JP2013088573A - Resist composition for euv or eb, and method for forming resist pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resist composition useful for EUV and EB and to provide a method for forming a resist pattern.SOLUTION: A resist composition comprises a polymer (A1) having a structural unit (a5) including a group represented by general formula (a5-0-1) or (a5-0-2), in which an amount of monomers that derives the structural unit (a5) is 100 ppm or less based on the polymer (A1). In the formula, Qand Qrepresent a single bond or a divalent linking group. R, Rand Rrepresent an organic group, in which Rand Rmay be bonded to each other to form a ring together with a sulfur atom in the formula with the proviso that the group -R-S(R)(R) in the formula has only one aromatic ring as a whole or does not have an aromatic ring.

Description

  The present invention relates to a resist composition in which an acid is generated by exposure and the solubility in a developer is changed by the action of the acid, and a resist pattern forming method using the resist composition.

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, and the resist film is selectively exposed and developed to form a resist pattern having a predetermined shape on the resist film. The process to perform is performed. A resist material in which the exposed portion of the resist film changes to a property that dissolves in the developer is referred to as a positive type, and a resist material that changes to a property in which the exposed portion does not dissolve in the developer is referred to as a negative type.
In recent years, in the manufacture of semiconductor elements and liquid crystal display elements, pattern miniaturization has been rapidly progressing due to advances in lithography technology.
As a technique for miniaturization, the 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.

Resist materials are required to have lithography characteristics such as sensitivity to these exposure light sources and resolution capable of reproducing patterns with fine dimensions.
Conventionally, as a resist material satisfying such requirements, there is a chemically amplified resist 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. It is used. For example, when the developer is an alkali developer (alkaline development process), the positive chemically amplified resist composition includes a resin component (base resin) whose solubility in an alkali developer is increased by the action of an acid, an acid Those containing a generator component are generally used. When a resist film formed using such a resist composition is selectively exposed at the time of resist pattern formation, an acid is generated from the acid generator component in the exposed portion, and the alkali developer of the base resin is generated by the action of the acid. As a result, the exposed area becomes soluble in an alkaline developer. Therefore, by performing alkali development, a positive pattern in which an unexposed portion remains as a pattern is formed.
Here, as the base resin, a resin whose polarity is increased by the action of an acid is used, and the solubility in an alkali developer is increased while the solubility in an organic solvent is decreased. Therefore, when a solvent development process using an organic solvent-containing developer (organic developer) is applied instead of an alkali development process, the solubility in the organic developer is relatively reduced in the exposed area. In the solvent development process, the unexposed portion of the resist film is dissolved and removed by the organic developer, and a negative resist pattern is formed in which the exposed portion remains as a pattern. Such a solvent development process for forming a negative resist pattern is sometimes referred to as a negative development process (see, for example, Patent Document 1).

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. Resins (acrylic resins) and the like are generally used (see, for example, Patent Document 2).
Here, “(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. “(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.
Various acid generators used in chemically amplified resist compositions have been proposed so far, for example, onium salt acid generators, oxime sulfonate acid generators, diazomethane acid generators. Nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators and the like are known.

  As the base resin of the chemically amplified resist composition, one having an acid generating group that generates an acid upon exposure has been proposed. For example, a resin component having an acid-generating group that generates an acid upon exposure and an acid-decomposable group that changes its polarity by the action of an acid has been proposed in the structure (see, for example, Patent Document 3). Such a resin component has both a function as an acid generator and a function as a base material component, and a chemical amplification resist composition can be constituted by only one component. In other words, when the resin component is exposed to light, an acid is generated from the acid-generating group in the structure, the acid-decomposable group is decomposed by the action of the acid, and a polar group such as a carboxy group is generated to increase the polarity. To do. Therefore, if selective exposure is performed on a resin film (resist film) formed using the resin component, the polarity of the exposed portion increases. Therefore, development using an alkaline developer dissolves the exposed portion. And a positive resist pattern is formed.

In recent years, studies have also been made on EUV (extreme ultraviolet), EB (electron beam), X-rays, and the like having shorter wavelengths (higher energy) than ArF excimer lasers.
Resist materials used for EUV lithography and EB lithography are required to have lithography characteristics such as sensitivity to EUV and EB and resolution capable of forming a fine resist pattern as a target.
At present, chemically amplified resists that have been proposed for KrF excimer lasers, ArF excimer lasers and the like are generally used as resist materials in EUV lithography and EB lithography because of their excellent lithography properties. . In particular, chemically amplified resists containing an acrylic resin as a base resin are said to be excellent in their lithography properties.

JP 2009-025723 A JP 2003-241385 A JP 2011-118310 A

However, when a chemically amplified resist proposed for KrF excimer laser, ArF excimer laser, or the like is used for EUV lithography or EB lithography, there is a problem that the shape of the formed resist pattern becomes defective.
For example, in EUV lithography, light of a wavelength outside the EUV region, so-called OoB (Out of Band) light, which is included in light generated from a light source of an EUV exposure apparatus, is a problem. The OoB light enters the unexposed portion of the resist film together with the flare that is generated at the same time (that is, the selectivity of the exposed region at the time of EUV light irradiation is lost), and the acid generator component also in the unexposed portion As a result of decomposition, acid is generated, resulting in a decrease in contrast of the resist pattern, a reduction in film thickness, roughness (roughness of the upper surface of the pattern and the surface of the side wall), and the like. Roughness causes a defective shape of the resist pattern. For example, the roughness of the pattern side wall surface causes a shape defect represented by non-uniform line width in the line and space pattern, distortion around the hole in the hole pattern, and the like.

The problem of the shape defect due to the OoB light tends to be noticeable particularly when a chemically amplified resist for a lithography process in which exposure is performed using light having a wavelength in the DUV region such as ArF excimer laser light. . That is, the chemically amplified resist generally generates an acid when irradiated with light having a wavelength in the DUV region, and the solubility in the developer changes.
OoB light includes EUV around 13.5 nm, DUV of 150 to 300 nm, light in the infrared region, etc., and conventionally used onium salt-based acid generators are light in the wavelength of DUV region. It is easy to generate acid by absorbing. For this reason, a portion that is originally an unexposed portion during EUV exposure is also exposed to light, resulting in degradation of resolution, roughness, shape degradation, and the like, which may adversely affect device performance.
Also in EB lithography, depending on electron beam irradiation conditions such as acceleration voltage, electrons may diffuse (scatter) on the resist film surface and cause the same problems as OoB light in the EUV lithography (forward scatter, back scatter, etc.). .
The defective shape of the resist pattern may adversely affect the formation of fine semiconductor elements. Therefore, a resist material used for EUV lithography or EB lithography is required to improve the pattern characteristics as well as the lithography properties.

  This invention is made | formed in view of the said situation, Comprising: It makes it a subject to provide a resist composition useful for EUV or EB, and a resist pattern formation method.

In order to solve the above problems, the present invention employs the following configuration.
That is, the first aspect of the present invention is an EUV or EB resist composition containing a base material component (A) that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid. The base component (A) is a polymer having a structural unit (a5) containing a group represented by the following general formula (a5-0-1) or general formula (a5-0-2) ( A resist composition for EUV or EB characterized in that the amount of monomer containing A1) and deriving the structural unit (a5) is 100 ppm (mass basis) or less with respect to the polymer (A1). is there.

［式中、Ｑ^１及びＱ^２はそれぞれ独立に単結合又は２価の連結基である。Ｒ^３、Ｒ^４及びＲ^５はそれぞれ独立に有機基であり、Ｒ^４とＲ^５とは相互に結合して式中のイオウ原子と共に環を形成してもよい。ただし、式中の基−Ｒ^３−Ｓ^＋（Ｒ^４）（Ｒ^５）は全体で芳香環を１個のみ有するか又は芳香環を有さない。Ｖ⁻は対アニオンである。Ａ⁻はアニオンを含む有機基である。Ｍ^ｍ＋はｍ価の有機カチオンであり、ｍは１〜３の整数である。ただし、Ｍ^ｍ＋は芳香環を１個のみ有するか又は芳香環を有さない。］

[Wherein, Q ¹ and Q ² are each independently a single bond or a divalent linking group. R ³ , R ⁴ and R ⁵ are each independently an organic group, and R ⁴ and R ⁵ may be bonded to each other to form a ring together with the sulfur atom in the formula. However, group -R ^{< 3 >} -S ^<+> (R ^{< 4 >} ) (R ^{< 5 >} ) in a formula has only one aromatic ring as a whole, or does not have an aromatic ring. V ⁻ is a counter anion. A ^- is an organic group containing anion. M ^{m +} is an m-valent organic cation, and m is an integer of 1 to 3. However, M ^{m +} has only one aromatic ring or no aromatic ring. ]

  The second aspect of the present invention is a step of forming a resist film on the support using the resist composition for EUV or EB of the first aspect, and exposing the resist film by EUV or EB. A resist pattern forming method comprising: a step; and a step of developing the resist film to form a resist pattern.

In the present specification and claims, “for EUV or EB” means that a resist pattern formed using the resist composition is EUV (extreme ultraviolet) or EB (electron) as an exposure light source (radiation source). Line).
“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.
Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups. The same applies to the alkyl group in the alkoxy group.
The “alkylene group” includes linear, branched, and cyclic divalent saturated hydrocarbon groups unless otherwise specified.
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, and the “halogenated alkylene group” is the part of or all of the hydrogen atoms in the alkylene group is a halogen atom. The halogen atom includes a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
The “fluorinated alkyl group” is a group in which part or all of the hydrogen atoms of the alkyl group are substituted with fluorine atoms. The “fluorinated alkylene group” is a group in which part or all of the hydrogen atoms of the alkylene group are substituted with fluorine atoms.
A “hydroxyalkyl group” is a group in which some or all of the hydrogen atoms of an alkyl group have been substituted with hydroxyl groups.
“Structural unit” means a monomer unit (monomer unit) constituting a polymer compound (resin, polymer, copolymer).

  According to the present invention, it is possible to provide a resist composition useful for EUV or EB, and a resist pattern forming method using the resist composition.

<< EUV or EB resist composition >>
The resist composition according to the first aspect of the present invention generates a base material component (A) (hereinafter also referred to as “component (A)”) that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid. .) Containing a resist composition for EUV or EB.
Since the resist composition of this embodiment contains the component (A), the resist composition has a property that its solubility in a developing solution is changed by exposure. When a resist film is formed using the resist composition and selective exposure is performed on the resist film, an acid is generated from the component (A) in the exposed portion, and the acid is a developer containing the component (A). Change the solubility in As a result, the solubility of the exposed portion in the developer changes, while the solubility in the unexposed portion does not change in the developer. Therefore, when the resist film is developed, when the resist composition is positive, the exposed portion Is removed by dissolution to form a positive resist pattern. When the resist composition is negative, the unexposed portion is dissolved and removed to form a negative resist pattern.
In this specification, a resist composition in which an exposed portion is dissolved and removed to form a positive resist pattern is referred to as a positive resist composition, and a resist composition that forms a negative resist pattern in which an unexposed portion is dissolved and removed. Is referred to as a negative resist composition.
The resist composition of this embodiment may be a positive resist composition or a negative resist composition. Further, the resist composition of this embodiment may be used for an alkali development process using an alkali developer for the development process at the time of forming a resist pattern, and a developer (organic developer) containing an organic solvent is used for the development process. It may be for the solvent development process used. Preferably, it is used for forming a positive resist pattern in an alkali development process. In this case, as the component (A), one whose solubility in an alkali developer is increased by the action of an acid is used. It is done.

<(A) component>
The component (A) used in the resist composition of this embodiment is a base material component that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid, and is a structural unit (a5) described later. (A1) (hereinafter also referred to as “component (A1)”).
Here, the “base component” is an organic compound having a film forming ability, and an organic compound having a molecular weight of 500 or more is preferably used. When the molecular weight of the organic compound is 500 or more, the film-forming ability is improved and a nano-level resist pattern is easily formed. “Organic compounds having a molecular weight of 500 or more” used as the base component are roughly classified into non-polymers and polymers.
As the non-polymer, those having a molecular weight of 500 or more and less than 4000 are usually used. Hereinafter, a nonpolymer having a molecular weight of 500 or more and less than 4000 is referred to as a low molecular compound.
As the polymer, those having a molecular weight of 1000 or more are usually used. Hereinafter, a polymer having a molecular weight of 1000 or more is referred to as a polymer compound. In the case of a polymer compound, the “molecular weight” is a polystyrene-reduced mass average molecular weight measured by GPC (gel permeation chromatography). Hereinafter, the polymer compound may be simply referred to as “resin”.

[(A1) component]
Component (A1) may have increased solubility in a developer due to the action of an acid, or may decrease solubility in a developer due to the action of an acid.
The component (A1) has at least a site that generates an acid upon exposure (acid generating site) in at least the structural unit (a5).

  When the resist composition of this embodiment is a resist composition that forms a negative resist pattern in an alkali development process (or forms a positive resist pattern in a solvent development process), the component (A1) is preferably A resin component that generates an acid upon exposure and is soluble in an alkaline developer (hereinafter also referred to as “component (A1-2)”) is used, and a crosslinking agent component is further blended. In such a resist composition, when an acid is generated from an acid generation site (at least the structural unit (a5)) in the component (A1-2) by exposure, the acid acts to cause the component (A1-2) and the crosslinking agent component. As a result, the solubility in the alkaline developer decreases (the solubility in the organic developer increases). Therefore, in the formation of a resist pattern, when a resist film obtained by coating the resist composition on a support is selectively exposed, the exposed portion is hardly soluble in an alkali developer (to an organic developer). On the other hand, the unexposed area remains soluble (almost insoluble in the organic developer) while remaining undissolved in the alkali developer, so that a negative resist pattern can be formed by developing with an alkali developer. . At this time, if an organic developer is used as the developer, a positive resist pattern can be formed.

As the component (A1-2), an acid generation site (at least a general formula described later) that generates an acid upon exposure to a resin known as a resin soluble in an alkali developer (hereinafter referred to as “alkali-soluble resin”). And (a5-0-1) or a group represented by the general formula (a5-0-2)).
Examples of the alkali-soluble resin (before introduction of the acid generating site) include α- (hydroxyalkyl) acrylic acid or alkyl of α- (hydroxyalkyl) acrylic acid disclosed in JP-A-2000-206694. A resin having a structural unit derived from at least one selected from an ester (preferably an alkyl ester having 1 to 5 carbon atoms); an α-position carbon atom having a sulfonamide group disclosed in US Pat. No. 6,949,325 Acrylic resin or polycycloolefin resin to which an atom other than a hydrogen atom or a substituent may be bonded, and disclosed in US Pat. No. 6,949,325, Japanese Patent Application Laid-Open No. 2005-336452, and Japanese Patent Application Laid-Open No. 2006-317803. Contains a fluorinated alcohol, and the carbon atom at the α-position is an atom other than a hydrogen atom or Have substituents attached also good acrylic resin; disclosed in Japanese 2006-259582 discloses, polycycloolefin resins having fluorinated alcohol, with minimal swelling can formation of a satisfactory resist pattern.
In addition, the α- (hydroxyalkyl) acrylic acid is an α-position carbon atom to which a carboxy group is bonded among acrylic acids in which an atom other than a hydrogen atom or a substituent may be bonded to the α-position carbon atom. One or both of acrylic acid to which a hydrogen atom is bonded and α-hydroxyalkyl acrylic acid to which a hydroxyalkyl group (preferably a hydroxyalkyl group having 1 to 5 carbon atoms) is bonded to the α-position carbon atom Show.

The acid generation site contains at least a group represented by the following general formula (a5-0-1) or general formula (a5-0-2), and in addition, is known as an acid generator for resist compositions. The thing of the structure similar to the acid generation | occurrence | production site | part which a compound has is applicable.
In addition to the side chain part or side chain part, the main chain terminal may be sufficient as the introduction position of the acid generation site | part to alkali-soluble resin. The introduction of the acid generation site to the main chain terminal can be carried out, for example, by using a polymerization initiator having an acid generation site as a polymerization initiator when producing an alkali-soluble resin. When the alkali-soluble resin is produced, the introduction into the side chain moiety is performed by using an alkali-soluble group such as a hydroxyl group or a carboxy group as a polar group in a monomer having an alkali-soluble group (for example, a constituent unit (a3) described later). Monomer having an acid generation site together with a precursor thereof (for example, an alkali-soluble group protected with a protecting group) or a precursor thereof (a monomer for inducing a structural unit (a5) described later) Can be carried out by polymerizing.

  As the crosslinking agent component, for example, it is usually preferable to use an amino crosslinking agent such as glycoluril having a methylol group or an alkoxymethyl group, a melamine crosslinking agent, etc., because a good resist pattern with little swelling can be formed. It is preferable that the compounding quantity of a crosslinking agent component is 1-50 mass parts with respect to 100 mass parts of alkali-soluble resin.

When the resist composition of this embodiment is a resist composition that forms a positive resist pattern in an alkali development process (or forms a negative resist pattern in a solvent development process), the component (A1) is preferably A resin component (hereinafter also referred to as “(A1-1) component”) that generates an acid upon exposure and increases its polarity by the action of the acid is used. Since the polarity of the component (A1-1) changes before and after exposure, by using the component (A1-1), a good development contrast can be obtained not only in the alkali development process but also in the solvent development process.
That is, when the alkali development process is applied, the component (A1-1) is hardly soluble in an alkali developer before exposure, and an acid generation site (at least a structural unit) in the component (A1-1) by exposure. When an acid is generated from (a5)), the polarity is increased by the action of the acid and the solubility in an alkali developer is increased. Therefore, in the formation of a resist pattern, when a resist film obtained by applying the resist composition on a support is selectively exposed, the exposed portion turns from poorly soluble to soluble in an alkaline developer. Since the unexposed area remains hardly soluble in alkali and does not change, a positive resist pattern can be formed by alkali development. On the other hand, when the solvent development process is applied, the component (A1-1) is highly soluble in an organic developer before exposure, and an acid generation site (at least a component of the component (A1-1) is exposed by exposure. When an acid is generated from the unit (a5)), the polarity of the acid increases due to the action of the acid, and the solubility in an organic developer decreases. Therefore, in the formation of the resist pattern, when the resist film obtained by coating the resist composition on the support is selectively exposed, the exposed portion changes from being soluble to hardly soluble in the organic developer. Since the unexposed portion remains soluble and does not change, by developing with an organic developer, a contrast can be provided between the exposed portion and the unexposed portion, and a negative resist pattern can be formed.

(Structural unit (a5))
The structural unit (a5) is a structural unit containing a group represented by the following general formula (a5-0-1) or general formula (a5-0-2).

［式中、Ｑ^１及びＱ^２はそれぞれ独立に単結合又は２価の連結基である。Ｒ^３、Ｒ^４及びＲ^５はそれぞれ独立に有機基であり、Ｒ^４とＲ^５とは相互に結合して式中のイオウ原子と共に環を形成してもよい。ただし、式中の基−Ｒ^３−Ｓ^＋（Ｒ^４）（Ｒ^５）は全体で芳香環を１個のみ有するか又は芳香環を有さない。Ｖ⁻は対アニオンである。Ａ⁻はアニオンを含む有機基である。Ｍ^ｍ＋はｍ価の有機カチオンであり、ｍは１〜３の整数である。ただし、Ｍ^ｍ＋は芳香環を１個のみ有するか又は芳香環を有さない。］

[Wherein, Q ¹ and Q ² are each independently a single bond or a divalent linking group. R ³ , R ⁴ and R ⁵ are each independently an organic group, and R ⁴ and R ⁵ may be bonded to each other to form a ring together with the sulfur atom in the formula. However, group -R ^{< 3 >} -S ^<+> (R ^{< 4 >} ) (R ^{< 5 >} ) in a formula has only one aromatic ring as a whole, or does not have an aromatic ring. V ⁻ is a counter anion. A ^- is an organic group containing anion. M ^{m +} is an m-valent organic cation, and m is an integer of 1 to 3. However, M ^{m +} has only one aromatic ring or no aromatic ring. ]

Structural unit having a group represented by formula (a5-0-1) In formula (a5-0-1), Q ¹ represents a single bond or a divalent linking group.
Examples of the divalent linking group for Q ^1, is not particularly limited, a 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 The hydrocarbon group as the divalent linking group in Q ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. May be.
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 have a substituent. The aromatic ring 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. 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, and the like. Can be 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. And a group obtained by further removing one hydrogen atom 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.
The aromatic hydrocarbon group may or may not 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 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.

.. Divalent linking group containing a hetero atom The hetero atom of the divalent linking group containing a hetero atom in Q ¹ 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, a silicon atom, etc. are mentioned.
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 Examples thereof include non-hydrocarbon linking groups such as — and —SiH ₂ —O—, and combinations of at least one of these non-hydrocarbon linking groups and 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—, —NH—C (═NH) — in —C (═O) —NH—, and H in —SiH ₂ —O— are an alkyl group and an acyl, respectively. It may be substituted with a substituent such as a group. The substituent preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
Examples of the divalent linking group that is a combination of a non-hydrocarbon linking group and a divalent hydrocarbon group include, for example, —Y ²¹ —O—Y ²² —, — [Y ²¹ —C (═O). —O] _{m ′} —Y ²² —, —Y ²¹ —O—C (═O) —Y ²² — (wherein Y ²¹ and Y ²² each independently have a substituent) A hydrocarbon group, O is an oxygen atom, m ′ is an integer of 0 to 3), — [Y ²³ —O] _{n ′} — (wherein Y ²³ is an alkylene group, and O is oxygen And n ′ is an integer of 1 or more.
The ^{-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 the same groups as those described above as the “divalent hydrocarbon group optionally having substituent (s)”.
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.
^{- [Y 21 -C (= O} ) -O] m '-Y 22 - In, m' is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, 1 is particularly preferred. ^{That, - [Y 21 -C (=} O) -O] m '-Y 22 - ^{The, -Y 21 -C (= O)} -O-Y 22 - is particularly preferred. Among _{them, - (CH 2) a '} -C (= O) -O- (CH 2) b' - it is preferred. 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.
The _{^{- [Y 23 -O] n '}} - alkylene group for ^{Y 23} is preferably an alkylene group having 1 to 4 carbon atoms.

Among them, the divalent linking group of Q ¹ may be a single bond, an ester bond [—C (═O) —O—], an ether bond (—O—), an alkylene group, or a combination thereof. preferable.

In formula (a5-0-1), R ³ , R ⁴ and R ⁵ are each independently an organic group, and R ⁴ and R ⁵ are bonded to each other to form a ring together with the sulfur atom in the formula. May be.
The organic group of R ^{3 to} R ^{5 is} a group containing a carbon atom, and includes an atom other than a carbon atom (for example, a hydrogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom (fluorine atom, chlorine atom, etc.)). You may have.
Examples of the organic group include hydrocarbon groups in which some or all of the hydrogen atoms may be substituted with a substituent, and a linking group may be inserted between carbon atoms. Examples of the linking group include those similar to the divalent linking group containing a hetero atom. The organic group may or may not have an aromatic group.
However, group -R ^{< 3 >} -S ^<+> (R ^{< 4 >} ) (R ^{< 5 >} ) in a formula has only one aromatic ring as a whole, or does not have an aromatic ring. That is, when R ⁴ and R ⁵ are not bonded to each other to form a ring with the sulfur atom in the formula, only one of R ³ , R ⁴ and R ⁵ has one aromatic ring. The other two are organic groups that do not have an aromatic ring, or all of R ³ , R ^4, and R ⁵ are organic groups that do not have an aromatic ring. When R ⁴ and R ⁵ are bonded to each other to form one aromatic ring together with the sulfur atom in the formula, R ³ is an organic group having no aromatic ring. When R ⁴ and R ⁵ are bonded to each other to form a ring with the sulfur atom in the formula, and the ring is an aliphatic ring (ring having no aromaticity), R ³ is an organic group having one aromatic ring or an organic group having no aromatic ring. When the ring formed by combining R ⁴ and R ⁵ together with the sulfur atom in the formula is a ring containing two or more aromatic rings, the structural unit does not correspond to the structural unit (a5).
The aromatic ring absorbs OoB light having a DUV wavelength. The number of aromatic rings in the whole group -R ³ -S ⁺ (R ⁴ ) (R ⁵ ) composed of S ⁺ and R ³ , R ⁴ and R ⁵ directly bonded thereto is 1 or less. Thus, the influence of OoB light can be suppressed. It is particularly preferable that the group —R ³ —S ⁺ (R ⁴ ) (R ⁵ ) has no aromatic ring as a whole because this effect is further enhanced.
The aromatic ring 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 is the same as the aromatic ring mentioned in the description of the divalent hydrocarbon group. Can be mentioned. Specific examples 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 is substituted with a heteroatom. 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.
A substituent may be bonded to the aromatic ring. Examples of the substituent include the same substituents as those described as the substituent that the aromatic hydrocarbon group may have in the description of the divalent hydrocarbon group.

In formula (a5-0-1), the organic group for R ³ is preferably an alkylene group which may have a substituent, or an arylene group which may have a substituent.
Examples of the alkylene group which may have a substituent in R ³ include an unsubstituted alkylene group, a substituted alkylene group in which part or all of the hydrogen atoms of the unsubstituted alkylene group are substituted with a substituent, and the like. Is mentioned.
The unsubstituted alkylene group may be linear, branched or cyclic. From the viewpoint of excellent resolution, an alkylene group having 1 to 10 carbon atoms is preferable, and an alkylene group having 1 to 5 carbon atoms is more preferable. Specifically, methylene group, ethylene group, n-propylene group, isopropylene group, n-butylene group, isobutylene group, n-pentylene group, cyclopentylene group, hexylene group, cyclohexylene group, nonylene group, decylene group. Etc.

Examples of the substituent that the substituted alkylene group has include a halogen atom, an oxo group (═O), a cyano group, an alkyl group, an alkoxyalkyloxy group, an alkoxycarbonylalkyloxy group, —C (═O) —O—R ⁷ ″, ^{-O-C (= O) -R} 8 ", -O-R 9", an aryl group ^.R 7 ^", R ^8", the ^{R 9} "are each independently, a hydrogen atom or a hydrocarbon group is there.
Among these, examples of the halogen atom as a substituent include a fluorine atom, a chlorine atom, an iodine atom, and a bromine atom, and a fluorine atom is preferable.

The alkyl group as a substituent in the substituted alkylene group may be linear, branched or cyclic. The carbon number is preferably 1-30.
Among them, the linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, heicosyl group, docosyl group and the like.
The branched alkyl group preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, Examples include 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like.
The cyclic alkyl group may be monocyclic or polycyclic. 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. 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; one or more polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Examples include a group excluding a hydrogen atom.
The cyclic alkyl group is preferably a polycyclic group, preferably a group obtained by removing one or more hydrogen atoms from polycycloalkane, and most preferably a group obtained by removing one or more hydrogen atoms from adamantane.
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 alkoxyalkyloxy group as a substituent in the substituted alkylene group include:
General formula: -O-C ( ^R47 ) ( ^R48 ) -O- ^R49
[Wherein, R ⁴⁷ and R ⁴⁸ each independently represent a hydrogen atom or a linear or branched alkyl group, and R ⁴⁹ represents an alkyl group. ]
The group represented by these is mentioned.
In R ⁴⁷ and R ⁴⁸ , the alkyl group preferably has 1 to 5 carbon atoms, may be linear or branched, and is preferably an ethyl group or a methyl group, and most preferably a methyl group.
At least one of R ⁴⁷ and R ⁴⁸ is preferably a hydrogen atom. In particular, it is more preferable that one is a hydrogen atom and the other is a hydrogen atom or a methyl group.
The alkyl group for R ⁴⁹ preferably has 1 to 15 carbon atoms, and may be linear, branched or cyclic.
The linear or branched alkyl group for R ⁴⁹ preferably has 1 to 5 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group. Can be mentioned.
The cyclic alkyl group for R ⁴⁹ preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane, etc., which may or may not be substituted with an alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated alkyl group, etc. And a group obtained by removing one or more hydrogen atoms from the polycycloalkane. Examples of the monocycloalkane include cyclopentane and cyclohexane. Examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.

Examples of the alkoxycarbonylalkyloxy group as a substituent in the substituted alkylene group include:
General formula: —O—R ⁵⁰ —C (═O) —O—R ⁵⁶
[Wherein, R ⁵⁰ represents a linear or branched alkylene group, and R ⁵⁶ represents a tertiary alkyl group. ]
The group represented by these is mentioned.
The linear or branched alkylene group for R ⁵⁰ preferably has 1 to 5 carbon atoms, such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, or a 1,1-dimethylethylene group. Etc.
The tertiary alkyl group for R ⁵⁶ includes a 2-methyl-2-adamantyl group, a 2- (2-propyl) -2-adamantyl group, a 2-ethyl-2-adamantyl group, and a 1-methyl-1-cyclopentyl group. 1-ethyl-1-cyclopentyl group, 1-methyl-1-cyclohexyl group, 1-ethyl-1-cyclohexyl group, 1- (1-adamantyl) -1-methylethyl group, 1- (1-adamantyl)- 1-methylpropyl group, 1- (1-adamantyl) -1-methylbutyl group, 1- (1-adamantyl) -1-methylpentyl group; 1- (1-cyclopentyl) -1-methylethyl group, 1- ( 1-cyclopentyl) -1-methylpropyl group, 1- (1-cyclopentyl) -1-methylbutyl group, 1- (1-cyclopentyl) -1-methylpentyl group; 1- (1-cyclohexyl) -1-methylethyl group, 1- (1-cyclohexyl) -1-methylpropyl group, 1- (1-cyclohexyl) -1-methylbutyl group, 1- (1-cyclohexyl) -1 -Methylpentyl group, tert-butyl group, tert-pentyl group, tert-hexyl group and the like can be mentioned.
Moreover, the general ^formula: the ^{R 56} in the -O-R 50 -C (= O ) -O-R 56, also include groups replaced by ^{R 56} '. R ⁵⁶ ′ is a hydrogen atom, an alkyl group, a fluorinated alkyl group, or an aliphatic cyclic group that may contain a hetero atom.
^Examples of the alkyl group for R ⁵⁶ ′ include the same alkyl groups as those described above for R ⁴⁹ .
^Examples of the fluorinated alkyl group for R ⁵⁶ ′ include groups in which some or all of the hydrogen atoms within the alkyl group for R ⁴⁹ have been substituted with fluorine atoms.
Examples of the aliphatic cyclic group which may contain a hetero atom in R ⁵⁶ ′ include an aliphatic cyclic group containing no hetero atom, an aliphatic cyclic group containing a hetero atom in the ring structure, and an aliphatic cyclic group. Examples include those in which a hydrogen atom in the group is substituted with a heteroatom.
Regarding R ⁵⁶ ′, the aliphatic cyclic group containing no hetero atom includes a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane, and the like. Can be mentioned. Examples of the monocycloalkane include cyclopentane and cyclohexane. Examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
Regarding R ⁵⁶ ′, specific examples of the aliphatic cyclic group containing a hetero atom in the ring structure include groups represented by formulas (L1) to (L5) and (S1) to (S4) described below. Can be mentioned.
As for R ⁵⁶ ′, the hydrogen atom in the aliphatic cyclic group is specifically substituted with a hetero atom, specifically, the hydrogen atom in the aliphatic cyclic group is substituted with an oxo group (═O), etc. Is mentioned.
As for R ⁵⁶ ′, the hydrogen atom in the aliphatic cyclic group is specifically substituted with a hetero atom, specifically, the hydrogen atom in the aliphatic cyclic group is substituted with an oxo group (═O), etc. Is mentioned.

R ⁷ ″ in —C (═O) —O—R ⁷ ″ represents a hydrogen atom or a hydrocarbon group.
The hydrocarbon group for R ⁷ ″ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group may be a saturated hydrocarbon group or an aliphatic unsaturated hydrocarbon group. Any of these may be used.

The saturated hydrocarbon group for R ⁷ ″ may be linear, branched or cyclic, or a combination thereof.
1-25 are preferable, as for carbon number of a linear or branched saturated hydrocarbon group, 1-15 are more preferable, and 4-10 are more preferable.
Examples of the linear saturated hydrocarbon group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group.
The branched saturated hydrocarbon radicals, for example, tertiary alkyl groups mentioned in the description of the R ^56. Examples of branched saturated hydrocarbon groups other than tertiary alkyl groups include 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3 -Methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, 4-methylpentyl group and the like can be mentioned.
The linear or branched saturated hydrocarbon group may have a substituent. Examples of the substituent include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxo group (═O), a cyano group, and a carboxy group.
As the alkoxy group as a substituent of the linear or branched saturated hydrocarbon group, an alkoxy group having 1 to 5 carbon atoms is preferable, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, An n-butoxy group and a tert-butoxy group are preferable, and a methoxy group and an ethoxy group are most preferable.
Examples of the halogen atom as a substituent of the linear or branched saturated hydrocarbon group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
As the halogenated alkyl group as a substituent of the linear or branched saturated hydrocarbon group, part or all of the hydrogen atoms of the linear or branched saturated hydrocarbon group are the halogen atoms. And a group substituted with.
The number of carbon atoms of the cyclic saturated hydrocarbon group in R ⁷ ″ is preferably 3 to 20. The cyclic saturated hydrocarbon group may be either a polycyclic group or a monocyclic group. A group in which one hydrogen atom is removed from a polycycloalkane such as bicycloalkane, tricycloalkane, tetracycloalkane, etc. More specifically, cyclopentane, cyclohexane, Examples thereof include monocycloalkanes such as cycloheptane and cyclooctane, and groups obtained by removing one hydrogen atom from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
The cyclic saturated hydrocarbon group may have a substituent. For example, part of the carbon atoms constituting the ring of the cyclic alkyl group may be substituted with a heteroatom, or the hydrogen atom bonded to the ring of the cyclic alkyl group may be substituted with a substituent. Good.
Examples of the former include one or more hydrogen atoms from a heterocycloalkane in which a part of the carbon atoms constituting the ring of the monocycloalkane or polycycloalkane is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Examples include groups other than atoms. The ring structure may have an ester bond (—C (═O) —O—). Specifically, a lactone-containing monocyclic group such as a group obtained by removing one hydrogen atom from γ-butyrolactone, or a group obtained by removing one hydrogen atom from a bicycloalkane, tricycloalkane, or tetracycloalkane having a lactone ring. And other lactone-containing polycyclic groups.
Examples of the substituent in the latter example include the same as those described above as the substituent that the linear or branched alkyl group may have, an alkyl group having 1 to 5 carbon atoms, and the like. .
The saturated hydrocarbon group for R ⁷ ″ may be a combination of a linear or branched saturated hydrocarbon group and a cyclic saturated hydrocarbon group.
As a combination of a linear or branched saturated hydrocarbon group and a cyclic saturated hydrocarbon group, a cyclic saturated hydrocarbon group as a substituent is bonded to the linear or branched saturated hydrocarbon group. Examples include a group (for example, 1- (1-adamantyl) methyl group), a group in which a linear or branched saturated hydrocarbon group is bonded to a cyclic saturated hydrocarbon group as a substituent.

The aliphatic unsaturated hydrocarbon group for R ⁷ ″ is preferably linear or branched. Examples of the linear aliphatic unsaturated hydrocarbon group include a vinyl group, a propenyl group (allyl group), and butynyl. Examples of the branched aliphatic unsaturated hydrocarbon group include 1-methylpropenyl group, 2-methylpropenyl group, etc. These linear or branched aliphatic unsaturated groups. The saturated hydrocarbon group may have a substituent, and examples of the substituent are the same as those exemplified as the substituent which the linear or branched alkyl group may have. Can be mentioned.

The aromatic hydrocarbon group for R ⁷ ″ is a monovalent hydrocarbon group having at least one aromatic ring and may have a substituent.
The aromatic ring 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. 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; 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 heterocycle (aryl group or heteroaryl group); the aromatic hydrocarbon ring or aromatic heterocycle Groups in which one of the ring hydrogen atoms is substituted with an alkylene group (for example, arylalkyl such as benzyl, phenethyl, 1-naphthylmethyl, 2-naphthylmethyl, 1-naphthylethyl, 2-naphthylethyl, etc.) Group, heteroarylalkyl group) and the like. 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 or may not have a substituent. However, in the present invention, since the total number of aromatic rings in the group —R ³ —S ⁺ (R ⁴ ) (R ⁵ ) is 1 or less, the substituent in the substituted alkylene group is —C (═O) —O. ^"a, R 7 ^'-R 7 when it is an aromatic hydrocarbon group, a substituent possessed by the aromatic hydrocarbon group is a non-aromatic substituents. “Non-aromatic” indicates no aromaticity. Non-aromatic substituents may be any group that does not contain an aromatic group (such as an aromatic hydrocarbon group) in the structure. For example, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxo group. Group (= O) and the like.
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.

Among the above, R ⁷ ″ is preferably a hydrogen atom, a saturated hydrocarbon group or an aliphatic unsaturated hydrocarbon group because of excellent lithography characteristics and resist pattern shape. Are more preferably a linear or branched saturated hydrocarbon group or a cyclic saturated hydrocarbon group having 3 to 20 carbon atoms.

R ⁸ ″ in —O—C (═O) —R ⁸ ″ represents a hydrogen atom or a hydrocarbon group.
As R ⁸ ″, the same as R ⁷ ″ can be mentioned. Among them, a hydrogen atom, a saturated hydrocarbon group or an aliphatic unsaturated hydrocarbon group is preferable because of its good lithography characteristics and resist pattern shape, and a hydrogen atom, a linear or branched group having 1 to 15 carbon atoms. A chain-like saturated hydrocarbon group or a cyclic saturated hydrocarbon group having 3 to 20 carbon atoms is more preferable.

^{"R 9} in" ^{-O-R 9} is hydrogen atom or a hydrocarbon group.
Examples of R ⁹ ″ include the same as R ⁷ ″. Among them, a hydrogen atom, a saturated hydrocarbon group or an aliphatic unsaturated hydrocarbon group is preferable because of its good lithography characteristics and resist pattern shape, and a hydrogen atom, a linear or branched group having 1 to 15 carbon atoms. A chain-like saturated hydrocarbon group or a cyclic saturated hydrocarbon group having 3 to 20 carbon atoms is more preferable.
The —O—R ⁹ ″ as the non-aromatic substituent is preferably a hydroxyl group or an alkoxy group having 1 to 5 carbon atoms, such as a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, or n-butoxy. Most preferably, it is a tert-butoxy group.

The aryl group as a substituent in the substituted alkylene group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group. However, in the present invention, since the total number of aromatic rings in the group —R ³ —S ⁺ (R ⁴ ) (R ⁵ ) is 1 or less, R ³ is a substituted alkylene group, and the substituted alkylene group is substituted. In the case of having an aryl group as a group, the number of aryl groups that can be present as the substituent is one.
The aryl group as the substituent may have a substituent. However, in the present invention, since the total number of aromatic rings in the group —R ³ —S ⁺ (R ⁴ ) (R ⁵ ) is 1 or less, the substituent of the aryl group as the substituent is non-aromatic. It is a substituent. The non-aromatic substituent is not particularly limited as long as it does not contain an aromatic group (aromatic hydrocarbon group or the like) in the structure. For example, the aromatic hydrocarbon group in R ⁷ ″ may have. The thing similar to what was mentioned as a non-aromatic substituent is mentioned.

In the formula (a5-0-1), the arylene group which may have a substituent for R ^{3 includes} an unsubstituted arylene group having 6 to 20 carbon atoms; one of the hydrogen atoms of the unsubstituted arylene group Examples thereof include a substituted arylene group in which part or all are substituted with a substituent.
The unsubstituted arylene group is preferably an arylene group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenylene group and a naphthylene group.
Examples of the substituent in the substituted arylene group include the same groups as those described above as the substituent in the substituted alkylene group. However, in the present invention, since R ³ , R ⁴ and R ^{5 as a} whole have one or less aromatic rings, when R ³ is a substituted arylene group, the substituted arylene group has a non-aromatic substituent. Is a substituent. The non-aromatic substituent may be any as long as it does not contain an aromatic group (such as an aromatic hydrocarbon group) in the structure. Specifically, among those listed as the substituent in the substituted alkylene group, a halogen atom, an oxo group (═O), a cyano group, an alkyl group, an alkoxyalkyloxy group, an alkoxycarbonylalkyloxy group, —C (═O ) —O—R ⁷ ″, —O—C (═O) —R ⁸ ″, —O—R ⁹ ″ (where R ⁷ ″, R ⁸ ″, R ⁹ ″ are independently hydrogen atom, saturated carbonization) A hydrogen group or an aliphatic unsaturated hydrocarbon group).

In formula (a5-0-1), the organic group of R ^{4 to} R ⁵ is not particularly limited, but may have an aryl group which may have a substituent or a substituent. Examples thereof include a good alkyl group and an alkenyl group which may have a substituent. Among these, an aryl group which may have a substituent or an alkyl group which may have a substituent is preferable, and an alkyl group which may have a substituent is more preferable.
The aryl group which may have a substituent includes an unsubstituted aryl group having 6 to 20 carbon atoms; a substituted aryl group in which part or all of the hydrogen atoms of the unsubstituted aryl group are substituted with a substituent Etc.
The unsubstituted aryl group is preferably an aryl group having 6 to 10 carbon atoms because it can be synthesized at a low cost. Specific examples include a phenyl group and a naphthyl group.
Examples of the substituent in the substituted aryl group include non-aromatic substituents. Examples of the non-aromatic substituent include the same non-aromatic substituents listed as the substituent that the substituted arylene group may have.

Examples of the alkyl group in R ^{4 to} R ⁵ include an unsubstituted alkyl group, a substituted alkyl group in which part or all of the hydrogen atoms of the unsubstituted alkyl group are substituted with a substituent, and the like.
The unsubstituted alkyl group is preferably an alkyl group having 1 to 5 carbon atoms from the viewpoint of excellent resolution, and the unsubstituted alkyl group may be linear, branched or cyclic. . From the point which is excellent in resolution, a C1-C10 alkyl group is preferable and a C1-C5 alkyl group is more preferable. Specific examples include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a nonyl group, and a decyl group. .
Examples of the substituent in the substituted alkyl group include the same as those described as the substituent that the substituted alkylene group in R ³ may have.

Examples of the alkenyl group for R ⁴ and R ⁵ include an unsubstituted alkenyl group and a substituted alkenyl group in which part or all of the hydrogen atoms of the unsubstituted alkenyl group are substituted with a substituent.
The unsubstituted alkenyl group is preferably linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, and still more preferably 2 to 4. Specific examples include a vinyl group, a propenyl group (allyl group), a butynyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group.
Examples of the substituent in the substituted alkenyl group include the same groups as those described above as the substituent that the substituted alkylene group in R ³ may have.

In formula (a5-0-1), R ⁴ and R ⁵ may be bonded to each other to form a ring together with the sulfur atom in the formula. The ring may be saturated or unsaturated. The ring may be monocyclic or polycyclic. For example, when one or both of R ⁴ and R ⁵ forming a ring is a cyclic group (cyclic alkyl group or aryl group), a polycyclic ring (fused ring) is formed by combining them. The
As the ring to be formed, one ring containing a sulfur atom in the ring skeleton in the formula is preferably a 3- to 10-membered ring, particularly a 5- to 7-membered ring, including the sulfur atom. preferable.
The ring may have a hetero atom other than the sulfur atom to which R ⁴ and R ⁵ are bonded as an atom constituting the ring skeleton. Examples of the hetero atom include a sulfur atom, an oxygen atom, and a nitrogen atom.
Specific examples of the ring formed include a thiophene ring, a thiazole ring, a benzothiophene ring, a tetrahydrothiophenium ring, a tetrahydrothiopyranium ring, and the like.

In formula (a5-0-1), V ⁻ represents a counter anion.
The counter anion of V ⁻ is not particularly limited, and for example, those conventionally known as the anion part of the onium salt acid generator can be used as appropriate.
As V ⁻ , for example, the general formula “R ⁴ ” SO ₃ ^— (R ⁴ ”represents a linear, branched or cyclic alkyl group, halogenated alkyl group, aryl which may have a substituent. An anion represented by a group or an alkenyl group.

In the general formula “R ⁴ ″ SO ₃ ⁻ ”, R ⁴ ″ represents a linear, branched or cyclic alkyl group, halogenated alkyl group, aryl group, or alkenyl which may have a substituent. Represents a group.

The linear or branched alkyl group as R ⁴ ″ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and 1 to 4 carbon atoms. Most preferred.
The cyclic alkyl group as R ⁴ ″ preferably has 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.
In the case where R ⁴ ″ is an alkyl group, examples of “R ⁴ ″ SO ₃ ⁻ ” include methane sulfonate, n-propane sulfonate, n-butane sulfonate, n-octane sulfonate, 1-adamantane sulfonate, 2-norbornane sulfonate, Examples thereof include alkyl sulfonates such as d-camphor-10-sulfonate.

The halogenated alkyl group as R ⁴ ″ is one in which part or all of the hydrogen atoms in the alkyl group are substituted with halogen atoms, and the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, Among them, a linear or branched alkyl group is more preferable, and it is a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, a tert-pentyl group, or an isopentyl group. More preferable examples of the halogen atom substituted with a hydrogen atom include a fluorine atom, a chlorine atom, an iodine atom, a bromine atom, etc. In a halogenated alkyl group, a hydrogen atom of an alkyl group (an alkyl group before halogenation) It is preferable that 50 to 100% of all the hydrogen atoms are substituted with halogen atoms, and all the hydrogen atoms are substituted with halogen atoms. It is more preferable to have.
Here, the halogenated alkyl group is preferably a fluorinated alkyl group. The fluorinated alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 4 carbon atoms.
Further, the fluorination rate of the fluorinated alkyl group is preferably 10 to 100%, more preferably 50 to 100%. Particularly, when all the hydrogen atoms are substituted with fluorine atoms, the strength of the acid is increased. preferable.
Specific examples of such a preferred fluorinated alkyl group include a trifluoromethyl group, a heptafluoro-n-propyl group, and a nonafluoro-n-butyl group.

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

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

Examples of the substituent include a halogen atom, a hetero atom, an alkyl group, and a formula: X ³ -Q ′-[where Q ′ is a divalent linking group containing an oxygen atom, and X ³ represents a substituent. It is a C3-C30 hydrocarbon group which may have. ] Etc. which are represented by these.
Examples of the halogen atom and alkyl group include the same groups as those described as the halogen atom and alkyl group in the halogenated alkyl group in R ⁴ ″.
Examples of the hetero atom include an oxygen atom, a nitrogen atom, and a sulfur atom.

In the group represented by X ³ —Q′—, Q ′ is a divalent linking group containing an oxygen atom.
Q ′ may contain atoms other than oxygen atoms. Examples of atoms other than oxygen atoms include carbon atoms, hydrogen atoms, oxygen atoms, sulfur atoms, and nitrogen atoms.
Examples of the divalent linking group containing an oxygen atom include an oxygen atom (ether bond: —O—), an ester bond (—C (═O) —O—), and an amide bond (—C (═O) —NH. -), A carbonyl group (-C (= O)-), a non-hydrocarbon oxygen atom-containing linking group such as a carbonate bond (-O-C (= O) -O-); the non-hydrocarbon oxygen atom Examples include a combination of a containing linking group and an alkylene group. A sulfonyl group (—SO ₂ —) may be further linked to the combination.
Examples of the combination include —R ⁹¹ —O—, —R ⁹² —O—C (═O) —, —C (═O) —O—R ⁹³ —O—C (═O) —, —SO _2- O—R ⁹⁴ —O—C (═O) —, —R ⁹⁵ —SO ₂ —O—R ⁹⁴ —O—C (═O) — (wherein R ^{91 to} R ⁹⁵ are each independently alkylene. Group.) And the like.
The alkylene group for R ^{91 to} R ⁹⁵ is preferably a linear or branched alkylene group, and the alkylene group preferably has 1 to 12 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably 1 to 3 carbon atoms. 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.
Q ′ is preferably a divalent linking group containing an ester bond or an ether bond, and among them, —R ⁹¹ —O—, —R ⁹² —O—C (═O) — or —C (═O) — O—R ⁹³ —O—C (═O) — is preferred.

In the group represented by X ³ -Q′—, the hydrocarbon group of X ³ 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.
The aromatic ring 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. 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; 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 one hydrogen atom from the aromatic hydrocarbon ring or aromatic heterocyclic ring (aryl group or heteroaryl group); A group obtained by removing one hydrogen atom 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 hydrocarbon ring or aromatic heterocyclic ring is substituted with an alkylene group ( Examples thereof include arylalkyl groups such as benzyl group, phenethyl group, 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. .
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 a substituent of the aromatic hydrocarbon group 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. preferable.
The alkoxy group as a substituent of the aromatic hydrocarbon group is preferably an alkoxy group having 1 to 5 carbon atoms, and is a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, 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 the substituent of the aromatic hydrocarbon group include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.
When X ³ has an aromatic ring, it is preferable that there is only one aromatic ring in the entire X ³ . Also, ^{if X 3} is an aromatic ^ring, R 3, ^{R 4} and ^{R 5} preferably has no aromatic ring.

The aliphatic hydrocarbon group for X ³ may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. The aliphatic hydrocarbon group may be linear, branched or cyclic.
In X ³ , 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 “heteroatom” in X ³ 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 oxygen atom (═O), and a cyano group.
The alkoxy group 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, 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 5 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, decyl 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 aliphatic cyclic 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.
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; one or more polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. 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 groups represented by the following formulas (L1) to (L6) and (S1) to (S4), respectively.

［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 ″ represents an alkylene group having 1 to 5 carbon atoms, —O—, —S—, —O—R ⁹⁴ ′ — or —S—R ⁹⁵ ′ —, and 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, examples of the alkylene group for Q ″, R ⁹⁴ ′ and R ⁹⁵ ′ include the same alkylene groups as those described above for R ^{91 to} R ⁹⁵ .
In these aliphatic 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 an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and an oxygen atom (═O).
As said alkyl group, a C1-C5 alkyl group is preferable, and it is especially preferable that they are a methyl group, an ethyl group, a propyl group, n-butyl group, and a tert- butyl group.
Examples of the alkoxy group and the halogen atom are the same as those exemplified as the substituent for substituting part or all of the hydrogen atoms.

In the present invention, X ³ 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 aliphatic cyclic group that may be used.
The aromatic hydrocarbon group is preferably a naphthyl group which may have a substituent or a phenyl 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. The polycyclic aliphatic cyclic group is a group obtained by removing one or more hydrogen atoms from the polycycloalkane, represented by any one of (L2) to (L6) and (S3) to (S4). And the like are preferred.

Among the above, R ⁴ ″ preferably has a halogenated alkyl group or X ³ -Q′— as a substituent.
In the case of having X ³ -Q′- as a substituent, R ⁴ ″ is X ³ -Q′-Y ^3- [wherein Q ′ and X ³ are the same as defined above, and Y ³ represents a substituent. A C1-C4 alkylene group which may have or a C1-C4 fluorinated alkylene group which may have a substituent.] Is preferable.
In the group represented by X ³ -Q′—Y ³ —, the alkylene group for Y ³ includes the same alkylene groups as those described above for Q ′ having 1 to 4 carbon atoms.
Examples of the fluorinated alkylene group include groups in which part or all of the hydrogen atoms of the alkylene group have been substituted with fluorine atoms.
As Y ^3, _{specifically, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF (CF 2 CF 3) -, _{-C (CF 3) 2 -,} - CF 2 CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF ₃ ) —, —C (CF ₃ ) ₂ CF ₂ —, —CF (CF ₂ CF ₃ ) CF ₂ —, —CF (CF ₂ CF ₂ CF ₃ ) —, —C (CF ₃ ) (CF _{2 CF 3) -; - CHF} -, - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -, - CH (CF 3) CH 2 -, - CH (CF 2 _{CF 3) -, - C (} CH 3) (CF 3) -, - CH 2 CH 2 CH 2 CF 2 -, - C H ₂ CH ₂ CF ₂ CF ₂ —, —CH (CF ₃ ) CH ₂ CH ₂ —, —CH ₂ CH (CF ₃ ) CH ₂ —, —CH (CF ₃ ) CH (CF ₃ ) —, —C ( _{CF 3) 2 CH 2 -;} - CH 2 -, - CH 2 CH 2 -, - CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 -, - CH (CH 2 CH 3) -, - _{C (CH 3) 2 -,} - CH 2 CH 2 CH 2 CH 2 -, - CH (CH 3) CH 2 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 -, - CH (CH 2 CH 2 CH 3) -, - C (CH 3) (CH 2 CH ₃ ) — and the like.

Y ³ is preferably a fluorinated alkylene group, and particularly preferably a fluorinated alkylene group in which the carbon atom bonded to the adjacent sulfur atom is fluorinated. Examples of such fluorinated alkylene _{group, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, - CF (CF 3) CF 2 -, - CF 2 CF 2 CF 2 CF 2 _{-, - CF (CF 3)} CF 2 CF 2 -, - CF 2 CF (CF 3) CF 2 -, - CF (CF 3) CF (CF 3) -, - C (CF 3) 2 CF 2 -, _{-CF (CF 2 CF 3) CF} 2 -; - CH 2 CF 2 -, - CH 2 CH 2 CF 2 -, - CH 2 CF 2 CF 2 -; - CH 2 CH 2 CH 2 CF 2 -, - CH ₂ CH ₂ CF ₂ CF ₂ —, —CH ₂ CF ₂ CF ₂ CF ₂ — and the like can be mentioned.
Of _{these, -CF 2 -, - CF 2} CF 2 -, - CF 2 CF 2 CF 2 -, or _CH 2 _CF 2 CF ₂ - is _{preferable, -CF 2 -, - CF 2} CF 2 - or -CF ₂ CF ₂ CF ₂ - is more preferable, -CF ₂ - is particularly preferred.

The alkylene group or fluorinated alkylene group may have a substituent. An alkylene group or a fluorinated alkylene group has a “substituent” means that part or all of the hydrogen atom or fluorine atom in the alkylene group or fluorinated alkylene group is substituted with an atom or group other than a hydrogen atom and a fluorine atom. Means that
Examples of the substituent that the alkylene group or fluorinated alkylene group may have include an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a hydroxyl group.

R ⁴ "is ^{X 3 -Q'-Y} 3 - is a group represented by ^R 4" SO ₃ ^- Examples of, for example anion represented by any one of the following formulas (b1) ~ (b9) Is mentioned.

［式中、ｑ１〜ｑ２はそれぞれ独立に１〜５の整数であり、ｑ３は１〜１２の整数であり、ｔ３は１〜３の整数であり、ｒ１〜ｒ２はそれぞれ独立に０〜３の整数であり、ｇは１〜２０の整数であり、Ｒ^７は置換基であり、ｎ１〜ｎ６はそれぞれ独立に０または１であり、ｖ０〜ｖ６はそれぞれ独立に０〜３の整数であり、ｗ１〜ｗ６はそれぞれ独立に０〜３の整数であり、Ｑ”は前記と同じである。］

[Wherein, q1 to q2 are each independently an integer of 1 to 5, q3 is an integer of 1 to 12, t3 is an integer of 1 to 3, and r1 to r2 are each independently 0 to 3] G is an integer of 1 to 20, R ⁷ is a substituent, n1 to n6 are each independently 0 or 1, v0 to v6 are each independently an integer of 0 to 3, w1 to w6 are each independently an integer of 0 to 3, and Q ″ is the same as above.]

Examples of the substituent for R ⁷ include those listed as the substituents that may substitute part of the hydrogen atoms bonded to the carbon atoms constituting the ring structure of the aliphatic cyclic group in the description of X ³ above, The thing similar to what was mentioned as a substituent which may substitute the hydrogen atom couple | bonded with the aromatic ring which an aromatic hydrocarbon group has is mentioned.
Code (r1 and r2, W1 to W6) attached to R ⁷ when is an integer of 2 or more, a plurality of the ^{R 7} groups may be the same, respectively, may be different.

Examples of V ⁻ in formula (a5-0-1) include an anion represented by the following general formula (b-3) and an anion represented by the following general formula (b-4).

［式中、Ｘ”は、少なくとも１つの水素原子がフッ素原子で置換された炭素数２〜６のアルキレン基を表し；Ｙ”、Ｚ”は、それぞれ独立に、少なくとも１つの水素原子がフッ素原子で置換された炭素数１〜１０のアルキル基を表す。］

[Wherein X ″ represents an alkylene group having 2 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom; Y ″ and Z ″ each independently represent at least one hydrogen atom as a fluorine atom; Represents an alkyl group having 1 to 10 carbon atoms and substituted with

In the formula (b-3), X ″ is a linear or branched alkylene group in which at least one hydrogen atom is substituted with a fluorine atom, and the alkylene group preferably has 2 to 6 carbon atoms. More preferably 3 to 5 carbon atoms, most preferably 3 carbon atoms.
In formula (b-4), Y ″ and Z ″ each independently represent a linear or branched alkyl group in which at least one hydrogen atom is substituted with a fluorine atom, and the carbon number of the alkyl group Is preferably 1 to 10, more preferably 1 to 7 carbon atoms, and most preferably 1 to 3 carbon atoms.
The number of carbon atoms of the X ″ alkylene group or the number of carbon atoms of the Y ″ and Z ″ alkyl groups is preferably as small as possible because the solubility in a resist solvent is good within the above-mentioned range of carbon numbers.
In addition, in the alkylene group of X ″ or the alkyl group of Y ″ and Z ″, the strength of the acid increases as the number of hydrogen atoms substituted with fluorine atoms increases, and high-energy light or electron beam of 200 nm or less This is preferable because the transparency to the surface is improved.
The fluorination rate of the alkylene group or alkyl group is preferably 70 to 100%, more preferably 90 to 100%, and most preferably a perfluoroalkylene group or a perfluoroalkylene group in which all hydrogen atoms are substituted with fluorine atoms. A fluoroalkyl group;

V ⁻ in formula (a5-0-1) is an anion represented by the general formula “R ⁴ ″ SO ₃ ⁻ ” (in particular, R ⁴ ″ is a group represented by X ³ -Q′-Y ³ —). And an anion represented by any one of the above formulas (b1) to (b9).

Specific examples of the group represented by formula (a5-0-1) are shown below. In the following chemical formula, V ⁻ is the same as described above.

  As the structural unit having a group represented by the general formula (a5-0-1) (hereinafter referred to as “structural unit (a5-1)”), the general formula (a5-0-1) in the structure may be used. Although it will not specifically limit if it has the group represented by this, It is preferable that it is a structural unit induced | guided | derived from the compound which has an ethylenic double bond.

Here, “a 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. means.
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.
An “organic group” is a group containing a carbon atom and has an atom other than a carbon atom (for example, a hydrogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom (fluorine atom, chlorine atom, etc.)). Also good.
The organic group of the (α-substituted) acrylate ester is not particularly limited, but includes, for example, the above-described aromatic groups, polar conversion groups, characteristic groups such as acid-decomposable groups described later, and these characteristic groups in the structure. Examples include characteristic group-containing groups. Examples of the characteristic group-containing group include a group in which a divalent linking group is bonded to the characteristic group. As a bivalent coupling group, the thing similar to the bivalent coupling group in Q < ¹ > in the said formula (a5-0-1) is mentioned, for example.

Examples of “acrylamide or a derivative thereof” include 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, which may be bonded to the benzene ring of styrene or a derivative thereof, is not particularly limited. For example, the halogen atom, the 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. ]

  The structural unit (a5-1) is a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and the general formula (a5-0- The structural unit containing a group represented by 1) is particularly preferable. Examples of the structural unit include structural units represented by the following formula (a5-11).

［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、Ｑ^１、Ｒ^３〜Ｒ^５、Ｖ⁻は前記同様である。］

[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, and Q ¹ , R ^{3 to} R ⁵ , and V ⁻ are the same as described above. ]

In formula (a5-11), the alkyl group of R is preferably a linear or branched alkyl group, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, 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 (a5-11), Q ¹ , R ^{3 to} R ⁵ , and V ⁻ are the same as described above.

· Formula constitutional unit above formula having a group represented by ^{(a5-0-2) (a5-0-2), Q} 2 is a single bond or a divalent linking group. Examples of the divalent linking group for Q ² include the same divalent linking groups as those for Q ¹ in formula (a5-0-1).
Q ² may or may not have an aromatic ring. However, in formula (a5-0-2), M ^{m +} has only one aromatic ring or no aromatic ring, and Q ² also has only one aromatic ring, Or it is preferable that it does not have an aromatic ring. If Q ² is an aromatic ring, it is preferred that M m ⁺ is no aromatic ring.
Q ² includes a single bond, a linear or branched alkylene group, a linear or branched fluorinated alkylene group, a substituent (preferably a fluorine atom) among the divalent linking groups described above. ) May be an arylene group, an ester bond [—C (═O) —O—], or a combination thereof.

In formula (a5-0-2), A ⁻ represents an organic group containing an anion.
A ⁻ is not particularly limited as long as it includes a site which is generated by exposure and becomes an acid anion, but is not limited thereto. A group capable of generating an imide anion or a tris (alkylsulfonyl) methide anion is preferred.
Among them, A ^- as is preferably a group represented by the following formula (a5-2-an1) ~ (a5-2 -an4).

［式中、Ｗ^０は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。Ｚ^３は−Ｃ（＝Ｏ）−Ｏ−、−ＳＯ_２−又は置換基を有していてもよい炭化水素基であり、Ｚ^４及びＺ^５はそれぞれ独立に−Ｃ（＝Ｏ）−又は−ＳＯ_２−である。Ｒ^６２及びＲ^６３はそれぞれ独立にフッ素原子を有していてもよい炭化水素基である。Ｚ^１は−Ｃ（＝Ｏ）−、−ＳＯ_２−、−Ｃ（＝Ｏ）−Ｏ−又は単結合であり、Ｚ^２は−Ｃ（＝Ｏ）−又は−ＳＯ_２−である。Ｒ^６１はフッ素原子を有していてもよい炭化水素基である。Ｒ^６４はフッ素原子を有していてもよい炭化水素基である。］

[Wherein, W ⁰ represents a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent. Z ³ is —C (═O) —O—, —SO ₂ — or an optionally substituted hydrocarbon group, and Z ⁴ and Z ⁵ are each independently —C (═O) — or -SO ₂ - is. R ⁶² and R ⁶³ are each independently a hydrocarbon group optionally having a fluorine atom. Z ¹ is —C (═O) —, —SO ₂ —, —C (═O) —O— or a single bond, and Z ² is —C (═O) — or —SO ₂ —. R ⁶¹ is a hydrocarbon group which may have a fluorine atom. R ⁶⁴ is a hydrocarbon group which may have a fluorine atom. ]

In formula (a5-2-an1), W ⁰ is a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent.
The hydrocarbon group having 1 to 30 carbon atoms which may have a substituent of W ⁰ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may have the above formula (a5-0- divalent aliphatic hydrocarbon groups described in linking group for to Q ¹ 1), include the same aromatic hydrocarbon group.
Preferable examples of W ⁰ include a group represented by — [C (R ^f1 ) (R ^f2 )] _p0 —. In the formula, R ^f1 and R ^f2 are each independently a hydrogen atom, an alkyl group, a fluorine atom, or a fluorinated alkyl group, and at least one of R ^f1 and R ^f2 is a fluorine atom or a fluorinated alkyl group, p0 is an integer of 1-8.
When W ⁰ is a group represented by — [C (R ^f1 ) (R ^f2 )] _p0 —, the formula (a5-2-an1) is represented by the following formula (a5-2-an1-1). The

［式中、Ｒ^ｆ１及びＲ^ｆ２はそれぞれ独立に水素原子、アルキル基、フッ素原子、又はフッ素化アルキル基であり、Ｒ^ｆ１、Ｒ^ｆ２のうち少なくとも１つはフッ素原子又はフッ素化アルキル基であり、ｐ０は１〜８の整数である。］

[Wherein, R ^f1 and R ^f2 each independently represent a hydrogen atom, an alkyl group, a fluorine atom, or a fluorinated alkyl group, and at least one of R ^f1 and R ^f2 is a fluorine atom or a fluorinated alkyl group. , P0 is an integer of 1-8. ]

In formula-[C (R ^f1 ) (R ^f2 )] _p0 -and formula (a5-2-an1-1), R ^f1 and R ^f2 each independently represent a hydrogen atom, an alkyl group, a fluorine atom, or fluorine And at least one of R ^f1 and R ^f2 is a fluorine atom or a fluorinated alkyl group.
As the alkyl group for R ^f1 and R ^f2 , an alkyl group having 1 to 5 carbon atoms is preferable. Specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group Group, pentyl group, isopentyl group, neopentyl group and the like.
Examples of the fluorinated alkyl group of ^{R f1,} R ^f2, group in which part or all of the hydrogen atoms of the alkyl group of the ^{R f1, R f2} is substituted with a fluorine atom is preferred.
R ^f1 and R ^f2 are preferably a fluorine atom or a fluorinated alkyl group.
In formula-[C (R ^f1 ) (R ^f2 )] _p0 -and formula (a5-2-an1-1), p0 is an integer of 1 to 8, preferably an integer of 1 to 4. Or 2 is more preferable.

Other preferable examples of W ⁰ include an aliphatic cyclic group or an aromatic hydrocarbon group which may have a substituent. Among them, a group in which two or more hydrogen atoms are removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, camphor, benzene or the like (which may have a substituent) is preferable.

In formula (a5-2-an2), Z ³ represents —C (═O) —O—, —SO ₂ — or a hydrocarbon group which may have a substituent. As the hydrocarbon group optionally having a substituent for Z ³ , “having a substituent” mentioned in the description of the divalent linking group in Q ¹ in the above formula (a5-0-1) is used. The same thing as "a good divalent hydrocarbon group" is mentioned. Among these, Z ³ is preferably —SO ₂ —.
In formula (a5-2-an2), Z ⁴ and Z ⁵ are each independently —C (═O) — or —SO ₂ —, preferably at least one of —SO ₂ —, Is more preferably —SO ₂ —.
R ⁶² and R ⁶³ are each independently a hydrocarbon group which may have a fluorine atom, and examples thereof include those similar to the hydrocarbon group which may have a fluorine atom in R ⁶¹ described later. .

In formula (a5-2-an3), Z ¹ represents —C (═O) —, —SO ₂ —, —C (═O) —O—, or a single bond. When Z ¹ is a single bond, N ^{− in} the formula is preferably not directly bonded to —C (═O) — on the side opposite to the side bonded to Z ² (that is, the left end in the formula).
In formula (a5-2-an3), Z ² represents —C (═O) — or —SO ₂ —, and preferably —SO ₂ —.
R ⁶¹ is a hydrocarbon group which may have a fluorine atom. Examples of the hydrocarbon group for R ⁶¹ include an alkyl group, a monovalent alicyclic hydrocarbon group, an aryl group, and an aralkyl group.
The alkyl group for R ⁶¹ is preferably one having 1 to 8 carbon atoms, more preferably one having 1 to 6 carbon atoms, still more preferably one having 1 to 4 carbon atoms, and even if linear, it is branched. It may be a chain. Specifically, a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group and the like are preferable.
The monovalent alicyclic hydrocarbon group in R ⁶¹ is preferably those having 3 to 20 carbon atoms, more preferably those having 3 to 12 carbon atoms, and may be polycyclic or monocyclic. As the monocyclic alicyclic hydrocarbon 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 alicyclic hydrocarbon group is preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane, and the polycycloalkane is preferably one having 7 to 12 carbon atoms. Adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.
The aryl group for R ⁶¹ is preferably one having 6 to 18 carbon atoms, more preferably one having 6 to 10 carbon atoms, and particularly preferably a phenyl group.
Aralkyl group in R ⁶¹ include those in which the "aryl group for R ^61" alkylene group and the above C1-8 bonded are preferred examples. More preferred is an aralkyl group in which an alkylene group having 1 to 6 carbon atoms and the above “aryl group in R ⁶¹ ” are bonded, and an aralkyl group in which an alkylene group having 1 to 4 carbon atoms and the above “aryl group in R ⁶¹ ” are bonded. Is particularly preferred.
In the hydrocarbon group for R ⁶¹ , part or all of the hydrogen atoms of the hydrocarbon group are preferably substituted with fluorine atoms, and 30 to 100% of the hydrogen atoms of the hydrocarbon group are substituted with fluorine atoms. More preferably. Especially, it is especially preferable that it is the perfluoroalkyl group by which all the hydrogen atoms of the alkyl group mentioned above were substituted by the fluorine atom.

In the formula (a5-2-an4), R ⁶⁴ represents a hydrocarbon group that may have a fluorine atom. As the hydrocarbon group for R ⁶⁴ , an alkylene group, a divalent alicyclic hydrocarbon group, a group in which one or more hydrogen atoms have been removed from an aryl group, a group in which one or more hydrogen atoms have been removed from an aralkyl group, etc. Is mentioned.
Specific examples of the hydrocarbon group for R ⁶⁴ include those exemplified in the description of the hydrocarbon group for R ⁶¹ (alkyl group, monovalent alicyclic hydrocarbon group, aryl group, aralkyl group, etc.). And a group in which one or more hydrogen atoms are removed.
In the hydrocarbon group for R ⁶⁴ , part or all of the hydrogen atoms of the hydrocarbon group are preferably substituted with fluorine atoms, and 30 to 100% of the hydrogen atoms of the hydrocarbon group are substituted with fluorine atoms. More preferably.

Among the above, for example, when A ⁻ is a group having a fluorine atom among the groups represented by the formula (a5-2-an1) (particularly, the group represented by the formula (a5-2-an1-1)). Or a group represented by (a5-2-an2) or a group represented by formula (a5-2-an3) in which Z ¹ and Z ² are —SO ₂ —, the structural unit ( From a5), relatively strong acids such as fluorinated alkyl sulfonate anions, carbanions, sulfonylimide anions can be generated.
On the other hand, in the case where A ⁻ has no fluorine atom among the groups represented by the formula (a5-2-2-an1), the group represented by the formula (a5-2-2-an4), and Z ¹ and Z ² are When having a group represented by the formula (a5-2-2-an3) which is —C (═O) —, the structural unit (a5) is exposed to an alkylsulfonate anion, an arylsulfonate anion, a carboxylate anion, an imide anion by exposure. A relatively weak acid such as can be generated.

Since the acid having the desired acid strength can be generated from the structural unit (a5) as described above, the function of the acid generated from the structural unit (a5) in the resist composition can be appropriately determined, and the desired according to the function a ^- it can also be selected.
For example, when the structural unit (a5) plays the same role as that of the acid generator usually used in a resist composition, it is preferable to select A ⁻ that generates a strong acid.
For example, when the structural unit (a5) has the same function as a quencher (quencher that traps a strong acid by salt exchange with a strong acid generated from an acid generator) usually used in a resist composition, a weak acid is used. It is preferable to select A ⁻ to be generated.
Here, the strong acid and the weak acid are the relationship with the activation energy of an acid-decomposable group that is decomposed by the action of an acid as contained in the structural unit (a1) described later, and the acid generator acid used together. It is determined in relation to strength. Therefore, the above-mentioned “relatively weak acid” cannot always be used as a quencher.

In formula (a5-0-2), M ^{m +} is an m-valent organic cation, and m is an integer of 1 to 3. However, M ^{m +} has only one aromatic ring or no aromatic ring.
When the number of aromatic rings present in the organic cation is 1 or less, a resist pattern having good lithography characteristics and pattern shape is formed in EUV lithography or EB lithography. Since these effects are further enhanced, it is particularly preferable that M ^{m +} is an organic cation having no aromatic ring.
The organic cation of M ^{m +} is not particularly limited as long as it has only one aromatic ring or does not have an aromatic ring. For example, a photodegradable base conventionally used for a quencher of a resist composition Alternatively, an organic cation known as a cation moiety such as an onium-based acid generator of the resist composition can be used.
As such an organic cation, for example, a cation represented by the following general formula (m1-1) or (m2-1) can be used.

［式中、Ｒ^１１”〜Ｒ^１３”，Ｒ^１５”〜Ｒ^１６”はそれぞれ独立に置換基を有していてもよいアリール基、アルキル基またはアルケニル基を表す。式（ｍ１−１）中、Ｒ^１１”〜Ｒ^１３”のうち、いずれか２つが相互に結合して式中のイオウ原子と共に環を形成してもよい。ただし、式中の基Ｓ^＋（Ｒ^１１”）（Ｒ^１２”）（Ｒ^１３”）は全体で芳香環を１個のみ有するか又は芳香環を有さない。式（ｍ２−１）中の基Ｉ^＋（Ｒ^１５”）（Ｒ^１６”）は全体で芳香環を１個のみ有するか又は芳香環を有さない。］

[Wherein, R ¹¹ ″ to R ¹³ ″ and R ¹⁵ ″ to R ¹⁶ ″ each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent. In formula (m1-1), any two of R ¹¹ ″ to R ¹³ ″ may be bonded to each other to form a ring together with the sulfur atom in the formula. However, the group S ⁺ (R ¹¹ ″) (R ¹² ″) (R ¹³ ″) in the formula has only one aromatic ring or no aromatic ring as a whole. In the formula (m2-1) The group I ⁺ (R ¹⁵ ″) (R ¹⁶ ″) has only one aromatic ring or no aromatic ring in total.]

In the formula (m1-1), the aryl group which may have a substituent in R ¹¹ ″ to R ¹³ ″, the alkyl group which may have a substituent, and the substituent may be included. Examples of the alkenyl group include those similar to the aryl group, alkyl group, and alkenyl group mentioned in the description of R ^{4 to} R ^{5 in} the general formula (a5-0-1).
As the ring formed when any two of R ¹¹ ″ to R ¹³ ″ in the formula (m1-1) are bonded to each other to form a ring together with the sulfur atom in the formula, the general formula (a5 The same thing as what was mentioned as a ring which R < ⁴ > -R < ⁵ > in -0-1) couple | bonds together and forms with the sulfur atom in a formula is mentioned.
However, the group S ⁺ (R ¹¹ ″) (R ¹² ″) (R ¹³ ″) in the formula (m1-1) has only one aromatic ring or no aromatic ring in total. When R ¹² ″ and R ¹³ ″ are not bonded to each other to form a ring with the sulfur atom in the formula, only one of R ¹¹ ″, R ¹² ″ and R ¹³ ″ is one An organic group having an aromatic ring and the other two are organic groups having no aromatic ring, or R ¹¹ ″, R ¹² ″ and R ¹³ ″ are all organic groups having no aromatic ring. When R ¹² ″ and R ¹³ ″ are bonded to each other to form one aromatic ring together with the sulfur atom in the formula, R ¹¹ ″ is an organic group having no aromatic ring. In the case where R ¹² ″ and R ¹³ ″ are bonded to each other to form a ring together with the sulfur atom in the formula, and the ring is an aliphatic ring (ring having no aromaticity) , R ¹¹ ″ is an organic group having one aromatic ring or an organic group having no aromatic ring. R ¹² ″ and R ¹³ ″ are bonded to each other to form a sulfur atom in the formula In the case where the ring formed together is a ring containing two or more aromatic rings, the structural unit does not correspond to the structural unit (a5).

In the formula (m2-1), the aryl group which may have a substituent in R ¹⁵ ″ to R ¹⁶ ″, the alkyl group which may have a substituent, and the substituent may be included. Examples of the alkenyl group include those similar to R ¹¹ ″ to R ¹³ ″.
However, the group I ⁺ (R ¹⁵ ″) (R ¹⁶ ″) in formula (m2-1) has only one aromatic ring as a whole or no aromatic ring. That is, only one of R ¹⁵ ″ to R ¹⁶ ″ is an aromatic ring, or none is an aromatic ring.

The radicals S ⁺ (R ¹¹ ″) (R ¹² ″) (R ¹³ ″) as a whole, or the radicals I ⁺ (R ¹⁵ ″) (R ¹⁶ ″) as a whole, with less than one aromatic ring In EUV lithography or EB lithography, a resist pattern having good lithography characteristics and pattern shape is formed.These effects are further enhanced, so that the group S ⁺ (R ¹¹ ″) (R ¹² ″) (R ¹³ ″) It is particularly preferred that the radicals or radicals I ⁺ (R ¹⁵ ″) (R ¹⁶ ″) as a whole have no aromatic rings.

  Specifically as a suitable thing in the cation part of the compound represented by Formula (m1-1), the cation represented by each of following formula (m1-1-1)-(m1-1-3) is respectively. Can be mentioned.

Moreover, in the cation part of the compound represented by the formula (m1-1), any two of R ¹¹ ″ to R ¹³ ″ are bonded to each other to form a ring together with the sulfur atom in the formula. Preferable specific examples of the case include, for example, cations represented by the following formulas (m1-2), (m1-3), and (m1-4), respectively.

［式中、ｕは１〜３の整数である。Ｒ^６ａは置換基を有していてもよいアルキレン基であり、Ｒ^６ｂは水素原子、置換基を有していてもよいアルキル基、非芳香族の置換基を有していてもよいフェニル基またはナフチル基である。ただしＲ^６ａ−Ｃ（＝Ｏ）−Ｏ−Ｒ^６ｂはこれらの全体で芳香環を１個のみ有するか、または芳香環を有さない。Ｒ^７ａは置換基を有していてもよいアルキレン基であり、Ｒ^７ｂは置換基を有していてもよいアルキル基、置換基を有していてもよいフェニル基またはナフチル基である。ただしＲ^７ａ−Ｃ（＝Ｏ）−Ｒ^７ｂはこれらの全体で芳香環を１個のみ有するか、または芳香環を有さない。Ｒ^８は置換基を有していてもよいアルキル基、非芳香族の置換基を有していてもよいフェニル基またはナフチル基である。ただし、Ｒ^８は芳香環を１個のみ有するか、または芳香環を有さない。］

[Wherein u is an integer of 1 to 3. R ^6a is an alkylene group which may have a substituent, R ^6b is a hydrogen atom, an alkyl group which may have a substituent, or a phenyl group which may have a non-aromatic substituent. Or it is a naphthyl group. However, R < ^6a > -C (= O) -O-R < ^6b > has only one aromatic ring as a whole, or does not have an aromatic ring. R ^7a is an alkylene group which may have a substituent, and R ^7b is an alkyl group which may have a substituent, a phenyl group which may have a substituent, or a naphthyl group. However, R < ^7a > -C (= O) -R < ^7b > has only one aromatic ring as a whole, or does not have an aromatic ring. R ⁸ is an alkyl group which may have a substituent, a phenyl group or a naphthyl group which may have a non-aromatic substituent. However, R ⁸ has only one aromatic ring or no aromatic ring. ]

In the formula, u is an integer of 1 to 3, and 1 or 2 is most preferable.
In the formula, the alkylene group in R ^6a and R ^7a is preferably a linear or branched alkylene group. 1-12 are preferable, as for carbon number of this alkylene group, 1-5 are more preferable, 1-3 are more preferable, and 1 or 2 is especially preferable.
Examples of the substituent that the alkylene group may have are the same as those described above as the substituent for the substituted alkylene group in the description of R ^{3 in} the general formula (a5-0-1) (halogen atom). , An oxo group (═O), a cyano group, an alkyl group, an alkoxyalkyloxy group, an alkoxycarbonylalkyloxy group, —C (═O) —O—R ⁷ ″, —O—C (═O) —R ⁸ ″ , —O—R ⁹ ″, an aryl group, and the like.
In the formula, as the alkyl group which may have a substituent in R ^6b , R ^7b , and R ^8, the substituted alkyl exemplified in the description of R ⁴ and R ^{5 in} the general formula (a5-0-1) The same thing as a group is mentioned.
Examples of the non-aromatic substituent that the phenyl group or naphthyl group in R ^6b , R ^7b , and R ⁸ may have include in the description of R ⁴ and R ^{5 in} the formula (a5-0-1). Examples of the non-aromatic substituent that the substituted aryl group may have are the same as those described above.

  Preferable examples of the cation represented by the formula (m1-2), (m1-3) or (m1-4) include those shown below.

In formula (m1-4-1), R ^C represents a substituent. Examples of the substituent include the substituents exemplified in the description of the substituted aryl group (alkyl group, alkoxy group, alkoxyalkyloxy group, alkoxycarbonylalkyloxy group, halogen atom, hydroxyl group, oxo group (═O), Aryl groups, —C (═O) —O—R ⁷ ″, —O—C (═O) —R ⁸ ″, —O—R ⁹ ″).

  The structural unit having a group represented by the general formula (a5-0-2) (hereinafter referred to as “structural unit (a5-2)”) is represented by the general formula (a5-0-2) in the structure. Although it will not specifically limit if it has group represented, Comprising: It is a structural unit derived from the compound which has an ethylenic double bond, Comprising: It represents with the said general formula (a5-0-2) The structural unit containing a group is preferable, and the structural unit represented by the following general formula (a5-21) is particularly preferable.

［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。Ｑ^２ａは単結合又は２価の連結基である。Ｑ^２ｂは単結合又は２価の連結基である。Ａ⁻はアニオンを含む有機基である。Ｍ^ｍ＋はｍ価の有機カチオンであり、ｍは１〜３の整数である。ただし、Ｍ^ｍ＋は芳香環を１個のみ有するか又は芳香環を有さない。］

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Q ^2a is a single bond or a divalent linking group. Q ^2b is a single bond or a divalent linking group. A ^- is an organic group containing anion. M ^{m +} is an m-valent organic cation, and m is an integer of 1 to 3. However, M ^{m +} has only one aromatic ring or no aromatic ring. ]

In formula (a5-21), R is the same as R in formula (a5-11).
_{^{A -, (M m +)}} 1 / m in A of each of the formulas (a5-0-2) in ^{- the} same as the _{^{(M m +) 1 / m}} .
Examples of the divalent linking group for Q ^2a include the same divalent linking groups as those for Q ¹ in formula (a5-0-1).
Among ^them, as the ^{Q 2A,} a single ^{bond, -C (= O) -Q 22} -N (R n) - , or ^-Q 23 -CF ^{(R q1)} - it is preferred.
In —C (═O) —Q ²² —N (R ⁿ ) —, Q ²² is a divalent linking group, and R ⁿ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms.
-Q ²³ -CF ^{(R q1)} - ^{In, Q 23} is -O _-, - CH 2 -O-, or -C (= O) is a group containing ^{-O-, R q1} is fluorine atom or fluorine Alkyl group.

In —C (═O) —Q ²² —N (R ⁿ ) —, the divalent linking group for Q ²² is the same as the divalent linking group for Q ¹ in formula (a5-0-1). Among them, a linear or branched alkylene group, a cyclic aliphatic hydrocarbon group, or a divalent aromatic hydrocarbon group is preferable, and a linear alkylene group is particularly preferable, Most preferred is a methylene group or an ethylene group.
The alkyl group of 1 to 5 carbon atoms for R ^n, the same alkyl group of 1 to 5 carbon atoms of the R and the like. Of these, R ⁿ is preferably a hydrogen atom or a methyl group.

-Q ²³ -CF ^{(R q1)} - ^In, specifically as _{^{Q 23, -O -, - CH}} 2 -O-, or -C (= O) consisting of -O- group; -O -, - And a group composed of CH ₂ —O— or —C (═O) —O— and a divalent hydrocarbon group which may have a substituent.
The divalent hydrocarbon group which may have such a substituent may have the substituents mentioned for the divalent linking group in Q ¹ in the formula (a5-0-1). The thing similar to a bivalent hydrocarbon group is mentioned. Among these, the “divalent hydrocarbon group” in Q ²³ is preferably an aliphatic hydrocarbon group, and more preferably a linear or branched alkylene group.
Q ²³ is preferably a group consisting of —C (═O) —O— and a divalent hydrocarbon group which may have a substituent, and —C (═O) —O— and aliphatic carbonization. A group consisting of a hydrogen group is more preferred, and a group consisting of —C (═O) —O— and a linear or branched alkylene group is more preferred.

-Q ²³ -CF ^{(R q1)} - in ⁱⁿ fluorinated alkyl group for ^{R q1,} alkyl group of states that are not substituted with fluorine atoms may be linear, branched or cyclic.
In the case of a linear or branched alkyl group, the number of carbon atoms is preferably 1 to 5, more preferably 1 to 3, and particularly preferably 1 to 2. .
In the case of a cyclic alkyl group, the number of carbon atoms is preferably 4 to 15, more preferably 4 to 12, and still more preferably 5 to 10. Specific examples include monocycloalkanes; groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as bicycloalkanes, tricycloalkanes, and tetracycloalkanes. More specifically, examples include monocycloalkanes such as cyclopentane and cyclohexane; groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. .
In the fluorinated alkyl group, the ratio of the number of fluorine atoms to the total number of fluorine atoms and hydrogen atoms contained in the fluorinated alkyl group (fluorination rate (%)) is preferably 30 to 100%. 50 to 100% is more preferable. The higher the fluorination rate, the higher the hydrophobicity of the resist film.
Among the above, R ^q1 is preferably a fluorine atom.

In formula (a5-21), examples of the divalent linking group for Q ^2b include the same divalent linking groups as those for Q ¹ in formula (a5-0-1). Among these, Q ^2b is preferably a linear or branched alkylene group, a cyclic aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a divalent linking group containing a hetero atom; A branched alkylene group, a combination of a linear or branched alkylene group and a divalent linking group containing a heteroatom, a cyclic aliphatic hydrocarbon group and a divalent linking group containing a heteroatom. A combination or a combination of an aromatic hydrocarbon group and a divalent linking group containing a hetero atom is more preferable; a linear or branched alkylene group, a linear or branched alkylene group and an ester bond [- A combination of C (═O) —O—] with a divalent alicyclic hydrocarbon group and an ester bond [—C (═O) —O—] is particularly preferred; linear or branched An alkylene group of A combination of a branched alkylene group and an ester bond [—C (═O) —O—] is most preferred.

Preferred examples of the structural unit (a5-2) include the following formulas (a5-211) to (a5-2-13), (a5-221) to (a5-2-25), At least one selected from the group consisting of structural units represented by (a5-231) to (a5-232) and (a5-241) to (a5-244) is preferable. .
Among these, as the structural units represented by the following formulas (a5-211) to (a5-2-13), the following formulas (a5-211-1) and (a5-2-12) are given respectively. -1) and the structural unit represented by (a5-213-1) are preferable.

［式中、Ｒ、Ｗ^０、（Ｍ^ｍ＋）_１／ｍは前記同様であり、Ｑ^２１はそれぞれ独立に単結合又は２価の連結基である。Ｑ^２２は２価の連結基である。Ｑ^２３は−Ｏ−、−ＣＨ_２−Ｏ−、又は−Ｃ（＝Ｏ）−Ｏ−を含有する基である。Ｒ^ｑ１はフッ素原子又はフッ素化アルキル基である。Ｒ^ｎは水素原子又は炭素数１〜５のアルキル基である。ｐ０１は０又は１である。］

[Wherein, R, W ⁰ and (M ^{m +} ) _{1 / m} are the same as defined above, and Q ²¹ each independently represents a single bond or a divalent linking group. Q ²² is a divalent linking group. Q ²³ is a group containing —O—, —CH ₂ —O—, or —C (═O) —O—. R ^q1 is a fluorine atom or a fluorinated alkyl group. R ⁿ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. p01 is 0 or 1. ]

［式中、Ｒ、Ｒ^ｆ１、Ｒ^ｆ２、Ｒ^ｑ１、Ｒ^ｎ、Ｑ^２１〜Ｑ^２３、ｐ０、（Ｍ^ｍ＋）_１／ｍは前記と同様である。］

[Wherein, R, R ^f1 , R ^f2 , R ^q1 , R ⁿ , Q ^{21 to} Q ²³ , ^p 0, (M ^{m +} ) _{1 / m} are the same as described above. ]

［式中、Ｒ、Ｑ^２１〜Ｑ^２３、Ｚ^３〜Ｚ^５、Ｒ^６２〜Ｒ^６３、Ｒ^ｎ、Ｒ^ｑ１、（Ｍ^ｍ＋）_１／ｍは前記同様である。ｎ６０は０〜３の整数である。］

[Wherein, R, Q ^{21 to} Q ²³ , Z ^{3 to} Z ⁵ , R ^{62 to} R ⁶³ , R ⁿ , R ^q1 , (M ^{m +} ) _{1 / m} are the same as described above. n60 is an integer of 0-3. ]

［式中、Ｒ、Ｚ^１〜Ｚ^２、Ｒ^６１、Ｒ^ｎ、（Ｍ^ｍ＋）_１／ｍは前記と同様であり、Ｑ^２４、Ｑ^２５はそれぞれ独立に単結合又は２価の連結基である。］

[Wherein, R, Z ^{1 to} Z ² , R ⁶¹ , R ⁿ , (M ^{m +} ) _{1 / m} are the same as described above, and Q ²⁴ and Q ²⁵ are each independently a single bond or a divalent linking group. is there. ]

［式中、Ｒ、Ｒ^ｎ、（Ｍ^ｍ＋）_１／ｍは前記と同様であり、Ｑ^２６〜Ｑ^２８はそれぞれ独立に単結合又は２価の連結基である。ｎ３０は０〜３の整数である。］

[Wherein, R, R ⁿ and (M ^{m +} ) _{1 / m} are the same as defined above, and Q ^{26 to} Q ²⁸ each independently represent a single bond or a divalent linking group. n30 is an integer of 0-3. ]

Wherein (a5-2-11) ~ (a5-2-13), R, (M m +) 1 / m is, ^R in each of the formulas ^(a5-21), similar to ^(M m _{+) 1 / m} It is.
W ⁰ is the same as ^{W 0} in the formula (a5-2-an1).
Q ²¹ is a single bond or a divalent linking group. Examples of the divalent linking group for Q ²¹ include the same divalent linking groups as those for Q ¹ in formula (a5-0-1). Among these, Q ²¹ is preferably a linear or branched alkylene group, a cyclic aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a divalent linking group containing a hetero atom; A branched alkylene group, a combination of a linear or branched alkylene group and a divalent linking group containing a heteroatom, a cyclic aliphatic hydrocarbon group and a divalent linking group containing a heteroatom. A combination or a combination of an aromatic hydrocarbon group and a divalent linking group containing a hetero atom is more preferable; a linear or branched alkylene group, a linear or branched alkylene group and an ester bond [- A combination of C (═O) —O—] with a divalent alicyclic hydrocarbon group and an ester bond [—C (═O) —O—] is particularly preferred; linear or branched An alkylene group of A combination of a branched alkylene group and an ester bond [—C (═O) —O—] is most preferred.
p01 is 0 or 1, and 1 is preferable.

In formula (a5-2-12), Q ²² is a divalent linking group, and examples thereof include the same divalent linking groups as those in Q ¹ in formula (a5-0-1). Are preferably a linear or branched alkylene group, a cyclic aliphatic hydrocarbon group, or a divalent aromatic hydrocarbon group, particularly preferably a linear alkylene group, a methylene group or an ethylene group Is most preferred.
In formula (a5-2-12), R ⁿ represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. As a C1-C5 alkyl group, the same thing as the C1-C5 alkyl group of said R is mentioned. Of these, R ⁿ is preferably a hydrogen atom or a methyl group.

In formula (a5-2-13), Q ²³ represents a group containing —O—, —CH ₂ —O—, or —C (═O) —O—.
Q ²³ is specifically a group consisting of —O—, —CH ₂ —O—, or —C (═O) —O—; —O—, —CH ₂ —O— or —C (═O). And a group composed of —O— and a divalent hydrocarbon group which may have a substituent.
The divalent hydrocarbon group which may have such a substituent may have the substituents mentioned for the divalent linking group in Q ¹ in the formula (a5-0-1). The thing similar to a bivalent hydrocarbon group is mentioned. Among these, as the “divalent hydrocarbon group”, an aliphatic hydrocarbon group is preferable, and a linear or branched alkylene group is more preferable.
Q ²³ is preferably a group consisting of —C (═O) —O— and a divalent hydrocarbon group which may have a substituent, and —C (═O) —O— and aliphatic carbonization. A group consisting of a hydrogen group is more preferred, and a group consisting of —C (═O) —O— and a linear or branched alkylene group is more preferred.
Specific examples suitable for Q ^23, in particular, a group represented by the following general formula ^(Q 23 -1).

［式（Ｑ^２３−１）中、Ｒ^ｑ２及びＲ^ｑ３はそれぞれ独立に水素原子、アルキル基又はフッ素化アルキル基であり、互いに結合して環を形成していてもよい。］

[In Formula (Q ²³ -1), R ^q2 and R ^q3 each independently represent a hydrogen atom, an alkyl group, or a fluorinated alkyl group, and may be bonded to each other to form a ring. ]

In the formula (Q ²³ -1), the alkyl group in R ^q2 and R ^q3 may be linear, branched or cyclic, and is preferably linear or branched.
In the case of a linear or branched alkyl group, the number of carbon atoms is preferably 1 to 5, more preferably an ethyl group or a methyl group, and particularly preferably an ethyl group.
In the case of a cyclic alkyl group, the number of carbon atoms is preferably 4 to 15, more preferably 4 to 12, and most preferably 5 to 10. Specific examples include monocycloalkanes; groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as bicycloalkanes, tricycloalkanes, and tetracycloalkanes. More specifically, monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. It is done. Of these, a group in which one or more hydrogen atoms have been removed from adamantane is preferable.

The fluorinated alkyl group for R ^q2 and R ^q3 is a group in which part or all of the hydrogen atoms in the alkyl group are substituted with fluorine atoms.
In the fluorinated alkyl group, the alkyl group not substituted with a fluorine atom may be linear, branched or cyclic, and the same as the above-mentioned “alkyl group in R ^q2 and R ^q3 ”. Can be mentioned.

R ^q2 and R ^q3 may be bonded to each other to form a ring, and the ring formed by R ^q2 and R ^q3 and the carbon atom to which they are bonded includes a monocyclo group in the cyclic alkyl group. The thing remove | excluding two hydrogen atoms from alkane or polycycloalkane can be illustrated, It is preferable that it is a 4-10 membered ring, and it is more preferable that it is a 5-7 membered ring.

Among the above, R ^q2 and R ^q3 are preferably a hydrogen atom or an alkyl group.

In formula (a5-2-13), R ^q1 represents a fluorine atom or a fluorinated alkyl group.
In the fluorinated alkyl group for R ^q1 , the alkyl group that is not substituted with a fluorine atom may be linear, branched, or cyclic.
In the case of a linear or branched alkyl group, the number of carbon atoms is preferably 1 to 5, more preferably 1 to 3, and particularly preferably 1 to 2. .
In the case of a cyclic alkyl group, the number of carbon atoms is preferably 4 to 15, more preferably 4 to 12, and still more preferably 5 to 10. Specific examples include monocycloalkanes; groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as bicycloalkanes, tricycloalkanes, and tetracycloalkanes. More specifically, examples include monocycloalkanes such as cyclopentane and cyclohexane; groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. .
In the fluorinated alkyl group, the ratio of the number of fluorine atoms to the total number of fluorine atoms and hydrogen atoms contained in the fluorinated alkyl group (fluorination rate (%)) is preferably 30 to 100%. 50 to 100% is more preferable. The higher the fluorination rate, the higher the hydrophobicity of the resist film.
Among the above, R ^q1 is preferably a fluorine atom.

In the formulas (a5-21-1-1), (a5-22-1-1), and (a5-213-1), R, Q ^{21 to} Q ²³ , R ⁿ , R ^q1 , (M ^{m +} _{1 / m} is the same as R, Q ^{21 to} Q ²³ , R ⁿ , R ^q1 , (M ^{m +} ) _{1 / m in the} formulas (a5-211) to (a5-2-13). is there.
R ^{f1, R} f2, p0 are respectively similar to the ^{R f1, R} f2, p0 in the formula (a5-2-an1-1).

In the formulas (a5-221) to (a5-2-25), R, Q ^{21 to} Q ²³ , R ⁿ , R ^q1 , (M ^{m +} ) _{1 / m} are the same as those in the formula (a5-2-11). Are the same as R, Q ^{21 to} Q ²³ , R ⁿ , R ^q1 , and (M ^{m +} ) _{1 / m in} .about. (A5-2-13).
^{Z 3 ~Z 5, R 62 ~R} 63 are respectively similar to the ^{Z 3 ~Z 5, R 62 ~R} 63 in the formula (a5-2-an2).
In formula (a5-2-24), n60 is an integer of 0 to 3, and preferably 0 or 1.

In the formulas (a5-231) to (a5-232), R, R ⁿ , (M ^{m +} ) _{1 / m} are the same as those in the formulas (a5-211) to (a5-2-13). Are the same as R, R ⁿ and (M ^{m +} ) _{1 / m} .
Z ¹ ~Z ^{2, R 61} are each similar to the formula ^{(a5-2-an3) Z 1 ~Z} 2, R 61 in.
Q ²⁴ and Q ²⁵ are each independently a single bond or a divalent linking group.
Examples of the divalent linking group for Q ²⁴ and Q ²⁵ include the same divalent linking groups as those for Q ¹ in formula (a5-0-1). As described above, if ^{Z 1} is a single ^bond, end which binds to ^{Z 1} of Q ^{24, Q 25} is -C (= O) - is not preferred. The divalent linking group for Q ²⁴ and Q ²⁵ is particularly preferably a linear or branched alkylene group, a cyclic aliphatic hydrocarbon group, or a divalent linking group containing a hetero atom. Among these, a linear or branched alkylene group and a cyclic aliphatic hydrocarbon group are preferable, and a linear alkylene group and a cyclic aliphatic hydrocarbon group are more preferable.

In the formulas (a5-241) to (a5-244), R, R ⁿ , (M ^{m +} ) _{1 / m} are the same as those in the formulas (a5-211) to (a5-2-13). Are the same as R, R ⁿ and (M ^{m +} ) _{1 / m} .
Q ^{26 to} Q ²⁸ are each independently a single bond or a divalent linking group. Q ²⁶ to Q ²⁸ are the same as the ^{Q 24, Q 25.}
In formula (a5-244), n30 is an integer of 0 to 3, and preferably 0 or 1.

Specific examples of the structural unit (a5-2) are shown below. In the following formulas, R ^α is a hydrogen atom, a methyl group or a trifluoromethyl group, and (M ^{m +} ) _{1 / m} is the same as described above.

The component (A1) may have only one type of structural unit (a5), or may have two or more types in combination.
In the component (A1), the proportion of the structural unit (a5) is preferably 1 to 50 mol%, more preferably 1 to 45 mol%, based on all the structural units constituting the polymer (A1). 3-40 mol% is further more preferable, and 5-35 mol% is especially preferable. By setting it to 1 mol% or more, the effect of improving the lithography properties such as sensitivity and resolution and the resist pattern shape can be sufficiently obtained, and by setting it to the upper limit or less, it becomes easy to balance with other structural units . Moreover, sufficient solubility with respect to the resist solvent (component (S) described later) can be secured.

The component (A1) may have a structural unit other than the structural unit (a5).
As such a structural unit, a number of hitherto known compounds can be used as resist resins for ArF excimer laser, KrF excimer laser (preferably for ArF excimer laser), and the like. For example, a structural unit (a1) containing an acid-decomposable group whose polarity is increased by the action of an acid, a structural unit (a2) containing a —SO ₂ — containing cyclic group or a lactone-containing cyclic group, and a structural unit containing a polar group Examples thereof include (a3) and a structural unit (a4) containing an acid non-dissociable cyclic group.

When the component (A1) is the component (A1-2), the component (A1-2) preferably contains a polar group.
Examples of the polar group include the same polar groups as those described later in the structural unit (a3), and alkali-soluble groups such as a hydroxyl group and a carboxy group are preferable.
When the structural unit (a5) contains a polar group, the component (A1-2) may be composed only of the structural unit (a5), and in addition to the structural unit (a5), the structural unit (a3) You may have.
When the structural unit (a5) does not include a component containing a polar group, the component (A1-2) needs to further include the structural unit (a3) in addition to the structural unit (a5).

When the component (A1) is the component (A1-1), the component (A1-1) preferably includes an acid-decomposable group that increases in polarity by the action of an acid.
The “acid-decomposable group” is an acid-decomposable group produced by the action of an acid (an acid generated from the structural unit (a5) by exposure or an acid generated from the later-described acid generator component (B)). A group having acid-decomposability that can be cleaved at least part of the bonds in
When the structural unit (a5) contains an acid-decomposable group, the component (A1-1) may consist of only the structural unit (a5), and in addition to the structural unit (a5), the structural unit (a1) ).
When the structural unit (a5) does not include an acid-decomposable group, the component (A1-1) needs to have a structural unit (a1) in addition to the structural unit (a5).

  In the resist composition of this embodiment, the component (A1) is preferably the component (A1-1). That is, the component (A1) is a resin component that generates an acid upon exposure and increases its polarity by the action of the acid, and the resist composition of this embodiment becomes a positive type in the alkali development process and is negative in the solvent development process. It is preferably a chemically amplified resist composition that becomes a mold.

(Structural unit (a1))
The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity is increased by the action of an acid.
The “acid-decomposable group” is an acid-decomposable group that can cleave at least part of bonds in the structure of the acid-decomposable group by the action of an acid.
Examples of the acid-decomposable group whose polarity increases by the action of an acid include a group that decomposes by the action of an acid to generate a polar group.
Examples of the polar group include a carboxy group, a hydroxyl group, an amino group, a sulfo group (—SO ₃ H), and the like. Among these, a polar group containing —OH in the structure (hereinafter sometimes referred to as “OH-containing polar group”) is preferable, a carboxy group or a hydroxyl group is preferable, and a carboxy group is particularly preferable.
More specifically, examples of the acid-decomposable group include a group in which the polar group is protected with an acid-dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected with an acid-dissociable group).
The “acid-dissociable group” is a group having an acid-dissociable property capable of cleaving at least a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by the action of an acid. The acid-dissociable group constituting the acid-decomposable group must be a group having a lower polarity than the polar group generated by dissociation of the acid-dissociable group. Is dissociated, a polar group having a polarity higher than that of the acid dissociable group is generated to increase the polarity. As a result, the polarity of the entire component (A1-1) increases. As the polarity increases, the solubility in the developer changes relatively, and when the developer is an alkaline developer, the solubility increases.

The acid-dissociable group is not particularly limited, and those that have been proposed as acid-dissociable groups for base resins for chemically amplified resists can be used. In general, a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group in (meth) acrylic acid or the like; an acetal-type acid dissociable group such as an alkoxyalkyl group is widely known.
Here, the “tertiary alkyl ester” is an ester formed by replacing a hydrogen atom of a carboxy group with a chain or cyclic alkyl group, and the carbonyloxy group (—C (═O The structure in which the tertiary carbon atom of the chain or cyclic alkyl group is bonded to the terminal oxygen atom of) -O-). In this tertiary alkyl ester, when an acid acts, a bond is cut between an oxygen atom and a tertiary carbon atom to form a carboxy group.
The chain or cyclic alkyl group may have a substituent.
Hereinafter, a group that is acid dissociable by constituting a carboxy group and a tertiary alkyl ester is referred to as a “tertiary alkyl ester type acid dissociable group” for convenience.

Examples of the tertiary alkyl ester type acid dissociable group include an aliphatic branched acid dissociable group and an acid dissociable group containing an aliphatic cyclic group.
Here, “aliphatic branched” means having a branched structure having no aromaticity. The structure of the “aliphatic branched acid dissociable group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated.
Examples of the aliphatic branched acid dissociable group include a group represented by —C (R ⁷¹ ) (R ⁷² ) (R ⁷³ ). ^Wherein, R 71 ^{to R 73} each independently represents a linear alkyl group of 1 to 5 carbon atoms. The group represented by —C (R ⁷¹ ) (R ⁷² ) (R ⁷³ ) preferably has 4 to 8 carbon atoms, specifically a tert-butyl group or a 2-methyl-2-butyl group. , 2-methyl-2-pentyl group, 3-methyl-3-pentyl group and the like. A tert-butyl group is particularly preferable.

The “aliphatic cyclic group” means a monocyclic group or a polycyclic group having no aromaticity.
The aliphatic cyclic group in the “acid-dissociable group containing an aliphatic cyclic group” may or may not have 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 substituted with a fluorine atom, an oxygen atom (= O), and the like. Is mentioned.
The basic ring structure excluding the substituent of the aliphatic cyclic group is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The hydrocarbon group may be either saturated or unsaturated, but is usually preferably saturated.
The aliphatic cyclic group may be monocyclic or polycyclic.
Examples of the aliphatic cyclic group include one or more hydrogens from a monocycloalkane which may or may not be substituted with an alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated alkyl group. A group in which one or more hydrogen atoms have been removed from a polycycloalkane such as bicycloalkane, tricycloalkane, or tetracycloalkane; More specifically, a group in which one 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. An alicyclic hydrocarbon group such as a group excluding a hydrogen atom is exemplified. Moreover, a part of carbon atoms constituting the ring of these alicyclic hydrocarbon groups may be substituted with an ether group (—O—).

Examples of the acid dissociable group containing an aliphatic cyclic group include:
(I) On the ring skeleton of a monovalent aliphatic cyclic group, the substituent ( An atom or group other than a hydrogen atom) to form a tertiary carbon atom;
(Ii) a group having a monovalent aliphatic cyclic group and a branched alkylene having a tertiary carbon atom bonded thereto.
In the group (i), examples of the substituent bonded to the carbon atom bonded to the atom adjacent to the acid dissociable group on the ring skeleton of the aliphatic cyclic group include an alkyl group. Examples of the alkyl group include those similar to R ¹⁴ in formulas (1-1) to (1-9) described later.
Specific examples of the group (i) include groups represented by the following general formulas (1-1) to (1-9).
Specific examples of the group (ii) include groups represented by the following general formulas (2-1) to (2-6).

［式中、Ｒ^１４はアルキル基であり、ｇは０〜８の整数である。］

[Wherein, R ¹⁴ represents an alkyl group, and g represents an integer of 0 to 8. ]

［式中、Ｒ^１５およびＲ^１６は、それぞれ独立してアルキル基である。］

[Wherein, R ¹⁵ and R ¹⁶ each independently represents an alkyl group. ]

In formulas (1-1) to (1-9), the alkyl group of R ¹⁴ may be linear, branched or cyclic, and is preferably linear or branched.
The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and still more preferably 1 or 2. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. Among these, a methyl group, an ethyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.
The branched alkyl group preferably has 3 to 10 carbon atoms, and more preferably 3 to 5 carbon atoms. Specific examples include isopropyl group, isobutyl group, tert-butyl group, isopentyl group, neopentyl group and the like, and isopropyl group is most preferable.
g is preferably an integer of 0 to 3, more preferably an integer of 1 to 3, and still more preferably 1 or 2.
In formulas (2-1) to (2-6), examples of the alkyl group for R ^{15 to} R ¹⁶ include the same alkyl groups as those described above for R ¹⁴ .
In the formulas (1-1) to (1-9) and (2-1) to (2-6), a part of the carbon atoms constituting the ring is substituted with an etheric oxygen atom (—O—). May be.
In formulas (1-1) to (1-9) and (2-1) to (2-6), a hydrogen atom bonded to a carbon atom constituting the ring may be substituted with a substituent. Examples of the substituent include an alkyl group having 1 to 5 carbon atoms, a fluorine atom, and a fluorinated alkyl group.

The “acetal-type acid dissociable group” is generally bonded to an oxygen atom by substituting a hydrogen atom at the terminal of an OH-containing polar group such as a carboxy group or a hydroxyl group. Then, the acid acts to cut the bond between the acetal acid dissociable group and the oxygen atom to which the acetal acid dissociable group is bonded, and OH-containing polar groups such as a carboxy group and a hydroxyl group are formed. The
Examples of the acetal type acid dissociable group include a group represented by the following general formula (p1).

［式中、Ｒ^１’，Ｒ^２’はそれぞれ独立して水素原子または炭素数１〜５のアルキル基を表し、ｎは０〜３の整数を表し、Ｙは炭素数１〜５のアルキル基または脂肪族環式基を表す。］

[Wherein, R ¹ 'and R ² ' each independently represents a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, n represents an integer of 0 to 3, and Y represents an alkyl group having 1 to 5 carbon atoms. Or represents an aliphatic cyclic group. ]

In formula (p1), n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.
Examples of the alkyl group for R ¹ ′ and R ² ′ include the same alkyl groups listed as the substituents that may be bonded to the α-position carbon atom in the description of the α-substituted acrylate ester. A methyl group or an ethyl group is preferred, and a methyl group is most preferred.
In the present invention, it is preferable that at least one of R ¹ ′ and R ² ′ is a hydrogen atom. That is, the acid dissociable group (p1) is preferably a group represented by the following general formula (p1-1).

［式中、Ｒ^１’、ｎ、Ｙは上記と同じである。］

[Wherein R ¹ ′, n and Y are the same as described above. ]

Examples of the alkyl group for Y include the same alkyl groups as those described above for the substituent that may be bonded to the carbon atom at the α-position in the description of the α-substituted acrylate ester.
The aliphatic cyclic group for Y can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups that have been proposed in a number of conventional ArF resists. For example, the above “aliphatic ring” Examples thereof are the same as the aliphatic cyclic groups mentioned in “Acid-dissociable groups containing formula groups”.

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

［式中、Ｒ^１７、Ｒ^１８はそれぞれ独立して直鎖状若しくは分岐鎖状のアルキル基または水素原子であり；Ｒ^１９は直鎖状、分岐鎖状若しくは環状のアルキル基である。または、Ｒ^１７およびＲ^１９がそれぞれ独立に直鎖状若しくは分岐鎖状のアルキレン基であって、Ｒ^１７の末端とＲ^１９の末端とが結合して環を形成していてもよい。］

[Wherein, R ¹⁷ and R ¹⁸ each independently represents a linear or branched alkyl group or a hydrogen atom; and R ¹⁹ represents a linear, branched or cyclic alkyl group. Alternatively, R ¹⁷ and R ¹⁹ may be each independently a linear or branched alkylene group, and the end of R ^{17 and} the end of R ¹⁹ may be bonded to form a ring. ]

In R ¹⁷ and R ¹⁸ , the alkyl group preferably has 1 to 15 carbon atoms, may be linear or branched, and is preferably an ethyl group or a methyl group, and most preferably a methyl group.
In particular, it is preferable that one of R ¹⁷ and R ¹⁸ is a hydrogen atom and the other is a methyl group.
R ¹⁹ is a linear, branched or cyclic alkyl group, preferably having 1 to 15 carbon atoms, and may be any of linear, branched or cyclic.
When R ¹⁹ is linear or branched, it preferably has 1 to 5 carbon atoms, more preferably an ethyl group or a methyl group, and most preferably an ethyl group.
When R ¹⁹ is cyclic, it preferably has 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, one or more polycycloalkanes such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group. And the like, in which a hydrogen atom is removed. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among them, a group obtained by removing one or more hydrogen atoms from adamantane is preferable.
In the formula (p2), R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group (preferably an alkylene group having 1 to 5 carbon atoms), and the end of R ¹⁹ is The terminal of R ¹⁷ may be bonded.
In this case, a cyclic group is formed by R ¹⁷ , R ¹⁹ , the oxygen atom to which R ¹⁹ is bonded, and the carbon atom to which the oxygen atom and R ¹⁷ are bonded. The cyclic group is preferably a 4- to 7-membered ring, and more preferably a 4- to 6-membered ring. Specific examples of the cyclic group include a tetrahydropyranyl group and a tetrahydrofuranyl group.

  The structural unit (a1) is not particularly limited as long as it has an acid-decomposable group, but an acrylic group in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. A structural unit derived from an acid ester and comprising a structural unit (a11) containing an acid-decomposable group, a hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent, and hydrogen bonded to a benzene ring A structural unit in which a hydrogen atom of a hydroxyl group of a structural unit derived from hydroxystyrene which may be substituted with a substituent other than a hydroxyl group is substituted with an acid-dissociable group or a substituent containing an acid-dissociable group ( a12), a hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, and a hydrogen atom bonded to the naphthalene ring may be substituted with a substituent other than a hydroxyl group (hydroxynaphtho Structural units hydroxyl hydrogen atoms of constituent units derived from alkylene) is replaced by a substituent containing an acid-dissociable group or an acid-dissociable group (a13), and the like. The structural unit (a11) is preferable in terms of improvement in roughness (reduction in line width roughness and line edge roughness), and the structural unit (in terms of easy absorption of EUV wavelength and reduction in the influence of OoB light on the acid generation component). a12) to (a13) are preferred.

{Structural unit (a11)}
The structural unit (a11) is a structural unit derived from an acrylate ester in which the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent and includes an acid-decomposable group.
Examples of the structural unit (a11) include a structural unit represented by the following general formula (a1-0-1), a structural unit represented by the following general formula (a1-0-2), and the like.

［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；Ｘ^１は酸解離性基であり；Ｙ^２は２価の連結基であり；Ｘ^２は酸解離性基である。］

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; X ¹ is an acid dissociable group; Y ² is a divalent linking group. Yes; X ² is an acid-dissociable group. ]

In general formula (a1-0-1), the alkyl group and halogenated alkyl group represented by R are the alkyl group and halogenated alkyl group mentioned as the substituent at the α-position in the description of the α-substituted acrylate ester, respectively. The same thing is mentioned. 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 most preferably a hydrogen atom or a methyl group.
X ¹ is not particularly limited as long as it is an acid dissociable group, and examples thereof include the above-described tertiary alkyl ester type acid dissociable groups, acetal type acid dissociable groups, and the like. An ester type acid dissociable group is preferred.
In general formula (a1-0-2), R is the same as defined above.
X ² is the same as X ¹ in formula (a1-0-1).
Examples of the divalent linking group of Y ^2, 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. As the divalent hydrocarbon group which may have these substituents and the divalent linking group containing a hetero atom, respectively, the divalent linking group for Q ¹ in the formula (a5-0-1) The same thing is mentioned.
Y ² is particularly preferably a linear or branched alkylene group, a divalent alicyclic hydrocarbon group, or a divalent linking group containing a hetero atom.
When Y ² 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 linking group in R ^1, the same as the linear alkylene group and the branched alkylene group mentioned as the linear or branched aliphatic hydrocarbon group. Things.
When Y ² is a divalent alicyclic hydrocarbon group, as the alicyclic hydrocarbon group, in the description of the divalent linking group in R ^0-1 , “aliphatic containing a ring in the structure”. The thing similar to the alicyclic hydrocarbon group quoted as "hydrocarbon group" is mentioned.
The alicyclic hydrocarbon group is particularly preferably a group in which two or more hydrogen atoms have been removed from cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane or tetracyclododecane.

When Y ² 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 Y ² is —NH—, H may be substituted with a substituent such as an alkyl group or an aryl group (aromatic group). The substituent (alkyl group, aryl 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 the same groups as those described above as the “divalent hydrocarbon group which may have a substituent” for Y ² .
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.
The divalent linking group containing a hetero atom in Y ² is preferably an organic group comprising a combination of at least one kind, a non-hydrocarbon group and a divalent hydrocarbon group. 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.

Among these, Y ² is preferably a linear or branched alkylene group or a divalent linking group containing a hetero atom, and is a linear or branched alkylene group, the formula -Y ²¹ A group represented by —O—Y ²² —, 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 ( The group represented by ═O) —Y ²² — is more preferable.

  More specifically, examples of the structural unit (a11) include structural units represented by general formulas (a1-1) to (a1-4) shown below.

［式中、Ｒ、Ｒ^１’、Ｒ^２’、ｎ、ＹおよびＹ^２はそれぞれ前記と同じであり、Ｘ’は第３級アルキルエステル型酸解離性基を表す。］’

[Wherein, R, R ¹ ′, R ² ′, n, Y and Y ² are the same as defined above, and X ′ represents a tertiary alkyl ester-type acid dissociable group. ] '

In the formula, X ′ is the same as the tertiary alkyl ester-type acid dissociable group.
^{R 1 ', R 2',} n, as the Y, respectively, ^{R 1} in the general formula listed in the description of "acetal-type acid dissociable group" described above ^{(p1) ', R 2'} , n, similarly to the Y Can be mentioned.
The Y ^2, the same groups as those described above for ^{Y 2} in the general formula (a1-0-2).
Specific examples of the structural units represented by the general formulas (a1-1) to (a1-4) are shown below.
In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

  In the present invention, as the structural unit (a11), a structural unit represented by the following general formula (a1-0-11), a structural unit represented by the following general formula (a1-0-12), and the following general formula ( It preferably has at least one selected from the group consisting of a structural unit represented by a1-0-13) and a structural unit represented by the following general formula (a1-0-2). Among these, a structural unit represented by the formula (a1-0-11), a structural unit represented by the following general formula (a1-0-12), and a structure represented by the following general formula (a1-0-2) It is preferable to have at least one selected from the group consisting of units.

［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^２１はアルキル基であり、Ｒ^２２は、当該Ｒ^２２が結合した炭素原子と共に脂肪族単環式基を形成する基であり、Ｒ^２３は分岐鎖状のアルキル基であり、Ｒ^２４は、当該Ｒ^２４が結合した炭素原子と共に脂肪族多環式基を形成する基であり、Ｒ^２５は炭素数１〜５の直鎖状のアルキル基である。Ｒ^１５およびＲ^１６は、それぞれ独立してアルキル基である。Ｙ^２は２価の連結基であり、Ｘ^２は酸解離性基である。］

[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 ²¹ is an alkyl group, and R ²² is a carbon to which R ²² is bonded. A group that forms an aliphatic monocyclic group together with an atom; R ²³ is a branched alkyl group; and R ²⁴ is a group that forms an aliphatic polycyclic group together with the carbon atom to which R ²⁴ is bonded. R ²⁵ is a linear alkyl group having 1 to 5 carbon atoms. R ¹⁵ and R ¹⁶ are each independently an alkyl group. Y ² is a divalent linking group, and X ² is an acid dissociable group. ]

In each formula, the description of R, Y ² and X ² is the same as described above.
In formula (a1-0-11), examples of the alkyl group for R ²¹ include the same alkyl groups as those described above for R ¹⁴ in formulas (1-1) to (1-9). Group or isopropyl group is preferred.
R ²² is, the aliphatic monocyclic group formed together with the carbon atom to which R ²² is bonded, the same aliphatic cyclic groups as those in the aforementioned tertiary alkyl ester-type acid dissociable groups, a monocyclic group The thing similar to what is is mentioned. Specific examples include groups in which one or more hydrogen atoms have been removed from a monocycloalkane. The monocycloalkane is preferably a 3- to 11-membered ring, more preferably a 3- to 8-membered ring, further preferably a 4- to 6-membered ring, and particularly preferably a 5- or 6-membered ring.
In the monocycloalkane, a part of carbon atoms constituting the ring may or may not be substituted with an ether group (—O—).
Moreover, this monocycloalkane may have a C1-C5 alkyl group, a fluorine atom, or a C1-C5 fluorinated alkyl group as a substituent.
Examples of R ²² constituting such an aliphatic monocyclic group include a linear alkylene group in which an ether group (—O—) may be interposed between carbon atoms.

Specific examples of the structural unit represented by the formula (a1-0-11) include the formulas (a1-1-16) to (a1-1-23), (a1-1-27), and (a1-1 -31)-the structural unit represented by (a1-1-33) is mentioned. Among these, the formulas (a1-1-16) to (a1-1-17), (a1-1-20) to (a1-1-23), (a1-1-27), (a1-1-1- The structural unit represented by the following (a1-1-02) including the structural units represented by 31) to (a1-1-33) is preferable. Moreover, the structural unit represented by the following (a1-1-02 ′) is also preferable.
In each formula, h is preferably 1 or 2.

［式中、Ｒ、Ｒ^２１はそれぞれ前記と同じであり、ｈは１〜４の整数である。］

[Wherein, R and R ²¹ are the same as defined above, and h is an integer of 1 to 4. ]

In formula (a1-0-12), as the branched alkyl group for R ²³ , the branched alkyl group described for the alkyl group for R ¹⁴ in formulas (1-1) to (1-9) above. Examples thereof are the same as those described above, and an isopropyl group is most preferable.
R ²⁴ is, the aliphatic polycyclic group formed together with the carbon atom to which R ²⁴ is bonded, the same aliphatic cyclic groups as those in the aforementioned tertiary alkyl ester-type acid dissociable group, polycyclic group The thing similar to what is is mentioned.
Specific examples of the structural unit represented by the formula (a1-0-12) include those represented by the formulas (a1-1-26) and (a1-1-28) to (a1-1-30). Units are listed.
As the structural unit represented by the formula (a1-0-12), those in which R ²⁴ is an aliphatic polycyclic group formed together with the carbon atom to which R ²⁴ is bonded are preferably a 2-adamantyl group, The structural unit represented by the formula (a1-1-26) is preferable.

In formula (a1-0-13), R and R ²⁴ are the same as defined above.
Examples of the linear alkyl group for R ²⁵ include the same linear alkyl groups as those described above for the alkyl group for R ^{14 in} the formulas (1-1) to (1-9), and methyl Most preferred are groups or ethyl groups.
Specific examples of the structural unit represented by formula (a1-0-13) include formulas (a1-1-1) to (a1-1-3) exemplified as specific examples of general formula (a1-1). ), Structural units represented by (a1-1-7) to (a1-1-15).
As the structural unit represented by the formula (a1-0-13), those in which R ²⁴ is an aliphatic polycyclic group formed together with the carbon atom to which R ²⁴ is bonded are preferably a 2-adamantyl group, The structural unit represented by the formula (a1-1-1), (a1-1-2) or (a1-1-9) is preferable.

In formula (a1-0-14), R and R ²² are the same as defined above. R ¹⁵ and ^{R 16} are the same as ^{R 15} and ^{R 16} in each of the general formulas (2-1) to (2-6).
Specific examples of the structural unit represented by the formula (a1-0-14) include the formulas (a1-1-35) and (a1-1-36) exemplified as specific examples of the general formula (a1-1). ).

In formula (a1-0-15), R and R ²⁴ are the same as defined above. R ¹⁵ and ^{R 16} are the same as ^{R 15} and ^{R 16} in each of the general formulas (2-1) to (2-6).
Specific examples of the structural unit represented by formula (a1-0-15) include formulas (a1-1-4) to (a1-1-6) exemplified as specific examples of general formula (a1-1). ) And (a1-1-34).

Examples of the structural unit represented by the formula (a1-0-2) include the structural unit represented by the formula (a1-3) or (a1-4), and particularly represented by the formula (a1-3). Are preferred.
As the structural unit represented by the formula (a1-0-2), in particular, Y ² in the formula is a group represented by the formula —Y ²¹ —O—Y ²² —, or the formula — [Y ²¹ —C _{(= O) -O] m '} -Y 22 - group represented by or the formula ^{-Y 21 -O-C (= O} ) -Y 22, - what is a group represented by are preferred.
Preferred examples of the structural unit include a structural unit represented by the following general formula (a1-3-01); a structural unit represented by the following general formula (a1-3-02); 3-03) and the like.

［式中、Ｒは前記と同じであり、Ｒ^１３は水素原子またはメチル基であり、Ｒ^１４はアルキル基であり、ｙは１〜１０の整数であり、ｎ’は０〜３の整数である。］

[Wherein, R is the same as above, R ¹³ is a hydrogen atom or a methyl group, R ¹⁴ is an alkyl group, y is an integer of 1 to 10, and n ′ is an integer of 0 to 3] is there. ]

［式中、Ｒは前記と同じであり、Ｙ^２’およびＹ^２”はそれぞれ独立して２価の連結基であり、Ｘ’は酸解離性基であり、ｗは０〜３の整数である。］

[Wherein, R is the same as defined above, Y ² ′ and Y ² ″ are each independently a divalent linking group, X ′ is an acid-dissociable group, and w is an integer of 0 to 3] is there.]

In formulas (a1-3-01) to (a1-3-02), R ¹³ is preferably a hydrogen atom.
R ¹⁴ is the same as ^{R 14} in the formula (1-1) to (1-9).
y is preferably an integer of 1 to 8, more preferably an integer of 1 to 5, and most preferably 1 or 2.
n ′ is preferably 1 or 2, and most preferably 2.
Specific examples of the structural unit represented by the formula (a1-3-01) include structural units represented by the formulas (a1-3-25) to (a1-3-26).
Specific examples of the structural unit represented by the formula (a1-3-02) include structural units represented by the formulas (a1-3-27) to (a1-3-28).

In formula (a1-3-03), examples of the divalent linking group for Y ² ′ and Y ² ″ include the same groups as those described above for Y ² in formula (a1-3).
Y ² ′ is preferably a divalent hydrocarbon group which may have a substituent, more preferably a linear aliphatic hydrocarbon group, and even more preferably a linear alkylene group. Among these, a linear alkylene group having 1 to 5 carbon atoms is preferable, and a methylene group and an ethylene group are most preferable.
Y ² ″ is preferably a divalent hydrocarbon group which may have a substituent, more preferably a linear aliphatic hydrocarbon group, and still more preferably a linear alkylene group. A linear alkylene group of 1 to 5 is preferable, and a methylene group and an ethylene group are most preferable.
Examples of the acid dissociable group in X ′ include the same groups as described above, and are preferably tertiary alkyl ester-type acid dissociable groups, and the ring skeleton of the above-described (i) monovalent aliphatic cyclic group In addition, a group in which a substituent is bonded to a carbon atom bonded to an atom adjacent to the acid dissociable group to form a tertiary carbon atom is more preferable, and among them, the group represented by the general formula (1-1) is preferable. Preferred are the groups
w is an integer of 0 to 3, and w is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 1.
As the structural unit represented by the formula (a1-3-03), a structural unit represented by the following general formula (a1-3-03-1) or (a1-3-03-2) is preferable. The structural unit represented by the formula (a1-3-03-1) is preferable.

［式中、ＲおよびＲ^１４はそれぞれ前記と同じであり、ａ’は１〜１０の整数であり、ｂ’は１〜１０の整数であり、ｔは０〜３の整数である。］

[Wherein, R and R ¹⁴ are the same as defined above, a ′ is an integer of 1 to 10, b ′ is an integer of 1 to 10, and t is an integer of 0 to 3, respectively. ]

In formulas (a1-3-03-1) to (a1-3-03-2), a ′ is preferably an integer of 1 to 8, more preferably an integer of 1 to 5, and particularly preferably 1 or 2.
b ′ is preferably an integer of 1 to 8, more preferably an integer of 1 to 5, and particularly preferably 1 or 2.
t is preferably an integer of 1 to 3, and 1 or 2 is particularly preferable.
Specific examples of the structural unit represented by formula (a1-3-03-1) or (a1-3-03-2) include those represented by formulas (a1-3-29) to (a1-3-32). The structural unit represented is mentioned.

{Structural unit (a12)}
In the structural unit (a12), 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 may be substituted with a substituent other than a hydroxyl group. It is a structural unit in which a hydrogen atom of a hydroxyl group of a structural unit derived from styrene is substituted with an acid dissociable group or a substituent containing an acid dissociable group.
Examples of the acid dissociable group for substituting the hydrogen atom of the hydroxyl group include the same groups as those described above, preferably a tertiary alkyl ester type acid dissociable group or an acetal type acid dissociable group, and an acetal type acid dissociable group is More preferred.
Examples of the substituent containing an acid dissociable group include a group composed of an acid dissociable group and a divalent linking group. Examples of the divalent linking group include those similar to the divalent linking group for Q ¹ in the formula (a5-0-1). Particularly, the terminal structure on the acid-dissociable group side is a carbonyloxy group. Certain groups are preferred. In this case, it is preferable that an acid dissociable group is bonded to the oxygen atom (—O—) of the carbonyloxy group.
Examples of the substituent containing an acid dissociable group include a group represented by R ¹¹ ′ —O—C (═O) — and a group represented by R ¹¹ ′ —O—C (═O) —R ¹² ′ —. Is preferred. In the formula, R ¹¹ ′ is an acid dissociable group, and R ¹² ′ is a linear or branched alkylene group.
The acid dissociable group for R ¹¹ ′ is preferably a tertiary alkyl ester type acid dissociable group or an acetal type acid dissociable group, more preferably a tertiary alkyl ester type acid dissociable group. As a preferable example of the tertiary alkyl ester type acid dissociable group, the aliphatic branched acid dissociable group represented by the above-described —C (R ⁷¹ ) (R ⁷² ) (R ⁷³ ), the formula (1- Examples include groups represented by 1) to (1-9), groups represented by formulas (2-1) to (2-6), and the like.
Examples of the alkylene group for R ¹² ′ include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, and a 1,1-dimethylethylene group. R ¹² ′ is preferably a linear alkylene group.
Specifically, as the structural unit (a12), for example, in general formula (U-3), _px of — (OX ^c ) _px bonded to a benzene ring is an integer of 1 to 3, and at least one of X ^c is And an acid dissociable group or a substituent containing an acid dissociable group. When px is 2 or 3, the plurality of X ^c may be the same or different. For example, one may be an acid-dissociable group or a substituent containing an acid-dissociable group, and the other one or two may be a hydrogen atom.

{Structural unit (a13)}
In the structural unit (a13), a hydrogen atom bonded to the α-position carbon atom may be substituted with a substituent, and a hydrogen atom bonded to the naphthalene ring may be substituted with a substituent other than a hydroxyl group. It is a structural unit formed by replacing the hydrogen atom of the hydroxyl group of a structural unit derived from (hydroxynaphthalene) with an acid-dissociable group or a substituent containing an acid-dissociable group.
In the structural unit (a13), examples of the acid dissociable group for substituting a hydrogen atom of a hydroxyl group and the substituent containing an acid dissociable group include the same groups as those described above for the structural unit (a12). It is done.
Specifically, as the structural unit (a13), for example, in the general formula (U-4), _x of — (OX ^d ) _x bonded to a benzene ring is an integer of 1 to 3, and at least one of X ^d is And an acid dissociable group or a substituent containing an acid dissociable group. When x is 2 or 3, the plurality of X ^d may be the same or different. For example, one may be an acid-dissociable group or a substituent containing an acid-dissociable group, and the other one or two may be a hydrogen atom.

As the structural unit (a1) contained in the component (A1-1), 1 type of structural unit may be used, or 2 or more types may be used.
In the component (A1-1), the proportion of the structural unit (a1) is preferably 15 to 70 mol%, more preferably 15 to 60 mol%, based on all the structural units constituting the component (A1-1). More preferred is ˜55 mol%. By setting it to the lower limit value or more, a pattern can be easily obtained when a resist composition is formed, and lithography properties such as sensitivity, resolution, and pattern shape are improved. Moreover, the balance with another structural unit can be taken by making it below an upper limit.

(Structural unit (a2))
The component (A1-1) preferably further has a structural unit (a2) containing a —SO ₂ — containing cyclic group or a lactone-containing cyclic group in addition to the structural units (a5) and (a1).
The —SO ₂ -containing cyclic group or lactone cyclic group of the structural unit (a2) is used for improving the adhesion of the resist film to the substrate when the component (A1-1) is used for forming a resist film. It is effective. Moreover, it is effective in the alkali development process in that the affinity with a developer containing water such as an alkali developer is improved.
In addition, when the structural unit (a5) or (a1) includes a —SO ₂ — containing cyclic group or a lactone-containing cyclic group in the structure, the structural unit also corresponds to the structural unit (a2). Such a structural unit corresponds to the structural unit (a5) or (a1) and does not correspond to the structural unit (a2).

Here, the “—SO ₂ -containing cyclic group” refers to a cyclic group containing a ring containing —SO ₂ — in the ring skeleton, specifically, a sulfur atom in —SO ₂ — ( S) is a cyclic group that forms part of the ring 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 halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (═O), —COOR ″, —OC (═O) R ″, a hydroxyalkyl group, a cyano group, and the like. Is mentioned.
The alkyl group as the substituent is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. 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 for the substituent include groups in which part or all of the hydrogen atoms of the alkyl group have been substituted with the halogen atoms.
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.
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.
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.
As the hydroxyalkyl group as the substituent, those having 1 to 6 carbon atoms are preferable. Specifically, at least one hydrogen atom of the alkyl group mentioned as the alkyl group as the substituent is substituted with a hydroxyl group. Group.
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、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり、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 halogenated alkyl group, a hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group, 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.
A ′ is preferably an alkylene group having 1 to 5 carbon atoms or —O—, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methylene group.
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, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group in R ²⁷ , the —SO ₂ — containing cyclic group has the above-mentioned, respectively. And the same alkyl groups, alkoxy groups, halogenated alkyl groups, —COOR ″, —OC (═O) R ″, and hydroxyalkyl groups as those which may be substituted.
Below, the specific cyclic group represented by the said general formula (3-1)-(3-4) is illustrated. In the formula, “Ac” represents an acetyl group.

Among the above, the —SO ₂ -containing cyclic group is preferably a group represented by the general formula (3-1), and the chemical formulas (3-1-1), (3-1-18), ( It is more preferable to use at least one selected from the group consisting of groups represented by any of 3-3-1) and (3-4-1), and represented by the chemical formula (3-1-1). Are most preferred.

The “lactone-containing cyclic group” refers to a cyclic group containing a ring (lactone ring) containing —O—C (═O) — in the 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 (a2) is not particularly limited, and any one can be used. Specifically, as the lactone-containing monocyclic group, a group in which one hydrogen atom is removed from a 4- to 6-membered ring lactone, for example, a group in which one hydrogen atom is removed 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.

The structural unit (a2) is not particularly limited as long as it has a —SO ₂ — containing cyclic group or a lactone-containing cyclic group, but the hydrogen atom bonded to the α-position carbon atom is A structural unit derived from an acrylate ester optionally substituted with a substituent, including a structural unit (a2 ^S ) containing a —SO ₂ -containing cyclic group, and a hydrogen atom bonded to the α-position carbon atom; At least one structural unit selected from the group consisting of a structural unit (a2 ^L ) that is a structural unit derived from an acrylate ester that may be substituted with a substituent and that contains a lactone-containing cyclic group is preferred.

-Structural unit (a2 ^S ):
More specifically, examples of the structural unit (a2 ^S ) include structural units represented by general formula (a2-0) 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−ＳＯ_２−含有環式基であり、Ｒ^２９は単結合または２価の連結基である。］

[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, R ²⁸ represents a —SO ₂ — containing cyclic group, and R ²⁹ represents a single bond. Or it is a bivalent coupling group. ]

In formula (a2-0), R is the same as defined above.
R ²⁸ is the same as the —SO ₂ — containing cyclic group mentioned above.
R ²⁹ may be a single bond or a divalent linking group. Since it is excellent in the effect of this invention, it is preferable that it is a bivalent coupling group.
The divalent linking group for R ²⁹ is not particularly limited, and examples thereof include the same divalent linking groups as those for Q ¹ in formula (a5-0-1). Among these, those containing an alkylene group or an ester bond (—C (═O) —O—) are 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 exemplified as the aliphatic hydrocarbon group for Y ² in the formula (a1-0-2) can be given.
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 (a2 ^S ) is preferably a structural unit represented by the following general formula (a2-0-1).

［式中、ＲおよびＲ^２８はそれぞれ前記と同様であり、Ｒ^３０は２価の連結基である。］

[Wherein, R and R ²⁸ are the same as defined above, and R ³⁰ is a divalent linking group. ]

R ³⁰ is not particularly limited, and examples thereof include the same divalent linking groups as Q ¹ in formula (a5-0-1).
As the divalent linking group for R ^30, a linear or branched alkylene group, an aliphatic hydrocarbon group containing a ring in the structure, or a divalent linking group containing a hetero atom is preferable. Alternatively, a branched alkylene group or a divalent linking group containing an oxygen atom as a hetero atom is preferable.
As the linear alkylene group, a methylene group or an ethylene group is preferable, and a methylene group is particularly preferable.
As the branched alkylene group, an alkylmethylene group or an alkylethylene group is preferable, and —CH (CH ₃ ) —, —C (CH ₃ ) ₂ — or —C (CH ₃ ) ₂ CH ₂ — is particularly preferable.
The divalent linking group containing an oxygen atom is preferably a divalent linking group containing an ether bond or an ester bond, and the above-described —Y ²¹ —O—Y ²² —, — [Y ²¹ —C (═O) —O] _{m ′} —Y ²² — or —Y ²¹ —O—C (═O) —Y ²² — is more preferable. Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent, and m ′ is an integer of 0 to 3. Among them, —Y ²¹ —O—C (═O) —Y ²² — is preferable, and a group represented by — (CH ₂ ) _c —O—C (═O) — (CH ₂ ) _d — is particularly preferable. . c is an integer of 1 to 5, and 1 or 2 is preferable. d is an integer of 1-5, and 1 or 2 is preferable.

As the structural unit (a2 ^S ), a structural unit represented by general formula (a2-0-11) or (a2-0-12) shown below is particularly desirable, and represented by formula (a2-0-12). A structural unit is more preferable.

［式中、Ｒ、Ａ’、Ｒ^２７、ｚおよびＲ^３０はそれぞれ前記と同じである。］

[Wherein, R, A ′, R ²⁷ , z and R ³⁰ are the same as defined above. ]

In formula (a2-0-11), A ′ is preferably a methylene group, an oxygen atom (—O—) or a sulfur atom (—S—).
R ³⁰ is preferably a linear or branched alkylene group or a divalent linking group containing an oxygen atom. As the linear or branched alkylene group and the divalent linking group containing an oxygen atom in R ^30, the linear or branched alkylene group mentioned above and a divalent linking group containing an oxygen atom are mentioned. Examples are the same as the linking group.
As the structural unit represented by the formula (a2-0-12), a structural unit represented by the following general formula (a2-0-12a) or (a2-0-12b) is particularly preferable.

［式中、ＲおよびＡ’はそれぞれ前記と同じであり、ｃ〜ｅはそれぞれ独立に１〜３の整数である。］

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

-Structural unit (a2 ^L ):
Examples of the structural unit (a2 ^L ) include those obtained by substituting R ²⁸ in the general formula (a2-0) with a lactone-containing cyclic group, and more specifically, the following general formula (a2- The structural unit represented by 1)-(a2-5) is mentioned.

［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’はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン化アルキル基、水酸基、−ＣＯＯＲ”、−ＯＣ（＝Ｏ）Ｒ”、ヒドロキシアルキル基またはシアノ基であり、Ｒ”は水素原子またはアルキル基であり；Ｒ^２９は単結合または２価の連結基であり、ｓ”は０〜２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 ′ is independently a hydrogen atom, an alkyl group, an alkoxy group, or a halogenated alkyl group; , Hydroxyl group, —COOR ″, —OC (═O) R ″, a hydroxyalkyl group or a cyano group, R ″ is a hydrogen atom or an alkyl group; R ²⁹ is a single bond or a divalent linking group; s ″ is an integer of 0 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 0 or 1. ]

R in the general formulas (a2-1) to (a2-5) is the same as described above.
As the alkyl group, alkoxy group, halogenated alkyl group, —COOR ″, —OC (═O) R ″, and hydroxyalkyl group in R ′, the —SO ₂ — containing cyclic group has the above-mentioned, respectively. And the same alkyl groups, alkoxy groups, halogenated alkyl groups, —COOR ″, —OC (═O) R ″, and hydroxyalkyl groups as those which may be substituted.
R ′ is preferably a hydrogen atom in view of industrial availability.
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, and more preferably 1 to 5 carbon atoms.
When R ″ is a cyclic alkyl group, it preferably has 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, a fluorine atom Or a group in which one or more hydrogen atoms have been removed from a polycycloalkane such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorinated alkyl group Specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Etc.
Examples of A ″ include the same as A ′ in the general formula (3-1). A ″ represents an alkylene group having 1 to 5 carbon atoms, an oxygen atom (—O—) or a sulfur atom (— S-) is preferable, and an alkylene group having 1 to 5 carbon atoms or -O- is more preferable. The alkylene group having 1 to 5 carbon atoms is more preferably a methylene group or dimethylmethylene group, and most preferably a methylene group.
R ²⁹ is the same as ^{R 29} in the aforementioned general formula (a2-0).
In formula (a2-1), s ″ is preferably 1 to 2.
Specific examples of the structural units represented by the general formulas (a2-1) to (a2-5) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

As the structural unit (a2 ^L ), at least one selected from the group consisting of structural units represented by the general formulas (a2-1) to (a2-5) is preferable, and the general formula (a2-1) to More preferably, at least one selected from the group consisting of structural units represented by (a2-3) is selected from the group consisting of structural units represented by the general formula (a2-1) or (a2-3) Particularly preferred is at least one of the above.
Among them, the formulas (a2-1-1), (a2-1-2), (a2-2-1), (a2-2-7), (a2-2-12), (a2-2-2-) 13), (a2-2-15), (a2-3-1), and at least one selected from the group consisting of structural units represented by (a2-3-5) is preferable.

Moreover, as the structural unit (a2 ^L ), structural units represented by the following formulas (a2-6) to (a2-7) are also preferable.

［式中、Ｒ、Ｒ^２９は前記同様である。］

[Wherein, R and R ²⁹ are the same as defined above. ]

The structural unit (a2) contained in the component (A1-1) may be one type or two or more types. For example, as the structural unit (a2), only the structural unit (a2 ^S ) may be used, or only the structural unit (a2 ^L ) may be used, or they may be used in combination. As the structural unit (a2 ^S ) or the structural unit (a2 ^L ), one type may be used alone, or two or more types may be used in combination.
In the component (A1-1), the proportion of the structural unit (a2) is preferably 1 to 80 mol%, preferably 10 to 70 mol based on the total of all the structural units constituting the component (A1-1). % Is more preferable, 10 to 65 mol% is further preferable, and 10 to 60 mol% is particularly preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units, such as various kinds of DOF, CDU, etc. The lithography characteristics and pattern shape of the film are improved.

(Structural unit (a3))
In addition to the structural units (a5) and (a1), or in addition to the structural units (a5), (a1) and (a2), the component (A1-1) is a structural unit (a3) containing a polar group You may have. When the component (A1-1) has the structural unit (a3), the polarity of the component (A1-1) after exposure is further improved. The improvement in polarity contributes to an improvement in resolution and the like, particularly in the case of an alkali development process.
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 (a3) 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 (where n is 0 and a natural number) 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, and the like. Can be 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 (a3), structural units represented by general formula (a3-1) 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。Ｐ^０は−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｏ）−ＮＲ^０−（Ｒ^０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。Ｗ^０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、−ＣＯＯＨ、又は−ＣＯＮＨＣＯ−Ｒ^ａ３（Ｒ^ａ３は炭化水素基）であり、該炭化水素基は任意の位置に酸素原子又は硫黄原子を有していてもよく、ハロゲン原子で置換されていてもよい。］

[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. P ⁰ is —C (═O) —O—, —C (═O) —NR ⁰ — (R ⁰ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms) or a single bond. W 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, —COOH, or —CONHCO—R ^a3. (R ^a3 is a hydrocarbon group), and the hydrocarbon group may have an oxygen atom or a sulfur atom at an arbitrary position, and may be substituted with a halogen atom. ]

In the formula (a3-1), the alkyl group of R is preferably a linear or branched alkyl group, specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, Examples include isobutyl 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 the formula (a3-1), P ⁰ is —C (═O) —O—, —C (═O) —NR ⁰ — (R ⁰ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. ) Or a single bond. The alkyl group for R ⁰ is the same as the alkyl group for R.

In the formula (a3-1), W 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. , -COOH, or -CONHCO-R ^a3 (R ^a3 is a hydrocarbon group), and the hydrocarbon group may have an oxygen atom or a sulfur atom at any position, and is substituted with a halogen atom. Also good.
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 W ⁰ or R ^a3 may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
Examples of the aliphatic hydrocarbon group for W ⁰ or R ^a3 include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group), an aliphatic cyclic group (monocyclic group, A polycyclic group), and the description thereof is the same as described above.
The aromatic hydrocarbon group for W ⁰ or R ^a3 is a hydrocarbon group having at least one aromatic ring, and the description thereof is the same as described above.

However, W 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.
In the hydrocarbon group in W ⁰ , a hydrogen atom bonded to the hydrocarbon group may be substituted with 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.
The following is an example of W ⁰ having an oxygen atom (O) at an arbitrary position.

［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 W ⁰ in the formula (a3-1). 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 preferable examples of the structural unit (a3) include more specifically structural units derived from (α-substituted) acrylic acid esters, any of the following general formulas (a3-11) to (a3-13): And the like. Examples of the structural unit derived from the (α-substituted) acrylate ester include a structural unit in which P ⁰ in the formula (a3-1) is a single bond and W 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−、−Ｃ（＝Ｏ）−ＮＲ^０−（Ｒ^０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。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、又は−ＣＯＮＨＣＯ−Ｒ^ａ３２（Ｒ^ａ３２は環状の炭化水素基）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鎖状の炭化水素基、又は−ＣＯＮＨＣＯ−Ｒ^ａ３３（Ｒ^ａ３３は鎖状の炭化水素基）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 —C (═O) —O—, —C (═O) —NR ⁰ — (R ⁰ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms) or a single bond, respectively. . W ⁰² is -OH as a substituent, -COOH, -CN, cyclic hydrocarbon radical having at least one group selected from the group consisting of _-SO 2 NH ₂ and -CONH _2, or ^{-CONHCO-R a32} ( R ^a32 is a cyclic hydrocarbon group) and may have an oxygen atom or a sulfur atom at an arbitrary position. W ⁰³ is a chain 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, or —CONHCO—R ^a33. (R ^a33 is a chain hydrocarbon group). ]

[Structural Unit Represented by General Formula (a3-11)]
In the formula (a3-11), R is the same as described for R in the formula (a3-1).
The aromatic hydrocarbon group for W ⁰¹ is the same as that described for the aromatic hydrocarbon group for W ⁰ in formula (a3-1).
Specific examples of preferable structural units represented by general formula (a3-11) 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 (a3-12)]
In the formula (a3-12), R is the same as described for R in the formula (a3-1).
P ⁰² is —C (═O) —O— or —C (═O) —NR ⁰ — (R ⁰ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), and —C (═O ) -O-. The alkyl group for R ⁰ is the same as the alkyl group for R.
The cyclic hydrocarbon group in W ⁰² or R ^a32 is an aliphatic cyclic group (monocyclic group or polycyclic group) exemplified in the description of W ⁰ in the formula (a3-1), aromatic The same thing as each group hydrocarbon group is mentioned.
W ⁰² or R ^a32 may have an oxygen atom or a sulfur atom at an arbitrary position, and this description is the same as the description of W ⁰ in the formula (a3-1).
Specific examples of preferred structural units represented by general formula (a3-12) 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 (a3-13)]
In the formula (a3-13), R is the same as described for R in the formula (a3-1).
P ⁰³ is —C (═O) —O— or —C (═O) —NR ⁰ — (R ⁰ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms), and —C (═O ) -O-. The alkyl group for R ⁰ is the same as the alkyl group for R.
The chain hydrocarbon group for W ⁰³ or R ^a33 preferably has 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and still more preferably 1 to 3 carbon atoms.
The chain hydrocarbon group in W ⁰³ or R ^a33 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 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 two or more hydrogen atoms are 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.
In addition, the chain hydrocarbon group in W ⁰³ may have a plurality of substituents (a) as a structural unit represented by the following general formula (a3-13-a) as an example. The 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 (a3-13-a), R is the same as described for R in the formula (a3-1).
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 preferable structural units represented by general formula (a3-13) are shown below. In the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

As the structural unit (a3) contained in the component (A1-1), one type of structural unit may be used, or two or more types may be used.
In the component (A1-1), the proportion of the structural unit (a3) is preferably 0 to 85 mol%, and 0 to 80 mol% is the total structural unit constituting the component (A1-1). More preferred. By setting the proportion of the structural unit (a3) 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 (a3) can be sufficiently obtained, and the upper limit value or less. This makes it easier to balance with other structural units.

(Structural unit (a4))
The component (A1-1) may further have a structural unit (a4) containing an acid non-dissociable cyclic group as necessary. When the component (A1-1) has the structural unit (a4), the dry etching resistance of the formed resist pattern is improved. Moreover, the hydrophobicity of (A1-1) component increases. The improvement in hydrophobicity contributes to the improvement in resolution, resist pattern shape, etc., particularly in the case of organic solvent development.
The “acid non-dissociable cyclic group” in the structural unit (a4) means that the acid acts when an acid is generated from the structural unit (a5) or an arbitrary acid generator component (B) described later by exposure. However, the cyclic group remains in the structural unit as it is without dissociating.
As the structural unit (a4), a structural unit obtained by substituting the acid dissociable group in the structural unit (a1) with an acid non-dissociable cyclic group can be given. Among them, 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 a non-acid-dissociable aliphatic cyclic group ( a41), a structural unit derived from styrene in which 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 carbon atom at the α-position is substituted with a substituent The structural unit (a43) derived from vinyl naphthalene which may be present is preferred.

As the non-acid dissociable aliphatic cyclic group in the structural unit (a41), for example, an atom adjacent to the aliphatic cyclic group (for example, —O— in —C (═O) —O—) is bonded. A monovalent aliphatic cyclic group in which a substituent (atom or group other than a hydrogen atom) is not bonded to a carbon atom, one of the hydrogen atoms of a primary or secondary alkyl group is a monovalent aliphatic cyclic group And a group substituted with a group.
The monovalent aliphatic cyclic group is not particularly limited as long as it is non-acid dissociable, and is used as a resin component of a resist composition such as for ArF excimer laser or KrF excimer laser (preferably for ArF excimer laser). Many known in the art can be used. The aliphatic cyclic group may be saturated, unsaturated, or saturated.
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, 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).
The basic ring structure excluding the substituent of the aliphatic cyclic group is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The hydrocarbon group may be either saturated or unsaturated, but is usually preferably saturated.
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, specifically adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like. Moreover, a part of carbon atoms constituting the ring of these aliphatic cyclic groups may be substituted with an ether group (—O—).
The aliphatic cyclic group is preferably polycyclic because it is excellent in the above effects. In particular, those having 2 to 4 rings are preferable, and among them, at least one selected from a tricyclodecyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group and a norbornyl group is preferable in terms of industrial availability. .

Specific examples of the monovalent aliphatic cyclic group as the non-acid-dissociable aliphatic cyclic group include, for example, an atom adjacent to the aliphatic cyclic group (for example, in —C (═O) —O—). A monovalent aliphatic cyclic group in which a substituent (an atom or group other than a hydrogen atom) is not bonded to a carbon atom bonded to —O—). Specifically, a group in which R ¹⁴ in the groups represented by formulas (1-1) to (1-9) given in the description of the acid dissociable group is substituted with a hydrogen atom; a carbon atom constituting the ring skeleton And a group obtained by removing a hydrogen atom from the tertiary carbon atom of a cycloalkane having a tertiary carbon atom formed only by the above.
Examples of the group in which one hydrogen atom of the primary or secondary alkyl group is substituted with a monovalent aliphatic cyclic group include those represented by the formulas (2-1) to (2- And a group in which at least one of R ^{15 and} R ^{16 in} 6) is a hydrogen atom.

As the structural unit (a41), structural units in which the acid dissociable group in the structural unit (a11) is substituted with an acid non-dissociable aliphatic cyclic group can be mentioned, and in the general formula (a1-0-1), A structural unit in which X ¹ is substituted with a non-acid-dissociable aliphatic polycyclic group, that is, a structural unit represented by the following general formula (a4-1-1) is preferred, and in particular, the following general formula (a4-1-1- The structural units represented by 11) to (a4-1-15) are preferred.

［式中、Ｒは前記と同じであり、Ｒ^４０は酸非解離性の脂肪族多環式基である。］

[Wherein, R is the same as defined above, and R ⁴⁰ represents a non-acid-dissociable aliphatic polycyclic group. ]

Specific examples of the structural unit (a42) include those in which px is 0 in — (OX ^c ) _px bonded to the benzene ring in the general formula (U-3).
Specific examples of the structural unit (a43) include those in which _{x in} — (OX ^d ) _x bonded to the benzene ring is 0 in the general formula (U-4).

As the structural unit (a4) contained in the component (A1-1), 1 type of structural unit may be used, or 2 or more types may be used.
When the component (A1-1) contains the structural unit (a4), the proportion of the structural unit (a4) in the component (A1-1) is the sum of all the structural units constituting the component (A1-1). On the other hand, 1-30 mol% is preferable, 1-20 mol% is more preferable, and 5-20 mol% is further more preferable. By setting it to the lower limit value or more, the effect of containing the structural unit (a4) can be sufficiently obtained, and by setting the upper limit value or less, it is possible to balance with other structural units.

The component (A1-1) may contain other structural units other than the structural units (a1) to (a5) as long as the effects of the present invention are not impaired.
The other structural units are not particularly limited as long as they are other structural units not classified into the above structural units (a1) to (a5), and are not limited to ArF excimer laser, KrF excimer laser, EB, and EUV. A number of hitherto known materials that can be used for resist resins such as those for use can be used.

In the resist composition of this embodiment, the component (A1-1) is preferably a copolymer having a structural unit (a1) in addition to the structural unit (a5). Among these, a copolymer having the structural units (a5), (a1) and (a2) is more preferable.
As the copolymer having the structural unit (a1) in addition to the structural unit (a5), for example, a copolymer comprising the structural units (a5) and (a1), structural units (a5), (a1) and ( a copolymer consisting of structural units (a5), (a1) and (a3), and a copolymer consisting of structural units (a5), (a1), (a2) and (a3). From the polymer, the copolymer comprising the structural units (a5), (a1), (a2) and (a4), the structural units (a5), (a1), (a2), (a3) and (a4) The copolymer etc. which become can be illustrated.

The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography (GPC)) is not particularly limited, preferably 1000 to 50000, more preferably 1500 to 30000, and 2000 to 2000 20000 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) of the component (A1) 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.

As the component (A), one type may be used alone, or two or more types may be used in combination.
The proportion of the component (A1) in the component (A) is preferably 25% by mass or more, more preferably 50% by mass or more, still more preferably 75% by mass or more, and 100% by mass with respect to the total mass of the component (A). It may be. When the ratio is 25% by mass or more, the pattern shape, limit resolution performance, and the like of the resist pattern formed by EUV exposure or EB exposure are improved.
Component (A) is a base material component (hereinafter referred to as “(A2) other than component (A1)” that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid, as long as the effects of the present invention are not impaired. ) Component ”)). The component (A2) is not particularly limited, and conventionally proposed components can be used.
In the resist composition of this embodiment, the content of the component (A) may be adjusted according to the resist film thickness to be formed.

<Monomer Deriving the Structural Unit (a5)>
In the resist composition of this embodiment, the amount of the monomer for deriving the structural unit (a5) is 100 ppm (mass basis) or less with respect to the polymer (A1). In this way, by controlling the monomer amount for deriving the structural unit (a5), a resist pattern having good lithography characteristics and pattern shape is formed in EUV lithography or EB lithography.
The “monomer that derives the structural unit (a5)” includes a monomer that directly or indirectly derives the structural unit (a5), specifically, the above-described formula (a5-0-1) In addition to the monomer having a group represented by formula (a5-0-2) and the monomer having a group represented by formula (a5-0-2), a monomer having a cation moiety of the group represented by formula (a5-0-1), A monomer having an anion moiety of the group represented by formula (a5-0-2) is included.
The monomer amount for deriving the structural unit (a5) in the resist composition is, for example, when synthesizing the component (A1), the monomer deriving each structural unit constituting the component (A1), and a radical polymerization initiator. It can control by performing operation which superposes | polymerizes by the well-known radical polymerization etc. which were used, and wash | cleans with water or an organic solvent with respect to the obtained polymer.

As an example of a method for controlling the monomer amount for deriving the structural unit (a5), in the case of the component (A1) having the structural unit (a5) having the group represented by the formula (a5-0-1), for example, And a method of washing a polymer obtained by polymerizing the monomer for deriving the structural unit (a5) and the monomer for deriving the other structural unit constituting the component (A1) with an organic solvent.
As the organic solvent for washing, methanol, isopropanol, methyl ethyl ketone, heptane, diisopropyl ether and the like can be preferably cited, and these may be used alone or in combination.

  As another example of the method for controlling the monomer amount for deriving the structural unit (a5), in the case of the component (A1) having the structural unit (a5) having the group represented by the formula (a5-0-2) For example, a monomer for deriving the structural unit (a5) and a monomer for deriving another structural unit constituting the component (A1) are polymerized to synthesize a precursor polymer, and the precursor polymer is After washing, the method (I) in which the precursor polymer is subjected to salt exchange with a predetermined organic cation to synthesize the component (A1). According to the method (I), the amount of the monomer for deriving the structural unit (a5) can be easily controlled. Hereinafter, the method (I) will be described by dividing it into a step of synthesizing a precursor polymer, a step of washing the precursor polymer with water, and a step of salt-exchanging the precursor polymer after washing with water with an organic cation. .

Step of synthesizing precursor polymer: In this step, a monomer for deriving structural unit (a5) and a monomer for deriving other structural unit are dissolved in a polymerization solvent, and a radical polymerization initiator is added thereto. The aspect which manufactures a precursor polymer by making it superpose | polymerize (known radical polymerization etc.) is mentioned.
In the polymerization, a chain transfer agent such as HS—CH ₂ —CH ₂ —CH ₂ —C (CF ₃ ) ₂ —OH is used in combination to form a —C (CF ₃ ) ₂ —OH group at the terminal. May be introduced. 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

As the monomer for deriving each structural unit constituting the component (A1), a commercially available monomer may be used, or a monomer synthesized using a known method may be used.
Examples of the radical polymerization initiator include azobisisobutyronitrile (AIBN) and dimethyl azobisisobutyrate.
Any polymerization solvent may be used as long as it can dissolve the raw material monomer, and examples thereof include ethyl lactate, γ-butyrolactone, methyl ethyl ketone, propylene glycol monomethyl ether acetate, tetrahydrofuran, and a mixed solvent thereof.
The use amount of the monomer for deriving the structural unit (a5) and the monomer for deriving the other structural unit may be appropriately determined in consideration of the desired copolymer composition ratio (ratio of each structural unit in the polymer compound). Good.
50-100 degreeC is preferable and, as for reaction temperature, 65-85 degreeC is more preferable.
The reaction time varies depending on the reactivity between the monomers, the reaction temperature, and the like, but is usually preferably 60 to 480 minutes, more preferably 240 to 420 minutes.
After the monomers are polymerized, the reaction polymerization solution is dropped into, for example, a large amount of water or an organic solvent (isopropanol, heptane, methanol, etc.) to precipitate the polymer, and the precursor is separated by filtration or the like. A polymer is obtained.

The cation part of the monomer for deriving the structural unit (a5) may be a cation capable of salt exchange with an organic cation, and examples thereof include ammonium ions; H ⁺ , metal cations, phosphonium ions, and other inorganic cations.
Examples of ammonium ions include ammonium ions (NH ₄ ⁺ ), quaternary ammonium ions, and primary to tertiary ammonium ions.
Examples of the quaternary ammonium ion include cations represented by the following general formula (a5-ca1).

［式中、Ｒ^Ｎ１〜Ｒ^Ｎ４はそれぞれ独立にアリール基、カルボキシ基、水酸基、炭素数１〜５のアルコキシ基もしくは炭素数１〜５のアルキルカルボニルオキシ基で置換されていてもよい炭素数１〜２０のアルキル基またはアリール基である。］

[Wherein, R ^{N1 to} R ^N4 each independently represents an aryl group, a carboxy group, a hydroxyl group, an alkoxy group having 1 to 5 carbon atoms, or an alkylcarbonyloxy group having 1 to 5 carbon atoms, which may have 1 carbon atom. ˜20 alkyl groups or aryl groups. ]

The alkyl group having 1 to 20 carbon atoms of R ^{N1 to} R ^N4 in formula (a5-ca1) may be linear or cyclic, and is preferably a linear alkyl group.
As the aryl group of R ^{N1 to} R ^N4 , those having 6 to 18 carbon atoms are preferable, those having 6 to 10 carbon atoms are more preferable, and specifically, a phenyl group is particularly preferable.
In the case of having an aryl group as a substituent for the alkyl group or aryl group of R ^{N1 to} R ^N4, the aryl group is preferably those having 6 to 18 carbon atoms, more preferably those having 6 to 10 carbon atoms, A phenyl group is preferred.
When it has a C1-C5 alkoxy group as a substituent of the alkyl group or aryl group of R ^{< N1} > -R < ^N4 >, as this alkoxy group, a C1-C5 alkoxy group is preferable, a methoxy group, an ethoxy group, n -Propoxy group, iso-propoxy group, n-butoxy group, tert-butoxy group are preferable.
In the case of having an alkylcarbonyloxy group having 1 to 5 carbon atoms as a substituent for the alkyl group or aryl group of R ^{N1 to} R ^N4, the alkylcarbonyloxy group includes a methylcarbonyloxy group, an ethylcarbonyloxy group, a butylcarbonyloxy group. Groups are preferred.
Further, the quaternary ammonium ion may be a cation having two or more (preferably two) nitrogen atoms (N ⁺ ).
Specific examples of the quaternary ammonium ion include tetramethylammonium ion, tetraethylammonium ion (Et ₄ N ⁺ ), trimethylethylammonium ion (Me ₃ EtN ⁺ ), and tetra-n-propylammonium ion (n-Pr ₄ N ^+). ), Tetra-i-propylammonium ion (i-Pr ₄ N ⁺ ), tetra-n-butylammonium ion (n-Bu ₄ N ⁺ ), quaternary ammonium ions exemplified by the following chemical formula, and the like.

Specific examples of the primary to tertiary ammonium ions include methylammonium ion, dimethylammonium ion, trimethylammonium ion, ethylammonium ion, diethylammonium ion, triethylammonium ion, n-propylammonium ion, and di-n-propylammonium ion. , Tri-n-propylammonium ion, i-propylammonium ion, di-i-propylammonium ion, tri-i-propylammonium ion, n-butylammonium ion, di-n-butylammonium ion, tri-n-butyl Ammonium ion, sec-butylammonium ion, di-sec-butylammonium ion, tri-sec-butylammonium ion, tert-butylammonium ion On, di -tert- butyl ammonium ion, tri -tert- butyl ammonium ion, diisopropylethyl ammonium, phenyl ammonium ion, diphenyl ammonium ion, triphenyl ammonium ions _(Ph 3 NH ⁺⁾ and the like.
Moreover, what is illustrated by the following chemical formula as an ammonium ion is illustrated.

  Examples of the metal cation include alkali metal ions such as sodium ion, potassium and lithium, alkaline earth metal ions such as magnesium and calcium, iron ions and aluminum ions.

  Among the above, the cation moiety is preferably a highly polar one. Among them, ammonium ion is preferable, tertiary ammonium ion is more preferable, quaternary ammonium ion is more preferable, and quaternary ammonium ion is further preferable because water solubility of the monomer is increased and removal efficiency of unreacted monomer is better. Among these, a quaternary ammonium ion represented by the formula (a5-ca1) is preferable, and a tetramethylammonium ion is particularly preferable.

The step of washing the precursor polymer with water: the amount of monomer for deriving the structural unit (a5) is 100 ppm (mass basis) or less with respect to the component (A1) in the resist composition by washing with water in this step. Controlled.
Examples of the method for washing the precursor polymer with water include the following methods (a) to (c).
Method (a): A method by liquid-liquid extraction of a solution obtained by dissolving the obtained precursor polymer in an organic solvent (dichloromethane, chloroform, etc.) and water.
Method (b): A method of dispersing the obtained precursor polymer in water.
Method (c): A method in which a solution obtained by dissolving the obtained precursor polymer in an organic solvent (dichloromethane, chloroform, etc.) is dropped into water.
Among the above methods (a) to (c), the method (a) is preferable because the removal efficiency of unreacted monomers during the polymerization reaction is higher.
In addition, after washing | cleaning a precursor polymer with water, it is also preferable to use the method (d) with respect to the precursor polymer after washing | cleaning filtered etc. as needed.
Method (d): A method of washing the obtained precursor polymer with an organic solvent. Examples of the organic solvent include methanol, isopropanol, methyl ethyl ketone, heptane, diisopropyl ether and the like, and these may be used alone or in combination.
Further, the method (d) can be used in place of the above methods (a) to (c), or can be used before the methods (a) to (c).
The number of times of washing with water and an organic solvent and the washing time are appropriately set so that the monomer amount for deriving the structural unit (a5) is 100 ppm (mass basis) or less with respect to the component (A1) in the resist composition.

The step of salt exchange of the precursor polymer after washing with water with an organic cation: The salt exchange is performed by combining the precursor polymer and a compound having an organic cation (salt exchange compound) with water, dichloromethane, acetonitrile, methanol, It can be carried out by dissolving in a solvent such as chloroform or methylene chloride and stirring.
The reaction temperature is preferably about 20 to 40 ° C, more preferably about 23 to 30 ° C. The reaction time varies depending on the reactivity between the precursor polymer and the salt exchange compound, the reaction temperature, and the like, but is usually preferably from 10 minutes to 24 hours, more preferably from 0.5 to 6 hours.
In general, the amount of the salt exchange compound used in such salt exchange is preferably about 1 to 3 moles per mole of the precursor polymer.

The salt exchange compound is preferably such that the cation portion is the organic cation (M ^{m +} ) and the anion portion is a non-nucleophilic ion.
Examples of non-nucleophilic ions include halogen ions such as bromine ions and chlorine ions; ions that can be acids with lower acidity than the precursor polymer, BF ₄ ⁻ , AsF ₆ ⁻ , SbF ₆ ⁻ , PF ₆ ⁻ or And ClO ₄ ^{— and the} like. Examples of ions that can be an acid having a lower acidity than the precursor polymer include sulfonate ions such as p-toluenesulfonate ion, methanesulfonate ion, and benzenesulfonate ion.

After completion of the salt exchange reaction between the precursor polymer and the salt exchange compound, the polymer (A1) (final target product) in the reaction solution may be isolated and purified.
For isolation and purification, conventionally known methods can be used. For example, concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography and the like can be used alone or in combination of two or more.

According to the method for producing the component (A1) described above, the monomer for deriving the structural unit (a5) (in which the cation moiety is salt-exchanged with the organic cation (M ^{m +} ), and quaternary ammonium ions and the like are included. ) Component (A1) is produced so that the content thereof is 100 ppm (mass basis) or less with respect to the polymer (A1).
In the method (I) described above, since the precursor polymer is washed with water, residual monomers such as unreacted components can be removed easily and efficiently. In addition, since the precursor polymer is prepared and then subjected to salt exchange with a desired organic cation, the degree of freedom of the type of cation moiety that can be introduced is high.

<Other optional components>
[Acid generator component (B)]
The resist composition of this embodiment does not fall under the component (A) as an optional component as long as the effects of the present invention are not impaired, and an acid generator component (B) that generates an acid upon exposure (hereinafter referred to as “(B)”. It may also be included as “component”.
The component (B) is not particularly limited, and those that have been proposed as acid generators for chemically amplified resists can be used. Examples of such acid generators include onium salt acid generators such as iodonium salts and sulfonium salts, oxime sulfonate acid generators, bisalkyl or bisarylsulfonyldiazomethanes, poly (bissulfonyl) diazomethanes, and the like. There are various known diazomethane acid generators, nitrobenzyl sulfonate acid generators, imino sulfonate acid generators, disulfone acid generators, and the like.
As the onium salt acid generator, for example, a compound represented by the following general formula (b-1) or (b-2) can be used.

［式中、Ｒ^１”〜Ｒ^３”はそれぞれ独立に置換基を有していてもよいアリール基、アルキル基又はアルケニル基を表し、Ｒ^１”〜Ｒ^３”のうちのいずれか二つが相互に結合して式中のイオウ原子と共に環を形成してもよい。Ｒ^５”〜Ｒ^６”はそれぞれ独立に置換基を有していてもよいアリール基、アルキル基又はアルケニル基を表す。Ｒ^４”は、置換基を有していてもよいアルキル基、ハロゲン化アルキル基、アリール基、またはアルケニル基を表す。］

[Wherein, R ¹ ″ to R ³ ″ each independently represents an aryl group, an alkyl group or an alkenyl group which may have a substituent, and any two of R ¹ ″ to R ³ ″ are mutually To form a ring together with the sulfur atom in the formula. R ⁵ ″ to R ⁶ ″ each independently represents an aryl group, alkyl group or alkenyl group which may have a substituent. R ⁴ ″ represents an alkyl group, a halogenated alkyl group, an aryl group, or an alkenyl group which may have a substituent.

In formula (b-1), R ¹ ″ to R ³ ″ each independently has an aryl group which may have a substituent, an alkyl group which may have a substituent, or a substituent. Represents an alkenyl group which may optionally be present. Any two of R ¹ ″ to R ³ ″ may be bonded to each other to form a ring together with the sulfur atom in the formula.
R ¹ ″ to R ³ ″ are an aryl group that may have a substituent in R ¹¹ ″ to R ¹³ ″ in the formula (m1-1), an alkyl group that may have a substituent, It is the same as the alkenyl group which may have a substituent.

  Specific examples of the cation moiety in the compound represented by the formula (b-1) include those shown below.

［式中、ｇ１は繰返し数を示し、１〜５の整数である。ｇ２、ｇ３は繰返し数を示し、ｇ２は０〜２０の整数であり、ｇ３は０〜２０の整数である。］

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

In formula (b-2), R ⁵ ″ to R ⁶ ″ each independently has an aryl group which may have a substituent, an alkyl group which may have a substituent, or a substituent. Represents an alkenyl group which may be substituted.
R ⁵ ″ to R ⁶ ″ are an aryl group which may have a substituent in R ¹⁵ ″ to R ¹⁶ ″ in the formula (m2-1), an alkyl group which may have a substituent, It is the same as the alkenyl group which may have a substituent.
Specific examples of the cation moiety in the compound represented by the formula (b-2) include diphenyliodonium and bis (4-tert-butylphenyl) iodonium.

“R ⁴ ” SO ₃ ⁻ ”in the formulas (b-1) to (b-2) is exemplified in the description of V ^{− in} the general formula (a5-0-1) exemplified in the structural unit (a5). The same as “R ⁴ ” SO ₃ ⁻ ”.

  Moreover, as an onium salt type | system | group acid generator, in the said general formula (b-1) or (b-2), an anion part is made into the anion represented by the said general formula (b-3) or (b-4). A substituted onium salt acid generator can also be used (the cation moiety is the same as the cation represented by formula (b-1) or (b-2)).

  Moreover, as an onium salt acid generator, a sulfonium salt having a cation represented by the following general formula (b-5) or (b-6) in the cation part can also be used.

［式中、Ｒ^８１〜Ｒ^８６はそれぞれ独立してアルキル基、アセチル基、アルコキシ基、カルボキシ基、水酸基またはヒドロキシアルキル基であり；ｎ_１〜ｎ_５はそれぞれ独立して０〜３の整数であり、ｎ_６は０〜２の整数である。］

[Wherein R ^{81 to} R ⁸⁶ are each independently an alkyl group, acetyl group, alkoxy group, carboxy group, hydroxyl group or hydroxyalkyl group; n _{1 to} n ₅ are each independently an integer of 0 to 3; There, _{n 6} is an integer of 0-2. ]

In R ^{81 to} R ⁸⁶ , the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group, and a methyl group, an ethyl group, a propyl group, an isopropyl group, n A butyl group or a tert-butyl group is particularly preferable.
The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a linear or branched alkoxy group, and particularly preferably a methoxy group or an ethoxy group.
The hydroxyalkyl group is preferably a group in which one or more hydrogen atoms in the alkyl group are substituted with a hydroxy group, and examples thereof include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group.
When the symbols n _{1 to} n ₆ attached to R ^{81 to} R ⁸⁶ are integers of 2 or more, the plurality of R ^{81 to} R ⁸⁶ may be the same or different.
n ₁ is preferably 0 to 2, more preferably 0 or 1, and still more preferably 0.
n ₂ and n ₃ are preferably each independently 0 or 1, more preferably 0.
n ₄ is preferably 0 to 2, more preferably 0 or 1.
n ₅ is preferably 0 or 1, more preferably 0.
n ₆ is preferably 0 or 1, more preferably 1.

  Preferable examples of the cation represented by the formula (b-5) or the formula (b-6) include those shown below.

Furthermore, a sulfonium salt having a cation represented by the above formula (m1-2), (m1-3) or (m1-4) in the cation part can also be used.
The anion part of the sulfonium salt having a cation represented by the formula (b-5), (b-6), (m1-2) or (m1-3) in the cation part is not particularly limited and has been proposed so far. It may be the same as the anion portion of the onium salt acid generator. Examples of the anion moiety include fluorinated alkyl sulfonate ions such as the anion moiety (R ⁴ ″ SO ₃ ⁻ ) of the onium salt acid generator represented by the general formula (b-1) or (b-2). An anion represented by the general formula (b-3) or (b-4), an anion represented by any one of the formulas (b1) to (b9), and the like.
However, in the present invention, the cation part of the onium salt-based acid generator has only one aromatic ring or no aromatic ring, like M ^{m +} in the general formula (a5-0-2). Is preferred. As an organic cation which has only one aromatic ring or does not have an aromatic ring, the same thing as Mm ⁺ in the said general formula (a5-0-2) is mentioned.

  In this specification, the oxime sulfonate acid generator is a compound having at least one group represented by the following general formula (B-1), and has a property of generating an acid upon irradiation with radiation. is there. Such oxime sulfonate-based acid generators are frequently used for chemically amplified resist compositions, and can be arbitrarily selected and used.

［式（Ｂ−１）中、Ｒ^３１、Ｒ^３２はそれぞれ独立に有機基を表す。］

[In formula (B-1), R ³¹ and R ³² each independently represents an organic group. ]

The organic groups of R ³¹ and R ³² are groups containing carbon atoms, and atoms other than carbon atoms (for example, hydrogen atoms, oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms (fluorine atoms, chlorine atoms, etc.), etc.) You may have.
As the organic group for R ^31, a linear, branched, or cyclic alkyl group or aryl group is preferable. These alkyl groups and aryl groups may have a substituent. There is no restriction | limiting in particular as this substituent, For example, a fluorine atom, a C1-C6 linear, branched or cyclic alkyl group etc. are mentioned. Here, “having a substituent” means that part or all of the hydrogen atoms of the alkyl group or aryl group are substituted with a substituent.
As an alkyl group, C1-C20 is preferable, C1-C10 is more preferable, C1-C8 is more preferable, C1-C6 is especially preferable, and C1-C4 is the most preferable. As the alkyl group, a partially or completely halogenated alkyl group (hereinafter sometimes referred to as a halogenated alkyl group) is particularly preferable. The partially halogenated alkyl group means an alkyl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated alkyl group means that all of the hydrogen atoms are halogen atoms. Means an alkyl group substituted with Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is particularly preferable. That is, the halogenated alkyl group is preferably a fluorinated alkyl group.
The aryl group preferably has 4 to 20 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms. As the aryl group, a partially or completely halogenated aryl group is particularly preferable. The partially halogenated aryl group means an aryl group in which a part of hydrogen atoms is substituted with a halogen atom, and the fully halogenated aryl group means that all of the hydrogen atoms are halogen atoms. Means an aryl group substituted with.
R ³¹ is particularly preferably an alkyl group having 1 to 4 carbon atoms having no substituent or a fluorinated alkyl group having 1 to 4 carbon atoms.
As the organic group for R ^32, a linear, branched, or cyclic alkyl group, aryl group, or cyano group is preferable. As the alkyl group and aryl group for R ^32, the same alkyl groups and aryl groups as those described above for R ³¹ can be used.
R ³² is particularly preferably a cyano group, an alkyl group having 1 to 8 carbon atoms having no substituent, or a fluorinated alkyl group having 1 to 8 carbon atoms.

  More preferable examples of the oxime sulfonate-based acid generator include compounds represented by the following general formula (B-2) or (B-3).

［式（Ｂ−２）中、Ｒ^３３は、シアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３４はアリール基である。Ｒ^３５は置換基を有さないアルキル基またはハロゲン化アルキル基である。］

[In Formula (B-2), R ³³ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁴ is an aryl group. R ³⁵ represents an alkyl group having no substituent or a halogenated alkyl group. ]

In the general formula (B-2), the alkyl group or halogenated alkyl group having no substituent of R ³³ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and carbon atoms. Numbers 1 to 6 are most preferable.
R ³³ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³³ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred.
As the aryl group of R ³⁴ , one hydrogen atom is removed from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthryl group, or a phenanthryl group. And a heteroaryl group in which a part of carbon atoms constituting the ring of these groups is substituted with a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. Among these, a fluorenyl group is preferable.
The aryl group of R ³⁴ may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, or an alkoxy group. The alkyl group or halogenated alkyl group in the substituent preferably has 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. The halogenated alkyl group is preferably a fluorinated alkyl group.
The alkyl group or halogenated alkyl group having no substituent of R ³⁵ preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and most preferably 1 to 6 carbon atoms.
R ³⁵ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.
The fluorinated alkyl group for R ³⁵ is preferably such that the hydrogen atom of the alkyl group is 50% or more fluorinated, more preferably 70% or more fluorinated, and 90% or more fluorinated. Particularly preferred is the strength of the acid generated. Most preferably, it is a fully fluorinated alkyl group in which a hydrogen atom is 100% fluorine-substituted.

［式（Ｂ−３）中、Ｒ^３６はシアノ基、置換基を有さないアルキル基またはハロゲン化アルキル基である。Ｒ^３７は２または３価の芳香族炭化水素基である。Ｒ^３８は置換基を有さないアルキル基またはハロゲン化アルキル基である。ｐ”は２または３である。］

[In Formula (B-3), R ³⁶ represents a cyano group, an alkyl group having no substituent, or a halogenated alkyl group. R ³⁷ is a divalent or trivalent aromatic hydrocarbon group. ^R38 is an alkyl group having no substituent or a halogenated alkyl group. p ″ is 2 or 3.]

In the general formula (B-3), the alkyl group or halogenated alkyl group having no substituent for R ³⁶ is the same as the alkyl group or halogenated alkyl group having no substituent for R ^33. Is mentioned.
Examples of the divalent or trivalent aromatic hydrocarbon group for R ³⁷ include groups obtained by further removing one or two hydrogen atoms from the aryl group for R ³⁴ .
Examples of the alkyl group or halogenated alkyl group having no substituent of R ³⁸ include the same alkyl groups or halogenated alkyl groups as those having no substituent of R ³⁵ .
p ″ is preferably 2.

Specific examples of the oxime sulfonate acid generator include α- (p-toluenesulfonyloxyimino) -benzyl cyanide, α- (p-chlorobenzenesulfonyloxyimino) -benzyl cyanide, α- (4-nitrobenzenesulfonyloxy). Imino) -benzylcyanide, α- (4-nitro-2-trifluoromethylbenzenesulfonyloxyimino) -benzylcyanide, α- (benzenesulfonyloxyimino) -4-chlorobenzylcyanide, α- (benzenesulfonyl) Oxyimino) -2,4-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -2,6-dichlorobenzyl cyanide, α- (benzenesulfonyloxyimino) -4-methoxybenzyl cyanide, α- ( 2-Chlorobenzenesulfonyloxyimino) 4-methoxybenzylcyanide, α- (benzenesulfonyloxyimino) -thien-2-ylacetonitrile, α- (4-dodecylbenzenesulfonyloxyimino) -benzylcyanide, α-[(p-toluenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α-[(dodecylbenzenesulfonyloxyimino) -4-methoxyphenyl] acetonitrile, α- (tosyloxyimino) -4-thienyl cyanide, α- (methylsulfonyloxyimino) -1-cyclo Pentenyl acetonitrile, α- (methylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -1-cycloheptenylacetonitrile, α- (methylsulfonyloxyimino) -1-cyclooctene Acetonitrile, α- (trifluoromethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -cyclohexylacetonitrile, α- (ethylsulfonyloxyimino) -ethylacetonitrile, α- (propyl Sulfonyloxyimino) -propylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclopentylacetonitrile, α- (cyclohexylsulfonyloxyimino) -cyclohexylacetonitrile, α- (cyclohexylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- ( Ethylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclope N-tenyl acetonitrile, α- (n-butylsulfonyloxyimino) -1-cyclopentenylacetonitrile, α- (ethylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (isopropylsulfonyloxyimino) -1-cyclohexenylacetonitrile , Α- (n-butylsulfonyloxyimino) -1-cyclohexenylacetonitrile, α- (methylsulfonyloxyimino) -phenylacetonitrile, α- (methylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (trifluoro Methylsulfonyloxyimino) -phenylacetonitrile, α- (trifluoromethylsulfonyloxyimino) -p-methoxyphenylacetonitrile, α- (ethylsulfonyloxyimino) -p- Butoxy phenylacetonitrile, alpha-(propylsulfonyl oxyimino)-p-methylphenyl acetonitrile, alpha-like (methylsulfonyloxyimino)-p-bromophenyl acetonitrile.
Further, an oxime sulfonate-based acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014] [Chemical 18] to [Chemical 19]), pamphlet of International Publication No. 04/074242, An oxime sulfonate-based acid generator disclosed in Examples 1 to 40) on pages 65 to 86 can also be suitably used.
Moreover, the following can be illustrated as a suitable thing.

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

As the component (B), one type of acid generator described above may be used alone, or two or more types may be used in combination.
When the resist composition of this aspect contains (B) component, 0-60 mass parts is preferable with respect to 100 mass parts of (A) component, and 0-40 mass parts is more preferable. Preferably, 0 to 10 parts by mass is more preferable. When it is 40 parts by mass or less, a uniform solution is obtained when each component of the resist composition is dissolved in an organic solvent, and the storage stability is improved, which is preferable. In particular, when the content is 10 parts by mass or less, it is possible to balance the suppression of the deterioration of the lithography characteristics with respect to the OoB light and the enhancement of sensitivity.

[(D) component]
The resist composition of this embodiment may contain a basic compound (D) (hereinafter also referred to as “component (D)”) as an optional component. In the present invention, the component (D) acts as an acid diffusion control agent, that is, a quencher that traps the acid generated from the component (A), the component (B), etc. by exposure. In the present invention, the “basic compound” refers to a compound that is relatively basic with respect to the component (A) or the component (B).
The component (D) in the present invention may be a basic compound (D1) (hereinafter referred to as “component (D1)”) composed of a cation moiety and an anion moiety, and a base not corresponding to the component (D1). Compound (D2) (hereinafter referred to as “component (D2)”).

-Component (D1) As the component (D1), the compound (d1-1) represented by the following general formula (d1-1) (hereinafter referred to as "(d1-1) component"), the following general formula (d1- 2) (d1-2) (hereinafter referred to as “(d1-2) component”) and a compound (d1-3) represented by the following general formula (d1-3) (hereinafter referred to as “(d1- 3) It is preferably at least one selected from the group consisting of “component”.

［式中、Ｒ^４は置換基を有していてもよい炭化水素基であり、Ｚ^２ｃは置換基を有していてもよい炭素数１〜３０の炭化水素基（ただし、Ｓに隣接する炭素にはフッ素原子は置換されていないものとする）であり、Ｒ^５は有機基であり、Ｙ^５は直鎖状、分岐鎖状若しくは環状のアルキレン基またはアリーレン基であり、Ｒｆ^３はフッ素原子を含む炭化水素基であり、Ｍ^＋はそれぞれ独立にスルホニウム又はヨードニウムカチオンである。］

[Wherein, R ⁴ is a hydrocarbon group which may have a substituent, and Z ^2c is a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent (however, adjacent to S R ⁵ is an organic group, Y ⁵ is a linear, branched or cyclic alkylene group or an arylene group, and Rf ³ is fluorine. It is a hydrocarbon group containing an atom, and each M ⁺ is independently a sulfonium or iodonium cation. ]

.. (d1-1) component.
... Anion moiety In formula (d1-1), R ⁴ is a hydrocarbon group which may have a substituent.
The hydrocarbon group which may have a substituent of R ⁴ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. In the description of the structural unit (a5), the general formula “ Examples thereof include the same groups as those described above for X ³ in the formula: X ³ -Q′— exemplified as the substituent that R ⁴ ″ may have in R ⁴ ″ SO ₃ ⁻ ″.
Among them, the hydrocarbon group which may have a substituent of R ⁴ is an aromatic hydrocarbon group which may have a substituent, or an aliphatic cyclic group which may have a substituent. A phenyl group or naphthyl group which may have a substituent; one or more hydrogen atoms are removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane. More preferably, it is a group.

In addition, the hydrocarbon group which may have a substituent for R ⁴ is preferably a linear or branched alkyl group or a fluorinated alkyl group.
The number of carbon atoms of the linear or branched alkyl group of R ⁴ is preferably 1 to 10, specifically, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, Linear alkyl group such as heptyl group, octyl group, nonyl group, decyl group, 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3- Examples thereof include branched alkyl groups such as methylbutyl group, 1-ethylbutyl group, 2-ethylbutyl group, 1-methylpentyl group, 2-methylpentyl group, 3-methylpentyl group, and 4-methylpentyl group.

The fluorinated alkyl group for R ⁴ may be linear or cyclic, but is preferably linear or branched.
1-11 are preferable, as for carbon number of a fluorinated alkyl group, 1-8 are more preferable, and 1-4 are more preferable. Specifically, for example, a part or all of a linear alkyl group such as methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, etc. Or a branched chain such as a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, or a 3-methylbutyl group. And a group in which some or all of the hydrogen atoms constituting the alkyl group are substituted with fluorine atoms.
Moreover, the fluorinated alkyl group for R ⁴ may contain an atom other than a fluorine atom. Examples of atoms other than fluorine atoms include oxygen atoms, carbon atoms, hydrogen atoms, oxygen atoms, sulfur atoms, and nitrogen atoms.
Among them, the fluorinated alkyl group for R ⁴ is preferably a group in which some or all of the hydrogen atoms constituting the linear alkyl group are substituted with fluorine atoms. It is preferable that all the hydrogen atoms which comprise are the group (perfluoroalkyl group) substituted by the fluorine atom.

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

... Cation moiety In formula (d1-1), M ⁺ is an organic cation.
Although it does not specifically limit as an organic cation of M ^<+> , For example, the thing similar to the cation part of the compound represented by the said Formula (b-1) or (b-2) is mentioned.
As the component (d1-1), one type may be used alone, or two or more types may be used in combination.

-(D1-2) component.
... In the anion moiety (d1-2), Z ^2c is a hydrocarbon group having 1 to 30 carbon atoms which may have a substituent.
The hydrocarbon group having 1 to 30 carbon atoms which may have a substituent of Z ^2c may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and the above formula (d1-1) those in the same manner as R ⁴ of the like.
Among them, the hydrocarbon group which may have a substituent of Z ^2c is preferably an aliphatic cyclic group which may have a substituent, adamantane, norbornane, isobornane, tricyclodecane, It is more preferably a group obtained by removing one or more hydrogen atoms from tetracyclododecane, camphor or the like (which may have a substituent).
Hydrocarbon group of Z ^2c may have a substituent, examples of the substituent include those similar to the substituent in the X ³ -Q'- X ³ medium. However, in Z ^2c , the carbon adjacent to the S atom in SO ₃ ^— is not fluorine-substituted. Since SO ₃ ^— and a fluorine atom are not adjacent to each other, the anion of the component (d1-2) becomes an appropriate weak acid anion, and the quenching ability of the component (D) is improved.
Preferred specific examples of the anion moiety of the component (d1-2) are shown below.

During ... Cation formula (d1-2), ^{M +} is the same as ^{M +} in the formula (d1-1).
As the component (d1-2), one type may be used alone, or two or more types may be used in combination.

-(D1-3) component.
... Anion moiety In formula (d1-3), R ⁵ represents an organic group.
The organic group for R ⁵ is not particularly limited, but is an alkyl group, an alkoxy group, —O—C (═O) —C (R ^C2 ) ═CH ₂ (R ^C2 is a hydrogen atom, a carbon number of 1 to 5 is an alkyl group of 5 or a halogenated alkyl group having 1 to 5 carbon atoms), or —O—C (═O) —R ^C3 (R ^C3 is a hydrocarbon group).
The alkyl group of R ⁵ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group. Tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. A part of hydrogen atoms of the alkyl group of R ² may be substituted with a hydroxyl group, a cyano group, or the like.
The alkoxy group of R ⁵ is preferably an alkoxy group having 1 to 5 carbon atoms. Specific examples of the alkoxy group having 1 to 5 carbon atoms include methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n- Examples include butoxy group and tert-butoxy group. Of these, a methoxy group and an ethoxy group are most preferable.

When R ⁵ is —O—C (═O) —C (R ^C2 ) ═CH ₂ , R ^C2 is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. is there.
The alkyl group having 1 to 5 carbon atoms in R ^C2 is preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, n -Butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like can be mentioned.
The halogenated alkyl group in R ^C2 is 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. 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 ^C2 is preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or a fluorinated alkyl group having 1 to 3 carbon atoms, and is most preferably a hydrogen atom or a methyl group from the viewpoint of industrial availability.

When R ⁵ is —O—C (═O) —R ^C3 , R ^C3 is a hydrocarbon group.
The hydrocarbon group for R ^C3 may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. Specific examples of the hydrocarbon group for R ^C3 include the same groups as those described above for R ⁴ in formula (d1-1).
Among them, as the hydrocarbon group for R ^C3 , an alicyclic group in which one or more hydrogen atoms are removed from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like, or Aromatic groups such as phenyl group and naphthyl group are preferred. When R ^C3 is an alicyclic group, the resist composition is well dissolved in an organic solvent, so that the lithography properties are improved. Further, when R ^C3 is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition is excellent in light absorption efficiency, and sensitivity and lithography characteristics are good.

Among them, as R ⁵ , —O—C (═O) —C (R ^C2 ′) ═CH ₂ (R ^C2 ′ is a hydrogen atom or a methyl group), or —O—C (═O ) -R ^C3 ′ (R ^C3 ′ is an aliphatic cyclic group).

In formula (d1-3), Y ⁵ represents a linear, branched or cyclic alkylene group or an arylene group.
As the linear, branched or cyclic alkylene group or arylene group for Y ⁵ , among the divalent linking groups for Y ^{2 in} the above formula (a1-0-2), “linear or branched chain” And the same as the “cyclic aliphatic hydrocarbon group”, “cyclic aliphatic hydrocarbon group”, and “aromatic hydrocarbon group”.
Among these, Y ⁵ is preferably an alkylene group, more preferably a linear or branched alkylene group, and even more preferably a methylene group or an ethylene group.

In formula (d1-3), Rf ³ represents a hydrocarbon group containing a fluorine atom.
The hydrocarbon group containing a fluorine atom of Rf ³ is preferably a fluorinated alkyl group, and more preferably the same as the fluorinated alkyl group of R ⁴ above.
Preferred specific examples of the anion moiety of the component (d1-3) are shown below.

During ... Cation formula (d1-3), ^{M +} is the same as ^{M +} in the formula (d1-1).
As the component (d1-3), one type may be used alone, or two or more types may be used in combination.

The component (D1) may contain only one of the above components (d1-1) to (d1-3), or may contain two or more. Especially, it is especially preferable to contain (d1-2) component.
The content of the component (D1) is preferably 0.5 to 10.0 parts by mass and more preferably 0.5 to 8.0 parts by mass with respect to 100 parts by mass of the component (A). 1.0 to 8.0 parts by mass is more preferable, and 2.5 to 5.5 parts by mass is particularly preferable. When it is at least the lower limit of the above range, particularly good lithography properties and resist pattern shape can be obtained. When the amount is not more than the upper limit of the above range, the sensitivity can be maintained satisfactorily and the throughput is excellent.

(Method for producing components (d1-1) to (d1-3))
The manufacturing method of (d1-1) component and (d1-2) component is not specifically limited, It can manufacture by a well-known method.
If (d1-3) component manufacturing method is not particularly limited, for example, the formula (d1-3) is R ⁵ in a group having an oxygen atom at the terminal which binds to Y ⁵ By reacting the compound (i-1) represented by the following general formula (i-1) with the compound (i-2) represented by the following general formula (i-2), the following general formula ( The compound (i-3) represented by i-3) is obtained, and the compound (i-3) is reacted with Z ⁻ M ⁺ (i-4) having a desired cation M ⁺ to give a general formula The compound (d1-3) represented by (d1-3) is produced.

［式中、Ｒ^５、Ｙ^５、Ｒｆ^３、Ｍ^＋は、それぞれ、前記一般式（ｄ１−３）中のＲ^５、Ｙ^５、Ｒｆ^３、Ｍ^＋と同じである。Ｒ^５ａはＲ^５から末端の酸素原子を除いた基であり、Ｚ⁻は対アニオンである。］

^{Wherein, R 5, Y 5, Rf} 3, M + , respectively, the general formula (d1-3) ^R 5 ^in, Y ^5, Rf 3, is the same as ^{M +.} R ^5a is a group obtained by removing a terminal oxygen atom from R ⁵ , and Z ⁻ is a counter anion. ]

First, compound (i-1) and compound (i-2) are reacted to obtain compound (i-3).
In formula (i-1), R ^5a is a group obtained by removing a terminal oxygen atom from R ⁵ . In formula (i-2), Y ⁵ and Rf ³ are the same as described above.
As compound (i-1) and compound (i-2), commercially available compounds may be used or synthesized.
The method for obtaining compound (i-3) by reacting compound (i-1) with compound (i-2) is not particularly limited. For example, compound (i- After reacting 2) and compound (i-1) in an organic solvent, the reaction mixture can be washed and recovered.

The acid catalyst in the said reaction is not specifically limited, For example, toluenesulfonic acid etc. are mentioned, The usage-amount is about 0.05-5 mol with respect to 1 mol of compounds (i-2).
The organic solvent in the above reaction may be any material that can dissolve the compound (i-1) and the compound (i-2) as raw materials, and specifically includes toluene and the like. It is preferable that it is 0.5-100 mass parts with respect to (i-1), and it is more preferable that it is 0.5-20 mass parts. A solvent may be used individually by 1 type and may use 2 or more types together.
The amount of compound (i-2) used in the above reaction is usually preferably about 0.5 to 5 mol, more preferably about 0.8 to 4 mol, per 1 mol of compound (i-1).

The reaction time in the above reaction varies depending on the reactivity between the compound (i-1) and the compound (i-2), the reaction temperature, etc., but is usually preferably 1 to 80 hours, more preferably 3 to 60 hours. .
The reaction temperature in the above reaction is preferably 20 ° C to 200 ° C, more preferably about 20 ° C to 150 ° C.

Subsequently, the obtained compound (i-3) and the compound (i-4) are reacted to obtain the compound (d1-3).
In formula (i-4), M ⁺ is the same as described above, and Z ⁻ is a counter anion.
The method of reacting compound (i-3) and compound (i-4) to obtain compound (d1-3) is not particularly limited. For example, the compound is obtained in the presence of a suitable alkali metal hydroxide. It can be carried out by dissolving (i-3) in a suitable organic solvent and water, adding compound (i-4) and reacting with stirring.

The alkali metal hydroxide in the above reaction is not particularly limited, and examples thereof include sodium hydroxide, potassium hydroxide and the like, and the amount used is 0.3 to 1 mol per 1 mol of compound (i-3). About 3 mol is preferable.
Examples of the organic solvent in the above reaction include solvents such as dichloromethane, chloroform, and ethyl acetate, and the amount used is preferably 0.5 to 100 parts by mass with respect to compound (i-3). More preferably, it is 5-20 mass parts. A solvent may be used individually by 1 type and may use 2 or more types together.
The amount of compound (i-4) used in the above reaction is usually preferably about 0.5 to 5 mol, more preferably about 0.8 to 4 mol, relative to 1 mol of compound (i-3).

The reaction time in the above reaction varies depending on the reactivity between the compound (i-3) and the compound (i-4), the reaction temperature, etc., but is usually preferably 1 to 80 hours, more preferably 3 to 60 hours. .
The reaction temperature in the above reaction is preferably 20 ° C to 200 ° C, more preferably about 20 ° C to 150 ° C.
After completion of the reaction, the compound (d1-3) in the reaction solution may be isolated and purified. For isolation and purification, conventionally known methods can be used. For example, concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography, etc. can be used alone or in combination of two or more thereof. it can.

The structure of the compound (d1-3) obtained as described above is as follows: ¹ H-nuclear magnetic resonance (NMR) spectrum method, ¹³ C-NMR spectrum method, ¹⁹ F-NMR spectrum method, infrared absorption (IR) spectrum method. It can be confirmed by a general organic analysis method such as mass spectrometry (MS) method, elemental analysis method, X-ray crystal diffraction method.

-Component (D2) Component (D2) is a compound that is relatively basic with respect to component (A) or component (B), and is an acid diffusion controller, that is, component (A) or (B) It does not specifically limit if it acts as a quencher which traps the acid generated from component, and does not correspond to (D1) component, What is necessary is just to use arbitrarily from a well-known thing. Examples thereof include amines such as aliphatic amines and aromatic amines, among which aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines are preferred.
An aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic groups preferably have 1 to 12 carbon atoms.
Examples of the aliphatic amine include amines (alkylamines or alkylalcoholamines) in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or hydroxyalkyl group having 20 or less carbon atoms, cyclic amines, other amines An aliphatic amine etc. are mentioned.

The alkyl group of the alkylamine may be linear, branched or cyclic.
When the alkyl group is linear or branched, the carbon number thereof is more preferably 2-20, and further preferably 2-8.
When the alkyl group is cyclic (when it is a cycloalkyl group), the carbon number is preferably 3 to 30, more preferably 3 to 20, still more preferably 3 to 15, and 4 to 12 carbon atoms. It is particularly preferred that the number of carbon atoms is 5-10. The alkyl group may be monocyclic or polycyclic. Specific examples include groups in which one or more hydrogen atoms have been removed from monocycloalkane, groups in which one or more hydrogen atoms have been removed from polycycloalkanes such as bicycloalkane, tricycloalkane, and tetracycloalkane. . Specific examples of the monocycloalkane include cyclopentane and cyclohexane. Specific examples of the polycycloalkane include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.
Examples of the alkyl group in the hydroxyalkyl group possessed by the alkyl alcohol amine include the same alkyl groups as those possessed by the alkyl amine.

Specific examples of the alkylamine include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; diethylamine, di-n-propylamine, di-n- Dialkylamines such as heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-hexylamine, tri-n-pentylamine, tri- Examples include trialkylamines such as n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decanylamine, and tri-n-dodecylamine.
Specific examples of the alkyl alcohol amine include diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, tri-n-octanolamine, stearyl diethanolamine, lauryldiethanolamine and the like.
Among these, a trialkylamine having 5 to 10 carbon atoms is more preferable, and tri-n-pentylamine or tri-n-octylamine is particularly preferable.

Examples of the cyclic amine include heterocyclic compounds containing a nitrogen atom as a hetero atom. The heterocyclic compound may be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable. Specifically, 1,5-diazabicyclo [4.3.0] -5-nonene, 1,8-diazabicyclo [5. 4.0] -7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane, and the like.

  Other aliphatic amines include tris (2-methoxymethoxyethyl) amine, tris {2- (2-methoxyethoxy) ethyl} amine, tris {2- (2-methoxyethoxymethoxy) ethyl} amine, tris {2 -(1-methoxyethoxy) ethyl} amine, tris {2- (1-ethoxyethoxy) ethyl} amine, tris {2- (1-ethoxypropoxy) ethyl} amine, tris [2- {2- (2-hydroxy Ethoxy) ethoxy} ethyl] amine, triethanolamine triacetate and the like.

  Aromatic amines include aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, diphenylamine, triphenylamine, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxy. And carbonylpyrrolidine.

As the component (D2), any one type may be used alone, or two or more types may be used in combination.
(D2) A component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component. By setting the content in the above range, the resist pattern shape, the stability over time and the like are improved.

(D) A component may be used individually by 1 type and may be used in combination of 2 or more type.
When the resist composition of this embodiment contains the component (D), the content of the component (D) (the total amount of the component (D1) and the component (D2)) is 100 parts by mass of the component (A). The amount is preferably 0.1 to 15 parts by mass, more preferably 0.3 to 12 parts by mass, and still more preferably 0.5 to 12 parts by mass. When it is at least the lower limit of the above range, lithography properties such as roughness are further improved. Further, a better resist pattern shape can be obtained. When the amount is not more than the upper limit of the above range, the sensitivity can be maintained satisfactorily and the throughput is excellent.

[(E) component]
The resist composition of this embodiment comprises an organic carboxylic acid and phosphorus oxo acid and its derivatives as optional components for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, retention time stability, etc. At least one compound (E) selected from the group (hereinafter referred to as “component (E)”) can be contained.
As the organic carboxylic acid, for example, acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.
Examples of phosphorus oxo acids include phosphoric acid, phosphonic acid, and phosphinic acid. Among these, phosphonic acid is particularly preferable.
Examples of the oxo acid derivative of phosphorus include esters in which the hydrogen atom of the oxo acid is substituted with a hydrocarbon group, and the hydrocarbon group includes an alkyl group having 1 to 5 carbon atoms and 6 to 6 carbon atoms. 15 aryl groups and the like.
Examples of phosphoric acid derivatives include phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.
Examples of phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid-di-n-butyl ester, phenylphosphonic acid, phosphonic acid diphenyl ester, and phosphonic acid dibenzyl ester.
Examples of the phosphinic acid derivatives include phosphinic acid esters such as phenylphosphinic acid.
(E) A component may be used individually by 1 type and may use 2 or more types together.
When the resist composition of this aspect contains (E) component, (E) component is normally used in 0.01-5.0 mass parts with respect to 100 mass parts of (A) component.

  If desired, the resist composition of this embodiment further contains miscible additives such as an additional resin for improving the performance of the resist film, a surfactant for improving coating properties, a dissolution inhibitor, a plasticizer. An agent, a stabilizer, a colorant, an antihalation agent, a dye, and the like can be appropriately added and contained.

[(S) component]
The resist composition of this embodiment can be produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as “(S) component”).
As the component (S), any component can be used as long as it can dissolve each component to be used to form a uniform solution. Conventionally, any one of known solvents for chemically amplified resists can be used. Two or more types can be appropriately selected and used.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; Monohydric alcohols; compounds having an ester bond, such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, monomethyl ether, monoethyl of the polyhydric alcohols or compound having the ester bond Ether alkyl such as ether, monopropyl ether, monobutyl ether or monophenyl ether Derivatives of polyhydric alcohols such as compounds having a propylene glycol monomethyl ether acetate (PGMEA) or propylene glycol monomethyl ether (PGME) among these]; cyclic ethers such as dioxane, methyl lactate, Esters such as ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, Aromatic organics such as dibenzyl ether, phenetol, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, mesitylene A solvent etc. can be mentioned.
These organic solvents may be used independently and may be used as 2 or more types of mixed solvents.
Among these, γ-butyrolactone, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), cyclohexanone, and ethyl lactate (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 component (S) used is not particularly limited, but is a concentration that can be applied to a substrate or the like, and is appropriately set according to the coating film thickness. In general, the solid content concentration of the resist composition is 1 -20% by mass, preferably 2-15% by mass.

The resist composition according to the first aspect of the present invention is excellent in lithography properties such as resolution and exposure margin when forming a resist pattern by EUV exposure or EB exposure, and has a low roughness and a cross section. It is possible to form a resist pattern having a good shape with high rectangularity (higher verticality of the pattern side wall).
This is because the base resin contains the component (A1) into which an acid generation site is introduced, so that the distribution of the acid generation site in the resist film is made uniform, and a resist pattern is formed by EUV exposure or EB exposure. Increased sensitivity when doing so;
Containing the component (A1) having the structural unit (a5) having one or less aromatic ring, which is present in the acid generation site and has absorption with respect to light in the DUV region (in particular, a wavelength of 150 to 300 nm); In addition, when the amount of the monomer for deriving the structural unit (a5) is 100 ppm (mass basis) or less, the absorption of light in the DUV region particularly in the unexposed area is suppressed, or the resist film surface of electrons during EB exposure It is considered that the influence of diffusion (scattering) at the surface is suppressed and the generation of acid due to photosensitivity in the unexposed area is suppressed and the like is acting synergistically.

≪Resist pattern formation method≫
The resist pattern forming method of the present invention includes a step of forming a resist film on the support using the EUV or EB resist composition of the first aspect, a step of exposing the resist film with EUV or EB, And a step of developing the resist film to form a resist pattern.
The resist pattern forming method of the present invention can be performed, for example, as follows.
First, the resist composition of the first aspect of the present invention is applied onto a support with a spinner or the like, and a baking (post-apply bake (PAB)) treatment is performed at a temperature of 80 to 150 ° C., for example, at 40 to 120 ° C. Seconds, preferably 60 to 90 seconds, to form a resist film.
Next, the resist film is exposed by EUV or EB, for example, exposure through a mask (mask pattern) on which a predetermined pattern is formed using an exposure apparatus such as an EB drawing apparatus or an EUV exposure apparatus, or a mask After performing selective exposure such as drawing by direct irradiation of an electron beam without using a pattern, a baking (post-exposure baking (PEB)) treatment is performed, for example, at a temperature of 80 to 150 ° C. for 40 to 120 seconds, preferably Apply for 60-90 seconds.
Next, the resist film is developed. In the case of an alkali development process, an alkali development treatment is performed using an alkali developer, for example, a 0.1 to 10% by mass tetramethylammonium hydroxide (TMAH) aqueous solution. In the case of a solvent development process, development processing is performed using an organic solvent. The organic solvent is not particularly limited as long as it can dissolve the component (A) (component (A) before exposure), and can be appropriately selected from known organic solvents. Specifically, a polar solvent such as a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent, an ether solvent, or a hydrocarbon solvent can be used.
A rinsing treatment is preferably performed after the development treatment. In the case of an alkali development process, water rinsing using pure water is preferable. In the case of the solvent development process, it is preferable to use a rinse solution containing the organic solvent mentioned above.
Thereafter, drying is performed. In some cases, a baking process (post-bake) may be performed after the development process.
In this way, a resist pattern can be obtained. The resist composition of the present invention is particularly suitably used for a method of forming a positive resist pattern by an alkali development process.

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.
Moreover, as a support body, the inorganic type and / or organic type film | membrane may be provided on the above substrates. 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).

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.

Examples of the alkali developer used for the development treatment in the alkali development process include a 0.1 to 10% by mass tetramethylammonium hydroxide (TMAH) aqueous solution.
The organic solvent contained in the organic developer used for the development process in the solvent development process is not particularly limited as long as it can dissolve the component (A) (component (A) before exposure). It can be selected as appropriate. Specifically, polar solvents such as ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, or hydrocarbon solvents can be used, and ester solvents are particularly preferable. As the ester solvent, butyl acetate is preferred.
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.
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.
The development treatment can be carried out by a known development method, for example, a method in which a support is immersed in a developer for a certain period of time (dip method), and the developer is raised on the surface of the support by surface tension and left stationary for a certain period of time. Method (Paddle method), Method of spraying developer on the surface of support (spray method), Continuous application of developer while scanning developer coating nozzle at constant speed on support rotating at constant speed And a method (dynamic dispensing method).

As the organic solvent contained in the rinsing liquid used for the rinsing treatment after the development process in the solvent development process, for example, among the organic solvents mentioned as the organic solvent contained in the organic developer, those which are difficult to dissolve the resist pattern are appropriately used. You can select and use. 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 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 on 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.

EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited by these examples.
In this example, the compound represented by the chemical formula (1) is described as “compound (1)”, and the compounds represented by other chemical formulas are also described in the same manner.

<Synthesis example of component (A)>
[Synthesis Example 1: Synthesis of copolymer (11)]
Step of synthesizing the precursor polymer:
6. 14.00 g (82.28 mmol) of compound (21), 41.84 g (159.48 mmol) of compound (11) in a separable flask connected with a thermometer, a reflux tube and a nitrogen introduction tube; 70 g (25.38 mmol) of the compound (51) was dissolved in 80.53 g of a mixed solvent (EL / GBL = 80/20 (mass ratio)). To this solution, 18.70 mmol of dimethyl azobisisobutyrate (V-601, manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator was added and dissolved.
The resultant was dropwise added to 44.29 g of a mixed solvent (EL / GBL = 80/20 (mass ratio)) heated to 80 ° C. in a nitrogen atmosphere over 4 hours. After completion of dropping, the reaction solution was heated and stirred for 1 hour, and then the reaction solution was cooled to room temperature.
Next, the obtained reaction polymerization solution was dropped into a large amount of isopropanol to perform the operation of precipitating the polymer, and the precipitated white powder (precursor polymer) was separated by filtration.

Washing the precursor polymer with water:
Next, the obtained precursor polymer was dissolved in dichloromethane and washed with water (liquid-liquid extraction). Thereafter, the operation of dropping the polymer again into a large amount of isopropanol was performed, and the precipitated white powder was separated by filtration.
Thereafter, the obtained white powder was dried to obtain 31.77 g of a copolymer (11-0).

Step of salt exchange of precursor polymer after washing with water with organic cation:
The obtained 31.77 g of the copolymer (11-0) was put in an eggplant flask, dissolved in 127.08 g of dichloromethane, and then 7.86 g of the compound for salt exchange (c3) and 127.08 g of water. And stirred for 30 minutes (salt exchange), and then the organic layer was extracted.
Subsequently, the extracted organic layer was washed with water, and the solvent was distilled off to obtain 30.99 g of the target product, copolymer (11).

[Synthesis Examples 2-27: Synthesis of Copolymers (1) to (10), (12) to (20), (22) to (28)]
Copolymers (1) to (10), (12) to (20), and (22) to (28) are steps for synthesizing a precursor polymer in the above [Synthesis of copolymer (11)]. Except that the compounds represented by the following chemical formulas were used as the monomers at a predetermined molar ratio, and the compounds represented by the following chemical formulas (c1) to (c8) were used as the salt exchange compounds, respectively, It was obtained in the same manner as in the method of synthesis of union (11).
The residual monomer amount (monomer amount for deriving the structural unit (a5)) in each copolymer is the mixing time (minutes) of the two layers in the liquid-liquid extraction in the step of washing the precursor polymer with water. It adjusted suitably by changing the frequency | count of shaking a liquid funnel.

[Synthesis Example 28: Synthesis of Copolymer (21)]
In a separable flask connected with a thermometer, a reflux tube and a nitrogen introduction tube, 14.00 g (82.28 mmol) of compound (21), 41.84 g (159.48 mmol) of compound (11), and 16. 21 g (25.38 mmol) of the compound (56) was dissolved in 91.47 g of a mixed solvent (EL / GBL = 80/20 (mass ratio)). To this solution, 18.70 mmol of dimethyl azobisisobutyrate (V-601, manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator was added and dissolved.
The resultant was dropwise added to 50.22 g of a mixed solvent (EL / GBL = 80/20 (mass ratio)) heated to 80 ° C. over 4 hours under a nitrogen atmosphere. After completion of dropping, the reaction solution was heated and stirred for 1 hour, and then the reaction solution was cooled to room temperature.
Next, the obtained reaction polymerization liquid was dropped into a large amount of isopropanol to perform the operation of precipitating the polymer, and the precipitated white powder was separated by filtration, then washed with methanol and dried. As a result, a copolymer (21) was obtained.

  Table 1 shows the monomers and salt exchange compounds used in the synthesis of each copolymer; and the washing solvent used to remove unreacted monomers during the synthesis.

<Preparation of resist composition>
(Examples 1-18, Comparative Examples 1-10)
Each component shown in Tables 2 and 3 was mixed and dissolved to prepare a resist composition.
In Tables 2 and 3, “monomer amount (ppm) for deriving structural unit (a5)” indicates the monomer amount (mass basis) for deriving structural unit (a5) with respect to the copolymer as component (A). .

In Tables 2 and 3, each abbreviation has the following meaning. The numerical value in [] is a compounding amount (part by mass).
(A) -1 to (A) -28: Copolymers (1) to (28) represented by the following chemical formulas (A) -1 to (A) -28, respectively.
(B) -1: a compound represented by the following chemical formula (B) -1.
(S) -1: γ-butyrolactone.
(S) -2: Mixed solvent of PGMEA / PGME / cyclohexanone = 1500/1000/2500 (mass ratio).

Regarding the component (A), the copolymer composition ratio of each copolymer (ratio of each structural unit in the chemical formula (molar ratio)), mass average molecular weight (Mw) and molecular weight dispersity (Mw / Mn) are shown below together with the chemical formula. Show.
The weight average molecular weight (Mw) and molecular weight dispersity (Mw / Mn) of each copolymer are values in terms of standard polystyrene determined by GPC measurement. The copolymer composition ratio (ratio (molar ratio) of each structural unit in the structural formula) of each copolymer was determined by carbon 13 nuclear magnetic resonance spectrum (600 MHz — ¹³ C-NMR). The internal standard for ¹³ C-NMR is tetramethylsilane (TMS).

（Ａ）−１：ｌ/ｍ/ｎ＝４５/４１/１４，Ｍｗ１３１００，Ｍｗ/Ｍｎ１．７０
（Ａ）−２：ｌ/ｍ/ｎ＝４５/４１/１４，Ｍｗ１３１００，Ｍｗ/Ｍｎ１．７０
（Ａ）−３：ｌ/ｍ/ｎ＝４５/４１/１４，Ｍｗ１３０００，Ｍｗ/Ｍｎ１．６８
（Ａ）−４：ｌ/ｍ/ｎ＝４５/４１/１４，Ｍｗ１３０００，Ｍｗ/Ｍｎ１．６８

(A) -1: l / m / n = 45/41/14, Mw13100, Mw / Mn1.70
(A) -2: l / m / n = 45/41/14, Mw13100, Mw / Mn1.70
(A) -3: l / m / n = 45/41/14, Mw13000, Mw / Mn1.68
(A) -4: l / m / n = 45/41/14, Mw13000, Mw / Mn1.68

（Ａ）−５：ｌ/ｍ/ｎ＝４５/４１/１４，Ｍｗ１２９００，Ｍｗ/Ｍｎ１．６８
（Ａ）−１１：ｌ/ｍ/ｎ＝４５/４１/１４，Ｍｗ１２９００，Ｍｗ/Ｍｎ１．６８
（Ａ）−７：ｌ/ｍ/ｎ＝４５/４１/１４，Ｍｗ１２９００，Ｍｗ/Ｍｎ１．６９
（Ａ）−１２：ｌ/ｍ/ｎ＝４５/４１/１４，Ｍｗ１２９００，Ｍｗ/Ｍｎ１．６９

(A) -5: l / m / n = 45/41/14, Mw12900, Mw / Mn1.68
(A) -11: 1 / m / n = 45/41/14, Mw12900, Mw / Mn1.68
(A) -7: l / m / n = 45/41/14, Mw12900, Mw / Mn1.69
(A) -12: l / m / n = 45/41/14, Mw12900, Mw / Mn1.69

（Ａ）−９：ｌ/ｍ/ｎ＝４４/４２/１４，Ｍｗ１２１００，Ｍｗ/Ｍｎ１．８０
（Ａ）−１３：ｌ/ｍ/ｎ＝４４/４２/１４，Ｍｗ１２１００，Ｍｗ/Ｍｎ１．８０
（Ａ）−１４：ｌ/ｍ/ｎ＝４５/４１/１４，Ｍｗ１３４００，Ｍｗ/Ｍｎ１．６５

(A) -9: l / m / n = 44/42/14, Mw12100, Mw / Mn1.80
(A) -13: l / m / n = 44/42/14, Mw12100, Mw / Mn1.80
(A) -14: l / m / n = 45/41/14, Mw13400, Mw / Mn1.65

（Ａ）−６：ｌ/ｍ/ｎ＝４５/４１/１４，Ｍｗ１２９００，Ｍｗ/Ｍｎ１．６７
（Ａ）−１５：ｌ/ｍ/ｎ＝４５/４１/１４，Ｍｗ１２９００，Ｍｗ/Ｍｎ１．６７
（Ａ）−１６：ｌ/ｍ/ｎ＝４５/４１/１４，Ｍｗ１３０００，Ｍｗ/Ｍｎ１．７０

(A) -6: l / m / n = 45/41/14, Mw12900, Mw / Mn1.67
(A) -15: l / m / n = 45/41/14, Mw12900, Mw / Mn1.67
(A) -16: l / m / n = 45/41/14, Mw13000, Mw / Mn1.70

（Ａ）−１７：ｌ/ｍ/ｎ＝４４/４２/１４，Ｍｗ１２１００，Ｍｗ/Ｍｎ１．６０
（Ａ）−８：ｌ/ｍ/ｎ＝４５/４２/１３，Ｍｗ１１９００，Ｍｗ/Ｍｎ１．８０
（Ａ）−１８：ｌ/ｍ/ｎ＝４５/４２/１３，Ｍｗ１１９００，Ｍｗ/Ｍｎ１．８０

(A) -17: l / m / n = 44/42/14, Mw12100, Mw / Mn1.60
(A) -8: l / m / n = 45/42/13, Mw11900, Mw / Mn1.80
(A) -18: l / m / n = 45/42/13, Mw11900, Mw / Mn1.80

（Ａ）−１９：ｌ/ｍ/ｎ＝４５/４２/１３，Ｍｗ１１９００，Ｍｗ/Ｍｎ１．８０
（Ａ）−２０：ｌ/ｍ/ｎ＝４５/４２/１３，Ｍｗ１１９００，Ｍｗ/Ｍｎ１．８０

(A) -19: l / m / n = 45/42/13, Mw11900, Mw / Mn1.80
(A) -20: l / m / n = 45/42/13, Mw11900, Mw / Mn1.80

（Ａ）−２１：ｌ/ｍ/ｎ＝４４/４２/１４，Ｍｗ１２５００，Ｍｗ/Ｍｎ１．７２
（Ａ）−２２：ｌ/ｍ/ｎ/ｏ＝３０/３０/３０/１０，Ｍｗ１０７００，Ｍｗ/Ｍｎ１.６０

(A) -21: l / m / n = 44/42/14, Mw12500, Mw / Mn1.72
(A) -22: l / m / n / o = 30/30/30/10, Mw10700, Mw / Mn1.60

（Ａ）−１０：ｌ/ｍ/ｎ/ｏ＝３０/３０/３０/１０，Ｍｗ１０７００，Ｍｗ/Ｍｎ１.６０
（Ａ）−２３：ｌ/ｍ/ｎ/ｏ＝３０/３０/３０/１０，Ｍｗ１０７００，Ｍｗ/Ｍｎ１.６０
（Ａ）−２４：ｌ/ｍ/ｎ/ｏ/ｐ＝１１/２５/３５/１５/１４，Ｍｗ１２５００，Ｍｗ/Ｍｎ１.７５

(A) -10: 1 / m / n / o = 30/30/30/10, Mw10700, Mw / Mn1.60
(A) -23: l / m / n / o = 30/30/30/10, Mw10700, Mw / Mn1.60
(A) -24: l / m / n / o / p = 11/25/35/15/14, Mw12500, Mw / Mn1.75

（Ａ）−２５：ｌ/ｍ/ｎ＝４６/４０/１４，Ｍｗ１２６００，Ｍｗ/Ｍｎ１.６７
（Ａ）−２６：ｌ/ｍ/ｎ/ｏ＝３０/３０/３０/１０，Ｍｗ１０４００，Ｍｗ/Ｍｎ１.６０

(A) -25: 1 / m / n = 46/40/14, Mw12600, Mw / Mn1.67
(A) -26: 1 / m / n / o = 30/30/30/10, Mw10400, Mw / Mn1.60

（Ａ）−２７：ｌ/ｍ/ｎ/ｏ/ｐ＝１４/２６/３５/１２/１３，Ｍｗ１２０００，Ｍｗ/Ｍｎ１.６１
（Ａ）−２８：ｌ/ｍ/ｎ/ｏ＝３４/３４/１８/１４，Ｍｗ１３０００，Ｍｗ/Ｍｎ１.７７

(A) -27: 1 / m / n / o / p = 14/26/35/12/13, Mw 12000, Mw / Mn 1.61
(A) -28: l / m / n / o = 34/34/18/14, Mw13000, Mw / Mn1.77

<Measurement of monomer amount for deriving structural unit (a5)>
The monomer amount for deriving the structural unit (a5) was measured by the following procedure.
Procedure 1: HPLC measurement was performed on solutions having different concentrations (5 points) in which the monomer for deriving the structural unit (a5) was dissolved in γ-butyrolactone, and a calibration curve was prepared. The relational expression of “concentration” was obtained.
Procedure 2: For Synthesis Examples 1 to 27, the synthesis product (copolymer before salt exchange) obtained in the above-mentioned “step of washing precursor polymer with water” was used. Each synthesized product was dissolved in γ-butyrolactone to prepare a 1% by mass solution.
Procedure 3: HPLC measurement was performed on a solution having a concentration of 1% by mass, and the monomer amount (ppm, based on mass) relative to the solid content of the copolymer was calculated from the above relational expression. The results are shown in Tables 2 and 3 as “monomer amount (ppm) for deriving the structural unit (a5)”.

As a monomer for deriving the structural unit (a5),
Compounds (51) to (56),
This corresponds to a compound obtained by exchanging the cation part of each of the compounds (51) to (55) with the cation part of the corresponding salt exchange compound (c1) to (c8).
The HPLC measurement was performed under the following measurement conditions.
[HPLC measurement conditions]
Developing solvent: acetonitrile / buffer solution (80/20 volume ratio),
Buffer solution: trifluoroacetic acid / ion exchanged water (0.1 room weight%),
Column: Superiorex-ODS,
Oven temperature: 30 ° C
Measurement wavelength: 210 nm,
Flow rate: 1 mL / min (up to 7 minutes) 3 mL / min (up to 20 minutes).
The mixing ratio of the developing solvent for HPLC was appropriately changed between acetonitrile / buffer solution = 90 / 10-30 / 70 volume ratio according to the type of monomer used.

The following evaluation was performed using the obtained resist composition.
<Formation of resist pattern>
The resist composition of each example was uniformly applied using a spinner on an 8-inch silicon substrate subjected to hexamethyldisilazane (HMDS) treatment at 90 ° C. for 36 seconds, and the baking temperature shown in Table 4 was 60 ° C. A second baking process (PAB) was performed to form a resist film (film thickness 60 nm). The resist film is drawn (exposed) at an accelerating voltage of 70 kV using an electron beam lithography machine HL800D (VSB) (manufactured by Hitachi), and subjected to a baking process (PEB) for 60 seconds at the baking temperature shown in Table 4. Further, alkali development was performed at 23 ° C. for 60 seconds using a 2.38 mass% aqueous solution of tetramethylammonium hydroxide (TMAH) (trade name: NMD-3, manufactured by Tokyo Ohka Kogyo Co., Ltd.).
As a result, in each example, a line-and-space resist pattern (hereinafter referred to as “LS pattern”) having a line width of 100 nm and a pitch of 200 nm was formed.

[Evaluation of sensitivity]
The optimum exposure dose Eop (μC / cm ² ) at which the LS pattern is formed was determined. The results are shown in Table 4.

[Evaluation of line width roughness (LWR)]
With respect to the LS pattern having a line width of 100 nm and a pitch of 200 nm formed in the above <resist pattern formation>, 3σ, which is a measure indicating LWR, was obtained.
“3σ” is a standard obtained from a measurement result obtained by measuring 400 line widths in the longitudinal direction of a line with a scanning electron microscope (acceleration voltage 800 V, trade name: S-9220, manufactured by Hitachi High-Technologies Corporation). The triple value (3 s) (unit: nm) of the deviation (σ) is shown. The smaller the value of 3s, the smaller the roughness of the line side wall, which means that an LS pattern having a more uniform width was obtained. The results are shown in Table 4 as “LWR (nm)”.

[Evaluation of exposure margin (10% EL)]
In the above <resist pattern formation>, the exposure amount when the line of the LS pattern is formed within a range of ± 10% (90 nm to 110 nm) of the target dimension (line width 100 nm) is obtained. The degree (unit:%) was determined.
The exposure margin indicates that the larger the value is, the smaller the change amount of the pattern size with the fluctuation of the exposure amount. The results are shown in Table 4 as “10% EL (%)”.
Exposure margin (%) = (| E1-E2 | / Eop) × 100
In the formula, E1 represents an exposure amount (μC / cm ² ) when an LS pattern having a line width of 90 nm is formed, and E2 represents an exposure amount (μC / cm ² ) when an LS pattern having a line width of 110 nm is formed. .

[Evaluation of resolution]
The limiting resolution (nm) in the Eop was determined using a scanning electron microscope S-9380 (manufactured by Hitachi High-Technology Corporation). The results are shown in Table 4 as “resolution (nm)”.

[Evaluation of resist pattern shape]
The cross-sectional shape of the LS pattern having a line width of 100 nm and a pitch of 200 nm formed in the above <resist pattern formation> was observed using a scanning electron microscope (trade name: SU-8000, manufactured by Hitachi High-Technologies Corporation), and the shape Was evaluated according to the following evaluation criteria. The results are shown in Table 4.
(Evaluation criteria)
○: High rectangularity and good shape.
X: Film reduction was observed.

From the results shown in Table 4, each of the resist compositions of Examples 1 to 18 has a low LWR, a large exposure margin, excellent resolution, and lithography characteristics as compared with the resist compositions of Comparative Examples 1 to 10. It was confirmed that the film had a good shape and a good rectangular shape.
Further, from the comparison between Examples 1, 5, 2, 8, 3, 13 and Comparative Examples 5 to 10 (composition is the same, only the amount of monomer that induces structural unit (a5) is different), the structural unit ( The resist composition of the example in which the monomer amount for deriving a5) is 100 ppm or less has a good lithography property as compared with the resist composition of the comparative example in which the monomer amount exceeds 100 ppm, and in addition, a rectangular shape. It turns out that it is a good shape with high property.

Claims (3)

An EUV or EB resist composition containing a base material component (A) that generates an acid upon exposure and changes its solubility in a developer due to the action of the acid,
The base component (A) is a polymer (A1) having a structural unit (a5) containing a group represented by the following general formula (a5-0-1) or general formula (a5-0-2). Contains,
The resist composition for EUV or EB, wherein the monomer amount for deriving the structural unit (a5) is 100 ppm (mass basis) or less with respect to the polymer (A1).

[Wherein, Q ¹ and Q ² are each independently a single bond or a divalent linking group. R ³ , R ⁴ and R ⁵ are each independently an organic group, and R ⁴ and R ⁵ may be bonded to each other to form a ring together with the sulfur atom in the formula. However, group -R ^{< 3 >} -S ^<+> (R ^{< 4 >} ) (R ^{< 5 >} ) in a formula has only one aromatic ring as a whole, or does not have an aromatic ring. V ⁻ is a counter anion. A ^- is an organic group containing anion. M ^{m +} is an m-valent organic cation, and m is an integer of 1 to 3. However, M ^{m +} has only one aromatic ring or no aromatic ring. ]   The resist composition for EUV or EB according to claim 1, wherein the polymer (A1) has a structural unit (a1) containing an acid-decomposable group whose polarity is increased by the action of an acid.   A step of forming a resist film on the support using the resist composition for EUV or EB according to claim 1, a step of exposing the resist film by EUV or EB, and developing the resist film A resist pattern forming method including a step of forming a resist pattern.