JPH11258813A - Composition for forming antireflection film and antireflection film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inorg.-org. hybrid compsn. for forming an antireflection film having high antireflection efficiency and capable of forming a resist pattern excellent in resolution and precision by a simple spin coating method without causing intermixing by incorporating a polytitanoxane and a solvent. SOLUTION: A polytitanoxane and a solvent are incorporated. The polytitanoxane may be modified with other org. compd. or a mixture of unmodified and modified polytitanoxanes may be used. The org. compd. for modification is appropriately at least one compd. selected from the group consisting of organopolysiloxanes, acid anhydrides and carboxylic acids. The polytitanoxane is a polycondensation product having Ti-O-Ti bonds as repeating units formed by hydrolyzing and condensing a hydrolyzable alkoxy titanium compd.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for forming an antireflection film, and more particularly, to an inorganic-organic composition which is useful for fine processing in a lithography process using various radiations, and is particularly suitable for manufacturing integrated circuit devices. The present invention relates to a composition for forming a hybrid antireflection film.

[0002]

2. Description of the Related Art In the manufacture of integrated circuit devices, the processing size in a lithography process is becoming finer in order to obtain an integrated circuit with a higher degree of integration. This lithography process applies a resist composition on a substrate,
Exposure to radiation through a mask pattern (exposure mask having a pattern) by a reduction projection exposure apparatus (stepper), and developing the formed pattern-like latent image with an appropriate developer to obtain a desired pattern. Is a way to get
However, in a substrate having high reflectivity such as aluminum, aluminum-silicon alloy, aluminum-silicon-copper alloy, polysilicon, and tungsten silicide used in this process, the irradiated radiation is reflected on the surface of the resist film. For this reason, there is a problem that a halation or a standing wave is generated in the exposure process, and a fine resist pattern cannot be accurately reproduced. To solve this problem,
It has been proposed to provide a so-called lower antireflection film that absorbs radiation reflected from the substrate below the resist film to be formed on the substrate. As such an antireflection film, conventionally, inorganic films such as a titanium film, a titanium dioxide film, a titanium nitride film, a chromium oxide film, a carbon film, and an α-silicon film are known. However, in order to form such an inorganic antireflection film, it is necessary to use a method such as vacuum deposition, CVD, or sputtering.
There are drawbacks such as the necessity of special equipment such as an apparatus and a sputtering apparatus.

On the other hand, as a simpler method than these methods, a method of forming an inorganic-organic hybrid antireflection film having both inorganic and organic properties by a spin coating method is also known. As this inorganic-organic hybrid antireflection film, for example, a silicon film containing a dye or a compound that absorbs light used in photolithography (JP-A-6-138664) has been proposed. However, the inorganic-organic hybrid antireflection film having the above composition has a hale, because the amount of the dye added is limited.
And standing waves cannot be sufficiently prevented, and the adhesiveness and adhesion to the substrate and the resist film are insufficient. Further, in the conventional antireflection film, a phenomenon called intermixing occurs in which the components of the film and the components of the positive or negative resist film are mixed.
There is also a problem that the resist pattern is degraded such as skirting.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a resist pattern which has a high antireflection effect, does not cause intermixing, and has excellent resolution and accuracy. It is an object of the present invention to provide a composition for forming an inorganic-organic hybrid antireflection film, which can form a film using a simple spin coating method.

[0005]

The present invention provides a composition for forming an antireflection film, comprising (A) polytitanoxane and (B) a solvent. Further, the present invention provides an antireflection film obtained by applying the composition for forming an antireflection film on a substrate and heating the composition. Further, the present invention provides a method for forming a resist pattern using such a composition for forming an antireflection film, wherein (i) applying the above composition on a substrate and baking to form a lower antireflection film. Process, (i
i) a step of applying a resist composition on the antireflection film and baking to form a resist film; (iii) exposing the resist film to radiation through a mask pattern; and (iv) forming the resist film. And developing the latent image pattern.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. (A) Polytitanoxane The polytitanoxane used in the composition for forming an antireflection film of the present invention may be modified by another organic compound, or may be a mixture of a non-modified product and a modified product.
Preferred examples of the modified product include organopolysiloxane,
Examples include polytitanoxane modified with at least one compound selected from the group consisting of acid anhydride and carboxylic acid (for example, organopolysiloxane-modified polytitanoxane, acid anhydride-modified polytitanoxane, carboxylic acid-modified polytitanoxane). The polytitanoxane that can be used in the present invention is a polycondensate having, as a repeating unit, a Ti—O—Ti bond generated by hydrolyzing and condensing a hydrolyzable alkoxytitanium compound.

The polytitanoxane may contain an alkoxy group such as a methoxy group, an ethoxy group, an isopropoxy group, a butoxy group; a phenoxy group; a benzyloxy group; a phenylethoxy group, a phenoxyethoxy group; a naphthyloxy group; . Such polytitanoxane can be produced by a usual method of hydrolyzing tetraalkoxytitanium in the presence of an organic solvent to produce titanol and condensing it.

Examples of the tetraalkoxytitanium used in the production of polytitanoxane include tetramethoxytitanium, tetraethoxytitanium, tetraisopropoxytitanium, tetrabutoxytitanium, tetrakis (methoxypropoxy) titanium, tetranoniloxytitanium, tetraphenoxytitanium , Tetrabenzyloxytitanium, tetraphenylethoxytitanium, tetraphenoxyethoxytitanium, tetranaphthyloxytitanium, and alkoxytitanium obtained by an exchange reaction between these tetraalkoxytitanium and alcohols. The amount of water to be added when hydrolyzing and condensing the tetraalkoxytitanium depends on the amount of alkoxy group 1 in the tetraalkoxytitanium.
0.2 to 0.4 mole per mole is preferred.

[0009] Of the above-mentioned modified polytitanoxane usable in the present invention, the organopolysiloxane-modified polytitanoxane is usually prepared by adding an appropriate amount of water when the silane compound and the tetraalkoxytitanium are compounded, so that the silane is prepared at the time of preparing the composition. It is produced by hydrolyzing and (cross-) condensing a compound and a tetraalkoxytitanium. The organopolysiloxane-modified polytitanoxane thus obtained is obtained by hydrolysis of tetraalkoxytitanium, polytitanoxane having a Ti-O-Ti bond generated by condensation as a repeating unit, and hydrolysis of hydrolyzable organosilane compound, Si-O generated by condensation. Contains an organopolysiloxane having -Si bond as a repeating unit, and a polycondensate having a Si-O-Ti bond as a repeating unit generated by co-hydrolysis and cross-condensation of tetraalkoxytitanium and a hydrolyzable organosilane compound. . In the present invention, instead of such an organopolysiloxane-modified polytitanoxane, a polytitanoxane and an organopolysiloxane can be separately produced, and these can be mixed and used as an organopolysiloxane-containing polytitanoxane.

The hydrolyzable organosilane compound includes the following general formula (1): (R ¹ ) _n Si (OR ² ) _4-n (1) (where R ¹ is an organic compound having 1 to 8 carbon atoms) A group represented by R ²
Is an alkyl group having 1 to 5 carbon atoms or 1 to 5 carbon atoms
4 represents an acyl group, and n is an integer of 0 to 2. ) Is preferred.

In the general formula (1), examples of the organic group having 1 to 8 carbon atoms for R ¹ include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group and an i-butyl group.
-Butyl group, sec-butyl group, t-butyl group, n-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, etc., as well as 3-chloropropyl Group, 3-bromopropyl group, 3,3,3-trifluoropropyl group, 3-glycidoxypropyl group, 3-
(Meth) acryloxypropyl group, 3-mercaptopropyl group, 3-aminopropyl group, 3-dimethylaminopropyl group, 2- (3,4-epoxycyclohexyl) ethyl group, vinyl group, phenyl group and the like. it can. In the general formula (1), when two R ¹ are present,
Each R ¹ may be the same or different from each other.

The alkyl group having 1 to 5 carbon atoms for R ² includes, for example, methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, and
Examples thereof include linear or branched alkyl groups such as c-butyl group, t-butyl group, and n-pentyl group. Examples of the acyl group having 1 to 4 carbon atoms include an acetyl group,
Examples thereof include a propionyl group and a butyryl group.
In the general formula (2), when two R ² exist, each R ²
May be the same or different from each other.

Specific examples of such a silane compound include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-i-propoxysilane, tetra-n-butoxysilane, tetra-i-butoxysilane and the like. Tetraalkoxysilanes; methyltriethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-
Alkyltrialkoxysilanes such as propyltriethoxysilane, i-propyltrimethoxysilane, i-propyltriethoxysilane, n-butyltrimethoxysilane, i-butyltrimethoxysilane; 3-chloropropyltrimethoxysilane; Haloalkyl trialkoxysilanes such as chloropropyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, 3,3,3-trifluoropropyltriethoxysilane; 3
Glycidoxyalkyl trialkoxysilanes such as 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane; 3- (meth) acryloxypropyltrimethoxysilane and 3- (meth) acryloxypropyltrimethoxysilane (Meth) acryloxyalkyl trialkoxysilanes such as ethoxysilane; mercaptoalkyl trialkoxysilanes such as 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane; 3-aminopropyltrimethoxysilane and 3-aminopropyl Aminoalkyl trialkoxysilanes such as triethoxysilane; vinyltrialkoxysilanes such as vinyltrimethoxysilane and vinyltriethoxysilane; phenyltrimethoxysilane;
Phenyltrialkoxysilanes such as phenyltriethoxysilane; 3,4-epoxycyclohexylalkyltrialkoxysilanes such as 3,4-epoxycyclohexylethyltrimethoxysilane and 3,4-epoxycyclohexylethyltriethoxysilane; dimethyldimethoxysilane , Dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, di-n-
Dialkoxysilanes such as propyldimethoxysilane, di-n-propyldiethoxysilane, diphenyldimethoxysilane and diphenyldiethoxysilane; tetraacetoxysilane, methyltriacetoxysilane, ethyltriacetoxysilane, dimethyldiacetoxysilane, diethyldiacetoxy Examples include acyloxysilanes such as silane. Of these silane compounds,
Preferred are tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane and the like. These silane compounds may be used alone or
A mixture of more than one species can be used.

Among the above-mentioned modified polytitanoxane usable in the present invention, carboxylic acid-modified polytitanoxane or acid anhydride-modified polytitanoxane is produced by subjecting tetraisopropoxytitanium to a carboxylic acid or acid anhydride to a de-alcohol condensation reaction. Is a polycondensate having titanium carboxylates produced by this condensation reaction as repeating units.

The carboxylic acid is represented by the following general formula (2): R ³ _n (COOH) _4-n (2) (where R ³ represents an organic group having 1 to 12 carbon atoms;
n is an integer of 3 to 4. ) Is preferred.

In the general formula (2), examples of the carboxylic acid having an organic group having 1 to 12 carbon atoms of R ³ include acetic acid, propionic acid, n-butyric acid, n-valeric acid, hexanoic acid, n- Heptanoic acid, n-octanoic acid, n-nonanoic acid, n
-Linear alkyl carboxylic acids such as decanoic acid, n-undecanoic acid and lauric acid; isobutyric acid, pivalic acid, isovaleric acid, 2-methylbutyric acid, 2-ethylbutyric acid, 3,3-dimethylbutyric acid, and 3-methylbutyric acid Folic acid, diisopropylacetic acid, 2-
Branched alkyl carboxylic acids such as ethylhexanoic acid; malonic acid, methylmalonic acid, dimethylmalonic acid, ethylmalonic acid, diethylmalonic acid, n-butylmalonic acid, succinic acid, methylsuccinic acid, 2,2-succinic acid, 2-ethyl-
2-methylsuccinic acid, 2,3-dimethylsuccinic acid, glutaric acid, 2-methylglutaric acid, 3-methylglutaric acid, 2,4-dimethylglutaric acid, 3,3-dimethylglutaric acid, 2,2-dimethyl Glutaric acid, adipic acid, 3
-Alkyl diacids such as methyl adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid; acrylic acid, methacrylic acid, crotonic acid, vinyl acetic acid, 4-pentenoic acid, tiglic acid, 3,3-dimethylacrylic acid, 2-hexenoic acid, 3-hexenoic acid, 2-octenoic acid, fumaric acid, maleic acid, mesaconic acid, unsaturated alkyl dicarboxylic acids such as itaconic acid; phenylacetic acid, 3-phenylpropionic acid, 2-phenylpropionic acid, Cyclohexylphenylacetic acid, triphenylacetic acid, diphenylacetic acid,
2,2-diphenylpropionic acid, 4-phenylbutyric acid,
Phenoxyacetic acid, 2-phenoxybutyric acid, thiophenoxyacetic acid, 3-benzoylpropionic acid, phenylmalonic acid, benzylmalonic acid, phenylsuccinic acid, 1,2-phenylene diacetic acid, 1,3-phenylene diacetic acid, 1,4- Examples include aromatic-containing carboxylic acids such as phenylene diacetate, cinnamic acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, and pyromellitic acid. As the acid anhydride, the following general formula (3):

[0017]

Embedded image (Where n is an integer of 2 to 3 and R ⁴ is 1 carbon atom)
To 12 organic groups. )) Are preferred.

The acid anhydride represented by the general formula (3) includes, for example, succinic anhydride, methylsuccinic anhydride,
1,2-cyclohexanedicarboxylic anhydride, cis-1,
2,3,6-tetrahydrophthalic anhydride, cis-norbornene-2,3-dicarboxylic anhydride, maleic anhydride, 2,3-dimethylmaleic anhydride, glutaric anhydride, 3,3-dimethylglutaric Acid anhydride, phthalic anhydride, 3,3 ', 4,4'benzophenonetetracarboxylic anhydride, trimellitic anhydride and the like can be mentioned.

In the composition of the present invention, the polytitanoxane may be used alone without modification, or may be modified with an organopolysiloxane, a carboxylic acid and / or an acid anhydride, depending on the desired properties of the antireflection film. The modified polytitanoxane may be used alone or in combination of two or more thereof, or an unmodified polytitanoxane and at least one of the above-mentioned modified products may be used in combination. In the composition of the present invention,
It is desirable to use the following components in combination with the polytitanoxane (A).

This component has the general formula (I): R ⁵ COCH ₂ COR ⁶ (I) (where R ⁵ and R ⁶ may be the same or different from each other, and R ⁵ is a linear or branched chain) 1 to 6 carbon atoms
R ⁶ represents a linear or branched alkyl group having 1 to 5 carbon atoms, or a linear or branched alkyl group having 1 to 16 carbon atoms. ), Β-diketones and / or β-ketoesters. This compound has an effect of further improving the storage stability of the composition by coordinating to a metal atom contained in the composition for forming an antireflection film of the present invention.

Specific examples of such β-diketones and / or β-ketoesters include acetylacetone, methyl acetoacetate, ethyl acetoacetate, n-propyl acetoacetate, i-propyl acetoacetate, and n-acetoacetate.
Butyl, i-butyl acetoacetate, sec-butyl acetoacetate, t-butyl acetoacetate, 2,4-hexanedione,
2,4-pentanedione, 2,4-heptanedione, 3,
5-heptanedione, 2,4-octanedione, 3,5-
Octanedione, 2,4-nonanedione, 3,5-nonanedione, 5-methyl-2,4-hexanedione and the like can be mentioned. Of these compounds, acetylacetone and ethyl acetoacetate are preferred. These components can be used alone or in combination of two or more. The proportion of this component is usually 1 mol or more, preferably 1 to 20 mol, more preferably 2 mol, per 1 mol of the total of titanium atoms and silicon atoms in the composition for forming an antireflection film.
10 to 10 mol. When the compounding ratio of this component is less than 1 mol, the effect of improving the storage stability of the obtained composition for forming an antireflection film tends to decrease.

(B) Solvent The solvent constituting the composition for forming an antireflection film of the present invention is a solvent capable of dissolving the antireflection film material, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene Ethylene glycol monoalkyl ethers such as glycol monopropyl ether and ethylene glycol monobutyl ether; ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether ―Ethylene glycol monoalkyl ether acetates such as teracetate, ethylene glycol monobutyl ether teracetate; diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl Diethylene glycol dialkyl ethers such as ether and diethylene glycol dibutyl ether; propylene such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monobutyl ether Glycol monoalkyl ethers; propylene glycol dimethyl ether, propylene glycol
Propylene glycol dialkyl ethers such as diethyl ether, propylene glycol dipropyl ether, propylene glycol dibutyl ether; propylene glycol monomethyl ether acetate, propylene glycol monoether ether tereate, propylene glycol monopropyl Propylene glycol monoalkyl ether acetates such as ether acetate and propylene glycol monobutyl ether acetate;
Lactic esters such as methyl lactate, ethyl lactate, n-propyl lactate, isopropyl lactate, n-butyl lactate, n-isobutyl lactate; methyl formate, ethyl formate, n-propyl formate, isopropyl formate, n-butyl formate, isobutyl formate N-amyl formate, isoamyl formate, methyl acetate,
Ethyl acetate, n-amyl acetate, isoamyl acetate, n-acetic acid
-Hexyl, methyl propionate, ethyl propionate, n-propyl propionate, isopropyl propionate, n-butyl propionate, isobutyl propionate, methyl butyrate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, n-butyl butyrate, Aliphatic carboxylic esters such as isobutyl butyrate; ethyl hydroxyacetate;
-Ethyl hydroxy-2-methylpropionate, methyl 3-methoxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutyrate, ethyl methoxyacetate, ethyl ethoxyacetate, methyl 3-methoxypropionate, 3-
Ethyl ethoxypropionate, ethyl 3-methoxypropionate, 3-methoxybutyl acetate, 3-methoxypropyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutylpropione -To, 3-methyl-3-methoxybutyl butyrate
And other esters such as methyl acetoacetate, methyl pyruvate and ethyl pyruvate; aromatic hydrocarbons such as toluene and xylene; methyl ethyl ketone, methyl propyl ketone, methyl butyl ketone, 2-heptanone, 3-heptanone, -Ketones such as heptanone and cyclohexanone; amides such as N-methylformamide, N, N-dimethylformamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone; γ
-Lactones such as butyrolactone are appropriately selected and used. Among these, ethylene glycol monoethyl ether is a particularly preferable solvent from the viewpoint of safety to the human body.
Examples include teracetate, ethyl lactate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, 2-heptanone, and propylene glycol monomethyl ether acetate. These solvents are used alone or in combination of two or more. The compounding amount of the solvent is such that the solid content concentration is about 0.01 to 70% by weight, preferably 0.0
The proportion is 5 to 60% by weight, more preferably 1 to 20% by weight.

Other Additives Various additives can be added to the composition for forming an antireflection film of the present invention as long as the desired effects of the present invention are not impaired. Examples of the additive include a surfactant and a radiation absorbing compound. The surfactant has an action of improving coating properties, striation, wettability, developability, and the like. Examples of such a surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenyl ether, and polyoxyethylene nonylphenyl ether.
In addition to nonionic surfactants such as ter, polyethylene glycol dilaurate, and polyethylene glycol distearate, commercially available products include, for example, an organosiloxane polymer, KP341 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), ( Polyfluoro No.75 and No.95 (trade names, manufactured by Kyoeisha Yushi Kagaku Kogyo Co., Ltd.), which are (meth) acrylic acid (co) polymers, F-Top EF101, EF204, EF303, and EF352
(Trade name, manufactured by Tochem Products), Mega Fuck F17
1, F172, F173 (trade name, manufactured by Dainippon Ink and Chemicals), Florad FC430, FC431, FC135, FC93
(Trade name, manufactured by Sumitomo 3M), Asahi Guard AG710,
Surflon S382, SC101, SC102, SC103, SC10
4, SC105, SC106 (trade name, manufactured by Asahi Glass) and the like. The amount of these surfactants is usually 15 parts by weight or less, and preferably 10 parts by weight or less, per 100 parts by weight of the solid content of the antireflection coating composition.

The radiation absorbing compound has a function of further improving the antireflection effect. Examples of such radiation-absorbing compounds include dyes such as oil-soluble dyes, disperse dyes, basic dyes, methine dyes, pyrazole dyes, imidazole dyes, hydroxyazo dyes, and the like; bixin derivatives, norbixin , Stilbene, 4,4'-
Fluorescent whitening agents such as diaminostilbene derivatives, coumarin derivatives and pyrazoline derivatives; hydroxyazo dyes, tinuvin 234 (manufactured by Ciba-Geigy), tinuvin 1130
Ultraviolet absorbers (manufactured by Ciba Geigy); aromatic compounds such as anthracene derivatives and anthraquinone derivatives. The amount of the radiation absorbing compound to be blended is usually 100 parts by weight or less, preferably 50 parts by weight or less, per 100 parts by weight of the solid content of the composition for forming an antireflection film. Also as other additives storage stabilizers, defoamers,
An adhesion aid or the like can be blended.

Method of Use To form an anti-reflection film and a resist pattern using the above-described composition for forming an anti-reflection film of the present invention, basically, (i) a composition for forming an anti-reflection film on a substrate Coating and baking (heating) to form a lower antireflection film, (i.
i) a step of applying and baking a resist composition on the antireflection film to form a resist film; (iii) exposing the resist film to radiation through a mask pattern; and (iv) forming the formed resist film. A step of developing the latent image pattern may be performed.

Hereinafter, each step will be described in more detail. First, in the first step, a method such as spin coating, casting coating, roll coating, etc., is applied so that the antireflection coating composition has a predetermined film thickness on the substrate, for example, 100 to 5000 angstroms. To apply. Next, the coating film is baked on a hot plate to evaporate the solvent. The baking temperature at this time is, for example, about 90 to 250 ° C. Usually, the time required for this bake is 10 seconds to 360 seconds, preferably 6 seconds.
0 second to 120 seconds.

After forming the anti-reflection film on the substrate as described above, in the second step, a resist is applied on the anti-reflection film so as to have a predetermined film thickness, and the resist is coated on a hot plate. Then, the solvent in the resist film is volatilized to form a resist film. The prebaking temperature at this time is appropriately adjusted according to the type of the resist used and the like, but is usually about 30 to 200 ° C, preferably 50 to 150 ° C.
It is. This pre-baking time is usually 30 seconds to 360 seconds.
Seconds, preferably 60 seconds to 120 seconds.

When forming a resist film, each resist is put in an appropriate solution at a solid concentration of, for example, 5 to 50% by weight.
Then, the solution is filtered through a filter having a pore diameter of about 0.2 μm, for example, to prepare a solution, which is then applied to a silicon wafer by a method such as spin coating, casting coating, or roll coating. Is applied on an antireflection film of a substrate such as a wafer coated with aluminum. In this case, a commercially available resist solution can be used as it is. Examples of the resist used for forming the resist pattern in the present invention include a positive resist composed of an alkali-soluble resin and a quinonediazide-based photosensitizer, a negative resist composed of an alkali-soluble resin and a radiation-sensitive crosslinking agent, and a radiation-sensitive resist. Positive or negative chemically amplified resists containing an acid generator may be mentioned.

Then, in a third step, the resist film is exposed to radiation through an exposure mask pattern. As the radiation, visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam, γ-ray, molecular beam, ion beam, or the like can be appropriately used depending on the type of the resist. Among these radiations, preferred are ultraviolet rays and far ultraviolet rays, and particularly g-rays (wavelength 4).
36 nm), i-ray (wavelength 365 nm), KrF excimer laser (wavelength 248 nm) and ArF excimer laser
Zir (wavelength 193 nm) is suitable for the composition of the present invention.

Next, in a fourth step, the latent image pattern formed by exposure is developed. Thereafter, by washing and drying, a desired resist pattern is formed. During this process, in order to improve resolution, pattern shape, developability, etc., baking after exposure and before development (hereinafter referred to as “post exposure baking”).
C). The post-exposure bake conditions are:
On a hot plate, usually at a temperature of 80 to 160 ° C, 60
Heat for seconds to 360 seconds.

The developer used for forming the resist pattern in the present invention includes, for example, sodium hydroxide,
Potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxy , Tetraethylammonium hydroxide, pyrrol, piperidine, choline,
Examples thereof include an alkaline aqueous solution in which 1,8-diazabicyclo (5,4,0) -7-undecene, 1,5-diazabicyclo- (4,3,0) -5-nonane and the like are dissolved. The alkali concentration of the alkali developer is usually 1 to 10% by weight, preferably 1 to 5% by weight, and the developing temperature is 10%.
To 35 ° C., and the development time is about 30 to 300 seconds. Examples of the developing method include an immersion method, a paddle method, and a spray method. Further, to these developers, a water-soluble organic solvent, for example, alcohols such as methanol and ethanol, and a surfactant can be added in an appropriate amount. Finally, dry etching is performed using the resist pattern as a mask to remove the antireflection film, thereby obtaining a resist pattern for substrate processing. Examples of the dry etching method include a reactive ion etching method, and raw materials of the reactive ion include oxygen, halogen, and halogenated hydrocarbon. At this time, the operation can be continuously performed from the selective removal of the antireflection film to the pattern processing of the substrate.

[0032]

EXAMPLES Hereinafter, embodiments of the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these embodiments at all unless it exceeds the gist. In the following examples, all parts are parts by weight. Example 1 A mixture of 29 parts of water and 1087 parts of ethyl lactate was added dropwise to a separable flask equipped with a thermometer and a condenser under a nitrogen stream, and heated at 85 ° C. Stirred. One hour later, 200 parts of acetylacetone was added, the mixture was stirred at room temperature for 30 minutes, and then filtered through a membrane filter having a pore size of 0.2 μm to obtain a composition (1) for forming an antireflection film. Example 2 Under a nitrogen stream, 284 parts of tetraisopropoxytitanium and 136 parts of methyltrimethoxysilane were added to a separable flask equipped with a thermometer and a condenser, and then water 50
And a mixed solution of 700 parts of ethyl lactate was added dropwise, and heated and stirred at 85 ° C. One hour later, acetylacetone 300
After stirring at room temperature for 30 minutes, the pore size was 0.2
The mixture was filtered through a μm membrane filter to obtain a composition (2) for forming an antireflection film. Example 3 To a separable flask equipped with a thermometer and a condenser under a nitrogen stream, 284 parts of tetraisopropoxytitanium, 130 parts of ethyl acetoacetate, 104 parts of malonic acid, and 1320 parts of ethyl lactate were added, and the mixture was heated at 60 ° C. for 1.5 hours. After stirring for a while, the mixture was filtered through a membrane filter having a pore size of 0.2 μm to obtain a composition (3) for forming an antireflection film.

Evaluation Example 1 The composition (1) for forming an antireflection film was applied on an aluminum substrate having a hole pattern having a depth of 0.2 μm and a diameter of 2 μm, followed by spin coating, followed by hot coating.
The film was baked at 90 ° C. for 1 minute and at 200 ° C. for 2 minutes to form an antireflection film having a thickness of 0.1 μm. The absorbance of the obtained antireflection film at a wavelength of 248 nm was 0.39.
The refractive index was 1.88, showing extremely excellent optical characteristics. Then, a positive resist for KrF (trade name: KrF K2G, manufactured by Nippon Synthetic Rubber Co., Ltd.) is spin-coated to a thickness of 0.7 μm on the antireflection film to form a resist film, and a hot plate at 80 ° C. Baked on the plate for 2 minutes. Then, through an exposure mask (mask pattern) having a ball pattern, a Nikon Corporation stepper NSR2005E
Using an X8A (KrF excimer laser, wavelength 248 nm, aperture number 0.5), a 0.5 μm line-and-spattern pattern with a 1: 1 line width (hereinafter referred to as “optimum”) Exposure was performed for only "exposure time." Then, after exposure on a hot plate at 100 ° C for 2 minutes,
After developing, a resist pattern was formed by developing with a 2.38% by weight aqueous solution of tetramethylammonium hydroxide at 25 ° C. for 1 minute, washing with water, and drying.
The resulting resist pattern has a small depth of “graining” due to reflection (hereinafter referred to as “notching depth”).
The pattern shape was excellent with no tailing and no effect of standing waves. Evaluation Examples 2-3 The composition for forming an antireflection film obtained in Examples 2-3 (2)
Using (3) to (3), a resist pattern was formed in the same manner as in Evaluation Example 1. The obtained resist pattern had a small notch depth, a good pattern shape without tailing, and no effect of standing waves. In addition, each of the obtained antireflection films has an absorbance of 0.25 or more and a refractive index of 1.7 to 1.0 for light having a wavelength of 248 nm.
8, indicating good optical characteristics.

[0034]

The lower antireflection film formed by using the composition for forming an antireflection film of the present invention has a high antireflection effect,
In addition, since there is no intermixing with the resist, a resist pattern excellent in resolution, precision, etc. can be formed in cooperation with a positive or negative resist. Therefore, the composition for forming an antireflection film of the present invention greatly contributes to the production of a highly integrated circuit.

Claims (4)

[Claims] 1. A composition for forming an antireflection film, comprising (A) a polytitanoxane and (B) a solvent. 2. The formation of an antireflection film, wherein the polytitanoxane (A) is a polytitanoxane modified with at least one compound selected from the group consisting of organopolysiloxanes, acid anhydrides and carboxylic acids. Composition. Further, (C) the following general formula (I): R ⁵ COCH ₂ COR ⁶ (I) (where R ⁵ and R ⁶ may be the same or different from each other, and R ⁵ is a linear Or 1 to 6 carbon atoms in the branched chain
R ⁶ represents a linear or branched alkyl group having 1 to 5 carbon atoms, or a linear or branched alkyl group having 1 to 16 carbon atoms. The composition for forming an antireflection film according to claim 1, comprising a compound represented by the formula (1). 4. An anti-reflection film obtained by applying the composition for forming an anti-reflection film according to claim 1 on a substrate and heating the composition.