KR102438832B1 - How to form a resist pattern - Google Patents

Abstract

(식 (a10-1) 중, R 은 수소 원자, 알킬기 또는 할로겐화알킬기이다. Ya^x1 은 단결합 또는 2 가의 연결기이다. Wa^x1 은 (n_ax1 ＋ 1) 가의 방향족 탄화수소기이다. n_ax1 은 1 ∼ 3 의 정수이다).A step of forming a resist film having a thickness of 7 μm or more on a support by using a resist composition, a step of exposing the resist film, and a step of developing the resist film after exposure to form a resist pattern, wherein the resist composition has the general formula (a10) Formation of a resist pattern comprising a resin component having a structural unit represented by -1), a structural unit containing an acid-non-dissociable aliphatic cyclic group, and a structural unit containing an acid-decomposable group whose polarity increases by the action of an acid Way

(In formula (a10-1), R is a hydrogen atom, an alkyl group, or a halogenated alkyl group. Ya ^x1 is a single bond or a divalent linking group. Wa ^x1 is a (n _ax1 + 1) valent aromatic hydrocarbon group. n _ax1 is 1 to 3).

Description

How to form a resist pattern

The present invention relates to a method for forming a resist pattern.

This application claims priority based on Japanese Patent Application No. 2017-254871 for which it applied to Japan on December 28, 2017, and uses the content here.

In the lithography technique, for example, a step of forming a resist film made of a resist material on a substrate, selectively exposing the resist film, and performing a development treatment to form a resist pattern having a predetermined shape on the resist film This is carried out A resist material in which the exposed portion of the resist film changes in a characteristic which dissolves in a developer is called a positive type, and a resist material in which the exposed portion of the resist film changes in a characteristic in which the characteristic does not dissolve in a developer is referred to as a negative type.

In recent years, in manufacture of a semiconductor element and a liquid crystal display element, the refinement|miniaturization of a pattern is advancing with the progress of lithography technology. As a method of miniaturization, the wavelength reduction (higher energy) of an exposure light source is generally implemented. Specifically, conventionally, ultraviolet rays typified by g-rays and i-rays have been used. Currently, semiconductor devices using KrF excimer lasers and ArF excimer lasers are being mass-produced. Moreover, EUV (extreme ultraviolet rays), EB (electron beam), X-rays, etc. which have a shorter wavelength (high energy) than these excimer lasers are also being investigated.

The resist material is required to have lithographic properties such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with fine dimensions.

As a resist material that satisfies these requirements, conventionally, a chemically amplified resist composition containing a base component whose solubility in a developer changes due to the action of an acid and an acid generator component that generates an acid upon exposure has been used. have.

For example, when the developer is an alkali developer (alkali developing process), the positive chemically amplified resist composition includes a resin component (base resin) whose solubility in an alkali developer increases due to the action of an acid (base resin) and an acid generator Those containing ingredients are generally used. When a resist film formed using such a resist composition is selectively exposed during resist pattern formation, an acid is generated from the acid generator component in the exposed portion, and the polarity of the base resin is increased by the action of the acid, The exposed portion of the resist film becomes soluble to the alkali developer. Therefore, by performing alkali development, a positive pattern in which the unexposed portion of the resist film remains as a pattern is formed.

On the other hand, when such a chemically amplified resist composition is applied to a solvent development process using a developer containing an organic solvent (organic developer), as the polarity of the base resin increases, the solubility in the organic developer decreases relatively. The unexposed portion of the resist film is dissolved and removed by the organic developer to form a negative resist pattern in which the exposed portion of the resist film remains as a pattern. The solvent developing process for forming a negative resist pattern in this way is sometimes referred to as a negative developing process.

Up to now, as the base resin for chemically amplified resist compositions, for example, polyhydroxystyrene (PHS) with high transparency to KrF excimer laser (248 nm), or a resin in which the hydroxyl group is protected with an acid dissociable dissolution inhibitor. (PHS-based resin) has been used. Also, for example, for an ArF excimer laser (193 nm), a resin ((meth)acrylic resin) in which a hydroxyl group in the carboxy group of (meth)acrylic acid is protected with an acid dissociable dissolution inhibitor has been used (for example, , see Patent Document 1).

Examples of the acid dissociable dissolution inhibiting group include a so-called acetal group such as a chain ether group represented by a 1-ethoxyethyl group or a cyclic ether group represented by a tetrahydropyranyl group, a tertiary alkyl group represented by a tert-butyl group, A tertiary alkoxycarbonyl group represented by a tert-butoxycarbonyl group is mainly used.

In addition, various types of acid generator components used in chemically amplified resist compositions have been proposed so far, for example, onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators Acid generators, diazomethane-based acid generators, nitrobenzylsulfonate-based acid generators, iminosulfonate-based acid generators, disulfone-based acid generators, and the like are known.

Among these, onium salt-based acid generators are widely used, and those having an onium ion such as triphenylsulfonium in the cation moiety are mainly used. For the anion moiety of the onium salt-based acid generator, generally, an alkylsulfonic acid ion or a fluorinated alkylsulfonate ion in which some or all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms are used.

However, at present, along with higher integration of LSI and higher speed of communication, an increase in memory capacity is required, and further miniaturization of patterns is rapidly progressing. However, although electron beam or EUV lithography aims to form a fine pattern of several tens of nm, there are still many problems such as low productivity, and there is a limit to the technique by micromachining.

On the other hand, in addition to miniaturization, development of a three-dimensional structure device is progressing for increasing the capacity of a memory by stacking cells by stacking them.

Japanese Patent Laid-Open No. 2003-241385

In the production of the three-dimensional structure device, a process of forming a thick resist film having a higher film thickness, for example, a film thickness of 7 µm or more, on the surface of the workpiece, forming a resist pattern, and performing etching, etc. have When a chemically amplified resist composition is used here, as the film thickness of the resist increases, it becomes more difficult to maintain the sensitivity during exposure. When a thick resist film is to be formed using a conventional chemically amplified resist composition, there is a problem in that a large amount of exposure is required and the sensitivity is lowered. In addition, there is also a problem in that the resolution for development is lowered and a desired resist pattern shape is difficult to be obtained.

The present invention has been made in view of the above circumstances, and provides a resist pattern forming method capable of forming a pattern with high sensitivity and good shape even when forming a thick resist film having a film thickness of 7 µm or more. make it a task

In order to solve the said subject, this invention employ|adopted the following structure.

That is, the resist pattern forming method according to one aspect of the present invention comprises a step (i) of forming a resist film having a thickness of 7 µm or more on a support by using a resist composition, a step of exposing the resist film (ii) ) and a step (iii) of developing the resist film after exposure to form a resist pattern, wherein the resist composition generates an acid upon exposure, and solubility in a developer is changed by the action of the acid and a structural unit (a10) represented by the following general formula (a10-1), a structural unit (a4) containing an acid non-dissociable aliphatic cyclic group, and an acid-decomposable group whose polarity increases by the action of an acid It is characterized by containing the resin component (A1) which has the structural unit (a1) which says.

[Formula 1]

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya ^x1 is a single bond or a divalent linking group. Wa ^x1 is a (n _ax1 +1) valent aromatic hydrocarbon group. n _ax1 is an integer of 1 to 3.]

ADVANTAGE OF THE INVENTION According to this invention, even when forming a thick-film resist film with a film thickness of 7 micrometers or more into a film, it shows high sensitivity and can provide the resist pattern formation method which can form a pattern of a favorable shape.

In this specification and claims, "aliphatic" is a concept relative to aromatic, and is defined as meaning a group, compound, or the like having no aromaticity.

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

The "alkylene group" shall include divalent saturated hydrocarbon groups of linear, branched and cyclic unless otherwise specified.

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

A "fluorinated alkyl group" or "fluorinated alkylene group" refers to a group in which part or all of the hydrogen atoms of an alkyl group or an alkylene group are substituted with fluorine atoms.

A "structural unit" means a monomer unit (monomer unit) constituting a high molecular compound (resin, polymer, copolymer).

When describing "you may have a substituent", both a case where a hydrogen atom (-H) is substituted with a monovalent group and a case where a methylene group (-CH ₂ -) is substituted with a divalent group is included.

"Exposure" is a concept including the overall irradiation of radiation.

"Structural unit derived from acrylic acid ester" means a structural unit constituted by cleavage of the ethylenic double bond of acrylic acid ester.

"Acrylic acid ester" is a compound in which the hydrogen atom of the carboxyl group terminal of acrylic acid (CH2=CH _- COOH) was substituted with the 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 ) for substituting a 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 having 1 to 5 carbon atoms and a halogenated alkyl group having 1 to 5 carbon atoms. have. In addition, diesters of itaconic acid in which the substituent (R ^α 0 ) is substituted with a substituent containing an ester bond, and α hydroxyacrylic esters in which the substituent (R α ⁰ ) is substituted with a hydroxyalkyl group or a group modified with a hydroxyl group thereof are also included. do. In addition, unless otherwise stated, the carbon atom at the alpha-position of acrylic acid ester is a carbon atom to which the carbonyl group of acrylic acid is couple|bonded.

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

The "structural unit derived from acrylamide" means a structural unit constituted by cleavage of the ethylenic double bond of acrylamide.

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

Examples of the substituent for substituting the hydrogen atom bonded to the carbon atom at the α-position of acrylamide include those same as those listed as the substituent at the α-position in the above-mentioned α-substituted acrylic acid ester (substituent (R ^α0 )).

The "structural unit derived from hydroxystyrene" means a structural unit constituted by cleavage of the ethylenic double bond of hydroxystyrene. The "structural unit derived from a hydroxystyrene derivative" means a structural unit constituted by cleavage of the ethylenic double bond of the hydroxystyrene derivative.

The "hydroxystyrene derivative" is a concept including those in which the hydrogen atom at the α-position of hydroxystyrene is substituted with another substituent such as an alkyl group or a halogenated alkyl group, and derivatives thereof. As those derivatives, the hydrogen atom of the hydroxyl group of the hydroxystyrene which the hydrogen atom at the alpha-position may be substituted with the substituent is substituted by the organic group; The thing in which the substituent other than a hydroxyl group couple|bonded with the benzene ring of hydroxystyrene which the hydrogen atom at the alpha-position may be substituted with the substituent, etc. are mentioned. In addition, the α-position (a carbon atom at the α-position) refers to a carbon atom to which the benzene ring is bonded, unless otherwise specified.

Examples of the substituent for substituting the hydrogen atom at the α-position of hydroxystyrene include the same as the substituent at the α-position in the α-substituted acrylic acid ester.

"Structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative" means a structural unit constituted by cleavage of an ethylenic double bond of vinylbenzoic acid or a vinylbenzoic acid derivative.

"Vinyl benzoic acid derivative" is a concept including those in which the hydrogen atom at the α-position of vinyl benzoic acid is substituted with another substituent such as an alkyl group or a halogenated alkyl group, and derivatives thereof. What substituted the hydrogen atom of the carboxy group of vinylbenzoic acid by which the hydrogen atom at the α-position may be substituted with a substituent as those derivatives with an organic group; and those in which a substituent other than a hydroxyl group and a carboxy group couple|bonded with the benzene ring of vinylbenzoic acid which the hydrogen atom at the alpha-position may be substituted with the substituent, etc. are mentioned. In addition, the α-position (a carbon atom at the α-position) refers to a carbon atom to which the benzene ring is bonded, unless otherwise specified.

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

Specific examples of the halogenated alkyl group as the substituent at the α-position include a group in which some or all of the hydrogen atoms of the “alkyl group as a substituent at the α-position” are substituted with halogen atoms. A fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned as this halogen atom, A fluorine atom is especially preferable.

Further, specific examples of the hydroxyalkyl group as a substituent at the α-position include a group in which a part or all of the hydrogen atoms of the “alkyl group as a substituent at the α-position” are substituted with a hydroxyl group. 1-5 are preferable and, as for the number of the hydroxyl groups in this hydroxyalkyl group, 1 is the most preferable.

In the present specification and claims, depending on the structure represented by the chemical formula, an asymmetric carbon may exist, and enantiomers and diastereomers may exist, but in that case, one formula They represent isomers. These isomers may be used independently and may be used as a mixture.

(Resist pattern formation method)

The resist pattern formation method of this embodiment comprises a step (i) of forming a resist film with a film thickness of 7 μm or more on a support using a resist composition, a step (ii) of exposing the resist film, and developing the resist film after the exposure. It has a process (iii) of forming a resist pattern. In the resist pattern formation method of this aspect, in the process (i), a specific resist composition is selected.

The resist pattern formation method according to this aspect can be implemented, for example, as follows.

Process (i):

First, on a support, a specific resist composition described later is applied with a spinner or the like, and a bake (post-apply bake (PAB)) treatment is performed, for example, at 80 to 150°C, preferably at 100 to 150°C (more preferably Preferably, it is carried out for 40 to 120 seconds, preferably 60 to 120 seconds (more preferably 80 to 100 seconds) under temperature conditions of more than 100°C and 150°C or less) to form a resist film having a thickness of 7 µm or more.

Process (ii):

Next, the resist film is subjected to selective exposure by exposure or the like through a mask (mask pattern) having a predetermined pattern formed thereon using, for example, an exposure apparatus, followed by a bake (post-exposure bake (PEB)) process. For example, 80 to 150°C, preferably 90 to 130°C, for 40 to 120 seconds, preferably 60 to 100 seconds.

Process (iii):

Next, the resist film after the exposure is developed. In the case of an alkali developing process, the developing treatment is performed using an alkali developing solution, and in the case of a solvent developing process, using the developing solution (organic type developing solution) containing an organic solvent.

After the developing treatment, preferably a rinse treatment is performed. As for the rinse treatment, in the case of an alkali developing process, a water rinse using pure water is preferable, and in the case of a solvent developing process, it is preferable to use the rinse liquid containing an organic solvent.

In the case of a solvent developing process, after the said developing process or a rinse process, you may perform the process which removes the developing solution or rinse liquid adhering on the pattern with a supercritical fluid.

Drying is performed after developing or rinsing. Moreover, you may implement a baking process (post-baking) after the said developing process depending on a case.

In this way, a resist pattern can be formed.

It does not specifically limit as a support body, A conventionally well-known thing can be used, For example, the board|substrate for electronic components, the thing in which the predetermined|prescribed wiring pattern was formed, etc. are mentioned. More specifically, a silicon wafer, a metal substrate, such as copper, chromium, iron, and aluminum, a glass substrate, etc. are mentioned. As a material of a wiring pattern, copper, aluminum, nickel, gold|metal|money, etc. can be used, for example.

Moreover, as a support body, the thing in which the film|membrane of the inorganic type and/or organic type was formed on the above-mentioned board|substrate may be sufficient. Examples of the inorganic film include an inorganic antireflection film (inorganic BARC). As an organic film|membrane, organic films, such as an organic antireflection film (organic BARC) and the lower layer organic film in a multilayer resist method, are mentioned.

Here, in the multilayer resist method, at least one organic film (lower organic film) and at least one resist film (upper resist film) are formed on a substrate, and the resist pattern formed on the upper resist film is used as a mask. This is a method of patterning the lower organic film, and it is said that a pattern with a high aspect ratio can be formed. That is, according to the multilayer resist method, since the required thickness can be ensured by the lower layer organic film, the resist film can be thinned, and a fine pattern with a high aspect ratio can be formed.

In the multilayer resist method, basically, the upper resist film and the lower organic film have a two-layer structure (two-layer resist method), and one or more intermediate layers (such as a metal thin film) are formed 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 resist pattern formation method of this aspect is a method useful when forming a high-thickness resist film, and the film thickness of the resist film formed in the said process (i) is 7 micrometers or more.

The film thickness of the resist film formed in the step (i) is more preferably 8 µm or more, particularly preferably 10 µm or more, and the upper limit of the film thickness is substantially 30 µm or less.

The wavelength used for exposure is not particularly limited, ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. This can be done using radiation.

The resist pattern forming method according to this aspect is particularly preferable when, in the step (ii), the resist film is irradiated with a KrF excimer laser beam.

The exposure method of the resist film may be ordinary exposure (dry exposure) performed in an inert gas such as air or nitrogen, or liquid immersion lithography.

Liquid immersion exposure is an exposure method in which a space between a resist film and a lens at the lowest position of the exposure apparatus is previously filled with a solvent (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 larger than the refractive index of air and smaller than the refractive index of the resist film to be exposed is preferable. The refractive index of the 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 silicone-based solvent, and a hydrocarbon-based solvent.

Specific examples of the fluorine-based inert liquid include a liquid containing a fluorine-based compound such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , and C ₅ H ₃ F ₇ as a main component. It can be, and the thing of 70-180 degreeC is preferable and the thing of 80-160 degreeC is more preferable with a boiling point. If the fluorine-based inert liquid has a boiling point within the above range, it is preferable that the medium used for immersion can be removed by a simple method after exposure is complete.

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

Further, specifically, as the perfluoroalkyl ether compound, perfluoro(2-butyl-tetrahydrofuran) (boiling point 102° C.) is exemplified. As the perfluoroalkylamine compound, perfluoro and lotributylamine (boiling point 174°C).

As the immersion medium, water is preferably used from the viewpoints of cost, safety, environmental problems, versatility, and the like.

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

The organic solvent contained in the organic developer used for the developing treatment in the solvent development process should just be one that can dissolve the component (A) (component (A) before exposure), and can be appropriately selected from known organic solvents. Specific examples thereof include polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents and ether solvents, and hydrocarbon solvents.

A ketone-based solvent is an organic solvent containing C-C(=O)-C in its structure. The ester solvent is an organic solvent containing C-C(=O)-O-C in its structure. The alcohol-based solvent is an organic solvent containing an alcoholic hydroxyl group in its structure. "Alcoholic hydroxyl group" means the hydroxyl group couple|bonded with the carbon atom of the aliphatic hydrocarbon group. The nitrile-based solvent is an organic solvent containing a nitrile group in its structure. The amide-based solvent is an organic solvent containing an amide group in its structure. The etheric solvent is an organic solvent containing C-O-C in its structure.

In the organic solvent, there is also an organic solvent containing a plurality of types of functional groups that characterize each of the solvents in the structure. For example, diethylene glycol monomethyl ether shall correspond to any of the alcohol solvents and ether solvents in the said classification|category.

A hydrocarbon solvent is a hydrocarbon solvent which consists of hydrocarbons which may be halogenated and does not have substituents other than a halogen atom. As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.

As the organic solvent contained in the organic developer, among the above, a polar solvent is preferable, and a ketone solvent, an ester solvent, a nitrile solvent, and the like are preferable.

Examples of the ketone solvent include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, and diisobutyl. Ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methylethylketone, methylisobutylketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methylnaphthylketone, isophorone, propylene carbonate, γ-butyrolactone, methyl amyl ketone (2-heptanone), and the like. Among these, as the ketone solvent, methyl amyl ketone (2-heptanone) is preferable.

As an ester solvent, for example, methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, methoxy ethyl acetate, ethoxyethyl acetate, ethylene glycol monoethyl ether acetate, ethylene glycol Monopropyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate , Diethylene glycol monoethyl ether acetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl Acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, 2-ethoxybutyl acetate, 4-ethoxybutyl acetate, 4-propoxybutyl acetate, 2-methoxypentyl acetate , 3-methoxypentyl acetate, 4-methoxypentyl acetate, 2-methyl-3-methoxypentyl acetate, 3-methyl-3-methoxypentyl acetate, 3-methyl-4-methoxypentyl acetate, 4- Methyl-4-methoxypentyl acetate, propylene glycol diacetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, ethyl carbonate, propyl carbonate, butyl carbonate, methyl pyruvate, ethyl pyruvate, Propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, methyl-3-methoxypropionate , ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, propyl-3-methoxypropionate, and the like. Among these, as an ester solvent, butyl acetate is preferable.

As a nitrile-type solvent, acetonitrile, propionitrile, valeronitrile, butyronitrile, etc. are mentioned, for example.

A well-known additive can be mix|blended with an organic type developing solution as needed. As the additive, surfactant is mentioned, for example. Although it does not specifically limit as surfactant, For example, ionic or nonionic fluorine type and/or silicone type surfactant etc. can be used. As surfactant, a nonionic surfactant is preferable, and a nonionic fluorochemical surfactant or a nonionic silicone type surfactant is more preferable.

When mix|blending surfactant, the compounding quantity is 0.001-5 mass % normally with respect to the whole quantity of an organic type developing solution, 0.005-2 mass % is preferable, and its 0.01-0.5 mass % is more preferable.

The developing treatment can be carried out by a known developing method, for example, a method in which the support is immersed in a developer for a certain time (dip method), a method in which the developer is raised on the surface of the support by surface tension and stopped for a certain time (puddle) method), a method of spraying a developer on the surface of a support (spray method), a method of continuously drawing out a developer while scanning a developer extraction nozzle at a constant speed on a support rotating at a constant speed (dynamic dispensing method), etc. are mentioned. .

As an organic solvent contained in the rinsing solution used for the rinsing treatment after the development in the solvent developing process, for example, from among the organic solvents used for the above organic developer, an organic solvent that is difficult to dissolve the resist pattern is appropriately selected and used. can Usually, at least one solvent selected from hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents and ether solvents is used. Among these, at least one selected from hydrocarbon-based solvents, ketone-based solvents, ester-based solvents, alcohol-based solvents and amide-based solvents is preferable, and at least one selected from alcohol-based solvents and ester-based solvents is more preferable, and alcohol-based solvents Solvents are particularly preferred.

The alcohol solvent used for the rinse liquid is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched or cyclic. Specifically, 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4 - octanol, benzyl alcohol, etc. are mentioned. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferable, and 1-hexanol and 2-hexanol are more preferable.

These organic solvents may be used individually by any 1 type, and may use 2 or more types together. Moreover, you may use it, mixing with organic solvents and water other than the above. However, in consideration of the development characteristics, the amount of water in the rinse liquid is preferably 30 mass% or less, more preferably 10 mass% or less, still more preferably 5 mass% or less, with respect to the total amount of the rinse liquid, 3 % by mass or less is particularly preferred.

A well-known additive can be mix|blended with a rinse liquid as needed. As the additive, surfactant is mentioned, for example. As for surfactant, the thing similar to the above is mentioned, A nonionic surfactant is preferable, and a nonionic fluorochemical surfactant or a nonionic silicone type surfactant is more preferable.

When mix|blending surfactant, the compounding quantity is 0.001-5 mass % normally with respect to the whole quantity of a rinse liquid, 0.005-2 mass % is preferable, and its 0.01-0.5 mass % is more preferable.

The rinsing process (washing process) using a rinsing liquid can be performed by a well-known rinsing method. As a method of the rinsing treatment, for example, a method of continuously drawing out a rinse solution on a support rotating at a constant speed (rotary coating method), a method of immersing the support in a rinse liquid for a certain period of time (dip method), on the surface of the support The method of spraying a rinse liquid (spray method), etc. are mentioned.

<resist composition>

In the resist pattern formation method of the present embodiment described above, a specific resist composition is used in the step (i).

Such a specific resist composition generates an acid upon exposure, and its solubility in a developer changes due to the action of the acid. Examples of the resist composition include an embodiment containing a base component (A) (hereinafter also referred to as “component (A)”) whose solubility in a developer changes due to the action of an acid.

The resist composition of the present embodiment is suitable for forming a resist pattern subjected to exposure to KrF excimer laser light.

Moreover, the resist composition of this embodiment is useful as a resist agent for forming a high-thickness resist film on a support body, and is suitable for forming a resist film with a film thickness of 7 micrometers or more.

When a resist film is formed using the resist composition of the present embodiment and the resist film is selectively exposed, an acid is generated in the exposed portion of the resist film, and by the action of the acid, the solubility of component (A) in a developer solution is performed. On the other hand, since the solubility of component (A) in the developer does not change in the unexposed portion of the resist film, a difference in solubility in the developer occurs between the exposed portion and the unexposed portion of the resist film. Therefore, when the resist film is developed, when the resist composition is of a positive type, the exposed portion of the resist film is dissolved and removed to form a positive resist pattern. type resist pattern is formed.

In the present specification, the resist composition in which the resist film exposed portion is dissolved and removed to form a positive resist pattern is referred to as a positive resist composition, and the resist composition in which the unexposed portion of the resist film is dissolved and removed to form a negative resist pattern is referred to as negative. It is called a resist composition.

The resist composition of the present embodiment may be a positive resist composition or a negative resist composition.

In addition, the resist composition of this embodiment may be for an alkali developing process using an alkali developer for the developing process at the time of forming a resist pattern, and a solvent developing process using a developing solution containing an organic solvent (organic developer) for the developing process. It could be a dragon.

In short, the resist composition of the present embodiment is a "positive resist composition for an alkali developing process" that forms a positive resist pattern in an alkali developing process, and a "solvent developing process" that forms a negative resist pattern in a solvent developing process negative resist composition".

The resist composition of the present embodiment has an acid-generating ability to generate an acid upon exposure, the component (A) may generate an acid upon exposure, and an additive component blended separately from the component (A) is subjected to exposure. acid may be generated by

Specifically, the resist composition of the embodiment may contain (1) an acid generator component (B) that generates an acid upon exposure (hereinafter referred to as “component (B)”); (2) (A) The component which generate|occur|produces an acid by exposure may be sufficient; (3) (A) component is a component which generate|occur|produces an acid by exposure, and may contain (B) component further.

That is, in the case of the above (2) or (3), the component (A) becomes "a base component that generates an acid upon exposure and whose solubility in a developer changes due to the action of the acid". When component (A) is a base component that generates an acid upon exposure and changes solubility in a developer by the action of an acid, component (A1) to be described later generates an acid upon exposure, and It is preferable that it is a high molecular compound whose solubility with respect to a developing solution changes by the action of an acid. As such a high molecular compound, the copolymer which has a structural unit which generate|occur|produces an acid by exposure can be used.

As a structural unit which generate|occur|produces an acid by exposure, a well-known thing is mentioned, for example.

It is especially preferable that the resist composition of this embodiment is the case of said (1).

≪(A) ingredient≫

Component (A) is a base component whose solubility in a developing solution changes by the action of an acid.

In the present embodiment, the "base component" is an organic compound having film-forming ability, and preferably an organic compound having 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 resist pattern.

Organic compounds used as the base component are broadly classified into non-polymers and polymers.

As a non-polymer, the thing of molecular weight 500 or more and less than 4000 is used normally. Hereinafter, when "low molecular weight compound", molecular weight shows the non-polymer of 500 or more and less than 4000.

As a polymer, the thing of molecular weight 1000 or more is used normally. Hereinafter, when "resin", "polymer compound", or "polymer", molecular weight shows the polymer of 1000 or more.

As molecular weight of a polymer, the weight average molecular weight of polystyrene conversion by GPC (gel permeation chromatography) shall be used.

The component (A) in the resist composition of the present embodiment includes a resin component (A1) (hereinafter also referred to as “component (A1)”) whose solubility in a developer changes due to the action of an acid.

As (A) component, (A1) component is used at least, and you may use together another high molecular compound and/or a low molecular compound with the (A1) component.

In the present embodiment, component (A1) includes a structural unit (a10) represented by general formula (a10-1) described later, a structural unit (a4) containing an acid non-dissociable aliphatic cyclic group, and an acid It has a structural unit (a1) containing an acid-decomposable group whose polarity increases by this. In addition to the structural unit (a10), the structural unit (a4), and the structural unit (a1), such component (A1) may have another structural unit as needed.

In the resist composition of the present embodiment, since the structural unit (a1) contains an acid dissociable group, the polarity of the resin component changes before and after exposure by using the component (A1), so that not only the alkali development process but also the solvent development process Also in the process, good development contrast can be obtained between the exposed portion and the unexposed portion of the resist film.

When an alkali developing process is applied, the component (A1) is poorly soluble in an alkali developing solution before exposure. For example, when an acid is generated from component (B) by exposure, the polarity increases due to the action of the acid. Thus, solubility in an alkali developer is increased. Therefore, in the formation of a resist pattern, when a resist film obtained by applying the resist composition onto a support is selectively exposed to light, the exposed portion of the resist film changes from poorly soluble to soluble in an alkali developer, while the resist film is not exposed. Since the miner is hardly soluble in alkali and does not change, a positive resist pattern is formed by alkali development.

On the other hand, when a solvent development process is applied, the component (A1) has high solubility in an organic developer before exposure. This increases, and the solubility in an organic developer decreases. Therefore, in the formation of a resist pattern, when the resist film obtained by coating the resist composition on a support is selectively exposed to light, the exposed portion of the resist film changes from soluble to poorly soluble in an organic developer, while the resist film is not coated with the resist film. Since the miner remains soluble and does not change, a negative resist pattern is formed by developing with an organic developer.

・About the structural unit (a10):

The structural unit (a10) is a structural unit represented by the following general formula (a10-1).

[Formula 2]

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya ^x1 is a single bond or a divalent linking group. Wa ^x1 is a (n _ax1 +1) valent aromatic hydrocarbon group. n _ax1 is an integer of 1 to 3.]

In said formula (a10-1), R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group.

The C1-C5 alkyl group of R is preferably a C1-C5 linear or branched alkyl group, Specifically, a methyl group, an ethyl group, a propyl group, isopropyl group, n-butyl group, isobutyl group group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, and the like. The halogenated alkyl group having 1 to 5 carbon atoms for R is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms. A fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned as this halogen atom, A fluorine atom is especially preferable.

As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is most preferable.

In the formula (a10-1), Ya ^x1 is a single bond or a divalent linking group.

Preferable examples of the divalent linking group for Ya ^x1 include a divalent hydrocarbon group which may have a substituent and a divalent linking group containing a hetero atom.

· A divalent hydrocarbon group which may have a substituent:

When Ya ^{x 1} is a divalent hydrocarbon group which may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

... aliphatic hydrocarbon group for Ya ^x1

The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and it is usually preferable that it is saturated.

Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group or an aliphatic hydrocarbon group having a ring in its structure.

... linear or branched aliphatic hydrocarbon group

The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more 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 -], a trimethylene group [-( CH ₂ ) ₃ -], tetramethylene group [-(CH ₂ ) ₄ -], pentamethylene group [-(CH ₂ ) ₅ -], and the like.

The branched aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms.

The branched chain aliphatic hydrocarbon group is preferably a branched chain alkylene group, specifically -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, - alkylmethylene groups such as C(CH ₃ )(CH ₂ CH ₃ )-, —C(CH ₃ )(CH ₂ CH ₂ CH 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 ) alkylethylene groups such as ₂ -CH ₂ -; Alkyltrimethylene groups, such as -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ -; Alkylalkylene groups, such as alkyltetramethylene groups, such as -CH(CH ₃ )CH ₂ CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ CH ₂ -, etc. are mentioned. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

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.

... an aliphatic hydrocarbon group containing a ring in its structure

Examples of the aliphatic hydrocarbon group having a ring in its structure include a cyclic aliphatic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring) which may contain a substituent containing a hetero atom in the ring structure, and the cyclic aliphatic group described above. and a group in which a hydrocarbon group is bonded to a terminal of a linear or branched aliphatic hydrocarbon group, and a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as those described above.

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

The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane is preferably a monocycloalkane having 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms have been removed from a polycycloalkane, and the polycycloalkane is preferably a polycycloalkane having 7 to 12 carbon atoms, specifically adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like.

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, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and a methoxy group time, the ethoxy group is most preferred.

A fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned as a halogen atom as said substituent, A fluorine atom is preferable.

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

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

··Aromatic hydrocarbon group for Ya ^x1

The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.

The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. It is preferable that carbon number of an aromatic ring is 5-30, 5-20 are more preferable, 6-15 are still more preferable, 6-12 are especially preferable. However, carbon number in a substituent shall not be included in the carbon number. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocyclic rings in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with hetero atoms. As a hetero atom in an aromatic heterocyclic ring, an oxygen atom, a sulfur atom, a nitrogen atom, etc. are mentioned.

Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring.

Specific examples of the aromatic hydrocarbon group include groups in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring or aromatic heterocycle (arylene group or heteroarylene group); a group obtained by removing two hydrogen atoms from an aromatic compound containing two or more aromatic rings (eg, biphenyl, fluorene, etc.); A group in which one hydrogen atom of the group (aryl group or heteroaryl group) in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocyclic ring is substituted with an alkylene group (eg, benzyl group, phenethyl group, 1-naph group in which one hydrogen atom is further removed from the aryl group in an arylalkyl group such as a tylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, and a 2-naphthylethyl group). It is preferable that carbon number of the alkylene group couple|bonded with the said aryl group or heteroaryl group is 1-4, It is more preferable that it is C1-C2, It is especially preferable that it is C1.

As for the said aromatic hydrocarbon group, the hydrogen atom which the said aromatic hydrocarbon group has may be substituted by the substituent. For example, the hydrogen atom couple|bonded with the aromatic ring in the said aromatic hydrocarbon group may be substituted by the 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 for substituting a hydrogen atom in the cyclic aliphatic hydrocarbon group.

· A divalent linking group containing a hetero atom:

When Ya ^x1 is a divalent linking group containing a hetero atom, preferred examples of the linking group include -O-, -C(=O)-O-, -C(=O)-, -OC(=O)-O -, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an 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 -, -Y ²¹ -OC(=O)-Y ²² - or -Y ²¹ -S(=O ) a group represented by ₂ -OY ²² - [wherein Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m" is an integer of 0 to 3.] and the like.

The divalent linking group containing the hetero atom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, -NH-C(=NH)- In this case, H may be substituted with substituents, such as an alkyl group and an acyl group. It is preferable that carbon number is 1-10, as for the substituent (an alkyl group, an acyl group, etc.), it is more preferable that it is 1-8, It is especially preferable that it is 1-5.

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 -, -Y ²¹ -OC(=O)-Y ²² - or -Y ²¹ -S(=O) ₂ -OY ²² -, wherein Y ²¹ and Y ²² are each independently and may have a substituent, is a divalent hydrocarbon group.The divalent hydrocarbon group includes the same as (divalent hydrocarbon group which may have a substituent) in the description of the divalent linking group.

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. A C1-C5 linear alkyl group is preferable, as for the alkyl group in this alkylmethylene group, a C1-C3 linear alkyl group is more preferable, A methyl group is the most preferable.

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, more preferably 0 or 1 preferred, and 1 is particularly preferred. That is, the group represented by the formula -[Y ²¹ -C(=O)-O] _m" -Y ²² - is particularly preferably a group represented by the formula -Y ²¹ -C(=O)-OY ²² -. Among these, the group represented by the formula -Y 21 -C(=O)-OY 22 - , a group represented by the formula -(CH ₂ ) _a' -C(=O)-O-(CH ₂ ) _b' - is preferable, wherein a' is an integer of 1 to 10, and 1 to 8 An integer is preferable, an integer of 1 to 5 is more preferable, 1 or 2 is still more preferable, and most preferably 1. b' is an integer of 1-10, preferably an integer of 1-8, 1 The integer of -5 is more preferable, 1 or 2 is still more preferable, and 1 is the most preferable.

As Ya ^x1 , a single bond, an ester bond [-C(=O)-O-], an ether bond (-O-), -C(=O)-NH-, a linear or branched alkylene group; Or it is preferable that it is a combination thereof, and a single bond is especially more preferable especially.

In the formula (a10-1), Wa ^x1 is a (n _ax1 +1) valent aromatic hydrocarbon group.

Examples of the aromatic hydrocarbon group for Wa ^x1 include a group in which (n _ax1 +1) hydrogen atoms have been removed from an aromatic ring. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n+2 π electrons, and may be monocyclic or polycyclic. It is preferable that carbon number of an aromatic ring is 5-30, C5-C20 is more preferable, C6-C15 is still more preferable, C6-C12 is especially preferable. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocyclic rings in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with hetero atoms. As a hetero atom in an aromatic heterocyclic ring, an oxygen atom, a sulfur atom, a nitrogen atom, etc. are mentioned. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring.

In said formula (a10-1), n _ax1 is an integer of 1-3, 1 or 2 is preferable and 1 is more preferable.

Specific examples of the structural unit represented by the general formula (a10-1) are shown below.

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

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

(A1) The number of structural units (a10) which a component has may be 1 type, or 2 or more types may be sufficient as it.

Among the above, the structural unit (a10) is preferably a structural unit containing a hydroxystyrene skeleton, and particularly preferably a structural unit represented by the following general formula (a10-1-0).

[Formula 7]

[In the formula, R ^st represents a hydrogen atom or a methyl group. m ₀₁ represents an integer of 1 to 3.]

In the component (A1), the proportion of the structural unit (a10) is preferably 40 to 80 mol%, preferably 45 to 75 mol%, with respect to the total (100 mol%) of all structural units constituting the component (A1). is more preferable, and 50 to 70 mol% is particularly preferable.

By setting the proportion of the structural unit (a10) to be equal to or higher than the lower limit of the preferred range, the sensitivity, developing characteristics, and the effect of suppressing the occurrence of defects are further improved. lithographic properties are further improved.

・About the structural unit (a4):

The structural unit (a4) is a structural unit containing an acid non-dissociable aliphatic cyclic group.

When the component (A1) has the structural unit (a4), the light transmittance of the resist film is increased compared to the case where the component has a structural unit containing an aromatic cyclic group. Moreover, dry etching resistance of the resist pattern to be formed improves, and the hydrophobicity of (A) component becomes high. The improvement of hydrophobicity contributes to improvement of resolution, resist pattern shape, and the like, particularly in the case of resist pattern formation by a solvent development process.

The "acid non-dissociable cyclic group" in the structural unit (a4) acts when an acid is generated in the resist composition upon exposure (for example, when an acid is generated from component (B), which will be described later). It is a cyclic group which remains in the structural unit as it is without dissociation.

The acid non-dissociable aliphatic cyclic group in the structural unit (a4) may be a monocyclic group or a polycyclic group, preferably a monocyclic group.

The monocyclic group here is preferably a group obtained by removing one or more hydrogen atoms from a monocycloalkane. As this monocycloalkane, a C3-C8 thing is more preferable, A C5-C8 thing is still more preferable, cyclopentane, cyclohexane, cyclooctane, etc. are mentioned specifically,. The polycyclic group here is preferably a group in which one or more hydrogen atoms have been removed from the polycycloalkane, and the polycycloalkane is preferably a polycycloalkane having 7 to 12 carbon atoms, specifically adamantane, norbornane, iso Bornane, tricyclodecane, tetracyclododecane, etc. are mentioned.

The monocyclic group and the polycyclic group may each have, for example, a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.

Examples of the structural unit (a4) include 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, a structural unit derived from acrylamide, etc., which are bonded to the carbon atom at the α-position A structural unit derived from an acrylic acid ester in which a hydrogen atom may be substituted with a substituent is preferable.

Specific examples of the structural unit (a4) are shown below.

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

[Formula 8]

(A1) The number of structural units (a4) which a component has may be 1 type, or 2 or more types may be sufficient as it.

The structural unit (a4), among the above, is preferably an acid non-dissociable structural unit containing a monocyclic aliphatic cyclic group, and is composed of a structural unit represented by any of the above formulas (a4-7) to (a4-10). At least one selected from the group is more preferred.

It is preferable that the ratio of the structural unit (a4) in the component (A1) is 1-50 mol% with respect to the sum total (100 mol%) of all the structural units which comprise the (A1) component, and it is 2-50 mol % is more preferable, and 5-45 mol% is still more preferable.

By setting the ratio of the structural unit (a4) to be equal to or higher than the lower limit of the preferred range, the light transmittance of the resist film becomes higher, and the sensitivity and resolution are further improved. On the other hand, by setting it as below the upper limit of the said preferable range, it becomes easy to balance with another structural unit.

・About the structural unit (a1):

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

The "acid-decomposable group" is a group having acid-decomposable properties capable of cleaving at least some bonds in the structure of the acid-decomposable group by the action of an acid.

As an acid-decomposable group whose polarity increases by the action of an acid, for example, a group which is decomposed by the action of an acid to produce a polar group is exemplified.

As a polar group, a carboxy group, a hydroxyl group, an amino group, a sulfo group (-SO ₃ H), etc. are mentioned, for example. Among these, a polar group containing -OH in the structure (hereinafter sometimes referred to as "OH-containing polar group") is preferable, a carboxy group or a hydroxyl group is more preferable, and a carboxy group is particularly preferable.

More specific examples of the acid-decomposable group include a group in which the polar group is protected by an acid-dissociable group (eg, a group in which a hydrogen atom of an OH-containing polar group is protected by an acid-dissociable group).

Here, the term "acid dissociable group" refers to (i) a group having acid dissociation 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) an acid It refers to both groups in which the bond between the acid dissociable group and the atom adjacent to the acid dissociable group can be cleaved by further decarboxylation reaction after cleavage of some bonds by the action of .

The acid-dissociable group constituting the acid-dissociable group must be a group having a lower polarity than the polar group generated by dissociation of the acid-dissociable group, and thus, when the acid-dissociable group is dissociated by the action of an acid, the acid-dissociable group A polar group with a higher polarity is formed and the polarity is increased. As a result, the polarity of the whole component (A1) increases. As the polarity increases, the solubility with respect to the developer is relatively changed, the solubility increases when the developer is an alkaline developer, and the solubility decreases when the developer is an organic developer.

Examples of the acid dissociable group include those that have been proposed as an acid dissociable group in base resins for chemically amplified resist compositions.

As acid-dissociable groups for base resins for chemically amplified resist compositions, specifically, "acetal-type acid-dissociable groups", "tertiary alkyl ester-type acid-dissociable groups", and "tertiary-type acid-dissociable groups" are described below. alkyloxycarbonyl acid dissociable group".

· Acetal-type acid dissociative group:

Among the 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 referred to as “acetal-type acid-dissociable group” in some cases). can be heard

[Formula 9]

[Wherein, Ra' ¹ and Ra' ² are a hydrogen atom or an alkyl group, Ra' ³ is a hydrocarbon group, and Ra' ³ may be bonded to any of Ra' ¹ and Ra' ² to form a ring.]

In formula (a1-r-1), it is preferable that at least one is a hydrogen atom among Ra' ¹ and Ra' ² , and it is more preferable that both are a hydrogen atom.

When Ra' ¹ or Ra' ² is an alkyl group, examples of the alkyl group include the same alkyl groups as the substituents that may be bonded to the carbon atom at the α-position in the description of the α-substituted acrylic acid ester, and have 1 to The alkyl group of 5 is preferable. Specifically, a linear or branched alkyl group is preferably mentioned. More specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. are mentioned, A methyl group or an ethyl group is more preferably, a methyl group is particularly preferable.

In the formula (a1-r-1), examples of the hydrocarbon group for Ra' ³ include a linear or branched alkyl group or a cyclic hydrocarbon group.

It is preferable that carbon number is 1-5, as for this linear alkyl group, 1-4 are more preferable, and 1 or 2 is still more preferable. Specifically, a methyl group, an ethyl group, n-propyl group, n-butyl group, n-pentyl group, etc. are mentioned. Among these, a methyl group, an ethyl group, or n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

It is preferable that carbon number is 3-10, and, as for this branched alkyl group, 3-5 are more preferable. Specific examples thereof include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, etc., which are isopropyl group it is preferable

When Ra' ³ is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, or may be a polycyclic group or a monocyclic group.

As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. The monocycloalkane is preferably a monocycloalkane having 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane.

As the polycyclic group, the aliphatic hydrocarbon group is preferably a group in which one hydrogen atom has been removed from a polycycloalkane, and the polycycloalkane is preferably a polycycloalkane having 7 to 12 carbon atoms, specifically adamantane, norbornane, iso Bornane, tricyclodecane, tetracyclododecane, etc. are mentioned.

When the cyclic hydrocarbon group of Ra' ³ becomes an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.

The aromatic ring is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons, and may be monocyclic or polycyclic. It is preferable that carbon number of an aromatic ring is 5-30, 5-20 are more preferable, 6-15 are still more preferable, 6-12 are especially preferable.

Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocyclic rings in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with hetero atoms. As a hetero atom in an aromatic heterocyclic ring, an oxygen atom, a sulfur atom, a nitrogen atom, etc. are mentioned. Specific examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring.

Specific examples of the aromatic hydrocarbon group for Ra' ³ include a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group); a group in which one hydrogen atom is removed from an aromatic compound containing two or more aromatic rings (eg, biphenyl, fluorene, etc.); A group in which one of the hydrogen atoms of the aromatic hydrocarbon ring or the aromatic heterocyclic ring is substituted with an alkylene group (eg, a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, 2 -arylalkyl groups, such as a naphthylethyl group, etc.) etc. are mentioned. It is preferable that carbon number of the alkylene group couple|bonded with the said aromatic hydrocarbon ring or aromatic heterocyclic ring is 1-4, It is more preferable that it is 1-2, It is especially preferable that it is 1.

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

A tertiary alkyl ester type acid dissociable group:

Among the polar groups, examples of the acid dissociable group that protects the carboxy group include an acid dissociable group represented by the following general formula (a1-r-2).

In addition, among the acid dissociable groups represented by the following formula (a1-r-2), what is comprised by an alkyl group may be hereinafter referred to as a "tertiary alkyl ester type acid dissociable group" for convenience.

[Formula 10]

[Wherein, Ra' ⁴ to Ra' ⁶ are each a hydrocarbon group, and Ra' ⁵ and Ra' ⁶ may be bonded to each other to form a ring.]

Examples of the hydrocarbon group for Ra' ⁴ to Ra' ⁶ include the same as those for Ra' ³ above.

It is preferable that Ra' ⁴ is a C1-C5 alkyl group. When ^Ra'5 and ^Ra'6 combine with each other to form a ring, the group represented by the following general formula (a1-r2-1) is mentioned. On the other hand, when Ra' ⁴ to Ra' ⁶ are not mutually bonded and are independent hydrocarbon groups, a group represented by the following general formula (a1-r2-2) is exemplified.

[Formula 11]

[Wherein, Ra' ¹⁰ is an alkyl group having 1 to 10 carbon atoms, Ra' ¹¹ is a group forming 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. indicate.]

In the formula (a1-r2-1), the alkyl group having 1 to 10 carbon atoms for Ra' ¹⁰ is preferably a group mentioned as the linear or branched alkyl group for Ra' ³ in the formula (a1-r-1). do.

In formula (a1-r2-1), the aliphatic cyclic group formed together with the carbon atom to which Ra' ¹¹ and Ra' ¹⁰ are bonded is a monocyclic group or polyvalent group of Ra' ³ in formula (a1-r-1). The group mentioned as an aliphatic hydrocarbon group which is a cyclic group is preferable, and the group mentioned as an aliphatic hydrocarbon group which is a monocyclic group is more preferable.

In the formula (a1-r2-2), Ra' ¹² and Ra' ¹⁴ are each independently preferably an alkyl group having 1 to 10 carbon atoms, and the alkyl group is Ra' in the formula (a1-r-1). The group mentioned as a linear or branched alkyl group of ³ is more preferable, It is more preferable that it is a C1-C5 linear alkyl group, It is especially preferable that it is a methyl group or an ethyl group.

In the formula (a1-r2-2), Ra' ¹³ is a linear or branched alkyl group, a monocyclic group or a polycyclic group exemplified as the hydrocarbon group of Ra' ³ in the formula (a1-r-1). It is preferable that it is an aliphatic hydrocarbon group which is a group. Among these, the group mentioned as an aliphatic hydrocarbon group which is a monocyclic group or a polycyclic group of ^Ra'3 is more preferable.

Specific examples of the group represented by the formula (a1-r2-1) are given below. * represents a bond (the same in the present specification).

[Formula 12]

[Formula 13]

Specific examples of the group represented by the formula (a1-r2-2) are given below.

[Formula 14]

· Tertiary alkyloxycarbonyl acid dissociable group:

Among the polar groups, the acid dissociable group for protecting the hydroxyl group is, for example, an acid dissociable group represented by the following general formula (a1-r-3) (hereinafter referred to as “tertiary alkyloxycarbonyl acid dissociable group” for convenience) There is) can be mentioned.

[Formula 15]

[Wherein, Ra' ⁷ to Ra' ⁹ are each an alkyl group.]

In formula (a1-r-3), a C1-C5 alkyl group is preferable, respectively, and, as for ^Ra'7 - ^Ra'9 , 1-3 are more preferable.

Moreover, it is preferable that it is 3-7, as for carbon number of the sum total of each alkyl group, it is more preferable that it is 3-5, It is most preferable that it is 3-4.

Among the above, the acid-decomposable group in the structural unit (a1) is preferably a group containing an aliphatic cyclic group from the viewpoint of higher degradability by the action of an acid, and a polar group (carboxy group) as an acid-dissociable group containing an aliphatic cyclic group. , a hydroxyl group, an amino group, a sulfo group, etc.) is more preferably a protected group. Among these, the acid-decomposable group in the structural unit (a1) includes an acid-dissociable group represented by the above general formula (a1-r2-1) from the viewpoint that the resolution is improved and a pattern having a better shape is easily formed. The following group is preferable, and the group containing an acid-dissociable group represented by the following general formula (a1-r2-11) is more preferable.

[Formula 16]

[In the formula, Ra' ¹⁰ is a hydrocarbon group having 1 to 10 carbon atoms. Ra" ¹¹ is a group forming a monocyclic aliphatic cyclic group together with the carbon atom to which Ra' ¹⁰ is bonded. * is a bond.]

In the formula (a1-r2-11), the alkyl group having 1 to 10 carbon atoms for Ra' ¹⁰ is preferably a group mentioned as the linear or branched alkyl group for Ra' ³ in the formula (a1-r-1). do.

It is preferable that carbon number is 1-5, as for this linear alkyl group, 1-4 are more preferable, and 1 or 2 is still more preferable. Specifically, a methyl group, an ethyl group, n-propyl group, n-butyl group, n-pentyl group, etc. are mentioned. Among these, a methyl group, an ethyl group, or n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

It is preferable that carbon number is 3-10, and, as for this branched alkyl group, 3-5 are more preferable. Specific examples thereof include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group, 1,1-diethylpropyl group, 2,2-dimethylbutyl group, etc., which are isopropyl group it is preferable

In the formula (a1-r2-11), the aliphatic cyclic group formed together with the carbon atom to which Ra" ¹¹ and Ra' ¹⁰ are bonded is an aliphatic hydrocarbon which is a monocyclic group of Ra' ³ in the formula (a1-r-1). The group mentioned as a group is preferable.

As the aliphatic hydrocarbon group which is a monocyclic group, a group obtained by removing one hydrogen atom from a monocycloalkane is preferable. As this monocycloalkane, a C3-C8 thing is preferable, A C3-C6 thing is more preferable, cyclopentane, cyclohexane, etc. are mentioned specifically,.

As the structural unit (a1), 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, a structural unit derived from acrylamide, a structural unit derived from hydroxystyrene or a hydroxystyrene derivative At least a part of hydrogen atoms in -C(=O)-OH in a structural unit in which at least a part of hydrogen atoms in the hydroxyl group of the unit is protected by an acid dissociable group, or in a structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative and structural units protected by an acid dissociable 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 a preferable specific example of such a structural unit (a1), the structural unit represented by the following general formula (a1-1) or general formula (a1-2) is mentioned.

[Formula 17]

[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 which may have an ether bond, n _a1 is 0 to 2, and Ra ¹ is an acid dissociable group represented by the above formula (a1-r-1) or (a1-r-2). Wa ¹ is n _a2 + monovalent hydrocarbon group, n _a2 is 1-3, and Ra ² is an acid dissociable group represented by the above formula (a1-r-1) or (a1-r-3)]

In the formula (a1-1), the alkyl group having 1 to 5 carbon atoms for R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, a methyl group, an ethyl group, a propyl group, or isopropyl group. group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, and the like. The 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 substituted with halogen atoms. A fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned as this halogen atom, A fluorine atom is especially preferable.

As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is most preferable.

In the formula (a1-1), the divalent hydrocarbon group for Va ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

The aliphatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ may be saturated or unsaturated, and is usually preferably saturated.

More specifically, examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, or an aliphatic hydrocarbon group having a ring in its structure.

It is preferable that carbon number is 1-10, as for the said linear or branched aliphatic hydrocarbon group, 1-6 are more preferable, 1-4 are still more preferable, and 1-3 are the most preferable.

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 -], a trimethylene group [-( CH ₂ ) ₃ -], tetramethylene group [-(CH ₂ ) ₄ -], pentamethylene group [-(CH ₂ ) ₅ -], and the like.

The branched chain aliphatic hydrocarbon group is preferably a branched chain alkylene group, specifically, -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, Alkylmethylene groups, such as -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH 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 ) alkylethylene groups such as ₂ -CH ₂ -; Alkyltrimethylene groups, such as -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ -; Alkylalkylene groups, such as alkyltetramethylene groups, such as -CH(CH ₃ )CH ₂ CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ CH ₂ -, etc. are mentioned. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the terminus of a linear or branched aliphatic hydrocarbon group and a group in which the alicyclic hydrocarbon group is interposed in the middle of the linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same as the linear or branched aliphatic hydrocarbon group.

It is preferable that carbon number is 3-20, and, as for the said alicyclic hydrocarbon group, it is more preferable that it is 3-12.

Polycyclic type may be sufficient as the said alicyclic hydrocarbon group, and monocyclic type may be sufficient as it. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane is preferably a monocycloalkane having 3 to 6 carbon atoms, and specific examples thereof 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 a polycycloalkane having 7 to 12 carbon atoms, specifically adamantane, norbornane, iso Bornane, tricyclodecane, tetracyclododecane, etc. are mentioned.

The aromatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ is a hydrocarbon group having an aromatic ring.

It is preferable that carbon number of this aromatic hydrocarbon group is 3-30, It is more preferable that it is 5-30, 5-20 are still more preferable, 6-15 are especially preferable, and 6-10 are the most preferable. However, carbon number in a substituent shall not be included in the carbon number.

Specific examples of the aromatic ring included in the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; and aromatic heterocyclic rings in which some of the carbon atoms constituting the aromatic hydrocarbon ring are substituted with hetero atoms. As a hetero atom in an aromatic heterocyclic ring, an oxygen atom, a sulfur atom, a nitrogen atom, etc. are mentioned.

Specific examples of the aromatic hydrocarbon group include groups in which two hydrogen atoms have been removed from the aromatic hydrocarbon ring (arylene group); A group in which one hydrogen atom of the group (aryl group) in which one hydrogen atom is removed from the aromatic hydrocarbon ring is substituted with an alkylene group (eg, benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group) , a group in which one hydrogen atom is further removed from an aryl group in an arylalkyl group such as 1-naphthylethyl group and 2-naphthylethyl group). It is preferable that carbon number of the said alkylene group (alkyl chain in an arylalkyl group) is 1-4, It is more preferable that it is 1-2, It is especially preferable that it is 1.

In the formula (a1-2), the n _a2 + monovalent 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 is a combination of a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group including a ring in the structure, or a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group including a ring in the structure. You can pick up one.

2-4 valence is preferable and, as for said n _a2 +1 value, 2 or 3 valence is more preferable.

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

[Formula 18]

[Formula 19]

[Formula 20]

[Formula 21]

[Formula 22]

Specific examples of the structural unit represented by the formula (a1-2) are shown below.

[Formula 23]

As the structural unit (a1), among them, a structural unit represented by the general formula (a1-1) is more preferable, and among these, a structural unit represented by the general formula (a1-1), wherein Ra ¹ is the above formula (a1) A structural unit which is an acid dissociable group represented by -r2-11) is particularly preferable.

(A1) The number of structural units (a1) which a component has may be one, or 2 or more types may be sufficient as it.

(A1) The proportion of the structural unit (a1) in the component is preferably 5 to 20 mol%, more preferably 7 to 20 mol%, based on all the structural units (100 mol%) constituting the component (A1), 10-20 mol% is more preferable.

By setting the proportion of the structural unit (a1) to be equal to or higher than the lower limit of the preferred range, a resist pattern can be easily obtained, resolution is further improved, and a pattern having a favorable shape is easily formed. Moreover, by setting it as below an upper limit, a balance with another structural unit can be achieved.

・About other structural units:

In addition to the structural unit (a10), the structural unit (a4), and the structural unit (a1), such component (A1) may have another structural unit as needed.

Examples of the other structural unit include a structural unit (a2) including a lactone-containing cyclic group, -SO ₂ --containing cyclic group, or carbonate-containing cyclic group; Structural unit (a3) containing a polar group-containing aliphatic hydrocarbon group (however, the thing corresponding to structural unit (a1) or structural unit (a2) is excluded); and structural units derived from styrene or derivatives thereof.

··Constituting unit (a2)

(A1) In addition to the structural unit (a10), the structural unit (a4), and the structural unit (a1), the component (A1) is, if necessary, further a lactone-containing cyclic group, a -SO ₂ - containing cyclic group, or a carbonate-containing cyclic group. You may have a structural unit (a2) containing

The lactone-containing cyclic group, -SO ₂ --containing cyclic group, or carbonate-containing cyclic group of the structural unit (a2) is effective in enhancing the adhesion of the resist film to the substrate when the component (A1) is used to form the resist film. will be. Moreover, by having a structural unit (a2), in the alkali developing process, the solubility with respect to the alkali developing solution of a resist film becomes high at the time of image development.

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

The lactone-containing cyclic group in the structural unit (a2) is not particularly limited, and any arbitrary group can be used. Specific examples thereof include groups represented by the following general formulas (a2-r-1) to (a2-r-7).

[Formula 24]

[wherein, 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, an alkyl group, a lactone containing cyclic group, a carbonate containing cyclic group, or a -SO ₂ - containing cyclic group. A" may contain an oxygen atom (-O-) or a sulfur atom (-S-) an alkylene group having 1 to 5 carbon atoms, an oxygen atom, or a sulfur atom. n' is an integer of 0 to 2, and m' is 0 or 1.]

In the formulas (a2-r-1) to (a2-r-7), the alkyl group for Ra′ ²¹ is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and a hexyl group. Among these, a methyl group or an ethyl group is preferable, and a methyl group is especially preferable.

The alkoxy group for Ra' ²¹ is preferably an alkoxy group having 1 to 6 carbon atoms.

It is preferable that the alkoxy group is linear or branched. Specific examples include a group in which an oxygen atom (-O-) is linked to the alkyl group mentioned as the alkyl group in Ra' ²¹ .

As a halogen atom in Ra' ²¹ , a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.

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

In -COOR" and -OC(=O)R" for Ra' ²¹ , R" is all a hydrogen atom, an alkyl group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a -SO ₂ - containing cyclic group.

The alkyl group for R" may be linear, branched or cyclic, and preferably has 1 to 15 carbon atoms.

When R" is a linear or branched alkyl group, it is preferably from 1 to 10 carbon atoms, more preferably from 1 to 5 carbon atoms, particularly preferably a methyl group or an 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 still more preferably 5 to 10 carbon atoms. Specifically, substituted with a fluorine atom or a fluorinated alkyl group A group in which one or more hydrogen atoms have been removed from a monocycloalkane which may or may not be present; a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, etc. More specifically, a group in which one or more hydrogen atoms are removed from a monocycloalkane such as cyclopentane or cyclohexane; and a group obtained by removing one or more hydrogen atoms from a polycycloalkane.

Examples of the lactone-containing cyclic group for R" include the same groups as the groups represented by the general formulas (a2-r-1) to (a2-r-7).

Examples of the carbonate-containing cyclic group for R" are the same as the carbonate-containing cyclic groups described later, and specific examples thereof include groups represented by the general formulas (ax3-r-1) to (ax3-r-3).

The -SO ₂ - containing cyclic group for R" is the same as the -SO ₂ - containing cyclic group described later, specifically, each of the formulas (a5-r-1) to (a5-r-4) and the group that represents it.

The hydroxyalkyl group for Ra' ²¹ preferably has 1 to 6 carbon atoms, and specific examples include groups in which at least one hydrogen atom of the alkyl group for Ra' ²¹ is substituted with a hydroxyl group.

In the general formulas (a2-r-2), (a2-r-3) and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A” is linear or branched. An alkylene group is preferable, and examples thereof include a methylene group, an ethylene group, an n-propylene group, an isopropylene group, etc. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include the alkylene group and a group in which -O- or -S- is interposed between the terminals or carbon atoms of, for example, -O-CH ₂ -, -CH ₂ -O-CH ₂ -, -S-CH ₂ -, - CH ₂ -S-CH ₂ -, etc. A" is preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group. .

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

[Formula 25]

[Formula 26]

"-SO ₂ - containing cyclic group" refers to a cyclic group containing a ring containing -SO ₂ - in its cyclic skeleton, 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 -SO ₂ - in the ring skeleton The ring containing the ring is counted as the first ring, and when it is only the ring, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of its structure. The -SO ₂ - containing cyclic group may be a monocyclic group or a polycyclic group.

The -SO ₂ - containing cyclic group is, in particular, a cyclic group containing -O-SO ₂ - in its ring backbone, that is, a sultone in which -OS- in -O-SO ₂ - forms part of the ring backbone. ) is preferably a cyclic group containing a ring.

More specifically, examples of the -SO ₂ - containing cyclic group include groups represented by the following general formulas (a5-r-1) to (a5-r-4).

[Formula 27]

[wherein, Ra' ⁵¹ is each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group or a cyano group. R" is a hydrogen atom, an alkyl group, a lactone containing cyclic group, a carbonate containing cyclic group, or a -SO ₂ - containing cyclic group. A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, oxygen atom or sulfur atom.

n' is an integer of 0 to 2.]

In the general formulas (a5-r-1) to (a5-r-2), A" is the general formulas (a2-r-2), (a2-r-3), (a2-r-5) Same as "A" in

The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, -COOR", -OC(=O)R", and hydroxyalkyl group for Ra' ⁵¹ are, respectively, from the above general formulas (a2-r-1) to (a2). -r-7), the same as those mentioned in the description for Ra' ²¹ can be mentioned.

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

[Formula 28]

[Formula 29]

[Formula 30]

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

The carbonate ring-containing cyclic group is not particularly limited, and any one can be used. Specific examples thereof include groups represented by the following general formulas (ax3-r-1) to (ax3-r-3).

[Formula 31]

[wherein, Ra' x ³¹ 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, an alkyl group, a lactone containing cyclic group, a carbonate containing cyclic group, or a -SO ₂ - containing cyclic group. A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom; an oxygen atom or a sulfur atom. p' is an integer from 0 to 3, and q' is 0 or 1.]

In the general formulas (ax3-r-2) to (ax3-r-3), A" is the general formulas (a2-r-2), (a2-r-3), (a2-r-5) Same as "A" in

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

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

[Formula 32]

As the structural unit (a2), 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 a preferable specific example of such a structural unit (a2), the structural unit represented by the following general formula (a2-1) is mentioned.

[Formula 33]

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya ²¹ is a single bond or a divalent linking group. 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 lactone-containing cyclic group, —SO ₂ ——containing cyclic group, or carbonate-containing cyclic group.]

In the formula (a2-1), R is the same as above.

As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is particularly preferable.

In the formula (a2-1), the divalent linking group for Ya ²¹ is not particularly limited, and preferable examples include a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like.

Examples of the divalent hydrocarbon group for Ya ²¹ include the same groups as described for the divalent hydrocarbon group for Va ¹ in formula (a1-1) described above. As a substituent which the divalent hydrocarbon group in Ya ²¹ may have, a C1-C5 alkyl group, an alkoxy group, a halogen atom, a C1-C5 halogenated alkyl group, a hydroxyl group, a carbonyl group, etc. are mentioned, for example.

Preferred examples of the divalent linking group containing a hetero atom for Ya ²¹ include -O-, -C(=O)-O-, -C(=O)-, -OC(=O). )-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an 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 -, -Y ²¹ -OC(=O)-Y ²² - or -Y ²¹ -S (=O) a group represented by ₂ -OY ²² - [wherein Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m" is an integer of 0 to 3 is.] and the like.

The divalent linking group containing the hetero atom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, -NH-C(=NH)- In this case, H may be substituted with substituents, such as an alkyl group and an acyl group. It is preferable that carbon number is 1-10, as for the substituent (an alkyl group, an acyl group, etc.), it is more preferable that it is 1-8, It is especially preferable that it is 1-5.

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 -, -Y ²¹ -OC(=O)-Y ²² - or -Y ²¹ -S(=O) ₂ -OY ²² -, wherein Y ²¹ and Y ²² are each independently and may have a substituent, is a divalent hydrocarbon group.The divalent hydrocarbon group includes the same as (divalent hydrocarbon group which may have a substituent) in the description of the divalent linking group.

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. A C1-C5 linear alkyl group is preferable, as for the alkyl group in this alkylmethylene group, a C1-C3 linear alkyl group is more preferable, A methyl group is the most preferable.

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, more preferably 0 or 1 and 1 is particularly preferred. That is, the group represented by the formula -[Y ²¹ -C(=O)-O] _m" -Y ²² - is particularly preferably a group represented by the formula -Y ²¹ -C(=O)-OY ²² -. Among these, the group represented by the formula -Y 21 -C(=O)-OY 22 - , a group represented by the formula -(CH ₂ ) _a' -C(=O)-O-(CH ₂ ) _b' - is preferable, wherein a' is an integer of 1 to 10, and 1 to 8 An integer is preferable, an integer of 1 to 5 is more preferable, 1 or 2 is still more preferable, and most preferably 1. b' is an integer of 1-10, preferably an integer of 1-8, 1 The integer of -5 is more preferable, 1 or 2 is still more preferable, and 1 is the most preferable.

Ya ²¹ is preferably a single bond, an ester bond [-C(=O)-O-], an ether bond (-O-), a linear or branched alkylene group, or a combination thereof.

In said formula (a2-1), La ²¹ is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO-, or -CONHCS-.

R' represents a hydrogen atom or a methyl group.

However, when La ²¹ is -O-, Ya ²¹ does not become -CO-.

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

The lactone-containing cyclic group, -SO ₂ --containing cyclic group, and carbonate-containing cyclic group for Ra ²¹ are each represented by the above general formulas (a2-r-1) to (a2-r-7), respectively. group, a group each represented by the general formulas (a5-r-1) to (a5-r-4), and a group each represented by the general formulas (ax3-r-1) to (ax3-r-3) are preferably mentioned. .

Among them, Ra ²¹ is preferably a lactone-containing cyclic group or a -SO ₂ --containing cyclic group, and is represented by the general formulas (a2-r-1), (a2-r-2), (a2-r-6), or The groups each represented by (a5-r-1) are more preferable. Specifically, the above formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), (r-lc Any group represented by -6-1), (r-sl-1-1) and (r-sl-1-18) is more preferable.

(A1) The number of structural units (a2) which a component has may be 1 type, or 2 or more types may be sufficient as it.

When the component (A1) has a structural unit (a2), the proportion of the structural unit (a2) is 1-80 mol% with respect to the total (100 mol%) of all structural units constituting the component (A1). It is preferable, and it is more preferable that it is 3-70 mol%, It is still more preferable that it is 5-60 mol%, It is still more preferable that it is 10-50 mol%.

When the ratio of the structural unit (a2) is equal to or greater than the lower limit of the preferred range, the effect of containing the constituent unit (a2) is sufficiently obtained. can be grasped, and various lithographic properties and pattern shapes are improved.

··Constituting unit (a3)

(A1) component, in addition to the structural unit (a10), the structural unit (a4) and the structural unit (a1), if necessary, may further have a structural unit (a3) containing a polar group-containing aliphatic hydrocarbon group ( However, the thing corresponding to any of the structural unit (a0), structural unit (a1), and structural unit (a2) mentioned above is excluded).

(A1) When component has a structural unit (a3), the hydrophilicity of (A) component becomes high, and it contributes to the improvement of resolution.

Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of the hydrogen atoms of the alkyl group are substituted with fluorine atoms, and a hydroxyl group is particularly preferable.

Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a cyclic aliphatic hydrocarbon group (cyclic group). The cyclic group may be a monocyclic group or a polycyclic group, and may be appropriately selected from among many proposed resins for resist compositions for ArF excimer lasers, for example. The cyclic group is preferably a polycyclic group, more preferably 7 to 30 carbon atoms.

Among them, a structural unit derived from an acrylic acid ester containing an aliphatic polycyclic group containing a hydroxyl group, a cyano group, a carboxy group, or a hydroxyalkyl group in which a part of the hydrogen atoms of the alkyl group is substituted with a fluorine atom is more preferable. Examples of the polycyclic group include a group obtained by removing two or more hydrogen atoms from a bicycloalkane, tricycloalkane, tetracycloalkane, or the like. Specific examples thereof include groups in which two or more hydrogen atoms have been removed from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane and tetracyclododecane. Among these polycyclic groups, a group obtained by removing two or more hydrogen atoms from adamantane, a group obtained by removing two or more hydrogen atoms from norbornane, and a group obtained by removing two or more hydrogen atoms from tetracyclododecane are industrially preferable.

As a structural unit (a3), if it contains a polar group containing aliphatic hydrocarbon group, it will not specifically limit, Any arbitrary thing can be used.

The structural unit (a3) 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 a structural unit containing a polar group-containing aliphatic hydrocarbon group is preferable.

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 examples include a structural unit represented by the following formula (a3-1), a structural unit represented by the formula (a3-2), and a structural unit represented by the formula (a3-3).

[Formula 34]

[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), it is preferable that it is 1 or 2, and, as for j, it is more preferable that it is 1. When j is 2, it is preferable that the hydroxyl group is couple|bonded with the 3-position and 5-position of an adamantyl group. When j is 1, it is preferable that the hydroxyl group is couple|bonded with the 3-position of an adamantyl group.

It is preferable that j is 1, and it is especially preferable that the hydroxyl group is couple|bonded at the 3-position of an adamantyl group.

In formula (a3-2), it is preferable that k is 1. It is preferable that the cyano group is couple|bonded with the 5-position or 6-position of a norbornyl group.

In formula (a3-3), it is preferable that t' is 1. l is preferably 1. s is preferably 1. As for these, it is preferable that the 2-norbornyl group or 3-norbornyl group couple|bonded with the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5 or 6 position of the norbornyl group.

(A1) The number of structural units (a3) which a component has may be 1 type, or 2 or more types may be sufficient as it.

When the component (A1) has a structural unit (a3), the proportion of the structural unit (a3) is 1 to 50 mol% with respect to the total (100 mol%) of all structural units constituting the component (A1). It is preferable that it is 3-40 mol%, It is more preferable that it is 5-30 mol%, It is still more preferable, 10-30 mol% is especially preferable.

When the ratio of the structural unit (a3) is equal to or more than a preferable lower limit, resolution becomes higher in resist pattern formation. On the other hand, by setting it as below a preferable upper limit, it becomes easy to balance with another structural unit.

-Structural unit derived from styrene or its derivative (structural unit (st))

"Styrene" is a concept including those in which the hydrogen atom at the α-position of styrene and styrene is substituted with a substituent such as an alkyl group or a halogenated alkyl group. Examples of the alkyl group as the substituent here include an alkyl group having 1 to 5 carbon atoms, and the halogenated alkyl group as the substituent includes a halogenated alkyl group having 1 to 5 carbon atoms.

Examples of the "styrene derivative" include those in which a substituent is bonded to a benzene ring of styrene in which the hydrogen atom at the α-position may be substituted with a substituent.

In addition, the α-position (a carbon atom at the α-position) refers to a carbon atom to which the benzene ring is bonded, unless otherwise specified.

"Structural unit derived from styrene" and "structural unit derived from a styrene derivative" mean a structural unit constituted by cleavage of an ethylenic double bond of styrene or a styrene derivative.

(A1) The number of structural units (st) which a component has may be 1 type, or 2 or more types may be sufficient as it.

When the component (A1) has a structural unit (st), the proportion of the structural unit (st) is 1 to 30 mol% with respect to the total (100 mol%) of all structural units constituting the component (A1). It is preferable, and it is more preferable that it is 3-20 mol%.

In the resist composition of the present embodiment, the resin component as the component (A1) has a structural unit (a10), a structural unit (a4), and a structural unit (a1), and one type of polymer may be used alone, You may use 2 or more types together.

As a preferable component (A1), the copolymer which has a structural unit (a10), a structural unit (a4), and a structural unit (a1) is mentioned, Among these, a structural unit (a10), a structural unit (a4), and a structural unit A copolymer consisting of (a1) is particularly preferred.

(A1) 5000-30000 are preferable, as for the weight average molecular weight (Mw) (based on polystyrene conversion by gel permeation chromatography (GPC)) of component, 6000-25000 are more preferable, 10000-20000 are still more preferable .

When the Mw of the component (A1) is equal to or less than the upper limit of the above preferred range, it is easy to suppress excessively high viscosity of the resist composition. In addition, if there is sufficient solubility in a resist solvent for use as a resist, and it is more than the lower limit of the said preferable range, a high-thickness resist film is easily formed. Moreover, dry etching resistance and resist pattern cross-sectional shape become more favorable.

(A1) The dispersion degree (Mw/Mn) of a component is not specifically limited, 1.0-4.0 are preferable, 1.0-3.0 are more preferable, 1.5-2.5 are especially preferable. In addition, Mn represents a number average molecular weight.

The component (A1) is, for example, a monomer that induces the structural unit (a10) (a monomer in which at least a part of the hydrogen atoms in the hydroxyl group bonded to the benzene ring is protected), and a monomer that induces the structural unit (a4); , A monomer for deriving the structural unit (a1) and, if necessary, a monomer for deriving other structural units are dissolved in a polymerization solvent, and thereto, for example, azobisisobutyronitrile (AIBN), dimethyl azobisisobutyrate It can manufacture by adding radical polymerization initiators, such as (For example, V-601 etc.), superposing|polymerizing, and performing a deprotection reaction after that.

Further, at the time of polymerization, for example, by using in combination with a chain transfer agent such as HS-CH ₂ -CH ₂ -CH ₂ -C(CF ₃ ) ₂ -OH, -C(CF ₃ ) ₂ -OH at the terminal may be introduced. As described above, the copolymer introduced with a hydroxyalkyl group in which a part of the hydrogen atoms of the alkyl group are substituted with fluorine atoms is effective in reducing development defects and LER (line edge roughness: unevenness of line sidewalls).

The component (A1) contained in the resist composition may be used individually by 1 type, and may use 2 or more types together.

25 mass % or more is preferable with respect to the total mass of (A) component, as for the ratio of (A1) component in (A) component, 50 mass % or more is more preferable, 75 mass % or more is still more preferable, 100 It may be mass %. When the ratio of the component (A1) is equal to or greater than the lower limit of the preferred range, a resist pattern having a good shape with excellent resolution, resolution, dimensional uniformity (CDU) within the support surface (Shot), and other lithography characteristics is easily formed. .

The component (A) in the resist composition of the present embodiment is a resin component whose solubility in a developer changes due to the action of an acid, and may contain a resin component other than component (A1).

In the resist composition of the present embodiment, the content of component (A) may be appropriately adjusted according to the thickness of the resist film to be formed or the like.

≪Other Ingredients≫

The resist composition of the present embodiment may further contain components other than the component (A) in addition to the component (A) described above. As other components, (B) component, (D) component, (E) component, (F) component, (S) component etc. which are shown below are mentioned, for example.

・About the acid generator component (B)

The resist composition of the present embodiment may contain, in addition to the component (A), an acid generator component (hereinafter referred to as “component (B)”).

The component (B) is not particularly limited, and those previously proposed as acid generators for chemically amplified resists can be used.

As such an acid generator, Onium salt-type acid generators, such as an iodonium salt and a sulfonium salt, an oxime sulfonate-type acid generator; diazomethane-based acid generators such as bisalkyl or bisarylsulfonyldiazomethanes and poly(bissulfonyl)diazomethanes; and various kinds of nitrobenzylsulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators. Especially, it is preferable to use an onium salt type acid generator.

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

[Formula 35]

[Wherein, R ¹⁰¹ , R ¹⁰⁴ to R ¹⁰⁸ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. R ¹⁰⁴ and R ¹⁰⁵ 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 each independently represent 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 each independently represent a single bond, -CO-, or -SO ₂ -. m is an integer greater than or equal to 1, and M' ^m+ is an m-valent onium cation.]

{Anion part}

-(b-1) anion part of component

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

Cyclic group which may have a substituent:

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. An aliphatic hydrocarbon group means a hydrocarbon group which does not have aromaticity. Moreover, saturated or unsaturated may be sufficient as an aliphatic hydrocarbon group, and it is preferable that it is usually saturated.

The aromatic hydrocarbon group for R ¹⁰¹ is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. . However, carbon number in a substituent shall not be included in the carbon number.

Specifically, as the aromatic ring of the aromatic hydrocarbon group for R ¹⁰¹ , benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heterocyclic ring in which a part of carbon atoms constituting these aromatic rings is substituted with a hetero atom. and the like. As a hetero atom in an aromatic heterocyclic ring, an oxygen atom, a sulfur atom, a nitrogen atom, etc. are mentioned.

Specifically, the aromatic hydrocarbon group for R ¹⁰¹ is a group in which one hydrogen atom is removed from the aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), and one hydrogen atom in the aromatic ring is substituted with an alkylene group groups (for example, arylalkyl groups such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, etc.) and the like. It is preferable that carbon number of the said alkylene group (the alkyl chain in an arylalkyl group) is 1-4, C1-C2 is more preferable, C1 is especially preferable.

Examples of the cyclic aliphatic hydrocarbon group for R ¹⁰¹ include an aliphatic hydrocarbon group having a ring in its structure.

Examples of the aliphatic hydrocarbon group containing a ring in this structure include an alicyclic hydrocarbon group (a group in which one hydrogen atom has been removed from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the terminus of a linear or branched aliphatic hydrocarbon group. and a group in which the alicyclic hydrocarbon group is interposed in the middle of the linear or branched aliphatic hydrocarbon group.

It is preferable that carbon number is 3-20, and, as for the said alicyclic hydrocarbon group, it is more preferable that it is 3-12.

The alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane is preferably a monocycloalkane having 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group in which one or more hydrogen atoms have been removed from the polycycloalkane, and the polycycloalkane preferably has 7 to 30 carbon atoms. Among them, examples of the polycycloalkane include polycycloalkanes having a polycyclic skeleton of a bridged ring system such as adamantane, norbornane, isobornane, tricyclodecane and tetracyclododecane; A polycycloalkane having a polycyclic skeleton of a condensed ring system such as a cyclic group having a steroid skeleton is more preferable.

Among them, the cyclic aliphatic hydrocarbon group for R ¹⁰¹ is preferably a group in which one or more hydrogen atoms are removed from monocycloalkane or polycycloalkane, more preferably a group in which one hydrogen atom is removed from polycycloalkane, and adamant A tyl group and a norbornyl group are especially preferable, and an adamantyl group is most preferable.

The linear or branched aliphatic hydrocarbon group which may be bonded to the alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and still more preferably has 1 carbon atom. to 3 are particularly preferred.

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 -], a trimethylene group [-( CH ₂ ) ₃ -], tetramethylene group [-(CH ₂ ) ₄ -], pentamethylene group [-(CH ₂ ) ₅ -], and the like.

The branched chain aliphatic hydrocarbon group is preferably a branched chain alkylene group, specifically, -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, Alkylmethylene groups, such as -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH 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 ) alkylethylene groups such as ₂ -CH ₂ -; Alkyltrimethylene groups, such as -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ -; Alkylalkylene groups, such as alkyltetramethylene groups, such as -CH(CH ₃ )CH ₂ CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ CH ₂ -, etc. are mentioned. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

Moreover, the cyclic hydrocarbon group for R ¹⁰¹ may contain a hetero atom like a heterocyclic ring. Specifically, the lactone-containing cyclic groups represented by the general formulas (a2-r-1) to (a2-r-7), and the general formulas (a5-r-1) to (a5-r-4), respectively -SO ₂ - containing cyclic group shown, and a heterocyclic group respectively represented by the following formulas (r-hr-1) to (r-hr-16) are mentioned.

[Formula 36]

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

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

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

As a halogen atom as a substituent, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.

Examples of the halogenated alkyl group as the substituent include an alkyl group having 1 to 5 carbon atoms, for example, a group in which part or all of hydrogen atoms such as a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are substituted with the above halogen atoms. have.

The carbonyl group as a substituent is a group that substitutes for the methylene group (-CH ₂ -) constituting the cyclic hydrocarbon group.

A chain alkyl group which may have a substituent:

The linear 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, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decanyl group, an undecyl group, a dodecyl group, a tridecyl group, an isotridecyl group , tetradecyl group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, henicosyl group, docosyl group and the like.

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.

A chain alkenyl group which may have a substituent:

The chain alkenyl group for R ¹⁰¹ may be either linear or branched, preferably having 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, still more preferably 2 to 4 carbon atoms. and having 3 carbon atoms is particularly preferable. As a linear alkenyl group, a vinyl group, a propenyl group (allyl group), a butynyl group etc. are mentioned, for example. As a branched alkenyl group, 1-methylvinyl group, 2-methylvinyl group, 1-methylpropenyl group, 2-methylpropenyl group etc. are mentioned, for example.

As the chain alkenyl group, among the above, a linear alkenyl group is preferable, a vinyl group and a propenyl group are more preferable, and a vinyl group is particularly preferable.

Examples of the substituent in the chain alkyl or alkenyl group for R ¹⁰¹ include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and a cyclic group for R ¹⁰¹ . can

Among them, R ¹⁰¹ is preferably a cyclic group which may have a substituent, and more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, for example, a group in which one or more hydrogen atoms have been removed from a phenyl group, a naphthyl group, or a polycycloalkane; lactone-containing cyclic groups each represented by the general formulas (a2-r-1) to (a2-r-7); -SO ₂ - containing cyclic groups each represented by the above 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 atoms other than an oxygen atom. As atoms other than an oxygen atom, a carbon atom, a hydrogen atom, a sulfur atom, a nitrogen atom, etc. are mentioned, for example.

As a divalent linking group containing an oxygen atom, for example, an oxygen atom (ether bond: -O-), ester bond (-C(=O)-O-), oxycarbonyl group (-OC(=O)-) ), amide bond (-C(=O)-NH-), carbonyl group (-C(=O)-), carbonate bond (-OC(=O)-O-), non-hydrocarbon type oxygen atom-containing linking group ; The combination of the non-hydrocarbon type oxygen atom containing coupling group and an alkylene group, etc. are mentioned. A sulfonyl group (-SO ₂ -) may be further linked to this combination. Examples of the divalent linking group containing such an oxygen atom include linking groups represented by the following general formulas (y-al-1) to (y-al-7).

[Formula 37]

[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.]

It is preferable that the divalent saturated hydrocarbon group in ^V'102 is a C1-C30 alkylene group, It is more preferable that it is a C1-C10 alkylene group, It is still more preferable that it is a C1-C5 alkylene group.

The alkylene group for V' ¹⁰¹ and V' ¹⁰² may be a linear alkylene group or a branched alkylene group, and a linear alkylene group is preferable.

Specific examples of the alkylene group for V' ¹⁰¹ and V' ¹⁰² include a methylene group [-CH ₂ -]; -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ an alkylmethylene group such as CH ₂ CH ₃ )-, —C(CH ₂ CH ₃ ) ₂ —; ethylene group [-CH ₂ CH ₂ -] ; Alkylethylene groups such as -CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH ₃ )-, -C(CH ₃ ) ₂ CH ₂ -, -CH(CH ₂ CH ₃ )CH ₂ - ; trimethylene group (n-propylene group) [-CH ₂ CH ₂ CH ₂ -] ; Alkyltrimethylene groups, such as -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ -; tetramethylene group [-CH ₂ CH ₂ CH ₂ CH ₂ -] ; alkyltetramethylene groups, such as -CH(CH ₃ )CH ₂ CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ CH ₂ -; and a pentamethylene group [-CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ -].

Moreover, a part of the methylene group in the said alkylene group in ^V'101 or ^V'102 may be substituted by the C5-C10 divalent aliphatic cyclic group. The aliphatic cyclic group is obtained by removing an additional hydrogen atom from the cyclic aliphatic hydrocarbon group (monocyclic alicyclic hydrocarbon group, polycyclic alicyclic hydrocarbon group) for R ¹⁰¹ in the formula (b-1). A bivalent group is preferable, and a cyclohexylene group, a 1, 5- adamantylene group, or a 2, 6- adamantylene group is more preferable.

Y ¹⁰¹ is preferably a divalent linking group containing an ester bond or a divalent linking group containing an ether bond, more preferably a linking group each represented by the formulas (y-al-1) to (y-al-5) do.

In formula (b-1), V ¹⁰¹ is a single bond, an alkylene group, or a fluorinated alkylene group. The alkylene group and the fluorinated alkylene group for V ¹⁰¹ preferably have 1 to 4 carbon atoms. Examples of the fluorinated alkylene group for V ¹⁰¹ include a group in which a part or all of the hydrogen atoms of the alkylene group for V ¹⁰¹ are substituted with fluorine atoms. Among them, 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. It is preferable that it is a fluorine atom or a C1-C5 perfluoroalkyl group, and, as for R ¹⁰² , it is more preferable that it is a fluorine atom.

Specific examples of the anion moiety of the component (b-1) include, for example, when Y ¹⁰¹ is a single bond, fluorinated alkylsulfo such as trifluoromethanesulfonate anion or perfluorobutanesulfonate anion nate anions; When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, an anion represented by any of the following formulas (an-1) to (an-3) is exemplified.

[Formula 38]

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

The aliphatic cyclic group which may have a substituent for R" ¹⁰¹ , R" ¹⁰² and R" ¹⁰³ is preferably the group exemplified as the cyclic aliphatic hydrocarbon group for R ^101. As the substituent, R ¹⁰¹ The same thing as the substituent which may substitute the cyclic aliphatic hydrocarbon group in this is mentioned.

The aromatic cyclic group which may have a substituent in R" ¹⁰³ is preferably the group exemplified as the aromatic hydrocarbon group in the cyclic hydrocarbon group in R ^101. As the substituent, the substituent in R ¹⁰¹ is The same thing as the substituent which may substitute the aromatic hydrocarbon group is mentioned.

The chain alkyl group which may have a substituent for R" ¹⁰¹ is preferably the group exemplified as the chain alkyl group for R ¹⁰¹ above. The chain alkyl group which may have a substituent for R" ¹⁰³ is preferable. The kenyl group is preferably the group exemplified as the chain alkenyl group for R ¹⁰¹ .

-(b-2) anion part of component

In formula (b-2), R ¹⁰⁴ and R ¹⁰⁵ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent, The same thing as R ¹⁰¹ in Formula (b-1) is mentioned, respectively. 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 which 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 carbon number of the chain alkyl group of R ¹⁰⁴ , R ¹⁰⁵ is preferably smaller within the above carbon number range 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 higher the transparency to high energy light of 200 nm or less or electron beam. desirable.

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 substituted with fluorine atoms. to be.

In formula (b-2), V ¹⁰² and V ¹⁰³ are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and the same as those of V ¹⁰¹ in formula (b-1) can be mentioned.

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

-(b-3) anion part of component

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

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

{Cathion part}

In formulas (b-1), (b-2) and (b-3), m is an integer of 1 or more, M' ^m+ is an m-valent onium cation, preferably a sulfonium cation or an iodonium cation can be heard For example, it is especially preferable that M' ^m+ is an organic cation each represented by the following general formula (ca-1) - (ca-5).

[Formula 39]

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

Examples of the aryl group for R ²⁰¹ to R ²⁰⁷ and R ²¹¹ to R ²¹² include 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.

Examples of the substituent which R ²⁰¹ to R ²⁰⁷ , and R ²¹⁰ to R ²¹² may have include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and a formula (ca-r-1 ) to (ca-r-8).

[Formula 40]

[Wherein, ^R'201 is each independently a hydrogen atom, 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.]

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

When R ²⁰¹ to R ²⁰³ , R ²⁰⁶ to R ²⁰⁷ , R ²¹¹ to R ²¹² are combined with each other to form a ring together with a sulfur atom in the formula, a hetero atom such as a sulfur atom, an oxygen atom, a nitrogen atom, or a carbonyl group; -SO-, -SO ₂ -, -SO ₃ -, -COO-, -CONH-, or -N(R _N )- (R _N is an alkyl group having 1 to 5 carbon atoms.) It bonds through a functional group You can do it. As the ring to be formed, one ring including a sulfur atom in the ring skeleton in the formula is preferably a 3- to 10-membered ring including a sulfur atom, particularly preferably a 5- to 7-membered ring. Specific examples of the ring to be formed include, for example, a thiophene ring, a thiazole ring, a benzothiophene ring, a thianthrene ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring a ring, a thianthrene ring, a phenoxatiin ring, a tetrahydrothiophenium ring, a tetrahydrothiopyranium ring, etc. are mentioned.

R ²⁰⁸ to R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and in the case of an alkyl group, they may combine with each other to form a ring.

R ²¹⁰ is 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 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 which may have a substituent for R ²¹⁰ include -SO ₂ -containing cyclic groups represented by the general formulas (a5-r-1) to (a5-r-4), respectively. The same can be mentioned, Among these, "-SO2 _- containing polycyclic group" is preferable, and the group represented by general formula (a5-r-1) is more preferable.

In the formulas (ca-4) and (ca-5), Y ²⁰¹ each independently represents an arylene group, an alkylene group, or an alkenylene group.

Examples of the arylene group for Y ²⁰¹ include a group in which one hydrogen atom has been removed from the aryl group exemplified as the aromatic hydrocarbon group for R ¹⁰¹ in the above formula (b-1).

Examples of the alkylene group and alkenylene group for Y ²⁰¹ include groups in which one hydrogen atom has been removed from the groups exemplified as the chain alkyl group and chain alkenyl group for R ¹⁰¹ in the above formula (b-1). .

In the formulas (ca-4) and (ca-5), x is 1 or 2.

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

As the divalent linking group for W ²⁰¹ , a divalent hydrocarbon group which may have a substituent is preferable, and the same divalent hydrocarbon group which may have a substituent as for Ya ²¹ in the above-mentioned general formula (a2-1) is exemplified. can The divalent linking group for 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 the arylene group is preferable. As an arylene group, a phenylene group, a naphthylene group, etc. are mentioned, A phenylene group is especially preferable.

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

Specific examples of preferred cations represented by the formula (ca-1) include cations represented by the following formulas (ca-1-1) to (ca-1-129).

[Formula 41]

[Formula 42]

[Formula 43]

[Wherein, 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 44]

[Formula 45]

[Formula 46]

[Formula 47]

[Wherein, R" ²⁰¹ is a hydrogen atom or a substituent, and the substituent is the same as the substituents mentioned above as the substituents R ²⁰¹ to R ²⁰⁷ and R ²¹⁰ to R ²¹² may have.]

[Formula 48]

[Formula 49]

Specific examples of the preferable cation represented by the formula (ca-2) include diphenyliodonium cation, bis(4-tert-butylphenyl)iodonium cation, and the like.

Specific examples of preferred cations represented by the formula (ca-3) include cations represented by the following formulas (ca-3-1) to (ca-3-5).

[Formula 50]

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

[Formula 51]

Moreover, as a cation represented by the said formula (ca-5), the cation respectively represented by the following general formula (ca-5-1) - (ca-5-3) is preferable.

[Formula 52]

Among the above, the cation represented by general formula (ca-1) is preferable, and, as for the cation moiety [(M' ^m+ ) _1/m ], the cation of a monophenyl type is more preferable.

Moreover, as a preferable cation moiety [(M' ^m+ ) _1/m ], the monophenyl type cation represented by the following general formula (ca-1-0) is mentioned.

[Formula 53]

[In the formula, R ^b1 is an aryl group which may have a substituent. R ^b2 and R ^b3 are each independently an aliphatic hydrocarbon group. R ^b2 and R ^b3 may be bonded to each other to form a ring structure. L ^b1 , L ^b2 and L ^b3 are each independently a divalent linking group or a single bond.]

In the formula (ca-1-0), R ^b1 is an aryl group which may have a substituent, and is the same as the aryl group which may have a substituent for R ²⁰¹ to R ²⁰³ . That is, as an aryl group in ^Rb1 , a C6-C20 aryl group is mentioned, A phenyl group and a naphthyl group are preferable. Examples of the substituent R ^b1 may have include an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and the formulas (ca-r-1) to (ca-r-8) and groups each represented.

In the formula (ca-1-0), R ^b2 and R ^b3 are each independently an aliphatic hydrocarbon group. The aliphatic hydrocarbon group for R ^b2 and R ^b3 may be linear or cyclic, and examples of the aliphatic hydrocarbon group include a chain or cyclic alkyl group and alkenyl group.

The chain or cyclic alkyl group here preferably has 1 to 30 carbon atoms.

As an alkenyl group here, a C2-C10 thing is preferable.

R ^b2 and R ^b3 may be bonded to each other to form a ring structure. When combining with each other to form a ring together with the sulfur atom in the formula, hetero atoms such as sulfur atom, oxygen atom, nitrogen atom, or carbonyl group, -SO-, -SO ₂ -, -SO ₃ -, -COO-, - You may couple|bond through functional groups, such as CONH- or -N(R _N )- (where R _N is a C1-C5 alkyl group.). As the ring to be formed, one ring including a sulfur atom in the ring skeleton in the formula is preferably a 3- to 10-membered ring including a sulfur atom, particularly preferably a 5- to 7-membered ring. Specific examples of the ring to be formed include, for example, a thiophene ring, a thiazole ring, a benzothiophene ring, a thianthrene ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring a ring, a thianthrene ring, a phenoxatiin ring, a tetrahydrothiophenium ring, a tetrahydrothiopyranium ring, etc. are mentioned.

In the formula (ca-1-0), L ^b1 , L ^b2 and L ^b3 each independently represent a divalent linking group or a single bond.

The divalent linking group for L ^b1 , L ^b2 and L ^b3 is each independently -C(=O)-, -C(=O)-O-, -OC(=O)-, an arylene group; and an alkylene group or an alkenylene group.

Examples of the arylene group for L ^b1 , L ^b2 , and L ^b3 include groups in which one hydrogen atom has been removed from the aryl group exemplified as the aromatic hydrocarbon group for R ¹⁰¹ in the above formula (b-1). That is, groups in which two hydrogen atoms have been removed from an aromatic ring (benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heterocyclic ring in which some of the carbon atoms constituting these aromatic rings are substituted with hetero atoms) are mentioned. can

The alkylene group or alkenylene group in L ^b1 , L ^b2 and L ^b3 is a hydrogen atom from the groups exemplified as the chain alkyl group and chain alkenyl group for R ¹⁰¹ in the above formula (b-1). The group from which one additionally was removed is mentioned. That is, a group in which one hydrogen atom is further removed from a linear alkyl group having 1 to 20 carbon atoms and a group in which an additional hydrogen atom is removed from a branched alkyl group having 3 to 20 carbon atoms are mentioned.

L ^b1 is preferably a single bond from the viewpoint of higher acid generation efficiency by exposure.

(B) As a cation moiety of component, More preferably, the cation represented by the following general formula (ca-1-01) or the cation represented by general formula (ca-1-02) is mentioned. Especially preferably, it is a cation represented by general formula (ca-1-01).

[Formula 54]

[Wherein, R ^b11 and R ^b12 are each independently an aryl group which may have a substituent. L ^b11 is -C(=O)- or -C(=O)-O-. R ^b121 and R ^b122 are each independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. nb1 is an integer of 1-3. nb2 is an integer of 1 to 3.]

In the above formula, R ^b11 and R ^b12 are each the same as R ^b1 in the above formula (ca-1-0). Especially, Preferably, it is an unsubstituted aryl group. A phenyl group and a naphthyl group are mentioned as a preferable aryl group.

R ^b121 and R ^b122 are each a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom, a methyl group or an ethyl group, and more preferably a hydrogen atom.

nb1 is an integer of 1-3, Preferably it is 1 or 2, More preferably, it is 2.

nb2 is an integer of 1-3, Preferably it is 1 or 2, More preferably, it is 1.

The cation represented by the general formula (ca-1-01) is preferably a cation represented by the above formulas (ca-1-104) to (ca-1-129), and among these, the cations represented by the general formula (ca-1) -104) and a cation represented by the general formula (ca-1-105) (R" ²⁰¹ is a hydrogen atom) are more preferable.

As the cation represented by the general formula (ca-1-02), a cation represented by the general formula (ca-1-102) and a cation represented by the general formula (ca-1-103) are preferable.

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

As component (B) in this embodiment, the compound represented by the following general formula (b-1-0) is especially preferable.

[Formula 55]

[wherein, R ¹⁰¹ , Y ¹⁰¹ , V ¹⁰¹ and R ¹⁰² are the same as R ¹⁰¹ , Y ¹⁰¹ , V ¹⁰¹ and R ¹⁰² in the formula (b-1), respectively. R ^b11 and nb1 are the same as R ^b11 and nb1 in the above formula (ca-1-01), respectively.]

When the resist composition contains the component (B), the content of the component (B) is preferably from 0.5 to 7 parts by mass, more preferably from 1 to 4 parts by mass, and from 1 to 3 parts by mass relative to 100 parts by mass of the component (A). Addition is more preferable.

(B) By making content of a component into the said range, pattern formation is fully performed. Moreover, when each component of a resist composition is melt|dissolved in the organic solvent, since it is easy to obtain a uniform solution and the storage stability as a resist composition becomes favorable, it is preferable. Moreover, by making content of (B) component more than the lower limit of the said preferable range, the light transmittance of a resist film tends to become high, and high sensitivity is easy to be achieved.

・About the acid diffusion control agent component (D)

In the resist composition of the present embodiment, in addition to component (A), or in addition to component (A) and component (B), an acid diffusion control agent component (hereinafter referred to as “component (D)”) is added. may contain. Component (D) acts as an agent (acid diffusion controlling agent) that traps acids generated by exposure in the resist composition.

The component (D) may be a photodegradable base (D1) (hereinafter referred to as “component (D1)”) which decomposes upon exposure and loses acid diffusion controllability (hereinafter referred to as “component (D1)”.) Organic compound (D2) (hereinafter referred to as "component (D2)") may be sufficient.

・・(D1) About component

By setting it as the resist composition containing component (D1), when forming a resist pattern, the contrast of the exposed part and unexposed part of a resist film can be improved.

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

Since components (d1-1) to (d1-3) are decomposed in the exposed part of the resist film and lose the acid diffusion controllability (basic property), they do not act as a target, but act as a target in the unexposed part. .

[Formula 56]

[Wherein, 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, the fluorine atom shall not be couple|bonded with the carbon atom adjacent to the S atom in ^Rd2 in Formula (d1-2). Yd ¹ is a single bond or a divalent linking group. m is an integer greater than or equal to 1, and M ^m+ is each independently an organic cation having a valence of m.]

{(d1-1) component}

···Anion section

In the 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, respectively, in the formula (b-1) The same thing as R101 in R ^<101 > is mentioned.

Among these, as Rd ¹ , an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkyl group which may have a substituent is preferable. Examples of the substituent which these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, and a lactone-containing cyclic group each represented by the general formulas (a2-r-1) to (a2-r-7). , an ether bond, an ester bond, or a combination thereof. When an ether bond or an ester bond is included as a substituent, an alkylene group may be interposed, and as a substituent in this case, the linking group each represented by said formula (y-al-1) - (y-al-5) is preferable. do.

As said 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 a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane and tetracyclododecane.

The chain alkyl group preferably has 1 to 10 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, etc. A linear alkyl group of ; 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methyl group Branched alkyl groups, such as a pentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group, are mentioned.

When the chain alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the fluorinated alkyl group preferably has 1 to 11 carbon atoms, more preferably 1 to 8 carbon atoms, and still more preferably 1 to 4 carbon atoms. . The fluorinated alkyl group may contain atoms other than a fluorine atom. As atoms other than a fluorine atom, an oxygen atom, a sulfur atom, a nitrogen atom, etc. are mentioned, for example.

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 of the hydrogen atoms constituting the linear alkyl group are substituted with fluorine atoms. (a linear perfluoroalkyl group) is particularly preferable.

Preferred specific examples of the anion moiety of the component (d1-1) are shown below.

[Formula 57]

... cation part

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

As an organic cation of M ^m+ , the same thing as the cation respectively represented by the said general formula (ca-1) - (ca-5) is mentioned preferably, The cation represented by the said general formula (ca-1) is More preferably, the cations respectively represented by the formulas (ca-1-1) to (ca-1-129) are still more preferable.

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

{(d1-2) component}

···Anion section

In the 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, wherein the formula (b-1) The same thing as R101 in R ^<101 > is mentioned.

However, in Rd ² , a fluorine atom is not bonded to a carbon atom adjacent to the S atom (not substituted with fluorine). Thereby, the anion of (d1-2) component becomes a suitable weak acid anion, and the quenching ability as (D)component improves.

Rd ² is preferably a chain alkyl group which may have a substituent or an aliphatic cyclic group which may have a substituent. As a chain|strand-type alkyl group, it is preferable that it is C1-C10, and it is more preferable that it is 3-10. Examples of the aliphatic cyclic group include a group (which may have a substituent) in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like; It is more preferable that it is a group obtained by removing one or more hydrogen atoms from camphor or the like.

The hydrocarbon group of Rd ² may have a substituent, and as the substituent, the substituent which the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain alkyl group) in Rd ¹ of the above formula (d1-1) may have. can be the same as

Preferred specific examples of the anion moiety of the component (d1-2) are shown below.

[Formula 58]

... cation part

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

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

{(d1-3) component}

···Anion section

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 in the formula (b-1) The same thing as R ¹⁰¹ is mentioned, It is preferable that it is a cyclic group containing a fluorine atom, a chain|strand-type alkyl group, or a chain|strand-type alkenyl group. Among these, a fluorinated alkyl group is preferable, and the same group as the fluorinated alkyl group for Rd ¹ is more preferable.

In the 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, wherein the formula (b-1) The same thing as R ¹⁰¹ in R<101> is mentioned.

Especially, it is preferable that they are an alkyl group which may have a substituent, an alkoxy group, an alkenyl group, and a cyclic group.

The alkyl group for Rd ⁴ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, etc. are mentioned. A part of the hydrogen atoms 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, and specifically as an alkoxy group having 1 to 5 carbon atoms, a methoxy group, an ethoxy group, n-propoxy group, iso-propoxy group, n- butoxy group and tert-butoxy group. Especially, a methoxy group and an ethoxy group are preferable.

Examples of the alkenyl group for Rd ⁴ include the same ones as those for R ¹⁰¹ in the formula (b-1), and a vinyl group, a propenyl group (allyl group), a 1-methylpropenyl group, and a 2-methylpropenyl group are preferable. . These groups may further have a C1-C5 alkyl group or a C1-C5 halogenated alkyl group as a substituent.

Examples of the cyclic group for Rd ⁴ include the same groups as those for R ¹⁰¹ in the formula (b-1), cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, and tetracyclo. An alicyclic group obtained by removing one or more hydrogen atoms from a cycloalkane such as dodecane, or an aromatic group such as a phenyl group or a naphthyl group is preferable. When Rd ⁴ is an alicyclic group, when the resist composition dissolves favorably in the organic solvent, the lithographic properties are improved. Moreover, when ^Rd4 is an aromatic group, the resist composition is excellent in light absorption efficiency, and a sensitivity and a lithographic characteristic become favorable.

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

Although it does not specifically limit as a divalent linking group in Yd ¹ , A divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent, a divalent linking group containing a hetero atom, etc. are mentioned. Examples of these are the same as the divalent hydrocarbon group which may have a substituent and the divalent linking group containing a hetero atom, which are mentioned in the description of the divalent linking group for Ya ²¹ in the formula (a2-1), respectively.

Yd ¹ is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group, or a combination thereof. As an alkylene group, it is more preferable that it is a linear or branched alkylene group, and it is still more preferable that it is a methylene group or an ethylene group.

Preferred specific examples of the anion moiety of the component (d1-3) are shown below.

[Formula 59]

[Formula 60]

... cation part

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

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

(D1) component may use only 1 type in any one of said (d1-1)-(d1-3) component, and may use it in combination of 2 or more type.

When the resist composition contains component (D1), the content of component (D1) is preferably 0.5 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, with respect to 100 parts by mass of component (A), 1 It is more preferable that it is -8 mass parts.

When the content of the component (D1) is equal to or more than the preferred lower limit, particularly favorable lithography characteristics and resist pattern shape can be easily obtained. On the other hand, if it is below an upper limit, a sensitivity can be maintained favorably and it is excellent also in throughput.

(D1) Method of Preparation of Component:

The manufacturing method of the said (d1-1) component and (d1-2) component is not specifically limited, It can manufacture by a well-known method.

Moreover, the manufacturing method of (d1-3) component is not specifically limited, For example, it carries out similarly to the method of US2012-0149916, and manufactures.

・(D2) About component

As an acid diffusion controlling agent component, you may contain the nitrogen-containing organic compound component (henceforth "(D2) component") which does not correspond to the said (D1) component.

The component (D2) is not particularly limited as long as it acts as an acid diffusion controlling agent and does not correspond to the component (D1), and any known component may be used arbitrarily. Especially, an aliphatic amine is preferable, and especially a secondary aliphatic amine and a tertiary aliphatic amine are more preferable among these.

The aliphatic amine is an amine having at least one aliphatic group, and the aliphatic group preferably has 1 to 12 carbon atoms.

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

Specific examples of the alkylamine and the alkyl alcoholamine include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; Trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri trialkylamines such as -n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkyl alcoholamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine and tri-n-octanolamine. Among these, a C5-C10 trialkylamine is more preferable, and tri-n-pentylamine or tri-n-octylamine is especially preferable.

As a cyclic amine, the heterocyclic compound which contains a nitrogen atom as a hetero atom is mentioned, for example. The heterocyclic compound may be a monocyclic compound (aliphatic monocyclic amine) or a polycyclic compound (aliphatic polycyclic amine).

Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.

The aliphatic polycyclic amine preferably has 6 to 10 carbon atoms, and specifically, 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo[2.2.2]octane, etc. are mentioned.

Examples of other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl} amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine; tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, triethanolamine triacetate, etc. are mentioned, Triethanolamine triacetate is preferable.

Moreover, you may use an aromatic amine as (D2) component.

Examples of the aromatic amine include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine, and the like. can be heard

(D2) A component may be used independently and may be used in combination of 2 or more type.

When the resist composition contains the component (D2), the component (D2) is usually used in an amount of 0.01 to 5 parts by mass based on 100 parts by mass of the component (A). By setting it as the said range, a resist pattern shape, delayed-standing time-lapse|temporal stability, etc. improve.

With respect to at least one compound (E) selected from the group consisting of organic carboxylic acids and phosphorus oxo acids and derivatives thereof

In the resist composition of the present embodiment, for the purpose of preventing sensitivity deterioration, improving resist pattern shape, stability with delayed standing, and the like, as optional components, the group consisting of organic carboxylic acids, phosphorus oxo acids and derivatives thereof. At least one compound (E) selected from (hereinafter referred to as "component (E)") can be contained.

As organic carboxylic acid, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid, etc. are preferable, for example.

Phosphoric acid, phosphonic acid, phosphinic acid etc. are mentioned as an oxo acid of phosphorus, Among these, phosphonic acid is especially preferable.

Examples of the derivative of phosphorus oxo acid include esters in which a hydrogen atom of the oxo acid is substituted with a hydrocarbon group. Examples of the hydrocarbon group include an alkyl group having 1 to 5 carbon atoms, an aryl group having 6 to 15 carbon atoms, and the like. can be heard

Phosphoric acid esters, such as phosphoric acid di-n-butyl ester and phosphoric acid diphenyl ester, etc. are mentioned as a derivative of phosphoric acid.

Examples of the derivative of phosphonic acid include phosphonic acid esters such as dimethyl phosphonic acid, phosphonic acid-di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.

As a derivative of a phosphinic acid, a phosphinic acid ester, phenylphosphinic acid, etc. are mentioned.

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

When the resist composition contains the component (E), the component (E) is usually used in an amount of 0.01 to 5 parts by mass relative to 100 parts by mass of the component (A).

・About the fluorine additive component (F)

The resist composition of the present embodiment may contain a fluorine additive component (hereinafter referred to as "component (F)") in order to impart water repellency to the resist film.

(F) As a component, Unexamined-Japanese-Patent No. 2010-002870, Unexamined-Japanese-Patent No. 2010-032994, Unexamined-Japanese-Patent No. 2010-277043, Unexamined-Japanese-Patent No. 2011-13569, Unexamined-Japanese-Patent No. The fluorinated polymer compound described in Publication No. 2011-128226 can be used.

(F) The polymer which has a structural unit (f1) represented by a following formula (f1-1) more specifically as a component is mentioned. Examples of the polymer include a polymer (homopolymer) comprising only the structural unit (f1) represented by the following formula (f1-1); A copolymer of the structural unit (a1) containing an acid-decomposable group whose polarity increases by the action of an acid, and the structural unit (f1); A copolymer of the structural unit (f1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1) is preferable. Here, as preferable examples of the structural unit (a1) copolymerized with the structural unit (f1), for example, a structural unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate, 1-methyl-1 - A structural unit derived from adamantyl (meth)acrylate is mentioned.

[Formula 61]

[Wherein, R is the same as above, Rf ¹⁰² and Rf ¹⁰³ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, and Rf ¹⁰² and Rf ¹⁰³ are the same It may or may not be different. nf ¹ is an integer of 1 to 5, and Rf ¹⁰¹ is an organic group containing a fluorine atom.]

In the formula (f1-1), R bonded to the carbon atom at the α-position is the same as described above. As R, a hydrogen atom or a methyl group is preferable.

In the formula (f1-1), examples of the halogen atom for Rf ¹⁰² and Rf ¹⁰³ include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, 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 groups as the alkyl group 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 a group in which part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are substituted with halogen atoms.

A fluorine atom, a chlorine atom, a bromine atom, an iodine atom etc. are mentioned as this halogen atom, A fluorine atom is especially preferable. Especially, as Rf ¹⁰² and Rf ¹⁰³ , a hydrogen atom, a fluorine atom, or a C1-C5 alkyl group is preferable, 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 1-5, the integer of 1-3 is preferable, and it is more preferable that it is 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 any of linear, branched or cyclic, preferably having 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, more preferably 1 to 10 carbon atoms. Especially preferred.

Moreover, as for the hydrocarbon group containing a fluorine atom, it is preferable that 25% or more of the hydrogen atoms in the said hydrocarbon group are fluorinated, it is more preferable that 50% or more is fluorinated, that 60% or more is fluorinated, It is especially preferable at the point which the hydrophobicity of the resist film at the time of immersion exposure becomes high.

Especially, as Rf ¹⁰¹ , a C1-C6 fluorohydrocarbon group is more preferable, and a trifluoromethyl 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 particularly preferred.

(F) 1000-50000 are preferable, as for the weight average molecular weight (Mw) (based on polystyrene conversion by gel permeation chromatography) of component, 5000-40000 are more preferable, and 10000-30000 are the most preferable. If it is below the upper limit of this range, there exists sufficient solubility to the solvent for resists for using as a resist, and if it is more than the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are favorable.

(F) 1.0-5.0 are preferable, as for the dispersion degree (Mw/Mn) of component, 1.0-3.0 are more preferable, 1.2-2.5 are the most preferable.

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

When the resist composition contains the component (F), the component (F) is usually used in an amount of 0.5 to 10 parts by mass with respect to 100 parts by mass of the component (A).

・About the organic solvent component (S)

The resist composition of the present embodiment can be produced by dissolving a resist material in an organic solvent component (hereinafter sometimes referred to as "(S) component").

As the component (S), each component to be used can be dissolved to form a uniform solution, and any solvent can be appropriately selected and used from conventionally known solvents for chemically amplified resist compositions.

For example, as (S) component, Lactones, such as (gamma)-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; A compound having an ester bond, such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate, monomethyl ether, monoethyl ether of the polyhydric alcohol or compound having an ester bond, Derivatives of polyhydric alcohols such as monoalkyl ethers such as monopropyl ether and monobutyl ether, or compounds having ether bonds such as monophenyl ether [among these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME) is preferable]; cyclic ethers such as dioxane, esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; Anisole, ethylbenzyl ether, cresylmethyl ether, diphenyl ether, dibenzyl ether, phenetol, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene, etc. of aromatic organic solvents, dimethyl sulfoxide (DMSO), and the like.

(S) A component may be used independently and may be used as 2 or more types of mixed solvent.

Especially, PGMEA, PGME, (gamma)-butyrolactone, EL, and cyclohexanone are preferable.

Moreover, the mixed solvent which mixed PGMEA and the polar solvent is also preferable. The compounding ratio (mass ratio) may be appropriately determined in consideration of the compatibility of PGMEA and the polar solvent, etc., but preferably within the range of 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. desirable.

More specifically, when EL or cyclohexanone is blended 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. : is 2. Moreover, when mix|blending PGME as a polar solvent, the mass ratio of PGMEA:PGME becomes like this. Preferably it is 1:9-9:1, More preferably, it is 2:8-8:2, More preferably, it is 3:7- It is 7:3. A mixed solvent of PGMEA, PGME, and cyclohexanone is also preferable.

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

(S) The usage-amount of component is not specifically limited, It is a density|concentration which can be apply|coated to a board|substrate etc., and it sets suitably according to the coating film thickness. Generally, component (S) is used so that the solid content concentration of the resist composition is in the range of 20 to 55 mass%, preferably 30 to 45 mass%.

The resist composition of the present embodiment may further contain miscible additives as desired, for example, additional resins for improving the performance of the resist film, surfactants (eg, fluorine-based surfactants, etc.), dissolution inhibitors, A plasticizer, a stabilizer, a coloring agent, an antihalation agent, dye, etc. can be added and contained suitably.

The resist pattern forming method according to this aspect described above is a method useful for forming a high-thickness resist film having a film thickness of 7 µm or more, and is carried out using a specific resist composition.

By using a specific resist composition, that is, a resist composition containing a structural unit (a10) and a resin component (A1) having a structural unit (a4) and a structural unit (a1), the light transmittance of the high-thickness resist film is increased. Thereby, even when forming a high-thickness resist film having a film thickness of 7 mu m or more, high sensitivity is achieved, resolution is improved, and a resist pattern having a good shape can be formed.

Moreover, according to such a resist pattern formation method, the solubility with respect to a developing solution improves by using the said specific resist composition. Thereby, generation|occurrence|production of a defect can be suppressed and stability of a pattern dimension can be improved. Moreover, according to such a resist pattern formation method, sufficient etching resistance is maintained.

Such a resist pattern formation method is useful for the manufacture of a three-dimensional structure device, and is a preferable method for the use (superposition etc.) of processing a multi-stage step structure. By applying the resist pattern forming method of the present embodiment, it is possible to achieve stacking of memory films (three-dimensionalization, manufacture of large-capacity memory) with high precision.

Example

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

<Preparation of resist composition>

Each component shown in Table 1 was mixed and dissolved to prepare resist compositions (1) to (6) (all of which had a solid content concentration of 40% by mass).

In Table 1, each symbol has the following meaning, respectively. Numerical values in [] are compounding amounts (parts by mass).

(A)-1: A high molecular compound represented by the following formula (A1)-1. The weight average molecular weight (Mw) in terms of standard polystyrene calculated|required by GPC measurement is 10000, and molecular weight dispersion degree (Mw/Mn) is 2.5. The copolymer composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by ¹³ C-NMR is structural unit (a101)/structural unit (a41)/structural unit (a11) = 50/35/15.

(A)-2: A high molecular compound represented by the following formula (A1)-1. The weight average molecular weight (Mw) in terms of standard polystyrene calculated|required by GPC measurement is 10000, and molecular weight dispersion degree (Mw/Mn) is 2.5. The copolymer composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by ¹³ C-NMR is: structural unit (a101)/structural unit (a41)/structural unit (a11)=65/20/15.

(A)-3: A high molecular compound represented by the following formula (A1)-1. The weight average molecular weight (Mw) in terms of standard polystyrene calculated|required by GPC measurement is 10000, and molecular weight dispersion degree (Mw/Mn) is 2.5. The copolymer composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by ¹³ C-NMR is: structural unit (a101)/structural unit (a41)/structural unit (a11)=70/15/15.

(A)-4: A high molecular compound represented by the following formula (A1)-1. The weight average molecular weight (Mw) in terms of standard polystyrene calculated|required by GPC measurement is 10000, and molecular weight dispersion degree (Mw/Mn) is 2.5. The copolymer composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by ¹³ C-NMR is: structural unit (a101)/structural unit (a41)/structural unit (a11) = 40/45/15.

(A)-5: A high molecular compound represented by the following formula (A1)-1. The weight average molecular weight (Mw) in terms of standard polystyrene calculated|required by GPC measurement is 10000, and molecular weight dispersion degree (Mw/Mn) is 2.5. The copolymer composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by ¹³ C-NMR is: structural unit (a101)/structural unit (a41)/structural unit (a11) = 80/5/15.

(A)-6: A high molecular compound represented by the following formula (A2)-1. The weight average molecular weight (Mw) in terms of standard polystyrene calculated|required by GPC measurement is 10000, and molecular weight dispersion degree (Mw/Mn) is 2.5. The copolymer composition ratio (ratio (molar ratio) of each structural unit in the structural formula) determined by ¹³ C-NMR is: structural unit (a101)/structural unit (st1)/structural unit (a12)=65/20/15.

[Formula 62]

(B)-1: An acid generator comprising a compound represented by the following formula (B)-1.

[Formula 63]

(D)-1: tri-n-pentylamine.

(E)-1: Phenylphosphonic acid.

(Add)-1: Fluorine-based surfactant, DIC Co., Ltd. brand name "R-40".

(S)-1: propylene glycol monomethyl ether acetate/propylene glycol monomethyl ether = 5/5 (mass ratio).

<Formation of resist pattern (I)>

(Examples 1 to 3)

Process (i):

On an 8-inch silicon wafer, each of the resist compositions (1) to (3) is applied using a coater, and a prebaking (PAB) treatment is performed at 130° C. for 90 seconds on a hot plate, followed by drying. A resist film having a thickness of 15 µm was formed.

Process (ii):

Next, a KrF excimer laser (248 nm) was applied to the resist film with a KrF exposure apparatus NSR-S203B (manufactured by Nikon Corporation; NA (numerical aperture) = 0.68, σ = 0.40) with a mask pattern (6% halftone). ) was selectively investigated.

Subsequently, post-exposure heating (PEB) treatment was performed at 110°C for 90 seconds.

Process (iii):

Next, alkali development was performed under the conditions for 60 second at 23 degreeC using 2.38 mass % tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (trade name, Tokyo Oka Kogyo Co., Ltd. make) as a developing solution.

Then, using pure water, the water was rinsed for 30 seconds, and it was shaken off and dried.

(Comparative Example 1)

Except having used the resist composition (6), it carried out similarly to Examples 1-3, and formed the resist pattern.

As a result of the formation (I) of the resist pattern described above, in any of the examples, a pattern of isolated lines having a space width of 5 µm (hereinafter referred to as an "IS pattern") was formed in the resist film.

[Sensitivity]

The optimal exposure dose Eop (mJ/cm<2>) when the IS pattern of the target size was formed by formation (I) of the resist pattern mentioned above was calculated|required, and it was set as the sensitivity. This was shown in Table 2 as "Eop (mJ/cm<2>).

[Shape of resist pattern]

The shape of the IS pattern formed by the formation (I) of the resist pattern described above was observed with a length-length SEM (scanning electron microscope, accelerating voltage 800 V, trade name: SU-8000, manufactured by Hitachi High-Technologies Corporation), and the following According to the evaluation criteria, the evaluation result was shown in Table 2 as "shape".

Evaluation criteria A: Tapered shape B: Top-round top

From the results shown in Table 2, according to the resist pattern forming methods of Examples 1 to 3, even when a resist film having a thickness of 15 µm is formed into a film, it is possible to show high sensitivity and form a pattern of a good shape. It is acknowledged.

On the other hand, in the resist pattern formation method of Comparative Example 1, the sensitivity was low and the shape was also poor.

<Formation of resist pattern (II)>

(Examples 4 to 8)

Process (i):

On an 8-inch silicon wafer, each of the resist compositions (1) to (5) is applied using a coater, and a prebaking (PAB) treatment is performed at 130° C. for 90 seconds on a hot plate, followed by drying. A resist film having a thickness of 15 µm was formed.

Process (ii):

Next, a KrF excimer laser (248 nm) was applied to the resist film with a KrF exposure apparatus NSR-S203B (manufactured by Nikon Corporation; NA (numerical aperture) = 0.68, σ = 0.40) with a mask pattern (6% halftone). ) was selectively investigated.

Subsequently, post-exposure heating (PEB) treatment was performed at 110°C for 90 seconds.

process (iii):

Then, alkali development was performed at 23 degreeC for 60 second conditions using 2.38 mass % tetramethylammonium hydroxide (TMAH) aqueous solution "NMD-3" (trade name, Tokyo Oka Kogyo Co., Ltd. make) as a developing solution.

Then, using pure water, the water was rinsed for 30 seconds, and it was shaken off and dried.

As a result of formation (II) of the resist pattern described above, in any of the examples, a pattern of isolated lines having a space width of 3 µm (hereinafter referred to as an "IS pattern") was formed in the resist film.

[defect (defective function)]

For the IS pattern formed by the formation (II) of the resist pattern described above, the total number of defects in the wafer (the total number of defects) was measured using a surface defect observation apparatus (manufactured by KLA Tencor, product name: KLA2371). .

Two wafers were used for these measurements, respectively, and the average value was adopted for the total number of defects in the wafer (total number of defects). And according to the following evaluation criteria, the evaluation result was shown in Table 3 as "defect (Defect)."

Evaluation standard

A: 200 defects or less

B: More than 200 defects and less than 300 defects

C: more than 300 defects

[Dimensional Uniformity (CDU) in Wafer Surface (Shot)]

With respect to the IS pattern formed by the formation (II) of the resist pattern described above, the IS pattern was measured by a length measurement SEM (scanning electron microscope, accelerating voltage 300 V, trade name: S-9380, manufactured by Hitachi High-Technologies Corporation). (7×15 shot) was observed from above, and the space width of the IS pattern (38 points in the shot) was measured. Three batches (3σ) of the calculated standard deviation (σ) were obtained from the measurement results. The smaller the value of 3σ obtained in this way, the higher the dimensional (CD) uniformity of the space width formed in the resist film.

And according to the following evaluation criteria, the evaluation result was shown in Table 3 as "CDU".

Evaluation standard

A: The value of 3σ is 60 nm or less

B: The value of 3σ is greater than 60 nm and less than 70 nm

C: The value of 3σ is 70 nm or more

From the result shown in Table 3, according to the resist pattern formation method of Examples 4-8, it is recognized that generation|occurrence|production of a defect is reduced and the dimensional (CD) uniformity is also high. In particular, it is recognized that these effects become higher when the resist compositions (1), (2) and (3) are used (especially preferably the resist composition (2) is used).

As mentioned above, although the preferred Example of this invention was described, this invention is not limited to these Examples. In the range which does not deviate from the meaning of this invention, addition, omission, substitution, and other changes of a structure are possible. The present invention is not limited by the above description, but is limited only by the scope of the appended claims.

Claims (8)

Step (i) of forming a resist film with a thickness of 7 µm or more on a support by using a resist composition, (ii) exposing the resist film, and developing the resist film after exposure (iii) to form a resist pattern; As a method of forming a resist pattern having,
The resist composition generates an acid upon exposure, and its solubility in a developer changes due to the action of the acid. A resin component (A1) having a structural unit (a4) containing a type group and a structural unit (a1) containing an acid-decomposable group whose polarity increases by the action of an acid (A1);
A resist pattern forming method comprising a compound represented by the following general formula (b-10), a compound represented by the following general formula (b-20), or a compound represented by the following general formula (b-30).

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya ^x1 is a single bond or a divalent linking group. Wa ^x1 is a (n _ax1 +1) valent aromatic hydrocarbon group. n _ax1 is an integer of 1 to 3.]

[Wherein, R ¹⁰¹ , R ¹⁰⁴ to R ¹⁰⁸ are each independently a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a chain alkenyl group which may have a substituent. R ¹⁰⁴ and R ¹⁰⁵ 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 divalent linking group containing an oxygen atom. V ¹⁰¹ to V ¹⁰³ each independently represent 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 each independently represent a single bond, -CO-, or -SO ₂ -. R ²⁰¹ is an aryl group. The hydrogen atom which the said aryl group has may be substituted by the substituent. R ²⁰² to R ²⁰³ each independently represent an optionally substituted aryl group, alkyl group or alkenyl group, and R ²⁰¹ to R ²⁰³ may be bonded to each other to form a ring together with the sulfur atom in the formula.] The method of claim 1,
The acid-decomposable group in the structural unit (a1) includes an aliphatic cyclic group. 3. The method of claim 2,
The acid-decomposable group in the structural unit (a1) includes an acid-decomposable group represented by the following general formula (a1-r2-11).

[In the formula, Ra' ¹⁰ is a hydrocarbon group having 1 to 10 carbon atoms. Ra" ¹¹ is a group forming a monocyclic aliphatic cyclic group together with the carbon atom to which Ra' ¹⁰ is bonded. * is a bond.] 4. The method according to any one of claims 1 to 3,
The content rate of the said structural unit (a10) is 45-75 mol% with respect to all the structural units (100 mol%) which comprise the said resin component (A1), The resist pattern formation method. 4. The method according to any one of claims 1 to 3,
The content rate of the said structural unit (a1) is 5-20 mol% with respect to all the structural units (100 mol%) which comprise the said resin component (A1), The resist pattern formation method. 4. The method according to any one of claims 1 to 3,
In the step (ii), the resist film is irradiated with a KrF excimer laser beam. The method of claim 1,
The said process (i) is a process of forming a resist film with a film thickness of 15 micrometers or more using a resist composition, The resist pattern formation method. The method of claim 1,
A resist pattern formation method comprising a compound represented by the general formula (b-10).