WO2006040918A1

WO2006040918A1 - Composition for forming of lithographic antireflection film, containing nitrogenous aromatic ring structure

Info

Publication number: WO2006040918A1
Application number: PCT/JP2005/017613
Authority: WO
Inventors: Tomoyuki Enomoto; Yoshiomi Hiroi; Keisuke Nakayama
Original assignee: Nissan Chemical Industries, Ltd.
Priority date: 2004-10-12
Filing date: 2005-09-26
Publication date: 2006-04-20
Also published as: JPWO2006040918A1; TW200621828A; JP4697464B2; TWI411622B

Abstract

An antireflection film that exhibits a high antireflection effect, being free from any intermixing with photoresist, and that has a dry etching rate greater than that of photoresist, being available in a lithographic process for production of semiconductor devices; and a composition for forming of such an antireflection film. There is provided a composition for forming of lithographic antireflection film, comprising a reaction product, a crosslinking compound, a crosslinking catalyst and a solvent, wherein the reaction product is obtained by polyaddition reaction between an epoxy compound having two glycidyl groups and a nitrogenous aromatic compound having two thiol or hydroxyl groups.

Description

Specification

Antireflection film-forming composition for lithography containing nitrogen-containing aromatic ring structure

The present invention relates to an antireflection film forming composition for lithography used in a lithography process for manufacturing a semiconductor device. More specifically, the present invention relates to a composition for forming an antireflection film for lithography for forming an antireflection film under a photoresist, which is used for reducing reflection of exposure light from a semiconductor substrate. The present invention also relates to a method for forming a photoresist pattern using the composition for forming an antireflection film for lithography. Background art

[0002] Conventionally, in the manufacture of semiconductor devices, fine processing by lithography using a photoresist has been performed. The microfabrication is obtained by forming a photoresist thin film on a semiconductor substrate such as a silicon wafer, irradiating it with an actinic ray such as ultraviolet rays through a mask pattern on which a device pattern is drawn, and developing it. This is a processing method for etching a semiconductor substrate using the photoresist pattern as a protective film. However, in recent years, the degree of integration of devices has increased, and the actinic rays used have also been shortened to i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm) force, and ArF excimer laser (wavelength 193 nm). It tends to be. Along with this, reflection of irradiation light from the substrate has become a problem. Therefore, a method of providing an anti-reflective coating (bottom anti-reflective coating) between the photoresist and the substrate has been widely studied.

As the antireflection film, inorganic antireflection films such as titanium dioxide and titanium nitride, and organic antireflection films made of a light-absorbing substance and a polymer compound are known. The former requires equipment such as vacuum deposition equipment, CVD equipment, and sputtering equipment for film formation, while the latter is advantageous in that it does not require special equipment, and many studies have been conducted. For example, an acrylic resin-type antireflection film having a hydroxyl group and a light-absorbing group in the same molecule as a crosslink forming substituent described in US Pat. No. 5,919,599, and a crosslink forming replacement described in US Pat. No. 5693691 Examples thereof include a novolak resin type antireflection film having a hydroxyl group and a light absorbing group in the same molecule. Physical properties desired as an organic antireflection film include a large absorbance for light used for exposure and no intermixing with photoresist (insoluble in photoresist solvent). In other words, there is no diffusion of low molecular weight compounds from the antireflection film to the upper photoresist, and there is a large dry etching rate compared to the photoresist.

In recent years, in the lithography process using a KrF excimer laser and an ArF excimer laser, the processing dimension has been reduced, that is, the photoresist pattern size to be formed has been reduced. As the miniaturization of the photoresist pattern proceeds, a thin film of photoresist has been desired to prevent the photoresist pattern from collapsing. In the case of using a photoresist as a thin film, it can be removed by etching in a shorter time in order to suppress a decrease in the thickness of the photoresist layer in the removal process by etching of the antireflection film used together. Anti-reflective coatings are increasingly desired. In other words, in order to shorten the etching removal process, an antireflection film that can be used in a thinner film than before, or an antireflection film that has a higher etching rate selection ratio than before in comparison with a photoresist. Is now required.

Further, the antireflection film is required to be able to form a photoresist pattern having a good shape. In particular, it is required to be able to form a photo-registry pattern that does not have footing in the lower part. This is because if the photoresist pattern has a skirt shape, it adversely affects subsequent processing steps. In addition, with the development of lithography technology, the types of photoresists used are increasing. Therefore, development of a new antireflection film is always desired in order to cope with the use of various photoresists.

By the way, a composition for an antireflection film using a reaction product from an epoxy compound is known (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3). Further, a composition for an antireflection film containing a compound having a triazine trione ring structure is known (for example, see Patent Document 4).

Patent Document 1: US Pat. No. 6,670,425 specification Patent Document 2: JP-A-2004-212907

Patent Document 3: International Publication No. 04Z034435 Pamphlet

Patent Document 4: International Publication No. 04Z034148 Pamphlet

Disclosure of the invention

Problems to be solved by the invention

[0004] The present invention relates to a lithography process that can be used in a lithography process for manufacturing a semiconductor device using a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), or an F2 excimer laser (wavelength 157 nm). An object of the present invention is to provide a composition for forming an antireflection film.

Further, the present invention effectively absorbs the reflected light from the substrate when the KrF excimer laser, ArF excimer laser or F2 excimer laser is used for microfabrication, and does not cause intermixing with the photoresist layer. An object of the present invention is to provide an antireflection film having a higher dry etching rate than that of a photoresist, and an antireflection film forming composition therefor. Another object of the present invention is to provide a method for forming an antireflection film for lithography using such an antireflection film forming composition and a method for forming a photoresist pattern. Means for solving the problem

[0005] In view of the current situation, the present inventors have conducted extensive research, and as a result, polyaddition reaction of an epoxy compound having two glycidyl groups and a nitrogen-containing aromatic compound having two thiol groups or hydroxyl groups. It has been found that an excellent antireflection film can be formed by using the composition containing the obtained reaction product, and the present invention has been completed.

That is, the present invention provides, as a first aspect, a reaction product obtained by a polyaddition reaction between an epoxy compound having two glycidyl groups and a nitrogen-containing aromatic compound having two thiol groups or hydroxyl groups, a crosslinkable compound, A composition for forming an antireflection film for lithography, comprising a crosslinking catalyst and a solvent,

As a second aspect, the composition for forming an antireflective film for lithography according to the first aspect, wherein the epoxy compound is a diglycidinole ether compound or a dicarboxylic acid diglycidyl ester compound. As a third aspect, the epoxy compound has the formula (1):

[Chemical 1]

(1)

(Wherein R is an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 3 to 6 carbon atoms,

1

An antireflective film-forming composition for lithography according to the first aspect, characterized in that it is a compound represented by the following formula:

As a fourth aspect, the antireflection for lithography according to the first aspect, wherein the nitrogen-containing aromatic compound is a triazine compound, a thiadiazole compound or a pyrimidine compound having two hydroxyl groups or thiol groups. The film forming composition, as a fifth aspect, for the lithography according to the first aspect, wherein the crosslinkable compound is a nitrogen-containing compound having a nitrogen atom substituted with a hydroxymethyl group or an alkoxymethyl group Antireflection film-forming composition,

As a sixth aspect, the crosslinking catalyst is an aromatic sulfonic acid compound. The antireflection film-forming composition for lithography according to the first aspect,

As a seventh aspect, the composition for forming an antireflection film for lithography according to the first aspect, further comprising a photoacid generator,

As an eighth aspect, the step of applying the antireflective film forming composition for lithography according to any one of the first to seventh aspects on a semiconductor substrate and baking to form an antireflective film, Manufacturing a semiconductor device, comprising: forming a photoresist layer on an antireflection film; exposing a semiconductor substrate covered with the antireflection film and the photoresist layer; and developing the photoresist layer after the exposure. Of photoresist pattern used for Forming method.

The invention's effect

[0006] The present invention is intended to form an antireflection film that exhibits strong absorption in short wavelength light, particularly KrF excimer laser (wavelength 248nm), ArF excimer laser (wavelength 193nm) or F2 excimer laser (wavelength 157nm). It is a composition. The obtained antireflection film efficiently absorbs the reflected light from the substrate.

The present invention provides an antireflection film that effectively absorbs reflected light from a semiconductor substrate and does not cause intermixing with a photoresist layer in microfabrication using a KrF excimer laser, an ArF excimer laser, or the like. Can do.

According to the present invention, it is possible to provide an antireflection film having an etching rate larger than that of a photoresist.

In addition, by using the antireflection film of the present invention, a photoresist pattern having a good shape can be formed in a lithography process using a KrF excimer laser, an ArF excimer laser, or the like.

BEST MODE FOR CARRYING OUT THE INVENTION

[0007] The composition for forming an antireflection film for lithography of the present invention is a reaction obtained by a polyaddition reaction between an epoxy compound having two glycidyl groups and a nitrogen-containing aromatic compound having two thiol groups or hydroxynor groups. Contains product, crosslinkable compound, crosslinking catalyst and solvent. The composition for forming an antireflective film for lithography of the present invention can contain a photoacid generator, a surfactant and the like. The ratio of the solid content in the antireflection film-forming composition is not particularly limited as long as each component is uniformly dissolved in the solvent, but is, for example, 0.5 to 50% by mass, or:! To 30 % By weight, or 3 to 25% by weight, or 5 to 15% by weight. Here, the solid content is obtained by removing the solvent component from all components of the antireflection film-forming composition.

The antireflection film-forming composition for lithography according to the present invention is produced by a polyaddition reaction between an epoxy compound having two glycidyl groups and a nitrogen-containing aromatic compound having two thiol groups or hydroxynore groups. Contains the reaction product.

The epoxy compound is not particularly limited as long as it is a compound having two glycidinole groups. Can be used.

As the epoxy compound having two glycidyl groups, a diglycidyl ether compound or a dicarboxylic acid diglycidyl ester compound can be used.

Examples of the diglycidyl ether compound include ethylene glycol diglycidyl ether, 1,4_butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, 1,2_bis (2,3_epoxy Propoxy) benzene, 1,3_bis (2,3_epoxypropoxy) benzene, 1,4_bis (2,3_epoxypropoxy) benzene, and 2,2bis [4- (2,3 epoxypropoxy) Phenyl] propane and the like. The diglycidyl ether compound can be obtained by reacting a compound having two hydroxyl groups with a compound such as epichlorohydrin and glycidyl tosylate.

Examples of dicarboxylic acid diglycidyl ester compounds include phthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, 1,2-cyclohexanedicarboxylic acid diglycidyl ester, 1,4-butanedicarboxylic acid diglycidyl ester, and 1,4- And naphthalenedicarboxylic acid diglycidyl ester. The dicarboxylic acid diglycidyl ester compound can be obtained by reacting a compound having two carboxyl groups with epichlorohydrin, glycidyl tosylate, or the like.

As an epoxy compound having two glycidyl groups, formula (1):

[Chemical 2]

(1) The compound represented by these is mentioned. In the formula (1), R is an alkyl group having 1 to 6 carbon atoms, carbon

1

An alkenyl group having 3 to 6 atoms, a phenyl group, or a benzyl group. Examples of the alkyl group include a methylol group, an ethyl group, an isopropyl group, and a cyclohexyl group. Examples of the alkenyl group include a propenyl group, a 2-butur group, and a 4_pentur group. Specific examples of the compound represented by the formula (1) include, for example, allyl diglycidyl isocyanurate.

Epoxy compounds with two glycidyl groups also include bis [4— (2,3-epoxypropylthio) phenol] sulfide, bis (2,3 epoxypropyl) sulfide, 1,3—diglycidyl-5,5 There may be mentioned compounds such as —jetylbarbituric acid, 1,3-diglycidyl-5-phenol-5-ethylbarbituric acid, and 1,3-diglycidyl 5,5-dimethylhydantoin.

As the nitrogen-containing aromatic compound for producing a reaction product by polyaddition reaction contained in the antireflection film-forming composition for lithography of the present invention, a nitrogen-containing aromatic compound having two thiol groups or hydroxyleno groups If so, it can be used without any particular restrictions.

As the nitrogen-containing aromatic compound, a triazine compound, a thiadiazole compound or a pyrimidine compound having two hydroxyl groups or thiol groups can be used. Examples of the triazine compound include 2-dimethylenoleamino-1,3,5-triazine-1,4,6-dithiol, 2-jetylamino-1,3,5_triazine_4,6-dithiol, 2-dibutinoreamino 1,3,5_triazine_4,6-dithiol, 2-methoxy-1,3,5-triazine 1,4,6-dithiol, 2_dibutylamino-1,3,5_triazine_4,6-dithiol, 2-methylthio-1,3,5_triazine_4,6-dithiol, 2_N_phenylamino-1,1,3,5_triazine-1,4,6-dithiol, and dicyclohexylamino-1,3,5_triazine_4, Examples include 6-dithiol.

Examples of the thiadiazole compound include bismuthiol and 5,5 ′-(ethylenedithio) bis (1,3,4-thiazole-2-thiol). Examples of pyrimidine compounds include 2,6_dithiopurine, 2,8-dimercapto_6_ hydroxypurine, pyrimidine_2,4_dithiomonore, 5,6,7,8-tetrahydroquinazoline-2,4-dithiol, 5_ ( 4—Black mouth 1-phenyl) 1 pyrimidine 1 4, 6-dithiol, 5 — phenyl 1 pyrimidine _4, 6-dithiol, 5-methoxy 1 pyrimidine _4, 6_dithiol, 5-thiomethyl 1 pyrimidine _4, 6 —Dithiol, 2,4-dimercapto-5-methylpyrimidine, 2,6-dimercapto_7_methylpurine, and the like.

[0010] An epoxy compound having two glycidyl groups and a nitrogen-containing aromatic compound having two thiol groups or hydroxyl groups for obtaining a reaction product contained in the antireflection film-forming composition for lithography of the present invention The polyaddition reaction of benzene, toluene, xylene, ethyl acetate, butyl lactate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and N-methylpyrrolidone in a reaction time of 0.1 to 100 hours The reaction temperature can be appropriately selected from the range of 20 ° C to 200 ° C. For example, it can be carried out by selecting appropriate conditions from a reaction time of 5 to 30 hours and a reaction temperature of 80 ° C to 150 ° C. In this reaction, quaternary ammonium salts such as benzinoretriemonium chloride, tetraptyl ammonium chloride, and tetraethyl ammonium bromide can be used as a catalyst. When using a catalyst, it can be used in the range of, for example, 0.001 to 30% by mass, or 0.01 to 5% by mass, or 0.:! To 3% by mass with respect to the total mass of the compound to be used.

In the polyaddition reaction, the epoxy compound having two glycidyl groups and the nitrogen-containing aromatic compound having two thiol groups or two hydroxyl groups can each use only one kind of compound. Use two or more compounds in combination.

The ratio of the epoxy compound having two glycidinole groups used in the polyaddition reaction and the nitrogen-containing aromatic compound having two thiol groups or hydroxynore groups is the molar ratio of epoxy compound: nitrogen-containing aromatic compound, For example, 3 ::! To 1: 3, or 3: 2 to 2: 3, or 4: 3 to 3: 4, or 1: 1.

[0011] In a polyaddition reaction between an epoxy compound having two glycidyl groups and a nitrogen-containing aromatic compound having two thiol groups or hydroxynore groups, The reaction between the xinole group and the epoxy group occurs continuously between the compounds. As a result, a high molecular weight reaction product is obtained. The reaction product produced by the polyaddition reaction of an epoxy compound having two glycidinole groups and a nitrogen-containing aromatic compound having two thiol groups or hydroxynore groups has the structure represented by the formula (2). It is a high molecular weight compound having a repeating unit structure.

[Chemical 3]

(2)

In the formula (2), R is a portion excluding two glycidyl groups in the epoxy compound having two glycidyl groups. For example, when the epoxy compound having two glycidinole groups is ethylene glycol diglycidyl ether, R becomes _OCH CH 0-. Ma

twenty two

In the formula (2), X represents an oxygen atom or a sulfur atom. Ar is a portion corresponding to the aromatic ring structure of a nitrogen-containing aromatic compound having two thiol groups or hydroxynore groups. For example, when the nitrogen-containing aromatic compound having two thiol groups or hydroxyl groups is 2_dimethylolamino-1,3,5_triazine_4,6-dithiol, both X represent sulfur atoms, and Ar is 2 —Dimethylamino _ 1, 3, 5_ represents the triazine structure.

Molecular weight of reaction product by polyaddition reaction of an epoxy compound having two glycidyl groups and a nitrogen-containing aromatic compound having two thiol groups or hydroxyl groups, contained in the composition for forming an antireflection film for lithography of the present invention The weight average molecular weight is, for example, 1,000 to 100,000, or 2000 to 50,000, or 3000 to 20,000.

The ratio of the reaction product to the solid content of the antireflection film-forming composition for lithography of the present invention is, for example, 50 to 99% by mass, 60 to 95% by mass, or 70 to 90% by mass. When the ratio of the reaction product is smaller than the lower limit of the mass% range, The light absorption performance of the formed antireflection film may be insufficient.

In the composition for forming an antireflection film for lithography of the present invention, the reaction product can be isolated and used. In addition, the reaction solution containing the reaction product without isolating the reaction product can be used as it is for the antireflection film forming composition for lithography of the present invention.

The composition for forming an antireflection film for lithography of the present invention contains a crosslinkable compound.

As a crosslinkable compound, it can react with a hydroxyl group contained in a reaction product of a polyaddition reaction between an epoxy compound having two glycidinole groups and a nitrogen-containing aromatic compound having two thiol groups or hydroxynore groups. A compound having two or more such substituents, for example, 2 to 6, or 2 to 4, is used.

By using such a crosslinkable compound, a reaction occurs between the reaction product and the crosslinkable compound during the baking for forming the antireflection film, and the formed antireflection film has a crosslinked structure. Will have. As a result, the antireflection film becomes strong and has low solubility in the organic solvent used in the photoresist solution applied to the upper layer. Examples of the substituent capable of reacting with the hydroxyl group contained in the reaction product include an isocyanate group, an epoxy group, a hydroxymethylamino group, and an alkoxymethylamino group. Therefore, a compound having two or more of these substituents, for example, 2 to 6, or 2 to 4, can be used as the crosslinkable compound.

Examples of the crosslinkable compound contained in the antireflection film-forming composition for lithography of the present invention include nitrogen-containing compounds having a nitrogen atom substituted with a hydroxymethyl group or an alkoxymethyl group. This is a nitrogen-containing compound having a nitrogen atom substituted with a group such as a hydroxymethylol group, a methoxymethyl group, an ethoxymethyl group, a butoxymethyl group, and a hexyloxymethyl group.

Specifically, hexamethoxymethyl melamine, tetramethoxymethyl benzoguanamine, 1, 3, 4, 6-tetrakis (butoxymethyl) glycoluril, 1, 3, 4, 6-tetrakis (hydroxymethyl) glycoluril 1,3_bis (hydroxymethyl) urea, 1,1,3,3-tetrakis (butoxymethyl) urea, 1,1,3,3-tetrakis (methoxymethyl) urea, 1,3-bis ( Hydroxymethyl) 4,5-dihydroxy-1,2-imidazolinone and 1,3-bis (methoxy) (Cimethyl) _4,5-dimethoxy_2_imidazolinone and the like nitrogen-containing compounds. As cross-linkable compounds, methoxymethyl type melamine compounds (trade names: Saimenole 300, Saimenole 301, Saimenole 303, Saimenole 350) manufactured by Mitsui Cytec Co., Ltd., butoxymethyl type melamine compounds (trade name: Mycoat 506) , Mycoat 508), Glicolinolinorei compound (trade name: Cymel 1170, Powder Link 1174), methylated urea resin (trade name: UFR65), butylated urea resin (trade name: UFR300, U—VAN10S60) U-V AN10R, U-VAN11HV), urea / formaldehyde resin (highly condensed type, trade name Beccamin J-300S, Beccamin P-955, Beccamin N) manufactured by Dainippon Ink and Chemicals, etc. The commercially available compound can be mentioned. In addition, even a compound obtained by condensing a melamine compound in which a hydrogen atom of an amino group is substituted with a hydroxymethyl group or an alkoxymethyl group, a urea compound, a glycoluryl compound, and a benzoguanamine compound. For example, a high molecular weight compound produced by melamine compound (trade name Cymel 303) and benzoguanamine compound (trade name Cymel 1123) described in US Pat. No. 6323310 can also be mentioned.

Examples of the crosslinkable compound include N-hydroxymethylacrylamide, N-methoxymethylmethacrylamide, N-ethoxymethylacrylamide, N-butoxymethylmethacrylamide, and other acrylamide compounds substituted with hydroxymethyl groups or alkoxymethyl groups. Alternatively, a polymer produced using a methacrylamide compound can be used. Examples of such a polymer include poly (N-butoxymethylacrylamide), a copolymer of N-butoxymethylacrylamide and styrene, a copolymer of N-hydroxymethylmethacrylamide and methylmetatalate, and N-ethoxy. Examples thereof include a copolymer of methyl methacrylamide and benzyl methacrylate, and a copolymer of N-butoxymethyl acrylamide, benzyl methacrylate and 2-hydroxypropyl methacrylate.

As the crosslinkable compound, only one kind of compound can be used, or two or more kinds of compounds can be used in combination.

The proportion of the crosslinkable compound in the solid content of the antireflection film-forming composition for lithography of the present invention is, for example, 0.:! To 40% by mass, or 3 to 35% by mass, or 5 to 25% by mass. %. [0014] The antireflection film-forming composition for lithography of the present invention contains a crosslinking catalyst. By using a crosslinking catalyst, the reaction of the crosslinking compound is accelerated.

Examples of crosslinking catalysts include p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium_p-toluenesulfonic acid, salicylic acid, camphorsulfonic acid, sulfosalicylic acid, citrate, benzoic acid, and hydroxybenzoic acid. Can be used.

An aromatic sulfonic acid compound can be used as the crosslinking catalyst. Specific examples of the aromatic sulfone compound include p-toluenesulfonic acid, pyridinium_p-toluenesulfonic acid, sulfosalicylic acid, 4-chlorobenzenesulfonic acid, 4-hydroxybenzenesulfonic acid, benzenedisulfonic acid, and 1 naphthalenesulfone. Acid, pyridinium 1-naphthalene sulfonic acid and the like.

Only one type of crosslinking catalyst can be used, or two or more types can be used in combination.

The proportion of the crosslinking catalyst in the solid content of the antireflection film-forming composition for lithography of the present invention is, for example, 0.1 to 10% by mass, 0.2 to 5% by mass, or 0. 5 to 5% by mass.

[0015] The antireflection film-forming composition for lithography of the present invention may contain a photoacid generator. The photoacid generator generates an acid upon exposure of the photoresist. Therefore, the acidity of the antireflection film can be adjusted. This is a method for adjusting the acidity of the antireflection film to the acidity of the upper photoresist. Moreover, the pattern shape of the photoresist formed in the upper layer can be adjusted by adjusting the acidity of the antireflection film. Examples of the photoacid generator include onium salt compounds, sulfonimide compounds, and disulfonyl diazomethane compounds.

Examples of ionic salt compounds include diphenylhydrohexafluorophosphate, diphenyldon trifluoromethane sulfonate, diphenordone nonafluo, non-no-remano levenosnorefonate, diphenino. Rhedonium perfonoreo Nonorremanoleo octane sulfonate, diphenyl rhodoneum camphor sulfonate, bis (4-tert-butylphenol) jordon camphor sulfonate and bis (4 _tert_butylphenyl) Jodonium salt compounds such as Jodonium trifluoromethanesulfonate, and Trid Sulfonium salts such as phenylsulfonium hexafluoroantimonate, triphenylsulfonium nonaf noreloro n-butanesulfonate, triphenylsulfonium camphorsulfonate, and triphenylsulfonyltrifluoromethanesulfonate Compounds and the like.

Examples of the sulfonimide compounds include N— (trifluoromethanesulfonyloxy) succinimide, N— (nonafluoro-n-butanesulfonyloxy) succinimide, N— (camphorsulfonyloxy) succinimide, and N— (trifluoromethanesulfonyl). And oxy) naphthalimide.

Examples of the disulfonyldiazomethane compound include bis (trifluoromethylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, bis (phenylsulfonyl) diazomethane, bis (p-toluenesulfonino) diazomethane, Examples thereof include bis (2,4-dimethylbenzenesulfonyl) diazomethane and methylsulfonyl-p-toluenesulfonyl diazomethane.

Only one photoacid generator can be used, or two or more photoacid generators can be used in combination.

When the composition for forming an antireflection film for lithography of the present invention contains a photoacid generator, the content thereof is, for example, 0.01 to 5% by mass in the solid content, or 0. % By weight or 0.5 to 2% by weight.

In the composition for forming an antireflection film for lithography of the present invention, a surfactant, a rheology adjusting agent, an adhesion aid and the like can be added as necessary. Surfactants are effective in suppressing the occurrence of pinholes and strains. The rheology modifier improves the fluidity of the antireflective film-forming composition, and is effective in enhancing the filling property of the antireflective film-forming composition into the holes, particularly in the firing step. The adhesion aid improves the adhesion between the semiconductor substrate or the photoresist and the antireflection film, and is particularly effective for suppressing the peeling of the photoresist during development.

Examples of the surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether, polyoxyethylene vinyl ether, and polyoxyethylene ether. Polyoxyethylene alkylaryl ethers such as octylphenol ether, polyoxyethylene noolphenol ether, polyoxyethylene polyoxypropylene block copolymers, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan Sorbitan fatty acid esters such as monooleate, sorbitan trioleate, sorbitan tristearate, polyoxyethylene such as polyoxyethylene sorbitan monolaurate nostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate Nonionic surfactants such as sorbitan fatty acid esters, trade names EFTOP EF301, EF303, EF352 (manufactured by Tochem Product Co., Ltd.), trade names Megafu F171, F173, R—08, R—30 (Dainippon Ink Chemical Co., Ltd.), Florard FC430, FC431 (Sumitomo 3EM), trade name Asahi Guard A G710, Surflon S—382, Fluorosurfactants such as SC101, SC102, SC103, SC104, SC105, SC10 6 (manufactured by Asahi Glass Co., Ltd.), and onoreganosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). These surfactants may be used alone or in combination of two or more. If the surfactant is included in the anti-reflective coating forming composition of the present invention, the content thereof in solids, from 0.0001 to 5 mass ^_0/0, or 0.001 to 2 mass ^_0/0.

As the solvent used in the antireflection film-forming composition for lithography of the present invention, any solvent that can dissolve the above-mentioned solid content can be used. Examples of such solvents include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cetyl sorb acetate, cetyl solv acetate, diethylene glycol monomethyl methenoate, and diethylene glycol monomethenoate. Tenole, Propylene glycolate, Propylene glycolate monomethylenoateolate, Propylene glycolenomonomethinoleateolate acetate, Propylene glycolenopropenoleateolate acetate, Tonorene, Xylene, Methylethylketone, Cyclopentanone, Cyclopentane Hexanone, 2-hydroxypropionate ethyl, 2-hydroxy-1-ethyl propionate, ethoxy acetate, hydroxyethyl acetate, 2-hydroxy-1-methyl Methyl phosphate, 3-methoxy propionitrile phosphate, 3- methoxypropionate Echiru, 3-ethoxy propionate Echiru, 3- Examples thereof include methyl ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, butyl acetate, ethyl acetate, and butyl lactate. These solvents are used alone or in combination of two or more. Furthermore, high boiling point solvents such as propylene glycol monobutyl ether and propylene glycol monobutyl ether acetate can be mixed and used.

Hereinafter, the use of the composition for forming an antireflection film for lithography of the present invention will be described. On a semiconductor substrate (for example, a silicon wafer substrate, a silicon / silicon dioxide-coated substrate, a silicon nitride substrate, an ITO substrate, etc.) The antireflection film-forming composition of the present invention is applied by an appropriate coating method such as a coater, and then fired to form an antireflection film. The conditions for firing are appropriately selected from firing temperatures of 80 ° C to 250 ° C and firing times of 0.3 to 60 minutes. Preferably, the firing temperature is 150 ° C to 250 ° C, and the firing time is 0.5 to 5 minutes. Here, the thickness of the antireflection film to be formed is, for example, 0.01 to 3. Ο μ ΐη, and preferably, for example, 0.03 to: 1.0 / im, and ί or 0. 05 to 0.5 xm, and ί to 0.05 to 0.5 μm.

Next, a layer of a photoresist is formed on the antireflection film. Formation of the photoresist layer can be performed by a well-known method, that is, by applying and baking a photoresist composition solution on the antireflection film.

The photoresist applied and formed on the antireflection film of the present invention is not particularly limited as long as it is sensitive to light used for exposure. Either negative photoresist or positive photoresist can be used. A positive photoresist comprising a novolac resin and 1,2-naphthoquinonediazide sulfonate, a chemically amplified photoresist comprising a binder having a group capable of decomposing with an acid and increasing the alkali dissolution rate, and a photoacid generator, Chemically amplified photoresist consisting of a low molecular weight compound that decomposes with acid to increase the alkali dissolution rate of the photoresist, an alkali-soluble binder, and a photoacid generator, and a group that decomposes with acid to increase the alkali dissolution rate There is a chemically amplified photoresist composed of a low-molecular compound that decomposes with a binder having acid and an acid to increase the alkali dissolution rate of the photoresist and a photoacid generator. For example, Pro SPIE, Vol. 3999, 330- 334 (2000), Pro SPIE, Vol. 3999, 357—364 (2000), and Pro SPIE, Vol. 39 99, 365—374 (2000) You can list strikes.

Next, exposure is performed through a predetermined mask. For the exposure, a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), an F2 excimer laser (wavelength 157 nm), or the like can be used. After exposure, post-exposure bake can be performed as necessary. The post-exposure calorie heat is appropriately selected from the range of 70 ° C. to 150 ° C. and 0.3 to 10 minutes.

Next, development is performed with a developer. Thus, for example, when a positive photoresist is used, the exposed portion of the photoresist is removed, and a photoresist pattern is formed.

Developers include aqueous solutions of alkali metal hydroxides such as potassium hydroxide and sodium hydroxide, aqueous solutions of quaternary ammonium hydroxides such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, choline, and ethanol. Examples include alkaline aqueous solutions such as amine aqueous solutions such as min, propylamine, and ethylene diamine. As the image liquid, 2.38 mass% tetramethylammonium hydroxide aqueous solution which is widely used can be used. Further, a surfactant or the like can be added to these developers. The conditions for the image are appropriately selected from a temperature of 5 to 50 ° C and a time of 10 to 300 seconds.

Then, using the photoresist pattern thus formed as a protective film, the antireflection film is removed and the semiconductor substrate is processed. The antireflection film can be removed by using tetrafluoromethane, perfluorocyclobutane (CF), perfluoropropane (CF), trifluoromethane, carbon monoxide, argon, oxygen, nitrogen, sulfur hexafluoride, difluoromethane, trifluoromethane. This is performed using a gas such as nitrogen fluoride or chlorine trifluoride.

A flat film or a gap fill material layer may be formed on the semiconductor substrate before the antireflection film is formed by the composition for forming an antireflection film for lithography of the present invention. When a semiconductor substrate having a large step is used, it is preferable that a flat film or a gap fill material layer is formed before the antireflection film is formed.

In addition, the semiconductor substrate to which the antireflection film-forming composition of the present invention is applied has C on its surface. The antireflection film of the present invention can be formed on an inorganic antireflection film formed by the VD method or the like.

Further, the antireflection film formed from the composition for forming an antireflection film for lithography of the present invention comprises a layer for preventing the interaction between the substrate and the photoresist, a material used for the photoresist, or exposure to the photoresist. A layer to prevent adverse effects of substances that are sometimes generated on the substrate, a layer to prevent diffusion of substances generated from the substrate upon firing into the upper photoresist, and a voiding effect of the photoresist layer by the dielectric layer of the semiconductor substrate It is also possible to use it as a barrier layer for reducing the above.

In addition, the antireflection film formed from the antireflection film forming composition of the present invention, when applied to a substrate having via holes used in a dual damascene process, can fill the via holes without gaps. It can also be used as Further, it can be used as a flattening material for flattening the surface of an uneven semiconductor substrate.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.

Example

[0021] Synthesis Example 1

Propylene glycol monomethyl ether 21. 50 g 2-dimethylamino-1,6-dithiol- 1,3,5-triazine 2.25 g, ethylene glycol diglycidyl ether 2. OOg, and benzenotriethyl ether as catalyst After adding 0.14 g of chloride, the mixture was reacted for 24 hours under reflux to obtain a solution containing the reaction product. When the GPC analysis of the obtained reaction product was conducted, the weight average molecular weight was 5800 in terms of standard polystyrene. The obtained reaction product is considered to have a repeating unit structure represented by the formula (3).

[Chemical 4]

[0022] Synthesis Example 2

Propylene glycol monomethyl ether 30. 71 g of 2-Jibuchiruamino one 4, 6-dithiadiphosphetane ol _ 1, ^3, ⁵ -. Toriajin (Sankyo Kasei Co., Ltd., trade name Jisunetto BD) ³ 53 g, terephthalic Tal acid diglycidyl ester After adding 4.00 g and 0.15 g of benzyltriethyl ammonium chloride as a catalyst, the mixture was reacted for 24 hours under reflux to obtain a solution containing the reaction product. When the GPC analysis of the obtained reaction product was performed, the weight average molecular weight was 7000 in standard polystyrene conversion. The obtained reaction product is considered to have a repeating unit structure represented by the formula (4).

[Chemical 5]

(Four)

[0023] Synthesis Example 3

, Etenore 24. 45 § 2_ Dibutino Leamino_ 4,6 _ Dithiol 1,3,5_ Triazine (trade name Gisnet BD, manufactured by Sankyo Kasei Co., Ltd.) 2. 99g, Monoa U / Le, i ί Modified 3.000g and as catalyst: After adding 0.12 g of umchloride, the mixture was reacted for 24 hours under reflux to obtain a solution containing the reaction product. When the GPC analysis of the obtained reaction product was conducted, the weight average molecular weight was 15400 in terms of standard polystyrene. The obtained reaction product is considered to have a repeating unit structure represented by the formula (5).

[Chemical 6]

(5) Synthesis example 4

Propylene glycol monomethyl ether 63 · 77 g with 2-thiomethyl-4,6-diol 1,3,5-triazine 5.54 g, monoallyl diglycidyl isocyanuric acid 10.00 g, and benzyltriethyl ammonium as the catalyst After adding 0.40 g of umchloride, the mixture was reacted under reflux for 24 hours to obtain a solution containing the reaction product. When the GPC analysis of the obtained reaction product was conducted, the weight average molecular weight was 15500 in standard polystyrene conversion. The obtained reaction product is considered to have a repeating unit structure represented by the formula (6).

[Chemical 7]

[0025] Synthesis Example 5

Propylene glycol monomethyl ether (43.80 g), Bismuthiol (4.00 g), Ethylene glycol diglycidyl ether (6,68 g) and Benzyltriethyl ammonium chloride (0.18 g) as a catalyst were added and reacted under reflux for 24 hours. A solution containing the product was obtained. When the GPC analysis of the obtained reaction product was conducted, the weight average molecular weight was 4500 in standard polystyrene conversion. The obtained reaction product is considered to have a repeating unit structure represented by the formula (7).

[Chemical 8]

(7)

[0026] Example 1

3.92 g of the solution obtained in the synthesis example 1, ether 2.56 g, ethyl lactate 13.3 g, tetramethoxymethyldariko, Mitsui Cytec Co., Ltd., trade name Powder Link 1174) 0.20 g, and pyridinium p Phonic acid 0 02g was mixed to make a 5 mass% solution. Then, the solution was filtered using a polyethylene microfilter having a pore diameter of 0.05 xm to prepare a solution of an antireflection film forming composition for lithography.

[0027] Examples 2 to 5

In the same manner as in Example 1, 3.92 g of the solutions obtained in Synthesis Examples 2 to 5, respectively, 2.56 g of propylene glycol monomethyl ether, 13.3 g of lactic acid ethynole, tetramethoxymethyldarlicoluril (Mitsui Cytec Co., Ltd.) Product name Powder Link 1174) 0.20 g and pyridinium-p-toluenesulfonic acid 0.02 g were mixed to obtain a 5 mass% solution. And it filtered using the polyethylene micro filter with the hole diameter of 0.05 micrometer, and prepared the solution of the antireflection film formation composition for lithography.

[0028] Dissolution test in solvent

Each of the solutions obtained in Examples 1 to 5 was applied onto a silicon wafer substrate using a spinner. Then, it was baked on a hot plate at 205 ° C. for 1 minute to form an antireflection film (film thickness: 0.078 μm). These antireflection films were immersed in ethyl lactate and propylene glycol monomethyl ether, which are solvents used for photoresist, and confirmed to be insoluble in the solvent. It was also immersed in an alkaline developer for developing a photoresist and confirmed to be insoluble.

[0029] Testing optical parameters

Each of the solutions obtained in Examples 1 to 5 was applied onto a silicon wafer substrate using a spinner. Then, it was baked on a hot plate at 205 ° C. for 1 minute to form an antireflection film (film thickness: 0.078 μm). These antireflective coatings are made using a spectroscopic ellipsometer, A. Woollam, VUV—VASE VU—302, with a refractive index ( _n value) and an attenuation coefficient (k) at wavelengths of 248 nm and 193 nm. Value). The results are shown in Tables 1 and 2.

[0030] Measurement of dry etching rate

By the same method as described above, an antireflection film was formed on the silicon wafer substrate from the solutions of Examples 1 to 5. The dry etching rate of these antireflection films was adjusted using the RIE system ES401 manufactured by Nippon Scientific and CF as the dry etching gas.

4 Measured under the conditions used. A photoresist solution (product name: PAR710, manufactured by Sumitomo Chemical Co., Ltd.) is applied onto a silicon wafer substrate with a spinner and baked on a hot plate at 90 ° C for 1 minute to form a photoresist layer. did. Then, using RIE system ES401 made by Nippon Scientific, the dry etching of photoresist PAR710 under the condition that CF is used as the dry etching gas.

Four

The punching speed was measured. The anti-reflection coating obtained from Examples 1 to 5 and the photoresist were compared in dry etching speed. The results are shown in Tables 1 and 2.

Table 1 shows the refractive index (n value) and attenuation coefficient (k value) at a wavelength of 248 nm, and Table 2 shows the refractive index (n value) and attenuation coefficient (k value) at a wavelength of 193 nm.

In Tables 1 and 2, the selectivity represents the dry etching rate of the antireflection film formed from each example when the dry etching rate of the photoresist PAR710 is 1.00.

[Table 1] Table 1 n value k value selectivity Example 1 1. 70 0. 39 2. 02 Example 2 1. 73 0. 45 1. 64

Example 3 1.68 0. 30 1.69

[Table 2] Table 2 n value k value selection ratio Example 2 1. 62 0. 32 1. 64 Example 4 1. 69 0. 31 1. 84 Example 5 1. 85 0. 36 1. 79

From Table 1 and Table 2, the antireflection film obtained from the antireflection film-forming composition of the present invention is It can be seen that it has an effective refractive index and attenuation coefficient for light of 248 nm and 193 nm. It can also be seen that the photoresist has a high dry etching rate.

Claims

The scope of the claims

[1] It contains a reaction product, a crosslinkable compound, a crosslinking catalyst and a solvent obtained by a polyaddition reaction between an epoxy compound having two glycidyl groups and a nitrogen-containing aromatic compound having two thiol groups or hydroxyl groups. A composition for forming an antireflection film for lithography.

[2] The composition for forming an antireflection film for lithography according to [1], wherein the composition is an epoxy compound strength S, a diglycidyl ether compound or a dicarboxylic acid diglycidyl ester compound.

[3] The epoxy compound has the formula (1):

[Chemical 1]

(1)

1

Represents a nyl group or a benzyleno group. The composition for forming an antireflection film for lithography according to claim 1, wherein the composition is a compound represented by

[4] The antireflection film for lithography according to claim 1, wherein the nitrogen-containing aromatic compound is a triazine compound, a thiadiazole compound, or a pyrimidine compound having two hydroxyl groups or thiol groups. Forming composition.

[5] The composition for forming an antireflection film for lithography according to claim 1, wherein the crosslinkable compound is a nitrogen-containing compound having a nitrogen atom substituted with a hydroxymethyl group or an alkoxymethyl group. object.

6. The antireflection film-forming composition for lithography according to claim 1, wherein the crosslinking catalyst is an aromatic sulfonic acid compound.

[7] The composition for forming an antireflection film for lithography according to [1], further comprising a photoacid generator.

[8] A step of applying the antireflection film forming composition for lithography according to any one of claims 1 to 7 on a semiconductor substrate and baking to form an antireflection film, the antireflection film For manufacturing a semiconductor device including a step of forming a photoresist layer on a film, a step of exposing a semiconductor substrate covered with the antireflection film and the photoresist layer, and a step of developing the photoresist layer after the exposure Method for forming a photoresist pattern to be used.