JPH10177247A - Radiation-sensitive resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation-sensitive resin composition having excellent sensitivity, resolution and pattern shape, excellent PED stability, and capable of stably forming a fine resist pattern with high accuracy. . SOLUTION: The composition comprises (A) a repeating unit derived from a monomer represented by vinylphenol and a repeating unit derived from a monomer represented by 2- (phenoxycarbonyl) ethyl (meth) acrylate. And (B) a radiation-sensitive acid generator.

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 resist suitable for fine processing using various radiations such as a beam or a charged particle beam.

[0002]

2. Description of the Related Art In the field of microfabrication represented by the manufacture of integrated circuit elements, design rules in lithography have been rapidly miniaturized in order to obtain a higher degree of integration of integrated circuits. The development of a lithography process capable of stably performing high-precision fine processing with a line width of 0.5 μm or less has been strongly promoted. However, conventional visible light (wavelength 700 to 400n)
m) or near-ultraviolet rays (wavelength 400 to 300 nm), it is difficult to form such a fine pattern with high precision, and therefore a wider depth of focus can be achieved, which is effective for miniaturizing design rules. Short wavelength (wavelength 3
A lithography process using radiation of less than or equal to 00 nm has been proposed. The lithography process using such short-wavelength radiation includes, for example, far ultraviolet rays such as KrF excimer laser (wavelength 248 nm) and ArF excimer laser (wavelength 193 nm), and charging of X-ray or electron beam such as synchrotron radiation. A method using a particle beam has been proposed. As a high-resolution resist corresponding to such short-wavelength radiation, International Business Machines (IBM) has proposed a "chemically amplified resist". Currently, improvement and development of this chemically amplified resist are under way. It is being energetically advanced. The chemically amplified resist generates an acid by irradiation of a radiation-sensitive acid generator contained therein (hereinafter, referred to as “exposure”), and the acid acts as a catalyst.
A pattern is formed by using a phenomenon in which a chemical reaction (for example, a change in polarity, decomposition of a chemical bond, a cross-linking reaction, and the like) occurs in a resist film and solubility in a developing solution changes in an exposed portion. . Conventionally, among such chemically amplified resists, those showing relatively good resist performance, as a resin component, an alkali-affinity group in an alkali-soluble resin was protected with a t-butyl ester group or a t-butoxycarbonyl group. Resin (see Japanese Patent Publication No. 2-27660), a resin in which an alkali-affinity group in an alkali-soluble resin is protected with a silyl group (see Japanese Patent Publication No. 3-44290), a resin containing a (meth) acrylic acid component ( JP-B-4-39665), a resin in which an alkali-affinity group in an alkali-soluble resin is protected with a ketal group (see JP-A-7-140666), and an alkali-affinity group in an alkali-soluble resin with an acetal group. Protected resin (JP-A-2-161436 and JP-A-5-2496)
No. 82) is known. However, it has been pointed out that each of these chemically amplified resists has its own problems and involves various difficulties in practical use. One major problem is the post-exposure bake time (Post Exposur
e Time Delay, hereinafter referred to as “PED”. ), The line width of the resist pattern is changed, or an eave is formed at the top of the pattern to form a T-top shape. Moreover, in addition to the above problems, the resolution, baking temperature dependency, process stability, and the like are not sufficient, and further improvement is strongly demanded from the viewpoint of overall characteristics as a chemically amplified resist. Further, among the chemically amplified resists using the specific resin component, a resist using a resin in which an alkali-affinity group in an alkali-soluble resin is protected by a ketal group or an acetal group is given as a positive resist. Although it has been reported that the above-mentioned problems as an amplification type resist can be improved to some extent, on the other hand, resins protected with these ketal groups or acetal groups have poor stability, are easily affected by moisture and the like, and have poor storage stability. Problems such as lack are pointed out. Furthermore, P
In order to improve the ED stability, heat treatment after exposure (hereinafter referred to as “post-exposure bake”) may be performed at a relatively high temperature of about 130 ° C., but post-exposure bake at such a high temperature. Is performed, there is a problem that the pattern shape, sensitivity, resolution, and the like are impaired.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to effectively respond to various kinds of radiation such as ultraviolet rays, far ultraviolet rays, X-rays and charged particle beams, to have excellent sensitivity, resolution and pattern shape, and to have a PED stability. It is possible to stably form a high-precision fine resist pattern,
An object of the present invention is to provide a radiation-sensitive resin composition useful as a chemically amplified positive resist.

[0004]

According to the present invention, the above objects are achieved by (A) a repeating unit (1) represented by the following general formula (1) and a repeating unit (1) represented by the following general formula (2): 2)
And (B) a radiation-sensitive resin composition containing a radiation-sensitive acid generator.

[0005]

Embedded image [In the general formula (1), R ¹ represents a hydrogen atom or a methyl group. ]

[0006]

Embedded image [In the general formula (2), R ² , R ³ and R ⁴ each independently represent a hydrogen atom or a methyl group, and R ⁵ represents an alkylene group having 1 to 6 carbon atoms or an alkylene group having 2 to 6 carbon atoms. R ⁶ represents a linear or branched alkyl group having 1 to 10 carbon atoms, a linear or branched halogenated alkyl group having 1 to 10 carbon atoms, a cyclic alkyl group having 3 to 11 carbon atoms, Group, aryl group having 6 to 10 carbon atoms or 7 carbon atoms
Represents an aralkyl group of 1 to 11, and n is an integer of 0 to 5. ]

Hereinafter, the present invention will be described in detail. (A) Copolymer The copolymer (A) used in the present invention comprises a repeating unit (1) represented by the general formula (1) and a repeating unit (2) represented by the following general formula (2). ) Is an essential constituent unit. Specific examples of the monomer giving the repeating unit (1) include o-vinylphenol, m-vinylphenol, p-vinylphenol, o-isopropenylphenol, m-isopropenylphenol, p-vinylphenol, and p-vinylphenol.
-Isopropenylphenol. Of these monomers, p-vinylphenol and p-isopropenylphenol are preferred. As the repeating unit (1) in the copolymer (A), one or more kinds may be present. (A) The content of the repeating unit (1) in the copolymer is usually 20 to 80 mol%, preferably 40 to 80 mol%, more preferably 40 to 75 mol%. In this case, when the content of the repeating unit (1) is less than 20 mol%, the sensitivity and dry etching resistance as a resist tend to decrease, while when it exceeds 80 mol%, the resolution as a resist tends to decrease. is there.

Next, in the general formula (2), examples of the alkylene group having 1 to 6 carbon atoms for R ⁵ include a methylene group,
Ethylene group, trimethylene group, propylene group, tetramethylene group, 1,2-butylene group, 1,3-butylene group,
Examples thereof include a 2,3-butylene group, a pentamethylene group, and a hexamethylene group. Examples of the alkylidene group having 2 to 6 carbon atoms for R ⁵ include an ethylidene group, a propylidene group, an i-propylidene group, a butylidene group, a pentylidene group, and a hexylidene group. Examples of the linear or branched alkyl group having 1 to 10 carbon atoms for R ⁶ include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, and an i-butyl group. , Sec-butyl group, t-butyl group, n-pentyl group, neopentyl group, n-hexyl group, n-heptyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group, etc. Can be mentioned. Examples of the linear or branched halogenated alkyl group having 1 to 10 carbon atoms for R ⁶ include a fluorinated derivative, a chlorinated derivative, and a brominated derivative of the alkyl group having 1 to 10 carbon atoms.
Specifically, trifluoromethyl, pentafluoroethyl, heptafluoropropyl, nonafluorobutyl, undecafluoropentyl, undecafluorohexyl, tridecafluoroheptyl, pentadecafluorooctyl, heptadeca Examples thereof include a fluorononyl group, a nonadecafluorodecyl group, a chloromethyl group, a 1,2-dichloroethyl group, a 1,2,3-trichloropropyl group, a bromomethyl group, and a 1,2-dibromoethyl group. Examples of the cyclic alkyl group having 3 to 11 carbon atoms of R ⁶ include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecanyl group, a norbornyl group, and an isobornyl group. Can be. Examples of the aryl group having 6 to 10 carbon atoms for R ⁶ include a phenyl group, a tolyl group, a xylyl group, a cumenyl group, and a 1-naphthyl group. Examples of the aralkyl group having 7 to 11 carbon atoms of R ⁶ include a benzyl group, an α-methylbenzyl group, a phenethyl group, and a naphthylmethyl group. Further, n is preferably an integer of 0 to 2, and more preferably 0 or 1.

Among the monomers giving the repeating unit represented by the general formula (2), specific examples of the monomer having n = 0 include 2
-(Methoxycarbonyl) ethyl (meth) acrylate, 2- (ethoxycarbonyl) ethyl (meth) acrylate, 2- (n-propoxycarbonyl) ethyl (meth) acrylate, 2- (i-propoxycarbonyl)
Ethyl (meth) acrylate, 2- (n-butoxycarbonyl) ethyl (meth) acrylate, 2- (t-butoxycarbonyl) ethyl (meth) acrylate, 2-
(Trifluoromethoxycarbonyl) ethyl (meth) acrylate, 2- (pentafluoroethoxycarbonyl) ethyl (meth) acrylate, 2- (heptafluoropropoxycarbonyl) ethyl (meth) acrylate, 2- (cyclopentyloxycarbonyl) ethyl (meth) ) Acrylate, 2- (cyclohexyloxycarbonyl) ethyl (meth) acrylate, 2- (cyclodecanyloxycarbonyl) ethyl (meth) acrylate, 2- (isobornyloxycarbonyl) ethyl (meth) acrylate, 2- (phenoxy) Carbonyl) ethyl (meth) acrylate, 2- (benzyloxycarbonyl) ethyl (meth) acrylate, 1-methyl-2-
(Methoxycarbonyl) ethyl (meth) acrylate,
1-methyl-2- (ethoxycarbonyl) ethyl (meth) acrylate, 1-methyl-2- (n-propoxycarbonyl) ethyl (meth) acrylate, 1-methyl-2- (i-propoxycarbonyl) ethyl (meth) Acrylate, 1-methyl-2- (n-butoxycarbonyl) ethyl (meth) acrylate, 1-methyl-2-
(T-butoxycarbonyl) ethyl (meth) acrylate, 1-methyl-2- (trifluoromethoxycarbonyl) ethyl (meth) acrylate, 1-methyl-2-
(Pentafluoroethoxycarbonyl) ethyl (meth)
Acrylate, 1-methyl-2- (heptafluoropropoxycarbonyl) ethyl (meth) acrylate, 1-
Methyl-2- (cyclohexyloxycarbonyl) ethyl (meth) acrylate, 1-methyl-2- (cyclodecanyloxycarbonyl) ethyl (meth) acrylate, 1-methyl-2- (isobornyloxycarbonyl) ethyl (meth) ) Acrylate, 1-methyl-2-
(Phenoxycarbonyl) ethyl (meth) acrylate, 1-methyl-2- (benzyloxycarbonyl) ethyl (meth) acrylate, 2-methyl-2- (methoxycarbonyl) ethyl (meth) acrylate, 2-methyl-2- ( Ethoxycarbonyl) ethyl (meth) acrylate, 2-methyl-2- (n-propoxycarbonyl) ethyl (meth) acrylate, 2-methyl-2-
(I-propoxycarbonyl) ethyl (meth) acrylate, 2-methyl-2- (n-butoxycarbonyl) ethyl (meth) acrylate, 2-methyl-2- (t-butoxycarbonyl) ethyl (meth) acrylate, 2-
Methyl-2- (trifluoromethoxycarbonyl) ethyl (meth) acrylate, 2-methyl-2- (pentafluoroethoxycarbonyl) ethyl (meth) acrylate, 2-methyl-2- (heptafluoropropoxycarbonyl) ethyl (meth) Acrylate, 2-methyl-2
-(Cyclohexyloxycarbonyl) ethyl (meth)
Acrylate, 2-methyl-2- (cyclodecanyloxycarbonyl) ethyl (meth) acrylate, 2-methyl-2- (isobornyloxycarbonyl) ethyl (meth) acrylate, 2-methyl-2- (phenoxycarbonyl) Ethyl (meth) acrylate, 2-methyl-2
-(Benzyloxycarbonyl) ethyl (meth) acrylate and the like. Among these monomers, 2- (n-butoxycarbonyl) ethyl (meth) acrylate, 2- (t-butoxycarbonyl) ethyl (meth) acrylate, 2- (cyclohexyloxycarbonyl) ethyl (meth) acrylate, -(Cyclodecanyloxycarbonyl) ethyl (meth) acrylate, 2- (isobornyloxycarbonyl) ethyl (meth) acrylate, 2- (phenoxycarbonyl) ethyl (meth) acrylate and the like are preferable.

Further, specific examples of the monomer having n = 1 include:
2- (methoxyethoxycarbonyl) ethyl (meth) acrylate, 2- (ethoxyethoxycarbonyl) ethyl (meth) acrylate, 2- (n-propoxyethoxycarbonyl) ethyl (meth) acrylate, 2- (i
-Propoxyethoxycarbonyl) ethyl (meth) acrylate, 2- (n-butoxyethoxycarbonyl) ethyl (meth) acrylate, 2- (t-butoxyethoxycarbonyl) ethyl (meth) acrylate, 2- (trifluoromethoxyethoxycarbonyl) Ethyl (meth) acrylate, 2- (pentafluoroethoxyethoxycarbonyl) ethyl (meth) acrylate, 2-
(Heptafluoropropoxyethoxycarbonyl) ethyl (meth) acrylate, 2- (cyclohexyloxyethoxycarbonyl) ethyl (meth) acrylate, 2
-(Cyclodecanyloxyethoxycarbonyl) ethyl (meth) acrylate, 2- (isobornyloxyethoxycarbonyl) ethyl (meth) acrylate, 2-
(Phenoxyethoxycarbonyl) ethyl (meth) acrylate, 2- (benzyloxyethoxycarbonyl)
Ethyl (meth) acrylate, 1-methyl-2- (methoxyethoxycarbonyl) ethyl (meth) acrylate, 1-methyl-2- (ethoxyethoxycarbonyl)
Ethyl (meth) acrylate, 1-methyl-2- (n-
Propoxyethoxycarbonyl) ethyl (meth) acrylate, 1-methyl-2- (i-propoxyethoxycarbonyl) ethyl (meth) acrylate, 1-methyl-
2- (n-butoxyethoxycarbonyl) ethyl (meth) acrylate, 1-methyl-2- (t-butoxyethoxycarbonyl) ethyl (meth) acrylate, 1-
Methyl-2- (trifluoromethoxyethoxycarbonyl) ethyl (meth) acrylate, 1-methyl-2-
(Pentafluoroethoxyethoxycarbonyl) ethyl (meth) acrylate, 1-methyl-2- (heptafluoropropoxyethoxycarbonyl) ethyl (meth) acrylate, 1-methyl-2- (cyclohexyloxyethoxycarbonyl) ethyl (meth) acrylate, 1
-Methyl-2- (cyclodecanyloxyethoxycarbonyl) ethyl (meth) acrylate, 1-methyl-2-
(Isobornyloxyethoxycarbonyl) ethyl (meth) acrylate, 1-methyl-2- (phenoxyethoxycarbonyl) ethyl (meth) acrylate, 1-methyl-2- (benzyloxyethoxycarbonyl) ethyl (meth) acrylate, 2 -Methyl-2- (methoxyethoxycarbonyl) ethyl (meth) acrylate, 2
-Methyl-2- (ethoxyethoxycarbonyl) ethyl (meth) acrylate, 2-methyl-2- (n-propoxyethoxycarbonyl) ethyl (meth) acrylate, 2-methyl-2- (i-propoxyethoxycarbonyl) ethyl ( Meth) acrylate, 2-methyl-2-
(N-butoxyethoxycarbonyl) ethyl (meth) acrylate, 2-methyl-2- (t-butoxyethoxycarbonyl) ethyl (meth) acrylate, 2-methyl-2- (trifluoromethoxyethoxycarbonyl) ethyl (meth) acrylate , 2-Methyl-2- (pentafluoroethoxyethoxycarbonyl) ethyl (meth)
Acrylate, 2-methyl-2- (heptafluoropropoxyethoxycarbonyl) ethyl (meth) acrylate, 2-methyl-2- (cyclohexyloxyethoxycarbonyl) ethyl (meth) acrylate, 2-methyl-2- (cyclodecanyloxy) Ethoxycarbonyl) ethyl (meth) acrylate, 2-methyl-2- (isobornyloxyethoxycarbonyl) ethyl (meth) acrylate, 2-methyl-2- (phenoxyethoxycarbonyl) ethyl (meth) acrylate, 2-methyl- 2
-(Benzyloxyethoxycarbonyl) ethyl (meth) acrylate and the like. Of these monomers, 2- (n-butoxyethoxycarbonyl)
Ethyl (meth) acrylate, 2- (t-butoxyethoxycarbonyl) ethyl (meth) acrylate, 2-
(Cyclohexyloxyethoxycarbonyl) ethyl (meth) acrylate, 2- (cyclodecanyloxyethoxycarbonyl) ethyl (meth) acrylate, 2-
(Isobornyloxyethoxycarbonyl) ethyl (meth) acrylate, 2- (phenoxyethoxycarbonyl) ethyl (meth) acrylate, 2- (benzyloxyethoxycarbonyl) ethyl (meth) acrylate and the like are preferable.

(A) Repeating unit (2) in copolymer
Can be one or more. (A) The content of the repeating unit (2) in the copolymer is usually 20 to 80 mol%, preferably 20 to 60 mol%, more preferably 25 to 60 mol%. In this case, the repeating unit (2)
If the content is less than 20 mol%, the resolution as a resist tends to decrease, while if it exceeds 80 mol%,
The sensitivity as a resist and the dry etching resistance tend to decrease. The repeating unit (2) in the (A) copolymer has a group that can be decomposed by the action of an acid, and is decomposed by the action of an acid generated from an acid generator (B) described below, and It is a component that produces a carboxyl group having an affinity and is capable of being decomposed by an acid even at a lower temperature than a conventional repeating unit having a t-butyl ester group. Therefore, the radiation-sensitive resin composition of the present invention containing the copolymer (A) can lower the post-exposure bake temperature.

The copolymer (A) may have at least one other repeating unit in addition to the repeating unit (1) and the repeating unit (2). Examples of the monomer that gives the other repeating unit include styrene, α-methylstyrene, p-methylstyrene, chlorostyrenes, p-methoxystyrene, pt-butoxystyrene, and pt-butoxycarbonyloxy. Styrene, p-
aromatic vinyl compounds such as t-butoxycarbonyloxymethoxystyrene; heteroatom-containing alicyclic vinyl compounds such as N-vinylpyrrolidone and N-vinylcaprolactam; vinyl compounds containing cyano groups such as (meth) acrylonitrile and vinylidene cyanide; Amide group-containing vinyl compounds such as (meth) acrylamide and N, N-dimethyl (meth) acrylamide; methyl (meth) acrylate,
Ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-
Butyl (meth) acrylate, i-butyl (meth) acrylate, sec-butyl (meth) acrylate, t-
Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, cyclohexyl (meth) acrylate, cyclodecanyl (meth) acrylate, isobornyl (meth) acrylate, (Meth) acrylic esters such as phenyl (meth) acrylate and benzyl (meth) acrylate can be exemplified. Among these monomers, styrene, pt-butoxystyrene, pt-butoxycarbonyloxystyrene, t-butyl (meth) acrylate, cyclodecanyl (meth) acrylate, isobornyl (meth) acrylate, phenyl (meth) Acrylate, benzyl (meth) acrylate and the like are preferred.
The monomer giving the other repeating unit may be used alone or
A mixture of more than one species can be used. In the present invention, when the copolymer (A) has the other repeating unit, the alkali solubility of the copolymer, particularly after exposure, can be controlled. The content of the other repeating units in the copolymer (A) differs depending on the proportion of the repeating units (1) and (2) used. Usually, it is 0 to 50 mol%, preferably 0 to 40 mol%, and more preferably 10 to 40 mol%. In this case, the content of other repeating units is 50
If it exceeds mol%, the solubility in an alkali developer as a resist tends to decrease.

The copolymer (A) can be prepared, for example, by adding (a) p-hydroxystyrene or p-isopropenylphenol and a monomer which gives the repeating unit (2), and optionally a monomer which gives another repeating unit. (B) p-acetoxystyrene or p-acetoxy-α-methylstyrene and a monomer giving a repeating unit (2), and optionally a monomer giving another repeating unit In addition, it can be produced by a method of copolymerizing and then hydrolyzing under basic conditions. The above (a)
The copolymerization in the methods (b) and (b) can be carried out by a known method using a polymerization initiator, a molecular weight regulator and the like. Examples of the polymerization initiator include benzoyl peroxide, lauroyl peroxide, 2,2 ′
-Azobisisobutyronitrile, 4,4'-azobis (4-cyanovaleric acid), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), etc., alone or in combination of two or more Can be used in combination. Further, as the molecular weight regulator, for example, carbon tetrachloride,
Halogenated hydrocarbons such as chloroform and carbon tetrabromide;
Mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, n-decyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, thioglycolic acid, thiopropionic acid; dimethyl xanthogen disulfide, di-i-propyl xanthogen disulfide Xanthogens; terpinolene, α
-Methylstyrene dimer and the like can be used alone or in combination of two or more.

The preferred copolymer (A) in the present invention is a combination of a monomer corresponding to each repeating unit,
More specifically, p-vinylphenol / 2-
(N-butoxycarbonyl) ethyl (meth) acrylate copolymer, p-vinylphenol / 2- (t-butoxycarbonyl) ethyl (meth) acrylate copolymer,
p-vinylphenol / 2- (cyclohexyloxycarbonyl) ethyl (meth) acrylate copolymer, p-
Vinylphenol / 2- (cyclodecanyloxycarbonyl) ethyl (meth) acrylate copolymer, p-vinylphenol / 2- (isobornyloxycarbonyl)
Ethyl (meth) acrylate copolymer, p-vinylphenol / 2- (phenoxycarbonyl) ethyl (meth)
Acrylate copolymer, p-vinylphenol / 2-
(Benzyloxycarbonyl) ethyl (meth) acrylate copolymer, p-isopropenylphenol / 2-
(N-butoxycarbonyl) ethyl (meth) acrylate copolymer, p-isopropenylphenol / 2- (t
-Butoxycarbonyl) ethyl (meth) acrylate copolymer, p-isopropenylphenol / 2- (cyclohexyloxycarbonyl) ethyl (meth) acrylate copolymer, p-isopropenylphenol / 2- (cyclodecanyloxycarbonyl) Ethyl (meth) acrylate copolymer, p-isopropenylphenol / 2-
Isobornyloxycarbonylethyl (meth) acrylate copolymer, p-isopropenylphenol / 2-
(Phenoxycarbonyl) ethyl (meth) acrylate copolymer, p-isopropenylphenol / 2- (benzyloxycarbonyl) ethyl (meth) acrylate copolymer, p-vinylphenol / 2- (n-butoxycarbonyl) ethyl ( (Meth) acrylate / styrene copolymer, p-vinylphenol / 2- (t-butoxycarbonyl) ethyl (meth) acrylate / styrene copolymer, p-vinylphenol / 2- (cyclohexyloxycarbonyl) ethyl (meth) acrylate / Styrene copolymer, p-vinylphenol / 2- (cyclodecanyloxycarbonyl) ethyl (meth) acrylate / styrene copolymer, p-vinylphenol / 2- (isobornyloxycarbonyl) ethyl (meth) acrylate / Styrene copolymer P-vinylphenol / 2- (phenoxycarbonyl) ethyl (meth) acrylate / styrene copolymer, p-vinylphenol / 2- (benzyloxycarbonyl) ethyl (meth) acrylate / styrene copolymer, p-isopropenyl Phenol / 2-
(N-butoxycarbonyl) ethyl (meth) acrylate / styrene copolymer, p-isopropenylphenol / 2- (t-butoxycarbonyl) ethyl (meth) acrylate / styrene copolymer, p-isopropenylphenol / 2- (Cyclohexyloxycarbonyl) ethyl (meth) acrylate / styrene copolymer, p-isopropenylphenol / 2- (cyclodecanyloxycarbonyl) ethyl (meth) acrylate / styrene copolymer, p-isopropenylphenol / 2- (Isobornyloxycarbonyl) ethyl (meth) acrylate /
Styrene copolymer, p-isopropenylphenol / 2
-(Phenoxycarbonyl) ethyl (meth) acrylate / styrene copolymer, p-isopropenylphenol / 2- (benzyloxycarbonyl) ethyl (meth) acrylate / styrene copolymer and the like.

Among these copolymers, p-vinylphenol / 2- (t-butoxycarbonyl) ethyl (meth) acrylate copolymer and p-vinylphenol / 2- (cyclohexyloxycarbonyl) ethyl (meth) ) Acrylate copolymer, p-vinylphenol / 2
-(Cyclodecanyloxycarbonyl) ethyl (meth)
Acrylate copolymer, p-vinylphenol / 2-
(Isobornyloxycarbonyl) ethyl (meth) acrylate copolymer, p-vinylphenol / 2- (phenoxycarbonyl) ethyl (meth) acrylate copolymer, p-vinylphenol / 2- (benzyloxycarbonyl) ethyl ( (Meth) acrylate copolymer, p-isopropenylphenol / 2- (t-butoxycarbonyl) ethyl (meth) acrylate copolymer, p-isopropenylphenol / 2- (cyclohexyloxycarbonyl) ethyl (meth) acrylate copolymer Union, p-isopropenylphenol / 2- (cyclodecanyloxycarbonyl) ethyl (meth) acrylate copolymer, p
-Isopropenylphenol / 2- (isobornyloxycarbonyl) ethyl (meth) acrylate copolymer,
p-isopropenylphenol / 2- (phenoxycarbonyl) ethyl (meth) acrylate copolymer, p-isopropenylphenol / 2- (benzyloxycarbonyl) ethyl (meth) acrylate copolymer, p-vinylphenol / 2- (T-butoxycarbonylethyl (meth) acrylate / styrene copolymer, p-vinylphenol / 2- (cyclohexyloxycarbonyl)
Ethyl (meth) acrylate / styrene copolymer, p-
Vinylphenol / 2- (cyclodecanyloxycarbonyl) ethyl (meth) acrylate / styrene copolymer, p-vinylphenol / 2- (isobornyloxycarbonyl) ethyl (meth) acrylate / styrene copolymer, p- Vinylphenol / 2- (phenoxycarbonyl) ethyl (meth) acrylate / styrene copolymer, p-vinylphenol / 2- (benzyloxycarbonyl) ethyl (meth) acrylate / styrene copolymer, p-isopropenylphenol / 2 -(T-butoxycarbonyl) ethyl (meth) acrylate / styrene copolymer, p-isopropenylphenol / 2- (cyclohexyloxycarbonyl) ethyl (meth) acrylate / styrene copolymer, p-isopropenylphenol / 2- (Cyclode Nyloxycarbonyl) ethyl (meth) acrylate / styrene copolymer, p-isopropenylphenol / 2- (isobornyloxycarbonyl) ethyl (meth) acrylate / styrene copolymer, p-isopropenylphenol / 2- ( Phenoxycarbonyl) ethyl (meth) acrylate / styrene copolymer, p-isopropenylphenol / 2- (benzyloxycarbonyl) ethyl (meth) acrylate / styrene copolymer and the like are preferable. (A) The copolymer has a weight average molecular weight in terms of polystyrene (hereinafter referred to as “Mw”) by gel permeation chromatography (GPC) of usually 1,000 to 100,000, preferably 3,000 to 70. 000, more preferably 5,
000 to 50,000. In this case, if the Mw of the copolymer (A) is less than 1,000, the sensitivity, heat resistance and the like as a resist tend to decrease, while 100,00
If it exceeds 0, the solubility in an alkaline developer as a resist tends to decrease. In the present invention,
(A) The copolymer can be used alone or in combination of two or more.

(B) Radiation-Sensitive Acid Generator The (B) radiation-sensitive acid generator (hereinafter referred to as “(B) acid generator”) used in the present invention includes, for example, onium salts and sulfones. Compounds, sulfonic acid ester compounds, sulfonimide compounds, diazomethane compounds and the like can be mentioned. Examples of these (B) acid generators are shown below. Onium salt Examples of the onium salt include an iodonium salt, a sulfonium salt, a phosphonium salt, a diazonium salt, a pyridinium salt and the like. Specific examples of the onium salt include diphenyliodonium triflate, diphenyliodonium pyrene sulfonate, diphenyliodonium dodecylbenzenesulfonate, triphenylsulfonium triflate, diphenyliodonium hexafluoroantimonate, triphenylsulfonium naphthalenesulfonate, triphenylsulfonium camphorsulfonate, ( (Hydroxyphenyl) benzylmethylsulfonium toluenesulfonate; Sulfone compound As the sulfone compound, for example, β-ketosulfone,
β-sulfonylsulfone, and α-diazo compounds thereof. Specific examples of the sulfone compound include phenacylphenylsulfone, mesitylphenacylsulfone, bis (phenylsulfonyl) methane, 4-trisphenacylsulfone, and the like. Sulfonic acid ester compound Examples of the sulfonic acid ester compound include an alkylsulfonic acid ester, a haloalkylsulfonic acid ester, an arylsulfonic acid ester, and iminosulfonate. Specific examples of the sulfonic acid ester compound include benzoin tosylate, pyrogallol tris triflate, pyrogallol methanesulfonic acid triester, nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate, α-methylol benzoin tosylate, α-methylol benzoin tosylate Examples include methylol benzoin octane sulfonic acid ester, α-methylol benzoin trifluoromethane sulfonic acid ester, α-methylol benzoindodecane sulfonic acid ester, and the like. Sulfonimide compound Examples of the sulfonimide compound include a compound represented by the following general formula (3).

[0017]

Embedded image

[In the general formula (3), Q represents a divalent group such as an alkylene group, an arylene group or an alkoxylene group, and R ⁷ represents an alkyl group, an aryl group, a halogenated alkyl group, a halogenated aryl group or the like. Represents a monovalent group of Specific examples of the sulfonimide compound include N- (trifluoromethylsulfonyloxy) succinimide, N-
(Trifluoromethylsulfonyloxy) phthalimide, N- (trifluoromethylsulfonyloxy) diphenylmaleimide, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-
2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) -7-oxabicyclo [2.2.
1] Hept-5-ene-2,3-dicarboximide, N
-(Trifluoromethylsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3-dicarboximide, N- (trifluoromethylsulfonyloxy) naphthyldicarboximide, N- (camphor N-sulfonyloxy) succinimide, N- (campanylsulfonyloxy) phthalimide, N- (campanylsulfonyloxy) diphenylmaleimide, N-
(Camphanylsulfonyloxy) bicyclo [2.2.
1] Hept-5-ene-2,3-dicarboximide, N
-(Campanylsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (campanylsulfonyloxy) bicyclo [2.2.1] heptane -5,6-oxy-2,
3-dicarboximide, N- (campanylsulfonyloxy) naphthyldicarboximide, N- (4-methylphenylsulfonyloxy) succinimide, N- (4
-Methylphenylsulfonyloxy) phthalimide, N
-(4-methylphenylsulfonyloxy) diphenylmaleimide, N- (4-methylphenylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3
-Dicarboximide, N- (4-methylphenylsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (4-
Methylphenylsulfonyloxy) bicyclo [2.2.
1] Heptane-5,6-oxy-2,3-dicarboximide, N- (4-methylphenylsulfonyloxy) naphthyldicarboximide, N- (2-trifluoromethylphenylsulfonyloxy) succinimide, N-
(2-trifluoromethylphenylsulfonyloxy)
Phthalimide, N- (2-trifluoromethylphenylsulfonyloxy) diphenylmaleimide, N- (2-
Trifluoromethylphenylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (2-trifluoromethylphenylsulfonyloxy) -7-oxabicyclo [2.2 .1] hept-5-ene-2,3-dicarboximide, N- (2
-Trifluoromethylphenylsulfonyloxy) bicyclo [2.2.1] heptane-5,6-oxy-2,3
-Dicarboximide, N- (2-trifluoromethylphenylsulfonyloxy) naphthyldicarboximide,
N- (4-fluorophenylsulfonyloxy) succinimide, N- (2-fluorophenylsulfonyloxy) phthalimide, N- (4-fluorophenylsulfonyloxy) diphenylmaleimide, N- (4-fluorophenylsulfonyloxy) bicyclo [2 2.1]
Hept-5-ene-2,3-dicarboximide, N-
(4-Fluorophenylsulfonyloxy) -7-oxabicyclo [2.2.1] hept-5-ene-2,3-
Dicarboximide, N- (4-fluorophenylsulfonyloxy) bicyclo [2.2.1] heptane-5,6
-Oxy-2,3-dicarboximide, N- (4-fluorophenylsulfonyloxy) naphthyldicarboximide and the like. Diazomethane compound Examples of the diazomethane compound include a compound represented by the following formula (4).

[0019]

Embedded image

[In the general formula (4), R ⁸ and R ⁹ each independently represent a monovalent group such as an alkyl group, an aryl group, a halogen-substituted alkyl group, and a halogen-substituted aryl group. Specific examples of the diazomethane compound include bis (trifluoromethylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (phenylsulfonyl) diazomethane, bis (p-toluenesulfonyl) diazomethane, methylsulfonyl-p-toluenesulfonyldiazomethane, Examples thereof include 1-cyclohexylsulfonyl-1- (1,1-dimethylethylsulfonyl) diazomethane and bis (1,1-dimethylethylsulfonyl) diazomethane. Of these acid generators (B), onium salts, sulfonic acid ester compounds, sulfonimide compounds and diazomethane compounds are preferred, and in particular, triphenylsulfonium triflate, pyrogallol methanesulfonic acid triester,
α-methylol benzoin tosylate, α-methylol benzoin octane sulfonate, α-methylol benzoin trifluoromethane sulfonate,
α-methylol benzoindodecansulfonic acid ester, N- (trifluoromethylsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (campanylsulfonyloxy) bicyclo [ 2.2.1] Hept-5-ene-2,3-dicarboximide, N- (campanylsulfonyloxy)
Naphthyldicarboximide, bis (cyclohexylsulfonyl) diazomethane and the like are preferred. In the present invention,
(B) The acid generators can be used alone or in combination of two or more. The amount of the acid generator (B) used in the present invention is appropriately selected depending on the type of each acid generator, and is usually from 1 to 2 per 100 parts by weight of the copolymer (A).
0 parts by weight, preferably 1 to 10 parts by weight. In this case, if the amount of (B) the acid generator used is less than 1 part by weight, it may be difficult to sufficiently cause a chemical change due to the catalytic action of the acid generated by exposure, and if it exceeds 20 parts by weight. When applying the composition, there is a possibility that uneven coating may occur or scum may occur during development.

Acid Diffusion Control Agent In the present invention, furthermore, the action of controlling the diffusion phenomenon of the acid generated from the acid generator (B) in the resist film by exposure to light, thereby suppressing an undesirable chemical reaction in the unexposed area. It is preferable to add an acid diffusion controller having the following.
By using such an acid diffusion controller, the storage stability of the composition is improved, the resolution as a resist is improved, and the line width change of the resist pattern due to the fluctuation of the PED can be suppressed. It becomes extremely excellent in stability. As such an acid diffusion controlling agent, a nitrogen-containing organic compound whose basicity does not change by exposure or baking during a resist pattern forming step is preferable. Such nitrogen-containing organic compounds include, for example, those represented by the general formula R ¹⁰ R
¹¹ R ¹² N (wherein R ¹⁰ , R ¹¹ and R ¹² each independently represent 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 polymer having three or more nitrogen atoms (hereinafter, referred to as" nitrogen-containing compound (III) ) "), An amide group-containing compound,
Examples include urea compounds and nitrogen-containing heterocyclic compounds.

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, di-n-decylamine; triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine , Tri-n-hexylamine, tri-n-heptylamine,
Tri-n-octylamine, tri-n-nonylamine,
Trialkylamines such as tri-n-decylamine; aniline, N-methylaniline, N, N-dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline, diphenylamine, triphenyl Examples thereof include aromatic amines such as amine and naphthylamine.

Examples of the nitrogen-containing compound (II) include ethylenediamine, N, N, N ', N'-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenylmethane,
4,4'-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, 1,4-bis [1- (4-aminophenyl) -1-
Methylethyl] benzene, 1,3-bis [1- (4-aminophenyl) -1-methylethyl] benzene and the like.

Examples of the nitrogen-containing compound (III) include (co) polymers of polyethyleneimine, polyallylamine and dimethylaminoethyl (meth) acrylamide. 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. Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, and tributylthiourea. be able to. Examples of the nitrogen-containing heterocyclic compound include imidazole, benzimidazole, 4-methylimidazole, and 4-methyl-2.
Imidazoles such as -phenylimidazole; pyridine, 2-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,
Quinozaline, 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 controller can be used alone or in combination of two or more. The amount of the acid diffusion controller used in the present invention is (A) per 100 parts by weight of the copolymer,
Usually, it is 15 parts by weight or less, preferably 0.001 to 10 parts by weight, more preferably 0.005 to 5 parts by weight.
In this case, when the use amount of the acid diffusion controller exceeds 15 parts by weight, the sensitivity as a resist and the developability of an exposed portion tend to decrease. The amount of the acid diffusion controller used was 0.001.
If the amount is less than part by weight, the pattern shape and dimensional fidelity as a resist may be reduced depending on the process conditions.

Alkali-Soluble Resin In the present invention, an alkali-soluble resin other than the copolymer (A) can be blended, if necessary. The alkali-soluble resin is a resin which is soluble in an alkali developer and has at least one kind of a functional group having an affinity for an alkali developer, 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, vinylphenol, isopropenylphenol, vinylbenzoic acid,
Ethylenically unsaturated monomers having acidic functional groups such as carboxymethylstyrene, carboxymethoxystyrene, (meth) acrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, and cinnamic acid Examples thereof include addition polymerization resins containing at least one kind of repeating unit having a bond broken, and polycondensation resins containing at least one kind of condensation type repeating unit having an acidic functional group represented by a novolak resin. The alkali-soluble resin composed of the addition polymerization resin may be composed of only a repeating unit derived from the monomer having the acidic functional group, but other repeating units may be used as long as the generated resin is alkali-soluble. One or more units may be contained. As the other repeating unit, for example, styrene,
α-methylstyrene, vinyltoluene, maleic anhydride, (meth) acrylonitrile, crotonitrile, maleinitrile, fumaronitrile, mesaconitrile,
Citraconitrile, itaconitrile, (meth) acrylamide, crotonamide, maleamide, fumaramide, mesaconamide, citraconamide, itaconamide, vinylaniline, vinylpyridine, N-vinyl-ε-caprolactam, N-vinylpyrrolidone, N-vinylimidazole And other units in which the ethylenic unsaturated bond of the monomer is cleaved. Among the above addition-polymer resins, a (co) polymer of vinylphenol or isopropenylphenol is particularly preferred from the viewpoint of high radiation permeability when formed into a resist film and excellent dry etching resistance. Further, the alkali-soluble resin composed of the polycondensation resin may be composed only of a condensation-type repeating unit having an acidic functional group, but other resins may be used as long as the generated resin is soluble in an alkali developer. One or more condensation-type repeating units may be contained. As the polycondensation resin, 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, an acidic catalyst or a basic catalyst It can be produced by (co) polycondensation in an aqueous medium or in a mixed medium of water and a hydrophilic solvent in the presence. 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 100,000, preferably 1,000 to
50,000, more preferably 2,000 to 30,0
00. In the present invention, the alkali-soluble resin is
They can be used alone or in combination of two or more. The amount of the alkali-soluble resin used in the present invention is
(A) It is usually 200 parts by weight or less per 100 parts by weight of the copolymer.

Other Additives The radiation-sensitive resin composition of the present invention may further contain various additives such as a surfactant and a sensitizer, if necessary. Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyethylene glycol dilaurate, and polyethylene glycol distearate. And the like. The amount of the surfactant used is usually 2 parts per 100 parts by weight of the copolymer (A).
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, thereby improving the apparent sensitivity as a resist. Has the effect of causing. Preferred sensitizers include, for example, benzophenones, acetophenones, anthracenes, rose bengals, pyrenes, phenothiazines and the like. The use amount of the sensitizer is usually 50 parts by weight or less per 100 parts by weight of the copolymer (A). In addition, by blending a dye and / or a pigment, the latent image in the exposed area can be visualized to reduce the influence of halation at the time of exposure, and by blending an adhesion aid, the adhesion to the substrate is improved. be able to. In addition, as other additives,
An antihalation agent, a storage stabilizer, an antifoaming agent and the like can be added.

Solvent The radiation-sensitive resin composition of the present invention may be used,
The composition is obtained by uniformly dissolving in a solvent so that the concentration of the total solid content is, for example, 5 to 50% by weight, preferably 10 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 acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether, propylene glycol monomethyl ether Ethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dipropyl ether, propylene glycol dibutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, Pyrene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, methyl lactate, ethyl lactate, n-propyl lactate, i-propyl lactate, ethyl acetate, n-propyl acetate, i-propyl acetate, n-butyl acetate, i-acetate Butyl, n-amyl acetate, i-amyl acetate, n-propionate
-Propyl, i-propyl propionate, n-butyl propionate, i-butyl propionate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate,
Methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate,
Toluene, xylene, 2-heptanone, 3-heptanone, 4-heptanone, cyclohexanone, N, N-dimethylformamide, N-methylacetamide, N, N-
Examples thereof include dimethylacetamide, N-methylpyrrolidone, and 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. By a proper coating means, for example, a resist film is formed by coating on a substrate such as a silicon wafer or a wafer coated with aluminum, and, if necessary, pre-baking and then exposing through a predetermined mask pattern. I do. The radiation used at this time may be (B) ultraviolet rays such as i-ray (wavelength 365 nm), distant rays such as KrF excimer laser (wavelength 248 nm) or ArF excimer laser (wavelength 193 nm), depending on the type of acid generator. X-rays such as ultraviolet rays and synchrotron radiation, or charged particle beams such as electron beams are appropriately selected and 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, in order to improve the apparent sensitivity as a resist, it is preferable to perform post-exposure baking. The heating conditions vary depending on the composition of the composition, the type of each additive, and the like.
-200 ° C, preferably 40-150 ° C. Next, the exposed resist film is washed with an alkali developing solution.
Usually, a predetermined resist pattern is formed by developing at 10 to 50 ° C. for 30 to 200 seconds.
Examples of the alkaline developer include mono-, di- or tri-alkylamines; mono-, di- or tri-alkanolamines; heterocyclic amines; tetraalkylammonium hydroxides;
Alkaline compounds such as 8-diazabicyclo- [5,4,0] -7-undecene and 1,5-diazabicyclo- [4,3,0] -5-nonene are usually added in an amount of 1 to 10% by weight,
Preferably, an alkaline aqueous solution dissolved to a concentration of 1 to 5% by weight is used. Further, for example, an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant may be added to the developer comprising the alkaline aqueous solution. When a developer composed of an alkaline aqueous solution is used as described above, the developer is generally washed with water after development. In 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.

[0029]

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. The measurement of Mw and the evaluation of each resist in Examples and Comparative Examples were performed in the following manner. GPC columns manufactured by Mw Tosoh Corporation (G2000H _XL
G3000H _XL 1 present, using G4000H _XL 1 present), Flow rate: 1.0 ml / minute, eluting solvent tetrahydrofuran, in the analysis conditions of column temperature 40 ° C, by gel permeation chromatography for the monodisperse polystyrene as a standard (GPC) It was measured. When a sensitivity resist pattern was formed, a line-and-space pattern (1L1S) having a line width of 0.3 μm was one-to-one.
The exposure amount formed at the line width of was set as the optimum exposure amount, and the sensitivity was evaluated based on the optimum exposure amount. Resolution The minimum dimension (μm) of the resist pattern that was resolved when exposed at the optimum exposure amount was defined as the resolution. Pattern shape In the line and space pattern (1L1S) having a line width of 0.3 μm, a pattern having a substantially rectangular cross section and no irregularities on the side wall due to standing waves was recognized as “good”. . PED stability The pattern shapes were compared between those subjected to exposure baking and alkali development immediately after exposure at the optimum exposure dose and those subjected to baking and alkali development after exposure for 2 hours. At this time, when there is no difference between the two patterns, the PED stability is regarded as “good”, and when the line width at the top of the latter pattern is wider than the center, “T
−top ”.

(A) Synthesis of Copolymer Synthesis Example 1 19 g of p-isopropenylphenol and 34 g of 2- (benzyloxycarbonyl) ethyl acrylate
It was mixed with 50 g of dioxane to obtain a homogeneous solution. After bubbling this solution with nitrogen gas for 30 minutes, 2,2'-
1.1 g of azobisisobutyronitrile was added. Next, the polymerization was carried out for 7 hours while maintaining the reaction temperature at 70 ° C. while bubbling with nitrogen gas was continued. After completion of the polymerization, the reaction solution was mixed with a large amount of hexane to coagulate the resulting polymer. Then, after re-dissolving the polymer in dioxane, the operation of coagulating again with hexane is repeated several times to completely remove unreacted monomers and drying at 50 ° C. under reduced pressure to obtain a white polymer. Obtained. The obtained polymer had an Mw of 17,000, and as a result of H-NMR measurement, the copolymerization molar ratio of p-isopropenylphenol to 2- (benzyloxycarbonyl) ethyl acrylate was 48:52.
Was a copolymer of This copolymer is referred to as copolymer (A-
1).

Synthesis Example 2 The monomers were 19 g of p-isopropenylphenol and 2 g of
A polymer was obtained in the same manner as in Synthesis Example 1 except that 32 g of-(cyclohexyloxycarbonyl) ethyl acrylate was used. The obtained polymer had a Mw of 17,000, and as a result of H-NMR measurement, a copolymerization molar ratio of p-isopropenylphenol to 2- (cyclohexyloxycarbonyl) ethyl acrylate was 49:51. It was united. This copolymer is referred to as copolymer (A-2).

Synthesis Example 3 The monomers were 19 g of p-isopropenylphenol and 2-
Synthesis Example 1 except that 21 g of (cyclohexyloxycarbonyl) ethyl acrylate and 10 g of styrene were used.
A polymer was obtained in the same manner as described above. The obtained polymer had Mw of 13,000, and as a result of H-NMR measurement, the copolymerization molar ratio of p-isopropenylphenol, 2- (cyclohexyloxycarbonyl) ethyl acrylate and styrene was 43:28:29. Was a copolymer of This copolymer is referred to as a copolymer (A-3).

Synthesis Example 4 A homogeneous solution was prepared by mixing 30 g of p-acetoxystyrene and 20 g of 2- (phenoxycarbonyl) ethyl acrylate with 200 g of dioxane. After bubbling this solution with nitrogen gas for 30 minutes, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) 6
g was added. Next, the polymerization was carried out for 7 hours while maintaining the reaction temperature at 50 ° C. while bubbling with nitrogen gas was continued. After completion of the polymerization, the reaction solution was mixed with a large amount of hexane to coagulate the resulting polymer. Then, after re-dissolving the polymer in dioxane, the operation of coagulating again with hexane is repeated several times to completely remove unreacted monomers and drying at 50 ° C. under reduced pressure to obtain a white polymer. Obtained. This polymer is treated with propylene glycol monomethyl ether 5
After dissolving in 00 g, 50 g of a 25% by weight aqueous ammonia solution was added, and the mixture was stirred at 80 ° C. for 5 hours to perform hydrolysis. Next, the reaction solution was put into a 0.2% by weight aqueous oxalic acid solution to coagulate the polymer, followed by filtration, washing with water, and drying at 50 ° C. under reduced pressure to obtain a white polymer. The obtained polymer had Mw of 12,000, and as a result of elemental analysis, the copolymerization molar ratio of p-vinylphenol to 2- (phenoxycarbonyl) ethyl acrylate was 67:
33 of the copolymer. This copolymer is referred to as copolymer (A-4).

[0034]

【Example】

Examples 1 to 4 and Comparative Example 1 The components shown in Table 1 (where "parts" are on a weight basis) were mixed to form a uniform solution, which was then filtered through a membrane filter having a pore size of 0.2 µm. A composition solution was prepared.
Thereafter, each composition solution was spin-coated on a silicon wafer, and prebaked at 110 ° C. for 60 seconds to form a 0.7 μm-thick resist film. Next, after performing exposure using a KrF excimer laser stepper (NSR-2005 EX8A manufactured by Nikon Corporation), baking was performed at 130 ° C. for 60 seconds after exposure. Thereafter, using a 2.38% by weight aqueous solution of tetramethylammonium hydroxide, the resist was developed by a paddle method at 23 ° C. for 1 minute, washed with pure water, and dried to form a resist pattern. Table 2 shows the evaluation results of the obtained resist patterns. Here, (B) the acid generator, the acid diffusion controller and the solvent in each of Examples and Comparative Examples are as follows. (B) Acid generator B-1: triphenylsulfonium triflate B-2: bis (cyclohexylsulfonyl) diazomethane acid diffusion controller C-1: nicotinamide C-2: tributylamine solvent PGMEA: propylene glycol monomethyl ether acetate

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

The radiation-sensitive resin composition of the present invention has excellent sensitivity, resolution and pattern shape,
It is excellent in D stability, and can stably form a high-precision fine resist pattern. Moreover, the radiation-sensitive resin composition of the present invention effectively responds to various kinds of radiation such as ultraviolet rays, far ultraviolet rays, X-rays and charged particle beams, and has a very good balance of properties as a chemically amplified positive resist. Are better. Therefore, the radiation-sensitive resin composition of the present invention can be suitably used for the production of semiconductor devices in which miniaturization is expected to further advance in the future.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Norihiro Natsume 2-11-24 Tsukiji, Chuo-ku, Tokyo Inside Nippon Gosei Rubber Co., Ltd. (72) Inventor Yukio Tanaka 1-chome Azuchicho, Chuo-ku, Osaka-shi, Osaka 7-20 Inside Osaka Organic Chemical Industry Co., Ltd. (72) Inventor Naoki Nakagome 1-7-20 Azuchicho, Chuo-ku, Osaka City, Osaka Inside Osaka Organic Chemical Industry Co., Ltd.

Claims (1)

[Claims] 1. A copolymer having a repeating unit (1) represented by the following general formula (1) and a repeating unit (2) represented by the following general formula (2), and (B) A radiation-sensitive resin composition comprising a radiation-sensitive acid generator. Embedded image [In the general formula (1), R ¹ represents a hydrogen atom or a methyl group. [Chemical formula 2] [In the general formula (2), R ² , R ³ and R ⁴ each independently represent a hydrogen atom or a methyl group, and R ⁵ has 1 to 6 carbon atoms.
Represents an alkylene group or an alkylidene group having 2 to ⁶ carbon atoms, R ⁶ represents a linear or branched alkyl group having 1 to 10 carbon atoms, or a linear or branched alkyl halide having 1 to 10 carbon atoms. Group, cyclic alkyl group having 3 to 11 carbon atoms, aryl group having 6 to 10 carbon atoms or 7 to 11 carbon atoms
Wherein n is an integer of 0 to 5. ]