KR102612641B1 - Resist composition, method of forming resist pattern and compound - Google Patents

Abstract

(Project) Provision of resist compositions, resist pattern formation methods, and compounds.
(Solution) A resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid, comprising an acid generator component that generates acid upon exposure and a compound represented by general formula (d0). A resist composition containing a photobase activator component. A resist pattern forming method comprising the steps of forming a resist film using the resist composition on a support, exposing the resist film, and developing the exposed resist film to form a resist pattern. [In formula (d0), R ¹ and R ² are each independently a C1-C20 chain, branched, or cyclic hydrocarbon group that may have a substituent. However, the substituent bonded to the carbon atom adjacent to the carbonyl group or sulfonyl group does not have a group having a halogen atom, an aromatic group, or a proton acceptor functional group. M ^m+ is an m-valent organic cation. m is an integer greater than 1.]
[Formula 1]

Description

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

The present invention relates to resist compositions, methods and compounds 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 carrying out the treatment, a process of forming a resist pattern of a predetermined shape is performed on the resist film.

A resist material whose exposed portion changes in properties to be soluble in a developer is called a positive type, and a resist material whose exposed portions change to a property that does not dissolve in a 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 begun. In addition, electron beams with shorter wavelengths (higher energy) than these excimer lasers, EUV (extreme ultraviolet rays), and X-rays are also being examined.

Resist materials are required to have lithographic properties such as sensitivity to these exposure light sources and resolution capable of reproducing fine-dimensional patterns.

As a resist material that satisfies such requirements, a chemically amplified resist composition containing a base component whose solubility in a developer solution changes due to the action of an acid and an acid generator component that generates acid upon exposure has been conventionally used. . For example, when the developer is an alkaline developer (alkaline development process), the positive-type chemically amplified resist composition includes a resin component (base resin) whose solubility in the alkaline developer increases by the action of an acid, and an acid-generated resist composition. Products containing these ingredients are commonly used. When a resist film formed using such a resist composition is selectively exposed during formation of a resist pattern, acid is generated from the acid generator component in the exposed area, and the polarity of the base resin increases due to the action of the acid. The exposed area is soluble in alkaline developer. Therefore, through alkali development, a positive pattern is formed in which the unexposed portion remains as a pattern. On the other hand, when a solvent development process using a developer containing an organic solvent (organic developer) is applied, as the polarity of the base resin increases, the solubility in the organic developer relatively decreases, so that the unexposed portion of the resist film is exposed to the organic developer. It is dissolved and removed, forming a negative resist pattern in which the exposed portion remains as a pattern. In this way, the solvent development process for forming a negative resist pattern is sometimes referred to as a negative development process (for example, patent document 1).

Generally, in a resist composition, in addition to the base component and the acid generator component, a quencher component such as an amine component is appropriately blended in order to control the diffusion of an acid generated from the acid generator during exposure (for example, For example, patent document 2). In such resist compositions, there is a problem that when the resist composition is prepared and stored for a certain period of time, the dimensions of the resist pattern formed before and after storage vary due to the interaction between the amine component and other compounding components.

In contrast, for example, in Patent Document 2, decomposition (deterioration over time) of other blended components during the storage period is suppressed by combining two specific types of components as quencher components.

Japanese Patent Publication No. 2009-025723 Japanese Patent Publication No. 2013-3512

As resist patterns become increasingly finer, resist materials are increasingly required to have good lithographic properties. There is still room for improvement in resist materials in order to suppress dimensional changes due to the effect of resist materials over time and to achieve good lithographic properties.

However, compounds with high quench efficiency have a large time-lapse risk, and conversely, compounds with a small time-lapse risk have low quench efficiency, so suppressing dimensional changes due to effects over time and ensuring quench efficiency It was difficult to achieve both improvement in lithography characteristics.

The present invention was made in view of the above circumstances, and its object is to provide a resist composition that suppresses dimensional changes due to effects over time and has good lithographic properties, and a method of forming a resist pattern using the resist composition.

A first aspect of the present invention is a resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, comprising an acid generator component (B) that generates an acid upon exposure, and the following general components: A resist composition characterized by containing a photobase quencher component (D0) containing a compound represented by the formula (d0).

A second aspect of the present invention provides a resist pattern comprising the steps of forming a resist film using the resist composition of the first aspect, exposing the resist film, and developing the exposed resist film to form a resist pattern. It is a method of formation.

The third aspect of the present invention is a compound represented by the following general formula (d0).

[Formula 1]

[In the formula, R ¹ is a chain, branched chain or cyclic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. However, when a substituent is bonded to the carbon atom of R ¹ adjacent to the carbonyl group in the formula, the substituent is at least one selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. Pretend not to have it. R ² is a chain, branched chain or cyclic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. However, when a substituent is bonded to the carbon atom of R ² adjacent to the sulfonyl group in the formula, the substituent is at least one selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. It is assumed that it does not have . M ^m+ is an m-valent organic cation. m is an integer greater than 1.]

According to the present invention, it is possible to provide a resist composition that suppresses dimensional changes due to effects over time and has good lithographic properties, and a method of forming a resist pattern using the resist composition.

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

Unless otherwise specified, the term “alkyl group” includes linear, branched, and cyclic monovalent saturated hydrocarbon groups. The alkyl group in the alkoxy group is the same.

Unless otherwise specified, the term “alkylene group” includes straight-chain, branched-chain, and cyclic divalent saturated hydrocarbon groups.

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) that constitutes a high molecular compound (resin, polymer, copolymer).

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 (-CH ₂ -) with a divalent group.

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

“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 carboxyl group terminal of acrylic acid (CH ₂ =CH-COOH) is substituted 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 (R ^α0 ) that replaces the hydrogen atom bonded to the carbon atom at the α position is an atom or group other than a hydrogen atom, and examples include an alkyl group with 1 to 5 carbon atoms, a halogenated alkyl group with 1 to 5 carbon atoms, etc. there is. It also includes itaconic acid diesters in which the substituent (R ^α0 ) is substituted with a substituent containing an ester bond, and α-hydroxyacrylic esters in which the substituent (R ^α0 ) is substituted with a hydroxyalkyl group or a group modified with the hydroxyl group. do. In addition, unless otherwise specified, the carbon atom at the α position of acrylic acid ester refers to the carbon atom to which the carbonyl group of acrylic acid is bonded.

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 acrylamide” means a structural unit formed by cleavage of the ethylenic double bond of acrylamide.

In acrylamide, the hydrogen atom bonded to the carbon atom at the α position may be substituted with a substituent, and one or both hydrogen atoms of the amino group of acrylamide may be substituted with a substituent. Additionally, the carbon atom at the α position of acrylamide is the carbon atom to which the carbonyl group of acrylamide is bonded, unless otherwise specified.

The substituent that replaces the hydrogen atom bonded to the carbon atom at the α position of acrylamide includes the same substituents as those exemplified as the substituent at the α position (substituent (R ^α0 )) in the α-substituted acrylate ester.

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

“Hydroxystyrene derivatives” is a concept that includes those in which the hydrogen atom at the α position of hydroxystyrene is substituted with other substituents such as alkyl groups and halogenated alkyl groups, as well as derivatives thereof. Their derivatives include those obtained by replacing the hydrogen atom of the hydroxyl group of hydroxystyrene, where the hydrogen atom at the α position may be substituted with a substituent, with an organic group; the benzene ring of hydroxystyrene, where the hydrogen atom at the α position may be substituted with a substituent; Examples include those in which substituents other than hydroxyl groups are bonded. 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 substituent at the α position in the α-substituted acrylic acid ester.

“Structural 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.

The term “vinylbenzoic acid derivative” is a concept that includes those in which the hydrogen atom at the α position of vinylbenzoic acid is replaced with 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 replaced with an organic group; Those to which a substituent other than a carboxyl group is bonded can 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.

The term “styrene derivative” is intended to include those in which 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 straight-chain or branched-chain alkyl group, and specifically, an alkyl group having 1 to 5 carbon atoms (methyl, ethyl, propyl, isopropyl, n-butyl, iso). butyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group), etc.

Additionally, 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 replaced with hydroxyl groups. The number of hydroxyl groups in the hydroxyalkyl group is preferably 1 to 5, and 1 is most preferable.

≪Resist composition≫

The present invention provides a resist composition that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid, comprising an acid generator component (B) that generates an acid upon exposure and a formula (d0) A resist composition characterized by containing a photobase quencher component (D0) containing the indicated compound.

In the present invention, the resist composition includes a base component (A) (hereinafter also referred to as “component (A)”) whose solubility in a developer changes due to the action of an acid, and an acid generator that generates acid upon exposure. It is preferable that it contains component (B) (hereinafter also referred to as “component (B)”).

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. do.

In this specification, a resist composition that forms a positive resist pattern by dissolving and removing exposed areas is referred to as a positive resist composition, and a resist composition that forms a negative resist pattern by dissolving and removing unexposed areas 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 solvent development using a developer containing an organic solvent (organic developer) for the development process. It may be for process purposes.

In the present invention, the resist composition has an acid-generating ability to generate acid upon exposure, and component (A) may generate acid upon exposure, and an additive component blended separately from component (A) may be used to generate acid upon exposure. Acid may be generated by

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, and may further contain the component (B).

That is, in the case of (2) 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) generates an acid upon exposure and is a base component whose solubility in a developer changes due to the action of the acid, the component (A1) described later generates an acid upon exposure and further, It is preferable that it is a high molecular compound whose solubility in a developer changes due to the action of an acid. As such a polymer compound, a resin having a structural unit that generates acid upon exposure can be used. As the structural unit that generates acid upon exposure, a known unit can be used.

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

＜Photobase activator component＞

The resist composition of the present invention contains a photobase quencher component (D0) (hereinafter sometimes referred to as “(D0) component”) containing a compound represented by the general formula (d0) below.

The (D0) component acts as a quencher (acid diffusion control agent) that traps acids generated from, for example, the (B) component, which will be described later, upon exposure, and contributes to the improvement of lithography characteristics.

Conventionally, it is known that compounds that act as quenchers have low quench efficiency when the pKa of their conjugate acid is low, and high quench efficiency when the pKa of the conjugate acid is high.

On the other hand, compounds with a high pKa of the conjugate acid tend to react with other polymers in the resist composition, and by interacting with other components, decomposition (deterioration over time) of the other components progresses (in other words, storage stability). It was thought that this was falling.

Therefore, as a result of intensive study, the present inventors have developed a resist composition that maintains a high acid quenching effect and at the same time has excellent storage stability by employing a photobase quencher component (D0) containing a compound represented by the general formula (d0). It came down to this.

[Formula 2]

[In the formula, R ¹ is a chain, branched chain or cyclic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. However, when a substituent is bonded to the carbon atom of R ¹ adjacent to the carbonyl group in the formula, the substituent is at least one selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. Pretend not to have it. R ² is a chain, branched chain or cyclic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. However, when a substituent is bonded to the carbon atom of R ² adjacent to the sulfonyl group in the formula, the substituent is at least one selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. It is assumed that it does not have . M ^m+ is an m-valent organic cation. m is an integer greater than 1.]

In formula (d0), R ¹ and R ² each independently represent a chain, branched chain or cyclic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent.

The chain or branched hydrocarbon group having 1 to 20 carbon atoms for R ¹ and R ² is more preferably an alkyl group having 1 to 10 carbon atoms; the straight or branched alkyl group is specifically: , methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, 1,1-dimethylethyl group, 1,1-diethyl group. Preferred examples include propyl group, 2,2-dimethylpropyl group, 2,2-dimethylbutyl group, hexyl group, octyl group, nonyl group, and decyl group.

Among them, methyl group, t-butyl group, and decyl group are more preferable.

When the hydrocarbon group having 1 to 20 carbon atoms in R ¹ and R ² is a cyclic hydrocarbon group, it may be aliphatic, 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 is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, and cycloalkane. Heptane, isobornane, tricyclodecane, tetracyclododecane, etc. can be mentioned.

When the hydrocarbon group having 1 to 20 carbon atoms in R ¹ and R ² is a cyclic hydrocarbon group, among the above, cyclohexane or adamantane is more preferable.

Substituents that the hydrocarbon group having 1 to 20 carbon atoms for R ¹ and R ² may have, for example, an alkyl group, an oxygen atom (=O), -COOR", -OC(=O)R", and a hydroxyalkyl group. etc. can be mentioned.

The alkyl group as the substituent is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, hexyl group, etc. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.

In -COOR" and -OC(=O)R", R" is a hydrogen atom or a straight-chain, branched-chain or cyclic alkyl group having 1 to 15 carbon atoms.

When R" is a straight-chain or branched alkyl group, it is preferable to have 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and especially preferably a methyl or ethyl group.

When R" is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, examples include groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as monocycloalkanes, bicycloalkanes, tricycloalkanes, and tetracycloalkanes. More specifically, one or more hydrogen atoms have been removed from monocycloalkanes such as cyclopentane and cyclohexane, or polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. etc. can be mentioned.

The hydroxyalkyl group as the substituent preferably has 1 to 6 carbon atoms. Specifically, the alkyl group as the substituent includes groups in which at least one hydrogen atom of the alkyl group exemplified above is substituted with a hydroxyl group.

In the present invention, when a substituent is bonded to the carbon atom of R ¹ adjacent to the carbonyl group in formula (d0), the substituent is selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. It is assumed that there is no more than one selected type.

In addition, when a substituent is bonded to the carbon atom of R ² adjacent to the sulfonyl group in formula (d0), the substituent is selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. Do not have more than one type.

Examples of the group having a halogen atom include only a halogen atom, a halogenated alkyl group, etc.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and it is particularly preferable that the substituent does not have a fluorine atom.

Examples of the halogenated alkyl group include halogenated alkyl groups in which some or all of the hydrogen atoms in the alkyl group are replaced with halogen atoms (especially fluorine atoms), and examples of the alkyl group include straight-chain alkyl groups (methyl, ethyl, propyl, butyl, pentyl, octyl). etc.), branched chain alkyl groups (isopropyl, isobutyl, sec-butyl, tert-butyl, etc.), cycloalkyl groups (cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, etc.).

The aromatic group specifically includes aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; aromatic heterocycles in which a portion of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms; etc. I can hear it. Hetero atoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms.

Specifically, the aromatic hydrocarbon group includes a group in which one hydrogen atom is removed 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, phenene group) Arylalkyl groups such as thyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, and 2-naphthylethyl group); and the like.

A proton acceptor functional group is a group that can interact electrostatically with a proton or a functional group with a lone pair of electrons, for example, a functional group with a macrocyclic structure such as a cyclic polyether, or an isolated group with little contribution from π conjugation. A functional group having a nitrogen atom with an electron pair can be mentioned.

Preferred partial structures of the proton acceptor functional group include, for example, crown ether, azacrown ether, tertiary amine, secondary amine, primary amine, pyridine, imidazole, pyrazine, and aniline structures.

In the present invention, hydrocarbon groups having 1 to 20 carbon atoms that may have substituents for R ¹ and R ² include, in addition to those exemplified above, general formulas (a2-r-1) to (a2-r) described later. -7), a group represented by any of general formulas (a5-r-1) to (a5-r-4), a group represented by any of general formulas (ax3-r-1) to (ax3-r-3) It can also be a contribution expressed as something.

In the present invention, among the above, a group represented by the general formula (a2-r-2) is preferable.

In general formula (d0), M ^m+ is an m-valent organic cation, and m is an integer of 1 or more.

Examples of the m-valent organic cation of M ^m+ include the same organic cations as the m-valent organic cation in general formulas (b-1) to (b-3) described later.

In the present invention, the compound represented by general formula (d0) is preferably a compound represented by the following general formula (d0-1).

[Formula 3]

[In the formula, one of R ¹¹ and R ¹² is a cyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent, and the other is a chain, branched chain or cyclic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. It is a type of hydrocarbon group. However, when a substituent is bonded to the carbon atom of R ¹¹ adjacent to the carbonyl group in the formula, the substituent is at least one selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. Pretend not to have it. When a substituent is bonded to the carbon atom of R ¹² adjacent to the sulfonyl group in the formula, the substituent has at least one selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. Make sure not to do so. M ^m+ is an m-valent organic cation. m is an integer greater than 1.]

In formula (d0-1), either R ¹¹ or R ¹² is a cyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent, and the other is a chain or branched hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. It is a chain or cyclic hydrocarbon group.

The description of the cyclic hydrocarbon group having 3 to 20 carbon atoms, which may have a substituent, and the chain, branched chain or cyclic hydrocarbon group having 1 to 20 carbon atoms, which may have a substituent, for R ¹¹ and R ¹² is given above. Same as

As the compound represented by general formula (d0-1), a compound represented by any of the following general formulas (d0-1a), (d0-1b), or (d0-1c) is preferable.

[Formula 4]

[Wherein, R ^11a is a cyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent, and R ^12a is a chain or branched hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. However, when a substituent is bonded to the carbon atom of R ^11a adjacent to the carbonyl group in the formula, the substituent is one or more selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. Pretend not to have it. When a substituent is bonded to the carbon atom of R ^12a adjacent to the sulfonyl group in the formula, the substituent has at least one selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. Make sure not to do so. M ^m+ is an m-valent organic cation. m is an integer greater than 1.]

In general formula (d0-1a), the cyclic hydrocarbon group having 3 to 20 carbon atoms that may have a substituent for R ^11a includes 3 to 20 carbon atoms that may have the substituent described for R ¹ or R ² above. Hydrocarbon groups that are the same as cyclic hydrocarbon groups can be mentioned.

In general formula (d0-1a), the chain or branched hydrocarbon group having 1 to 20 carbon atoms that may have a substituent for R ^12a includes the number of carbon atoms that may have the substituent described for R ¹ or R ² above. The same hydrocarbon group as the chain or branched chain hydrocarbon group of 1 to 20 can be mentioned.

[Formula 5]

[Wherein, R ^11b is a chain or branched hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, and R ^12b is a cyclic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent. However, when a substituent is bonded to the carbon atom of R ^11b adjacent to the carbonyl group in the formula, the substituent is at least one selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. Pretend not to have it. When a substituent is bonded to the carbon atom of R ^12b adjacent to the sulfonyl group in the formula, the substituent has at least one selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. Make sure not to do so. M ^m+ is an m-valent organic cation. m is an integer greater than 1.]

In general formula (d0-1b), the chain or branched hydrocarbon group having 1 to 20 carbon atoms that may have a substituent for R ^11b includes the number of carbon atoms that may have the substituent described for R ¹ or R ² above. The same hydrocarbon group as the chain or branched chain hydrocarbon group of 1 to 20 can be mentioned.

In general formula (d0-1b), the cyclic hydrocarbon group having 3 to 20 carbon atoms that may have a substituent for R ^12b includes those having 3 to 20 carbon atoms that may have the substituent described for R ¹ or R ² above. Hydrocarbon groups that are the same as cyclic hydrocarbon groups can be mentioned.

[Formula 6]

[In the formula, R ^11c and R ^12c are chain or branched hydrocarbon groups having 1 to 20 carbon atoms which may have a substituent. R ^11c and R ^12c may be the same or different. However, when a substituent is bonded to the carbon atom of R ^11c adjacent to the carbonyl group in the formula, the substituent is at least one selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. Pretend not to have it. When a substituent is bonded to the carbon atom of R ^12c adjacent to the sulfonyl group in the formula, the substituent has at least one selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. Make sure not to do so. M ^m+ is an m-valent organic cation. m is an integer greater than 1.]

In general formula (d0-1c), the chain or branched hydrocarbon group having 1 to 20 carbon atoms that may have a substituent at R ^11c and R ^12c includes a substituent group described above for R ¹ or R ² Examples of the same hydrocarbon group include a chain or branched chain hydrocarbon group having 1 to 20 carbon atoms. In general formula (d0-1c), R ^11c and R ^12c may be the same or different, but are preferably different hydrocarbon groups.

Below, specific examples of the compound represented by general formula (d0) are described. In the formula below, M ^m+ is an m-valent organic cation, and examples thereof include the same organic cation as the m-valent organic cation in general formulas (b-1) to (b-3) described later.

[Formula 7]

[Formula 8]

[Formula 9]

The compound represented by the general formula (d0) has a halogen atom in the substituent bonded to the carbon atom of R ¹ adjacent to the carbonyl group in formula (d0) or to the carbon atom of R ² adjacent to the sulfonyl group in formula (d0). Since it does not have one or more types selected from the group consisting of a group having, an aromatic group, and a proton acceptor functional group, the pKa of the conjugate acid can be kept relatively high.

In the present invention, the acid dissociation constant (pKa) of the conjugate acid of the compound represented by general formula (d0) is preferably greater than 2.5. In the present invention, the pKa of the conjugate acid of the compound represented by general formula (d0) is more preferably 3.0 or more, and particularly preferably 4.0 or more.

In the present invention, “acid dissociation constant (pKa)” refers to something generally used as an indicator of the acid strength of the target substance. The pKa value of the conjugate acid of the compound represented by general formula (d0) can be determined by measurement by a conventional method. Additionally, calculated values using known software such as “ACD/Labs” (trade name, manufactured by Advanced Chemistry Development) can also be used.

When the pKa of the conjugate acid is more than the above lower limit, the quench efficiency of the acid increases, and diffusion of the acid generated from component (B), etc., which will be described later, can be appropriately controlled.

(D0) As for the component, the above-mentioned compound may be used individually by 1 type, or may be used in combination of 2 or more types.

In the resist composition of the present invention, the content of component (D0) is preferably 0.5 to 20 parts by mass, more preferably 1 to 10 parts by mass, and still more preferably 1 to 8 parts by mass, per 100 parts by mass of component (A). . By keeping the content of the component (D0) within the above range, the quenching effect of the acid generated from the acid generator, etc., which will be described later, is sufficiently exhibited, and when each component of the resist composition is dissolved in an organic solvent, a uniform solution is obtained, This is preferable because it improves storage stability.

Since the resist composition of the present invention contains the compound (D0) represented by the general formula (d0), the acid quenching effect can be highly maintained, the diffusion length of the acid can be controlled, and at the same time, it has excellent storage stability. will be.

The compound represented by the general formula (d0) has a halogen atom in the substituent bonded to the carbon atom of R ¹ adjacent to the carbonyl group in formula (d0) or to the carbon atom of R ² adjacent to the sulfonyl group in formula (d0). Since it does not have at least one selected from the group consisting of a group having, an aromatic group, and a proton acceptor functional group, the pKa of the conjugate acid can be kept high and the diffusion length of the acid can be appropriately controlled, so quench Efficiency can be made high.

In conventional quencher components, if the pKa of the conjugate acid is increased, it is likely to react with other polymers in the resist composition. In other words, the decomposition (deterioration over time) of the other compounding ingredients progressed due to interaction with the ester bonds of other compounding ingredients, etc., in other words, the storage stability was poor.

On the other hand, in the present invention, since the anion skeleton of the compound represented by general formula (d0) is bulky, it is thought that contact with other compounding components can be suppressed due to steric hindrance. Accordingly, it is believed that it is possible to prevent deterioration of the resist composition over time, and a resist composition with excellent storage stability can be obtained.

In other words, the present invention is capable of both improving quench efficiency and reducing risk over time, and is a very useful resist composition.

<Acid generator component; (B) component>

The resist composition of the present invention contains an acid generator component (B) that generates acid upon exposure (hereinafter referred to as component (B)). The component (B) is not particularly limited, and those proposed so far as acid generators 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 the general formula (b-2) (hereinafter also referred to as “component (b-1)”). , “(b-2) component”), or a compound represented by general formula (b-3) (hereinafter also referred to as “(b-3) component”) can be used.

[Formula 10]

[In the formula, R ¹⁰¹ , R ¹⁰⁴ to R ¹⁰⁸ each independently represents 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}

· Anionic part of component (b-1)

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 formula (a1-1) described later, or a hydrogen atom from an aromatic compound containing two or more aromatic rings. Examples include aryl groups that have been removed, and phenyl groups and naphthyl groups are preferred.

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 formula (a1-1) described later. 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, lactones each represented by the general formulas (a2-r-1) to (a2-r-7) described later. cyclic groups, -SO ₂ -containing cyclic groups each represented by general formulas (a5-r-1) to (a5-r-4) described later, and other groups (r-hr-1) to (r-hr below) -16) Heterocyclic groups exemplified by .

[Formula 11]

Examples of the substituent in the cyclic hydrocarbon group of R ¹⁰¹ include an alkyl group, an alkoxy group, a halogen atom, alkyl halide group, hydroxyl group, carbonyl group, and 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.

Examples of the halogenated alkyl group as a substituent 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 substituted with the halogen atoms described above. there is.

(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, decanyl group, undecyl group, dodecyl group, tridecyl group, and 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 formulas (a2-r-1) to (a2-r-7) described later, and -SO ₂ --containing cyclic groups each represented by the general 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. A sulfonyl group (-SO ₂ -) may be further 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 12]

[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.

As the alkylene group in V' ¹⁰¹ and V' ¹⁰² , specifically, methylene group [-CH ₂ -];-CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) _2- , etc. Alkylmethylene groups; Ethylene group [-CH ₂ CH ₂ -]；-CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH ₃ )-, -C(CH ₃ ) ₂ CH ₂ -, -CH(CH ₂ Alkylethylene group such as CH ₃ )CH ₂ -; Trimethylene group (n-propylene group) [-CH ₂ CH ₂ CH ₂ -]; -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ ) Alkyltrimethylene group such as CH ₂ -; tetramethylene group [-CH ₂ CH ₂ CH ₂ CH ₂ -]; -CH(CH ₃ )CH ₂ CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ ) Alkyl tetramethylene groups such as CH ₂ CH ₂ -; pentamethylene groups [-CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ -] and the like.

Additionally, some 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) described later, and is preferably a cyclohexylene group, 1,5 -Adamantylene group or 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 are included; Y ¹⁰¹ is a divalent linkage containing an oxygen atom. In the case of a group, an anion represented by any of the following formulas (an-1) to (an-3) can be mentioned.

[Formula 13]

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

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

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 above. Examples of the substituent include the same substituents that may substitute the aromatic hydrocarbon group for R ¹⁰¹ .

The chain alkyl group that may have a substituent for R$ ¹⁰¹ is preferably a group exemplified as the chain alkyl group for R ¹⁰¹ above. The chain alkenyl group that may have a substituent at R$ ¹⁰³ is preferably a group exemplified as the chain alkenyl group at 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 -.

· Anionic part of (b-2) component

In formula (b-2), R ¹⁰⁴ and R ¹⁰⁵ 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, Each of them may be the same as R ¹⁰¹ in formula (b-1). However, R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring.

R ¹⁰⁴ and R ¹⁰⁵ 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 more preferable it is for reasons such as good 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 each may be 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 component (b-3)

In formula (b-3), R ¹⁰⁶ to R ¹⁰⁸ 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, Each of them may be the same as R ¹⁰¹ in formula (b-1).

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

{Cation Department}

In formulas (b-1), (b-2) and (b-3), M' ^m+ is an m-valent organic cation other than the cation in the compound of formula (b1-1), and among them, A sulfonium cation or an iodonium cation is preferable, and cations each represented by the following general formulas (ca-1) to (ca-4) are particularly preferable.

[Formula 14]

[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 to R ²¹² may be bonded to 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 valent 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 a chain or cyclic alkyl group, and preferably has 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, halogen atom, halogenated alkyl group, carbonyl group, cyano group, amino group, aryl group, arylthio group, and 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 15]

[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 formula (a1-r-2) described later.

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 a sulfur atom, an oxygen atom, or a nitrogen atom, a 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. As for the ring formed, one ring containing the sulfur atom of the formula in its ring skeleton is preferably a 3- to 10-membered ring including the sulfur atom, and is particularly preferably a 5- to 7-membered ring. Specific examples of the formed ring include, for example, a thiophene ring, a thiazole ring, a benzothiophene ring, a thiantrene ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, Examples include a thiantrene ring, a phenoxathiin ring, a tetrahydrothiophenium ring, and a tetrahydrothiopyranium ring.

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 an alkyl group, 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 a chain or cyclic alkyl group and preferably has 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 general formula (a2-1) described later, A group represented by the general formula (a5-r-1) described later 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 general formula (a1-1) described later.

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

W ²⁰¹ is a (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 general formula (a2-1) described later. 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, suitable cations represented by formula (ca-1) include cations each represented by the following formulas (ca-1-1) to (ca-1-63).

[Formula 16]

[Formula 17]

[Formula 18]

[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 19]

[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.]

Suitable cations represented by the above formula (ca-3) specifically include cations each represented by the following formulas (ca-3-1) to (ca-3-6).

[Formula 20]

Specific examples of suitable cations represented by the formula (ca-4) include cations represented by the following formulas (ca-4-1) to (ca-4-2), respectively.

[Formula 21]

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

The content of component (B) in the resist composition of the present invention is preferably 0.5 to 60 parts by mass, more preferably 1 to 50 parts by mass, and still more preferably 1 to 40 parts by mass, per 100 parts by mass of component (A). By setting the content of component (B) within the above range, pattern formation can be sufficiently performed. 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.

＜(A) Ingredient＞

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 it is easy to form a nano-level photosensitive resin pattern.

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

As a non-polymer, those having a molecular weight of 500 or more and less than 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 weight 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.

Component (A) may be one whose solubility in a developer solution increases due to the action of an acid, or may be one whose solubility in a developer solution is reduced by the action of an 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)”), -SO ₂ - containing A structural unit derived from an acrylic acid ester containing a cyclic group (hereinafter sometimes referred to as “structural unit (a2)”), a structural unit containing a polar group-containing aliphatic hydrocarbon group (hereinafter referred to as “structural unit (a3)”) ), a structural unit containing an acid non-dissociable cyclic group (hereinafter sometimes referred to as “structural unit (a4)”), a structural unit containing a lactone-containing cyclic group or a carbonate-containing cyclic group ( Hereinafter, it may be referred to as “structural unit (a5).”) It is preferable that it contains a polymer compound (A1) having.

(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 under the action of an acid to generate a polar group.

Examples of polar groups include carboxyl group, hydroxyl group, amino group, and sulfo group (-SO ₃ H). Among these, a polar group containing -OH in the structure (hereinafter sometimes referred to as "OH-containing polar group") is preferable, a carboxyl group or a hydroxyl group is preferable, and a carboxyl 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 the bond between the acid dissociable group and an atom adjacent to the acid dissociable group can be cleaved by a decarboxylation reaction occurring after some of the bonds are cleaved by the action of the acid.

refers to both sides.

The acid dissociable group constituting the acid dissociable group must be a group with lower polarity than the polar group generated by dissociation of the acid dissociable group. Accordingly, when the acid dissociable group dissociates due to the action of acid, the acid dissociates. A polar group with higher polarity than a sexual group is generated, and polarity increases. As a result, the polarity of the entire component (A1) increases. As polarity increases, solubility in a developer relatively changes, and when the developer is an organic developer, solubility decreases.

The acid dissociable group is not particularly limited, and those proposed so far as acid dissociable groups 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 22]

[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.]

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.

The hydrocarbon group for Ra' ³ is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms; a straight-chain or branched alkyl group is preferable, and specifically, a methyl group, an ethyl group, Propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl 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, aromatic, 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 is preferably one having 7 to 12 carbon atoms, specifically adamantane, norbornane, and isocarbon group. Bornane, tricyclodecane, tetracyclododecane, etc. can be mentioned.

In the case of an aromatic hydrocarbon group, the aromatic ring included specifically includes an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. aromatic heterocyclic ring; and the like. Hetero atoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms.

Specifically, the aromatic hydrocarbon group includes a group in which one hydrogen atom is removed 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, phenene group) Arylalkyl groups such as thyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, and 2-naphthylethyl group); can be mentioned. The number of carbon atoms 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 23]

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

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 24]

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

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). One group 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 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 Ra' ³ in formula (a1-r-1). The groups exemplified as straight-chain or branched alkyl groups are more preferable, a straight-chain alkyl group having 1 to 5 carbon atoms is more preferable, and a methyl group or ethyl group is particularly preferable.

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). do. 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 formula below, “*” represents a bond.

[Formula 25]

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

[Formula 26]

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 27]

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

In the formula (a1-r-3), Ra' ⁷ to Ra' ⁹ is 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; hydroxy A structural unit in which at least part of the hydrogen atom in the hydroxyl group of a structural unit derived from styrene or a hydroxystyrene derivative is protected by a substituent containing the acid-decomposable group; -C of a structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative and structural units in which at least part of the hydrogen atoms in (=O)-OH are 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 28]

[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,

Ra ¹ is an acid dissociable group represented by the above formulas (a1-r-1) to (a1-r-2). 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, and 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 due to ease of industrial availability.

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

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

Also, Va ¹ may include a divalent hydrocarbon group bonded through 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.

As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, 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( _CH3 )-, -CH( _{CH2CH3 )} -, -C( _CH3 ) _2- , Alkylmethylene groups such as -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ H ₃ )-, -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 ₂ CH ₃ ) Alkyl ethylene groups such as ₂ -CH ₂ -; Alkyl trimethylene groups such as -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ -; -CH(CH ₃ )CH ₂ CH Alkyl alkylene groups such as alkyl tetramethylene groups such as _{2CH 2} -, -CH ₂ CH(CH ₃ )CH ₂ CH ₂ -, etc. are mentioned. The alkyl group in the alkylakylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.

Among the aliphatic hydrocarbon groups containing a ring in the above structure, an alicyclic hydrocarbon group (a group in which two hydrogen atoms are removed from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the terminal of a linear 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, and especially preferably 6 to 15 carbon atoms, 6 to 10 is most preferable. However, the carbon number shall not include the carbon number in the substituent.

The aromatic ring possessed by the aromatic hydrocarbon group specifically includes an aromatic hydrocarbon ring such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; an aromatic heterocyclic ring in which a portion of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms. ；etc. Hetero atoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms.

Specifically, the aromatic hydrocarbon group includes a group in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring (arylene group); one of the hydrogen atoms in the group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring (aryl group) is alkylene. A hydrogen atom from an aryl group in an arylalkyl group such as a group substituted with a group (e.g., benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc. Group with one additional removed); etc. can be mentioned. The number of carbon atoms 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 means 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 in the above-mentioned formula (a1-1) can be mentioned.

The value of n _a2 +1 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 29]

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 30]

[Formula 31]

[Formula 32]

[Formula 33]

[Formula 34]

The ratio 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% with respect to all structural units constituting component (A). % is more preferable. 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))

The structural unit (a2) is a structural unit containing a -SO ₂ --containing cyclic group.

The -SO ₂ --containing cyclic group of the structural unit (a2) is effective in increasing the adhesion of the resist film to the substrate when component (A1) is used to form a resist film.

In the present invention, it is preferable that component (A1) has a structural unit (a2).

In addition, when the structural unit (a1) contains an -SO ₂ --containing cyclic group in its structure, the structural unit also corresponds to the structural unit (a2), but such structural unit is not included in the structural unit (a1). It is assumed to be applicable and not applicable to structural unit (a2).

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

[Formula 35]

[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.]

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

(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 means 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 in the formula (a1-1) described above. The groups exemplified in ¹ can be mentioned.

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.

Examples of the aliphatic hydrocarbon group containing a ring in the above structure include a cyclic aliphatic hydrocarbon group that may contain a substituent containing a hetero atom in the ring structure (a group in which two hydrogen atoms have been removed from the aliphatic hydrocarbon ring), and the above-mentioned cyclic aliphatic group. Examples include a group in which a hydrocarbon group is bonded to the end of a straight-chain or branched aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a straight-chain 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 has 3 to 12 carbon atoms.

Specifically, the cyclic aliphatic hydrocarbon group includes the group exemplified by Va ¹ 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. .

Specifically, the aromatic hydrocarbon group as the divalent hydrocarbon group includes the group exemplified by Va ¹ in the above-mentioned formula (a1-1).

As for the aromatic hydrocarbon group, 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 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, the linking group is preferably -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 [where Y ²¹ and Y ²² is each independently a divalent hydrocarbon group that may have a substituent, O is an oxygen atom, and m' is an integer of 0 to 3.] and the like.

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. . 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, 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. That is, 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. It is desirable.

In the above formula (a2-1), Ra ²¹ is a -SO ₂ --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 of. 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 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 as the cyclic hydrocarbon group in R ¹ is, in particular, a cyclic group containing -O-SO ₂ - in its ring skeleton, that is, -OS- in -O-SO ₂ - It is preferable that it is a cyclic group containing a sultone ring that forms part of the ring skeleton. More specifically, the -SO ₂ --containing cyclic group includes groups represented by the following general formulas (a5-r-1) to (a5-r-4).

[Formula 36]

[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; 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 n' is an integer of 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 in Ra' ⁵¹ are represented by the above general formulas (a2-r-1) to (a2- It is the same as Ra' ²¹ in r-7).

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

[Formula 37]

[Formula 38]

[Formula 39]

Among the -SO ₂ -containing cyclic groups, groups represented by the general formula (a5-r-1) are preferable, and those represented by the general formula (r-sl-1-1) and (r-sl-1-18) are preferred. , (r-sl-3-1), and (r-sl-4-1). It is more preferable to use at least one member selected from the group consisting of groups represented by the formula (r-sl-1- 1) The group represented by is most preferable.

The number of structural units (a2) contained in the component (A1) may be one or two or more.

When the component (A1) has a structural unit (a2), the ratio of the structural unit (a2) is preferably 1 to 80 mol% relative to the total of all structural units constituting the component (A1), and is preferably 5 It is more preferable that it is -70 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) can be 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.

Polar groups include hydroxyl groups, cyano groups, carboxyl groups, and hydroxyalkyl groups in which part of the hydrogen atoms of the alkyl group are replaced with fluorine atoms, and hydroxyl groups are 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 bicycloalkane, tricycloalkane, tetracycloalkane, 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.

As the structural unit (a3), any unit can be used without particular limitation 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 an aliphatic hydrocarbon group containing a polar 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 40]

[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, or two or more types may be used.

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). And, 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.

(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 dissociating even when the acid acts on it when an acid is generated from the component (B) 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 structural unit (a1) 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 to be used 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.

As the structural unit (a4), specifically, those having the structures of the following general formulas (a4-1) to (a4-7) can be exemplified.

[Formula 41]

[In the formula, 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% relative to the total of all structural units constituting the (A1) component, and is preferably 10 It is more preferable that it is ~20 mol%.

(Constitutive unit (a5))

The structural unit (a5) is a structural unit containing a lactone-containing cyclic group or a carbonate-containing cyclic group.

The lactone-containing cyclic group or carbonate-containing cyclic group of structural unit (a5) is effective in increasing the adhesion of the resist film to the substrate when component (A1) is used to form a resist film.

In addition, when the structural unit (a1) contains a lactone-containing cyclic group or a carbonate-containing cyclic group in its structure, that structural unit also corresponds to structural unit (a5), but such structural unit is the structural unit (a1 ) and does not correspond to structural unit (a5).

The structural unit (a5) is preferably a structural unit in which Ra ²¹ in the formula (a2-1) is a lactone-containing cyclic group or a carbonate-containing cyclic group.

“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, and in the case of only a lactone ring, it is called a monocyclic group, and in the case of having 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 as the cyclic hydrocarbon group for R ¹ , and any one can be used. Specifically, groups represented by the following general formulas (a2-r-1) to (a2-r-7) can be mentioned. Hereinafter, “*” represents a bond.

[Formula 42]

[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 of 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 0 or It is 1.]

In the general formulas (a2-r-1) to (a2-r-7), A" is alkyl having 1 to 5 carbon atoms that may contain an oxygen atom (-O-) or a sulfur atom (-S-). It is a ren group, an oxygen atom, or a sulfur atom. The alkylene group having 1 to 5 carbon atoms in A$ is preferably a linear or branched alkylene group, and examples include methylene group, ethylene group, n-propylene group, and isopropylene group. 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. As A$, an alkylene group having 1 to 5 carbon atoms or -O- is preferable, an alkylene group having 1 to 5 carbon atoms is more preferable, and a methylene group is most preferable. Ra' ²¹ each independently represents an alkyl group, an alkoxy group, 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 alkyl group exemplified as the alkyl group for Ra' ²¹ above and an oxygen atom (-O-) is linked is 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 for Ra' ²¹ include groups in which some or all of the hydrogen atoms of the alkyl group for Ra' ²¹ are replaced with the halogen atoms. As the halogenated alkyl group, a fluoroalkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

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

[Formula 43]

“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 has 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 44]

[In the ^formula , Ra' 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 q' is 0 or 1.]

A" in the general formulas (ax3-r-1) to (ax3-r-3) is 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 in Ra' ³¹ are each of the above general formulas (a2-r-1) to (a2). The same thing as exemplified in the explanation of Ra' ²¹ in -r-7) can be mentioned.

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

[Formula 45]

Among the above, as the lactone-containing cyclic group, a group represented by the general formula (a2-r-1) or (a2-r-2) is preferable, and a group represented by the formula (r-lc-1-1) is more preferable. .

The number of structural units (a5) contained in the component (A1) may be one or two or more.

When the component (A1) has a structural unit (a5), the proportion of the structural unit (a5) is preferably 1 to 80 mol% relative to the total of all structural units constituting the component (A1), and 5 It is more preferable that it is -70 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 (a5) is sufficiently obtained, and by setting it below the upper limit, it is possible to achieve balance with other structural units, and various lithographic characteristics such as DOF and CDU and pattern shapes become good.

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. there is.

In addition, in component (A1), during the above polymerization, for example, by using a chain transfer agent such as HS-CH ₂ -CH ₂ -CH ₂ -C(CF ₃ ) ₂ -OH in combination, -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) (based on polystyrene conversion by gel permeation chromatography) of component (A1) 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). It may be mass%. When the ratio is 25% by mass or more, lithography characteristics are further improved.

In the resist composition of the present invention, component (A) may be used individually or in combination of two or more types.

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

<Basic compound component; (D) component>

In addition to the component (D0), the resist composition of the present invention may further contain an acid diffusion controller component (hereinafter also referred to as “component (D)”).

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

The (D) component in the present invention may be a photodegradable base (D1) (hereinafter referred to as “component (D1)”) that decomposes upon exposure and loses acid diffusion control, or the (D1) component. A nitrogen-containing organic compound (D2) (hereinafter referred to as “(D2) component”) that does not fall under may be used.

[(D1) component]

By using a resist composition containing the 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 is 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 46]

[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.

As the aromatic hydrocarbon group, a phenyl group or a naphthyl group is more preferable.

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.

As the chain hydrocarbon group, a chain alkyl group is preferable. The chain alkyl group preferably has 1 to 10 carbon atoms, and specifically includes methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, etc. Straight-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-ethyl Branched chain alkyl groups such as butyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group; are included.

When the chain-like alkyl group is a fluoroalkyl group having a fluorine atom or a fluoroalkyl group as a substituent, the number of carbon atoms of the fluoroalkyl group is preferably 1 to 11, more preferably 1 to 8, and even 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.

Rd ¹ 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 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 47]

· Cation part

In formula (d1-1), M ^m+ is an m-valent organic cation.

The organic cation of M ^m+ is not particularly limited and includes, for example, the same cations as the cations each represented by the above general formulas (ca-1) to (ca-4), and the above formula (ca-1) Cations each represented by -1) to (ca-1-63) are preferred.

(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 there is.

However, in Rd ² , the fluorine atom is not bonded to the carbon atom adjacent to the S atom (it is not substituted with fluorine). Accordingly, the anion of component (d1-2) becomes an appropriate weak acid anion, and the quenching ability of component (D) is improved.

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 in which one or more hydrogen atoms have been removed 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 48]

· Cation part

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 there is.

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 includes methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, Examples include tert-butyl group, pentyl group, isopentyl group, and neopentyl group. A 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 and tert-butoxy group can be mentioned. 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 also have an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms as a substituent.

The cyclic group for Rd ⁴ may be the same as for R ¹⁰¹ , and may be selected from cycloalkanes such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. An alicyclic group from which one or more hydrogen atoms have been removed, or an aromatic group such as a phenyl group or a naphthyl group, is 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, and sensitivity and lithography characteristics become good.

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

The divalent linking group 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 49]

[Formula 50]

· Cation part

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

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

As for the (D1) component, only one type among 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 even 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 method for producing the above-mentioned component (d1-1) and component (d1-2) is not particularly limited, and they can be produced by a known method.

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). 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; diethylamine, di-n- Dialkylamines such as propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri- Tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine, etc. Alkylamine; 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.

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), you may use an aromatic amine.

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) A component may be used individually, or may be used in combination of 2 or more types.

The component (D2) is usually used in an amount of 0.01 to 5.0 parts by mass per 100 parts by mass of the 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. When the resist composition of the present invention 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, based on 100 parts by mass of component (A), It is more preferable that it is 0.5 to 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.

＜Arbitrary ingredients＞

[(E) component]

In the present invention, the resist composition contains organic carboxylic acid, oxo acid of phosphorus, and its derivatives as optional components for the purpose of preventing sensitivity deterioration, improving resist pattern shape, stability over time after exposure, etc. It can contain at least one compound (E) (hereinafter referred to as (E) component) selected from the group consisting of.

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

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.

(E) Component 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).

[(F) component]

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

(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, and Japanese Patent Laid-Open No. 2010-002870. The fluorinated polymer compound described in Publication No. 2011-128226 can be used.

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

[Formula 51]

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

In formula (f1-1), R is the same as above. R is preferably a hydrogen atom or a methyl group.

In formula (f1-1), the halogen atom for Rf ¹⁰² and Rf ¹⁰³ includes a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc., and a fluorine atom is particularly preferable. Examples of the alkyl group having 1 to 5 carbon atoms for Rf ¹⁰² and Rf ¹⁰³ include the same alkyl groups having 1 to 5 carbon atoms for R, and a methyl group or an ethyl group is preferable. Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms for Rf ¹⁰² and Rf ¹⁰³ include groups in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. Among them, Rf ¹⁰² and Rf ¹⁰³ are preferably a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms, and a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group is preferable.

In formula (f1-1), nf ¹ is an integer of 1 to 5, preferably an integer of 1 to 3, and more preferably 1 or 2.

In formula (f1-1), Rf ¹⁰¹ is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom.

The hydrocarbon group containing a fluorine atom may be linear, branched, or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and more preferably 1 to 10 carbon atoms. Particularly desirable.

In addition, as for the hydrocarbon group containing a fluorine atom, it is preferable that 25% or more of the hydrogen atoms in the hydrocarbon group are fluorinated, more preferably 50% or more are fluorinated, and 60% or more are fluorinated. This is particularly preferable because the hydrophobicity of the resist film during immersion exposure increases.

Among them, as Rf ¹⁰¹ , a fluorinated hydrocarbon group having 1 to 5 carbon atoms is particularly preferable, and a methyl group, -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 the 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 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.

(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 usually used in a ratio of 0.5 to 10 parts by mass with respect to 100 parts by mass of component (A).

In the present invention, the resist composition may optionally contain miscible additives, such as additional resins for improving the performance of the resist film, dissolution inhibitors, plasticizers, stabilizers, colorants, anti-halation agents, dyes, etc. It can be added.

[(S) component]

In the present invention, the resist composition can be produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as the (S) component).

The (S) component may be any material that can dissolve each component used and form a uniform solution. One or two or more types may be appropriately selected from among those conventionally known as solvents for chemically amplified resists. You can use it.

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; ethylene glycol , polyhydric alcohols such as 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, and the above polyhydric alcohols Derivatives of polyhydric alcohols, such as monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, or compounds having ether bonds such as monophenyl ether, or compounds having the above ester bond [among these is preferably propylene glycol monomethyl ether acetate (PGMEA) or propylene glycol monomethyl ether (PGME)]; cyclic ethers such as dioxane, methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, acetic acid Esters such as butyl, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; anisole, ethylbenzyl ether, crezyl methyl ether, diphenyl ether, dibenzyl ether, phenetol, butylphenyl ether, ethyl Aromatic organic solvents such as benzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene, and dimethyl sulfoxide (DMSO).

These organic solvents may be used individually or as a mixed solvent of two or more types.

Among them, PGMEA, PGME, γ-butyrolactone, and EL are preferable.

Additionally, a mixed solvent in which PGMEA and a polar solvent are mixed is also preferable. The mixing ratio (mass ratio) may be determined appropriately taking into account the compatibility of PGMEA with the polar solvent, etc., but is preferably within the range of 1:9 to 9:1, more preferably within the range of 2:8 to 8:2. desirable.

More specifically, when mixing EL or cyclohexanone as a polar solvent, the mass ratio of PGMEA:EL or cyclohexanone is preferably 1:9 to 9:1, more preferably 2:8 to 8:1. It is 2. Additionally, when blending PGME as a polar solvent, the mass ratio of PGMEA:PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and even more preferably 3:7 to 3:7. It is 7:3.

Additionally, as the (S) component, a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95:5.

The amount of component (S) used is not particularly limited, and is appropriately set to a concentration that can be applied to a substrate or the like, depending on the coating film thickness. 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%.

The resist composition of the present invention further contains miscible additives as desired, such as additional resins, dissolution inhibitors, plasticizers, stabilizers, colorants, anti-halation agents, dyes, etc. to improve the performance of the resist film. You can do it.

≪Resist pattern formation method≫

The resist pattern forming method of the second aspect of the present invention includes the steps of forming a resist film on a support using the resist composition of the present invention, exposing the resist film, and developing the resist film after the exposure to form a resist pattern. Including the forming process.

The resist pattern forming method of the present invention can be carried out, for example, as follows.

First, the resist composition of the present invention is applied onto a 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. This is carried out for 60 to 90 seconds to form a resist film.

Next, the resist film is exposed through a mask (mask pattern) on which a predetermined pattern is formed using an exposure device such as an ArF exposure device, an electron beam drawing device, or an EUV exposure device, or through a mask pattern. After selective exposure such as drawing by direct irradiation of an electron beam is performed, a bake (Post Exposure Bake (PEB)) process is performed, for example, at a temperature of 80 to 150°C for 40 to 120 seconds, preferably 60 to 120 seconds. Perform for 90 seconds.

Next, the resist film after the exposure is developed.

In the case of an alkaline development process, development 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. For the rinsing treatment, in the case of an alkaline development process, a water rinse using pure water is preferable, and in the case of a solvent development process, it is preferable to use a rinse liquid 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.

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. It is said that a pattern with a high aspect ratio can be formed by this method of patterning the lower layer organic film. That is, according to the multilayer resist method, the thickness required by the lower organic film can be secured, so the resist film can be thinned, and fine patterns with a high aspect ratio can be formed.

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 multilayer structure of three or more layers (three-layer resist method).

The wavelength used for exposure is not particularly limited, and includes ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet ray), VUV (vacuum ultraviolet ray), EB (electron beam), X-ray, soft X-ray, etc. It can be performed using radiation. The above resist composition is highly useful for KrF excimer laser, ArF excimer laser, EB or EUV.

The exposure method for the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or liquid immersion exposure (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 exposure (immersion exposure) is performed in that state.

As the immersion medium, a solvent having a refractive index greater than that of air and less 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 the solvent having a refractive index greater than the refractive index of air and smaller than the refractive index of the resist film include water, a fluorine-based inert liquid, a silicon-based solvent, and a hydrocarbon-based solvent.

Specific examples of 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. It is preferable that the fluorine-based inert liquid has a boiling point in the above range 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 perfluoro(2-butyl-tetrahydrofuran) (boiling point 102°C). and rottributylamine (boiling point 174°C).

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

Examples of the alkaline developing solution used for development in the alkaline developing process include a 0.1 to 10% by mass tetramethylammonium hydroxide (TMAH) aqueous solution.

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), mounting the developer on the surface of the support by surface tension and allowing it to remain still for a certain period of time. A method (paddle method), a method of spraying the developer on the surface of a support (spray method), a method of continuously dispensing the developer while scanning the nozzle that dispenses the developer at a constant speed on a support rotating at a constant speed (dynamic dispensing) law), etc.

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.

The third aspect of the present invention is a compound represented by the following general formula (d0).

[Formula 52]

[In the formula, R ¹ is a chain, branched chain or cyclic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. However, when a substituent is bonded to the carbon atom of R ¹ adjacent to the carbonyl group in the formula, the substituent is at least one selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. Pretend not to have it. R ² is a chain, branched chain or cyclic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. However, when a substituent is bonded to the carbon atom of R ² adjacent to the sulfonyl group in the formula, the substituent is at least one selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. It is assumed that it does not have . M ^m+ is an m-valent organic cation. m is an integer greater than 1.]

In the above formula, the descriptions of R ^{1 ,} R ² , and M ^m+ are the same as above.

Additionally, the compound of the third aspect of the present invention is preferably a compound represented by the general formula (d0-1), and has a compound represented by the general formula (d0-1a), (d0-1b) or (d0-1c). A compound represented by any one is more preferable.

Example

Hereinafter, the present invention will be described in more detail by way of examples, but the present invention is not limited to the following examples.

[Example of compound synthesis]

5.23 g (55.0 mmol) of methanesulfonamide was dissolved in 52.3 g of tetrahydrofuran (THF), and cooled on ice while stirring. After adding 6.07 g (60.0 mmol) of triethylamine dropwise to this, a solution of 6.03 g (50.0 mmol) of pivaloyl chloride dissolved in 30.2 g of THF was added dropwise over 1 hour, and stirred for 3 hours. It was carried out.

A 5% aqueous hydrochloric acid solution and t-butylmethyl ether were added dropwise to the reaction solution, the temperature was raised to room temperature, and then liquid separation was performed to extract the organic phase. After repeating the process of washing the obtained organic phase with 52.3 g of pure water, the organic phase was concentrated to obtain 7.17 g of intermediate D0-1-1.

71.7 g of pure water and 1.76 g of sodium hydroxide were added to 7.17 g of intermediate D0-1-1 and dissolved. To this, 15.10 g of triphenylsulfonium bromide and 71.7 g of dichloromethane were added, stirred, and a liquid separation operation was performed to extract the organic phase. After repeating the process of washing the obtained organic phase with 71.7 g of pure water, the organic phase was concentrated to obtain 14.66 g of photobase activator (D0)-1.

The obtained compound was subjected to NMR measurement, and its structure was identified from the following results.

[Formula 53]

The following (D0)-2 to (D0)-19 were synthesized by the same method as above. Below, the pKa values of the conjugate acids of the compounds are written together. The following pKa values were calculated using ACD/Labs Software V11.02.

[Formula 54]

[Formula 55]

[Formula 56]

<Preparation of resist composition>

(Examples 1 to 23, Comparative Examples 1 to 16)

Each component shown in Tables 1 to 3 was mixed and dissolved to prepare a resist composition.

Each symbol in the table above has the following meaning. In addition, the numerical value in [ ] is the mixing amount (parts by mass).

(A)-1 to (A)-3: The following polymer compounds (A)-1 to (A)-3.

(B)-1: The following compound (B)-1.

(D0)-1 to (D0)-19: The above compounds (D0)-1 to (D0)-19.

(F)-1: The following polymer compound (F)-1.

(S)-1: Mixed solvent of PGMEA/PGME/cyclohexanone (mass ratio 45/30/25).

(S)-2: γ-butyrolactone.

[Formula 57]

[Formula 58]

<Formation of resist pattern 1: Alkaline development positive type>

(Examples 1 to 9, Comparative Examples 1 to 7)

On an 8-inch silicon wafer, an organic anti-reflective coating composition "ARC29" (brand name, manufactured by Brewer Science) was applied using a spinner, baked on a hot plate at 205°C for 60 seconds, and dried to obtain an organic anti-reflective coating composition with a film thickness of 82 nm. An antireflection film was formed.

Next, the resist composition was applied onto the film using a spinner, prebake (PAB) was applied on a hot plate at a temperature of 110°C for 60 seconds, and dried, thereby forming a film with a film thickness of 90 nm. A resist film was formed.

Subsequently, the resist film was selectively treated with an ArF excimer laser (193 nm) using an exposure device NSR-S609B (NA = 1.07 Dipole 0.97/0.78 with polano manufactured by Nikon Corporation) through a mask pattern (6% halftone). was investigated.

Next, alkali development was performed at 23°C for 10 seconds using a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution “NMD-3” (brand name, manufactured by Tokyo Oka Kogyo Co., Ltd.).

As a result, a line and space pattern (hereinafter sometimes referred to as an “LS pattern”) was formed in all examples.

In both examples, a line and space pattern with a line width of 50 nm/pitch of 100 nm was formed.

＜Formation of resist pattern 2: Solvent development negative type＞

(Examples 10 to 23, Comparative Examples 8 to 16)

On an 8-inch silicon wafer, an organic anti-reflective coating composition "ARC29" (brand name, manufactured by Brewer Science) was applied using a spinner, baked on a hot plate at 205°C for 60 seconds, and dried to obtain an organic anti-reflective coating composition with a film thickness of 82 nm. An antireflection film was formed.

Next, the resist composition was applied onto the film using a spinner, prebake (PAB) was applied on a hot plate at a temperature of 90°C for 60 seconds, and dried, thereby forming a resist with a film thickness of 100 nm. A membrane was formed.

Subsequently, the resist film was selectively treated with an ArF excimer laser (193 nm) using an exposure device NSR-S609B (NA = 1.07 Dipole 0.97/0.78 with polano manufactured by Nikon Corporation) through a mask pattern (6% halftone). was investigated.

Next, solvent development was performed at 23°C for 16 seconds with butyl acetate, and then dried by shaking.

As a result, a line and space pattern was formed in both examples. In both examples, a line and space pattern with a line width of 50 nm/pitch of 100 nm was formed.

[Evaluation of optimal exposure amount (Eop)]

The optimal exposure amount Eop (mJ/cm2) at which an LS pattern of the target size is formed was obtained by the above resist pattern formation method. The results are shown in Tables 4 to 6 below as “Sensitivity (mJ/cm2).”

[Evaluation of exposure margin (EL margin)]

Regarding the exposure amount at which the LS pattern was formed, the exposure amount at which the line of the LS pattern was formed within ±5% of the target dimension was determined, and the EL margin (unit: %) was determined using the following equation. The results are shown in Tables 4 to 6 below as “5% EL (%).”

EL margin (%) = (｜E1 - E2｜/Eop) × 100

E1: Exposure dose when an LS pattern with a hole width of 47.5 nm is formed (mJ/cm2)

E2: Exposure dose when an LS pattern with a hole width of 52.5 nm is formed (mJ/cm2)

Additionally, the EL margin indicates that the larger the value, the smaller the amount of change in pattern size due to the change in exposure amount.

In addition, in the calculation formula for the above EL margin, “Eop” means the optimal exposure amount (mJ/cm2). The Eop was obtained by a conventional method.

[Evaluation of mask error factor (MEEF)]

Following the same procedure as the formation of the resist pattern above, each mask pattern with a target size (line width) of 45 to 55 nm (1 nm interval, total of 11 points) is used, and each line and space pattern with a pitch of 100 nm is formed. It was formed with the same exposure amount.

At that time, the slope (MEEF) of the straight line was calculated when the target size (nm) was plotted on the horizontal axis and the line width (nm) of the pattern formed on the resist film using each mask pattern was plotted on the vertical axis. The results are shown in Tables 4 to 6 below as “MEEF”.

MEEF (slope of a straight line) means that the closer the value is to 1, the better the mask reproducibility.

[Evaluation of LWR (Line With Roughness)]

In the LS pattern formed by the above <Formation of a resist pattern>, the hole width was measured by measurement SEM (scanning electron microscope, acceleration voltage 300 V, brand name: S-9380, manufactured by Hitachi High-Technologies), and the hole length was measured. Measurements were made at 400 points in each direction, three times the standard deviation (s) (3s) was obtained from the results, and the averaged value of 3s at 400 points was calculated as a measure of LWR. The results are shown in Tables 4 to 6 below as “LWR (nm).”

The smaller the value of 3s, the smaller the roughness of the line width, meaning that an LS pattern with a more uniform width was obtained.

[Evaluation of shape]

The LS pattern was observed using a measurement SEM (scanning electron microscope, acceleration voltage 800 V, brand name: S-9220, manufactured by Hitachi Ltd.). The results were listed in Tables 4 to 6 below as “sphericity.”

[Storage stability]

1) For each of the resist compositions before and after storage at room temperature for one month, a contact hole pattern was formed by the above resist pattern formation method at the above optimal exposure amount Eop, and the hole diameter (CD) was measured.

2) For each resist composition, the difference (CD variation value) before and after storage when stored at room temperature for one month was calculated. The results are shown in Tables 4 to 6 below as “storage stability.”

Cases where ΔCD was less than 1 nm were designated as “○” because the resist composition had excellent storage stability, and other cases were designated as “×”.

As shown in the above results, the resist composition of the present invention had excellent storage stability and also had good lithographic properties.

Among the above, Example 4 using compound (D0)-4 and Example 5 using compound (D0)-5, where at least one of the terminal groups is a cyclic hydrocarbon group as the (D0) component, have MEEF and EL margins. , LWR was particularly excellent.

Claims (5)

A resist composition that generates acid upon exposure and whose solubility in a developer changes due to the action of the acid,
an acid generator component (B) that generates acid upon exposure,
A resist composition comprising a photobase quencher component (D0) containing a compound represented by the following general formula (d0-1a) or (d0-1b).
[Formula 1]

[In the formula, R ^11a is a monocyclic or polycyclic aliphatic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent. However, when a substituent is bonded to the carbon atom of R ^11a adjacent to the carbonyl group in the formula, the substituent is one or more selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. Pretend not to have it. R ^12a is a chain or branched hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. However, when a substituent is bonded to the carbon atom of R ^12a adjacent to the sulfonyl group in the formula, the substituent is at least one selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. It is assumed that it does not have . M ^m+ is an m-valent organic cation. m is an integer greater than 1.]
[Formula 2]

[In the formula, R ^11b is a chain or branched hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. However, when a substituent is bonded to the carbon atom of R ^11b adjacent to the carbonyl group in the formula, the substituent is one or more selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. Pretend not to have it. R ^12b is a monocyclic or polycyclic aliphatic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent. However, when a substituent is bonded to the carbon atom of R ^12b adjacent to the sulfonyl group in the formula, the substituent is at least one selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. It is assumed that it does not have . M ^m+ is an m-valent organic cation. m is an integer greater than 1.] delete According to claim 1,
A resist composition wherein the pKa of the conjugate acid of the compound represented by the general formula (d0-1a) or (d0-1b) is greater than 2.5. A resist pattern comprising the steps of forming a resist film on a support using the resist composition according to claim 1 or 3, exposing the resist film, and developing the exposed resist film to form a resist pattern. How to form. A compound represented by the following general formula (d0-1a).
[Formula 3]

[In the formula, R ^11a is a monocyclic or polycyclic aliphatic hydrocarbon group having 3 to 20 carbon atoms which may have a substituent. However, when a substituent is bonded to the carbon atom of R ^11a adjacent to the carbonyl group in the formula, the substituent is one or more selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. Pretend not to have it. R ^12a is a chain or branched hydrocarbon group having 1 to 20 carbon atoms which may have a substituent. However, when a substituent is bonded to the carbon atom of R ^12a adjacent to the sulfonyl group in the formula, the substituent is at least one selected from the group consisting of a group having a halogen atom, an aromatic group, and a proton acceptor functional group. It is assumed that it does not have . M ^m+ is an m-valent organic cation. m is an integer greater than 1.]