JP3344063B2 - Base blocking antireflection film and method for forming resist pattern - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base-blocking antireflection film useful for fine processing by a lithography process using a resist sensitive to various radiations, particularly a chemically amplified resist, and the base-blocking antireflection film. And a method of forming a resist pattern using the same.

[0002]

2. Description of the Related Art In the field of microfabrication represented by the manufacture of integrated circuit elements, the processing size in a lithography process has been reduced in order to obtain a higher degree of integration of integrated circuits. A lithography process capable of stably performing high-precision fine processing with a width of 0.5 μm or less has been strongly developed. However, it is difficult to form such a fine pattern with high precision by a conventional method using visible light (wavelength 800 to 400 nm) or near ultraviolet light (wavelength 400 to 300 nm). Short wavelength that can be achieved and is effective for miniaturization of design rules (wavelength 300 nm or less)
Lithography processes using different types of radiation have been proposed. A lithography process using such short wavelength radiation includes a KrF excimer laser (wavelength 24).
8 nm), a method using far ultraviolet rays such as an ArF excimer laser (wavelength 193 nm), and charged particle beams such as X-rays or electron beams such as synchrotron radiation. As a high-resolution resist corresponding to such short-wavelength radiation, a so-called “chemically-amplified resist” has attracted attention.
It is an important technical theme in the lithography process. The chemically amplified resist generates an acid by irradiating a compound (hereinafter, referred to as “acid generator”) that generates an acid by irradiation with radiation contained therein to the radiation (hereinafter, referred to as “exposure”). The catalytic action of this acid causes a chemical reaction (eg, change in polarity, cleavage of chemical bond, cross-linking reaction, etc.) in the resist film, and utilizes the phenomenon that solubility in a developing solution changes in the exposed area. It forms a pattern. For such a chemically amplified resist, a combination of a resin in which an alkali-affinity group in an alkali-soluble resin is protected with a t-butyl ester group or a t-butoxycarbonyl group and an acid generator (for example, JP-A-59-45439) Combination of a resin in which an alkali-affinity group in an alkali-soluble resin is protected with a silyl group and an acid generator (for example, JP-A-60-52845).
JP-A-2-25850), in addition to a combination of an acetal group-containing resin and an acid generator, a combination of an alkali-soluble resin, a dissolution controlling agent and an acid generator; Many proposals have been made such as combinations of acid generators.

[0003] However, the chemically amplified resist is susceptible to moisture, oxygen, basic substances and the like existing in the atmosphere in the lithography process, and has a problem in process stability. For example, SPIE, Vol. 1466, “Adva
nce in Resist Technology and Processing ", p.2 (1991,
A. MacDonald et al.) Found that a trace amount of dimethylaniline contained in the atmosphere deactivated the acid near the surface of the acid generated in the resist film by exposure, forming a poorly soluble layer on the surface of the resist film. It has been reported that this hardly-solubilized layer remains on the surface of the resist pattern in an eaves shape after development. Such a hardly-solubilized layer not only reduces the sensitivity and resolution of the resist, but also causes the eaves formed in the resist pattern to adversely affect the subsequent etching accuracy. In addition, the size of the eaves tends to increase with an increase in the standing time interposed between a series of processes of exposure, post-exposure bake, and development. This phenomenon is caused by the post-exposure time delay ( Hereinafter, "PE
D ". ), Which significantly reduces the time tolerance of the lithography process. As a method for solving such PED-related problems, it has been proposed to laminate a protective film on the chemically amplified resist film to shield the film surface from the atmosphere. For example, WO 92/05474 discloses polyacrylic acid. By laminating a protective film such as polyvinyl butyral, polyvinyl alcohol, and polystyrene sulfonic acid on the chemically amplified resist film, the infiltration of basic substances into the resist film is suppressed, and the sensitivity and resolution of the resist are reduced. It is described to prevent. However, among such protective films, polyacrylic acid, polyvinyl butyral, and polyvinyl alcohol have a barrier function, but cannot necessarily prevent the formation of the hardly-solubilized layer as described above. Sulfonic acid has a disadvantage in that the acidity is too strong, and a chemical reaction due to the catalytic action of the acid in the chemically amplified resist is started regardless of the presence or absence of exposure. Further, these protective films are generally applied as an aqueous solution onto the resist film, but the aqueous solution is not sufficiently wettable with the resist film, and thus has the disadvantage that coating unevenness is likely to occur.

On the other hand, the radiation usually used in the lithography process has a single wavelength, so that the incident radiation and the radiation reflected at the upper and lower interfaces of the resist film interfere with each other in the resist film, and as a result, the "standing wave" A phenomenon called "effect" or "multiple interference effect", that is, even if the exposure dose is constant, if the thickness of the resist coating fluctuates, the effective exposure dose to the resist coating fluctuates due to mutual interference of radiation in the film. In some cases, adversely affecting the formation of the resist pattern. For example, the coating thickness changes due to slight differences in the composition and viscosity of the resist, the coating conditions of the resist, and the like, or a difference in the coating thickness occurs due to a step in the substrate (a concave portion is more convex than a convex portion). When the thickness increases, the effective exposure amount to the resist film changes due to the difference in the film thickness, and the pattern size changes or the dimensional accuracy of the resist pattern decreases. In order to solve such a problem relating to the standing wave effect, a method has been proposed in which an antireflection film is formed on a resist film to suppress reflection at an interface of the resist film and reduce multiple interference in the film. For example, J. Eectroche
m.Soc., Vol. 137, No. 12, 3900 (1990), reduces the standing wave effect by laminating polysiloxane, polyethyl vinyl ether, polyvinyl alcohol, etc. as an antireflection film on a resist film Is described. In this case, the reflection suppressing effect at the interface of the resist film mainly depends on the refractive index and the thickness of the antireflection film, and the ideal refractive index of the antireflection film is Δn (n is the refractive index of the resist). The ideal thickness of the anti-reflection film is assumed to be an odd multiple of λ / 4m (where λ is the wavelength of radiation and m is the refractive index of the anti-reflection film). However, the antireflection film made of polysiloxane, polyethylvinyl ether or polyvinyl alcohol has a fundamental problem that the standing wave effect cannot be sufficiently suppressed because the difference in refractive index from the resist is small. In addition, in the case of an anti-reflection film insoluble in water or a developer such as polysiloxane, a step of separately removing the film with an anti-reflection film removing agent before development is required.
The solubility in water or the developing solution is not always sufficient, and there are drawbacks such as residues remaining on the resist film and deterioration of the resist performance such as resolution, developability, and pattern shape. In addition, when it is applied as an aqueous solution on a resist film as in the case of polyethyl vinyl ether or polyvinyl alcohol, there is a disadvantage that the wettability of the aqueous solution with the resist film is not sufficient and coating unevenness easily occurs.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to completely eliminate the influence of a basic substance in the atmosphere in a lithography process for producing a highly integrated circuit using a resist. It can reduce the standing wave effect sufficiently, and has excellent solubility in water and developing solutions.It does not require special removers other than water and developing solutions. An object of the present invention is to provide a novel base-blocking antireflection film having good wettability with a film and excellent coatability. Another object of the present invention is to simultaneously solve the formation of the hardly-solubilized layer on the surface of the chemically amplified resist film and the effect of the standing wave effect, and also to improve the resolution, developability, pattern shape, coatability, etc. An object of the present invention is to provide an excellent method for forming a resist pattern.

[0006]

According to the present invention, the above-mentioned object is firstly attained by (a) at least one kind of repeating unit represented by the following formula (1) and the following formula (2). A copolymer having at least one type of repeating unit (hereinafter, referred to as “copolymer (a-1)”) and / or a salt thereof (hereinafter, referred to as “copolymer salt (a-2)”). And (ii) a fluoroalkylsulfonic acid having a fluoroalkyl group having 5 to 15 carbon atoms (hereinafter referred to as “fluoroalkylsulfonic acid (II-1)”) and / or having 5 to 1 carbon atoms.
5 fluoroalkylcarboxylic acid having a fluoroalkyl group (hereinafter referred to as “fluoroalkylcarboxylic acid (b-
2) ". ) And a base-blocking antireflection film, characterized by comprising:

[0007]

Embedded image

[In the formula (1), R ¹ represents a hydrogen atom or an organic group, and R ² represents a divalent organic group. ]

[0009]

Embedded image

[In the formula (2), R ³ represents a hydrogen atom or an organic group, Rf represents a fluoroalkyl group, and A represents a direct bond, an alkylene group or a fluoroalkylene group. ]

Further, according to the present invention, the above-mentioned problem is caused by the following.
On the substrate, a resist is applied to form a resist film, the resist film is exposed to a predetermined pattern shape, and then developed to form a resist pattern. It is achieved by a method of forming a resist pattern, which comprises exposing after forming a base-blocking antireflection film.

Hereinafter, the present invention will be described in detail, which will clarify the objects, configurations and effects of the present invention. Copolymer (a-1) and copolymer salt (a-2) The copolymer (a) constituting the base-blocking antireflection film of the present invention (a)
-1) is, for example, at least one kind of unsaturated monomer containing a sulfonic acid group (hereinafter, referred to as a “sulfonic acid group-containing monomer”) corresponding to the repeating unit represented by the formula (1) and the formula ( 2)
Copolymerizing a monomer mixture containing at least one type of unsaturated monomer having a fluoroalkyl group corresponding to the repeating unit represented by the formula (hereinafter, referred to as “fluoroalkyl group-containing monomer”): Can be manufactured by

In the formula (1), R ¹ represents a hydrogen atom or an organic group, and R ² represents a divalent organic group. These organic groups may be linear or branched. As the organic group for R ¹ , an organic group having 1 to 12 carbon atoms is preferable, and specific examples thereof include:
Methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group,
an alkyl group having 1 to 12 carbon atoms such as a t-butyl group, an n-pentyl group, an n-hexyl group; a carboxyl group; a carboxymethyl group, a 2-carboxyethyl group, a 2-carboxypropyl group, a 3-carboxypropyl group, A carboxyalkyl group having 2 to 12 carbon atoms such as a 2-carboxybutyl group, a 3-carboxybutyl group, and a 4-carboxybutyl group;
Methoxycarbonyl group, ethoxycarbonyl group, n-propoxycarbonyl group, isopropoxycarbonyl group,
an alkoxycarbonyl group having 2 to 12 carbon atoms such as n-butoxycarbonyl group and t-butoxycarbonyl; acetyloxy group, propionyloxy group, butanoyloxy,
A C2-C12 acyloxy group such as a benzoyloxy group; a C6-C12 aryl group such as a phenyl group or a cumenyl group; a C7-C12 aralkyl group such as a benzyl group or an α-methylbenzyl group; Ethoxy group, n
-A propoxy group, an isopropoxy group, an n-butoxy group,
an alkoxy group having 1 to 12 carbon atoms such as a t-butoxy group;
Methoxymethyl group, ethoxymethyl group, 2-methoxyethyl group, 2-ethoxyethyl group, 2-methoxypropyl group, 3-methoxypropyl group, 2-methoxybutyl group,
C2-C12 alkoxyalkyl groups such as 3-methoxybutyl group and 4-methoxybutyl group; C3-C12 cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cycloheptyl group and cyclooctyl group; cyano group And groups derived from these organic groups.

The divalent organic group of R ² has 1 carbon atom.
~ 12 divalent organic groups are preferable, and specific examples thereof include a methylene group, an ethylene group, a 1,2-propylene group,
1,3-propylene group, 1,1-dimethylethylene group,
1-methyl-1,3-propylene group, 1,4-butylene group, 1-methyl-1,4-butylene group, 2-methyl-
1,4-butylene group, 1,5-pentylene group, 1,1-
Dimethyl-1,4-butylene group, 2,2-dimethyl-
Examples thereof include a 1,4-butylene group, a 1,2-dimethyl-1,4-butylene group, and a 1,6-hexylene group. Among these divalent organic groups, a 1,1-dimethylethylene group is particularly preferred.

Specific examples of such sulfonic acid group-containing monomers include 2- (meth) acrylamido-2-methylpropanesulfonic acid, 2-α-carboxyacrylamido-2-methylpropanesulfonic acid, 2-α -Carboxymethylacrylamide-2-methylpropanesulfonic acid, 2-α-methoxycarbonylacrylamide-2-
Methylpropanesulfonic acid, 2-α-acetyloxyacrylamide-2-methylpropanesulfonic acid, 2-α
-Phenylacrylamide-2-methylpropanesulfonic acid, 2-α-benzylacrylamide-2-methylpropanesulfonic acid, 2-α-methoxyacrylamide-
2-methylpropanesulfonic acid, 2-α- (2-methoxyethyl) acrylamide-2-methylpropanesulfonic acid, 2-α-cyclohexylacrylamide-2-methylpropanesulfonic acid, 2-α-cyanoacrylamide-2-methyl And propanesulfonic acid. These sulfonic acid group-containing monomers can be used alone or in combination of two or more. In the present invention, the sulfonic acid group-containing monomer is
(Meth) acrylamide-2-methylpropanesulfonic acid is preferred.

Next, in the formula (2), R ³ represents a hydrogen atom or an organic group, Rf represents a fluoroalkyl group,
Represents a direct bond, an alkylene group or a fluoroalkylene group, and the organic group for R ³ may be linear or branched. The fluoroalkyl group for Rf may be a hydrofluoroalkyl group or a perfluoroalkyl group, and may be linear or branched. Further, the fluoroalkylene group of A is
It may be a hydrofluoroalkylene group or a perfluoroalkylene group, and may be linear or branched.

As the organic group for R ³ , an organic group having 1 to 12 carbon atoms is preferable.
The same organic group having 1 to 12 carbon atoms as in R ¹ can be mentioned.

The fluoroalkyl group for Rf has 1 carbon atom.
To 15 fluoroalkyl groups are preferable, and specific examples thereof include a difluoromethyl group and a perfluoromethyl group;
2,2-difluoroethyl group, 2,2,2-trifluoroethyl group, perfluoroethyl group; 1- (perfluoromethyl) ethyl group, 2- (perfluoromethyl) ethyl group, 2,2,3 3-tetrafluoropropyl group, perfluoroethylmethyl group, di (perfluoromethyl)
Methyl group, perfluoropropyl group; 1-methyl-2,
2,3,3-tetrafluoropropyl group, 1- (perfluoroethyl) ethyl group, 2- (perfluoroethyl)
Ethyl group, 2,2,3,3,4,4-hexafluorobutyl group, 2,2,3,4,4,4-hexafluorobutyl group, perfluoropropylmethyl group, perfluorobutyl group; 1-dimethyl-2,2,3,3-tetrafluoropropyl group, 1,1-dimethyl-2,2,3
3,3-pentafluoropropyl group, 1-methyl-2,
2,3,3,4,4-hexafluorobutyl group, 1-
(Perfluoropropyl) ethyl group, 2- (perfluoropropyl) ethyl group, 2,2,3,3,4,4,5
5-octafluoropentyl group, perfluorobutylmethyl group, perfluoropentyl group; 1,1-dimethyl-
2,2,3,3,4,4-hexafluorobutyl group,
1,1-dimethyl-2,2,3,3,4,4,4-heptafluorobutyl group, 1-methyl-2,2,3,3
4,4,5,5-octafluoropentyl group, 1- (perfluorobutyl) ethyl group, 2- (perfluorobutyl) ethyl group, 2,2,3,3,4,4,5,5,6 ,
6-decafluorohexyl group, perfluoropentylmethyl group, perfluorohexyl group; 1,1-dimethyl-
2,2,3,3,4,4,5,5-octafluoropentyl group, 1,1-dimethyl-2,2,3,3,4,4,4
5,5,5-nonafluoropentyl group, 1-methyl-
2,2,3,3,4,4,5,5,6,6-decafluorohexyl group, 1- (perfluoropentyl) ethyl group, 2- (perfluoropentyl) ethyl group, 2,2
3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl group, perfluorohexylmethyl group, perfluoroheptyl group; 1- (perfluorohexyl) ethyl group, 2- (per Fluorohexyl) ethyl group, 2,
2,3,3,4,4,5,5,6,6,7,7,8,8
-Tetradecafluorooctyl group, perfluoroheptylmethyl group, perfluoroheptylmethyl group, perfluorooctyl group; 1- (perfluoroheptyl) ethyl group, 2- (perfluoroheptyl) ethyl group, 2,2,
3,3,4,4,5,5,6,6,7,7,8,8,
9,9-hexadecafluorononyl group, perfluorooctylmethyl group, perfluorononyl group; 1- (perfluorooctyl) ethyl group, 2- (perfluorooctyl) ethyl group, 2,2,3,3,4 , 4,5,5,6,
6,7,7,8,8,9,9,10,10-octadecafluorodecyl group, perfluorononylmethyl group, perfluorodecyl group and the like can be mentioned.

The alkylene group represented by A has 1 carbon atom.
To 5 alkylene groups are preferred, and specific examples thereof include:
Methylene group, ethylene group, 1,2-propylene group, 1,
3-propylene group, 1,1-dimethylethylene group, 1-
Examples thereof include a methyl-1,3-propylene group and a 1,4-butylene group. The fluoroalkylene group of A is preferably a fluoroalkylene group having 1 to 5 carbon atoms,
Specific examples thereof include a perfluoromethylene group, 1,1
-Difluoroethylene group, perfluoroethylene group,
1,1-difluoro-1,2-propylene group, 2,2
3,3-tetrafluoro-1,3-propylene group, perfluoro-1,3-propylene group, 1,1-dimethyl-
2,2-difluoroethylene group, 1-methyl-2,2,
3,3-tetrafluoro-1,3-propylene group, 2,
2,3,3,4,4-hexafluoro-1,4-butylene group, perfluoro-1,4-butylene group and the like can be mentioned.

Specific examples of such a fluoroalkyl group-containing monomer include difluoromethyl (meth) acrylate, perfluoromethyl (meth) acrylate;
2-difluoroethyl (meth) acrylate, 2,2
2-trifluoroethyl (meth) acrylate, perfluoroethyl (meth) acrylate; 1- (perfluoromethyl) ethyl (meth) acrylate, 2- (perfluoromethyl) ethyl (meth) acrylate, 2,2
3,3-tetrafluoropropyl (meth) acrylate, perfluoroethylmethyl (meth) acrylate,
Di (perfluoromethyl) methyl (meth) acrylate, perfluoropropyl (meth) acrylate; 1-
Methyl-2,2,3,3-tetrafluoropropyl (meth) acrylate, 1- (perfluoroethyl) ethyl (meth) acrylate, 2- (perfluoroethyl) ethyl (meth) acrylate, 2,2,3 3,4,4-
Hexafluorobutyl (meth) acrylate, perfluoropropylmethyl (meth) acrylate, perfluorobutyl (meth) acrylate; 1,1-dimethyl-
2,2,3,3-tetrafluoropropyl (meth) acrylate, 1,1-dimethyl-2,2,3,3,3-pentafluoropropyl (meth) acrylate, 2- (perfluoropropyl) ethyl (meth) ) Acrylate,
2,2,3,3,4,4,5,5-octafluoropentyl (meth) acrylate group, perfluorobutylmethyl (meth) acrylate, perfluoropentyl (meth) acrylate; 1,1-dimethyl-2, 2,3
3,4,4-hexafluorobutyl (meth) acrylate, 1,1-dimethyl-2,2,3,3,4,4,4-
Heptafluorobutyl (meth) acrylate, 2- (perfluorobutyl) ethyl (meth) acrylate, 2,
2,3,3,4,4,5,5,6,6-decafluorohexyl (meth) acrylate, perfluoropentylmethyl (meth) acrylate, perfluorohexyl (meth) acrylate; 1,1-dimethyl-2 , 2,3
3,4,4,5,5-octafluoropentyl (meth)
Acrylate, 1,1-dimethyl-2,2,3,3
4,4,5,5,5-nonafluoropentyl (meth) acrylate, 2- (perfluoropentyl) ethyl (meth) acrylate, 2,2,3,3,4,4,5,5
6,6,7,7-dodecafluoroheptyl (meth) acrylate, perfluorohexylmethyl (meth) acrylate, perfluoroheptyl (meth) acrylate;
2- (perfluorohexyl) ethyl (meth) acrylate, 2,2,3,3,4,4,5,5,6,6,7,
7,8,8-tetradecafluorooctyl (meth) acrylate, perfluoroheptylmethyl (meth) acrylate, perfluorooctyl (meth) acrylate;
2- (perfluoroheptyl) ethyl (meth) acrylate, 2,2,3,3,4,4,5,5,6,6,7,
7,8,8,9,9-hexadecafluorononyl (meth) acrylate, perfluorooctylmethyl (meth) acrylate, perfluorononyl (meth) acrylate; 2- (perfluorooctyl) ethyl (meth)
Acrylate, 2,2,3,3,4,4,5,5,6
6,7,7,8,8,9,9,10,10-octadecafluorodecyl (meth) acrylate, perfluorononylmethyl (meth) acrylate, perfluorodecyl (meth) acrylate, etc. In addition to fluoroalkyl (meth) acrylates having 1 to 20 carbon atoms,

(2,2,2-trifluoroethyl) α-
Carboxyacrylate, (perfluoroethylmethyl) α-carboxyacrylate; (2,2,2-trifluoroethyl) α-carboxymethylacrylate, (perfluoroethylmethyl) α-carboxymethylacrylate; (2,2,2 -Trifluoroethyl)
α-methoxycarbonyl acrylate, (perfluoroethylmethyl) α-methoxycarbonyl acrylate;
(2,2,2-trifluoroethyl) α-acetyloxyacrylate, (perfluoroethylmethyl) α-acetyloxyacrylate; (2,2,2-trifluoroethyl) α-phenylacrylate, (perfluoroethylmethyl) ) Α-phenyl acrylate;
2-trifluoroethyl) α-benzyl acrylate,
(Perfluoroethylmethyl) α-benzyl acrylate; (2,2,2-trifluoroethyl) α-ethoxy acrylate, (perfluoroethylmethyl) α-ethoxy acrylate; (2,2,2-trifluoroethyl) α -2-methoxyethyl acrylate, (perfluoroethylmethyl) α-2-methoxyethyl acrylate; (2,2,2-trifluoroethyl) α-cyclohexyl acrylate, (perfluoroethylmethyl) α
-Cyclohexyl acrylate; (2,2,2-trifluoroethyl) α-cyanoacrylate, (perfluoroethylmethyl) α-cyanoacrylate and the like. These fluoroalkyl group-containing monomers can be used alone or in combination of two or more.

In the present invention, the fluoroalkyl group-containing monomer has a fluoroalkyl group having 1 to 2 carbon atoms.
Fluoroalkyl (meth) acrylates which are 0 are preferable, and among them, perfluoroalkyl (meth) acrylates and fluoroalkyl (meth) acrylates in which a perfluoroalkyl group is bonded to an ester oxygen atom via a methylene group or an ethylene group are preferred. Particularly preferred.

In the copolymer (a-1), the copolymerization ratio of the sulfonic acid group-containing monomer and the fluoroalkyl group-containing monomer is determined based on the total amount of both monomers. The amount of the monomer is usually 1 to 99% by weight, preferably 3 to 5% by weight.
0% by weight, particularly preferably 5 to 30% by weight, and the fluoroalkyl group-containing monomer is usually 99 to 1% by weight, preferably 97 to 50% by weight, particularly preferably 95% by weight.
７０70% by weight. In this case, when the amount of the sulfonic acid group-containing monomer used is less than 1% by weight and the amount of the fluoroalkyl group-containing monomer exceeds 99% by weight, the solubility of the base-blocking antireflection film in water or a developer decreases. When the amount of the sulfonic acid group-containing monomer exceeds 99% by weight and the amount of the fluoroalkyl group-containing monomer is less than 1% by weight, the pattern shape and the developability tend to decrease. Of the standing wave effect tends to be insufficient, or the film-forming property tends to decrease.

In the present invention, a monomer containing a sulfonic acid group and a monomer containing a fluoroalkyl group can be copolymerized with another comonomer copolymerizable with these monomers. In this case, the amount of the other comonomer to be used is usually 50% by weight or less, preferably 40% by weight, based on all monomers.
% By weight or less.

Examples of such other comonomers include (meth) acrylic acid, crotonic acid, cinnamic acid, atropic acid, 3-acetyloxy (meth) acrylic acid, and 3-benzoyloxy (meth) acrylic acid. Unsaturated monocarboxylic acid compounds such as acid, α-methoxyacrylic acid and 3-cyclohexyl (meth) acrylic acid; methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl ( Alkyl (meth) acrylate compounds such as meth) acrylates and unsaturated monocarboxylic acid ester compounds such as methyl crotonate and methyl cinnamate; unsaturated compounds such as fumaric acid, maleic acid, citraconic acid, mesaconic acid and itaconic acid; A saturated polycarboxylic acid compound; a mono- or di-methyl ester of the unsaturated polycarboxylic acid, - or di - ethyl ester,
Mono- or di-ester compounds such as mono- or di-n-propyl ester; unsaturated alcohol ester compounds such as vinyl acetate, vinyl propionate and vinyl caproate; (meth) acrylonitrile, α-methylacrylonitrile, α -Vinyl cyanide compounds such as chloroacrylonitrile, α-chloromethylacrylonitrile, α-trifluoromethylacrylonitrile, and vinylidene cyanide; aromatic monovinyl compounds other than the above such as styrene, α-methylstyrene, vinyltoluene; vinyl chloride , Halogenated olefin compounds such as vinylidene chloride, vinyl fluoride, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene; butadiene,
Diene compounds such as isoprene, chloroprene, piperylene, 2,3-dimethylbutadiene, methylpentadiene, cyclopentadiene, vinylcyclohexene, ethylidene norbornene, divinylbenzene, and dimethylvinylstyrylsilane; Saturated ether compounds; unsaturated compounds containing epoxy groups such as glycidyl (meth) acrylate and allyl glycidyl ether;
2-chloroethyl vinyl ether, vinyl chloroacetate,
Other halogen-containing unsaturated compounds such as allyl chloroacetate and chloromethylstyrene; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, hydroxystyrene, N-methylol (meth) acrylamide, 2-propenyl Hydroxyl-containing unsaturated compounds such as alcohols and 2-methyl-2-propenyl alcohol; unsaturated amide-containing unsaturated compounds such as (meth) acrylamide, crotonic amide, and cinnamic acid amide;

2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl phthalic acid, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, 2- (meth) acryloyloxyethyl maleic acid, Other examples include a carboxyl group-containing unsaturated compound such as a carboxyl group-containing acrylamide compound represented by the following formula (3).

[0027]

Embedded image

[In the formula (3), R ⁴ represents a hydrogen atom or an organic group, and R ⁵ represents a divalent organic group. Examples of the organic group for R ⁴ include the same organic groups having 1 to 12 carbon atoms as those for R ¹ in the formula (1). Examples of the divalent organic group for R ⁵ include The same divalent organic group having 1 to 12 carbon atoms as in R ² in (1) can be mentioned.

Specific examples of the carboxyl group-containing acrylamide compound include 2- (meth) acrylamido-2-methylpropanecarboxylic acid, 2-α-carboxyacrylamido-2-methylpropanecarboxylic acid,
α-carboxymethylacrylamide-2-methylpropanecarboxylic acid, 2-α-methoxycarbonylacrylamide-2-methylpropanecarboxylic acid, 2-α-acetyloxyacrylamide-2-methylpropanecarboxylic acid, 2-α-phenylacrylamide- 2-methylpropanecarboxylic acid, 2-α-benzylacrylamide-
2-methylpropanecarboxylic acid, 2-α-methoxyacrylamide-2-methylpropanecarboxylic acid, 2-α-
(2-methoxyethyl) acrylamide-2-methylpropanecarboxylic acid, 2-α-cyclohexylacrylamide-2-methylpropanecarboxylic acid, 2-α-cyanoacrylamide-2-methylpropanecarboxylic acid, and the like. These other comonomers can be used alone or in combination of two or more. In the present invention, the other comonomer includes the alkyl (meth) acrylate-based compound, particularly methyl (meth) acrylate and ethyl (meth) acrylate; and the carboxyl group-containing acrylamide-based compound, particularly 2-
(Meth) acrylamide-2-methylpropanecarboxylic acid is preferred.

The copolymerization for producing the copolymer (a-1) is carried out by a suitable method such as radical polymerization, anionic polymerization, cationic polymerization, or coordination polymerization, for example, bulk polymerization, suspension polymerization, bulk-suspension. It can be produced in various polymerization forms such as suspension polymerization, emulsion polymerization, solution polymerization and precipitation polymerization. During these copolymerization, each monomer, a reaction component such as a polymerization initiator,
It can be added all at once, or in portions or continuously. In addition, the copolymer (a-1) can be produced by a chemical post-treatment of a suitable precursor copolymer, as the case may be.

Next, the copolymer salt (a-2) is obtained by neutralizing at least a part of the sulfonic acid groups of the copolymer (a-1). The copolymer salt (a-2) is, for example, a method of (i) neutralizing at least a part of the sulfonic acid group of the sulfonic acid group-containing monomer in the copolymer (a-1) with an alkaline compound, (Ii) after previously neutralizing at least a part of the sulfonic acid groups of the sulfonic acid group-containing monomer with an alkaline compound,
It can be produced together with the fluoroalkyl group-containing monomer and, if necessary, other comonomers by, for example, a method of copolymerizing in the same manner as in producing the copolymer (a-1). In the method (i), when an acidic group other than the sulfonic acid group of the sulfonic acid group-containing monomer is present,
The acidic groups may also be neutralized. Further, in the method (ii), the copolymerization ratio between the sulfonic acid group-containing monomer and the fluoroalkyl group-containing monomer is the same as in the case of the copolymer (a-1). When the other comonomer used also has an acidic group, at least a part of the acidic group can be neutralized. In the present invention, the copolymer salt (a-2) is preferably produced by the method (i), for example, by adding and mixing the copolymer (a-1) into an aqueous solution of an alkaline compound.

In the present invention, it is preferable to use ammonia and / or an organic amine as the alkaline compound used for producing the copolymer salt (a-2). Examples of the organic amine include methylamine, ethylamine, propylamine, butylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, ethanolamine,
Primary to aminomethylpropanol, 2-dimethylethanolamine, diethanolamine, triethanolamine, cyclohexylamine, pyrrole, pyrrolidine, oxazole, pyridine, piperidine, morpholine, etc.
Tertiary monovalent amines; and primary to tertiary polyvalents such as ethylenediamine, diethylenediamine, tetraethylenediamine, diethylenetriamine, tetraethylenetriamine, imidazole, imidazolidine, oxazole, pyrazine, piperazine, s-triazine and the like. Amines can be mentioned. Of these organic amines,
Mono- or polyvalent tertiary organic amines are preferred. The organic amines can be used alone or in combination of two or more. In the present invention, ammonia and monovalent tertiary organic amines are particularly preferred as the alkaline compound. The degree of neutralization of the copolymer salt (a-2) in the present invention is usually 5 to 100 mol%, preferably 30 to 90 mol%, based on the sulfonic acid group of the sulfonic acid group-containing monomer.

The copolymer (a-1) and the copolymer salt (a-
2) can take various structures such as a random copolymer, a block copolymer, and a graft copolymer. In the case of a block copolymer, the sulfonic acid group-containing monomer and the fluoroalkyl group-containing monomer may coexist in the same polymer block or may be present in different polymer blocks, In the case of a graft copolymer, both the sulfonic acid group-containing monomer and the fluoroalkyl group-containing monomer can coexist in the trunk polymer and / or the branch polymer, and Any of the polymers may be composed of only the sulfonic acid group-containing monomer.

In the present invention, preferred copolymers (a-
1) Alternatively, the copolymer salt (a-2) comprises (a) 2- (meth) acrylamido-2-methylpropanesulfonic acid and a fluoroalkyl (meth) acrylate having a fluoroalkyl group having 1 to 20 carbon atoms. (Salts) with (b) 2- (meth) acrylamide-2
-Methylpropanesulfonic acid, fluoroalkyl (meth) acrylates having 1 to 20 carbon atoms in the fluoroalkyl group, and the above alkyl (meth) acrylate-based compound and / or the carboxyl group as another comonomer (Salt) with acrylamide-containing compound
It is.

Among the copolymers (salts) of the above (a) or (b), particularly preferred copolymers (salts) are (c)
2- (meth) acrylamide-2-methylpropanesulfonic acid, a group of perfluoroalkyl (meth) acrylates and fluoroalkyl (meth) acrylates in which a perfluoroalkyl group is bonded to an ester oxygen atom via a methylene group or an ethylene group Copolymers (salts) with fluoroalkyl (meth) acrylates selected from: and (d) 2- (meth) acrylamide-2
-Methylpropanesulfonic acid, perfluoroalkyl (meth) acrylate and fluoroalkyl (meth) acrylate selected from the group of fluoroalkyl (meth) acrylates in which a perfluoroalkyl group is bonded to an ester oxygen atom via a methylene group or an ethylene group A copolymer (salt) of an acrylate and the alkyl (meth) acrylate compound and / or the carboxyl group-containing acrylamide compound. More specifically, the copolymer (a-1) and the copolymer salt (a-2) in the present invention are more specifically described below.
Is a copolymer (salt) of (c-1) 2- (meth) acrylamide-2-methylpropanesulfonic acid and perfluoroalkyl (meth) acrylates; (c-2) 2- (meth)
Copolymer (salt) of acrylamide-2-methylpropanesulfonic acid and a fluoroalkyl (meth) acrylate in which a perfluoroalkyl group is bonded to an ester oxygen atom via a methylene group; (c-3) 2- ( (C-4) a copolymer (salt) of (meth) acrylamide-2-methylpropanesulfonic acid and a fluoroalkyl (meth) acrylate having a perfluoroalkyl group bonded to an ester oxygen atom via an ethylene group; A mixture of 2- (meth) acrylamido-2-methylpropanesulfonic acid, perfluoroalkyl (meth) acrylates and fluoroalkyl (meth) acrylates in which a perfluoroalkyl group is bonded to an ester oxygen atom via a methylene group (C-5) 2- (meth) acrylamido-2-methylpropane Copolymer (salt) of sulfonic acid with a mixture of perfluoroalkyl (meth) acrylates and fluoroalkyl (meth) acrylates in which a perfluoroalkyl group is bonded to an ester oxygen atom via an ethylene group; (c- 6) 2- (meth) acrylamido-2-methylpropanesulfonic acid, a fluoroalkyl (meth) acrylate in which a perfluoroalkyl group is bonded to an ester oxygen atom via a methylene group, and a perfluoroalkyl group which is bonded via an ethylene group (Salt) with a mixture of fluoroalkyl (meth) acrylates bonded to an ester oxygen atom by means of (c-7) 2- (meth) acrylamido-2-methylpropanesulfonic acid and perfluoroalkyl ( Meth) acrylates, a perfluoroalkyl group is Fluoroalkyl (meth) acrylates and perfluoroalkyl group attached to the Le oxygen atom is a copolymer of a mixture of fluoroalkyl (meth) acrylates linked to the ester oxygen atom through an ethylene group (salt),

The copolymer (salt) of the group (d)
Are (d-1) 2- (meth) acrylamide-2-methylpropanesulfonic acid, perfluoroalkyl (meth) acrylates, the alkyl (meth) acrylate compound and / or the carboxyl group-containing acrylamide compound (D-2) 2- (meth) acrylamido-2-methylpropanesulfonic acid and a fluoroalkyl (meth) in which a perfluoroalkyl group is bonded to an ester oxygen atom via a methylene group Copolymer (salt) of acrylates with the alkyl (meth) acrylate compound and / or the carboxyl group-containing acrylamide compound; (d-3) 2- (meth)
Acrylamide-2-methylpropanesulfonic acid, fluoroalkyl (meth) acrylates in which a perfluoroalkyl group is bonded to an ester oxygen atom via an ethylene group, and the alkyl (meth) acrylate-based compound and / or the carboxyl group-containing (D-4) 2- (meth) acrylamido-2-methylpropanesulfonic acid, perfluoroalkyl (meth) acrylates and perfluoroalkyl group via methylene group (D-5): a copolymer (salt) of a mixture of fluoroalkyl (meth) acrylates bonded to an ester oxygen atom with the alkyl (meth) acrylate compound and / or the carboxyl group-containing acrylamide compound; 2- (meth) acrylamide-2-methyl A mixture of lopansulfonic acid, perfluoroalkyl (meth) acrylates, and fluoroalkyl (meth) acrylates in which a perfluoroalkyl group is bonded to an ester oxygen atom via an ethylene group; Or (d-6) 2- (meth) acrylamido-2-methylpropanesulfonic acid with a perfluoroalkyl group having an ester oxygen atom via a methylene group, or a copolymer (salt) with the carboxyl group-containing acrylamide compound. A mixture of a fluoroalkyl (meth) acrylate and a fluoroalkyl (meth) acrylate in which a perfluoroalkyl group is bonded to an ester oxygen atom via an ethylene group, and the alkyl (meth) acrylate compound and / or Carboki Copolymers of Le group-containing acrylamide compound (salt); and (d-
7) 2- (meth) acrylamide-2-methylpropanesulfonic acid, perfluoroalkyl (meth) acrylates, fluoroalkyl (meth) having a perfluoroalkyl group bonded to an ester oxygen atom via a methylene group
A mixture of an acrylate and a fluoroalkyl (meth) acrylate in which a perfluoroalkyl group is bonded to an ester oxygen atom via an ethylene group, and the alkyl (meth) acrylate compound and / or the carboxyl group-containing acrylamide compound It is a copolymer (salt).

The copolymer (a-1) and the copolymer salt (a-
2) can be used after hydrogenation when a carbon-carbon unsaturated bond exists. The hydrogenation rate in this case is usually 90% or less, preferably 70% or less,
It is particularly preferably at most 50%.

The copolymer (a-1) and the copolymer salt (a-
2) weight average molecular weight in terms of polystyrene (hereinafter referred to as “M
w ". ) Is usually from 1,000 to 1,000,000
00, preferably 1,500 to 500,000,
Particularly preferably, it is 2,000 to 100,000. Mw of the copolymer (a-1) and the copolymer salt (a-2) is 1,
If it is less than 000, the coating properties and film-forming properties at the time of forming the base-blocking antireflection film tend to decrease, and
If it exceeds 000, the solubility in water or a developing solution, the coating property and the like tend to decrease. In the present invention,
Each of the copolymer (a-1) and the copolymer salt (a-2) can be used alone or in combination of two or more.

Fluoroalkylsulfonic acid (II) and
Fluoroalkylcarboxylic acid (II) Next, the fluoroalkylsulfonic acid (II) and the fluoroalkylcarboxylic acid (II) constituting the base-blocking antireflection film of the present invention have 5 carbon atoms. It has from 15 to 15 fluoroalkyl groups. The fluoroalkyl group may be a hydrofluoroalkyl group or a perfluoroalkyl group, and may be linear or branched. Examples of the fluoroalkyl group include a C5 to C15 fluoroalkyl group exemplified for Rf in the formula (2), and 1,1,2,2,3,3,4,4,5,5-decafluoroalkyl group. Fluoropentyl group; 1,1,2,2,3,3,4,4
5,5,6,6-dodecafluorohexyl group; 1,1,
2,2,3,3,4,4,5,5,6,6,7,7-tetradecafluoroheptyl group; 1,1,2,2,3
3,4,4,5,5,6,6,7,7,8,8-hexadecafluorooctyl group; 1,1,2,2,3,3
4,4,5,5,6,6,7,7,8,8,9,9-octadecafluorononyl group; 1,1,2,2,3,3
4,4,5,5,6,6,7,7,8,8,9,9,1
0,10-eicosafluorodecyl group; 2- (perfluorononyl) ethyl group, 2,2,3,3,4,4,5
5,6,6,7,7,8,8,9,9,10,10,1
1,11-eicosafluoroundecyl group, perfluorodecylmethyl group, 1,1,2,2,3,3,4,4,4
5,5,6,6,7,7,8,8,9,9,10,1
0,11,11-docosafluoroundecyl group, perfluoroundecyl group; 2- (perfluorodecyl) ethyl group, 2,2,3,3,4,4,5,5,6,6,7,
7, 8, 8, 9, 9, 10, 10, 11, 11, 12,
12-docosafluorododecyl group, perfluoroundecylmethyl group, 1,1,2,2,3,3,4,4,5
5,6,6,7,7,8,8,9,9,10,10,1
1,11,12,12-tetracosafluorododecyl group, perfluorododecyl group; 2- (perfluoroundecyl) ethyl group, 2,2,3,3,4,4,5,5
6, 6, 7, 7, 8, 8, 9, 9, 10, 10, 11,
11,12,12,13,13-tetracosafluorotridecyl group, perfluorododecylmethyl group, 1,1,
2,2,3,3,4,4,5,5,6,6,7,7,
8, 8, 9, 9, 10, 10, 11, 11, 12, 1
2,13,13-hexacosafluorotridecyl group, perfluorotridecyl group; 2- (perfluorododecyl) ethyl group, 2,2,3,3,4,4,5,5,6
6,7,7,8,8,9,9,10,10,11,1
1,12,12,13,13,14,14-hexacosafluorotetradecyl group, perfluorotridecylmethyl group, 1,1,2,2,3,3,4,4,5,5,6,
6,7,7,8,8,9,9,10,10,11,1
1,12,12,13,13,14,14-octacosafluorotetradecyl group, perfluorotetradecyl group; 2- (perfluorotridecyl) ethyl group, 2,
2,3,3,4,4,5,5,6,6,7,7,8,
8, 9, 9, 10, 10, 11, 11, 12, 12, 1
3,13,14,14,15,15-octacosafluoropentadecyl group, perfluorotetradecylmethyl group, 1,1,2,2,3,3,4,4,5,5,6
6,7,7,8,8,9,9,10,10,11,1
1,12,12,13,13,14,14,15,15
-A triacontafluoropentadecyl group, a perfluoropentadecyl group and the like.

Specific examples of such a fluoroalkylsulfonic acid (II) include 2- (perfluoropropyl) ethanesulfonic acid, 1,1,2,2,3,3,4,4
4,5,5-decafluoropentanesulfonic acid, perfluoropentanesulfonic acid; 2- (perfluorobutyl) ethanesulfonic acid, 1,1,2,2,3,3,4
4,5,5,6,6-dodecafluorohexanesulfonic acid, perfluorohexanesulfonic acid; 2- (perfluoropentyl) ethanesulfonic acid, 1,1,2,2
3,3,4,4,5,5,6,6,7,7-tetradecafluoroheptanesulfonic acid, perfluoroheptanesulfonic acid; 2- (perfluorohexyl) ethanesulfonic acid, 1,1,2,2 2,3,3,4,4,5,5,6
6,7,7,8,8-hexadecafluorooctanesulfonic acid, perfluorooctanesulfonic acid; 2- (perfluoroheptyl) ethanesulfonic acid, 1,1,2,2
2,3,3,4,4,5,5,6,6,7,7,8,
8,9,9-octadecafluorononanesulfonic acid, perfluorononanesulfonic acid; 2- (perfluorooctyl) ethanesulfonic acid, 1,1,2,2,3,3
4,4,5,5,6,6,7,7,8,8,9,9,1
0,10-eicosafluorodecanesulfonic acid, perfluorodecanesulfonic acid; 2- (perfluorononyl)
Ethanesulfonic acid, 1,1,2,2,3,3,4,4
5,5,6,6,7,7,8,8,9,9,10,1
0,11,11-docosafluoroundecanesulfonic acid, perfluoroundecanesulfonic acid; 2- (perfluorodecyl) ethanesulfonic acid, 1,1,2,2,
3,3,4,4,5,5,6,6,7,7,8,8,
9,9,10,10,11,11,12,12-tetracosafluorododecanesulfonic acid, perfluorododecanesulfonic acid; 2- (perfluoroundecyl) ethanesulfonic acid, 1,1,2,2,3 , 3,4,4,5
5,6,6,7,7,8,8,9,9,10,10,1
1,11,12,12,13,13-hexacosafluorotridecanesulfonic acid, perfluorotridecanesulfonic acid; 2- (perfluorododecyl) ethanesulfonic acid, 1,1,2,2,3,3, 4,4,5,5,6
6,7,7,8,8,9,9,10,10,11,1
1,12,12,13,13,14,14-octacosafluorotetradecanesulfonic acid, perfluorotetradecanesulfonic acid; 2- (perfluorotridecyl) ethanesulfonic acid, 1,1,2,2,3,3 , 4,4,
5,5,6,6,7,7,8,8,9,9,10,1
0,11,11,12,12,13,13,14,1
4,15,15-Triacontafluoropentadecanesulfonic acid, perfluoropentadecanesulfonic acid and the like can be mentioned.

Further, a fluoroalkylcarboxylic acid (b-
As a specific example of 2), 2- (perfluoropropyl)
Ethanecarboxylic acid, 1,1,2,2,3,3,4,4
5,5-decafluoropentanecarboxylic acid, perfluoropentanecarboxylic acid; 2- (perfluorobutyl) ethanecarboxylic acid, 1,1,2,2,3,3,4,4,4
5,5,6,6-dodecafluorohexanecarboxylic acid,
Perfluorohexanecarboxylic acid; 2- (perfluoropentyl) ethanecarboxylic acid, 1,1,2,2,3
3,4,4,5,5,6,6,7,7-tetradecafluoroheptanecarboxylic acid, perfluoroheptanecarboxylic acid; 2- (perfluorohexyl) ethanecarboxylic acid, 1,1,2,2 3,3,4,4,5,5,6
6,7,7,8,8-hexadecafluorooctanecarboxylic acid, perfluorooctanecarboxylic acid; 2- (perfluoroheptyl) ethanecarboxylic acid, 1,1,2,2
2,3,3,4,4,5,5,6,6,7,7,8,
8,9,9-octadecafluorononanecarboxylic acid, perfluorononanecarboxylic acid; 2- (perfluorooctyl) ethanecarboxylic acid, 1,1,2,2,3,3
4,4,5,5,6,6,7,7,8,8,9,9,1
0,10-eicosafluorodecanecarboxylic acid, perfluorodecanecarboxylic acid; 2- (perfluorononyl)
Ethanecarboxylic acid, 1,1,2,2,3,3,4,4
5,5,6,6,7,7,8,8,9,9,10,1
0,11,11-docosafluoroundecanecarboxylic acid, perfluoroundecanecarboxylic acid; 2- (perfluorodecyl) ethanecarboxylic acid, 1,1,2,2
3,3,4,4,5,5,6,6,7,7,8,8,
9,9,10,10,11,11,12,12-Tetracosafluorododecanecarboxylic acid, perfluorododecanecarboxylic acid; 2- (perfluoroundecyl) ethanecarboxylic acid, 1,1,2,2,3 , 3,4,4,5
5,6,6,7,7,8,8,9,9,10,10,1
1,11,12,12,13,13-hexacosafluorotridecanecarboxylic acid, perfluorotridecanecarboxylic acid; 2- (perfluorododecyl) ethanecarboxylic acid, 1,1,2,2,3,3 4,4,5,5,6
6,7,7,8,8,9,9,10,10,11,1
1,12,12,13,13,14,14-octacosafluorotetradecanecarboxylic acid, perfluorotetradecanecarboxylic acid; 2- (perfluorotridecyl) ethanecarboxylic acid, 1,1,2,2,3,3 , 4,4,
5,5,6,6,7,7,8,8,9,9,10,1
0,11,11,12,12,13,13,14,1
4,15,15-triacontafluoropentadecanecarboxylic acid, perfluoropentadecanecarboxylic acid and the like can be mentioned.

These fluoroalkylsulfonic acids (II)
-1) and the fluoroalkylcarboxylic acid (b-2) can be used alone or in combination of two or more.
In the present invention, the fluoroalkylsulfonic acid (II)
And fluoroalkylcarboxylic acid (b-2)
Compounds in which the fluoroalkyl group has 6 to 14 carbon atoms are preferred, and in particular, the fluoroalkyl group has 7 to 12 carbon atoms.
Are preferred.

In the present invention, the blending amounts of the fluoroalkylsulfonic acid (II) and / or the fluoroalkylcarboxylic acid (II) are determined by the copolymer (I-1) and the copolymer salt (II-2). ), Usually 1 to 10
0 parts by weight, preferably 5 to 80 parts by weight, particularly preferably 10 to 70 parts by weight. If the amount of the fluoroalkylsulfonic acid (II-1) and / or the fluoroalkylcarboxylic acid (II-2) is less than 1 part by weight, the effect of reducing the standing wave effect of the base-blocking antireflection film and the applicability are reduced. When the amount exceeds 100 parts by weight, the copolymer (a)
-1) and / or copolymer salt (a-2) blended with fluoroalkylsulfonic acid (b-1) and / or fluoroalkylcarboxylic acid (b-2) has reduced storage stability Show a tendency to.

Various Additives The base-blocking antireflection film of the present invention comprises the copolymer (a-1) and / or the copolymer salt (a-2) and a fluoroalkylsulfonic acid (b-1) And / or a fluoroalkylcarboxylic acid (b-2) as an essential component (hereinafter referred to as “anti-reflective coating material”). Various additives can be blended as long as the desired effect is not impaired. Examples of the additives include other water-soluble polymers and alkali-soluble polymers, surfactants, and acid generators. -Other water-soluble polymers and alkali-soluble resins-Other water-soluble polymers and alkali-soluble polymers include, for example, polyvinyl alcohol, polymethyl vinyl ether, polyethyl vinyl ether, polyethylene glycol, ammonium polyacrylate, sodium polyacrylate. , Polyhydroxystyrene or a derivative thereof, a styrene-maleic anhydride copolymer or a hydrolyzate thereof, polyvinylhydroxybenzoate, a carboxyl group-containing (meth) acrylic resin, and the like. These other water-soluble polymers or alkali-soluble polymers can be used alone or in combination of two or more. The mixing amount of the other water-soluble polymer and / or alkali-soluble polymer is usually 2 parts by weight per 100 parts by weight of the total of the copolymer (a-1) and the copolymer salt (a-2).
It is at most 00 parts by weight, preferably at most 100 parts by weight. -Surfactant- The surfactant has an action of improving coatability, striation, wettability, developability, and the like. Examples of such a surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether,
In addition to nonionic surfactants such as polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyethylene glycol dilaurate, and polyethylene glycol distearate, KP341 is commercially available.
(Trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75,
No. 95 (trade name, manufactured by Kyoeisha Yushi Kagaku Kogyo), F-Top EF301, EF303, EF352, and E
F204 (trade name, manufactured by Tochem Products), Megafac F171, F173 (trade name, manufactured by Dainippon Ink and Chemicals), Florard FC430, FC431 (trade name, manufactured by Sumitomo 3M), Asahi Guard AG710, Surflon S- 382, SC-101, SC-10
2, SC-103, SC-104, SC-10
5, SC-106 (trade name, manufactured by Asahi Glass) and the like. These surfactants can be used alone or in combination of two or more. The amount of the surfactant is 10% in total of the polymer component in the antireflection film material.
The amount is usually 100 parts by weight or less, preferably 70 parts by weight or less, particularly preferably 0.1 to 50 parts by weight, per 0 parts by weight.

-Acid Generator- The acid generator has an effect of improving the resist pattern shape, resolution, developability, and the like. Examples of such an acid generator include the following onium salts, haloalkyl group-containing compounds, o-quinonediazide compounds, nitrobenzyl compounds, sulfonic acid ester compounds,
Sulfone compounds and the like can be mentioned.

Onium salt A compound represented by the following formula (4), (5) or (6).

Embedded image

Embedded image

Embedded image [In the formulas (4) to (6), R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ ,
R ¹¹ , R ¹² and R ¹³ may be the same or different from each other, and represent a hydrogen atom, an amino group, a nitro group, a cyano group, an alkyl group or an alkoxy group, and X ¹ , X ² and X ³ are Sb
F ₆ , AsF ₆ , PF ₆ , BF ₄ , CF ₃ CO ₂ , ClO ₄ , CF ₃ SO ₃ ,

Embedded image (Here, R ¹⁴ is a hydrogen atom, an amino group, a nitro group, a cyano group, an alkyl group or an alkoxy group.)

Embedded image (Here, R ¹⁵ and R ¹⁶ may be the same or different from each other and are alkoxy groups.)

Embedded image (Here, R ¹⁷ is a hydrogen atom, an amino group, an anilino group, an alkyl group or an alkoxy group.) Or

Embedded image Is shown. ]

Haloalkyl group-containing compound A compound represented by the following formula (7) or (8).

Embedded image [In the formula (7), R ¹⁸ represents a trichloromethyl group, a phenyl group, a methoxyphenyl group, a naphthyl group or a methoxynaphthyl group. ]

Embedded image [In the formula (8), R ¹⁹ , R ²⁰ and R ²¹ may be the same or different from each other and represent a hydrogen atom, a halogen atom, a methyl group, a methoxy group or a hydroxyl group. ]

O-Quinonediazide compound A compound represented by the following formula (9) or (10).

Embedded image [In the formula (9), Ar ¹ is

Embedded image Or

Embedded image (Where D ¹ and D ² may be the same or different from each other, and represent a hydrogen atom or 1,2-naphthoquinonediazide-
A 4-sulfonyl group, n and m are each an integer of 0 to 3 (however, n and m are not simultaneously 0).
And a plurality of D ¹ or D ² may be mutually the same or different. ). ]

Embedded image [In the formula (10), Ar ² is

Or

Embedded image (Here, D ³ is a hydrogen atom or a 1,2-naphthoquinonediazido-4-sulfonyl group.) ]

Nitrobenzyl compound A compound represented by the following formula (11).

Embedded image [In the formula (11), p is an integer of 1 to 3, and R ²²
Represents an alkyl group, R ²³ represents a hydrogen atom or an alkyl group, and R ²⁴ represents

Embedded image (Where R ²⁵ is a hydrogen atom or an alkyl group),

Embedded image (Here, R ²⁶ and R ²⁷ may be the same or different from each other and are alkoxy groups.) Or

Embedded image Is shown. ]

Sulfonic ester compound A compound represented by the following formula (12), (13), (14) or (15).

Embedded image [In the formula (12), R ²⁸ and R ³¹ may be the same or different from each other, and represent a hydrogen atom or an alkyl group;
R ²⁹ and R ³⁰ may be the same or different from each other and represent a hydrogen atom, an alkyl group or an aryl group. ]

Embedded image [In the formula (13), R ³² represents a hydrogen atom or an alkyl group, and R ³³ and R ³⁴ may be the same or different from each other, and represent an alkyl group or an aryl group, or are formed by bonding to each other. The structural unit of a ring is shown. ]

Embedded image [In the formula (14), R ³⁵ , R ³⁶ and R ³⁷ may be the same or different from each other, and may be a methyl group, a trifluoromethyl group, a trichloromethyl group, a phenyl group, a tolyl group, a cyanophenyl group, a trichlorophenyl group. Or a trifluoromethylphenyl group. ]

Embedded image [In the formula (15), Z ¹ , Z ² and Z ³ may be the same or different from each other, and may be a fluorine atom, a chlorine atom, a hydrogen atom,
Represents an alkyl group or an aryl group, and there are three of each
Z ¹ , Z ² or Z ³ may be the same or different from each other. ]

Sulfone compound A compound represented by the following formula (16).

Embedded image [In the formula (16), Y represents a —CO— group or a —SO ₂ — group, and R ³⁸ , R ³⁹ , R ⁴⁰ and R ⁴¹ may be the same or different from each other and represent a halogen atom or an alkyl group. , M
Is an integer of 0 to 3, and a plurality of R ⁴¹ may be mutually the same or different. These acid generators can be used alone or in combination of two or more. In the present invention, a particularly preferred acid generator is an onium salt. The amount of the acid generator is usually 20 parts by weight or less, preferably 10 parts by weight or less based on 100 parts by weight of the total of the polymer components in the antireflection film material. When the amount of the acid generator exceeds 20 parts by weight, the developability tends to decrease. -Other additives-Further, as additives other than the above, a light absorbing agent, storage stabilizer,
Examples include antifoaming agents, adhesion aids, preservatives, dyes and pigments.

Example of Composition of Antireflective Coating Material As described in detail above, the base-blocking antireflective coating of the present invention comprises a copolymer (a-1) and / or a copolymer salt (a-2). Anti-reflective coating material comprising, as essential constituents, and fluoroalkylsulfonic acid (II-1) and / or fluoroalkylcarboxylic acid (II-2), and blending various additives described above as necessary. Here, the preferred composition of the antireflection film material is more specifically described as follows: (e) the copolymer (a-1) and / or A polymer salt (a-2);
An anti-reflective coating material containing a fluoroalkylsulfonic acid (II) and / or a fluoroalkylcarboxylic acid (II), wherein the fluoroalkyl group has 6 to 14 carbon atoms; )) And / or a copolymer salt (a-2) and a fluoroalkylsulfonic acid (b-1) and / or fluoroalkyl having a fluoroalkyl group having 6 to 14 carbon atoms. An anti-reflective coating material containing an alkyl carboxylic acid (b-2) can be mentioned, and a more preferred combination is (g) the copolymer (a-1) and / or the copolymer salt of the above (c). An anti-reflective coating material containing (a-2) and a fluoroalkylsulfonic acid (b-1) and / or a fluoroalkylcarboxylic acid (b-2) having a fluoroalkyl group having 6 to 14 carbon atoms; And (h) the above (d) A copolymer (a-1) and / or a copolymer salt (a-2) and a fluoroalkylsulfonic acid (b-1) and / or a fluoroalkylcarboxylic acid having a fluoroalkyl group having 6 to 14 carbon atoms An anti-reflective coating material containing an acid (b-2), and a particularly preferred combination is (i) a copolymer (a-1) and / or a copolymer salt (a-2) of the above (c). An anti-reflective coating material comprising: and a fluoroalkylsulfonic acid (II) and / or a fluoroalkylcarboxylic acid (II), wherein the fluoroalkyl group has 7 to 12 carbon atoms; and (j)
The copolymer (d) and / or the copolymer salt (a-2) of the above (d) and a fluoroalkyl group having 7 to 12 carbon atoms
Fluoroalkylsulfonic acid (II) and / or
Or an antireflection film material containing a fluoroalkylcarboxylic acid (b-2).

Solvent In the present invention, when a base-blocking anti-reflection film is formed from the above-described anti-reflection film material, a predetermined amount of the anti-reflection film material is added to the solvent at a solid concentration of, for example, 2 to 10% by weight. Then, a solution is prepared by filtering through, for example, a filter having a pore size of about 0.2 μm, and the solution is applied on the resist film by an appropriate application method such as spin coating, casting coating, and roll coating. Examples of the solvent used for preparing the solution of the anti-reflective coating material include solvents capable of dissolving the anti-reflective coating material, for example, water, alcohols such as methanol, ethanol, and isopropanol, 2-methoxyethyl acetate, and 2-methoxyethyl acetate. Ethoxyethyl acetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether,
Diethylene glycol monobutyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, methyl ethyl ketone,
Cyclohexanone, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl ethoxyacetate, ethyl oxyacetate 2, Methyl-hydroxy-3-methylbutyrate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, ethyl acetate, butyl acetate, 3- Methyl methoxypropionate, ethyl pyruvate, benzylethyl ether, dihexyl ether, acetonylacetone, isophorone, caproic acid, caprylic acid, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ
-Butyrolactone, ethylene carbonate, propylene carbonate, phenyl cellosolve acetate and the like can be used. These solvents are used alone or in combination of two or more. Among the above solvents, those containing 10% by weight or more of water and / or alcohols are preferable.

Method for Forming a Resist Pattern Next, in the method for forming a resist pattern of the present invention, a resist is coated on a substrate to form a resist film, and the base-blocking antireflection film of the present invention is formed on the resist film. After the formation, it is exposed to a predetermined pattern shape and then developed. Examples of the resist used in the method for forming a resist pattern according to the present invention include a positive resist such as a novolak resist containing a quinonediazide compound, and particularly a positive or negative chemically amplified resist. When a resist film is formed from such a resist, the resist is dissolved in a suitable solvent at a solid concentration of, for example, 5 to 50% by weight, and then filtered through a filter having a pore diameter of about 0.2 μm, for example. The resist solution, spin coating, cast coating, by a suitable coating method such as roll coating, for example, silicon wafer, coated on a substrate such as a wafer coated with aluminum, usually pre-baked, A resist film is formed by evaporating the solvent. In this case, it goes without saying that a commercially available resist solution can be used as it is.
Examples of the solvent used for preparing the resist solution include the same as the solvent for the antireflection coating material solution. Next, as described above, an anti-reflective coating material solution is applied on the resist film, and usually baked again to form a base-blocking anti-reflective film of the present invention. In this case, as the thickness of the base-blocking antireflection film is closer to an odd multiple of λ / 4m (λ is the wavelength of the radiation, m is the refractive index of the base-blocking antireflection film), the reflection suppression at the upper interface of the resist film is suppressed. The effect increases. In the present invention, any of the pre-baking after the application of the resist solution and the baking after the application of the anti-reflective coating material solution may be omitted for simplification of the process. After that, it is partially exposed so as to have a predetermined pattern shape. The radiation used at this time may be, for example, visible light; ultraviolet light such as g-ray, i-ray, or the like; ArF excimer laser, KrF excimer laser, etc. X-rays such as synchrotron radiation; various radiations such as charged particle beams such as electron beams. In this case, it is preferable to perform post-exposure baking in order to improve the resolution, pattern shape, developability, and the like of the resist. The temperature of post-exposure baking is appropriately adjusted depending on the resist to be used.
It is about 200 ° C. Thereafter, the resist film is developed with a developer and washed to form a desired resist pattern. In this case, the base-blocking antireflection film of the present invention does not need to be subjected to a separate peeling step, and is easily removed during development or during washing after development. This is an important point of the present invention. This is one of the features.

Examples of the developing solution used in the method for forming a resist pattern of the present invention include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, and the like. Di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, choline,
1,8-diazabicyclo- [5,4,0] -7-undecene, 1,5-diazabicyclo- [4,3,0] -5
Examples thereof include an alkaline aqueous solution in which an alkaline compound such as nonene is dissolved. Also, in these developers,
An appropriate amount of a water-soluble organic solvent, for example, alcohols such as methanol and ethanol, and a surfactant can also be added. When development is performed using the alkaline aqueous solution, washing is usually performed after development. As described above, the components constituting the base-blocking antireflection film of the present invention and the relationship between these components, and the method of forming a resist pattern of the present invention have been described in detail, but the present invention does not depart from the gist thereof. In addition to the above, various modifications can be adopted.

[0056]

EXAMPLES The present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. Where parts and%
Is based on weight. The types of resist used in each of the examples and comparative examples are as follows. Type of resist Resist A: m-cresol novolak resin in which 10% of hydroxyl groups are t-butoxycarbonylated (Mw = 7000
0) 100 parts by weight, 5 parts by weight of a condensate (acid generator) of 1 mol of 2,3,4,4'-tetrahydroxybenzophenone and 4 mol of 1,2-naphthoquinonediazide-4-sulfonic acid chloride and ethyl lactate A chemically amplified positive resist comprising a solution obtained by uniformly mixing 300 parts by weight and then filtering through a membrane filter having a pore size of 0.2 μm. Resist B: polyhydroxystyrene in which 50% of hydroxyl groups are t-butoxycarbonylated (Mw = 10,000)
100 parts by weight, 2 parts by weight of triphenylsulfonium hexafluoroantimonate (acid generator) and 300 parts by weight of propylene glycol methyl ether acetate are uniformly mixed and then chemically amplified by a solution filtered through a membrane filter having a pore diameter of 0.2 μm. Type positive resist. The formation of the resist pattern and the performance evaluation of the antireflection film were performed in the following manner. Formation of Resist Pattern A resist A or a resist B was spin-coated on a silicon wafer having a diameter of 6 inches, and then pre-baked on a hot plate at 90 ° C. for 2 minutes to form a 1 μm-thick resist film. Thereafter, an aqueous solution of each anti-reflective coating material is coated on the resist film. The spin coating was performed so as to be in the range of Next, as a reduction projection exposure machine, resist A
In the case of Nikon Corporation stepper NSR1505i6
A (numerical aperture = 0.45, wavelength = 365 nm)
In the case of resist B, Nikon Corporation stepper NSR1
Exposure was performed for a predetermined time using 505EX (numerical aperture = 0.42, wavelength = 248 nm). Immediately after exposure, 11
After exposure and baking for 1 minute on a hot plate at 0 ° C., 2.38 of tetramethylammonium hydroxide was obtained.
It was developed at 25 ° C. for 1 minute using a weight% aqueous solution, washed with water and dried to form a resist pattern.

Resolution of performance evaluation of antireflection film Resolution: The resolution of the smallest resolved resist pattern was measured with a scanning electron microscope to determine the resolution. Developability: The degree of scum and undeveloped residue due to the residue of the anti-reflection film or the resist film is examined by a scanning electron microscope. In the case, the developability was determined to be poor. Pattern shape and base blocking property: The cross-sectional shape of the resist pattern was observed with a scanning electron microscope, and evaluated based on the criteria shown in FIG. In particular, as shown in FIG. 1F, when an eave is observed above the pattern, it is determined that there is no blocking effect on the basic substance in the atmosphere. Standing wave effect: After a resist film is formed on a silicon wafer having a diameter of 6 inches so that the film thickness varies by 0.01 μm in a range of 1.00 to 1.15 μm, an antireflection film is formed as described above. Then, each wafer was exposed by using the above-mentioned reduction projection exposure machine while changing the exposure amount, and then baked and developed after exposure as described above to form a resist pattern. Each of the wafers thus obtained was observed with an optical microscope, the minimum exposure amount at which a residual film was eliminated in a space portion having a width of 100 μm was obtained, and the value was defined as the sensitivity at each film thickness. The maximum value of the obtained sensitivity is Emax, the minimum value is Emin, and the S value (fluctuation in sensitivity due to a change in film thickness, that is, dimensional fluctuation) is used as an index of the standing wave effect. When the standing wave effect was small, when S was 10 to 25, the standing wave effect was medium, and when S was larger than 25, the standing wave effect was large. S = (Emax-Emin) × 100 / Emax Coatability: After forming a resist film on a silicon wafer having a diameter of 6 inches as described above, an antireflection film material is applied so as to have a target film thickness. Using an ellipsometer, the film thickness of the antireflection film was measured at a total of 14 points every 1 cm along the wafer diameter. At this time, the maximum value of the film thickness of the antireflection film is Tmax, the minimum value is Tmin, and the average film thickness is Tave.
When R was 7 or less, the coatability was determined to be good, and when R was greater than 7, the coatability was determined to be poor. R = (Tmax−Tmin) × 100 / Tave

The copolymer (a-1) and the copolymer salt (a-2) constituting the base-blocking antireflection film used in each Example
Was produced according to the following synthesis examples. The polymer constituting the antireflection film used in each comparative example is shown in each table. Evaluation of copolymer (a-1) and copolymer salt (a-2) Mw of copolymer (a-1) and copolymer salt (a-2), and sulfonic acid group-containing monomer, The copolymerization ratio of the fluoroalkyl group-containing monomer and the other comonomer was evaluated as follows. Mw: Tosoh Corporation GPC column (G2000H _XL :
Two, G3000H _XL : One, G4000H _XL : One)
Was measured by gel permeation chromatography using monodisperse polystyrene as a standard under the analysis conditions of a flow rate of 1.0 ml / min, an elution solvent of tetrahydrofuran, and a column temperature of 40 ° C. Copolymerization ratio: Determined by the area ratio of peaks derived from the side chain groups of each monomer in the absorption spectra by ¹ H-NMR and ¹³ C-NMR.

Synthesis Example 1 In a stainless steel autoclave equipped with a stirrer, a thermometer, a heater, a monomer addition pump and a nitrogen gas introducing device, 140 parts of butyl cellosolve was charged, and the gas phase was cooled to 15 parts.
After purging with nitrogen for minutes, the internal temperature was raised to 80 ° C. Next, while maintaining the internal temperature at 80 ° C., 10 parts of 2-acrylamido-2-methylpropanesulfonic acid, 2,2,3,
3,3-pentafluoropropyl acrylate 50 parts,
40 parts of methyl methacrylate and benzoyl peroxide 2
Parts of the mixture were added continuously over 3 hours.
After completion of the addition, the mixture was further reacted at 85 to 95 ° C for 2 hours, and then cooled to 25 ° C. Subsequently, the solvent was removed by vacuum drying to obtain a copolymer (a-1). Mw of the copolymer was 3.0 × 10 ⁴ , and 2-acrylamide-2-
The copolymerization ratio of methylpropanesulfonic acid / 2,2,3,3,3-pentafluoropropyl acrylate / methyl methacrylate was 10/51/39 (%). This copolymer (a-1) is referred to as “copolymer (A)”.

Synthesis Example 2 A separable flask equipped with a stirrer, a thermometer, and a condenser was charged with 170 parts of methanol, bubbled with nitrogen gas for 15 minutes, and then 10 parts of 2-acrylamide-2-methylpropanesulfonic acid. , 2,2-trifluoroethyl acrylate 60 parts, ethyl acrylate 30
And 2, 4'-azobisisobutyronitrile were added, and the internal temperature was raised to 60 ° C. One hour later, the internal temperature was raised to 80 ° C., and the reaction was further performed for 4 hours.
Cooled to ° C. Subsequently, the solvent was removed by vacuum drying to obtain a copolymer (a-1). Mw of the copolymer is 1.5 × 1
0 is ^4, and the copolymerization ratio of 2-acrylamido-2-methylpropanesulfonic acid / 2,2,2-trifluoroethyl acrylate / ethyl acrylate 10/5
9/31 (%). This copolymer (a-1) is referred to as “copolymer (B)”.

Synthesis Example 3 Into the same separable flask as in Synthesis Example 2, methanol 1 was added.
After charging 70 parts and bubbling nitrogen gas for 15 minutes, 20 parts of 2-acrylamido-2-methylpropanesulfonic acid, 80 parts of 2,2,3,3,3-pentafluoropropyl methacrylate and 2,2′-azo 4 parts of bisisobutyronitrile was added, and the internal temperature was raised to 60 ° C. One hour later, the internal temperature was raised to 80 ° C., and the mixture was further reacted for 4 hours, and then cooled to 25 ° C. Subsequently, the solvent was removed by vacuum drying to obtain a copolymer (a-1). Mw of the copolymer was 0.5 × 10 ⁴ , and 2-acrylamido-2-methylpropanesulfonic acid / 2,2,3,3
The copolymerization ratio of 3,3-pentafluoropropyl methacrylate was 20/80 (%). This copolymer (a
-1) is referred to as "copolymer (C)".

Synthesis Example 4 The same autoclave as in Synthesis Example 1 was charged with 140 parts of butyl cellosolve, the gas phase was purged with nitrogen for 15 minutes, and the internal temperature was raised to 80 ° C. Then, while maintaining the internal temperature at 80 ° C., 20 parts of 2-acrylamide-2-methylpropanesulfonic acid, 60 parts of 2,2,3,3,3-pentafluoropropyl acrylate, and methyl methacrylate 20
Parts and 2 parts of benzoyl peroxide were added continuously over 3 hours. 85-95 ° C after completion of addition
, And then cooled to 25 ° C. Subsequently, the solvent was removed by vacuum drying to obtain a copolymer (a-1). The Mw of the copolymer was 4.8 × 10 ⁴ , and 2-acrylamido-2-methylpropanesulfonic acid /
The copolymerization ratio of 2,2,3,3,3-pentafluoropropyl acrylate / methyl methacrylate is 21/60
/ 19 (%). The obtained copolymer (a-1) is
The 2-acrylamide-2-methylpropanesulfonic acid was dissolved in an aqueous solution containing the same amount of ammonia as the charged amount to obtain a copolymer salt (a-2) solution having a solid content of 10%. This copolymer salt (a-2) is referred to as “copolymer (D)”.

Synthesis Example 5 Methanol 1 was placed in the same separable flask as in Synthesis Example 2.
After charging 70 parts and bubbling nitrogen gas for 15 minutes, 10 parts of 2-methacrylamido-2-methylpropanesulfonic acid, 50 parts of 2,2,2-trifluoroethyl acrylate, 40 parts by weight of methyl methacrylate and
4 parts of 2'-azobisisobutyronitrile was added, and the internal temperature was raised to 60C. One hour later, the internal temperature was raised to 70 ° C, and the reaction was further performed for 5 hours, and then cooled to 25 ° C.
Next, the solvent is removed by vacuum drying, and the copolymer (a-1)
I got The Mw of the copolymer is 3.8 × 10 ⁴ , and the copolymerization ratio of 2-methacrylamide-2-methylpropanesulfonic acid / 2,2,2-trifluoroethyl acrylate / methyl methacrylate is 10/50. / 40
(%)Met. The obtained copolymer (a-1) is dissolved in an aqueous solution containing ammonia in the same amount as the charged amount of 2-methacrylamido-2-methylpropanesulfonic acid to give a copolymer having a solid content of 10%. A salt (a-2) solution was obtained. This copolymer salt (a-2) is referred to as “copolymer (E)”.

Synthesis Example 6 A polymerization solvent was a mixture of 150 parts of t-butanol and 20 parts of methanol, and the charged monomers were 10 parts of 2-acrylamido-2-methylpropanesulfonic acid, 2,2,2-
A copolymer (a-1) was obtained in the same manner as in Synthesis Example 5 except that 55 parts of trifluoroethyl acrylate and 35 parts of 2- (perfluorooctyl) ethyl acrylate were used. The Mw of the copolymer was 9.9 × 10 ⁴ and 2
-Acrylamide-2-methylpropanesulfonic acid /
2,2,2-trifluoroethyl acrylate / 2-
The copolymerization ratio of (perfluorooctyl) ethyl acrylate was 10/55/35 (%). This copolymer (a-1) is referred to as “copolymer (F)”.

Synthesis Example 7 The polymerization solvent was 170 parts of t-butanol, and the charged monomers were 5 parts of 2-methacrylamido-2-methylpropanesulfonic acid, 65 parts of 2,2,2-trifluoroethyl acrylate and 2 parts of 2,2,2-trifluoroethyl acrylate. -In the same manner as in Synthesis Example 5 except that 30 parts of-(perfluorooctyl) ethyl acrylate was used,
A copolymer (a-1) was obtained. Mw of the copolymer is 7.9 ×
10 is ^4, and 2-methacrylamide-2-methylpropanesulfonic acid / 2,2,2-trifluoroethyl acrylate / 2-copolymerization ratio of (perfluorooctyl) ethyl acrylate 5/66/29 (% )Met. The obtained copolymer (a-1) was dissolved in an aqueous solution containing モ ル mole of triethanolamine of the charged amount of 2-methacrylamide-2-methylpropanesulfonic acid, and the solid content was 10%. Was obtained as a copolymer salt (a-2) solution. This copolymer salt (a-2) is referred to as “copolymer (G)”.

Synthesis Example 8 The polymerization solvent was 170 parts of t-butanol, and the charged monomers were 10 parts of 2-acrylamido-2-methylpropanesulfonic acid, 70 parts of 2,2,2-trifluoroethyl acrylate, and (Perfluorooctyl) ethyl acrylate Except that 20 parts were used, in the same manner as in Synthesis Example 5,
A copolymer (a-1) was obtained. Mw of the copolymer is 9.0 ×
10 ⁴ , and the copolymerization ratio of 2-acrylamido-2-methylpropanesulfonic acid / 2,2,2-trifluoroethyl acrylate / 2- (perfluorooctyl) ethyl acrylate is 10/70/20 (%). Met. The obtained copolymer (a-1) was treated with 2-acrylamide-
It was dissolved in an aqueous solution containing triethanolamine at 1/2 mol of the charged amount of 2-methylpropanesulfonic acid to obtain a copolymer salt (a-2) solution having a solid content of 10%. This copolymer salt (a-2) is referred to as “copolymer (H)”.

Synthesis Example 9 The polymerization solvent was 170 parts of t-butanol, and the charged monomers were 20 parts of 2-methacrylamido-2-methylpropanesulfonic acid, 40 parts of 2,2,2-trifluoroethyl acrylate and A copolymer (a-1) was obtained in the same manner as in Synthesis Example 5, except that 40 parts of-(perfluorooctyl) ethyl acrylate was used. Mw of the copolymer is 9.
5 × a 10 ^4, also 2-methacrylamide-2-methylpropanesulfonic acid / 2,2,2-trifluoroethyl acrylate / 2-copolymerization ratio of (perfluorooctyl) ethyl acrylate 20/39/41 (%)Met. The obtained copolymer (a-1) was mixed with 1/1/2 of the charged amount of 2-methacrylamido-2-methylpropanesulfonic acid.
It was dissolved in an aqueous solution containing 2 mol of triethanolamine to obtain a copolymer salt (a-2) solution having a solid content of 10%. This copolymer salt (a-2) is referred to as “copolymer (I)”.

Examples 1 to 18 100 parts of each of the copolymers (A) to (I) obtained in Synthesis Examples 1 to 9 and 50 parts of perfluorooctanesulfonic acid were uniformly mixed with water to give a solid content of 4%. % Or 5%, and filtered through a membrane filter having a pore size of 0.2 μm to prepare aqueous solutions of the antireflection coating materials (A) to (I). Antireflection films (A) to (I) were formed using this aqueous solution, and a resist pattern was formed and the performance of the antireflection film was evaluated as described above. The evaluation results are shown in Tables 1 and 2.

Comparative Examples 1 to 5 Antireflection was performed in the same manner as in the above Examples except that the antireflection film materials shown in Tables 1 and 2 were used instead of the antireflection film materials (A) to (I). A film was formed, a resist pattern was formed, and the performance of the antireflection film was evaluated. The evaluation results are shown in Tables 1 and 2.

[0070]

[Table 1]

[0071]

[Table 2]

[0072]

As described in detail above, according to the present invention,
In a lithography process using a resist, especially a chemically amplified resist, it can prevent basic substances in the atmosphere from penetrating into the resist film, prevent the resist pattern from deteriorating, and provide a base-blocking antireflection film and a resist film. A base-blocking antireflection film capable of significantly suppressing the reflection of radiation at the interface with the base and sufficiently reducing the standing wave effect can be provided. In addition, the base-blocking antireflection film of the present invention has excellent solubility in water and a developing solution, has good wettability with a resist film, and has excellent coatability. Further, according to the method for forming a resist pattern of the present invention using the base-blocking antireflection film, without being affected by a basic substance in the atmosphere, even if the time from exposure to development changes. The dimensional fluctuation of the resist pattern can be kept extremely small, and is not affected by the standing wave effect, even if there is a step on the substrate surface, or the composition and viscosity of the resist,
Even if the application conditions of the resist are changed, the dimensional fluctuation of the resist pattern can be suppressed extremely small, and a highly accurate fine resist pattern can be stably formed. Further, the method for forming a resist pattern according to the present invention comprises:
Excellent resist resolution, developability, pattern shape, coatability, etc. Therefore, the present invention largely contributes to the manufacture of an integrated circuit with a high degree of integration.

[Brief description of the drawings]

FIG. 1 is a diagram showing a cross-sectional shape of a pattern and criteria for determining each pattern shape.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Koji Yumoto 2-11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (56) References JP-A-5-188598 (JP, A) JP-A-5-216244 (JP, A) JP-A-6-118630 (JP, A) JP-A-6-214380 (JP, A) JP-A-4-344648 (JP, A) JP-A-61-223733 ( JP, A) JP-A-61-226746 (JP, A) JP-A-4-335354 (JP, A) JP-A-5-181266 (JP, A) (58) Fields studied (Int. Cl. ⁷ , (DB name) G03F 7/00-7/42

Claims (2)

(57) [Claims] 1. A copolymer having at least one type of repeating unit represented by the following formula (1) and at least one type of repeating unit represented by the following formula (2) and / or a salt thereof: And (ii) a fluoroalkylsulfonic acid having a fluoroalkyl group having 5 to 15 carbon atoms and / or a fluoroalkylcarboxylic acid having a fluoroalkyl group having 5 to 15 carbon atoms. Blocking anti-reflective coating. Embedded image [In the formula (1), R ¹ represents a hydrogen atom or an organic group, and R ² represents a divalent organic group. [Chemical formula 2] [In the formula (2), R ³ represents a hydrogen atom or an organic group, Rf represents a fluoroalkyl group, and A represents a direct bond, an alkylene group or a fluoroalkylene group. ] 2. A resist film is formed by applying a resist on a substrate, irradiating the resist film with radiation in a predetermined pattern shape, and then developing the resist film. On the coating,
After forming the base-blocking antireflection film according to claim 1,
A method for forming a resist pattern, comprising irradiating radiation.