TW201314371A - Resist underlayer film forming composition containing polyhydroxy benzene novolak resin - Google Patents

Abstract

The invention provides a resist underlayer film forming composition which is provided with heat resistance and pattern bending resistance that are required for use in a lithography process for the production of semiconductor devices. A resist underlayer film forming composition for lithography, which contains a polymer having a unit structure represented by formula (1). (In formula (1), A represents a hydroxy group-substituted phenylene group that is derived from a polyhydroxybenzene, and B represents a monovalent fused aromatic hydrocarbon ring group wherein two to six benzene rings are fused.) In this connection, A is a hydroxy group-substituted phenylene group which is derived from catechol, resorcinol, hydroquinone, pyrogallol, hydroxyquinol or phloroglucinol; the fused aromatic hydrocarbon ring group represented by B is a naphthalene ring group, an anthracene ring group or a pyrene ring group; and the fused aromatic hydrocarbon ring group represented by B comprises, as a substituent, a halogen group, a hydroxy group, a nitro group, an amino group, a carboxyl group, a carboxylic acid ester group, a nitrile group, or a combination of two or more of these groups.

Description

Photoresist underlayer film forming composition containing polyhydroxy phenol novolak resin

The present invention relates to a photoresist formation underlayer film forming composition effective for processing a semiconductor substrate, and a photoresist pattern forming method for forming a composition using the photoresist underlayer film, and a method of manufacturing a semiconductor device.

In the past, in the manufacture of semiconductor devices, the photoresist composition was microfabricated by lithography. The microfabrication process forms a thin film of a photoresist composition on a substrate to be processed such as a tantalum wafer, and transmits an active light such as an ultraviolet ray through a reticle pattern on which a semiconductor device is drawn, and is subjected to imaging. And the obtained photoresist pattern is used as a protective film to etch a processing method of a substrate to be processed such as a germanium wafer. In recent years, as semiconductor devices have become more integrated, the active light rays used tend to have a shorter wavelength from the KrF excimer laser (wavelength 248 nm) toward the ArF excimer laser (wavelength 193 nm). Along with this, the influence of the scattered light or the standing wave of the active light from the substrate becomes a big problem, and thus an extensive anti-reflection film is disposed between the photoresist and the substrate to be processed (bottom anti-reflective coating, Bottom Anti-Reflective Coating: BARC) ) method.

In the future, when the photoresist pattern is miniaturized, there is a problem of resolution or a problem that the photoresist pattern collapses after development. Therefore, it is desired to form a thin film of photoresist. However, the thinning of the photoresist means that it is difficult to obtain a sufficient photoresist pattern thickness in the substrate processing. Therefore, not only the photoresist pattern has a function as a mask for processing the substrate, but also needs to be in the photoresist and the processed semiconductor. Between substrates The formed photoresist underlayer film also has a function as a function of a mask during substrate processing. Unlike the conventional high etch rate (fast etch rate) photoresist underlayer film used as the photoresist for this process, it is required to have a lower ratio of the dry etching rate to the photoresist, and a photoresist for the lithography. The lithographic photoresist underlayer film having a lower than dry resist etch rate than the photoresist is selected as the lithographic photoresist underlayer film or a selection ratio of dry etching speed smaller than that of the semiconductor substrate.

As the polymer used in the above-mentioned photoresist underlayer film forming composition, a novolak resin of phenol, resorcin, naphthol, and benzaldehyde or furfural is disclosed (see Patent Document 1).

Further, the polymer used in the composition for forming a resist underlayer film is a novolac resin obtained by using a hydroxy group or an aldehyde group or a naphthalene and an aqueous formaldehyde solution (see Patent Document 2).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] JP-A-2005-114921

[Patent Document 2] JP-A-2010-117629

An object of the present invention is to provide a photoresist underlayer film forming composition for use in a lithography process for fabricating a semiconductor device. Further, the subject of the present invention is to provide an excellent photoresist pattern which does not cause mutual mixing with a photoresist, and has a selection ratio of dry etching speed close to the photoresist, and a lower layer of lithography photoresist. The lithographic photoresist underlayer film having a film having a dry etching rate smaller than that of the photoresist is selected as the lithographic underlayer film or a dry etching rate smaller than that of the semiconductor substrate to be processed. Further, an object of the present invention is to provide a photoresist underlayer film which has a function of providing a conventional antireflection film which can effectively absorb the reflected light from a substrate, when irradiation light having a wavelength of 248 nm, 193 nm, or 157 nm is used for microfabrication. The lithography uses a photoresist underlayer film. Accordingly, an object of the present invention is to provide a photoresist underlayer film forming composition for forming a photoresist underlayer film which also has heat resistance. Further, an object of the present invention is to provide a method for forming a photoresist pattern using a photoresist underlayer film forming composition and a method for manufacturing a semiconductor device.

A first aspect of the present invention is a lithographic underlayer film forming composition comprising a polymer having a repeating unit structure represented by the formula (1):

(In the formula (1), A represents a phenyl group derived from a hydroxy group substituted by a hydroxy group, and B represents a valence condensed aromatic hydrocarbon ring group in which 2 to 6 benzene rings are condensed).

The second viewpoint is the photoresist underlayer film forming composition described in the first aspect, wherein A is a benzene-substituted benzene derived from benzenediol or benzenetriol base.

The third viewpoint is the photoresist underlayer film forming composition described in the first aspect, wherein A is derived from catechol, resorcin, hydroquinone, pyrogallol, pyrogallol, or phloroglucinol. (phloroglucinol) is a phenyl group substituted by a hydroxy group.

The fourth aspect is the photoresist underlayer film forming composition described in any one of the first to third aspects, wherein the condensed aromatic hydrocarbon ring group of B is a naphthalene ring group, an anthracene ring group or an anthracene ring group.

The fifth aspect is the photoresist underlayer film forming composition described in any one of the first to fourth aspects, wherein the condensed aromatic hydrocarbon ring group of B has a halogen group, a hydroxyl group, a nitro group, an amine group, a carboxyl group, A carboxylate group, a nitrile group, or a combination thereof is used as a substituent.

A sixth aspect is the photoresist underlayer film forming composition described in any one of the first to fifth aspects, which further comprises a crosslinking agent.

The seventh aspect is the photoresist underlayer film forming composition described in any one of the first to sixth aspects, which further comprises an acid and/or an acid generator.

The eighth aspect is a photoresist underlayer film obtained by applying a photoresist underlayer film forming composition described in any one of the first to seventh aspects to a semiconductor substrate and firing it.

A ninth aspect is a method for forming a photoresist pattern for semiconductor manufacturing, comprising applying a photoresist underlayer film forming composition described in any one of the first to seventh aspects to a semiconductor substrate and burning the same. The step of forming an underlayer film.

A tenth aspect is a method of fabricating a semiconductor device, comprising a step of coating a photoresist underlayer film forming composition onto a semiconductor substrate and firing it to form a lower layer film as described in any one of the first to seventh aspects, and forming a photoresist film on the underlayer film, using a step of forming a photoresist pattern on the photoresist film by irradiation and development of light or electron beams, a step of etching the underlayer film by the photoresist pattern, and processing the semiconductor substrate by using the patterned underlayer film step.

An eleventh aspect is a method of producing a semiconductor device, comprising: coating a photoresist underlayer film forming composition described in any one of the first to seventh aspects on a semiconductor substrate and firing to form an underlayer film; a step of forming a hard mask on the underlayer film; further forming a photoresist film on the hard mask; forming a photoresist pattern on the photoresist film by irradiation or development of light or electron beam a step of etching the hard mask by the photoresist pattern; a step of etching the underlayer film by using a patterned hard mask; and a step of processing the semiconductor substrate by using the patterned underlayer film.

A twelfth aspect is the manufacturing method according to the eleventh aspect, wherein the hard mask is formed by vapor deposition of a coating material or an inorganic material of an inorganic material.

The photoresist underlayer film forming composition of the present invention does not cause mutual mixing of the upper layer portion of the photoresist underlayer film and the layer of the photoresist layer coated thereon, and can form a pattern shape of good photoresist.

Moreover, the photoresist underlayer film forming composition of the present invention can also impart effective inhibition The performance of reflection from the substrate can also have the effect of being an anti-reflection film of exposed light.

In recent years, as the photoresist pattern is miniaturized, thinning of the photoresist for preventing collapse after photo resist pattern development is performed. In the process of using the photoresist of the film, there is a step of transferring the photoresist pattern onto the underlying film by etching, and performing the substrate processing by using the underlying film of the pattern transfer as a mask, or repeating the process The transfer pattern is used on the layer film under the pattern transfer, and the etching gas having the composition of different gases of the etching gas used in the previous pattern transfer is used, and the pattern is transferred to the film of the lower layer, and finally The process of substrate processing is performed.

The photoresist underlayer film forming composition of the present invention and the underlayer film obtained from the composition are particularly effective for the process of repeating the pattern transfer, and the photoresist underlayer film of the present invention can be used for processing a substrate (for example, heat on a substrate) A film having a sufficient etching resistance, such as a hafnium oxide film, a tantalum nitride film, or a polyfluorene film.

Moreover, the photoresist underlayer film forming composition of the present invention can provide a selection ratio of a dry etching rate close to the photoresist, a selection ratio of a dry etching rate smaller than the photoresist, or a selection ratio of a dry etching speed smaller than that of the semiconductor substrate. Excellent photoresist underlayer film.

Therefore, the photoresist underlayer film of the present invention can be used as a planarization film, a photoresist underlayer film, a photoresist film of a photoresist layer, and a film having dry etching selectivity. According to this, it is possible to easily and accurately form the photoresist pattern in the lithography process for semiconductor fabrication.

Further, the photoresist underlayer film of the present invention can form a pattern excellent in anti-wiggling of the pattern. Therefore, the semi-guide according to the present invention The method of manufacturing the bulk device can form a pattern excellent in anti-wiggling when dry etching with a dry etching gas.

Further, in the method of fabricating the semiconductor device of the present invention, a hard mask can be formed on the underlayer film of the photoresist, and the hard mask has a coating type containing an organic polymer or an inorganic polymer (germanium polymer) and a solvent. The case where the composition is carried out and the case where the composition is carried out by vacuum evaporation of an inorganic substance. The vacuum deposition of an inorganic substance (for example, cerium nitride oxide) causes the vapor deposition material to deposit on the surface of the underlayer film of the photoresist, but at this time, the temperature of the surface of the lower layer film of the photoresist rises to about 400 °C. The polymer used in the photoresist underlayer film forming composition of the present invention is a polymer having a unit structure containing a large amount of benzene, so that the heat resistance is extremely high, and even if the deposited material is deposited, thermal deterioration does not occur. The manufacturing method of stability.

The present invention is a composition for forming a lithographic underlayer film comprising a polymer having a repeating unit structure represented by the above formula (1).

The polymer having a structural unit represented by the above formula (1) used in the present invention has a weight average molecular weight of from 600 to 1,000,000, or preferably from 600 to 200,000.

In the formula (1), A represents a phenyl group substituted by a hydroxy group derived from polyhydroxybenzene, and B represents a monovalent condensed aromatic hydrocarbon ring group obtained by condensing 2 to 6 benzene rings.

Here, the phenyl group derived from the hydroxy group of polyhydroxybenzene refers to a phenyl group substituted by 2 to 4 hydroxy groups (a phenyl group which is polysubstituted by a hydroxy group).

Preferably, A is a phenyl group derived from a phenyl group or a benzene triol substituted by a hydroxy group. The phenyl group substituted by a hydroxy group derived from a benzene diol or a benzene diol is referred to herein as a dihydroxy benzene. Base, trihydroxyphenylene.

More specifically, A is preferably a phenyl substituted phenyl group derived from catechol, resorcin, hydroquinone, pyrogallol, pyrogallol, or phloroglucin. Phenyl or trihydroxyphenylene).

Further, the aromatic hydrocarbon ring obtained by condensing 2 to 6 benzene rings is exemplified by a naphthalene ring, a phenanthrene ring, a phenanthrene ring, an anthracene ring, a biphenyl ring, an anthracene ring, Ring, tetraphene ring, naphthacene ring, picene ring, perylene ring, pentaphene ring, pentacene ring, hexadesene Hexahelicene) ring, hexaphene ring, hexacene ring, coronene ring, etc., but one of the B valence condensed aromatic hydrocarbon ring groups is preferably a naphthalene ring group, fluorene The ring group or the anthracene ring group is preferably a naphthalene ring group or an anthracene ring group. More preferably, the condensed aromatic hydrocarbon group of B is an anthracene ring group.

Further, the condensed aromatic hydrocarbon ring group of B may have a halogen group, a hydroxyl group, a nitro group, an amine group, a carboxyl group, a carboxylate group, a nitrile group, or a combination thereof as a substituent.

The above halogen group is exemplified by a fluorine group, a chlorine group, a bromine group or an iodine group.

The above-mentioned carboxylate group means a group represented by a -COOR group, and R is exemplified by an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 40 carbon atoms.

The alkyl group having 1 to 10 carbon atoms is exemplified by methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, t-butyl, t-butyl, cyclobutyl. , 1-methylcyclopropyl, 2-methyl-cyclopropyl, n-pentyl, 1-methyl-n-butyl, 2-methyl-n-butyl, 3-methyl-n-butyl, 1,1-dimethyl-n-propyl, 1,2-dimethyl-n-propyl , 2,2-dimethyl-n-propyl, 1-ethyl-n-propyl, cyclopentyl, 1-methyl-cyclobutyl, 2-methyl-cyclobutyl, 3-methyl-cyclo Butyl, 1,2-dimethyl-cyclopropyl, 2,3-dimethyl-cyclopropyl, 1-ethyl-cyclopropyl, 2-ethyl-cyclopropyl, n-hexyl, 1- Methyl-n-pentyl, 2-methyl-n-pentyl, 3-methyl-n-pentyl, 4-methyl-n-pentyl, 1,1-dimethyl-n-butyl, 1,2- Dimethyl-n-butyl, 1,3-dimethyl-n-butyl, 2,2-dimethyl-n-butyl, 2,3-dimethyl-n-butyl, 3,3-dimethyl Base-n-butyl, 1-ethyl-n-butyl, 2-ethyl-n-butyl, 1,1,2-trimethyl-n-propyl, 1,2,2-trimethyl-n-propyl , 1-ethyl-1-methyl-n-propyl, 1-ethyl-2-methyl-n-propyl, cyclohexyl, 1-methyl-cyclopentyl, 2-methyl-cyclopentyl , 3-methyl-cyclopentyl, 1-ethyl-cyclobutyl, 2-ethyl-cyclobutyl, 3-ethyl-cyclobutyl, 1,2-dimethyl-cyclobutyl, 1 ,3-dimethyl-cyclobutyl, 2,2-dimethyl-cyclobutyl, 2,3-dimethyl-cyclobutyl, 2,4-dimethyl-ring Butyl, 3,3-dimethyl-cyclobutyl, 1-n-propyl-cyclopropyl, 2-n-propyl-cyclopropyl, 1-isopropyl-cyclopropyl, 2-isopropyl -cyclopropyl, 1,2,2-trimethyl-cyclopropyl, 1,2,3-trimethyl-cyclopropyl, 2,2,3-trimethyl-cyclopropyl, 1-B 2-methyl-cyclopropyl, 2-ethyl-1-methyl-cyclopropyl, 2-ethyl-2-methyl-cyclopropyl and 2-ethyl-3-methyl-cyclo Propyl and the like.

The aryl group having 6 to 40 carbon atoms is exemplified by phenyl, o-methylphenyl, m-methylphenyl, p-methylphenyl, o-chlorophenyl, m-chlorophenyl, p-chloro Phenyl, o-fluorophenyl, p-fluorophenyl, o-methoxyphenyl, p-methoxyphenyl, p-nitrophenyl, p-cyanophenyl, α-naphthyl, --naphthalene Base, o-biphenyl, m-biphenyl, p-biphenyl, 1-indenyl, 2-indenyl, 9-fluorenyl, 1-phenanthryl, 2-phenanthryl, 3-phenanthryl, 4-phenanthryl, fluorenyl, and 9-phenanthryl.

The repeating unit structure represented by the above formula (1) can be exemplified as the structures exemplified by the following formulas (1-1) to (1-18).

The use of the photoresist underlayer film forming composition of the present invention is as described above As the polymer of the repeating unit structure represented by the formula (1), a so-called novolac resin obtained by condensing a polyhydroxyphenol with an aldehyde can be used.

The polyhydroxyphenol is preferably exemplified by benzenediol or benzenetriol, more specifically catechol, resorcinol, hydroquinone, pyrogallol, pyrogallol, or meta-benzene. phenol.

The aldehyde is preferably an aldehyde having a condensed aromatic hydrocarbon ring group in which 2 to 6 benzene rings of a naphthalene, an anthracene or an anthracene are condensed, preferably naphthaldehyde, hydrazine carboxaldehyde or hydrazine carboxaldehyde. Wait.

In the condensation reaction of the above polyhydroxyphenol with the above aldehyde, an aldehyde reaction can be obtained for the above phenol 1 molar with a ratio of 0.1 to 10 moles, preferably 0.8 to 2.2 moles, more preferably 1.0 mole. .

An acid catalyst can be used for the condensation reaction, for example, a mineral acid such as sulfuric acid, phosphoric acid or perchloric acid, an organic sulfonic acid such as p-toluenesulfonic acid or p-toluenesulfonic acid monohydrate, or a carboxylic acid such as formic acid or oxalic acid. The amount of the acid catalyst used in the above condensation reaction can be variously selected depending on the type of the acid to be used. In general, the acid catalyst is used in an amount of from 0.001 to 10,000 parts by mass, preferably from 0.01 to 1,000 parts by mass, more preferably from 0.1 to 100 parts by mass, per 100 parts by mass of the total of the above phenols and aldehydes.

The above condensation reaction may also be carried out without a solvent, but it is usually carried out using a solvent. The solvent can be used as long as it does not interfere with the above condensation reaction. Listed as a cyclic ether such as tetrahydrofuran or dioxane. Further, when the acid catalyst is used, for example, a liquid of formic acid, it may have a role as a solvent.

The reaction temperature at the time of condensation is usually from 40 ° C to 200 ° C. The reaction time is variously selected depending on the reaction temperature, but it is usually 30 minutes to 50 hours. Around.

The weight average molecular weight Mw of the polymer obtained as described above is usually from 600 to 1,000,000, or from 600 to 200,000.

In the lithographic light group lower layer film-forming composition of the present invention, in addition to the polymer having the repeating structural unit represented by the above formula (1), it may be within 30% by mass based on the total mass of the polymer used. Mix other polymers for use.

Other polymers are exemplified by polyacrylate compounds, polymethacrylate compounds, polypropylene decylamine compounds, polymethacrylamide compounds, polyvinyl compounds, polystyrene compounds, polymaleimide compounds, poly Maleic anhydride and polyacrylonitrile compounds.

The raw material monomers of the polyacrylate compound are exemplified by methyl acrylate, ethyl acrylate, isopropyl acrylate, benzyl acrylate, naphthyl acrylate, decyl acrylate, decyl methacrylate, phenyl acrylate, 2-hydroxy acrylate. Ester, 2-hydroxypropyl acrylate, 2,2,2-trifluoroethyl acrylate, 4-hydroxybutyl acrylate, isobutyl acrylate, tert-butyl acrylate, cyclohexyl acrylate, isobornyl acrylate, acrylic acid 2-methoxyethyl ester, methoxytriethylene glycol acrylate, 2-ethoxyethyl acrylate, tetrahydrofurfuryl acrylate, 3-methoxybutyl acrylate, 2-methyl-2-acrylate Adamantyl ester, 2-ethyl-2-adamantyl acrylate, 2-propyl-2-adamantyl acrylate, 2-methoxybutyl-2-adamantyl acrylate, 8-methyl-8 acrylate Tricyclodecyl ester, 8-ethyl-8-tricyclodecyl acrylate and 5-propenyloxy-6-hydroxynorbornene-2-carboxylic acid-6-lactone.

The raw material monomer of the polymethacrylate compound is exemplified as methacrylic acid Ethyl ester, n-propyl methacrylate, n-amyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, naphthyl methacrylate, decyl methacrylate, decyl methyl methacrylate, Phenyl methacrylate, 2-phenylethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2,2,2-trifluoroethyl methacrylate, methyl 2,2,2-trichloroethyl acrylate, methyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, isodecyl methacrylate, n-lauryl methacrylate, A N-stearyl acrylate, methoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, tetrahydrofurfuryl methacrylate, isobornyl methacrylate, methacrylic acid Tributyl ester, isostearyl methacrylate, n-butoxyethyl methacrylate, 3-chloro-2-hydroxypropyl methacrylate, 2-methyl-2-adamantyl methacrylate, A 2-ethyl-2-adamantyl acrylate, 2-propyl-2-adamantyl methacrylate, 2-methoxybutyl-2-adamantane methacrylate , 8-methyl-8-tricyclodecyl methacrylate, 8-ethyl-8-tricyclodecyl methacrylate, 5-methylpropenyloxy-6-hydroxynorbornene methacrylate 2-carboxylic acid-6-lactone and 2,2,3,3,4,4,4-heptafluorobutyl methacrylate and the like.

The raw material monomers of the polypropylene guanamine compound are exemplified by acrylamide, N-methyl acrylamide, N-ethyl propyl decylamine, N-benzyl acrylamide, N-phenyl acrylamide, and N. , N-dimethyl methacrylate and the like.

The raw material monomers of the polymethacrylamide compound are exemplified by methacrylamide, N-methylmethacrylamide, N-ethylmethylpropylamine, N-benzylmethacrylamide, N-phenylmethacrylamide, and N,N-dimethylmethacrylamide.

The raw material monomers of the polyethylene compound are exemplified by vinyl ether, methyl vinyl ether, benzyl vinyl ether, 2-hydroxyethyl vinyl ether, phenyl vinyl ether, and propyl vinyl ether.

The raw material monomers of the polystyrene compound are exemplified by styrene, methyl styrene, chlorostyrene, bromostyrene, and hydroxystyrene.

The raw material monomers of the polymaleimide compound are listed as maleimide, N-methylmaleimide, N-phenylmaleimide, and N-cyclohexylmaleimide. .

These other polymers can be added by dissolving the raw material monomer (addition polymerizable monomer) and, if necessary, a chain transfer agent (10 mass% or less based on the mass of the monomer) in an organic solvent. The initiator is subjected to a polymerization reaction, followed by addition of a polymerization terminator. The addition amount of the polymerization initiator is from 1 to 10% based on the mass of the above-mentioned raw material monomer, and the addition amount of the polymerization terminator is also from 0.01 to 0.2% by mass.

The organic solvents used are exemplified by propylene glycol monomethyl ether, propylene glycol monopropyl ether, ethyl lactate, cyclohexanone, methyl ethyl ketone, and N,N-dimethylformamide, and the chain transfer agent is listed as ten. Examples of the polymerization initiators include azobisisobutyronitrile and azobiscyclohexanecarbonitrile, and the polymerization terminator is 4-methoxyphenol. .

The reaction temperature is from 30 to 100 ° C, and the reaction time is appropriately selected from 1 to 48 hours.

The lithographic underlayer film forming composition for lithography of the present invention contains the above polymer, that is, a polymer having a repeating structural unit represented by the formula (1), and other polymers as needed, and a solvent to be described later. In addition, the micro of the present invention The photo-resist layer underlayer film forming composition may contain a crosslinking agent, a catalyst (acid or the like) for promoting a crosslinking reaction, and may further contain an additive such as an acid generator or a surfactant, as needed.

The ratio of the solid content in the above composition of the present invention is from 0.1 to 70% by mass, or from 0.1 to 60% by mass. The solid content refers to the content of all the components of the solvent from the photoresist underlayer film forming composition (hereinafter also referred to as "total solid content").

Further, in the solid component, the content of the polymer (having a polymer having a repeating unit structure represented by the formula (1) and other polymers as needed) may be from 1 to 100% by mass, or from 1 to 99.9% by mass, Or a ratio of 50 to 99.9% by mass, or 50 to 95% by mass, or 50 to 90% by mass.

<Crosslinking agent>

The photoresist-forming underlayer film forming composition for lithography of the present invention may contain a crosslinking agent component. The crosslinking agent is exemplified by a melamine-based, substituted urea-based, or a polymer-based polymer thereof. Preferably, it is a crosslinking agent having at least two methylol groups and a methoxymethyl group to form a substituent, and is a methoxymethylated acetylene urea, a butoxymethylated acetylene urea, a methoxy group. Melamine melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, methoxymethylated urea, butoxymethylated urea, methoxy A compound such as methylated thiourea or methoxymethylated thiourea. Further, a condensate of these compounds can also be used.

Further, as the crosslinking agent, a crosslinking agent having high heat resistance can be used. High heat resistance As the crosslinking agent, a compound having a crosslinking group having an aromatic ring (for example, a benzene ring or a naphthalene ring) to form a substituent in the molecule can be suitably used.

The compound containing a crosslinking group having an aromatic ring to form a substituent is exemplified by a compound having a partial structure represented by the following formula (2) or a polymer or oligomer having a repeating unit represented by the following formula (3).

In the above formula (2), R ₁₀ and R ₁₁ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms, n10 represents an integer of 1 to 4, and n11 represents 1 to An integer of (5-n10), (n10+n11) represents an integer of 2 to 5.

In the above formula (3), R ₁₂ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, R ₁₃ represents an alkyl group having 1 to 10 carbon atoms, n12 represents an integer of 1 to 4, and n13 represents 0 to (4). -n12), (n12+n13) represents an integer from 1 to 4. The polymer or oligomer having a repeating unit represented by the above formula (3) may be an oligomer or a polymer having a repeating unit configuration represented by the formula (3) of from 2 to 100, or from 2 to 50. .

The above-mentioned alkyl group having 1 to 10 carbon atoms and aryl group having 6 to 20 carbon atoms can be exemplified as the above-exemplified groups as the alkyl group and the aryl group, respectively.

The compound represented by the above formula (2) and the polymer or oligomer having the repeating unit represented by the above formula (3) can be exemplified by the compounds represented by the following formulas (2-1) to (2-27).

The above compounds can be obtained from the products of Asahi Organic Industry Co., Ltd. and Honshu Chemical Industry Co., Ltd. For example, the compound of the formula (2-21) in the above crosslinking agent (2,2-bis(4-hydroxy-3,5-dihydroxy-methylphenyl)propane) can be used in the organic materials industry, the trade name TM -BIP-A obtained.

The amount of the crosslinking agent added is the (coating) solvent used in the photoresist underlayer film forming composition of the present invention, the underlying substrate using the composition, the solution viscosity required for use of the composition, and the composition The film shape or the like required for the obtained film varies, but the mass of the total solid content of the composition is 0.001 to 80% by mass, preferably 0.01 to 50% by mass, more preferably 0.05 to 40% by mass. . These crosslinkers can also be self Condensation causes a cross-linking reaction, but when the above-mentioned polymer used in the photo-resisting underlayer film-forming composition of the present invention has the above-mentioned cross-linking to form a substituent, it can form a substituent with the cross-linking to cause a cross-linking reaction. .

<catalyst>

In the present invention, the acidity of the p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium p-toluenesulfonic acid, salicylic acid, sulfosalicylic acid, citric acid, benzoic acid, hydroxybenzoic acid, naphthalenecarboxylic acid, etc. a thermal acid generator such as a compound and/or 2,4,4,6-tetrabromocyclohexadienone, benzoin tosylate, 2-nitrobenzyl tosylate, or other organic sulfonic acid alkyl ester As a catalyst for promoting the above crosslinking reaction. The blending amount of the catalyst may be 0.0001 to 20% by mass, preferably 0.0005 to 10% by mass, and preferably 0.01 to 3% by mass, based on the mass of the total solid content of the photoresist underlayer film forming composition of the present invention. .

Acid generator

In the lithographic photoresist underlayer film forming composition of the present invention, a photoacid generator can be added in order to match the acidity of the photoresist coated on the upper layer in the lithography step. Preferred photoacid generators are exemplified by bismuth salt photoacid generators such as bis(4-t-butylphenyl)phosphonium trifluoromethanesulfonate and triphenylsulfonium trifluoromethanesulfonate, and benzene. A sulfonic acid generator such as a bis-(trichloromethyl)-s-triazine or a halogenated compound, a sulfonic acid generator such as benzoin tosylate or N-hydroxysuccinimide trifluoromethanesulfonate It is a photoacid generator or the like. The amount of the photoacid generator to be added is 0.2 to 10% by mass, preferably 0.4 to 5 by mass based on the total solid content of the photoresist underlayer film forming composition of the present invention. %.

<Other Additives>

In addition to the above, the light-blocking underlayer film forming composition for lithography of the present invention may optionally contain a light absorbing agent, a rheology adjusting agent, an auxiliary agent, a surfactant, and the like.

Further, as a light absorbing agent, for example, a commercially available light absorbing agent such as "Technology and Market for Industrial Colors" (CMC Publishing Co., Ltd.) or "Dye Handbook" (edited by the Society of Organic Synthetic Chemistry), for example, CI Disperse Yellow 1 can be suitably used. , 3, 4, 5, 7, 8, 13, 23, 31, 49, 50, 51, 54, 60, 64, 66, 68, 79, 82, 88, 90, 93, 102, 114 and 124; CI Disperse orange 1, 5, 13, 25, 29, 30, 31, 44, 57, 72 and 73; CI disperse red 1, 5, 7, 13, 17, 19, 43, 50, 54, 58, 65, 72 , 73, 88, 117, 137, 143, 199 and 210; CI Disperse Violet 43; CI Disperse Blue 96; CI Fluorescent Brighteners 112, 135 and 163; CI Solvent Orange 2 and 45; CI Solvent Red 1, 3 , 8, 23, 24, 25, 27 and 49; CI Pigment Green 10; CI Pigment Brown 2, etc. The light absorbing agent is usually formulated in an amount of 10% by mass or less, preferably 5% by mass or less based on the total mass of the total solid content of the photoresist underlayer film forming composition.

The rheology modifier mainly improves the fluidity of the photoresist film forming composition, especially in the baking step, in order to improve the uniformity of the film thickness of the photoresist film or to improve the film formation composition under the photoresist inside the hole. Added for filling. Specific examples thereof include dimethyl phthalate, diethyl phthalate, diisobutyl phthalate, dihexyl phthalate, and butyl phthalate. A phthalic acid derivative such as isodecyl ester, di-n-butyl adipate, diisobutyl adipate, diisooctyl adipate, octyl adipate phthalate, maleic acid, maleic acid Maleic acid derivatives such as di-n-butyl ester, diethyl maleate, dinonyl maleate, oleic acid derivatives such as methyl oleate, butyl oleate, tetrahydrofurfuryl oleate, or stearic acid Stearic acid derivatives such as n-butyl acrylate and glyceryl stearate. The mass of the rheology modifier relative to the total solid content of the photoresist underlayer film forming composition is usually formulated in a ratio of less than 30% by mass.

Then, the main purpose of the auxiliary agent is to improve the adhesion of the substrate or the photoresist and the underlying film forming composition of the photoresist, especially when the image is formed without the peeling of the photoresist. Specific examples thereof include chlorodecanes such as trimethylchlorodecane, dimethylvinylchlorocyclohexane, methyldiphenylchlorodecane, and chloromethyldimethylchloromethane; trimethylmethoxydecane, and Alkoxy decane such as methyl diethoxy decane, methyl dimethoxy decane, dimethyl vinyl ethoxy decane, diphenyl dimethoxy decane, phenyl triethoxy decane, etc. a decazane such as methyl diazoxide, N,N'-bis(trimethyldecyl)urea, dimethyltrimethyldecylamine or trimethyldecyl imidazole, vinyltrichloromethane, a decane such as γ-chloropropyltrimethoxydecane, γ-aminopropyltriethoxydecane or γ-glycidoxypropyltrimethoxydecane, benzotriazole, benzimidazole, carbazole, a heterocyclic compound such as imidazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, ureazazole, thiouracil, mercapto imidazole, mercaptopyrimidine, or 1,1-dimethyl Urea such as urea or 1,3-dimethylurea, or a thiourea compound. The mass of the above-mentioned auxiliary agent relative to the total solid content of the photoresist underlayer film forming composition is usually less than 5% by mass, preferably less than 2% by mass.

In the photoresist-forming underlayer film forming composition for lithography of the present invention, a surfactant can be adjusted in order to improve the coating property against surface unevenness without causing pinholes or streaks. 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, or polyoxyethylene octane. Polyoxyethylene alkyl aryl ethers such as phenol ethers, polyoxyethylene nonyl phenol ethers, polyoxyethylene. Polyoxypropylene block copolymers, sorbitan monolaurate, sorbitol monopalmitate, sorbitan monostearate, sorbitan monooleate, sorbitan III Sorbitol fatty acid esters such as oleate, sorbitan tristearate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitol Nonionic interface such as polyoxyethylene sorbitan fatty acid esters such as monosaccharide monostearate, polyoxyethylene sorbitan trioleate, and polyoxyethylene sorbitan tristearate Active agent, EF TOP EF301, EF303, EF352 (TOKEMU PRODUCTS) (currently manufactured by Mitsubishi Materials Electronics Co., Ltd., trade name), MEGAFAC F171, F173, R-30 (made by DIC) FLORARD FC430, FC431 (Sumitomo 3M (manufacturing), trade name), ASAHI GUARD AG710, SURFLON S-382, SC101, SC102, SC103, SC104, SC105, SC106 (asahi Glass (manufacturing), trade name) Surfactant, organic siloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), etc. The amount of active agent formulation with respect to the total mass of the solid content of the composition of the resist underlayer film is formed according to the present invention is generally 2.0 mass% or less, preferably 1.0 mass% or less. Such surfactant may be added separately Add, and you can also add two or more combinations.

<solvent>

The solvent used in the photoresist underlayer film forming composition for lithography of the present invention may be a compound which can dissolve the above-mentioned polymer, a crosslinking agent component, and other components such as a crosslinking catalyst. Alcohol 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 monoethyl ether, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, toluene, xylene, methyl ethyl Ketone, cyclopentanone, cyclohexanone, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropanoate, ethyl ethoxyacetate, ethyl hydroxyacetate, 2-hydroxy-3-methyl Methyl butyrate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, methyl pyruvate An organic solvent such as ethyl pyruvate, ethyl acetate, butyl acetate, ethyl lactate or butyl lactate. These organic 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 in combination.

Among these solvents, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, butyl lactate, and cyclohexanone are preferable for improving the advection property.

[Photoresist underlayer film]

The photoresist underlayer film obtained by applying the above-described photoresist-forming underlayer film forming composition of the present invention to a semiconductor substrate and firing it is also an object of the present invention.

[Formation method of photoresist pattern]

Further, a method of forming a photoresist pattern which is used in semiconductor production including a step of applying the photoresist underlayer film forming composition onto a semiconductor substrate and firing to form a lower film is also an object of the present invention.

The method for forming a photoresist pattern of the present invention is specifically a substrate (a semiconductor substrate such as a tantalum/yttria-coated substrate, a glass substrate, or a transparent substrate such as an ITO substrate) used for the production of a precision integrated circuit device. A suitable coating method such as a spinner or an applicator is applied to the photoresist underlayer film forming composition, and then baked to form a coating type photoresist underlayer film. Here, the film thickness of the photoresist underlayer film is preferably from 0.01 to 3.0 μm. And the baking condition after coating is 0.5 to 120 minutes at 80 to 350 °C.

Subsequently, a photoresist film may be formed on the underlying film of the photoresist directly or, if necessary, one or more layers of the coating material are formed on the underlayer film of the photoresist, and the photoresist layer is formed by a specific mask. The photoresist film is irradiated with light or an electron beam, and after development, washing, and drying, a good photoresist pattern can be obtained. It can also be heated after exposure to light or electron beams (PEB: post-exposure bake).

Then, the photoresist underlayer film from which the photoresist has been removed by the foregoing steps can be removed by dry etching to form a desired pattern on the substrate.

The above-mentioned photoresist used in the present invention means a photoresist or an electron beam photoresist.

As for the photoresist which is applied to the upper portion of the photoresist film for lithography of the present invention, any of a negative type and a positive type may be used, and it is exemplified by a novolac resin and a 1,2-naphthoquinone diazosulfonate. a positive-type photoresist consisting of a chemically amplified photoresist composed of a binder and a photoacid generator having a base for increasing the alkali dissolution rate by acid decomposition, and an increase in photoresist by an alkali-soluble binder and decomposition by acid a chemically amplified photoresist composed of a low molecular compound and a photoacid generator having a base dissolution rate, a binder having a base for increasing the alkali dissolution rate by acid decomposition, and an alkali dissolution which enhances photoresist by acid decomposition A chemically amplified photoresist composed of a low molecular weight compound and a photoacid generator, a photoresist having Si atoms on the skeleton, and the like, and is exemplified by a trade name APEX-E manufactured by Rohm and Haas Company.

Further, the electron beam resist applied to the upper portion of the photoresist film for lithography of the present invention is exemplified by, for example, a resin having a Si-Si bond in its main chain and having an aromatic ring at its end and an acid generated by irradiation with an electron beam. a composition of an acid generator, or a composition of a poly(p-hydroxystyrene) substituted with an organic group containing an N-carboxyamine and an acid generator which generates an acid by irradiation with an electron beam Wait. The electron beam resist composition of the latter is an acid generated by an electron beam to react with an N-carboxylamine group of a polymer side chain, and the polymer side chain is decomposed into a hydroxyl group to exhibit alkali solubility and to be dissolved in a base. Like the liquid, the pattern of the photoresist pattern is formed. The acid generator which generates acid by irradiation of the electron beam is exemplified by 1,1-bis[p-chlorophenyl]-2,2,2-trichloroethane, 1,1-bis[p-methoxy group. Phenyl]-2,2,2-trichloroethane, 1,1-bis[p-chlorophenyl]-2,2-dichloroethane, 2-chloro-6-(trichloromethyl)pyridine Halogenated organic compounds, triphenylsulfonium salts, diphenylsulfonium salts and the like, nitrobenzyl tosylate, dinitrate a sulfonate such as a benzyl tosylate.

The light for exposure of the above-mentioned photoresist is a chemical beam such as near ultraviolet light, far ultraviolet light, or extreme ultraviolet light (for example, EUV, wavelength 13.5 nm), for example, 248 nm (KrF laser light), 193 nm (ArF laser light), 157 nm (F). ₂ laser light) light of the same wavelength. The light irradiation is not particularly limited as long as it can generate an acid from the photoacid generator, and the exposure amount is 1 to 2000 mJ/cm ² , or 10 to 1500 mJ/cm ² , or 50 to 1000 mJ/cm ² .

Further, electron beam irradiation of the electron beam resist can be irradiated using, for example, an electron beam irradiation device.

In the present invention, the developing solution used for the development of the photoresist film formed by the photoresist (photoresist, electron beam photoresist) may be sodium hydroxide, potassium hydroxide, sodium carbonate, sodium citrate or hemiplegia. Inorganic bases such as sodium and ammonia, primary amines such as ethylamine and n-propylamine, secondary amines such as diethylamine and di-n-butylamine, triethylamine, methyldiethylamine, etc. Tertiary amines, alcohol amines such as dimethylethanolamine and triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, choline and other quaternary ammonium salts, and cyclic amines such as pyrrole and piperidine An aqueous solution of the class. Further, an aqueous solution of an alkali such as isopropyl alcohol or a surfactant such as a nonionic surfactant may be added to the aqueous solution of the above-mentioned base. Preferred of these developing solutions are quaternary ammonium salts, preferably tetramethylammonium hydroxide and choline.

[Method of Manufacturing Semiconductor Device]

Further, a method of manufacturing a semiconductor device using the above-described photoresist-forming underlayer film forming composition for lithography of the present invention is also an object of the present invention.

In detail, it is a semiconductor including the following steps (a) to (e) The manufacturing method of the device.

(a) a step of applying the photoresist underlayer film forming composition onto a semiconductor substrate and firing to form an underlayer film on the semiconductor substrate, and (b) forming a photoresist film on the underlayer film, ( c) a step of forming a photoresist pattern on the photoresist film by irradiation and development of light or electron beams, (d) a step of etching the underlayer film by the photoresist pattern, and (e) utilizing a pattern The step of processing the semiconductor substrate under the layered film.

Alternatively, the method of manufacturing a semiconductor device including the following steps (f) to (l) is also an object of the present invention.

(f) a step of applying the photoresist underlayer film forming composition onto the semiconductor substrate and firing to form an underlayer film on the semiconductor substrate; (g) forming a hard mask on the underlayer film; h) a step of forming a photoresist film on the hard mask; (i) a step of forming a photoresist pattern on the photoresist film by irradiation and development of light or electron beams; (j) utilizing the light a step of etching the hard mask by pattern etching; (k) a step of etching the underlying film by using a patterned hard mask; and (1) a step of processing the semiconductor substrate by using the patterned underlayer film.

The hard mask is preferably a coating material of an inorganic material or a vapor deposition by an inorganic material, and may be, for example, a coating material containing a cerium-containing component or the like. A hard mask formed or a hard mask formed by evaporation (for example, tantalum nitride).

In the present invention, the etching gas used in the step of etching the photoresist underlayer film after forming the photoresist pattern may be a halogen-based gas.

Further, the etching gas used in the step of etching the hard mask after forming the photoresist pattern may be a halogen-based gas. Further, the etching gas used in the step of etching the photoresist underlayer film by the patterned hard mask may be an oxygen-based gas or a hydrogen-based gas.

Further, the etching gas used in the step of processing the semiconductor substrate after the patterned photoresist underlayer film is exemplified by a halogen-based gas.

As described above, in the technical field of microfabrication by using a photoresist composition, as the photoresist pattern is miniaturized, not only the photoresist pattern must have a function as a mask, but also a photoresist is required. The underlayer film also has a function as a function of the photomask during substrate processing. As the photoresist underlayer film used in the process, it is required that the dry etching speed is selected to be different from that of the photoresist which is close to the photoresist, smaller than the photoresist, or smaller than the semiconductor substrate, and the light of the conventional high etching resistive underlayer film. Block the underlayer film.

On the other hand, in order to obtain a fine photoresist pattern, when the photoresist underlayer is dry-etched, the photoresist pattern and the photoresist underlayer film are also used in a process in which the pattern width is thinner than that in the photoresist development. . The photoresist underlayer film for this process is also different from the conventional high-etching anti-reflection film, and it is required to have a lower resistivity of the photoresist than the photoresist.

Furthermore, these photoresist underlayer films are also required to have the function of the conventional anti-reflection film while imparting anti-reflection energy.

In the present invention, after the photoresist underlayer film of the present invention is formed on the substrate, a layer of a plurality of layers of the coating material (for example, a hard mask forming material) may be directly formed on the underlayer film of the photoresist or, if necessary, After the photoresist is placed on the underlayer film, a photoresist is applied to form a photoresist film. Thereby, the width of the pattern of the photoresist is narrowed, and even if the photoresist is thin to prevent the pattern from collapsing, the substrate can be finely processed by selecting an appropriate etching gas.

The lithographic photoresist underlayer film forming composition of the present invention has high thermal stability, and can prevent contamination of the upper film (photoresist film, hard mask, etc.) due to decomposition products during firing, and the firing step The temperature limit has a margin.

Further, when the photoresist forming underlayer film forming composition of the present invention is considered as an antireflection film, since the light absorbing portion such as an anthracene ring has a sufficiently large light absorbing property, not only the antireflection effect is enhanced, but also the light absorbing portion It is incorporated into the polymer skeleton, so that when the photoresist film is heated and dried at the time of formation, there is no diffuser from the photoresist underlying film to the photoresist.

In addition, the lithographic underlayer film material of the present invention can be used as a function of preventing reflection of light, thereby preventing interaction between the substrate and the photoresist or the use of the photoresist or the photoresist in accordance with the process conditions. It is used as a film which functions as a function of adverse effects on the substrate.

[Examples] Synthesis Example 1

In a 200 ml three-necked flask, 10.09 g of glycinol (manufactured by Tokyo Chemical Industry Co., Ltd.), 1-indole formaldehyde (manufactured by Aldrich Co., Ltd.), 18.42 g, and 1,4-dioxane (Kanto Chemical Co., Ltd.) were fed. Stock) manufacturing) 49.61 g of p-toluenesulfonic acid monohydrate (manufactured by Tokyo Chemical Industry Co., Ltd.) was 4.56 g. It was then heated to 110 ° C and stirred under reflux for about 5 hours. After completion of the reaction, it was diluted with 24.80 g of tetrahydrofuran (manufactured by Kanto Chemical Co., Ltd.) to remove the precipitate by filtration. The recovered filtrate was added to a methanol/water mixed solution to cause reprecipitation. The resulting precipitate was filtered with suction, and the filtrate was dried under reduced pressure at 85 ° C overnight. Thus, 25.26 g of a brownish-brown powder was obtained between the benzenetriol resin. The obtained polymer corresponds to a polymer containing a repeating unit structure represented by the above formula (1-16). The weight average molecular weight Mw measured by GPC in terms of polystyrene was 2,800, and the polydispersity Mw/Mn was 2.18.

Synthesis Example 2

In a 50 ml pear-shaped flask, 2.53 g of phloroglucin (manufactured by Tokyo Chemical Industry Co., Ltd.), 1-naphthaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.), 3.32 g, 1,4-dioxane (Kanto Chemical Co., Ltd.) were fed. (manufactured by Ltd.) 6.83 g of p-toluenesulfonic acid monohydrate (manufactured by Tokyo Chemical Industry Co., Ltd.) 1.16 g. It was then heated to 110 ° C and stirred at reflux for about 6 hours. After completion of the reaction, it was diluted with 3.42 g of tetrahydrofuran (manufactured by Kanto Chemical Co., Ltd.) to remove the precipitate by filtration. The recovered filtrate was added to a methanol/water mixed solution to cause reprecipitation. The resulting precipitate was filtered with suction, and the filtrate was dried under reduced pressure at 85 ° C overnight. Thus, 1.94 g of a brownish-brown powder was obtained between the benzenetriol resin. The obtained polymer corresponds to a polymer containing a repeating unit structure represented by the above formula (1-4). The weight average molecular weight Mw measured by GPC in terms of polystyrene was 1,000, and the polydispersity Mw/Mn was 1.09.

Synthesis Example 3

In a 200 ml pear-shaped flask, 2.22 g of resorcinol (manufactured by Tokyo Chemical Industry Co., Ltd.), 1.17 g of 1-furfural (manufactured by Aldrich), and 62.99 g of toluene (manufactured by Kanto Chemical Co., Ltd.), p-toluene were fed. Sulfonic acid monohydrate (manufactured by Tokyo Chemical Industry Co., Ltd.) 6.834 g. The inside of the flask was then replaced with nitrogen, heated to 130 ° C, and stirred under reflux for about 6 hours. After completion of the reaction, the mixture was diluted with tetrahydrofuran (manufactured by Kanto Chemical Co., Ltd.) at 31.44 g, and the precipitate was removed by filtration. The recovered filtrate was added to a methanol/water mixed solution to cause reprecipitation. The resulting precipitate was filtered with suction, and the filtrate was dried under reduced pressure at 85 ° C overnight. Thus, 1.32 g of a tawny resin of a brownish brown powder was obtained. The obtained polymer corresponds to a polymer having a repeating unit structure represented by the above formula (1-14). The weight average molecular weight Mw measured by GPC and polystyrene conversion was 1,800, and the polydispersity Mw/Mn was 1.13.

Comparative Synthesis Example 1

In a 100 ml three-necked flask, phloroglucin (manufactured by Tokyo Chemical Industry Co., Ltd.), 5.51 g, benzaldehyde (manufactured by Tokyo Chemical Industry Co., Ltd.), 4.27 g, 1,4-dioxane (Kanto Chemical Co., Ltd.) were fed. ) Manufactured: 10.09 g, p-toluenesulfonic acid monohydrate (manufactured by Tokyo Chemical Industry Co., Ltd.), 0.76 g. It was then heated to 110 ° C and stirred under reflux for about 2 hours. After completion of the reaction, it was diluted with 7.54 g of tetrahydrofuran (manufactured by Kanto Chemical Co., Ltd.) to remove the precipitate by filtration. The recovered filtrate was added to a methanol/water mixed solution to cause reprecipitation. The resulting precipitate was filtered with suction, and the filtrate was dried under reduced pressure at 85 ° C overnight. because Instead, 7.25 g of a tea brown powder was obtained between the benzenetriol resin. The obtained polymer corresponds to a polymer containing a repeating unit structure represented by the following formula (3-1). The weight average molecular weight Mw measured by GPC in terms of polystyrene was 3,600, and the polydispersity Mw/Mn was 1.34.

Example 1

To the 1 g of the resin obtained in Synthesis Example 1 (containing a polymer having a repeating unit structure of the formula (1-16)), 10.34 g of propylene glycol monomethyl ether and 2.59 g of cyclohexanone were added and dissolved, and the preparation was carried out by using a multilayer film. The photoresist underlayer film used in the shadowing process forms a solution of the composition.

Example 2

To the 0.8 g of the resin obtained in Synthesis Example 2 (containing a polymer having a repeating unit structure of the formula (1-4)), 10.34 g of propylene glycol monomethyl ether was added and dissolved, and a multilayer film was used for the lithography process. The photoresist underlayer film forms a solution of the composition.

Example 3

Between the resin obtained in Synthesis Example 3 (containing a polymer having a repeating unit structure of the formula (1-14)), 2.07 g of propylene glycol monomethyl ether and 8.27 g of cyclohexanone were added and dissolved, and the mixture was prepared by using a multilayer film. The photoresist underlayer film used in the lithography process forms a solution of the composition.

Comparative example 1

To a 1 g of a cresol novolak resin (commercial product, weight average molecular weight: 4,000), 10.34 g of propylene glycol monomethyl ether and 2.59 g of cyclohexanone were added and dissolved to prepare a photoresist underlayer film for use in a lithography process using a multilayer film. A solution of the composition is formed.

Comparative example 2

Into 0.8 g of the resin obtained in Synthesis Example 1 (polymer containing a repeating unit structure of the previous formula (3-1)), 10.34 g of propylene glycol monomethyl ether was added and dissolved, and a multilayer film was used for the lithography process. The underlying film forms a solution of the composition.

(Measurement of optical parameters)

Each of the photoresist underlayer film forming compositions (solutions) prepared in Examples 1 to 3 and Comparative Examples 1 to 2 was coated on each of the tantalum wafers using a spin coater. The film was fired at 400 ° C for 2 minutes on a hot plate (Comparative Example 1 was 205 ° C for 1 minute) to form a photoresist underlayer film (film thickness: 0.05 μm). The refractive index (n value) and optical absorption coefficient (k value, also referred to as attenuation coefficient) of the underlying film of the photoresist at a wavelength of 193 nm were determined using a spectroscopic ellipsometer. Result In Table 1.

(Dissolution test for photoresist solvent)

A solution of the photoresist underlayer film forming compositions prepared in Examples 1 to 3 and Comparative Example 2 was applied onto each of the germanium wafers using a spin coater. The film was fired at 240 ° C for 1 minute on a hot plate or at 400 ° C for 2 minutes to form a photoresist underlayer film (film thickness: 0.20 μm) of two different firing temperatures and firing times.

Using the photoresist underlayer film, an immersion test was performed on ethyl lactate, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate or cyclohexanone, which are common solvents used for the photoresist.

Each of the solutions of Examples 1 to 3 and Comparative Example 2 was applied to each of the substrates, and the film obtained by firing at 240 ° C for 1 minute was dissolved in the above four solvents, but baked at 400 ° C for 2 minutes. The film was confirmed to be insoluble in the solvents.

(Measurement of dry etching speed)

Etching machine and etching gas system used for measuring dry etching rate The following.

Etching machine: RIE-10NR (made by SAMCO)

Etching gas: CF ₄

A solution of each of the photoresist underlayer film forming compositions prepared in Examples 1 to 3 and Comparative Examples 1 to 2 was applied onto each of the germanium wafers using a spin coater. The film was fired at 400 ° C for 2 minutes on a hot plate (Comparative Example 1 was 205 ° C for 1 minute) to form a photoresist underlayer film (film thickness: 0.20 μm). The dry etching rate was measured using CF ₄ gas as an etching gas.

The dry etching rate of the photoresist underlayer films of Examples 1 to 3 and Comparative Example 2 was compared with the dry etching rate of the photoresist underlayer film of Comparative Example 1, respectively. The results are shown in Table 2. The speed ratios indicate the ratio of the dry etching rate of the photoresist underlayer film obtained in Examples 1 to 3 or Comparative Example 2/the dry etching rate of the photoresist underlayer film obtained in Comparative Example 1, respectively.

(Measurement of bending resistance of pattern)

Using the photoresist underlayer film forming composition prepared in the above Examples and Comparative Examples, the following pattern forming step was carried out, and the pattern width formed by the scanning pattern formed by electron microscopy began to be generated.

Generally, as the width of the pattern is narrowed, it is easy to bend (wiggling). The curvature of the irregular pattern. When the wiggling of the pattern occurs, since the substrate processing cannot be performed based on the faithful pattern, it is necessary to perform the substrate processing in the pattern width (critical pattern width) before the pattern is to be bent. The value of the critical pattern width at which the wiggling starts to occur is as narrow as possible, indicating that it can be processed by a fine substrate.

[pattern formation]

A solution of each of the photoresist underlayer film forming compositions prepared in Examples 1 to 3 and Comparative Example 2 was applied onto a tantalum wafer to which each of the ruthenium oxide film was attached, using a spin coater. The film was fired at 400 ° C for 2 minutes on a hot plate to form a photoresist underlayer film (film thickness: 200 nm). The tantalum hard mask forming composition solution was applied onto the photoresist underlayer film, and baked at 240 ° C for 1 minute to form a tantalum hard mask (film thickness: 45 nm). A photoresist solution was applied thereon, and baked at 100 ° C for 1 minute to form a photoresist layer (film thickness: 120 nm). A photoresist pattern was obtained by development using a variety of masks having different pattern widths, exposing at a wavelength of 193 nm, and heating PEB after exposure (1 minute at 105 ° C).

Subsequently, dry etching is performed using a fluorine-based gas (component is CF ₄ ), and the photoresist pattern is transferred onto the hard mask. Subsequently, dry etching is performed with an oxygen-based gas (component is O ₂ ), and the photoresist pattern is transferred onto the photoresist underlayer film of the present invention. Subsequently, dry etching is performed using a fluorine-based gas (component is C ₄ F ₈ ) to remove the cerium oxide film on the germanium wafer.

The shape of each pattern obtained by the above steps was observed with an electron microscope.

The measurement of the resolution was performed using a measurement scanning electron microscope (manufactured by Hitachi, Ltd.). The measurement results are shown in Table 3.

As shown in Table 3, the critical pattern width of the pattern obtained by using the photoresist underlayer film forming compositions of Examples 1 to 3 was narrower than that obtained by using the photoresist underlayer film forming composition of Comparative Example 2. The result of finer substrate processing by using the photoresist underlayer film forming composition of the present invention is obtained.

[Industry possible use]

The photoresist underlayer film composition used in the lithography process of the multilayer film of the present invention is different from the conventional high etchable anti-reflection film, and can provide a selection ratio of dry etch rate which is close to the photoresist or smaller than the photoresist. The ratio of the dry etching rate of the semiconductor substrate is smaller than that of the semiconductor substrate, and further has a photoresist underlayer film as an effect of the antireflection film. Further, the underlayer film forming composition of the present invention can be obtained by vapor deposition on the upper layer to form a hard mask to obtain heat resistance. Moreover, even if the pattern size is narrow, it is not easy to cause wiggling to obtain a good pattern, and a good pattern in which the pattern width at least around 45 nm is not bent is obtained.

Claims (12)

A lithographic photoresist underlayer film forming composition comprising a polymer having a repeating unit structure represented by the formula (1): (In the formula (1), A is a phenyl group derived from a hydroxy group substituted by a hydroxy group, and B is a valence condensed aromatic hydrocarbon ring group obtained by condensing 2 to 6 benzene rings). A photoresist underlayer film forming composition according to claim 1, wherein A is a phenyl group derived from a phenyl group or a benzenetriol substituted by a hydroxyl group. Such as the photoresist underlayer film forming composition of claim 1, wherein A is derived from catechol, resorcinol, hydroquinone, pyrogallol, pyrogallol, or phloroglucinol. a phenyl group substituted by a hydroxy group. The photoresist underlayer film forming composition according to any one of claims 1 to 3, wherein the condensed aromatic hydrocarbon ring group of B is a naphthalene ring group, an anthracene ring group or an anthracene ring group. The photoresist underlayer film forming composition according to any one of claims 1 to 4, wherein the condensed aromatic hydrocarbon ring group of B has a halogen group, a hydroxyl group, a nitro group, an amine group, a carboxyl group, a carboxylate group, A nitrile group, or a combination thereof, is used as a substituent. The photoresist underlayer film forming composition according to any one of claims 1 to 5, which further contains a crosslinking agent. The photoresist underlayer film forming composition according to any one of claims 1 to 6, which further comprises an acid and/or an acid generator. A photoresist underlayer film obtained by applying a photoresist underlayer film forming composition according to any one of claims 1 to 7 to a semiconductor substrate and firing it. A method for forming a photoresist pattern for semiconductor manufacturing, comprising coating a photoresist underlayer film forming composition according to any one of claims 1 to 7 on a semiconductor substrate and firing to form a lower layer The step of the membrane. A method of manufacturing a semiconductor device, comprising the step of applying a photoresist underlayer film forming composition according to any one of claims 1 to 7 to a semiconductor substrate and firing to form an underlayer film; a step of forming a photoresist film on the underlayer film; a step of forming a photoresist pattern on the photoresist film by irradiation and development of light or electron beams; a step of etching the underlayer film by using the photoresist pattern; and utilizing The step of processing the semiconductor substrate by patterning the underlying film. A method of manufacturing a semiconductor device, comprising the step of applying a photoresist underlayer film forming composition according to any one of claims 1 to 7 to a semiconductor substrate and firing to form an underlayer film; a step of forming a hard mask on the underlayer film; a step of forming a photoresist film on the hard mask; and a step of forming a photoresist pattern on the photoresist film by irradiation and development of light or electron beams; The photoresist pattern etches the hard mask a step of etching the underlayer film by using a patterned hard mask; and a step of processing the semiconductor substrate using the patterned underlayer film. The manufacturing method of claim 11, wherein the hard mask is formed by vapor deposition of a coating material or an inorganic material of an inorganic material.