JP2013174663A - Method for forming resist pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new method for forming a resist pattern by which a negative resist pattern can be formed by use of a developing solution containing an organic solvent.SOLUTION: The method for forming a resist pattern includes steps of: forming a resist film on a support body by using a resist composition comprising a resin component (X) having a group (I) that is decomposed by an action of a base to increase its polarity and a base generator component (Y) that generates a base by exposure; exposing the resist film; and developing the resist film by using a developing solution containing an organic solvent to form a negative resist pattern.

Description

  The present invention relates to a resist pattern forming method.

A technique (pattern formation technique) for forming a fine pattern on a substrate and processing the lower layer of the pattern by performing etching using the fine pattern as a mask is widely adopted in the manufacture of semiconductor elements and liquid crystal display elements. The fine pattern is usually made of an organic material, and is formed by a technique such as a lithography method or a nanoimprint method. For example, in a lithography method, a resist film is formed on a support such as a substrate using a resist material containing a base material component such as a resin, and the resist film is selected by radiation such as light or an electron beam. A step of forming a resist pattern having a predetermined shape on the resist film is performed by performing a general exposure and developing. And a semiconductor element etc. are manufactured through the process of processing a board | substrate by an etching using the said resist pattern as a mask.
The resist material is classified into a positive type and a negative type. A resist material whose solubility in an exposed portion of a developer is increased is called a positive type, and a resist material whose solubility in an exposed portion of a developer is reduced is called a negative type. .
As the developer, an alkaline aqueous solution (alkali developer) such as a tetramethylammonium hydroxide (TMAH) aqueous solution is usually used. In addition, an organic solvent such as an aromatic solvent, an aliphatic hydrocarbon solvent, an ether solvent, a ketone solvent, an ester solvent, an amide solvent, or an alcohol solvent is also used as a developer (for example, (See Patent Documents 1 and 2).

In recent years, pattern miniaturization is rapidly progressing due to the advancement of lithography technology.
As a technique for miniaturization, the exposure light source is generally shortened in wavelength (increased energy). Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but at present, mass production of semiconductor elements using a KrF excimer laser or an ArF excimer laser has started. Further, studies have been made on EB (electron beam), EUV (extreme ultraviolet), X-rays, and the like having shorter wavelengths (higher energy) than these excimer lasers.
Along with the shortening of the wavelength of the exposure light source, the resist material is required to be improved in lithography characteristics such as sensitivity to the exposure light source and resolution capable of reproducing a pattern with a fine dimension. A chemically amplified resist is known as a resist material that satisfies such requirements.
As the chemically amplified resist, a composition containing a base material component whose solubility in a developing solution is changed by the action of an acid and an acid generator component that generates an acid upon exposure is generally used. For example, when the developer is an alkali developer (alkaline development process), a substrate component that has increased solubility in an alkali developer due to the action of an acid is used.
Conventionally, a resin (base resin) is mainly used as a base component of a chemically amplified resist composition. At present, as a base resin of a chemically amplified resist composition used in ArF excimer laser lithography and the like, it has a structural unit derived from (meth) acrylic acid ester in its main chain because of its excellent transparency near 193 nm. Resin (acrylic resin) is the mainstream.
Here, “(meth) acrylic acid” means one or both of acrylic acid having a hydrogen atom bonded to the α-position and methacrylic acid having a methyl group bonded to the α-position. “(Meth) acrylic acid ester” means one or both of an acrylic acid ester having a hydrogen atom bonded to the α-position and a methacrylic acid ester having a methyl group bonded to the α-position. “(Meth) acrylate” means one or both of an acrylate having a hydrogen atom bonded to the α-position and a methacrylate having a methyl group bonded to the α-position.
The base resin generally contains a plurality of structural units in order to improve lithography properties and the like. For example, a structural unit having an acid-decomposable group that decomposes by the action of an acid generated from an acid generator to generate an alkali-soluble group, a structural unit having a lactone structure, a structural unit having a polar group such as a hydroxyl group, etc. are used. (For example, refer to Patent Document 3). When the base resin is an acrylic resin, as the acid-decomposable group, generally, a carboxy group in (meth) acrylic acid or the like is protected with an acid-dissociable group such as a tertiary alkyl group or an acetal group Is used.

As one of the methods for further improving the resolution, exposure (immersion exposure) is performed by interposing a liquid (immersion medium) having a higher refractive index than air between the objective lens of the exposure machine and the sample. A so-called immersion lithography (hereinafter referred to as “immersion exposure”) is known (for example, see Non-Patent Document 1).
According to immersion exposure, even when a light source having the same exposure wavelength is used, the same high resolution as when using a light source with a shorter wavelength or using a high NA lens can be achieved, and the depth of focus can be reduced. It is said that there is no decline. In addition, immersion exposure can be performed by applying an existing exposure apparatus. For this reason, immersion exposure is expected to be able to form resist patterns with low cost, high resolution, and excellent depth of focus. In particular, in terms of lithography characteristics such as resolution, the semiconductor industry is attracting a great deal of attention.
Immersion exposure is effective in forming all pattern shapes, and can be combined with super-resolution techniques such as the phase shift method and the modified illumination method that are currently being studied. Currently, as an immersion exposure technique, a technique mainly using an ArF excimer laser as a light source is being actively researched. Currently, water is mainly studied as an immersion medium.

One recently proposed lithography technique is a double patterning process in which a resist pattern is formed by performing patterning twice or more (see, for example, Non-Patent Documents 2 and 3). There are several methods for the double patterning process. For example, (1) a method of forming a pattern by repeating a lithography process (from application of a resist composition to exposure and development) and an etching process at least twice, and (2) lithography. There is a method of repeating the process twice or more. According to the double patterning process, a resist pattern having a higher resolution than that formed by a single lithography process (single patterning), whether using the same exposure wavelength light source or the same resist composition. Can be formed. The double patterning process can be performed using an existing exposure apparatus.
In addition, a double exposure method has been proposed in which after a resist film is formed, the resist film is exposed twice or more and developed to form a resist pattern (see, for example, Patent Document 4). According to this double exposure method, it is possible to form a high-resolution resist pattern as in the above-described double patterning process, and there is an advantage that the number of steps is small compared to double patterning.

In a positive development process in which a positive chemically amplified resist composition, that is, a chemically amplified resist composition whose solubility in an alkaline developer is increased by exposure and an alkaline developer is combined, as described above, The exposed portion is dissolved and removed with an alkali developer to form a resist pattern. A positive development process that combines a positive chemically amplified resist composition and an alkaline developer is a photomask compared to a negative development process that combines a negative chemically amplified resist composition and an alkaline developer. There are advantages such that the structure can be simplified, sufficient contrast for image formation can be easily obtained, and the characteristics of the pattern to be formed are excellent. Therefore, at present, there is a tendency that a positive development process in which a positive chemically amplified resist composition and an alkali developer are combined is mainly used for forming a fine resist pattern.
However, in a positive development process combining a positive chemically amplified resist composition and an alkali developer, when forming a trench pattern (isolated space pattern) or hole pattern, when forming a line pattern or dot pattern. In comparison, the pattern formation under weak light incident intensity is forced, and the contrast of the intensity of light incident on the exposed area and the unexposed area is also small. Therefore, there is a tendency that the pattern forming ability such as the resolution is limited, and it is difficult to form a high resolution resist pattern.
Therefore, a negative development process is considered advantageous for forming a trench pattern or a hole pattern. On the other hand, the negative development process includes a method of combining a chemically amplified resist composition whose solubility in an alkali developer is reduced by exposure and an alkali developer, and a developer containing an organic solvent by exposure (hereinafter referred to as organic). There is a method of combining a chemically amplified resist composition having a reduced solubility in an organic developer with an organic developer.

Japanese Patent Laid-Open No. 06-194847 JP 2009-025723 A JP 2003-241385 A JP 2010-040849 A

Proceedings of SPIE, 5754, 119-128 (2005). Proceedings of SPIE, 5256, 985-994 (2003). Proceedings of SPIE, 6153, 615301-1-19 (2006).

However, the conventional negative development process still has problems to be improved. For example, a defect problem can be considered. As an acid generator component in a conventional chemically amplified resist composition, an onium salt-based one is widely used. However, an onium salt-based acid generator is ionic and highly polar. Therefore, the solubility in an organic developer is low, and there is a concern about the risk of precipitation during development.
In the future, as further progress in lithography technology and expansion of application fields are expected, a negative development process is also required by a new mechanism.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a novel resist pattern forming method capable of forming a negative resist pattern using a developer containing an organic solvent.

As a result of intensive studies, the inventors combined a base generator component that generates a base by exposure and a resin component that increases in polarity by the action of a base, so that an exposed portion and an unexposed portion are combined. It was found that a dissolution contrast with respect to an organic developer can be expressed and a negative pattern can be formed, and the present invention has been completed.
That is, the present invention uses a resist composition containing a resin component (X) containing a group (I) that is decomposed by the action of a base and increasing in polarity, and a base generator component (Y) that generates a base upon exposure. Forming a resist film on the support,
Exposing the resist film;
Developing the resist film with a developer containing an organic solvent to form a negative resist pattern;
Is a resist pattern forming method.

In the present specification and claims, “exposure” is a concept including general irradiation of radiation.
“Aliphatic” is a relative concept with respect to aromatics, and is defined to mean groups, compounds, etc. that do not have aromaticity.
The “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups unless otherwise specified. The same applies to the alkyl group in the alkoxy group.
Unless otherwise specified, the “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups.
The “halogenated alkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with halogen atoms. The halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
A “hydroxyalkyl group” is a group in which part or all of the hydrogen atoms of an alkyl group are substituted with a hydroxyl group.
The “structural unit” means a monomer unit (monomer unit) constituting a resin (polymer compound, polymer, copolymer).

  ADVANTAGE OF THE INVENTION According to this invention, the novel resist pattern formation method which can form a negative resist pattern using the developing solution containing an organic solvent can be provided.

No. of Test Example 1 40 ° C. samples A1 to A3, a chart showing ¹ H-NMR analysis results after 13hr storage. No. of Test Example 1 40 ° C. samples B1 to B3, a chart showing ¹ H-NMR analysis results after 13hr storage.

The resist pattern forming method of the present invention includes a resin component (X) (hereinafter referred to as “component (X)”) containing a group (I) that is decomposed by the action of a base to increase the polarity, and generation of a base that generates a base upon exposure. A step of forming a resist film on a support using a resist composition containing an agent component (Y) (hereinafter “(Y) component”) (hereinafter “resist film forming step”);
A step of exposing the resist film (hereinafter “exposure step”);
The resist film is developed using a developer containing an organic solvent (hereinafter referred to as “organic developer”) to form a negative resist pattern (hereinafter referred to as “negative pattern”) (hereinafter referred to as “development process”). )When,
including.
When the resist composition used in the present invention is exposed (irradiated with radiation), a base is generated from the (Y) component. The component (X) contains a group (I) that is decomposed by the action of a base to increase the polarity, and the polarity of the component (X) increases when a base is generated. As the increase in polarity increases, the solubility in organic developers decreases.
Therefore, when selective exposure is performed on a resist film formed using the resist composition, the exposed portion has reduced solubility in an organic developer due to an increase in the polarity of the component (X), Since the solubility in the organic developer does not change in the unexposed area, a difference in solubility (dissolution contrast) in the organic developer occurs between the exposed area and the unexposed area. Therefore, when the resist film is developed with an organic developer, unexposed portions are selectively dissolved and removed to form a negative pattern.
Hereinafter, each process will be described in more detail.

[Resist film forming step]
In this step, a resist film is formed on the support using a resist composition containing the component (X) and the component (Y).
The resist composition used in this step will be described in detail later.
The resist film can be formed by a known method except that a specific resist composition is used. For example, the resist composition is applied onto a support with a spinner or the like, and a baking (post-apply bake (PAB)) treatment is performed, for example, at a temperature of 80 to 150 ° C. for 40 to 120 seconds, preferably 60 to 90. By applying for 2 seconds, a resist film can be formed.
The support is not particularly limited, and a conventionally known one can be used, and examples thereof include a substrate for electronic components and a substrate on which a predetermined wiring pattern is formed. More specifically, a silicon substrate, a metal substrate such as copper, chromium, iron, and aluminum, a glass substrate, and the like can be given. As a material for the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used.
Further, the support may be a substrate in which an inorganic and / or organic film is provided on the above-described substrate. An inorganic antireflection film (inorganic BARC) is an example of the inorganic film. Examples of the organic film include organic films such as an organic antireflection film (organic BARC) and a lower organic film in a multilayer resist method.
Here, the multilayer resist method is a method in which at least one organic film (lower organic film) and at least one resist film (upper resist film) are provided on a substrate, and the resist pattern formed on the upper resist film is used as a mask. This is a method of patterning a 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, the required thickness can be secured by the lower organic film, so that the resist film can be thinned and a fine pattern with a high aspect ratio can be formed.
In the multilayer resist method, basically, a method of forming a two-layer structure of an upper resist film and a lower organic film (two-layer resist method), and one or more intermediate layers between the upper resist film and the lower organic film And a method of forming a multilayer structure of three or more layers (metal thin film etc.) (three-layer resist method).

[Exposure process]
Next, the formed resist film is exposed through a mask (mask pattern) in which a predetermined pattern is formed using an exposure apparatus such as an ArF exposure apparatus, an electron beam drawing apparatus, or an EUV exposure apparatus, or Selective exposure is performed by drawing or the like by direct irradiation of an electron beam without passing through a mask pattern.
The wavelength used for the exposure is not particularly limited, and ArF excimer laser, KrF excimer laser, F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, soft X-ray, etc. Can be done using radiation. The resist composition that can be used in the present invention as described later is highly useful for KrF excimer laser, ArF excimer laser, EB, or EUV, and is particularly useful for ArF excimer laser, EB, or EUV.

The exposure method of the resist film may be normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or may be immersion exposure (Liquid Immersion Lithography).
In immersion exposure, the space between the resist film and the lens at the lowest position of the exposure apparatus is previously filled with a solvent (immersion medium) having a refractive index larger than that of air, and exposure (immersion exposure) is performed in that state. It is an exposure method.
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 such a solvent is not particularly limited as long as it is within the above range.
Examples of the solvent having a refractive index larger than the refractive index of air and smaller than the refractive index of the resist film include water, a fluorine-based inert liquid, a silicon-based solvent, and a hydrocarbon-based solvent.
Specific examples of the fluorine-based inert liquid include a fluorine-based compound such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , and C ₅ H ₃ F ₇ as a main component. Examples thereof include liquids, and those having a boiling point of 70 to 180 ° C are preferable, and those having a boiling point of 80 to 160 ° C are more preferable. It is preferable that the fluorine-based inert liquid has a boiling point in the above range since the medium used for immersion can be removed by a simple method after the exposure is completed.
As the fluorine-based inert liquid, a perfluoroalkyl compound in which all hydrogen atoms of the alkyl group are substituted with fluorine atoms is particularly preferable. Specific examples of the perfluoroalkyl compound include a perfluoroalkyl ether compound and a perfluoroalkylamine compound.
More specifically, examples of the perfluoroalkyl ether compound include perfluoro (2-butyl-tetrahydrofuran) (boiling point 102 ° C.). Examples of the perfluoroalkylamine compound include perfluorotributylamine ( Boiling point of 174 ° C.).
As the immersion medium, water is preferably used from the viewpoints of cost, safety, environmental problems, versatility, and the like.

In order to sufficiently advance the generation of the base from the (Y) component by exposure and the accompanying reaction of the (X) component (reaction in which the group (I) is decomposed and the polarity is increased by the action of the base) after the exposure. Baking (post-exposure baking (PEB)) is preferably performed.
The PEB treatment is preferably performed, for example, at a temperature of 80 to 150 ° C. for 40 to 120 seconds, preferably 60 to 90 seconds.

[Development process]
Next, the exposed resist film is developed using an organic developer. Thereby, the unexposed part of the resist film is dissolved and removed, and a negative pattern is formed.
Development processing using an organic developer can be carried out by a known development method. Examples of the method include a method in which a support is immersed in a developer for a certain period of time (dip method), a method in which a developer is raised on the surface of the support by surface tension and is allowed to stand for a certain period of time (paddle method), and is developed on the surface of the support. Examples thereof include a method of spraying a liquid (spray method), a method of continuously applying a developer while scanning a developer application nozzle at a constant speed on a support rotating at a constant speed (dynamic dispensing method), and the like.
After the development treatment, it is preferable to carry out a rinsing treatment using a rinsing liquid containing an organic solvent and then drying. By performing the rinsing process, a good pattern can be formed.
The rinsing process (cleaning process) using the rinsing liquid can be performed by a known rinsing method. Examples of the method include a method of continuously applying a rinsing liquid on a support rotating at a constant speed (rotary coating method), a method of immersing the support in the rinsing liquid for a predetermined time (dip method), and the surface of the support. And a method of spraying a rinse liquid (spray method).
After the development process or the rinse process, a process of removing the organic developer or rinse liquid adhering to the pattern with a supercritical fluid may be performed.
In some cases, a baking (post-baking) treatment may be performed after the development treatment, the rinsing treatment or the supercritical fluid treatment in order to remove the remaining organic solvent.
In this way, a negative pattern in which the unexposed portion of the resist film is dissolved and removed can be obtained.

(Organic developer)
As the organic solvent contained in the organic developer used for development, the component (X) (the component (X) before exposure, that is, the component (X) before the group (I) is decomposed by the action of a base to increase polarity)) is dissolved. What is necessary is just to be able to obtain, and it can select suitably from well-known organic solvents. Specific examples include ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, ether solvents, and other polar solvents, hydrocarbon solvents, and the like.
The ketone solvent is an organic solvent containing C—C (═O) —C in the structure.
The ester solvent is an organic solvent containing C—C (═O) —O—C in the structure.
The alcohol solvent is an organic solvent containing an alcoholic hydroxyl group in the structure, and “alcoholic hydroxyl group” means a hydroxyl group bonded to a carbon atom of an aliphatic hydrocarbon group.
A nitrile solvent is an organic solvent containing a nitrile group in its structure.
The amide solvent is an organic solvent containing an amide group in the structure.
The ether solvent is an organic solvent containing C—O—C in the structure.
Among organic solvents, there are organic solvents that contain a plurality of types of functional groups that characterize each of the above solvents in the structure. Shall. For example, diethylene glycol monomethyl ether corresponds to both alcohol solvents and ether solvents in the above classification.
The hydrocarbon solvent is a hydrocarbon solvent made of a hydrocarbon which may be halogenated and having no substituent other than a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.

  Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, and methyl ethyl ketone. , Methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methylnaphthyl ketone, isophorone, propylene carbonate, γ-butyrolactone, methyl amyl ketone (also referred to as 2-heptanone), and the like. Can be mentioned. Of these, methyl amyl ketone is most preferred.

Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, ethyl methoxyacetate, ethyl ethoxyacetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono Propyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monophenyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monopropyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene Recall 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-methoxy Nethyl 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, pyrubin Methyl acid, ethyl pyruvate, propyl pyruvate, butyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl propionate, ethyl propionate, propyl propionate, isopropyl propionate, methyl 2-hydroxypropionate, 2-hydroxypropionate Examples include ethyl acid, methyl-3-methoxypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, and propyl-3-methoxypropionate.
As the ester solvent, a solvent represented by the following general formula (1) or (2) is preferable, a solvent represented by the general formula (1) is more preferable, alkyl acetate is further more preferable, and butyl acetate is most preferable. preferable.

  Examples of the alcohol solvent include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, isobutyl alcohol, n-hexyl alcohol, n-heptyl alcohol, monohydric alcohols such as n-octyl alcohol, n-decanol and 3-methoxy-1-butanol; glycol solvents such as ethylene glycol, diethylene glycol and triethylene glycol; ethylene glycol monomethyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, Triethylene glycol monoethyl ether, methoxymethylbutanol, ethylene glycol monoethyl ether, Glycol monopropyl ether, ethylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, and propylene glycol monophenyl ether, glycol ether solvent containing a hydroxyl group; and the like. Among these, monohydric alcohol is preferable, and isopropyl alcohol is most preferable.

Examples of the nitrile solvent include acetonitrile, propionitryl, valeronitrile, butyronitryl and the like.
Examples of the amide solvent include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, hexamethylphosphoric triamide, 1,3-dimethyl-2-imidazolidinone and the like. Can be mentioned.

Examples of ether solvents include glycol ether solvents containing the above hydroxyl groups; glycol ether solvents that do not contain hydroxyl groups, such as propylene glycol dimethyl ether, propylene glycol diethyl ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether; dioxane, tetrahydrofuran, anisole, Examples include perfluoro-2-butyltetrahydrofuran, perfluorotetrahydrofuran, and 1,4-dioxane.
Of these, glycol ether solvents such as glycol ether solvents containing hydroxyl groups and glycol ether solvents not containing hydroxyl groups are preferred.

  Examples of the hydrocarbon solvent include aliphatic hydrocarbons such as pentane, hexane, heptane, octane, decane, 2,2,4-trimethylpentane, 2,2,3-trimethylhexane, perfluorohexane, and perfluoroheptane. Solvents: aromatic hydrocarbons such as toluene, xylene, ethylbenzene, propylbenzene, 1-methylpropylbenzene, 2-methylpropylbenzene, dimethylbenzene, diethylbenzene, ethylmethylbenzene, trimethylbenzene, ethyldimethylbenzene, dipropylbenzene A solvent; Among these, aliphatic hydrocarbon solvents are preferable, and those not fluorine-substituted are more preferable.

Among the above, the organic developer is selected from the group consisting of ketone solvents, alcohol solvents, nitrile solvents, solvents represented by the following general formula (1) or (2), and hydrocarbon solvents. It is preferable to contain at least one kind. Among these, it is preferable to contain at least one selected from the group consisting of ketone solvents, nitrile solvents, and solvents represented by the following general formula (1).
R ⁰⁰ —C (═O) —O—R ⁰¹ (1)
R ⁰² —C (═O) —O—R ⁰⁴ —O—R ⁰³ (2)
In Expression (1), R ⁰⁰ is a hydrogen atom, an alkyl group, an alkoxy group, an alkoxycarbonyl group, a cyano group or a halogen atom, R ⁰¹ is a hydrogen atom, an alkyl group, a cyano group or a halogen atom, R ⁰⁰ And R ⁰¹ may combine with each other to form a ring. In the formula (2), R ⁰² is a hydrogen atom, an alkyl group, an alkoxy group, an alkoxycarbonyl group, a cyano group or a halogen atom, R ⁰³ is a hydrogen atom, an alkyl group, a cyano group or a halogen atom, and R ⁰³ is They may combine with each other to form a ring, and R ⁰⁴ is an alkylene group. ]

In formula (1), the alkyl group in R ⁰⁰ may be linear, branched or cyclic, and is preferably linear or branched, and the number of carbon atoms is preferably 1 to 5. The alkyl group may have a substituent. Examples of the substituent include a hydroxyl group, a carboxy group, and a cyano group.
Examples of the alkyl group in the alkoxy group and alkoxycarbonyl group include the same alkyl groups as those described above.
Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
R ⁰⁰ is preferably a hydrogen atom or an alkyl group.
In formula (1), examples of the alkyl group and halogen atom for R ⁰¹ include the same alkyl groups and halogen atoms as those described above for R ⁰⁰ .
R ⁰¹ is preferably a hydrogen atom or an alkyl group.
Specific examples of the solvent represented by the formula (1) include, for example, methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, lactic acid Butyl, 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, Examples include isopropyl propionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, and the like.
Among the above, the solvent represented by the formula (1) is preferably one in which R ⁰⁰ and R ⁰¹ are unsubstituted alkyl groups, more preferably alkyl acetate, and particularly preferably butyl acetate.

In the formula (2), R ⁰² and R ⁰³ are the same as R ⁰⁰ and R ⁰¹ , respectively.
The alkylene group for R ⁰⁴ may be linear, branched or cyclic, and is preferably linear or branched, and preferably has 1 to 5 carbon atoms. The alkylene group may have a substituent. Examples of the substituent include a hydroxyl group, a carboxy group, and a cyano group. When the alkylene group has 2 or more carbon atoms, an oxygen atom (—O—) may be interposed between carbon atoms of the alkylene group.
Specific examples of the solvent represented by the formula (2) include, for example, 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 monoacetate. Propyl ether acetate, diethylene glycol monophenyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, methyl-3-meth Cypropionate, ethyl-3-methoxypropionate, ethyl-3-ethoxypropionate, propyl-3-methoxypropionate, ethyl methoxyacetate, ethyl ethoxyacetate, 2-methoxybutyl acetate, 3-methoxybutyl acetate, 4 -Methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-ethyl-3-methoxybutyl 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-methoxy pentyl acetate, and the like.

Any one of these organic solvents may be used alone, or two or more thereof may be mixed and used. Moreover, you may mix and use other organic solvents and water other than the above. The other organic solvent is not particularly limited as long as it becomes a uniform solution without being separated during mixing, and can be appropriately selected from known organic solvents.
As the organic solvent used in the organic developer, an organic solvent containing no halogen atom is preferably used from the viewpoint of cost reduction of the solvent used in the development. The content of the organic solvent not containing halogen atoms in the total weight of the organic developer is preferably 60% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, and 100% by mass. Also good.
The boiling point of the organic solvent used in the organic developer is desirably 50 ° C. or higher and lower than 250 ° C.
The ignition point of the organic solvent used in the organic developer is preferably 200 ° C. or higher.

A known additive can be blended in the organic developer as required. Examples of the additive include a surfactant. The surfactant is not particularly limited. For example, ionic or nonionic fluorine-based and / or silicon-based surfactants can be used.
Examples of commercially available surfactants that can be used include F-top EF301 and EF303 (manufactured by Shin-Akita Kasei Co., Ltd.), Florard FC430 and 431 (manufactured by Sumitomo 3M Co., Ltd.), MegaFuck F171, F173, F176 and F189, Fluorine-based interfaces such as R08 (manufactured by DIC Corporation), Surflon S-382, SC101, 102, 103, 104, 105, 106 (manufactured by Asahi Glass Co., Ltd.), Troisol S-366 (manufactured by Troy Chemical Co., Ltd.) An activator or a silicon-based surfactant can be mentioned. Polysiloxane polymer KP-341 (manufactured by Shin-Etsu Chemical Co., Ltd.) can also be used as a silicon-based surfactant.
In addition to known surfactants as described above, the surfactant is derived from a fluoroaliphatic compound produced by a telomerization method (also called telomer method) or an oligomerization method (also called oligomer method). A surfactant using a polymer having a fluoroaliphatic group can be used. The fluoroaliphatic compound can be synthesized by the method described in JP-A-2002-90991.
As the polymer having a fluoroaliphatic group, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate and / or (poly (oxyalkylene)) methacrylate is preferable and distributed irregularly. Or may be block copolymerized. Examples of the poly (oxyalkylene) group include a poly (oxyethylene) group, a poly (oxypropylene) group, a poly (oxybutylene) group, and the like, and a poly (oxyethylene, oxypropylene, and oxyethylene group). A unit having different chain lengths in the same chain length, such as a block linked body) or a poly (block linked body of oxyethylene and oxypropylene) group, may be used. Furthermore, a copolymer of a monomer having a fluoroaliphatic group and (poly (oxyalkylene)) acrylate (or methacrylate) is not only a binary copolymer but also a monomer having two or more different fluoroaliphatic groups. Further, it may be a ternary or higher copolymer obtained by simultaneously copolymerizing two or more different (poly (oxyalkylene)) acrylates (or methacrylates).
Examples of commercially available surfactants include Megafac F178, F-470, F-473, F-475, F-476, and F-472 (manufactured by DIC Corporation). Further, a copolymer of an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxyalkylene)) acrylate (or methacrylate), an acrylate (or methacrylate) having a C ₆ F ₁₃ group and (poly (oxy Copolymer) of (ethylene)) acrylate (or methacrylate) and (poly (oxypropylene)) acrylate (or methacrylate), acrylate (or methacrylate) and (poly (oxyalkylene)) acrylate having C ₈ F ₁₇ groups (or Copolymer of acrylate (or methacrylate), (poly (oxyethylene)) acrylate (or methacrylate), and (poly (oxypropylene)) acrylate (or methacrylate) having a C ₈ F ₁₇ group. Coalescence And the like.
As the surfactant, a nonionic surfactant is preferable, and a fluorine-based surfactant or a silicon-based surfactant is more preferable.
When the surfactant is blended, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and 0.01 to 0. 0% with respect to the total amount of the organic developer. 5 mass% is more preferable.

(Rinse solution)
After the development treatment, before the drying, a rinsing treatment can be performed using a rinsing liquid containing an organic solvent. By rinsing, a good pattern can be formed.
As the organic solvent used in the rinsing liquid, for example, organic solvents that are difficult to dissolve the resist pattern among the organic solvents mentioned as the organic solvent used in the organic developer can be used. 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 solvents, ketone solvents, ester solvents, alcohol solvents and amide solvents is preferable, and at least one selected from alcohol solvents and ester solvents is preferable. More preferred are alcohol solvents.
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. Specific examples include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and benzyl alcohol. It is done. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferable, and 1-hexanol or 2-hexanol is more preferable.
Any one of these organic solvents may be used alone, or two or more thereof may be mixed and used. Moreover, you may mix and use the organic solvent and water other than the above. However, in consideration of development characteristics, the blending amount of water in the rinsing liquid is preferably 30% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, more preferably 3% by mass or less based on the total amount of the rinsing liquid. Is particularly preferred.
A known additive can be blended in the organic developer as required. Examples of the additive include a surfactant. Examples of the surfactant include those described above, and nonionic surfactants are preferable, and fluorine-based surfactants or silicon-based surfactants are more preferable.
When the surfactant is blended, the blending amount is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and 0.01 to 0.5% by mass with respect to the total amount of the rinse liquid. % Is more preferable.
The rinsing treatment (washing treatment) using the rinsing liquid can be carried out by a known rinsing method. For example, the rinsing liquid is continuously applied onto a support rotating at a constant speed (rotary coating method). A method of immersing the support in a rinsing solution for a certain time (dip method), a method of spraying a rinsing solution on the surface of the support (spray method), and the like.

≪Resist composition≫
The resist composition used in the resist pattern forming method of the present invention contains the (X) component and the (Y) component as described above.
As described above, when the resist composition is exposed (irradiated with radiation), a base is generated from the component (Y). The component (X) contains a group (I) that is decomposed by the action of a base to increase the polarity, and the polarity of the component (X) increases when a base is generated. As the increase in polarity increases, the solubility in organic developers decreases.
Therefore, when selective exposure is performed on a resist film formed using the resist composition, the exposed portion has reduced solubility in an organic developer due to an increase in the polarity of the component (X), Since the solubility in the organic developer does not change in the unexposed area, a difference in solubility (dissolution contrast) in the organic developer occurs between the exposed area and the unexposed area. Therefore, when the resist film is developed with an organic developer, unexposed portions are selectively dissolved and removed to form a negative pattern.

<(X) component>
(X) A component is a resin component containing specific group (I).
In the present specification, the “resin component” indicates an organic compound having a film forming ability and a polymer. As the resin component, a polymer compound having a molecular weight of 500 or more, preferably 1000 or more is usually used because it is easy to form a nano-level resist pattern. In the case of the resin component, as the “molecular weight”, a mass average molecular weight in terms of polystyrene by GPC (gel permeation chromatography) is used.

The group (I) is a group that decomposes in the presence of a base to increase the polarity.
As a base here, the base generate | occur | produced by exposure from the (Y) component mentioned later is mentioned.
Examples of the group (I) include a group having a hydrogen atom that becomes a proton that is easily extracted by a base.
As the group (I), a group represented by the following general formula (I-1) is preferable because decomposability is good (proton extraction reaction with a base easily proceeds).

［式中、Ｒ^１は水素原子または置換基であり、Ｒ^２は置換基であり、ｓは１〜４の整数であり、ｔは０〜２の整数である。］

[Wherein, R ¹ is a hydrogen atom or a substituent, R ² is a substituent, s is an integer of 1 to 4, and t is an integer of 0 to 2. ]

  When a base acts on the resin component having a group represented by the formula (I-1), the following decomposition reaction due to proton extraction proceeds. As a result, the group (I) becomes —OH and the polarity increases. In the formula, Base is a base.

In formula (I-1), R ¹ is a hydrogen atom or a substituent.
The substituent in R ¹ is not particularly limited as long as the polar group after decomposition with a base is expressed within a range not impairing the reactivity of the group (I-1). For example, a mercapto group (—SH) , —COOR ″ (R ″ is a hydrogen atom or an alkyl group), an acyl group, an alkyl group (an ether bond or a carbonyl group may be inserted between carbon atoms), a hydroxyl group, and the like. Among these, R ″ in —COOR ″ includes the same as R ″ in —COOR ″ and —OC (═O) R ″ described in the description of R ² below. As the acyl group, What has a C1-C5 alkyl group is preferable, for example, an acetyl group, an ethylcarbonyl group, etc. As an alkyl group, a C1-C5 alkyl group is preferable.
R ¹ is preferably a hydrogen atom, an acyl group (particularly an acetyl group), —COOR ″ or a mercapto group, and most preferably a hydrogen atom.

In formula (I-1), R ² is a substituent.
R ² is not particularly limited, and examples thereof include an alkyl group, an alkoxy group, a hydroxyalkyl group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a cyano group, —COOR ″, —OC (═O) R ″, and the like. It is done. R ″ in —COOR ″ and —OC (═O) R ″ is a hydrogen atom or an alkyl group.
The alkyl group in R ^2, preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an 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 particularly preferable.
The alkoxy group in R ^2, preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the group couple | bonded with the oxygen atom (-O-) to the alkyl group quoted as the alkyl group as the said substituent is mentioned.
The hydroxyalkyl group for R ^2, preferred hydroxyalkyl group having 1 to 6 carbon atoms. The hydroxyalkyl group is preferably linear or branched. Specific examples include those obtained by substituting a part of hydrogen atoms of the alkyl group mentioned as the alkyl group as the substituent with a hydroxyl group. The number of hydroxyl groups that the hydroxyalkyl group has is preferably 1 to 3, and particularly preferably 1.
Examples of the halogen atom in R ^2, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a fluorine atom is preferable.
Examples of the halogenated alkyl group for R ² include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with halogen atoms. Examples of the halogen atom are the same as those described above. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.
R ″ in —COOR ″ and —OC (═O) R ″ is a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms.
As for carbon number of the alkyl group in R ", 1-15 are preferable.
The alkyl group in R ″ may be linear, branched or cyclic, or a combination thereof.
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. preferable.
When R ″ is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a fluorine atom Alternatively, one or more hydrogen atoms are removed from a polycycloalkane such as a monocycloalkane, bicycloalkane, tricycloalkane, or tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group. More specifically, one or more hydrogen atoms are removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Group.

In formula (I-1), s is an integer of 1 to 4, preferably 1 or 2, and most preferably 1.
t is an integer of 0 to 2, an integer of 0 to 1 is preferable, and 0 is most preferable.
When t is an integer of 2 or more, the plurality of R ² in the formula may be the same or different.
Preferable specific examples of the group represented by the formula (I-1) include, for example, those shown below.

The group (I) is preferably contained in the structural unit constituting the component (X).
Here, the structural unit constituting the component (X) is not particularly limited, but is preferably a structural unit derived from a compound having an ethylenic double bond.
The “structural unit derived from a compound having an ethylenic double bond” means a structural unit having a structure in which an ethylenic double bond in a compound having an ethylenic double bond is cleaved to form a single bond.
Examples of the compound having an ethylenic double bond include acrylic acid or an ester thereof in which a hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, and a hydrogen atom bonded to the α-position carbon atom. Acrylamide or a derivative thereof optionally substituted with a substituent, a vinyl aromatic compound in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, a cycloolefin or a derivative thereof, a vinyl sulfonate, etc. Is mentioned. Among these, a hydrogen atom bonded to the α-position carbon atom may be substituted with an acrylic acid or an ester thereof, and a hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent. Acrylamide or a derivative thereof, and a vinyl aromatic compound in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent are preferable.

“Acrylic acid ester” is a compound in which the hydrogen atom at the carboxy group end of acrylic acid (CH ₂ ═CH—COOH) is substituted with an organic group.
In the present specification, acrylic acid and acrylic ester in which a hydrogen atom bonded to a carbon atom at the α-position is substituted with a substituent may be referred to as α-substituted acrylic acid and α-substituted acrylic ester, respectively. In addition, acrylic acid and α-substituted acrylic acid may be collectively referred to as “(α-substituted) acrylic acid”, and α-substituted acrylic acid ester may be collectively referred to as “(α-substituted) acrylic acid ester”.
Examples of the substituent bonded to the α-position carbon atom of the α-substituted acrylic acid or ester thereof include a halogen atom, an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, and a hydroxyalkyl group. It is done. Note that the α-position (α-position carbon atom) of a structural unit derived from an acrylate ester means a carbon atom to which a carbonyl group is bonded, unless otherwise specified.
Examples of the halogen atom as the α-position substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Specific examples of the alkyl group having 1 to 5 carbon atoms as the α-position substituent include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, Examples thereof include linear or branched alkyl groups such as isopentyl group and neopentyl group.
Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms as the α-position substituent 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 a halogen atom. Is mentioned. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
The hydroxyalkyl group as the α-position substituent is preferably a hydroxyalkyl group having 1 to 5 carbon atoms, specifically, a part or all of the hydrogen atoms of the above alkyl group having 1 to 5 carbon atoms. Examples thereof include a group substituted with a hydroxy group.
In the present invention, it is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms that is bonded to the α-position carbon atom of (α-substituted) acrylic acid or an ester thereof. It is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and is a hydrogen atom or a methyl group because of industrial availability. Most preferred.
The organic group of the (α-substituted) acrylate ester is not particularly limited, and examples thereof include a characteristic group such as the above-described group (I) and a characteristic group-containing group containing the characteristic group in the structure. Examples of the characteristic group-containing group include a group in which a divalent linking group is bonded to the characteristic group. Examples of the divalent linking group, for example include the same divalent linking group include the description of X ⁰ in formula (x1-1) in which will be described later.

Examples of “acrylamide or a derivative thereof” include an acrylamide in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent (hereinafter sometimes referred to as (α-substituted) acrylamide), (α-substituted) acrylamide. Amino groups (compounds in which one or both of the terminal hydrogen atoms are substituted with a substituent, and the like).
Examples of the substituent that may be bonded to the α-position carbon atom of acrylamide or a derivative thereof are the same as those described as the substituent bonded to the α-position carbon atom of the α-substituted acrylate ester.
As the substituent that substitutes one or both of the hydrogen atoms at the amino group terminal of (α-substituted) acrylamide, an organic group is preferable. Although it does not specifically limit as this organic group, For example, the thing similar to the organic group which the said ((alpha) substituted) acrylate ester has is mentioned.
As the compound in which one or both of the hydrogen atoms at the terminal of the amino group of (α-substituted) acrylamide are substituted with a substituent, for example, —C (= bonded to the α-position carbon atom in the (α-substituted) acrylic acid ester O) —O—, —C (═O) —N (R ^b ) — [wherein R ^b is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ] Are substituted.
In the formula, the alkyl group in R ^b is preferably linear or branched.

The “vinyl aromatic compound” is a compound having an aromatic ring and one vinyl group bonded to the aromatic ring, and examples thereof include styrene or a derivative thereof, vinyl naphthalene or a derivative thereof.
Examples of the substituent that may be bonded to the α-position carbon atom of the vinyl aromatic compound (the carbon atom bonded to the aromatic ring among the carbon atoms of the vinyl group) include the α-position carbon atom of the α-substituted acrylate ester. Examples thereof are the same as those listed as the substituents bonded to.
Hereinafter, a vinyl aromatic compound in which a hydrogen atom bonded to a carbon atom at the α-position is substituted with a substituent may be referred to as an (α-substituted) vinyl aromatic compound.

As “styrene or a derivative thereof”, a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, or a hydrogen atom bonded to a benzene ring may be substituted with a substituent other than a hydroxyl group. Good styrene (hereinafter, also referred to as (α-substituted) styrene), a hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, and a hydrogen atom bonded to the benzene ring is other than a hydroxyl group Hydroxystyrene which may be substituted with a substituent (hereinafter also referred to as (α-substituted) hydroxystyrene), (α-substituted) a compound in which the hydrogen atom of the hydroxyl group of hydroxystyrene is substituted with an organic group, The hydrogen atom bonded to the carbon atom may be substituted with a substituent, and the hydrogen atom bonded to the benzene ring may be substituted with a substituent other than a hydroxyl group and a carboxy group. Sulfonyl benzoic acid (hereinafter sometimes referred to (alpha-substituted) vinyl benzoic acid.), (Alpha-substituted) hydrogen atom of the carboxyl group of the vinyl benzoate compounds substituted with organic groups, and the like.
Hydroxystyrene is a compound in which one vinyl group and at least one hydroxyl group are bonded to a benzene ring. 1-3 are preferable and, as for the number of the hydroxyl groups couple | bonded with a benzene ring, 1 is especially preferable. The bonding position of the hydroxyl group in the benzene ring is not particularly limited. When the number of hydroxyl groups is one, the para 4-position of the vinyl group bonding position is preferred. When the number of hydroxyl groups is an integer of 2 or more, any bonding position can be combined.
Vinyl benzoic acid is a compound in which one vinyl group is bonded to the benzene ring of benzoic acid. The bonding position of the vinyl group in the benzene ring is not particularly limited.
The substituent other than the hydroxyl group and the carboxy group that may be bonded to the benzene ring of styrene or a derivative thereof is not particularly limited, and examples thereof include a halogen atom, an alkyl group having 1 to 5 carbon atoms, and an alkyl group having 1 to 5 carbon atoms. Examples include halogenated alkyl groups. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
The organic group in the compound in which the hydrogen atom of the hydroxyl group of (α-substituted) hydroxystyrene is substituted with an organic group is not particularly limited, and examples thereof include the organic groups mentioned as the organic group of the (α-substituted) acrylate ester. It is done.
The organic group in the compound in which the hydrogen atom of the carboxy group of (α-substituted) vinylbenzoic acid is substituted with an organic group is not particularly limited. For example, the organic groups mentioned as the organic group of the (α-substituted) acrylic acid ester Is mentioned.

As "vinyl naphthalene or a derivative thereof", the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and the hydrogen atom bonded to the naphthalene ring is substituted with a substituent other than a hydroxyl group. A good vinyl naphthalene (hereinafter sometimes referred to as (α-substituted) vinyl naphthalene), a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and a hydrogen atom bonded to the naphthalene ring is Vinyl (hydroxynaphthalene) optionally substituted with a substituent other than a hydroxyl group (hereinafter sometimes referred to as (α-substituted) vinyl (hydroxynaphthalene)), (α-substituted) hydrogen atom of hydroxyl group of vinyl (hydroxynaphthalene) Are compounds substituted with a substituent, and the like.
Vinyl (hydroxynaphthalene) is a compound in which one vinyl group and at least one hydroxyl group are bonded to a naphthalene ring. The vinyl group may be bonded to the 1-position of the naphthalene ring or may be bonded to the 2-position. 1-3 are preferable and, as for the number of the hydroxyl groups couple | bonded with a naphthalene ring, 1 is especially preferable. The bonding position of the hydroxyl group in the naphthalene ring is not particularly limited. In the case where a vinyl group is bonded to the 1-position or 2-position of the naphthalene ring, any one of the 5- to 8-positions of the naphthalene ring is preferable. In particular, when the number of hydroxyl groups is one, any one of 5 to 7 positions of the naphthalene ring is preferable, and 5 or 6 positions are preferable. When the number of hydroxyl groups is an integer of 2 or more, any bonding position can be combined.
Examples of the substituent which may be bonded to the naphthalene ring of vinyl naphthalene or a derivative thereof are the same as those described above as the substituent which may be bonded to the benzene ring of the (α-substituted) styrene.
The organic group in the compound in which the hydrogen atom of the hydroxyl group of (α-substituted) vinyl (hydroxynaphthalene) is substituted with an organic group is not particularly limited. For example, the same organic group as the (α-substituted) acrylic acid ester has Is mentioned.

Specific examples of structural units derived from (α-substituted) acrylic acid or esters thereof include structural units represented by the following general formula (U-1).
Specific examples of the structural unit derived from the structural unit derived from (α-substituted) acrylamide or a derivative thereof include a structural unit represented by the following general formula (U-2).
Among the (α-substituted) vinyl aromatic compounds, specific examples of the structural unit derived from (α-substituted) styrene or a derivative thereof include a structural unit represented by the following general formula (U-3). Specific examples of the structural unit derived from (α-substituted) vinylnaphthalene or a derivative thereof include a structural unit represented by the following general formula (U-4).

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基である。Ｘ^ａ〜Ｘ^ｄはそれぞれ独立に水素原子または有機基である。Ｒ^ｂは水素原子または炭素数１〜５のアルキル基である。Ｒ^ｃおよびＲ^ｄはそれぞれ独立にハロゲン原子、−ＣＯＯＸ^ｅ（Ｘ^ｅは水素原子または有機基である。）、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基である。ｐｘは０〜３の整数であり、ｑｘは０〜５の整数であり、ｐｘ＋ｑｘは０〜５である。ｑｘが２以上の整数である場合、複数のＲ^ｃはそれぞれ同じであっても異なってもよい。ｘは０〜３の整数であり、ｙは０〜３の整数であり、ｚは０〜４の整数であり、ｘ＋ｙ＋ｚは０〜７である。ｙ＋ｚが２以上の整数である場合、複数のＲ^ｄはそれぞれ同じであっても異なってもよい。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. X ^{a to} X ^d are each independently a hydrogen atom or an organic group. R ^b is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R ^c and R ^d are each independently a halogen atom, —COOX ^e (X ^e is a hydrogen atom or an organic group), an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. . px is an integer of 0 to 3, qx is an integer of 0 to 5, and px + qx is 0 to 5. When qx is an integer of 2 or more, the plurality of R ^c may be the same or different. x is an integer of 0-3, y is an integer of 0-3, z is an integer of 0-4, and x + y + z is 0-7. When y + z is an integer of 2 or more, the plurality of R ^d may be the same or different. ]

  When the component (X) has a structural unit containing the group (I) (hereinafter referred to as the structural unit (x1)), the structural unit (x1) is derived from a compound having an ethylenic double bond. A structural unit that includes the group (I) is preferable, and a structural unit represented by the following general formula (x1-1) is particularly preferable.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり、Ｒ^１は水素原子または置換基であり、Ｒ^２は置換基であり、ｓは１〜４の整数であり、ｔは０〜２の整数であり、Ａは−Ｏ−又は−ＮＨであり、ｖは０又は１であり、Ｘ^０は単結合又は２価の連結基である。］

[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, R ¹ is a hydrogen atom or a substituent, and R ² is a substituent, s is an integer of 1 to 4, t is an integer of 0 to 2, A is —O— or —NH, v is 0 or 1, and X ⁰ is a single bond or a divalent linking group. It is. ]

In formula (x1-1), the alkyl group and halogenated alkyl group in R are the alkyl groups and halogenated alkyls mentioned as the substituent bonded to the α-position carbon atom of the α-substituted acrylic acid or ester thereof, respectively. The same thing as a group is mentioned.
^{R 1, R 2, s,} t are the same as ^{R 1, R 2, s,} t of each of the formulas (I-1) in.
A is —O— or —NH, and preferably —O—.
v is 0 or 1, and is preferably 1.
Note that v is 0 means that —C (═O) —A— in the formula is a single bond.
Examples of the divalent linking group for X ^0, but are not limited to, divalent hydrocarbon group which may have a substituent group, and a divalent linking group containing a hetero atom as preferred.

(Divalent hydrocarbon group which may have a substituent)
In the hydrocarbon group as the divalent linking group, “may have a substituent” means that a part of carbon atoms constituting the hydrocarbon group is a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. And a part or all of the hydrogen atoms constituting the hydrocarbon group may be substituted with a substituent.
The hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.
An aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.
More specific examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, and the like.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and still more preferably 1 to 5 carbon atoms.
As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable. 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 can be mentioned.
As the branched aliphatic hydrocarbon group, a branched alkylene group is preferred, and specifically, —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ). _{2 -, - C (CH 3} ) (CH 2 CH 3) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as - _{CH (CH 3) CH 2 -} , - CH (CH 3) CH (CH 3) -, - C (CH 3) 2 CH 2 -, - CH (CH 2 CH 3) CH 2 -, - C (CH 2 CH _{3) 2} -CH ₂ - alkyl groups such _{as; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - alkyl trimethylene groups such as; -CH _(CH 3) _{CH 2 CH 2 CH 2 -,} - CH 2 CH (CH 3) CH 2 CH 2 - And the like alkyl alkylene group such as an alkyl tetramethylene group of. The alkyl group in the alkyl alkylene group is preferably a linear alkyl group having 1 to 5 carbon atoms.
The linear or branched aliphatic hydrocarbon group may or may not have a substituent (a group or atom other than a hydrogen atom) that replaces a hydrogen atom. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, and an oxo group (═O).

As the aliphatic hydrocarbon group containing a ring in the structure, a cyclic aliphatic hydrocarbon group which may contain a substituent containing a hetero atom in the ring structure (excluding two hydrogen atoms from the aliphatic hydrocarbon ring) Group), a group in which the cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and the cyclic aliphatic hydrocarbon group is a linear or branched chain fatty acid. Group intervening in the middle of the group hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include 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 polycyclic or monocyclic. As the monocyclic aliphatic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic aliphatic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically adamantane, Examples include norbornane, isobornane, tricyclodecane, and tetracyclododecane.
The cyclic aliphatic hydrocarbon group may or may not have a substituent (a group or atom other than a hydrogen atom) that replaces a hydrogen atom. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxo group (═O).
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group or a tert-butoxy group. Most preferred is an ethoxy group.
Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent include groups in which part or all of the hydrogen atoms of the alkyl group have been 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 the substituent containing the hetero atom, —O—, —C (═O) —O—, —S—, —S (═O) ₂ —, and —S (═O) ₂ —O— are preferable.

The aromatic hydrocarbon group as the divalent hydrocarbon group is a divalent hydrocarbon group having at least one aromatic ring, and may be composed only of an aromatic ring. It may be composed of an aliphatic hydrocarbon group bonded to an aromatic ring.
The aromatic hydrocarbon group may have a substituent. For example, a part of carbon atoms constituting the aromatic ring of the aromatic hydrocarbon group may be substituted with a hetero atom, and the hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group is substituted with the substituent. May be. In addition, when the aromatic hydrocarbon group has an aliphatic hydrocarbon group bonded to an aromatic ring, a part of carbon atoms constituting the aliphatic hydrocarbon group is substituted with a divalent linking group containing a hetero atom. Or a part or all of the hydrogen atoms constituting the aliphatic hydrocarbon group may be substituted with a substituent.
Examples of the aliphatic hydrocarbon group and the divalent linking group containing a hetero atom include the same aliphatic hydrocarbon groups as those described above, and the same divalent linking groups containing a hetero atom as will be described later. It is done.

The aromatic ring of the aromatic hydrocarbon group is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 (where n is 0 and a natural number) π electrons, and may be monocyclic or polycyclic. . 5-30 are preferable, as for the number of atoms which comprise the ring skeleton of an aromatic ring, 5-20 are more preferable, 5-15 are more preferable, 6-15 are especially preferable, and 6-10 are the most preferable. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene and phenanthrene; aromatic heterocycles in which a part of carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms; etc. Is mentioned. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, the aromatic hydrocarbon group as the divalent hydrocarbon group is a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocyclic ring (arylene group or heteroarylene group); A group in which two hydrogen atoms have been removed from an aromatic compound (for example, biphenyl, fluorene, etc.) containing one aromatic ring; a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (aryl group or hetero group) A group in which one of the hydrogen atoms of the aryl group is substituted with an alkylene group (for example, a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc. A group in which one hydrogen atom is further removed from the aryl group in the arylalkyl group); The alkylene group bonded to the aryl group or heteroaryl group preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.
5-30 are preferable, as for carbon number of these aromatic hydrocarbon groups, 5-20 are more preferable, 5-15 are more preferable, 6-15 are especially preferable, and 6-10 are the most preferable. However, when the aromatic hydrocarbon group has a part or all of the hydrogen atoms having a substituent, the number of carbons in the aromatic hydrocarbon group does not include the number of carbons in the substituent.

A substituent that the aromatic hydrocarbon group may have (for example, a substituent that may substitute a hydrogen atom bonded to an aromatic ring of the aromatic hydrocarbon group, or an aliphatic hydrocarbon group in the aromatic ring Examples of the substituent (which may substitute a hydrogen atom of the aliphatic hydrocarbon group when bonded) include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxo group (═O ) And the like.
The alkyl group as a substituent of the aromatic hydrocarbon group is preferably an alkyl group having 1 to 6 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. preferable.
The alkoxy group as a substituent of the aromatic hydrocarbon group is preferably an alkoxy group having 1 to 6 carbon atoms, and is a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a tert- A butoxy group is preferable, and a methoxy group and an ethoxy group are most preferable.
Examples of the halogen atom as a substituent for the aromatic hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as a substituent of the aromatic hydrocarbon group include an alkyl group having 1 to 6 carbon atoms, such as an alkyl group such as a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group. And a group in which part or all of the hydrogen atoms are substituted with the halogen atoms.

(Divalent linking group containing a hetero atom)
The hetero atom in the divalent linking group containing a hetero atom is an atom other than a carbon atom and a hydrogen atom, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom.
As the divalent linking group containing a hetero atom, specifically, —O—, —C (═O) —, —C (═O) —O—, —O—C (═O) —O—, _{-S -, - S (= O} ) 2 -, - S (= O) 2 -O -, - NH -, - NH-C (= O) -, - NH-C (= NH) -, = N Non-hydrocarbon linking groups such as-, and combinations of at least one of these non-hydrocarbon linking groups with a divalent hydrocarbon group. Examples of the divalent hydrocarbon group include the same divalent hydrocarbon groups that may have a substituent as described above, and a linear or branched aliphatic hydrocarbon group is preferable. .
Among the above, -NH-, -NH- in -C (= O) -NH-, and H in -NH-C (= NH)-are each substituted with a substituent such as an alkyl group or an acyl group. May be. The substituent preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.

X ⁰ is, among the above, a single bond, a linear or branched alkylene group, a cyclic aliphatic hydrocarbon group which may have a substituent, and an aromatic which may have a substituent. A group hydrocarbon group or a divalent linking group containing a hetero atom is preferred.
When X ⁰ is a linear or branched alkylene group, the alkylene group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and 1 to 4 carbon atoms. It is particularly preferred that it has 1 to 3 carbon atoms. Specifically, in the description of the “divalent hydrocarbon group which may have a substituent” as the divalent linking group, it is exemplified as a linear or branched aliphatic hydrocarbon group. Examples are the same as the linear alkylene group and the branched alkylene group.
In the case where X ⁰ is a cyclic aliphatic hydrocarbon group which may have a substituent, the cyclic aliphatic hydrocarbon group includes “having a substituent as the divalent linking group”. In the description of “may be a divalent hydrocarbon group”, the same cyclic aliphatic hydrocarbon groups as those listed as “aliphatic hydrocarbon groups containing a ring in the structure” can be mentioned.
As the cyclic aliphatic hydrocarbon group, a group in which two or more hydrogen atoms have been removed from cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane or tetracyclododecane is particularly preferable. Further, some of the carbon atoms constituting the ring structure of these cyclic aliphatic hydrocarbon groups are —O—, —C (═O) —O—, —S—, —S (═O) ₂ — or A group substituted with —S (═O) ₂ —O— is also preferable. As such a group, for example, one hydrogen atom is further removed from the cyclic groups represented by the formulas (L1) to (L6) and (S1) to (S4) mentioned in the description of the (Y) component described later. And the like.
In the case where X ⁰ is an aromatic hydrocarbon group which may have a substituent, the aromatic hydrocarbon group may be “a divalent optionally having a substituent” as the divalent linking group. Examples thereof include the same aromatic hydrocarbon groups as mentioned in the explanation of “hydrocarbon group of”. Of these, a phenylene group or a naphthylene group which may be substituted with a fluorine atom is preferable.

When X ⁰ is a divalent linking group containing a hetero atom, preferred examples of the linking group include —O—, —C (═O) —O—, —C (═O) —, —O—C. (═O) —O—, —C (═O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group or an acyl group), —S—, —S ( _{= O) 2 -, - S} (= O) 2 -O-, the formula ^{-Y 21 -O-Y 22 -,} - [Y 21 -C (= O) -O] m '-Y 22 - or - A group represented by Y ²¹ —O—C (═O) —Y 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 0-3. ] Etc. are mentioned.
When X ⁰ is —NH—, the H may be substituted with a substituent such as an alkyl group or acyl. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
Formula ^{-Y 21 -O-Y 22 -,} - [Y 21 -C (= O) -O] m '-Y 22 - or ^{-Y 21 -O-C (= O} ) -Y 22 - ^{In, Y 21} And Y ²² are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include those similar to the “divalent hydrocarbon group optionally having substituent (s)” mentioned in the description of the divalent linking group.
Y ²¹ is preferably a linear aliphatic hydrocarbon group, more preferably a linear alkylene group, still more preferably a linear alkylene group having 1 to 5 carbon atoms, and particularly preferably a methylene group or an ethylene group. preferable.
Y ²² is preferably a linear or branched aliphatic hydrocarbon group, and more preferably a methylene group, an ethylene group or an alkylmethylene group. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.
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, Or 1 is more preferable, and 1 is particularly preferable. That is, the group represented by the formula — [Y ²¹ —C (═O) —O] _{m ′} —Y ²² — is represented by the formula —Y ²¹ —C (═O) —O—Y ²² —. The group is particularly preferred. Among these, a group represented by the formula — (CH ₂ ) _{a ′} —C (═O) —O— (CH ₂ ) _{b ′} — is preferable. In the formula, a ′ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, further preferably 1 or 2, and most preferably 1. b ′ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, more preferably 1 or 2, and most preferably 1.
As the divalent linking group containing a hetero atom in X ^0, an organic group comprising a combination of at least one kind, a non-hydrocarbon group and a divalent hydrocarbon group is preferable. Among these, a linear group having an oxygen atom as a hetero atom, for example, a group containing an ether bond or an ester bond, is preferable, and the above formulas -Y ²¹ -O-Y ²² -,-[Y ²¹ -C (= O ) —O] _{m ′} —Y ²² — or —Y ²¹ —O—C (═O) —Y ²² — is more preferred, and the group represented by the formula — [Y ²¹ —C (═O) —O] is preferred. _The group represented by m′—Y ²² — or —Y ²¹ —O—C (═O) —Y ²² — is preferred.

X ⁰ is preferably a single bond, a linear or branched alkylene group, a cyclic aliphatic hydrocarbon group, or a divalent linking group containing a hetero atom among the above. Alternatively, a branched alkylene group or a divalent linking group containing a hetero atom is more preferable, which is represented by a single bond, a linear or branched alkylene group, and the formula —Y ²¹ —O—Y ²² —. Or a group represented by the formula — [Y ²¹ —C (═O) —O] _{m ′} —Y ²² — or a group represented by the formula —Y ²¹ —O—C (═O) —Y ²² —. More preferred are single bonds.

As the structural unit (x1), a structural unit derived from an acrylate ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, and including the group (I) is particularly preferable. preferable. As such a structural unit, v in the general formula (x1-1) is 0, X ⁰ is a single bond, v in the general formula (x1-1) is 1, and A is And a structural unit in which X ⁰ is a divalent linking group. Specific examples include a structural unit represented by the following general formula (x1-11), a structural unit represented by the following general formula (x1-12), and the like.

［式中、Ｒ、Ｒ^１、Ｒ^２、ｓ、ｔはそれぞれ前記と同じであり、Ｘ^０１は２価の連結基である。］

[Wherein, R, R ¹ , R ² , s, and t are the same as defined above, and X ⁰¹ is a divalent linking group. ]

Equation (x1-11), (x1-12) ^in, the same ^{R, R 1, R 2,} s, R of t each the formula (x1-1) in, R ^1, R 2, s, and t is there.
The ^{X 01} in the formula (x1-12), the same as the divalent linking group for ^{X 0} in formula (x1-1) in like.

As the structural unit (x1), one type may be used alone, or two or more types may be used in combination.
In the component (X), the proportion of the structural unit (x1) is preferably 10 mol% or more, more preferably 20 mol% or more, and more preferably 30 mol% or more with respect to the total of all the structural units constituting the component (X). Further preferred.
By setting the proportion of the structural unit (x1) to 10 mol% or more, when exposure is performed in the formation of a resist pattern, a sufficient increase in polarity occurs and good pattern formation can be performed.
In addition, when the structural unit (x1) has a group represented by the general formula (I-1) as the group (I), the group includes a lactone cyclic group. Therefore, the component (X) is added to the resist film. When used for formation, the effect of improving the adhesion of the resist film to the substrate is exhibited. Therefore, the higher the proportion of the structural unit (x1), the better the adhesion to the substrate.
The upper limit of the proportion of the structural unit (x1) is not particularly limited, and may be 100 mol%. The dissolution rate with respect to the organic developer, and optionally containing other structural units, What is necessary is just to adjust suitably in consideration of a balance etc.
For example, by adjusting the proportion of the structural unit (x1), the dissolution rate in the organic developer can be adjusted. The structural unit (x1) has a relatively high polarity, particularly when the group (I) has a group represented by the general formula (I-1) as the group (I). Therefore, as the proportion of the structural unit (x1) is increased, the polarity of the (X) component before exposure (or unexposed portion) is increased and the solubility in an organic developer tends to be decreased. By reducing the proportion of the structural unit (x1) by including a structural unit having a lower polarity (higher hydrophobicity) than the structural unit (x1), the solubility in an organic developer can be increased.
When the component (X) is a copolymer containing the structural unit (x1) and other structural units, the proportion of the structural unit (x1) is 10 with respect to the total of all the structural units constituting the component (X). -90 mol% is preferable, 20-80 mol% is more preferable, 30-70 mol% is further more preferable.

The component (X) may have a structural unit other than the structural unit (x1) as long as the effects of the present invention are not impaired. Such a constitutional unit is not particularly limited as long as it can form a copolymer with the constitutional unit (x1). For example, resist compositions for ArF excimer laser, KrF excimer laser (preferably for ArF excimer laser), etc. Many conventionally known structural units can be used as the structural unit used for the resin component (base resin or the like) used as the base material component of the product.
As such a structural unit, for example,
A structural unit (x2) that is less polar than the structural unit (x1) and stable to the base;
A structural unit (x3) containing a polar group,
Structural unit (x4) having —SO ₂ -containing cyclic group or lactone cyclic group which is inert to the base
Etc.

[Structural unit (x2)]
The structural unit (x2) is a structural unit that is less polar than the structural unit (x1) and stable to the base.
“Stable to base” means that when a base is generated from component (Y) by exposure, the structure does not change even if the base acts.
As a structural unit (x2), the structural unit (x2) represented by the following general formula (x2-1) is mentioned, for example.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基、又は炭素数１〜５のハロゲン化アルキル基であり、Ａは−Ｏ−又は−ＮＨ−であり、ｖは０又は１であり、Ｘ^０は単結合又は２価の連結基であり、Ｒ^２０は塩基非脱離性の環式基である。］

[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, A is —O— or —NH—, and v is 0 or 1] X ⁰ is a single bond or a divalent linking group, and R ²⁰ is a non-base-leaving cyclic group. ]

^{Wherein, R, A, v, X} 0 R in each of the general formulas (x1-1) in, A, v, are the same as those for ^{X 0.}
The “base non-leaving cyclic group” in R ²⁰ remains in the structural unit as it is without leaving even when the base acts when the base is generated from the component (Y) by exposure. It is a cyclic group.
The cyclic group for R ²⁰ may be an aliphatic cyclic group or an aromatic cyclic group.
The ring skeleton of the aliphatic cyclic group may be composed only of carbon atoms or may be interspersed with atoms other than carbon atoms, but is preferably composed only of carbon atoms. The aliphatic cyclic group may be either saturated or unsaturated, but is usually preferably saturated.
As the aliphatic cyclic group, those having 3 to 30 carbon atoms are preferable, those having 5 to 30 are more preferable, 5 to 20 are more preferable, 6 to 15 are particularly preferable, and 6 to 12 is most preferable. .
The aliphatic cyclic group may be monocyclic or polycyclic. As the monocyclic aliphatic cyclic group, a group in which one or more hydrogen atoms have been removed from a monocycloalkane is preferable. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples include cyclobutane, cyclopentane, and cyclohexane. The polycyclic aliphatic cyclic group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms. Moreover, as a polycycloalkane, a 2-4 ring thing is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
In addition, an aliphatic cyclic group in which a part of carbon atoms constituting the ring of these aliphatic cyclic groups is substituted with an ether group (—O—) can also be used.
In these aliphatic cyclic groups, the hydrogen atom bonded to the ring skeleton may be substituted with a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms, and an oxygen atom (= O).
As the aliphatic cyclic group, at least one selected from a cyclopentyl group, a cyclohexyl group, a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. .

The aromatic cyclic group is a group obtained by removing one hydrogen atom from an aromatic ring which may have a substituent.
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 (where n is 0 and a natural number), and may be monocyclic or polycyclic. 5-30 are preferable, as for the number of atoms which comprise the ring skeleton of an aromatic ring, 5-20 are more preferable, 5-15 are more preferable, 6-15 are especially preferable, and 6-10 are the most preferable. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene and phenanthrene; aromatic heterocycles in which a part of carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms; etc. Is mentioned. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, the aromatic hydrocarbon group is a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group); an aromatic compound containing two or more aromatic rings A group in which one hydrogen atom is removed from (eg, biphenyl, fluorene, etc.); 5-30 are preferable, as for carbon number of these aromatic hydrocarbon groups, 5-20 are more preferable, 5-15 are more preferable, 6-15 are especially preferable, and 6-10 are the most preferable. However, when the aromatic hydrocarbon group has a part or all of the hydrogen atoms having a substituent, the number of carbons in the aromatic hydrocarbon group does not include the number of carbons in the substituent.
Among the above, the aromatic cyclic group is preferably an aryl group, and is preferably a phenyl group or a naphthyl group.
In the aromatic cyclic group, a hydrogen atom bonded to the ring skeleton may be substituted with a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms, and an oxygen atom (= O).

As the structural unit (x2), among the above, v is 1, A is —O—, X ⁰ is a single bond, R ²⁰ is an aliphatic cyclic group, v is 0, X ⁰ is a single bond, the structural unit R ²⁰ is a phenyl group optionally having substituent (x22), v is 0, X ⁰ is a single bond, R ²⁰ is an optionally substituted naphthyl The structural unit (x23) as a group is preferable.
Specifically, as the structural unit (x21), for example, X ^a in the general formula (U-1) exemplified in the description of “structural unit derived from (α-substituted) acrylic acid or an ester thereof” represents an aliphatic ring. What is a formula group is mentioned.
Specifically, as the structural unit (x22), for example, —OX bonded to a benzene ring in the general formula (U-3) mentioned in the description of the “structural unit derived from (α-substituted) styrene or a derivative thereof”. The number p of ^c is 0, and the number qx of any substituent R ^c is an integer of 0 to 5.
Specifically, as the structural unit (x23), for example, the structural unit (x23) is bonded to the naphthalene ring in the general formula (U-4) mentioned in the description of the “structural unit derived from ((α-substituted) vinylnaphthalene or a derivative thereof”. The number x of -OX ^d is 0, and the number y + z of any substituent R ^d is an integer of 0 to 7.

The structural unit (x2) contained in the component (X) may be one type or two or more types.
When the component (X) contains the structural unit (x2), the proportion of the structural unit (x2) in the component (X) is 1 to 70 mol with respect to the total of all the structural units constituting the component (X). % Is preferable, 10 to 70 mol% is more preferable, and 20 to 60 mol% is more preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (x2) can be sufficiently obtained, and by setting it to the upper limit value or less, appropriate solubility is maintained in the resist solvent and the unexposed portion is dissolved in the organic developer. It expresses sex and can be balanced with other structural units.

[Structural unit (x3)]
The component (X) may have a structural unit (x3) containing a polar group in addition to the structural unit (x1) or in addition to the structural units (x1) and (x2). By adjusting the proportion of the structural unit (x3), the dissolution rate in the organic developer can be adjusted. For example, the higher the proportion of the structural unit (x3) in the component (X), the higher the polarity of the component (X) after exposure and the lower the solubility in an organic developer.
Examples of the polar group include —OH, —COOH, —CN, —SO ₂ NH ₂ , —CONH ₂ , and the like. Those containing —COOH also include structural units of (α-substituted) acrylic acid.
The structural unit (x3) is preferably a structural unit containing a hydrocarbon group in which a part of hydrogen atoms is substituted with a polar group. The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. Of these, the hydrocarbon group is more preferably an aliphatic hydrocarbon group.
Examples of the aliphatic hydrocarbon group in the hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and an aliphatic cyclic group (monocyclic group, polycyclic group). Cyclic group).
As the aliphatic cyclic group (monocyclic group, polycyclic group), for example, a resin for a resist composition for ArF excimer laser can be appropriately selected from those proposed. The aliphatic cyclic group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. Specifically, for example, a group in which two or more hydrogen atoms have been removed from a monocycloalkane; a group in which two or more hydrogen atoms have been removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, etc. Can be mentioned. More specifically, a group in which two or more hydrogen atoms are removed from a monocycloalkane such as cyclopentane or cyclohexane; two or more groups from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples include a group excluding a hydrogen atom. The aliphatic cyclic group may or may not have a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, and a fluorinated alkyl group having 1 to 5 carbon atoms.

The aromatic hydrocarbon group in the 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 more preferable, and 6-12 are especially preferable. However, the carbon number does not include the carbon number in the substituent. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene and phenanthrene; aromatic heterocycles in which a part of carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms; etc. Is mentioned. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, the aromatic hydrocarbon group as the divalent hydrocarbon group is a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring or aromatic heterocyclic ring (arylene group or heteroarylene group); A group obtained by removing two hydrogen atoms from an aromatic compound containing an aromatic ring (for example, biphenyl, fluorene, etc.); a group in which one of the hydrogen atoms of the aromatic ring is substituted with an alkylene group (for example, a benzyl group, a phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, arylalkyl groups such as 2-naphthylethyl group and heteroarylalkyl groups), a group obtained by further removing one hydrogen atom from the aromatic ring; Can be mentioned. The number of carbon atoms of the alkylene group that replaces the hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocyclic ring is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1. .
The aromatic hydrocarbon group may have a substituent. For example, the hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
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 halogen atom as a substituent for the aromatic hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent include groups in which some or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.

  As the structural unit (x3), structural units represented by general formula (x3-1) shown below are preferred.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基、又は炭素数１〜５のハロゲン化アルキル基である。Ｌ^０は−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｏ）−ＮＲ^ｎ−（Ｒ^ｎは水素原子又は炭素数１〜５のアルキル基である）又は単結合である。Ｒ^０は−ＣＯＯＨ、または置換基として−ＯＨ、−ＣＯＯＨ、−ＣＮ、−ＳＯ_２ＮＨ_２及び−ＣＯＮＨ_２からなる群より選択される少なくとも一種の基を有する炭化水素基であり、任意の位置に酸素原子又は硫黄原子を有していてもよい。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. L ⁰ is —C (═O) —O—, —C (═O) —NR ⁿ — (R ⁿ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms) or a single bond. R ⁰ is —COOH or a hydrocarbon group having at least one group selected from the group consisting of —OH, —COOH, —CN, —SO ₂ NH ₂ and —CONH ₂ as a substituent, May have an oxygen atom or a sulfur atom. ]

In the formula (x3-1), the alkyl group represented by R is preferably a linear or branched alkyl group, and specifically includes a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, and an isobutyl group. Group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like.
Examples of the halogenated alkyl group for R include groups in which some or all of the hydrogen atoms of the aforementioned R alkyl group have been substituted with halogen atoms. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable.
R is preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms, and particularly preferably a hydrogen atom or a methyl group.
In Formula (x3-1), L ⁰ is —C (═O) —O— or —C (═O) —NR ⁿ — (R ⁿ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms). Or it is a single bond. ^Examples of the alkyl group for R ⁿ include the same alkyl groups as those for R.
In Formula (x3-1), R ⁰ is a hydrocarbon group having at least one group selected from the group consisting of —OH, —COOH, —CN, —SO ₂ NH ₂ and —CONH ₂ as a substituent. Yes, it may have an oxygen atom or a sulfur atom at any position.
The “hydrocarbon group having a substituent” means that at least a part of hydrogen atoms bonded to the hydrocarbon group is substituted with a substituent.
The hydrocarbon group for R ⁰ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
As the aliphatic hydrocarbon group for R ^{0, a} linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) or an aliphatic cyclic group (monocyclic group, polycyclic group) Group), and the description thereof is the same as described above.
The aromatic hydrocarbon group in R ⁰ is a hydrocarbon group having an aromatic ring, and this description is the same as described above.
However, R ⁰ may have an oxygen atom or a sulfur atom at an arbitrary position. The phrase “may have an oxygen atom or a sulfur atom at any position” means a carbon atom constituting a hydrocarbon group or a hydrocarbon group having a substituent (including the carbon atom of the substituent portion). ) May be substituted with an oxygen atom or a sulfur atom, or a hydrogen atom bonded to a hydrocarbon group may be substituted with an oxygen atom or a sulfur atom.
Hereinafter, R ⁰ having an oxygen atom (O) at an arbitrary position will be exemplified as an example.

［式中、Ｗ^００は炭化水素基であり、Ｒ^ｍは炭素数１〜５のアルキレン基である。］

[Wherein, W ⁰⁰ is a hydrocarbon group, and R ^m is an alkylene group having 1 to 5 carbon atoms. ]

In the above formula, W ⁰⁰ is a hydrocarbon group, and examples thereof include the same as R ⁰ in the formula (x3-1). W ⁰⁰ is preferably an aliphatic hydrocarbon group, more preferably an aliphatic cyclic group (monocyclic group or polycyclic group).
R ^m is preferably linear or branched, preferably an alkylene group having 1 to 3 carbon atoms, and more preferably a methylene group or an ethylene group.

More preferred as the structural unit (x3) is more specifically a structural unit derived from (α-substituted) acrylic acid, and any one of the following general formulas (x3-11) to (x3-13) Examples of the structural unit are as follows.
Examples of the structural unit derived from (α-substituted) acrylic acid include structural units in which L ⁰ in the formula (x3-1) is a single bond and R ⁰ is —COOH.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基、又は炭素数１〜５のハロゲン化アルキル基である。Ｗ^０１は置換基として−ＯＨ、−ＣＯＯＨ、−ＣＮ、−ＳＯ_２ＮＨ_２及び−ＣＯＮＨ_２からなる群より選択される少なくとも一種の基を有する芳香族炭化水素基である。Ｐ^０２及びＰ^０３はそれぞれ−Ｃ（＝Ｏ）−Ｏ−又は−Ｃ（＝Ｏ）−ＮＲ^ｎ−（Ｒ^ｎは水素原子又は炭素数１〜５のアルキル基である）である。Ｗ^０２は置換基として−ＯＨ、−ＣＯＯＨ、−ＣＮ、−ＳＯ_２ＮＨ_２及び−ＣＯＮＨ_２からなる群より選択される少なくとも一種の基を有する環状の炭化水素基であり、任意の位置に酸素原子又は硫黄原子を有していてもよい。Ｗ^０３は置換基として−ＯＨ、−ＣＯＯＨ、−ＣＮ、−ＳＯ_２ＮＨ_２及び−ＣＯＮＨ_２からなる群より選択される少なくとも一種の基を有する直鎖状の炭化水素基である。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. W ⁰¹ is an aromatic hydrocarbon group having at least one group selected from the group consisting of —OH, —COOH, —CN, —SO ₂ NH ₂ and —CONH ₂ as a substituent. P ⁰² and P ⁰³ are each —C (═O) —O— or —C (═O) —NR ⁿ — (R ⁿ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms). W ⁰² is a cyclic hydrocarbon group having at least one group selected from the group consisting of —OH, —COOH, —CN, —SO ₂ NH ₂ and —CONH ₂ as a substituent, and oxygen at any position. You may have an atom or a sulfur atom. W ⁰³ is a linear hydrocarbon group having at least one group selected from the group consisting of —OH, —COOH, —CN, —SO ₂ NH ₂ and —CONH ₂ as a substituent. ]

[Structural Unit Represented by General Formula (x3-11)]
In the formula (x3-11), R is the same as described for R in the formula (x3-1).
The aromatic hydrocarbon group for W ⁰¹ is the same as that described for the aromatic hydrocarbon group for R ⁰ in formula (x3-1).
The aromatic hydrocarbon group in W ⁰¹ may have a substituent other than at least one selected from the group consisting of —OH, —COOH, —CN, —SO ₂ NH ₂ and —CONH ₂ . Examples of the substituent include a halogen atom, an alkyl group having 1 to 5 carbon atoms, and a halogenated alkyl group having 1 to 5 carbon atoms. Among these, a halogen atom is preferable and a fluorine atom is particularly preferable.
Specific examples of preferable structural units represented by general formula (x3-11) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

[Structural Unit Represented by General Formula (x3-12)]
In the formula (x3-12), R is the same as described for R in the formula (x3-1).
P ⁰² is —C (═O) —O— or —C (═O) —NR ⁿ — (R ⁿ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), and —C (═O ) -O-. The alkyl group for R ⁿ is the same as the alkyl group for R.
The cyclic hydrocarbon group in W ⁰² is an aliphatic cyclic group (monocyclic group or polycyclic group) or aromatic hydrocarbon exemplified in the description of R ⁰ in the formula (x3-1). Examples of each group are the same.
W ⁰² may have an oxygen atom or a sulfur atom at an arbitrary position, and this description is the same as the description of R ⁰ in the formula (x3-1).
Specific examples of preferable structural units represented by general formula (x3-12) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

[Structural Unit Represented by General Formula (x3-13)]
In the formula (x3-13), R is the same as described for R in the formula (x3-1).
P ⁰³ is —C (═O) —O— or —C (═O) —NR ⁿ — (R ⁿ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), and —C (═O ) -O-. The alkyl group for R ⁿ is the same as the alkyl group for R.
The linear hydrocarbon group for W ⁰³ preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and still more preferably 1 to 3 carbon atoms.
The linear hydrocarbon group for W ⁰³ may further have a substituent (a) other than —OH, —COOH, —CN, —SO ₂ NH _2, and —CONH ₂ . Examples of the substituent (a) include an alkyl group having 1 to 5 carbon atoms, an aliphatic cyclic group (monocyclic group, polycyclic group), a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms, and the like. Can be mentioned. The number of carbon atoms of the aliphatic cyclic group (monocyclic group or polycyclic group) in the substituent (a) is preferably 3 to 30, more preferably 5 to 30, and further preferably 5 to 20 Preferably, 6-15 is especially preferable, and 6-12 is the most preferable. Specifically, for example, a group in which two or more hydrogen atoms are removed from a monocycloalkane; a group in which one or more hydrogen atoms are removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, etc. Can be mentioned. More specifically, a group in which two or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; one or more polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane Examples include a group excluding a hydrogen atom.
Further, straight-chain hydrocarbon group for W ^03, as in the structural unit represented by the following general formula as an example (x3-13-a), may have a plurality of substituents (a), A plurality of substituents (a) may be bonded to each other to form a ring.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基、又は炭素数１〜５のハロゲン化アルキル基である。Ｒ^ａ１及びＲ^ａ２はそれぞれ独立に炭素数１〜５のアルキル基、脂肪族環式基（単環式基、多環式基）、フッ素原子、又は炭素数１〜５のフッ素化アルキル基である。但し、Ｒ^ａ１とＲ^ａ２とが相互に結合して環を形成してもよい。ｑ^０は１〜４の整数である。］

[Wherein, R represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. R ^a1 and R ^a2 are each independently an alkyl group having 1 to 5 carbon atoms, an aliphatic cyclic group (monocyclic group or polycyclic group), a fluorine atom, or a fluorinated alkyl group having 1 to 5 carbon atoms. is there. However, R ^a1 and R ^a2 may be bonded to each other to form a ring. q ⁰ is an integer of 1 to 4. ]

In the formula (x3-13-a), R is the same as described for R in the formula (x3-1).
The aliphatic cyclic group (monocyclic group or polycyclic group) in R ^a1 and R ^a2 is the same as the aliphatic cyclic group (monocyclic group or polycyclic group) in the substituent (a). is there.
R ^a1 and R ^a2 may be bonded to each other to form a ring. In this ^case, a ^{R a1,} and ^{R a2,} cyclic group is formed by the carbon atoms to which the ^{R a1} and ^{R a2} are bonded together. The cyclic group may be a monocyclic group or a polycyclic group. Specifically, an aliphatic cyclic group (monocyclic group, Examples thereof include groups in which one or more hydrogen atoms have been removed from the monocycloalkane or polycycloalkane exemplified in the description of the polycyclic group).
q ⁰ is preferably 1 or 2, and more preferably 1.

Specific examples of preferred structural units represented by general formula (x3-13) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

The structural unit (x3) contained in the component (X) may be one type or two or more types.
In the component (X), the proportion of the structural unit (x3) is preferably 0 to 85 mol%, more preferably 0 to 80 mol%, based on all the structural units constituting the component (X). More preferred is ˜30 mol%. By setting the proportion of the structural unit (x3) to be equal to or higher than the lower limit value, the effects (resolution, lithography characteristics, pattern shape improvement effect) due to the inclusion of the structural unit (x3) are sufficiently obtained, and the upper limit value or less. This makes it easier to balance with other structural units.

[Structural unit (x4)]
The component (X) is inert to the base in addition to the structural unit (x1), or in addition to the structural units (x1) and (x2), or in addition to the structural units (x1) to (x3). there -SO 2 _- may have a structural unit having a containing cyclic group or the lactone-containing cyclic group (x4).
By having a —SO ₂ -containing cyclic group or lactone cyclic group that is inactive to the base, the substrate adhesion of the pattern in the exposed area and the collapse-improving property are improved. Further, it is conceivable that the —SO ₂ — group supplements the base generated in the exposure part in some form, thereby suppressing the catalytic decomposition reaction by the base and contributing to the control of the exposure margin during patterning. .
The —SO ₂ -containing cyclic group or lactone cyclic group is “inactive with respect to the base” when the base acts from the (Y) component by exposure, even if the base acts. It means that the structure of the ₂ -containing cyclic group or the lactone cyclic group does not change. Since the structure of the lactone cyclic group in the group (I-1) mentioned in the description of the structural unit (x1) changes when a base acts, the lactone cyclic group that is “inactive with respect to the base” Not applicable.

· -SO 2 _-, where-containing cyclic group, "- SO 2 _- containing cyclic group" is a, -SO 2 _- within the ring skeleton thereof shows a cyclic group containing a ring containing, specifically, , —SO ₂ — is a cyclic group in which the sulfur atom (S) forms part of the cyclic skeleton of the cyclic group. The ring containing —SO ₂ — in the ring skeleton is counted as the first ring, and when it is only the ring, it is a monocyclic group, and when it has another ring structure, it is a polycyclic group regardless of the structure. Called. The —SO ₂ — containing cyclic group may be monocyclic or polycyclic.
-SO ₂ - containing cyclic group, in particular, -O-SO ₂ - within the ring skeleton cyclic group containing, i.e. -O-SO ₂ - -O-S- medium is a part of the ring skeleton It is preferably a cyclic group containing a sultone ring to be formed.
The —SO ₂ — containing cyclic group preferably has 3 to 30 carbon atoms, more preferably 4 to 20 carbon atoms, still more preferably 4 to 15 carbon atoms, and particularly preferably 4 to 12 carbon atoms. preferable. However, the carbon number is the number of carbon atoms constituting the ring skeleton, and does not include the carbon number in the substituent.
The —SO ₂ — containing cyclic group may be an —SO ₂ — containing aliphatic cyclic group or an —SO ₂ — containing aromatic cyclic group. Preferably -SO ₂ - containing aliphatic cyclic group.
The —SO ₂ -containing aliphatic cyclic group includes at least a hydrogen atom from an aliphatic hydrocarbon ring in which a part of carbon atoms constituting the ring skeleton is substituted with —SO ₂ — or —O—SO ₂ —. One group is excluded. More specifically, a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring in which —CH ₂ — constituting the ring skeleton is substituted with —SO ₂ —, —CH ₂ — constituting the ring And a group obtained by removing at least one hydrogen atom from an aliphatic hydrocarbon ring in which CH ₂ — is substituted with —O—SO ₂ —.
The alicyclic hydrocarbon ring preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon ring may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group in which two hydrogen atoms are removed from a monocycloalkane having 3 to 6 carbon atoms. Examples of the monocycloalkane include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon ring, a group in which two hydrogen atoms are removed from a polycycloalkane having 7 to 12 carbon atoms is preferable. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane. , Tricyclodecane, tetracyclododecane and the like.

The —SO ₂ — containing cyclic group may have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a hydroxyalkyl group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a cyano group, —COOR ″, —OC (═O) R ″, and the like. Each of these substituents may be the same as those described as R ² in the group (I-1) in the description of the structural unit (x1).
More specifically, examples of the —SO ₂ -containing cyclic group include groups represented by the following general formulas (3-1) to (3-4).

［式中、Ａ’は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子であり、ｚは０〜２の整数であり、Ｒ^２７はアルキル基、アルコキシ基、ヒドロキシアルキル基、ハロゲン原子、ハロゲン化アルキル基、水酸基、シアノ基、−ＣＯＯＲ” または−ＯＣ（＝Ｏ）Ｒ”であり、Ｒ”は水素原子またはアルキル基である。］

[In the formula, 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, z is an integer of 0 to 2, and R ²⁷ is an alkyl group. , An alkoxy group, a hydroxyalkyl group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a cyano group, —COOR ″ or —OC (═O) R ″, and R ″ is a hydrogen atom or an alkyl group.]

In the general formulas (3-1) to (3-4), A ′ represents an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (—O—) or a sulfur atom (—S—), An oxygen atom or a sulfur atom.
The alkylene group having 1 to 5 carbon atoms in A ′ is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group.
When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group in which —O— or —S— is interposed between the terminal or carbon atoms of the alkylene group, such as —O—CH _{2. -, - CH 2 -O-CH} 2 -, - S-CH 2 -, - CH 2 -S-CH 2 - , and the like.
As A ′, an alkylene group having 1 to 5 carbon atoms or —O— is preferable, and a methylene group or —O— is most preferable.
z may be any of 0 to 2, and is most preferably 0.
When z is 2, the plurality of R ²⁷ may be the same or different.
As the alkyl group, alkoxy group, hydroxyalkyl group, halogen atom, halogenated alkyl group, hydroxyl group, cyano group, —COOR ″ or —OC (═O) R ″ in R ²⁷ , each of the above includes —SO ₂ —. The alkyl group, alkoxy group, hydroxyalkyl group, halogen atom, halogenated alkyl group, hydroxyl group, cyano group, —COOR ″ or —OC (═O) R ″, which are listed as the substituents that the cyclic group may have The same thing is mentioned.
Among the above, the —SO ₂ -containing cyclic group is preferably a group represented by the general formula (3-1).

Lactone-containing cyclic group “Lactone-containing cyclic group” refers to a cyclic group containing a ring (lactone ring) containing —O—C (═O) — in its ring skeleton. The lactone ring is counted as the first ring. When only the lactone ring is present, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.
The lactone cyclic group in the structural unit (x4) is not particularly limited as long as it is inert to the base, and any lactone cyclic group can be used. Specifically, the lactone-containing monocyclic group is a group obtained by removing one hydrogen atom from a 4- to 6-membered ring lactone, such as a group obtained by removing one hydrogen atom from β-propionolactone, or γ-butyrolactone. Examples thereof include a group in which one hydrogen atom has been removed and a group in which one hydrogen atom has been removed from δ-valerolactone. Examples of the lactone-containing polycyclic group include groups in which one hydrogen atom has been removed from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring.
More specifically, examples of the lactone-containing cyclic group include groups represented by the following general formulas (4-1) to (4-7). However, in the group represented by the general formula (4-1), the bond is not bonded to the β-position of the lactone ring.

［式中、Ｒ’はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ヒドロキシアルキル基、ハロゲン原子、ハロゲン化アルキル基、水酸基、シアノ基、−ＣＯＯＲ” または−ＯＣ（＝Ｏ）Ｒ”であり、Ｒ”は水素原子またはアルキル基であり；ｓ”は０または１〜２の整数であり；Ａ”は酸素原子もしくは硫黄原子を含んでいてもよい炭素数１〜５のアルキレン基、酸素原子または硫黄原子であり；ｍは０または１の整数である。］

[Wherein, each R ′ is independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyalkyl group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a cyano group, —COOR ″ or —OC (═O) R ″. , R ″ is a hydrogen atom or an alkyl group; s ″ is 0 or an integer of 1 to 2; 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; m is an integer of 0 or 1.]

As R ′ alkyl group, alkoxy group, hydroxyalkyl group, halogen atom, halogenated alkyl group, hydroxyl group, cyano group, —COOR ″ or —OC (═O) R ″, respectively, —SO ₂ — containing cyclic group Similar to the alkyl group, alkoxy group, hydroxyalkyl group, halogen atom, halogenated alkyl group, hydroxyl group, cyano group, —COOR ″ or —OC (═O) R ″, which are exemplified as the substituents that the group may have Can be mentioned.
As A ″, an alkylene group having 1 to 5 carbon atoms or —O— is preferable, and a methylene group or —O— is most preferable.
s ″ is preferably an integer of 1 to 2.

The structural unit (x4) is not particularly limited as long as it has an —SO ₂ -containing cyclic group or lactone cyclic group that is inert to the base, but the α-position carbon is not particularly limited. -SO ₂ -containing cyclic group or lactone-containing cyclic group which is a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the atom may be substituted with a substituent, and is inert to the base At least one structural unit selected from the group consisting of structural units containing is preferred.
More specifically, examples of the structural unit (x4) include structural units represented by general formula (x4-0) shown below.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基であり、Ｒ^２８は塩基に対して不活性である−ＳＯ_２−含有環式基またはラクトン含有環式基であり、Ｙ^４は単結合または２価の連結基である。］

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, and R ²⁸ is a —SO ₂ — containing cyclic group which is inert to the base. or a lactone containing cyclic group, Y ⁴ is a single bond or a divalent linking group. ]

In formula (x4-0), R is the same as defined above.
R ²⁸ is the same as the —SO ₂ -containing cyclic group or the lactone-containing cyclic group mentioned above.
Y ⁴ may be either a single bond or a divalent linking group, but is preferably a divalent linking group.
The divalent linking group in Y ⁴ is not particularly limited, and examples thereof include the same divalent linking groups as in X ⁰ in (x1-1).
As the divalent linking group for Y ⁴ , an alkylene group or an ester bond (—C (═O) —O—) is preferable.
The alkylene group is preferably a linear or branched alkylene group. Specifically, the same as the linear alkylene group and the branched alkylene group mentioned as the aliphatic hydrocarbon group for Y ² can be used.
As the divalent linking group containing an ester bond, in particular, the general formula: —R ³⁰ —C (═O) —O— [wherein R ³⁰ is a divalent linking group. ] Is preferable. That is, the structural unit (x4) is preferably a structural unit represented by the following general formula (x4-0-1).

［式中、ＲおよびＲ^２８はそれぞれ前記と同様であり、ｃ〜ｅはそれぞれ独立に１〜３の整数である。］

[Wherein, R and R ²⁸ are the same as defined above, and c to e are each independently an integer of 1 to 3. ]

As the structural unit (x4), it is particularly preferable that R ²⁸ is a group represented by the general formula (3-1), (4-1), or (4-2). ), (28-2), (28-3), (28-4) or (28-5) is preferred.

The structural unit (x4) contained in the component (X) may be one type or two or more types.
When (X) component contains a structural unit (x4), the ratio of the structural unit (x4) in (X) component is 1-70 mol with respect to the sum total of all the structural units which comprise the said (X) component. % Is preferable, 5 to 50 mol% is more preferable, and 5 to 35 mol% is more preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (x4) is sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

The mass average molecular weight (Mw) of the component (X) (polystyrene conversion standard by gel permeation chromatography (GPC)) is not particularly limited, preferably 1000 to 50000, more preferably 1500 to 30000, 2000 to 2000 25000 is most preferred. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
The dispersity (Mw / Mn) is not particularly limited, but is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5. In addition, Mn shows a number average molecular weight.

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

In the resist composition, as the component (X), one type may be used alone, or two or more types may be used in combination.
The content of the component (X) in the resist composition may be adjusted according to the resist film thickness to be formed.

<(Y) component>
The component (Y) is a base generator component that generates a base by exposure (radiation irradiation).
The component (Y) may be any component that can be decomposed by exposure to generate a base, and can be appropriately selected from known compounds as a photobase generator.
Examples of the component (Y) include a compound containing a carbamate group (urethane bond), a compound containing an acyloxyimino group, an ionic compound (anion-cation complex), a compound containing a carbamoyloxyimino group, and the like. Among these, a compound containing a carbamate group (urethane bond), a compound containing an acyloxyimino group, and an ionic compound (anion-cation complex) are preferable.
Moreover, what has a ring structure in a molecule | numerator is preferable, and what has ring skeletons, such as benzene, naphthalene, anthracene, xanthone, thioxanthone, anthraquinone, fluorene, is mentioned as the said ring structure.

As the component (Y), a compound represented by the following general formula (Y1) (hereinafter referred to as “component (Y1)”) is particularly preferable from the viewpoint of photodegradability. (Y1) component corresponds to the compound containing a carbamate group (urethane bond) among the above.
When this component (Y1) is irradiated with radiation, at least the bond between the nitrogen atom in the formula (Y1) and the carbon atom of the carbonyl group adjacent to the nitrogen atom is cleaved, resulting in amine or ammonia , Carbon dioxide and produce. After decomposition, it is preferred that the product having —N (R ⁰¹ ) (R ⁰² ) has a high boiling point. Moreover, it is preferable from the point of the diffusion control at the time of PEB that the molecular weight of the product which has -N ( ^R01 ) ( ^R02 ) is large or has a bulky skeleton.

［式中、Ｒ^０１およびＲ^０２はそれぞれ独立にヘテロ原子を含んでいてもよい１価の炭化水素基または水素原子であり、Ｒ^０１およびＲ^０２が相互に結合して隣接する窒素原子とともに環式基を形成してもよく；Ｒ^０３は１価の光官能基である。］

[Wherein R ⁰¹ and R ⁰² are each independently a monovalent hydrocarbon group or hydrogen atom which may contain a hetero atom, and R ⁰¹ and R ⁰² are bonded to each other to form a ring together with the adjacent nitrogen atom. Formula groups may be formed; R ⁰³ is a monovalent photofunctional group. ]

In formula (Y1), the hetero atom that the hydrocarbon group in R ⁰¹ and R ⁰² may have is an atom other than a carbon atom and a hydrogen atom, such as an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom, etc. Is mentioned. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
The monovalent hydrocarbon group which may contain a hetero atom may be an aromatic hydrocarbon group which may have a substituent, or an aliphatic hydrocarbon group which may have a substituent, An aliphatic hydrocarbon group which may have a substituent is preferable.
“Optionally substituted” means that a part of the carbon atoms constituting the aromatic hydrocarbon group or aliphatic hydrocarbon group includes a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom. It shows that it may be substituted with a group, and part or all of the hydrogen atoms constituting the aromatic hydrocarbon group or aliphatic hydrocarbon group may be substituted with a substituent.

In the aromatic hydrocarbon group which may have a substituent in R ⁰¹ and R ⁰² , the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring, and is composed only of an aromatic ring It may be composed of an aromatic ring and an aliphatic hydrocarbon group bonded to the aromatic ring.
The aromatic hydrocarbon group may have a substituent. For example, a part of carbon atoms constituting the aromatic ring of the aromatic hydrocarbon group may be substituted with a hetero atom, and the hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group is substituted with the substituent. May be. In addition, when the aromatic hydrocarbon group has an aliphatic hydrocarbon group bonded to an aromatic ring, a part of carbon atoms constituting the aliphatic hydrocarbon group is substituted with a divalent linking group containing a hetero atom. Or a part or all of the hydrogen atoms constituting the aliphatic hydrocarbon group may be substituted with a substituent.
The aliphatic hydrocarbon group and the divalent linking group containing a hetero atom each include an aliphatic hydrocarbon group and a hetero atom, which will be described later in the explanation of the aliphatic hydrocarbon group in R ⁰¹ and R ⁰² . The thing similar to a bivalent coupling group is mentioned.

The aromatic ring of the aromatic hydrocarbon group is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 (where n is 0 and a natural number) π electrons, and may be monocyclic or polycyclic. . 5-30 are preferable, as for the number of atoms which comprise the ring skeleton of an aromatic ring, 5-20 are more preferable, 5-15 are more preferable, 6-15 are especially preferable, and 6-10 are the most preferable. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene and phenanthrene; aromatic heterocycles in which a part of carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms; etc. Is mentioned. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, the aromatic hydrocarbon group is a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group); an aromatic compound containing two or more aromatic rings A group in which one hydrogen atom is removed from (for example, biphenyl, fluorene, etc.); a group in which one of the hydrogen atoms of the aromatic hydrocarbon ring or aromatic heterocyclic ring is substituted with an alkylene group (for example, benzyl group, phenethyl group, Arylalkyl groups such as 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, and heteroarylalkyl groups). The number of carbon atoms of the alkylene group that replaces the hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocyclic ring is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1. .
5-30 are preferable, as for carbon number of these aromatic hydrocarbon groups, 5-20 are more preferable, 5-15 are more preferable, 6-15 are especially preferable, and 6-10 are the most preferable. However, when the aromatic hydrocarbon group has a part or all of the hydrogen atoms having a substituent, the number of carbons in the aromatic hydrocarbon group does not include the number of carbons in the substituent.

A substituent that the aromatic hydrocarbon group in R ⁰¹ and R ⁰² may have (for example, a substituent that may substitute a hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group, Examples of the substituent which may substitute the hydrogen atom of the aliphatic hydrocarbon group when the aromatic hydrocarbon group is bonded include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and a hydroxyalkyl. Group, hydroxyl group, oxo group (═O), —COOR ″, —OC (═O) R ″, —O—C (═O) —C (R) ═CH ₂ , cyano group, nitro group, —NR ″. _{^{2, -R 9 '-N (R}} 10') -C (= O) -O-R 5 ', include nitrogen-containing heterocyclic group.
The alkyl group as the substituent is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an 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 particularly preferable.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably linear or branched. Specifically, the group couple | bonded with the oxygen atom (-O-) to the alkyl group quoted as the alkyl group as the said substituent is mentioned.
Examples of the halogen atom as the substituent include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as the substituent include groups in which part or all of the hydrogen atoms of the alkyl group mentioned as the alkyl group as the substituent are substituted with the halogen atom. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.
The hydroxyalkyl group as the substituent is preferably one having 1 to 6 carbon atoms. Specifically, at least one of the hydrogen atoms of the alkyl group mentioned as the alkyl group as the substituent is substituted with a hydroxyl group. Group.

R ″ in —COOR ″, —OC (═O) R ″, and —NR ″ ₂ is a hydrogen atom or an alkyl group having 1 to 15 carbon atoms.
The alkyl group in R ″ may be linear, branched or cyclic.
When R ″ is a linear or branched alkyl group, it preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group. preferable.
When R ″ is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a fluorine atom Or a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group More specifically, one or more hydrogen atoms are removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Group and the like.
Two R ″ in —NR ″ ₂ may be the same or different.

Wherein a -O-C (= O) -C (R) = CH 2 in the R is a hydrogen atom, a halogenated alkyl group of 1 to 5 alkyl group or a C1-5 carbon.
Examples of the alkyl group and the halogenated alkyl group in R include the same alkyl groups and halogenated alkyl groups as the substituents bonded to the α-position carbon atom of the α-substituted acrylic acid or ester thereof. .
As —O—C (═O) —C (R) ═CH ₂ , R is preferably a hydrogen atom or a methyl group, that is, a (meth) acryloyloxy group. The (meth) acryloyloxy group represents an acryloyloxy group or a methacryloyloxy group.

'During, ^{R 9'} wherein ^{-R 9 '-N (R 10'} ) -C (= O) -O-R 5 is a divalent hydrocarbon group which may contain a hetero ^{atom, R 10} ' Is a monovalent hydrocarbon group or a hydrogen atom which may contain a hetero atom, and R ⁵ ′ is a monovalent organic group having an aliphatic ring or an aromatic ring.
Examples of the hydrocarbon group for R ⁹ ′ include groups in which one hydrogen atom has been removed from the hydrocarbon group for R ⁰¹ in formula (Y1).
Examples of R ¹⁰ ′ and R ⁵ ′ are the same as R ⁰² and R ^{03 in} formula (Y1).
In —R ⁹ ′ —N (R ¹⁰ ′) —C (═O) —O—R ⁵ ′, R ¹⁰ ′ may be bonded to R ⁹ ′ to form a ring.
Of R ⁰¹ and R ^{02 in} formula (Y1), for example, when R ⁰¹ has —R ⁹ ′ —N (R ¹⁰ ′) —C (═O) —O—R ⁵ ′ as a substituent, the formula R ¹⁰ ′ therein may be bonded to R ⁰² in Formula (Y1) to form a ring.
(Y1) when R ⁰¹ has —R ⁹ ′ —N (R ¹⁰ ′) —C (═O) —O—R ⁵ ′ as a substituent among R ⁰¹ and R ^{02 in} formula (Y1) As the component, the following general formula: R ⁵ ′ —O—C (═O) —N (R ¹⁰ ′) —R ⁴ —N (R ⁰² ) —C (═O) —O—R ⁰³ [wherein , R ^{02 to} R ⁰³ , R ¹⁰ ′ and R ⁵ ′ are the same as defined above, and R ⁴ is a divalent aliphatic hydrocarbon group. ] The compound represented by this is preferable.
Examples of the divalent aliphatic hydrocarbon group for R ⁴ include a group obtained by removing one hydrogen atom from the aliphatic hydrocarbon group for R ⁰¹ and R ⁰² shown below.

The nitrogen-containing heterocyclic group as the substituent is a group obtained by removing one or more hydrogen atoms from a nitrogen-containing heterocyclic compound containing a nitrogen atom in the ring skeleton. The nitrogen-containing heterocyclic compound may have a hetero atom (for example, an oxygen atom, a sulfur atom, etc.) other than a carbon atom and a nitrogen atom in its ring skeleton.
The nitrogen-containing heterocyclic compound may be aromatic or aliphatic. Moreover, when aliphatic, it may be saturated or unsaturated. The nitrogen-containing heterocyclic compound may be monocyclic or polycyclic.
The nitrogen-containing heterocyclic compound preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, and still more preferably 5 to 20 carbon atoms.
Specific examples of the monocyclic nitrogen-containing heterocyclic compound include pyrrole, pyridine, imidazole, pyrazole, 1,2,3-triazole, 1,2,4-triazole, pyrimidine, pyrazine, 1,3,5- Examples include triazine, tetrazole, piperidine, piperazine, pyrrolidine, morpholine and the like.
Specific examples of the polycyclic nitrogen-containing heterocyclic compound include quinoline, isoquinoline, indole, pyrrolo [2,3-b] pyridine, indazole, benzimidazole (benzimidazole), benzotriazole, carbazole, acridine, 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. Is mentioned.
The nitrogen-containing heterocyclic group may have a substituent. Examples of the substituent include those similar to those exemplified as the substituent for substituting the hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group.

In the formula (Y1), in the aliphatic hydrocarbon group which may have a substituent in R ⁰¹ and R ⁰² , the aliphatic hydrocarbon group may be saturated (alkyl group) or unsaturated. May be. Usually, it is preferably saturated. The aliphatic hydrocarbon group may be linear, branched, or cyclic, or a combination thereof. Examples of the combination include a group in which a cyclic aliphatic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a cyclic aliphatic hydrocarbon group in a linear or branched chain. And a group intervening in the middle of the aliphatic hydrocarbon group.
The linear or branched alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and still more preferably 1 to 10 carbon atoms.
Specific examples of the linear alkyl group include, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, Examples include tridecyl group, isotridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group and the like.
Specific examples of the branched alkyl group include 1-methylethyl group (iso-propyl group), 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3- Examples include methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, tert-butyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.
The cyclic alkyl group may be a monocyclic group or a polycyclic group. The carbon number is preferably 3 to 30, more preferably 5 to 30, further preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 12. Specific examples include a group in which one hydrogen atom has been removed from a monocycloalkane; a group in which one hydrogen atom has been removed from a polycycloalkane such as bicycloalkane, tricycloalkane, and tetracycloalkane. . More specifically, examples of the group obtained by removing one hydrogen atom from a monocycloalkane include a cyclopentyl group and a cyclohexyl group. Examples of the group obtained by removing one hydrogen atom from polycycloalkane include an adamantyl group, norbornyl group, isobornyl group, tricyclodecyl group, tetracyclododecyl group, and the like.

The aliphatic hydrocarbon group may have a substituent. For example, part of the carbon atoms constituting the aliphatic hydrocarbon group may be substituted with a divalent linking group containing a hetero atom, and part or all of the hydrogen atoms constituting the aliphatic hydrocarbon group May be substituted with a substituent.
In the divalent linking group containing a heteroatom, examples of the heteroatom include the same as those given as the heteroatom in the aromatic heterocyclic ring. Specifically, an oxygen atom, a sulfur atom, a nitrogen atom, etc. are mentioned.
Examples of the divalent linking group containing a hetero atom include —O—, —C (═O) —, —C (═O) —O—, and carbonate bond (—O—C (═O) —O—. _{), - S -, - S} (= O) 2 -, - S (= O) 2 -O -, - NH -, - NR 04 - (R 04 is an alkyl group, a substituent such as an acyl group. ), -NH-C (= O)-, = N- and the like, and divalent non-hydrocarbon groups containing a hetero atom. Moreover, the combination etc. of these "divalent non-hydrocarbon groups containing a hetero atom" and a divalent aliphatic hydrocarbon group are mentioned. Examples of the divalent aliphatic hydrocarbon group include groups obtained by removing one hydrogen atom from the above-described aliphatic hydrocarbon group, and a linear or branched aliphatic hydrocarbon group is preferable.
Examples of the substituent of the aliphatic hydrocarbon group in the latter example include the same substituents as those mentioned as the substituents for substituting the hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group.

In the general formula (Y1), R ⁰¹ and R ⁰² may be bonded to each other to form a cyclic group together with the adjacent nitrogen atom.
The cyclic group may be an aromatic cyclic group or an aliphatic cyclic group. When it is an aliphatic cyclic group, it may be saturated or unsaturated. Usually, it is preferably saturated.
The cyclic group may have a nitrogen atom other than the nitrogen atom to which R ⁰¹ and R ⁰² are bonded in its ring skeleton. Further, the ring skeleton may have a hetero atom other than a carbon atom and a nitrogen atom (for example, an oxygen atom, a sulfur atom, etc.).
The cyclic group may be monocyclic or polycyclic.
In the case of monocyclic, the number of atoms constituting the skeleton of the cyclic group is preferably 4 to 7, and more preferably 5 to 6. That is, the cyclic group is preferably a 4-7 membered ring, more preferably a 5-6 membered ring. Specific examples of the monocyclic group include ring structures such as piperidine, pyrrolidine, morpholine, pyrrole, imidazole, pyrazole, 1,2,3-triazole, 1,2,4-triazole, tetrazole, and piperazine. And a group obtained by removing a hydrogen atom from —NH— of a heterocyclic monocyclic compound having —NH—.
When it is polycyclic, the cyclic group is preferably bicyclic, tricyclic or tetracyclic, and the number of atoms constituting the skeleton of the cyclic group is 7-12. 7-10 are more preferable. Specific examples of the polycyclic nitrogen-containing heterocyclic group include heteropolycyclic compounds having —NH— in the ring structure, such as indole, isoindole, carbazole, benzimidazole, indazole, and benzotriazole. A group obtained by removing a hydrogen atom from NH- is exemplified.
The cyclic group may have a substituent. Examples of the substituent include those similar to those exemplified as the substituent for substituting the hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group.
As the cyclic group formed by R ⁰¹ and R ⁰² bonded to each other and the adjacent nitrogen atom, a group represented by the following general formula (II) is particularly preferable.

［式中、Ｒ^０５およびＲ^０６はそれぞれ独立に水素原子またはアルキル基であり；Ｒ^０７は、炭素原子が酸素原子または窒素原子で置換されていてもよく、水素原子が置換基で置換されていてもよい炭素数１〜３の直鎖状のアルキレン基である。］

[Wherein R ⁰⁵ and R ⁰⁶ each independently represent a hydrogen atom or an alkyl group; R ⁰⁷ represents a carbon atom optionally substituted with an oxygen atom or a nitrogen atom, and a hydrogen atom substituted with a substituent It is a C1-C3 linear alkylene group. ]

In formula (II), examples of the alkyl group for R ⁰⁵ and R ⁰⁶ include the same alkyl groups as those described in the description of the aliphatic hydrocarbon group for R ⁰¹ and R ⁰² . And an alkyl group is preferred, and a methyl group is particularly preferred.
In R ⁰⁷ , examples of the alkylene group in which the carbon atom may be substituted with an oxygen atom or a nitrogen atom include —CH ₂ —, —CH ₂ —O—, —CH ₂ —NH—, and —CH ₂ —CH. _{2 -, - CH 2 -O-} CH 2 -, - CH 2 -NH-CH 2 -, - CH 2 -CH 2 -CH 2 -, - CH 2 -CH 2 -O-CH 2 -, - CH 2 -CH ₂ -NH-CH ₂ -, and the like.
Examples of the substituent for substituting the hydrogen atom of the alkylene group include the same groups as those described above as the substituent for substituting the hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group. The hydrogen atom substituted with the substituent may be a hydrogen atom bonded to a carbon atom or a hydrogen atom bonded to a nitrogen atom.

In the formula (Y1), R ⁰³ is a monovalent photofunctional group.
As used herein, the “photofunctional group” refers to a group that absorbs exposure energy of exposure performed in an exposure process when forming a resist pattern.
The photofunctional group is preferably a ring-containing group, which may be a hydrocarbon ring or a heterocyclic ring, preferably a group having the ring structure described for R ⁰¹ and R ⁰² above, and other aromatic rings A group having Specific examples of the ring skeleton of the ring-containing group include benzene, biphenyl, indene, naphthalene, fluorene, anthracene, phenanthrene, xanthone, thioxanthone, and anthraquinone.
These ring skeletons may have a substituent, and the substituent is particularly preferably a nitro group from the viewpoint of base generation efficiency.

  The component (Y1) is particularly preferably selected from the group consisting of compounds represented by the following general formula (Y1-11) or (Y1-12).

［式中、Ｒ^４ａ〜Ｒ^４ｂはそれぞれ独立に、置換基を有していてもよいベンゼン、ビフェニル、インデン、ナフタレン、フルオレン、アントラセン、フェナントレン、キサントン、チオキサントンおよびアントラキノンから選ばれる環骨格であり、Ｒ^１ａ及びＲ^２ａはそれぞれ独立に、水素原子、炭素数１〜１５のアルキル基、シクロアルキル基又はアリール基であり、Ｒ^１１ａは炭素数１〜５のアルキル基、水酸基又は（メタ）アクリロイルオキシ基であり、ｍ”は０又は１であり、ｎ”は０〜３の整数であり、ｐ”は０〜３の整数である。］

[Wherein, R ^{4a to} R ^4b are each independently a ring skeleton selected from optionally substituted benzene, biphenyl, indene, naphthalene, fluorene, anthracene, phenanthrene, xanthone, thioxanthone, and anthraquinone, R ^1a and R ^2a are each independently a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, a cycloalkyl group or an aryl group, and R ^11a is an alkyl group having 1 to 5 carbon atoms, a hydroxyl group or (meth) acryloyloxy. M ″ is 0 or 1, n ″ is an integer from 0 to 3, and p ″ is an integer from 0 to 3.]

In formulas (Y1-11) and (Y1-12), R ^{4a to} R ^4b preferably have a nitro group as a substituent from the viewpoint of base generation efficiency, and particularly preferably substituted at the ortho position.
R ^1a and R ^2a are each independently preferably a hydrogen atom, a cycloalkyl group, or an aryl group, and in particular, a cycloalkyl group having 5 to 10 carbon atoms can control the diffusion length of the generated base. This is more preferable. The aryl group for R ^1a and R ^2a is preferably a phenyl group.
m ″ is preferably 1. n ″ is preferably 0-2. p ″ is preferably 0 or 1.

  Specific examples of the component (Y1) are shown below.

In addition to the component (Y1), a compound represented by the following general formula (C2) (hereinafter referred to as “component (Y2)”) is also preferable as the component (Y).
The component (Y2) absorbs exposure energy by exposure in the exposure step, and then the (—CH═CH—C (═O) —) moiety isomerizes to a cis isomer, and further cyclized by heating to form a base (NHR). ⁰¹ R ⁰² ).

［式（Ｙ２）中、Ｒ^０１及びＲ^０２は、上記式（Ｙ１）中のＲ^０１及びＲ^０２と同様であり、Ｒ^３’はオルト位に水酸基を有する芳香族環式基である。］

Wherein ^{(Y2), R 01} and ^{R 02} are the same as ^{R 01} and ^{R 02} in the formula (Y1) in, ^{R 3} 'is an aromatic cyclic group having a hydroxyl group in the ortho position. ]

In the formula (Y2), R ⁰¹ and R ⁰² are preferably bonded to each other to form a cyclic group represented by the formula (II) together with an adjacent nitrogen atom. Alternatively, R ⁰¹ and R ⁰² are each independently a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, a cycloalkyl group, or an aryl group, similarly to R ^1a and R ^2a in the formula (Y1-12). Is preferred.
Examples of the aromatic cyclic group for R ³ ′ include the same groups as those having an aromatic ring exemplified for R ⁰³ in the above formula (Y1), and examples of the ring skeleton include benzene, biphenyl, indene, naphthalene, and fluorene. , Anthracene and phenanthrene are preferable, and a benzene ring is more preferable.
The aromatic cyclic group for R ³ ′ may have a substituent other than the hydroxyl group at the ortho position. Examples of the substituent include a halogen atom, a hydroxyl group, a mercapto group, a sulfide group, a silyl group, a silanol group, Examples thereof include monovalent organic groups such as nitro group, nitroso group, sulfino group, sulfo group, sulfonate group, phosphino group, phosphinyl group, phosphono group, phosphonate group, amino group, ammonio group, and other alkyl groups.

  Specific examples of the component (Y2) are shown below.

In addition to the component (Y1) and the component (Y2), a compound represented by the following general formula (Y3) (hereinafter referred to as “component (Y3)”) is also preferable as the component (Y).
(Y3) component absorbs exposure energy by exposure in the exposure step, decarboxylates, and then reacts with water to produce an amine (base).

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

[Wherein, R ^a and R ^d are each a hydrocarbon group having 1 to 30 carbon atoms or a hydrogen atom which may have a substituent (provided that both R ^a and R ^d have a substituent) In the case of an optionally substituted hydrocarbon group having 1 to 30 carbon atoms, they are bonded to each other to form a ring); and R ^b is an aryl group or an aliphatic cyclic group which may have a substituent. is there. ]

In the formula (Y3), R ^a is a hydrocarbon group having 1 to 30 carbon atoms or a hydrogen atom which may have a substituent.
The “optionally substituted” in the hydrocarbon group having 1 to 30 carbon atoms which may have ^a substituent for ^Ra is that a part of carbon atoms constituting the hydrocarbon group is oxygen. It shows that it may be substituted with a substituent containing a hetero atom such as an atom, sulfur atom or nitrogen atom, and that part or all of the hydrogen atoms constituting the hydrocarbon group may be substituted with a substituent.
The hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.

The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring, and may be composed only of an aromatic ring, an aromatic ring and an aliphatic hydrocarbon group bonded to the aromatic ring; It may be comprised from.
The aromatic hydrocarbon group may have a substituent. For example, a part of carbon atoms constituting the aromatic ring of the aromatic hydrocarbon group may be substituted with a hetero atom, and the hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group is substituted with the substituent. May be. In addition, when the aromatic hydrocarbon group has an aliphatic hydrocarbon group bonded to an aromatic ring, a part of carbon atoms constituting the aliphatic hydrocarbon group is substituted with a divalent linking group containing a hetero atom. Or a part or all of the hydrogen atoms constituting the aliphatic hydrocarbon group may be substituted with a substituent.
Examples of the aliphatic hydrocarbon group and the divalent linking group containing a hetero atom include an aliphatic hydrocarbon group and a divalent linking group containing a hetero atom, which will be described later in the explanation of the aliphatic hydrocarbon group in ^Ra . Examples are the same as the linking group.

The aromatic ring of the aromatic hydrocarbon group is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 (where n is 0 and a natural number) π electrons, and may be monocyclic or polycyclic. . 5-30 are preferable, as for the number of atoms which comprise the ring skeleton of an aromatic ring, 5-20 are more preferable, 5-15 are more preferable, 6-15 are especially preferable, and 6-10 are the most preferable. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene and phenanthrene; aromatic heterocycles in which a part of carbon atoms constituting the aromatic hydrocarbon ring are substituted with heteroatoms; etc. Is mentioned. Examples of the hetero atom in the aromatic heterocyclic ring include an oxygen atom, a sulfur atom, and a nitrogen atom. Specific examples of the aromatic heterocycle include a pyridine ring and a thiophene ring.
Specifically, the aromatic hydrocarbon group is a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group); an aromatic compound containing two or more aromatic rings A group in which one hydrogen atom is removed from (for example, biphenyl, fluorene, etc.); a group in which one of the hydrogen atoms of the aromatic hydrocarbon ring or aromatic heterocyclic ring is substituted with an alkylene group (for example, benzyl group, phenethyl group, Arylalkyl groups such as 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group, and heteroarylalkyl groups). The number of carbon atoms of the alkylene group that replaces the hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocyclic ring is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1. .
5-30 are preferable, as for carbon number of these aromatic hydrocarbon groups, 5-20 are more preferable, 5-15 are more preferable, 6-15 are especially preferable, and 6-10 are the most preferable. However, when the aromatic hydrocarbon group has a part or all of the hydrogen atoms having a substituent, the number of carbons in the aromatic hydrocarbon group does not include the number of carbons in the substituent.

A substituent that the aromatic hydrocarbon group in R ^a may have (for example, a substituent that may substitute a hydrogen atom bonded to the aromatic ring of the aromatic hydrocarbon group or an aliphatic hydrocarbon in the aromatic ring; Examples of the substituent that may substitute the hydrogen atom of the aliphatic hydrocarbon group when the group is bonded include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxo group ( = O) and the like.
The alkyl group as a substituent of the aromatic hydrocarbon group is preferably an alkyl group having 1 to 6 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group. preferable.
The alkoxy group as a substituent of the aromatic hydrocarbon group is preferably an alkoxy group having 1 to 6 carbon atoms, and is a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a tert- A butoxy group is preferable, and a methoxy group and an ethoxy group are most preferable.
Examples of the halogen atom as a substituent for the aromatic hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
Examples of the halogenated alkyl group as a substituent of the aromatic hydrocarbon group include an alkyl group having 1 to 6 carbon atoms, such as an alkyl group such as a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group. And a group in which part or all of the hydrogen atoms are substituted with the halogen atoms.

The aliphatic hydrocarbon group for R ^a may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear, branched or cyclic.
In R ^a , the aliphatic hydrocarbon group may be a group in which a part of carbon atoms constituting the aliphatic hydrocarbon group may be substituted with a substituent containing a hetero atom, and hydrogen constituting the aliphatic hydrocarbon group A part or all of the atoms may be substituted with a substituent containing a hetero atom. The hetero atom is not particularly limited as long as it is an atom other than a carbon atom and a hydrogen atom, and examples thereof include a halogen atom, an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom.
The substituent containing a hetero atom may be composed of only the hetero atom, or may be a group containing a group or atom other than the hetero atom.
Specific examples of the substituent for substituting a part of the carbon atom include —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O. —, —C (═O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group, an acyl group, etc.), —S—, —S (═O) ₂ —, — S (= O) ₂ —O— and the like can be mentioned. When the aliphatic hydrocarbon group is cyclic, these substituents may be included in the ring structure.
Specific examples of the substituent for substituting part or all of the hydrogen atoms include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxo group (═O), and a cyano group.
The alkoxy group is preferably an alkoxy group having 1 to 6 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and a methoxy group or an ethoxy group. Is most preferred.
As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
As the halogenated alkyl group, a part or all of hydrogen atoms of an alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc. And a group substituted with a halogen atom.

Examples of the aliphatic hydrocarbon group include a linear or branched saturated hydrocarbon group, a linear or branched monovalent unsaturated hydrocarbon group, or a cyclic aliphatic hydrocarbon group (aliphatic ring). Formula group) is preferred.
The linear saturated hydrocarbon group (alkyl group) preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decanyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group and the like.
The branched saturated hydrocarbon group (alkyl group) preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, Examples include 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.

As an unsaturated hydrocarbon group, it is preferable that carbon number is 2-10, 2-5 are preferable, 2-4 are preferable, and 3 is especially preferable. Examples of the linear monovalent unsaturated hydrocarbon group include a vinyl group, a propenyl group (allyl group), and a butynyl group. Examples of the branched monovalent unsaturated hydrocarbon group include a 1-methylpropenyl group and a 2-methylpropenyl group.
Among the above, the unsaturated hydrocarbon group is particularly preferably a propenyl group.

The cyclic aliphatic hydrocarbon group (aliphatic cyclic group) is an aliphatic cyclic group having 3 to 30 carbon atoms which may have a substituent.
In R ^a , the aliphatic cyclic group may be a group in which a part of carbon atoms constituting the aliphatic cyclic group may be substituted with a substituent containing a hetero atom, and hydrogen constituting the aliphatic cyclic group A part or all of the atoms may be substituted with a substituent containing a hetero atom. The hetero atom is not particularly limited as long as it is an atom other than a carbon atom and a hydrogen atom, and examples thereof include a halogen atom, an oxygen atom, a sulfur atom, and a nitrogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom.
The substituent containing a hetero atom may be composed of only the hetero atom, or may be a group containing a group or atom other than the hetero atom.
Specific examples of the substituent for substituting a part of carbon atoms include, for example, —O—, —C (═O) —O—, —C (═O) —, —O—C (═O) —O—. , —C (═O) —NH—, —NH— (H may be substituted with a substituent such as an alkyl group or an acyl group), —S—, —S (═O) ₂ —, —S (═O) ₂ —O— and the like. These substituents may be contained in the ring structure.
Specific examples of the substituent for substituting part or all of the hydrogen atoms include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), and a cyano group.
The alkoxy group is preferably an alkoxy group having 1 to 6 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, or a tert-butoxy group, and a methoxy group or an ethoxy group. Is most preferred.
As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned, A fluorine atom is preferable.
As the halogenated alkyl group, a part or all of hydrogen atoms of an alkyl group having 1 to 6 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc. And a group substituted with a halogen atom.

The aliphatic cyclic group may be a monocyclic group or a polycyclic group. The number of carbon atoms is 3 to 30, preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12.
Specifically, for example, a group in which one or more hydrogen atoms have been removed from a monocycloalkane; a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, etc. Can be mentioned. More specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane; Examples include a group excluding a hydrogen atom.
When the aliphatic cyclic group does not contain a substituent containing a hetero atom in the ring structure, the aliphatic cyclic group is preferably a polycyclic group, and has one or more hydrogen atoms from the polycycloalkane. Excluded groups are preferred, and most preferred are groups in which one or more hydrogen atoms have been removed from adamantane.
When the aliphatic cyclic group includes a substituent containing a hetero atom in the ring structure, examples of the substituent containing a hetero atom include —O—, —C (═O) —O—, —S—. , —S (═O) ₂ — and —S (═O) ₂ —O— are preferable. Specific examples of the aliphatic cyclic group include cyclic groups represented by the following formulas (L1) to (L6) and (S1) to (S4).

［式中、Ｑ”は炭素数１〜５のアルキレン基、−Ｏ−、−Ｓ−、−Ｏ−Ｒ^９４’−または−Ｓ−Ｒ^９５’−であり、Ｒ^９４’およびＲ^９５’はそれぞれ独立に炭素数１〜５のアルキレン基であり、ｍは０または１の整数である。］

[In the formula, Q ″ is an alkylene group having 1 to 5 carbon atoms, —O—, —S—, —O—R ^{94 ′} — or —S—R ^{95 ′} —, wherein R ^{94 ′} and R ^{95 ′} are Each independently represents an alkylene group having 1 to 5 carbon atoms, and m is an integer of 0 or 1.]

In the formula, each of the alkylene groups in Q ″, R ^{94 ′} and R ^{95 ′} is preferably a linear or branched alkylene group, and the alkylene group preferably has 1 to 12 carbon atoms, 5 is more preferable, and 1 to 3 is more preferable.
Specific examples of the alkylene group include a methylene group [—CH ₂ —]; —CH (CH ₃ ) —, —CH (CH ₂ CH ₃ ) —, —C (CH ₃ ) ₂ —, —C ( _{CH 3) (CH 2 CH 3} ) -, - C (CH 3) (CH 2 CH 2 CH 3) -, - C (CH 2 CH 3) 2 - ; alkylethylene groups such as ethylene group _[-CH 2 CH _2— ]; —CH (CH ₃ ) CH ₂ —, —CH (CH ₃ ) CH (CH ₃ ) —, —C (CH ₃ ) ₂ CH ₂ —, —CH (CH ₂ CH ₃ ) CH ₂ — and the like. Alkylethylene groups; trimethylene groups (n-propylene groups) [—CH ₂ CH ₂ CH ₂ —]; alkyls such as —CH (CH ₃ ) CH ₂ CH ₂ — and —CH ₂ CH (CH ₃ ) CH ₂ — trimethylene; tetramethylene group _[-CH 2 _CH 2 C _{2 CH 2 -]; - CH} (CH 3) CH 2 CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 CH 2 - alkyl tetramethylene group and the like; pentamethylene group _[-CH 2 _CH 2 CH ₂ CH ₂ CH ₂ —] and the like. Among these, a methylene group or an alkylmethylene group is preferable, and a methylene group is particularly preferable.
In these cyclic groups, a part of hydrogen atoms bonded to carbon atoms constituting the ring structure may be substituted with a substituent. Examples of the substituent include the same substituents as those which may be substituted for some or all of the hydrogen atoms bonded to the carbon atoms constituting the ring structure of the cyclic alkyl group.

The aliphatic cyclic group which may have ^a substituent in R ^a is preferably ^a polycyclic aliphatic cyclic group which may have a substituent. Examples of the polycyclic aliphatic cyclic group include groups obtained by removing one or more hydrogen atoms from the polycycloalkane, and groups represented by the above (L2) to (L6) and (S3) to (S4). Etc. are preferred.

When R ^a in the formula (Y3) is an optionally substituted hydrocarbon group having 1 to 30 carbon atoms, it may form a ring with an adjacent carbon atom. The ring formed may be monocyclic or polycyclic. The number of carbon atoms is preferably 5-30 (including bonded carbon atoms), more preferably 5-20.
Specifically, (regarded as part carbon atom bonded even ring) of the cyclic aliphatic hydrocarbon group in R ^a as described above (aliphatic cyclic group), of 5 to 30 carbon atoms aliphatic ring And a formula group.

R ^a in the formula (Y3) is preferably ^a hydrogen atom or a cyclic group which may have a substituent. The cyclic group may be an aromatic hydrocarbon group which may have a substituent, or an aliphatic cyclic group which may have a substituent.
As the aliphatic cyclic group which may have a substituent, a polycyclic aliphatic cyclic group which may have a substituent is preferable. Examples of the polycyclic aliphatic cyclic group include groups obtained by removing one or more hydrogen atoms from the polycycloalkane, and groups represented by the above (L2) to (L6) and (S3) to (S4). Etc. are preferred.
As the aromatic hydrocarbon group which may have a substituent, a naphthyl group which may have a substituent or a phenyl group which may have a substituent is more preferable.

Examples of the aryl group for R ^b in the formula (Y3) include those obtained by removing the arylalkyl group from those exemplified as the aromatic hydrocarbon group for R ^a in the formula (Y3). The aryl group for R ^b is more preferably a phenyl group.
The aliphatic cyclic group for R ^b in the formula (Y3) is the same as the aliphatic cyclic group for R ^a in the formula (Y3). The aliphatic cyclic group for R ^b is preferably an aliphatic polycyclic group, more preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and particularly preferably one or more groups from adamantane. A group excluding a hydrogen atom.
^Examples of the substituent that the aryl group or aliphatic cyclic group of R ^b may have include the same substituents as those described in the description of R ^a in the formula (Y3).

Examples of R ^d in the formula (Y3) include the same as R ^a in the formula (Y3).
R ^d in the formula (Y3) is preferably a cyclic group which may have a substituent. The cyclic group may be an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a substituent. It is preferably an aromatic hydrocarbon group that may be used.
As the aliphatic cyclic group which may have a substituent, a polycyclic aliphatic cyclic group which may have a substituent is preferable. Examples of the polycyclic aliphatic cyclic group include groups obtained by removing one or more hydrogen atoms from the polycycloalkane, and groups represented by the above (L2) to (L6) and (S3) to (S4). Etc. are preferred.
R ^d in the formula (Y3) is more preferably a naphthyl group which may have a substituent or a phenyl group which may have a substituent, and a phenyl group which may have a substituent. Most preferred.

When both R ^a and R ^d in the formula (Y3) are a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent, they are bonded to each other to form a ring. The ring formed may be monocyclic or polycyclic. The number of carbon atoms, the formula (Y3) including the carbon atom bonded to ^{R a} and ^{R d} in, preferably 5 to 30, 5 to 20 is more preferable.
Specifically, in the formula (Y3), the carbon atom to which R ^a and R ^d are bonded is also considered to be a part of the formed ring, and the cyclic aliphatic hydrocarbon group in R ^a described above ( Among the aliphatic cyclic groups, an aliphatic cyclic group having 5 to 30 carbon atoms can be mentioned.

  Specific examples of the (Y3) component are shown below.

  In addition to the components (Y1) to (Y3), compounds (Y4) represented by the following general formula (Y4-1) or (Y4-2) are also preferable as the component (Y). It is done. The compound (Y4) corresponds to a base generator component containing an acyloxyimino group.

［式中、Ｒ^１１、Ｒ^１２、Ｒ^４３、Ｒ^４４はそれぞれ独立に水素原子又は炭素数１〜５のアルキル基を表し、ｎ７〜ｎ１０はそれぞれ独立に０〜３である。］

[Wherein, R ¹¹ , R ¹² , R ⁴³ and R ⁴⁴ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and n7 to n10 each independently represent 0 to 3. ]

Moreover, what was proposed as a photobase generator for chemical amplification resists can be used as a component other than what was illustrated above (Y) component.
Examples of such a photobase generator include ionic ones (anion-cation complex), triphenylsulfonium compounds, triphenylmethanol; photoactive carbamates such as benzyl carbamate and benzoin carbamate; o-carbamoyl hydroxylamide, o -Amides such as carbamoyloxime, aromatic sulfonamide, alpha-lactam and N- (2-allylethynyl) amide; oxime ester, α-aminoacetophenone, cobalt complex, etc .; those described in JP-A-2007-279493 Etc.

(Y) A component may be used individually by 1 type and may be used in combination of 2 or more type.
As the component (Y), among the above, the component (Y1) is more preferable, and one or more selected from the compounds represented by any one of the general formulas (Y1-11) or (Y1-12) are included. More preferred is a compound represented by formula (Y1-12).

  In the resist composition, the content of the (Y) component is preferably 1 to 50 parts by mass, more preferably 3 to 30 parts by mass, and particularly preferably 5 to 20 parts by mass with respect to 100 parts by mass of the (X) component. When the content of the component (Y) is within the above range, pattern formation is sufficiently performed. Moreover, a sensitivity and resolution improve by being 3 mass parts or more. On the other hand, when the content of the component (Y) is 50 parts by mass or less, the formed resist film has good transparency and heat resistance and can maintain good resolution.

<(F) component>
If necessary, the resist composition may contain a fluorine additive (hereinafter referred to as “component (F)”) in order to impart water repellency to the resist film. As the component (F), many compounds have been proposed so far, for example, a fluorine-containing polymer compound described in JP-A-2010-002870, and can be appropriately selected and used.
Specific examples of the component (F) include a polymer having a structural unit represented by the following formula (f1-1) (hereinafter referred to as the component (F1)).

［式中、Ｒは前記同様であり、Ｒ^４１およびＲ^４２はそれぞれ独立して水素原子、ハロゲン原子、炭素数１〜５のアルキル基、又は炭素数１〜５のハロゲン化アルキル基を表し、複数のＲ^４１またはＲ^４２は同じであっても異なっていてもよい。ａ１は１〜５の整数であり、Ｒ^７”はフッ素原子を含む有機基である。］

[Wherein, R is the same as defined above, and R ⁴¹ and R ⁴² 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, A plurality of R ⁴¹ or R ⁴² may be the same or different. a1 is an integer of 1 to 5, and R ⁷ ″ is an organic group containing a fluorine atom.]

In formula (f1-1), R is the same as described above. R is preferably a hydrogen atom or a methyl group.
In formula (f1-1), examples of the halogen atom for R ⁴¹ and R ⁴² 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 of R ⁴¹ and R ⁴² include the same as the alkyl group having 1 to 5 carbon atoms of R, and a methyl group or an ethyl group is preferable. Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms of R ⁴¹ and R ⁴² 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 a halogen atom. Can be mentioned. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. The Above all ^{R 41, R 42,} a hydrogen atom, a fluorine atom, or an alkyl group of 1 to 5 carbon atoms is preferable, a hydrogen atom, a fluorine atom, a methyl group or an ethyl group, preferred.
In formula (f1-1), a1 is an integer of 1 to 5, preferably an integer of 1 to 3, and more preferably 1 or 2.

In formula (f1-1), R ⁷ ″ is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom.
The hydrocarbon group containing a fluorine atom may be linear, branched or cyclic, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms. The carbon number of 1 to 10 is particularly preferable.
The hydrocarbon group containing a fluorine atom preferably has 25% or more of the hydrogen atoms in the hydrocarbon group fluorinated, more preferably 50% or more fluorinated, and 60% or more. Fluorination is particularly preferable because the hydrophobicity of the resist film during immersion exposure is increased.
Among these, as R ⁷ ″, a fluorinated hydrocarbon group having 1 to 5 carbon atoms is particularly preferable, and a methyl group, —CH ₂ —CF ₃ , —CH ₂ —CF ₂ —CF ₃ , —CH (CF ₃ ) _{2, -CH 2 -CH 2 -CF 3} , and most preferably _{-CH 2 -CH 2 -CF 2 -CF 2} -CF 2 -CF 3.

The component (F1) may be a polymer composed only of the structural unit (f1), and a copolymer having the structural unit (f1) and other structural units (hereinafter referred to as the structural unit (f2)). It may be.
The structural unit (f2) is not particularly limited as long as it is another structural unit that is copolymerizable with the monomer that derives the structural unit (f1) and is not classified as the structural unit (f1). Examples thereof include units (x2) to (x4). In addition, a number of conventionally known resins that can be used for resist resins for ArF excimer laser, KrF excimer laser, EB, EUV, etc. can be used.

1000-150,000 are preferable, as for the mass mean molecular weight (Mw) (polystyrene conversion reference | standard by gel permeation chromatography) of (F1) component, 5000-40000 are more preferable, and 10000-30000 are the most preferable. If it is below the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and if it is above the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
The dispersity (Mw / Mn) of the component (F1) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5.

Component (F1) is, for example, a monomer for deriving each structural unit such as dimethyl-2,2-azobis (2-methylpropionate) (V-601), azobisisobutyronitrile (AIBN). It can be obtained by polymerization by known radical polymerization using a radical polymerization initiator. In the polymerization, for example, a chain transfer agent such as HS—CH ₂ —CH ₂ —CH ₂ —C (CF ₃ ) ₂ —OH is used in combination, so that —C (CF ₃ ) is terminally used. _{A 2-} OH group may be introduced. As described above, a copolymer in which a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is substituted with a fluorine atom is introduced has reduced defects and LER (line edge roughness: uneven unevenness of line side walls). Effective for reduction.
As the monomer for deriving each structural unit, a commercially available monomer may be used, or a monomer produced by a known method may be used.

(F) A component may be used individually by 1 type and may use 2 or more types together.
When (F) component is mix | blended, (F) component is normally used in the ratio of 0.5-10 mass parts with respect to 100 mass parts of (A) component.

  In the resist composition, as long as the effects of the present invention are not impaired, further, miscible additives, for example, additional resins for improving the performance of the resist film, surface activity for improving coating properties An agent, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent, a dye, and the like can be appropriately added and contained.

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

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.
In the analysis by NMR, the internal standard of ¹ H-NMR and ¹³ C-NMR is tetramethylsilane (TMS).

<Test Example 1>
In order to confirm the relationship between the structure of the group (I) and the base decomposability, the following evaluation was performed using the following monomer A or B as a representative example and triethylamine (TEA) as a base.
Monomers A and B are both methacrylic acid esters having a γ-butyrolactone ring, and differ only in the bonding position of the methacryloyloxy group in the γ-butyrolactone ring (monomer A is bonded to the β-position and monomer B is bonded to the α-position).

[Evaluation method and evaluation results]
Monomer A or B, PGMEA, and TEA were mixed and dissolved in the blending amounts shown in Table 1 to prepare six types of samples (No. A1 to A3, B1 to B3).
Each sample was preserve | saved on the conditions of 40 degreeC, and ¹ H-NMR analysis and ¹³ C-NMR analysis were performed about each sample 13 hours (hr) and 40 hours after the storage start. In FIG. The results of ¹ H-NMR analysis of the samples A1 to A3 after storage at 40 ° C. for 13 hours are shown in FIG. The result of ¹ H-NMR analysis after storage of 40 ° C. and 13 hours of samples B1 to B3 is shown. 1-2, “PM” indicates PGMEA.
Further, from the ¹³ C-NMR analysis results, the decomposition ratio (%) of each of the monomers A and B was determined by calculating the integration ratio of the monomer A or B and the integration ratio of the lactone to be produced. The results are also shown in Table 1.
As shown in the results of FIGS. Among the samples A1 to A3, No. 1 containing TEA together with the monomer A In 2-3 samples, peaks derived from degradation products (methacrylic acid and γ-crotonolactone) were confirmed. In addition, the intensity of the peak derived from the decomposition product is No. with a high ratio of TEA to monomer. 3 was bigger. On the other hand, no. In the sample 1, no peak derived from the decomposition product was confirmed. No. 1 using monomer B In any of the samples B1 to B3, no peak derived from the decomposition product was confirmed.
The same result can be confirmed from the decomposition rate, and the combination of monomer A and TEA No. In a few samples, decomposition of monomer A was confirmed.
From these results, it was shown that when a base is brought into contact with the monomer A which is a methacrylic acid ester having a group corresponding to the group (I), methacrylic acid having a higher polarity is produced. A similar reaction occurs even when a resin is used instead of a monomer.

<Test Example 2>
Each component shown in Table 2 was mixed and dissolved to prepare a resist composition, and the following [ArF exposure evaluation] was performed on the obtained resist composition.

[ArF exposure evaluation]
The prepared resist composition is applied onto an 8-inch silicon wafer using a spinner, prebaked (PAB) at 90 ° C. for 60 seconds on a hot plate, and dried to form a resist film having a thickness of 196 nm. Formed.
The resist film was selectively exposed with an ArF excimer laser (193 nm) at an exposure amount of 50 mJ / cm ² using an ArF exposure apparatus NSR-S302 (product name, manufactured by Nikon). Thereafter, a post-exposure heating (PEB) treatment at 130 ° C. for 180 seconds was performed. Further, the resist film was developed under the development conditions (developer, development time) shown in Table 2, and then shaken and dried.
About each of the unexposed part and exposed part of a resist film, the film thickness (residual film, unit: nm) after development with each developer was measured by NANOSPEC MODEL 6100A manufactured by NANOMETRICS. The results are shown in Table 2.

In Table 2, the numerical value in [] shows a compounding quantity (part by mass). Moreover, the symbol in Table 2 shows the following, respectively.
(X) -1: Copolymer represented by the following chemical formula (X) -1: Mw = 7800, Mw / Mn = 1.65 (copolymerization composition ratio (molar ratio): 1 / m = 52/48) ).
(Y) -1: a compound represented by the following chemical formula (Y) -1.
(S) -1: PGMEA / PGME = 960/640 (mass ratio) mixed solvent.
[Developer]
D1: Heptane / methyl amyl ketone = 1/5 (mass ratio).
D2: heptane / butyl acetate = 1/5 (mass ratio).

As shown in Table 2, in any of Examples 1 and 2, the unexposed portion of the resist film was completely removed by development with an organic developer, while the exposed portion remained, and the unexposed portion and exposed It was confirmed that a difference in solubility (dissolution contrast) with respect to the organic developer was developed between the two parts.
From the above results, according to the present invention, it is confirmed that the dissolution contrast can be expressed in a system completely different from the dissolution contrast expression system (system using an acid generator component) in the conventional chemically amplified resist. did it.

Claims (3)

On a support using a resist composition containing a resin component (X) containing a group (I) that is decomposed by the action of a base to increase polarity and a base generator component (Y) that generates a base upon exposure Forming a resist film;
Exposing the resist film;
Developing the resist film with a developer containing an organic solvent to form a negative resist pattern;
A resist pattern forming method comprising: The resist pattern forming method according to claim 1, wherein the group (I) is represented by the following general formula (I-1).

[Wherein, R ¹ is a hydrogen atom or a substituent, R ² is a substituent, s is an integer of 1 to 4, and t is an integer of 0 to 2. ]   The resist pattern formation method of Claim 1 or 2 in which the said base generator component (Y) contains the base generator component containing a carbamate group.

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