JPH10319601A - Composition for forming antireflection film and resist pattern forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure a high antireflection effect and to form a resist pattern excellent in resolution, precision, etc., without causing intermixing by incorporating a specified polymer and a solvent for the polymer. SOLUTION: This compsn. contains a polymer contg. repeating units represented by the formula and a solvent for the polymer. In the formula, R<1> and R<2> which are the same or different, are H atom or a monovalent org. group, preferably alkyl, cycloalkyl, aryl or acyl, R<1> and R<2> may on to each other to form an alicyclic group in combination with C to which they bond and R<3> is H atom or methine. This compsn. has a high antireflection effect and can form a resist pattern excellent in resolution, precision, etc., without causing intermixing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a composition for forming an antireflection film and a method for forming a resist pattern using the same. More specifically, the present invention relates to a composition for forming an antireflection film, which is useful for fine processing in a lithography process using various radiations and is particularly suitable for manufacturing an integrated circuit device, and a method for forming a resist pattern using the same.

[0002]

2. Description of the Related Art In a method of manufacturing an integrated circuit device, a processing size in a lithography process is becoming finer in order to obtain a higher degree of integration. In this lithography process, a desired pattern is obtained by applying the resist composition on a resist composition substrate, transferring a mask pattern by a reduction projection exposure apparatus (stepper), and developing with a suitable developer. However, substrates having high reflectivity such as aluminum, aluminum-silicon alloy, aluminum-silicon-copper alloy, polysilicon, and tungsten silicide used in this process reflect the irradiated radiation on the surface. As a result, halation occurs in the resist pattern, and a fine resist pattern cannot be accurately reproduced.

In order to solve this problem, there has been proposed a method of forming an antireflection film having a property of absorbing radiation reflected from the substrate under a resist film to be formed on the substrate. As such an antireflection film, first, vacuum deposition,
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 formed by a method such as CVD and sputtering are known. Since the barrier film has conductivity, it cannot be used for manufacturing integrated circuits,
The formation of the anti-reflection film has disadvantages such as requiring a special device such as a vacuum deposition device, a CVD device, and a sputtering device. To compensate for the disadvantages of the inorganic anti-reflection coating, Japanese Patent Application Laid-Open No. S59-93448 proposes an organic anti-reflection coating comprising a polyamic acid (co) polymer or polysulfone (co) polymer and a dye. ing. This anti-reflective coating,
Without conductivity, and by dissolving in a suitable solvent,
It can be applied on a substrate by a method similar to a resist without requiring a special device. However,
The anti-reflective coating composed of a polyamic acid (co) polymer or polysulfone (co) polymer and a dye cannot sufficiently prevent halation or standing waves due to the limited amount of the dye, and is slightly different from the resist. Mix (this is
(Referred to as intermixing), there is a problem that the resist pattern shape is deteriorated such as a missing defect and a skirting.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel composition for forming an antireflection film and a method for forming a resist pattern using the same. Another object of the present invention is to provide a composition for forming an anti-reflection film capable of forming a resist pattern having a high anti-reflection effect, no intermixing, and excellent resolution and accuracy, which overcomes the above-mentioned conventional problems. To provide things.

It is still another object of the present invention to provide a method of forming a resist pattern using the composition for forming an antireflection film of the present invention. Still other objects and advantages of the present invention will become apparent from the following description.

[0006]

According to the present invention, the above objects and advantages of the present invention are firstly achieved by the following formula (1).

[0007]

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[0008] Here, R ¹ and R ² are identical or different, or R ¹ is a hydrogen atom or a monovalent organic group
And R ² may be bonded to each other to form an alicyclic group together with the carbon atom to which they are bonded;
³ is a hydrogen atom or a methyl group, which is achieved by a polymer containing a repeating unit represented by the formula: and a composition for forming an antireflection film, comprising a solvent for the polymer.

The polymer used in the present invention has a repeating unit represented by the above formula (1). Equation (1) above
Wherein R ¹ and R ² are the same or different and are a hydrogen atom or a monovalent organic group, or R ¹ and R ² are bonded to each other to form an alicyclic ring together with the carbon atom to which they are bonded. Formula groups can also be formed. R ³ is a hydrogen atom or a methyl group.

Preferred examples of the monovalent organic group in the definition of R ¹ and R ² include an alkyl group, a cycloalkyl group, an aryl group and an acyl group. Examples of the alkyl group include methyl, ethyl,
Examples include straight-chain or branched-chain alkyl such as propyl, butyl, pentyl, hexyl, and heptyl.

The cycloalkyl group includes, for example, cyclopentyl, cyclohexyl and the like. Examples of the aryl group include a phenyl group, a halogen atom such as chloro at the p-position or 0-position, an alkyl such as nitro and methyl, or a phenyl group substituted by phenyl, a naphthyl group, an anthracenyl group, a tetralone group and a fluorenone group. Can be mentioned. Examples of the acyl group include an acetyl group, a propionyl group, and a benzoyl group.

The alicyclic group formed by R ¹ and R ² bonded together with the carbon atom to which they are bonded is, for example, a cyclohexyl group, represented by the following formula (2): Group,

[0013]

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(Where R _a and R _b represent a hydrogen atom, an alkyl group, etc.), the following formula (3)

[0015]

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(R _c represents a hydrogen atom, an alkyl group, or the like). The repeating unit represented by the above formula (1) is represented by the following formula (4)

[0017]

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Here, the definitions of R ¹ , R ² and R ³ are the same as in the above formula (1), and are derived from an iminosulfonate group-containing unsaturated monomer represented by the formula:

Examples of such an iminosulfonate group-containing unsaturated monomer include, for example, 2-propylideneimino p
-(Α-methyl) styrene sulfonate, methylethylideneimino p- (α-methyl) styrene sulfonate,
Alkylideneimino p- (α-methyl) such as 3-heptylideneimino p- (α-methyl) styrene sulfonate
Styrene sulfonate derivative; benzylidene imino p-
Arylidene imino p- (α-methyl) styrene sulfonate derivatives such as (α-methyl) styrene sulfonate and naphthylideneimino p- (α-methyl) styrene sulfonate; 1-phenylethylideneimino p- (α-methyl) styrene sulfonate, -(P-nitrophenyl) ethylidene imino p- (α-methyl) styrene sulfonate, 1- (m-nitrophenyl) ethylidene imino p- (α-methyl) styrene sulfonate, 1- (0
Allylalkylidene imino p- (α-methyl) styrene sulfonate derivatives such as -nitrophenyl) ethylidene imino p- (α-methyl) styrene sulfonate; cyclohexylidene imino p- (α-methyl) styrene sulfonate, cycloheptylidene imino cycloalkylidene imino p- (α-methyl) styrene sulfonate derivatives such as p- (α-methyl) styrene sulfonate; 9
An aromatic ring-containing cycloalkylidene imino p- (α-methyl) such as fluorenylidene imino p- (α-methyl) styrene sulfonate, 1,2,3,4-tetrahydronaphthylidene imino p- (α-methyl) styrene sulfonate; ) Styrene sulfonate derivatives and the like. Of these, preferred are 9-fluorenylideneimino p-styrenesulfonate, 1,2,3,4-tetrahydronaphthylideneimino p-styrenesulfonate,
-Propylidene imino p-styrenesulfonate, 1-
Phenylethylidene imino p-styrenesulfonate;

These iminosulfonate group-containing unsaturated monomers can be used alone or in combination of two or more, depending on the desired properties of the antireflection film. It is also possible to use dioximes such as 1,2-cyclohexanedionedioxime styrene sulfonate and 1,2-cyclohexanedionedioxime α-methylstyrene sulfonate together with these iminosulfonate group-containing unsaturated monomers. it can. Further, when producing a polymer constituting the antireflective coating composition of the present invention, for the purpose of improving coatability, heat resistance, etc., an unsaturated monomer other than the iminosulfonate group-containing unsaturated monomer is used. The body can be copolymerized.

Such unsaturated monomers include, for example, styrene, α-methylstyrene, 0-methylstyrene, m-methylstyrene, p-methylstyrene, 0-hydroxystyrene, m-hydroxystyrene, p-methylstyrene. Substituted styrene compounds such as hydroxystyrene, 0-acetoxystyrene, m-acetoxystyrene, p-acetoxystyrene, pt-butoxystyrene; vinyl acetate;
Vinyl carboxylate compounds such as vinyl propionate and vinyl caproate; (meth) acrylonitrile,
vinyl cyanide compounds such as α-chloroacrylonitrile; methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, n-hexyl (meth) acrylate, glycidyl (meth) ) Unsaturated carboxylic acid ester compounds such as acrylate; olefin compounds such as ethylene and propylene; vinyl chloride, vinylidene chloride,
Halogenated olefin compounds such as vinylidene fluoride, tetrafluoroethylene and hexafluoropropylene; butadiene, isoprene, chloroprene, piperylene,
Diene compounds such as 2,3-dimethylbutadiene and methylpentadiene; ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate,
Unsaturated group-containing unsaturated carboxylic acid esters such as vinyl (meth) acrylate and dimethylvinylmethacryloyloxymethylsilane; vinyl compounds containing halogen such as 2-chloroethyl vinyl ether, vinyl chloroacetate and allyl chloroacetate; 2-hydroxyethyl (Meth) acrylate, 2-hydroxypropyl (meth) acrylate, N
Hydroxyl-containing vinyl compounds such as methylol (meth) acrylamide and (meth) allyl alcohol; amide group-containing vinyl compounds such as (meth) acrylamide and crotonamide; 2-methacryloyloxyethylsuccinic acid;
Carboxyl group-containing vinyl compounds such as 2-methacryloyloxyethylmaleic acid; 1-vinylnaphthalene;
And vinylaryl compounds such as -vinylnaphthalene, 9-vinylanthracene and 9-vinylcarbazole. Among these unsaturated monomers, unsaturated carboxylic acid ester compounds are preferred.
These unsaturated monomers can be used alone or in combination of two or more. These unsaturated monomers are
It is contained at less than 98 mol%, preferably less than 90 mol%, based on the total polymerized units of the polymer used in the present invention.

The polymer used in the present invention is composed of a repeating unit of the above formula (1) derived from the above-mentioned unsaturated monomer having an iminosulfonate group and a polymerized unit derived from the above-mentioned other unsaturated monomer. Based on the sum, the above equation (1)
Is preferably 2 mol% or more, more preferably 10 mol% or more. If the proportion of the repeating unit of the formula (1) is less than 2 mol%, the radiation reflected from the substrate cannot be absorbed sufficiently, and the effect of preventing halation will be reduced. The polymer constituting the antireflection film-forming composition of the present invention is, for example, radical polymerization,
It can be produced in a polymerization form such as solution polymerization by an appropriate method such as anionic polymerization and cationic polymerization.

The polymer constituting the composition for forming an antireflection film of the present invention has a weight average molecular weight in terms of polystyrene (hereinafter referred to as Mw).
That. ) Is appropriately selected according to the desired properties of the antireflection film, but is usually 3,000 to 1,000,000, preferably 4,000 to 700,000, and particularly preferably 5,000 to 500,000. 000. Mw is 3,000
If less than, the coating properties when forming the anti-reflective film, the film-forming properties, etc. tend to decrease, and if more than 1,000,000, depending on the type of constituent monomers, copolymerization ratio, etc. ,
In some cases, solubility in a solvent, coatability, storage stability, and the like are reduced.

As the solvent constituting the composition for forming an antireflection film of the present invention, a solvent capable of dissolving the antireflection film material, for example, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol Ethylene glycol monoalkyl ethers such as monobutyl ether; ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, and ethylene glycol monobutyl ether acetate; diethylene glycol dimethyl ether, diethylene glycol Diethyl ether, diethylene glycol dipropyl ether, Diethylene dialkyl ethers such as ethylene glycol dibutyl ether; propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monoalkyl ethers such as propylene glycol monobutyl ether; propylene glycol dimethyl ether,
Propylene glycol dialkyl ethers such as propylene glycol diethyl ether, propylene glycol dipropyl ether and propylene glycol dibutyl ether; propylene glycol monomethyl ether acetate, propylene glycol monoether ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate and the like Propylene glycol monoalkyl ether acetates; methyl lactate, ethyl lactate, lactate n-
Propyl, isopropyl lactate, n-butyl lactate, n-lactic acid
Lactates such as isobutyl; methyl formate, ethyl formate, n-propyl formate, isopropyl formate, n-formate
Butyl, isobutyl formate, n-amyl formate, isoamyl formate, methyl acetate, ethyl acetate, n-amyl acetate, isoamyl acetate, n-hexyl acetate, methyl propionate,
Ethyl propionate, n-propyl propionate, isopropyl propionate, n-butyl propionate, isobutyl propionate, methyl butyrate, ethyl butyrate, n-butyrate
Aliphatic carboxylic esters such as -propyl, isopropyl butyrate, n-butyl butyrate, isobutyl butyrate; ethyl hydroxyacetate, ethyl 2-hydroxy-2-methylpropionate, methyl 3-methoxy-2-methylpropionate, 2-hydroxy Methyl-3-methylbutyrate, ethyl methoxyacetate, ethyl ethoxyacetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, 3-
Ethyl methoxypropionate, 3-methoxybutyl acetate, 3-methoxypropyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutyl propionate, 3-methyl-3-methoxybutyl butyrate, 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-
Ketones such as heptanone, 3-heptanone, 4-heptanone and cyclohexanone; N-methylformamide;
Amides such as N, N-dimethylformamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone; lactones such as γ-butyrolactone are appropriately selected and used. Among these, preferred solvents are ethylene glycol monoethyl ether acetate, ethyl lactate, methyl 3-methoxypropionate,
Examples thereof include 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 concentration is 0.01 to
The content is about 70% by weight, preferably 0.05 to 60% by weight, and more preferably 0.1 to 50% by weight.
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 effect 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 octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyethylene glycol dilaurate, and polyethylene glycol distearate. In addition to nonionic surfactants such as rates, commercially available products include, for example, organosiloxane polymers,
KP341 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No.75 and No.95 which are (meth) acrylic acid (co) polymers
(Trade name, manufactured by Kyoeisha Yushi Kagaku Kogyo), F-Top EF10
1, EF204, EF303, EF352 (trade name, manufactured by Tochem Products), Megafac F171, F172, F173 (trade name, manufactured by Dainippon Ink and Chemicals), Florad FC430, F
C431, FC135, FC93 (trade name, manufactured by Sumitomo 3M), Asahi Guard AG710, Surflon S382, SC101,
SC102, SC103, SC104, 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, and hydroxyazo dyes; bixin derivatives, norbixin, stilbene, 4,4'-diaminostilbene derivative, coumarin derivative, pyrazoline derivative, etc .; fluorescent brightener; hydroxyazo dye, tinuvin 234 (manufactured by Ciba Geigy), tinuvin 1130
UV absorbers (manufactured by Ciba-Geigy); and 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.

Next, according to the present invention, there is also provided a method for forming a resist pattern using the composition for forming an antireflection film of the present invention. That is, according to the present invention, secondly, (i) a step of applying an antireflection film-forming composition on a substrate, followed by baking to form an antireflection film,
(Ii) a step of applying a resist composition on the antireflection film and then baking to form a resist film; (iii) irradiating the resist film with radiation through an exposure mask; and (iv) developing. And a method of forming a resist pattern.

Next, a method for forming a resist pattern according to the present invention will be described. First, an antireflection film composition is applied on a substrate to a predetermined thickness, for example, 100 to 5000 angstroms by a method such as spin coating or cast coating roll coating. Next, baking is performed 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 baking is 10 seconds to 360 seconds, preferably 60 seconds to 12 seconds.
0 seconds.

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

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

Thereafter, in a third step, the resist film is irradiated with radiation through an exposure mask (hereinafter, referred to as "exposure"). Depending on the type of the resist, appropriate radiation such as visible light, ultraviolet light, far ultraviolet light, X-ray, electron beam, γ-ray, molecular beam, and ion beam can be used. Of these radiations, preferred are ultraviolet rays, far ultraviolet rays, and particularly g
Line (wavelength 436 nm), i-line (wavelength 365 nm), Kr
An F excimer laser (wavelength 248 nm) and an ArF excimer laser (wavelength 193 nm) are suitably used for the composition of the present invention.

Next, this is developed in a fourth step. Thereafter, by washing and drying, a desired resist pattern is formed. During this process, resolution, pattern shape,
In order to improve developability and the like, baking before development (hereinafter, referred to as “post-exposure bake”) may be performed after exposure. The conditions of the post-exposure bake are usually 80 to 1 on a hot plate.
Heat at a temperature of 60 ° C. for 60 seconds to 360 seconds.

As the developer used for forming the resist pattern in the present invention, 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 hydroxide , Tetraethylammonium hydroxide, pyrrole, 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. In addition, a proper 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, 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.

[0035]

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. The types of resist used in each of the examples and comparative examples are as follows. Type of Resist The positive resist for KrF (trade name KrF K2G, manufactured by Nippon Synthetic Rubber Co., Ltd.) was evaluated for the performance of the antireflection coating composition in the following manner.

Evaluation of performance of antireflection film Notch prevention effect: An antireflection film composition 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, and then on a hot plate. The film was baked at 1 ° C. for 1 minute and at 200 ° C. for 2 minutes to form a 0.1 μm-thick antireflection film. Thereafter, a resist was spin-coated to a thickness of 0.7 μm on the antireflection film to form a resist film, and baked on a hot plate at 80 ° C. for 2 minutes. Then, through an exposure mask having a hole pattern, a Nikon Corporation stepper NSR2005EX8
Using A (KrF excimer laser, wavelength 248 nm, numerical aperture 0.5), an exposure time for forming a line and space pattern having a width of 0.5 μm with a line width of 1: 1 (hereinafter referred to as “optimal exposure time”). ) Only exposure was performed. Next, after baking after exposure for 2 minutes on a hot plate at 100 ° C., development is performed at 25 ° C. for 1 minute using a 2.38% by weight aqueous solution of tetramethylammonium hydroxide, washed with water, and dried to form a resist. A pattern was formed.
And the reflection of the pattern at the optimal exposure time "
"Egure" depth (hereinafter referred to as "notching depth")
Was examined. When the ratio of the notching depth to the line pattern having a width of 0.5 μm is less than 10%, the antireflection effect is “excellent”, when it is 10 to 20%, the antireflection effect is “good”, and when it exceeds 20%. The antireflection effect was determined to be “poor”.

Resolution: Formation of an antireflection film and a resist film, pre-baking, exposure at an optimal exposure time, and the like, except that a 4-inch silicon wafer was used instead of the aluminum substrate. After development, the dimensions of the smallest resist pattern resolved were measured using a scanning electron microscope.

Intermixing prevention effect: The evaluation of the notching prevention effect was performed in the same manner as in the evaluation of the notching prevention effect except that a 4-inch silicon wafer was used instead of the aluminum substrate.
An antireflection film and a resist film were formed, prebaked, exposed and developed, and the degree of footing of the resist film at the contact with the substrate was examined using a scanning electron microscope.

Standing Wave Prevention Effect: Except for using a 4-inch silicon wafer instead of an aluminum substrate, in the same manner as in the evaluation of the notching prevention effect, the formation of an antireflection film and a resist film, prebaking, exposure and development Then, the presence or absence of standing waves in the resist film was examined using a scanning electron microscope.

Synthesis Example 1 In a separable flask equipped with a thermometer and a condenser, 1000 parts of pyridine and 217 parts of 9-fluorenone oxime were added, and the mixture was cooled to 10 ° C. or lower, and 270 parts of p-styrenesulfonyl chloride was gradually dropped. And below 10 ° C for 20
Stirred for hours. The contents were poured into 5000 parts of 5% hydrochloric acid ice water, extracted with 1000 parts of chloroform, and the solvent was removed under reduced pressure. The obtained solid was recrystallized from n-hexane-toluene (2: 1) to obtain 9-fluorenylideneimino p-styrenesulfonate represented by the following chemical structural formula.

[0041]

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Synthesis Example 2 To a separable flask equipped with a thermometer and a cooling tube was added 1,000 parts of ethylene glycol monobutyl ether, and the temperature was raised to 100.degree. A solution prepared by dissolving 55 parts of methyl methacrylate, 200 parts of 9-fluorenone oxime p-styrenesulfonate obtained in Synthesis Example 1, and 5 parts of azobisisobutyronitrile in 500 parts of ethylene glycol was used for 4 hours. 30 minutes after the dropwise addition, a solution prepared by dissolving 4 parts of azobisisobutyronitrile in 10 parts of ethylene glycol monobutyl ether was added for 30 minutes.
Minutes, and reacted at the same temperature for 1 hour. After the reaction,
This solution was dropped into methanol, and the precipitated resin was dried at 40 ° C. overnight in a vacuum dryer. The resin obtained is M
w = 50000 (GPC column (G20 manufactured by Tosoh Corporation)
00HXL, G3000HXL, G4000X
L1), measured by gel permeation chromatography using monodisperse polystyrene as a standard under the analysis conditions of flow rate 1.0 ml / min, effluent solvent tetrahydrofuran, and column temperature of 40 ° C.). , Methyl methacrylate and 9-fluorenylideneimino p-styrenesulfonate were copolymerized at a molar ratio of 1: 1.

Synthesis Example 3 The same operation as in Example 2 was carried out except that 55 parts of methyl methacrylate in Synthesis Example 2 was changed to 27.5 parts of methyl methacrylate. A resin having a structure in which 9-fluorenylideneimino p-styrenesulfonate was copolymerized at a molar ratio of 2: 1 was obtained.

Synthesis Example 4 The same operation as in Example 2 was carried out except that 55 parts of methyl methacrylate in Synthesis Example 2 was replaced with 57 parts of ethyl methacrylate, whereby Mw = 50,000 and ethyl methacrylate were mixed with 9-ethyl methacrylate. A resin having a structure in which fluorenylidene imino p-styrene sulfonate was copolymerized at a molar ratio of 1: 1 was obtained.

Synthesis Example 5 The same procedure as in Example 2 was repeated except that 55 parts of methyl methacrylate in Synthesis Example 2 was replaced with 57 parts of styrene, to obtain styrene and 9-fluorenylidene imino at Mw = 30000. 1: 1 p-styrene sulfonate
A resin having a structure copolymerized by (molar ratio) was obtained.

Synthesis Example 6 The same operation as in Example 2 was carried out except that methyl methacrylate in Synthesis Example 2 was replaced by 76 parts of p-acetoxystyrene, so that Mw = 30000 and p-acetoxystyrene was replaced with p-acetoxystyrene. A resin having a structure in which 9-fluorenylideneimino p-styrenesulfonate was copolymerized at a molar ratio of 1: 1 was obtained.

Examples 1 to 5 10 parts of each of the resins obtained in Synthesis Examples 2 to 6 were dissolved in 90 parts of cyclohexanone, and the solution was filtered through a membrane filter having a pore size of 0.2 μm. Was prepared. Next, a resist pattern was formed and the performance of the antireflection film was evaluated as described above. Table 1 shows the evaluation results.

Comparative Example 1 A resist pattern was formed and the performance of the antireflection film was evaluated in the same manner as in each example except that the antireflection film composition was not used. Table 1 shows the evaluation results.

[0049]

[Table 1]

[0050]

The antireflection film formed by using the composition for forming an antireflection film of the present invention has a high antireflection effect and does not cause intermixing with a resist.
In cooperation with the positive and negative resists, a resist pattern having excellent resolution, accuracy, and the like can be provided.
Therefore, the composition for forming an antireflection film of the present invention greatly contributes to the production of a highly integrated circuit.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Motoyuki Shima 2--11-24 Tsukiji, Chuo-ku, Tokyo Inside Nippon Gosei Rubber Co., Ltd. (72) Ken Sugimoto 2- 11-24 Tsukiji, Chuo-ku, Tokyo No. Nippon Gosei Rubber Co., Ltd.

Claims (2)

[Claims] [Claim 1] The following formula (1) Here, R ¹ and R ² are the same or different and are a hydrogen atom or a monovalent organic group, or R ¹ and R ² are bonded to each other to form an oil together with the carbon atom to which they are bonded. A polymer containing a repeating unit represented by the formula (I), which may form a cyclic group, and R ³ is a hydrogen atom or a methyl group; A composition for forming a protective film. 2. (i) a step of applying the composition for forming an anti-reflective film according to claim 1 on a substrate, followed by baking to form an anti-reflective film; A step of applying a resist composition, followed by baking to form a resist film, (iii) irradiating the resist film with radiation through an exposure mask, and (iv) developing. Method of forming a resist pattern.