TWI395066B - Method for forming positive photoresist composition and photoresist pattern - Google Patents

Description

Method for forming positive photoresist composition and photoresist pattern

The present invention relates to a second patterning process using a first photoresist composition, and a second patterning process using a second photoresist composition for a second patterning process, which is suitable for the second A positive photoresist composition of the photoresist composition and a method of forming a photoresist pattern.

The present application claims priority from Japanese Patent Application No. 2008-006293, filed on Jan. 15, 2008, and Japanese Patent Application No. 2008-097432, filed on Apr. 03, 2008. In the invention.

A technique of forming a fine pattern on a substrate and etching it as a mask, and processing the lower layer of the pattern (pattern forming technique) has been widely used in IC manufacturing of the semiconductor industry, etc. Great attention.

The fine pattern is usually formed by an organic material such as a photolithography method or a nano printing method. For example, in the lithography method, a photoresist film obtained by using a photoresist composition containing a substrate component such as a resin is formed on a support such as a substrate, and a specific film is formed on the photoresist film. A pattern mask (mask pattern) in which a selective exposure is performed by radiation such as light or an electron beam, and a development process is applied to form a photoresist pattern having a specific shape on the photoresist film. In addition, as a mask of the resist pattern type, a semiconductor element or the like is manufactured by performing steps such as processing by etching a substrate.

The photoresist composition having a characteristic of being changed to be soluble in the developer is referred to as a positive type, and a photoresist composition in which a portion of the exposure is changed to be insoluble in the developer is referred to as a negative type.

In recent years, with the advancement of the lithography etching technology, the pattern has been rapidly refined. 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. However, KrF excimer lasers or ArF excimer lasers are now being used for mass production of semiconductor components. For example, when lithography is performed using an ArF excimer laser, a pattern having a resolution of about 45 nm can be formed. Further, in order to improve the resolution more, F ₂ excimer lasers, electron beams, EUV (extreme ultraviolet rays), or X-rays, which are shorter wavelengths than the aforementioned excimer laser, have been studied.

The photoresist composition is intended to have sensitivity to the above-mentioned exposure light source, and has lithographic etching characteristics such as resolution which can reproduce a fine-sized pattern. A photoresist composition which satisfies the above requirements, and generally comprises a chemically amplified photoresist composition which contains a substrate component which changes the solubility of an alkali developer based on an acid action, and an acid generator which generates an acid via exposure (for example) Refer to Patent Document 1). For example, a positive type chemically amplified photoresist generally has a base component containing a resin which increases solubility in an alkali developing solution by an action of an acid, and an acid generator is generated by exposure when a resist pattern is formed. The acid is formed so that the exposed portion is made soluble to the alkali developer.

Further, the base resin of the chemically amplified photoresist is mainly a base resin of a photoresist (KrF photoresist) used for KrF excimer laser lithography etching, and has a highly transparent polyhydroxystyrene near 248 nm. (PHS) or a resin (PHS-based resin) whose hydroxyl group is protected by an acid-dissociable dissolution inhibiting group. Further, since the base resin of the photoresist (ArF photoresist) used in the ArF excimer laser lithography etching or the like has excellent transparency in the vicinity of 193 nm, it is generally mainly used as a (meth) acrylate in the main chain. Resin (acrylic resin) of the structural unit derived.

One of the methods for improving the analyticity is, for example, exposure between a counter lens of an exposure machine and a reagent, and exposure (immersion exposure) through a liquid having a higher refractive index than air (immersion medium). The lithography method, that is, liquid immersion lithography (hereinafter, also referred to as immersion exposure) (for example, Non-Patent Document 1).

According to the method of immersion exposure, even if a light source of the same exposure wavelength is used, the same high resolution can be obtained as in the case of using a light source of a shorter wavelength or a case where a high NA lens is used, and the depth of focus of the focus is not caused. Reduced. Further, the immersion exposure can be carried out using a conventional exposure apparatus. Therefore, the immersion exposure can realize a photoresist pattern with low cost and high resolution and excellent focus depth of field, and in the manufacture of semiconductor components that require a large amount of equipment investment, regardless of cost, resolution, etc. The effect of the etched etching characteristics, which can provide the semiconductor industry, has attracted great attention.

Infiltrating exposure is effective for the formation of all pattern shapes, and it can also be combined with super-analytical techniques such as the phase shift method and the deformed illumination method currently studied. At present, the immersion exposure technology is mainly active in the research of the technology of using ArF excimer laser as a light source. Also, at present, infiltration media is mainly for research on water.

Recently, one of the lithography techniques of the new proposal is a repetitive patterning process in which a pattern of two or more patterns is formed to form a photoresist pattern (for example, refer to Non-Patent Documents 2 to 3).

In the repeated patterning process, for example, after the first photoresist composition is patterned to form a first photoresist pattern, the first photoresist pattern is formed on the support. On the support, the second photoresist composition is used for patterning, so as to form a photoresist pattern having a higher resolution than the photoresist pattern formed by the patterning of the first time.

Patent Document 1: JP-A-2003-241385

Non-Patent Document 1: Proceedings of SPIE, Vol. 5754, pp. 119-128 (2005).

Non-Patent Document 2: Proceedings of SPIE, Vol. 5256, pp. 985-994 (2003).

Non-Patent Document 3: Proceedings of SPIE, Vol. 6153, pp. 615301-1 - 19 (2006).

In the above repeated patterning process, when the second photoresist composition is applied, it is susceptible to the first photoresist pattern. Therefore, for example, when the solvent of the second photoresist composition dissolves part or all of the first photoresist pattern, film reduction or the like is caused to damage the shape, and the first photoresist pattern and the second When the photoresist composition is dissolved and mixed, a "mixing" phenomenon occurs, and there is a problem that a good photoresist pattern cannot be produced.

This problem is generally presumed to be avoided when a photoresist composition which is soluble in a solvent which does not easily dissolve the first photoresist pattern is used. Therefore, in the case where a positive photoresist composition as the first photoresist composition is conventionally used, the second photoresist composition mainly has an organic solvent having low compatibility with the positive photoresist composition. A good solubility negative photoresist composition. An organic solvent having low compatibility with the positive resist composition may be, for example, an alcohol solvent or an ether organic solvent having no hydroxyl group.

Further, in the case where the second photoresist composition is the same as the first photoresist composition of the first photoresist composition, it is often necessary to use a refrigerant or the like to protect the first photoresist pattern, the phase thereof. There are more steps than in the case of using a negative-type photoresist composition, and there is a problem that workability is deteriorated. At present, the acrylic resin used as the base resin of the ArF positive resist is soluble in propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), cyclohexanone, 2-glycol. a positive photoresist composition of an organic solvent such as a ketone or an ethyl lactate (EL). When the positive photoresist composition is directly applied to the first photoresist pattern, the first photoresist can be made. The pattern is dissolved.

The present invention, which is proposed in view of the above circumstances, is to provide a resistive pattern by using a positive resist composition which is a first photoresist composition to form a photoresist pattern, which can be used as the second The positive photoresist composition of the photoresist composition and the formation method of the photoresist pattern are for the purpose.

The present inventors have proposed the following means in order to solve the above problems.

That is, the first aspect of the present invention is a positive-type photoresist composition which contains a resin component (A) which increases the solubility to an alkali developer via the action of an acid, and is exposed through exposure. And an acid generator component (B) and an organic solvent (S), wherein the resin component (A) and the acid generator component (B) are dissolved in the organic solvent (S), the positive light The resist composition is a step of coating the positive photoresist composition on the support to form the first photoresist film, and forming the first photoresist film by selective exposure and alkali development. a step of forming a first photoresist pattern and a step of forming a second photoresist film on the support body on which the first photoresist pattern is formed, and Forming a positive resistive pattern for the second photoresist film by forming a positive photoresist pattern of the second photoresist film by selective exposure and alkali development to form a photoresist pattern In the composition, the organic solvent (S) is an organic solvent that does not dissolve the first photoresist film, and the resin component (A) The structural unit (a0-1) represented by the following general formula (a0-1) and the structural unit (a0-2) represented by the following general formula (a0-2).

[In the formula (a0-1), R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; Y ¹ is an aliphatic cyclic group; z is a group containing a tertiary alkyl group or an alkoxyalkyl group; a is 1 An integer of ～3, b is an integer of 0 to 2, and a+b=1 to 3; c, d, and e are independent integers of 0 to 3, respectively; in the formula (a0-2), R is a hydrogen atom, Lower alkyl or halogenated lower alkyl; Y ³ is an alkyl or aliphatic cyclic group; g, h are each an integer from 0 to 3; i is an integer from 1 to 3.

Moreover, a second aspect of the present invention is a method for forming a photoresist pattern, characterized in that it is included in a support, and a step of applying a positive photoresist composition to form a first photoresist film, And the step of forming the first photoresist pattern by selectively exposing and alkali developing the first photoresist film, and coating the support body on which the first photoresist pattern is formed The step of forming the second photoresist film in the first aspect of the first photoresist layer and the step of selectively exposing and alkali developing the second photoresist film to form a photoresist pattern.

In the specification and the patent application, the term "structural unit" means the monomer unit (single body unit) constituting the resin component (polymer, copolymer).

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

"Aliphatic" means the concept of a compound having no aromaticity, a compound, etc., with respect to the concept of aromaticity.

"Exposure" is intended to include full illumination of radiation.

"(Meth)acrylic acid" means one or both of acrylic acid having a hydrogen atom bonded to the α-position and one or both of the methacrylic acid having a methyl group bonded to the α-position.

"Acidic acid ester" means one or both of an acrylate having a hydrogen atom bonded to the α-position and a methacrylate having a methyl group bonded to the α-position.

"(Meth) acrylate" means one or both of an acrylate having a hydrogen atom bonded to the α-position and a methacrylate having a methyl group bonded to the α-position.

The present invention provides a repeating patterning process in which a first pattern is formed using a first photoresist composition and a second pattern is formed using a second photoresist composition, and is not dissolved. The first photoresist pattern formed by the first photoresist composition forms a resistive pattern positive resist composition and a photoresist pattern formation method by repeating patterning.

Positive photoresist composition

The positive photoresist composition of the present invention is a step of coating a positive photoresist composition to form a first photoresist film on the support, and selectively exposing the first photoresist film a step of forming a first photoresist pattern by alkali development, and applying a positive photoresist composition to form the second photoresist film on the support body on which the first photoresist pattern is formed And a step of forming a positive photoresist pattern of the step of selectively exposing and alkali developing the second photoresist film to form a photoresist pattern, wherein the second photoresist film is formed. The photoresist composition.

The description of each step in the method for forming the photoresist pattern is the same as the description of each step in the method for forming a photoresist pattern of the present invention to be described later.

The positive-type resist composition of the present invention contains a resin component (A) (hereinafter also referred to as (A) component) which increases solubility in an alkali developing solution by an action of an acid, and an acid is generated by exposure. The acid generator component (B) (hereinafter also referred to as (B) component), and the organic solvent (S), the resin component (A) and the acid generator component (B) are dissolved in the organic solvent (S) The organic solvent (S) is an organic solvent that does not dissolve the first photoresist film, and the resin component (A) has a structural unit (a0-1) represented by the above formula (a0-1). The structural unit (a0-2) represented by the above formula (a0-2).

In the positive resist composition of the present invention, the component (A) is insoluble to the alkali developing solution before exposure, and when the acid generated by the component (B) is caused to act by exposure, the acid dissociable dissolution inhibiting group is dissociated. Thus, the solubility of the entire component (A) to the alkali developer is increased, and the alkali-insoluble property is changed to alkali solubility. 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 is converted to alkali solubility, and the unexposed portion is not changed in alkali insolubility. The alkali development is carried out to form a photoresist pattern.

<(A) ingredient>

In the present invention, the component (A) is a structural unit (a0-1) represented by the above formula (a0-1) and a structural unit (a0-2) represented by the above formula (a0-2).

The structural unit (a0-1) and the structural unit (a0-2) are all structural units derived from acrylate.

In the specification and the scope of the patent application, "the structural unit derived from acrylate" means the structural unit constituted by the cleavage of the ethylenic double bond of the acrylate.

The "acrylate" has a concept of obtaining a carbon atom-bonded substituent at the α-position (atom or a group other than a hydrogen atom) in addition to the acrylate obtained by bonding a hydrogen atom at the α-position to a hydrogen atom. A substituent such as a lower alkyl group, a halogenated lower alkyl group or the like.

Further, the α-position (carbon atom at the α-position) of the structural unit derived from the acrylate means, unless otherwise specified, the carbon atom to which the carbonyl group is bonded.

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

The "lower alkyl group" is an alkyl group having 1 to 5 carbon atoms.

In the acrylate, the lower alkyl group of the substituent at the α-position, specifically, for example, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, A lower linear or branched alkyl group such as isopentyl or neopentyl.

The halogenated lower alkyl group having a substituent at the α-position is a group in which a part or all of a hydrogen atom of the above lower alkyl group is substituted by a halogen atom, such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom. Etc., especially fluorine atoms are preferred.

In the present invention, the group bonded to the α-position of the acrylate is preferably a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and more preferably a hydrogen atom, a lower alkyl group or a fluorinated lower alkyl group. In terms of ease of availability, a hydrogen atom or a methyl group is preferred.

‧Structural unit (a0-1)

In the above formula (a0-1), R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group.

The lower alkyl group or the halogenated lower alkyl group of R is the same as the above-mentioned lower alkyl group or halogenated lower alkyl group which may be bonded to the α position of the acrylate. Among them, it is preferred that R is a hydrogen atom or a methyl group.

In the above formula (a0-1), Y ¹ is an aliphatic cyclic group.

In the present specification and the patent application, the "aliphatic cyclic group" means a monocyclic or polycyclic group which does not have aromaticity.

The "aliphatic cyclic group" in the structural unit (a0-1) may or may not have a substituent. The substituent is, for example, a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted by a fluorine atom, or an oxygen atom (=O).

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

The aliphatic cyclic group may be any of a polycyclic group and a monocyclic group. The aliphatic cyclic group may be, for example, substituted by a lower alkyl group, a fluorine atom or a fluorinated alkyl group, and a monocyclic alkane, a bicycloalkane, a tricycloalkane or a tetracyclic ring which may be unsubstituted may also be used. A polycyclic alkane such as an alkane removes a base of two or more hydrogen atoms. More specifically, for example, a monocyclic alkane such as cyclopentane or cyclohexane, or a polycyclic alkane removal of adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane A base of two or more hydrogen atoms, and the like.

The aliphatic cyclic group in the structural unit (a0-1) is preferably a polycyclic group, and it is preferred that adamantane is used to remove two or more hydrogen atoms.

In the above formula (a0-1), Z is a group containing a tertiary alkyl group or an alkoxyalkyl group.

In the present specification and the scope of the patent application, "trialkyl" means an alkyl group having a tertiary carbon atom. The "alkyl group" as described above represents a monovalent saturated hydrocarbon group which includes a chain (linear, branched) alkyl group and an alkyl group having a cyclic structure.

The "group containing a tertiary alkyl group" means a group containing a tertiary alkyl group in the structure. The group containing a tertiary alkyl group may be composed only of a tertiary alkyl group or may be composed of other atoms or groups other than a tertiary alkyl group and a tertiary alkyl group.

The above-mentioned "other atom or group other than the tertiary alkyl group" which may constitute a group containing a tertiary alkyl group together with the tertiary alkyl group means a carbonyloxy group, a carbonyl group, an alkylene group, an oxygen atom or the like.

The group containing a tertiary alkyl group of Z, for example, a group containing a tertiary alkyl group having no cyclic structure, a group containing a tertiary alkyl group having a cyclic structure, and the like.

The group containing a tertiary alkyl group having no cyclic structure is a branched tertiary alkyl group containing a tertiary alkyl group, and has no cyclic structure in the structure.

The branched tertiary alkyl group is, for example, a group represented by the following formula (I).

In the formula (I), R ²¹ to R ²³ are each independently a linear or branched alkyl group. The alkyl group preferably has 1 to 5 carbon atoms and more preferably 1 to 3 carbon atoms.

Further, the total carbon number of the group represented by the formula (I) is preferably 4 to 7, more preferably 4 to 6, and most preferably 4 to 5.

The group represented by the formula (I) is preferably tert-butyl, tert-pentyl or the like, and more preferably tert-butyl.

a trialkyl-containing group having no cyclic structure, such as a branched tertiary alkyl group; the branched tertiary alkyl group bonded to a linear or branched alkyl group a tertiary alkyl group having a tertiary alkyl group; a tertiary alkyl oxycarbonyl group having a branched tertiary alkyl group; and a tertiary alkyl group having the above branched chain A tertiary alkyl oxycarbonylalkyl group of an alkyl group or the like.

The alkylene group in the chain alkyl group having a tertiary alkyl group is preferably an alkylene group having 1 to 5 carbon atoms, more preferably an alkylene group having 1 to 4 carbon atoms, and more preferably an alkylene group having 2 to 4 carbon atoms. The base is the best.

The chain tertiary alkyl oxycarbonyl group is, for example, a group represented by the following formula (II). R ²¹ to R ²³ in the formula (II) are the same as those of R ²¹ to R ²³ in the above formula (I). The chain tertiary alkyloxycarbonyl group is preferably tert-butyloxycarbonyl (t-boc) or tert-pentyloxycarbonyl.

The chain tertiary alkyl oxycarbonylalkyl group is, for example, a group represented by the following formula (III). Formula (III), the R ²¹ ~ R ²³ lines as in the above formula (I) R ²¹ ~ R ²³ is the same as the contents. In the formula (III), f is an integer of from 1 to 3, more preferably 1 or 2. A chain tertiary alkyl oxocarbonylalkyl group is preferably tert-butyloxycarbonylmethyl or tert-butyloxycarbonylethyl.

Wherein, the trialkyl-containing group having no cyclic structure is preferably a tertiary alkyloxycarbonyl group or a tertiary alkyloxycarbonylalkyl group, and more preferably a tertiary alkyloxycarbonyl group; Tert-butyloxycarbonyl is preferred.

A trialkyl-containing group having a cyclic structure, which is a group having a tertiary carbon atom and a cyclic structure in the structure.

In the cyclic structure containing a tertiary alkyl group, the number of carbon atoms constituting the ring is preferably 4 to 12, more preferably 5 to 10, and most preferably 6 to 10. The cyclic structure is, for example, a polycyclic alkane such as a monocyclic alkane, a bicycloalkane, a tricycloalkane or a tetracycloalkane, which removes one or more hydrogen atoms. Preferably, a monocyclic alkane such as cyclopentane or cyclohexane or a polycyclic alkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane is removed by one or more. The base of a hydrogen atom, etc.

A group containing a tertiary alkyl group having a cyclic structure, for example, a group having a group of the following (1) or (2), such as a tertiary alkyl group.

(1) A carbon atom of a ring constituting a cyclic alkyl group (cycloalkyl group) is bonded to a linear or branched alkyl group, and the carbon atom forms a group of a tertiary carbon atom.

(2) A carbon atom of a ring constituting a cycloalkyl group bonded to an alkyl group having a tertiary carbon atom (a branched alkyl group).

In the group of the above (1), the linear or branched alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.

The group of (1), such as 2-methyl-2-adamantyl, 2-ethyl-2-adamantyl, 1-methyl-1-cycloalkyl, 1-ethyl-1-cycloalkyl Wait.

In the above (2), the cycloalkyl group bonded to the branched alkyl group may have a substituent. The substituent is, for example, a fluorine atom or a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted by a fluorine atom or a fluorine atom, or an oxygen atom (=O).

The group of (2) is, for example, a group represented by the following formula (IV).

In the formula (IV), R ²⁴ is a cycloalkyl group which may have a substituent or may have no substituent. The cycloalkyl group may have a substituent such as a fluorine atom, a fluorinated lower alkyl group having 1 to 5 carbon atoms substituted by a fluorine atom, an oxygen atom (=O), or the like.

R ²⁵ and R ²⁶ are each independently a linear or branched alkyl group, and the alkyl group is, for example, the same as the linear or branched alkyl group of R ²¹ to R ^{23 in} the above formula (I). content.

The alkoxyalkyl group of Z is, for example, a group represented by the following formula (V).

In the formula, R ⁴¹ is a linear, branched or cyclic alkyl group.

When R ⁴¹ is a linear or branched form, 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 ⁴¹ 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. For example, a fluorine atom or a polycyclic alkane such as a monocyclic alkane, a bicycloalkane, a tricycloalkane or a tetracycloalkane which may be substituted by a fluorinated alkyl group or may be unsubstituted may be removed by one or more. The base of a hydrogen atom or the like. More specifically, for example, a monocyclic alkane such as cyclopentane or cyclohexane, or a polycyclic alkane removal of adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane One or more hydrogen atom groups and the like. Among them, it is preferred that adamantane is used to remove one or more hydrogen atoms.

R ⁴² is a linear or branched alkyl group. The alkylene group is preferably a carbon number of 1 to 5, more preferably a carbon number of 1 to 3, and most preferably a carbon number of 1 to 2.

The alkoxyalkyl group of z is particularly preferably a group represented by the following formula (VI).

In the formula (VI), R ⁴¹ is the same as R ₄₁ in the above formula (V), and each of R ⁴³ and R ⁴⁴ is an independently linear or branched alkyl group or a hydrogen atom.

In R ⁴³ and R ⁴⁴ , the carbon number of the alkyl group is preferably from 1 to 15, which may be either a linear chain or a branched chain, and preferably an ethyl group or a methyl group, and a methyl group. optimal. In particular, in R ⁴³ and R ⁴⁴ , one is a hydrogen atom and the other is preferably a methyl group.

In the above, Z is preferably a group containing a tertiary alkyl group, more preferably a group represented by the above formula (I1), and most preferably a tert-butyloxycarbonyl group (t-boc).

In the above formula (a0-1), a is an integer of 1 to 3, b is an integer of 0 to 2, and a + b = 1 to 3.

A is preferably 1.

b is preferably 0.

A+b is preferably 1.

c is an integer of 0 to 3, preferably 0 or 1, more preferably 0.

d is an integer of 0 to 3, preferably 0 or 1, and more preferably 0.

e is an integer of 0 to 3, preferably 0 or 1, and more preferably 0.

The structural unit (a0-1) is particularly preferably a structural unit represented by the following formula (a0-1-1).

[In the formula, R, Z, b, c, d, and e are the same as those of R, Z, b, c, d, and e in the above formula (a0-1)].

The monomer derived from the structural unit (a0-1), for example, a compound represented by the following formula (a0-1') (an acrylate having an aliphatic cyclic group having 1 to 3 alcoholic hydroxyl groups) A part or all of the hydroxyl group is synthesized by a known method in such a manner as to be protected by a trialkyl group-containing group or an alkoxyalkyl group.

^{[Wherein, R, Y 1, a,} b, c, d, e Department of the above general formula (a0-1) in the ^{R, Y 1, a, b} , c, d, e is the same as the contents].

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

The ratio of the structural unit (a0-1) in the component (A) is preferably from 1 to 40 mol%, more preferably from 5 to 40 mol%, based on the total of the total structural units constituting the component (A). It is preferably 15 to 40 mol%, and particularly preferably 20 to 40 mol%. When the amount is 1 mol% or more, the solubility in an organic solvent can be improved, and when it is 40 mol% or less, a good balance with other structural units can be obtained.

‧Structural unit (a0-2)

In the above formula (a0-2), R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group. The lower alkyl group or the halogenated lower alkyl group of R in the formula (a0-2) is the same as the lower alkyl group or the halogenated lower alkyl group of R in the above formula (a0-1).

The alkyl group of Y ³ , for example, an alkylene group having 1 to 10 carbon atoms.

Y aliphatic cyclic group of ^3, as in the Department of the formula (a0-1) Y ¹ is the same as the contents. Y ³ , the basic ring (aliphatic ring) structure is preferably the same as Y ¹ .

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

h is an integer of 0 to 3, preferably 0 or 1, and more preferably 0.

i is an integer from 1 to 3, preferably 1 is preferred.

The structural unit (a0-2) is particularly preferably a structural unit represented by the following general formula (a0-2-1), wherein one of -(CH ₂ ) _h -OH is bonded to one of them. It is preferred for 3 of 1-adamantyl groups.

[In the formula, R, g, h, and i are the same as those of R, g, h, and i in the above formula (a0-2)].

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

The ratio of the structural unit (a0-2) in the component (A) is preferably from 1 to 35 mol%, more preferably from 5 to 30 mol%, based on the total of the total structural units constituting the component (A). It is preferably 10 to 30 mol%, and particularly preferably 20 to 30 mol%. When it is 1 mol% or more, a cross-sectional shape having a high rectangular shape and a good shape can be formed, and when it is 35 mol% or less, a good balance with other structural units can be obtained.

‧Structural unit (a1)

The component (A) is preferably a structural unit (a1) derived from an acrylate having an acid dissociable dissolution inhibiting group, in addition to the structural unit (a0-1) and the structural unit (a0-2).

The acid dissociable dissolution inhibiting group in the structural unit (a1) is such that, as long as the component (A) has an alkali-insoluble alkali dissolution inhibiting property before dissociation, the (A) component is increased after dissociation by acid. The base of the solubility of the alkali developer may be used, and an acid dissociable dissolution inhibiting group which has been proposed as a base resin for a chemically amplified resist composition can be used. In general, for example, a carboxyl group or a chain-like tertiary alkyl ester group or a acetal acid dissociable dissolution inhibiting group such as an alkoxyalkyl group can be formed with a carboxyl group in (meth)acrylic acid. Further, "(meth) acrylate" means one or both of an acrylate having a hydrogen atom bonded to the α-position and a methacrylate having a methyl group bonded to the α-position.

Here, the "trialkyl ester", for example, a hydrogen atom of a carboxyl group is substituted with a chain or a cyclic alkyl group to form an ester, and an oxygen atom at the terminal of the carbonyloxy group (-C(O)-O-) is bonded. A structure obtained by the tertiary carbon atom of the above-mentioned chain or cyclic alkyl group. In the above tertiary alkyl ester, the bond between the oxygen atom and the tertiary carbon atom can be interrupted by the action of an acid.

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

Hereinafter, the acid dissociable group composed of a carboxyl group and a tertiary alkyl ester is conveniently referred to as a "triester alkyl ester type acid dissociable dissolution inhibiting group".

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

"Aliphatic branched" means a branched structure having no aromaticity. The structure of the "aliphatic branched 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 generally preferred to saturate.

The aliphatic branched acid dissociable dissolution inhibiting group is preferably a C 4 to 8 tertiary alkyl group, specifically, for example, tert-butyl, tert-pentyl, tert-heptyl or the like.

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

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

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

Specific examples of the aliphatic cyclic group, for example, may be substituted by a lower alkyl group, a fluorine atom or a fluorinated alkyl group, or may be unsubstituted, or may be a monocyclic alkane, a bicycloalkane, a tricycloalkane or a tetra. A group obtained by removing one or more hydrogen atoms from a polycyclic alkane such as a cycloalkane. More specifically, for example, a monocyclic alkane such as cyclopentane or cyclohexane or a polycyclic alkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane is removed. A group obtained by one or more hydrogen atoms.

An acid dissociable dissolution inhibiting group containing an aliphatic cyclic group, for example, a group having a tertiary carbon atom on a ring skeleton of a cyclic alkyl group, and the like, specifically, for example, 2-methyl-2-adamantyl group, Or 2-ethyl-2-adamantyl and the like. Or, for example, in the structural unit represented by the following general formula (a1"-1) to (a1"-6), it is bonded to a group of an oxygen atom of a carbonyloxy group (-C(O)-O-), and has a diamond An aliphatic cyclic group such as an alkyl group, a cyclohexyl group, a cyclopentyl group, a norbornyl group, a tricyclodecyl group, a tetracyclododecyl group, or the like, and a branched chain having a tertiary carbon atom bonded thereto Alkyl group and the like.

Wherein R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; and R ¹⁵ and R ¹⁶ are an alkyl group (may be linear or branched, preferably having a carbon number of 1 to 5). .

In the formula (a1"-1) to (a1"-6), the lower alkyl group of the R or the halogenated lower alkyl group is, for example, a lower alkyl group or a halogenated lower alkyl group which may be bonded to the α-position of the acrylate. The same content.

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

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 '} each independently represent a hydrogen atom or a lower alkyl group, n is an integer of 0 to 3, and Y is a lower alkyl group or an aliphatic cyclic group].

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

The lower alkyl group of R ^{l '} and R ^{2 '} is, for example, the same as the lower alkyl group of the above R, and preferably a methyl group or an ethyl group, and a methyl group is most preferable.

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 those of R ^{1 '} , n, and Y in the above formula (p1)].

The lower alkyl group of Y is, for example, the same as the lower alkyl group of the above R.

The aliphatic ring group of Y may be appropriately selected from among the monocyclic or polycyclic aliphatic ring groups which have been proposed many times in the conventional ArF photoresist, for example, and the above-mentioned "aliphatic ring type". The base is the same 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 each independently represent a linear or branched alkyl group or a hydrogen atom, and R ¹⁹ is a linear, branched or cyclic alkyl group, or each of R ¹⁷ and R ¹⁹ independently represents alkylene of straight or branched chain, R ¹⁷ and R-terminal end of the bond of the junction ¹⁹ may form a ring].

In R ¹⁷ and R ¹⁸ , the alkyl group preferably has 1 to 15 carbon atoms, and may be linear or branched, preferably ethyl or methyl, and most preferably methyl. In particular, any of R ¹⁷ and R ¹⁸ is a hydrogen atom, and the other is preferably a methyl group.

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

When R ¹⁹ is linear or branched, the carbon number is preferably from 1 to 5, more preferably ethyl or methyl, and most preferably ethyl.

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, it may be substituted by a fluorine atom or a fluorinated alkyl group, or may be removed by a polycyclic alkane such as a monocyclic alkane, a bicycloalkane, a tricycloalkane or a tetracycloalkane which is not substituted. More than one hydrogen atom or the like. Specifically, for example, a monocyclic alkane such as cyclopentane or cyclohexane or one or more polycyclic alkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane is removed. The base of a hydrogen atom, etc. Among them, the base obtained by removing one or more hydrogen atoms from adamantane is preferred.

Further, in the above formula, R ¹⁷ and R ¹⁹ each independently represent a linear or branched alkyl group (preferably an alkyl group having 1 to 5 carbon atoms), and the terminal of R ¹⁹ may be bonded to R ¹⁷ The end bond can also be used.

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

The structural unit (a1) is one selected from the group consisting of the structural unit represented by the following general formula (a1-0-1) and the structural unit represented by the following general formula (a1-0-2). The above is better.

[wherein R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; and X ¹ is an acid dissociable dissolution inhibiting group].

[wherein R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; X ² is an acid dissociable dissolution inhibiting group; and Y ² is an alkylene group or an aliphatic cyclic group].

In the formula (a1-0-1), the lower alkyl group or the halogenated lower alkyl group of R is the same as the lower alkyl group or the halogenated lower alkyl group which may be bonded to the α-position of the acrylate.

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

In the formula (a1-0-2), R is the same as R in the above (a1-0-1).

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

Y ² is an alkylene group or an aliphatic cyclic group, preferably an alkylene group having 1 to 10 carbon atoms or a divalent aliphatic cyclic group. The aliphatic cyclic group can be used, for example, in the same manner as described above for the "aliphatic cyclic group", except that a group in which two or more hydrogen atoms are removed is used.

When Y ² is an alkylene group having 1 to 10 carbon atoms, it is more preferably 1 to 6 carbon atoms, particularly preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.

When Y ² is a divalent aliphatic cyclic group, two or more hydrogen atoms are removed by cyclopentane, cyclohexane, norbornane, isobornane, adamantane, tricyclodecane or tetracyclododecane. The basis of the obtained is particularly good.

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

[In the above formula, X' is a tertiary alkyl ester type acid dissociable dissolution inhibiting group; Y is a lower alkyl group having 1 to 5 carbon atoms, or an aliphatic cyclic group; n is an integer of 0 to 3; Y ² An alkyl group or an aliphatic cyclic group; R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; and R ^{1 '} and R ^{2 '} each independently represent a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms].

The lower alkyl group or the halogenated lower alkyl group of R in the above formulas (a1-1) to (a1-4) is the same as the above-mentioned lower alkyl group or halogenated lower alkyl group bonded to the α-position of the acrylate. content.

In the 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 lines were above the "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} , for example, an alkylene group or an aliphatic cyclic group which is the same as Y ² in the above formula (a1-0-2).

The following are specific examples of the structural unit represented by the above general formulae (a1-1) to (a1-4).

The structural unit (a1) may be used alone or in combination of two or more. Among them, the structural unit represented by the formula (a1-1) is preferred. Specifically, at least one selected from the group consisting of the formulas (a1-1-1) to (a1-1-6) and the formulas (a1-1-35) to (a1-1-41) is used. For better.

Further, the structural unit (a1) is, in particular, a unit represented by the following general formula (a1-1-01) including structural units of the formulae (a1-1-1) to (a1-1-4), or an inclusion formula. The following general formula (a1-1-02) of the structural unit of (a1-1-35) to (a1-1-41) is preferred.

[wherein R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹¹ is a lower alkyl group].

[wherein R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹² is a lower alkyl group, and h is an integer of from 1 to 3].

In the formula (a1-1-01), R is the same as R in the above formula (a0-1). The lower alkyl group of R ¹¹ is the same as the lower alkyl group represented by R, and a methyl group or an ethyl group is preferred.

In the formula (a1-1-02), R is the same as R in the above formula (a0-1). The lower alkyl group of R ¹² is the same as the lower alkyl group represented by the above R, and is preferably a methyl group or an ethyl group, and preferably an ethyl group. h is preferably 1 or 2, and 2 is the best.

In the component (A), the ratio of the structural unit (a1) is preferably from 10 to 80 mol%, more preferably from 20 to 70 mol%, based on the entire structural unit constituting the component (A), and is preferably 25 to 50% Mo is the best. When it is 10 mol% or more, it can form a pattern easily as a photoresist composition, and when it is 80 mol% or less, it can balance with other structural unit.

‧Structural unit (a2)

The component (A) may further contain a cyclic group having a lactone in addition to the structural unit (a0-1), the structural unit (a0-2), and the structural unit (a1) within a range not impairing the effects of the present invention. Structural unit derived from acrylate (a2).

Here, the cyclic group containing a lactone means a ring group containing one ring (lactone ring) having a -O-C(O)- structure. When the lactone ring is counted as one ring, it is a monocyclic group only in the case of a lactone ring, and when it has other ring structures, it is called a polycyclic group regardless of its structure.

The cyclic group containing a lactone of the structural unit (a2) can effectively improve the adhesion of the photoresist film to the substrate, improve the hydrophilicity, and improve the water content when used to form the photoresist film with the component (A). The affinity of the developer, and the like.

The structural unit (a2) can be used without any limitation.

Specifically, a monocyclic group containing a lactone, for example, a group obtained by removing one hydrogen atom from γ-butyrolactone or the like. Further, the polycyclic group having a lactone is, for example, a group obtained by removing one hydrogen atom from a bicycloalkane having a lactone ring, a tricycloalkane or a tetracycloalkane.

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).

Wherein R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, R' is a hydrogen atom, a lower alkyl group, or an alkoxy group having 1 to 5 carbon atoms or -COOR, and each of the aforementioned R" is independently a hydrogen atom, or a linear, branched or cyclic alkyl group having 1 to 15 carbon atoms, m is an integer of 0 or 1, and A" is a carbon number of 1 to 5 which may contain an oxygen atom or a sulfur atom. An alkyl group, an oxygen atom or a sulfur atom].

R in the general formulae (a2-1) to (a2-5) has the same content as R in the general formula (a1-0-1) in the above structural unit (a1).

The lower alkyl group of R' has the same content as the lower alkyl group of R in the above formula (a1 - 0) in the structural unit (a1).

In the case where R" is a linear or branched alkyl group, the carbon number is preferably from 1 to 10, and the carbon number is preferably from 1 to 5.

In the case where R" is a cyclic alkyl group, a carbon number of 3 to 15 is preferred, a carbon number of 4 to 12 is more preferred, and a carbon number of 5 to 10 is most preferred. Specifically, for example, a fluorine atom can be used. Or a group obtained by removing one or more hydrogen atoms by a monocyclic alkane, a bicycloalkane, a tricycloalkane or a tetracycloalkane polycycloalkane which are substituted by a fluorinated alkyl group, or the like. The content includes one or more hydrogen atoms such as a monocyclic alkane such as cyclopentane or cyclohexane or a polycyclic alkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane. The basis of the obtained.

In the general formulae (a2-1) to (a2-5), R' is preferably a hydrogen atom in view of industrial availability.

A" may have an alkyl group having 1 to 5 carbon atoms of an oxygen atom or a sulfur atom, specifically, for example, a methyl group, an ethyl group, an n-propyl group, an exo-propyl group, and -O-CH. ₂ -, -CH ₂ -O-CH ₂ -, -S-CH ₂ -, -CH ₂ -S-CH ₂ -, and the like.

The following are examples of specific structural units of the above general formulae (a2-1) to (a2-5).

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

In the structural unit (a2), at least one selected from the group consisting of the structural units represented by the above formulas (a2-1) to (a2-5) is preferred, and the formula (a2-) It is more preferable that at least one selected from the group consisting of the structural units shown in (a2-3) is preferable. Among them, by the chemical formulas (a2-1-1), (a2-1-2), (a2-1-3), (a2-1-4), (a2-2-1), (a2-2) -2), (a2-2-9), (a2-2-10), (a2-3-1), (a2-3-2), (a2-3-9), and (a2-3-10) At least one selected from the group of structural units shown is preferred.

(A) When the component contains the structural unit (a2), the ratio of the structural unit (a2) in the component (A) is less than 20 mol% to the total of the structural units constituting the component (A). The ear % is preferably from 1 to 15 mol%, preferably from 5 to 15 mol%. When the content is 1 mol% or more, the effect is sufficiently obtained when the structural unit (a2) is contained, and when it is 20 mol% or less, the solubility of the component (A) can be sufficiently improved in addition to the organic solvent (S) to be described later. A balance with other structural units is available.

. Structural unit (a3)

The component (A) may have a structure other than the structural unit (a0-1), the structural unit (a0-2), and the structural unit (a1), which may not be included in the above formula (a0), without impairing the effects of the present invention. -1) or a structural unit (a3) derived from an acrylate containing a polar group-containing aliphatic hydrocarbon group in the structural unit represented by (a0-2).

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

A polar group such as a hydroxyl group, a cyano group, a carboxyl group, a hydroxyalkyl group in which a part of a hydrogen atom of an alkyl group is substituted with a fluorine atom (i.e., a fluorinated alkyl alcohol), and the like, particularly preferably a hydroxyl group.

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

Further, a structural unit derived from an acrylate having a hydroxyl group, a cyano group, a carboxyl group, or an aliphatic polycyclic group containing a hydroxyalkyl group in which one of hydrogen atoms in the 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, for example, a group obtained by removing two or more hydrogen atoms from a polycyclic alkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane is used. In the polycyclic group, it is more suitable for industrially to remove two or more hydrogen atoms from adamantane, to remove two or more hydrogen atoms from norbornane, and to remove two or more hydrogen atoms from tetracyclododecane. use.

In the structural unit (a3), when the hydrocarbon group in the aliphatic hydrocarbon group containing a polar group is a polycyclic group, for example, the structural unit represented by the following formula (a3-1) and the structural unit represented by (a3-2) are preferable. .

Wherein R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, k is an integer of from 1 to 3, t' is an integer of from 1 to 3, 1 is an integer of from 1 to 5, and s is an integer of from 1 to 3. ].

In the formulae (a3-1) to (a3-2), the lower alkyl group or the halogenated lower alkyl group of R is the same as the lower alkyl group or the halogenated lower alkyl group which may be bonded to the α position of the acrylate. content.

In the general formula (a3-1), it is preferred that k is one. It is preferred that the cyano group is bonded to the 5 or 6 position of the norbornyl group.

In the formula (a3-2), it is preferred that t' is 1 and 1 is preferred, and s is preferably 1. It is preferably bonded to the terminal of the carboxyl group of the acrylic acid 2-norbornyl group or 3-norbornyl group. The fluorinated alkyl alcohol (the hydroxyalkyl group in which a part of the hydrogen atom of the alkyl group is substituted by a fluorine atom) is preferably bonded to the 5 or 6 position of the norbornyl group.

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

(A) When the component (a3) is contained in the component, the ratio of the structural unit (a3) in the component (A) is preferably 1 to 30 mol% based on the entire structural unit constituting the component (A). 5 to 30 mol% is more preferable, and 10 to 20 mol% is the best.

‧Structural unit (a4)

The component (A) may contain other structural units (a4) in addition to the structural unit (a0-1), the structural unit (a0-2), and the structural unit (a1) within the range not impairing the effects of the present invention.

The structural unit (a4) is not particularly limited as long as it is not classified into the structural units (a0-1), (a0-2), and (a1) to (a3) described above, and may be used. It is known as a majority of structural units used for resistive resins such as ArF excimer lasers and KrF excimer lasers (preferably for ArF excimer lasers).

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

In particular, at least one selected from the group consisting of a tricyclic fluorenyl group, an adamantyl group, a tetracyclododecyl group, an isobornyl group, and a norbornyl group is preferred from the viewpoint of industrial availability. These polycyclic groups may have a substituent or may have no substituent, and the substituent may be, for example, a linear or branched alkyl group having 1 to 5 carbon atoms.

The structural unit (a4) is specifically a structure of the following general formulas (a4-1) to (a4-5), for example.

[In the formula, R is the same as a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group].

The lower alkyl group or the halogenated lower alkyl group of the formula (a4-1) to (a4-5) is the same as the above-mentioned lower alkyl group or halogenated lower alkyl group which may be bonded to the α-position of the acrylate. content.

(A) In the case where the component contains the structural unit (a4), the structural unit (a4) preferably contains 1 to 30 mol%, and contains 10 to 20 mol, based on the total of the total structural units constituting the component (A). Ear % is better.

In the present invention, the component (A) is copolymerized with the structural unit (a0-1) represented by the above formula (a0-1) and the structural unit (a0-2) represented by the above formula (a0-2). The substance (A2) is preferred. The copolymer (A2), for example, a ternary copolymer formed by the above structural units (a0-1), (a0-2) and (a1), or the above structural units (a0-1), (a0-2) And a 4-membered copolymer formed by (a1) and (a2).

In the present invention, the copolymer (A2), in particular, a copolymer (A-21) having three structural units containing a combination of the following formula (A-21), and the following formula (A-22) a copolymer (A-22) containing three structural units and a combination of three structural units (A-23) having the combination of the following formula (A-23) and a general formula of the following formula One or more of the copolymers (A-24) having four structural units in the combination shown in (A-24) are preferred. Among them, those containing a copolymer (A-21) are preferred. Further, in the component (A), the copolymer (A2) may be used singly or in combination of two or more.

In the formula (A-21), R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group (wherein R as a structural unit (a0-2) is a hydrogen atom, a halogen atom, a lower alkyl group or halogenated lower alkyl group), e is the above general formula (a0-1) is the same as the contents of e, R ²¹ ~ R ²³ of the general formula (I), the R ²¹ ~ R ²³ is the same as the contents, a plurality of R may be the same or different from each other, and R ²⁷ is a lower alkyl group. In the formula (A-22), R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, wherein (in the structural unit of the structural unit (a0-2), R is a hydrogen atom, a halogen atom, a lower alkyl group or halogenated lower alkyl group), e is the above general formula (a0-1) is the same as the contents of e, R ²¹ ~ R ²³ of the general formula (I), the R ²¹ ~ R ²³ is the same as the contents, a plurality of R may be the same or different from each other, and R ²⁸ is a lower alkyl group].

In the formula (A-21), the lower alkyl group of R ²⁷ is the same as the lower alkyl group of R.

In the formula (A-22), the lower alkyl group of R ²⁸ is the same as the lower alkyl group of R.

[In the formula (A-23), R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group (wherein R as a structural unit (a0-2) is a hydrogen atom, a halogen atom, a lower alkyl group or halogenated lower alkyl group), e is the above general formula (a0-1) is the same as the contents of e, R ²¹ ~ R ²³ of the general formula (I), the R ²¹ ~ R ²³ is the same as the contents, a plurality of R may be the same or different from each other, and n is the same as n in the above formula (p1). In the formula (A-24), R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group (wherein R is a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated group in the structural unit of the structural unit (a0-2). a lower alkyl group), and e of the formula e (a0-1) is the same as the contents, R ²¹ ~ R ²³ of the general formula (I), the R ²¹ ~ R ²³ is the same as the contents, a plurality of R can be the same or different from each other].

The component (A) may be a component containing one or more copolymers having both a structural unit (a0-1) and a structural unit (a0-2) as described above, and may have at least a structural unit ( The polymer of a0-1) may also be a mixture with a polymer having at least a structural unit (a0-2).

The component (A) can be obtained by subjecting a monomer derived from each structural unit to a radical polymerization initiator such as azobisisobutyronitrile (AIBN) by a polymerization reaction such as radical polymerization.

Further, in the above (A) component, for example, a chain transfer agent such as HS-CH ₂ -CH ₂ -CH ₂ -C(CF ₃ ) ₂ -OH may be used, and -C (CF) may be introduced at the end. ₃ ) _2- OH group. Thus, a copolymer in which a hydroxyalkyl group in which one of hydrogen atoms in the alkyl group is substituted with a fluorine atom is introduced can be obtained, and the effect of LWR (Line Width Roughness) can be effectively reduced. Further, it is possible to effectively reduce development defects or reduce the effect of LER (Line Edge Roughness).

(A) The mass average molecular weight (Mw) of the component (the polystyrene conversion standard of the gel permeation chromatography method) is not particularly limited, and is generally preferably 2,000 to 50,000, more preferably 3,000 to 30,000, and 5,000. ～20,000 is the best 5,000 to 10,000. When the mass average molecular weight of the component (A) is less than 50,000, sufficient solubility is obtained for the photoresist as a photoresist, and when it is more than 2,000, a good dry etching resistance or a resist pattern cross-sectional shape can be obtained.

Further, the degree of dispersion (Mw/number average molecular weight (Mn)) is not particularly limited, and is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5.

Further, Mn is a number average molecular weight.

<(B) ingredients>

The component (B) is not particularly limited, and a component which is currently proposed as an acid generator for chemically amplified photoresist can be used. These acid generators, for example, sulfonium-based acid generators such as iodonium salts or phosphonium salts, sulfonate-based acid generators, dialkyl or bisarylsulfonyldiazomethanes, poly (double A sulfonyl group, a diazomethane acid generator such as a diazomethane, a nitrobenzyl sulfonate acid generator, an iminosulfonate acid generator, a diterpenoid acid generator, etc. Know the compound.

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" and R ^6" each independently represent an aryl group which may have a substituent or an alkyl group which may have a substituent; R ¹ in the formula (b-1) To R ^3" , any two may be bonded to each other and form a ring together with a sulfur atom in the formula; R ^4" is a linear, branched or cyclic alkyl group or a fluorinated group which may have a substituent The alkyl group; at least one of R ^1" to R ^3" is the above-mentioned aryl group, and at least one of R ^5" to R ^6" is the above-mentioned aryl group].

In the formula (b-1), R ¹ " to R ³ " are each independently an aryl group or an alkyl group; and, in the formula (b-1), any of R ¹ " to R ³ " may be bonded to each other. And forming a ring together with the sulfur atom in the formula. Further, at least one of R ^l " to R ³ " is an aryl group. Among R ¹ " to R ³ ", it is preferred that two or more aryl groups are used, and all of R ¹ " to 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 all of a hydrogen atom of the aryl group may be an alkyl group or an alkoxy group. A halogen atom, a hydroxyl group, an alkoxyalkyloxy group, an alkoxycarbonylalkyloxy group or the like may be substituted or unsubstituted. From the viewpoint of inexpensive synthesis of an aryl group, it is preferred to use an aryl group having 6 to 10 carbon atoms. Specifically, for example, a phenyl group, a naphthyl group or the like.

The alkyl group which may be substituted for the hydrogen atom of the above aryl group is preferably an alkyl group having 1 to 5 carbon atoms, and more 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, 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, and an n- Butoxy and tert-butoxy are most preferred.

The alkoxy group which may be substituted for the hydrogen atom of the above aryl group is preferably an alkoxy group having 1 to 5 carbon atoms, and preferably a methoxy group or an ethoxy group.

A halogen atom which may be substituted for the hydrogen atom of the above aryl group is preferably a fluorine atom.

An alkoxyalkyloxy group which may be substituted for the hydrogen atom in the above aryl group, for example, the formula: -OC(R ⁴⁷ )(R ⁴⁸ )-OR ⁴⁹ [wherein, R ⁴⁷ and R ⁴⁸ are each independently hydrogen. An atom or a linear or branched alkyl group, and R ⁴⁹ is a group represented by an alkyl group.

In R ⁴⁷ and R ⁴⁸ , the carbon number of the alkyl group is preferably from 1 to 5, and it may be any of a linear chain and a branched chain, and an ethyl group or a methyl group is preferred, and a methyl group is the most. good.

R ⁴⁷ and R ⁴⁸ are preferably at least one of hydrogen atoms. In particular, it is more preferred that one is a hydrogen atom and the other is a hydrogen atom or a methyl group.

The alkyl group of R ⁴⁹ is preferably a carbon number of 1 to 15, which may be any of a straight bell shape, a branched chain or a cyclic shape.

The linear or branched alkyl group in R ⁴⁹ is preferably a carbon number of 1 to 5, and examples thereof include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group.

The cyclic alkyl group in R ⁴⁹ is preferably a carbon number of 4 to 15, preferably a carbon number of 4 to 12, and a carbon number of 5 to 10. Specifically, it is a monocyclic alkane, a bicycloalkane, a tricycloalkane or a tetra which may be substituted by an alkyl group having 1 to 5 carbon atoms, a fluorine atom or a fluorinated alkyl group, or may be unsubstituted. A polycyclic alkane such as a cycloalkane is removed from a group of one or more hydrogen atoms. Monocyclic alkane, such as cyclopentane, cyclohexane, and the like. Polycyclic alkane, such as adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, and the like. Among them, it is preferred that adamantane is used to remove one or more hydrogen atoms.

An alkoxycarbonylalkyloxy group which may be substituted for the hydrogen atom in the above aryl group, for example, the formula: -OR ⁵⁰ -C(=O)-OR ⁵¹ [wherein, R ⁵⁰ is linear or branched. An alkyl group, and R ⁵¹ is a group represented by a tertiary alkyl group.

The linear or branched alkyl group in R ⁵⁰ is preferably a carbon number of 1 to 5, for example, a methyl group, an ethyl group, a methyl group, a tetramethyl group, and 1, 1-dimethylexylethyl and the like.

a tertiary alkyl group in R ⁵¹ , such as 2-methyl-2-adamantyl, 2-ethyl-2-adamantyl, 1-methyl-1-cyclopentyl, 1-ethyl-1- Cyclopentyl, 1-methyl-1-cyclohexyl, 1-ethyl-1-cyclohexyl, 1-(1-adamantyl)-1-methylethyl, 1-(1-adamantyl) 1-methylpropyl, 1-(1-adamantyl)-1-methylbutyl, 1-(1-adamantyl)-1-methylpentyl; 1-(1-cyclopentyl) )-1-methylethyl, 1-(1-cyclopentyl)-1-methylpropyl, 1-(1-cyclopentyl)-1-methylbutyl, 1-(1-cyclopentyl) 1-methyl-1-pentyl; 1-(1-cyclohexyl)-1-methylethyl, 1-(1-cyclohexyl)-1-methylpropyl, 1-(1-cyclohexyl) 1-methylbutyl, 1-(1-cyclohexyl)-1-methylpentyl, tert-butyl, tert-pentyl, tert-hexyl, and the like.

The alkyl group of R ^1" to R ^3" is not particularly limited, and may be, for example, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms. From the viewpoints of excellent resolution, etc., it is preferable to use a carbon number of 1 to 5. Specifically, for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an n-pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, an anthracenyl group, an anthracenyl group and the like. From the viewpoint of having excellent resolution and being inexpensively synthesized, it is more preferable to use a methyl group.

Among them, those in which R ^{1 "} to R ^{3 "} are each a phenyl group or a naphthyl group are preferred.

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 to form a ring of 3 to 10 members containing a sulfur atom. It is better to form a ring containing 5 to 7 members.

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

R ^4" is a linear, branched or cyclic alkyl group or a fluorinated alkyl group which may have a substituent. R ^{4 "} may have a substituent such as a halogen atom, a hetero atom, an alkyl group or the like.

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

The cyclic alkyl group is a cyclic group represented by the above R ^{1 "} , and preferably has a carbon number of 4 to 15, preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms. good.

The fluorinated alkyl group is preferably a carbon number of 1 to 10, more preferably a carbon number of 1 to 8, and most preferably a carbon number of 1 to 4. Further, the fluorination ratio of the fluorinated alkyl group (the ratio of the fluorine atom in the alkyl group) is preferably from 10 to 100%, more preferably from 50 to 100%, particularly the fluorinated alkyl group in which the hydrogen atom is entirely substituted by a fluorine atom. (Perfluoroalkyl group) is more preferred because its acid strength is stronger.

R ^{4" is} preferably a linear or cyclic alkyl group or a fluorinated alkyl group.

In the formula (b-2), R ^5" and R ^6" are each independently an aryl group or an alkyl group; at least one of R5 ^" and R6 ^" is an aryl group, and all of R ^5" and R ^6" are aromatic. The base is the best.

The aryl group of R ^5" and R ^6" is, for example, the same as the aryl group of R ^1" to R ^3" .

The alkyl group of R ^5" and R ^6" is, for example, the same as the alkyl group of R ^1" to R ^3" .

Among them, those in which R ⁵ "and R ⁶ " are all phenyl groups are preferred.

Of formula (b-2) in the R ⁴ "and (b-1) in the above formula R ^4" is the same as the contents.

Specific examples of the phosphonium-based acid generator represented by the formula (b-1) or (b-2), 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 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, Fluoropropane sulfonate or its nonafluorobutane sulfonate, diphenyl(1-(4-methoxy)naphthyl)phosphonium trifluoromethanesulfonate, heptafluoropropane sulfonate or its nonafluorobutane Alkanesulfonate, tris(1-naphthyl)phenylphosphonium trifluoromethanesulfonate, heptafluoropropanesulfonate or its nonafluorobutanesulfonate, 1-phenyltetrahydrothiophene trifluoromethane Sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, trifluoromethanesulfonate of 1-(4-methylphenyl)tetrahydrothiophene, its heptafluoropropane sulfonate or its nonafluoro Butane sulfonate, trifluoromethanesulfonate of 1-(3,5-dimethyl-4-hydroxyphenyl)tetrahydrothiophene, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, Trifluoromethanesulfonate of 1-(4-methoxynaphthalen-1-yl)tetrahydrothiophene, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, 1-(4-ethoxynaphthalene) 1-yl) tetrahydrothiophene trifluoromethanesulfonate, heptafluoropropane sulfonate or its nonafluorobutane sulfonate, 1-(4-n-butoxynaphthalen-1-yl)tetrahydrogen Trifluoromethanesulfonate of thiophene oxime, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, trifluoropyranium trifluoromethane An alkane sulfonate, a heptafluoropropane sulfonate or a nonafluorobutane sulfonate thereof, a trifluoromethanesulfonate of 1-(4-hydroxyphenyl)tetrahydrothiopyranium, a heptafluoropropane sulfonate thereof or nine thereof Fluorobutane sulfonate, trifluoromethanesulfonate of 1-(3,5-dimethyl-4-hydroxyphenyl)tetrahydrothiopyranium, its heptafluoropropane sulfonate or its nonafluorobutane sulfonic acid Ethyl ester, trifluoromethanesulfonate of 1-(4-methylphenyl)tetrahydrothiopyrene, heptafluoropropane sulfonate or nonafluorobutanesulfonate thereof.

Further, an anthracene salt in which the anion portion of the above-mentioned phosphonium salt is substituted with methanesulfonate, n-propanesulfonate, n-butanesulfonate or n-octanesulfonate can be used.

Further, in the above formula (b-1) or (b-2), an anthracene salt-based acid generator obtained by substituting an anion moiety with an anion moiety represented by the following formula (b-3) or (b-4) can be used. Alternatively, the cationic moiety may be the same as the above formula (b-1) or (b-2).

[wherein, X" is an alkylene group having 2 to 6 carbon atoms in which at least one hydrogen atom is replaced by a fluorine atom; Y" and Z" are each independently a carbon number of 1 to 10 in which at least one hydrogen atom is replaced by a fluorine atom. Alkyl].

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

Y" and "z" are each independently a linear or branched alkyl group in which at least one hydrogen atom is substituted by a fluorine atom, and the alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 7 carbon atoms. The optimum carbon number is 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 above range, it is preferably as small as possible because of the excellent solubility to the photoresist solvent.

Further, in the alkyl group of X" or the alkyl group of Y" or z", the more the number of hydrogen atoms substituted by a fluorine atom, the stronger the strength of the acid, and the higher energy light or electron line with respect to 200 nm or less. Preferably, the transparency is improved by 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 hydrogen atoms are replaced by fluorine atoms.

Further, in the above formula (b-1) or (b-2), an anion portion may be an anion salt-based acid generator (cation portion) substituted with an anion portion represented by the following formula (b1-12). Same as (b-1) or (b-2)).

R ² -OY ^1' -SO ₃ ^- ...(b1-12)

[wherein, R ² is a monovalent aromatic organic group; and Y ^{1 '} is a alkylene group having 1 to 4 carbon atoms which may be substituted by fluorine].

In the above formula (b1-12), R ² is a monovalent aromatic organic group; Y ^{1 '} is an alkylene group having 1 to 4 carbon atoms which may be substituted by fluorine.

An aromatic hydrocarbon group having a monovalent value of R ² , for example, a ring of an aromatic hydrocarbon such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthyl group or a phenanthryl group; An aryl group of a hydrogen atom and a heteroaryl group obtained by substituting a part of a carbon atom constituting the ring of the aryl group with a hetero atom such as an oxygen atom, a sulfur atom or a nitrogen atom. For example, an arylalkyl group such as a benzyl group or a phenethyl group. The carbon number of the alkyl chain in the aforementioned arylalkyl group is preferably from 1 to 4, more preferably from 1 to 3, most preferably from 1 to 2. The aryl group, heteroaryl group or arylalkyl group may have a substituent such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group, an alkoxy group, a hydroxyl group or a halogen atom. The alkyl group or the halogenated alkyl group in the substituent is preferably a carbon number of 1 to 8, and more preferably a carbon number of 1 to 4. Further, the halogenated alkyl group is preferably a fluorinated alkyl group. The halogen atom is preferably a fluorine atom, for example, a fluorine atom, a chlorine atom, an iodine atom or a bromine atom.

The carbon number of the monovalent aromatic organic group of R ² is preferably 6 to 20, more preferably 6 to 10, and most preferably 10.

The monovalent aromatic organic group of R ² is preferably an arylalkyl group such as a benzyl group or a phenethyl group, and is preferably a benzyl group.

Y ^{1 '} the alkylene group having 1 to 4 carbon atoms which may be substituted by fluorine, such as -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.

Further, Y ^{1 '} the alkyl group having 1 to 4 carbon atoms which may be substituted by fluorine is preferably fluorinated with a carbon atom bonded to S, and the above-mentioned fluorinated alkyl group, for example, -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 - wait.

Wherein -CF ₂ CF ₂ -, -CF ₂ CF ₂ CF ₂ -, or -CH ₂ CF ₂ CF ₂ - is preferred, and -CF ₂ CF ₂ - or -CF ₂ CF ₂ CF ₂ - is more preferred. It is best to use -CF ₂ CF ₂ -.

Specific examples of the sulfonium-based acid generator substituted with the anion portion represented by the above formula (b1-12), for example, compounds represented by the following formulas (b-12-1) to (b-12-18) .

Further, an onium salt having a cationic portion represented by the following formula (b-5) or (b-6) can be used as the onium salt 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 preferred.

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

The hydroxyalkyl group is preferably a group in which one or a plurality of hydrogen atoms of the above alkyl group are substituted with a hydroxyl group, for example, a hydroxymethyl group, a hydroxyethyl group, a hydroxypropyl group or the like.

When the symbols n ₁ to n ₆ added to R ⁴¹ to R ⁴⁶ are integers of 2 or more, the plural R ⁴¹ to R ⁴⁶ may be the same or different.

n _{1 is} 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 a sulfonium salt of the cation portion represented by the formula (b-5) or (b-6) is not particularly limited, and it can be used in the same manner as the anion portion currently proposed as the sulfonium acid generator. Anion part. The anion portion is, for example, a fluorinated alkylsulfonic acid ion such as an anion portion (R ^{4 "} SO ₃ ^- ) of the sulfonium salt generator represented by the above formula (b-1) or (b-2); An anion moiety or the like represented by the formula (b-3) or (b-4), wherein a fluorinated alkylsulfonic acid ion is preferred, and a fluorinated alkylsulfonic acid ion having a carbon number of 1 to 4 is more preferred. It is preferred to use a linear perfluoroalkylsulfonic acid ion having a carbon number of 1 to 4. Specifically, for example, a trifluoromethanesulfonate ion, a heptafluoro-n-propylsulfonate ion, and a nonafluoro-n-butyl group. Sulfonic acid ion and the like.

In the present specification, the oxime sulfonate-based acid generator has, for example, a compound having at least one group represented by the following formula (B-1), which has a property of generating an acid by radiation irradiation. The above-mentioned oxime sulfonate-based acid generator is generally used for a chemically amplified positive-type photoresist composition, and the present invention can be arbitrarily selected and used.

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

The organic group of R ³¹ and R ³² is a group containing a carbon atom, but it may also contain 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.), etc.) ).

The organic group of R ³¹ is preferably a linear, branched or cyclic alkyl group or an aryl group. The aforementioned alkyl group or 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 or cyclic alkyl group, and the like. Here, the "having a substituent" means that at least one of the hydrogen atoms of the alkyl group or the aryl group is substituted with a substituent.

The alkyl group is preferably a carbon number of from 1 to 20, preferably a carbon number of from 1 to 10, more preferably a carbon number of from 1 to 8, a carbon number of from 1 to 6, and a carbon number of from 1 to 4. . Among them, an alkyl group is particularly preferably an alkyl group (hereinafter, also referred to as a halogenated alkyl group) obtained by partial or complete halogenation. Further, a partially halogenated alkyl group means an alkyl group in which a part of a hydrogen atom is substituted 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, preferably a carbon number of 4 to 10, and a carbon number of 6 to 10. The aryl group is particularly preferably an aryl group obtained by partially or completely halogenating. Further, a partially halogenated aryl group means an aryl group in which a part of a hydrogen atom is substituted by a halogen atom, and an aryl group which is completely halogenated means an aryl group in which a hydrogen atom is entirely substituted by a halogen atom.

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 has no substituent.

The organic group of R ³² is preferably a linear, branched or cyclic alkyl group, an aryl group or a cyano group. The alkyl group or the aryl group of R ³² is, for example, the same as the alkyl group or 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 an alkyl group halide; R ³⁴ is an aryl group; and R ³⁵ is an alkyl group having no substituent or an alkyl group having a halogenated group].

[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; and R ³⁸ is an alkyl group having no substituent or Halogenated alkyl group, 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, more preferably a carbon number of from 1 to 8, and a carbon number of from 1 to 6. optimal.

R ³³ is preferably a halogenated alkyl group, more preferably a fluorinated alkyl group.

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

The aryl group of R ³⁴ , for example, a ring of an aromatic hydrocarbon such as a phenyl group or a biphenyl group, a fluorenyl group, a naphthyl group, an anthyl group or a phenanthryl group, which removes one hydrogen atom group, And a heteroaryl group obtained by substituting a part of a carbon atom of the ring of the above-mentioned group 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 such as an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group or an alkoxy group. 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 more 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, more 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, more preferably a fluorinated alkyl group.

The fluorinated alkyl group in R ³⁵ preferably has a hydrogen atom of an alkyl group of 50% or more, more preferably 70% or more, and when it is fluorinated by 90% or more, the acid produced can be increased. For better. The most preferred is a perfluorinated alkyl group in which the hydrogen atom is 100% replaced by fluorine.

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

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

The alkyl group or the halogenated alkyl group having no substituent of R ³⁸ is, for example, the same as the alkyl group or halogenated alkyl group having no substituent represented by the above R ³⁵ .

p" is preferably 2.

Specific examples of the sulfonate-based acid generator, such as α-(p-toluenesulfonyloxyimido)-benzyl cyanide (cyanide), α-(p-chlorophenylsulfonyloxyimino) -benzyl cyanide, α-(4-nitrophenylsulfonyloxyimido)-benzyl cyanide, α-(4-nitro-2-trifluoromethylbenzenesulfonyloxyimido)- Benzyl cyanide, α-(phenylsulfonyloxyimido)-4-chlorobenzyl cyanide, α-(phenylsulfonyloxyimido)-2,4-dichlorobenzyl cyanide, --(phenylsulfonyloxyimino)-2,6-dichlorobenzyl cyanide, α-(phenylsulfonyloxyimino)-4-methoxybenzyl cyanide, α-(2 -Chlorobenzenesulfonyloxyimido)-4-methoxybenzyl cyanide, α-(phenylsulfonyloxyimino)-thien-2-ylacetonitrile, α-(4-dodecane Benzosulfonyloxyimido)-benzyl cyanide, α-[(p-toluenesulfonyloxyimino)-4-methoxyphenyl]acetonitrile, α-[(dodecylbenzenesulfonate)醯 亚 imino)-4-methoxyphenyl]acetonitrile, α-(p-toluenesulfonyloxyimino)-4-thyl cyanide, α-(methylsulfonyloxyimino) 1-cyclopentenylacetonitrile, α-(methylsulfonyloxyimino)-1-cyclohexenylacetonitrile, α-(methylsulfonyloxyimino)-1-ring Alkenyl acetonitrile, α-(methylsulfonyloxyimido)-1-cyclooctenylacetonitrile, α-(trifluoromethylsulfonyloxyimino)-1-cyclopentenylacetonitrile, α- (trifluoromethylsulfonyloxyimido)-cyclohexylacetonitrile, α-(ethylsulfonyloxyimino)-ethylacetonitrile, α-(propylsulfonyloxyimino)-propylacetonitrile , α-(cyclohexylsulfonyloxyimido)-cyclopentylacetonitrile, α-(cyclohexylsulfonyloxyimino)-cyclohexylacetonitrile, α-(cyclohexylsulfonyloxyimino)-1 -cyclopentenylacetonitrile, α-(ethylsulfonyloxyimino)-1-cyclopentenylacetonitrile, α-(isopropylsulfonyloxyimino)-1-cyclopentenylacetonitrile, Α-(n-butylsulfonyloxyimido)-1-cyclopentenylacetonitrile, α-(ethylsulfonyloxyimino)-1-cyclohexenylacetonitrile, α-(isopropyl Sulfonoxyimino)-1-cyclohexenylacetonitrile, α-(n-butylsulfonyloxyimino)-1-cyclohexenylacetonitrile, α-(methylsulfonyloxyimino) )-Phenylacetonitrile, α-(methylsulfonyloxyimido)-p-methoxyphenylacetonitrile, α-(trifluoromethylsulfonyloxyimino)-phenylacetonitrile, α-( Trifluoromethylsulfonyloxyimido)-p-methoxyphenylacetonitrile, α-(ethylsulfonyloxyimido )-p-methoxyphenylacetonitrile, α-(propylsulfonyloxyimido)-p-methylphenylacetonitrile, α-(methylsulfonyloxyimino)-p-bromobenzene Acetonitrile and the like.

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

Further, for example, a compound shown below or the like is suitable.

Specific examples of the dialkyl or bisarylsulfonyldiazomethane in the diazomethane acid generator, such as bis(isopropylsulfonyl)diazomethane or bis(p-toluenesulfonyl) Diazomethane, bis(1,1-dimethylethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(2,4-dimethylphenylsulfonyl) Diazomethane, etc.

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

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) Base heavy nitrogen methylsulfonyl) decane, 1,2-bis(cyclohexylsulfonyldiazomethylsulfonyl)ethane, 1,3-bis(cyclohexylsulfonyldiazomethylsulfonate) Mercapto)propane, 1,6-bis(cyclohexylsulfonyldiazomethylsulfonyl)hexane, 1,10-bis(cyclohexylsulfonyldiazomethylsulfonyl)decane, and the like.

(B) Component The acid generator may be used alone or in combination of two or more.

In the present invention, the component (B) is preferably a sulfonium salt 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 0.5 to 30 parts by mass, preferably 1 to 10 parts by mass, per 100 parts by mass of the component (A). In the above range, the pattern can be sufficiently formed. And a uniform solution can be obtained with good preservation stability.

<(S) ingredient>

The positive resist composition of the present invention is obtained by dissolving the component (A) and the component (B) in an organic solvent (S) (hereinafter also referred to as a component (S)).

In the positive resist composition of the present invention, the (S) component is an organic solvent which does not dissolve the first photoresist film described later and which dissolves the components (A) and (B). When the (S) component is contained, when the positive resist composition of the present invention is applied to the support having the first photoresist pattern formed of the first positive resist composition described later, It also does not dissolve the first photoresist pattern, but can repeat the pattern formation pattern of the pattern stabilization method.

The (S) component is not particularly limited as long as it has almost no compatibility with the first photoresist film described later and can dissolve the (A) component and the (B) component to form a homogeneous solution. In the case of the known solvent which is used as a solvent for the chemically amplified photoresist, one type or two or more types can be used arbitrarily.

. (S1) ingredients

In the positive resist composition of the present invention, the (S) component is particularly preferably an alcohol-based organic solvent (hereinafter also referred to as (S1) component).

In addition, the "alcohol-based organic solvent" refers to a compound in which at least one of hydrogen atoms of an aliphatic hydrocarbon is substituted with a hydroxyl group, and is a liquid compound at normal temperature and normal pressure.

The (S1) component is preferably a monovalent alcohol, which is also different depending on the carbon number, and is generally preferably a monovalent or a quaternary alcohol having a valence of 1 or more.

The boiling point of the alcohol-based organic solvent is preferably from 80 to 160 ° C, more preferably from 90 to 150 ° C, and from 100 to 135 ° C, the coating property, the stability of the composition at the time of storage, and the PAB step (pre-baking) The viewpoint of the heating temperature of the treatment or the PEB step (heat treatment after exposure) is optimal.

The monovalent alcohol herein means the case where the number of hydroxyl groups contained in the alcohol molecule is one, and it does not contain a divalent alcohol or a trivalent alcohol and a derivative thereof.

An alcohol-based organic solvent such as n-pentyl alcohol (boiling point 138.0 ° C), s-pentyl alcohol (boiling point 119.3 ° C), t-pentyl alcohol (101.8 ° C), isoamyl alcohol (boiling point 130.8 ° C), isobutyl Alcohol (isobutyl alcohol or 2-methyl-1-propanol) (boiling point 107.9 ° C), isopropyl alcohol (boiling point 82.3 ° C), 2-ethylbutanol (boiling point 147 ° C), neopentyl Alcohol (boiling point 114 ° C), n-butanol (boiling point 117.7 ° C), s-butanol (boiling point 99.5 ° C), t-butanol (boiling point 82.5 ° C), 1-propanol (boiling point 97.2 ° C), n-hex Alcohol (boiling point 157.1 ° C), 2-heptanol (boiling point 160.4 ° C), 3-heptanol (boiling point 156.2 ° C), 2-methyl-1-butanol (boiling point 128.0 ° C), 2-methyl-2-butyl Alcohol (boiling point 112.0 ° C), 4-methyl-2-pentanol (boiling point 131.8 ° C) and the like. In particular, when a good effect is obtained by containing the (S1) component, isobutanol (2-methyl-1-propanol), 4-methyl-2-pentanol, n-butanol or the like is preferred. Among them, isobutanol and n-butanol are preferred, and isobutanol is preferred.

These (S1) components may be used alone or in combination of two or more.

In the present invention, the component (S1) is preferably isobutanol.

The content of the component (S1) is preferably 50% by mass or more and 100% by mass or less, more preferably 80% by mass or more, and most preferably 100% by mass. When the content of the component (S1) is 50% by mass or more based on the (S) component, the first photoresist pattern can be prevented from being easily dissolved when the positive resist composition of the present invention is applied.

‧(S2) ingredients

In addition to the component (S1), the (S) component may further contain an ether-based organic solvent (hereinafter also referred to as (S2) component) having no hydroxyl group, insofar as the effect of the present invention is not impaired.

Here, the "ether-based organic solvent having no hydroxyl group" means a compound having an ether bond (C-O-C) in its structure, having no hydroxyl group, and being a liquid at normal temperature and normal pressure.

The above ether-based organic solvent having no hydroxyl group is preferably a carbonyl group having no hydroxyl group.

The ether-based organic solvent having no hydroxyl group is preferably a compound represented by the following formula (s1'-1).

R ⁴⁰ -OR ⁴¹ ...(s1'-1)

[wherein R ⁴⁰ and R ⁴¹ are each independently a hydrocarbon group, or R ⁴⁰ and R ⁴¹ may be bonded to each other to form a ring. -O- represents an ether bond].

In the above formula, a hydrocarbon group of R ⁴⁰ or R ⁴¹ such as an alkyl group or an aryl group is preferably an alkyl group. Further, it is preferred that any of R ⁴⁰ and R ⁴¹ is an alkyl group, and it is ^more preferred that R ⁴⁰ and R ^{41 are} both alkyl groups.

The alkyl group of R ⁴⁰ and R ⁴¹ is not particularly limited, and for example, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms can be used. In the alkyl group, part or all of the hydrogen atoms may be substituted by a halogen atom or the like, and may be unsubstituted.

The alkyl group preferably has a carbon number of from 1 to 15 and a carbon number of from 1 to 10, in view of good coating properties of the photoresist composition. Specifically, for example, ethyl, propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, cyclopentyl, hexyl, etc., and n-butyl, isoprene The base is the best.

A halogen atom which may be substituted for the hydrogen atom of the above alkyl group is preferably a fluorine atom.

The aryl group of R ⁴⁰ and R ⁴¹ is not particularly limited, and may, for example, be an aryl group having 6 to 12 carbon atoms, which is a part or all of a hydrogen atom which may be alkyl or alkoxy. The halogen atom or the like may be substituted or unsubstituted.

The aryl group may be synthesized at a low cost, and an aryl group having 6 to 10 carbon atoms is preferred. Specifically, for example, a phenyl group, a benzyl group, a naphthyl group or the like.

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

The alkoxy group which may be substituted for the hydrogen atom of the above aryl group is preferably an alkoxy group having 1 to 5 carbon atoms, more preferably a methoxy group or an ethoxy group.

A halogen atom which may be substituted for the hydrogen atom of the above aryl group is preferably a fluorine atom.

Further, in the above formula, R ⁴⁰ and R ⁴¹ may be bonded to each other to form a ring.

R ⁴⁰ and R ⁴¹ are each independently a linear or branched alkyl group (preferably an alkyl group having 1 to 10 carbon atoms), and the terminal of R ⁴⁰ may be bonded to the end of R ⁴¹ to form a ring. . Further, the carbon atom of the alkyl group may be substituted by an oxygen atom.

Specific examples of the ether-based organic solvent include, for example, 1,8-decyl ether, tetrahydrofuran, and Alkane, etc.

The boiling point of the ether-based organic solvent having no hydroxyl group (at normal pressure) is preferably from 30 to 300 ° C, more preferably from 100 to 200 ° C, and most preferably from 140 to 180 ° C. When the boiling point of the ether-based organic solvent having no hydroxyl group is 30 ° C or more, in the spin coating in which the positive-type resist composition of the present invention is applied, since the (S) component is not easily evaporated, the coating spot can be suppressed. Further, the coating property is improved. Further, when the boiling point is 300 ° C or less, the (S) component can be sufficiently removed from the photoresist film by prebaking to improve the formability of the second photoresist film. Further, when the boiling point of the ether-based organic solvent having no hydroxyl group is in the above range, the film-reducing effect of reducing the resist pattern can be improved, and the composition stability during storage can be improved. Further, it is preferable from the viewpoints of the heating temperature of the PAB step or the PEB step.

Specific examples of the ether-based organic solvent having no hydroxyl group, for example, 1,8-anthracene (boiling point: 176 ° C), dibutyl ether (boiling point: 142 ° C), diisoamyl ether (boiling point: 171 ° C), Alkane (boiling point 101 ° C), anisole (boiling point 155 ° C), ethyl benzyl ether (boiling point 189 ° C), diphenyl ether (boiling point 259 ° C), benzhydryl ether (boiling point 297 ° C), benzene Ether (boiling point 170 ° C), butyl phenyl ether, tetrahydrofuran (boiling point 66 ° C), ethyl propyl ether (boiling point 63 ° C), diisopropyl ether (boiling point 69 ° C), dihexyl ether (boiling point 226 ° C) Dipropyl ether (boiling point 91 ° C) and the like.

These (S2) components may be used alone or in combination of two or more.

In the present invention, the (S2) component preferably has a ring-shaped or chain-like ether-based organic solvent in order to reduce the film-reducing effect of the photoresist pattern, and further, it is composed of 1,8-anthracene, and At least one selected from the group consisting of butyl ether and diisoamyl ether is preferred.

‧(S3) ingredients

In the range of the effect of the present invention, the (S) component may be an organic solvent other than the (S1) component and the (S2) component (hereinafter also referred to as the (S3) component). When the (S3) component is used, the solubility or other characteristics of the component (A) or the component (B) can be adjusted.

The component (S3) is, for example, one or two or more kinds of components which are conventionally used as a solvent which is conventionally used as a chemically amplified photoresist.

(S3) components, such as lactones such as γ-butyrolactone, ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentanone, methyl isoamyl ketone, and 2-heptanone; Polyols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol; ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate An ester-bonded compound; the above polyhydric alcohol or a monoalkyl ether or monophenyl ether such as monomethyl ether, monoethyl ether, monopropyl ether or monobutyl ether having the above ester-bonded compound; a derivative of a polyol such as an ether-bonded compound [wherein, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME) is preferred]; a cyclic ether such as dioxane Or methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxy propionate Esters; anisole, ethylbenzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenylethyl ether, butylphenyl ether, ethylbenzene, diethylbenzene, pentyl Benzene, isopropyl An aromatic organic solvent such as benzene, toluene, xylene, cumene or trimethylbenzene.

These (S3) components may be used alone or in combination of two or more.

The amount of the component (S) used is not particularly limited, and the positive resist composition of the present invention is an amount of a liquid which can be applied to a concentration which can be applied to a support.

<arbitrary ingredients>

[(D) ingredients]

In the positive resistive composition of the present invention, in the case of a post exposure stability of the latent image formed by the pattern-wise exposure of the resist layer, any component may be added. Nitrogen organic compound (D) (hereinafter also referred to as (D) component).

As the component (D), proposals have been made for various compounds, and any of the known components may be used, and among them, a cyclic amine, an aliphatic amine, particularly a secondary aliphatic amine or a tertiary aliphatic amine is preferred. Among them, the aliphatic amine is an amine having one or more aliphatic groups, and the aliphatic group preferably has 1 to 12 carbon atoms.

An aliphatic amine such as an amine (alkylamine or alkanolamine) obtained by substituting at least one hydrogen atom of ammonia (NH ₃ ) with an alkyl group or a hydroxyalkyl group having 1 or more and 12 or less carbon atoms. Specific examples thereof include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-decylamine, n-nonylamine; diethylamine, di-n-propylamine, a dialkylamine such as di-n-heptylamine, di-n-octylamine or dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butyl Amine, tri-n-hexylamine, tri-n-pentylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-decylamine, tri-n-decylamine, three a trialkylamine such as -n-dodecylamine; an alkanol such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine or tri-n-octanolamine amine.

Among them, an alkanolamine and a trialkylamine are preferred, and an alkanolamine is preferred. Among the alkanolamines, triethanolamine or triisopropanolamine is preferred.

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

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

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

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

(D) The component (A) component is 100 parts by mass, and is usually used in the range of 0.01 to 5.0 parts by mass.

[(E) ingredients]

The positive resistive composition of the present invention is used to prevent the deterioration of the sensitivity, or to improve the resistive image of the latent image formed by the pattern-wise exposure of the resist layer. And the like, at least one compound (E) (hereinafter also referred to as (E) component) selected from the group consisting of an organic carboxylic acid of any composition or an oxoacid of phosphorus or a derivative thereof.

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, for example, an ester group obtained by substituting a hydrogen atom of the above-mentioned 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 (E) component is generally used in a ratio of 0.01 to 5.0 parts by mass for 100 parts by mass of the component (A).

In the repeated patterning method using the positive-type photoresist composition as the first photoresist composition, the positive-type photoresist composition of the present invention as the second photoresist composition is used in the support. When the positive photoresist composition of the present invention is directly coated on the first photoresist pattern, the second photoresist pattern can be formed without damaging the first photoresist pattern. The reason why this effect can be obtained is still unclear, but it is presumed to be the following reason. In other words, when the component (A) has the structural units (a0-1) and (a0-2), the positive resist composition which is not easily dissolved by the alcohol-based organic solvent or the like can be sufficiently dissolved in the organic solvent. An organic solvent which does not dissolve the positive resist composition in the past (S) can be used. That is, in the positive resist composition of the present invention, since the (S) component is an organic solvent which does not dissolve the first photoresist film described later, it is difficult to dissolve the first photoresist pattern, and the pattern can be repeated. Forming a resist pattern.

The reason why the positive-type resist composition of the present invention has high solubility in an organic solvent in which a conventional positive-type resist composition such as an alcohol-based organic solvent has high solubility is not known, but it should be as follows. Conventionally, a positive resist composition such as an ArF excimer laser lithography has a high affinity with a developer, and therefore contains a polar group-containing aliphatic group for the purpose of improving the alkali solubility of the exposed portion. The hydrocarbon group is, for example, a structural unit containing a large amount of a structure having "-Y ¹ (aliphatic cyclic group)-OH". Further, in the positive resist composition of the present invention, the component (A) is a structural unit (a0-1) having a structure of "-Y ¹ -(CH ₂ )eOZ". The Z in the "-Y ¹ -(CH ₂ )eOZ" exhibits a low polarity when compared with a hydrogen atom, and has an alcohol-based organic solvent of the component (A) because it has a long molecular chain length. Such as high affinity, and speculated to improve solubility. Further, in the positive-type photoresist composition of the present invention, the component (A) has a structural unit (a0-2) in addition to the structural unit (a0-1), so that the organic-based organic compound can be improved without impairing the lithographic etching property. Solubility of solvents and the like.

"Formation Method of Photoresist Pattern"

The method for forming a photoresist pattern of the present invention comprises: applying a positive photoresist composition (hereinafter also referred to as a first positive photoresist composition) onto a support to form a first photoresist a step of film (hereinafter, also referred to as film formation step (1)), and a step of selectively exposing and alkali developing the first photoresist film to form a first photoresist pattern (hereinafter, also referred to as For the patterning step (1)), the step of applying the positive-type photoresist composition of the present invention to form the second photoresist film on the support body on which the first photoresist pattern is formed ( Hereinafter, it is also referred to as a film forming step (2)), and a step of selectively exposing and alkali developing the second photoresist film to form a photoresist pattern (hereinafter, also referred to as a patterning step (2) )).

Hereinafter, each step will be described in more detail.

[Film formation step (1)]

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 circuit 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 wiring 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 first photoresist film can be formed by a conventionally known method, for example, by applying a positive photoresist composition onto a support. The application of the positive resist composition can be carried out by a conventionally known method such as a spin coater.

A positive-type photoresist composition (hereinafter also referred to as a first positive-type photoresist composition) used for forming the first photoresist film will be described later.

Specifically, for example, the first positive resist composition is applied onto a support using a spin coater or the like, and is subjected to a temperature of 80 to 150 ° C for 40 to 120 seconds, preferably After baking for 60 to 90 seconds (pre-baking), the organic solvent is volatilized to form a first photoresist film.

The thickness of the photoresist film is preferably from 50 to 500 nm, more preferably from 50 to 450 nm. When it is in this range, the photoresist pattern can be formed with high resolution, and sufficient effects such as resistance can be obtained for etching.

[Drawing step (1)]

The patterning step (1) can be carried out by a conventionally known method, for example, selective exposure of the first photoresist film via a mask (mask pattern) formed with a specific pattern, at 80 to 150 Under the temperature condition of °C, the baking treatment (PEB (heating after exposure)) is carried out for 40 to 120 seconds, preferably 60 to 90 seconds, for example, tetramethylammonium hydroxide (TMAH) at a concentration of 0.1 to 10% by mass. As a result of alkali development of the aqueous solution, the first photoresist pattern of the exposed portion of the first photoresist film is formed. Through this process, a complex photoresist pattern can be formed.

Further, depending on the case, the post-baking step may be further included after the alkali development.

The wavelength used for the exposure is not particularly limited, and a KrF excimer laser, an ArF excimer laser, an F ₂ excimer laser, an EUV (very ultraviolet ray), a VUV (vacuum ultraviolet ray), an EB (electron line) can be used. ), X-ray, soft X-ray, etc. are performed.

At this time, the selective exposure of the first photoresist film may be performed by ordinary exposure (dry exposure) in an inert gas such as air or nitrogen, or by immersion exposure.

The immersion exposure is as described above, and the portion between the lens filled with an inert gas such as air or nitrogen and the photoresist film on the wafer is filled with a refractive index higher than that of air at the time of exposure. The state of the solvent (infiltrated media).

More specifically, the immersion exposure is such that a solvent having a refractive index higher than that of air (infiltrated medium) is filled between the photoresist film obtained as described above and the lens at the lowest position of the exposure device. In the state, exposure is performed by the desired photoresist pattern (immersion exposure).

The immersion medium has a refractive index of a photoresist film having a refractive index higher than that of air and exposed to the immersion exposure (the first photoresist film in the patterning step (1)) A solvent having a small refractive index is preferred. 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 photoresist film, for example, water, a fluorine-based inert liquid, an oxime-based solvent, a hydrocarbon-based solvent, or the like.

Specifically, for example, fluorine-based inert liquids _{C 3 HCl 2 F 5, C} 4 F 9 OCH 3, C 4 F 9 OC liquid _{2 H 5, C 5 H 3} F 7 fluorine-based compound as the main ingredient and the like, again boiling It is preferably from 70 to 180 ° C, and more preferably from 80 to 160 ° C. In the fluorine-based inert liquid, when the boiling point is in the above range, the medium used for the wetting type can be removed by a simple method after the completion of the exposure, and is preferable.

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

[Film formation step (2)]

Next, the positive photoresist composition of the present invention is coated on the support having the first photoresist pattern, and the gap between the plurality of photoresist patterns is filled to form a second photoresist film. The second photoresist film can be formed by a conventionally known method similarly to the first photoresist film.

The film thickness of the second photoresist film is at least the same as the height of the first photoresist pattern, and is preferably thicker. That is, when the support is viewed from the second photoresist film side, it is preferable that the surface is flat.

[Drawing step (2)]

Next, another position different from the position of the second photoresist film in which the plurality of photoresist patterns are formed is selectively exposed and developed. In this way, the unexposed portions of the second photoresist film can be removed, and a new complex photoresist pattern can be formed between the plurality of photoresist patterns.

As a result, a photoresist pattern formed by a plurality of photoresist patterns and a plurality of newly formed photoresist patterns on the second photoresist film is formed on the support.

In the present invention, except for the case where the first photoresist pattern is completely identical, all of them are "other positions than the position at which the first photoresist pattern is formed", and all of them are not repeated, and A part of the repetition.

In the present invention, it is preferable that the position at which the first photoresist pattern is formed and the position at which the selective exposure is performed in the patterning step (2) are not repeated at all. Thus, a pattern of narrow pitches having a longer interval (pitch) between the narrower patterns than the first photoresist pattern formed by the patterning step (1) can be formed.

Selectively exposing the position at which the first photoresist pattern is formed to different positions, for example, a mask pattern different from the first mask pattern used in the patterning step (1), etc. Way to proceed.

For example, when forming a photoresist pattern of a line and a space, the patterning step (1) is to form a line and space using a mask pattern of a line and a space obtained by arranging a plurality of lines at a specific pitch. After the patterning, in the patterning step (2), the mask pattern is changed, and when the line pattern is formed by the intermediate position between the line pattern formed by the patterning step (1) and the line pattern, the pattern can be relatively A line-to-space photoresist pattern is formed at a distance of about 1/2 of the distance between the line and the space initially formed. That is, it is possible to form a dense photoresist pattern which is a narrower pitch than the originally formed pattern.

Among them, "sparse type" refers to the line and space photoresist pattern, which has the line width: space width = 1:2 or more wide space width line and space pattern meaning.

As described above, in the present invention, the first photoresist pattern is preferably a line and space photoresist pattern. In this way, a dense line and space pattern with a narrow pitch can be formed.

Specifically, for example, after forming a line and space pattern (sparse type) having a line width of 100 nm and a line width of a space width of 1:3, the mask pattern is moved in parallel by 200 nm in a vertical direction with respect to the direction of the line. And forming a line width of 100 nm, line width: space width = 1:3 line and space pattern, and can form a line width of 100 nm, line width: space width = 1:1 line and space pattern (closed map type).

Moreover, in the patterning step (1), the mask pattern is rotated, or in the patterning step (1), a mask pattern different from the mask pattern is used (for example, the patterning step (1) In the middle, the mask pattern of the line and the space, the mask pattern of the through hole in the patterning step (2), etc., can form a fine, and/or various photoresist pattern.

<First positive resist composition>

In the above film forming step (1), the first positive resist composition of the first photoresist film is formed as long as it is a positive resist composition having low compatibility with the above organic solvent (S) component. When it is not particularly limited, it is preferable to use a chemically amplified positive type resist composition. The chemically amplified positive-type photoresist composition is not particularly limited, and may be used in a conventional positive-type photoresist composition such as an ArF photoresist, etc., in combination with an exposure light source, a lithographic etching property, or the like. Just use the appropriate choice.

The chemically amplified positive-type photoresist composition generally contains a resin component (A') (hereinafter, also referred to as (A') component) which increases solubility in an alkali developer via an action of an acid, and is exposed through exposure. The composition of the acid generator component (B') (hereinafter, also referred to as (B') component) occurs.

[(A’) ingredients]

‧Structural unit (a1)

In the first positive resist composition, the (A') component is preferably a copolymer (A1) containing a structural unit (a1). Wherein, the structural unit (a1) is a structural unit derived from an acrylate containing an acid-dissociable dissolution inhibiting group, and the (A) component which can be contained in the positive-type photoresist composition which can be contained in the first aspect of the present invention The units listed in the description of the structural unit (a1) are the same.

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

Further, the structural unit (a1) is not particularly limited, and any unit can be used. In particular, it is preferably a structural unit represented by the above formula (a1-1), and specifically, for example, (a1-1-1) to (a1-1-6) and (a1-1-35) are used. At least one selected from the group of ~(a1-1-41) is more preferable.

In the copolymer (A1), the ratio of the structural unit (a1) is preferably from 10 to 80 mol%, more preferably from 20 to 70 mol%, based on the total structural unit constituting the copolymer (A1). 25 to 50 mol% is the best. When it is 10 mol% or more, the pattern can be easily obtained as a photoresist composition, and when it is 80 mol% or less, the balance with other structural units can be obtained.

‧Structural unit (a2)

The copolymer (A1) preferably has a structural unit (a2) in addition to the structural unit (a1). Wherein, the structural unit (a1) is a structural unit derived from an acrylate having a cyclic group containing a lactone, and the first aspect of the present invention may be contained in the positive resist composition (A) The units listed in the description of the structural unit (a2) of the components are the same.

The structural unit (a2) may be used alone or in combination of two or more.

Further, the structural unit (a2) is not particularly limited, and any unit can be used. In particular, at least one selected from the group consisting of the structural units represented by the above general formulae (a2-1) to (a2-5) is preferable, and the general formula (a2-1) to (a2-3) It is more preferable to select at least one selected from the group of structural units represented by chemical formulas (a2-1-1), (a2-1-2), (a2-2-1), (a2-2). -2), (a2-2-9), (a2-2-10), (a2-3-1), (a2-3-2), (a2-3-9), and (a2-3-10) It is more preferable that at least one selected from the group of structural units indicated is selected.

The ratio of the structural unit (a2) in the copolymer (A1) is preferably from 5 to 60 mol%, more preferably from 10 to 50 mol%, based on the total of the total structural units constituting the copolymer (A1). It is best to use 20 to 50 mol%. When the content is 5 mol% or more, a sufficient effect can be obtained when the structural unit (a2) is contained, and when it is 60 mol% or less, a balance with other structural units can be obtained.

‧Structural unit (a3’)

The copolymer (A1) is preferably a structural unit (a3') derived from an acrylate having a polar group-containing aliphatic hydrocarbon group, in addition to the structural unit (a1).

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, the alkali solubility of the exposed portion can be improved, and the resolution can be improved.

A polar group such as a hydroxyl group, a cyano group, a carboxyl group, a hydroxyalkyl group in which a part of a hydrogen atom of an alkyl group is substituted by a fluorine atom, or the like, particularly preferably a hydroxyl group.

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

Wherein, the structural unit derived from the hydroxy group having a hydroxyl group, a cyano group, a carboxyl group or an alkyl group as an aliphatic polycyclic group hydroxyalkyl group substituted with a fluorine atom is more preferred. . The polycyclic group is, for example, a group in which two or more hydrogen atoms are removed, such as a bicycloalkane, a tricycloalkane or a tetracycloalkane. Specifically, for example, a polycyclic alkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane removes a base of two or more hydrogen atoms. In the polycyclic group, a group in which two or more hydrogen atoms are removed by adamantane, a group in which two or more hydrogen atoms are removed by norbornane, and a group in which two or more hydrogen atoms are removed by tetracyclododecane are Industrial is better.

In the structural unit (a3'), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, the structural unit derived from the hydroxyethyl acrylate is preferred. When the hydrocarbon group is a polycyclic group, for example, 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 good.

Wherein R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, j is an integer of from 1 to 3, k is an integer of from 1 to 3, t' is an integer of from 1 to 3, and 1 is an integer of from 1 to 5. , s is an integer from 1 to 3].

In the general formulae (a3'-1) to (a3'-3), a lower alkyl group or a halogenated lower alkyl group of R, for example, a lower alkyl group or a halogenated lower alkyl group which may be bonded to the α-position of the above acrylate is The same content.

In the formula (a3'-1), j is preferably 1 or 2, and more preferably 1 is used. In the case where j is 2, it is preferred that the hydroxyl group is bonded to the 3 and 5 positions of the adamantyl group. In the case where 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. The cyano group is preferably bonded to the 5- or 6-position of the norbornyl group.

In the formula (a3'-3), t' is preferably 1. 1 is better than 1. s is better than 1. It is preferred that the terminal of the carboxyl group of acrylic acid is bonded to 2-norbornyl group or 3-norbornyl group. The fluorinated alkyl alcohol is preferably bonded to the 5 or 6 position of the norbornyl group.

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

In the copolymer (A1), the ratio of the structural unit (a3') is preferably 5 to 50 mol%, more preferably 5 to 40 mol%, and more preferably 5, based on the total structural unit constituting the copolymer. ～25 mol% is the best.

‧Structural unit (a4’)

The copolymer (A1) may contain other structural units (a4') other than the structural units (a1), (a2), and (a3') within the range not impairing the effects of the present invention.

The structural unit (a4') is not particularly limited as long as it is not classified into other structural units (a1), (a2), and (a3'), and can be used for ArF excimer lasers. In the conventionally known majority unit used for the photoresist for KrF excimer laser (preferably for ArF excimer laser), for example, the positive photoresist of the first aspect of the present invention can be used. The units listed in the composition, etc.

In the case where the structural unit (a4') is contained in the copolymer (A1), the structural unit (a4') preferably contains 1 to 30 mol%, based on the total of the total structural units constituting the copolymer (A1). It is more preferably contained in an amount of 10 to 20 mol%.

In the first positive resist composition, the copolymer (A1) is preferably a copolymer having a structural unit (a1), for example, from the above structural units (a1), (a2) and (a3). a copolymer or the like formed.

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

In the first positive resist composition, the copolymer (A1) is particularly preferably a combination of structural units having the following general formula (A-11).

[In the formula (A-11), R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ²⁰ is a lower alkyl group].

The component (A') can be obtained by polymerization of a monomer derived from each structural unit, for example, a radical polymerization initiator such as azobisisobutyronitrile (AIBN) by a known radical polymerization.

Further, in the above-mentioned polymerization, the (A') component may be, for example, a chain transfer agent such as Hs-CH ₂ -CH ₂ -CH ₂ -C(CF ₃ ) ₂ -OH or a -C ( CF ₃ ) ₂ -OH group. Thus, a copolymer in which a hydroxyalkyl group in which a part of a hydrogen atom in the alkyl group is substituted by a fluorine atom is introduced can be obtained, and the effect of LWR can be effectively reduced. Further, it is possible to effectively reduce development defects or reduce the effect of LER (Line Edge Roughness).

The mass average molecular weight (Mw) of the component (A') (the polystyrene equivalent amount of the gel permeation chromatography method) is not particularly limited, and is generally preferably 2,000 to 50,000, more preferably 3,000 to 30,000. 5,000 to 20,000 is the best. When the mass average molecular weight of the (A') component is less than 50,000, sufficient solubility is obtained for the photoresist as a photoresist, and when it is more than 2,000, a good dry etching resistance or a resist pattern cross-sectional shape can be obtained.

Further, the degree of dispersion (Mw/number average molecular weight (Mn)) is not particularly limited, and is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.2 to 2.5.

Further, Mn is a number average molecular weight.

[(B’) ingredients]

The component (B') is not particularly limited, and a component which has been proposed as an acid generator for chemically amplified photoresist has been used. The (B') component is, for example, the same as that exemplified in the description of the component (B) of the positive resist composition of the first aspect of the present invention.

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

In the present invention, the (B') component is preferably an anthracene salt of a fluorinated alkylsulfonic acid ion as an anion and an anthracene salt of the above formula (b1-12). The above formula (b1-12) is preferably an anion sulfonium salt, and a compound represented by the formulae (b-12-1) to (b-12-18) is more preferably used, and the formula (b-12-1) is used. The compounds indicated are optimal.

In the first positive resist composition, the content of the (B') component is 0.5 to 30 parts by mass, preferably 1 to 10 parts by mass, per 100 parts by mass of the (A') component. When the content of the (B') component is in the above range, the formation of the pattern can be sufficiently performed. Further, it is preferable to obtain a uniform solution and to obtain good storage stability and the like.

[(D’) ingredients]

The first positive type resist composition may be a nitrogen-containing organic compound (D') (hereinafter also referred to as a (D') component) in order to enhance the shape of the resist pattern and to preserve the stability.

There is a proposal for a plurality of compounds in the (D') component, and any of the known components may be used. The (D') component, and the positive photoresist composition of the first aspect of the present invention (D) The ingredients exemplified in the description of the ingredients are the same.

The (D') component 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 (A') component.

[(E’) ingredients]

The first positive-type photoresist composition can be added with an organic carboxylic acid, an oxyacid of phosphorus, and a derivative thereof in order to prevent deterioration of sensitivity, increase the shape of the resist pattern, and preserve stability. At least one compound (E') (hereinafter also referred to as (E') component) selected in the group.

The (E') component has various proposals for various components, and it can be used arbitrarily in any known component. The (E') component is the same as the component exemplified in the description of the component (E) of the positive resist composition of the first aspect of the present invention.

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

The (E') component is preferably an organic carboxylic acid, particularly salicylic acid.

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

In the first positive resist composition, additives having a blending property may be further added as desired, for example, an additive resin having an improved performance of an improved photoresist film, a surfactant for improving coating properties, and a surfactant capable of improving coating properties. Dissolution inhibitors, plasticizers, stabilizers, colorants, antihalation agents, dyes, and the like.

[(S’) ingredients]

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

(S') The component (S') can be used as long as it can dissolve the components to be used in a uniform solution, and it can be appropriately selected from one or more of the known materials which are conventionally used as solvents for chemically amplified photoresists. Ingredients. The (S') component is the same as the component exemplified in the description of the (S3) component of the above-mentioned positive-type photoresist composition.

These (S') components may be used alone or in combination of two or more.

In the first positive resist composition, the (S') component is preferably propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME) or ethyl lactate (EL).

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

More specifically, for example, the polar solvent is a case where EL is added, and the mass ratio of PGMEA:EL is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. Further, the polar solvent is a case where PGME is added, and 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, as the (S') component, for example, a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is preferred. In this case, the mixing ratio of the former and the latter is preferably 70:30 to 95:5.

The amount of use of the entire (S') component is not particularly limited, and the amount of the liquid which makes the first positive type resist composition reach the concentration which can be applied to the support can be used.

[Examples]

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

The following copolymers (A)-11 to 12, 21 to 28, 28-1, 27-1, 27-2, and 31 to 37 are the monomers (1) to (8) shown below, which are known. The dropping polymerization method is synthesized by copolymerization.

The Mw and Mw/Mn of the copolymers (A)-11 to 12, 21 to 28, 28-1, 27-1, 27-2, and 31 to 37 were measured by gel permeation chromatography (GPC).

In the formulas (A)-11 to 12, 21 to 28, 28-1, 27-1, 27-2, and 31 to 37, the number in the lower right of () is the ratio of each structural unit (% by mole) .

<Synthesis Example 1: Synthesis of Copolymer (A)-11>

5.85 g of the monomer (1), 7.65 g of the monomer (2), and 7.08 g of the monomer (3) were dissolved in 95.03 g of methyl ethyl ketone. To the solution, 3.02 mmol of V-601 (polymerization initiator) was softly added and dissolved. This was added dropwise 3.00 g of methyl ethyl ketone heated to 75 ° C over 6 hours under a nitrogen atmosphere. After completion of the dropwise addition, the reaction mixture was heated and stirred for 1 hour, and then the reaction liquid was cooled to room temperature. Thereafter, the reaction was dropped into a large amount of a methanol/water mixed solution, and the operation of precipitating the reaction product was repeated three times. The reaction product obtained in this manner was dried under reduced pressure at room temperature to give a white powder. The obtained resin (A)-11 was measured by GPC, and it was found that the mass average molecular weight (Mw) was 7,000 and the degree of dispersion (Mw/Mn) was 1.72.

The copolymers (A)-12, (A)-21 to 28, 28-1, 27-1, 27-2, and 31 to 37 were synthesized in the same manner as in Synthesis Example 1.

<Solubility of copolymers (A)-11 to 12, 21, 31 to 33 in organic solvents>

PGMEA, isobutanol (IBA), diisoamyl ether (DIAE), 1,8-桉 were added to the copolymers (A)-11 to 12, 21, and 31 to 33, respectively, in a 1% solution. The ether (CNL) was mixed and confirmed to be dissolved. The results obtained are shown in Table 1. In the table, "A" means dissolved, and "C" means undissolved. In PGMEA, all of the copolymers showed good dissolution. In isobutanol, only the structural unit (a0-1) represented by the above formula (a0-1), and the above formula (a0-2) The copolymer (A)-21 of the structural unit (a0-2) indicated was dissolved. Similarly, only the copolymer (A)-31 was dissolved in the diisoamyl ether. Further, in the 1,8-anthracene, four kinds of copolymers other than the copolymers (A)-11 to (A)-12 were dissolved.

From the results, it was found that when the structural units (a0-1) and (a0-2) were present, it was confirmed that the solubility of the positive resist composition to the alcohol-based organic solvent can be improved.

<Solubility of copolymers (A)-11 to 12, 21 to 28, 28-1, 27-1, 27-2, 34 to 37 for isobutanol and 4-methyl-2-pentanol>

0.1 g of each of the resin powders of the copolymers (A)-11 to 12, 21 to 28, 28-1, 27-1, 27-2, and 34 to 37 was added to form a 50% solution. Isobutanol was mixed and confirmed to be dissolved. In the case of not being dissolved, 0.2 g of isobutanol was further added as a 25% solution, and it was mixed to confirm whether it was dissolved. In the case of not being dissolved, 0.6 g of isobutanol was further added in the form of a 10% solution, followed by mixing to confirm whether or not it was dissolved. In the case of undissolved. To form a 5% solution, 1.0 g of isobutanol was further added and mixed to confirm whether it was dissolved. In the case of not being dissolved, 3.0 g of isobutanol was further added to form a 2% solution, followed by mixing to confirm whether or not it was dissolved. In the case of not being dissolved, 5.0 g of isobutanol was further added to form a 1% solution, followed by mixing to confirm whether or not it was dissolved. The results obtained are shown in Table 2. In the table, "A" or "C" has the same meaning as Table 1. As a result, it was confirmed that none of the copolymers (A)-11 to 12 and 34 to 37 was dissolved in isobutanol in all the concentrations. On the other hand, in the copolymers (A)-21 to 28, 28-1, 27-1, and 27-2, the solubility in isobutanol was improved as the concentration of the solution was lowered, and it was confirmed in a 2% solution. All of the copolymers were dissolved in isobutanol.

Further, the solubility of the copolymers (A)-28, 28-1 for 4-methyl-2-pentanol was evaluated in the same manner. As a result, it was confirmed that the copolymers (A)-28 and 28-1 were all dissolved in 4-methyl-2-pentanol in the 2% solution.

<Production of Positive Photoresist Composition>

The components shown in Tables 3 and 4 were mixed and dissolved to prepare a positive resist composition solution.

Each of the abbreviations in Tables 3 and 4 has the following meanings. Further, the value in [] is the added amount (parts by mass).

(A)-11: a polymer compound represented by the above formula (A)-11.

(A)-21: a polymer compound represented by the above formula (A)-21.

(A)-22: a polymer compound represented by the above formula (A)-22.

(A)-24: a polymer compound represented by the above formula (A)-24.

(A)-27: a polymer compound represented by the above formula (A)-27.

(A)-28: a polymer compound represented by the above formula (A)-28.

(A)-28-1: a polymer compound represented by the above formula (A)-28-1.

(A)-27-1: a polymer compound represented by the above formula (A)-27-1.

(A)-27-2: a polymer compound represented by the above formula (A)-27-2.

(B)-1: Triphenylsulfonium heptafluoro-n-propanesulfonate.

(B)-2: an acid generator represented by the above chemical formula (b-12-1).

(B)-3: Triphenylsulfonium trifluoromethanesulfonate.

(B)-4: 4-methylphenyldiphenylphosphonium nonabutanesulfonate.

(B)-5: an acid generator represented by the following chemical formula (B)-5.

(B)-6: An acid generator represented by the following chemical formula (B)-6.

(B)-7: 4-methylphenyldiphenylphosphonium trifluoromethanesulfonate.

(B)-8: An acid generator represented by the following chemical formula (B)-8.

(B)-9: an acid generator represented by the following chemical formula (B)-9.

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

(D)-2: Triethanolamine.

(E)-1: Salicylic acid.

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

(S)-2: PGMEA.

(S)-3: PGME.

(S)-4: isobutanol.

(S)-5: 4-methyl-2-pentanol.

<Repetitive patterning to form a photoresist pattern>

As shown in the following Tables 5 and 6, the photoresist compositions obtained in Tables 3 and 4 above were used as the positive photoresist composition forming the first photoresist film and as the second photoresist. The positive photoresist composition of the film forms a photoresist pattern by repeated patterning. In the following Tables 5 and 6, the "first photoresist film" is a positive photoresist composition which forms a first photoresist film, and the "second photoresist film" is a second photoresist. A positive photoresist composition of the film.

First, an organic anti-reflective film composition "ARC29" (trade name, manufactured by Privah Technology Co., Ltd.) was applied onto a 8-inch wafer using a spin coater, and passed through a hot plate at 205 ° C, 60 ° After baking in a second, it was dried to form an organic anti-reflection film having a film thickness of 77 nm.

The positive resist composition of the first photoresist film was formed on the organic anti-reflection film by a spin coater, and on Examples 1 to 5 and Comparative Examples 1 to 15 on a hot plate. In the conditions of 110 ° C and 60 seconds, Examples 6 to 22 were pre-baked (PAB) at 90 ° C for 60 seconds, and dried to form a photoresist film having a film thickness of 120 nm (first Light resist film).

Next, using the ArF exposure apparatus NSR-S302 (manufactured by Ricoh Co., Ltd.; NA (number of openings) = 0.60, 2/3 wheel illumination), the ArF excimer laser (193 nm) was used for the first photoresist film. A mask pattern (6% halftone) is used for selective illumination. Subsequently, Examples 1 to 5 and Comparative Examples 1 to 15 were subjected to post-exposure heating (PEB) treatment under conditions of 110 ° C and 60 seconds, and Examples 6 to 22 were carried out at 90 ° C for 60 seconds. Further, development was carried out at 23 ° C for 30 seconds using a 2.38 mass% aqueous solution of tetramethylammonium hydroxide (TMAH), followed by water washing with pure water for 30 seconds, and vibration drying. As a result, a photoresist pattern (also referred to as an L/S pattern) of a line and a space having a line width of 120 nm and a pitch of 480 nm was formed. Further, the optimum exposure amount (Eop) of the L/S pattern having a line width of 120 nm and a pitch of 480 nm (unit: mJ/cm ² (energy per unit area)) is shown in Tables 5 and 6.

Subsequently, the positive photoresist composition forming the second photoresist film was coated on a substrate on which a 1:3 L/S pattern was formed using a spin coater, and subjected to a hot plate at 90 ° C. After a second pre-baking (PAB) treatment, after drying, a positive-type photoresist film (second photoresist film) having a film thickness of 120 nm was formed.

Next, using the ArF exposure apparatus NSR-S302 (manufactured by Ricoh Co., Ltd.; NA (number of openings) = 0.60, 2/3 wheel illumination), the ArF excimer laser (193 nm) was used for the second photoresist film. A mask pattern (6% halftone) is used for selective illumination. Subsequently, post-exposure heating (PEB) treatment was carried out at 90 ° C for 60 seconds, and further developed at 23 ° C using a 2.38 mass % aqueous solution of tetramethylammonium hydroxide (TMAH) for 30 seconds. Thereafter, it was washed with water and shaken with pure water for 30 seconds.

Further, the exposure amount at this time is as shown in Tables 5 and 6.

The above repeated patterning results are disclosed in Tables 5 and 6. In the table, "A" is a pattern in which a line pattern of 120 nm is mixed between a line having an L/S pattern having a line width of 120 nm and a pitch of 480 nm, and "C" indicates that no pattern is formed. That is, the positive-type photoresist composition forming the second photoresist film is obtained in Examples 1 to 22 in which the photoresist compositions 2-1 to 2-22 of the photoresist composition of the present invention are used. A line pattern of 120 nm is mixed between the line of the L/S pattern with a line width of 120 nm and a pitch of 480 nm, and the photoresist composition is used 3-1 to 3-5, 4-1 to 4-5. In Comparative Examples 1 to 15 of 5-1 to 5-5, the lower layer was dissolved, and the pattern was not formed.

From these results, it was confirmed that the positive resist composition of the present invention, when used as the second photoresist film, does not dissolve on the support as in the formation method of the photoresist pattern of the present invention. The first photoresist pattern, and can be repeatedly patterned to form a photoresist pattern.

The above is a preferred embodiment of the present invention, but the present invention is not limited by the embodiments, and the technical content may be added, omitted, substituted, and other changes without departing from the spirit of the invention. . The present invention is not limited by the foregoing description, but is only limited to the scope of the appended claims.

Claims (6)

A positive-type photoresist composition comprising a resin component (A) which increases solubility in an alkali developing solution by an action of an acid, an acid generator component (B) which generates an acid by exposure, and an organic solvent (S), wherein the resin component (A) and the acid generator component (B) are dissolved in the organic solvent (S), and the positive photoresist composition is contained on a support and coated a step of forming a first photoresist film by the positive photoresist composition, and a step of forming the first photoresist pattern by selective exposure and alkali development of the first photoresist film, and forming a step of applying a positive photoresist composition to form a second photoresist film on the support having the first photoresist pattern, and selectively exposing the second photoresist film to a base In the method for forming a positive resist pattern for developing a step of forming a photoresist pattern, a positive photoresist composition for forming the second photoresist film, wherein the organic solvent (S) is Dissolving the organic solvent of the first photoresist film, wherein the resin component (A) is represented by the following formula (a0-1) Structural unit structural unit (a0-1), the following formula (a0-2) represented by the (a0-2), [In the formula (a0-1), R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; Y ¹ is an aliphatic cyclic group; Z is a group containing a tertiary alkyl group or an alkoxyalkyl group; a is 1 An integer of ~3, b is an integer of 0~2, and a+b=1~3; c, d, and e are independent integers of 0~3; in formula (a0-2), R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; Y ³ is an alkylene group or an aliphatic cyclic group; g and h are each an independent integer of 0 to 3; i is an integer of 1 to 3, and the aforementioned organic solvent (S) ) is a monovalent alcohol. The positive-type resist composition of claim 1, wherein the ratio of the structural unit (a0-1) in the resin component (A) is relative to a total structural unit constituting the resin component (A) The total is 1 to 40% by mole. The positive-type resist composition according to claim 1, wherein the structural unit (a0-2) contains a structural unit represented by the following general formula (a0-2-1) [wherein, R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; g and h are each independently an integer of 0 to 3; i is an integer of 1 to 3]. The positive resist composition according to claim 1, wherein the resin component (A) further has a structural unit (a1) derived from an acrylate having an acid dissociable dissolution inhibiting group. The positive-type photoresist composition of claim 1, which further contains a nitrogen-containing organic compound (D). A method for forming a photoresist pattern, comprising: a step of coating a positive photoresist composition on a support to form a first photoresist film, and selecting the first photoresist film a step of forming a first photoresist pattern by alkali exposure and alkali development, and coating the support body on which the first photoresist pattern is formed, and coating any one of the first to fifth patent claims The positive photoresist composition forms a second photoresist film, and the second photoresist film is selectively exposed and alkali developed to form a photoresist pattern.