JP2003177206A - Composition for formation of antireflection film and antireflection film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition for the formation of an inorganic antireflection film with which an antireflection film having a high antireflection effect even in a rather thin film and having excellent adhesion property and sticking property with a resist film can be formed and a resist pattern having excellent resolution and accuracy can be formed. <P>SOLUTION: The composition for the formation of an antireflection film contains at least one kind of tantalum-containing product selected from (A1) the reaction products of (a1) tantalum alkoxide and (a2) at least one kind of compound selected from a group consisting of aminoalcohols, compounds having two or more hydroxyl groups in the molecules (except for aminoalcohols), β-diketones, β-ketoesters, β-dicarboxylates, lactic acid, ethyl lactate, and 1,5- cyclooctadiene and (A2) hydrolyzed products of the above reaction products. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a composition for forming an antireflection film suitable for microfabrication by a lithographic process using various radiations, particularly for microfabrication in the production of integrated circuit devices, and an antireflection film using the same. And a method for forming a resist pattern.

[0002]

2. Description of the Related Art In the manufacture of integrated circuit devices, fine processing is performed by a lithographic process in order to form an integrated circuit having a high degree of integration. In this lithographic process, a resist composition is applied onto a substrate and exposed to radiation through a mask pattern (exposure mask having a pattern) by a reduction projection exposure device (stepper), and the formed pattern latent image is appropriately exposed. It is a method of obtaining a desired pattern by developing with a different developing solution. However, the highly reflective substrate such as aluminum, aluminum-silicon alloy, aluminum-silicon-copper alloy, polysilicon, or tungsten silicide used in this process reflects the irradiated radiation on the substrate surface.
Therefore, there is a problem that a fine resist pattern cannot be accurately reproduced due to halation or standing wave generated in the exposure process. In order to solve this problem, there has been proposed a method of forming a so-called lower layer antireflection film under the resist film to be formed on the substrate, which absorbs the radiation reflected from the substrate. Conventionally, as this type of antireflection film, a titanium film, a titanium dioxide film, a titanium nitride film, a chromium oxide film,
Inorganic films such as carbon films and α-silicon films are known. However, in order to form such an inorganic antireflection film, it is necessary to use a method such as vacuum vapor deposition, CVD, and sputtering, and thus a special apparatus such as a vacuum vapor deposition apparatus, a CVD apparatus, and a sputtering apparatus is required. There was a drawback. On the other hand, as a simpler method than these methods, there is also known a method of forming an organic antireflection film or an inorganic antireflection film containing a dye by using a spin coating method. However, a general organic antireflection film has a low selectivity with respect to the resist during the dry etching process because the resist component is also organic. That is, it is extremely difficult to etch only the antireflection film while leaving the resist. In addition, since the inorganic antireflection film containing a pigment (see Japanese Patent Laid-Open No. 6-138664) generally limits the addition amount of the dye,
There are problems that halation and standing waves cannot be sufficiently prevented, and that the adhesiveness and adhesiveness between the patterned layer 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 type resist film are mixed, so that there is a problem that the resist pattern is deteriorated such as defective removal and skirting. is there.

[0003]

The present invention has been made based on the above circumstances. Therefore, an object of the present invention is to form a resist pattern which has a high antireflection effect and excellent adhesiveness and adhesion to a resist film by a simple method, and which is excellent in resolution and accuracy. An object of the present invention is to provide a composition for forming an inorganic antireflection film.

Another object of the present invention is to provide a method for forming an antireflection film using the above composition of the present invention. Another object of the present invention is to provide a method for forming a resist pattern on a substrate having an antireflection film formed thereon using the composition of the present invention. Other objects and advantages of the present invention will be apparent from the following description.

[0005]

According to the present invention, the above objects and advantages of the present invention are as follows: (A1) (a1) tantalum alkoxide and (a2) amino alcohol; At least one compound selected from the group consisting of compounds having a hydroxyl group (excluding amino alcohols), β-diketones, β-ketoesters, β-dicarboxylic acid esters, lactic acid, ethyl lactate and 1,5-cyclooctadiene. Reaction product with (A2)
It is achieved by a composition for forming an antireflection film, which comprises at least one tantalum-containing product selected from the group consisting of a hydrolyzate of the reaction product.

[0006] Secondly, the above objects and advantages of the present invention are, secondly, a method for forming an antireflection film, which comprises coating the substrate with a composition for forming an antireflection film, followed by heat treatment and / or phototreatment. Achieved by

Further, the above objects and advantages of the present invention are
Third, (1) a step of forming a lower antireflection film by heat-treating and / or phototreating a coating film of the above composition applied on a substrate, (2) applying a resist composition on the antireflection film. Applying and baking to form a resist film,
This is achieved by a method of forming a resist pattern including (3) exposing the resist film to radiation through a mask pattern, and (4) developing the formed latent image pattern.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. Component (a1) In the present invention, as the tantalum alkoxide (a1), for example, the following formula (1) Ta (OR) ₅ (1) (wherein R is an alkyl group having 1 to 6 carbon atoms and 5 R Which may be the same or different, are preferably used.

Specific examples of the tantalum alkoxide include:
Examples thereof include tantalum pentamethoxide, tantalum pentaethoxide, tantalum pentaisopropoxide, tantalum pentabutoxide and the like. Of these, tantalum pentaethoxide, tantalum pentaisopropoxide, and tantalum pentabutoxide are preferable. These tantalum alkoxides can be used alone or in combination of two or more.

Component (a2) The component (a2) used in the present invention is amino alcohol, a compound having two or more hydroxyl groups in the molecule (excluding amino alcohol), β-diketone, β-ketoester, β. -At least one compound selected from the group consisting of dicarboxylic acid esters, lactic acid, ethyl lactate and 1,5-cyclooctadiene.

Examples of the compound having two or more hydroxyl groups in the molecule (excluding amino alcohol) are:
Examples thereof include alcohols having two or more hydroxyl groups in the molecule (excluding amino alcohols) and phenols having two or more hydroxyl groups in the molecule.

Of the above compounds, amino alcohols, alcohols having two or more hydroxyl groups in the molecule (excluding amino alcohols), and phenols having two or more hydroxyl groups in the molecule are preferably used.
Amino alcohols and alcohols having two or more hydroxyl groups in the molecule (excluding amino alcohols) are more preferable.

Examples of the amino alcohols include compounds such as triethanolamine, diethanolamine, triisopropanolamine, diisopropanolamine, methyldiethanolamine and ethyldiethanolamine. Of these, triethanolamine and diethanolamine are particularly preferably used.

Specific examples of the alcohols having two or more hydroxyl groups in the molecule (excluding amino alcohols) are, for example, ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, heptanediol, octane. Examples thereof include dialcohols such as diol, nonanediol, decanediol, diethylene glycol, bistrimethylene glycol, glycerol monomethyl ether, glycerol monoethyl ether and hydroquinone; and polyhydric alcohols such as glycerol. Of these, diethylene glycol, butanediol and pentanediol can be particularly preferably used.

Specific examples of the phenols having two or more hydroxyl groups in the molecule include polyphenols such as catechol, resorcin, hydroquinone and phloroglucin. Of these, hydroquinone is particularly preferably used.

Examples of the β-diketone include acetylacetone, propionylacetone, methyldiacetylmethane, dipropionylmethane, n-butyrylacetone, isobutyrylacetone, 3-methyl-2,4-hexanedione, diacetylethylmethane, n-valerylacetone, propionyl-n-butyrylmethane, 3-methyl-2,4-hexanedione, diacetylethylmethane, n-valerylacetone, propionyl-n-butyrylmethane, 3-methyl-2,4-heptanedione, Isovalerylacetone, pivaloylacetone, isopropyldiacetylmethane, caproylacetone, di-n-butyrylmethane, 2,2,6,6-tetramethyl-3,5-
Heptanedione, benzoylacetone, 3-phenyl-
2,4-pentanedione, dibenzoylmethane, ethoxycarbonyldiacetylmethane, 1,1,1,5,5,5
And compounds such as 5-hexafluoro-2,4-pentanedione. Of these, acetylacetone and propionylacetone are particularly preferably used.

Examples of the β-keto ester include compounds such as methyl acetoacetate, ethyl acetoacetate and methyl-α-methyl acetoacetate. Of these, methyl acetoacetate and ethyl acetoacetate are particularly preferable.

The above β-dicarboxylic acid ester includes
For example, dimethyl malonate, diethyl malonate, dibutyl malonate, dihexyl malonate, dioctyl malonate,
Examples include compounds such as diundecyl malonate, dihexadecyl malonate, di-9-octadecyl malonate, di-9,12-octadecadienyl malonate and di-9,11,13-octadecatrienyl malonate. Of these, dimethyl malonate and diethyl malonate are particularly preferably used. The above compounds can be used alone or in combination of two or more.

The above-mentioned (a1) tantalum alkoxide and (a)
In the reaction of the component 2), the component (a2) is preferably 0.1-1,000 with respect to 1 mol of the (a1) tantalum alkoxide.
It can be carried out using 0 mol, more preferably 0.5 to 100 mol, and particularly preferably 1 to 10 mol. The reaction temperature is preferably −30 to 150 ° C., more preferably 0.
To 100 ° C, more preferably 0 to 70 ° C. The reaction pressure may be normal pressure, but if necessary, it can be carried out under pressure or under reduced pressure.

(A1) tantalum alkoxide and (a2)
It is also possible to carry out the reaction of the components in the presence of monoalcohols (excluding aminoalcohols) and / or monophenols.

Specific examples of the above monoalcohols (excluding amino alcohols) include, for example, methanol, ethanol, propanol, isopropanol, butanol, tert-butanol, hexanol, cyclohexanol, octanol, ethylene glycol monomethyl ether, ethylene glycol. Monoethyl ether, ethylene glycol monoisopropyl ether,
Examples thereof include diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, glycerol dimethyl ether, glycerol diethyl ether and the like.

Examples of monophenols include phenol, methylphenol, dimethylphenol,
Examples include trimethylphenol, ethylphenol, diethylphenol, triethylphenol and the like. Of these, phenol, methylphenol and ethylphenol can be preferably used.

(A1) tantalum alkoxide and (a2)
When the reaction of the components is carried out in the presence of monoalcohols (excluding amino alcohols) and / or monophenols, the amount of these compounds used is preferably 10 mol per 1 mol of the component (a2). It is preferably 5 mol or less, more preferably 3 mol or less.
Here, if the amount used exceeds 10 moles, the reaction between the tantalum alkoxide (a1) and the component (a2) may be hindered.

The above reaction can be carried out in the presence of a solvent, if necessary. When using a solvent, (a1)
It is preferable to use a tantalum alkoxide and the component (a2), and a solvent that does not react with these reaction products.

Specific examples of such a solvent include, for example, n-pentane, cyclopentane, n-hexane, cyclohexane, n-heptane, cycloheptane, n-octane, cyclooctane, decane, cyclodecane, dicyclopentadiene hydrogen. Compound, benzene, toluene, xylene, durene, indene, tetrahydronaphthalene,
Hydrocarbon solvents such as decahydronaphthalene and squalane; diethyl ether, dipropyl ether, dibutyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, tetrahydrofuran, tetrahydropyran , 1, 2
-Ether solvents such as dimethoxyethane, bis (2-methoxyethyl) ether, p-dioxane; propylene carbonate, γ-butyrolactone, N-methyl-2
-Polar solvents such as pyrrolidone, dimethylformamide, acetonitrile, dimethylsulfoxide, methylene chloride, chloroform. Of these, diethyl ether, dipropyl ether, dibutyl ether,
Tetrahydrofuran, dimethylformamide, acetonitrile, dimethylsulfoxide, methylene chloride and chloroform can be particularly preferably used. These solvents may be used alone or in combination of two or more.

(A1) tantalum alkoxide and (a2)
When the reaction of the components is carried out in the presence of a solvent, the amount of the solvent used is preferably 1 to 100 mL, more preferably 5 to 50 mL, relative to 1 g of (a1) tantalum alkoxide.
More preferably, it is 5 to 30 mL.

The above reaction product can be inferred to be, for example, the following. i) When component (a2) contains amino alcohols, alcohols having two or more hydroxyl groups in the molecule, or phenols having two or more hydroxyl groups in the molecule, lactic acid, ethyl lactate, tantalum Part or all of the alkoxyl group of the alkoxide is eliminated, at least one hydroxyl group in the component (a2) loses its hydrogen atom, and the oxygen atom in the hydroxyl group that lost the hydrogen atom forms a bond with the tantalum atom. Reaction products. Here, when a plurality of hydroxyl groups in one molecule of the component (a2) participate in the reaction, the tantalum atoms bonded to them may be the same or different.

Ii) Component (a2) is β-diketone, β-ketone
Containing ester or β-dicarboxylic acid ester
Alkoxy of tantalum alkoxide, if one
Part or all of the groups are eliminated, and the two groups in the component (a2) are removed.
CH sandwiched between carbonyl groups ₂The group lost its hydrogen atom
The β-diketone structure that lost the hydrogen atom is a resonance structure.
, And a chelate bond is formed on one tantalum atom.
Reaction product.

Iii) When the component (a2) contains lactic acid, some or all of the alkoxyl groups of the tantalum alkoxide are eliminated, and at least one carboxyl group in the component (a2) has its hydrogen atom. And a reaction product in which the oxygen atom in the carboxyl group, which has lost the hydrogen atom, forms a bond with the tantalum atom. At this time, the carboxyl group that has lost the hydrogen atom may have a resonance structure and may be chelated to one tantalum atom.

Iv) A reaction product in which two oxygen atoms of the ester group bond with a tantalum atom when the component (a2) contains ethyl lactate.

V) In the above i) to iv), the oxygen atom or nitrogen atom in the component (a2) which has formed a bond with the tantalum atom is further bonded to the tantalum atom in the other reaction product or unreacted tantalum alkoxide. The reaction product that gave rise to.

Vi) When the component (a2) contains 1,5-cyclooctadiene, a part or all of the alkoxyl group of the tantalum alkoxide is eliminated to give 1,5
A composition in which at least one double bond in cyclooctadiene forms a coordinate bond with at least one tantalum atom.

Vii) The reaction according to any one of the above i) to vi), wherein the oxygen atom or the nitrogen atom in the unreacted product of the component (a2) or the optionally added monoalcohol or monophenol. A reaction product in which a tantalum atom in the product is bonded.

Viii) The tantalum atom in the reaction product according to any one of the above i) to vii) is bonded to another reaction product or the tantalum atom in the unreacted tantalum alkoxide via an oxygen atom. The resulting reaction product.

Ix) The reaction of the tantalum atom in the reaction product according to any one of the above i) to viii) with the tantalum atom in the other reaction product or the tantalum atom in the unreacted tantalum alkoxide. A reaction product in which an alkoxyl group remaining in the product or an alkoxyl group in an unreacted tantalum alkoxide is crosslinked through an oxygen atom.

X) A mixture of reaction products of any two or more of the above.

Here, the newly formed bond can be, for example, a covalent bond, an ionic bond, a coordinate bond, a hydrogen bond or an intermediate bond between these bonds.

The reaction product as described above may contain an unreacted alkoxyl group or an alkoxyl group in which an alkoxyl group in a tantalum alkoxide has undergone an exchange reaction with an optionally added monoalcohol.

The reaction product as described above may contain an unreacted alkoxyl group or an alkoxyl group in which an alkoxyl group in a tantalum alkoxide has undergone an exchange reaction with an optionally added monoalcohol (after this). , These may be collectively referred to simply as "unreacted alkoxyl group".)

The reaction product used as the component [A] of the present invention has a reaction conversion rate defined by the following formula (1) of 50.
It is preferably not less than 70% by mol, more preferably not less than 70% by mol, particularly preferably not less than 85% by mol.

Reaction conversion rate = {1- (total number of unreacted alkoxyl groups in reaction product / total number of alkoxyl groups in raw tantalum alkoxide)} × 100 (mol%) (1) This value is less than 50 mol%. If so, the electrical characteristics of the formed tantalum oxide film may be insufficient.

The hydrolyzate of the above reaction product is, for example, the above reaction product, preferably in the presence of 0.01 to 1,000 mol of water per 1 equivalent of tantalum atom, at room temperature to 10
It can be synthesized by treating at a temperature of 0 ° C. with stirring. The hydrolyzate of the reaction product includes a compound in which all the hydrolyzable moieties are hydrolyzed and a partial hydrolyzate in which a part of the hydrolyzable moiety is hydrolyzed and a part of which is not hydrolyzed and remains. .

In the present invention, the above reaction product and its hydrolyzate may be used alone or in combination of two or more kinds. The composition of the present invention may further contain [B] orthocarboxylic acid ester.

[B] Orthocarboxylic acid ester [B] The orthocarboxylic acid ester is the composition of the present invention,
In particular, in the step of forming a tantalum oxide film using the composition of the present invention in which the component (A) is a reaction product of the components (a1) and (a2), it reacts with water present in the environment,
The adverse effect of humidity in the atmosphere can be reduced. Therefore, the tantalum oxide film formed from the composition of the present invention containing [B] orthocarboxylic acid ester has high quality.

It can be presumed that the mechanism of the reaction of the above-mentioned [B] orthocarboxylic acid ester with water is as shown in the following formula (2). R ¹ C (OR ² ) ₃ + 3H ₂ O → R ¹ COOH + 3R ² OH + H ₂ O (2) (wherein R ¹ and R ² are alkyl groups or aryl groups, and three R ² are the same or different. Good too.)

Specific examples of [B] orthocarboxylic acid ester include, for example, trimethyl orthoformate, triethyl orthoformate, tripropyl orthoformate, tributyl orthoformate, tripentyl orthoformate, diethylpropyl orthoformate, triphenyl orthoformate, orthoformate. Trimethyl acetate, triethyl orthoacetate, tripropyl orthoacetate, tributyl orthoacetate, tripentyl orthoacetate,
Diethylpropyl orthoacetate, triphenyl orthoacetate, trimethyl orthopropionate, triethyl orthopropionate, tripropyl orthopropionate, tributyl orthopropionate, tripentyl orthopropionate, diethylpropyl orthopropionate, triphenyl orthopropionate, orthobutyric acid Trimethyl, triethyl orthobutyrate, tripropyl orthobutyrate, tributyl orthobutyrate, tripentyl orthobutyrate, diethylpropyl orthobutyrate, triphenyl orthobutyrate, trimethyl ortholaurate, triethyl ortholaurate, tripropyl ortholaurate, tributyl ortholaurate, Tripentyl ortholaurate, diethylpropyl ortholaurate, triphenyl ortholaurate,
Trimethyl orthobenzoate, triethyl orthobenzoate, tripropyl orthobenzoate, tributyl orthobenzoate, tripentyl orthobenzoate, diethylpropyl orthobenzoate, triphenyl orthobenzoate, trimethyl ortho-lactate, triethyl ortho-lactate, tripropyl ortho-lactate , Tributyl ortho-lactate, tripentyl ortho-lactate, diethylpropyl ortho-lactate, triphenyl ortho-lactate and the like.

Of these orthocarboxylic acid esters,
Aliphatic esters are preferred because of their reactivity with water, and methyl esters and ethyl esters are particularly preferred. Specifically, trimethyl orthoformate, triethyl orthoformate and trimethyl orthobenzoate are particularly suitable. These orthocarboxylic acid esters may be used alone or
It can also be used as a mixture of two or more species.

The amount of the [B] orthocarboxylic acid ester used in the composition of the present invention can be appropriately set according to the water content of the composition and the humidity of the atmosphere during the tantalum oxide film forming step. . Orthocarboxylic acid ester is
It is preferably contained in an amount of 0.05 to 50% by weight, more preferably 0.1 to 30% by weight, and further preferably 0.5 to 20% by weight, based on the entire composition.

The carboxylic acids and alcohols formed by the reaction of water and the orthocarboxylic acid ester and the hydroxyl groups of the ortholactic acid ester may react with the film-forming composition, which diminishes the effect of the present invention. Not a thing. Tantalum Oxide Film-Forming Composition The composition of the present invention is usually used as a solution composition in a state in which the above components are dissolved in a solvent.

The solvent that can be used in the present invention is not particularly limited as long as it dissolves the above-mentioned components and does not react with them. As such a solvent, the same solvents as those exemplified as the solvent that can be used in the reaction of the (a1) tantalum alkoxide and the (a2) component can be used, as well as methanol, ethanol, propanol, butanol, hexanol, cyclohexanol, octanol. , Decanol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol,
Alcoholic solvents such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, glycerol, glycerol monomethyl ether, glycerol dimethyl ether, glycerol monoethyl ether, glycerol diethyl ether; ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl Ester solvents such as ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, methyl lactate and ethyl lactate can be used.

These solvents can be used alone or as a mixture of two or more kinds. Of these, alcohol solvents, in terms of solubility of each component and stability of the composition,
Also, a mixed solvent of an alcohol solvent and another polar solvent is preferable.

Preferred alcohol solvents are, for example, propylene glycol monomethyl ether, propylene glycol monoethyl ether and propylene glycol monopropyl ether. Further, as the mixed solvent of the alcohol solvent and the other polar solvent, a mixed solvent of an alcohol solvent / ether solvent and a mixed solvent of an alcohol solvent / ester solvent are preferable.

Preferred specific examples of the above-mentioned mixed solvent of alcohol solvent / ether solvent include at least one alcohol solvent selected from propylene glycol monomethyl ether, propylene glycol monoethyl ether and propylene glycol monopropyl ether; A mixed solvent with at least one ether solvent selected from (2-methoxyethyl) ether, diethylene glycol diethyl ether and diethylene glycol methyl ethyl ether can be mentioned.

Preferred specific examples of the mixed solvent of alcohol solvent / ester solvent include at least one alcohol solvent selected from propylene glycol monomethyl ether, propylene glycol monoethyl ether and propylene glycol monopropyl ether, and propylene. A mixed solvent with at least one ester solvent selected from glycol monomethyl ether acetate and propylene glycol monomethyl ether acetate can be mentioned.

Of the above, propylene glycol monoalkyl ethers have isomers, but any of them can be used, and a mixture of isomers can also be used.

When a solvent is used in the reaction step of the tantalum alkoxide (a1) and the component (a2) described above, the solvent may be used as it is as a solvent for the composition of the present invention without being removed. After the reaction, the solvent may be removed, the reaction product of the tantalum alkoxide (a1) and the component (a2) may be purified, if necessary, and then the solvent may be added again. Further, the solvent used in the reaction step may not be removed, and a solvent may be further added to obtain the composition of the present invention.

When the solvent used contains a hydroxyl group, (a1) tantalum alkoxide and (a1)
Although it may react with the residual alkoxyl group of the reaction product with the component 2), this does not diminish the effect of the present invention.

When the composition of the present invention contains a solvent, the amount of the solvent used can be appropriately set according to the desired thickness of the coating film. The total concentration of components other than the solvent in the composition is preferably 50% by weight or less, more preferably 0.5 to 50% by weight, further preferably 1 to 30% by weight, and particularly preferably 1 to 20% by weight
Is.

The composition of the present invention may optionally contain a tantalum compound other than those mentioned above in order to increase the tantalum concentration in the composition. In addition, a fluorine-based, silicone-based, nonionic-based surface tension modifier or the like can be added to the composition of the present invention, if necessary, within a range that does not impair the intended function. The composition thus obtained can be appropriately mixed and used with, for example, fine particles of a metal oxide such as aluminum oxide, zirconium oxide, titanium oxide or silicon oxide, if necessary.

A radiation absorber (radiation absorbing compound) may be added to the composition of the present invention within a range not impairing the intended function. This has the effect of further improving the antireflection effect. Examples of such radiation absorbers include dyes such as oil-soluble dyes, disperse dyes, basic dyes, methine dyes, pyrazole dyes, imidazole dyes and hydroxyazo dyes; bixine derivatives, norbixin, stilbene, 4, Fluorescent whitening agents such as 4'-diaminostilbene derivatives, coumarin derivatives, and pyrazoline derivatives; hydroxyazo dyes, UV absorbers such as Tinuvin 234 (manufactured by Ciba Geigy), Tinuvin 1130 (manufactured by Ciba Geigy); anthracene derivatives, anthraquinone derivatives And aromatic compounds such as

Method of Forming Antireflection Film and Resist Pattern To form an antireflection film and a resist pattern using the composition for forming an antireflection film of the present invention, (1) an antireflection film applied on a substrate. A step of heat-treating and / or light-treating the coating film of the forming composition to form an antireflection film,
(2) A step of applying a resist solution on the antireflection film and baking to form a resist film, (3) a step of exposing the resist film to radiation through a mask pattern, and (4) the formed latent film. The step of developing the image pattern is performed. Hereinafter, each step will be described in more detail.

First, in the first step, the above composition is applied onto a substrate to form a coating film of the composition of the present invention. At this time, the surface shape of the substrate may be flat, non-planar with steps, or curved. The three-dimensional shape is not particularly limited. For example, it may be in the form of a block, a plate, a film, or the like.

The material of the substrate is preferably one that can withstand the heat treatment to be performed next. Specific examples of the material of such a substrate include glass, metal, metal compound, plastic, ceramics, and a laminated body thereof. As the glass, for example, quartz glass, borosilicate glass, soda glass, lead glass or the like can be used. Examples of metals and metal compounds include gold, silver,
Copper, nickel, silicon, aluminum, iron, platinum, ruthenium, tungsten, titanium, cobalt, molybdenum, iridium, stainless steel, aluminum alloy,
Silicide, tantalum nitride, titanium nitride, ruthenium oxide, etc. can be used. Examples of plastics include polyimide, polyether sulfone, norbornene ring-opening polymers and hydrogenated products thereof.

The method of applying the above solution is not particularly limited.
For example, spin coat, dip coat, flow coat,
Appropriate methods such as curtain coating, roll coating, spray coating, bar coating, inkjet and printing methods can be adopted. The application may be carried out once, or may be applied multiple times. The suitable thickness of the coating film can be appropriately set according to the desired thickness of the tantalum oxide film. For example, the film thickness is preferably 0.001 to 20 μm, and more preferably 0.01 to 2 μm. When the composition contains a solvent, the above film thickness should be understood as the film thickness after removal of the solvent. The coating step in the present invention is preferably carried out in an atmosphere having a humidity (water vapor content in the atmosphere) of 5 g / m ³ or less, more preferably 3 g / m ³ . If the humidity at this time exceeds 5 g / m ³ , the insulating properties of the tantalum oxide film formed may be adversely affected. However, when the composition of the present invention contains a predetermined amount of orthocarboxylic acid ester, the coating film forming step can be carried out without being affected by humidity (water vapor content in the atmosphere). For example, a high-quality tantalum oxide film can be obtained even when a coating film is formed in an atmosphere having a humidity of more than 5 g / m ³ , and further, in an atmosphere of a humidity of 7 g / m ³ or more, particularly 9 g / m ³ A high-quality tantalum oxide film can be obtained even if the coating film is formed under the above-mentioned humidity atmosphere. Then
The coating film formed as described above is converted into a tantalum oxide film by heat and / or light treatment. The temperature of the heat treatment is
The temperature is preferably 200 ° C. or higher, more preferably 30
0 to 900 ° C. or higher, more preferably 350 to 8
It is 00 ° C. The heating time can be appropriately set depending on the film thickness and the like, but in order to obtain a high-quality film, it is preferable to heat for 5 minutes or more, more preferably 15 to 90 minutes, further preferably 30 to 60 minutes. is there. In addition, the atmosphere during the heating step is preferably such that the oxygen concentration is higher. Examples of the heat treatment atmosphere include air, pure oxygen, ozone or N ₂ O, or a mixed gas thereof.
Further, a mixed gas of these oxidizing gases and an inert gas such as nitrogen, helium or argon can be used. As a light source for the light treatment, a low pressure or high pressure mercury lamp, a deuterium lamp, or discharge light of a rare gas such as argon, krypton, or xenon, YAG laser, argon laser, carbon dioxide gas laser, XeF,
XeCl, XeBr, KrF, KrCl, ArF, Ar
An excimer laser such as Cl can be used. The output of these light sources is preferably 10 to 5,000.
It is 0 W, and more preferably 100 to 1,000 W. The irradiation time is preferably 0.1 to 60 minutes, more preferably 1 to 30 minutes. The wavelengths of these light sources are not particularly limited, but those containing a wavelength of 170 nm to 600 nm are preferable. As the atmosphere during the light treatment, the same atmosphere as that during the above-mentioned heat treatment can be used. The temperature during these light treatments is not particularly limited, but is usually room temperature to 500 ° C. Further, when irradiating light, it may be irradiated through a mask in order to irradiate only a specific part. In order to obtain a higher quality tantalum oxide film, it is preferable to perform both the heat treatment and the light treatment. The processing order in that case can be set arbitrarily, and both may be performed simultaneously. The obtained tantalum oxide film can be made amorphous or crystalline depending on the conditions of heat treatment and / or light treatment. The tantalum oxide film formed as described above may be subjected to oxygen plasma or UV-ozone treatment, if necessary, and then used. The thickness of the tantalum oxide film thus formed is preferably 0.001 to 10 μm, more preferably 0.01 to 1 μm. As described above, it is one of the excellent advantages of the present invention that a thin antireflection film having a film thickness of 0.1 μm or less can be formed. The refractive index (n) of this film at a wavelength of 248 nm is 1.7 to
The absorbance is 2.5 and the absorbance (k) is 0.3 to 0.5.

After forming the antireflection film on the substrate in this way, in the second step, a resist solution is applied to the antireflection film so as to have a predetermined film thickness, and prebaked on, for example, a hot plate. The solvent in the coating film is volatilized to form a resist film. The prebaking temperature at this time is appropriately adjusted according to the type of resist used,
Preferably, it is 30 to 450 ° C., more preferably 50 to
It is 200 ° C. The prebaking time is preferably 30 seconds to 60 minutes, more preferably 60 seconds to 120 seconds. As a method for applying the resist solution, spin coating, cast coating, roll coating and the like can be adopted. The resist solution is prepared by dissolving a known resist in a suitable solvent so that the solid content concentration is, for example, 5 to 50% by weight, and then filtering with a filter having a pore size of about 0.2 μm.
As the resist solution, a commercially available resist solution can be used as it is. As the resist, for example, a positive resist containing an alkali-soluble resin and a quinonediazide-based photosensitizer, a negative resist containing an alkali-soluble resin and a radiation-sensitive crosslinking agent, a positive resist containing a radiation-sensitive acid generator or A negative chemically amplified resist or the like can be exemplified.

Then, in the third step, the resist film formed as described above is exposed to radiation through an exposure mask. In this case, depending on the type of resist, visible light, ultraviolet light, deep ultraviolet light, X-ray, electron beam, γ-ray, molecular beam,
Appropriate radiation such as ion beams can be used.
Among these radiations, ultraviolet rays and deep ultraviolet rays are preferable for the composition of the present invention, and particularly g-ray (wavelength 436n
m), i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm) and ArF excimer laser (wavelength 193 nm) are preferable.

Next, in the fourth step, the latent image pattern formed by exposure is developed. Then, by washing and drying, a desired resist pattern is formed. During this step, pre-development baking (hereinafter referred to as "post-exposure bake") may be performed after exposure in order to improve resolution, pattern shape, developability and the like. The post-exposure bake conditions are
Heat on a hot plate, preferably at a temperature of 80 to 160 ° C. for 60 seconds to 360 seconds. Examples of the developer used here include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyl. Diethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo (5,4,0) -7-undecene, 1,5-
Examples thereof include alkaline aqueous solutions in which diazabicyclo- [4.3.0] -5-nonane and the like are dissolved. The alkali concentration of such an alkali developer is preferably 1 to 1
It is 0% by weight, more preferably 1 to 5% by weight. The development temperature is preferably 10 to 35 ° C., and the development time is preferably about 30 to 300 seconds. Examples of the developing method include a dipping method, a paddle method and a spray method. Further, an appropriate amount of a water-soluble organic solvent, for example, alcohols such as methanol and ethanol, and a surfactant can be added to these developers. Finally, the antireflection film is removed by dry etching using the resist pattern as a mask to obtain a resist pattern for substrate processing. Examples of the dry etching method include a reactive ion etching method. In this case, oxygen, halogen, halogenated hydrocarbon or the like can be used as the ion source of the reactive ion. At this time, it is possible to continuously perform operations from the selective removal of the antireflection film to the patterning of the substrate.

[0068]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

Example 1 To a solution of 8.1 g of tantalum pentaethoxide in 67 mL of tetrahydrofuran (THF), a mixed solution of 10 g of triethanolamine and 67 mL of THF was added over 15 minutes while stirring at room temperature under a nitrogen atmosphere. After the addition was completed, the mixture was further stirred for 1 hour at room temperature. The reaction solution changed from colorless and transparent to slightly cloudy. Then, the mixture was concentrated under reduced pressure, the residue was washed with hexane, redissolved in a small amount of tetrahydrofuran, and reprecipitated with hexane. The white solid obtained was filtered off and dried under reduced pressure. ^When analyzed by ¹ H-NMR, the peak derived from ethoxy of tantalum pentaethoxide disappeared and the peak derived from triethanolamine appeared. The yield was 80%. The reaction conversion rate of the ethoxy group of the raw material tantalum pentaethoxide was 100 mol%. Obtained composition for forming antireflection film (1)
1.0 g was dissolved in 9.0 g of diethylene glycol monomethyl ether and filtered through a Teflon (registered trademark) filter having a pore size of 0.2 μm to prepare an antireflection film-forming composition (1). This composition was applied on a bare silicon substrate at a speed of 2,000 rpm by a spin coating method to a film thickness of 0.091 μm in an atmosphere having a humidity of 2 g / m ³ .
Then, after evaporating the solvent in air, 40
When heated at 0 ° C. for 30 minutes, a transparent antireflection film was obtained on the substrate. The film thickness of this film was 0.035 μm. The obtained antireflection film had an absorbance k of 0.43 with respect to light having a wavelength of 248 and a refractive index n of 2.3.

Example 2 In a 200 mL round-bottomed flask that had been sufficiently replaced with nitrogen, under a nitrogen atmosphere, 8.12 g of tantalum pentaethoxide (2
0 mmol) and tetrahydrofuran (THF) 50 mL
Then, while stirring, 8.1 g of diethylene glycol (7
6 mmol) was added at room temperature over 15 minutes. Then, the mixture was further stirred at room temperature for 1 hour. The reaction liquid remained colorless and transparent, and the viscosity slightly increased. Then, the solvent was completely removed under reduced pressure to obtain 7.8 g of a white solid (tantalum-containing product).
^{As a result of 1} H-NMR analysis, a peak derived from an unreacted ethoxyl group of tantalum pentaethoxide and a peak derived from a reactant of diethylene glycol were confirmed, and the integral ratio thereof was 1:20. From this ratio, the reaction conversion of the ethoxyl group of tantalum pentaethoxide was calculated to be 9
It was 1 mol%. 8.5 g of the obtained white solid was obtained.
It was dissolved in g of propylene glycol monomethyl ether and filtered through a Teflon (registered trademark) filter having a pore size of 0.2 μm to prepare an antireflection film-forming composition (2). This composition was applied on a bare silicon substrate at a speed of 2,000 rpm by a spin coating method so as to have a film thickness of 0.205 μm in an atmosphere having a humidity of 2 g / m ³ . Then, after evaporating the solvent in the air, it was heated at 400 ° C. for 30 minutes in the presence of air to obtain a transparent antireflection film on the substrate.
The thickness of the obtained film was 0.105 μm and the wavelength was 248
Absorbance k of light was 0.40, and refractive index n was 2.1.

Example 3 The composition (2) for forming an antireflection film obtained in Example 2 was applied on a bare silicon substrate in an atmosphere of a humidity of 2 g / m ^3.
0.780 μm film thickness by spin coating at 00 rpm
Was applied. Then, after evaporating the solvent in the air, it was heated at 400 ° C. for 30 minutes in the presence of air to obtain a transparent antireflection film on the substrate. The thickness of the obtained film is 0.3.
The absorbance k in the light of wavelength 248 was 0.45, and the refractive index n was 1.85.

Evaluation Example 1 A positive resist for KrF (KRF-M78Y) manufactured by JSR was spin-coated on the antireflection film obtained in Example 1 to a thickness of 0.41 μm to form a resist film.
The exposure was performed for such an exposure time as to form a 0.13 μm line-and-space one-to-one. Then, a resist pattern was formed by developing using a 2.38 wt% tetramethylammonium hydroxide aqueous solution. The obtained resist pattern was excellent in that it had a small "cut-out" depth (hereinafter referred to as "notching depth") due to reflection, and the pattern shape had little skirting, and the influence of standing waves was extremely small. .

Evaluation Example 2 A resist pattern was formed on the antireflection film produced in Example 2 in the same manner as in Evaluation Example 1. The obtained resist pattern has a small notching depth, and the pattern shape is
It was a good one with little skirting and no effect of standing waves.

Evaluation Example 3 A resist pattern was formed on the antireflection film produced in Example 3 in the same manner as in Evaluation Example 1. The obtained resist pattern had a small notching depth, and the pattern shape was excellent with no skirting and no influence of standing waves.

[0075]

INDUSTRIAL APPLICABILITY The composition for forming an antireflection film of the present invention has a high antireflection effect even with a relatively thin film by a simple method, is excellent in adhesiveness and adhesion to a resist film, and intermixes with a resist component. It is possible to form a lower-layer antireflection film having no layer. Further, for this reason, it is possible to form a resist pattern excellent in resolution, accuracy, etc., in cooperation with a positive type or negative type resist. Therefore, the composition for forming an antireflection film of the present invention greatly contributes to the production of an integrated circuit having a high degree of integration.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Isamu Yonekura             2-11-21 Tsukiji, Chuo-ku, Tokyo J             Within SRL Co., Ltd. F-term (reference) 2H025 AA02 AA14 AB16 DA34                 2K009 AA02 CC45 DD02 DD05                 4J030 CC23 CE02 CG06                 5F046 PA05 PA07

Claims (3)

[Claims] 1. [A1] (a1) tantalum alkoxide and (a2) amino alcohol, a compound having two or more hydroxyl groups in the molecule (excluding amino alcohol), β
-A reaction product with at least one compound selected from the group consisting of diketones, β-ketoesters, β-dicarboxylic acid esters, lactic acid, lactic acid esters and 1,5-cyclooctadiene, and [A2] the reaction product An antireflection film-forming composition containing at least one tantalum-containing product selected from the group consisting of hydrolysates of 2. A method for forming an antireflection film, which comprises applying the above composition further containing a solvent onto a substrate, and then subjecting it to heat treatment and / or light treatment. 3. A step of (1) heat-treating and / or phototreating a coating film of the composition according to claim 1 applied on a substrate to form a lower antireflection film, (2) the antireflection film. A resist including a step of applying a resist composition thereon and baking to form a resist film, (3) exposing the resist film to radiation through a mask pattern, and (4) developing a latent image pattern Pattern formation method.