TWI471700B - A positive resist composition, a photoresist pattern formation method, and a polymer compound - Google Patents

Description

Positive photoresist composition, formation method of photoresist pattern, polymer compound

The present invention relates to a novel polymer compound which can be utilized as a substrate component of a positive-type photoresist composition, a positive-type photoresist composition containing the polymer compound, and light using the positive-type photoresist composition The formation method of the resistance pattern.

In the lithography technique, for example, a photoresist film obtained from a photoresist material is formed on a substrate, and the photoresist film is selectively exposed to radiation such as light or electron lines by forming a mask of a specific pattern. The development process is carried out to form the photoresist film into a photoresist pattern having a specific shape.

The portion of the exposure which is changed to have a property of dissolving in the developer is referred to as a positive type, and the portion of the photoresist which is changed to have a property of not being dissolved in the developer is referred to as a negative type.

In recent years, in the manufacture of semiconductor elements or liquid crystal display elements, the micro-image etching technology has been rapidly advanced to refine the pattern.

The method of miniaturization is generally performed in such a manner as to shorten the wavelength of the exposure light source. Specifically, ultraviolet rays represented by g lines and i lines are conventionally used. But now it is starting to use KrF excimer lasers, or ArF excimer lasers for mass production of semiconductor components. Further, research has been started on F ₂ excimer lasers, electron beams, EUV (extreme ultraviolet rays) or X-rays having shorter wavelengths than the aforementioned excimer lasers.

The photoresist material is sought to have sensitivity to the exposure light sources, and has lithographic etching characteristics such as resolving the resolution of the fine size pattern.

A photoresist material which satisfies the above requirements is generally a chemically amplified photoresist composition containing a substrate component which changes the solubility of an alkali developer based on an acid action and an acid generator which generates an acid by exposure.

For example, a positive-type chemically amplified resist composition generally uses a resin component (base resin) containing an acid generator to increase the solubility to an alkali developer, and a photoresist having an acid generator component. When the photoresist film formed by the photoresist composition is selectively exposed during the formation of the photoresist pattern, the acid generated by the acid generator in the exposed portion is increased by the action of the acid. The solubility of the resin component in the alkali developer makes the exposed portion soluble in the alkali developer.

At present, the base resin of the photoresist used in ArF excimer laser lithography etching and the like has excellent transparency in the vicinity of 193 nm, and generally uses a structural unit derived from a (meth) acrylate in a main chain. Resin (acrylic resin) or the like (for example, Patent Documents 1 and 2). Here, "(meth)acrylic acid" means one or both of acrylic acid having a hydrogen atom bonded to the α-position and methacrylic acid having a methyl group bonded to the α-position. "(acrylic acid ester)" means an acrylate having a hydrogen atom bonded to the α-position and one or both of a methyl methacrylate bonded to the α-position. "(Meth)acrylate" means an acrylate having a hydrogen atom bonded to the α-position, and one or both of a methyl methacrylate bonded to the α-position.

Further, at present, a base resin for a chemically amplified photoresist has a resin containing a plurality of structural units for the purpose of improving the lithographic etching property and the like. In the case of a positive type, for example, a structural unit containing an acid dissociable dissolution inhibiting group which is dissociated by an action of an acid generated by an acid generator is used, and a structural unit having a polar group having a hydroxyl group or the like is also used. A resin such as a structural unit of an ester structure. Among these resins, a structural unit having a lactone structure generally improves the adhesion of the photoresist film to the substrate, improves the affinity with the alkali developing solution, and the like, and expects to improve the lithographic etching characteristics.

[Previous Technical Literature]

[Patent Document 1] JP-A-2003-241385

[Patent Document 2] JP-A-2006-016379

In the future, it is speculated that the micro-etching technology will be more advanced, and the application field will be more expanded. Therefore, there are various requirements for the novel materials used in the lithography etching application. For example, with the miniaturization of the pattern, the photoresist material also requires various lithographic etching characteristics such as resolution to be improved.

One of the lithographic etching characteristics is, for example, a mask defect factor-(MEF). MEF refers to the degree to which the different size resist patterns can faithfully reproduce (mask reproducibility) when the mask size is changed under the same exposure amount and at a fixed pitch. In the conventional photoresist composition, when the photoresist pattern is formed, it is often changed by the size of the mask used (the diameter of the through hole in the through hole pattern or the line width in the line and space pattern). As a result of the reduction in the amount of light received by the exposure portion, the size of the formed photoresist pattern is deviated from the size of the mask, or when a fine pattern is formed at a narrow pitch, the shape collapses. For example, when a via pattern having a via diameter of about 100 nm or less is formed, the roundness of the via hole may be lowered.

In view of the above, the present invention provides a useful novel polymer compound suitable as a substrate component of a positive photoresist composition, a compound suitable as a monomer of the polymer compound, and a polymer compound as described above. The positive resistive composition and the method of forming the photoresist pattern using the positive resist composition are for the purpose.

In order to achieve the above object, the present invention adopts the following constitution.

That is, the first aspect of the present invention is a positive-type photoresist composition which comprises a substrate component (A) which increases the solubility to an alkali developer via an action of an acid, and which occurs via exposure. The acid generator component (B) is characterized in that the substrate component (A) contains a structural unit (a0-1) represented by the following formula (a0-1), and the following formula a polymer compound (A1) of the structural unit (a0-2) represented by (a0-2),

In the formula, R ¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, R ² is a divalent bond group, and R ³ is a ring skeleton containing -SO _a cyclic group of ₂ -, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ²¹ is a branched alkyl group; and R ²² is a bondable with R ²² The bonded carbon atoms together form the base of the aliphatic monocyclic group].

A second aspect of the present invention is a method for forming a photoresist pattern, comprising the steps of forming a photoresist film on a support and using the positive photoresist composition of the first aspect; a step of exposing the photoresist film and a step of causing the photoresist film to be alkali developed to form a photoresist pattern.

According to a third aspect of the present invention, a polymer compound characterized by having the structural unit (a0-1) represented by the following formula (a0-1) and the following formula (a0-2) The structural unit represented (a0-2),

In the formula, R ¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, R ² is a divalent bond group, and R ³ is a ring skeleton containing -SO _a cyclic group of ₂ -, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ²¹ is a branched alkyl group; and R ²² is a bondable with R ²² The bonded carbon atoms together form the base of the aliphatic monocyclic group].

In the present specification and the scope of the present patent application, "aliphatic" is a concept of relativity with respect to aromatics, and is defined as a group or a compound having no aromaticity.

The "alkyl group" is a monovalent saturated hydrocarbon group containing a linear chain, a branched chain, and a ring, unless otherwise specified.

The "alkylene group" is a divalent saturated hydrocarbon group containing a linear chain, a branched chain, and a ring, unless otherwise specified. The alkyl group in the alkoxy group is also the same.

The "halogenated alkyl group" is a group in which a part or all of a hydrogen atom of an alkyl group is substituted by a halogen atom, and the halogen atom is, for example, a fluorine atom, a chlorine atom, a bromine atom or an iodine atom.

The "fluorinated alkyl group" or "fluorinated alkyl group" means a group in which a part or all of a hydrogen atom of an alkyl group or an alkyl group is substituted by a fluorine atom.

The "structural unit" means a monomer unit constituting a polymer compound (resin, polymer, copolymer).

The "structural unit derived from acrylate" means the structural unit composed of the cleavage of the ethylenic double bond of the acrylate.

The "acrylate" has a concept in which a carbon atom bonded to a hydrogen atom at the alpha atom is bonded to a carbon atom in the alpha position (atom or a group other than a hydrogen atom). The substituent bonded to the carbon atom at the α-position is, for example, an alkyl group having 1 to 5 carbon atoms, a halogenated alkyl group having 1 to 5 carbon atoms, or a hydroxyalkyl group. Further, the carbon atom at the α position of the acrylate means, unless otherwise specified, the meaning of the carbon atom to which the carbonyl group is bonded.

"Exposure" is the concept of including radiation exposure.

The present invention provides a novel polymer compound which can be utilized as a substrate component of a positive photoresist composition, a positive photoresist composition containing the polymer compound, and a positive photoresist composition using the same The formation method of the photoresist pattern.

<Positive photoresist composition> filial

The positive-type resist composition of the present invention (hereinafter also referred to as a photo-resist composition) is a substrate component (A) containing an increase in solubility in an alkali developer via an action of an acid (hereinafter, Also known as (A) component, and an acid generator component (B) (hereinafter, also referred to as component (B)) which generates an acid via irradiation with radiation.

In the positive resist composition, when irradiated with radiation (exposure), an acid is generated from the component (B), and the solubility of the component (A) to the alkali developer is increased by the action of the acid. Therefore, in the formation of the photoresist pattern, when the photoresist film obtained by using the positive photoresist composition is selectively exposed, the exposed portion of the photoresist film is increased in solubility to the alkali developer. At the same time, in the case where the unexposed portion does not change in the solubility of the alkali developing solution, an alkali development method can be employed to form a photoresist pattern.

Here, the "substrate component" means an organic compound having the ability to form a film. The substrate component is preferably an organic compound having a molecular weight of 500 or more. When the molecular weight of the organic compound is 500 or more, the film forming ability can be improved, and a photoresist pattern of a nanometer degree can be easily formed.

The "organic compound having a molecular weight of 500 or more" used as the substrate component can be roughly classified into a non-polymer and a polymer.

The non-polymer is usually a substance having a molecular weight of 500 or more and less than 4,000. Hereinafter, a non-polymer having a molecular weight of 500 or more and less than 4,000 is referred to as a low molecular compound.

The polymer is usually a substance having a molecular weight of 2,000 or more. Hereinafter, a polymer having a molecular weight of 2,000 or more is referred to as a polymer compound. In the case of a polymer compound, "molecular weight" is a polystyrene-converted mass average molecular weight obtained by GPC (gel permeation chromatography). Hereinafter, the polymer compound may also be referred to as "resin".

<(A) component> [polymer compound (A1)]

The polymer compound (A1) (hereinafter also referred to as (A1) component) contains the structural unit (a0-1) represented by the above formula (a0-1) and represented by the above formula (a0-2) The structural unit (a0-2).

The component (A1), other than the structural unit (a0-1), and (a0-2), is derived from an acrylate having a structural unit different from each of the above structural units and containing an acid dissociable dissolution inhibiting group. The structural unit (a1) is preferred.

(A1) component, in addition to structural units (a0-1), and (a0-2), or structural units (a0-1), (a0-2), and (a1), further containing a lactone-containing The structural unit (a2) derived from the cyclic acrylate is preferred.

Further, the component (A1), other than the structural unit (a0-1), and (a0-2), or the structural unit (a0-1), (a0-2), and (a1), or the structural unit (a0) In addition to -1), (a0-2), and (a2), or structural units (a0-1), (a0-2), (a1), and (a2), further having an aliphatic group containing a polar group The structural unit (a3) derived from the hydrocarbyl acrylate is preferred.

(Structural unit (a0-1))

The structural unit (a0-1) is a structural unit represented by the above formula (a0-1).

In the formula (a0-1), R ¹ 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 alkyl group of R ¹ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, specifically, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group or an n-butyl group. Isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, and the like.

The halogenated alkyl group having 1 to 5 carbon atoms of R ¹ , for example, a part or all of a hydrogen atom of the alkyl group having 1 to 5 carbon atoms is substituted by a halogen atom. The halogen atom is, for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom or the like, and particularly preferably a fluorine atom.

R ^{1 is} preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms, and is preferably a hydrogen atom or a methyl group in terms of ease of industrial availability.

In the formula (a0-1), R ² is a divalent bond group.

R ^{2 is} preferably a divalent hydrocarbon group which may have a substituent, a divalent bond group containing a hetero atom, or the like.

The "having a substituent" of the hydrocarbon group means that a part or all of a hydrogen atom in the hydrocarbon group is substituted by a group or an atom other than a hydrogen atom.

The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. The aliphatic hydrocarbon group is intended to be a hydrocarbon group having no aromaticity.

The aliphatic hydrocarbon group may be either saturated or unsaturated, and is usually saturated.

More specifically, the aliphatic hydrocarbon group is, for example, a linear or branched aliphatic hydrocarbon group or a hydrocarbon group having a ring in the structure.

The linear or branched aliphatic hydrocarbon group preferably has a carbon number of from 1 to 10, preferably from 1 to 8, more preferably from 1 to 5, most preferably from 1 to 2.

a linear aliphatic hydrocarbon group, preferably a linear alkyl group, specifically, for example, methyl [-CH ₂ -], ethyl (-(CH ₂ ) ₂ -), or The group [-(CH ₂ ) ₃ -], tetramethyl [-(CH ₂ ) ₄ -], pentamethyl [-(CH ₂ ) ₅ -], and the like.

The branched aliphatic hydrocarbon group is preferably a branched alkyl group, specifically, for example, -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 - or the like alkyl-methyl group; CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH ₃ )-, -C(CH ₃ ) ₂ CH ₂ -, -CH(CH ₂ CH ₃ )CH ₂ -, -C(CH ₂ CH _{3) 2} -CH ₂ -, etc. extending ethyl _{group; -CH (CH 3) CH 2} CH 2 -, - CH 2 CH (CH 3) CH 2 - , etc. extending trimethyl alkyl; -CH (CH ₃ ) An alkyl group such as CH ₂ CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ CH ₂ - or the like is extended to an alkyl group such as a tetramethyl group. The alkyl group in the alkylalkyl group is preferably a linear alkyl group having 1 to 5 carbon atoms.

The chain aliphatic hydrocarbon group may have a substituent or may have no substituent. The substituent is, for example, a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms substituted by a fluorine atom, an oxygen atom (=O) or the like.

The structure contains a ring-shaped aliphatic hydrocarbon group, for example, a cyclic aliphatic hydrocarbon group (a group obtained by removing two hydrogen atoms from an aliphatic hydrocarbon ring), and the cyclic aliphatic hydrocarbon group is bonded to the terminal of the aforementioned chain aliphatic hydrocarbon group. Or a group in the middle of a chain aliphatic hydrocarbon group.

The cyclic aliphatic hydrocarbon group preferably has a carbon number of from 3 to 20, more preferably from 3 to 12.

The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. The monocyclic group, for example, a monocyclic alkane having 3 to 6 carbon atoms is preferably a group in which two hydrogen atoms are removed, and the monocyclic alkane is, for example, cyclopentane or cyclohexane. A polycyclic group, for example, a polycycloalkane having 7 to 12 carbon atoms is preferred, and a base of 2 hydrogen atoms is preferably removed, and specific examples of the polycyclic alkane, such as adamantane, raw spinel, isopentane, and tricyclic guanidine Alkane, tetracyclododecane, and the like.

The cyclic aliphatic hydrocarbon group may have a substituent or may have no substituent. The substituent is, for example, an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted by a fluorine atom, an oxygen atom (=O) or the like.

The hetero atom in the "two-valent bond group containing a hetero atom" means an atom other than a carbon atom and a hydrogen atom, for example, an oxygen atom, a nitrogen atom, a sulfur atom, or a halogen atom.

a divalent bond group containing a hetero atom, specifically, for example, -O-, -C(=O)-, -C(=O)-O-, carbonate bond (-OC(=O) -O-), -NH-, -NR ⁰⁴ (R ⁰⁴ is an alkyl group)-, -NH-C(=O)-, =N-, and the like. Further, the combination of "a divalent bond group containing a hetero atom" and a divalent hydrocarbon group. The divalent hydrocarbon group is, for example, the same as the above-mentioned hydrocarbon group which may have a substituent, and is preferably a linear or branched aliphatic hydrocarbon group.

R ² may have an acid dissociable site in its structure, and may have no acid dissociable site. The "acid dissociable portion" means a portion in the organic group which is dissociated by the action of an acid generated by exposure. In the case where R ² has an acid dissociable moiety, it is preferred to have an acid dissociable moiety having a tertiary carbon atom.

In the present invention, the divalent bond group of R ² is preferably, for example, an alkylene group, a divalent aliphatic ring group or a divalent bond group containing a hetero atom. Among them, alkylene is particularly preferred.

When R ² is an alkylene group, the alkylene group is preferably a carbon number of 1 to 10, more preferably a carbon number of 1 to 6, a carbon number of 1 to 4, and a carbon number of 1 to 3. good. Specifically, for example, it is the same as the above-mentioned linear alkyl group and branched chain alkyl group.

When R ² is a divalent aliphatic cyclic group, the aliphatic cyclic group is the same as the cyclic aliphatic hydrocarbon group exemplified in the above-mentioned "aliphatic hydrocarbon group having a ring in the structure".

The aliphatic cyclic group is particularly preferably obtained by removing two or more hydrogen atoms from cyclopentane, cyclohexane, raw spinane, isopentane, adamantane, tricyclodecane or tetracyclododecane. .

R ² is a case of a divalent bond group containing a hetero atom, and preferred of the bond group is, for example, -O-, -C(=O)-O-, -C(=O)-, -OC (=O)-O-, -C(=O)-NH-, -NH- (H can be substituted by a substituent such as an alkyl group or a fluorenyl group), -S-, -S(=O) ₂ -, -S(=O) ₂ -O-, a group represented by the formula -AOB-, a group represented by the formula -[AC(=O)-O] _m -B-, and the like. Here, A and B are each a divalent hydrocarbon group which may have a substituent, and m is an integer of 0-3.

In the case where R ² is -NH-, H may be substituted with a substituent such as an alkyl group or a thiol group. The substituent (alkyl group, mercapto group or the like) is preferably a carbon number of from 1 to 10, more preferably from 1 to 8, particularly preferably from 1 to 5.

-AOB- or -[AC(=O)-O] _m -B-, A and B, each independently a divalent hydrocarbon group which may have a substituent.

The divalent hydrocarbon group which may have a substituent in A and B is, for example, the same as those listed in the above-mentioned R ² "a divalent hydrocarbon group which may have a substituent".

A, a linear aliphatic hydrocarbon group is preferred, a linear alkyl group is preferred, and a linear alkyl group having 1 to 5 carbon atoms is more preferred. The base is especially good.

B, preferably a linear or branched aliphatic hydrocarbon group, more preferably a methyl group, an ethyl group or an alkyl group. The alkyl group in the alkyl 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.

Further, in the group represented by the formula -[AC(=O)-O] _m -B-, m is an integer of 0 to 3, an integer of 0 to 2 is preferably used, and 0 or 1 is more preferable, and 1 is optimal.

In the formula (a0-1), R ³ is a cyclic group containing -SO ₂ - in the ring skeleton.

The cyclic group in R ³ means a ring group containing a ring containing -SO ₂ - in the ring skeleton, and the ring is counted as a ring, and only the ring is in the form of a monocyclic group. In the case of other ring configurations, the structure is referred to as a polycyclic base. The cyclic group in R ³ may be a monocyclic group or a polycyclic group.

R ^{3 is} particularly preferably a cyclic group having -O-SO ₂ - in its ring skeleton.

The ring group in R ³ preferably has a carbon number of from 3 to 30, preferably from 4 to 20, more preferably from 4 to 15, and particularly preferably from 4 to 12. Here, the carbon number is the number of carbon atoms constituting the ring skeleton, and is the number of carbon atoms in the substituent.

The cyclic group in R ³ may be an aliphatic cyclic group or an aromatic cyclic group. It is preferably an aliphatic cyclic group.

The aliphatic cyclic group in R ³ is, for example, a group in which one of the carbon atoms of the ring skeleton constituting the cyclic aliphatic hydrocarbon group exemplified above is substituted with -SO ₂ - or -O-SO ₂ - or the like.

More specifically, for example, the monocyclic group is a group in which a monocyclic alkane in which -CH ₂ - which is a ring skeleton is substituted by -SO ₂ - removes one hydrogen atom, and -CH ₂ constituting the ring -CH ₂ - A monocyclic alkane substituted with -O-SO ₂ - removes a group of one hydrogen atom or the like. Further, as the polycyclic group constituting the skeleton of the ring -CH ₂ - is -SO ₂ - as much as cycloalkane (bicyclo alkane, tricyclo alkane, tetracyclo alkane, etc.) substituted with one removed A group obtained by a hydrogen atom, a group obtained by removing one hydrogen atom from a polycyclic alkane in which -CH ₂ -CH ₂ - substituted by -O-SO ₂ - is substituted.

The cyclic group in R ³ may have a substituent. The substituent is, for example, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (=O), -COOR", -OC(=O)R", a hydroxyalkyl group, a cyano group or the like.

The alkyl group of the substituent is preferably, for example, an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably a linear or branched chain. Specifically, for example, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl and the like. Among them, methyl or ethyl is preferred, and methyl is particularly preferred.

The alkoxy group of the substituent is preferably, for example, an alkoxy group having 1 to 6 carbon atoms. The alkoxy group is preferably a linear or branched chain. Specifically, for example, a group bonded to an oxygen atom (-O-) in the alkyl group exemplified as the alkyl group of the above substituent.

The halogen atom of the substituent, for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom or the like, is preferably a fluorine atom.

The halogenated alkyl group of the substituent, for example, a part or all of a hydrogen atom of the above-mentioned alkyl group is substituted by the aforementioned halogen atom or the like.

The halogenated alkyl group of the substituent, for example, a part or all of a hydrogen atom in the alkyl group exemplified by the alkyl group of the above substituent is substituted by the above halogen atom. The halogenated alkyl group is preferably a fluorinated alkyl group, particularly preferably a perfluoroalkyl group.

Any of R-" in the above -COOR" and -OC(=O)R" is a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms.

When R" is a linear or branched alkyl group, it is preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group.

When R" is a cyclic alkyl group, it is preferably 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, for example, a fluorine atom can be used. Or a fluorinated alkyl group may be substituted, and a polycyclic alkane such as a monocyclic alkane, a bicycloalkane, a tricycloalkane or a tetracycloalkane which is not substituted may be one obtained by removing one or more hydrogen atoms. More specifically, a monocyclic alkane such as cyclopentane or cyclohexane, or a polycyclic alkane such as adamantane, raw spinane, isopentane, tricyclodecane or tetracyclododecane is removed. The base obtained by more than one hydrogen atom, and the like.

The hydroxyalkyl group of the substituent is preferably, for example, a carbon number of 1 to 6, and specifically, for example, a group in which at least one hydrogen atom of the alkyl group recited in the alkyl group of the substituent is substituted with a hydroxyl group. Wait.

R ^{3 is} more specifically, for example, a group represented by the following general formulae (3-1) to (3-4).

[wherein 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, a is an integer of 0 to 2, and R ⁶ is an alkyl group, an alkoxy group, or a halogenated group. Alkyl, hydroxy, -COOR", -OC(=O)R", hydroxyalkyl or cyano, R" is a hydrogen atom or an alkyl group].

In the above formulae (3-1) to (3-4), A' is an alkylene group having 1 to 5 carbon atoms which may contain an oxygen atom (-O-) or a sulfur atom (-S-), or an oxygen atom or Sulfur atom.

The alkylene group having 1 to 5 carbon atoms in A' is preferably a linear or branched alkyl group, for example, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group or the like.

The alkylene group contains an inert form of an oxygen atom or a sulfur atom, and specifically, for example, a terminal of the alkylene group or a group having a -O- or -S- group, such as -O-CH ₂ -, CH ₂ -O-CH ₂ -, -S-CH ₂ -, -CH ₂ -S-CH ₂ -, and the like.

A' is preferably, for example, an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methyl group.

a is 0 to 2, and 0 is the best.

In the case where a is 2, the plural R ² may be the same or different.

R ⁶ in the alkyl group, alkoxy group, halogenated alkyl group, -COOR ", - OC (= O) R", a hydroxyl group, in the group may have a substituent respectively and the ³ in the cyclic group of R The alkyl, alkoxy, alkyl halide, -COOR", -OC(=O)R", and hydroxyalkyl groups are the same.

Hereinafter, specific ring groups represented by the above formulas (3-1) to (3-4) will be exemplified. Also, the "Ac" in the formula is the meaning of the acetamino group.

R ³ , in the above, is preferably a group represented by the following formula (3-1), and the above chemical formulas (3-1-1), (3-1-18), (3-3-) are used. It is more preferable that at least one selected from the group represented by any of 1) and (3-4-1) is the group represented by the chemical formula (3-1-1).

In the present invention, the structural unit (a0-1) is particularly preferably a structural unit represented by the following general formula (a0-1-11).

[wherein R ¹ is the same as described above, and R ^{2 '} is a linear or branched alkyl group, and A' is the same as described above].

The linear or branched chain alkyl group in R ^{2 '} is preferably 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 5 carbon atoms, and particularly preferably 1 to 3 carbon atoms. , 1 to 2 is the best.

A' is preferably a methyl group, an oxygen atom (-O-) or a sulfur atom (-S-).

The structural unit (a0-1) may be used singly or in combination of two or more.

(A1) The ratio of the structural unit (a0-1) in the composition, when the photoresist pattern is formed using the positive photoresist composition containing the (A1) component, the MEF is formed, and the formed photoresist pattern is formed. The shape, CDU (in-plane uniformity), LWR (line width unevenness), etc., are preferably 1 to 60 mol%, and 5 to 50 mol%, based on the total structural unit of the component (A1). Preferably, it is more preferably 10 to 45 mol%.

(Structural unit (a0-2))

The structural unit (a0-2) is a structural unit represented by the above formula (a0-2). Further, it is a structural unit derived from an acrylate which does not have the above structural unit (a0-1) and which contains an acid dissociable dissolution inhibiting group.

The acid dissociable dissolution inhibiting group in the structural unit (a0-2) has an alkali dissolution inhibiting property which is insoluble to the alkali developing solution by the entire component (A1) before dissociation, and is caused by dissociation of the acid (A1). The entire composition increases the solubility of the alkali developer.

In the formula (a0-2), R is the same as R ¹ in the above formula (a0-1).

In the formula (a0-2), R ²² is a group which can form an aliphatic monocyclic group together with the carbon atom bonded to the R ²² .

Here, the "aliphatic monocyclic group" means a monocyclic group having no aromatic property.

The aliphatic monocyclic group in R ²² is preferably a carbon number of 4 to 8 and more preferably 5 to 8.

Here, the carbon number is the number of carbon atoms constituting the ring skeleton, and is the number of carbon atoms in the substituent.

The aliphatic monocyclic group in R ²² may have a substituent or may have no substituent. The substituent is, for example, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted by a fluorine atom, or an oxygen atom (=O).

The basic ring structure of the aliphatic monocyclic group-removing substituent is not limited to a group (hydrocarbon group) formed of carbon and hydrogen, but a hydrocarbon group is preferred. Further, the "hydrocarbon group" may be either saturated or unsaturated, and it is usually preferred to saturate.

The aliphatic monocyclic group may be, for example, substituted by an alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated alkyl group, and the unsubstituted polycycloalkane may be obtained by removing one or more hydrogen atoms. Base. More specifically, for example, a monocyclic alkane such as cyclopentane or cyclohexane is obtained by removing one or more hydrogen atoms. Further, a part of the carbon atoms of the ring constituting the group obtained by removing one or more hydrogen atoms of the monocyclic alkane may be substituted by an etheric oxygen atom (-O-).

In the formula (a0-2), R ²¹ is a branched alkyl group.

The branched chain alkyl group preferably has 3 to 10 carbon atoms and more preferably 3 to 5 carbon atoms. Specifically, for example, isopropyl, isobutyl, tert-butyl, isopentyl, neopentyl, etc., and isopropyl are most preferred.

Specific examples of the structural unit represented by the formula (a0-2) are, for example, structural units represented by the following formulas (a0-2-1) to (a0-2-20).

[wherein, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group. ]

The structural unit (a0-2) may be used singly or in combination of two or more.

The ratio of the structural unit (a0-2) in the component (A1) is preferably from 1 to 60 mol%, more preferably from 5 to 50 mol%, based on the total structural unit constituting the component (A1). 10 to 45 mol% is better.

(Structural unit (a1))

The structural unit (a1) is a structural unit derived from an acrylate containing an acid dissociable dissolution inhibiting group of the structural unit (a0-1) and the structural unit (a0-2).

The acid dissociable dissolution inhibiting group in the structural unit (a1) has an alkali dissolution inhibitory property in which the entire component (A1) is insoluble to the alkali developing solution before dissociation, and the (A1) component is obtained by dissociation of the acid. As the group which increases the solubility to the alkali developing solution, the acid dissociable dissolution inhibiting group which has been proposed as a base resin for a chemical smear type resist can be used. In general, it refers to a group which forms a cyclic or chain-like tertiary alkyl ester with a carboxyl group in (meth)acrylic acid or the like; it is widely known as an acetal type acid dissociable dissolution inhibiting group such as an alkoxyalkyl group. Wait. Moreover, "(meth) acrylate" means one or both of an acrylate in which a hydrogen atom is bonded to the α-position, and a methacrylate in which a methyl group is bonded to the α-position.

Here, the "trialkyl ester" means a hydrogen atom of a carboxyl group which is substituted by a chain or a cyclic alkyl group to form an ester, and an oxygen atom at the terminal of a carbonyloxy group (-C(O)-O-) a structure formed by bonding to a tertiary carbon atom of the aforementioned chain or cyclic alkyl group. In the tertiary alkyl ester, when an acid acts, the bond between the oxygen atom and the tertiary carbon atom can be cut.

Further, the aforementioned chain or cyclic alkyl group may have a substituent.

Hereinafter, in the case of forming a tertiary alkyl ester with a carboxyl group, an acid dissociable group is formed, and for convenience, it is referred to as a "trialkyl ester type acid dissociable dissolution inhibiting group".

The tertiary alkyl ester type acid dissociable dissolution inhibiting group is, for example, an aliphatic branched chain acid dissociable dissolution inhibiting group, an acid dissociable dissolution inhibiting group containing an aliphatic cyclic group, or the like.

Here, the "aliphatic branched chain" means a structure having a branched chain shape containing no aromaticity. The structure of the "aliphatic branched chain acid dissociable dissolution inhibiting group" is not limited to a group (hydrocarbon group) formed of carbon and hydrogen, but a hydrocarbon group is preferred. Further, the "hydrocarbon group" may be either saturated or unsaturated, and it is usually preferred to saturate.

The aliphatic branched chain acid dissociable dissolution inhibiting group is, for example, a group represented by -C(R ⁷¹ )(R ⁷² )(R ⁷³ ). In the formula, R ⁷¹ to R ⁷³ are each independently a linear alkyl group having 1 to 5 carbon atoms. a group represented by -C(R ⁷¹ )(R ⁷² )(R ⁷³ ), preferably having a carbon number of 4 to 8, specifically, for example, tert-butyl, 2-methyl-2-butyl, 2- Methyl-2-pentyl, 3-methyl-3-pentyl and the like. Especially tert-butyl is preferred.

The "aliphatic cyclic group" is a monocyclic group or a polycyclic group having no aromaticity.

The "aliphatic cyclic group" in the structural unit (a1) may have a substituent or may have no substituent. The substituent is, for example, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted by a fluorine atom, or an oxygen atom (=O).

The structure of the basic ring from which the substituent of the "aliphatic cyclic group" is removed is not limited to a group (hydrocarbon group) formed of carbon and hydrogen, but a hydrocarbon group is preferred. Further, the "hydrocarbon group" may be either saturated or unsaturated, and it is usually preferred to saturate. The "aliphatic ring group" is preferably a polycyclic group.

The aliphatic cyclic group may be, for example, substituted by an alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated alkyl group, or a monocyclic alkane which is not substituted may be obtained by removing one or more hydrogen atoms. A group obtained by removing one or more hydrogen atoms from a polycyclic alkane such as a bicycloalkane, a tricycloalkane or a tetracycloalkane. More specifically, a monocyclic alkane such as cyclopentane or cyclohexane is used to remove one or more hydrogen atoms, or adamantane, raw spinel, iso-araconine, tricyclodecane, tetracycline A group obtained by removing one or more hydrogen atoms from a polycyclic alkane such as dioxane. Further, a part of the carbon atoms of the constituent ring of the group obtained by removing one or more hydrogen atoms from the monocyclic alkane and removing one or more hydrogen atoms by the polycyclic alkane may be an etheric oxygen atom ( -O-) can also be replaced.

An acid dissociable dissolution inhibiting group containing an aliphatic cyclic group, for example, (i) a group having a tertiary carbon atom in a ring skeleton of a monovalent aliphatic ring group; (ii) having a monovalent aliphatic ring type a group, a group having a branched chain alkyl group having a tertiary carbon atom bonded thereto; and the like.

(i) Specific examples of the group having a tertiary carbon atom in the ring skeleton of the monovalent aliphatic ring group, for example, a group represented by the following general formulae (1-1) to (1-9).

(ii) Specific examples of a monovalent aliphatic cyclic group and a branched alkyl group having a tertiary carbon atom bonded thereto, for example, the following general formula (2-1) to (2) -6) The base represented.

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

[wherein, R ¹⁵ and R ¹⁶ are independently alkyl groups].

The alkyl group of the above R ¹⁴ is preferably a linear or branched alkyl group.

The linear alkyl group preferably has a carbon number of 1 to 5, preferably 1 to 4, more preferably 1 or 2. Specifically, for example, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group or the like. Among them, a methyl group, an ethyl group or an n-butyl group is preferred, and a methyl group or an ethyl group is more preferred.

The branched chain alkyl group preferably has 3 to 10 carbon atoms and more preferably 3 to 5 carbon atoms. Specifically, for example, isopropyl, isobutyl, tert-butyl, isopentyl, neopentyl, etc., and isopropyl are most preferred.

Wherein, the aliphatic cyclic group is a monocyclic group, and the alkyl group of R ¹⁴ does not contain a branched alkyl group.

g is preferably an integer of 0 to 3, more preferably an integer of 1 to 3, and most preferably 1 or 2.

The alkyl group of R ¹⁵ to R ¹⁶ is, for example, the same as the alkyl group of R ¹⁴ .

In the above formulae (1-1) to (1-9) and (2-1) to (2-6), a part of the carbon atoms constituting the ring may be substituted by an etheric oxygen atom (-O-). can.

Further, in the formulae (1-1) to (1-9) and (2-1) to (2-6), the hydrogen atom bonded to the carbon atom constituting the ring may be substituted with a substituent. The substituent is, for example, an alkyl group having 1 to 5 carbon atoms, a fluorine atom, a fluorinated alkyl group or the like.

The "acetal type acid dissociable dissolution inhibiting group" is generally bonded to an oxygen atom by substituting a hydrogen atom at the terminal of an alkali-soluble group such as a carboxyl group or a hydroxyl group. Subsequently, when an acid is generated by exposure, the acetal type acid dissociable dissolution inhibiting group is blocked by the action of the acid, and the bond between the oxygen atom bonded to the acetal type acid dissociating dissolution inhibiting group is cut off. .

The acetal type acid dissociable dissolution inhibiting group is, for example, a group represented by the following formula (p1).

Wherein R ^{1 '} and R ^2' represent independently hydrogen atoms or alkyl groups having 1 to 5 carbon atoms, n represents an integer of 0 to 3, and Y represents an alkyl group having 1 to 5 carbon atoms or an aliphatic cyclic group. base].

In the above formula (p1), n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.

The alkyl group having 1 to 5 carbon atoms of R ^{1 '} and R ^{2 '} is, for example, the same as the alkyl group having 1 to 5 carbon atoms of the above R, preferably a methyl group or an ethyl group, and preferably a methyl group. .

In the present invention, it is preferred that at least one of R ^{1 '} and R ^2' is a hydrogen atom. In other words, the acid dissociable dissolution inhibiting group (p1) is preferably a group represented by the following formula (p1-1).

[wherein, R ^{1 '} , n, and Y are the same as described above].

The alkyl group having 1 to 5 carbon atoms of Y is, for example, the same as the alkyl group having 1 to 5 carbon atoms of the above R.

The aliphatic cyclic group of Y may be appropriately selected from among the monocyclic or polycyclic aliphatic cyclic groups which have been proposed by conventional ArF photoresists, for example, and the above-mentioned "aliphatic cyclic group" is The same example content.

Further, the acetal type acid dissociable dissolution inhibiting group is, for example, a group represented by the following formula (p2).

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

In R ¹⁷ and R ¹⁸ , the carbon number of the alkyl group is preferably from 1 to 15, and may be either a linear chain or a branched chain, and an ethyl group or a methyl group is preferred, and a methyl group is preferred. .

In particular, one of R ¹⁷ and R ¹⁸ is a hydrogen atom, and the other is preferably a methyl group.

R ¹⁹ is a linear, branched or cyclic alkyl group, preferably has 1 to 15 carbon atoms, and may be any of a linear chain, a branched chain or a cyclic group.

When R ¹⁹ is a linear or branched chain, it is preferably a carbon number of 1 to 5, more preferably an ethyl group or a methyl group, and particularly preferably an ethyl group.

When R ¹⁹ is a ring, it is preferably 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, for example, a fluorine atom or a fluorinated alkyl group may be substituted, and an unsubstituted polycyclic alkane such as a monocyclic alkane, a bicycloalkane, a tricycloalkane or a tetracycloalkane may be removed. The base obtained by more than one hydrogen atom, and the like. Specifically, it is one monocyclic alkane such as cyclopentane or cyclohexane, or one polycyclic alkane such as adamantane, raw spinane, isopentane, tricyclodecane or tetracyclododecane. The base obtained by the above hydrogen atom and the like. Among them, the base obtained by removing one or more hydrogen atoms from adamantane is preferred.

Further, in the above formula (p2), when R ¹⁷ and R ¹⁹ are each independently a linear or branched alkyl group (preferably an alkyl group having 1 to 5 carbon atoms), the end of R ¹⁹ is A bond can be formed at the end of R ¹⁷ .

At this time, R ^17, and R ^19, and R ¹⁹ bonded to an oxygen atom of the carbon and the oxygen atom bonding the R ¹⁷ atoms to form a cyclic group. The ring type is preferably a 4 to 7 member ring, and a 4 to 6 member ring is more preferred. Specific examples of the cyclic group include, for example, a tetrahydropyranyl group, a tetrahydrofuranyl group and the like.

Specific examples of the acetal type acid dissociable dissolution inhibiting group are, for example, groups represented by the following formulas (p3-1) to (p3-12).

[wherein R ¹³ is a hydrogen atom or a methyl group, and g is the same as described above].

The structural unit (a1) is more specifically, for example, a structural unit represented by the following general formula (a1-0-1), a structural unit represented by the following general formula (a1-0-2), and the like.

Wherein R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; X ¹ is an acid dissociable dissolution inhibiting group; Y ² is a divalent bond group, and X ^{2 is a} group ^; It is an acid dissociative dissolution inhibitory group].

In the formula (a1-0-1), R is the same as R ¹ in the above formula (a0-1).

X ¹ is not particularly limited as long as it is an acid dissociable dissolution inhibiting group, and may be, for example, the above-mentioned tertiary alkyl ester type acid dissociable dissolution inhibiting group or acetal acid dissociating dissolution inhibiting group, and The alkyl ester type acid dissociable dissolution inhibiting group is preferred.

In the formula (a1-0-2), R is the same as described above.

X ² is the same as X ¹ in the formula (a1-0-1).

The two-valent bond group of Y ² is, for example, the same as R ² in the above formula (a0-1).

Y ^{2 is} preferably an alkylene group, a divalent aliphatic ring group or a divalent bond group containing a hetero atom. Further, it is preferably a divalent bond group containing a hetero atom, and particularly a linear group having an oxygen atom as a hetero atom, and for example, a group containing an ester bond is particularly preferable.

Wherein the base represented by the aforementioned -AOB- or -AC(=O)-OB- is preferred, especially represented by -(CH ₂ ) _a -C(=O)-O-(CH ₂ ) _b - The basis is better.

a is an integer of 1 to 5, preferably 1 or 2, and 1 is most preferred.

b is an integer of 1 to 5, preferably 1 or 2, and 1 is most preferred.

The structural unit (a1) is more specifically, for example, a structural unit represented by the following general formulae (a1-1) to (a1-4).

[wherein, X' represents a tertiary alkyl ester type acid dissociable dissolution inhibiting group, Y represents an alkyl group having 1 to 5 carbon atoms, or an aliphatic cyclic group; n represents an integer of 0 to 3; and Y ² represents a divalent value. The bonding group; R is the same as the above, and R ^{1 '} and R ^{2 '} represent a hydrogen atom independently or an alkyl group having 1 to 5 carbon atoms].

In the above formula, X' is the same as the tertiary alkyl ester type acid dissociable dissolution inhibiting group exemplified in the above X ¹ .

^{R 1 ', R 2',} n, Y, each of the above-described "acetal-type acid dissociable, dissolution inhibiting group" exemplified in the description of general formula (p1) in the ^{R 1 ', R 2',} n, Y is the same content.

Y ² is the same as Y ² in the above formula (a1-0-2).

Hereinafter, specific examples of the structural unit represented by the above general formulae (a1-1) to (a1-4) will be exemplified.

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

The structural unit (a1) may be used singly or in combination of two or more.

In the present invention, the structural unit (a1) has a structure represented by the following general formula (a1-0-12), in particular, in view of excellent lithographic etching characteristics such as an analytical property and a shape of a resist pattern. It is preferred that at least one selected from the group consisting of structural units represented by the following general formula (a1-0-2).

Wherein R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ²³ is an alkyl group; and R ²⁴ is a carbon atom which can be bonded to the R ²⁴ bond; An aliphatic polycyclic group, Y ² is a divalent bond group, and X ² is an acid dissociable dissolution inhibiting group].

In the respective formulas, the description of R, Y ² and X ² is the same as described above.

In the formula (a1-0-12), the alkyl group of R ²³ is the same as the alkyl group exemplified for the alkyl group of R ^{14 in} the above formulae (1-1) to (1-9), and is different. The propyl is the best.

R ²⁴ is an aliphatic polycyclic group which can form a carbon atom bonded to the R ²⁴ , and is, for example, an aliphatic cyclic group exemplified in the above-mentioned tertiary alkyl ester type acid dissociable dissolution inhibiting group. The basis of the polycyclic base is the same.

Specific examples of the structural unit represented by the formula (a1-0-12) are, for example, the above formulas (a1-1-1) to (a1-1-15), (a1-1-26) to (a1-1-29). The structural unit represented, etc.

The structural unit represented by the formula (a1-0-2), for example, the structural unit represented by the above formula (a1-3) or (a1-4), and the like, in particular, the structural unit represented by the formula (a1-3) good.

Of formula (a1-0-2) represented by the structural unit, in particular in the formula Y ² is the -AOB- or -AC (= O) -OB- preferably the group represented.

In the structural unit, a preferred structural unit is, for example, a structural unit represented by the following general formula (a1-3-01); a structural unit represented by the following general formula (a1-3-02); A1-3-03) The structural unit represented by etc.

(wherein R and R ¹⁴ are the same as those described above, R ¹³ is a hydrogen atom or a methyl group, and a is an integer of from 1 to 10.)

(wherein R and R ¹⁴ are the same as defined above, R ¹³ is a hydrogen atom or a methyl group, a is an integer of 1 to 10, and n' is an integer of 0 to 3.)

[wherein R is the same as described above, and Y ² ' and Y ² " are each a two-valent bond group independently, and X' is an acid dissociable dissolution inhibiting group, and n is an integer of 0 to 3].

In the formulae (a1-3-01) to (a1-3-02), R ^{13 is} preferably a hydrogen atom.

a is preferably an integer of from 1 to 8, more preferably an integer of from 1 to 5, and most preferably 1 or 2.

n' is preferably 1 or 2, and 2 is most preferred.

Specific examples of the structural unit represented by the formula (a1-3-01) include structural units represented by the above formulas (a1-3-25) to (a1-3-26).

Specific examples of the structural unit represented by the formula (a1-3-02) include structural units represented by the above formulas (a1-3-27) to (a1-3-28).

In the formula (a1-3-03), the divalent bond group in Y ² ', Y ² " is the same as Y ² in the above formula (a1-3).

Y ² ' is preferably a divalent hydrocarbon group having a substituent, more preferably a linear aliphatic hydrocarbon group, and most preferably a linear alkyl group. Among them, a linear alkyl group having a carbon number of 1 to 5 is preferred, and a methyl group and an ethyl group are preferred.

Y ² ", preferably a divalent hydrocarbon group having a substituent, more preferably a linear aliphatic hydrocarbon group, and a linear alkyl group is preferred, wherein the carbon number is 1-5. The chain-like alkyl group is preferred, and the methyl group and the ethyl group are most preferred.

The acid dissociable dissolution inhibiting group in X' is, for example, the same as the above, preferably a tertiary alkyl ester type acid dissociable dissolution inhibiting group, and the above (i) monovalent aliphatic ring group ring skeleton The group having a tertiary carbon atom is more preferable, and the group represented by the above formula (1-1) is preferred.

n is an integer of 0 to 3, n is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 1.

The structural unit represented by the formula (a1-3-03) is preferably a structural unit represented by the following formula (a1-3-03-1) or (a1-3-03-2). Further, the structural unit represented by the formula (a1-3-03-1) is preferable, and the structural unit represented by the above formulas (a1-3-29) to (a1-3-30) is particularly preferable.

In the formula, R and R ¹⁴ are each the same as defined above, R ²⁰ is a hydrogen atom or a methyl group, a is an integer of from 1 to 10, b is an integer of from 1 to 10, and t is an integer of from 0 to 3.

a is preferably an integer of 1 to 5, and particularly preferably 1 or 2.

b is preferably an integer of 1 to 5, and particularly preferably 1 or 2.

t is preferably an integer of 1 to 3, and particularly preferably 1 or 2.

In the present invention, it is particularly preferred to have at least two structural units (a1). From the viewpoint of improving the excellent lithographic etching characteristics, the structural unit (a1) of the component (A1) is preferably 2 to 4, more preferably 2 or 3.

In this case, at least one of the at least two types is a group consisting of a structural unit represented by the above formula (a1-0-12) and a structural unit represented by the above formula (a1-0-2). At least one of the choices selected is preferred.

In this case, the at least two structural units (a1) may be formed only by the structural unit represented by the above formula (a1-0-12) and the structural unit represented by the above formula (a1-0-2). The selected one of the groups may be configured, or at least one of the structural units may be combined with a structural unit (a1) not belonging to the content.

A combination of at least one selected from the group consisting of the structural unit represented by the above formula (a1-0-12) and the structural unit represented by the above formula (a1-0-2) may not be used. The structural unit (a1) of the content includes, for example, the formula (a1-1-1) to (a1-1-2), (a1-1-7) to (example) of the specific example of the above formula (a1-1). A1-1-15) a structural unit represented by the following general formula (a1-0-10), a structural unit represented by the above formula (a1-2), and a structure represented by the above formula (a1-4) Units, etc.

The structural unit represented by the above formula (a1-0-10), in particular, the following formula (a1-1-101) containing the above formula (a1-1-1) to formula (a1-1-2) The structural unit represented is preferred.

In the formula, R is the same as described above, and R ²⁵ and R ¹¹ are each independently a linear alkyl group having 1 to 5 carbon atoms, and R ²⁴ is the same as described above.

In the component (A1), the ratio of the structural unit (a1) is preferably from 10 to 80 mol%, more preferably from 12 to 70 mol%, and more preferably from 15 to 70 mol% based on the total structural unit constituting the component (A1). 50% Mo is the best. When it is more than the lower limit value, the pattern can be easily obtained as a photoresist composition, and when it is at most the upper limit value, a balance with other structural units can be obtained.

(Structural unit (a2))

The structural unit (a2) is a structural unit derived from an acrylate containing a lactone-containing cyclic group.

Here, the lactone-containing cyclic group means a cyclic group containing one ring (lactone ring) having a -O-C(O)-structure. The ring count of the lactone ring as a unit is only a monocyclic group in the case of a lactone ring, and has other ring structures, and the structure is called a polycyclic group irrespective of its structure.

The lactone ring group of the structural unit (a2), when the copolymer (A1) is used for the formation of the photoresist film, can effectively improve the adhesion of the photoresist film to the substrate and improve the affinity with the developer containing water. Sex and so on.

The structural unit (a2) is not particularly limited, and any unit can be used.

Specifically, a monocyclic group containing a lactone, for example, a group obtained by removing one hydrogen atom from 4 to 6 membered ring lactones, for example, a group obtained by removing one hydrogen atom from β-propiolactone, γ-butyrolactone A group obtained by removing one hydrogen atom, a group obtained by removing one hydrogen atom by δ-valerolactone, and the like. Further, the polycyclic group having a lactone is, for example, a group obtained by removing a hydrogen atom from a dicycloalkane, a tricycloalkane or a tetracyclic alkane having a lactone ring.

In the example of the structural unit (a2), more specifically, for example, a structural unit represented by the following general formulae (a2-1) to (a2-5).

[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, and R' each independently represents a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, and a carbon number of 1 to 5; Alkoxy or -COOR", R" is a hydrogen atom or an alkyl group, R ²⁹ is a single bond or a divalent bond group, s" is an integer of 0 or 1-2, and A" may contain an oxygen atom or sulfur The alkyl group having 1 to 5 carbon atoms, an oxygen atom or a sulfur atom, and m is an integer of 0 or 1.

R in the general formulae (a2-1) to (a2-5) is the same as R in the above structural unit (a1).

The alkyl group having 1 to 5 carbon atoms of R', for example, a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group or the like.

The alkoxy group having 1 to 5 carbon atoms of R', for example, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a tert-butoxy group or the like.

R' is preferably a hydrogen atom from the viewpoint of easy industrial availability.

When R" is a linear or branched alkyl group, the carbon number is preferably from 1 to 10, more preferably from 1 to 5.

When R" is a cyclic alkyl group, it is preferably 3 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, for example, a fluorine atom can be used. Or a fluorinated alkyl group may be substituted, and a polycyclic alkane such as a monocyclic alkane, a bicycloalkane, a tricycloalkane or a tetracycloalkane which is not substituted may be one obtained by removing one or more hydrogen atoms. Specifically, it is removed by a monocyclic alkane such as cyclopentane or cyclohexane, or a polycyclic alkane such as adamantane, raw spinane, isopentane, tricyclodecane or tetracyclododecane. The base obtained by more than one hydrogen atom, and the like.

A" is, for example, preferably an alkylene group having 1 to 5 carbon atoms or -O-, more preferably an alkylene group having 1 to 5 carbon atoms, and most preferably a methyl group.

R ²⁹ is a single bond or a divalent bond group. The divalent bond group is the same as the divalent bond group described by Y ² in the above formula (a1-0-2), wherein the alkyl group and the ester bond (- C(=O)-O-), or a combination of these is preferred. The alkylene group as a divalent bond group in R ²⁹ is more preferably a linear or branched alkyl group. Specifically, the linear alkyl group and the branched alkyl group which are exemplified in the aliphatic hydrocarbon group in A in the above Y ² are the same.

s" is preferably an integer of 1 to 2.

The following is a specific example of the structural unit represented by the above-described general formulae (a2-1) to (a2-5). In the following formulae, R ^α represents a hydrogen atom, a methyl group or a trifluoromethyl group.

In the component (A1), the structural unit (a2) may be used singly or in combination of two or more.

The structural unit (a2) is preferably at least one selected from the group consisting of the structural units represented by the above formulas (a2-1) to (a2-5), and is represented by the general formula (a2-1) to A2-3) It is more preferable that at least one selected from the group of structural units represented is a group. Wherein the structural units represented by the chemical formulas (a2-1-1), (a2-2-1), (a2-2-7), (a2-3-1), and (a2-3-5) are used. At least one selected from the group is preferred.

The ratio of the structural unit (a2) in the component (A1) is the adhesion of the photoresist film formed of the positive resist composition containing the component (A1) to the support of the substrate or the like, and the developer The viewpoint of excellent affinity is preferably 1 to 50 mol% or more, more preferably 5 to 50 mol%, and more preferably 10 to 45 mol%, based on the total structural unit constituting the component (A1). .

Further, in the component (A1), the total ratio of the structural unit (a0-1), the structural unit (a0-2), and the structural unit (a2) is excellent in various lithographic etching characteristics (there is no structural unit) In the case of (a2), the total ratio of the structural units (a0-1) and (a0-2) is preferably 30 to 85 mol% with respect to the total structural unit constituting the component (A1), 35 to 85% Mo is more preferred, with 35 to 82 mol% being the best. When it is within the above range, the MEF, CDU, and pattern shape can be made better.

(Structural unit (a3))

The structural unit (a3) is a structural unit derived from an acrylate containing a polar group-containing aliphatic hydrocarbon group.

When the component (A3) has a structural unit (a3), the hydrophilicity of the component (A) can be improved, the affinity with the developer can be improved, and the alkali solubility of the exposed portion can be improved, which contributes to the improvement of the resolution.

The polar group is, for example, a hydroxyalkyl group in which a part of a hydrogen atom of a hydroxyl group, a cyano group, a carboxyl group or an alkyl group is substituted with a fluorine atom, and particularly preferably a hydroxyl group.

The aliphatic hydrocarbon group is, for example, a linear or branched hydrocarbon group (preferably an alkylene group) having 1 to 10 carbon atoms, or a polycyclic aliphatic hydrocarbon group (polycyclic group). The polycyclic group may be, for example, a resin for use in an ArF excimer laser photoresist composition, and is appropriately selected from most of the proposed materials. The polycyclic group has a carbon number of 7 to 30.

Further, a structural unit derived from an aliphatic polycyclic acrylate having a hydroxyalkyl group in which a part of a hydrogen atom containing a hydroxyl group, a cyano group, a carboxyl group or an alkyl group is substituted by a fluorine atom is more preferable. The polycyclic group is, for example, a group obtained by removing two or more hydrogen atoms from a bicycloalkane, a tricycloalkane or a tetracycloalkane. Specifically, a group obtained by removing two or more hydrogen atoms from a polycyclic alkane such as adamantane, prorotane, isopentane, tricyclodecane or tetracyclododecane is used. 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 raw spinel, and a tetracyclododecane removing two or more hydrogen atoms. The results obtained are based on industry.

In the structural unit (a3), when the hydrocarbon group in the aliphatic hydrocarbon group having a polar group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, the structural unit derived from the hydroxyethyl acrylate is preferred. When the hydrocarbon group is a polycyclic group, the structural unit represented by the following formula (a3-1), the structural unit represented by (a3-2), and the structural unit represented by (a3-3) are preferably exemplified.

[wherein R is the same as the 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, 1 is an integer of 1 to 5, and s is 1 to 3. The integer. ]

In the formula (a3-1), j is preferably 1 or 2, and more preferably 1 is used. When j is 2, it is preferred that the hydroxyl group is bonded to the 3 and 5 positions of the adamantyl group. When j is 1, it is preferred that the hydroxy group is bonded to the adamantyl group.

j is preferably 1 and particularly preferably a hydroxyl group bonded to the adamantyl group.

In the formula (a3-2), k is preferably 1. It is preferred that the cyano group is bonded to the 5- or 6-position of the original spinnyl group.

In the formula (a3-3), t' is preferably 1. 1 is better than 1. s is better than 1. These are preferably bonded to the 2-originyl group or the 3-pyrosyl group at the carboxyl end of the acrylic acid. The fluorinated alkanol is preferably bonded to the 5 or 6 position of the original spinnyl group.

The structural unit (a3) may be used singly or in combination of two or more.

The ratio of the structural unit (a3) in the component (A1) is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, and more preferably 5 to 50% of the total structural unit constituting the component (A1). 25% Mo is the best.

(other structural units)

The copolymer (A1) may contain other structural units (hereinafter also referred to as structural units (a4)) other than the above structural units (a1) to (a3) insofar as the effects of the present invention are not impaired.

The structural unit (a4) is not particularly limited as long as it is other structural units not classified into the above structural units (a1) to (a3), and an ArF excimer laser or KrF excimer laser can be used. A plurality of conventionally known structural units used for resistive resins such as shots (preferably for ArF excimer lasers).

The structural unit (a4) is preferably, for example, a structural unit derived from an acrylate having a non-acid dissociable aliphatic polycyclic group. The polycyclic group may be, for example, the same as those exemplified in the case of the structural unit (a1) described above, and may be used for ArF excimer laser or KrF excimer laser (preferably ArF A conventionally known structural unit used for the resin component of a photoresist composition such as a molecular laser.

In particular, when at least one selected from the group consisting of a tricyclic fluorenyl group, an adamantyl group, a tetradecanedecyl group, an iso-spinyl group, and a linalyl group is preferable, it is preferable from the viewpoint 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 of the following general formulae (a4-1) to (a4-5).

[where R is the same as the above]

(A1) In the case where the component (a4) is contained in the component, the ratio of the structural unit (a4) is preferably 1 to 30 mol%, and 10 to 10% of the total structural unit constituting the component (A1). 20% of the mole is better.

The component (A1) is preferably a copolymer having a structural unit (a0-1) and (a0-2). The copolymer, for example, a copolymer formed from the above structural units (a-1), (a0-2), and (a1), structural units (a0-1), (a0-2), and (a3) Copolymer formed, structural unit (a0-1), (a0-2), (a1) and (a3) copolymer, structural unit (a0-1), (a0-2), (a1) And a copolymer formed by (a2) and (a3).

In the present invention, particularly in the copolymers, the structural unit (a1) has a structural unit represented by the above formula (a1-0-12) and a structural unit represented by the formula (a1-0-2) At least one selected from the group is preferred.

Further, as described above, the copolymer preferably has at least two structural units (a1), and at least one of the at least two types is represented by the above formula (a1-0-12). The structural unit selected from the structural unit and the structural unit represented by the general formula (a1-0-2) is preferably selected.

The mass average molecular weight (Mw) of the component (A1) (the polystyrene conversion standard of the gel permeation chromatography method) is not particularly limited, and is preferably 2,000 to 50,000, more preferably 3,000 to 30,000, and 5,000. ~20000 is the best. When it is less than the upper limit of the range, it has sufficient solubility to the resist solvent when used as a photoresist, and when it is larger than the lower limit of the range, a good dry etching resistance or a resist pattern cross-sectional shape can be obtained.

Further, the degree of dispersion (Mw/Mn) is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5. Further, Mn represents a number average molecular weight.

In the component (A), the component (A1) may be used singly or in combination of two or more.

When two or more types are used in combination, the synthesis of the polymer can be easily performed, and good lithographic etching characteristics can be obtained. In this case, two or more (A1) components are preferably different from each other (a1).

Further, at least one of the two or more (A1) components is a structural unit represented by the above formula (a1-0-12) and a structure represented by the above formula (a1-0-2). It is preferred that at least one selected from the group is a group.

In this case, the structural units (a1) which are different from each other in the two or more (A1) components may be the structural unit represented by the above formula (a1-0-12) and the above formula (a1-0). -2) The selected one of the structural units indicated may be formed, or at least one of the structural units may be combined with a structural unit (a1) not belonging to the content.

The ratio of the component (A1) in the component (A) is preferably 25% by mass or more based on the total mass of the component (A), preferably 50% by mass, more preferably 75% by mass, or more preferably 100% by mass. When the ratio is 25% by mass or more, the effect of the lithographic etching characteristics and the like can be improved.

The component (A1) can be obtained by polymerizing a monomer derived from each structural unit, for example, by radical polymerization or the like using a radical polymerization initiator such as azobisisobutyronitrile (AIBN).

And, (A1) component in the occasion of the above-described polymerization, for example, may be used in _{HS-CH 2 -CH 2 -CH 2} -C (CF 3) 2 -OH chain transfer agent and the like, at the end introduced -C (CF ₃ ) ₂ -OH group. When a copolymer obtained by introducing a hydroxyalkyl group substituted with a fluorine atom into a part of a hydrogen atom of an alkyl group, the development defect or the LER (line edge unevenness: unevenness of the line side wall) can be effectively reduced.

The monomer derived from each structural unit may be a commercially available one or may be synthesized by a known method.

For example, a monomer derived from the structural unit (a0-1) is, for example, a compound represented by the following formula (I) (hereinafter also referred to as a compound (I)).

[In the formula (I), R ¹ to R ³ are each the same as described above].

The method for producing the compound (I) is not particularly limited, and it can be produced by a known method. For example, a compound represented by the following formula (X-2) is added to a solution obtained by dissolving the compound (X-1) represented by the following formula (X-1) in a reaction solvent in the presence of a base. (X-2), the result of the reaction was carried out to obtain the above compound (I).

A base such as an inorganic base such as sodium hydride, K ₂ CO ₃ or Cs ₂ CO ₃ ; an organic base such as triethylamine, 4-dimethylaminopyridine (DMAP) or pyridine. a condensing agent such as ethyldiisopropylaminocarbodiimide (EDCI) hydrochloride, dicyclohexylcarboximine (DCC), diisopropylcarbodiimide, carbodiimidazole or the like A carbodiimide reagent or a tetraethyl pyrophosphate, a benzotriazole-N-hydroxytrimethylamine sulfonium hexafluorophosphide salt (Bop reagent) or the like.

Also, acid can be used if necessary. As the acid, a substance which is usually used, such as dehydration condensation, can be used. Specifically, for example, an inorganic acid such as hydrochloric acid, sulfuric acid or phosphoric acid, or methanesulfonic acid, trifluoromethanesulfonic acid, benzenesulfonic acid or p-toluenesulfonic acid or the like. Organic acids, etc. These may be used singly or in combination of two or more types.

In the resist composition of the present invention, the component (A) may contain a substrate component which does not belong to the above (A1) component and which increases the solubility to the alkali developer via the action of an acid (hereinafter, also referred to as (A2). ) ingredients).

The component (A2) is not particularly limited, and any of the conventionally known components (for example, ArF excimer laser, KrF excimer) which are used as a substrate component for a chemical smectic positive photoresist composition can be arbitrarily selected and used. A base resin for lasers (preferably for ArF excimer lasers). For example, the base resin for the ArF excimer laser is a resin having the structural unit (a1) as a necessary structural unit and having any of the above structural units (a2) to (a4).

The component (A2) may be used singly or in combination of two or more.

In the photoresist composition of the present invention, the content of the component (A) may be adjusted in accordance with the thickness of the photoresist film to be formed.

<(B) ingredients>

The component (B) is not particularly limited, and a component which has been proposed so far as an acid generator for a chemical smear type resist can be used. These acid generators have heretofore been known as sulfonium acid generators such as iodonium salts or phosphonium salts, sulfonate acid generators, dialkyl or bisarylsulfonyldiazomethanes. , a diazomethane acid generator such as poly(disulfonyl)diazomethane, a nitrobenzylsulfonate acid generator, an imidosulfonate acid generator, a diterpene acid generator And many other ingredients.

As the onium salt acid generator, for example, a compound represented by the following formula (b-1) or (b-2) can be used.

[wherein R ¹ " to R ³ "R ⁵ " to R ⁶ " each independently represent an aryl group or an alkyl group; and in the formula (b-1), any of R ¹ " to R ³ "" may mutually Bonding and forming a ring together with a sulfur atom in the formula; R ⁴ ", representing an alkyl group, a halogenated alkyl group, an aryl group or an alkenyl group which may have a substituent; at least one of R ¹ " to R ³ " One represents an aryl group, and at least one of R ⁵ ' to R ⁶ ' represents an aryl group].

In the formula (b-1), R ¹ " to R ³ " each independently represent an aryl group or an alkyl group. Further, of R ¹ ' to R ³ ' in the formula (b-1), any two of them may be bonded to each other and may form a ring together with the sulfur atom in the formula.

Further, at least one of R ¹ " to R ³ " represents an aryl group. In R ¹ ' to R ³ ', two or more aryl groups are preferred, and all of R ¹ '-R ³ ' are aryl groups.

The aryl group of R ¹ " to R ³ " is not particularly limited, and is, for example, an aryl group having 6 to 20 carbon atoms, and a part or the whole of the hydrogen atom of the aryl group may be an alkyl group or an alkoxy group. The halogen atom, the hydroxyl group, and the like may be substituted, and may be unsubstituted.

The aryl group is preferably an inexpensive aryl group, and an aryl group having 6 to 10 carbon atoms is preferred. Specifically, for example, a phenyl group, a naphthyl group or the like.

The alkyl group which may substitute the hydrogen atom of the above aryl group is preferably an alkyl group having 1 to 5 carbon atoms, and most preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group.

An alkoxy group which may be substituted for the hydrogen atom of the above aryl group, for example, an alkoxy group having 1 to 5 carbon atoms, preferably a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, or an n- Butoxy and tert-butoxy are preferred, and methoxy and ethoxy are preferred.

A halogen atom which may be substituted for the hydrogen atom of the aforementioned aryl group, for example, a fluorine atom is preferred.

The alkyl group of R ¹ " to R ³ " is not particularly limited, and examples thereof include a linear one having a carbon number of 1 to 10, a branched chain or a cyclic alkyl group. From the viewpoints of excellent resolution and the like, the carbon number is preferably from 1 to 5. Specifically, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, cyclopentyl, hexyl, cyclohexyl, decyl, decyl, and the like, It has excellent analytical properties and can be synthesized inexpensively, such as a methyl group.

In the case of R ¹ ′′ to R ³ ′ in the formula (b-1), any two of them may be bonded to each other and form a ring together with the sulfur atom in the formula, and it is preferred to form a ring of 3 to 10 members including a sulfur atom. It is especially good to form a 5- to 5-member ring.

In the case of R ¹ " to R ³ " in the formula (b-1), any two of them may be bonded to each other and form a ring together with the sulfur atom in the formula, and the remaining one is preferably an aryl group. The above aryl group is the same as the above aryl group of R ¹ " to R ³ ".

Among the cation portions of the compound represented by the formula (b-1), for example, a cation moiety represented by the following formulas (I-1-1) to (I-1-10) is preferable. Among them, those having a triphenylmethane skeleton such as a cation portion represented by the formulae (I-1-1) to (I-1-8) are preferred.

In the following formulas (I-1-9) to (I-1-10), R ⁹ and R ¹⁰ each independently represent a phenyl group, a naphthyl group or an alkyl group having 1 to 5 carbon atoms which may have a substituent. Alkoxy group, hydroxyl group.

u is an integer from 1 to 3, and 1 or 2 is optimal.

R ⁴ "" represents an alkyl group, a halogenated alkyl group, an aryl group or an alkenyl group which may have a substituent.

The alkyl group in R ⁴ " may be any of a linear chain, a branched chain, and a cyclic group.

The linear or branched alkyl group is preferably a carbon number of 1 to 10, preferably a carbon number of 1 to 8, and preferably a carbon number of 1 to 4.

The cyclic alkyl group is preferably, for example, 4 to 15 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms.

a halogenated alkyl group in R ⁴ ", for example, a group in which a part or all of a hydrogen atom of the above-mentioned linear, branched or cyclic alkyl group is substituted by a halogen atom, etc. The halogen atom, for example, a fluorine atom A chlorine atom, a bromine atom, an iodine atom or the like is preferably a fluorine atom.

In the halogenated alkyl group, the ratio of the number of halogen atoms (halogenation ratio (%)) to the total number of halogen atoms and hydrogen atoms contained in the halogenated alkyl group is preferably from 10 to 100%, and from 50 to 100%. Better, 100% is the best. When the halogenation rate is higher, the stronger the strength of the acid, the more preferable.

The aryl group in the above R ⁴ " is preferably an aryl group having 6 to 20 carbon atoms.

The alkenyl group in the above R ⁴ " is preferably an alkenyl group having 2 to 10 carbon atoms.

In the above R ⁴ "", "may have a substituent" means that a part or all of a hydrogen atom in a linear, branched or cyclic alkyl group, a halogenated alkyl group, an aryl group or an alkenyl group is substituted. A group (an atom other than a hydrogen atom or a group) may be substituted.

The number of substituents in R ⁴ " may be one, or two or more.

The above substituent, for example, a halogen atom, a hetero atom, an alkyl group, a formula: XQ ¹ - [wherein, Q ¹ is a divalent bond group containing an oxygen atom, and X is a carbon number of 3 to 30 which may have a substituent. The base represented by the hydrocarbon group].

The halogen atom or the alkyl group is the same as those exemplified in the halogen atom and the alkyl group in the halogenated alkyl group in R ⁴ '.

The aforementioned hetero atom is, for example, an oxygen atom, a nitrogen atom, a sulfur atom or the like.

In the group represented by XQ ¹ -, Q ¹ is a divalent bond group containing an oxygen atom.

Q ¹ may contain atoms other than oxygen atoms. An atom other than an oxygen atom, such as a carbon atom, a hydrogen atom, an oxygen atom, a sulfur atom, a nitrogen atom or the like.

a divalent bond group containing an oxygen atom, for example, an oxygen atom (ether bond; -O-), an ester bond (-C(=O)-O-), a guanamine bond (-C(=O) a non-hydrocarbon oxygen atom-containing bond group such as -NH-), a carbonyl group (-C(=O)-), a carbonate bond (-OC(=O)-O-), etc.; A combination of a bond group containing an oxygen atom and an alkyl group.

The combination is, for example, -R ⁹¹ -O-, -R ⁹² -OC(=O)-, -C(=O)-OR ⁹³ -OC(=O)- (wherein, R ⁹¹ to R ⁹³ are respectively Independent alkyl group) and the like.

The alkylene group in R ⁹¹ to R ⁹³ is preferably a linear or branched alkyl group, and the carbon number of the alkyl group is preferably from 1 to 12, more preferably from 1 to 5. 1 to 3 is especially good.

The alkylene group, specifically, for example, methyl [-CH ₂ -]; -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C (CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ - or the like alkyl-extended methyl; ex-ethyl [- CH ₂ CH ₂ -]; -CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH ₃ )-, -C(CH ₃ ) ₂ CH ₂ -, -CH(CH ₂ CH ₃ )CH ₂ -etc. Alkyl extended ethyl; extended trimethyl (n-propyl)[-CH ₂ CH ₂ CH ₂ -]; -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ ) CH ₂ -etc. The alkyl group extends to trimethyl; tetramethyl [-CH ₂ CH ₂ CH ₂ CH ₂ -]; -CH(CH ₃ )CH ₂ CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ ) The alkyl group of CH ₂ CH ₂ -etc. is tetramethyl; the pentamethyl group [-CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ -] and the like.

Q ¹ , preferably a divalent bond group containing an ester bond or an ether bond, wherein -R ⁹¹ -O-, -R ⁹² -OC(=O)- or -C(=O) -OR ⁹³ -OC(=O)- is preferred.

In the group represented by XQ ¹ -, the hydrocarbon group of X may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group.

The aromatic hydrocarbon group is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, most preferably 6 to 15 carbon atoms, and most preferably 6 to 12 carbon atoms. Wherein, the carbon number is those which do not contain the carbon number in the substituent.

The aromatic hydrocarbon group, specifically, for example, a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthyl group, a phenanthryl group or the like is obtained by removing one hydrogen atom from an aromatic hydrocarbon ring. An aralkyl group such as an aryl group, a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group or a 2-naphthylethyl group. The number of carbon atoms of the alkyl chain in the above aralkyl group is preferably from 1 to 4, more preferably from 1 to 2, most preferably from 1.

The aromatic hydrocarbon group may have a substituent. For example, a part of the carbon atom constituting the aromatic ring which the aromatic hydrocarbon group has may be substituted by a hetero atom, or a hydrogen atom to which the aromatic ring group has a bonded aromatic ring may be substituted by a substituent.

In the former, for example, the heteroaryl group in which one of the carbon atoms constituting the ring of the aryl group is substituted with a hetero atom such as an oxygen atom, a sulfur atom or a nitrogen atom, and the carbon atom constituting the aromatic hydrocarbon ring in the aforementioned aralkyl group. A heteroarylalkyl group or the like partially substituted by the aforementioned hetero atom.

The substituent of the aromatic hydrocarbon group in the latter exemplified is, for example, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (=O) or the like.

The alkyl group as a substituent of the aromatic hydrocarbon group is preferably, for example, 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 of the above aromatic hydrocarbon group is preferably, for example, an alkoxy group having 1 to 5 carbon atoms, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, and an n- group. Butoxy and tert-butoxy are preferred, and methoxy and ethoxy are preferred.

The halogen atom as a substituent of the aromatic hydrocarbon group, for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom or the like, is preferably a fluorine atom.

The halogenated alkyl group as a substituent of the aromatic hydrocarbon group is, for example, a group in which a part or all of a hydrogen atom of the alkyl group is substituted by the halogen atom.

The aliphatic hydrocarbon group in X may be a saturated aliphatic hydrocarbon group or an unsaturated aliphatic hydrocarbon group. Further, the aliphatic hydrocarbon group may be any of a linear chain, a branched chain, and a cyclic group.

In X, in the aliphatic hydrocarbon group, a part of the carbon atom constituting the aliphatic hydrocarbon group may be substituted by a substituent containing a hetero atom, or a part or all of the hydrogen atom constituting the aliphatic hydrocarbon group may be contained. Substituents for heteroatoms can also be substituted.

The "hetero atom" in X is not particularly limited as long as it is an atom other than a carbon atom or a hydrogen atom, and examples thereof include a halogen atom, an oxygen atom, a sulfur atom, and a nitrogen atom. A halogen atom, for example, a fluorine atom, a chlorine atom, an iodine atom, a bromine atom or the like.

The substituent containing a hetero atom may be composed only of the above-mentioned hetero atom, or may contain a group other than the above hetero atom or an atom.

Substituents which may replace a part of carbon atoms, specifically, for example, -O-, -C(=O)-O-, -C(=O)-, -OC(=O)-O-, - C(=O)-NH-, -NH- (H can be substituted by a substituent such as an alkyl group or a fluorenyl group), -S-, -S(=O) ₂ -, -S(=O) ₂ -O -Wait. Where the aliphatic hydrocarbon group is cyclic, the substituents may be included in the ring configuration.

A substituent which substitutes a part or all of a hydrogen atom, specifically, for example, an alkoxy group, a halogen atom, an alkyl halide group, a hydroxyl group, an oxygen atom (=O), a cyano group or the like.

The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, and a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group. The base is preferred, and the methoxy group and the ethoxy group are the most preferable.

The halogen atom, for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom or the like, is preferably a fluorine atom.

The halogenated alkyl group, for example, an alkyl group having 1 to 5 carbon atoms, such as a part or all of hydrogen atoms in an alkyl group such as a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group, is A group substituted by a halogen atom or the like.

The aliphatic hydrocarbon group is preferably a linear or branched saturated hydrocarbon group, a linear or branched monovalent unsaturated hydrocarbon group, or a cyclic aliphatic hydrocarbon group (aliphatic cyclic group).

The linear saturated hydrocarbon group (alkyl group) has, for example, preferably 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and most preferably 1 to 10 carbon atoms. Specifically, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, decyl, decyl, undecyl, dodecyl, tridecyl, Isotridecyl, tetradecyl, pentadecyl, hexadecyl, isohexadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, twenty-one Alkyl, behenyl or the like.

The branched saturated hydrocarbon group (alkyl group) preferably has 3 to 20 carbon atoms, more preferably 3 to 15 carbon atoms, and most preferably 3 to 10 carbon atoms. Specifically, for example, 1-methylethyl, 1-methylpropyl, 2-methylpropyl, 1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1- Ethyl butyl, 2-ethylbutyl, 1-methylpentyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, and the like.

The unsaturated hydrocarbon group has, for example, preferably 2 to 10 carbon atoms, preferably 2 to 5 carbon atoms, preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. A linear monovalent unsaturated hydrocarbon group, for example, a vinyl group, a propenyl group, a butenyl group or the like. A branched monovalent unsaturated hydrocarbon group, for example, a 1-methylpropenyl group, a 2-methylpropenyl group or the like.

The unsaturated hydrocarbon group is preferably a propylene group among the above.

The aliphatic cyclic group may be a monocyclic group or a polycyclic group. The carbon number is preferably from 3 to 30, preferably from 5 to 30, more preferably from 5 to 20, most preferably from 6 to 15, and most preferably from 6 to 12.

Specifically, for example, a monocyclic alkane is obtained by removing one or more hydrogen atoms; and a polycyclic alkane such as a bicycloalkane, a tricycloalkane or a tetracycloalkane is removed by removing one or more hydrogen atoms. Base. More specifically, a monocyclic alkane such as cyclopentane or cyclohexane is obtained by removing one or more hydrogen atoms; adamantane, raw spinel, iso-araconine, tricyclodecane, tetracyclic twelve A group obtained by removing one or more hydrogen atoms from a polycyclic alkane such as an alkane.

An aliphatic cyclic group having a ring structure which does not contain a substituent containing a hetero atom, an aliphatic cyclic group, preferably a polycyclic group, and a group obtained by removing one or more hydrogen atoms from a polycyclic alkane More preferably, the base obtained by removing one or more hydrogen atoms from adamantane is preferred.

An aliphatic cyclic group having a ring structure containing a substituent of a hetero atom, and a substituent containing the hetero atom, -O-, -C(=O)-O-, -S-, - S(=O) ₂ -, -S(=O) ₂ -O- is preferred. Specific examples of the aliphatic cyclic group include, for example, the following formulae (L1) to (L5), (S1) to (S4), and the like.

[wherein Q" is an alkylene group having 1 to 5 carbon atoms, -O-, -S-, -OR ⁹⁴ - or -SR ⁹⁵ -, and R ⁹⁴ and R ⁹⁵ are each independently a carbon number of 1 to 5 Alkyl, m is an integer of 0 or 1.

In the formula, the alkylene group in Q", R ⁹⁴ and R ⁹⁵ is the same as the alkylene group in the above R ⁹¹ to R ⁹³ , respectively.

The aliphatic cyclic group, a part of the hydrogen atom bonded to the carbon atom constituting the ring structure may be substituted by a substituent. The substituent is, for example, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, an oxygen atom (=O) or the like.

The alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, and particularly preferably a methyl group, an ethyl group, a propyl group, an n-butyl group or a tert-butyl group.

The alkoxy group and the halogen atom are the same as those exemplified for the substituent of the above-mentioned partial or all hydrogen atom.

In the present invention, X is preferably a cyclic group which may have a substituent. The cyclic group may be an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, and an aliphatic cyclic group which may have a substituent.

The aromatic hydrocarbon group is preferably a naphthyl group which may have a substituent or a phenyl group which may have a substituent.

The aliphatic cyclic group which may have a substituent is preferably a polycyclic aliphatic ring group which may have a substituent. The polycyclic aliphatic cyclic group is preferably a group obtained by removing one or more hydrogen atoms from the polycyclic alkane, and the above (L2) to (L5), (S3) to (S4), and the like.

In the present invention, R ⁴ ′ is preferably ^one having a substituent of XQ ¹ −. In this case, R ⁴ ′ is XQ ¹ —Y ¹ —[wherein Q ¹ and X are the same as described above, Y ¹ The group represented by the alkylene group having 1 to 4 carbon atoms which may have a substituent or the fluorinated alkyl group having 1 to 4 carbon atoms which may have a substituent is preferred.

In the group represented by XQ ¹ -Y ¹ -, the alkylene group of Y ¹ is the same as the alkyl group having 1 to 4 carbon atoms in the alkylene group recited in the above Q ¹ .

The fluorinated alkyl group is, for example, a group in which a part or all of a hydrogen atom of the alkyl group is substituted by a fluorine atom.

Y ¹ , specifically, for example, -CF ₂ -, -CF ₂ CF ₂ -, -CF ₂ CF ₂ CF ₂ -, -CF(CF ₃ )CF ₂ -, -CF(CF ₂ CF ₃ )-, -C(CF ₃ ) ₂ -, -CF ₂ CF ₂ CF ₂ CF ₂ -, -CF(CF ₃ )CF ₂ CF ₂ -, -CF ₂ CF(CF ₃ )CF ₂ -, -CF(CF ₃ ) CF(CF ₃ )-, -C(CF ₃ ) ₂ CF ₂ -, -CF(CF ₂ CF ₃ )CF ₂ -, -CF(CF ₂ CF ₂ CF ₃ )-, -C(CF ₃ )(CF ₂ CF ₃ )-;-CHF-, -CH ₂ CF ₂ -, -CH ₂ CH ₂ CF ₂ -, -CH ₂ CF ₂ CF ₂ -, -CH(CF ₃ )CH ₂ -, -CH(CF ₂ CF ₃ )-, -C(CH ₃ )(CF ₃ )-, -CH ₂ CH ₂ CH ₂ CF ₂ -, -CH ₂ CH ₂ CF ₂ CF ₂ -, -CH(CF ₃ )CH ₂ CH ₂ - , -CH ₂ CH(CF ₃ )CH ₂ -, -CH(CF ₃ )CH(CF ₃ )-, -C(CF ₃ ) ₂ CH ₂ -; -CH ₂ -, -CH ₂ CH ₂ -, - CH ₂ CH ₂ CH ₂ -, -CH(CH ₃ )CH ₂ -, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -CH ₂ CH ₂ CH ₂ CH ₂ -, -CH (CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH ₃ )-, -C(CH ₃ ) ₂ CH ₂ -, -CH(CH ₂ CH ₃ )CH ₂ -, -CH(CH ₂ CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₃ )-, and the like.

Y ^{1 is} preferably a fluorinated alkyl group, and particularly preferably a fluorinated alkyl group obtained by fluorinating a carbon atom adjacent to a sulfur atom. The fluorinated alkyl groups, such as -CF ₂ -, -CF ₂ CF ₂ -, -CF ₂ CF ₂ CF ₂ -, -CF(CF ₃ )CF ₂ -, -CF ₂ CF ₂ CF ₂ CF ₂ - , -CF(CF ₃ )CF ₂ CF ₂ -, -CF ₂ CF(CF ₃ )CF ₂ -, -CF(CF ₃ )CF(CF ₃ )-, -C(CF ₃ ) ₂ CF ₂ -,- CF(CF ₂ CF ₃ )CF ₂ -; -CH ₂ CF ₂ -, -CH ₂ CH ₂ CF ₂ -, -CH ₂ CF ₂ CF ₂ -; -CH ₂ CH ₂ CH ₂ CF ₂ -, -CH ₂ CH ₂ CF ₂ CF ₂ -, -CH ₂ CF ₂ CF ₂ CF ₂ -, and the like.

Wherein -CF ₂ -, -CF ₂ CF ₂ -, -CF ₂ CF ₂ CF ₂ -, or CH ₂ CF ₂ CF ₂ - is preferred, with -CF ₂ -, -CF ₂ CF ₂ - or -CF ₂ CF ₂ CF ₂ - is more preferred, and -CF ₂ - is particularly preferred.

The aforementioned alkylene or fluorinated alkyl group may have a substituent. The alkyl group or the fluorinated alkyl group has a "substituent group" means that a part or all of a hydrogen atom or a fluorine atom in the alkylene group or the fluorinated alkyl group may be other than a hydrogen atom and a fluorine atom. The meaning of replacing an atom or a base.

The substituent which the alkyl group or the fluorinated alkyl group may have, for example, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a hydroxyl group or the like.

In the formula (b-2), R ⁵ " to R ⁶ " each independently represent an aryl group or an alkyl group. At least one of R ⁵ " to R ⁶ " represents an aryl group. It is preferred that all of R ⁵ " to R ⁶ " is an aryl group.

The aryl group of R ⁵ " to R ⁶ " is the same as the aryl group of R ¹ " to R ³ ".

The alkyl group of R ⁵ " to R ⁶ " is the same as the alkyl group of R ¹ "R ³ ".

Among these, it is preferable that all of R ⁵ " to R ⁶ " are phenyl groups.

Of formula (b-2) in the R ^{4 "and} R in the above formula (b-1) of the ^4" of the same content.

Specific examples of the phosphonium-based acid generator represented by the formulae (b-1) and (b-2) are, for example, diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, bis(4- Tert-butylphenyl) iodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, triphenylsulfonium trifluoromethanesulfonate, heptafluoropropanesulfonate or its nonafluorobutanesulfonic acid Ethyl ester, tris(4-methylphenyl)phosphonium trifluoromethanesulfonate, heptafluoropropane sulfonate or its nonafluorobutane sulfonate, dimethyl(4-hydroxynaphthyl)phosphonium trifluoromethane a sulfonate, a heptafluoropropane sulfonate or a nonafluorobutane sulfonate thereof, a triphenylmethanesulfonate of monophenyldimethylhydrazine, a heptafluoropropane sulfonate thereof or a nonafluorobutane sulfonate thereof; a trifluoromethanesulfonate of phenylmonomethylhydrazine, a heptafluoropropanesulfonate thereof or a nonafluorobutanesulfonate thereof, a trifluoromethanesulfonate of (4-methylphenyl)diphenylphosphonium, Heptafluoropropane sulfonate or its nonafluorobutane sulfonate, (4-methoxyphenyl)diphenylphosphonium trifluoromethanesulfonate, heptafluoropropane sulfonate or its nonafluorobutane sulfonate, Tris(4-tert-butyl)phenylhydrazine trifluoromethanesulfonate, Heptafluoropropane sulfonate or its nonafluorobutane sulfonate, triphenylmethanesulfonate of diphenyl(1-(4-methoxy)naphthyl)anthracene, heptafluoropropane sulfonate or its nonafluorobutane a sulfonate, a trifluoromethanesulfonate of bis(1-naphthyl)phenylhydrazine, a heptafluoropropanesulfonate or a nonafluorobutanesulfonate thereof; a trifluoromethanesulfonate of 1-phenyltetrahydrothiophene An acid ester, a heptafluoropropane sulfonate or a nonafluorobutane sulfonate thereof; a trifluoromethanesulfonate of 1-(4-methylphenyl)tetrahydrothiophene, a heptafluoropropane sulfonate or a nonafluorobutane thereof Alkanesulfonate; trifluoromethanesulfonate of 1-(3,5-dimethyl-4-hydroxyphenyl)tetrahydrothiophene, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; -(4-methoxynaphthalen-1-yl)tetrahydrothiophene trifluoromethanesulfonate, heptafluoropropane sulfonate or its nonafluorobutane sulfonate; 1-(4-ethoxynaphthalene- 1-yl)tetrahydrothiophene trifluoromethanesulfonate, heptafluoropropane sulfonate or nonafluorobutane sulfonate; 1-(4-n-butoxynaphthalen-1-yl)tetrahydrothiophene Trifluoromethanesulfonate, heptafluoropropane sulfonate or nonafluorobutane sulfonate; 1-phenyltetrahydrothiopyran Trifluoromethanesulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate; trifluoromethanesulfonate of 1-(4-hydroxyphenyl)tetrahydrothiopyranium, its heptafluoropropane sulfonate or Its nonafluorobutane sulfonate; trifluoromethanesulfonate of 1-(3,5-dimethyl-4-hydroxyphenyl)tetrahydrothiopyranium, its heptafluoropropane sulfonate or its nonafluorobutane a sulfonate; a trifluoromethanesulfonate of 1-(4-methylphenyl)tetrahydrothiopyrene; a heptafluoropropane sulfonate or a nonafluorobutanesulfonate thereof.

Further, the anion portion of the cerium salt may be replaced by an alkyl sulfonate such as methanesulfonate, n-propane sulfonate, n-butane sulfonate or n-octane sulfonate.鎓 salt.

Further, an anthracene salt in which the anion portion of the onium salt is replaced by an anion portion represented by any one of the following formulas (b1) to (b8) may be used.

[wherein, p is an integer of 1 to 3, q1 to q2 are integers of 1 to 5, respectively, q3 is an integer of 1 to 12, t3 is an integer of 1 to 3, and r1 to r2 are independent of 0 to An integer of 3, g is an integer of 1 to 20, R ⁷ is a substituent, n1 to n5 are independently 0 or 1, and v1 to v5 are independent integers of 0 to 3, respectively, and w1 to w5 are independent of 0. An integer of ～3, Q” is the same as the above.].

The substituent of R ^{7 is} the same as those which may be mentioned in the above X, the substituent which the aliphatic hydrocarbon group may have, and the substituent which the aromatic hydrocarbon group may have.

In the case where the symbols (r1, w1 to w5) attached to R ⁷ are integers of 2 or more, the plural R ⁷ in the compound may be the same or different.

Further, the hydrazine salt-based acid generator may be an anion portion represented by the following formula (b-3) or (b-4) in the above formula (b-1) or (b-2). The substituted sulfonium acid generator (the cation moiety is the same as (b-1) or (b-2)).

[wherein, X" represents a C 2-6 alkyl group substituted with at least one hydrogen atom by a fluorine atom; Y", Z", respectively, wherein at least one hydrogen atom is independently replaced by a fluorine atom. An alkyl group having 1 to 10 carbon atoms].

X" is a linear or branched alkyl group in which at least one hydrogen atom is replaced by a fluorine atom, and the alkyl group has a carbon number of 2 to 6, preferably 3 to 5 carbon atoms, preferably It has a carbon number of 3.

Y", Z" are straight-chain or branched-chain alkyl groups in which at least one hydrogen atom is independently substituted by a fluorine atom, and the alkyl group has a carbon number of 1 to 10, preferably a carbon number of 1 to 7, more preferably a carbon number of 1-3.

When the carbon number of the alkyl group of X" or the carbon number of the alkyl group of Y" or Z" is in the range of the above carbon number, the solubility in the resist solvent is good, and the smaller the better.

Further, in the alkyl group of X" or the alkyl group of Y" or Z", the more the number of hydrogen atoms substituted by the fluorine atom, the stronger the strength of the acid, and the higher the energy of light below 200 nm. Or preferably, the ratio of the fluorine atom in the alkyl group or the alkyl group, that is, the fluorination rate is preferably from 70 to 100%, more preferably from 90 to 100%, most preferably A perfluoroalkylene or perfluoroalkyl group in which all of the hydrogen atoms are replaced by fluorine atoms.

Further, the onium salt having a cationic portion represented by the following formula (b-5) or (b-6) can also be used as a phosphonium-based acid generator.

Wherein R ⁴¹ to R ⁴⁶ are each independently an alkyl group, an ethyl group, an alkoxy group, a carboxyl group, a hydroxyl group or a hydroxyalkyl group; n ₁ to n ₅ are each independently an integer of 0 to 3, and n ₆ is An integer from 0 to 2].

In R ⁴¹ to R ⁴⁶ , the alkyl group is preferably an alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group, and a methyl group, an ethyl group, a propyl group or an isopropyl group. , n-butyl, or tert-butyl is particularly preferred.

The alkoxy group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a linear or branched alkoxy group, and particularly preferably a methoxy group or an ethoxy group.

The hydroxyalkyl group is preferably a group in which one of the above alkyl groups or a plurality of hydrogen atoms is substituted by a hydroxyl group, such as a methylol group, a hydroxyethyl group, a hydroxypropyl group or the like.

In the case where the symbols n ₁ to n ₆ attached to R ⁴¹ to R ⁴⁶ are integers of 2 or more, the plural numbers R ⁴¹ to R ⁴⁶ may be the same or different.

n ₁ , preferably 0 to 2, more preferably 0 or 1, most preferably 0.

n ₂ and n _{3 are} preferably each independently 0 or 1, more preferably 0.

n _{4 is} preferably 0 to 2, more preferably 0 or 1.

n _{5 is} preferably 0 or 1, more preferably 0.

n _{6 is} preferably 0 or 1, more preferably 1.

The anion portion having the sulfonium salt of the cation portion represented by the formula (b-5) or (b-6) is not particularly limited, and an anion portion of the sulfonium salt acid generator which has been proposed so far can be used. The same content. The anion portion is, for example, a fluorinated alkylsulfonic acid ion such as an anion portion (R ^{4 "} SO ₃ ^- ) of the onium salt acid generator represented by the above formula (b-1) or (b-2); for example An anion portion or the like represented by the above formula (b-3) or (b-4).

In the present specification, the oxime sulfonate-based acid generator is a compound having at least one group represented by the following formula (B-1) and having a property of generating an acid by irradiation with radiation. These oxime sulfonate-based acid generators are often used for chemical ruthenium-type photoresist compositions, and can be arbitrarily selected and used.

[In the formula (B-1), R ³¹ and R ³² each represent an independent organic group]

The organic group of R ³¹ and R ³² may have a group containing a carbon atom, and an atom other than a carbon atom (for example, a hydrogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom (a fluorine atom, a chlorine atom, etc.)) may be used. .

The organic group of R ³¹ is preferably a linear, branched or cyclic alkyl or aryl group. The alkyl group, the aryl group may have a substituent. The substituent is not particularly limited, and examples thereof include a fluorine atom, a linear chain having 1 to 6 carbon atoms, a branched chain or a cyclic alkyl group. Here, the "having a substituent" means that a part or the whole of a hydrogen atom of an alkyl group or an aryl group is substituted by a substituent.

The alkyl group is preferably a carbon number of 1 to 20, preferably a carbon number of 1 to 10, more preferably a carbon number of 1 to 8, a carbon number of 1 to 6 or a carbon number of 1 to 4. optimal. The alkyl group is particularly preferably an alkyl group which is partially or completely halogenated (hereinafter, also referred to as a halogenated alkyl group). Further, a partially halogenated alkyl group means an alkyl group in which a part of a hydrogen atom is replaced by a halogen atom, and a completely halogenated alkyl group means an alkyl group in which a hydrogen atom is entirely substituted by a halogen atom. The halogen atom, for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom or the like, is preferably a fluorine atom. That is, the halogenated alkyl group is preferably a fluorinated alkyl group.

The aryl group is preferably a carbon number of 4 to 20, more preferably a carbon number of 4 to 10, and most preferably a carbon number of 6 to 10. The aryl group is particularly preferably an aryl group which is partially or completely halogenated. Further, a partially halogenated aryl group means an aryl group in which a part of a hydrogen atom is replaced by a halogen atom, an aryl group which is completely halogenated, and an aryl group in which a hydrogen atom is entirely substituted by a halogen atom. meaning.

R ^{31 is} particularly preferably an alkyl group having 1 to 4 carbon atoms or a fluorinated alkyl group having 1 to 4 carbon atoms which does not have a substituent.

The organic group of R ³² is preferably a linear, branched or cyclic alkyl group, aryl group or cyano group. The alkyl group and the aryl group of R ³² are the same as those of the alkyl group and the aryl group exemplified in the above R ³¹ .

R ^{32 is} particularly preferably a cyano group, an alkyl group having 1 to 8 carbon atoms which does not have a substituent, or a fluorinated alkyl group having 1 to 8 carbon atoms.

The oxime sulfonate-based acid generator is more preferably a compound represented by the following formula (B-2) or (B-3).

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

[In the formula (B-3), R ³⁶ is a cyano group, an alkyl group having no substituent or a halogenated alkyl group. R ³⁷ is a 2 or 3 valent aromatic hydrocarbon group. R ³⁸ is an alkyl group or a halogenated alkyl group having no substituent. p" is 2 or 3].

In the above formula (B-2), the alkyl group or the halogenated alkyl group having no substituent of R ³³ is preferably a carbon number of from 1 to 10, preferably a carbon number of from 1 to 8, and a carbon number of from 1 to 8. 6 is the best.

R ^{33 is} preferably a halogenated alkyl group or more preferably a fluorinated alkyl group.

The fluorinated alkyl group in R ³³ is preferably one in which the hydrogen atom of the alkyl group is fluorinated by 50% or more, more preferably 70% or more of fluorinated, and particularly preferably 90% or more of fluorinated.

The aryl group of R ³⁴ is a group obtained by removing one hydrogen atom from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthyl group or a phenanthryl group. And a heteroaryl group in which a part of carbon atoms of the ring constituting the group is substituted with a hetero atom such as an oxygen atom, a sulfur atom or a nitrogen atom. Among them, the base is better.

The aryl group of R ³⁴ may have a substituent of an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, an alkoxy group or the like. The alkyl group or the halogenated alkyl group in the substituent is preferably a carbon number of from 1 to 8, more preferably a carbon number of from 1 to 4. Further, the halogenated alkyl group is preferably a fluorinated alkyl group.

The alkyl group or the halogenated alkyl group having no substituent of R ³⁵ is preferably a carbon number of from 1 to 10, preferably a carbon number of from 1 to 8, and most preferably a carbon number of from 1 to 6.

R ^{35 is} preferably a halogenated alkyl group or more preferably a fluorinated alkyl group.

The fluorinated alkyl group in R ³⁵ is preferably one in which the hydrogen atom of the alkyl group is fluorinated by 50% or more, more preferably 70% or more of fluorinated, and more preferably 90% or more of fluorinated. It is particularly good for the strength of the acid. Most preferred is a fully fluorinated alkyl group in which the hydrogen atom is replaced by 100% fluorine.

In the above formula (B-3), the alkyl group or the halogenated alkyl group having no substituent of R ³⁶ is the same as the alkyl group or the halogenated alkyl group having no substituent of R ³³ described above.

A 2 or 3 valent aromatic hydrocarbon group of R ³⁷ , for example, a group obtained by removing 1 or 2 hydrogen atoms from the aryl group of the above R ³⁴ or the like.

The alkyl group or the halogenated alkyl group having no substituent of R ³⁸ is the same as the alkyl group or the halogenated alkyl group having no substituent of R ³⁵ described above.

p", preferably 2.

Specific examples of the oxime sulfonate-based acid generator are, for example, α-(p-toluenesulfonyloxyimino)-benzyl cyanide (cyanide), α-(p-chlorophenylsulfonyloxyimino) )-Benzyl cyanide, α-(4-nitrophenylsulfonyloxyimino)-benzyl cyanide, α-(4-nitro-2-trifluoromethylbenzenesulfonyloxyimide Base)-benzyl cyanide, α-(phenylsulfonyloxyimido)-4-chlorobenzyl cyanide, α-(phenylsulfonyloxyimino)-2,4-dichloro Benzyl cyanide, α-(phenylsulfonyloxyimino)-2,6-dichlorobenzyl cyanide, α-(phenylsulfonyloxyimino)-4-methoxybenzyl Cyanide, α-(2-chlorophenylsulfonyloxyimino)-4-methoxybenzyl cyanide, α-(phenylsulfonyloxyimino)-thio-2-ylacetonitrile , α-(4-dodecylbenzenesulfonyloxyimino)-benzyl cyanide, α-[(p-toluenesulfonyloxyimino)-4-methoxyphenyl]acetonitrile , α-[(dodecylbenzenesulfonyloxyimino)-4-methoxyphenyl]acetonitrile, α-(methylsulfonyloxyimino)-4-thienyl cyanide, --(methylsulfonyloxyimino)-1-cyclopentenylacetonitrile, α-(methylsulfonyloxyimino)-1-cyclohexenyl B , α-(methylsulfonyloxyimino)-1-cycloheptenylacetonitrile, α-(methylsulfonyloxyimino)-1-cyclooctenylacetonitrile, α-(trifluoro Methylsulfonyloxyimino)-1-cyclopentenylacetonitrile, α-(trifluoromethylsulfonyloxyimino)-cyclohexylacetonitrile, α-(ethylsulfonyloxyimine Ethylacetonitrile, α-(propylsulfonyloxyimino)-propylacetonitrile, α-(cyclohexylsulfonyloxyimino)-cyclopentylacetonitrile, α-(cyclohexylsulfonate) Mercaptooxyimido)-cyclohexylacetonitrile, α-(cyclohexylsulfonyloxyimino)-1-cyclopentenylacetonitrile, α-(ethylsulfonyloxyimino)-1- Cyclopentenylacetonitrile, α-(isopropylsulfonyloxyimido)-1-cyclopentenylacetonitrile, α-(n-butylsulfonyloxyimino)-1-cyclopentene Acetonitrile, α-(ethylsulfonyloxyimino)-1-cyclohexenylacetonitrile, α-(isopropylsulfonyloxyimino)-1-cyclohexenylacetonitrile, α- (n-butylsulfonyloxyimino)-1-cyclohexenylacetonitrile, α-(methylsulfonyloxyimino)-phenylacetonitrile, α-(methylsulfonyloxy) Amino)-p-methoxyphenylacetonitrile, α-(trifluoromethylsulfonyloxyimino)-phenyl Nitrile, α-(trifluoromethylsulfonyloxyimino)-p-methoxyphenylacetonitrile, α-(ethylsulfonyloxyimino)-p-methoxyphenylacetonitrile, --(propylsulfonyloxyimino)-p-methylphenylacetonitrile, α-(methylsulfonyloxyimino)-p-bromophenylacetonitrile, and the like.

Further, an oxime sulfonate-based acid generator disclosed in JP-A-9-208554 (paragraphs [0012] to [0014] [Chem. 18] to [Chem. 19]), WO2004/074242A2 (65-) can also be used. The sulfonate-based acid generator disclosed in Examples 1 to 40 of page 85.

Further, the preferred content can be exemplified below, for example.

Among the diazomethane acid generators, specific examples of the dialkyl or bisarylsulfonyldiazomethanes are, for example, bis(isopropylsulfonyl)diazomethane and bis(p-toluenesulfonyl) Nitrogen methane, bis(1,1-dimethylethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(2,4-dimethylphenylsulfonyl) Nitrogen methane, etc.

Further, the diazomethane-based acid generator disclosed in JP-A-H11-035551, JP-A-H11-035552, and JP-A-11-035573 can also be used.

Further, poly(disulfonyl)diazomethane, for example, 1,3-bis(phenylsulfonyldiazomethylsulfonyl)propane disclosed in JP-A-11-322707, 1, 4 - bis(phenylsulfonyldiazomethylsulfonyl)butane, 1,6-bis(phenylsulfonyldiazomethylsulfonyl)hexane, 1,10-bis(phenylsulfonate) Mercaptodiazepinemethanesulfonyl)decane, 1,2-bis(cyclohexylsulfonyldiazomethylsulfonyl)ethane, 1,3-bis(cyclohexylsulfonyldiazomethyl) Sulfhydryl)propane, 1,6-bis(cyclohexylsulfonyldiazomethylsulfonyl)hexane, 1,10-bis(cyclohexylsulfonyldiazomethylsulfonyl)decane, etc. .

(B) The component may be used alone or in combination of two or more.

In the present invention, the component (B) is preferably an anthraquinone-based acid generator using a fluorinated alkylsulfonic acid ion as an anion.

The content of the component (B) in the positive resist composition of the present invention is preferably 0.5 to 50 parts by mass, more preferably 1 to 40 parts by mass, per 100 parts by mass of the component (A). When it is in the above range, pattern formation can be sufficiently performed. Further, it is preferred to obtain a uniform solution, good storage stability, and the like.

<arbitrary ingredients>

In the positive resist composition of the present invention, any component may further contain a nitrogen-containing organic compound (D) (hereinafter also referred to as a component (D)).

The component (D) is not particularly limited as long as it can act as an acid diffusion controlling agent, and can act as an inhibitor of an acid generated by the component (B) by exposure. The proposal of each component may be arbitrarily selected from known contents, and among them, an aliphatic amine, particularly a secondary aliphatic amine or a tertiary aliphatic amine is preferred. Here, the aliphatic amine means an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 20 carbon atoms.

The aliphatic amine is, for example, an amine (alkylamine or alkanolamine) or a cyclic amine in which at least one hydrogen atom of ammonia NH ₃ is substituted with an alkyl group having 20 or less carbon atoms or a hydroxyalkyl group.

Specific examples of the alkylamine and the alkanolamine are monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-decylamine, n-decylamine, etc.; diethylamine, di-n a dialkylamine such as propylamine, di-n-heptylamine, di-n-octylamine or dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n -butylamine, tri-n-hexylamine, tri-n-pentylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-decylamine, tri-n-decylamine, tri- a trialkylamine such as n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, tri-n-octanolamine, stearyl An alkyl alcohol amine such as diethanolamine or lauryl diethanolamine. Among them, a trialkylamine and/or an alkanolamine is preferred.

The cyclic amine is, for example, a heterocyclic compound containing a nitrogen atom of a hetero atom. The heterocyclic compound may be a monocyclic one (aliphatic monocyclic amine) or a polycyclic one (aliphatic polycyclic amine).

The aliphatic monocyclic amine is specifically, for example, piperidine, piperazine or the like.

The aliphatic polycyclic amine is preferably, for example, a carbon number of 6 to 10, specifically, for example, 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diaza Heterobicyclo[5.4.0]-7-undecene, heptamethyltetramine, 1,4-diazabicyclo[2.2.2]octane, and the like.

Aromatic amines such as aniline, pyridine, 4-dimethylaminopyridine, pyrrole, hydrazine, pyrazole, imidazole or derivatives thereof, diphenylamine, triphenylamine, tribenzylamine and the like.

Other aliphatic amines such as tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxy Ethylethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine And tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethylamine, and the like.

These may be used alone or in combination of two or more.

The component (D) is usually used in an amount of from 0.01 to 5.0 parts by mass based on 100 parts by mass of the component (A). When it is in the above range, the shape of the resist pattern, the stability over time of storage, and the like can be improved.

The positive resist composition of the present invention may contain any component of an organic carboxylic acid and an oxyacid of phosphorus in order to prevent deterioration of sensitivity, or to improve the shape of the resist pattern, the stability over time of storage, and the like. At least one compound (E) selected from the group consisting of its derivatives (hereinafter also referred to as (E) component).

An organic carboxylic acid such as acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid or the like is preferred.

Phosphorus oxyacids such as phosphoric acid, Phosphonic acid, Phosphinic acid, etc., wherein phosphonic acid is preferred.

The oxo acid derivative of phosphoric acid is, for example, an ester obtained by substituting a hydrogen atom of the oxo acid with a hydrocarbon group, and the hydrocarbon group is, for example, an alkyl group having 1 to 5 carbon atoms or an aryl group having 6 to 15 carbon atoms.

The phosphoric acid derivative is, for example, a phosphate such as di-n-butyl phosphate or diphenyl phosphate.

Phosphonic acid derivatives such as chromic acid esters such as dimethyl phosphonate, di-n-butyl phosphonate, phenylphosphonic acid, diphenyl phosphonate, dibenzyl phosphonate, and the like.

Phosphinic acid derivatives such as phosphinates such as phenylphosphinic acid.

(E) The components may be used singly or in combination of two or more.

The component (E) is usually used in an amount of 0.01 to 5.0 parts by mass based on 100 parts by mass of the component (A).

The positive-type photoresist composition of the present invention can be further blended with an additive which is suitable for mixing, for example, an additive resin which can improve the properties of the photoresist film, a surfactant for improving coating properties, a dissolution inhibitor, a plasticizer, Stabilizers, colorants, halo inhibitors, dyes, etc.

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

The (S) component may be used as long as it is a solvent which can be used to form a uniform solution. For example, one or two or more kinds of the above-mentioned known solvents can be used as a chemically amplified resist solvent.

For example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cycloheptanone, cyclohexanone, methyl-n-pentanone, methyl isoamyl ketone, and 2-heptanone Polyols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, etc.; having ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoethyl An ester-bonded compound such as an acid ester, a monoalkyl ether having a monohydric ether, a monoethyl ether, a monopropyl ether, a monobutyl ether or the like having the above-mentioned polyol or the ester-bonded compound or having a single a derivative of a polyol such as an ether-bonded compound such as a phenyl ether [wherein propylene glycol monomethyl ether acetate (PGMEA) or propylene glycol monomethyl ether (PGME) is preferred]; a ring type such as dioxane Ethers, or methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl phthalate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethoxypropionic acid Esters of ethyl esters, etc.; anisole, ethylbenzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenethyl ether, butylphenyl ether, ethylbenzene, diethylbenzene Pentylbenzene Cumene, toluene, xylene, cumene, mesitylene and the like, aromatic organic solvents.

These organic solvents may be used singly or in the form of a mixture of two or more.

Among them, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), and EL are preferred.

Further, a mixed solvent obtained by mixing PGMEA with a polar solvent is also preferred. The addition ratio (mass ratio) may be appropriately determined by considering the compatibility of PGMEA with a polar solvent, and is preferably in the range of 1:9 to 9:1, more preferably 2:8 to 8:2. good.

More specifically, for example, when the EL of the polar solvent is added, the mass ratio of PGMEA:EL is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. Further, when the PGME of the polar solvent is added, the mass ratio of PGMEA:PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, most preferably 3:7 to 7:3.

Further, the (S) component is preferably a mixed solvent of at least one selected from the group consisting of PGMEA and EL and γ-butyrolactone. At this time, the mixing ratio, the mass ratio of the former to the latter, is preferably from 70:30 to 95:5.

The amount of the component (S) used is not particularly limited, and the thickness of the coating film can be appropriately set in accordance with the concentration which can be applied to a substrate or the like. In general, the solid content concentration of the photoresist composition can be used for 1 to 20% by mass, preferably in the range of 2 to 15% by mass.

The positive-type photoresist composition of the present invention and the component (A1) added to the positive-type photoresist composition are novel materials which have not been known in the past.

Further, the positive resist composition of the present invention can form a photoresist film having good adhesion on a support such as a substrate. Further, the positive resist composition of the present invention has lithographic etching characteristics such as good sensitivity, focal depth of field (DOF), and exposure latitude (EL). Moreover, since it has excellent mask reproducibility (for example, mask defect factor-(MEF)), a photoresist pattern can be formed and a shape of a good photoresist pattern can be formed (for example, a via pattern is formed). The roundness of the through hole, etc.). When EL is used for exposure under varying exposure, when the target size shift is within a certain range, the exposure range of the resist pattern can still be formed, and the light of the faithful reaction mask pattern can be obtained. The range of the exposure amount of the resistive pattern, and the EL latitude, the larger the value, the smaller the amount of change in the pattern size caused by the variation in the amount of exposure, and the latitude of the process can be improved, which is preferable. DOF is the same exposure amount, when the focus is moved up and down for exposure, and the target size is shifted within a certain range, the range of the focal depth of the resist pattern can be formed, and the faithful response can be obtained. The larger the range of the resist pattern of the mask pattern, the better.

The reason why the above-mentioned effects can be obtained is still unclear. The main reason is that in the structural unit (a0-1), a terminal group having a polar group containing -SO ₂ - at the end of the longer side chain can be used. (B) The distribution of the components is uniform, thereby improving the lithographic etching characteristics. Further, in the structural unit (a0-2), since the aliphatic monocyclic group having a lower boiling point is formed, the decomposition product generated by the exposure after the development treatment and washing is less likely to remain in the photoresist film, thereby improving the lithography etching. characteristic.

<Formation method of photoresist pattern>

The method for forming a photoresist pattern of the present invention comprises the steps of forming a photoresist film using the positive photoresist composition of the present invention on the support, exposing the photoresist film, and forming the photoresist The step of developing the film to form a photoresist pattern.

The method for forming the photoresist pattern of the present invention can be carried out, for example, in the following manner.

That is, first, the positive resist composition of the present invention is applied onto a support by a spin coater or the like, and is subjected to a temperature of 80 to 150 ° C for 40 to 120 seconds, preferably 60 to 90. Post-Bake (PAB) is formed in seconds to form a photoresist film. Then, for example, an exposure apparatus such as an ArF exposure apparatus, an electron beam drawing apparatus, or an EUV exposure apparatus is used, and exposure is performed by a mask pattern, or a selective exposure is performed by direct irradiation with an electron beam without a mask pattern. The PEB (Post Exposure Bake) is carried out at a temperature of 80 to 150 ° C for 40 to 120 seconds, preferably 60 to 90 seconds. Next, it is subjected to development treatment using an alkali developer, for example, an aqueous solution of 0.1 to 10% by mass of tetramethylammonium hydroxide (TMAH), preferably washed with pure water and dried. Further, if necessary, baking treatment (post-baking; Post Bake) may be performed after the above development treatment. In this way, a photoresist pattern of a faithful response mask pattern can be obtained.

The support is not particularly limited, and conventionally known articles such as a substrate for an electronic component or an article on which a specific wiring pattern is formed may be used. More specifically, for example, a substrate made of a metal such as a germanium wafer, copper, chromium, iron, or aluminum, or a glass substrate. As the material of the circuit pattern, for example, copper, aluminum, nickel, gold, or the like can be used.

Further, for the support, for example, an inorganic or/or organic film may be provided on the substrate. An inorganic film such as an inorganic antireflection film (inorganic BARC). Organic film, such as organic anti-reflective film (organic BARC).

The wavelength used for the exposure is not particularly limited, and an ArF excimer laser, a KrF excimer laser, an F ₂ excimer laser, an EUV (very ultraviolet ray), a VUV (vacuum ultraviolet ray), or an EB (electron line) can be used. ), X-ray, soft X-ray and other radiation. The aforementioned photoresist composition is effective for KrF excimer laser, ArF excimer laser, EB or EUV, especially for ArF excimer laser.

The exposure method of the photoresist film may be performed by usual exposure (dry exposure) in an inert gas such as air or nitrogen, or by liquid immersion exposure (Liquid Immersion Lithography).

The immersion exposure is a solvent (wetting medium) having a refractive index higher than that of air, which is pre-exposed between the photoresist film and the lowermost position of the exposure device, and is exposed (immersion exposure) in this state. Exposure method.

It is preferred to wet the medium to use a solvent having a refractive index larger than that of air and having a refractive index smaller than that of the exposed photoresist film. The refractive index of the solvent is not particularly limited as long as it is within the above range.

A solvent having a refractive index larger than that of air and having a refractive index smaller than that of the resist film, for example, water, a fluorine-based inert liquid, an oxime-based solvent, a hydrocarbon-based solvent, or the like.

Specific examples of the fluorine-based inert liquid include a liquid containing a fluorine-based compound such as C ₃ HCl ₂ F ₅ , C ₄ F ₉ OCH ₃ , C ₄ F ₉ OC ₂ H ₅ , C ₅ H ₃ F ₇ or the like as a main component. Further, those having a boiling point of 70 to 180 ° C are preferred, and those having a boiling point of 80 to 160 ° C are more preferred. When the fluorine-based inert liquid is a liquid having a boiling point within the above range, it is preferred to remove the medium for wetting in a simple manner after the completion of the exposure.

The fluorine-based inert liquid is particularly preferably a perfluoroalkyl compound obtained by substituting all hydrogen atoms in the alkyl group with fluorine atoms. The perfluoroalkyl compound is specifically, for example, a perfluoroalkyl ether compound or a perfluoroalkylamine compound.

Further, more specifically, the perfluoroalkyl ether compound is, for example, perfluoro(2-butyl-tetrahydrofuran) (boiling point: 102 ° C), and the above perfluoroalkylamine compound, for example, perfluorotributylamine (boiling point 174) °C) and so on.

Infiltrating media, in terms of cost, safety, environmental issues, and generality, it is better to use water.

<polymer compound>

The polymer compound of the present invention has a structural unit (a0-1) represented by the following formula (a0-1) and a structural unit (a0-2) represented by the following formula (a0-2). Polymer compound.

The description of the polymer compound of the present invention is the same as that described for the component (A1) of the positive resist composition of the present invention.

In the formula, R ¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms, R ² is a divalent bond group, and R ³ is a ring skeleton containing -SO _a cyclic group of ₂ -, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ²¹ is a branched alkyl group; and R ²² is a bondable with R ²² The bonded carbon atoms together form the base of the aliphatic monocyclic group].

[Examples]

In the following, the invention will be described in more detail by way of examples, and the invention is not limited by the examples.

In the present embodiment, the unit represented by the chemical formula (1) is described as "compound (1)", and the compounds represented by the other formulae are also the same.

[Monomer Synthesis Example 1 (Synthesis of Compound (1))]

The compound (1) used in the polymer synthesis example described later is synthesized in the following order.

In a 500 ml three-necked flask under nitrogen atmosphere, 20 g (105.14 mmol) of alcohol (1), 30.23 g (157.71 mmol) of ethyl diisopropylaminocarbodiimide (EDCI) hydrochloride and two were added. 300 ml of a solution of methylaminopyridine (DMAP) 0.6 g (5 mmol) in THF was added thereto, and 16.67 g (115.66 mmol) of the precursor (1) was added thereto under ice cooling (0 ° C), followed by stirring at room temperature for 12 hours.

After confirming the disappearance of the starting material by thin layer chromatography (TLC), 50 ml of water was added to stop the reaction. The reaction solvent was concentrated under reduced pressure, and the obtained organic layer was extracted three times with ethyl acetate, and washed sequentially with water, saturated sodium hydrogen carbonate and 1N-HClaq. The product obtained by distilling off the solvent was dried under reduced pressure to give Compound (1).

The results of the machine analysis of the obtained compound (1) are shown below.

¹ H-NMR (CDCl ₃ , 400 MHz): δ (ppm) = 6.22 (s, 1H, H ^a ), 5.70 (s, 1H, H ^b ), 4.71-4.85 (m, 2H, H ^{c, d} ), 4.67(s,2H,H ^k ), 3.40-3.60(m,2H,H ^e,f ), 2.58-2.70(m,1H,H ^g ),2.11-2.21(m,2H,H ^h ), 2.00 ( s, 3H, H ⁱ ), 1.76-2.09 (m, 2H, H ^j ) ‧

[Monomer Synthesis Example 2 (Synthesis of Compound (2))]

The compound (2) used in the polymer synthesis example described later was synthesized in the following order.

37.6 g (494 mmol) of glycolic acid, 700 mL of DMF, 86.5 g (626 mmol) of potassium carbonate, and 28.3 g (170 mmol) of potassium iodide were added to a 2-liter three-necked flask equipped with a thermometer, a cooling tube, and a stirring apparatus, and stirred at room temperature. minute. Subsequently, a solution of 100 g (412 mmol) of 2-methyl-2-adamantyl chloroacetate in 300 mL of dimethylformamide was slowly added. The temperature was raised to 40 ° C and stirred for 4 hours. After completion of the reaction, 2000 mL of diethyl ether was added, followed by filtration, and the resulting solution was washed three times with 500 mL of distilled water. Crystallization was carried out in a mixed solution of toluene (300 mL) ‧ heptane (200 mL) to give the title compound (2-(2-(2-methyl-2-adamantyloxy)-2- oxy ethoxy) (2-oxoethanol) 78 g of a colorless solid (yield 67%, GC purity: 99%).

The results of the machine analysis of the obtained compound are shown below.

¹ H-NMR: 1.59 (d, 2H, J = 12.5 Hz), 1.64 (s, 3H), 1.71 to 1.99 (m, 10H), 2.29 (m, 2H), 2.63 (t, 1H, J = 5.2 Hz) ), 4.29 (d, 2H, J = 5.2 Hz), 4.67 (s, 2H).

¹³ C-NMR: 22.35, 26.56, 27.26, 32.97, 34.54, 36.29, 38.05, 60.54, 61.50, 89.87, 165.97, 172.81.

GC-MS: 282 (M+, 0.02%), 165 (0.09%), 149 (40%), 148 (100%), 133 (22%), 117 (2.57%), 89 (0.40%).

From the above results, it was confirmed that the obtained compound was 2-(2-(2-methyl-2-adamantyloxy)-2-oxoethoxyethoxy)-2-oxoethanol.

Subsequently, 2-(2-(2-methyl-2-adamantyloxy)-2-oxoethoxyethoxy) was added to a 2-L three-necked flask equipped with a thermometer, a cooling tube and a stirring device. 165 g (584 mmol) of 2-sided oxyethanol, 2000 mL of THF, 105 mL (754 mmol) of triethylamine, and 0.165 g (1000 ppm) of p-methoxyphenol were dissolved. After the dissolution, 62.7 mL (648 mmol) of methacrylic acid ruthenium chloride was gradually added to the ice bath, and the mixture was heated to room temperature and stirred for 3 hours. After completion of the reaction, 1000 mL of diethyl ether was added, and the mixture was washed 5 times with 200 mL of distilled water. The extract was concentrated to give 198 g (yield: 97%, GC purity: 99%) as a colorless liquid of the object (the compound (2)).

The results of the machine analysis of the obtained compound (2) are shown below.

¹ H-NMR: 1.58 (d, J = 12.5 Hz, 2H), 1.63 (s, 3H), 1.71 to 1.89 (m, 8H), 1.98 (s, 3H), 2.00 (m, 2H), 2.30 (m) , 2H), 4.62 (s, 2H), 4.80 (s, 2H), 5.66 (m, 1H), 6.23 (m, 1H).

¹³ C-NMR: 18.04, 22.15, 26.42, 27.14, 32.82, 34.38, 36.11, 37.92, 60.44, 61.28, 89.42, 126.79, 135.18, 165.61, 166.30, 167.20.

GC-MS: 350 (M+, 1.4%), 206 (0.13%), 149 (47%), 148 (100%), 133 (20%), 69 (37%).

[Polymer Synthesis Example 1]

In a multi-necked flask equipped with a thermometer, a reflux tube, and a nitrogen introduction tube, 15.80 g (50.00 mmol) of the compound (1), 5.83 g (16.67 mmol) of the compound (2), and 4.67 g (20.83 mmol) of the compound were obtained. (4) 3.93 g (20.00 mmol) of the compound (5) was dissolved in 55.71 g of methyl ethyl ketone (MEK). To the solution, 8.08 mmol of dimethyl azobisisobutyrate (V-601) of a polymerization initiator was added and dissolved. This was slowly dropped into a solution obtained by dissolving 25.66 g (97.92 mol) of the compound (3) of MEK (30.33 g) under a nitrogen atmosphere for 3 hours and heating to 80 °C. After the completion of the dropwise addition, the reaction mixture was heated and stirred for 2 hours, and then the reaction liquid was cooled to room temperature. The obtained reaction polymerization is dropped into a large amount of n-heptane to precipitate a polymer, and the precipitated white powder is filtered off, and sequentially washed with n-heptane, isopropyl alcohol and methanol. After drying, 35 g of the target compound 1 was obtained.

The polymer compound 1 had a mass average molecular weight (Mw) of 10,500 in terms of standard polystyrene measured by GPC measurement, and a molecular weight dispersion degree (Mw/Mn) of 1.75. Further, the copolymerization composition ratio (the ratio of each structural unit (mole ratio) in the structural formula) obtained by carbon 13 nuclear magnetic resonance spectrum (600 MHz_ ¹³ C-NMR) was, l/m/n/o/p. =34.3/9.4/33.0/11.0/12.3.

[Polymer Synthesis Examples 2 to 7]

With reference to the description of Synthesis Example 1, the monomer type, the addition ratio, and the amount of the polymerization initiator used were changed to synthesize the polymer compounds 2 to 7.

(Mw=11,900, Mw/Mn=2.07, l/m/n/o/p=34.3/9.7/24.1/19.5/12.4 (Morby))

(Mw=7,500, Mw/Mn=1.42, l/m/n/o/p=36.4/21.9/15.9/14.0/11.8 (Morby))

(Mw=8,400, Mw/Mn=1.56, l/m/n/o/o=35.2/22.3/16.1/13.8/12.6 (Morby))

(Mw = 8,900, Mw / Mn = 1.64, l / m / n / o = 34.7 / 11.1/42.6 / 11.6 (mr ratio)).

(Mw = 7,500, Mw / Mn = 1.60, l / m / n = 39.8 / 41.2 / 19.0 (mr ratio)).

(Mw = 6,700, Mw / Mn = 1.58, l / m / n = 40.4 / 38.7 / 20.9 (mr ratio)).

[Examples 1 to 5 and Comparative Examples 1 and 2]

The components were mixed and dissolved as shown in Table 1 to produce a positive photoresist composition.

In Table 1, the numerical value in [] indicates the amount of addition (parts by mass). Further, the symbols in Table 1 are as follows.

(A)-1: The above polymer compound 1.

(A)-2: The above polymer compound 2.

(A)-3: The above polymer compound 3.

(A)-4: The above polymer compound 4.

(A)-5: The above polymer compound 6.

(A)-6: The above polymer compound 5.

(A)-7: The above polymer compound 7.

(B)-1: a compound represented by the following chemical formula (B)-1.

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

(S)-1: a mixed solvent of PGMEA/PGME=6/4 (mass ratio).

(S)-2: γ-butyrolactone.

(Synthesis method will be described later)

Using the obtained photoresist composition, a photoresist pattern was formed in the following order, and the lithographic etching property was evaluated.

[Formation of Photoresist Pattern-1]

The organic anti-reflection film composition "ARC29A" (trade name, manufactured by Puliwa Co., Ltd.) was applied onto a 12-inch silicon wafer using a spin coater, and 205 ° C, 60 seconds on a hot plate. As a result of baking and drying, an organic antireflection film having a film thickness of 89 nm was formed. The photoresist composition prepared above was applied onto the antireflection film by using a spin coater, and subjected to prebaking (PAB) treatment at 90 ° C for 60 seconds on a hot plate, and dried. A photoresist film having a film thickness of 100 nm was formed.

Then, the coating liquid for forming a protective film "TILC-057" (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied onto the resist film using a spin coater, and heated at 90 ° C for 60 seconds. As a result, a top coat having a film thickness of 35 nm was formed.

Subsequently, an ArF excimer laser NSR-S609B (manufactured by Ricoh Co., Ltd.; NA (number of openings) = 1.07, 2/3 wheel illumination, 1/4 magnification reduction, infiltration media: water) was used, and an ArF excimer laser was used. (193 nm) was selectively irradiated by using a contact hole pattern (hereinafter, also referred to as CH pattern) having a via diameter of 90 nm/pitch of 157.5 nm as a target mask pattern.

Subsequently, the PEB treatment at 80 ° C for 60 seconds was carried out, and at 23 ° C, a 2.38 mass % TMAH aqueous solution NMD-3 (manufactured by Tokyo Ohka Kogyo Co., Ltd.) was used for development for 60 seconds, and thereafter, After 30 seconds, it was washed with pure water and subjected to vibration drying.

As a result, in any of the examples, a pattern of a CH pattern having a via diameter of 90 nm and a pitch of 157.5 nm was formed.

[Positive roundness assessment]

Using a length measuring SEM (manufactured by Hitachi, Ltd., product name: S-9220), the CH pattern formed by observing from above, the center of the through hole was measured in 24 directions for 25 through holes in each CH pattern. The distance to the outer edge is calculated from the result by a factor of three (3σ) of the standard deviation (σ). The smaller the value of 3σ obtained in this way, the smaller the meaning of the roundness of the through hole. The results are shown in Table 2.

From the above results, it is clear that when the photoresist compositions of Examples 1 to 5 are compared with Comparative Examples 1 and 2, the formed via pattern has a high roundness.

[Formation of photoresist pattern-2]

Using the photoresist compositions of Examples 1 and 2 and Comparative Example 1, a CH pattern having a via diameter of 90 nm (pitch of 157.5 nm) was obtained in the same manner as in the above [Formation of Photoresist Pattern Type-1]. The best EOP system for forming this CH pattern is shown in Table 3.

[Focus Depth of Field Width (DOF)]

The focal depth of field (DOF) in the CH pattern with the above-mentioned through hole diameter of 90 nm was evaluated.

In the EOP described above, when the focus is appropriately moved up and down, the same photoresist pattern as described above is formed, and the width (μm) of the depth of focus of the range in which the shape of the through-hole pattern is obtained is obtained as "Open". The results are shown in Table 3.

[Mask Defect Factor One (MEF)]

The mask pattern, except for the mask size of the through-hole diameters of 94 nm, 92 nm, 90 nm, 88 nm, and 86 nm (the pitch is 157.5 nm), the exposure is performed using the Eop obtained above, and the like. The contact hole pattern is formed in the same manner as in the above [Formation of the photoresist pattern 1]. At this time, the target size (nm) was used as the horizontal axis, and the diameter (nm) of the through hole formed in the photoresist film of each mask pattern was used as the MEF.

Moreover, the MEF whose value is closer to 1, the better the mask reproducibility. The results are shown in Table 3.

As shown in Table 3, the photoresist compositions of Examples 1 to 2 of the present invention exhibited good lithographic etching characteristics when compared with Comparative Example 1.

<Synthesis example of (B) component> [Synthesis of (B)-1]

(i) Add a small amount of phosphorus oxide (8.53g) and 2,6-dimethylphenol (8.81g) and diphenylarsenium (12.2g) to methanesulfonic acid (60.75g) controlled below 20 °C. . After the temperature was controlled at 15 to 20 ° C for 30 minutes, the temperature was raised to 40 ° C, and the mixture was aged for 2 hours. Subsequently, the reaction was dropped into pure water (109.35 g) cooled to below 15 °C. After completion of the dropwise addition, dichloromethane (54.68 g) was added, and after stirring, a dichloromethane layer was collected. In a separate vessel, hexane (386.86 g) at 20-25 ° C was added and the dichloromethane layer was added dropwise. After completion of the dropwise addition, the mixture was aged at 20 to 25 ° C for 30 minutes, and then filtered to give the desired intermediate compound (f-01) (yield 70.9%).

The obtained intermediate compound (f-01) was analyzed by ¹ H-NMR.

¹ H-NMR (DMSO-d6, 600 MHz): δ (ppm) = 7.61 - 7.72 (m, 10H, phenyl), 7.14 (S, 2H, H ^c ), 3.12 (S, 3H, H ^b ), 2.22 (s, 6H, H ^a ).

From the results of the above analysis, it was found that the obtained intermediate compound (f-01) had the structure shown below.

(ii) The above intermediate compound (f-01) (4 g) was dissolved in dichloromethane (79.8 g). After confirming dissolution, potassium carbonate (6.87 g) was added, followed by addition of 2-methyl-2-adamantane (3.42 g). After refluxing for 24 hours, it was filtered, washed with water, and crystallized from hexane. The obtained powder was dried under reduced pressure to give the title compound (yield: 66%).

The title compound was analyzed by ¹ H-NMR. The results are shown below.

¹ H-NMR (CDCl ₃ , 600 MHz): δ (ppm) = 7.83 - 7.86 (m, 4H, phenyl), 7.69-7.78 (m, 6H, phenyl), 7.51 (s, 2H, ^Hd ), 4.46 (s, 2H, H ^c ), 2.39 (s, 6H, H ^a ), 2.33 (s, 2H, Adamantane), 2.17 (s, 2H, Adamantane), 1.71-1.976 (m, 11H, Adamantane), 1.68 (s, 3H, H ^b ), 1.57-1.61 (m, 2H, Adamantane).

From the results of the above analysis, it was confirmed that the compound (f-1) having the structure shown below was contained in the objective compound.

In addition, it is confirmed by the measurement result of the ion chromatography method that the NMR data of the cation part is the same as the above-mentioned compound (f-2) and the compound (f-3) except the compound (f-1). ). The ratio of these compounds was 21.4 mol% of the compound (f-1), 11.4 mol% of the compound (f-2), and 67.2 mol% of the compound (f-3).

(iii) 5.00 g of the following compound (IX) was dissolved in 50.0 g of pure water, and 6.19 g of the above compound (f-3) was added thereto, and then 50.0 g of dichloromethane was added thereto, followed by stirring at room temperature for 10 hours. Subsequently, the organic layer was taken out by liquid separation. The organic layer was washed three times with a 1% aqueous HCl solution, and then washed once with a 1% aqueous ammonia solution, and then washed four times with pure water. The organic layer was concentrated to give the title compound ( Compound (B) -1) 8.58 g (yield: 90.4%).

The obtained compound (B)-1 was analyzed by ¹ H-NMR and ¹⁹ F-NMR.

¹ H-NMR (DMSO-d6, 400 MHz): δ (ppm) = 1.47-1.95 (m, 15H, Ad, 3H, anion), 2.13-2.16 (m, 2H, Ad, 1H, anion), 2.30 (s) , 6H, PhCH ₃ ), 2.49 (m, 1H, anion), 3.48 (m, 1H, anion), 3.88 (t, 1H, anion), 4.58 (s, 2H, CH ₂ ) 4.66 (t, 1H, anion ), 4.78 (m, 1H, anion), 7.57 (m, 2H, Ph), 7.72-7.84 (m, 10H, Ph).

¹⁹ F-NMR (DMSO-d6, 400 MHz): δ (ppm) - 107.8 (m, 2F, CF ₂ ) (wherein the peak of hexafluorobenzene was set to -160 ppm).

From the above results, it was confirmed that the compound (B)-1 had the structure represented by the above formula (g).

Claims (16)

A positive-type photoresist composition which comprises a substrate component (A) which increases the solubility to an alkali developer via an action of an acid, and a positive type of an acid generator component (B) which generates an acid via exposure The photoresist composition characterized in that the substrate component (A) contains a structural unit (a0-1) represented by the following general formula (a0-1), and a general formula (a0-2) a polymer compound (A1) representing the structural unit (a0-2), Wherein R ¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ² is a divalent bond group; and R ³ is a ring skeleton containing -SO ₂ - a cyclic group, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ²¹ is a branched alkyl group; and R ²² is bondable to the R ²² The carbon atoms together form the base of the aliphatic monocyclic group]. The positive resist composition according to claim 1, wherein R ³ is a cyclic group containing -O-SO ₂ - in the ring skeleton. The positive resist composition of claim 2, wherein R ³ is represented by the following formula (3-1), [wherein A' is an alkylene group, an oxygen atom or a sulfur atom having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, a is an integer of 0 to 2, and R ⁶ is an alkyl group, an alkoxy group, or a halogenated group. Alkyl, hydroxy, -COOR", -OC(=O)R", hydroxyalkyl or cyano, R" is a hydrogen atom or an alkyl group]. The positive-type resist composition according to the first aspect of the invention, wherein the polymer compound (A1) has a structural unit different from the structural units (a0-1) and (a0-2), and contains an acid. The carbon atom at the α position of the dissociative dissolution inhibiting group may be bonded to a structural unit (a1) derived from an alkyl group having 1 to 5 carbon atoms or an alkyl group having 1 to 5 carbon atoms. The positive-type resist composition of claim 4, wherein the polymer compound (A1) has at least two types of the structural units (a1). The positive-type resist composition according to the fourth or fifth aspect of the invention, wherein the polymer unit (A1) has the structural unit (a1) represented by the following formula (a1-0-12) At least one selected from the group consisting of structural units and structural units represented by the following general formula (a1-0-2), Wherein R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ²³ is an alkyl group; and R ²⁴ is a carbon atom which can bond with the R ²⁴ bond to form a fat. A group of a polycyclic group, Y ² is a divalent bond group, and X ² is an acid dissociable dissolution inhibiting group]. The positive-type resist composition according to the first aspect of the invention, wherein the polymer compound (A1) further has a carbon atom having an α-position containing a polar group-containing aliphatic hydrocarbon group, and a carbon number of 1 to 5 may be bonded. A structural unit derived from an acrylate having a halogenated alkyl group having 1 to 5 carbon atoms (a3). A positive-type photoresist composition as claimed in claim 1 which contains a nitrogen-containing organic compound (D). A method for forming a photoresist pattern, comprising the steps of: forming a photoresist film on a support by using a positive photoresist composition of claim 1; exposing the photoresist film; and The step of alkali developing the photoresist film to form a photoresist pattern. A polymer compound having a structural unit (a0-1) represented by the following formula (a0-1) and a structural unit represented by the following formula (a0-2) (a0-2) , Wherein R ¹ is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ² is a divalent bond group; and R ³ is a ring skeleton containing -SO ₂ - a cyclic group, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ²¹ is a branched alkyl group; and R ²² is bondable to the R ²² The carbon atoms together form the base of the aliphatic monocyclic group]. The polymer compound according to claim 10, wherein the R ³ is a ring-form group containing -O-SO ₂ - in the ring skeleton. The polymer compound according to claim 11, wherein the R ³ is represented by the following formula (3-1), [wherein A' is an alkylene group, an oxygen atom or a sulfur atom having 1 to 5 carbon atoms which may contain an oxygen atom or a sulfur atom, a is an integer of 0 to 2, and R ⁶ is an alkyl group, an alkoxy group, or a halogenated group. Alkyl, hydroxy, -COOR", -OC(=O)R", hydroxyalkyl or cyano, R" is a hydrogen atom or an alkyl group]. The polymer compound according to claim 10, wherein the polymer compound (A1) has a structural unit different from the structural units (a0-1) and (a0-2), and contains an acid dissociable solution. The carbon atom at the α position of the inhibiting group may be bonded to a structural unit (a1) derived from an alkyl group having 1 to 5 carbon atoms or an alkyl group having 1 to 5 carbon atoms. A polymer compound according to claim 13 which has at least two kinds of the above structural units (a1). The polymer compound according to claim 13 or 14, wherein the structural unit (a1) has a structural unit represented by the following formula (a1-0-12) and a formula (a1-0-) 2) at least one selected from the group of structural units indicated, Wherein R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms; R ²³ is an alkyl group; and R ²⁴ is a carbon atom which can bond with the R ²⁴ bond to form a fat. A group of a polycyclic group, Y ² is a divalent bond group, and X ² is an acid dissociable dissolution inhibiting group]. The polymer compound according to claim 10, which further has a carbon atom having an α-position of a polar group-containing aliphatic hydrocarbon group, and a C 1 to 5 alkyl group or a C 1 to 5 halogenated alkyl group. The structural unit derived from the acrylate (a3).