JP6726449B2 - Method for forming resist pattern, shrink agent composition and method for producing shrink agent composition - Google Patents

Description

The present invention relates to a resist pattern forming method, a shrink agent composition, and a method for producing a shrink agent composition.

In the lithography technique, for example, a resist film made of a resist material is formed on a substrate, and the resist film is selectively exposed to radiation such as light or an electron beam through a mask on which a predetermined pattern is formed. And performing a development process to form a resist pattern having a predetermined shape on the resist film.
A resist material in which the exposed portion changes to a characteristic that dissolves in a developing solution is called a positive type, and a resist material in which the exposed portion changes to a characteristic that does not dissolve in a developing solution is called a negative type.
2. Description of the Related Art In recent years, in the manufacture of semiconductor devices and liquid crystal display devices, miniaturization of patterns has been rapidly advanced due to the progress of lithography technology.
As a method of miniaturization, generally, the wavelength of an exposure light source is shortened (energy is increased). Specifically, conventionally, ultraviolet rays typified by g-line and i-line have been used, but now, mass production of semiconductor elements using KrF excimer laser or ArF excimer laser has started. Further, electron beams, EUV (extreme ultraviolet), X-rays, etc. having a shorter wavelength (high energy) than these excimer lasers are also being studied.

As a method of providing a finer pattern, a method of shrinking the hole pattern by making the pattern thicker has been proposed.
For example, Patent Document 1 describes a composition containing a polymer of allylamine as a composition for coating a resist pattern and thickening the pattern.
Patent Document 2 describes a method of forming a fine pattern by thickening a resist pattern using an amine-based polymer.

Japanese Patent Publication No. 2008-518260 JP, 2013-83818, A

However, in the inventions described in Patent Documents 1 and 2, there is room for improvement in order to obtain a fine pattern with a reduced pattern.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a resist pattern forming method capable of obtaining a good fine pattern by reducing the pattern.

A first aspect of the present invention includes a step A of forming a first resist pattern on a support, a step B of applying a shrink agent composition so as to cover the first resist pattern, and the step of A step C of forming a developer insoluble region on the surface of the first resist pattern coated with the shrink agent composition obtained in B, and a step D of developing the coated first resist pattern, And the degree of dispersion (weight average molecular weight/number average molecular weight) of the polymer compound (X) is 1.5 or less. And a resist pattern forming method.
A second aspect of the present invention is a shrink agent composition used for coating a resist pattern and increasing the thickness of the resist pattern, which comprises the polymer compound (X), The shrinkage agent composition is characterized in that the degree of dispersion (X) (weight average molecular weight/number average molecular weight) is 1.5 or less.
A third aspect of the present invention is a method for producing the shrink agent composition according to the second aspect of the present invention, which has a step of purifying by reprecipitation.

According to the present invention, it is possible to provide a resist pattern forming method capable of obtaining a good fine pattern by reducing the pattern.

It is a figure which shows an example of the schematic process of the resist pattern formation method of this invention.

In the present specification and claims, "aliphatic" is defined as a concept relative to aromatic and means a group, compound or the like having no aromaticity.
Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups.
Unless otherwise specified, the "alkylene group" includes linear, branched and cyclic divalent saturated hydrocarbon groups. The same applies to the alkyl group in the alkoxy group.
The “halogenated alkyl group” is a group in which a part or all of hydrogen atoms of an alkyl group are substituted with a halogen atom, and the halogen atom includes a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.
The “fluorinated alkyl group” or “fluorinated alkylene group” refers to a group in which part or all of the hydrogen atoms of the alkyl group or alkylene group are substituted with fluorine atoms.
The "structural unit" means a monomer unit (monomer unit) that constitutes a high molecular compound (resin, polymer, copolymer).
The “structural unit derived from an acrylate ester” means a constitutional unit formed by cleavage of an ethylenic double bond of an acrylate ester.
The “acrylic acid ester” is a compound in which a hydrogen atom at the carboxy group end of acrylic acid (CH ₂ ═CH—COOH) is substituted with an organic group.
In the acrylate ester, the hydrogen atom bonded to the carbon atom at the α-position may be substituted with a substituent. The substituent (R ^α ) for substituting the hydrogen atom bonded to the carbon atom at the α-position is an atom or a group other than a hydrogen atom, and is, for example, an alkyl group having 1 to 5 carbon atoms or a halogenated group having 1 to 5 carbon atoms. Examples thereof include an alkyl group and a hydroxyalkyl group. The α-position carbon atom of the acrylate ester is a carbon atom to which a carbonyl group is bonded, unless otherwise specified.
Hereinafter, an acrylic acid 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 an α-substituted acrylic acid ester. In addition, the acrylic ester and the α-substituted acrylic ester may be collectively referred to as “(α-substituted) acrylic ester”.
The "structural unit derived from a hydroxystyrene derivative" means a structural unit formed by cleavage of an ethylenic double bond of hydroxystyrene or a hydroxystyrene derivative.
The “hydroxystyrene derivative” is a concept including hydroxystyrene in which the hydrogen atom at the α-position is substituted with another substituent such as an alkyl group and a halogenated alkyl group, and derivatives thereof. As those derivatives, those obtained by substituting the hydrogen atom of the hydroxyl group of hydroxystyrene with an organic group which may substitute the hydrogen atom at the α-position with an organic group, or even if the hydrogen atom at the α-position is substituted with a substituent Examples thereof include those in which a substituent other than a hydroxyl group is bonded to the benzene ring of good hydroxystyrene. The α-position (carbon atom at the α-position) refers to the carbon atom to which the benzene ring is bonded, unless otherwise specified.
As the substituent for substituting the hydrogen atom at the α-position of hydroxystyrene, the same substituents as those mentioned above as the α-substituent for the α-substituted acrylate ester can be mentioned.
The “constituent unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative” means a constituent unit formed by cleavage of the ethylenic double bond of vinylbenzoic acid or a vinylbenzoic acid derivative.
The term “vinyl benzoic acid derivative” includes vinyl benzoic acid in which the α-position hydrogen atom is substituted with another substituent such as an alkyl group and a halogenated alkyl group, and a derivative thereof. Those derivatives include those in which the hydrogen atom of the carboxy group of vinylbenzoic acid, which may have a hydrogen atom at the α-position substituted by an organic group, and the hydrogen atom at the α-position are substituted by a substituent. And the like. Examples thereof include vinyl benzoic acid having a benzene ring to which a substituent other than a hydroxyl group and a carboxy group is bonded. The α-position (carbon atom at the α-position) refers to the carbon atom to which the benzene ring is bonded, unless otherwise specified.
The “styrene derivative” means one in which the hydrogen atom at the α-position of styrene is substituted with another substituent such as an alkyl group or a halogenated alkyl group.
The "structural unit derived from styrene" and "structural unit derived from styrene derivative" mean a structural unit formed by cleavage of the ethylenic double bond of styrene or a styrene derivative.
The alkyl group as the α-position substituent is preferably a linear or branched alkyl group, specifically, an alkyl group having 1 to 5 carbon atoms (methyl group, ethyl group, propyl group, isopropyl group , N-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group) and the like.
The halogenated alkyl group as the α-position substituent is specifically a group in which a part or all of the hydrogen atoms of the above-mentioned “alkyl group as the α-position substituent” is replaced with a halogen atom. To be 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.
Specific examples of the hydroxyalkyl group as the α-position substituent include groups in which a part or all of the hydrogen atoms of the above-mentioned “alkyl group as the α-position substituent” are substituted with hydroxyl groups. 1-5 are preferable and, as for the number of the hydroxyl groups in this hydroxyalkyl group, 1 is the most preferable.
Be referred to as a "may have a substituent", the case of replacing a hydrogen atom (-H) a monovalent group, methylene group - when substituting a divalent radical (-CH ₂₎ Including both.
“Exposure” is a concept that includes all radiation irradiation.

<<Method of forming resist pattern>>
The present invention was obtained in the step A of forming a first resist pattern on a support, the step B of applying a shrink agent composition so as to cover the first resist pattern, and the step B. And a step C of forming a developer insoluble region on the surface of the first resist pattern coated with the shrink agent composition, and a step D of developing the coated first resist pattern. A resist pattern, wherein the shrink agent composition contains the polymer compound (X) and the dispersity (weight average molecular weight/number average molecular weight) of the polymer compound (X) is 1.5 or less. It is a forming method.

[Process A]
The resist pattern forming method of the present invention includes a step A of forming a first resist pattern on a support.
Step A is a step of forming a resist film on a support, exposing the resist film, and developing the resist film to form a first resist pattern.
[Support]
The support is not particularly limited, and a conventionally known support can be used, and examples thereof include a substrate for electronic parts, and a support having a predetermined wiring pattern formed thereon. More specifically, a silicon wafer, a substrate made of metal such as copper, chromium, iron, and aluminum, a glass substrate, or the like can be given. As the material of the wiring pattern, for example, copper, aluminum, nickel, gold or the like can be used.
Further, the support may be the above-mentioned substrate provided with an inorganic and/or organic film. Examples of the inorganic film include an inorganic antireflection film (inorganic BARC). 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 multi-layer resist method means that 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. It is a method of patterning the lower organic film and is said to be capable of forming a pattern with a high aspect ratio. That is, according to the multi-layer resist method, since the required thickness can be secured by the lower organic film, the resist film can be thinned and a fine pattern with a high aspect ratio can be formed.
The multilayer resist method basically includes a method of forming a two-layer structure of an upper resist film and a lower organic film (two-layer resist method), and one or more intermediate layers between the upper resist film and the lower organic film. It is divided into a method of forming a multi-layer structure of three or more layers (three-layer resist method) provided with (metal thin film etc.).

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

The exposure method of the resist film may be either normal exposure (dry exposure) performed in an inert gas such as air or nitrogen, or liquid immersion exposure (Liquid Immersion Lithography).
In the 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 higher 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 higher than that of air and lower than that of the resist film to be exposed is preferable. The refractive index of the solvent is not particularly limited as long as it falls within the above range.
Examples of the solvent having a refractive index higher than that of air and lower than that 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, 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 within the above range because 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 the hydrogen atoms of the alkyl group are replaced 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.), and examples of the perfluoroalkylamine compound include perfluorotributylamine( The boiling point is 174° C.).
As the liquid immersion medium, water is preferably used from the viewpoints of cost, safety, environmental problems, versatility and the like.

The development may be an alkali development process or an organic solvent-based development process.
Examples of the alkaline developer used for the developing treatment in the alkaline developing process include an aqueous solution of tetramethylammonium hydroxide (TMAH) of 0.1 to 10% by mass.
Known additives may be added to the organic developer as needed. Examples of the additive include a surfactant. The surfactant is not particularly limited, but for example, an ionic or nonionic fluorine-based and/or silicon-based surfactant can be used.
When the surfactant is blended, the blending amount thereof is usually 0.001 to 5% by mass, preferably 0.005 to 2% by mass, and 0.01 to 0. 5% by mass is more preferable.

The development treatment can be carried out by a known development method, for example, a method of immersing the support in a developing solution for a certain period of time (dip method), or raising the developing solution to the surface of the support by surface tension and then standing still for a certain period of time. Method (paddle method), spraying the developer on the surface of the support (spray method), and applying the developer while scanning the developer application nozzle at a constant speed on the support rotating at a constant speed. A continuous method (dynamic dispensing method) and the like can be mentioned.

The rinse treatment (washing treatment) using the rinse liquid can be carried out by a known rinse method. Examples of the method include a method in which the rinse solution is continuously applied onto the support rotating at a constant speed (rotational coating method), a method in which the support is immersed in the rinse solution for a certain period of time (dip method), and the surface of the support. And a method of spraying a rinse liquid on the surface (spray method).

<Resist composition>
Hereinafter, the resist composition for forming the resist pattern will be described.
In the present invention, the resist composition is preferably a resist composition which generates an acid upon exposure and whose solubility in a developing solution is changed by the action of the acid.
In the present invention, the resist composition preferably contains a base component (A) whose solubility in a developing solution is changed by the action of an acid (hereinafter also referred to as “(A) component”).
When a resist film is formed using such a resist composition and the resist film is selectively exposed, an acid is generated in the exposed area, and the action of the acid causes the solubility of the component (A) in a developing solution. On the other hand, the solubility of the component (A) in the developing solution does not change in the unexposed area, but a difference in solubility in the developing solution occurs between the exposed area and the unexposed area. Therefore, when the resist film is developed, the exposed portion is dissolved and removed to form a positive resist pattern when the resist composition is a positive type, and the unexposed portion is dissolved when the resist composition is a negative type. The resist pattern is removed to form a negative resist pattern.
In the present 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 which forms a negative resist pattern in which an unexposed portion is dissolved and removed. Is referred to as a negative resist composition.
In the present invention, the resist composition may be either a positive resist composition or a negative resist composition.
Further, in the present invention, the resist composition may be for an alkali developing process in which an alkali developing solution is used for the developing treatment at the time of forming a resist pattern, and a developing solution containing an organic solvent in the developing treatment (organic developing solution). May be used for a solvent development process, but is preferably for a solvent development process.

The resist composition used for forming the resist pattern has an acid generating ability to generate an acid upon exposure, and the component (A) may generate an acid upon exposure, and separately from the component (A). The compounded additive component may generate an acid upon exposure.
Specifically, in the present invention, the resist composition is
(1) It may contain an acid generator component (B) that generates an acid upon exposure (hereinafter referred to as “(B) component”);
(2) The component (A) may be a component which generates an acid upon exposure to light;
(3) The component (A) may be a component that generates an acid upon exposure, and may further contain the component (B).
That is, in the cases of the above (2) and (3), the component (A) becomes “a base material component which generates an acid upon exposure and whose solubility in a developing solution is changed by the action of the acid”. When the component (A) is a base material component that generates an acid upon exposure to light and the solubility of the developer changes by the action of the acid, the component (A1) described below generates an acid upon exposure to light, and A polymer compound whose solubility in a developing solution is changed by the action of an acid is preferable. As such a polymer compound, a resin having a structural unit that generates an acid upon exposure can be used. As the structural unit that generates an acid upon exposure, a known unit can be used.
In the present invention, the resist composition is particularly preferably the case (1) above.

<(A) component>
In the present invention, the “base material 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, in addition, a nano-level photosensitive resin pattern is easily formed.
The organic compound used as the base material component is roughly classified into a non-polymer and a polymer.
As the non-polymer, one having a molecular weight of 500 or more and less than 4000 is usually used. Hereinafter, the term "low molecular weight compound" refers to a non-polymer having a molecular weight of 500 or more and less than 4000.
As the polymer, a polymer having a molecular weight of 1,000 or more is usually used. Hereinafter, the term "resin" refers to a polymer having a molecular weight of 1000 or more.
As the molecular weight of the polymer, a polystyrene-equivalent weight average molecular weight by GPC (gel permeation chromatography) is used.
As the component (A), a resin may be used, a low molecular weight compound may be used, or these may be used in combination.
The component (A) is one whose solubility in a developing solution is increased by the action of acid.
Moreover, in the present invention, the component (A) may generate an acid upon exposure.

In the present invention, the component (A) is a structural unit containing an acid-decomposable group whose polarity is increased by the action of an acid (hereinafter sometimes referred to as “structural unit (a1)”) and a —SO ₂ — containing cyclic structure. A polymer compound (A1) having a structural unit having a group, a lactone-containing cyclic group, a carbonate-containing cyclic group, or a heterocyclic group other than these (hereinafter, may be referred to as “structural unit (a2)”). It is preferable to include.

(Structural unit (a1))
The structural unit (a1) is a structural unit containing an acid-decomposable group whose polarity increases due to the action of an acid.
The "acid-decomposable group" is an acid-decomposable group capable of cleaving at least a part of the 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 groups that decompose to form a polar group by the action of an acid.
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.
Specific examples of the acid-decomposable group include groups 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).
Here, the "acid dissociable group" means
(I) an acid dissociable group capable of cleaving the bond between the acid dissociable group and an atom adjacent to the acid dissociable group by the action of an acid, or
(Ii) A group capable of cleaving a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by further decarboxylation reaction after a part of the bond is cleaved by the action of an acid. ,
To both sides.
The acid-dissociable group constituting the acid-decomposable group needs to be a group having a lower polarity than the polar group generated by dissociation of the acid-dissociable group. When is dissociated, a polar group having a higher polarity than the acid dissociable group is generated and the polarity is increased. As a result, the polarity of the entire component (A1) increases. The increase in polarity relatively changes the solubility in the developing solution, and decreases the solubility when the developing solution is an organic developing solution.

The acid dissociable group is not particularly limited, and those which have been proposed as the acid dissociable group of the base resin for the chemically amplified resist can be used.
Among the polar groups, examples of the acid dissociable group that protects a carboxy group or a hydroxyl group include, for example, an acid dissociable group represented by the following general formula (a1-r-1) (hereinafter, for convenience, "acetal-type acid dissociable group"). Sometimes referred to as "group").

［式中、Ｒａ’^１、Ｒａ’^２は水素原子またはアルキル基、Ｒａ’^３は炭化水素基、Ｒａ’^３は、Ｒａ’^１、Ｒａ’^２のいずれかと結合して環を形成してもよい。＊は結合手を意味する。］

[In the formula, Ra′ ¹ and Ra′ ² are each a hydrogen atom or an alkyl group, Ra′ ³ is a hydrocarbon group, and Ra′ ³ is bonded to either Ra′ ¹ or Ra′ ² to form a ring. Good. * Means a bond. ]

In the formula (a1-r-1), the alkyl group of Ra′ ¹ and Ra′ ² is mentioned as the substituent that may be bonded to the carbon atom at the α-position in the description of the α-substituted acrylate ester. Examples thereof include those similar to the alkyl group, a methyl group or an ethyl group is preferable, and a methyl group is most preferable.

As the hydrocarbon group for Ra′ ³ , an alkyl group having 1 to 20 carbon atoms is preferable, an alkyl group having 1 to 10 carbon atoms is more preferable; a linear or branched alkyl group is preferable, and specifically, , Methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, tert-butyl group, pentyl group, isopentyl group, neopentyl group, 1,1-dimethylethyl group, 1,1-diethylpropyl group 2,2-dimethylpropyl group, 2,2,-dimethylbutyl group and the like can be mentioned.

When Ra′ ³ is a cyclic hydrocarbon group, it may be aliphatic or aromatic, and may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from monocycloalkane. The monocycloalkane preferably has 3 to 8 carbon atoms, and specific examples thereof include cyclopentane, cyclohexane and cyclooctane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing one hydrogen atom from polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, specifically, adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

When it becomes an aromatic hydrocarbon group, specific examples of the aromatic ring contained include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, phenanthrene; and the like of the carbon atoms constituting the aromatic hydrocarbon ring. Aromatic heterocycles partially substituted with heteroatoms; and the like. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom and a nitrogen atom.
Specific examples of the aromatic hydrocarbon group include a group in which one hydrogen atom is removed from the aromatic hydrocarbon ring (aryl group); a group in which one of the hydrogen atoms in the aryl group is substituted with an alkylene group (for example, , Benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group and other arylalkyl groups); The alkylene group (alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

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

Among the polar groups, examples of the acid dissociable group that protects the carboxy group include acid dissociable groups represented by the following general formula (a1-r-2) (the following formula (a1-r-2). Among the acid dissociable groups represented by (4), those composed of an alkyl group may be hereinafter referred to as "tertiary alkyl ester type acid dissociable groups" for convenience).

［式中、Ｒａ’^４〜Ｒａ’^６は炭化水素基であり、Ｒａ’^５、Ｒａ’^６は互いに結合して環を形成してもよい。＊は結合手を意味する。］

[In the formula, Ra′ ^{4 to} Ra′ ⁶ are hydrocarbon groups, and Ra′ ⁵ and Ra′ ⁶ may be bonded to each other to form a ring. * Means a bond. ]

Examples of the hydrocarbon group for Ra′ ^{4 to} Ra′ ⁶ include the same as those for Ra′ ³ . Ra′ ⁴ is preferably an alkyl group having 1 to 5 carbon atoms. When Ra′ ⁵ and Ra′ ⁶ are bonded to each other to form a ring, a group represented by general formula (a1-r2-1) shown below can be mentioned.
On the other hand, when Ra′ ^{4 to} Ra′ ⁶ are not bonded to each other and are independent hydrocarbon groups, groups represented by general formula (a1-r2-2) shown below can be mentioned.

［式中、Ｒａ’^１０は炭素数１〜１０のアルキル基、Ｒａ’^１１はＲａ’^１０が結合した炭素原子と共に脂肪族環式基を形成する基、Ｒａ’^１２〜Ｒａ’^１４は、それぞれ独立に炭化水素基を示す。＊は結合手を意味する。］

[In the formula, Ra′ ¹⁰ is an alkyl group having 1 to ¹⁰ carbon atoms, Ra′ ¹¹ is a group forming an aliphatic cyclic group together with the carbon atom to which Ra′ ¹⁰ is bonded, and Ra′ ^{12 to} Ra′ ¹⁴ are respectively It independently represents a hydrocarbon group. * Means a bond. ]

In the formula (a1-r2-1), the alkyl group of the alkyl group having 1 to ¹⁰ carbon atoms of Ra′ ¹⁰ is the linear or branched alkyl group of Ra′ ³ in the formula (a1-r-1). The groups mentioned as are preferable. In the formula (a1-r2-1), the aliphatic cyclic group which Ra′ ¹¹ constitutes is preferably the group exemplified as the cyclic alkyl group for Ra′ ³ in the formula (a1-r-1).

In formula (a1-r2-2), it is preferable that Ra′ ¹² and Ra′ ¹⁴ are each independently an alkyl group having 1 to 10 carbon atoms, and the alkyl group is Ra in formula (a1-r-1). The group described as the linear or branched alkyl group of ' ³ is more preferable, a linear alkyl group having 1 to 5 carbon atoms is further preferable, and a methyl group or an ethyl group is particularly preferable. ..
In formula (a1-r2-2), Ra′ ¹³ is a linear, branched or cyclic alkyl group exemplified as the hydrocarbon group for Ra′ ³ in formula (a1-r-1). Is preferred. Among these, the groups mentioned as the cyclic alkyl group of Ra′ ³ are more preferable.

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

Specific examples of the formula (a1-r2-2) will be given below.

Moreover, as an acid dissociable group which protects a hydroxyl group among the polar groups, for example, an acid dissociable group represented by the following general formula (a1-r-3) (hereinafter, for the sake of convenience, "tertiary alkyloxycarbonyl acid") is used. Sometimes referred to as a “dissociative group”).

［式中、Ｒａ’^７〜Ｒａ’^９はアルキル基を示す。＊は結合手を意味する。］

Wherein, Ra ^'7 ~Ra' ⁹ is an alkyl group. * Means a bond. ]

In formula (a1-r-3), Ra′ ^{7 to} Ra′ ⁹ are preferably alkyl groups having 1 to 5 carbon atoms, and more preferably 1 to 3 carbon atoms.
The total carbon number of each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

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

Among the above, the structural unit (a1) is preferably 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.
As the structural unit (a1), a structural unit represented by general formula (a1-1) or (a1-2) shown below is preferable.

［式中、Ｒは水素原子、炭素数１〜５のアルキル基または炭素数１〜５のハロゲン化アルキル基である。Ｖａ^１はエーテル結合、ウレタン結合、又はアミド結合を有していてもよい２価の炭化水素基であり、ｎ_ａ１は０〜２であり、
Ｒａ^１は上記式（ａ１−ｒ−１）〜（ａ１−ｒ−２）で表される酸解離性基である。Ｗａ^１
はｎ_ａ２＋１価の炭化水素基であり、ｎ_ａ２は１〜３であり、Ｒａ^２は上記式（ａ１−ｒ−１）または（ａ１−ｒ−３）で表される酸解離性基である。］

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Va ¹ is a divalent hydrocarbon group which may have an ether bond, a urethane bond, or an amide bond, and na ₁ is 0 to 2,
Ra ¹ is an acid dissociable group represented by the above formulas (a1-r-1) to (a1-r-2). Wa ¹
Is a _{na 2} +1 valent hydrocarbon group, _{na 2} is 1 to 3, Ra ² is an acid dissociable group represented by the above formula (a1-r-1) or (a1-r-3). is there. ]

In the general formula (a1-1), the alkyl group having 1 to 5 carbon atoms is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, a methyl group, an ethyl group, Examples thereof include a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which a part or all of hydrogen atoms of the alkyl group having 1 to 5 carbon atoms is 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.
As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is most preferable from the viewpoint of industrial availability.
The hydrocarbon group of Va ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ may be saturated or unsaturated, and is usually preferably saturated.
Specific examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group and an aliphatic hydrocarbon group containing a ring in the structure.
Examples of Va ¹ include the divalent hydrocarbon groups bonded via an ether bond, a urethane bond, or an amide bond.

The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, more preferably 1 to 4, and most preferably 1 to 3.
As the linear aliphatic hydrocarbon group, preferably a linear alkylene group, and specific examples include a methylene group _[-CH 2 -], an ethylene group _{[- (CH 2) 2 -} ], trimethylene [ _{- (CH 2) 3 -]} , a tetramethylene group _{[- (CH 2) 4 -} ], a pentamethylene group _{[- (CH 2) 5 -} ] , and the like.
As the branched aliphatic hydrocarbon group, preferably a branched chain alkylene group, _{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 Alkylethylene group such as CH ₃ ) ₂ —CH ₂ —; alkyltrimethylene group such as —CH(CH ₃ )CH ₂ CH ₂ —, —CH ₂ CH(CH ₃ )CH ₂ —; —CH(CH ₃ ). Examples thereof include alkyl alkylene groups such as alkyl tetramethylene groups such as CH ₂ CH ₂ CH ₂ —, —CH ₂ CH(CH ₃ )CH ₂ CH ₂ — and the like. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

Examples of the aliphatic hydrocarbon group containing a ring in the structure include an alicyclic hydrocarbon group (a group in which two hydrogen atoms have been removed from an aliphatic hydrocarbon ring), and an alicyclic hydrocarbon group is linear or branched. Examples thereof include a group bonded to the terminal of a chain-like aliphatic hydrocarbon group and a group in which an alicyclic hydrocarbon group is present in the middle of a linear or branched aliphatic hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same ones as described above.
The alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
The alicyclic hydrocarbon group may be polycyclic or monocyclic. The monocyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from a monocycloalkane. The monocycloalkane preferably has 3 to 6 carbon atoms, and specific examples thereof include cyclopentane and cyclohexane. The polycyclic alicyclic hydrocarbon group is preferably a group obtained by removing two hydrogen atoms from polycycloalkane, and the polycycloalkane preferably has 7 to 12 carbon atoms, and specifically, adamantane. , Norbornane, isobornane, tricyclodecane, tetracyclododecane and the like.

The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring.
The aromatic hydrocarbon group as the divalent hydrocarbon group in Va ¹ preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, further preferably 5 to 20 carbon atoms, and 6 to 6 carbon atoms. 15 is particularly preferable, and 6 to 10 is the most preferable. However, the number of carbon atoms does not include the number of carbon atoms in the substituent.
Specific examples of the aromatic ring included in the aromatic hydrocarbon group include aromatic hydrocarbon rings such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene; some of the carbon atoms constituting the aromatic hydrocarbon ring are hetero. Aromatic heterocycles substituted with atoms; and the like. Examples of the hetero atom in the aromatic heterocycle include an oxygen atom, a sulfur atom and a nitrogen atom.
Specific examples of the aromatic hydrocarbon group include a group obtained by removing two hydrogen atoms from the aromatic hydrocarbon ring (arylene group); a group obtained by removing one hydrogen atom from the aromatic hydrocarbon ring (aryl group). Group in which one of the hydrogen atoms of) is substituted with an alkylene group (for example, arylalkyl such as benzyl group, phenethyl group, 1-naphthylmethyl group, 2-naphthylmethyl group, 1-naphthylethyl group, 2-naphthylethyl group). Group in which one more hydrogen atom is removed from the aryl group in the group); The alkylene group (alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

In the formula (a1-2), the na ₂ +1 valent hydrocarbon group for Wa ¹ may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity, may be saturated or unsaturated, and is usually preferably saturated. As the aliphatic hydrocarbon group, a linear or branched aliphatic hydrocarbon group, an aliphatic hydrocarbon group containing a ring in the structure, or a linear or branched aliphatic hydrocarbon group Examples thereof include groups in which an aliphatic hydrocarbon group containing a ring in the structure is combined, and specifically, the same groups as Va ^{1 in the} above formula (a1-1) can be mentioned.
The _{na 2} +1 valence is preferably 2 to 4, and more preferably 2 or 3.

As the formula (a1-2), a structural unit represented by general formula (a1-2-01) shown below is particularly desirable.

In formula (a1-2-01), Ra ² is an acid dissociable group represented by the above formula (a1-r-1) or (a1-r-3). n _a2 is an integer of 1 to 3, preferably 1 or 2, and more preferably 1. c is an integer of 0 to 3, preferably 0 or 1, and more preferably 1. R is the same as above.
Specific examples of the above formulas (a1-1) and (a1-2) are shown below. In each of the following formulas, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

The proportion of the structural unit (a1) in the component (A) is preferably 20 to 80 mol%, more preferably 20 to 75 mol%, and more preferably 25 to 70 mol%, based on all the structural units constituting the component (A). Is more preferable. By setting the ratio to the lower limit or more, the lithographic properties such as sensitivity, resolution and LWR are also improved. Further, by setting the content to the upper limit or less, it is possible to balance with other structural units.

(Structural unit (a2))
In the present invention, the resin component preferably contains a structural unit (a2) having a —SO ₂ — containing cyclic group, a lactone containing cyclic group, a carbonate containing cyclic group or a heterocyclic group other than these. ..
The —SO ₂ — containing cyclic group, the lactone containing cyclic group, the carbonate containing cyclic group or the heterocyclic group other than these of the structural unit (a2) can be used when the component (A) is used for forming a resist film. , Is effective in improving the adhesion of the resist film to the substrate.
When the aforementioned structural unit (a1) contains a —SO ₂ — containing cyclic group, a lactone containing cyclic group, a carbonate containing cyclic group or a heterocyclic group other than these in the structure, the structural unit Corresponds to the structural unit (a2), but such a structural unit corresponds to the structural unit (a1) and does not correspond to the structural unit (a2).

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

［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、Ｙａ^２１は単結合または２価の連結基であり、Ｌａ^２１は−Ｏ−、−ＣＯＯ−、−ＣＯＮ（Ｒ’）−、−ＯＣＯ−、−ＣＯＮＨＣＯ−又は−ＣＯＮＨＣＳ−であり、Ｒ’は水素原子またはメチル基を示す。ただしＬａ^２１が−Ｏ−の場合、Ｙａ^２１は−ＣＯ−にはならない。Ｒａ^２１は−ＳＯ_２−含有環式基、ラクトン含有環式基、カーボネート含有環式基又はこれら以外の複素環式基である。］

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

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

(A divalent hydrocarbon group which may have a substituent)
The hydrocarbon group as the divalent linking group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.
The aliphatic hydrocarbon group means a hydrocarbon group having no aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and is usually preferably saturated.
Examples of the aliphatic hydrocarbon group include a linear or branched aliphatic hydrocarbon group or an aliphatic hydrocarbon group containing a ring in the structure, and specifically, the above formula (a1- The groups exemplified as Va ¹ in 1) are mentioned.

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

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 (two hydrogen atoms are removed 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 linear or branched fat Examples thereof include groups intervening in the middle of the group hydrocarbon group. Examples of the linear or branched aliphatic hydrocarbon group include the same ones as described above.
The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably 3 to 12 carbon atoms.
Specific examples of the cyclic aliphatic hydrocarbon group include the groups exemplified as Va ¹ in the above formula (a1-1).
The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group and a carbonyl group.
The alkyl group as the substituent is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group.
The alkoxy group as the substituent is preferably an alkoxy group having 1 to 5 carbon atoms, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a tert-butoxy group, and a methoxy group. Most preferred is the group ethoxy.
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 a part or all of the hydrogen atoms of the alkyl group are substituted with the halogen atom.
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.

Specific examples of the aromatic hydrocarbon group as the divalent hydrocarbon group include the groups exemplified as Va ¹ in the above formula (a1-1).
In the aromatic hydrocarbon group, the hydrogen atom of the aromatic hydrocarbon group may be substituted with a substituent. For example, the hydrogen atom bonded to the aromatic ring in the aromatic hydrocarbon group may be substituted with a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group 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.
Examples of the alkoxy group, the halogen atom and the halogenated alkyl group as the substituent include those exemplified as the substituent for substituting the hydrogen atom of the cyclic aliphatic hydrocarbon group.

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

When Ya ²¹ is a divalent linking group containing a hetero atom, preferable examples of the linking group include —O—, —C(═O)—O—, —C(═O)—, and —O—C. (=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)-(H may be substituted with a substituent such as an alkyl group and an acyl group. _{.), - S -, -} S (= O) 2 -, - S (= O) 2 -O-, the formula ^{-Y 21 -O-Y 22 -,} - Y 21 -O -, - Y 21 - C (= O) -O -, - C (= O) -O - Y 21, [Y 21 -C (= O) -O] m '-Y 22 - or ^-Y 21 -O-C (= O) -Y 22 ^- group [wherein represented by, Y ²¹ and Y ²² are each independently may be substituted divalent hydrocarbon group, O is an oxygen atom, m'is an integer of 0-3. ] Etc. are mentioned.
When the divalent linking group containing a hetero atom is -C(=O)-NH-, -NH-, -NH-C(=NH)-, H is a substituent such as an alkyl group or acyl. It may be substituted. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.
Formula ^{-Y 21 -O-Y 22 -,} - Y 21 -O -, - Y 21 -C (= O) -O -, - C (= O) -O-Y 21, - [Y 21 -C ( _{= O) -O] m '-Y} 22 - or ^{-Y 21 -O-C (= O} ) -Y 22 - ^{in, Y 21} and ^{Y 22} each independently have a substituent It is a good divalent hydrocarbon group. Examples of the divalent hydrocarbon group include those similar to the "divalent hydrocarbon group which may have a substituent(s)" mentioned above in the description of the divalent linking group.
As Y ²¹ , a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 1 to 5 carbon atoms is further preferable, and a methylene group or an ethylene group is particularly preferable. preferable.
As Y ²² , a linear or branched aliphatic hydrocarbon group is preferable, and a methylene group, an ethylene group or an alkylmethylene group is more preferable. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.
Formula ^{- [Y 21 -C (= O} ) -O] m '-Y 22 - In the group represented by, m' is an integer of 0 to 3, preferably an integer of 0 to 2, 0 Alternatively, 1 is more preferable, and 1 is particularly preferable. In other words, the formula ^- Examples of the group represented by the formula ^{-Y 21 -C (= O) -O} -Y 22 - - [Y 21 -C (= O) -O] m '-Y 22 represented by Groups are particularly preferred. Among them, the formula _{- (CH 2) a '-C} (= O) -O- (CH 2) b' - a group represented by are 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, still more preferably 1 or 2, and most preferably 1. b′ is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, further preferably 1 or 2, and most preferably 1.

In the present invention, Ya ²¹ is a single bond, an ester bond [—C(═O)—O—], an ether bond (—O—), a linear or branched alkylene group, or a combination thereof. Preferably.

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

And _- "-SO 2 containing cyclic group", -SO 2 _- within the ring skeleton thereof shows a cyclic group containing a ring containing, in particular, -SO 2 _- sulfur atom (S) is in A cyclic group that forms part of the ring skeleton of the cyclic group. A ring containing —SO ₂ — in its ring skeleton is counted as the first ring, and if it is the only ring, it is a monocyclic group, and if it has another ring structure, it is a polycyclic group regardless of its structure. Called. The —SO ₂ — containing cyclic group may be monocyclic or polycyclic.
The —SO ₂ — containing cyclic group is particularly a cyclic group containing —O—SO ₂ — in its ring skeleton, that is, —O—S— in —O—SO ₂ — forms a part of the ring skeleton. It is preferably a cyclic group containing a sultone ring to be formed. Specific examples of the —SO ₂ — containing cyclic group include groups represented by general formulas (a5-r-1) to (a5-r-4) shown below.

［式中、Ｒａ’^５１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、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；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、ｎ’は０〜２の整数である。］

[Wherein Ra′ ⁵¹ is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR″, —OC(═O)R″, a hydroxyalkyl group or a cyano group. R" is a hydrogen atom or an alkyl group; A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, and n'is 0 to 2 Is an integer. ]

In the general formulas (a5-r-1) to (a5-r-4), A″ is the same as A″ in the general formulas (a2-r-1) to (a2-r-7) described later. .. Examples of the alkyl group, alkoxy group, halogen atom, halogenated alkyl group, —COOR″, —OC(═O)R″, and hydroxyalkyl group for Ra′ ⁵¹ , which will be described later, include general formulas (a2-r-1) to (a2-r-1). The same as Ra' ^{21 in} a2-r-7).

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

In the present invention, when the structural unit (a2) contains a —SO ₂ — containing cyclic group, among the above groups, the group represented by the general formula (a5-r-1) is preferable, and the chemical formula (r-sl). -1-1), (r-sl-1-18), (r-sl-3-1) and (r-sl-4-1) are selected from the group consisting of It is more preferable to use at least one kind, and the group represented by the chemical formula (r-sl-1-1) is most preferable.

The “lactone-containing cyclic group” refers to a cyclic group containing a ring (lactone ring) containing —O—C(═O)— in its ring skeleton. The lactone ring is counted as the first ring. A lactone ring alone is referred to as a monocyclic group, and a lactone ring having another ring structure is referred to as a polycyclic group regardless of the structure. The lactone-containing cyclic group may be either a monocyclic group or a polycyclic group.
The lactone-containing cyclic group is not particularly limited and any one can be used. Specific examples include groups represented by general formulas (a2-r-1) to (a2-r-7) shown below. Hereinafter, “*” represents a bond.

［式中、Ｒａ’^２１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、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；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、ｎ’は０〜２の整数であり、ｍ’は０または１である。］

[Wherein Ra′ ²¹ is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR”, —OC(═O)R”, a hydroxyalkyl group or a cyano group. R" is a hydrogen atom or an alkyl group; A" is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, and n'is 0 to 2 Is an integer and m′ is 0 or 1. ]

In the general formulas (a2-r-1) to (a2-r-7), A″ has 1 to 5 carbon atoms which may contain an oxygen atom (—O—) or a sulfur atom (—S—). And an oxygen atom or a sulfur atom. As the alkylene group having 1 to 5 carbon atoms in A″, a linear or branched alkylene group is preferable, and a methylene group, an ethylene group, an n-propylene group, Examples include isopropylene group and the like. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group in which —O— or —S— is present at the terminal or carbon atom of the alkylene group, and for example, —O—CH _{2 -, - CH 2 -O-CH} 2 -, - S-CH 2 -, - CH 2 -S-CH 2 - , and the like. As A″, an alkylene group having 1 to 5 carbon atoms or —O— is preferable, an alkylene group having 1 to 5 carbon atoms is more preferable, and a methylene group is most preferable. Ra′ ²¹ is independently an alkyl group or an alkoxy group. A group, a halogen atom, a halogenated alkyl group, -COOR", -OC(=O)R", a hydroxyalkyl group or a cyano group.
The alkyl group in Ra′ ²¹ is preferably an alkyl group having 1 to 5 carbon atoms.
As the alkoxy group for Ra′ ^21, an alkoxy group having 1 to 6 carbon atoms is preferable.
The alkoxy group is preferably linear or branched. Specific examples thereof include groups in which an alkyl group mentioned as the alkyl group in Ra′ ²¹ and an oxygen atom (—O—) are linked.
Examples of the halogen atom in Ra′ ²¹ 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 ^21, the Ra' Ra part or all of the hydrogen atoms of the alkyl group in ²¹ can be mentioned it has been substituted with the aforementioned halogen atoms. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

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

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

The “carbonate-containing cyclic group” refers to a cyclic group containing a ring (carbonate ring) containing —O—C(═O)—O— in its ring skeleton. The carbonate ring is counted as the first ring, and when it has only a carbonate ring, it is called a monocyclic group, and when it has another ring structure, it is called a polycyclic group regardless of its structure. The carbonate-containing cyclic group may be either a monocyclic group or a polycyclic group.
The carbonate ring-containing cyclic group as the cyclic hydrocarbon group for R ¹ is not particularly limited and any one can be used. Specific examples thereof include groups represented by general formulas (ax3-r-1) to (ax3-r-3) shown below.

［式中、Ｒａ’^ｘ３１はそれぞれ独立に水素原子、アルキル基、アルコキシ基、ハロゲン原子、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；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ｑ’は０または１である。］

[ ^Wherein Ra′ ^x31 is independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, —COOR”, —OC(═O)R”, a hydroxyalkyl group or a cyano group. R″ is a hydrogen atom or an alkyl group; A″ is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, an oxygen atom or a sulfur atom, and q′ is 0 or 1. is there. ]

A″ in the general formulas (ax3-r-1) to (ax3-r-3) is the same as A″ in the general formula (a2-r-1).
The alkyl group, alkoxy group, halogen atom, halogenated alkyl group, —COOR″, —OC(═O)R″, and hydroxyalkyl group for Ra′ ³¹ are each represented by the general formula (a2-r-1) to ( The same as those mentioned in the description of Ra′ ^{21 in} a2-r-7) can be mentioned.

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

The "heterocyclic group" refers to a cyclic group containing one or more atoms other than carbon in addition to carbon, and is a heterocyclic group described in each of (r-hr-1) to (r-hr-16) described later. Examples thereof include cyclic groups and nitrogen-containing heterocycles. Examples of the nitrogen-containing heterocyclic group include a cycloalkyl group having 3 to 8 carbon atoms which may be substituted with 1 or 2 oxo groups. Preferred examples of the cycloalkyl group include 2,5-dioxopyrrolidine and 2,6-dioxopiperidine.

The structural unit (a2) contained in the component (A) may be one type or two or more types.
When the component (A) has the structural unit (a2), the proportion of the structural unit (a2) is preferably 1 to 80 mol% based on the total of all the structural units constituting the component (A), It is more preferably from 5 to 70 mol%, further preferably from 10 to 65 mol%, particularly preferably from 10 to 60 mol%. When it is at least the lower limit value, the effect of containing the structural unit (a2) is sufficiently obtained, and when it is at most the upper limit value, it can be balanced with other structural units, and various lithographic characteristics and patterns can be obtained. Good shape.

The component (A1) may have the following structural unit (a3) and structural unit (a4) in addition to the above structural units (a1) and (a2).

(Structural unit (a3))
The structural unit (a3) is a structural unit containing a polar group-containing aliphatic hydrocarbon group (excluding those corresponding to the structural units (a1) and (a2) described above).
It is considered that the component (A1) having the structural unit (a3) increases the hydrophilicity of the component (A) and contributes to the improvement of resolution.
Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which a part of hydrogen atoms of an alkyl group is replaced with a fluorine atom, and the like, and a hydroxyl group is particularly preferable.
Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group) and a cyclic aliphatic hydrocarbon group (cyclic group). The cyclic group may be a monocyclic group or a polycyclic group, and for example, it can be appropriately selected and used from the many proposed ones in resins for resist compositions for ArF excimer lasers. The cyclic group is preferably a polycyclic group, and more preferably has 7 to 30 carbon atoms.
Among them, a structural unit derived from an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which a part of hydrogen atoms of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom. Is more preferable. Examples of the polycyclic group include groups in which two or more hydrogen atoms have been removed from bicycloalkane, tricycloalkane, tetracycloalkane, and the like. Specific examples thereof include groups in which two or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Among these polycyclic groups, a group obtained by removing two or more hydrogen atoms from adamantane, a group obtained by removing two or more hydrogen atoms from norbornane, and a group obtained by removing two or more hydrogen atoms from tetracyclododecane are Industrially preferred.

The structural unit (a3) is not particularly limited as long as it contains a polar group-containing aliphatic hydrocarbon group, and any unit can be used.
The structural unit (a3) is 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 includes a polar group-containing aliphatic hydrocarbon group. Structural units are preferred.
As the structural unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, it is derived from hydroxyethyl ester of acrylic acid. When the hydrocarbon group is a polycyclic group, a structural unit represented by the following formula (a3-1), a structural unit represented by the formula (a3-2), a formula (a3-2) The structural unit represented by a3-3) is mentioned as a preferable example.

［式中、Ｒは前記と同じであり、ｊは１〜３の整数であり、ｋは１〜３の整数であり、ｔ’は１〜３の整数であり、ｌは１〜５の整数であり、ｓは１〜３の整数である。］

[In the formula, R is the same as above, j is an integer of 1 to 3, k is an integer of 1 to 3, t'is an integer of 1 to 3, and l is an integer of 1 to 5. And s is an integer of 1 to 3. ]

In the formula (a3-1), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl groups are bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, it is preferable that the hydroxyl group be bonded to the 3-position of the adamantyl group.
j is preferably 1, and particularly preferably a hydroxyl group bonded to the 3-position of the adamantyl group.

In formula (a3-2), k is preferably 1. The cyano group is preferably bonded to the 5th or 6th position of the norbornyl group.
In formula (a3-3), t′ is preferably 1. It is preferable that l is 1. It is preferable that s is 1. It is preferable that a 2-norbornyl group or a 3-norbornyl group is bonded to the terminal of the carboxy group of acrylic acid. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group.

The structural unit (a3) contained in the component (A1) may be one type or two or more types.
In the component (A1), the proportion of the structural unit (a3) is preferably 5 to 50 mol %, more preferably 5 to 40 mol% based on the total of all structural units constituting the resin component (A1). It is preferably 5 to 25 mol %, and more preferably 5 to 25 mol %.
By setting the ratio of the structural unit (a3) to the lower limit or more, the effect of including the structural unit (a3) can be sufficiently obtained, and by setting the ratio to the upper limit or less, balance with other structural units can be achieved. It will be easier.

(Structural unit (a4))
The structural unit (a4) is a structural unit containing an acid non-dissociable cyclic group. When the component (A1) has the structural unit (a4), the dry etching resistance of the resist pattern formed is improved. Further, the hydrophobicity of the component (A1) is increased. It is considered that the improvement of hydrophobicity contributes to the improvement of 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 when an acid is generated from the component (B) described below by exposure, it does not dissociate in the structural unit as it is even when the acid acts. It is the remaining cyclic group.
As the structural unit (a4), for example, a structural unit derived from an acrylate ester containing an acid non-dissociable aliphatic cyclic group is preferable. Examples of the cyclic group include the same groups as those exemplified in the case of the structural unit (a1), for ArF excimer laser, KrF excimer laser (preferably for ArF excimer laser), etc. A large number of those conventionally known as those used as the resin component of the resist composition can be used.
Particularly, 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. These polycyclic groups may have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent.
Specific examples of the structural unit (a4) include those having the structures of the following general formulas (a4-1) to (a4-7).

［式中、Ｒ^αは、水素原子、メチル基またはトリフルオロメチル基を示す。］

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

The structural unit (a4) contained in the component (A1) may be one type or two or more types.
When the structural unit (a4) is contained in the component (A1), the proportion of the structural unit (a4) is preferably 1 to 30 mol% based on the total of all structural units constituting the component (A1), It is more preferably 10 to 20 mol %.

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

The component (A1) is obtained by polymerizing a monomer that induces each structural unit, for example, by known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN) or dimethyl azobisisobutyrate. be able to.
Further, as the component (A1), a chain transfer agent such as HS—CH ₂ —CH ₂ —CH ₂ —C(CF ₃ ) ₂ —OH is used in combination during the above polymerization, so that -C and _{(CF 3)} 2 -OH group may be introduced into the. As described above, the copolymer having a hydroxyalkyl group in which a part of hydrogen atoms of the alkyl group is substituted with a fluorine atom is introduced, the development defects are reduced and LER (line edge roughness: unevenness of line side wall unevenness) is obtained. Is effective in reducing

In the present invention, the weight average molecular weight (Mw) (polystyrene conversion standard by gel permeation chromatography) of the component (A1) is not particularly limited and is preferably 1,000 to 50,000, more preferably 1,500 to 30,000, and 2,000. Most preferred is 20,000. When it is at most the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and when it is at least the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.

As the component (A1), one type may be used alone, or two or more types may be used in combination.
The proportion of the component (A1) in the base component (A) is preferably 25% by mass or more, more preferably 50% by mass, further preferably 75% by mass, based on the total mass of the substrate component (A). It may be% by mass. When the proportion is 25% by mass or more, the lithography characteristics are further improved.

In the present invention, as the component (A), one type may be used alone, or two or more types may be used in combination.
In the present invention, the content of the component (A) may be adjusted according to the resist film thickness to be formed and the like.

<Acid generator component; (B) component>
In the present invention, the resist composition may contain an acid generator component (B) that generates an acid upon exposure (hereinafter referred to as the component (B)). The component (B) is not particularly limited, and those which have been proposed as acid generators for chemically amplified resists can be used.
Examples of such an acid generator include onium salt-based acid generators such as iodonium salts and sulfonium salts, oxime sulfonate-based acid generators, diazomethane-based acid generators such as bisalkyl or bisarylsulfonyldiazomethanes and poly(bissulfonyl)diazomethanes. There are various types such as an acid generator, a nitrobenzyl sulfonate-based acid generator, an imino sulfonate-based acid generator, and a disulfone-based acid generator. Among these, it is preferable to use an onium salt-based acid generator.

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

［式中、Ｒ^１０１、Ｒ^１０４〜Ｒ^１０８はそれぞれ独立に置換基を有していてもよい環式基、置換基を有していてもよい鎖状のアルキル基、または置換基を有していてもよい鎖状のアルケニル基である。Ｒ^１０４、Ｒ^１０５は、相互に結合して環を形成していてもよい。Ｒ^１０６〜Ｒ^１０７のいずれか２つは、相互に結合して環を形成していてもよい。Ｒ^１０２はフッ素原子または炭素数１〜５のフッ素化アルキル基である。Ｙ^１０１は単結合または酸素原子を含む２価の連結基である。Ｖ^１０１〜Ｖ^１０３はそれぞれ独立に単結合、アルキレン基、またはフッ素化アルキレン基である。Ｌ^１０１〜Ｌ^１０２はそれぞれ独立に単結合または酸素原子である。Ｌ^１０３〜Ｌ^１０５はそれぞれ独立に単結合、−ＣＯ−又は−ＳＯ_２−である。Ｍ’^ｍ＋はｍ価の有機カチオンである。］

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

{Anion part}
Anion part of component (b-1) In formula (b-1), R ¹⁰¹ represents a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, Alternatively, it is a chain alkenyl group which may have a substituent.

(R ¹⁰¹ is a cyclic group which may have a substituent)
The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.
The aromatic hydrocarbon group for R ¹⁰¹ is derived from the aromatic hydrocarbon ring mentioned as the divalent aromatic hydrocarbon group for Va ¹ of the formula (a1-1) or an aromatic compound containing two or more aromatic rings. An aryl group from which one hydrogen atom has been removed may be mentioned, and a phenyl group and a naphthyl group are preferable.
The cyclic aliphatic hydrocarbon group for R ¹⁰¹ is a group obtained by removing one hydrogen atom from the monocycloalkane or polycycloalkane mentioned for the divalent aliphatic hydrocarbon group for Va ¹ in formula (a1-1). And an adamantyl group and a norbornyl group are preferable.
The cyclic hydrocarbon group for R ¹⁰¹ may contain a heteroatom such as a heterocycle, and is specifically represented by any of the above general formulas (a2-r-1) to (a2-r-7). The lactone-containing cyclic group, the -SO ₂ -containing cyclic group respectively represented by the above general formulas (a5-r-1) to (a5-r-4), and the following (r-hr-1) to The heterocyclic group mentioned in (r-hr-16) can be mentioned.

Examples of the substituent in the cyclic hydrocarbon group of R ¹⁰¹ include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group and the like.
The alkyl group as a 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 a substituent is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a tert-butoxy group, and a methoxy group. Most preferred is the group ethoxy.
Examples of the halogen atom as a substituent 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, some or all of hydrogen atoms such as an alkyl group having 1 to 5 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group are the above Examples thereof include groups substituted with a halogen atom.

(A chain alkyl group which may have a substituent in R ¹⁰¹ )
The chain alkyl group for R ¹⁰¹ may be linear or branched.
The linear alkyl group preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, isotridecyl group, tetradecyl group. Group, pentadecyl group, hexadecyl group, isohexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, icosyl group, henicosyl group, docosyl group and the like.
The branched chain 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 thereof include a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group and a 4-methylpentyl group.

(A chain alkenyl group which may have a substituent in R ¹⁰¹ )
The chain alkenyl group for R ¹⁰¹ may be linear or branched and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, and even more preferably 2 to 4 Is particularly preferable. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), a butynyl group and the like. Examples of the branched alkenyl group include a 1-methylpropenyl group and a 2-methylpropenyl group.
Among the above, the chain alkenyl group is particularly preferably a propenyl group.

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

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

In formula (b-1), Y ¹⁰¹ is a single bond or a divalent linking group containing an oxygen atom.
When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, Y ¹⁰¹ may contain an atom other than an oxygen atom. Examples of the atom other than the oxygen atom include a carbon atom, a hydrogen atom, a sulfur atom and a nitrogen atom.
Examples of the divalent linking group containing an oxygen atom include an oxygen atom (ether bond: —O—), an ester bond (—C(═O)—O—), an oxycarbonyl group (—O—C(═O). )-), amide bond (-C(=O)-NH-), carbonyl group (-C(=O)-), carbonate bond (-O-C(=O)-O-) and other non-hydrocarbons. Examples include a combination of a non-hydrocarbon-based oxygen atom-containing linking group and an alkylene group. A sulfonyl group (—SO ₂ —) may be further linked to the combination. Examples of the combination include linking groups represented by the following formulas (y-al-1) to (y-al-7).

［式中、Ｖ’^１０１は単結合または炭素数１〜５のアルキレン基であり、Ｖ’^１０２は炭素数１〜３０の２価の飽和炭化水素基である。］

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

The divalent saturated hydrocarbon group for V′ ¹⁰² is preferably an alkylene group having 1 to 30 carbon atoms.

The alkylene group in V′ ¹⁰¹ and V′ ¹⁰² may be a linear alkylene group or a branched alkylene group, and a linear alkylene group is preferable.
As the alkylene group for V′ ¹⁰¹ and V′ ¹⁰² , specifically, a methylene group [—CH ₂ —]; —CH(CH ₃ )—, —CH(CH ₂ CH ₃ )—, and —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 ) Alkyl ethylene group such as CH ₂ -; trimethylene group (n-propylene group) [-CH ₂ CH ₂ CH ₂ -]; -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ ). tetramethylene group _{[-CH 2 CH 2 CH 2 CH} 2 -];; - CH 2 alkyltetramethylene groups such as _{- CH (CH 3) CH 2} CH 2 CH 2 -, - CH 2 CH (CH 3) CH 2 CH ₂ - and the like alkyl tetramethylene group; pentamethylene group _{[-CH 2 CH 2 CH 2 CH} 2 CH 2 -] , and the like.
Moreover, a part of the methylene groups in the alkylene group in V′ ¹⁰¹ or V′ ¹⁰² may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is preferably a divalent group obtained by further removing one hydrogen atom from the cyclic aliphatic hydrocarbon group of Ra′ ^{3 in} the above formula (a1-r-1), and a cyclohexylene group. , 1,5-adamantylene group or 2,6-adamantylene group is more preferred.

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

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

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

Specific examples of the anion moiety of the component (b-1) include, for example,
When Y ¹⁰¹ is a single bond, examples thereof include fluorinated alkylsulfonate anions such as trifluoromethanesulfonate anion and perfluorobutanesulfonate anion; when Y ¹⁰¹ is a divalent linking group containing an oxygen atom, the following formula (an Examples of the anion include any one of -1) to (an-3).

［式中、Ｒ”^１０１は、置換基を有していてもよい脂肪族環式基、前記式（ｒ−ｈｒ−１）〜（ｒ−ｈｒ−６）でそれぞれ表される基、又は置換基を有していてもよい鎖状のアルキル基であり；Ｒ”^１０２は、置換基を有していてもよい脂肪族環式基、前記式（ａ２−ｒ−１）〜（ａ２−ｒ−７）でそれぞれ表されるラクトン含有環式基、又は前記一般式（ａ５−ｒ−１）〜（ａ５−ｒ−４）でそれぞれ表される−ＳＯ_２−含有環式基であり；Ｒ”^１０３は、置換基を有していてもよい芳香族環式基、置換基を有していてもよい脂肪族環式基、又は置換基を有していてもよい鎖状のアルケニル基であり；Ｖ”^１０１は、フッ素化アルキレン基であり；Ｌ”^１０１は、−Ｃ（＝Ｏ）−又は−ＳＯ_２−であり；ｖ”はそれぞれ独立に０〜３の整数であり、ｑ”はそれぞれ独立に１〜２０の整数であり、ｎ”は０または１である。］

[In the formula, R" ¹⁰¹ is an aliphatic cyclic group which may have a substituent, a group represented by each of the formulas (r-hr-1) to (r-hr-6), or a substituent. Is a chain alkyl group which may have a group; R″ ¹⁰² is an aliphatic cyclic group which may have a substituent, and the above formulas (a2-r-1) to (a2-r) lactone-containing cyclic group represented respectively by -7), or the formula (a5-r-1) ~ (a5-r-4) with -SO ₂ respectively represented - be-containing cyclic group; R “ ¹⁰³ is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain alkenyl group which may have a substituent. Yes; V″ ¹⁰¹ is a fluorinated alkylene group; L″ ¹⁰¹ is —C(═O)— or —SO ₂ —; v″ is each independently an integer of 0 to 3; Are each independently an integer of 1 to 20, and n″ is 0 or 1. ]

The aliphatic cyclic group which may have a substituent of R″ ¹⁰¹ , R″ ¹⁰² and R″ ¹⁰³ is preferably the group exemplified as the cyclic aliphatic hydrocarbon group for R ¹⁰¹ . Examples of the substituent include those similar to the substituent that may substitute the cyclic aliphatic hydrocarbon group for R ¹⁰¹ .

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

The chain alkyl group which may have a substituent in R″ ¹⁰¹ is preferably the group exemplified as the chain alkyl group in the above R ^101. The chain alkyl group which may have a substituent in R″ ¹⁰³ The chain alkenyl group which may be mentioned is preferably the group exemplified as the chain alkenyl group for R ¹⁰¹ . V″ ¹⁰¹ is preferably a fluorinated alkylene group having 1 to 3 carbon atoms, and particularly preferably —CF ₂ —, —CF ₂ CF ₂ —, —CHFCF ₂ —, and —CF(CF ₃ )CF ₂ —. _{, -CH (CF 3) CF 2} - it is.

Anion Part of Component (b-2) In Formula (b-2), R ¹⁰⁴ and R ¹⁰⁵ each independently have a cyclic group which may have a substituent or a substituent which may have a substituent. It is a good chain alkyl group or a chain alkenyl group which may have a substituent, and examples thereof include the same groups as R ¹⁰¹ in the formula (b-1). However, R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring.
Each of R ¹⁰⁴ and R ¹⁰⁵ is preferably a chain alkyl group which may have a substituent, and is a linear or branched alkyl group or a linear or branched fluorinated alkyl group. Is more preferable.
The chain-like alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms, and further preferably 1 to 3 carbon atoms. The carbon number of the chain alkyl group of R ¹⁰⁴ and R ¹⁰⁵ is preferably as small as possible within the range of the above carbon number for the reason that solubility in the resist solvent is also good. Further, in the chain alkyl group of R ¹⁰⁴ and R ¹⁰⁵ , as the number of hydrogen atoms substituted with fluorine atoms is larger, the strength of the acid is stronger, and the high energy light of 200 nm or less and electron beam It is preferable because the transparency is improved. The ratio of fluorine atoms in the chain alkyl group, that is, the fluorination ratio is preferably 70 to 100%, more preferably 90 to 100%, and most preferably all hydrogen atoms are replaced with fluorine atoms. It is a perfluoroalkyl group.
In formula (b-2), V ¹⁰² and V ¹⁰³ each independently represent a single bond, an alkylene group, or a fluorinated alkylene group, and each of them is the same as V ¹⁰¹ in formula (b-1). Can be mentioned.
In formula (b-2), L ^{101 to} L ¹⁰² each independently represent a single bond or an oxygen atom.

-Anion part of component (b-3) In formula (b-3), R< ¹⁰⁶ > to R< ¹⁰⁸ > may each independently have a cyclic group which may have a substituent, or a substituent which may have a substituent. It is a good chain alkyl group or a chain alkenyl group which may have a substituent, and examples thereof include the same groups as R ¹⁰¹ in the formula (b-1).
L ^{103 to} L ¹⁰⁵ are each independently a single bond, —CO— or —SO ₂ —.

{Cation part}
In the formulas (b-1), (b-2) and (b-3), ^M'm+ is an m-valent organic cation, preferably a sulfonium cation or an iodonium cation, and the following general formula The cations represented by (ca-1) to (ca-4) are particularly preferable.

［式中、Ｒ^２０１〜Ｒ^２０７、およびＲ^２１１〜Ｒ^２１２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し、Ｒ^２０１〜Ｒ^２０３、Ｒ^２０６〜Ｒ^２０７、Ｒ^２１１〜Ｒ^２１２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。Ｒ^２０８〜Ｒ^２０９はそれぞれ独立に水素原子または炭素数１〜５のアルキル基を表し、Ｒ^２１０は置換基を有していてもよいアリール基、アルキル基、アルケニル基、又は−ＳＯ_２−含有環式基であり、Ｌ^２０１は−Ｃ（＝Ｏ）−または−Ｃ（＝Ｏ）−Ｏ−を表し、Ｙ^２０１は、それぞれ独立に、アリーレン基、アルキレン基またはアルケニレン基を表し、ｘは１または２であり、Ｗ^２０１は（ｘ＋１）価の連結基を表す。］

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

Examples of the aryl group in R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² include an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferable.
The alkyl group in R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.
The alkenyl group for R ^{201 to} R ²⁰⁷ and R ^{211 to} R ²¹² preferably has 2 to 10 carbon atoms.
Examples of the substituent that R ^{201 to} R ²⁰⁷ and R ^{210 to} R ²¹² may have include, for example, an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and arylthio. And a group represented by each of the following formulas (ca-r-1) to (ca-r-7).
The aryl group in the arylthio group as a substituent is the same as that described for R ¹⁰¹ , and specifically includes a phenylthio group or a biphenylthio group.

［式中、Ｒ’^２０１はそれぞれ独立に、水素原子、置換基を有していてもよい環式基、鎖状のアルキル基、または鎖状のアルケニル基である。］

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

The cyclic group which may have a substituent, the chain alkyl group which may have a substituent, or the chain alkenyl group which may have a substituent of R′ ²⁰¹ is as defined above. In addition to those similar to R ¹⁰¹ in the formula (b-1), a cyclic group which may have a substituent or a chain alkyl group which may have a substituent may be the above formula ( The same groups as the acid dissociable group represented by a1-r-2) are also included.

When R ^{201 to} R ²⁰³ , R ^{206 to} R ²⁰⁷ , and R ^{211 to} R ²¹² are bonded to each other to form a ring with a sulfur atom in the formula, a hetero atom such as a sulfur atom, an oxygen atom, or a nitrogen atom, or carbonyl _{group, -SO -, - SO 2 -} , - SO 3 -, - COO -, - CONH- , or -N _(R N) - (. the _{R N} is an alkyl group having 1 to 5 carbon atoms), etc. You may couple|bond together via the functional group of. As the ring to be formed, one ring containing a sulfur atom in the formula in its ring skeleton is preferably a 3 to 10-membered ring including a sulfur atom, and particularly preferably a 5 to 7-membered ring. preferable. Specific examples of the ring formed include, for example, thiophene ring, thiazole ring, benzothiophene ring, thianthrene ring, benzothiophene ring, dibenzothiophene ring, 9H-thioxanthene ring, thioxanthone ring, thianthrene ring, phenoxathiin ring, tetrahydro. Examples thereof include a thiophenium ring and a tetrahydrothiopyranium ring.

R ^{208 to} R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms,
A hydrogen atom or an alkyl group having 1 to 3 carbon atoms is preferable, and when it becomes an alkyl group, they may be bonded to each other to form a ring.

R ²¹⁰ may have an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or an substituent. -SO ₂ - containing cyclic group.
^Examples of the aryl group for R ²¹⁰ include an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferable.
The alkyl group for R ²¹⁰ is preferably a chain or cyclic alkyl group having 1 to 30 carbon atoms.
The alkenyl group for R ²¹⁰ preferably has 2 to 10 carbon atoms.
The —SO ₂ — containing cyclic group which may have a substituent in R ²¹⁰ is the same as the “—SO ₂ — containing cyclic group” of Ra ^{21 in} the above general formula (a2-1). And the groups represented by the above general formula (a5-r-1) are preferable.

Y ^201's each independently represent an arylene group, an alkylene group or an alkenylene group.
Examples of the arylene group for Y ²⁰¹ include a group obtained by removing one hydrogen atom from the aryl group exemplified as the aromatic hydrocarbon group for R ¹⁰¹ in the above formula (b-1).
Examples of the alkylene group and alkenylene group for Y ²⁰¹ include the same ones as the aliphatic hydrocarbon group as the divalent hydrocarbon group for Va ¹ in the general formula (a1-1).

In the formula (ca-4), x is 1 or 2.
W ²⁰¹ is a (x+1)-valent, that is, a divalent or trivalent linking group.
The divalent linking group for W ²⁰¹ is preferably a divalent hydrocarbon group which may have a substituent, and examples thereof include the same hydrocarbon group as Ya ²¹ in the general formula (a2-1). The divalent linking group for W ²⁰¹ may be linear, branched, or cyclic, and is preferably cyclic. Of these, a group in which two carbonyl groups are combined at both ends of the arylene group is preferable. Examples of the arylene group include a phenylene group and a naphthylene group, and a phenylene group is particularly preferable.
^Examples of the trivalent linking group for W ²⁰¹ include a group obtained by removing one hydrogen atom from the divalent linking group for W ²⁰¹ , a group in which the divalent linking group is further bonded to the divalent linking group, and the like. Can be mentioned. The trivalent linking group for W ²⁰¹ is preferably a group in which two carbonyl groups are bonded to an arylene group.

Specific examples of the suitable cation represented by the formula (ca-1) include cations represented by the following formulas (ca-1-1) to (ca-1-63).

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

[In formula, g1, g2, and g3 show a repeating number, g1 is an integer of 1-5, g2 is an integer of 0-20, and g3 is an integer of 0-20. ]

［式中、Ｒ”^２０１は水素原子又は置換基であって、置換基としては前記Ｒ^２０１〜Ｒ^２０７、およびＲ^２１０〜Ｒ^２１２が有していてもよい置換基として挙げたものと同様である。］

[In the formula, R″ ²⁰¹ is a hydrogen atom or a substituent, and the substituent is the same as those mentioned as the substituent which R ^{201 to} R ²⁰⁷ and R ^{210 to} R ²¹² may have. is there.]

Specific examples of the suitable cation represented by the formula (ca-3) include cations represented by the following formulas (ca-3-1) to (ca-3-6).

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

As the component (B), one type of the above-mentioned acid generator may be used alone, or two or more types may be used in combination.
In the present invention, when the resist composition contains the component (B), the content of the component (B) is preferably 0.5 to 60 parts by mass, and 1 to 50 parts by mass with respect to 100 parts by mass of the component (A). Is more preferable, and 1-40 mass parts is still more preferable. By setting the content of the component (B) within the above range, pattern formation is sufficiently performed. Further, when each component of the resist composition is dissolved in an organic solvent, a uniform solution is obtained, and the storage stability becomes favorable, which is preferable.

<Basic compound component; (D) component>
In the present invention, the resist composition further contains an acid diffusion control agent component (hereinafter also referred to as “(D) component”) in addition to the (A) component, or in addition to the (A) component and the (B) component. May be included.
The component (D) acts as a quencher (acid diffusion control agent) that traps the acid generated by exposure from the component (B) and the like.
The component (D) in the present invention may be a photodegradable base (D1) (hereinafter referred to as “(D1) component”) which decomposes upon exposure and loses acid diffusion controllability. It may be a nitrogen-containing organic compound (D2) that does not correspond (hereinafter referred to as “(D2) component”).

[(D1) component]
By using the resist composition containing the component (D1), it is possible to improve the contrast between the exposed portion and the non-exposed portion when forming a resist pattern.
The component (D1) is not particularly limited as long as it decomposes by exposure and loses the acid diffusion controllability, and is a compound represented by the following general formula (d1-1) (hereinafter referred to as “(d1-1) component”). ), a compound represented by the following general formula (d1-2) (hereinafter referred to as “(d1-2) component”) and a compound represented by the following general formula (d1-3) (hereinafter referred to as “(d1- 3) component"). One or more compounds selected from the group consisting of) are preferable.
The components (d1-1) to (d1-3) do not act as a quencher because they decompose in the exposed area and lose the acid diffusion controllability (basicity), but act as a quencher in the unexposed area.

［式中、Ｒｄ^１〜Ｒｄ^４は置換基を有していてもよい環式基、置換基を有していてもよい鎖状のアルキル基、または置換基を有していてもよい鎖状のアルケニル基である。ただし、式（ｄ１−２）中のＲｄ^２における、Ｓ原子に隣接する炭素原子にはフッ素原子は結合していないものとする。Ｙｄ^１は単結合、または２価の連結基である。Ｍ^ｍ＋はそれぞれ独立にｍ価の有機カチオンである。］

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

{(D1-1) component}
Anion moiety In the formula (d1-1), Rd ¹ has a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. Is a chain alkenyl group which may be the same as R ¹⁰¹ .
Among these, Rd ¹ may have an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a substituent. A chain hydrocarbon group is preferred. The substituent which these groups may have is preferably a hydroxyl group, a fluorine atom or a fluorinated alkyl group.
The aromatic hydrocarbon group is more preferably a phenyl group or a naphthyl group.
The aliphatic cyclic group is more preferably a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane and tetracyclododecane.
The chain hydrocarbon group is preferably a chain alkyl group. The chain alkyl group preferably has 1 to 10 carbon atoms, and specific examples thereof 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 and a nonyl group. Group, linear alkyl group such as decyl group; 1-methylethyl group, 1-methylpropyl group, 2-methylpropyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylbutyl group A branched chain alkyl group such as a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group and a 4-methylpentyl group.

When the chain alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the carbon number of the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8 and 1 The fluorinated alkyl group with 4 to 4 being more preferable may contain an atom other than a fluorine atom. Examples of the atom other than the fluorine atom include an oxygen atom, a carbon atom, a hydrogen atom, a sulfur atom and a nitrogen atom.
Rd ¹ is preferably a fluorinated alkyl group in which a part or all of hydrogen atoms constituting a linear alkyl group are substituted with a fluorine atom, and a hydrogen atom constituting a linear alkyl group is preferable. It is preferable that all are fluorinated alkyl groups (linear perfluoroalkyl groups) substituted with fluorine atoms.

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

-Cation part In formula (d1-1), Mm ⁺ is an m-valent organic cation.
The organic cation of M ^m+ is not particularly limited, and examples thereof include those similar to the cations represented by the general formulas (ca-1) to (ca-4), respectively. Cations represented by 1) to (ca-1-63) are preferable.
As the component (d1-1), one type may be used alone, or two or more types may be used in combination.

{(D1-2) component}
· During anion formula (d1-2), Rd ² is has an optionally substituted cyclic group which may have a substituent chain alkyl group or a substituted group, It may be a chain alkenyl group, and examples thereof include those similar to R ¹⁰¹ .
However, a fluorine atom is not bonded to the carbon atom adjacent to the S atom in Rd ² (not fluorine-substituted). Thereby, the anion of the component (d1-2) becomes an appropriate weak acid anion, and the quenching ability of the component (D) is improved.
Rd ² is preferably an aliphatic cyclic group which may have a substituent, and is a group obtained by removing one or more hydrogen atoms from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane and the like. (It may have a substituent); More preferably, it is a group obtained by removing one or more hydrogen atoms from camphor or the like.
The hydrocarbon group of Rd ² may have a substituent, and as the substituent, the hydrocarbon group in Rd ¹ of the formula (d1-1) (aromatic hydrocarbon group, aliphatic hydrocarbon group) The same as the substituent which may have.

Specific preferred examples of the anion moiety of the component (d1-2) are shown below.

-Cation part In formula (d1-2), Mm ⁺ is an m-valent organic cation and is the same as Mm ⁺ 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}
During Anion formula (d1-3), Rd ³ is have an optionally substituted cyclic group which may have a substituent chain alkyl group or a substituted group, Is a chain alkenyl group which may be the same as R ^101, and is preferably a cyclic group containing a fluorine atom, a chain alkyl group, or a chain alkenyl group. Among them, a fluorinated alkyl group is preferable, and a group similar to the fluorinated alkyl group for Rd ¹ is more preferable.

In formula (d1-3), Rd ⁴ may have a cyclic group which may have a substituent, a chain alkyl group which may have a substituent, or a substituent. It is a chain alkenyl group, and examples thereof include those similar to R ¹⁰¹ .
Among them, an alkyl group which may have a substituent, an alkoxy group, an alkenyl group and a cyclic group are preferable.
The alkyl group for Rd ⁴ 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, an n-butyl group, an isobutyl group. , Tert-butyl group, pentyl group, isopentyl group, neopentyl group and the like. Part of the hydrogen atoms of the alkyl group of Rd ⁴ may be substituted with a hydroxyl group, a cyano group or the like.
The alkoxy group for Rd ⁴ is preferably an alkoxy group having 1 to 5 carbon atoms, and 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 thereof include butoxy group and tert-butoxy group. Of these, a methoxy group and an ethoxy group are preferable.

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

Examples of the cyclic group for Rd ⁴ include the same groups as those for R ¹⁰¹ described above, and one or more hydrogen atoms are excluded from cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane and tetracyclododecane. Also preferred are alicyclic groups or aromatic groups such as phenyl and naphthyl groups. When Rd ⁴ is an alicyclic group, the resist composition is well dissolved in an organic solvent, and thus the lithographic properties are good. When Rd ⁴ is an aromatic group, the resist composition is excellent in light absorption efficiency in lithography using EUV or the like as an exposure light source, and sensitivity and lithographic characteristics are good.

In formula (d1-3), Yd ¹ is a single bond or a divalent linking group.
The divalent linking group for Yd ¹ is not particularly limited, but a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) optionally having a substituent, or a hetero atom-containing 2 Examples thereof include a valent linking group. Examples of each of these are the same as those mentioned in the description of the divalent linking group for Ya ²¹ in the formula (a2-1).
Yd ¹ is preferably a carbonyl group, an ester bond, an amide bond, an alkylene group or a combination thereof. The alkylene group is more preferably a linear or branched alkylene group, further preferably a methylene group or an ethylene group.

Specific preferred examples of the anion moiety of the component (d1-3) are shown below.

-Cation part In formula (d1-3), Mm ⁺ is an m-valent organic cation and is the same as Mm ⁺ 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.

As the component (D1), only one type of the above-mentioned components (d1-1) to (d1-3) may be used, or two or more types may be used in combination.
The content of the component (D1) is preferably 0.5 to 10 parts by mass, more preferably 0.5 to 8 parts by mass, and 1 to 8 parts by mass with respect to 100 parts by mass of the component (A). More preferably, it is parts by mass.
When the content of the component (D1) is at least the preferred lower limit value, particularly good lithographic properties and resist pattern shapes will be obtained. On the other hand, when it is at most the upper limit value, the sensitivity can be maintained well and the throughput is also excellent.

The method for producing the above-mentioned component (d1-1) and component (d1-2) is not particularly limited and can be produced by a known method.

The content of the component (D1) is preferably 0.5 to 10.0 parts by mass, more preferably 0.5 to 8.0 parts by mass, relative to 100 parts by mass of the component (A). , 1.0 to 8.0 parts by mass is more preferable. When it is at least the lower limit value of the above range, particularly good lithographic properties and resist pattern shape can be obtained. When it is at most the upper limit of the above range, the sensitivity can be favorably maintained and the throughput is also excellent.

((D2) component)
The component (D) may contain a nitrogen-containing organic compound component (hereinafter referred to as the component (D2)) that does not correspond to the component (D1).
The component (D2) is not particularly limited as long as it acts as an acid diffusion controller and does not correspond to the component (D1), and any known component may be used. Of these, aliphatic amines, especially secondary aliphatic amines and tertiary aliphatic amines are preferred.
The aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms.
Examples of the aliphatic amine include amines (alkylamines or alkylalcoholamines) or cyclic amines in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group or a hydroxyalkyl group having 12 or less carbon atoms.
Specific examples of the alkylamine and alkylalcoholamine include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine and n-decylamine; diethylamine, di-n-propylamine, di-amine. Dialkylamines such as -n-heptylamine, di-n-octylamine, dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine , Tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, tri-n-dodecylamine and like trialkylamines; diethanolamine, triethanolamine, diisopropanolamine, tri Examples include alkyl alcohol amines such as isopropanol amine, di-n-octanol amine, and tri-n-octanol amine. 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 a heterocyclic compound containing a nitrogen atom as a hetero atom. The heterocyclic compound may be a monocyclic compound (aliphatic monocyclic amine) or a polycyclic compound (aliphatic polycyclic amine).
Specific examples of the aliphatic monocyclic amine include piperidine and piperazine.
The aliphatic polycyclic amine preferably has 6 to 10 carbon atoms, and specifically, 1,5-diazabicyclo[4.3.0]-5-nonene and 1,8-diazabicyclo[5. 4.0]-7-undecene, hexamethylenetetramine, 1,4-diazabicyclo[2.2.2]octane and the like can be mentioned.

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 can be mentioned, with triethanolamine triacetate being preferred.

An aromatic amine may be used as the component (D2).
Examples of aromatic amines include aniline, pyridine, 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or their derivatives, diphenylamine, triphenylamine, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxy. Carbonyl pyrrolidine etc. are mentioned.

The component (D2) may be used alone or in combination of two or more kinds.
The component (D2) is usually used in the range of 0.01 to 5.0 parts by mass with respect to 100 parts by mass of the component (A). By setting the amount within the above range, the resist pattern shape, the stability over time with leaving and the like are improved.

As the component (D), one type may be used alone, or two or more types may be used in combination.
In the present invention, when the resist composition contains the component (D), the amount of the component (D) is preferably 0.1 to 15 parts by mass, and 0.3 to 100 parts by mass of the component (A). It is more preferably 12 parts by mass, further preferably 0.5 to 12 parts by mass. When it is at least the lower limit value of the above range, the lithographic properties such as LWR are further improved when the composition is used as a resist composition. Further, a better resist pattern shape can be obtained. When it is at most the upper limit of the above range, the sensitivity can be favorably maintained and the throughput is also excellent.

<Arbitrary ingredients>
[(E) component]
In the present invention, the resist composition contains an organic carboxylic acid, and an oxo acid of phosphorus and its derivative as an optional component for the purpose of preventing sensitivity deterioration and improving resist pattern shape, leaving stability over time, and the like. At least one compound (E) selected from the group consisting of (E) component may 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. Of these, phosphonic acid is particularly preferable.
Examples of the oxo acid derivative of phosphorus include esters in which the hydrogen atom of the above 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. The aryl group of 15 and the like can be mentioned.
Examples of phosphoric acid derivatives include phosphoric acid esters such as phosphoric acid di-n-butyl ester and phosphoric acid diphenyl ester.
Examples of the derivative of phosphonic acid include 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 derivative include phosphinic acid ester and phenylphosphinic acid.
As the component (E), one type may be used alone, or two or more types may be used in combination.
The component (E) is usually used in the range of 0.01 to 5.0 parts by mass with respect to 100 parts by mass of the component (A).

[(F) component]
In the present invention, the resist composition may contain a fluorine additive (hereinafter referred to as “component (F)”) in order to impart water repellency to the resist film.
Examples of the component (F) are disclosed in JP2010-002870A, JP2010-032994A, JP2010-277043A, JP2011-13569A, and JP2011-128226A. The fluorine-containing polymer compounds described can be used.
More specifically, the component (F) includes a polymer having a structural unit (f1) represented by the following formula (f1-1). As the polymer, a polymer (homopolymer) consisting only of the structural unit (f1) represented by the following formula (f1-1); a structural unit (f1) represented by the following formula (f1-1), Copolymer with the structural unit (a1); a structural unit (f1) represented by the following formula (f1-1), a structural unit derived from acrylic acid or methacrylic acid, and the structural unit (a1). Is preferably a copolymer of Here, as the structural unit (a1) copolymerized with the structural unit (f1) represented by the following formula (f1-1), 1-ethyl-1-cyclooctyl (meth)acrylate or the above formula (a1) 2-01) is preferred.

［式中、Ｒは前記同様であり、Ｒｆ^１０２およびＲｆ^１０３はそれぞれ独立して水素原子、ハロゲン原子、炭素数１〜５のアルキル基、又は炭素数１〜５のハロゲン化アルキル基を表し、Ｒｆ^１０２およびＲｆ^１０３は同じであっても異なっていてもよい。ｎｆ^１は１〜５の整数であり、Ｒｆ^１０１はフッ素原子を含む有機基である。］

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

In formula (f1-1), R is the same as the above. R is preferably a hydrogen atom or a methyl group.
In formula (f1-1), examples of the halogen atom of Rf ¹⁰² and Rf ¹⁰³ include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is particularly preferable. Examples of the alkyl group having 1 to 5 carbon atoms of Rf ¹⁰² and Rf ¹⁰³ are the same as those of the alkyl group having 1 to 5 carbon atoms of R above, and a methyl group or an ethyl group is preferable. Specific examples of the halogenated alkyl group having 1 to 5 carbon atoms of Rf ¹⁰² and Rf ¹⁰³ include a group in which a part or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms is substituted with a halogen atom. Can be mentioned. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom is particularly preferable. Among them, Rf ¹⁰² and Rf ¹⁰³ are preferably a hydrogen atom, a fluorine atom or an alkyl group having 1 to 5 carbon atoms, and a hydrogen atom, a fluorine atom, a methyl group or an ethyl group is preferable.
In formula (f1-1), nf ¹ is an integer of ¹ to 5, preferably an integer of 1 to 3, and more preferably 1 or 2.

In formula (f1-1), Rf ¹⁰¹ is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom.
The hydrocarbon group containing a fluorine atom may be linear, branched or cyclic, and has preferably 1 to 20 carbon atoms, and more preferably 1 to 15 carbon atoms. Particularly preferably, the carbon number is 1 to 10.
Further, in the hydrocarbon group containing a fluorine atom, 25% or more of the hydrogen atoms in the hydrocarbon group are preferably fluorinated, more preferably 50% or more, and more preferably 60% or more. Fluorination is particularly preferable because the hydrophobicity of the resist film at the time of immersion exposure increases.
Among them, as Rf ¹⁰¹ , a fluorinated hydrocarbon group having 1 to 5 carbon atoms is particularly preferable, and a methyl group, —CH ₂ —CF ₃ , —CH ₂ —CF ₂ —CF ₃ , or —CH(CF ₃ ) _{2 is used. , -CH} 2 _-CH 2 _-CF 3, and most preferably _{-CH 2 -CH 2 -CF 2 -CF 2} -CF 2 -CF 3.

The weight average molecular weight (Mw) of the component (F) (polystyrene conversion standard by gel permeation chromatography) is preferably from 1000 to 50,000, more preferably from 5,000 to 40,000, and most preferably from 10,000 to 30,000. When it is at most the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and when it is at least the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.
The dispersity (Mw/Mn) of the component (F) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5.

As the component (F), one type may be used alone, or two or more types may be used in combination.
The component (F) is usually used in a proportion of 0.5 to 10 parts by mass with respect to 100 parts by mass of the component (A).

In the present invention, the resist composition may further include a miscible additive, for example, an additional resin for improving the performance of the resist film, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent. , Dyes, etc. can be appropriately added and contained.

[(S) component]
In the present invention, the resist composition can be produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as component (S)).
As the component (S), any component capable of dissolving each component to be used to form a uniform solution may be used, and any one of the conventionally known solvents for a chemically amplified resist may be used, or Two or more kinds can be appropriately selected and used.
For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone (MEK), cyclohexanone, methyl-n-pentyl ketone (2-heptanone), and methyl isopentyl ketone; ethylene glycol, diethylene glycol, propylene glycol, diketone. A polyhydric alcohol such as propylene glycol; a compound having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate, a polyhydric alcohol or a compound having an ester bond Derivatives of polyhydric alcohols such as compounds having an ether bond such as monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether and monobutyl ether, and compounds having an ether bond such as monophenyl ether [among these, propylene glycol monomethyl ether acetate (PGMEA ), and propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane, methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methoxy. Esters such as methyl propionate and ethyl ethoxypropionate; anisole, ethylbenzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, Examples thereof include aromatic organic solvents such as cymene and mesitylene, dimethyl sulfoxide (DMSO), and the like.
These organic solvents may be used alone or as a mixed solvent of two or more kinds.
Of these, PGMEA, PGME, γ-butyrolactone and EL are preferable.
A mixed solvent obtained by mixing PGMEA and a polar solvent is also preferable. The compounding ratio (mass ratio) may be appropriately determined in consideration of the compatibility between PGMEA and the polar solvent, but is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. It is preferably within the range.
More specifically, when EL or cyclohexanone is blended as the polar solvent, the mass ratio of PGMEA:EL or cyclohexanone is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. .. When PGME is blended as the polar solvent, the mass ratio of PGMEA:PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and further preferably 3:7 to 7:. It is 3.
Further, as the component (S), a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, as the mixing ratio, the mass ratio of the former and the latter is preferably 70:30 to 95:5.
The amount of the component (S) used is not particularly limited and is appropriately set according to the coating film thickness at a concentration that can be applied to a substrate or the like. Generally, the resist composition is used so that the solid content concentration is in the range of 1 to 20% by mass, preferably 2 to 15% by mass.

[Step B]
In step B, the shrink agent composition is applied so as to cover the first resist pattern formed in [step A].
In the present invention, a shrink agent composition containing the polymer compound (X) and having a dispersity (weight average molecular weight/number average molecular weight) of the polymer compound (X) of 1.5 or less is used. And

<Shrinking agent composition>
The shrink agent composition used in the present invention will be described.
In the present invention, the shrink agent composition contains the polymer compound (X).

[Polymer compound (X)]
The polymer compound (X) is a polymer compound capable of forming a developer insoluble region on the surface of the first resist pattern.
In the present invention, the dispersity (weight average molecular weight/number average molecular weight) of the polymer compound (X) is preferably 1.49 or less, and more preferably 1.48 or less.
When the polydispersity of the polymer compound (X) is within the above range (in other words, the polymer compound (X) having a narrow dispersion), the variation in the molecular weight when used in the shrink agent composition results in a pattern. It is considered that when the thickness is increased, a gap is less likely to occur in the thickened portion, and the thickness can be favorably increased.

In the present invention, in order to obtain the narrowly dispersed polymer compound (X), a commercially available product may be used, or the polymer compound may be refined to be narrowly dispersed. The polymer compound (X) may be synthesized using a polymerization initiator. Especially, in the present invention, it is preferable to narrow the dispersion by purification.

[Narrow dispersion by purification]
In the case of narrower dispersion than purification, for example, a purification method by solvent fractionation can be adopted.
In the present invention, when narrowing the dispersion by purification, the low molecular weight compound may be removed or the high molecular weight compound may be removed. From the viewpoint of increasing the thickening amount of the pattern, it is preferable to remove the low molecular weight compound.
Purification by solvent fractionation is carried out in a solution state such as a liquid-liquid extraction method that removes residual monomer and oligomer components by washing with water or combining with an appropriate solvent, and ultrafiltration that extracts and removes only those with a specific molecular weight or less. Solidification method such as the purification method or reprecipitation method of removing residual monomers by coagulating the resin in the poor solvent by dropping the resin solution into the poor solvent or washing the filtered resin slurry with the poor solvent. A usual method such as a purification method in a state can be applied.
For example, after completion of the radical polymerization reaction, a solvent (poor solvent) in which the acid-decomposable resin is hardly soluble or insoluble is less than 5 times the volume of the reaction solution, preferably 4.5 to 0.5 times, more preferably Is 3 to 0.5 times, more preferably 1 to 0.5 times, and the resin is precipitated as a solid by contact.

The solvent used in the precipitation or reprecipitation operation from the polymer solution (precipitation or reprecipitation solvent) may be a poor solvent for the polymer, and depending on the type of the polymer, for example, hydrocarbons (pentane, hexane, Aliphatic hydrocarbons such as heptane and octane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; aromatic hydrocarbons such as benzene, toluene and xylene), halogenated hydrocarbons (methylene chloride, chloroform, carbon tetrachloride, etc.) Halogenated aliphatic hydrocarbons; halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene), nitro compounds (nitromethane, nitroethane, etc.), nitriles (acetonitrile, benzonitrile, etc.), ethers (diethyl ether, diisopropyl ether, dimethoxyethane) Chain ethers such as; cyclic ethers such as tetrahydrofuran and dioxane), ketones (acetone, methyl ethyl ketone, diisobutyl ketone, etc.), esters (ethyl acetate, butyl acetate, etc.), carbonates (dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, etc.) ), alcohol (methanol, ethanol, propanol, isopropyl alcohol, butanol, etc.), carboxylic acid (acetic acid, etc.), a mixed solvent containing these solvents, and the like can be appropriately selected and used. Among these, a solvent containing at least a hydrocarbon (particularly, an aliphatic hydrocarbon such as hexane) is preferable as the precipitation or reprecipitation solvent. In such a solvent containing at least hydrocarbon, the ratio of hydrocarbon (for example, aliphatic hydrocarbon such as hexane) to other solvent (for example, ester such as ethyl acetate, alcohols such as methanol and ethanol) is For example, the former/the latter (volume ratio; 25° C.)=10/90 to 99/1, preferably the former/the latter (volume ratio; 25° C.)=30/70 to 98/2, more preferably the former/the latter (volume) Ratio; 25° C.)=about 50/50 to 97/3.
The amount of the precipitation or reprecipitation solvent used can be appropriately selected in consideration of efficiency, yield, etc., but is generally 100 to 10000 parts by mass, preferably 200 to 2000 parts by mass, relative to 100 parts by mass of the polymer solution. More preferably, it is 300 to 1000 parts by mass.

[Living radical polymerization]
Next, living radical polymerization will be described.
Living radical polymerization is a polymerization reaction in which the termination reaction is suppressed to some extent by the equilibrium between the dormant species and the radical growth species, and the molecular weight can be controlled by a reversible exchange reaction. It is believed that a polymer with a narrow molecular weight distribution can be obtained if the exchange reaction takes place much faster than the polymerization reaction.
In the present invention, the narrow-dispersed polymer compound (X) may be synthesized using a living radical polymerization initiator.
Examples of living radical polymerization include those using chain transfer agents such as polysulfides, those using radical scavengers such as cobalt porphyrin complexes and nitroxide compounds, and atom transfer using transition metal complexes as catalysts with organic halides as initiators. Radical polymerization etc. are mentioned.

As the living radical polymerization initiator, a polymerization initiator composed of a transition metal complex, an organic halogen compound, and a Lewis acid or amine can be used.
As the central metal constituting the transition metal complex, elements of Groups 7 to 11 of the periodic table such as iron, copper, nickel, rhodium, ruthenium, and rhenium (edited by the Chemical Society of Japan, “Chemical Handbook Basic Edition I Revised 4th Edition” ( (According to the periodic table described in 1993)) is preferable. Of these, ruthenium and copper are preferable.

Specific examples of the transition metal complex having ruthenium as a central metal include dichlorotris(triphenylphosphine)ruthenium, dichlorotris(tributylphosphine)ruthenium, dichloro(cyclooctadiene)ruthenium, dichlorobenzeneruthenium, dichlorop-cymenruthenium, Dichloro(norbornadiene)ruthenium, cis-dichlorobis(2,2'-bipyridine)ruthenium, dichlorotris(1,10-phenanthroline)ruthenium, carbonylchlorohydridotris(triphenylphosphine)ruthenium, chlorocyclopentadienylbis(triphenyl) Phosphine)ruthenium, chloropentamethylcyclopentadienylbis(triphenylphosphine)ruthenium, chloroindenylbis(triphenylphosphine)ruthenium and the like, particularly dichlorotris(triphenylphosphine)ruthenium, chloropentamethylcyclopentadiene Preference is given to enylbis(triphenylphosphine)ruthenium or chloroindenylbis(triphenylphosphine)ruthenium.

The organic halogen compound functions as a polymerization initiator. As such an organic halogen compound, an α-halogenocarbonyl compound or an α-halogenocarboxylic acid ester can be used, among which an α-halogenocarboxylic acid ester is preferable, and specific examples thereof include ethyl 2-bromo-2-methylpropanoate, 2-hydroxyethyl 2-bromopropionate, dimethyl 2-chloro-2,4,4-trimethylglutarate and the like can be mentioned.

Lewis acids or amines act as activators. Examples of such a Lewis acid include aluminum trialkoxides such as aluminum triisopropoxide and aluminum tri(t-butoxide); bis(2,6-di-t-butylphenoxy)methylaluminum, bis(2,4,4). Bis(substituted aryloxy)alkyl aluminum such as 6-tri-t-butylphenoxy)methyl aluminum; Tris(substituted aryloxy)aluminum such as tris(2,6-diphenylphenoxy)aluminum; Titanium such as titanium tetraisopropoxide Examples thereof include tetraalkoxide, aluminum trialkoxide is preferable, and aluminum triisopropoxide is particularly preferable.
Examples of amines include aliphatic primary amines such as methylamine, ethylamine, propylamine, isopropylamine, and butylamine; aliphatic secondary amines such as dimethylamine, diethylamine, dipropylamine, diisopropylamine, and dibutylamine; and trimethylamine. , Aliphatic amines such as aliphatic tertiary amines such as triethylamine, tripropylamine, triisopropylamine and tributylamine; N,N,N′,N′-tetramethylethylenediamine, N,N,N′,N′ Aliphatic polyamines such as',N'-pentamethyldiethylenetriamine and 1,1,4,7,10,10-hexamethyltriethylenetetraamine; aromatic primary amines such as aniline and toluidine; aromatics such as diphenylamine Examples thereof include aromatic amines such as aromatic secondary amines and aromatic tertiary amines such as triphenylamine. Of these, aliphatic amines are preferable, and butylamine, dibutylamine, tributylamine and the like are particularly preferable.

The content ratio of each component in the polymerization initiator system consisting of a transition metal complex and an organic halogen compound, and a Lewis acid or an amine is not necessarily limited, but if the ratio of the transition metal complex to the organic halogen compound is too low. Polymerization tends to be slow, and conversely, if it is too high, the molecular weight distribution of the obtained polymer tends to be wide. Therefore, the transition metal complex:organohalogen compound molar ratio is 0.05:1 to 1:1. It is preferably in the range. Further, if the ratio of Lewis acid or amine to the transition metal complex is too low, the polymerization tends to be slow, and conversely, if it is too high, the molecular weight distribution of the resulting polymer tends to be wide. The molar ratio of is preferably in the range of 1:1 to 1:10.
The above living radical polymerization initiator system can be usually prepared by mixing a transition metal complex, a polymerization initiator of an organic halogen compound, and an activator of a Lewis acid or amine by a conventional method immediately before use. In addition, the transition metal complex, the polymerization initiator and the activator are separately stored, added separately to the polymerization reaction system, and mixed in the polymerization reaction system to function as a living radical polymerization initiator system. You may do it.

The polymerization initiator can be used in combination with a heat or photo radical generator. Specific examples of the heat radical generator include 2,2-azobis(isobutyronitrile), 2,2′-azobis(2-cyano-2-butane), dimethyl 2,2′-azobisdimethylisobutyrate. , 4,4'-azobis(4-cyanopentanoic acid), 1,1'-azobis(cyclohexanecarbonitrile), 2-(t-butylazo)-2-cyanopropane, 2,2'-azobis[2-methyl -N-(1,1)-bis(hydroxymethyl)-2-hydroxyethyl]propionamide, 2,2'-azobis[2-methyl-N-hydroxyethyl]]-propionamide, 2,2'-azobis (N,N'-dimethyleneisobutylamidine)dihydrochloride, 2,2'-azobis(2-amidinopropane)dihydrochloride, 2,2'-azobis(N,N'-dimethyleneisobutylamine),2,2 '-Azobis(2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide), 2,2'-azobis(2-methyl-N-[1,1-bis( Hydroxymethyl)ethyl]propionamide, 2,2′-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], 2,2-azobis(isobutyramide)dihydrate), 2,2′-azobis( 2,2,4-trimethylpentane), 2,2'-azobis(2-methylpropane), t-butylperoxyacetate, t-butylperoxybenzoate, t-butylperoxyoctate, t-butylperoxyneodeca. Noate, t-butylperoxyisobutyrate, t-amylperoxypivalate, t-butylperoxypivalate, di-isopropylperoxydicarbonate, dicyclohexylperoxydicarbonate, dicumylperoxide, dibenzoylperoxide, dilauroylperoxide. , Potassium peroxydisulfate, ammonium peroxydisulfate, di-t-butyl hyponitrite, dicumyl hyponitrite and the like.

Examples of the solvent used for living radical polymerization include cycloalkanes such as cyclohexane and cycloheptane; saturated carboxylic acids such as ethyl acetate, n-butyl acetate, i-butyl acetate, methyl propionate, and propylene glycol monomethyl ether acetate. Esters; Alkyl lactones such as γ-butyrolactone; Aethers such as tetrahydrofuran, dimethoxyethane, diethoxyethane; Alkyl ketones such as 2-butanone, 2-heptanone, methyl isobutyl ketone; Cycloalkyl ketones such as cyclohexanone Alcohols such as 2-propanol and propylene glycol monomethyl ether; aromatics such as toluene, xylene and chlorobenzene; aprotic polar solvents such as dimethylformamide, dimethylsulfoxide, dimethylacetamide and N-methyl-2-pyrrolidone; Alternatively, a non-solvent may be used.
These solvents can be used alone or in admixture of two or more.
Moreover, the reaction temperature in the said superposition|polymerization is 40-150 degreeC normally, Preferably it is 50-130 degreeC, and reaction time is 1-96 hours normally, Preferably it is 1-48 hours.

The polymer compound (X) narrow-dispersed using the above method has, for example, a cumulative value of volume% from a low molecular weight relative to a cumulative value of total molecular weight (100%) in a volume-based molecular weight distribution. The molecular weight corresponding to 50% is preferably 5,000 to 10,000.

In the present application, the ratio of the component having a molecular weight of 1000 or less in the polymer compound (X) is such that the pattern area of the component having a molecular weight of 1000 or less is 20% or less with respect to the total area of the pattern of gel permeation chromatography (GPC). The amount is preferably 0 to 10%, more preferably 0 to 5%.
More specifically, the ratio of components having a molecular weight of 1000 or less is detected on the lower molecular side than the standard by using monodisperse PS (polystyrene) having a molecular weight (Mw) of 1000 as a standard (reference). It is a value calculated by [(A)/((A)+(B))]×100(%), where (A) is the pattern area and the area detected on the polymer side is (B).

When the ratio of the component having a molecular weight of 1000 or less in the polymer compound (X) is within the above range, the amount of thickening of the pattern can be increased.

In the present invention, the proportion of the polymer compound (X) having a dissolution rate in butyl acetate of 5 nm/sec or less is 20% or less with respect to the total area in the pattern area of gel permeation chromatography. The amount is preferred.
Here, the dissolution rate with respect to butyl acetate is the rate when immersed in a butyl acetate solution at 23°C.
It is considered that when the solubility in butyl acetate is within the above range, it can contribute to the reduction of defects in the developing step in step D.

Hereinafter, preferable constituent units constituting the polymer compound (X) will be described.
The polymer compound (X) includes the structural unit (x1) represented by the general formula (x1-1), the structural unit (st) derived from styrene, and the structural unit (x2-1) represented by the general formula (x2-1). x2), the structural unit (hs) derived from hydroxystyrene, and the above-mentioned structural unit (a2), structural unit (a4), and the like.

(Structural unit (x1))
The structural unit (x1) is represented by the following general formula (x1-1).

［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。Ｖｘ^０１は、エーテル結合若しくはアミド結合を有する２価の炭化水素基、又は２価の芳香族炭化水素基、Ｙｘ^０１は単結合又は２価の連結基、Ｒｘ^１は窒素原子を有する置換基を示す。］

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Vx ⁰¹ is a divalent hydrocarbon group having an ether bond or an amide bond, or a divalent aromatic hydrocarbon group, Yx ⁰¹ is a single bond or a divalent linking group, and Rx ¹ is a substituent having a nitrogen atom. Show. ]

[R]
In general formula (x1-1), R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group.
The alkyl group having 1 to 5 carbon atoms in R is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specifically, methyl group, ethyl group, propyl group, isopropyl group, n- Examples thereof include a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, and a neopentyl group. The halogenated alkyl group having 1 to 5 carbon atoms is a group in which a part or all of hydrogen atoms of the alkyl group having 1 to 5 carbon atoms is 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.
As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and a hydrogen atom or a methyl group is most preferable from the viewpoint of industrial availability.

[Vx ⁰¹ ]
In general formula (x1-1), Vx ⁰¹ is a divalent hydrocarbon group having an ether bond or an amide bond, or a divalent aromatic hydrocarbon group.
The divalent hydrocarbon group having an ether bond or an amide bond in Vx ⁰¹ is a divalent hydrocarbon group optionally having an ether bond or an amide bond in Va ¹ in the general formula (a1-1). The explanation is the same.
The divalent aromatic hydrocarbon group for Vx ⁰¹ includes the aromatic hydrocarbon ring mentioned as the divalent aromatic hydrocarbon group for Va ¹ of the formula (a1-1) or two or more aromatic rings. An aryl group obtained by removing one hydrogen atom from an aromatic compound is mentioned, and a phenyl group and a naphthyl group are preferable.

[Yx ⁰¹ ]
In the general formula (x1-1), Yx ⁰¹ is a single bond or a divalent linking group. For the description of the divalent linking group in Yx ⁰¹ , the following is represented by Ya ²¹ in the general formula (a2-1). The same groups as those described for the divalent linking group can be mentioned. Among them, Yx ⁰¹ is preferably a linear or branched aliphatic hydrocarbon group, and the linear or branched aliphatic hydrocarbon group has 1 to 10 carbon atoms. Preferably, 1-6 are more preferable, 1-4 are more preferable, 1-3 are the most preferable.
As the linear aliphatic hydrocarbon group, preferably a linear alkylene group, and specific examples include a methylene group _[-CH 2 -], an ethylene group _{[- (CH 2) 2 -} ], trimethylene [ _{- (CH 2) 3 -]} , a tetramethylene group _{[- (CH 2) 4 -} ], a pentamethylene group _{[- (CH 2) 5 -} ] , and the like.
As the branched aliphatic hydrocarbon group, preferably a branched chain alkylene group, _{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 Alkylethylene group such as CH ₃ ) ₂ —CH ₂ —; alkyltrimethylene group such as —CH(CH ₃ )CH ₂ CH ₂ —, —CH ₂ CH(CH ₃ )CH ₂ —; —CH(CH ₃ ). Examples thereof include alkyl alkylene groups such as alkyl tetramethylene groups such as CH ₂ CH ₂ CH ₂ —, —CH ₂ CH(CH ₃ )CH ₂ CH ₂ — and the like. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

[Rx ¹ ]
In general formula (x1-1), Rx ¹ is a substituent having a nitrogen atom.
In the present invention, examples of suitable substituents having a nitrogen atom include primary, secondary, and tertiary aliphatic amines, aromatic amines, and heterocyclic amines.
As aliphatic amines, ethylamine, n-propylamine, sec-butylamine, tert-butylamine, hexylamine, cyclohexylamine, octylamine, dodecylamine, ethylenediamine, tetraethylenepentamine, dimethylamine, diethylamine, di-n-propyl. Amine, diisopropylamine, di-n-butylamine, diisobutylamine, di-sec-butylamine, dipentylamine, dihexylamine, dicyclohexylamine, dioctylamine, didodecylamine, N,N-dimethylethylenediamine, N,N-dimethyltetraethylene Pentamine, trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, triisobutylamine, tri-sec-butylamine, tripentylamine, trihexylamine, tricyclohexylamine, triheptylamine, Trioctylamine, tridecylamine, tridodecylamine, N,N,N',N'-tetramethylmethylenediamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N' -Tetramethyltetraethylenepentamine, dimethylethylamine, methylethylpropylamine, benzylamine, phenethylamine, benzyldimethylamine, monoethanolamine, diethanolamine, triethanolamine, N-ethyldiethanolamine, N,N-diethylethanolamine, triisopropanol Examples include amine, 2-aminoethanol, 3-amino-1-propanol, 4-amino-1-butanol, 2,2,6,6, tetramethylpiperidine, 2,2,6,6, pentamethylpiperidine, and the like. It

Examples of aromatic amines and heterocyclic amines include aniline, diphenyl(p-tolyl)amine, methyldiphenylamine, triphenylamine, phenylenediamine, naphthylamine, diaminonaphthalene, pyrrole, oxazole, thiazole, imidazole, pyrazole, furazan, pyrroline. , Pyrrolidine, imidazoline, imidazolidine, pyridine (preferably 2-(2-hydroxyethyl)pyridine), pyridazine, pyrimidine, pyrazine, pyrazoline, pyrazolidine, piperidine, piperazine (preferably 1-(2-hydroxyethyl)piperazine, 1 -[2-(2-hydroxyethoxy)ethyl]piperazine), morpholine (preferably 4-(2-hydroxyethyl)morpholine), indole, isoindole, 1H-indazole, indoline, quinoline, isoquinoline, cinnoline, quinazoline, quinoxaline. , Phthalazine, purine, pteridine, carbazole, phenanthridine, acridine, phenazine, 1,10-phenanthroline, adenine, adenosine, guanine, guanosine, uracil, uridine and the like.
These aromatic amines and heterocyclic amines may have a substituent. Preferred substituents which may be present are a hydroxyl group, an amino group, an alkyl group, an alkoxy group, an acyl group, an acyloxy group, an aryl group, an aryloxy group, a nitro group, a cyano group, an ester group and a lactone group.

Among them, Rx ¹ is preferably a group represented by any one of the following general formulas (Rx-1) and (Rx-2).

［式中、Ｒｘ^０１〜Ｒｘ^０４はそれぞれ独立に水素原子又は直鎖状若しくは分岐鎖状のアルキル基であり、ｎは０〜８の整数であり、＊はＹｘ^０１との結合手を示す。］

^Wherein, Rx 01 ^{to Rx 04} are each independently a hydrogen atom or a linear or branched alkyl group, n is an integer of 0-8, * represents a bond to ^{Yx 01.} ]

As the linear or branched alkyl group of Rx ^{01 to} Rx ⁰⁴ , an alkyl group having 1 to 10 carbon atoms is more preferable; 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, 1,1-dimethylethyl group, 1,1-diethylpropyl group, 2,2-dimethylpropyl group, 2,2,-dimethyl group A butyl group and the like can be mentioned.
Of these, a methyl group or an ethyl group is preferable.
n is an integer of 0 to 8, and is preferably 2 or 4.

Specific examples of the group represented by formula (Rx-1) are shown below. In the following specific examples, * indicates a bond.

The general formula (Rx-2) means a cyclic amine, and the group represented by the general formula (Rx-2) is preferably a group represented by the following general formula (Rx-2-1), and The group represented by General Formula (Rx-2-1) is particularly preferably the group represented by General Formula (Rx-2-1-1).

［式中、Ｒｘ^０５〜Ｒｘ^０６、Ｒｘ^０６１〜Ｒｘ^０６４はそれぞれ独立に水素原子又は直鎖状若しくは分岐鎖状のアルキル基であり、ｎ１は０〜８の整数であり、＊はＹｘ^０１との結合手を示す。］

[In the formula, Rx ^{05 to} Rx ⁰⁶ and Rx ^{061 to} Rx ⁰⁶⁴ are each independently a hydrogen atom or a linear or branched alkyl group, n1 is an integer of 0 to 8, and * represents Yx ⁰¹ and Shows the hand of joining. ]

The linear or branched alkyl group of Rx ^{05 to} Rx ⁰⁶ and Rx ^{061 to} Rx ⁰⁶⁴ is the same as described above for Rx ^{01 to} Rx ⁰⁴ . n1 is an integer of 0-8.
Specific examples of the group represented by formula (Rx-2) are shown below. In the following specific examples, * indicates a bond.

As the constitutional unit represented by the general formula (x1-1), a constitutional unit represented by any of the following general formulas (x1-1-1) to (x1-1-3) is 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。Ｙｘ^０１は単結合又は２価の連結基、Ｒｘ^１は窒素原子を有する置換基を示す。］

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Yx ⁰¹ represents a single bond or a divalent linking group, and Rx ¹ represents a substituent having a nitrogen atom. ]

In general formulas (x1-1-1) to (x1-1-3), R, Yx ⁰¹ , and Rx ¹ are the same as described above.

Below, the specific example of the structural unit represented by general formula (x1-1) is described. R in the following specific examples is the same as above.

The proportion of the structural unit (x1) in the polymer compound (X) is preferably from 1 to 80 mol%, more preferably from 1 to 75 mol%, based on all the constituent units constituting the polymer compound (X). ˜70 mol% is more preferred.

When the polymer compound (X) contains the structural unit (x1), a carboxy group, a hydroxyl group, a lactone, an acid anhydride, an ester, etc. present on the surface of the first resist pattern (hereinafter referred to as “hydroxyl group etc.”) In some cases, the first resist pattern can be thickened, which is preferable.

(Structural unit (st))
The structural unit (st) is a structural unit derived from styrene.
Here, the "structural unit derived from styrene" means that the hydrogen atom bonded to styrene and the carbon atom at the α-position of styrene is substituted with another substituent such as a halogen atom, an alkyl group or a halogenated alkyl group. And derivatives thereof (preferably those having a substituent such as the substituent described in the description of the divalent linking group of Ya ²¹ in the general formula (a2-1) bonded to the benzene ring, etc. ) Is included in the concept. The α-position (carbon atom at the α-position) of styrene is the carbon atom to which the benzene ring is bonded, unless otherwise specified.
Examples of the structural unit (st) include structural units (st1) represented by general formula (st1-1) shown below.

（式中、Ｒ^ｓｔは水素原子又はメチル基を表し、Ｒ^０１は炭素数１〜５のアルキル基を表し、ｍ_０２は０または１〜３の整数を表す。）

(In the formula, R ^st represents a hydrogen atom or a methyl group, R ⁰¹ represents an alkyl group having 1 to 5 carbon atoms, and m ₀₂ represents 0 or an integer of 1 to 3.)

In the structural unit (st1) represented by the general formula (st1-1), R ^st is a hydrogen atom or a methyl group, and preferably a hydrogen atom.
R ⁰¹ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and is 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, neopentyl group and the like. Industrially, a methyl group or an ethyl group is preferred.

The m ₀₂ is 0 or an integer of 1 to 3. Of these, m ₀₂ is preferably 0 or 1, and industrially preferably 0.
In addition, when m ₀₂ is 1, the substitution position of R ⁰¹ may be any of o-position, m-position and p-position, and when m ₀₂ is 2 or 3, any substitution is possible. The positions can be combined.

The proportion of the structural unit (st) in the polymer compound (X) is preferably 1 to 99 mol%, more preferably 1 to 97 mol%, based on all the constitutional units constituting the polymer compound (X). ˜96 mol% is more preferred.
When the polymer compound (X) in which the proportion of the bulky structural unit (st) is within the above range is adopted, the resist pattern surface can be easily thickened.

(Structural unit (x2))
The structural unit (x2) is represented by the following general formula (x2-1).

［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。Ｙｓ^０１は単結合又は２価の連結基、
Ｒｓ^０１はイソシアナート保護剤の残基を示す。］

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Ys ⁰¹ is a single bond or a divalent linking group,
Rs ⁰¹ represents a residue of an isocyanate protecting agent. ]

In general formula (x2-1), description of R is the same as the description of R in general formula (x1-1).
Ys ⁰¹ is a single bond or a divalent linking group. The description of the divalent linking group for Ys ⁰¹ is the same as the description of the divalent linking group for Ya ²¹ in the general formula (a2-1). Among the divalent linking groups described for Ya ²¹ in the general formula (a2-1), a divalent hydrocarbon group which may have a substituent is preferable, and a straight chain having 1 to 10 carbon atoms. Linear or branched aliphatic hydrocarbon groups are preferred.
The linear or branched aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, more preferably 1 to 4, and most preferably 1 to 3.
As the linear aliphatic hydrocarbon group, preferably a linear alkylene group, and specific examples include a methylene group _[-CH 2 -], an ethylene group _{[- (CH 2) 2 -} ], trimethylene [ _{- (CH 2) 3 -]} , a tetramethylene group _{[- (CH 2) 4 -} ], a pentamethylene group _{[- (CH 2) 5 -} ] , and the like.
As the branched aliphatic hydrocarbon group, preferably a branched chain alkylene group, _{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 Alkylethylene group such as CH ₃ ) ₂ —CH ₂ —; alkyltrimethylene group such as —CH(CH ₃ )CH ₂ CH ₂ —, —CH ₂ CH(CH ₃ )CH ₂ —; —CH(CH ₃ ). Examples thereof include alkyl alkylene groups such as alkyl tetramethylene groups such as CH ₂ CH ₂ CH ₂ —, —CH ₂ CH(CH ₃ )CH ₂ CH ₂ — and the like. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

In general formula (x2-1), Rs ⁰¹ represents a residue of an isocyanate protecting agent.
As the protective agent, for example, phenol, cresol, xylenol, ethylphenol, o-isopropylphenol, butylphenol such as p-tert-butylphenol, p-tert-octylphenol, nonylphenol, dinonylphenol, styrenated phenol, oxybenzoic acid ester, Phenols such as thymol, p-naphthol, p-nitrophenol, p-chlorophenol; methanol, ethanol, propanol, butanol, ethylene glycol, methyl cellosolve, butyl cellosolve, methyl carbitol, benzyl alcohol, phenyl cellosolve, furfuryl alcohol, Alcohols such as cyclohexanol; active methylenes such as dimethyl malonate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, acetylacetone; mercaptans such as butyl mercaptan, thiophenol, tert-dodecyl mercaptan; diphenylamine, phenylnaphthylamine, Amines such as aniline and carbazole; acid amides such as acetanilide, acetaniside, acetic acid amide, and benzamide; lactams such as ε-caprolactam, δ-valerolactam, γ-butyrolactam, β-propiolactam; succinimide and malein Acid imides such as acid imides; imidazoles such as imidazole, 2-methylimidazole, 2-ethylimidazole, pyrazoles such as pyrazole, 3,5-dimethyl-1H-pyrazole; ureas such as urea, thiourea and ethylene urea. System: Carbamic acid salt system such as phenyl N-phenylcarbamate, 2-oxazolidone: Imine system such as ethyleneimine, polyethyleneimine, propane-2-imine; formaldoxime, acetoaldoxime, acetoxime, methylethylketoxime, methyl Examples include oxime-based compounds such as isobutyl ketoxime and cyclohexanone oxime; bisulfite-based compounds such as sodium bisulfite and potassium bisulfite. These blocking agents may be used alone or in combination of two or more.

Among these, phenol-based, lactam-based, alcohol-based, oxime-based, pyrazole-based and imine-based are preferable, nonylphenol, styrenated phenol, oxybenzoic acid ester, acetoxime, methylethylketoxime, ε-caprolactam, pyrazole, 3,5. -Dimethyl-1H-pyrazole and propane-2-imine are particularly preferred.
The "residue of an isocyanate protecting agent" is a group obtained by removing a hydrogen atom from the above protecting agent.

The protecting group protects the highly reactive isocyanate group, but by heating above the dissociation temperature the protecting group is eliminated and an isocyanate group is generated, forming a cross-linked structure with the resist pattern and thickening the pattern. be able to.

As the residue of the isocyanate protecting agent in Rs ⁰¹ , more specifically, a nitrogen-containing cyclic group can be mentioned as a preferable group.
Examples of the nitrogen-containing cyclic group for Rs ⁰¹ include groups represented by any of the following (bc-r-1) to (bc-r-8).

［式中、Ｒｓ^００１は炭素数１〜５のアルキル基、ｎは０〜３の整数。＊は結合手を示す。］

^{Wherein, Rs 001} is an alkyl group having 1 to 5 carbon atoms, n represents an integer of 0 to 3. * Indicates a bond. ]

Examples of the alkyl group having 1 to 5 carbon atoms of Rs ⁰⁰¹ include a methyl group, an ethyl group, a propyl group, a butyl group, and a pentyl group, and a methyl group or an ethyl group is preferable.

Below, the specific example of the structural unit represented by general formula (x2-1) is described. In the following specific examples, 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.

In the present invention, when the first resist pattern coated with the crosslinking agent composition containing the polymer compound (X) is heated to the dissociation temperature or higher, protection in the structural unit (x2) in the polymer compound (X) is achieved. The group is eliminated and an isocyanate group is generated. This isocyanate group reacts with a hydroxyl group, a lactone, an acid anhydride, an ester and the like (hereinafter referred to as “hydroxyl group”) on the surface of the resist pattern, and a crosslinking reaction proceeds, so that the first resist pattern is thickened. Can be converted.

In the present invention, the structural unit (x2) may be a structural unit represented by general formula (x2)-2 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る。Ｙｓ^０１は２価の連結基、Ｒｓ^０２及びＲｓ^０３はそれぞれ独立に、メチル基、エチル基、ｎ−プロピル基、ｎ−ブチル基、及びｎ−ペンチル基からなる群から選択されるいずれか一つの基である。］

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Ys ⁰¹ is a divalent linking group, Rs ⁰² and Rs ⁰³ are each independently selected from the group consisting of a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group. It is one base. ]

In (x2)-2, R and Ys ⁰¹ are the same as described above.
Rs ⁰² and Rs ⁰³ each independently represent any one group selected from the group consisting of a methyl group, an ethyl group, an n-propyl group, an n-butyl group, and an n-pentyl group, and a methyl group or an ethyl group. Groups are preferred. Below, the specific example of the compound represented by general formula (x2)-2 is described. In the following specific examples, 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.

The structural unit (x2) may be derived from a commercially available compound. Examples of commercially available products include Karens MOI-BM (registered trademark) and Karens MOI-BP (registered trademark) manufactured by Showa Denko KK.

The proportion of the structural unit (x2) in the polymer compound (X) is preferably from 1 to 80 mol%, more preferably from 1 to 75 mol%, based on all the constituent units constituting the polymer compound (X). ˜70 mol% is more preferred.
It is considered that when the polymer compound (X) containing the structural unit (x2) in the above range is adopted, the pattern can be satisfactorily thickened by the crosslinking reaction.

(Structural unit (hs))
The structural unit (hs) is a structural unit derived from hydroxystyrene.
Here, the "hydroxystyrene derivative" means that the hydrogen atom bonded to the carbon atom at the α-position of hydroxystyrene is substituted with another substituent such as a halogen atom, an alkyl group or a halogenated alkyl group, and those The concept includes a derivative (preferably one having the above-mentioned substituent bonded to the benzene ring). The number of hydroxyl groups bonded to the benzene ring of hydroxystyrene is preferably an integer of 1 to 3, and more preferably 1. The α-position (carbon atom at the α-position) of hydroxystyrene is the carbon atom to which the benzene ring is bonded, unless otherwise specified.
The “structural unit derived from hydroxystyrene” means a structural unit formed by cleavage of the ethylenic double bond of hydroxystyrene or a hydroxystyrene derivative.
Examples of the structural unit (hs) include structural units (hs1) represented by the following general formula (I).

（式中、Ｒ^ｓｔは水素原子またはメチル基を表し、ｍ_０１は１〜３の整数を表す。）

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

In the structural unit (hs1) represented by the general formula (I), R ^st is a hydrogen atom or a methyl group, and preferably a hydrogen atom.
m ₀₁ is an integer of 1 to 3. Of these, m ₀₁ is preferably 1.
The position of the hydroxyl group may be any of the o-position, the m-position and the p-position, but since m is 1 and the hydroxyl group is at the p-position, it is easily available and inexpensive. preferable. When m ₀₁ is 2 or 3, arbitrary substitution positions can be combined.

The proportion of the structural unit (hs) in the polymer compound (X) is preferably from 1 to 99 mol%, more preferably from 1 to 97 mol%, based on all the constituent units constituting the polymer compound (X). More preferably, it is up to 98 mol %.
When the polymer compound (X) in which the proportion of the bulky structural unit (hs) is within the above range is adopted, it becomes easy to thicken the resist pattern surface.

In the present invention, as the polymer compound (X), the above structural unit (x1), structural unit (st), structural unit (x2) and structural unit (hs) may be used alone, respectively, and two or more types of structural units may be used. You may employ|adopt the high molecular compound which has.
In the present invention, a copolymer of the structural unit (x1) and the structural unit (a2) containing a lactone-containing cyclic group, the structural unit (x1), and the structural unit (a2) containing a lactone-containing cyclic group. A copolymer with the above structural unit (a4) and a copolymer with the structural unit (x1) and the structural unit (st) are preferable.

The polymer compound (X) is obtained by polymerizing a monomer that induces each structural unit by known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN) and dimethyl azobisisobutyrate. Can be obtained by
In the present invention, the degree of dispersion of the polymer compound (X) may be controlled to be 1.5 or less during radical polymerization.

In the present invention, the weight average molecular weight (Mw) (polystyrene conversion standard by gel permeation chromatography) of the polymer compound (X) is not particularly limited and is preferably 1,000 to 10,000,000, more preferably 1,500 to 500,000. , 2000 to 300000 is most preferable.
It is considered that the pattern can be satisfactorily thickened by setting the weight average molecular weight of the polymer compound (X) within the above range.

As the polymer compound (X), one type may be used alone, or two or more types may be used in combination.

〔solvent〕
The solvent contained in the shrink agent composition may be water or an organic solvent, and is not particularly limited as long as it does not dissolve the resist pattern, and the shrink agent composition material and the resist composition to be used are It can be selected as appropriate. When water is used as a solvent, pure water is preferable, and when an organic solvent is used, a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent, an ether solvent, etc., or a mixed solvent of two or more thereof. Is preferably used.
Among these, from the viewpoint of insolubility of the resist pattern, it is preferable to use an organic solvent, more preferably an ester solvent, and particularly preferably butyl acetate.
The total solid content concentration (total weight excluding the solvent) of the shrink agent composition is preferably 0.1 to 20% by mass, more preferably 0.1 to 10% by mass, and most preferably 0.1 to 10% by mass. It is 5% by mass.

In the step B, any method may be used as long as the above-mentioned shrink agent composition can be applied so as to cover the first resist pattern, and a conventionally known spin coating method, spraying method, roller coating method, dipping method may be used. Etc. can be used, and the shrink agent composition is preferably applied by spin coating.

[Step C]
In step C, a developer insoluble region is formed on the surface of the resist pattern.
As shown in FIG. 1C, carboxylic acid or the like is generated on the surface of the first resist pattern 2 by deprotection. When the shrink agent composition containing the polymer compound (X) is coated on the surface of the first resist pattern, for example, when the polymer compound (X) containing the structural unit (x1) is used. The carboxylic acid and the like and the base in the structural unit (x1) are neutralized, and a developing solution insoluble region is formed in the developing solution at the time of development in the subsequent step D.
More specifically, as shown in FIG. 1C, the developer insoluble region 2a is formed on the surface of the resist pattern 2.
Step C may or may not have a step of heating the resist pattern coated with the shrink agent composition after applying the shrink agent composition, but may have a step of heating. preferable. Thereby, the insoluble residual solvent can be removed, and further, the base in the shrink agent composition, the carboxylic acid on the resist pattern surface, the hydroxyl group, the lactone, the acid anhydride, the ester, etc. (hereinafter, described as “carboxylic acid etc.” Are neutralized to form a developer insoluble region.
In step C, the residual solvent can be removed by heating, and it is speculated that the neutralization reaction on the surface of the resist pattern proceeds better.

The heating temperature and time can be appropriately selected according to the type of resist material used, the type of shrink agent composition, and the reduction amount of the resist pattern. The heating temperature is preferably 0°C to 200°C, more preferably 50°C to 170°C. The heating time is preferably 30 to 300 seconds, more preferably 50 to 120 seconds, and particularly preferably 50 to 80 seconds.

When the shrink agent composition containing the polymer compound (X) having the structural unit (x2) is used, the shrink agent composition is applied, and then the resist pattern coated with the shrink agent composition is heated. As a result, the insoluble residual solvent can be removed, and further, the isocyanate group is generated, whereby the crosslinking reaction on the surface of the resist pattern proceeds.
The heating temperature and time can be appropriately selected according to the type of resist material used, the type of crosslinkable composition, and the reduction amount of the resist pattern. The heating temperature is preferably 80°C to 200°C, more preferably 100°C to 170°C. The heating time is preferably 30 to 300 seconds, more preferably 30 to 120 seconds, and particularly preferably 30 to 80 seconds.

When a shrink agent composition containing a polymer compound (X) containing a structural unit (st), a structural unit (hs), a structural unit (a2), a structural unit (a4), etc. is adopted, The polymer compound (X) adheres to the surface of the resist pattern to increase the thickness and form a developer insoluble region.

[Process D]
The present invention has a step D of developing the coated first resist pattern.
In step D, the excess shrink agent composition in step C and the unreacted shrink agent composition are removed.
The development treatment is performed using an alkali developing solution in the case of an alkali developing process and using a developing solution containing an organic solvent (organic developing solution) in the case of a solvent developing process.
After the development processing, rinsing processing is preferably performed. The rinse treatment is preferably a water rinse using pure water in the case of an alkali development process, and preferably a rinse liquid containing an organic solvent in the case of a solvent development process.
In the case of the solvent developing process, after the developing process or the rinsing process, a process of removing the developing solution or the rinsing solution adhering to the pattern with a supercritical fluid may be performed.
After development or rinsing, drying is performed. In some cases, a bake treatment (post bake) may be performed after the above development treatment. In this way, a resist pattern can be obtained.
In the present invention, the development treatment may be an alkali development process or a solvent development process, but is preferably a solvent development process from the viewpoint of removal efficiency of the shrink agent composition.
By the step D, as shown in FIG. 1D, a pattern thickened by forming the developer insoluble region 2a on the surface of the resist pattern 2 is formed. Thereby, a reduced pattern in which the hole pattern is reduced can be formed.

<<Shrinking agent composition>>
A second aspect of the present invention is a shrink agent composition used for coating a resist pattern and increasing the thickness of the resist pattern, which comprises the polymer compound (X), The shrinkage agent composition is characterized in that the degree of dispersion (X) (weight average molecular weight/number average molecular weight) is 1.5 or less.
The description of the shrink agent composition of the present invention is the same as the description of the shrink agent composition used in the resist pattern forming method of the first aspect of the present invention.

In the polymer compound (X) contained in the shrink agent composition of the present invention, the ratio of components having a molecular weight of 1000 or less in the polymer compound (X) is 20% with respect to the total area in the pattern area of gel permeation chromatography. The amount is preferably as follows.
In the polymer compound (X) contained in the shrink agent composition of the present invention, the ratio of the component having a solubility in butyl acetate of 5 nm/s or less in the polymer compound (X) is determined by gel permeation chromatography. The amount of the pattern area is preferably 20% or less of the total area.
Further, the shrink agent composition of the present invention preferably contains an organic solvent.

The shrink agent composition of the present invention can satisfactorily thicken the resist pattern, and for example, can form a reduced pattern in which the hole pattern formed using the resist composition is reduced.

<<Method for producing shrink agent composition>>
A third aspect of the present invention is a method for producing the shrink agent composition according to the second aspect of the present invention, which has a step of purifying by reprecipitation.
As described above, the shrink agent composition of the second aspect of the present invention contains the polymer compound (X), and the dispersity (weight average molecular weight/number average molecular weight) of the polymer compound (X) is 1. It is 5 or less. The polymer compound (X) contained in the shrink agent composition of the second aspect of the present invention has a step of purifying the polymer compound (X) by reprecipitation so that the polymer compound (X) has a predetermined dispersity.
Specifically, the degree of dispersion is 1.5 or less by polymerizing the monomer constituting the polymer compound (X) by radical polymerization or the like and purifying by the reprecipitation method described in the first aspect of the present invention. The polymer compound (X) can be obtained.

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

Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to the following examples.
<Preparation of resist composition>
100 parts by mass of the following polymer compound (A)-1, 6 parts by mass of the following compound (B)-1, 3 parts by mass of the following compound (D)-1, 1.5 parts by mass of the following polymer compound (F )-1, 100 parts by mass of γ-butyrolactone, and 4000 parts by mass of a solvent (a mixed solvent of PGMEA/PGME/cyclohexanone (mass ratio 45/30/25)) were mixed to prepare a resist composition.

<Formation of resist pattern>
A 12-inch silicon wafer is coated with an organic antireflection film composition "ARC29A" (trade name, manufactured by Brewer Science Co., Ltd.) using a spinner and baked on a hot plate at 205° C. for 60 seconds to be dried. As a result, an organic antireflection film having a film thickness of 89 nm was formed.
Then, the above resist composition was applied onto the film using a spinner, prebaked (PAB) was performed on a hot plate at a temperature of 105° C. for 60 seconds, and dried to give a film thickness of 85 nm. Was formed.
Then, the resist film was selectively irradiated with ArF excimer laser (193 nm) through a mask pattern (6% halftone) using an exposure apparatus NSRX609B (NA=1.07 Annular manufactured by Nikon Corporation).
Then, solvent development was performed for 13 seconds using butyl acetate.
After that, a heat treatment after exposure was performed at 80° C. (PEB (° C.)) for 60 seconds.
As a result, the following hole pattern (sometimes referred to as “resist pattern”) was formed.
Target 1: 75 nm mask/110 nm pitch/60 nm CH
Target 2: 155 nm mask/300 nm pitch/60 nm CH

[Process A]
<Preparation of shrink agent composition>
[Example of polymer synthesis]
In a separable flask connected with a thermometer, a reflux tube, and a nitrogen introduction tube, 10.00 g (58.77 mmol) of compound 1 and 13.24 g (58.77 mmol) of compound 2 were added to 34.86 g of methyl ethyl ketone (MEK). Dissolved. To this solution, 11.17 mmol of dimethyl 2,2′-azobis(isobutyrate) (V-601) was added as a polymerization initiator and dissolved to prepare a dropping solution.
The above dropping solution was added dropwise to MEK of 12.33 heated to 80° C. over 4 hours under a nitrogen atmosphere. After the completion of the dropping, the reaction solution was heated and stirred for 1 hour, and then the reaction solution was cooled to room temperature.
The reaction polymerization solution obtained was dropped into a large amount of n-heptane to precipitate the polymer, and the precipitated white powder was filtered off, washed with n-heptane and dried to obtain the desired product. 16.97 g of molecular compound 1 was obtained. The reaction formula is shown below.
The mass average molecular weight (Mw) in terms of standard polystyrene determined by GPC measurement of this polymer compound 1 was 7,700, and the molecular weight dispersity (Mw/Mn) was 2.68.
Further, the copolymerization composition ratio (the ratio (molar ratio) of each structural unit in the structural formula) determined by the carbon 13 nuclear magnetic resonance spectrum (600 MHz_ ¹³ C-NMR) was 1/m=50.5/49. It was 5.

By the same method as above, polymer compounds 2 to 7 having the monomer compositions shown in the following table were respectively synthesized, and the synthesized polymer compounds 1 to 7 were respectively dissolved in butyl acetate to prepare shrink agent compositions 1 to 7. did. The concentration of each of the polymer compounds 1 to 7 was 1.6 parts by mass.

In the above table, the symbols (M1 to M5) indicating monomers mean monomers having the following chemical structures.

<Application of shrink agent composition>
The shrink agent compositions 1 to 7 were applied using a spinner so as to cover the resist patterns obtained above.
The coating film thickness of the shrink agent composition was 60 nm. Table 2 shows the correspondence between the examples and the shrink agent compositions.

[Step B]
The resist pattern coated with the shrink agent composition obtained in the above [Step A] was heated to react the shrink agent composition with the resist pattern. The heating temperature at this time is described as "Shrink bake (° C.)" in Table 3 below. The heating time was 60 seconds.

[Step C]
After the above [Step B], solvent development was carried out for 13 seconds using butyl acetate to remove the unreacted portion of the shrink agent composition. As a result, the resist pattern was thickened and a reduced pattern in which holes were reduced was formed.

In Table 3, "SV (nm) 75M/110P" indicates the difference from the hole diameter of the first resist pattern in the 110-pitch pattern, and "SV (nm) 155M/300P" Shows the difference from the hole diameter of the first resist pattern in the pattern of 300 pitch. Further, “ID Bias (nm)” indicates the difference between “SV (nm) 75M/110P” and “SV (nm) 155M/300P”.

[Scum evaluation]
The shape of the reduced pattern obtained above was observed by a side length SEM and a cross section SEM, and evaluated according to the following criteria.
(Criteria)
◯: Scum did not occur after development.
X: Scum was generated after development.

As shown in the above results, the S.V. was improved when the shrink agent composition using the polymer compound having the dispersity of 1.5 or less was adopted.

1... Support, 2... Resist pattern, 3... Shrink agent composition layer, 2a... Developer insoluble region

Claims (10)

Step A of forming a first resist pattern on a support using a resist composition which generates an acid upon exposure and whose solubility in a developing solution changes due to the action of the acid,
A step B of applying a shrink agent composition containing the polymer compound (X) so as to cover the first resist pattern,
By the neutralization reaction between the acidic group on the surface of the first resist pattern coated with the shrink agent composition and the basic group in the polymer compound (X) obtained in the step B, a developer insoluble region is formed. Forming step C,
Step D of developing the coated first resist pattern,
Have
The polymer compound (X) contains a structural unit (x1) represented by the following general formula (x1-1), and the dispersity (weight average molecular weight/number average molecular weight) of the polymer compound (X) is Characterized by being 1.5 or less,
Resist pattern forming method.

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Vx ⁰¹ is a divalent hydrocarbon group having an ester bond or an amide bond, or a divalent aromatic hydrocarbon group, Yx ⁰¹ is a single bond or a divalent linking group, and Rx ¹ is the following general formula (Rx-2 ) Represents a cyclic amino group. ]

Wherein, ^{Rx 03} is a hydrogen atom, ^{Rx 04} is water atom or a linear or branched alkyl group, n is an integer of 0-8, * represents a bond with ^{Yx 01} Indicates. ] The method for forming a resist pattern according to claim 1, wherein the proportion of the component having a molecular weight of 1000 or less in the polymer compound (X) is 20% or less with respect to the total area in the pattern area of gel permeation chromatography. The proportion of a component having a solubility in butyl acetate of 5 nm/s or less in the polymer compound (X) is an amount such that it is 20% or less with respect to the entire area in the pattern area of gel permeation chromatography. Or the resist pattern forming method as described in 2 above. The resist pattern forming method according to claim 1, wherein the shrink agent composition contains an organic solvent. The resist pattern forming method according to claim 1, wherein the first resist pattern is a solvent development negative resist pattern. A shrink agent composition used for coating a resist pattern and thickening the resist pattern, comprising:
It contains a polymer compound (X) having a structural unit (x1) represented by the following general formula (x1-1), and the dispersity (weight average molecular weight/number average molecular weight) of the polymer compound (X) is 1 Shrinking agent composition characterized by being 0.5 or less.

[In formula, R is a hydrogen atom, a C1-C5 alkyl group, or a C1-C5 halogenated alkyl group. Vx ⁰¹ is a divalent hydrocarbon group having an ester bond or an amide bond, or a divalent aromatic hydrocarbon group, Yx ⁰¹ is a single bond or a divalent linking group, and Rx ¹ is the following general formula (Rx-2 ) Represents a cyclic amino group. ]

Wherein, ^{Rx 03} is a hydrogen atom, ^{Rx 04} is water atom or a linear or branched alkyl group, n is an integer of 0-8, * represents a bond with ^{Yx 01} Indicates. ] The shrink agent composition according to claim 6, wherein the proportion of the component having a molecular weight of 1000 or less in the polymer compound (X) is 20% or less with respect to the total area in the pattern area of gel permeation chromatography. The ratio of a component having a solubility in butyl acetate of 5 nm/s or less in the polymer compound (X) is an amount such that it is 20% or less with respect to the total area in the pattern area of gel permeation chromatography. Or the shrink agent composition according to item 7. The shrink agent composition according to any one of claims 6 to 8, wherein the shrink agent composition contains an organic solvent. The method for producing a shrink agent composition according to any one of claims 6 to 9, which has a step of purifying by reprecipitation.

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