TWI411622B - Anti-reflective coating-forming composition containing nitrogen-containing aromatic ring structure for lithography - Google Patents

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

a composition comprising an anti-reflection film formed by a lithography having a nitrogen-containing aromatic ring structure

The present invention relates to a composition for forming an antireflection film for use in lithography used in a lithography process for fabricating a semiconductor device. More specifically, a composition for forming an anti-reflection film for forming an anti-reflection film for lowering a photo resist lower layer of a reflection from a semiconductor substrate for reducing exposure light is used. Further, the present invention relates to a method of forming a photo resist pattern of a composition for forming an antireflection film using the lithography.

Conventionally, in the manufacture of a semiconductor device, microfabrication by lithography using photoresic is performed. The microfabrication is a film in which a photoresist is formed on a semiconductor substrate such as a silicon wafer, and the activity is irradiated through a mask pattern of a device depicted on the film. An active ray is used, and the obtained photoresist pattern is used as a protective film to perform an etching process of a semiconductor substrate. However, in recent years, due to the high integration of the device, the active light used has also progressed from the i-line (wavelength 365 nm), KrF (fluorene fluoride) excimer laser (wavelength 248 nm) to ArF. Short-wavelength of (argon fluoride) excimer laser (wavelength 193 nm). As the illumination from the substrate is reflected, it becomes a problem. Thus, a method of providing a bottom anti-reflective coating between a photoresist and a substrate has been widely studied.

In the antireflection film, an inorganic antireflection film such as titanium oxide or titanium nitride, and an organic antireflection film made of a light absorbing material and a polymer compound are known. The former requires a vacuum vapor deposition apparatus, a CVD (Chemical Vapor Deposition) apparatus, a sputtering apparatus, and the like at the time of film formation, whereas the latter is advantageous because it does not require special equipment. In the same molecule as described in the specification of U.S. Patent No. 5,919,599, an acrylic resin-based antireflection film having a hydroxyl group and a light-absorbing group which form a crosslinking substituent in the same molecule, and the same intramolecular composition as described in the specification of U.S. Patent No. 5,693,691 A novolak resin type antireflection film or the like which has a hydroxyl group and a light absorbing group which form a crosslinking substituent.

As an organic anti-reflection film, it is necessary to have physical properties, such as having a large absorbance for light used for exposure, and not causing intermixing with the photoresist (that is, insoluble in a photoresist solvent), The diffusion of the low molecular compound from the antireflection film to the photoresist of the upper layer, and the dry etching speed which is larger than the photoresist.

In recent years, in the lithography step using a KrF excimer laser or an ArF excimer laser, progress has been made in the miniaturization of the processing size, that is, the miniaturization of the formed photoresist pattern size. When the size of the photoresist pattern is miniaturized, it is necessary to prevent the photoresist from being thinned by a photoresist pattern or the like. Further, in the case where the film is used as a photoresist, it is necessary to suppress the film thickness of the photoresist layer in the removal step caused by etching in order to suppress the antireflection film used together. Development of an anti-reflection film for etching removal. That is, in order to make the etching removal step short-term, it is required to have a selection ratio of an anti-reflection film which is conventionally faster than the etching rate.

Further, the antireflection film must be a photoresist pattern capable of forming a good shape. In particular, it is necessary to form a photoresist pattern which does not have a hem shape at its lower portion. If the photoresist pattern has a hem shape, it will have a bad effect on the subsequent processing steps. Moreover, the types of photoresists used with the advancement of lithography are also increasing. Therefore, in order to respond to the use of diverse photoresists, development of new anti-reflection films is required.

At present, a composition for an antireflection film using a reaction product derived from an epoxy compound is known (for example, refer to Patent Document 1, Patent Document 2, and Patent Document 3). Also, well known to have three A composition for an antireflection film of a compound of a triketone ring structure (for example, refer to Patent Document 4).

Patent Document 1: U.S. Patent No. 6,670,425, Patent Document 2: Japanese Patent Laid-Open No. 2004-212907, Patent Document 3: International Publication No. 04/034435, Patent Document 4: International Publication No. 04/034148

It is an object of the present invention to provide a semiconductor which can be used for performing a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm) or a F ₂ (fluorine gas) excimer laser (wavelength 157 nm). The lithography of the lithographic step of the device is used to form a composition of the antireflective film.

Moreover, an object of the present invention is to provide a KrF excimer laser, an ArF excimer laser or a F ₂ excimer laser for micro-processing, which can effectively absorb reflected light from a substrate without causing a photoresist A mixture between layers, and an anti-reflection film having a faster dry etching speed than the photoresist, and a composition for forming an anti-reflection film. Further, a method of forming an antireflection film for lithography using the antireflection film and a method of forming a photoresist pattern are provided.

The inventors of the present invention have found that, as a result of intensive research, it has been found that the use of an epoxy compound having two glycidyl groups and a nitrogen-containing aromatic compound having two thiol groups or hydroxyl groups is used. The fact that the composition of the obtained reaction product is obtained by addition of a polgaddition reaction to form an excellent antireflection film is completed by the inventors.

That is, the first aspect of the present invention is a composition for forming an antireflection film for lithography, which comprises: comprising an epoxy compound having two glycidyl groups and having two thiol groups or hydroxyl groups; A reaction product obtained by an addition polymerization reaction between nitrogen-containing aromatic compounds, a crosslinkable compound, a crosslinking catalyst, and a solvent.

The second point is a composition for forming an antireflection film for lithography according to the first aspect, wherein the epoxy compound is a diglycidyl ether compound or a dicarboxylic acid diglycidyl ester compound.

The third point is a composition for forming an antireflection film for lithography according to the first point, wherein the epoxy compound is of the formula (1): (wherein, R ₁ represents a compound represented by an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 3 to 6 carbon atoms, a phenyl group or a benzyl group).

The fourth point is a composition for forming an antireflection film for lithography according to the first aspect, wherein the nitrogen-containing aromatic compound has two hydroxyl groups or thiol groups. (triazine) a compound, a thiadiazole compound or a pyrimidine compound.

The fifth point is a composition for forming an antireflection film for lithography according to the first aspect, wherein the crosslinkable compound is a nitrogen-containing compound having a nitrogen atom substituted with a methylol group or an alkoxymethyl group.

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

The seventh point is a composition for forming an antireflection film for lithography according to the first aspect, and further contains a photoinitiating acid generator.

The eighth aspect is a method for forming a photoresist pattern for use in the manufacture of a semiconductor device, characterized in that the lithography containing any one of the first to seventh points is coated with a composition for forming an antireflection film. a step of forming a photoresist layer on the semiconductor substrate by firing to form an anti-reflection film, and exposing the semiconductor substrate covered by the anti-reflection film and the photoresist layer to a step of exposing the semiconductor substrate The step of developing the photoresist layer after the exposure.

The present invention is for forming an anti-reflection capable of exhibiting high absorption for short-wavelength light, particularly KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm) or F ₂ excimer laser (wavelength 157 nm). The composition for the film. The obtained anti-reflection film can effectively absorb reflected light from the substrate.

According to the present invention, it is possible to provide an effective reflection of the reflected light from the semiconductor substrate without causing a mismatch with the photoresist layer when microfabrication using a KrF excimer laser and an ArF excimer laser or the like is performed. Reflective film.

According to the present invention, an antireflection film having an etching speed faster than that of light can be provided.

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

Best embodiment of the invention

The composition for forming an antireflection film for lithography of the present invention comprises an addition polymerization reaction between an epoxy compound having two glycidyl groups and a nitrogen-containing aromatic compound having two thiol groups or a hydroxyl group. The obtained reaction product, crosslinkable compound, crosslinking catalyst, and solvent. Further, the lithography of the present invention may contain a photo-initiated acid generator or the like for forming a composition of an anti-reflection film. Further, the ratio of the solid content in the composition for forming the antireflection film is not particularly limited as long as the components can be uniformly dissolved in the solvent, but is, for example, 0.5 to 50% by mass, or 1 to 30% by mass, or 3 to 25% by mass, or 5 to 15% by mass. Here, the solid content means the latter from which the solvent component is removed from the entire composition of the composition forming the antireflection.

The composition for forming an antireflection film for lithography of the present invention comprises an addition polymerization reaction between an epoxy compound having two glycidyl groups and a nitrogen-containing aromatic compound having two thiol groups or a hydroxyl group. The reaction product produced.

The epoxy compound is not particularly limited as long as it is a compound having two glycidyl groups.

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

The diglycidyl ether compound may, for example, be ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether or 1,6-hexanediol diglycidyl ether; 2-bis(2,3-epoxypropoxy)benzene, 1,3-bis(2,3-epoxypropoxy)benzene, 1,4-bis(2,3-epoxypropoxy) Benzene, and 2,2-bis[4-(2,3-epoxypropoxy)phenyl]propane, and the like. Further, the diglycidyl ether can be obtained by reacting a compound having two hydroxyl groups with a compound such as epichlorohydrin or glycidyl p-toluenesulfonate.

The dicarboxylic acid diglycidyl ester compound may, for example, be diglycidyl phthalate, diglycidyl terephthalate or 1,2-cyclohexanedicarboxylic acid diglycidyl ester, 1. 4-butanedicarboxylic acid diglycidyl ester, and 1,4-naphthalene dicarboxylic acid diglycidyl ester. Further, the dicarboxylic acid diglycidyl ester compound can be obtained by reacting a compound having two carboxyl groups with a compound of epichlorohydrin and glycidyl p-toluenesulfonate.

For the epoxy compound having two glycidyl groups, it is also exemplified that: (1): Expressed as a compound. In the formula (1), R ₁ represents an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 3 to 6 carbon atoms, a phenyl group or a benzyl group. The alkyl group is a methyl group, an ethyl group, an isopropyl group, a cyclohexyl group or the like. The alkenyl group is a propenyl group, a 2-butenyl group, a 4-pentenyl group or the like. Specific examples of the compound represented by the formula (1) include, for example, allyl diglycidyl trimeric isocyanic acid, methyl diglycidyl trimeric isocyanic acid, and isopropyl diglycidyl trimeric Cyanic acid, phenyl diglycidyl trimeric isocyanic acid, and benzyl diglycidyl trimeric isocyanic acid.

The epoxy compound having two glycidyl groups may, for example, be bis[4-(2,3-epoxypropylthio)phenyl]sulfide or bis(2,3-epoxypropyl). Sulfide, 1,3-diglycidyl-5,5-diethyl barbituric acid, 1,3-diglycidyl-5-phenyl-5-ethyl barbituric acid And compounds such as 1,3-diglycidyl-5,5-dimethylhydantoin.

The nitrogen-containing aromatic compound for the reaction product of the addition polymerization reaction contained in the composition for forming the antireflection film of the present invention for producing the lithography of the present invention, as long as it has two thiol groups or hydroxyl groups. The nitrogen-containing aromatic compound is not particularly limited and can be used.

For nitrogen-containing aromatic compounds, three having a hydroxyl group or a thiol group can be used. a compound, a thiadiazole compound or a pyrimidine compound.

three For the compound, it can be exemplified by 2-dimethylamino-1,3,5-three -4,6-dithiol, 2-diethylamino-1,3,5-three -4,6-dithiol, 2-dibutylamino-1,3,5-three -4,6-dithiol, 2-methoxy-1,3,5-three -dithiol, 2-dibutylamino-1,3,5-three -4,6-dithiol, 2-methylthio-1,3,5-three -4,6-dithiol, 2-N-anilino-1,3,5-three -4,6-dithiol, and dicyclohexylamino-1,3,5-three -4,6-dithiol and the like.

As the thiadiazole compound, a test agent (bismuthiol: 2,5-dimercapto-1,3,4-thiadiazole) and 5,5'-(ethylenedithio)-double can be exemplified. (1,3,4-thiazole-2-thiol) and the like.

The pyrimidine compound may, for example, be 2,6-dithioindole, 2,8-dimercapto-6-hydroxyindole, pyrimidine-2,4-dithiol or 5,6,7,8-tetrahydrogen. Quinazoline-2,4-dithiol, 5-(4-chloro-phenyl)pyrimidine-4,6-dithiol, 5-phenyl-pyrimidine-4,6-dithiol, 5- Methoxy-4,6-dithiol, 2,4-dimercapto-5-methylpyrimidine, and 2,6-dimercapto-7-methylpyrimidine.

An epoxy compound having two glycidyl groups and a nitrogen-containing aromatic compound having two thiol groups or hydroxyl groups for use in producing the reaction product contained in the composition for forming an antireflection film for lithography of the present invention The addition polymerization reaction between the compounds may be carried out from solvents such as benzene, toluene, xylene, ethyl lactate, butyl lactate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, and N-methylpyrrolidone. The reaction time is 0.1 to 100 hours, and the reaction temperature is suitably selected from the range of 20 ° C to 200 ° C to carry out. For example, conditions can be appropriately selected from the reaction time of 5 to 30 hours and the reaction temperature of 80 ° C to 150 ° C to carry out the conditions. Further, in this reaction, a quaternary ammonium salt such as benzyltriethylammonium chloride, tetrabutylammonium chloride or tetraethylammonium bromide may be used as a catalyst. When a catalyst is used, the total mass of the compound to be used can be used, for example, in the range of 0.001 to 30% by mass, or 0.01 to 5% by mass, or 0.1 to 3% by mass.

In the addition polymerization reaction, the epoxy compound having two glycidyl groups and the nitrogen-containing aromatic compound having two thiol groups or hydroxyl groups may be used alone or in combination of two or more compounds. use.

The ratio of the epoxy compound having two glycidyl groups used in the addition polymerization reaction to the nitrogen-containing aromatic compound having two thiol groups or hydroxyl groups is based on an epoxy compound: a molar of a nitrogen-containing aromatic compound The ratio is, for example, 3:1 to 1:3, or 3:2 to 2:3, or 4:3 to 3:4, or 1:1.

In the addition polymerization reaction between two glycidyl groups and a nitrogen-containing aromatic compound having two thiol groups or hydroxyl groups, the reaction between the thiol group or the hydroxyl group and the epoxy group is continuous between the compounds. occur. As a result, a high molecular weight reaction product is obtained. A reaction product formed by an addition polymerization reaction between an epoxy compound having two glycidyl groups and a nitrogen-containing aromatic compound having two thiol groups or a hydroxyl group is a repeating unit structure and has a formula ( 2) A high molecular weight compound of the structure indicated.

In the formula (2), R is a portion in which two glycidyl groups are removed in an epoxy compound having two glycidyl groups. For example, when the epoxy compound having two glycidyl groups is ethylene glycol diglycidyl ether, R becomes -OCH ₂ CH ₂ O-. Further, in the formula (2), X represents an oxygen atom or a sulfur atom. The Ar system corresponds to a portion of an aromatic ring structure having a nitrogen-containing aromatic compound having two thiol groups or a hydroxyl group. For example, a nitrogen-containing aromatic compound having two thiol groups or a hydroxyl group is 2-dimethylamino-1,3,5-three In the case of -4,6-dithiol, X represents a sulfur atom, and Ar represents 2-dimethylamino-1,3,5-three. structure.

The reaction formed by the addition polymerization reaction between the compound having two glycidyl groups contained in the composition for forming the antireflection film and the nitrogen-containing aromatic compound having a thiol group or a hydroxyl group by the lithography of the present invention The molecular weight of the product is, for example, from 1,000 to 100,000, or from 2,000 to 50,000, or from 3,000 to 20,000, based on the weight average molecular weight.

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

In the composition for forming an antireflection film of the lithography of the present invention, the right is isolated from the reaction product and used. Further, the reaction solution containing the reaction product may be directly used as a composition for forming an antireflection film for the lithography of the present invention, not separately from the reaction product.

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

For the crosslinkable compound, a reaction which can be formed by an addition polymerization reaction with an epoxy compound having two glycidyl groups and a nitrogen-containing aromatic compound having two thiol groups or a hydroxyl group can be used. The substituent contained in the product contains two or more substituents, for example, two to six or two to four compounds.

When such a crosslinkable compound is used, it is possible to react between the reaction product and the crosslinkable compound at the time of firing in forming the antireflection film, and the formed antireflection film has a crosslinked structure. As a result, the antireflection film becomes solid and becomes low in solubility in an organic solvent using a solution which is a photoresist which is applied to the upper layer. The substituent which can react with the hydroxyl group contained in the reaction product may, for example, be a trimeric isocyanate group, an epoxy group, a hydroxymethylamino group or an alkoxymethylamino group. Therefore, a compound having two or more such substituents, for example, two to six, or two to four, can be used as the crosslinkable compound.

In the lithographic composition of the present invention, the crosslinkable compound contained in the composition for forming the antireflection film may, for example, be a nitrogen-containing compound having a nitrogen atom substituted with a methylol group or an alkoxymethyl group. That is, a nitrogen-containing compound having a nitrogen atom substituted with a group such as a methylol group, a methoxymethyl group, an ethoxymethyl group, a butoxymethyl group, and a hexyloxymethyl group.

Specifically, hexamethoxymethyl melamine, tetramethoxymethyl benzoguanamine, guanamine, 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-tetra(methoxy) Methyl)urea, 1,3-bis(hydroxymethyl)-4,5-dihydroxy-2-imidazolidinone, and 1,3-bis(methoxymethyl)-4,5-dimethoxy A nitrogen-containing compound such as 2-imidazolidinone.

As the crosslinkable compound, a methoxymethyl type melamine compound manufactured by Mitsui Setek (trade name: Semel 300, Semel 301, Semel 303, Semel 350) can be exemplified. , butanoxymethyl melamine compound (trade name Mecote 506, McCort 508), glycoluril compound (trade name Semel 1170, budalinker 1174) and other compounds, methylated urea resin (trade name UFR65), butylated urea resin (trade name UFR300, U-VAN10S60, U-VAN10R, U-VAN11HV), urea/formaldehyde resin manufactured by Dainippon Ink Chemical Industry Co., Ltd. (high condensation type, product name Kamin Commercially available compounds such as J-300S, Bikamin P-955, and Bikamin N). Further, a compound obtained by condensing a hydrogen atom of such an amine group with a melamine compound, a urea compound, a glycoluril compound, and a benzoguanamine compound substituted with a methylol group or an alkoxymethyl group may also be exemplified: A high molecular weight compound produced from a melamine compound (trade name Semel 303) and a benzoguanamine compound (trade name Semel 1123) as described in U.S. Patent No. 6,323,310.

Further, as the crosslinking compound, N-methylol acrylamide, N-methoxymethylmethacrylamide, N-ethoxymethyl decylamine, N-butoxymethylmethyl group can be used. A polymer prepared from a acrylamide compound or a methacrylamide compound substituted with a methylol group or an alkoxymethyl group, such as acrylamide. Such a polymer may, for example, be a poly(N-butoxymethyl acrylamide), a copolymer of N-butoxymethyl acrylamide and styrene, or N-methylol methacrylamide. Copolymer with methyl methacrylate, copolymer of N-ethoxymethyl methacrylamide and benzyl methacrylate, and N-butoxymethyl acrylamide and benzyl methacrylate Copolymer with 2-hydroxypropyl methacrylate, etc.

The crosslinkable compound may be used alone or in combination of two or more.

The ratio of the crosslinkable compound in the solid content of the composition for forming the antireflection film of the present invention is, for example, 0.1 to 40% by mass, or 3 to 35% by mass, or 5 to 25% by mass.

The composition for forming an antireflection film for lithography of the present invention contains a crosslinking catalyst. If a cross-linking catalyst is used, the reaction of the crosslinkable compound can be promoted.

For the cross-linking catalyst, p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium p-toluenesulfonic acid, salicylic acid, camphorsulfonic acid, sulfosalicylic acid, citric acid, benzoic acid, and hydroxyl group can be used. An acid compound such as benzoic acid.

For the cross-linking catalyst, an aromatic sulfonic acid compound can be used. Specific examples of the aromatic sulfonic acid compound include p-toluenesulfonic acid, pyridinium p-toluenesulfonic acid, sulfosalicylic acid, 4-chlorobenzenesulfonic acid, 4-hydroxybenzenesulfonic acid, and benzene disulfonate. Acid, 1-naphthalenesulfonic acid, pyridinium-1-naphthalenesulfonic acid, and the like.

The cross-linking catalyst may be used alone or in combination of two or more.

The ratio of the cross-linking catalyst to the solid content of the composition for forming the anti-reflection film of the present invention is, for example, 0.1 to 10% by mass, or 0.2 to 5% by mass, or 0.5 to 5% by mass.

The composition for forming an antireflection film for lithography of the present invention may contain a photoinitiating acid generator. The photoinitiator generates an acid which generates an acid upon exposure to a photoresist. Thus, the adjustment of the acidity of the antireflection film can be performed. This is a method for matching the acidity of the antireflection film to the acidity of the photoresist of the upper layer. Moreover, the adjustment of the acidity of the antireflection film can also adjust the pattern shape of the photoresist formed by the upper layer.

The photo-initiating acid generator may, for example, be an onium salt compound, a sulfonium imine compound, or a disulfonyldiazomethane compound.

The onium salt compound may, for example, be diphenyliodonium hexafluorophosphate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluorobutanesulfonate or diphenyliodine.鎓Perfluoro-n-octane sulfonate, diphenyl iodonium sulfonate, bis(4-tert-butylphenyl) iodonium sulfonate, and bis(4-tert-butylphenyl) iodonium Iodine salt compound such as fluoromethanesulfonate, and sulfonium hexafluoroantimonate, triphenylsulfonium nonafluorobutane sulfonate, trifluoro camphorsulfonate, and triphenylsulfonium An onium salt compound such as trifluoromethanesulfonate or the like.

The sulfonimide compound may, for example, be N-(trifluoromethanesulfonyloxy)arene, N-(nonafluoro-n-butanesulfonyloxy)arene, N-( camphorsulfonate) Oxygen) amber imine and N-(trifluoromethanesulfonyloxy)naphthylimine.

The disulfonyldiazomethane compound may, for example, be bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane or bis(phenylsulfonyl) Nitrogen methane, bis(p-toluenesulfonyl)diazomethane, bis(2,4-dimethylphenylsulfonyl)diazomethane, and methylsulfonyl p-toluenesulfonyldiazomethane.

The photoinitiator may be used alone or in combination of two or more.

When the photo-initiated acid generator is contained in the composition for forming an anti-reflection film according to the present invention, the content thereof is, for example, 0.01 to 5% by mass, or 0.1 to 3% by mass, or 0.5 to 5% in the solid content. 2% by mass.

In the composition for forming an antireflection film for lithography of the present invention, a surfactant, a rheology modifier, an adhesion aid, and the like may be added as needed. The surfactant is effective for suppressing occurrence of pin holes or striations. The rheology modifier is for improving the fluidity of the composition forming the antireflection film, particularly in the step of firing, in order to improve the adhesion of the composition forming the antireflection film inside the hole. . The adhesion aid is used to improve the adhesion between the semiconductor substrate or the photoresist and the antireflection film, and is particularly effective for suppressing peeling of the photoresist during development.

The surfactant may, for example, be a polyoxyethylene alkyl ether such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene cetyl ether or polyoxyethylene oleyl ether; Polyoxyethylene alkyl aryl ethers such as oxyethylene octyl phenol ether and polyoxyethylene nonyl phenol ether; polyethylene oxide. Polypropylene oxide block copolymers; sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan monooleate, Sorbitol fatty acid esters such as sorbitan trioleate, sorbitan tristearate; polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate Non-ionic such as polyoxyethylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan trioleate, polyoxyethylene sorbitan tristearate Surfactant; trade name Effort EF301, EF303, EF352 (made by Dong Chemical Products Co., Ltd.), trade name Mecca F171, F173, R-08, R-30 (Daily Ink Chemical Industry Co., Ltd. )), Fullerate FC430, FC431 (Sumitomo 3M (share) system), trade name Xugete AG710, Schaffron S-382, SC101, SC102, SC103, SC104, SC105, SC106 (Asahi Glass Co., Ltd.) A fluorine-based surfactant, and an organic siloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.). These surfactants may be used singly or in combination of two or more. When a surfactant is contained in the composition for forming an antireflection film of the present invention, the content thereof is 0.0001 to 5% by mass, or 0.001 to 2% by mass in the solid content.

The solvent used for the composition for forming the antireflection film for lithography of the present invention can be used as long as it is a solvent capable of dissolving the solid component. Such a solvent may, for example, be ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl fibrin acetate, ethyl fibrin acetate, diethylene glycol monomethyl Ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, propylene glycol propyl ether, toluene, xylene, methyl ethyl ketone, cyclopentanone, Cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropanoate, ethyl ethoxyacetate, ethyl hydroxyacetate, methyl 2-hydroxy-3-methylbutanoate, 3 -methyl methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl pyruvate, ethyl pyruvate, ethyl acetate, acetic acid Butyl ester, ethyl lactate, and butyl lactate. These solvents may be used singly or in combination of two or more. Further, a high boiling point solvent such as propylene glycol monobutyl ether or propylene glycol monobutyl ether acetate may be used.

Hereinafter, the use of the composition for forming an antireflection film for lithography of the present invention will be described.

Applying on a semiconductor substrate (for example, a tantalum wafer substrate, a tantalum/yttria-coated substrate, a tantalum nitride substrate, and an ITO (indium tin oxide) substrate), using a spin coater, an applicator, or the like Method The composition for forming an antireflection film of the present invention is applied and then fired to form an antireflection film. The firing conditions may be appropriately selected from the range of firing temperature of 80 ° C to 250 ° C and firing time of 0.3 to 60 minutes. The firing temperature is preferably from 150 ° C to 250 ° C and the firing time is from 0.5 to 5 minutes. Here, the film thickness of the antireflection film formed is, for example, 0.01 to 3.0 μm, preferably 0.03 to 1.0 μm, or 0.05 to 0.5 μm, or 0.05 to 0.2 μm, for example.

Next, on the antireflection film, a layer of photoresist is formed. In the formation of the photoresist layer, the photoresist composition solution can be applied to the antireflection film by a known method and fired.

The photoresist which is applied to the antireflection film of the present invention is not particularly limited as long as it can be used for light exposure to be used for exposure. Any of a negative photoresist and a positive photoresist can be used. There are: a photoresist of a novolac resin and a 1,2-naphthoquinonediazide sulfonate, which is formed by a binder and a photo-initiated acid which are decomposed by an acid and have a base for accelerating the dissolution rate of the alkali. The chemically amplified photoresist, the chemically amplified photoresist formed by the low molecular compound which is decomposed by acid and accelerates the alkali dissolution rate of the photoresist, and the alkali-inducing binder and the photoinitiated acid generator, and the acid The binder which decomposes and accelerates the alkali dissolution rate and the low-molecular compound which decomposes by the acid and accelerates the alkali dissolution rate, and the photo-initiated acid generator form a chemically amplified photoresist. Also exemplified; such as the Society of Photographic Instrumentation Engineers (Proc. SPIE), Vol. 3999, pp. 330-334 (published in 2000), Society of Photographic Instrumentation Engineers, Vol. 3999, pp. 357-364 (published in 2000), or the fluorine atomic polymer system photoresist described in Journal of the Society of Photographic Instrumentation Engineers, Vol. 3999, pp. 365-374 (published in 2000).

Next, exposure is performed through a predetermined mask. At the time of exposure, a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (wavelength 193 nm), and an F ₂ excimer laser (wavelength 157 nm) can be used. After exposure, if necessary, post-exposure heating (bake treatment after post exposure bake exposure) can also be performed. The post-exposure heating can be appropriately selected from the range of a temperature of 70 ° C to 150 ° C and a time of 0.3 to 10 minutes.

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

The developing solution may, for example, be an aqueous solution of an alkali metal hydroxide such as potassium hydroxide or sodium hydroxide, or a tetraammonium hydroxide such as tetramethylammonium hydroxide, tetraethylammonium hydroxide or choline. An aqueous alkaline solution such as an aqueous solution, an amine solution such as ethanolamine, propylamine or ethylenediamine. For the developing liquid, a general-purpose 2.38 mass% aqueous solution of tetramethylammonium hydroxide can be used. Further, a surfactant may be added to the developing solution. The development conditions can be appropriately selected from a temperature of 5 to 50 ° C and a time of 10 to 300 seconds.

Then, the photoresist pattern thus formed is used as a protective film to remove the antireflection film and process the semiconductor substrate. For the removal of the antireflection film, tetrafluoromethane, perfluorocyclobutane (C ₄ F ₈ ), perfluoropropane (C ₃ F ₈ ), trifluoromethane, carbon monoxide, argon, oxygen, nitrogen, hexafluoride can be used. Gases such as sulfur, difluoromethane, nitrogen trifluoride, and chlorine trifluoride are used.

A planarization film or a gap filling material layer may be formed on the semiconductor substrate before the composition for forming the antireflection film is formed by using the lithography of the present invention to form the antireflection film. When a semiconductor substrate having a hole or a semiconductor substrate having a large height difference is used, it is preferable to form a planarizing film or a gap-filling material layer before forming anti-reflection.

Moreover, the semiconductor substrate to which the composition for forming an antireflection film of the present invention is applied may be an inorganic antireflection film formed by a CVD method, or an antireflection film of the present invention may be formed thereon.

Further, the anti-reflection film formed by the composition for forming an anti-reflection film of the lithography of the present invention can also be used as a layer for preventing interaction between the substrate and the photoresist, and a material for preventing photoresist or for light-proofing. The layer of the substance generated on the substrate during the exposure is resistant to the diffusion of the substance generated from the substrate during the firing to the upper layer resist, and the poisoning of the photoresist layer caused by the dielectric layer of the semiconductor substrate is reduced. It is used for a barrier layer or the like of a poisoning effect.

Further, when the antireflection film formed of the composition for forming an antireflection film of the present invention is applied to a substrate on which a via hole is formed for use in a dual damascene process, It can be used as a buried material that can fill a via hole in a gap-free manner. Further, it is also possible to use a planarizing material as a surface for flattening the surface of the semiconductor substrate having irregularities.

In the following, the present invention will be more specifically described by the examples, but the invention is not limited thereto.

Example Synthesis Example 1

Add 2-dimethylamino-4,6-dithiol-1,3,5-three to 21.5 g of propylene glycol monomethyl ether 2.25 g, ethylene glycol diglycidyl ether 2.00 g, and 0.14 g of benzyltriethylammonium chloride as a catalyst were reacted under reflux for 24 hours to obtain a solution containing a reaction product. The GPC (gel permeation chromatography) analysis of the obtained reaction product was carried out, and the weight average molecular weight was 5,800 in terms of standard polystyrene. The obtained reaction product can be estimated to have a structure in which a repeating unit represented by the formula (3) is present.

Synthesis Example 2

Add 2-dibutylamino-4,6-dithiol-1,3,5-three to propylene glycol monoethyl ether 30.71g (Sanxie Chemical Co., Ltd., product name: Kyrgyzstan BD) 3.53g, terephthalic acid diglycidyl ether 4.00g, and 0.15g of benzyltriethylammonium chloride as a catalyst, after reflow The reaction was carried out for 24 hours to obtain a solution containing the reaction product. The GPC analysis result of the obtained reaction product was carried out, and the weight average molecular weight was 7,000 in terms of standard polystyrene. The obtained reaction product can be estimated to have a structure in which a repeating unit represented by the formula (4) can be used.

Synthesis Example 3

Add 2-dibutylamino-4,6-dithiol-1,3,5-three to propylene glycol monomethyl ether 24.45g (Sanxiehuacheng (share) system, the product name JI shi BD) 2.99g, monoaryl diglycidyl trimeric isocyanate 3.00g, and 0.14g of benzyl triethylamine chloride as a catalyst The reaction was carried out under reflux for 24 hours to obtain a solution containing the reaction product. The GPC analysis result of the obtained reaction product was carried out, and the weight average molecular weight was 15,400 in terms of standard polystyrene. The obtained reaction product is presumed to have a structure in which a repeating unit represented by the formula (5) is present.

Synthesis Example 4

Add 2-thiomethyl-4,6-dithiol-1,3,5-three to 63.77g of propylene glycol monomethyl ether 5.54 g, 10.00 g of monoaryl diglycidyl tripolyisocyanate, and 0.40 g of benzyltriethylammonium chloride as a catalyst were reacted under reflux for 24 hours to obtain a solution containing a reaction product. The GPC analysis of the obtained reaction product was carried out, and the weight average molecular weight was 15,500 in terms of standard polystyrene. The obtained reaction product can be estimated to have a structure of a repeating unit which can be represented by (6).

Synthesis Example 5

Adding 4.50 g of bismuthiol, 6.68 g of ethylene glycol diglycidyl ether, and 0.18 g of benzyltriethylammonium chloride as a catalyst to 43.80 g of propylene glycol monomethyl ether, and reacting under reflux A solution containing the reaction product was obtained for 24 hours. The GPC analysis result of the obtained reaction product was carried out, and the weight average molecular weight was 4,500 in terms of standard polystyrene. The obtained reaction product is presumed to have a structure of a repeating unit which can be represented by (7).

Example 1

To 3.92 g of the solution obtained in the above Synthesis Example 1, 2.50 g of propylene glycol monomethyl ether, 13.3 g of ethyl lactate, and tetramethoxymethyl glycoluril (manufactured by Mitsui Setek Co., Ltd., trade name: budadolin 1174) were mixed. 0.20 g and 0.02 g of pyridinium p-toluenesulfonic acid were prepared as a 5 mass% solution. Then, it was filtered using a polyethylene microfilter having a sieve opening of 0.05 μm to prepare a solution for forming a composition of the antireflection film by lithography.

Examples 2 to 5

In the same manner as in Example 1, in the 3.92 g of the solutions obtained in Synthesis Examples 2 to 5, 2.66 g of propylene glycol monoethyl ether, 13.3 g of ethyl lactate, and tetramethoxymethyl glycoluril (triple dextran ( The product was made into a 5% by mass solution of 0.20 g of palladium ketone 1174) and 0.02 g of pyridinium p-toluenesulfonic acid. Then, it was filtered using a polyethylene microfilter having a sieve opening of 0.05 μm to prepare a solution for forming a composition of the antireflection film by lithography.

Solvent dissolution test

The solutions obtained in Examples 1 to 5 were each applied onto a tantalum wafer substrate using a spin coater. Then, it was baked at 205 ° C for 1 minute on a hot plate to form an antireflection film (film thickness: 0.078 μm). This antireflection film was immersed in ethyl lactate and propylene glycol monomethyl ether using a solvent which is a photoresist to confirm the fact that it was insoluble in the solvent. Further, it was immersed in an alkaline developing solution for developing a photoresist to confirm the fact that it was insoluble.

Optical parameter test

The solutions obtained in Examples 1 to 5 were each applied onto a tantalum wafer substrate using a spin coater. Then, it was baked at 205 ° C for 1 minute on a hot plate to form an antireflection film (film thickness: 0.078 μm). Then, using a ellipsometer (manufactured by JAWoollan Co., Ltd., VUV-VASE VU-302), the refractive index (n) value and the extinction coefficient of the antireflection film at a wavelength of 248 nm and a wavelength of 193 nm were measured. ) (k value). The results are shown in Tables 1 and 2.

Determination of dry etching speed

An antireflection film was formed on the tantalum wafer substrate by using the solutions of Examples 1 to 5 in the same manner as above. Then, in the case of using Japan Science (shares) manufactured by RIE (reactive ion etching system, a reactive ion etching systems) ES401, was used as dry etching gas CF ₄ conditions, the measurement of these anti-reflection film dry etching rate.

Further, a photoresist solution (manufactured by Sumitomo Chemical Co., Ltd., trade name PAR710) was applied onto a tantalum wafer substrate by a spin coater, and fired at a temperature of 90 ° C for 1 minute on a hot plate to form a photoresist. Floor. Then, the dry etching rate of the photoresist PAR710 was measured under the condition that CF ₄ was used as a dry etching gas using the RIE system ES401 manufactured by Nippon Scientific Co., Ltd. A comparison of the dry etching rates of the antireflection films obtained in Examples 1 to 5 and the photoresist was carried out. The results are shown in Tables 1 and 2.

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

Further, in Tables 1 and 2, the selection ratio indicates the dry etching rate of the antireflection film formed by each of the examples when the dry etching rate of the photoresist PAR710 is 1.00.

As is apparent from Tables 1 and 2, the antireflection film obtained from the composition for forming an antireflection film of the present invention has an effective refractive index and extinction coefficient for light having wavelengths of 248 nm and 193 nm. Moreover, the fact that the photoresist has a relatively fast etching speed is known.

Claims (5)

A composition for forming an antireflection film for lithography, comprising: a diglycidyl ether compound, a dicarboxylic acid diglycidyl ester compound or a compound of the formula (1) and three having two thiol groups or hydroxyl groups a reaction product obtained by an addition polymerization reaction between a compound, a thiadiazole compound or a pyrimidine compound, a crosslinkable compound, a crosslinking catalyst, and a solvent; Formula (1): (wherein R ₁ represents an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 3 to 6 carbon atoms, a phenyl group or a benzyl group). The composition for forming an antireflection film for lithography according to the first aspect of the patent application, wherein the crosslinkable compound is a nitrogen-containing compound having a nitrogen atom substituted with a methylol group or an alkoxymethyl group. The lithography of the first aspect of the patent application form a composition for forming an antireflection film, wherein the crosslinking catalyst is an aromatic sulfonic acid compound. The lithography of the first aspect of the patent application form a composition for forming an antireflection film, which further contains a photoinitiating acid generator. A method for forming a photoresist pattern for use in the manufacture of a semiconductor device, comprising: coating a composition for forming an antireflection film with a lithography according to any one of claims 1 to 4 to a semiconductor a step of forming an anti-reflection film on the substrate, forming a photoresist layer on the anti-reflection film, and exposing the semiconductor substrate covered by the anti-reflection film and the photoresist layer to the exposure The step of developing the photoresist layer is then performed.