JP2000313779A - Antireflection film-forming composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition having a high antireflection effect, capable of forming a resist pattern excellent in resolving power, etc., and useful for an integrated circuit of a high integration degree, by compounding a copolymer obtained from specific monomers. SOLUTION: This antireflection film-forming composition contains a copolymer, which have structural units of formula I [R1 is H, a halogen, nitro or the like; R2 is H or methyl; (n) is 1-5] [for example, (α-methyl)styrene] and structural units of formula II (R3 is H or methyl; R4 is methyl or a hydrocarbon residue) [for example, N-hydroxymethyl(meth)acrylamide], and a solvent for the copolymer. Another unsaturated monomer (for example, maleic anhydride) is added to the composition for improving heat resistance of the antireflaction film, wherein the structural units of formula I, the structural units of formula II and structural units derived from the unsaturated monomer are contained in amounts of, especially preferably, 20-80 mol%, especially preferably, 10-60 mol% and, preferably, not more than 60 mol%, respectively, based on total mol of the above three kinds of repeating units. Ethylene glycol monomethyl ether is exemplified as the solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a composition for forming an antireflection film. 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.

[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 a resist composition onto a substrate, transferring a mask pattern by a reduction projection exposure apparatus (stepper), and developing with a suitable developer. However, substrates such as aluminum, aluminum-silicon alloy, aluminum-silicon-copper alloy, polysilicon or tungsten silicide having high reflectivity used in this process reflect irradiated radiation on their surfaces. As a result, halation occurs in the resist pattern, and there is a problem that a fine resist pattern cannot be accurately reproduced.

In order to solve this problem, it has been proposed to form an antireflection film having a property of absorbing radiation reflected from the substrate under a resist film to be formed on the substrate. Such antireflection films include vacuum deposition, CV
D, a titanium film formed by a method such as sputtering, a titanium dioxide film, a titanium nitride film, a chromium oxide film,
An inorganic film such as a carbon film or an α-silicon film is known. However, since these inorganic antireflection films have conductivity, they cannot be used for manufacturing an integrated circuit, or a vacuum evaporation device, a CVD device,
There are drawbacks such as the need for a special device such as a sputtering device. In order to solve the drawbacks of the inorganic anti-reflection coating, an organic anti-reflection coating comprising, for example, a polyamic acid (co) polymer or a polysulfone (co) polymer and a dye has been proposed (for example, Japanese Patent Application Laid-Open No. H11-163873). Sho 59-9344
No. 8). Since this antireflection film has no conductivity and is dissolved in an appropriate solvent, there is an advantage that the antireflection film can be applied on a substrate in a solution state like a resist without requiring a special device.

However, the anti-reflection film composed of a polyamic acid (co) polymer or polysulfone (co) polymer and a dye is slightly mixed with the resist (this phenomenon is called intermixing), so that the anti-reflection film is poor.
There is a problem that the resist pattern shape is deteriorated such as skirting. Further, as the demand for miniaturization of integrated circuits has increased, it has been required to further reduce the thickness of the resist. However, the anti-reflection film has a low etching rate (hereinafter referred to as an etching rate), and is not suitable for dry etching. In the process of removing the lower anti-reflection film, a long time of gas plasma irradiation is required, so that the resist layer coated in a thin film is also eroded at the same time, resulting in a significant reduction in the thickness of the resist layer. Was.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to overcome the above-mentioned conventional problems, and in particular, has a high anti-reflection effect on ArF excimer laser light, does not cause intermixing, and reduces the etching rate. An object of the present invention is to provide an antireflection film-forming composition capable of forming a large resist pattern having excellent resolution and accuracy. Other objects and advantages of the present invention will become apparent from the following description.

[0006]

Means for Solving the Problems That is, as a result of intensive studies, the present inventors have found that a polymer containing a benzene nucleus-containing vinyl monomer and a (meth) acrylamide derivative as a monomer unit can be exposed to excimer laser light. The inventors have found that an excellent resist pattern having a high antireflection effect and a high etching rate and not causing intermixing can be formed, and the present invention has been accomplished.

Therefore, according to the present invention, the above objects and advantages of the present invention are represented by the following formula (1):

[0008]

Embedded image (Wherein R ₁ is a hydrogen atom, a halogen atom, a nitro group, an amino group, a hydroxyl group, an acyl group, a carboxyl group,
A sulfone group, a mercapto group or a hydrocarbon group;
_When two or more ₁ are present, they may be the same or different; R ₂ represents a hydrogen atom or a methyl group;
Represents an integer of 1 to 5. ) And the following formula (2)

[0009]

Embedded image (Wherein, R ₃ represents a hydrogen atom or a methyl group and R ₄ represents a hydrogen atom or a hydrocarbon group.)

This is achieved by a copolymer having a structural unit represented by the formula (1) and a composition for forming an antireflection film, characterized by containing a solvent for the copolymer.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
In the following description, terms such as (α-methyl) styrene, (meth) acrylic acid, (meth) acrylate, and (meth) acryloyl group are styrene and α-methylstyrene, acrylic acid and methacrylic acid, and acrylate, respectively. It is used to include methacrylate, acryloyl group and methacryloyl group.

[0012] Copolymer copolymer of the general formula (1)

[0013]

Embedded image (Wherein R ₁ , R ₂ and n are as described above).

R ₁ represents a hydrogen atom, a halogen atom, a nitro group, an amino group, a hydroxyl group, an acyl group, a carboxyl group, a sulfone group, a mercapto group or a hydrocarbon group. Examples of the hydrocarbon group include an alkyl group, an alkenyl group, and an aryl group. As the alkyl group, a linear alkyl group having 1 to 6 carbon atoms or a branched alkyl group having 3 to 6 carbon atoms is preferable. Specific examples include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group and a t-butyl group.
Butyl group and the like. The alkenyl group is preferably an alkenyl group having 2 to 6 carbon atoms, and specific examples include a vinyl group, a propenyl group and a butenyl group. Preferred examples of the halogen atom include fluorine, chlorine and bromine. As the acyl group, an aliphatic or aromatic acyl group having 1 to 6 carbon atoms can be preferably mentioned, and specific examples thereof include a formyl group, an acetyl group, and a phenacyl group. The structural unit represented by the above formula (1) is represented by the following formula (3)

[0015]

Embedded image (Here, the definitions of R ₁ , R ₂ and n are the same as in the above formula (1).)

The vinyl monomer containing a benzene nucleus of the formula (3) includes, for example, (α-methyl) styrene;
(α-methyl) styrene, m-methyl (α-methyl) styrene, p-methyl (α-methyl) styrene, o-ethyl (α
-Methyl) styrene, m-ethylstyrene, p-ethyl
Alkyl-substituted (α-methyl) styrenes such as (α-methyl) styrene; o-chloro (α-methyl) styrene, m-chloro (α-methyl) styrene, o-bromo (α-methyl) styrene, m- Halogen-substituted (α-methyl) styrenes such as bromo (α-methyl) styrene; nitro-substituted (α-methyl) styrenes such as o-nitro (α-methyl) styrene and m-nitro (α-methyl) styrene; amino-substituted (α-methyl) styrenes such as o-amino (α-methyl) styrene and m-amino (α-methyl) styrene; o-hydroxy (α-methyl) styrene, m-hydroxy (α-methyl) styrene And hydroxy-substituted (α-methyl) styrenes; acyl-substituted (α-methyl) styrenes such as o-acetyl (α-methyl) styrene and m-acetyl (α-methyl) styrene.

These monomers can be used alone or in combination of two or more depending on the desired properties of the antireflection film. Of these compounds, styrene is preferably used. Another essential structural unit of the copolymer used in the present invention has a general formula (2)

[0018]

Embedded image (Wherein, the definitions of R ₃ and R ₄ are as described above).

R ₄ represents a hydrogen atom or a hydrocarbon group. Preferred examples of the hydrocarbon group include a linear or branched alkyl group having 1 to 6 carbon atoms, and specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, A t-butyl group and the like can be exemplified.

The structural unit represented by the above formula (2) is represented by the following formula (4)

Embedded image (Where R ₃ and R ₄ are as described above)

It is derived from a (meth) acrylamide derivative monomer represented by the following formula. Among the (meth) acrylamide derivatives represented by the formula (4), those in which R ₄ is a hydrogen atom are represented by the following formula (5)

[0022]

Embedded image (Where R _{3 is} as defined above)

## EQU2 ## The compound represented by the formula (5) can be easily obtained by reacting (meth) acrylamide with formaldehyde and / or paraformaldehyde. In the case where R ₄ is the above-mentioned hydrocarbon group, the (meth) acrylamide represented by the above formula (5) is converted to a compound represented by the following formula in the presence of an alcohol having a group corresponding to R ₄ :
It is obtained by reacting formaldehyde and / or paraformaldehyde.

The (meth) acrylamide derivative includes:
For example, N- (hydroxymethyl) (meth) acrylamide; N- (methoxymethyl) (meth) acrylamide,
N- (ethoxymethyl) (meth) acrylamide, N-
(Propoxymethyl) (meth) acrylamide, N-
N- such as (butoxymethyl) (meth) acrylamide
(Alkoxymethyl) (meth) acrylamide and the like. These (meth) acrylamide derivatives can be used alone or in combination of two or more, depending on the desired properties of the antireflection film. Of the above monomers, N-hydroxymethyl (meth) acrylamide and N-methoxymethyl (meth) acrylamide are preferably used.

The copolymer used in the present invention has, in addition to the structural units of the formula (1) and the structural units of the formula (2), the coatability of the obtained composition, the heat resistance of the obtained antireflection film and the like. For the purpose of improvement, other structural units can be included.
Examples of such other structural units include structural units derived from a monomer having an unsaturated bond. By subjecting such unsaturated monomers to copolymerization with the compound of the general formula (3) and the compound of the general formula (4), these monomers are introduced into the copolymer structure.

Examples of such unsaturated monomers include, for example, maleic anhydride, dimethyl maleic anhydride,
-Unsaturated dicarboxylic anhydrides such as -norbornene-2,3-dicarboxylic acid, itaconic anhydride and citraconic anhydride; unsaturated imide compounds such as maleimide and N-phenylmaleimide; vinyl acetate, vinyl propionate, and capron Carboxylic acid vinyl ester compounds such as vinyl acrylate;
Vinyl cyanide compounds such as (meth) acrylonitrile and α-chloroacrylonitrile; methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate,
unsaturated carboxylic ester compounds such as n-hexyl (meth) acrylate, glycidyl (meth) acrylate, trifluoroethyl (meth) acrylate; ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, (meth) Unsaturated carboxylic esters containing unsaturated groups such as vinyl acrylate and dimethylvinylmethacryloyloxymethylsilane; vinyl compounds containing halogens such as 2-chloroethyl vinyl ether, vinyl chloroacetate and allyl chloroacetate; 2-hydroxyethyl (meth) Hydroxyl-containing vinyl compounds such as acrylate, 2-hydroxypropyl (meth) acrylate and (meth) allyl alcohol; amide-containing vinyl compounds such as (meth) acrylamide and crotonic acid amide; Carboxyl group-containing vinyl compounds such as oxyethylsuccinic acid and 2-methacryloyloxyethylmaleic acid; vinylaryl compounds such as 1-vinylnaphthalene, 2-vinylnaphthalene, 9-vinylanthracene and 9-vinylcarbazole; Can be
These unsaturated monomers can be used alone or in combination of two or more. Of the above monomers, maleic anhydride is particularly preferably used.

The copolymer used in the present invention is based on the total of the structural units represented by the above formulas (1) and (2) and the structural units derived from other unsaturated monomers as described above. And the structural unit of the formula (1) is preferably 5 to 9
0 mol%, more preferably 10 to 80%, particularly preferably 20 to 80%. The structural unit of the formula (2) is contained in an amount of preferably 5 to 80 mol%, more preferably 5 to 70 mol%, particularly preferably 10 to 60 mol%. When a structural unit derived from another unsaturated monomer is present, the content is preferably 60 mol% or less.

The copolymer constituting the antireflection film of the present invention can be produced in a polymerization form such as solution polymerization by an appropriate method such as radical polymerization, anion polymerization and cation polymerization. The weight average molecular weight in terms of polystyrene of the copolymer (hereinafter referred to as Mw) is appropriately selected according to the desired properties of the antireflection film, and is usually from 2,000 to 1,000.
It is preferably from 000, preferably from 3,000 to 700,000, particularly preferably from 5,000 to 500,000.

Examples of the solvent constituting the composition of the solvent present invention, a solvent capable of dissolving the anti-reflective coating composition comprising the copolymer, such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, Ethylene glycol monoalkyl ether such as ethylene glycol monobutyl ether; ethylene glycol monoalkyl ether acetate such as ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, ethylene glycol monobutyl ether acetate; diethylene glycol dimethyl ether, diethylene glycol Diethyl ether, diethylene glycol dipropyl ether Diethylene glycol dialkyl ethers such as diethylene glycol dibutyl ether; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monobutyl ether; propylene glycol dimethyl ether, propylene glycol diethyl ether, and propylene glycol dialkyl Propylene glycol dialkyl ethers such as propyl ether and propylene glycol dibutyl ether; propylene glycol monomethyl ether acetate, propylene glycol monoether ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl Propylene glycol monoalkyl ether acetate such as teracetate; lactate ester 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, butyl acetate, n-amyl acetate, isoamyl acetate, n-hexyl acetate, methyl propionate, ethyl propionate, n propionate Aliphatic carboxylic acid esters such as -propyl, isopropyl propionate, n-butyl propionate, isobutyl propionate, methyl butyrate, ethyl butyrate, n-propyl butyrate, isopropyl butyrate, n-butyl butyrate, isobutyl butyrate; hydroxy vinegar Ethyl acid, 2
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-methoxypropyl acetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, 3-methyl-3-methoxybutylpropionate, 3-methyl- Other esters such as 3-methoxybutyl butyrate, methyl acetoacetate, methyl pyruvate and ethyl pyruvate; aromatic hydrocarbons such as toluene and xylene; methyl ethyl ketone, methyl n-amyl ketone, methyl propyl ketone, methyl butyl ketone,
Ketones such as -heptanone, 3-heptanone, 4-heptanone, cyclohexanone; N-methylformamide;
An amide such as N, N-dimethylformamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone; a lactone such as γ-butyrolactone is appropriately selected and used. Among these, preferred solvents include ethylene glycol monoethyl ether acetate, ethyl lactate, ethyl 3-ethoxypropionate,
Examples thereof include methyl 3-methoxypropionate, methyl n-amyl ketone, cyclohexanone, and 2-heptanone. 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 of the resulting composition is preferably about 0.01 to 70% by weight, more preferably 0.05 to 60% by weight, and further preferably 0.1%.
It is in the range of ~ 50% by weight.

Other Ingredients The composition of the present invention may contain various additives, if necessary, as long as the desired effects of the present invention are not impaired. Examples of such additives include dyes, surfactants, curing agents, acid generators, basic modifiers, and the like.

Examples of the dye include dyes such as oil-soluble dyes, disperse dyes, basic dyes, methine dyes, pyrazole dyes, imidazole dyes, and hydroxyazo dyes; bixin derivatives, norbixin, stilbene,
Fluorescent whitening agents such as 4'-diaminostilbene derivatives, coumarin derivatives, and pyrazoline derivatives; hydroxyazo dyes, tinuvin 234 (manufactured by Ciba Specialty Chemicals), tinuvin 1130 (manufactured by Ciba Specialty Chemicals), and the like UV absorbers; and aromatic compounds such as anthracene derivatives and anthraquinone derivatives. The amount of the radiation absorbing compound to be blended is preferably 100 parts by weight or less, more preferably 50 parts by weight or less, per 100 parts by weight of the solid content of the antireflection film-forming composition.

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,
In addition to nonionic surfactants such as polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyethylene glycol dilaurate, and polyethylene glycol distearate, commercially available products include, for example, KP3 which is an organosiloxane polymer.
No. 41 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), polyflow Nos. 75 and 9 which are (meth) acrylic acid (co) polymers
5 (trade name, manufactured by Kyoeisha Yushi Kagaku Kogyo), F-Top EF
101, EF204, EF303, EF352
(Trade name, manufactured by Tochem Products), MegaFac F1
71, F172, F173 (trade name, manufactured by Dainippon Ink and Chemicals, Inc.), Florad FC430, FC431,
FC135, FC93 (trade name, manufactured by Sumitomo 3M), Asahi Guard AG710, Surflon S382,
SC101, SC102, SC103, SC1
04, SC105, SC106 (trade name, manufactured by Asahi Glass) and the like. The amount of these surfactants is
The amount is preferably 15 parts by weight or less, more preferably 10 parts by weight or less, per 100 parts by weight of the solid content of the antireflection film composition.

As the curing agent, for example, tolylene diisocyanate, diphenylmethane diisocyanate,
Isocyanates such as hexamethylene diisocyanate and cyclohexane diisocyanate; Epicoat 812;
815, 826, 828, 834, 836,
871, 1001, 1004, 1007, 1
009, 1031 (trade name: manufactured by Yuka Shell Epoxy), Araldite 6600, 6700, 680
0, 502, 6071, 6084, 6097,
6099 (trade name: Ciba Specialty Chemicals), DER331, 332, 333, 66
Epoxys such as 1, 644, 667 (trade name: Dow); Cymel 300, 301, 303, 35
0, 370, 771, 325, 327, 70
3, 712, 701, 272, 202, Mycoat 506, 508 (trade name: Mitsui Cyanamid) and other melamine-based curing agents, Cymel 1123, 11
23-10, 1128, My Court 102, 10
5, benzoguanamine-based curing agents such as 106 and 130 (trade name: manufactured by Mitsui Cyanamid); Cymel 117
And glycoluril-based curing agents such as No. 0 and 1172 (trade name: manufactured by Mitsui Cyanamid). The amount of these curing agents is usually 5000 parts by weight or less, preferably 1 part by weight, per 100 parts by weight of the solid content of the antireflection coating composition.
000 parts by weight or less.

As the acid generator, a photoacid generator and a thermal acid generator can be used. Examples of the photoacid generator include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium pyrene sulfonate, diphenyliodonium dodecylbenzenesulfonate, diphenyliodonium nonafluoro n-butanesulfonate, bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis ( 4-
t-butylphenyl) iodonium dodecylbenzenesulfonate, bis (4-t-butylphenyl) iodoniumnaphthalenesulfonate, bis (4-t-butylphenyl) iodonium hexafluoroantimonate,
Bis (4-t-butylphenyl) iodonium nonafluoro n-butanesulfonate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium naphthalene sulfonate, triphenylsulfonium nonafluoro n-butanesulfonate, (hydroxy Phenyl) benzenemethylsulfonium toluenesulfonate, cyclohexylmethyl (2-oxocyclohexyl) sulfonium trifluoromethanesulfonate, dicyclohexyl (2-oxocyclohexyl) sulfonium trifluoromethanesulfonate, dimethyl (2-oxocyclohexyl) sulfonium trifluoromethanesulfonate, diphenyliodonium hexafluoroan Monate, triphenylsulfonium camphorsulfonate, (4-hydroxyphenyl) benzylmethylsulfonium toluenesulfonate, 1-naphthyldimethylsulfonium trifluoromethanesulfonate, 1-naphthyldiethylsulfonium trifluoromethanesulfonate, 4-cyano-1-naphthyldimethylsulfonium trifluoromethanesulfonate 4-nitro-1-naphthyldimethylsulfonium trifluoromethanesulfonate, 4-methyl-1-
Naphthyldimethylsulfonium trifluoromethanesulfonate, 4-cyano-1-naphthyl-diethylsulfonium trifluoromethanesulfonate, 4-nitro-
1-naphthyl diethylsulfonium trifluoromethanesulfonate, 4-methyl-1-naphthyldiethylsulfonium trifluoromethanesulfonate, 4-hydroxy-1-naphthyldimethylsulfonium trifluoromethanesulfonate, 4-hydroxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-methoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-ethoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-methoxymethoxy-1-
Naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-ethoxymethoxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4- (1-methoxyethoxy) -1-naphthyltetrahydrothiopheniumtrifluoromethanesulfonate, 4- (2- Methoxyethoxy) -1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-methoxycarbonyloxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-ethoxycarbenyloxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-n-propoxycarbonyloxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4 i- propoxycarbonyloxy -
1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-n-butoxycarbyloxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4-t-butoxycarbonyloxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate 4- (2-tetrahydrofuranyloxy) -1-naphthyltetrahydrothiophenium trifluoromethanesulfonate, 4- (2-tetrahydropyranyloxy) -1-naphthyltetrahydrothiophenium trifluoromethanesulfonate,
Onium salt photoacid generators such as benzyloxy-1-naphthyltetrahydrothiophenium trifluoromethanesulfonate and 1- (naphthylacetomethyl) tetrahydrothiophenium trifluoromethanesulfonate; phenyl-bis (trichloromethyl) -s-triazine;
Methoxyphenyl-bis (trichloromethyl) -s-triazine, naphthyl-bis (trichloromethyl) -s-
Halogen-containing compound photoacid generators such as triazine; 1,2
-Naphthoquinonediazide-4-sulfonyl chloride,
1,2-naphthoquinonediazido-5-sulfonyl chloride, 1,2-naphthoquinonediazide-4-sulfonic acid ester of 2,3,4,4'-tetrabenzophenone, 1,2-naphthoquinonediazide-5-sulfonic acid ester and the like Diazoketone compound-based photoacid generators; 4-trisphenacylsulfone, mesitylphenacylsulfone, bis (phenylsulfonyl) methane and other sulfonic acid compound-based photoacid generators; benzoin tosylate, pyrogallol tristrifluoromethanesulfonate, Nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate, trifluoromethanesulfonylbicyclo [2,2,
1] Hept-5-ene-2,3-dicarbodiimide, N
And sulfonic acid compound-based photoacid generators such as -hydroxysuccinimide trifluoromethanesulfonate and 1,8-naphthalenedicarboxylic acid imide trifluoromethanesulfonate.

Examples of the thermal acid generator include 2,4,
4,6-tetrabromocyclohexadienone, benzoin tosylate, 2-nitrobenzyl tosylate, alkyl sulfonate and the like can be mentioned. The amount of these acid generators is preferably 100 parts by weight or less, more preferably 0.1 part by weight, per 100 parts by weight of the solid content of the antireflection film composition.
1 part by weight or more and 20 parts by weight or less.

The basic modifier has the function of improving the shape of the resist pattern. Examples of such a basic modifier include a monoamino compound, a diamino compound, a polymer having three or more nitrogen atoms, an amide group-containing compound, a urea compound, and a nitrogen-containing heterocyclic compound.

The monoamino compound includes, for example,
mono- (cyclo) alkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine, cyclohexylamine; di-n-butylamine, di-n-pentylamine;
Di-n-hexylamine, di-n-heptylamine, di-n-octylamine, di-n-nonylamine, di-n
Di (cyclo) alkylamines such as decylamine and dicyclohexylamine; triethylamine, tri-n-
Propylamine, tri-n-butylamine, tri-n-
Pentylamine, tri-n-hexylamine, tri-n
-Heptylamine, tri-n-octylamine, tri-
n-nonylamine, tri-n-decylamine, tri-n
Tri (cyclo) alkylamines such as dodecylamine, n-dodecyldimethylamine and tricyclohexylamine; alkanolamines such as cyclohexylethanolamine; aniline, N-methylaniline, N, N
-Dimethylaniline, 2-methylaniline, 3-methylaniline, 4-methylaniline, 4-nitroaniline,
Examples thereof include aromatic amines such as diphenylamine, triphenylamine, and naphthylamine.

Examples of the diamino compound include ethylenediamine, N, N, N ', N'-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenylmethane,
4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylamine, 2,2-bis (4'-aminophenyl) propane,
2- (3'-aminophenyl) -2- (4'-aminophenyl) propane, 2- (4'-aminophenyl) -2
-(3'-hydroxyphenyl) propane, 2- (4 '
-Aminophenyl) -2- (4'-hydroxyphenyl) propane, 1,4-bis [1 '-(4 "-aminophenyl) -1'-methylethyl] benzene, 1,3-bis [1' -(4 ''-aminophenyl) -1'-methylethyl] benzene and the like.

Examples of the polymer having three or more nitrogen atoms include polyvinylpyrrolidone, polyethyleneimine, polyallylamine, and acrylamide derivatives. As the amide group-containing compound,
For example, formamide, N-methylformamide, N,
Examples thereof include N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, and N-methylpyrrolidone.

Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea,
Examples thereof include 3-diphenylurea and tri-n-butylthiourea. Examples of the nitrogen-containing heterocyclic compound include imidazole, benzimidazole,
Imidazoles such as -methylimidazole and 4-methyl-2-phenylimidazole; pyridine, 2-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 4
-Ethylpyridine, 2-phenylpyridine, 4-phenylpyridine, N-methyl-4-phenylpyridine, nicotine, nicotinic acid, nicotinamide, quinoline, 8-
In addition to pyridines such as oxyquinoline and acridine, pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, morpholine, 4-methylmorpholine, piperazine, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2.2 .2] Octane and the like.

Among these nitrogen-containing organic compounds, polymers having three or more nitrogen atoms are preferred, and polyvinylpyrrolidone is particularly preferred. The basic modifiers can be used alone or in combination of two or more. The compounding amount of the basic modifier is usually 30 parts by weight or less, preferably 0.001 to 20 parts by weight, more preferably 0.02 parts by weight, per 100 parts by weight of the solid content of the antireflection film composition.
05 to 10 parts by weight. Further, other additives include a storage stabilizer, an antifoaming agent, an adhesion aid and the like.

Use of the composition The composition of the present invention is used for forming a resist pattern.
For example, it is used as follows. That is, the method of forming a resist includes: 1) a step of applying an antireflection film-forming composition on a substrate, followed by baking to form an antireflection film; 2) applying a resist composition on the antireflection film; Thereafter, a step of baking to form a resist film, a step of irradiating the resist film with radiation through an exposure mask, a step of developing, and a step of 5) etching the antireflection film are included.

A method for forming a resist pattern is as follows. First, an antireflection film forming composition is coated on a substrate to a predetermined thickness, for example, 10 μm.
Coating is performed by a method such as spin coating, casting coating roll coating, or the like so that the thickness becomes 0 to 5000 angstroms. Next, baking is performed to thermally cure the antireflection coating composition. The baking temperature at this time is, for example, about 90 to 350 ° C.
After forming the antireflection film on the substrate as described above,
In a second step, a resist film obtained on the antireflection film is applied so as to have a predetermined thickness, prebaked, and a solvent in the resist film is volatilized to form a resist film. The prebaking temperature at this time is appropriately adjusted depending on the type of the resist used, etc., but is preferably about 30 to 300 ° C, more preferably 50 to 260 ° C.

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, far-ultraviolet light is preferable, and an ArF excimer laser (193 nm) is particularly preferably used.

Next, this is developed in a fourth step. Thereafter, by washing and drying, a desired resist pattern is formed. During this step, baking may be performed after exposure and before development in order to improve resolution, pattern shape, developability, and the like. Finally, in a fifth step, using the resist pattern as a mask, dry etching of the antireflection film is performed using gas plasma such as oxygen plasma to obtain a resist pattern for processing a substrate.

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, tetraethyl Ammonium 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 concentration of the alkaline aqueous solution is usually 1
0% by weight or less, preferably 5% by weight or less, more preferably 0.01 to 3% by weight. In this case, if the concentration of the alkaline aqueous solution exceeds 10% by weight, unexposed portions may be dissolved in the developer, which is not preferable.

Further, an organic solvent, for example, can be added to the developer composed of the alkaline aqueous solution. Examples of the organic solvent include acetone, methyl ethyl ketone, methyl i-butyl ketone, cyclopentanone, cyclohexanone, 3-methylcyclopentanone, 2,6
Ketones such as dimethylcyclohexanone; methyl alcohol, ethyl alcohol, n-propyl alcohol,
i-propyl alcohol, n-butyl alcohol, t-
Alcohols such as butyl alcohol, cyclopentanol, cyclohexanol, 1,4-hexanediol and 1,4-hexanedimethylol; ethers such as tetrahydrofuran and dioxane; ethyl acetate, n-butyl acetate, i-pentyl acetate and the like Esters; aromatic hydrocarbons such as toluene and xylene, phenol, acetonylacetone, dimethylformamide and the like.

These organic solvents can be used alone or in combination of two or more. The amount of the organic solvent used is preferably 100% by volume or less based on the alkaline aqueous solution. In this case, if the amount of the organic solvent used exceeds 100% by volume, the developability is reduced, and the undeveloped portion of the exposed portion becomes remarkable, which is not preferable. In addition, an appropriate amount of a surfactant or the like can be added to a developer composed of an alkaline aqueous solution. After development with a developing solution composed of an alkaline aqueous solution, it is generally washed with water and dried.

[0052]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these embodiments. In the following description, “parts” means “parts by weight” unless otherwise specified. Further, in the following polymerization examples, Mw of the obtained copolymer was GP manufactured by Tosoh Corporation.
C column (G2000HXL: 2, G3000HX
L: 1), flow rate: 1.0 ml / min, elution solvent:
The measurement was performed by gel permeation chromatography (detector: differential refractometer) using monodisperse polystyrene as a standard under the analysis conditions of tetrahydrofuran and a column temperature of 40 ° C.

Exposure: The antireflection coating composition of the present invention was applied on a silicone wafer and baked at 250 ° C. for 120 seconds to form an antireflection coating having a thickness of 600 Å. After spin-coating a resist solution for ArF on the antireflection film, the resist solution was heated on a hot plate at 130 ° C. for 9 hours.
PB was performed for 0 second to form a resist film having a thickness of 0.5 μm. This resist film was exposed through a mask pattern by an ArF excimer laser exposure device (lens numerical aperture 0.60, exposure wavelength 193 nm) manufactured by ISI. Next, PEB was performed on a hot plate at 130 ° C. for 90 seconds, and then developed with a 2.38% by weight aqueous solution of tetramethylammonium hydroxide (TMAH) at 25 ° C. for 1 minute, washed with water, and dried. A positive resist pattern was formed.

Intermixing prevention effect: Similar to the above exposure, after formation, exposure and development of the antireflection film and the resist film, the bottom of the resist film at the contact point with the antireflection film in the portion removed by the development of the resist film. The extent was checked using a scanning electron microscope.

Standing Wave Preventing Effect: Like the above-mentioned exposure, after the formation of the antireflection film and the resist film, the exposure and the development, the presence or absence of the effect of the standing wave on the resist film was examined using a scanning electron microscope.

Pattern shape: As in the case of the above-described exposure, the formation of an anti-reflection film and a resist film, exposure and development, followed by a line width of 0.5 mm.
15 μm line and space pattern (1L1
The lower side dimension L1 and the upper and lower side dimensions L2 of the square cross section of S) were measured with a scanning electron microscope, and 0.85 ≦ L2 / L.
A case where 1 ≦ 1 was satisfied and the pattern shape did not have a tail was regarded as “good” in the pattern shape.

Etching rate: The formation, exposure and development of an antireflection film and a resist film were performed in the same manner as in the case of the above exposure. Thereafter, dry etching using oxygen plasma (pressure 15 Pa, RF power 300 W, etching gas oxygen) is performed, the etching rate of the antireflection film is measured, and the etching rate ratio between the antireflection film and the resist film (etching rate of the antireflection film) / Etching rate of the resist film).

1) Synthetic Polymerization Example 1 of ArF Resist In a separable flask equipped with a reflux tube, under a nitrogen stream, 8-methyl-8-t-butoxycarbonylmethoxycarbonyltetracyclo [4.4.0.1 ^{2 , 5.1 7,10} ] dodec-3-ene 29 parts, 8-hydroxytetracyclo [4.
4.0.1 ^2,5 .1 ^{7,1 0]} dodeca-3-ene 10 parts, 18 parts of maleic anhydride, 4 parts of 2,5-dimethyl-2,5-hexanediol diacrylate, t-dodecyl mercaptan 1 part, 4 parts of azobisisobutyronitrile and 1,2-
60 parts of diethoxyethane was charged and polymerized at 70 ° C. for 6 hours. After completion of the polymerization, a large amount of n-hexane / i
-Propyl alcohol (weight ratio = 1/1) is poured into a mixed solvent to coagulate the resin, and the coagulated resin is washed with the same mixed solvent several times, and then dried under vacuum to obtain the following formula (6):
The content of the repeating unit represented by each of the formulas (7) and (8) is 64 mol%, 18 mol% and 18 mol%, respectively.
And a copolymer having an Mw of 27,000 was obtained at a yield of 60%.
I got it. This copolymer is referred to as copolymer A.

[0059]

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Preparation Example 1 80 parts of the copolymer A obtained in Polymerization Example 1, 4-methoxy-
1.5 parts of 1-naphthyltetrahydrothiophenium nonafluoro-n-butanesulfonate and 0.04 parts of tri-n-octylamine were dissolved in 533 parts of propylene glycol monoethyl ether acetate to prepare an ArF resist solution.

Polymerization Example 2 In a separable flask equipped with a reflux tube, under a nitrogen stream, 60 parts of styrene, 20 parts of N-methoxymethylacrylamide, 40 parts of maleic anhydride, 5 parts of azobisisobutyronitrile and 250 parts of cyclohexanone 250 parts. And polymerized at 60 ° C. for 8 hours. After completion of the polymerization, the reaction solution was poured into a large amount of i-propyl alcohol solvent to coagulate the resin, and the coagulated resin was washed several times with the same solvent, and then dried under vacuum. ^From the results of ¹ H-NMR, the contents of styrene, N-methoxymethylacrylamide and maleic anhydride were 50 mol%, 15 mol% and 3 mol%, respectively.
A copolymer having 5 mol% and Mw of 18,000 was obtained in a yield of 80%. This copolymer is referred to as copolymer 1.

Polymerization Example 3 A copolymer having an Mw of 10,000 (in terms of polystyrene) was obtained in the same manner as in Polymerization Example 2 except that 30 parts of methyl methacrylate was used instead of 40 parts of maleic anhydride in Polymerization Example 2. Was. ^From the result of ¹ H-NMR, it was confirmed that the structure was such that styrene, methyl methacrylate and N- (hydroxymethyl) acrylamide were copolymerized in a molar ratio of 44:38:18. This copolymer is referred to as copolymer 2.

Polymerization Example 4 A copolymer having an Mw of 10,000 (in terms of polystyrene) was prepared in the same manner as in Polymerization Example 2, except that 50 parts of hydroxyethyl methacrylate was used instead of 40 parts of maleic anhydride in Polymerization Example 2. Obtained. ^From the result of ¹ H-NMR, it was confirmed that styrene, hydroxyethyl methacrylate and N- (hydroxymethyl) acrylamide were copolymerized at a molar ratio of 45:36:19. This copolymer is referred to as copolymer 3.

Examples 1 to 3 Using the copolymers 1 to 3 obtained in Polymerization Examples 2 to 4, three types of antireflection film forming compositions were prepared as follows. 5 parts of copolymer and bis (4-t-butylphenyl)
5 parts of iodonium camphorsulfonate was dissolved in 90 parts of ethyl lactate and filtered through a membrane filter having a pore size of 0.2 μm to prepare a composition. Next, for each of the obtained compositions, formation of a resist pattern and performance evaluation of the antireflection film were performed as described above. Table 1 shows the evaluation results.

[0065]

[Table 1]

[0066]

The composition for forming an antireflection film of the present invention has a high antireflection effect, does not cause intermixing with a resist, has a high etching rate, and cooperates with a positive type and a negative type resist. An anti-reflection film that can provide a resist pattern having excellent resolution, accuracy, and the like can be formed. Therefore, this composition greatly contributes particularly to the production of highly integrated circuits.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/027 H01L 21/30 574 (72) Inventor Shinichiro Iwanaga 2-11-24 Tsukiji, Chuo-ku, Tokyo JSR Co., Ltd. F-term (reference) 2H025 AA00 AA02 AB16 AC08 AD01 AD03 DA34 4J002 BC041 BC081 BC101 BC121 BG131 GP00 GP03 GQ05 4J100 AB03P AB07P AB08P AB09P AM17Q BA03P BA03Q BA04Q BA05Q BA06Q BA14P BA37 BA04P

Claims (1)

[Claims] [Claim 1] The following formula (1) (Wherein R ₁ is a hydrogen atom, a halogen atom, a nitro group, an amino group, a hydroxyl group, an acyl group, a carboxyl group,
A sulfone group, a mercapto group or a hydrocarbon group;
_When two or more ₁ are present, they may be the same or different; R ₂ represents a hydrogen atom or a methyl group;
Represents an integer of 1 to 5. ) And a structural unit represented by the following formula (2): Wherein R ₃ represents a hydrogen atom or a methyl group and R ₄ represents a hydrogen atom or a hydrocarbon group, and a copolymer having a structural unit represented by the formula: and a solvent for the copolymer. A composition for forming an antireflection film, characterized by comprising: