an oxygen atom include oxygen atom (ether bond: -O-), ester bond (-C(=O)-O-), and oxycarbonyl group (-OC(=O)- ), amide bond (-C(=O)-NH-), carbonyl group (-C(=O)-), carbonate bond (-OC(=O)-O-), non-hydrocarbon oxygen atom-containing linking group ; A combination of a non-hydrocarbon oxygen atom-containing linking group and an alkylene group may be included. In addition, a sulfonyl group (-SO ₂ -) may be connected to the combination. Examples of the combination include linking groups each represented by the following formulas (y-al-1) to (y-al-7).

[Formula 30]

[Wherein, V' ¹⁰¹ is a single bond or an alkylene group having 1 to 5 carbon atoms, and V' ¹⁰² is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.]

The divalent saturated hydrocarbon group at ^V'102 is preferably an alkylene group having 1 to 30 carbon atoms.

The alkylene group for ^V'101 and ^V'102 may be a straight-chain alkylene group or a branched-chain alkylene group, and a straight-chain alkylene group is preferable.

The alkylene group in V' ¹⁰¹ and V' ¹⁰² specifically includes a methylene group [-CH ₂ -]; -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ Alkylmethylene groups such as CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ -; Ethylene group [-CH ₂ CH 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 - ; Trimethylene group (n-propylene group) [-CH ₂ CH ₂ CH ₂ -] ; Alkyltrimethylene groups such as -CH(CH ₃ )CH ₂ CH ₂ - and -CH ₂ CH(CH ₃ )CH ₂ -; tetramethylene group [-CH ₂ CH ₂ CH ₂ CH ₂ -] ; Alkyl tetramethylene groups such as -CH(CH ₃ )CH ₂ CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ CH ₂ -; Pentamethylene group [-CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ -] and the like can be mentioned.

Additionally, some of the methylene groups in the alkylene group at V' ¹⁰¹ or V' ¹⁰² may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is preferably a divalent group obtained by removing one additional hydrogen atom from the cyclic aliphatic hydrocarbon group of Ra' ³ in the formula (a1-r-1), such as a cyclohexylene group, 1,5- An adamantylene group or a 2,6-adamantylene group is more preferable.

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

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

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

Specific examples of the anion portion of the component (b-1) include,

When Y ¹⁰¹ is a single bond, fluorinated alkyl sulfonate anions such as trifluoromethane sulfonate anion and perfluorobutane sulfonate anion can be used; When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, an anion represented by any of the following formulas (an-1) to (an-3) can be used.

[Formula 31]

[Wherein, R" ¹⁰¹ is an aliphatic cyclic group that may have a substituent, a group each represented by the above formulas (r-hr-1) to (r-hr-6), or a chain alkyl group that may have a substituent. and R" ¹⁰² is an aliphatic cyclic group which may have a substituent, a lactone-containing cyclic group each represented by the above formulas (a2-r-1) to (a2-r-7), or the above general formula (a5-r- 1) -SO ₂ --containing cyclic groups each represented by to (a5-r-4); R" ¹⁰³ is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent; V" ¹⁰¹ is a fluorinated alkylene group; L" ¹⁰¹ is -C(=O)- or -SO ₂ -; v" is each independently an integer from 0 to 3, q" is each independently an integer from 1 to 20, and n" is 0 or It is 1.]

The aliphatic cyclic group that may have a substituent at R" ¹⁰¹ , R" ¹⁰² and R" ¹⁰³ is preferably a group exemplified as the cyclic aliphatic hydrocarbon group for R ^101. The substituent for R ¹⁰¹ is Examples of the same substituent that may substitute for the cyclic aliphatic hydrocarbon group include the same substituents.

The aromatic cyclic group that may have a substituent for R" ¹⁰³ is preferably a group exemplified as the aromatic hydrocarbon group for the cyclic hydrocarbon group for R ^101. The substituent for R ¹⁰¹ is preferably The same substituent that may substitute the aromatic hydrocarbon group can be mentioned.

The chain alkyl group which may have a substituent at R" ¹⁰¹ is preferably the group exemplified as the chain alkyl group at R" ¹⁰¹ above. The chain alkyl group which may have a substituent at R" ¹⁰³ The kenyl group is preferably a group exemplified as the chain alkenyl group for R ¹⁰¹ above. V" ¹⁰¹ is preferably a fluorinated alkylene group having 1 to 3 carbon atoms, and particularly preferably -CF ₂ -, -CF ₂ CF ₂ -, -CHFCF ₂ -, -CF(CF ₃ )CF ₂ -, -CH(CF ₃ )CF ₂ -.

·(b-2) Anionic part of component

In formula (b-2), R ¹⁰⁴ and R ¹⁰⁵ each independently represent a cyclic group that may have a substituent, a chain alkyl group that may have a substituent, or a chain alkenyl group that may have a substituent, respectively. The same thing as R ¹⁰¹ in formula (b-1) can be mentioned. However, R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring.

R ¹⁰⁴ and R ¹⁰⁵ are preferably a linear alkyl group that may have a substituent, and more preferably a linear or branched alkyl group or a linear or branched fluorinated alkyl group.

The chain alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and still more preferably 1 to 3 carbon atoms. The smaller the carbon number of the chain alkyl group of R ¹⁰⁴ and R ¹⁰⁵ within the above-mentioned carbon number range, the better the solubility in the resist solvent. In addition, in the chain alkyl group of R ¹⁰⁴ and R ¹⁰⁵ , the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength, and the improved transparency to high-energy light or electron beams of 200 nm or less is preferable. do. The proportion of fluorine atoms in the chain alkyl group, that is, the fluorination rate, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably, a perfluoroalkyl group in which all hydrogen atoms are replaced with fluorine atoms. am.

In formula (b-2), V ¹⁰² and V ¹⁰³ each independently represent a single bond, an alkylene group, or a fluorinated alkylene group, and examples thereof include the same as V ¹⁰¹ in formula (b-1).

In formula (b-2), L ¹⁰¹ to L ¹⁰² are each independently a single bond or an oxygen atom.

·Anionic part of (b-3) component

In formula (b-3), R ¹⁰⁶ to R ¹⁰⁸ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, respectively. The same thing as R ¹⁰¹ in formula (b-1) can be mentioned.

L ¹⁰³ to L ¹⁰⁵ are each independently a single bond, -CO- or -SO ₂ -.

{Cation Department}

In formulas (b-1), (b-2) and (b-3), M' ^m+ is an m-valent organic cation, preferably a sulfonium cation or an iodonium cation, and has the following general formula: Cations each represented by (ca-1) to (ca-4) are particularly preferred.

[Formula 32]

[In the formula, R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² each independently represent an aryl group, an alkyl group, or an alkenyl group which may have a substituent, and R ²⁰¹ to R ²⁰³ , R ²⁰⁶ to R ²⁰⁷ , and R ²¹¹ ~R ²¹² may be combined with each other to form a ring with the sulfur atom in the formula. R ²⁰⁸ to R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, R ²¹⁰ is an aryl group, alkyl group, alkenyl group, or -SO ₂ -containing cyclic group that may have a substituent, and L ²⁰¹ is -C(=O)- or -C(=O)-O-, Y ²⁰¹ each independently represents an arylene group, alkylene group or alkenylene group, x is 1 or 2, and W ²⁰¹ is (x+1 ) indicates a linking group.]

The aryl group for R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² includes an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferable.

The alkyl group for R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.

The alkenyl group for R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² preferably has 2 to 10 carbon atoms.

Substituents that R ²⁰¹ to R ²⁰⁷ and R ²¹⁰ to R ²¹² may have include, for example, an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, an arylthio group, the following formula (ca Groups each represented by -r-1) to (ca-r-7) can be mentioned.

The aryl group in the arylthio group as a substituent is the same as that exemplified for R ¹⁰¹ , and specifically includes a phenylthio group or a biphenylthio group.

[Formula 33]

[In the formula, R' ²⁰¹ is each independently a hydrogen atom, a cyclic group that may have a substituent, a chain alkyl group, or a chain alkenyl group.]

The cyclic group that may have a substituent for R' ²⁰¹ , the chain alkyl group that may have a substituent, or the chain alkenyl group that may have a substituent may be the same as R ¹⁰¹ in the formula (b-1) above. In addition to those present, examples of the cyclic group that may have a substituent or the chain alkyl group that may have a substituent include those identical to the acid dissociable group represented by the above formula (a1-r-2).

When R ²⁰¹ to R ²⁰³ , R ²⁰⁶ to R ²⁰⁷ , and R ²¹¹ to R ²¹² combine with each other to form a ring with the sulfur atom in the formula, they are heteroatoms such as sulfur atom, oxygen atom, nitrogen atom, carbonyl group, Even if it is bonded through a functional group such as -SO-, -SO ₂ -, -SO ₃ -, -COO-, -CONH- or -N(R _N )- (where R _N is an alkyl group having 1 to 5 carbon atoms) do. The ring formed is preferably a 3- to 10-membered ring, with one ring containing the sulfur atom of the formula in its ring skeleton including a sulfur atom, and a 5- to 7-membered ring is particularly preferable. Specific examples of the formed ring include, for example, a thiophene ring, a thiazole ring, a benzothiophene ring, a thianthrene ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, and a thioxanthone. rings, thianthrene rings, phenoxathiin rings, tetrahydrothiophenium rings, tetrahydrothiopyranium rings, etc.

R ²⁰⁸ to R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group with 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group with 1 to 3 carbon atoms, and when they are alkyl groups, they may combine with each other to form a ring.

R ²¹⁰ is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or an -SO ₂ --containing cyclic group which may have a substituent.

The aryl group for R ²¹⁰ includes an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferable.

The alkyl group for R ²¹⁰ is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.

The alkenyl group for R ²¹⁰ preferably has 2 to 10 carbon atoms.

Examples of the -SO ₂ --containing cyclic group for R ²¹⁰ that may have a substituent include the same ones as the “-SO ₂ --containing cyclic group” for Ra ²¹ in the general formula (a2-1) above. A group represented by the general formula (a5-r-1) is preferred.

Y ²⁰¹ each independently represents an arylene group, an alkylene group, or an alkenylene group.

The arylene group for Y ²⁰¹ includes a group obtained by removing one hydrogen atom from the aryl group exemplified as the aromatic hydrocarbon group for R ¹⁰¹ in the formula (b-1).

The alkylene group and alkenylene group for Y ²⁰¹ may be the same as the aliphatic hydrocarbon group as the divalent hydrocarbon group for Va ¹ in the general formula (a1-1).

In the above formula (ca-4), x is 1 or 2.

W ²⁰¹ is (x+1) valent, that is, a divalent or trivalent linking group.

The divalent linking group for W ²⁰¹ is preferably a divalent hydrocarbon group that may have a substituent, and examples include the same hydrocarbon group as Ya ²¹ in the general formula (a2-1) above. The divalent linking group in W ²⁰¹ may be linear, branched, or cyclic, and is preferably cyclic. Among them, a group in which two carbonyl groups are combined at both ends of an arylene group is preferable. Examples of the arylene group include phenylene group and naphthylene group, and phenylene group is particularly preferable.

Examples of the trivalent linking group in W ²⁰¹ include a group in which one hydrogen atom is removed from the divalent linking group in W ²⁰¹ , a group in which the divalent linking group is further bonded to the divalent linking group, and the like. The trivalent linking group for W ²⁰¹ is preferably a group in which two carbonyl groups are bonded to an arylene group.

Specifically, preferred cations represented by formula (ca-1) include cations each represented by the following formulas (ca-1-1) to (ca-1-64).

[Formula 34]

[Formula 35]

[Formula 36]

[In the formula, g1, g2, and g3 represent the number of repetitions, g1 is an integer from 1 to 5, g2 is an integer from 0 to 20, and g3 is an integer from 0 to 20.]

[Formula 37]

[In the formula, R" ²⁰¹ is a hydrogen atom or a substituent, and the substituents are the same as those exemplified as the substituents that R ²⁰¹ to R ²⁰⁷ and R ²¹⁰ to R ²¹² may have above.]

Specifically, preferred cations represented by the formula (ca-3) include cations represented by the following formulas (ca-3-1) to (ca-3-6), respectively.

[Formula 38]

Specifically, preferred cations represented by the formula (ca-4) include cations represented by the following formulas (ca-4-1) to (ca-4-2), respectively.

[Formula 39]

(B) Component may use the above-mentioned acid generator individually by 1 type, or may use it in combination of 2 or more types.

In the present invention, when the resist composition contains component (B), the content of component (B) is preferably 0.5 to 60 parts by mass, more preferably 1 to 50 parts by mass, per 100 parts by mass of component (A), 1 to 40 parts by mass is more preferable. By keeping the content of component (B) within the above range, pattern formation is sufficiently achieved. Additionally, it is preferable because when each component of the resist composition is dissolved in an organic solvent, a uniform solution is obtained and storage stability is improved.

<Photo-reactive quencher component; (D) Ingredient>

In the present invention, the resist composition may further contain a photoreactive quencher component (hereinafter also referred to as “component (D)”).

The component (D) acts as a quencher (acid diffusion controller) that traps the acid generated by exposure from the component (B) and the like.

The (D) component in the present invention is preferably a photoreactive quencher component (D1) (hereinafter referred to as “component (D1)”), which decomposes upon exposure and loses acid diffusion control. Additionally, a nitrogen-containing organic compound (D2) (hereinafter referred to as “component (D2)”) that does not correspond to the component (D1) may be additionally contained.

[(D1) component]

By using a resist composition containing component (D1), the contrast between exposed and unexposed areas can be improved when forming a resist pattern.

The (D1) component is not particularly limited as long as it decomposes upon exposure and loses acid diffusion control, and includes a compound represented by the following general formula (d1-1) (hereinafter referred to as “(d1-1) component”), A compound represented by the following general formula (d1-2) (hereinafter referred to as “(d1-2) component”) and a compound represented by the following general formula (d1-3) (hereinafter referred to as “(d1-3) component”) At least one compound selected from the group consisting of is preferable.

Components (d1-1) to (d1-3) do not act as a quencher in the exposed area because they decompose and lose acid diffusion control (basicity), but act as a quencher in the unexposed area.

[Formula 40]

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

{(d1-1) component}

·Anion part

In formula (d1-1), Rd ¹ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and examples thereof include the same as R ¹⁰¹ .

Among these, Rd ¹ is preferably an aromatic hydrocarbon group that may have a substituent, an aliphatic cyclic group that may have a substituent, or a chain hydrocarbon group that may have a substituent. The substituent that these groups may have is preferably a hydroxyl group, a fluorine atom, or a fluorinated alkyl group.

The aromatic hydrocarbon group is more preferably a phenyl group or a naphthyl group.

The aliphatic cyclic group is more preferably a group obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

The chain-type hydrocarbon group is preferably a chain-type alkyl group. The chain alkyl group preferably has 1 to 10 carbon atoms, and specifically includes straight alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups. Chain alkyl group; 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methyl Examples include branched chain alkyl groups such as pentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

When the chain-like alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the number of carbon atoms of the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and still more preferably 1 to 4. The fluorinated alkyl group may contain atoms other than fluorine atoms. Atoms other than fluorine atoms include, for example, oxygen atoms, carbon atoms, hydrogen atoms, sulfur atoms, and nitrogen atoms.

Rd1 is preferably a fluorinated alkyl group in which some or all of the hydrogen atoms constituting the linear alkyl group are substituted with fluorine atoms, and a fluorinated alkyl group in which all of the hydrogen atoms constituting the linear alkyl group are substituted with fluorine atoms ( It is preferable that it is a linear perfluoroalkyl group).

Below, preferred specific examples of the anion portion of component (d1-1) are shown.

[Formula 41]

·Cation section

In formula (d1-1), M ^m+ is an m-valent organic cation, and is the same as M ^m+ in formulas (b-1) to (b-3) above.

(d1-1) A component may be used individually by 1 type, or may be used in combination of 2 or more types.

{(d1-2) component}

·Anion part

In formula (d1-2), Rd ² is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and examples thereof include the same as R ¹⁰¹ .

However, in Rd ² , two or more fluorine atoms are not bonded to the carbon atom adjacent to the S atom (not substituted with fluorine). As a result, the anion of component (d1-2) becomes an appropriate weak acid anion, and the quenching ability of component (D) improves.

Rd ² is preferably an aliphatic cyclic group that may have a substituent, and is a group obtained by removing one or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. (substituents You may have it) ; It is more preferable that it is a group obtained by removing one or more hydrogen atoms from camphor or the like.

The hydrocarbon group of Rd ² may have a substituent, and the substituent may be the same as the substituent that the hydrocarbon group (aromatic hydrocarbon group, aliphatic hydrocarbon group) in Rd ¹ in the above formula (d1-1) may have. there is.

Below, preferred specific examples of the anion portion of component (d1-2) are shown.

[Formula 42]

·Cation section

In formula (d1-2), M ^m+ is an m-valent organic cation, and is the same as M ^m+ in formula (d1-1).

(d1-2) A component may be used individually by 1 type, or may be used in combination of 2 or more types.

{(d1-3) component}

·Anion part

In formula (d1-3), Rd ³ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and examples thereof include the same as R ¹⁰¹ ; , a cyclic group containing a fluorine atom, a chain alkyl group, or a chain alkenyl group. Among these, a fluorinated alkyl group is preferable, and the same fluorinated alkyl group of Rd ¹ is more preferable.

In formula (d1-3), Rd ⁴ is a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, and examples thereof include the same as R ¹⁰¹ .

Among them, alkyl groups, alkoxy groups, alkenyl groups, and cyclic groups that may have substituents are preferable.

The alkyl group for Rd ⁴ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert- Butyl group, pentyl group, isopentyl group, neopentyl group, etc. are mentioned. Part of the hydrogen atom of the alkyl group of Rd ⁴ may be substituted with a hydroxyl group, a cyano group, or the like.

The alkoxy group for Rd ⁴ is preferably an alkoxy group having 1 to 5 carbon atoms. Specifically, the alkoxy group having 1 to 5 carbon atoms includes methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, and n-butoxy group. group, and tert-butoxy group. Among them, methoxy group and ethoxy group are preferable.

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

The cyclic group for Rd ⁴ may be the same as for R ¹⁰¹ above, and may be selected from cycloalkanes such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. An alicyclic group from which two or more hydrogen atoms have been removed, or an aromatic group such as a phenyl group or a naphthyl group, is preferable. When Rd ⁴ is an alicyclic group, the resist composition dissolves well in an organic solvent, thereby improving lithography characteristics. Moreover, when Rd ⁴ is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition has excellent light absorption efficiency, resulting in good sensitivity and lithography characteristics.

In formula (d1-3), Yd ¹ is a single bond or a divalent linking group.

The divalent linking group for Yd ¹ is not particularly limited, but includes a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent, a divalent linking group containing a hetero atom, and the like. These include the same ones as those exemplified in the description of the divalent linking group of Ya ²¹ in the above formula (a2-1).

Yd ¹ is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. The alkylene group is more preferably a straight-chain or branched alkylene group, and even more preferably a methylene group or an ethylene group.

Below, preferred specific examples of the anion portion of component (d1-3) are shown.

[Formula 43]

[Formula 44]

·Cation section

In formula (d1-3), M ^m+ is an m-valent organic cation, and is the same as M ^m+ in formula (d1-1).

(d1-3) A component may be used individually by 1 type, or may be used in combination of 2 or more types.

As the component (D1), only one type of the components (d1-1) to (d1-3) above may be used, or two or more types may be used in combination.

The content of component (D1) is preferably 0.5 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, and still more preferably 1 to 8 parts by mass, based on 100 parts by mass of component (A).

When the content of component (D1) is equal to or more than the preferred lower limit, particularly good lithographic properties and resist pattern shapes are obtained. On the other hand, if it is below the upper limit, sensitivity can be maintained well and throughput is also excellent.

The manufacturing method of the above-described component (d1-1) and (d1-2) is not particularly limited, and they can be manufactured by known methods.

The content of component (D1) is preferably 0.5 to 10.0 parts by mass, more preferably 0.5 to 8.0 parts by mass, and even more preferably 1.0 to 8.0 parts by mass, based on 100 parts by mass of component (A). If it is above the lower limit of the above range, particularly good lithographic properties and resist pattern shapes are obtained. If it is below the upper limit of the above range, sensitivity can be maintained well and throughput is also excellent.

((D2) component)

Component (D) may contain a nitrogen-containing organic compound component (hereinafter referred to as component (D2)) that does not correspond to the component (D1).

The component (D2) is not particularly limited as long as it acts as an acid diffusion controller and does not fall under the component (D1), and any known component may be used arbitrarily. Among them, aliphatic amines, especially secondary aliphatic amines and tertiary aliphatic amines, are preferable.

An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms.

Examples of aliphatic amines include amines (alkylamines or alkylalcoholamines) or cyclic amines in which at least one hydrogen atom of ammonia NH ₃ is replaced with an alkyl group or hydroxyalkyl group having 12 or less carbon atoms.

Specific examples of alkylamine and alkylalcoholamine include monoalkylamine such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; Trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri Trialkylamines such as -n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; Alkyl alcohol amines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine can be mentioned. Among these, trialkylamine having 5 to 10 carbon atoms is more preferable, and tri-n-pentylamine or tri-n-octylamine is particularly preferable.

Examples of cyclic amines 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 aliphatic monocyclic amines include piperidine and piperazine.

The aliphatic polycyclic amine preferably has 6 to 10 carbon atoms, 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, etc. are mentioned.

Other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, and tris{2-(2-methoxyethoxymethoxy)ethyl. }Amine, Tris{2-(1-methoxyethoxy)ethyl}amine, Tris{2-(1-ethoxyethoxy)ethyl}amine, Tris{2-(1-ethoxypropoxy)ethyl}amine , tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, triethanolamine triacetate, etc., and triethanolamine triacetate is preferable.

Additionally, as the component (D2), an aromatic amine may be used.

Aromatic amines include aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or their derivatives, diphenylamine, triphenylamine, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine, etc. can be mentioned.

(D2) The component may be used individually, or may be used in combination of two or more types.

Component (D2) is usually used in the range of 0.01 to 5.0 parts by mass with respect to 100 parts by mass of component (A). By setting it within the above range, the resist pattern shape, stability over time after exposure, etc. are improved.

(D) Component may be used individually by 1 type, or may be used in combination of 2 or more types. In the present invention, when the resist composition contains component (D), the amount of component (D) is preferably 0.1 to 15 parts by mass, more preferably 0.3 to 12 parts by mass, and 0.5 parts by mass relative to 100 parts by mass of component (A). It is more preferable that it is ~12 parts by mass. If it is more than the lower limit of the above range, lithography characteristics such as LWR are further improved when used as a resist composition. Additionally, a better resist pattern shape is obtained. If it is below the upper limit of the above range, sensitivity can be maintained well and throughput is also excellent.

[(F) component]

In the present invention, the resist composition contains a fluorine additive (hereinafter referred to as “component (F)”) to impart water repellency to the resist film.

As the component (F), a polymer (F) having a structural unit represented by the following formula (f1) is preferable.

[Formula 45]

Equation (f1)

(In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and L ₁ and L ₂ are the same or different from each other and have a single bond, a carbonyl group, an ether bond, or an ester bond. It is a hydrocarbon group optionally having 1 to 10 carbon atoms, x is 0 or 1, m is an integer of 1 to 20, n represents an integer of 1 to 2m+1, p is an integer of 1 to 20, and q is Represents an integer of 1 to 2p.)

In formula (f1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and a hydrogen atom or a methyl group is preferable.

Examples of the hydrocarbon group having 1 to 10 carbon atoms that may have a carbonyl group, ether bond, or ester bond include straight-chain or branched aliphatic hydrocarbon groups having 1 to 10 carbon atoms that may have a carbonyl group, ether bond, or ester bond. .

The linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and the like.

m and p are integers from 1 to 20, preferably from 1 to 15, and more preferably from 1 to 10.

Additional (F) components include, for example, Japanese Patent Laid-Open No. 2010-002870, Japanese Patent Laid-Open No. 2010-032994, Japanese Patent Laid-Open No. 2010-277043, Japanese Patent Laid-Open No. 2011-13569, Japanese Patent Laid-open No. The fluorinated polymer compound described in Patent Publication No. 2011-128226 can be used together.

More specifically, the (F) component includes a polymer having a structural unit (f1) represented by the formula (f1) above. Examples of the polymer include a polymer (homopolymer) consisting only of structural units represented by the formula (f1); A copolymer of the structural unit represented by the formula (f1) and the structural unit (a1); It is preferable that it is a copolymer of the structural unit represented by the above formula (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1). Here, the structural unit (a1) copolymerized with the structural unit represented by the formula (f1) is 1-ethyl-1-cyclooctyl (meth)acrylate or the structural unit represented by the formula (a1-2-01). desirable.

In addition, in the hydrocarbon group containing a fluorine atom (-C _m H _(2m+1-n) F _n ), it is preferable that 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, and 50% or more are fluorinated. It is more preferable that 60% or more of it is fluorinated, and it is especially preferable that it increases the hydrophobicity of the resist film during immersion exposure.

Among them, as the hydrocarbon group containing a fluorine atom, fluorinated hydrocarbon groups having 1 to 5 carbon atoms are particularly preferable, and are -CH ₂ -CF ₃ , -CH ₂ -CF ₂ -CF ₃ , -CH(CF ₃ ) ₂ , - CH ₂ -CH ₂ -CF ₃ , -CH ₂ -CH ₂ -CF ₂ -CF ₂ -CF ₂ -CF ₃ are most preferred.

The weight average molecular weight (Mw) of component (F) (based on polystyrene conversion by gel permeation chromatography) is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and most preferably 10,000 to 30,000. 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, the dry etching resistance and cross-sectional shape of the resist pattern are good.

(F) The dispersion degree (Mw/Mn) of component is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5.

(F) Component may be used individually by 1 type, or may use 2 or more types together.

Component (F) is used in a ratio of 0.5 to 10 parts by mass based on 100 parts by mass of component (A).

[(S) component]

The resist composition of the present invention is produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as the (S) component).

(S) Components include propylene carbonate, propylene glycol monomethyl ether acetate (PGMEA), and propylene glycol monomethyl ether (PGME).

The amount of propylene carbonate in the (S) component is 0.1 to 3% by mass based on the entire solvent.

For this reason, the resist composition of the present invention is capable of obtaining a sufficient receding angle and also capable of obtaining a clean edge state. If the amount of propylene carbonate exceeds the above range, residue easily remains on the edge, making it difficult to obtain a clean edge.

In addition to those mentioned above, one or two or more of those known as solvents for conventional chemically amplified resists may be appropriately selected and used.

For example, lactones such as γ-butyrolactone; Ketones such as acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl-n-pentyl ketone (2-heptanone), and methyl isopentyl ketone; Polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; Compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate, monomethyl ether, monoethyl ether of the above polyhydric alcohols or compounds having the above ester bond, Derivatives of polyhydric alcohols, such as monoalkyl ethers such as monopropyl ether and monobutyl ether, or compounds having an ether bond such as monophenyl ether [among these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether. (PGME) is excluded]; Cyclic ethers such as dioxane, esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; Anisole, ethylbenzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetol, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene aromatic organic solvents such as dimethyl sulfoxide (DMSO), and the like.

The amount of component (S) used is not particularly limited, and is appropriately set to a concentration that can be applied to a substrate or the like, depending on the thickness of the coating film. Generally, the resist composition is used so that the solid content concentration is within the range of 1 to 20 mass%, preferably within the range of 2 to 15 mass%.

<Arbitrary component>

[(E) component]

In the present invention, the resist composition includes an organic carboxylic acid as an optional component and a group consisting of phosphorus oxo acid and its derivatives for the purpose of preventing sensitivity deterioration and improving the resist pattern shape and stability over time after exposure. At least one type of compound (E) (hereinafter referred to as component (E)) selected from can be contained.

Preferred organic carboxylic acids include, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, and salicylic acid.

Examples of oxo acids of phosphorus include phosphoric acid, phosphonic acid, and phosphinic acid, and among these, phosphonic acid is particularly preferable.

Derivatives of phosphorus oxo acid include, for example, esters in which the hydrogen atom of the oxo acid is replaced with a hydrocarbon group, and the hydrocarbon group includes an alkyl group with 1 to 5 carbon atoms, an aryl group with 6 to 15 carbon atoms, etc. can be mentioned.

Derivatives of phosphoric acid include phosphoric acid esters such as di-n-butyl phosphoric acid ester and diphenyl phosphoric acid ester.

Derivatives of phosphonic acid include phosphonic acid esters such as dimethyl phosphonic acid, di-n-butyl phosphonic acid, phenylphosphonic acid, diphenyl phosphonic acid, and dibenzyl phosphonic acid.

Derivatives of phosphinic acid include phosphinic acid esters and phenylphosphinic acid.

(E) Component may be used individually by 1 type, or may use 2 or more types together.

Component (E) is usually used in the range of 0.01 to 5.0 parts by mass with respect to 100 parts by mass of component (A).

In the present invention, the resist composition may further contain miscible additives as desired, such as additional resins to improve the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, anti-halation agents, dyes, etc. It can be added and contained appropriately.

≪Resist pattern formation method≫

In the present invention, the resist pattern can be formed by forming a resist film on a support using the above-described resist composition, exposing the resist film, and developing the resist film.

The pattern formation method can be performed, for example, as follows.

First, the above-described resist composition is applied onto the support using a spinner or the like, and then subjected to a bake (post-apply bake (PAB)) treatment, for example, at a temperature of 80 to 150°C for 40 to 120 seconds, preferably 60°C. This is carried out for ~90 seconds to form a resist film.

Next, the resist film is exposed through a mask (mask pattern) on which a predetermined pattern is formed using an exposure device such as an ArF exposure device, an electron beam drawing device, or an EUV exposure device, or without a mask pattern. After selective exposure such as drawing by direct irradiation of an electron beam, bake (Post Exposure Bake (PEB)) treatment is performed, for example, at a temperature of 80 to 150°C for 40 to 120 seconds, preferably 60 to 90°C. Perform for seconds.

Next, the resist film is developed.

In the case of an alkaline development process, the development treatment is performed using an alkaline developer, and in the case of a solvent development process, a developer containing an organic solvent (organic developer) is used.

After development treatment, rinsing treatment is preferably performed. In the case of an alkaline development process, water rinsing using pure water is preferable, and in the case of a solvent development process, it is preferable to use a rinse solution containing an organic solvent.

In the case of the solvent development process, after the development or rinsing process, a process of removing the developer or rinse liquid adhering to the pattern with a supercritical fluid may be performed.

Drying is performed after development or rinsing. Additionally, depending on the case, a bake treatment (post-bake) may be performed after the development treatment. In this way, a resist pattern can be obtained.

In the present invention, the development treatment may be an alkaline development process or a solvent development process.

[Support]

The support is not particularly limited, and conventionally known ones can be used. For example, a substrate for electronic components or a substrate on which a predetermined wiring pattern is formed can be used. More specifically, examples include silicon wafers, metal substrates such as copper, chrome, iron, and aluminum, and glass substrates. Materials for the wiring pattern include, for example, copper, aluminum, nickel, and gold.

Additionally, the support may be one in which an inorganic and/or organic film is formed on a substrate as described above. Examples of inorganic films include inorganic antireflection films (inorganic BARC). Examples of organic films include organic anti-reflection films (organic BARC) and organic films such as the lower layer organic film in the multilayer resist method.

Here, the multilayer resist method refers to forming at least one layer of organic film (lower layer organic film) and at least one layer of resist film (upper layer resist film) on a substrate, and using the resist pattern formed on the upper resist film as a mask to form the lower layer. It is a method of patterning an organic film, and is known to be able to form a pattern with a high aspect ratio. That is, according to the multilayer resist method, the required thickness can be secured by the lower layer organic film, so the resist film can be made thin, making it possible to form a fine pattern with a high aspect ratio.

The multilayer resist method basically includes a method of forming a two-layer structure of an upper resist film and a lower layer organic film (two-layer resist method), and a method of forming one or more intermediate layers (metal thin film, etc.) between the upper resist film and the lower organic film. It is divided into a method of forming a multi-layer structure of three or more layers (three-layer resist method).

The wavelength used for exposure is not particularly limited, and radiation such as ArF excimer laser, KrF excimer laser, F2 excimer laser, EUV (extreme ultraviolet ray), VUV (vacuum ultraviolet ray), EB (electron beam), X-ray, and soft X-ray are used. It can be carried out using. The resist composition has high utility for KrF excimer laser, ArF excimer laser, EB or EUV.

The exposure method for the resist film is liquid immersion lithography.

Liquid immersion exposure is an exposure method in which the space between the resist film and the lens at the lowest position of the exposure apparatus is filled in advance with a solvent (liquid immersion medium) having a refractive index greater than that of air, and then exposure (immersion exposure) is performed in that state.

As the immersion medium, a solvent having a refractive index greater than that of air but smaller than the refractive index of the resist film to be exposed is preferable. The refractive index of this solvent is not particularly limited as long as it is within the above range.

Examples of solvents having a refractive index greater than that of air and less 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 fluorine-based inert liquids include liquids containing fluorine-based compounds such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , and C ₅ H ₃ F ₇ as main components. The boiling point is preferably 70 to 180°C, and more preferably 80 to 160°C. If the fluorine-based inert liquid has a boiling point in the above range, it is preferable because the medium used for liquid immersion can be removed in a simple manner after completion of exposure.

As the fluorine-based inert liquid, a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group are replaced with fluorine atoms is particularly preferable. Specific examples of perfluoroalkyl compounds include perfluoroalkyl ether compounds and perfluoroalkylamine compounds.

Additionally, specifically, the perfluoroalkyl ether compound includes perfluoro(2-butyl-tetrahydrofuran) (boiling point 102°C), and the perfluoroalkylamine compound includes perfluorotributyl. and amines (boiling point 174°C).

As an immersion medium, water is preferably used from the viewpoints of cost, safety, environmental issues, versatility, etc.

As an alkaline developing solution used for development in an alkaline development process, a 0.1-10 mass % tetramethylammonium hydroxide (TMAH) aqueous solution is mentioned, for example.

The organic solvent contained in the organic developer used for development in the solvent development process may be any solvent that can dissolve component (A) (component (A) before exposure), and may be appropriately selected from known organic solvents. Specifically, polar solvents such as ketone-based solvents, ester-based solvents, alcohol-based solvents, amide-based solvents, and ether-based solvents, and hydrocarbon-based solvents can be used.

Known additives can be added to the organic developer as needed. The additive may include, for example, a surfactant. The surfactant is not particularly limited, but for example, ionic or nonionic fluorine-based and/or silicon-based surfactants can be used.

When blending a surfactant, the blending amount is usually 0.001 to 5 mass%, preferably 0.005 to 2 mass%, and more preferably 0.01 to 0.5 mass%, relative to the total amount of the organic developer.

Development can be performed by known developing methods, for example, a method of immersing the support in a developing solution for a certain period of time (dip method), a method of placing the developer on the surface of the support by surface tension and stopping for a certain period of time (paddle method) ), a method of spraying the developer on the surface of the support (spray method), and a method of continuously dispensing the developer while scanning the developer discharge nozzle at a constant speed on a support rotating at a constant speed (dynamic dispensing method). .

Rinsing treatment (cleaning treatment) using a rinse liquid can be performed by a known rinsing method. The method includes, for example, a method of continuously drawing a rinse solution onto a support rotating at a constant speed (rotation application method), a method of immersing the support in a rinse solution for a certain period of time (dip method), or applying a rinse solution to the surface of the support. A method of spraying (spray method), etc. may be mentioned.

Example

Next, the present invention will be described in more detail by examples, but the present invention is not limited to these examples.

<Preparation of resist composition: Examples 1 to 12, Comparative Examples 1 to 11>

The resist compositions of each example were prepared by mixing and dissolving the components shown in Tables 1 and 2.

In [Table 1] and [Table 2], each symbol has the following meaning. The numbers in [ ] are the mixing amount (parts by mass).

(A)-1 to (A)-3: Polymer compounds (A)-1 to (A)-3 shown in Table 3 below.

(B)-1 to (B)-3: Acid generators consisting of compounds represented by the following formulas (B)-1 to (B)-3.

(D)-1 to (D)-3: Compounds consisting of compounds represented by the following formulas (D)-1 to (D)-3.

(F)-1 to (F)-6: Fluorine-containing polymer compounds represented by the following formulas (F)-1 to (F)-6.

(S1)-1:PGMEA

(S2)-1: PGME

(S2)-2: Cyclohexanone

(S3)-1: propylene carbonate

(S3)-2: γ-butyrolactone

(S3)-3: δ-valerolactone

(S3)-4: Dipropylene glycol ethyl ether acetate

[Mw = 15,000, Mw/Mn = 1.7, the figure at the bottom right of ( ) represents the copolymer composition ratio (molar ratio)]

[Mw = 7,000, Mw/Mn = 1.75, the figure at the bottom right of ( ) represents the copolymer composition ratio (molar ratio)]

[Mw = 7,000, Mw/Mn = 1.78, the figure at the bottom right of ( ) represents the copolymer composition ratio (molar ratio)]

[Mw = 17,000, Mw/Mn = 1.80, the figure at the bottom right of ( ) represents the copolymer composition ratio (molar ratio)]

[Mw = 7,000, Mw/Mn = 1.8, the figure at the bottom right of ( ) represents the copolymer composition ratio (molar ratio)]

[Mw = 14,000, Mw/Mn = 1.9, the figure at the bottom right of ( ) represents the copolymer composition ratio (molar ratio)]

In [Table 3], each symbol of the copolymer structural unit has the following meaning.

<Measurement of retreat angle>

The resist compositions of Examples 1 to 12 and Comparative Examples 1 to 11 were applied using a spinner on an 8-inch silicon wafer treated with hexamethyldisilazane (HMDS), and prebaked on a hot plate at 110°C for 60 seconds. By drying, a resist film with a film thickness of 90 nm was formed.

Water was dropped on the surface of the resist film (resist film before exposure), and the receding angle (RCA) was measured using DROP MASTER-700 (product name, manufactured by Kyowa Interface Science Co., Ltd.) (Measurement of the receding angle: 50 μL of water). These results are shown in [Table 4].

<Confirmation of edge>

The resist compositions of Examples 1 to 12 and Comparative Examples 1 to 11 were applied on a 12-inch wafer treated with hexamethylsilazane using a spinner at an appropriate rotation speed within the range of 1200-1800 rpm and PGME/PGMEA (70 After edge rinsing with a solvent (/30) for 10 seconds, baking was performed on a hot place at 110°C for 60 seconds to form an edge-treated resist film with a thickness of 85 nm.

Thereafter, the edge portion was observed with an optical microscope, and those that had resist residues or were not cut to a certain width due to swelling, etc. were judged to be NG. These results are shown in [Table 5].

As shown from the above results, polymer (F) having a specific structural unit of 0.2 to 10% by mass of the total solid content and propylene carbonate, propylene glycol monomethyl ether acetate and the amount of propylene carbonate are 0.1 to 3% by mass of the total solvent. The resist film formed using a resist composition containing a solvent (S) containing propylene glycol monomethyl ether exhibited excellent edge conditions with a retreat angle exceeding 70°.

Claims (8)

A base component (A) that has a structural unit represented by the following formula (a1-1) or (a1-2) and whose solubility in an alkaline developer is changed by the action of an acid, and an acid generator component that generates acid upon exposure ( B), a resist composition containing a solvent (S) and 0.2 to 10% by mass of a polymer (F) having a structural unit represented by the following formula (f1) based on the total solid content,
A resist composition in which the solvent (S) contains propylene carbonate, propylene glycol monomethyl ether acetate (PGMEA), and propylene glycol monomethyl ether (PGME), and the amount of propylene carbonate in the total solvent is 0.1 to 3% by mass.
Equation (f1)

(In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and L ₁ and L ₂ are the same or different from each other and have a single bond, a carbonyl group, an ether bond, or an ester bond. It is a hydrocarbon group optionally having 1 to 10 carbon atoms, x is 0 or 1, m is an integer of 1 to 20, n represents an integer of 1 to 2m+1, p is an integer of 1 to 20, and q is Represents an integer of 1 to 2p.)

[Wherein, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Va ¹ is a divalent hydrocarbon group that may have an ether bond, a urethane bond, or an amide bond, n _a1 is 0, and Ra ¹ is represented by the following formulas (a1-r-1) to (a1-r-2) It's a mountain dissociation penis. Wa ¹ is a hydrocarbon group with n _a2 + 1 valence, n _a2 is 1 to 3, and Ra ² is an acid dissociable group represented by the following formula (a1-r-1) or (a1-r-3).]
… (a1-r-1)
[In the formula, Ra' ¹ and Ra' ² are a hydrogen atom or an alkyl group, Ra' ³ is a hydrocarbon group, and Ra' ³ may be combined with any of Ra' ¹ and Ra' ² to form a ring. * means combined hand.]
… (a1-r-2)
[In the formula, Ra' ⁴ to Ra' ⁶ are hydrocarbon groups, and Ra' ⁵ and Ra' ⁶ may be combined with each other to form a ring. * means combined hand.]
… (a1-r-3)
[In the formula, Ra' ⁷ to Ra' ⁹ represent an alkyl group. * means combined hand.] According to claim 1,
A resist composition further containing a photoreactive quencher component (D). The method of claim 1 or 2,
A resist composition wherein the base component (A) is a base component whose solubility in a developer is increased by the action of an acid. A resist pattern forming method comprising the steps of forming a resist film on a support using the resist composition according to claim 1 or 2, exposing the resist film, and developing the resist film to form a resist pattern. . A base component (A) whose solubility in an alkaline developer changes due to the action of an acid, an acid generator component (B) that generates an acid upon exposure, a solvent (S), and 0.2 to 10% by mass of the total solids of the following formula: A resist composition containing a copolymer (F) of a structural unit represented by (f1) and a structural unit containing an acid-decomposable group,
A resist composition in which the solvent (S) contains propylene carbonate, propylene glycol monomethyl ether acetate (PGMEA), and propylene glycol monomethyl ether (PGME), and the amount of propylene carbonate in the total solvent is 0.1 to 3% by mass.
Equation (f1)

(In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and L ₁ and L ₂ are the same or different from each other and have a single bond, a carbonyl group, an ether bond, or an ester bond. It is a hydrocarbon group optionally having 1 to 10 carbon atoms, x is 0 or 1, m is an integer of 1 to 20, n represents an integer of 1 to 2m+1, p is an integer of 1 to 20, and q is Represents an integer of 1 to 2p.) According to claim 1,
A resist composition wherein the polymer (F) has an acid-decomposable group. According to claim 5,
A resist composition wherein the structural unit containing the acid-decomposable group contains an acid-dissociable group represented by any of the following formulas (a1-r-1a) to (a1-r-3a).
… (a1-r-1a)
[In the formula, Ra' ¹ and Ra' ² are a hydrogen atom or an alkyl group, Ra' ³ is a hydrocarbon group, and Ra' ³ may be combined with any of Ra' ¹ and Ra' ² to form a ring. * means combined hand.]
… (a1-r-2a)
[In the formula, Ra' ⁴ to Ra' ⁶ are hydrocarbon groups, and Ra' ⁵ and Ra' ⁶ are combined with each other to form a ring. * means combined hand.]
… (a1-r-3a)
[In the formula, Ra' ⁷ to Ra' ⁹ represent an alkyl group. * means combined hand.] According to claim 7,
A resist composition wherein the structural unit containing the acid-decomposable group contains an acid-dissociable group represented by the formula (a1-r-2a).