KR20210055629A - Resist composition and patterning process - Google Patents

Abstract

Provided is a resist composition and a pattern formation method using the resist composition, wherein in photolithography using high-energy rays such as KrF excimer laser light, electron beams, and extreme ultraviolet rays as a light source, specifically good mask dimension dependence (mask error factor: MEF) and dimensional uniformity (CDU) are exhibited. The resist composition comprises: (A) a resin including a repeating unit having an acid labile group and at least one repeating unit having an aromatic substituent; (B) a photo-acid generation agent represented by general formula (B-1); and (C) a solvent. In the formula, W_1 represents a cyclic divalent hydrocarbon group containing a C4-C12 hetero atom. W_2 represents a cyclic monovalent hydrocarbon group containing no heteroatoms having 4 to 14 carbon atoms. Rf is a divalent organic group represented by the general formula. M^+ represents an onium cation.

Description

RESIST COMPOSITION AND PATTERNING PROCESS TECHNICAL FIELD

The present invention relates to a resist composition and a method for forming a pattern.

With the high integration and high speed of LSI, miniaturization is rapidly progressing. As a state-of-the-art miniaturization technology, mass production is carried out by ArF immersion lithography in which a liquid such as water is inserted between a projection lens and a substrate to perform exposure. Reviews such as lithography are underway.

Among the chemically amplified resist materials used in the above lithography, a compound that decomposes by exposure to generate an acid (hereinafter referred to as ``acid generator'') is used, but by optimizing the structure in the acid generator, acid diffusion can be suppressed. It is possible, and it becomes possible to form a high-resolution pattern. As such an acid generator, those disclosed in Patent Documents 1 to 4, for example, have been studied.

[Patent Document 1] Japanese Patent Publication 2008-07484 [Patent Document 2] Japanese Patent Publication 2009-191054 [Patent Document 3] Japanese Patent Publication 2011-126869 [Patent Document 4] Japanese Patent Publication 2012-072108

In advancing further miniaturization, the acid generators that have been studied in the past were not necessarily sufficient from the viewpoint of resolution and various performances including the shape of a resist pattern.

The present invention has been made to solve the above problem, and an object of the present invention is to provide a resist composition and a pattern forming method showing good mask dimensional dependence (mask error factor: MEF) and dimensional uniformity (CDU) in photolithography. .

In order to solve the above problem, in the present invention, (A) a resin containing at least one repeating unit having an acid labile group and further having an aromatic substituent, (B) a general formula (B-1). It provides a resist composition characterized by containing the displayed photo-acid generator and (C) solvent.

(In the formula, W ₁ represents a cyclic divalent hydrocarbon group containing a hetero atom having 4 to 12 carbon atoms. W ₂ represents a cyclic monovalent hydrocarbon group containing no hetero atom having 4 to 14 carbon atoms. Rf is the above-described Is a divalent organic group represented by a general formula, A ₁ , A ₂ each independently represent a hydrogen atom or a trifluoromethyl group, and B ₁ and B ₂ are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group And * represents the number of bonds with a carbonyloxy group, m represents an integer of 0 to 4, n represents an integer of 0 to 1. M ⁺ represents an onium cation.)

Such a resist composition of the present invention exhibits good mask dimensional dependence (mask error factor: MEF) and dimensional uniformity (CDU) in photolithography.

_{In this case, it is preferable that W 1} in the general formula (B-1) is a cyclic divalent hydrocarbon group containing a lactone ring structure having 6 to 12 carbon atoms.

In the case of such a resist composition, by disposing a lactone ring at a position close to a sulfonic acid group upon generation of acid after exposure, since it becomes possible to further suppress acid diffusion, better mask dimensional dependence and dimensional uniformity can be exhibited.

_{Moreover, it is preferable that W 2} in the said general formula (B-1) is a polycyclic monovalent hydrocarbon group which does not contain a C7-14 hetero atom.

In the case of such a resist composition, since it is possible to impart an appropriate solubility by arranging a highly condensed hydrocarbon group at the terminal, it is possible to show even better mask size dependence and dimensional uniformity.

Further, it is preferable that the Rf group in the general formula (B-1) is selected from groups represented by the following formulas (Rf-1) to (Rf-6).

(* represents the number of bonds with a carbonyloxy group.)

In the case of such a resist composition, the solubility is improved due to the effect of the fluorine atom in Rf, and the sulfonic acid generated after exposure has an appropriate acid strength, so that better mask dimensional dependence, LWR, and dimensional uniformity can be exhibited.

In addition, it is preferable that one type of repeating unit having the aromatic substituent among the resin of the component (A) is a repeating unit represented by the following formula (A-1).

(In the formula, R ^A represents a hydrogen atom or a methyl group. R ₆₁ represents a hydrogen atom or a straight-chain, branched or cyclic hydrocarbon group which may be interposed by a hetero atom having 1 to 10 carbon atoms. R ₆₂ is a hetero atom interposed therebetween. It represents a straight-chain, branched or cyclic hydrocarbon group having 1 to 8 carbon atoms, where t is an integer of 1 to 3, and u is an integer that satisfies u≤5+2s-t, and s is 0 or 1. L ₁ represents a single bond or -C(=O)O-, -C(=O)NH-.)

The resist composition of the present invention can exhibit better mask dimensional dependence and dimensional uniformity by combining the component (A) with the component (B).

It is preferable that one kind of the repeating unit having the aromatic substituent among the resin of the component (A) is a repeating unit represented by the following general formulas (A-2) to (A-4).

(In the formula, R ^A is each independently a hydrogen atom or a methyl group, and R ²⁰¹ is a single bond, a phenylene group, -OR ²¹⁰ -or -C(=O)-Z ² -R ²¹⁰ -. Z ² is an oxygen atom. Or NH, R ²¹⁰ is a C 1 to C 6 linear, branched or cyclic alkylene group, alkenylene group or phenylene group, a carbonyl group (-CO-), an ester group (-COO-), an ether group (- O-) or may contain a hydroxy group L ₂ represents a single bond or -Z ³ -C(=O)-O-, and Z ³ represents a straight-chain, branched, optionally substituted hetero atom having 1 to 20 carbon atoms Represents a type or cyclic divalent hydrocarbon group Z ¹ is a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, -OR ²¹¹ -or -C(=O)-Z ⁴ -R ²¹¹ -. Z ⁴ is an oxygen atom or NH, and R ²¹¹ is a C 1 to C 6 linear, branched or cyclic alkylene group, alkenylene group or phenylene group, and may contain a carbonyl group, an ester group, an ether group or a hydroxy group. M ^- represents a non-nucleophilic counter ion, R ²⁰² , R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ , R ²⁰⁶ , R ²⁰⁷ , R ²⁰⁸ , R ²⁰⁹ may each independently be substituted with a hetero atom, even if a hetero atom is interposed It represents a good straight-chain type having 1 to 20 carbon atoms, or a branched type or cyclic monovalent hydrocarbon group having 3 to 20 carbon atoms In addition, R ²⁰² and R ²⁰³ may be bonded to each other to form a ring together with the sulfur atom in the formula, Alternatively ^{, any two or more of R 204} , R ²⁰⁵ and R ²⁰⁶ or any two or more of R ²⁰⁷ , R ²⁰⁸ and R ²⁰⁹ may be bonded to each other to form a ring together with the sulfur atom in the formula. The repeating units represented by -2) to (A-4) have one or more aromatic substituents.)

The resist composition of the present invention can exhibit even better mask dimensional dependence and dimensional uniformity by using such component (A).

The resist composition, as the component (D), is a resin different from the resin of the component (A), and is selected from repeating units represented by the following formulas (D-1), (D-2) and (D-3). It is preferable to further include a fluorine-containing resin having at least one type.

(In the formula, R ^A is each independently a hydrogen atom or a methyl group. R ₅₁ and R ₅₂ are each independently a hydrogen atom or a linear, branched or cyclic monovalent hydrocarbon group having 1 to 10 carbon atoms. R ₅₃ Is a single bond or a linear or branched divalent hydrocarbon group having 1 to 5 carbon atoms R ₅₄ , R ₅₅ and R ₅₆ are each independently a hydrogen atom or a straight chain, branched or cyclic C 1 to 15 Of, a monovalent hydrocarbon group, a fluorinated monovalent hydrocarbon group or an acyl group, or an acid labile group When R ₅₄ , R ₅₅ and R ₅₆ are monovalent hydrocarbon groups or fluorinated monovalent hydrocarbon groups, some of these carbon atoms are ether groups Alternatively, it may be substituted with a carbonyl group R ₅₇ is a linear, branched or cyclic C 1 to C 20 (v+1) valent hydrocarbon group or a fluorinated hydrocarbon group, v is an integer of 1 to 3.)

When the resist composition of the present invention further contains the component (D), the contact angle between the surface of the resist film and water is improved, and defects due to residual liquid immersion and elution of an acid generator or a quencher can be suppressed. In addition, the solubility of the surface of the resist film can be adjusted, and good dimensional uniformity can be achieved.

In addition, the present invention includes a step of forming a resist film by applying the resist composition on a substrate and performing heat treatment, a step of exposing the resist film to high energy rays, and a step of developing the exposed resist film using a developer. It provides a pattern forming method comprising a.

With such a pattern forming method, good mask dimensional dependence and dimensional uniformity can be achieved in photolithography.

In the pattern formation method of the present invention, the high energy ray may be an ArF excimer laser having a wavelength of 193 nm or a KrF excimer laser having a wavelength of 248 nm.

In addition, the exposure is performed by performing liquid immersion exposure with a liquid having a refractive index of 1.0 or higher between the resist film and the projection lens, or by forming an additional protective film on the resist film, and interposing the liquid between the protective film and the projection lens. It is also possible to form a pattern by performing liquid immersion exposure.

With such a pattern formation method, better mask dimensional dependence and dimensional uniformity can be achieved in photolithography.

Further, in the pattern formation method of the present invention, the high energy ray may be an electron beam or an extreme ultraviolet ray having a wavelength of 3 to 15 nm.

With such a pattern formation method, it is possible to form a pattern excellent in MEF and CDU with good sensitivity.

The resist composition of the present invention makes it possible to form a resist pattern having excellent mask dimension dependence (mask error factor: MEF) and LWR, in particular.

The present invention, in particular, in photolithography using high energy rays such as KrF excimer laser light, electron beam, and extreme ultraviolet rays as a light source, a resist composition showing good mask dimensional dependence (mask error factor: MEF) and dimensional uniformity (CDU) And a pattern forming method.

^{1 is a diagram showing a 1} HNMR spectrum of PAG1 obtained in Example 1-1.
Fig. 2 is ^{a diagram showing a 19} FNMR spectrum of PAG1 obtained in Example 1-1.
^{3 is a diagram showing a 1} HNMR spectrum of PAG2 obtained in Example 1-2.
^{4 is a diagram showing a 19} FNMR spectrum of PAG2 obtained in Example 1-2.

As described above, in progressing further miniaturization, the acid generators that have been studied in the past were not necessarily sufficient from the viewpoint of resolution and various performances including the shape of a resist pattern.

The inventors of the present invention have repeatedly studied intensively in order to achieve the above object. As a result, the resist composition using an acid generator represented by the following formula (B-1) has good mask dimensional dependence (mask error factor: MEF) and dimensional uniformity. It showed (CDU) and came to the knowledge that it is very effective for precise micro-machining.

That is, the present invention is a resin comprising (A) a repeating unit having an acid labile group and at least one repeating unit having an aromatic substituent, (B) a photoacid generator represented by the general formula (B-1). And (C) a solvent.

(In the formula, W ₁ represents a cyclic divalent hydrocarbon group containing a hetero atom having 4 to 12 carbon atoms. W ₂ represents a cyclic monovalent hydrocarbon group containing no hetero atom having 4 to 14 carbon atoms. Rf is the above-described Is a divalent organic group represented by a general formula, A ₁ , A ₂ each independently represent a hydrogen atom or a trifluoromethyl group, and B ₁ and B ₂ are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group And * represents the number of bonds with a carbonyloxy group, m represents an integer of 0 to 4, n represents an integer of 0 to 1. M ⁺ represents an onium cation.)

Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto. In addition, in the following chemical formulas, there are many cases in which enantiomers or diastereomers may exist in the chemical structure, but each chemical formula shall represent all of these stereoisomers in any case unless otherwise specified. . In addition, these stereoisomers may be used alone or as a mixture.

[Resist composition]

The resist composition of the present invention comprises (A) a repeating unit having an acid labile group, and a resin (base resin) containing at least one repeating unit having an aromatic substituent, (B) by general formula (B-1). It contains the indicated photoacid generator and (C) solvent. If necessary, other components such as a specific fluorine-containing resin different from the resin of the component (A) as the component (D), a quencher, and a surfactant may be further included. Hereinafter, each component is demonstrated.

[(A) Base resin]

In the resist composition of the present invention, the base resin (resin A) of the component (A) is a resin containing a repeating unit having an acid labile group and at least one repeating unit having an aromatic substituent.

The following general formula (A-1) is mentioned as a repeating unit which has an aromatic substituent in the base resin of (A) component.

(In the formula, R ^A represents a hydrogen atom or a methyl group. R ₆₁ represents a hydrogen atom or a straight-chain, branched or cyclic hydrocarbon group which may be interposed by a hetero atom having 1 to 10 carbon atoms. R ₆₂ is a hetero atom interposed therebetween. It represents a straight-chain, branched or cyclic hydrocarbon group having 1 to 8 carbon atoms, where t is an integer of 1 to 3, and u is an integer that satisfies u≤5+2s-t, and s is 0 or 1. L ₁ represents a single bond or -C(=O)O-, -C(=O)NH-.)

In the above formula, examples of the straight-chain, branched and cyclic hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms interposed therebetween, represented by _{R 61 include methyl, ethyl, propyl, and isopropyl groups.} , n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, cyclopentyl group, cyclohexyl group, 1-methyl-cyclopentyl group, 1-methyl-cyclohex Although practical techniques etc. are mentioned, it is not limited to these.

In the above formula, examples of the straight-chain, branched and cyclic hydrocarbon group having 1 to 8 carbon atoms, preferably 1 to 5 carbon atoms interposed therebetween, represented by _{R 62 include methyl, ethyl, propyl, and isopropyl groups.} In addition to, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group, cyclopentyl group, and cyclohexyl group, the following may be specifically exemplified, It is not limited to these.

Here, the broken line represents the number of bonds (the same applies hereinafter).

Although the following can be specifically illustrated as a repeating unit represented by the said general formula (A-1), it is not limited to these.

(In the formula, R ^A is the same as above)

(In the formula, R ^A is the same as above)

In the base resin of the component (A), as a repeating unit having an aromatic substituent, the following general formulas (A-2) to (A-4) can be mentioned.

(In the formula, R ^A is each independently a hydrogen atom or a methyl group, and R ²⁰¹ is a single bond, a phenylene group, -OR ²¹⁰ -or -C(=O)-Z ² -R ²¹⁰ -. Z ² is an oxygen atom. Or NH, R ²¹⁰ is a C 1 to C 6 linear, branched or cyclic alkylene group, alkenylene group or phenylene group, a carbonyl group (-CO-), an ester group (-COO-), an ether group (- O-) or may contain a hydroxy group L ₂ represents a single bond or -Z ³ -C(=O)-O-, and Z ³ represents a straight-chain, branched, optionally substituted hetero atom having 1 to 20 carbon atoms Represents a type or cyclic divalent hydrocarbon group Z ¹ is a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, -OR ²¹¹ -or -C(=O)-Z ⁴ -R ²¹¹ -. Z ⁴ is an oxygen atom or NH, and R ²¹¹ is a C 1 to C 6 linear, branched or cyclic alkylene group, alkenylene group or phenylene group, and may contain a carbonyl group, an ester group, an ether group or a hydroxy group. . M ^- shows the non-nucleophilic counter ion M ^-. Examples of hydroxyl ion, carboxylic acid ion, halogen ion, nitrate ion, nitrite ion, chlorate ion, bromate ion, methanesulfonate ion, p-toluene sulfonic acid ions, monomethyl sulfate Ions, carbonate ions, sulfate ions, etc. R ²⁰² , R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ , R ²⁰⁶ , R ²⁰⁷ , R ²⁰⁸ , R ²⁰⁹ may each independently be substituted with a hetero atom, and a hetero atom is interposed. It represents a straight-chain type having 1 to 20 carbon atoms, or a branched or cyclic monovalent hydrocarbon group having 3 to 20 carbon atoms, specifically methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, tert -Alkyl groups such as butyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, cyclopropylmethyl group, 4-methylcyclohexyl group, cyclohexylmethyl group, norbornyl group, and adamantyl group, vinyl group, allyl group, propenyl group , Butenyl group, hexenyl group, and Alkenyl groups such as chlorohexenyl group, aryl groups such as phenyl group, naphthyl group, thienyl group, and aralkyl groups such as benzyl group, 1-phenylethyl group, and 2-phenylethyl group, and the like, preferably an aryl group. In addition, some of the hydrogen atoms in these groups may be substituted with a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, or a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom may be interposed, as a result of which a hydroxy group , A cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride, a haloalkyl group, or the like may be formed or interposed therebetween. In addition, R ²⁰² and R ²⁰³ may be bonded to each other to form a ring together with a sulfur atom in the formula, or ^{any two or more of R 204} , R ²⁰⁵ and R ²⁰⁶ , or any two or more of R ²⁰⁷ , R ²⁰⁸ and R ²⁰⁹ May be bonded to each other to form a ring together with the sulfur atom in the formula. However, the repeating unit represented by the general formulas (A-2) to (A-4) has one or more aromatic substituents.)

In the above formula, when L ₂ is -Z ³ -C(=O)-O-, a straight chain, branched or cyclic divalent hydrocarbon group which may be substituted with a hetero atom having 1 to 20 carbon atoms represented by ^{Z 3} Although the following can be illustrated specifically as an example, it is not limited to these.

(In the formula, the broken line represents the number of bonds.)

In the above formula, R ²⁰² and R ²⁰³ may be bonded to each other to form a ring together with a sulfur atom in the formula, or any two or more of ^{R 204} , R ²⁰⁵ and R ^{206 , or any of R 207} , R ²⁰⁸ and R ²⁰⁹ Two or more may be bonded to each other to form a ring together with a sulfur atom in the formula, and in that case, a group represented by the following formula or the like may be mentioned.

(In the formula, R ²¹² represents the same as the group exemplified as R ²⁰¹ or R ²⁰² , R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ , R ²⁰⁶ , R ²⁰⁷ , R ²⁰⁸ and R ^{209 .)}

Specific structures of the sulfonium cation represented in the general formulas (A-3) to (A-4) include those shown below. However, the present invention is not limited to these.

The following general formula (a1) is mentioned as a repeating unit which has an acid labile group in the base resin of (A) component.

(In the formula, R ¹ is a hydrogen atom or a methyl group. X represents an acid labile group.)

The repeating unit represented by the said general formula (a1) decomposes by the action of an acid to generate a carboxylic acid, and gives a polymer which becomes alkali-soluble. As the acid labile group X, various types can be used, but specifically, a group represented by the following general formulas (L1) to (L9), a tertiary alkyl group having 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms, and each alkyl group A trialkylsilyl group having 1 to 6, an oxoalkyl group having 4 to 20 carbon atoms, and the like.

In formula (L1), R ^L01 and R ^L02 represent a hydrogen atom or a linear, branched or cyclic alkyl group having 1 to 18 carbon atoms, preferably 1 to 10, specifically methyl group, ethyl group, propyl group, iso Propyl group, n-butyl group, sec-butyl group, tert-butyl group, cyclopentyl group, cyclohexyl group, 2-ethylhexyl group, n-octyl group, norbornyl group, tricyclodecanyl group, tetracyclododeca A nil group, an adamantyl group, etc. can be illustrated. R ^L03 represents a monovalent hydrocarbon group which may have a hetero atom such as an oxygen atom having 1 to 18 carbon atoms, preferably 1 to 10, and a linear, branched or cyclic alkyl group, and some of these hydrogen atoms are hydroxyl or alkoxy. What is substituted with a group, an oxo group, an amino group, an alkylamino group, etc. are mentioned, Specifically, the following substituted alkyl group etc. can be illustrated.

R ^L01 and R ^L02 , R ^L01 and R ^L03 , R ^L02 and R ^L03 may be bonded to each other to form a ring with the carbon atom or oxygen atom to which they are bonded, and in the case of forming a ring, R ^L01 , R ^L02 , R ^L03 each represents a C 1 to C 18, preferably 1 to 10, linear or branched alkylene group.

In formula (L2), R ^L04 is a C4 to C20, preferably a 4 to 15 tertiary alkyl group, a trialkylsilyl group having 1 to 6 carbon atoms, each alkyl group having 1 to 6 carbon atoms, an oxoalkyl group having 4 to 20 carbon atoms, or the above general formula. The group represented by (L1) is represented, and as a tertiary alkyl group, specifically, tert-butyl group, tert-amyl group, 1,1-diethylpropyl group, 2-cyclopentylpropan-2-yl group, 2-cyclohexyl group Propan-2-yl group, 2-(bicyclo[2.2.1]heptan-2-yl)propan-2-yl group, 2-(adamantan-1-yl)propan-2-yl group, 1-ethylcyclophene Tyl group, 1-butylcyclopentyl group, 1-ethylcyclohexyl group, 1-butylcyclohexyl group, 1-ethyl-2-cyclopentenyl group, 1-ethyl-2-cyclohexenyl group, 2-methyl-2- An adamantyl group, a 2-ethyl-2-adamantyl group, etc. can be illustrated, and as a trialkylsilyl group, specifically, a trimethylsilyl group, a triethylsilyl group, a dimethyl-tert-butylsilyl group, etc. can be illustrated. In addition, specifically as an oxoalkyl group, a 3-oxocyclohexyl group, a 4-methyl-2-oxooxan-4-yl group, a 5-methyl-2-oxolan-5-yl group, etc. can be illustrated. l is an integer of 0-6.

In formula (L3), R ^L05 represents an optionally substituted linear, branched or cyclic alkyl group having 1 to 8 carbon atoms or an optionally substituted aryl group having 6 to 20 carbon atoms, and as an optionally substituted alkyl group, specifically Is a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, tert-amyl group, n-pentyl group, n-hexyl group, cyclopentyl group, cyclohexyl group, etc. Of straight-chain, branched or cyclic alkyl groups, and some of their hydrogen atoms are hydroxyl group, alkoxy group, carboxy group, alkoxycarbonyl group, oxo group, amino group, alkylamino group, cyano group, mercapto group, alkylthio group, sulfo group, etc. Substituted ones etc. can be illustrated, and as aryl group which may be substituted, specifically, a phenyl group, a methylphenyl group, a naphthyl group, an anthryl group, a phenanthryl group, a pyrenyl group, etc. can be illustrated. In formula (L3), m is 0 or 1, n is any one of 0, 1, 2, 3, and is a number satisfying 2m+n=2 or 3.

In formula (L4), R ^L06 represents an optionally substituted linear, branched or cyclic alkyl group having 1 to 8 carbon atoms, or an optionally substituted aryl group having 6 to 20 carbon atoms, specifically, the same as ^{R L05, etc.} Can be illustrated. R ^L07 to ^{R L16} each independently represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 15 carbon atoms, specifically methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl Group, tert-amyl group, n-pentyl group, n-hexyl group, n-octyl group, n-nonyl group, n-decyl group, cyclopentyl group, cyclohexyl group, cyclopentylmethyl group, cyclopentylethyl group, cyclopentyl Linear, branched or cyclic alkyl groups such as butyl group, cyclohexylmethyl group, cyclohexylethyl group, and cyclohexylbutyl group, and some of their hydrogen atoms are hydroxyl groups, alkoxy groups, carboxyl groups, alkoxycarbonyl groups, oxo groups, amino groups, alkyl Substituted with an amino group, a cyano group, a mercapto group, an alkylthio group, a sulfo group, etc. can be illustrated. R ^L07 ∼ ^{R L16} may be bonded to each other to form a ring (e.g., R ^L07 and R ^L08 , R ^L07 and R ^L09 , R ^L08 and R ^L10 , R ^L09 and R ^L10 , R ^L11 and R ^L12 , R ^L13 And R ^L14 and the like), in that case, a divalent hydrocarbon group having 1 to 15 carbon atoms is shown, and specifically, those exemplified in the monovalent hydrocarbon group above, excluding one hydrogen atom, and the like can be exemplified. In addition, R ^L07 to ^{R L16} may be bonded to adjacent carbons without passing through anything to form a double bond (e.g., R ^L07 and R ^L09 , R ^L09 and R ^L15 , R ^L13 and R ^L15, etc.) .

In formula (L5), R ^L17 , R ^L18 , and R ^L19 each independently represent a C1-C15 linear, branched or cyclic alkyl group. Specifically, methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, cyclopentyl group, cyclohexyl group, 2-ethylhexyl group, n-octyl group, 1- An adamantyl group, a 2-adamantyl group, etc. can be illustrated.

In formula (L6), R ^L20 represents an optionally substituted linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, or an optionally substituted aryl group having 6 to 20 carbon atoms, specifically, the same as ^{R L05, etc.} Can be illustrated.

In formula (L7), R ^L21 represents an optionally substituted linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, or an optionally substituted aryl group having 6 to 20 carbon atoms, and specifically, the same as ^{R L05.} Can be illustrated.

R ^L24 represents a divalent group forming a substituted or unsubstituted cyclopentane ring, a cyclohexane ring, or a norbornane ring together with the carbon atom to which it is bonded. R ^L22 and R ^L23 each independently represent a hydrogen atom or a C 1 to C 10 linear, branched or cyclic monovalent hydrocarbon group. R ^L22 and R ^L23 may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and in that case, represent a substituted or unsubstituted cyclopentane ring or a divalent group forming a cyclohexane ring. p represents 1 or 2.

In formula (L8), R ^L25 represents an optionally substituted linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, or an optionally substituted aryl group having 6 to 20 carbon atoms, specifically, the same as ^{R L05, etc.} Can be illustrated.

R ^L28 represents a divalent group forming a substituted or unsubstituted cyclopentane ring, a cyclohexane ring, or a norbornane ring together with the carbon atom to which it is bonded. R ^L26 and R ^L27 each independently represent a hydrogen atom or a linear, branched or cyclic monovalent hydrocarbon group having 1 to 10 carbon atoms. R ^L26 and R ^L27 may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and in that case, represent a substituted or unsubstituted cyclopentane ring or a divalent group forming a cyclohexane ring. q represents 1 or 2.

In formula (L9), R ^L29 represents an optionally substituted linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, or an optionally substituted aryl group having 6 to 20 carbon atoms, specifically, the same as ^{R L05, etc.} Can be illustrated.

R ^L32 represents a divalent group forming a substituted or unsubstituted cyclopentane ring, a cyclohexane ring, or a norbornane ring together with the carbon atom to which it is bonded. R ^L30 and R ^L31 each independently represent a hydrogen atom or a linear, branched or cyclic monovalent hydrocarbon group having 1 to 10 carbon atoms. R ^L30 and R ^L31 may be bonded to each other to form a ring together with the carbon atom to which they are bonded, and in that case, represent a substituted or unsubstituted cyclopentane ring or a divalent group forming a cyclohexane ring.

Among the acid labile groups represented by the above formula (L1), the following groups can be specifically exemplified as linear or branched ones.

Among the acid labile groups represented by the above formula (L1), as cyclic, specifically, tetrahydrofuran-2-yl group, 2-methyltetrahydrofuran-2-yl group, tetrahydropyran-2-yl group, and 2-methyltetra Hydropyran-2-yl group etc. can be illustrated.

As the acid labile group of the above formula (L2), specifically, tert-butoxycarbonyl group, tert-butoxycarbonylmethyl group, tert-amyloxycarbonyl group, tert-amyloxycarbonylmethyl group, 1,1-diethylpropyloxycarbonyl group , 1,1-diethylpropyloxycarbonylmethyl group, 1-ethylcyclopentyloxycarbonyl group, 1-ethylcyclopentyloxycarbonylmethyl group, 1-ethyl-2-cyclopentenyloxycarbonyl group, 1-ethyl-2-cyclo Pentenyloxycarbonylmethyl group, 1-ethoxyethoxycarbonylmethyl group, 2-tetrahydropyranyloxycarbonylmethyl group, 2-tetrahydrofuranyloxycarbonylmethyl group, etc. can be illustrated.

As the acid labile group of the above formula (L3), specifically, 1-methylcyclopentyl, 1-ethylcyclopentyl, 1-n-propylcyclopentyl, 1-isopropylcyclopentyl, 1-n-butylcyclopentyl, 1- sec-butylcyclopentyl, 1-tert-butylcyclopentyl, 1-cyclohexylcyclopentyl, 1-(4-methoxy-n-butyl)cyclopentyl, 1-methylcyclohexyl, 1-ethylcyclohexyl, 3 -Methyl-1-cyclopenten-3-yl, 3-ethyl-1-cyclopenten-3-yl, 3-methyl-1-cyclohexen-3-yl, 3-ethyl-1-cyclohexen-3-yl And the like can be illustrated.

As the acid labile group of the formula (L4), groups represented by the following formulas (L4-1) to (L4-4) are particularly preferred.

In the general formulas (L4-1) to (L4-4), a broken line indicates a bonding position and a bonding direction. R ^L41 each independently represents a monovalent hydrocarbon group such as a straight-chain, branched or cyclic alkyl group having 1 to 10 carbon atoms, specifically methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl Group, tert-butyl group, tert-amyl group, n-pentyl group, n-hexyl group, cyclopentyl group, cyclohexyl group, etc. can be illustrated.

In the general formulas (L4-1) to (L4-4), enantiomers or diastereomers may exist, and the general formulas (L4-1) to (L4-4) are It represents all of the isomers. These stereoisomers may be used alone or as a mixture.

For example, the general formula (L4-3) is assumed to represent one or a mixture of two selected from groups represented by the following general formulas (L4-3-1) and (L4-3-2). .

In addition, the above general formula (L4-4) is represented by representing one type or a mixture of two or more selected from groups represented by the following general formulas (L4-4-1) to (L4-4-4).

The general formulas (L4-1) to (L4-4), (L4-3-1), (L4-3-2) and (L4-4-1) to (L4-4-4) are Enantiomers and enantiomeric mixtures are also represented as a representative.

In addition, the bonding directions of (L4-1) to (L4-4), (L4-3-1), (L4-3-2) and (L4-4-1) to (L4-4-4) are respectively By being on the exo side with respect to the bicyclo[2.2.1]heptane ring, high reactivity in the acid-catalyzed desorption reaction is realized (refer to Japanese Patent Laid-Open No. 2000-336121). In the production of a monomer having a tertiary exo-alkyl group having a bicyclo[2.2.1]heptane skeleton as a substituent, endo- represented by the following general formulas (L4-1-endo) to (L4-4-endo) In some cases, a monomer substituted with an alkyl group is included, but in order to realize good reactivity, an exo ratio of 50% or more is preferable, and an exo ratio of 80% or more is more preferable.

(Refer to Japanese Patent Laid-Open No. 2000-336121)

As the acid labile group of the above formula (L4), the following groups can be specifically exemplified.

In addition, examples of the tertiary alkyl group having 4 to 20 carbon atoms, the trialkylsilyl group having 1 to 6 carbon atoms, and the oxoalkyl group having 4 to 20 carbon atoms, respectively, can be exemplified specifically as those exemplified ^{in R L04.} have.

Specific examples of the acid labile group of the formula (L5) include tert-butyl group, tert-amyl group, and the following groups.

As the acid labile group of the above formula (L6), the following groups can be specifically exemplified.

As the acid labile group of the above formula (L7), the following groups can be specifically exemplified.

Specific examples of the acid labile group of the formula (L8) include the following groups.

As the acid labile group of the above formula (L9), the following groups can be specifically exemplified.

Although the following can be specifically illustrated as a monomer represented by the said general formula (a1), it is not limited to these.

(In the formula, R ¹ represents a hydrogen atom or a methyl group)

(In the formula, R ¹ represents a hydrogen atom or a methyl group)

(In the formula, R ¹ represents a hydrogen atom or a methyl group)

(In the formula, R ¹ represents a hydrogen atom or a methyl group)

In addition, in the base resin of the component (A), in addition to the unit represented by the general formula (a1), it is preferable to use a monomer represented by the following general formulas (a2) to (a4) as necessary.

(In the formula, R ¹ is the same as above. R ⁵ and R ⁶ each independently represent a hydrogen atom or a hydroxyl group. Y represents a substituent having a lactone structure or a substituent having a sultone structure. Z is a hydrogen atom or a number of carbon atoms. It represents a fluorinated hydrocarbon group of 1 to 15 or a fluoroalcohol-containing substituent having 1 to 15 carbon atoms.)

Although the following can be specifically illustrated as a unit represented by the said general formula (a2), it is not limited to these.

Although the following can be illustrated specifically as a monomer represented by the said general formula (a3), it is not limited to these.

(In the formula, R ¹ represents a hydrogen atom or a methyl group)

(In the formula, R ¹ represents a hydrogen atom or a methyl group)

(In the formula, R ¹ represents a hydrogen atom or a methyl group)

(In the formula, R ¹ represents a hydrogen atom or a methyl group)

Although the following can be specifically illustrated as a repeating unit represented by the said general formula (a4), it is not limited to these.

In the resist composition of the present invention, monomers containing carbon-carbon double bonds other than those described above, such as substituted acrylic acid esters such as methyl methacrylate, methyl crotonate, dimethyl maleate and dimethyl itaconic acid, maleic acid, fumaric acid. , Unsaturated carboxylic acids such as itaconic acid, norbornene, norbornene derivatives, ^{cyclic olefins such as tetracyclo[4.4.0.1 2,5} .17 ^7,10 ]dodecene derivatives, and unsaturated acids such as itaconic anhydride. Anhydrides, α-methylene-γ-butyrolactones, α-methylstyrene, and other monomers may be used.

The weight average molecular weight (Mw) of the resin A (the base resin of the component (A)) is preferably 1,000 to 500,000, more preferably 3,000 to 100,000. Within the above range, there is no fear that the etching resistance is lowered or the contrast before and after exposure cannot be ensured, and the resolution is lowered. In addition, in the present invention, Mw is a measured value in terms of polystyrene by gel permeation chromatography (GPC) using tetrahydrofuran (THF) or dimethylacetamide (DMF) as a solvent.

Further, in the case of Resin A, when the molecular weight distribution (Mw/Mn) is wide, since a polymer having a low molecular weight or a high molecular weight exists, there is a concern that a foreign material may be seen on the pattern or the shape of the pattern may deteriorate after exposure. Therefore, as the pattern rule becomes finer, the influence of such molecular weight or molecular weight distribution tends to increase. In order to obtain a resist composition suitable for fine pattern dimensions, the molecular weight distribution of Resin A is 1.0 to 2.0, especially 1.0 to 1.5. It is preferably narrowly dispersed.

As a method of synthesizing resin A, for example, a repeating unit represented by formula (a1) and, if necessary, a monomer having an unsaturated bond for obtaining a repeating unit represented by formulas (a2) to (a4) or other repeating units, is organic Among the solvents, a method of performing heat polymerization by adding a radical initiator is exemplified. Examples of the organic solvent used during polymerization include toluene, benzene, THF, diethyl ether, dioxane, methyl ethyl ketone, γ-butyrolactone, propylene glycol monomethyl ether acetate (PGMEA), and the like. As a polymerization initiator, 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2-azobis (2-methylpropio Acid), benzoyl peroxide, lauroyl peroxide, and the like. The reaction temperature is preferably 50 to 150°C, more preferably 60 to 100°C. The reaction time is preferably 2 to 24 hours. The acid labile group may be used as it is, or may be protected or partially protected after polymerization. Further, in order to adjust the molecular weight, polymerization may be performed using a known chain transfer agent such as dodecyl mercaptan or 2-mercaptoethanol. In this case, the amount of the chain transfer agent added is preferably 0.01 to 10 in molar ratio with respect to all monomers to be polymerized.

In Resin A, the preferable content ratio of each repeating unit obtained from each monomer can be, for example, in the range shown below, but is not limited thereto.

(I) The repeating unit represented by the formula (a1) is preferably 1 to 99 mol%, more preferably 20 to 95 mol%, more preferably 30 to 90 mol%, if necessary,

(II) The repeating unit represented by the formula (A-1) is preferably 1 to 70 mol%, more preferably 5 to 60 mol%, more preferably 10 to 60 mol%,

(III) At least one selected from the repeating units represented by formulas (A-2) to (A-4) is preferably 1 to 40 mol%, more preferably 3 to 35 mol%, more preferably Contains 5 to 30 mol%,

(IV) At least one selected from the repeating units represented by formulas (a2) to (a4) is preferably 0 to 99 mol%, more preferably 0 to 90 mol%, further preferably 0 to 70 Including mole%,

(V) Other repeating units are preferably 0 to 99 mol%, more preferably 0 to 70 mol%, and still more preferably 0 to 50 mol%.

In addition, the base resin of the component (A) may contain two or more resins having different composition ratios, molecular weights, or molecular weight distributions, and if necessary, in addition to the resin having a repeating unit having an acid labile group, formula (a1) A resin that does not contain a repeating unit represented by may be included.

[(B) Photoacid generator]

The resist composition of the present invention contains a photoacid generator represented by the following formula (B-1) as the component (B).

(In the formula, W ₁ represents a cyclic divalent hydrocarbon group containing a hetero atom having 4 to 12 carbon atoms. W ₂ represents a cyclic monovalent hydrocarbon group containing no hetero atom having 4 to 14 carbon atoms. Rf is the above-described Is a divalent organic group represented by a general formula, A ₁ , A ₂ each independently represent a hydrogen atom or a trifluoromethyl group, and B ₁ and B ₂ are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group And * represents the number of bonds with a carbonyloxy group, m represents an integer of 0 to 4, n represents an integer of 0 to 1. M ⁺ represents an onium cation.)

As a cyclic divalent hydrocarbon group containing a C4-C12 hetero atom represented by _{W 1, the following can be specifically illustrated.}

(* represents the number of bonds with an oxycarbonyl group.)

Particularly preferred as W ₁ is a cyclic divalent hydrocarbon group containing a lactone ring structure, and particularly preferably a cyclic divalent hydrocarbon group containing a lactone ring structure having 6 to 12 carbon atoms. When the acid is generated after exposure, by disposing the lactone ring at a position close to the sulfonic acid group, acid diffusion can be further suppressed.

The following can be specifically illustrated as a cyclic monovalent hydrocarbon group which does not contain a C4-C14 hetero atom represented by _{W 2.}

(The broken line indicates the number of bonds.)

It is preferable that W ₂ is a polycyclic monovalent hydrocarbon group which does not contain a C7-14 hetero atom. An adamantyl group is mentioned as an especially preferable thing as _{W 2.} By arranging a highly condensed hydrocarbon group at the terminal, it becomes possible to impart an appropriate solubility.

Rf is a divalent organic group represented by the above general formula. Here, A ₁ and A ₂ each independently represent a hydrogen atom or a trifluoromethyl group, B ₁ and B ₂ each independently represent a hydrogen atom, a fluorine atom or a trifluoromethyl group, and * represents a carbonyloxy group Represents the number of bonds. m represents the integer of 0-4, and n represents the integer of 0-1. It is preferable that m+n>0.

In particular, it is preferable that the Rf group is selected from groups represented by the following formulas (Rf-1) to (Rf-6).

(* represents the number of bonds with a carbonyloxy group.)

If the photoacid generator represented by formula (B-1) has such Rf, the solubility is improved by the effect of the fluorine atom, and the sulfonic acid generated after exposure becomes an appropriate acid strength, which is preferable.

Specific examples of the structure of the anion moiety of the photoacid generator represented by formula (B-1) are shown below, but are not limited thereto.

In formula (B-1), ^{as the onium cation represented by M +} , it is preferably at least one type selected from cations represented by the following formulas (b1) and (b2).

In formulas (b1) and (b2), R ⁴¹ to ^{R 45} each independently represent a straight-chain, branched or cyclic monovalent hydrocarbon group having 1 to 20 carbon atoms, which may each independently contain a hetero atom. Further, ^{any two of R 41} , R ⁴² and R ⁴³ may be bonded to each other to form a ring together with the sulfur atom in the formula.

Examples of the monovalent hydrocarbon group represented by R ^{41 to R 45} include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, tert-butyl group, cyclopropyl group, cyclopentyl group, cyclohexyl group, and cyclo Alkyl groups such as propylmethyl group, 4-methylcyclohexyl group, cyclohexylmethyl group, norbornyl group, and adamantyl group; Alkenyl groups such as vinyl group, allyl group, propenyl group, butenyl group, hexenyl group, and cyclohexenyl group; Aryl groups such as phenyl group, naphthyl group, and thienyl group; Aralkyl groups, such as a benzyl group, a 1-phenylethyl group, and a 2-phenylethyl group, etc. are mentioned. Among these, an aryl group is preferable. In addition, some of the hydrogen atoms of the monovalent hydrocarbon group may be substituted with a heteroatom-containing group such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and a part of the carbon atoms of these groups is an oxygen atom, a sulfur atom, or nitrogen. It may be substituted with a hetero atom-containing group such as an atom, and as a result, a hydroxy group, a cyano group, a carbonyl group, an ether group, an ester group, a sulfonic acid ester group, a carbonate group, a lactone ring, a sultone ring, a carboxylic anhydride, a haloalkyl group, etc. You may include it.

Examples of the sulfonium cation represented by the formula (b1) include those shown below, but are not limited thereto.

Examples of the iodonium cation represented by the formula (b2) include those shown below, but are not limited thereto.

Further, the resist composition of the present invention may further contain a photoacid generator other than the photoacid generator described above in order to fine-tune the lithography performance. As the other photoacid generator, any compound that generates an acid by irradiation with high-energy rays may be used, and known ones used in conventional resist compositions, particularly chemically amplified resist compositions, may be used. Other suitable photoacid generators include sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, oxime-O-sulfonate type acid generators, etc. It can be mixed and used. As the acid generated from other photoacid generators, a strong acid such as sulfonic acid, (bisperfluoroalkanesulfonyl)imide, (trisperfluoromethanesulfonyl)methide, or a weak acid such as carboxylic acid is preferable.

Specific examples of other photoacid generators include the following formulas (B-2), (B-3), and (B-4).

In formula (B-2), A ¹ is a hydrogen atom or a trifluoromethyl group. R ²¹ is a linear, branched or cyclic monovalent hydrocarbon group having 1 to 35 carbon atoms, which may contain an oxygen atom, or a nitrogen-containing heterocyclic group, or a group represented by the following formula (i). M ⁺ is an onium cation.

In formula (i), R ³¹ and R ³² are each independently a hydrogen atom or a straight-chain, branched or cyclic monovalent hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. R ³¹ and R ³² may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded. R ³³ is a straight-chain, branched or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom.

Examples ^{of the monovalent hydrocarbon group which may contain an oxygen atom represented by R 21} include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, Heptyl group, octyl group, cyclopentyl group, cyclohexyl group, cycloheptyl group, cyclopropylmethyl group, 4-methylcyclohexyl group, cyclohexylmethyl group, norbornyl group, 1-adamantyl group, 1-adamantylmethyl group, etc. An alkyl group of; Steroid structure-containing groups; 2-oxocyclopentyl group, 2-oxocyclohexyl group, 4-oxocyclohexyl group, 2-oxopropyl group, 2-oxoethyl group, 2-cyclopentyl-2-oxoethyl group, 2-cyclohexyl-2-oxo Ethyl group, 2-(4-methylcyclohexyl)-2-oxoethyl group, 4-oxa-tricyclo[4.2.1.0 ^3,7 ]nonan-5-one-9-yl group, 4-oxo-1-adamantyl group Oxoalkyl groups such as; Phenyl group, 1-naphthyl group, 2-naphthyl group, anthranyl group, thienyl group, 4-hydroxyphenyl group, 4-methoxyphenyl group, 3-methoxyphenyl group, 2-methoxyphenyl group, 4-ethoxyphenyl group, 4- Alkoxyphenyl groups such as tert-butoxyphenyl group and 3-tert-butoxyphenyl group, 2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-n-butyl Alkylphenyl group such as phenyl group and 2,4-dimethylphenyl group, alkylnaphthyl group such as methylnaphthyl group and ethylnaphthyl group, alkoxynaphthyl group such as methoxynaphthyl group and ethoxynaphthyl group, dimethylnaphthyl group, diethylnaphthyl group, etc. Aryl groups such as a dialkylnaphthyl group such as a dialkylnaphthyl group, a dimethoxynaphthyl group, and a diethoxynaphthyl group. Aralkyl groups such as benzyl group, 1-phenylethyl group, and 2-phenylethyl group; Aryl oxo, such as 2-aryl-2-oxoethyl group, such as 2-phenyl-2-oxoethyl group, 2-(1-naphthyl)-2-oxoethyl group, and 2-(2-naphthyl)-2-oxoethyl group Alkyl group etc. are mentioned. In addition, a vinyl group, an isopropenyl group, etc. are mentioned.

As the ^{nitrogen-containing heterocyclic group represented by R 21} , aziridine, pyrrolidine, piperidine, morpholine, pyrrole, pyridine, azetin, oxazole, isoxazole, thiazole, isothiazole, imidazole, pyrazole Sol, pyridazine, pyrimidine, pyrazine, pyrroline, 2-imidazoline, imidazolidine, 3-pyrazoline, pyrazolidine, piperazine, triazine, oxadiazine, dithiazine, indole, isoindole , Quinoline, isoquinoline, cinnoline, phthalazine, quinazoline, quinoxaline, 1,8-naphthyridine, purine, pteridine, indolizine, carbazole, acridine, phenazine, phenanthridine, 1 , 10-phenanthroline, phenoxazine, indoline, isoindole, quinuclidine, benzo[e]indole, benzo[cd]indole, and the like.

Particularly preferable examples of R ²¹ include tert-butyl group, cyclohexyl group, 1-adamantyl group, 1-adamantylmethyl group, and 4-oxa-tricyclo[4.2.1.0 ^3,7 ]nonan-5-one- 9-yl group, 4-oxo-1-adamantyl group, steroid structure containing alkyl group, etc. are mentioned.

In formula (i) ^{, examples of the monovalent hydrocarbon group represented by R 31} and R ³² include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group, and hexyl group. Alkyl groups, such as a sil group, a heptyl group, an octyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopropylmethyl group, a 4-methylcyclohexyl group, a cyclohexylmethyl group, a norbornyl group, and an adamantyl group; Alkenyl groups such as vinyl group, allyl group, propenyl group, butenyl group, hexenyl group, and cyclohexenyl group; Aryl groups, such as a phenyl group, a naphthyl group, and thienyl group, and an aralkyl group, such as a benzyl group, 1-phenylethyl group, and 2-phenylethyl group, are mentioned. Further, in the hydrocarbon group, a part of the hydrogen atom may be substituted with the monovalent hydrocarbon group or a heteroatom-containing group such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, or a part of the carbon atoms of these groups May be substituted with a group containing a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, a hydroxy group, a cyano group, a carbonyl group, an ether group, an ester group, a sulfonic acid ester group, a carbonate group, a lactone ring, a sultone ring, a car It may contain an acid anhydride, a haloalkyl group, etc.

When R ³¹ and R ³² are bonded to each other to form a ring together with the nitrogen atom to which they are bonded, specific ring types include aziridine, pyrrolidine, piperidine, morpholine, pyrrole, pyridine, azetin, oxazole , Isoxazole, thiazole, isothiazole, imidazole, pyrazole, pyridazine, pyrimidine, pyrazine, pyrroline, 2-imidazoline, imidazolidine, 3-pyrazoline, pyrazolidine, pipette Razine, triazine, oxadiazine, dithiazine, indole, isoindole, quinoline, isoquinoline, cinnoline, phthalazine, quinazoline, quinoxaline, 1,8-naphthyridine, purine, pteridine, indolizine , Carbazole, acridine, phenazine, phenanthridine, 1,10-phenanthroline, phenoxazine, indoline, isoindole, quinuclidine, benzo[e]indole, benzo[cd]indole, etc. Can be lifted. In addition, some of the hydrogen atoms of these rings may be substituted with the above hydrocarbon group or a heteroatom-containing group such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, or a part of the carbon atoms of these rings is an oxygen atom or sulfur. It may be substituted with a hetero atom-containing group such as an atom or a nitrogen atom, and as a result, a hydroxy group, a cyano group, a carbonyl group, an ether group, an ester group, a sulfonic acid ester group, a carbonate group, a lactone ring, a sultone ring, a carboxylic anhydride, a halo It may contain an alkyl group or the like.

In formula (i), ^{as the divalent hydrocarbon group represented by R 33} , a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, Hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1, 11-diyl group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1, Straight-chain alkanediyl groups such as 16-diyl group and heptadecane-1,17-diyl group; A branched alkanediyl group in which side chains such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a sec-butyl group, and a tert-butyl group are added to the linear alkanediyl group; Saturated cyclic hydrocarbon groups such as cyclopentanediyl group, cyclohexanediyl group, norbornanediyl group, and adamantanediyl group; Unsaturated cyclic divalent hydrocarbon groups, such as a phenylene group and a naphthylene group, are mentioned. In addition, some of the hydrogen atoms of these groups may be substituted with a heteroatom-containing group such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, or a part of the carbon atoms of these groups is an oxygen atom, a sulfur atom, a nitrogen atom, etc. The hetero atom-containing group of may be interposed, and as a result, a hydroxy group, a cyano group, a carbonyl group, an ether group, an ester group, a sulfonic acid ester group, a carbonate group, a lactone ring, a sultone ring, a carboxylic anhydride, a haloalkyl group, etc. are included. You may have it.

Specific examples of the structure of the anion moiety of the photoacid generator represented by formula (B-2) are shown below, but are not limited thereto. In addition, in the following formula, A ¹ is the same as above.

In the formula (B-2), ^{the onium cation represented by M +} is preferably at least one selected from cations represented by the above formulas (b1) and (b2).

In formula (B-3), A ² is a hydrogen atom or a trifluoromethyl group. R ²² , R ²³ and R ²⁴ are each independently a hydrogen atom or a linear, branched or cyclic monovalent hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. p and q are each independently an integer of 0-5. r is an integer of 0-4. L is a single bond, an ether group, or a straight-chain, branched or cyclic divalent hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom.

Examples ^{of the monovalent hydrocarbon group represented by R 22} , R ²³ and R ²⁴ include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, tert-pentyl group, n- Pentyl group, n-hexyl group, n-octyl group, n-nonyl group, n-decyl group, cyclopentyl group, cyclohexyl group, 2-ethylhexyl group, cyclopentylmethyl group, cyclopentylethyl group, cyclopentylbutyl group, Alkyl groups, such as a cyclohexylmethyl group, a cyclohexylethyl group, a cyclohexylbutyl group, a norbornyl group, an oxanobornyl group, a tricyclo[5.2.1.0 ^2,6 ]decanyl group, and an adamantyl group, are mentioned. In addition, some of the hydrogen atoms of these groups may be substituted with a heteroatom-containing group such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, or a part of the carbon atoms of these groups is an oxygen atom, a sulfur atom, a nitrogen atom, etc. May be substituted with a hetero atom-containing group of, as a result, a hydroxy group, a cyano group, a carbonyl group, an ether group, an ester group, a sulfonic acid ester group, a carbonate group, a lactone ring, a sultone ring, a carboxylic anhydride, a haloalkyl group, etc. You may have it. R ²² , R ²³ and R ²⁴ are preferably a methyl group, a methoxy group, a tert-butyl group, a tert-butoxy group and the like.

In formula (B-3), ^{examples of the divalent hydrocarbon group represented by L include those exemplified as R 33} , and a combination of two or more of these groups may be used. In addition, some of the hydrogen atoms of these groups may be substituted with a heteroatom-containing group such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, or a part of the carbon atoms of these groups is an oxygen atom, a sulfur atom, a nitrogen atom, etc. May be substituted with a hetero atom-containing group of, as a result, a hydroxy group, a cyano group, a carbonyl group, an ether group, an ester group, a sulfonic acid ester group, a carbonate group, a lactone ring, a sultone ring, a carboxylic anhydride, a haloalkyl group, etc. You may have it.

Examples of the photoacid generator represented by formula (B-3) include those shown below, but are not limited thereto. In addition, in the following formula, A ² is the same as above.

(B) The photoacid generator may further contain a compound represented by the above formula (B-4). In formula (B-4), A ³ and A ⁴ each independently represent a hydrogen atom or a trifluoromethyl group, and do not simultaneously become a hydrogen atom. R ²⁵ is a linear, branched or cyclic monovalent hydrocarbon group having 1 to 35 carbon atoms, which may contain an oxygen atom, or a nitrogen-containing heterocyclic group, or a group represented by the above formula (i). M ⁺ is the same as the onium cation.

Specific examples of the structure of the anion moiety of the photoacid generator represented by formula (B-4) are shown below, but are not limited thereto.

Among the above-described other photoacid generators, a compound having a fluorine atom-containing structure including a trifluoromethyl group in the anionic structure portion has high hydrophobicity and is less eluted into liquid immersion water. Moreover, since it has a fluorine atom-containing structure, solvent solubility is high, and it becomes possible to reduce the residue after development in organic solvent development. Thereby, defects after development can be reduced, and it is suitable as a resist composition for ArF immersion exposure.

As specific examples other than the above-described photoacid generator, the compounds described in paragraphs [0122] to [0142] of JP 2008-111103 A can be cited, and particularly preferred ones are paragraphs of JP 2014-001259 A [ The compounds described in 0088] to [0092], the compounds described in paragraphs [0015] to [0017] of JP 2012-41320 A, and the compounds described in paragraphs [0015] to [0029] of JP 2012-106986 A Compounds, etc. are mentioned. The photoacid generator of the partially fluorinated sulfonic acid-generating type described in the above publication can be preferably used because the strength and diffusion length of the generated acid are appropriate, particularly in ArF lithography.

The content of the photoacid generator in the component (B) is preferably 0.1 to 50 parts by mass, more preferably 0.2 to 40 parts by mass, and still more preferably 0.3 to 35 parts by mass with respect to 100 parts by mass of the base resin of the component (A). Within the above range, the resolution does not deteriorate, and there is no fear of a problem of foreign matter occurring after development of the resist film or at the time of peeling. In addition, the content in the case of adding the compound represented by the formula (B-4) is preferably 0 to 50% by mass in the photoacid generator of the component (B).

[(C) Solvent]

The resist composition of the present invention contains a solvent as component (C). Examples of the solvent include ketones such as cyclohexanone and methyl-2-n-pentyl ketone described in paragraphs [0144] to [0145] of JP 2008-111103 A, 3-methoxybutanol, and 3-methyl- Alcohols such as 3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl Ethers such as ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, PGMEA, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, acetic acid esters such as tert-butyl, tert-butyl propionate, propylene glycol monotert-butyl ether acetate, lactones such as γ-butyrolactone, keto alcohols such as diacetone alcohol, and mixed solvents thereof. In the case of using an acetal acid labile group, an alcohol-based solvent with a high boiling point, specifically diethylene glycol, propylene glycol, glycerin, 1,4-butanediol, 1,3-butanediol, etc., to accelerate the deprotection reaction of the acetal. You can also add

The content of the solvent of the component (C) is preferably 100 to 10,000 parts by mass, more preferably 300 to 8,000 parts by mass, based on 100 parts by mass of the base resin of the component (A).

[(D) Fluorine-containing resin]

The resist composition of the present invention is a resin different from the resin A and contains fluorine containing at least one selected from repeating units represented by the following formulas (D-1), (D-2) and (D-3). Resin may be included.

In the formula, R ^A is a hydrogen atom or a methyl group. R ₅₁ and R ₅₂ are each independently a hydrogen atom or a linear, branched or cyclic monovalent hydrocarbon group having 1 to 10 carbon atoms. R ₅₃ is a single bond or a linear or branched divalent hydrocarbon group having 1 to 5 carbon atoms. R ₅₄ , R ₅₅ and R ₅₆ are each independently a hydrogen atom or a linear, branched or cyclic C 1 to C 15 monovalent hydrocarbon group, a fluorinated monovalent hydrocarbon group or an acyl group, or an acid labile group. When R ₅₄ , R ₅₅ and R ₅₆ are a monovalent hydrocarbon group or a fluorinated monovalent hydrocarbon group, some of these carbon atoms may be substituted with an ether group or a carbonyl group. R ₅₇ is a straight-chain, branched or cyclic C1-C20 (v+1) valent hydrocarbon group or a fluorinated hydrocarbon group. v is an integer of 1 to 3.

Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms represented by R ₅₁ and R ₅₂ include methyl group, ethyl group, n-propyl group, isopropyl group, cyclopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, cyclobutyl group, n-pentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, n-octyl group, n-nonyl group, n-decyl group, adamantyl group And alkyl groups such as norbornyl group. Among these, a linear, branched or cyclic monovalent hydrocarbon group having 1 to 6 carbon atoms is preferable.

Specific examples of the divalent hydrocarbon group having 1 to 5 carbon atoms represented by R ₅₃ include a methylene group, an ethylene group, a trimethylene group, a propylene group, a tetramethylene group, and a pentamethylene group.

Examples of the monovalent hydrocarbon group having 1 to 15 carbon atoms represented by R ₅₄ , R ₅₅ and R ₅₆ include an alkyl group, an alkenyl group, an alkynyl group, and the like, but an alkyl group is preferable. Examples of the alkyl group include n-undecyl group, n-dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, and the like in addition to those described above. Examples of the fluorinated monovalent hydrocarbon group having 1 to 15 carbon atoms include groups in which some or all of the hydrogen atoms bonded to the carbon atoms of the monovalent hydrocarbon group described above are substituted with fluorine atoms. As described above, some of these carbon atoms may be substituted with an ether group or a carbonyl group.

When R ₅₄ , R ₅₅ and R ₅₆ are acid labile groups, specific examples thereof include groups represented by the above formulas (L1) to (L9), tertiary alkyl groups having 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms, and each alkyl group. A trialkylsilyl group, each of which is an alkyl group having 1 to 6 carbon atoms, and an oxoalkyl group having 4 to 20 carbon atoms, respectively.

Examples of the (v+1) valent hydrocarbon group or fluorinated hydrocarbon group having 1 to 20 carbon atoms represented by R _{57 include groups excluding the necessary number of hydrogen atoms from the monovalent hydrocarbon group or fluorinated monovalent hydrocarbon group described above.}

Examples of the repeating unit represented by the formula (D-1) include those shown below, but are not limited thereto. In addition, in the following formula, R ^A is the same as above.

Although the thing shown below is mentioned as a repeating unit represented by Formula (D-2), it is not limited to these. In addition, in the following formula, R ^A is the same as above.

Although the thing shown below is mentioned as a repeating unit represented by Formula (D-3), it is not limited to these. In addition, in the following formula, R ^A is the same as above.

The Mw of the fluorine-containing resin of the component (D) is preferably 1,000 to 100,000, more preferably 3,000 to 15,000. 1.0-2.0 are preferable and, as for Mw/Mn, 1.0-1.6 are more preferable.

In order to synthesize the fluorine-containing resin of the component (D), as one method, a repeating unit represented by formulas (D-1) to (D-3), and, if necessary, having an unsaturated bond to obtain other repeating units. A method of performing heat polymerization by adding a radical initiator to a monomer in an organic solvent is mentioned. Examples of the organic solvent used during polymerization include toluene, benzene, THF, diethyl ether, dioxane, methyl ethyl ketone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and the like. As the polymerization initiator, AIBN, 2,2'-azobis (2,4-dimethylvaleronitrile), dimethyl 2,2-azobis (2-methylpropionate), benzoyl peroxide, lauroyl peroxide, etc. Can be lifted. The reaction temperature is preferably 50 to 100°C. The reaction time is preferably 4 to 24 hours. The acid labile group may be used as it is introduced into the monomer, or may be protected or partially protected after polymerization. Further, in order to adjust the molecular weight, polymerization may be performed using a known chain transfer agent such as dodecyl mercaptan or 2-mercaptoethanol. In this case, the amount of the chain transfer agent added is preferably 0.01 to 10 in molar ratio with respect to all monomers to be polymerized.

When the resist composition of the present invention contains the fluorine-containing resin of the component (D), the content is preferably 0.1 to 50 parts by mass, more preferably 0.5 to 10 parts by mass based on 100 parts by mass of the base resin of the component (A). Do. When the content is in the above range, the contact angle between the surface of the resist film and water is sufficiently improved, and defects due to residual liquid immersion and elution of an acid generator or a quencher can be suppressed. Moreover, it becomes possible to adjust the solubility of the surface of the resist film, and good dimensional uniformity can be achieved.

[Other ingredients]

The resist composition of the present invention may contain an amine compound, a sulfonic acid salt, or a carboxylate salt as a quencher, if necessary. In the present specification, a quencher refers to a compound capable of suppressing the diffusion rate when an acid generated from the photoacid generator diffuses into the resist film.

Among these quenchers, the amine compounds include primary, secondary, or tertiary amine compounds described in paragraphs [0146] to [0164] of JP 2008-111103 A, particularly hydroxy groups, ether groups, ester groups, lactone rings, and cyanides. An amine compound having either a no group or a sulfonic acid ester group may be mentioned as a preferable example. Moreover, like the compound described in Japanese Patent No. 3790649, a compound in which a primary or secondary amine is protected as a carbamate group is also exemplified. Such a protected amine compound is effective when there is a component that is unstable with respect to a base in the resist composition.

Examples of the sulfonate include compounds represented by the following formula (Z1). Moreover, as said carboxylate, the compound represented by following formula (Z2) is mentioned.

R ¹⁰¹ is a hydrogen atom or a hydrocarbyl group having 1 to 40 carbon atoms which may contain a hetero atom, except that the hydrogen atom bonded to the carbon atom at the α-position of the sulfo group is substituted with a fluorine atom or a fluoroalkyl group. . Each M ⁺ is independently an onium cation, and the same ones as exemplified above are exemplified.

The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, tert-pentyl group, n-pentyl group, n-hexyl group, n-octyl group, 2 -Alkyl groups such as ethylhexyl group, n-nonyl group, and n-decyl group; Cyclopentyl group, cyclohexyl group, cyclopentylmethyl group, cyclopentylethyl group, cyclopentylbutyl group, cyclohexylmethyl group, cyclohexylethyl group, cyclohexylbutyl group, norbornyl group, tricyclo[5.2.1.0 ^2,6 ]decanyl group , Cyclic saturated hydrocarbyl groups such as an adamantyl group and an adamantylmethyl group; Examples of the alkenyl group include alkenyl groups such as vinyl group, allyl group, propenyl group, butenyl group and hexenyl group; Unsaturated aliphatic cyclic hydrocarbyl groups such as cyclohexenyl groups; Phenyl group, naphthyl group, alkylphenyl group (2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-n-butylphenyl group, etc.), dialkylphenyl group (2, Aryl such as 4-dimethylphenyl group, 2,4,6-triisopropylphenyl group, etc.), alkylnaphthyl group (methylnaphthyl group, ethylnaphthyl group, etc.), dialkylnaphthyl group (dimethylnaphthyl group, diethylnaphthyl group, etc.) group; Heteroaryl groups such as thienyl groups; Aralkyl groups, such as a benzyl group, a 1-phenylethyl group, and a 2-phenylethyl group, etc. are mentioned.

In addition, some of the hydrogen atoms of these groups may be substituted with a heteroatom-containing group such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and a part of the carbon atoms of these groups is an oxygen atom, a sulfur atom, a nitrogen atom, etc. It may be substituted with a hetero atom-containing group, and as a result, even if it contains a hydroxy group, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride, a haloalkyl group, etc. good. Examples of the hydrocarbyl group containing a hetero atom include 4-hydroxyphenyl group, 4-methoxyphenyl group, 3-methoxyphenyl group, 2-methoxyphenyl group, 4-ethoxyphenyl group, 4-tert-butoxyphenyl group, and 3- alkoxyphenyl groups such as tert-butoxyphenyl group; Alkoxynaphthyl groups such as methoxynaphthyl group, ethoxynaphthyl group, n-propoxynaphthyl group, and n-butoxynaphthyl group; Dialkoxynaphthyl groups such as dimethoxynaphthyl group and diethoxynaphthyl group; Aryl oxo, such as 2-aryl-2-oxoethyl group, such as 2-phenyl-2-oxoethyl group, 2-(1-naphthyl)-2-oxoethyl group, and 2-(2-naphthyl)-2-oxoethyl group Alkyl group etc. are mentioned.

R ¹⁰² is a C1-C40 hydrocarbyl group which may contain a hetero atom. Examples of the hydrocarbyl group represented by R ¹⁰² include those exemplified as the hydrocarbyl group represented by ^{R 101.} In addition, as other specific examples, trifluoromethyl group, trifluoroethyl group, 2,2,2-trifluoro-1-methyl-1-hydroxyethyl group, 2,2,2-trifluoro-1-( Fluorine-containing alkyl groups such as trifluoromethyl)-1-hydroxyethyl group; Fluorinated aryl groups, such as pentafluorophenyl group and 4-trifluoromethylphenyl group, etc. are also mentioned.

Examples of the sulfonate represented by the formula (Z1) include those shown below, but are not limited thereto.

Examples of the carboxylate represented by formula (Z2) include those shown below, but are not limited thereto.

When the resist composition of the present invention contains the quencher, the content is preferably 0.001 to 12 parts by mass, more preferably 0.01 to 8 parts by mass, based on 100 parts by mass of the base resin of the component (A). By mixing the quencher, the resist sensitivity can be easily adjusted, the diffusion rate of the acid in the resist film is suppressed, the resolution is improved, the sensitivity change after exposure is suppressed, or the dependence on the substrate or the environment is reduced. Exposure margin, pattern profile, and the like can be improved. Further, by adding these quenchers, adhesion to the substrate can also be improved. The above quencher may be used alone or in combination of two or more.

[Surfactants]

The resist composition of the present invention may contain a surfactant component insoluble or poorly soluble in water and soluble in an alkali developer and/or a surfactant component insoluble or poorly soluble in water and an alkaline developer. As such a surfactant, the definition component (S) described in JP 2010-215608 A or JP 2011-16746 A can be referred.

As surfactants that are insoluble or poorly soluble in water and alkali developer, among the surfactants described in the above publication, FC-4430 (manufactured by 3M), Saffron (registered trademark) S-381 (manufactured by AGC Semichemical Co., Ltd.), and Safi Nol (registered trademark) E1004 (manufactured by Air Products), KH-20, KH-30 (manufactured by Asahi Glass Co., Ltd.) and an oxetane ring-opening polymer represented by the following structural formula (surf-1) are suitable. These can be used alone or in combination of two or more.

However, Rf, R, M, A, B, C, and N in the above formula shall be applied only to this formula.

In formula (surf-1), R is a divalent aliphatic group having 2 to 5 carbon atoms, specifically, divalent, and is an ethylene group, a tetramethylene group, a propylene group, and 2,2-dimethyl-1,3-propane. A diyl group, a pentamethylene group, etc. are mentioned, As a trivalent or tetravalent thing, the thing shown below, etc. are mentioned.

(In the formula, the broken line represents the number of bonds, and is a partial structure derived from glycerol, trimethylolethane, trimethylolpropane, and pentaerythritol, respectively.)

Among these, a tetramethylene group or a 2,2-dimethyl-1,3-propanediyl group is preferably used. Rf is a trifluoromethyl group or a pentafluoroethyl group, preferably a trifluoromethyl group. M is an integer of 0 to 3, N is an integer of 1 to 4, the sum of M and N represents the valence of R, and is an integer of 2 to 4. A is 1, B is an integer of 2 to 25, and C is an integer of 0 to 10. Preferably, B is an integer of 4 to 20, and C is 0 or 1. In addition, each constituent unit of the above structure is not defined in its arrangement, and may be combined in block form or randomly. The preparation of a partially fluorinated oxetane ring-opening polymeric surfactant is described in detail in the specification of U.S. Patent No. 5650483 or the like.

[Pattern formation method]

The present invention also provides a pattern forming method using the above-described resist composition. In order to form a pattern using the resist composition of the present invention, a known lithography technique can be employed. Specifically, for example, a substrate for manufacturing an integrated circuit (Si, SiO ₂ , SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflection film, etc.) or a substrate for manufacturing a mask circuit (Cr, CrO, CrON, MoSi ₂ , SiO _2, etc.) by a method such as spin coating, so that the resist composition of the present invention is applied to a film thickness of 0.05 to 2 µm, and this is preferably applied on a hot plate at 60 to 150°C for 1 to 10 minutes, more preferably at 80. Pre-baking is performed at -140 DEG C for 1 to 5 minutes to form a resist film.

Subsequently, a mask for forming a desired pattern is covered on the above-described resist film, and high energy rays such as KrF excimer laser, ArF excimer laser, EUV, EB, etc. having a wavelength of 3 to 15 nm are exposed to preferably 1 to Irradiation is performed so that it may be 200 mJ/cm 2, more preferably 10 to 100 mJ/cm 2, or preferably 0.1 to 100 µC/cm 2, and more preferably 0.5 to 50 µC/cm 2. In addition to the usual exposure method, the exposure may be performed by using a liquid immersion method in which a liquid having a refractive index of 1.0 or more is interposed between the resist film and the projection lens. The upper limit of the refractive index is not particularly limited, but may be set to 2.1. In that case, a protective film insoluble in water can also be used. Subsequently, on a hot plate, post-exposure bake (PEB) is performed preferably at 60 to 150°C for 1 to 5 minutes, more preferably at 80 to 140°C for 1 to 3 minutes. Further, preferably 0.1 to 5% by mass, more preferably 2 to 3% by mass of a developer of an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH) or an organic solvent such as butyl acetate is used, preferably Is developed by a conventional method such as a dip method, a puddle method, or a spray method for 0.1 to 3 minutes, more preferably 0.5 to 2 minutes, thereby forming a desired pattern on the substrate. do.

The above-described water-insoluble protective film is used to prevent elution from the resist film and increase the slidability of the film surface, and is largely divided into two types. One is an organic solvent peeling type that requires peeling before alkali development by an organic solvent that does not dissolve the resist film, and the other is an alkali-soluble type that is soluble in an alkaline developer and removes the protective film together with the removal of the soluble portion of the resist film. The latter is based on a polymer compound having a 1,1,1,3,3,3-hexafluoro-2-propanol residue, which is particularly insoluble in water and soluble in an alkaline developer, and is an alcohol-based solvent with 4 or more carbon atoms, and 8 carbon atoms. Materials dissolved in the ether solvents of to 12 and a mixed solvent thereof are preferable. The above-described surfactant, which is insoluble in water and soluble in an alkali developer, may be dissolved in an alcohol-based solvent having 4 or more carbon atoms, an ether-based solvent having 8 to 12 carbon atoms, or a mixed solvent thereof.

In addition, as a means of the pattern formation method, after forming the photoresist film, pure rinsing (post soak) may be performed to extract an acid generator from the surface of the film, or to wash off particles, or water remaining on the film after exposure. Rinse (post soak) may be performed to remove the material.

In addition, as the developer of the pattern formation method of the present invention, as described above, preferably 0.1 to 5% by mass, more preferably 2 to 3% by mass of an alkaline aqueous solution such as TMAH can be used, but an organic solvent may also be used. have. In this case, negative tone development in which the unexposed portion is developed/dissolved can be performed.

In this organic solvent development, as a developer, 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methyl Cyclohexanone, acetophenone, methylacetophenone, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, butenyl acetate, isopentyl acetate, phenyl acetate, propyl formate, butyl formate, isobutyl formate, pentyl formate, isoformate Pentyl, methyl valerate, methyl pentate, methyl crotonate, ethyl crotonate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, pentyl lactate, isopentyl lactate, 2-hydroxyisobutyrate methyl, 2 -One type selected from ethyl hydroxyisobutyrate, methyl benzoate, ethyl benzoate, benzyl acetate, methyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, and 2-phenylethyl acetate You can use the above.

Example

Examples and comparative examples are shown below to specifically describe the present invention, but the present invention is not limited to the following examples.

[1] Synthesis of photoacid generator (PAG)

[Example 1-1]

After mixing 100 g of ammonium salt 1, 68.7 g of cationic intermediate 1, 100 g of pure water and 400 g of methylene chloride, the mixture was aged with stirring for 1 hour. After the organic layer was separated and taken, it was washed twice with a mixed solution of 5.7 g of a cationic intermediate 1 and 100 g of pure water, five times with 100 g of pure water, and two times with 100 g of a 20 wt% methanol aqueous solution. The obtained organic layer was concentrated, PGMEA was added, and it was concentrated again to obtain a 20 wt% PGMEA solution. After the obtained PGMEA solution was stirred at room temperature overnight to precipitate a solid, further 500 g of hexane was added, followed by stirring for 2 hours. The obtained solid was separated by filtration, rinsed with 200 g of hexane, and finally dried under reduced pressure at 50°C to obtain 104.8 g (yield 88%) of PAG1. 1HNMR of the obtained PAG1 is shown in Fig. 1, and 19FNMR is shown in Fig. 2.

IR(D-ATR): ν=3087, 3002, 2906, 2852, 1785, 1727, 1477, 1448, 1344, 1240, 1180, 1103, 1076, 1035, 1010, 997, 943, 750, 684, 642, 551 , 522, 501 cm ^-1

[Example 1-2]

After mixing 417 g of ammonium salt 2, 268 g of cationic intermediate, 1400 g of pure water and 2000 g of methylene chloride, the mixture was aged with stirring for 1 hour. After separating and taking the organic layer, the organic layer was washed 6 times with 600 g of pure water and 6 times with 600 g of 20 wt% methanol aqueous solution. To the obtained organic layer, 25 g of activated carbon was added, followed by stirring at room temperature overnight. After removing the activated carbon by filtration, the organic layer was washed once with 600 g of 1% hydrochloric acid, twice with 600 g of pure water, once with 600 g of 1% hydrochloric acid, and three times with 600 g of pure water. Further, it was washed once with 600 g of 0.04 eq. of ammonia water, three times with 600 g of pure water, once with 600 g of 0.5% hydrochloric acid, and three times with 600 g of pure water. The organic layer was concentrated, PGMEA was added, and it was concentrated again to obtain a 50 wt% PGMEA solution. A concentrated solution was added dropwise to 3.5 L of diisopropyl ether to precipitate crystals. After stirring for 1 hour, this was separated by filtration, rinsed with diisopropyl ether, and finally dried by heating under reduced pressure at 50°C to obtain 535 g (yield 86%) of PAG2. Fig. 3 shows the 1HNMR of the obtained PAG2, and Fig. 4 shows the 19FNMR.

IR(D-ATR): ν=3089, 2907, 2853, 1785, 1729, 1476, 1449, 1344, 1237, 1180, 1104, 1076, 1035, 1010, 947, 761, 707, 681, 642, 585, 551 , 525 cm ^-1

[Examples 1-3 to 1-9] Synthesis of other PAGs (PAG-3 to PAG-9)

Using the corresponding raw materials, PAG-3 to PAG-9 were synthesized by a known organic synthesis method.

[2] synthesis of polymers

The polymer used for the resist composition of the present invention was synthesized by the method shown below. In addition, Mw of the obtained polymer was measured as a polystyrene conversion value by GPC using THF or DMF as a solvent.

[Synthesis Example 1] Synthesis of Resist Polymer 1

Under a nitrogen atmosphere, p-hydroxystyrene (27.8 g), 1-methylcyclopentyl methacrylate (72.2 g) and dimethyl 2,2'-azobisisobutyrate (6.08 g) were dissolved in PGMEA (155 g). A solution was prepared. The solution was added dropwise over 6 hours to PGMEA (78 g) stirred at 80°C under a nitrogen atmosphere. After completion of the dropwise addition, the mixture was stirred for 2 hours while maintaining 80°C, and after cooling to room temperature, the reaction solution was added dropwise to n-hexane (3000 g). The precipitated solid was separated by filtration and vacuum-dried at 50° C. for 20 hours to obtain a resist polymer 1 as a white powder solid. The yield was 85 g and the yield was 85%.

[Synthesis Examples 2 to 7] Synthesis of Resist Polymers 2 to 7

Resist polymers 2 to 7 shown below were prepared in the same manner as in Synthesis Example 1, except that the type and mixing ratio of the monomers were changed.

[3] Preparation of resist composition

[Examples 2-1 to 2-40, Comparative Examples 1-1 to 1-38]

Onium salts of the present invention (PAG-1 to PAG-9), comparative photoacid generators PAG-A to PAG-H, resist polymers 1 to 7, other photoacid generators PAG-X to PAG-Z, quencher Q-1 -Q-4 and alkali-soluble surfactant SF-1, in the composition shown in Tables 1 and 2 below, were dissolved in a solvent containing 0.01% by mass of surfactant A (manufactured by Omnova) to prepare a solution. A resist composition was prepared by filtering the solution through a 0.2 µm Teflon (registered trademark) filter.

In addition, in Tables 1 and 2, solvents, comparative photoacid generators PAG-A to PAG-H, other photoacid generators PAG-X to PAG-Z, quencher Q-1 to Q-4, and alkali-soluble surfactants (Fluorinated polymer) SF-1 is as follows.

PAG-A to PAG-H:

PAG-X∼PAG-Z:

SF-1:

Q-1 to Q-4:

·solvent:

S-1: PGMEA (propylene glycol monomethyl ether acetate)

S-2: GBL (γ-butyrolactone)

Surfactant A:

3-methyl-3-(2,2,2-trifluoroethoxymethyl)oxetane·tetrahydrofuran·2,2-dimethyl-1,3-propanediol copolymer (manufactured by Omnova Corporation)

[4] Evaluation of resist composition: EUV exposure patterning evaluation (hole pattern evaluation)

[Examples 3-1 to 3-40, Comparative Examples 2-1 to 2-38]

The resist composition (R-1 to R-40) of the present invention and the resist composition for comparison (R-41 to R-78) were used as a 20 nm film manufactured by BRUWER SCIENCE using Clean Track Lithius ProZ manufactured by Tokyo Electron. It coated on the substrate on which the organic antireflection film AL-412 was formed with a thickness, and baked on a hot plate at 105° C. for 60 seconds to form a 50 nm resist film. Using an EUV exposure machine NXE3300 manufactured by ASML, a lattice pattern having a size of 27.5 nm on a mask with a pitch of 46 nm was exposed, a suitable PEB temperature was applied for each resist composition after exposure, and a 2.38% tetramethylammonium aqueous solution was added to the wafer. It was made to discharge while rotating, developed for a total of 30 seconds, washed off the alkali solution with water, and rotated the wafer on a highway to remove water.

[Sensitivity evaluation]

The created resist pattern was observed with a Hitachi High Technologies CD-SEM CG-5000, and the exposure amount having a hole diameter of 23 nm at a pitch of 46 nm was taken as the optimum exposure amount Eop (mJ/cm 2 ).

[MEF evaluation]

When the dimension on the mask is a pitch of 46 nm and the grating pattern is 27.5 nm, when a hole diameter of around 23 nm is observed when observed with CD-SEM, the dimension on the mask is a pitch of 46 nm and the grating pattern is 26.0 nm, 26.5 nm, The CD of the hole pattern at 27.0 nm, 27.5 nm, 28.0 nm, 28.5 nm, and 29.0 nm was measured. The dimensions on the mask and the inclination of the observed CD were taken as MEF (Mask Error Enhancement Factor). It is assumed that the MEF is good at approximately 3.0 or less.

[Dimension Uniformity (CDU) Evaluation]

The obtained hole pattern was observed with Hitachi High Technologies' CD-SEM CG-5000, and the hole diameter was measured at 32 points in one hole per sample, and 49 holes were measured from one SEM image. Three batches (3σ) of the calculated standard deviation (σ) were obtained, 30 SEM images were obtained, and the average value of the standard deviation was taken as CDU. CDU means that the smaller the value, the better the dimensional uniformity. A CDU of approximately 3.2 or less is considered good.

From the results shown in Table 3, it was found that the resist composition (Example) of the present invention has good sensitivity and excellent MEF and CDU. On the other hand, as shown in Table 4, conventional photoacid generators PAG-A to PAG-E (refer to Patent Documents 1 to 4), and PAG-F, PAG-H, and W2 in which W1 does not contain a hetero atom are heterogeneous. The resist composition (Comparative Example) using PAG-G and PAG-H containing atoms was insufficient in MEF and CDU. From the above, it has been revealed that the resist composition of the present invention is particularly suitable as a material for EUV lithography.

In addition, this invention is not limited to the said embodiment. The above-described embodiment is an example, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits the same operating and effects is included in the technical scope of the present invention.

Claims (18)

(A) a resin containing a repeating unit having an acid labile group, and containing at least one repeating unit having an aromatic substituent, (B) a photoacid generator represented by the general formula (B-1) and (C) a solvent. Resist composition comprising a.

(In the formula, W ₁ represents a cyclic divalent hydrocarbon group containing a hetero atom having 4 to 12 carbon atoms. W ₂ represents a cyclic monovalent hydrocarbon group containing no hetero atom having 4 to 14 carbon atoms. Rf is the above-described Is a divalent organic group represented by a general formula, A ₁ , A ₂ each independently represent a hydrogen atom or a trifluoromethyl group, and B ₁ and B ₂ are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group And * represents the number of bonds with a carbonyloxy group, m represents an integer of 0 to 4, n represents an integer of 0 to 1. M ⁺ represents an onium cation.) _{The resist composition according to claim 1, wherein W 1} in the general formula (B-1) is a cyclic divalent hydrocarbon group containing a lactone ring structure having 6 to 12 carbon atoms. _{The resist composition according to claim 1, wherein W 2} in the general formula (B-1) is a polycyclic monovalent hydrocarbon group that does not contain a hetero atom having 7 to 14 carbon atoms. _{The resist composition according to claim 2, wherein W 2} in the general formula (B-1) is a polycyclic monovalent hydrocarbon group that does not contain a hetero atom having 7 to 14 carbon atoms. The resist composition according to claim 1, wherein the Rf group in the general formula (B-1) is selected from groups represented by the following formulas (Rf-1) to (Rf-6).

(* represents the number of bonds with a carbonyloxy group.) The resist composition according to claim 2, wherein the Rf group in the general formula (B-1) is selected from groups represented by the following formulas (Rf-1) to (Rf-6).

(* represents the number of bonds with a carbonyloxy group.) The resist composition according to claim 3, wherein the Rf group in the general formula (B-1) is selected from groups represented by the following formulas (Rf-1) to (Rf-6).

(* represents the number of bonds with a carbonyloxy group.) The resist composition according to claim 4, wherein the Rf group in the general formula (B-1) is selected from groups represented by the following formulas (Rf-1) to (Rf-6).

(* represents the number of bonds with a carbonyloxy group.) The resist composition according to claim 1, wherein one of the repeating units having the aromatic substituent in the resin of the component (A) is a repeating unit represented by the following formula (A-1).

(In the formula, R ^A represents a hydrogen atom or a methyl group. R ₆₁ represents a hydrogen atom or a straight-chain, branched or cyclic hydrocarbon group which may be interposed by a hetero atom having 1 to 10 carbon atoms. R ₆₂ is a hetero atom interposed therebetween. It represents a straight-chain, branched or cyclic hydrocarbon group having 1 to 8 carbon atoms, where t is an integer of 1 to 3, and u is an integer that satisfies u≤5+2s-t, and s is 0 or 1. L ₁ represents a single bond or -C(=O)O-, -C(=O)NH-.) The resist composition according to claim 1, wherein one of the repeating units having the aromatic substituent in the resin of the component (A) is a repeating unit represented by the following general formulas (A-2) to (A-4). .

(In the formula, R ^A is each independently a hydrogen atom or a methyl group, and R ²⁰¹ is a single bond, a phenylene group, -OR ²¹⁰ -or -C(=O)-Z ² -R ²¹⁰ -. Z ² is an oxygen atom. Or NH, R ²¹⁰ is a C 1 to C 6 linear, branched or cyclic alkylene group, alkenylene group or phenylene group, a carbonyl group (-CO-), an ester group (-COO-), an ether group (- O-) or may contain a hydroxy group L ₂ represents a single bond or -Z ³ -C(=O)-O-, and Z ³ represents a straight-chain, branched, optionally substituted hetero atom having 1 to 20 carbon atoms Represents a type or cyclic divalent hydrocarbon group Z ¹ is a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, -OR ²¹¹ -or -C(=O)-Z ⁴ -R ²¹¹ -. Z ⁴ is an oxygen atom or NH, and R ²¹¹ is a C 1 to C 6 linear, branched or cyclic alkylene group, alkenylene group or phenylene group, and may contain a carbonyl group, an ester group, an ether group or a hydroxy group. M ^- represents a non-nucleophilic counter ion, R ²⁰² , R ²⁰³ , R ²⁰⁴ , R ²⁰⁵ , R ²⁰⁶ , R ²⁰⁷ , R ²⁰⁸ , R ²⁰⁹ may each independently be substituted with a hetero atom, even if a hetero atom is interposed It represents a good straight-chain type having 1 to 20 carbon atoms, or a branched type or cyclic monovalent hydrocarbon group having 3 to 20 carbon atoms In addition, R ²⁰² and R ²⁰³ may be bonded to each other to form a ring together with the sulfur atom in the formula, Alternatively ^{, any two or more of R 204} , R ²⁰⁵ and R ²⁰⁶ or any two or more of R ²⁰⁷ , R ²⁰⁸ and R ²⁰⁹ may be bonded to each other to form a ring together with the sulfur atom in the formula. The repeating units represented by -2) to (A-4) have one or more aromatic substituents.) The method according to claim 1, wherein the (D) component is a resin different from the resin of the component (A), and is selected from repeating units represented by the following formulas (D-1), (D-2) and (D-3). A resist composition, further comprising a fluorine-containing resin having at least one type of.

(In the formula, R ^A is each independently a hydrogen atom or a methyl group. R ₅₁ and R ₅₂ are each independently a hydrogen atom or a linear, branched or cyclic monovalent hydrocarbon group having 1 to 10 carbon atoms. R ₅₃ Is a single bond or a linear or branched divalent hydrocarbon group having 1 to 5 carbon atoms R ₅₄ , R ₅₅ and R ₅₆ are each independently a hydrogen atom or a straight chain, branched or cyclic C 1 to 15 Of, a monovalent hydrocarbon group, a fluorinated monovalent hydrocarbon group or an acyl group, or an acid labile group When R ₅₄ , R ₅₅ and R ₅₆ are monovalent hydrocarbon groups or fluorinated monovalent hydrocarbon groups, some of these carbon atoms are ether groups Alternatively, it may be substituted with a carbonyl group R ₅₇ is a linear, branched or cyclic C 1 to C 20 (v+1) valent hydrocarbon group or a fluorinated hydrocarbon group, v is an integer of 1 to 3.) A step of forming a resist film by applying the resist composition according to any one of claims 1 to 11 on a substrate and performing heat treatment, a step of exposing the resist film with high energy rays, and exposure using a developer. A method of forming a pattern comprising the step of developing a resist film. The method of claim 12, wherein the high energy ray is an ArF excimer laser having a wavelength of 193 nm or a KrF excimer laser having a wavelength of 248 nm. The pattern formation method according to claim 12, wherein the exposure is liquid immersion exposure performed by interposing a liquid having a refractive index of 1.0 or higher between the resist film and the projection lens. The pattern formation method according to claim 13, wherein the exposure is liquid immersion exposure performed by interposing a liquid having a refractive index of 1.0 or more between the resist film and the projection lens. The pattern formation method according to claim 14, wherein a protective film is further formed on the resist film, and liquid immersion exposure is performed with the liquid interposed between the protective film and the projection lens. The pattern formation method according to claim 15, wherein a protective film is further formed on the resist film, and liquid immersion exposure is performed with the liquid interposed between the protective film and the projection lens. The method according to claim 12, wherein the high energy ray is an electron beam or an extreme ultraviolet ray having a wavelength of 3 to 15 nm.

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