JPH1130856A - Radiation-sensitive resin composition - Google Patents

Abstract

(57) Abstract: A radiation-sensitive resin composition that can use various resist solvents and has particularly excellent resolution and pattern shape and is useful as a chemically amplified positive resist that does not cause scum. Offer things. SOLUTION: The radiation-sensitive resin composition comprises (A) a polymer having a substituent which can be decomposed by an acid and having increased solubility in an alkali developing solution by the action of an acid; and (B) a polymer represented by the following formula (1): ) Is contained. Embedded image [In the formula (1), R ¹ represents an alkyl group having 1 to 6 carbon atoms or a phenyl group, and three R ^{1 s} may be the same or different, and R ² is an alkyl group having 1 to 10 carbon atoms. ,
C1-C10 perfluoroalkyl group, C6-C
It represents a 10-aryl group, an aralkyl group having 7 to 10 carbon atoms, or a group having an alicyclic skeleton having 4 to 12 carbon atoms. )

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation-sensitive resin composition.
The present invention relates to a radiation-sensitive resin composition useful as a chemically amplified positive resist suitable for fine processing using various radiations such as a beam and a charged particle beam.

[0002]

2. Description of the Related Art In the field of microfabrication represented by the manufacture of integrated circuit elements, the processing size in lithography has been reduced in order to obtain a higher degree of integration. The development of a lithography process capable of stably performing fine processing has been strongly promoted. However, conventional visible light (wavelength 700 to 400 nm) and near ultraviolet light (wavelength 400 to 300)
It is difficult to form such a fine pattern with high accuracy by the method using (nm), so that a wider depth of focus can be achieved and a short wavelength (wavelength of 300 nm or less) effective for miniaturization of design rules can be achieved. Lithographic processes using radiation have been proposed. Examples of such short-wave radiation include far ultraviolet rays such as a KrF excimer laser (wavelength 248 nm) or ArF excimer laser (wavelength 193 nm), X-rays such as synchrotron radiation, and charged particle beams such as electron beams. be able to. As a high-resolution resist corresponding to these short-wavelength radiations, International Business Machines (IBM) has proposed a "chemically amplified resist". Currently, the improvement of this chemically amplified resist is vigorous. It is being advanced. A chemically amplified resist generates an acid by irradiation of a radiation-sensitive acid generator contained therein (hereinafter referred to as “exposure”), and the acid causes a chemical change in the resist film due to its catalytic action. For example, a change in polarity, decomposition of a chemical bond, a cross-linking reaction, etc.) is caused, and a resist pattern is formed using a phenomenon in which solubility in a developing solution changes in an exposed portion. Among the conventional chemically amplified resists, those showing relatively good resist performance include resins in which an alkali-affinity group in an alkali-soluble resin is protected by a t-butyl ester group or a t-butoxycarbonyl group as a resin component. Tokuhei 2
No. 27660), an alkali-soluble group in an alkali-soluble resin is protected with a silyl group to form a resin (Japanese Patent Publication No. 3-4).
No. 4290), a resin in which an alkali-affinity group in an alkali-soluble resin is protected by a ketal group (Japanese Patent Laid-Open No. 7-1).
No. 40666), a resin in which an alkali-affinity group in an alkali-soluble resin is protected by an acetal group (Japanese Patent Laid-Open No.
JP-A-161436 and JP-A-5-249682) are known. Further, as the radiation-sensitive acid generator used in these chemically amplified resists, for example, onium salts such as triphenylsulfonium trifluoromethanesulfonate,
Sulfonic acid esters of 2,6-dinitrobenzyl, tris (methanesulfonyloxy) benzene, bis (cyclohexylsulfonyl) diazomethane and the like have been used. However, in these radiation-sensitive acid generators,
Various problems have been pointed out. For example, an onium salt is
In general, due to low solubility in resist solvents, careful preparation is required during the preparation of the resist, and there is a problem that a great deal of labor is required for quality control. Also, dissolution residues (scum) in exposed areas occur during pattern formation. In some cases, the rectangularity of the head of the resist pattern is insufficient, which is not practically satisfactory. In addition, 2,6-dinitrobenzyl sulfonic acid ester, tris (methanesulfonyloxy) benzene and bis (cyclohexylsulfonyl) diazomethane have good solubility in resist solvents, but have low sensitivity and low sensitivity for chemically amplified resists. Not suitable as an agent. Incidentally, as for the sensitivity of the resist, the exposure amount required for pattern formation is 10 to 100 mJ.
/ Cm ² is preferable, and more preferably 15 to 7
The range is 0 mJ / cm ² . If the exposure required for pattern formation is too large, the productivity of the device will decrease, and if it is too low, it will be difficult to control the exposure,
It is also difficult to control the line width of the resist pattern.
Under these circumstances, excellent resist performance (high resolution,
It is strongly desired to develop a radiation-sensitive acid generator which not only can provide a good pattern shape, good sensitivity, etc.) but also has excellent solubility in resist solvents.

[0003]

SUMMARY OF THE INVENTION In view of such circumstances, the present invention has been made as a result of intensive studies particularly on the radiation-sensitive acid generator component constituting a chemically amplified resist. Resist solvents can be used,
In particular, it is an object of the present invention to provide a radiation-sensitive resin composition which is excellent in resolution and pattern shape and is useful as a chemically amplified positive resist which does not cause scum.

[0004]

According to the present invention, the object is to provide (A) a polymer having a substituent which can be decomposed by an acid and having increased solubility in an alkali developing solution by the action of an acid; B) It is achieved by a radiation-sensitive resin composition comprising a radiation-sensitive acid generator represented by the following formula (1).

[0005]

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[In the formula (1), R ¹ has 1 to 6 carbon atoms.
And three R ^{1 s} may be the same or different, and R ² is an alkyl group having 1 to 10 carbon atoms, a perfluoroalkyl group having 1 to 10 carbon atoms, and 6 carbon atoms. An aryl group having from 10 to 10; an aralkyl group having from 7 to 10 carbon atoms; or a group having an alicyclic skeleton having from 4 to 12 carbon atoms. )

Hereinafter, the present invention will be described in detail. Component (A) The component (A) in the present invention is a polymer having a substituent decomposable by an acid and having increased solubility in an alkali developing solution by the action of an acid (hereinafter referred to as “polymer (A)”). )). Examples of the substituent which may be decomposed by an acid in the polymer (A), for _{example, -OC (CH 3) 3,} -O
C (= O) -OC (CH 3) 3, -OCH 2 C (= O) -
_{OC (CH 3) 3, -OC} (CH 3) H-C (= O) -OC
(CH ₃ ) ₃ , —OC (CH ₃ ) ₂ —C (＝ O) —OC (C
H ₃ ) ₃ , —OC (R ³ ) H—OR ⁴ (where R ³ represents an alkyl group having 1 to 6 carbon atoms or a phenyl group, and R ⁴ represents an alkyl group having 1 to 10 carbon atoms or 6 carbon atoms) or shows a 10 aryl group, or R ³ and R ⁴ are 5 attached
It forms a seven-membered ring structure. ) And the like. In the —OC (R ³ ) H—OR ⁴ , the alkyl group having 1 to 6 carbon atoms of R ³ can be linear, branched or cyclic, and examples thereof include a methyl group and an ethyl group. , N-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group,
Examples thereof include an n-pentyl group, a neopentyl group, an n-hexyl group, a cyclopentyl group, a cyclohexyl group, and the like, and an alkyl group having 1 to 10 carbon atoms of R ⁴ is linear,
It can be branched or cyclic, examples of which include:
Methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, sec-butyl group,
t-butyl group, n-pentyl group, neopentyl group, n-
Hexyl group, n-octyl group, 2-ethylhexyl group,
n-decyl group, cyclopentyl group, cyclohexyl group,
A cyclooctyl group and the like can be mentioned, and the aryl group having 6 to 10 carbon atoms of R ⁴ may be unsubstituted or substituted, and examples thereof include a phenyl group, an o-methylphenyl group, and an m-methylphenyl. Group, p-methylphenyl group, p
-Ethylphenyl group, o-methoxyphenyl group, m-methoxyphenyl group, p-methoxyphenyl group, p-ethoxyphenyl group, pn-propoxyphenyl group, p-
Examples thereof include an n-butoxyphenyl group, a pt-butoxyphenyl group, a 1-naphthyl group, a 2-naphthyl group, and a 5- to 7-membered ring structure in which R ³ and R ⁴ are bonded. Examples thereof include a tetrahydrofuranyl group and a tetrahydropyranyl group. As the substituents decomposable by these acids, one kind alone or two or more kinds can be present in the polymer (A). As the polymer (A), a polymer in which the substituent decomposable by the acid is decomposed to generate an acidic functional group such as a phenolic hydroxyl group and a carboxyl group is preferable. Specific examples of such a polymer (A) include a partial t-butoxycarbonyl derivative of polyhydroxy (α-methyl) styrene represented by the following formula (2):

[0008]

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[In the formula (2), R ⁵ and R ⁶ independently represent a hydrogen atom or a methyl group;
Is the number of each repeat unit. A portion of polyhydroxy (α-methyl) styrene represented by the following formula (3):
Butoxycarbonylmethylated derivatives,

[0010]

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[In the formula (3), R ⁵ and R ⁶ independently represent a hydrogen atom or a methyl group;
Is the number of each repeat unit. A part of polyhydroxy (α-methyl) styrene represented by the following formula (4):
Butylated derivatives,

[0012]

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[In the formula (4), R ⁵ and R ⁶ independently represent a hydrogen atom or a methyl group, and n and m
Is the number of each repeat unit. A partially (alkoxy-substituted methyl) derivative or partially (aryloxy-substituted methyl) derivative of polyhydroxy (α-methyl) styrene represented by the following formula (5):

[0014]

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[In the formula (5), R ³ has 1 to 6 carbon atoms.
R ⁴ represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, or R ³ and R ⁴ are combined to form a 5- to 7-membered ring. R ⁵ and R ⁶ each independently represent a hydrogen atom or a methyl group, and n and m are the numbers of each repeating unit. ]; Represented by the following formula (6):
Hydroxy (α-methyl) styrene / t-butyl (meth) acrylate copolymer,

[0016]

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[In the formula (6), R ⁵ and R ⁶ independently represent a hydrogen atom or a methyl group;
Is the number of each repeat unit. A hydroxy (α-methyl) styrene / alkoxy. Represented by the following formula (7):
Substituted methyl (meth) acrylate copolymer or hydroxy (α-methyl) styrene / aryloxy-substituted methyl (meth) acrylate copolymer,

[0018]

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[In the formula (7), R ³ has 1 to 6 carbon atoms.
R ⁴ represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms, or R ³ and R ⁴ are combined to form a 5- to 7-membered ring. R ⁵ and R ⁶ each independently represent a hydrogen atom or a methyl group, and n and m are the numbers of each repeating unit. And the like. The polymer (A) represented by the formulas (2) to (5) may be prepared, for example, by a method of copolymerizing each monomer corresponding to a repeating unit in each polymer, a polyhydroxy (α-methyl) styrene The polymer (A) represented by the formulas (6) and (7) can be produced, for example, by modifying the phenolic hydroxyl group therein with a substituent that can be decomposed by an acid. A method of copolymerizing each monomer corresponding to the repeating unit in the union, and a method of modifying a carboxyl group in a hydroxy (α-methyl) styrene / (meth) acrylic acid copolymer with an acid-decomposable substituent And the like. In the polymer (A) represented by the formulas (2) to (7), each repeating unit can be bonded in a random shape or a block shape. Further, the polymer (A) represented by the formulas (2) to (7) may further contain a repeating unit other than the above-mentioned repeating units. In the polymer (A) represented by the above formulas (2) to (7), the ratio of the number of repeating units is usually 0.1.
40 to 0.90, preferably 0.60 to 0.85, m
/ (N + m) is usually 0.10 to 0.60, preferably 0.15 to 0.40. Weight average molecular weight in terms of polystyrene (hereinafter, referred to as “Mw”) by gel permeation chromatography (hereinafter, referred to as “GPC”) of the polymer (A) represented by the formulas (2) to (7).
Is usually 1,000 to 100,000, preferably 3,000 to 40,000, and the ratio (Mw / Mn) of Mw to the number average molecular weight in terms of polystyrene by GPC (hereinafter, referred to as “Mn”). ) Is usually 1 to 3, preferably 1 to 2.5. In the present invention, the polymer (A) can be used alone or in combination of two or more.

Component (B) The component (B) in the present invention is composed of at least one of the compounds represented by the formula (1), and undergoes a chemical reaction upon exposure to light to generate a radiation-sensitive acid. Agent (hereinafter,
It is referred to as "acid generator (B)". ). Acid generator (B)
Wherein the alkyl group having 1 to 6 carbon atoms of R ¹ can be linear, branched or cyclic, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-pentyl group, neopentyl group,
Examples thereof include an n-hexyl group, a cyclopentyl group, and a cyclohexyl group. Examples of the alkyl group and phenyl group for R ¹ include a methyl group, an ethyl group, an n-butyl group,
A phenyl group is preferred.

The alkyl group having 1 to 10 carbon atoms of R ² may be linear or branched, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, n-butyl group, i-butyl group, sec-butyl group, t-butyl group, n-pentyl group, neopentyl group,
Examples thereof include an n-hexyl group, an n-octyl group, a 2-ethylhexyl group, and an n-decyl group.
The perfluoroalkyl group of 0 may be linear, branched or cyclic, and examples thereof include a trifluoromethyl group, a pentafluoroethyl group, and a perfluoro-n- group.
Propyl, perfluoro-i-propyl, perfluoro-n-butyl, perfluoro-i-butyl, perfluoro-sec-butyl, perfluoro-t-butyl, perfluoro-n-pentyl Perfluoroneopentyl group, perfluoro-n-hexyl group, perfluoro-n-octyl group, perfluoro-2-ethylhexyl group, perfluoro-n-decyl group, perfluorocyclopentyl group, perfluorocyclohexyl group,
Perfluorocyclooctyl group and the like,
The aryl group having 6 to 10 carbon atoms may be unsubstituted or substituted, and examples thereof include a phenyl group, an o-methylphenyl group, an m-methylphenyl group, a p-methylphenyl group, and a p-ethylphenyl group. , O-methoxyphenyl group,
m-methoxyphenyl group, p-methoxyphenyl group, p
-Ethoxyphenyl group, pn-propoxyphenyl group, pn-butoxyphenyl group, pt-butoxyphenyl group, 1-naphthyl group, 2-naphthyl group and the like, and having 7 to 10 carbon atoms. May be unsubstituted or substituted, and examples thereof include a benzyl group, a p-methylbenzyl group, a p-ethylbenzyl group,
-Phenylethyl group, 1- (p-methylphenyl) ethyl group, 2-phenylethyl group, 2- (p-methylphenyl) ethyl group, 1-phenylpropyl group, 2-phenylpropyl group, 2-phenyl-2 -Propyl group, 3-phenylpropyl group and the like, having 4 to 12 carbon atoms.
Examples of the group having an alicyclic skeleton include a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, a norbornyl group, a camphanyl group, and the like. You. R
^Examples of the alkyl group, perfluoroalkyl group, aryl group, aralkyl group and alicyclic group having 4 to 12 carbon atoms include n-butyl group, n-hexyl group and n-hexyl group.
-Octyl group, cyclohexyl group, trifluoromethyl group, pentafluoroethyl group, perfluoro-n-propyl group, perfluoro-n-butyl group, phenyl group, p
-A methylphenyl group and a camphanyl group are preferred.

In the present invention, among the compounds represented by the above formula (1), preferred compounds are those represented by the following formulas (8) and (9), and particularly preferred compounds are those represented by the following formula (8) It is a compound represented by these.

[0023]

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[0024]

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In the present invention, specific examples of particularly preferred acid generator (B) include tri (p-methoxyphenyl) sulfonyltrifluoromethanesulfonate, tri (p-methoxyphenyl) sulfonylnonafluorobutanesulfonate and tri (p-methoxyphenyl) sulfonylnonafluorobutanesulfonate. (Methoxyphenyl) sulfonyl p-toluenesulfonate, tri (p-methoxyphenyl) sulfonylnaphthalenesulfonate, tri (p
-Methoxyphenyl) sulfonyl camphorsulfonate, tri (p-methoxyphenyl) sulfonylcyclohexylsulfonate, tri (p-ethoxyphenyl) sulfonyltrifluoromethanesulfonate, tri (p-
Examples thereof include (ethoxyphenyl) sulfonylnonafluorobutanesulfonate, tri (p-ethoxyphenyl) sulfonylcamphorsulfonate, and tri (p-phenoxyphenyl) sulfonylnonafluorobutanesulfonate.

The amount of the acid generator (B) used in the present invention is usually 0.1 to 100 parts by weight of the polymer (A).
It is 30 parts by weight, preferably 0.5 to 20 parts by weight, more preferably 1 to 15 parts by weight. In this case, if the amount of the acid generator (B) used is less than 0.1 part by weight, the sensitivity tends to decrease, and if it exceeds 30 parts by weight, the pattern shape tends to deteriorate.

[0027] In the alkali-soluble resin present invention can be optionally added an alkali-soluble resin other than the polymer (A) and acid generator (B). The alkali-soluble resin is a resin that is soluble in an alkali developing solution and has at least one functional group having an affinity for an aqueous alkali solution, such as a phenolic hydroxyl group or a carboxyl group. By using such an alkali-soluble resin, it becomes easy to control the dissolution rate of a resist coating formed from the radiation-sensitive resin composition of the present invention in an alkali developer, thereby further improving developability. Can be. The alkali-soluble resin is not particularly limited as long as it is soluble in an alkali developer, but preferred alkali-soluble resins include
For example, hydroxystyrenes, hydroxy-α-methylstyrenes, vinylbenzoic acids, carboxymethylstyrenes, carboxymethoxystyrenes, (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesacon Addition-based resins containing at least one repeating unit in which the polymerizable double bond is cleaved from a monomer having an acidic functional group such as an acid or cinnamic acid, or condensation having an acidic functional group represented by a novolak resin Polycondensation resins containing at least one type of repeating unit can be given. The alkali-soluble resin composed of the addition polymerization resin may be composed of only a repeating unit in which the polymerizable double bond of the monomer having the acidic functional group is cleaved, but the produced resin is alkali-soluble. Insofar as it is, one or more other repeating units may be contained. Such other repeating units include, for example, styrene, α-methylstyrene, vinyl toluene, maleic anhydride, (meth) acrylonitrile, crotonitrile, maleinitrile, fumaronitrile, mesaconitrile, citraconitrile, itaconitrile, ( (Meth) acrylamide, crotonamide, maleamide, fumaramide, mesaconamide, citraconamide, itaconamide, vinylaniline, vinylpyridine, vinyl-ε-caprolactam, vinylpyrrolidone,
Examples of the unit include a unit in which a polymerizable double bond of a monomer such as vinylimidazole is cleaved. Among the addition polymerization resins, poly (hydroxystyrene) s and hydroxy-α-methylstyrene copolymers are particularly preferred from the viewpoint of high radiation transmittance when formed into a resist film and excellent dry etching resistance. Is preferred.

The alkali-soluble resin composed of the polycondensation resin may be composed of only a condensation type repeating unit having an acidic functional group. However, as long as the formed resin is soluble in an alkali developing solution. And other condensed repeating units. Such a polycondensation resin is, for example, one or more phenols and one or more aldehydes, optionally together with a polycondensation component capable of forming another condensation type repeating unit, in the presence of an acidic catalyst. It can be produced by (co) polycondensation in an aqueous medium or in a mixed medium of water and a hydrophilic solvent. Examples of the phenols include o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-
Xylenol, 2,5-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol and the like can be mentioned. Examples thereof include formaldehyde, trioxane, paraformaldehyde, benzaldehyde, acetaldehyde, propylaldehyde, phenylacetaldehyde and the like. Mw of the alkali-soluble resin is usually
1,000 to 150,000, preferably 3,000 to
100,000. These alkali-soluble resins can be used alone or in combination of two or more. The amount of the alkali-soluble resin used is usually 2 parts by weight per 100 parts by weight of the total of the polymer (A) and the acid generator (B).
Not more than 00 parts by weight.

Acid Diffusion Control Agent In the present invention, the action of controlling the diffusion phenomenon of the acid generated from the acid generator (B) by exposure in the resist film, and suppressing an undesired chemical reaction in the unexposed area, etc. It is preferable to add an acid diffusion controller having the same. By using such an acid diffusion controlling agent, the storage stability of the composition is improved, the resolution as a resist is further improved, and the line width of the resist pattern can be suppressed from changing over time. An extremely excellent composition can be obtained. As the acid diffusion controller, a nitrogen-containing organic compound whose basicity is not changed by exposure or baking is preferable. As such a nitrogen-containing organic compound, for example, the following formula (8): R ⁶ R ⁷ R ⁸ N... (8) [In the formula (8), R ⁶ , R ⁷ and R ⁸ are mutually independent. Represents a hydrogen atom, an alkyl group, an aryl group or an aralkyl group. (Hereinafter, referred to as "nitrogen-containing compound (I)"), a diamino compound having two nitrogen atoms in the same molecule (hereinafter, referred to as "nitrogen-containing compound (II)"), and a nitrogen atom Having three or more (hereinafter, referred to as
It is called "nitrogen-containing compound (III)". ), Amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds and the like.

Examples of the nitrogen-containing compound (I) include, for example, n
Monoalkylamines such as hexylamine, n-heptylamine, n-octylamine, n-nonylamine and n-decylamine; di-n-butylamine, di-n-pentylamine, di-n-hexylamine, di- dialkylamines such as n-heptylamine, di-n-octylamine, di-n-nonylamine and di-n-decylamine; tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-pentylamine Trialkylamines such as -n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine; aniline, N-methylaniline, N, N-dimethyl Aniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-
Aromatic amines such as nitroaniline, diphenylamine, triphenylamine and naphthylamine can be mentioned. Examples of the nitrogen-containing compound (II) include ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diaminodiphenylmethane,
4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylamine, 2,2-bis (4-aminophenyl) propane, 2
-(3-aminophenyl) -2- (4-aminophenyl) propane, 2- (4-aminophenyl) -2- (3
-Hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4-hydroxyphenyl) propane,
Examples thereof include 1,4-bis [1- (4-aminophenyl) -1-methylethyl] benzene and 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzene. Examples of the nitrogen-containing compound (III) include a polymer of polyethyleneimine, polyallylamine, dimethylaminoethylacrylamide, and the like. Examples of the amide group-containing compound include formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide,
N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone and the like can be mentioned. Examples of the urea compound include urea, methylurea, 1,1-dimethylurea,
Examples thereof include 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, and tri-n-butylthiourea. Examples of the nitrogen-containing heterocyclic compound include imidazoles such as imidazole, benzimidazole, 4-methylimidazole, and 4-methyl-2-phenylimidazole; pyridine,
-Methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4-ethylpyridine, 2-phenylpyridine,
4-phenylpyridine, N-methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 8-oxyquinoline, pyridines such as acridine, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, Piperidine, morpholine, 4
-Methylmorpholine, piperazine, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane, and the like. Among these nitrogen-containing organic compounds, a nitrogen-containing compound (I), a nitrogen-containing heterocyclic compound and the like are preferable. Further, among the nitrogen-containing compounds (I), trialkylamines are particularly preferable, and among the nitrogen-containing heterocyclic compounds, pyridines are particularly preferable.

In the present invention, the acid diffusion controlling agents can be used alone or in combination of two or more. The amount of the acid diffusion controller to be used is generally 5 parts by weight or less, preferably 0.001 to 3 parts by weight, more preferably 0.005 to 2 parts by weight, per 100 parts by weight of the polymer (A).
In this case, if the amount of the acid diffusion controller exceeds 5 parts by weight, the sensitivity and developability as a resist tend to decrease. If the amount of the acid diffusion controller is less than 0.001, the effect of improving the resolution and process stability as a resist may be insufficient.

Various Additives In the present invention, various additives such as surfactants and sensitizers can be added, if necessary. The surfactant, the coating properties and striation of the composition,
It has the effect of improving the developability of the resist. Examples of such surfactants include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyethylene glycol dilaurate, and polyethylene glycol dilaurate. In addition to stearate, the following brand names are used as F Top EF301, EF
303, EF352 (manufactured by Tochem Products), Megafac F171, F173 (manufactured by Dainippon Ink and Chemicals, Inc.), Florado FC430, FC431 (manufactured by Sumitomo 3M Limited), Asahi Guard AG710, Surflon S-382 SC-101, SC-102, SC
-103, SC-104, SC-105, SC-106
(Made by Asahi Glass Co., Ltd.), KP341 (Shin-Etsu Chemical Co., Ltd.)
Manufactured by Polyflow No. 75, no. 95 (manufactured by Kyoeisha Yushi Kagaku Kogyo KK) and the like. These surfactants can be used alone or in combination of two or more. The amount of the surfactant is usually 2 parts by weight per 100 parts by weight of the total of the polymer (A), the acid generator (B) and the alkali-soluble resin to be added.
Not more than parts by weight. The sensitizer absorbs radiation energy and transmits the energy to the acid generator (B), thereby increasing the amount of acid generated by exposure. Has the effect of improving the sensitivity of Preferred sensitizers include, for example, acetone, benzene, acetophenones, benzophenones, naphthalenes, biacetyls, eosine, rose bengal, pyrenes, anthracenes, phenothiazines and the like. These sensitizers can be used alone or in combination of two or more.
The compounding amount of the sensitizer is 1 solid content of the radiation-sensitive resin composition.
It is usually at most 50 parts by weight, preferably at most 30 parts by weight, per 100 parts by weight. Furthermore, the radiation-sensitive resin composition of the present invention, by blending a dye and / or a pigment, makes it possible to visualize a latent image in an exposed portion, reduce the influence of halation at the time of exposure, and blend an adhesion aid. Thereby, the adhesiveness with the substrate can be further improved. Further, as other additives, an antihalation agent such as 4-hydroxy-4′-methylchalcone, a shape improver, a storage stabilizer, an antifoaming agent, and the like can be blended.

Solvent The radiation-sensitive resin composition of the present invention may be used,
The composition is obtained by uniformly dissolving in a solvent such that the concentration of the total solid content is, for example, 5 to 50% by weight, preferably 15 to 40% by weight, and then filtering through, for example, a filter having a pore size of about 0.2 μm. Prepared as a solution. As the solvent used for preparing the composition solution, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n
Ethylene glycol monoalkyl ethers such as -propyl ether and ethylene glycol mono-n-butyl ether; ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol mono-n-propyl ether acetate, ethylene glycol mono-n-butyl Ethylene glycol monoalkyl ether acetates such as ether acetate; diethylene glycol dialkyl ether acetates such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol di-n-propyl ether, diethylene glycol di-n-butyl ether; propylene glycol monomethyl ether, propylene glycol monoethyl ether, Propylene glycol monoalkyl ethers such as propylene glycol mono-n-propyl ether and propylene glycol mono-n-butyl ether; propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol mono-n-propyl ether acetate, propylene glycol Propylene glycol monoalkyl ether acetates such as mono-n-butyl ether acetate; propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol di-n-propyl ether;
Propylene glycol dialkyl ethers such as propylene glycol di-n-butyl ether; methyl lactate,
Lactic esters such as ethyl lactate, n-propyl lactate, i-propyl lactate, n-butyl lactate, i-butyl lactate; methyl formate, ethyl formate, n-propyl formate, i-propyl formate, formic acid n-butyl, i-butyl formate, n-amyl formate, i-amyl formate, methyl acetate, ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-butyl acetate, n-acetic acid -Amyl, i-amyl acetate, n-hexyl acetate, methyl propionate, ethyl propionate, n-propyl propionate, i-propyl propionate, n-butyl propionate, i-butyl propionate, methyl butyrate, ethyl butyrate Aliphatic carboxylic acid esters such as n-propyl butyrate, i-propyl butyrate, n-butyl butyrate, i-butyl butyrate; ethyl hydroxyacetate;
Ethyl-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutyrate, ethyl methoxyacetate, ethyl ethoxyacetate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, methyl 3-ethoxypropionate, 3 -Ethyl ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-
Methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, methyl acetoacetate, ethyl acetoacetate,
Other esters such as methyl pyruvate and ethyl pyruvate; aromatic hydrocarbons such as toluene and xylene; methyl ethyl ketone, methyl n-propyl ketone, and methyl n-
Butyl ketone, 2-heptanone, 3-heptanone, 4-
Ketones such as heptanone and cyclohexanone; N-methylformamide, N, N-dimethylformamide, N-
Methylacetamide, N, N-dimethylacetamide,
Amides such as N-methylpyrrolidone; lactones such as γ-butyrolactone; These solvents are used alone or in combination of two or more.

Formation of Resist Pattern When forming a resist pattern from the radiation-sensitive resin composition of the present invention, the composition solution prepared as described above is applied by spin coating, casting coating, roll coating, or the like. For example, a resist film is formed by applying the resist to a substrate such as a silicon wafer or a wafer coated with aluminum by an appropriate coating means, and a heat treatment (hereinafter, referred to as “PB”) is performed in advance in some cases. After that, exposure is performed through a predetermined mask pattern. As the radiation used at that time, depending on the type of the acid generator (B), for example,
UV light such as i-ray (wavelength 365 nm), far ultraviolet light such as ArF excimer laser (wavelength 193 nm) and KrF excimer laser (wavelength 248 nm), X-rays such as synchrotron radiation, and charged particle beams such as electron beams are appropriately selected. Used. Exposure conditions such as the amount of exposure are appropriately selected according to the composition of the composition, the type of each additive, and the like. In the present invention, a heat treatment (hereinafter, “PEB”) is performed after exposure.
That. ) Is preferably performed. The heating conditions vary depending on the composition of the composition, the type of each additive and the like, but are usually 30 to 200 ° C, preferably 40 to 150 ° C. Next, a predetermined resist pattern is formed by developing the exposed resist film with an alkaline developer. Examples of the alkali developer include alkali metal hydroxides; aqueous ammonia; mono-, di- or tri-alkylamines; mono-, di- or tri-alkanolamines; heterocyclic amines; Ammonium hydroxides, choline, 1,8-diazabicyclo- [5,4,0] -7-undecene, 1,
Usually, at least one kind of alkaline compound such as 5-diazabicyclo- [4,3,0] -5-nonene is used in an amount of 1 to 10
An aqueous alkaline solution dissolved to a concentration of 1% by weight, preferably 1 to 5% by weight is used. Further, in the developer comprising the alkaline aqueous solution, for example, methanol,
An appropriate amount of a water-soluble organic solvent such as ethanol or a surfactant can be added. When a developer composed of an alkaline aqueous solution is used, washing is generally performed after development. When forming the resist pattern, a protective film may be provided on the resist film in order to prevent the influence of basic impurities and the like contained in the environmental atmosphere.

[0035]

Embodiments of the present invention will be described below more specifically with reference to examples. However, the present invention is not limited to these embodiments. Here, the measurement of Mw and Mn and the evaluation of each resist were performed in the following manner. Mw and Mn GPC columns manufactured by Tosoh Corporation (2 G2000H _XL , G
The measurement was performed by GPC using monodisperse polystyrene as a standard under the analysis conditions of 1.0 mL / min flow rate, elution solvent tetrahydrofuran, and column temperature of 40 ° C. using one 3000H _{XL and} one G4000H _XL ). Exposing the resist film formed on a sensitivity silicon wafer,
Immediately after exposure baking, alkali development,
When washed and dried to form a resist pattern,
The exposure amount for forming a line-and-space pattern (1L1S) having a line width of 0.26 μm with a line width of 1: 1 was defined as an optimum exposure amount, and the sensitivity was evaluated based on the optimum exposure amount. Resolution The minimum dimension (μm) of the line-and-space pattern resolved when the exposure was performed at the optimum exposure amount was defined as the resolution. In a line-and-space pattern having a pattern line width of 0.26 μm, the pattern cross section was measured using a scanning electron microscope, and when the upper line width of the pattern cross section was La and the lower line width was Lb, 0 .9 <La / Lb <1.1, the pattern shape was determined to be “good” and 0.9 ≧ La / Lb
Is the case where the pattern shape is “round-top” and L
When a / Lb ≧ 1.1, the pattern shape is “T-type”
Was evaluated.

[0036]

【Example】

Synthesis Example 1 Poly (p-hydroxystyrene) (Mw = 12,000
0) 24 g of acetone was dissolved in 96 ml of acetone, 9.7 g of t-butyl bromoacetate and 7.6 g of potassium carbonate were added, and the mixture was reacted under reflux with stirring for 8 hours. Then, the reaction solution was extracted with ethyl acetate, and 5% by weight.
After washing with an aqueous acetic acid solution and water, ethyl acetate and the like were distilled off under reduced pressure. Next, the obtained polymer was redissolved in acetone, and the solution was added dropwise to water to precipitate the polymer. The polymer was dried in a vacuum dryer at 50 ° C. overnight. The obtained polymer had Mw of 12,000 and M
w / Mn was 1.8. The ¹³ C-
As a result of NMR measurement, the product had a structure in which 23% of the hydrogen atoms in the phenolic hydroxyl group were replaced with a t-butoxycarbonyl group. This polymer was converted to a polymer (A
-1).

Synthesis Example 2 Poly (p-hydroxystyrene) (Mw = 12,000
0) 300 g was dissolved in 1200 ml of tetrahydrofuran, 650 g of triethylamine was added, and then di-t-butyl carbonate 20 was added under stirring at 60 ° C.
0 g was added and reacted for 6 hours. Next, the reaction solution was dropped into water to precipitate a polymer, and the polymer was dried overnight in a vacuum dryer at 50 ° C. The obtained polymer had Mw of 7,000 and Mw / Mn of 1.7. Further, when the ¹³ C-NMR of this polymer was measured, it was found that the polymer had a structure in which 25% of the hydrogen atoms in the phenolic hydroxyl group were substituted with a t-butoxycarbonyl group. This polymer is referred to as a polymer (A-2).

Synthesis Example 3 24 g of p-hydroxystyrene, 17 g of t-butyl acrylate and 50 g of propylene glycol monomethyl ether were mixed to form a homogeneous solution. Next, after bubbling this solution with nitrogen gas for 30 minutes,
1.9 g of 2'-azobis (4-methoxy-2,4-dimethylvaleronitrile) was added, and polymerization was carried out for 7 hours while maintaining the reaction temperature at 40 ° C. while bubbling with nitrogen gas was continued. After completion of the polymerization, the reaction solution was mixed with a large amount of n-hexane to coagulate the polymer. Next, after redissolving the polymer in acetone, the operation of coagulating again with n-hexane is repeated several times to remove unreacted monomers, and dried overnight in a vacuum dryer at 50 ° C. to give a white color. (A yield of 55% by weight) was obtained. The obtained polymer had Mw of 31,000 and Mw / Mn of 2.0. When ¹³ C-NMR of this polymer was measured, it was a copolymer having a copolymerization molar ratio of p-hydroxystyrene and t-butyl acrylate of 60:40. This copolymer is referred to as a polymer (A-3).

Synthesis Example 4 Poly (p-hydroxystyrene) (Mw = 12,000
0) 24 g was dissolved in 100 ml of dioxane, followed by bubbling with nitrogen gas for 30 minutes. To this solution, 8 g of ethyl vinyl ether and 1 g of pyridinium p-toluenesulfonate were added, and reacted under stirring for 12 hours. Next, the reaction solution was added dropwise to a 1% by weight aqueous ammonia solution to precipitate a polymer, and the polymer was dried overnight in a vacuum dryer at 50 ° C. The obtained polymer had Mw of 12,000 and Mw / Mn of 1.6. When ¹³ C-NMR of this polymer was measured, it was found that the polymer had a structure in which 45% of the hydrogen atoms in the phenolic hydroxyl group were substituted with 1-ethoxyethyl groups. This polymer is referred to as a polymer (A-4).

Synthesis Example 5 78 g of p-hydroxystyrene, 62 g of p-butoxystyrene and 150 g of propylene glycol monomethyl ether were mixed to form a homogeneous solution. Next, after bubbling this solution with nitrogen gas for 30 minutes, 7 g of azobisisobutyronitrile was added, and the reaction temperature was maintained at 70 ° C. while bubbling with nitrogen gas was continued.
The polymerization was carried out for 7 hours. After the polymerization, a large amount of n-
The polymer was coagulated by mixing with hexane. Next, after redissolving the polymer in acetone, the operation of coagulating again with n-hexane is repeated several times to remove unreacted monomers, and dried overnight in a vacuum dryer at 50 ° C. to give a white color. (A yield of 89% by weight) was obtained. The obtained polymer had Mw of 15,000 and Mw / Mn of 1.67.
Met. When ¹³ C-NMR of this polymer was measured, it was a copolymer having a copolymerization molar ratio of p-hydroxystyrene and p-butoxystyrene of 65:35.
This copolymer is referred to as a polymer (A-5).

Examples 1 to 5 and Comparative Examples 1 and 2 Each component shown in Table 1 (parts are based on weight) was mixed to form a homogeneous solution, which was then filtered through a membrane filter having a pore size of 0.2 μm. Thus, a composition solution was prepared. Next, each composition solution was spin-coated on a silicone wafer, and then subjected to PB for 90 seconds at a temperature shown in Table 2 to form a 0.7 μm-thick resist film. Next, after exposing this resist film using a KrF excimer laser stepper (trade name: NSR-2005 EX8A) manufactured by Nikon Corporation, PEB was performed for 90 seconds at the temperature shown in Table 2. Next, a 2.38% by weight aqueous solution of tetramethylammonium hydroxide was used for alkali development at 23 ° C. for 1 minute by an immersion method, followed by washing with pure water and drying to form a resist pattern. Table 2 shows the evaluation results of the respective resists. The acid generator (B), other acid generators, acid diffusion controllers and solvents shown in Table 1 are as follows. Acid generator (B)

B-1:

Embedded image

B-2:

Embedded image

Other acid generators

B-1:

Embedded image

B-2:

Embedded image

Acid diffusion controller C-1: tri-n-octylamine C-2: 4-phenylpyridine solvent PGMEA: propylene glycol monomethyl ether acetate EL: ethyl lactate EEP: ethyl 1-ethoxy-2-propionate MAK: Methyl n-amyl ketone

[0048]

[Table 1]

[0049]

[Table 2]

[0050]

The radiation-sensitive resin composition of the present invention can use various resist solvents, and is particularly excellent in resolution and pattern shape, and does not cause scum.
A high-precision fine pattern can be formed stably. Moreover, the radiation-sensitive resin composition of the present invention can effectively respond to various radiations such as ultraviolet rays, far ultraviolet rays, X-rays, and charged particle beams. Therefore, the radiation-sensitive resin composition of the present invention can be extremely suitably used, particularly as a chemically amplified positive resist, in the production of semiconductor devices in which miniaturization is expected to further advance in the future.

Continuation of the front page (72) Inventor Shinichiro Iwanaga 2-11-24 Tsukiji, Chuo-ku, Tokyo Inside Nippon Gosei Rubber Co., Ltd.

Claims (1)

[Claims] (1) (A) having a substituent which can be decomposed by an acid,
A radiation-sensitive resin composition comprising: a polymer whose solubility in an alkali developer is increased by the action of an acid; and (B) a radiation-sensitive acid generator represented by the following formula (1). Embedded image [In the formula (1), R ¹ represents an alkyl group having 1 to 6 carbon atoms or a phenyl group, and three R ^{1 s} may be the same or different, and R ² is an alkyl group having 1 to 10 carbon atoms. ,
C1-C10 perfluoroalkyl group, C6-C
It represents a 10-aryl group, an aralkyl group having 7 to 10 carbon atoms, or a group having an alicyclic skeleton having 4 to 12 carbon atoms. )