JP4409524B2 - Resist pattern thickening material, resist pattern manufacturing method, and semiconductor device manufacturing method - Google Patents

Description

  The present invention is a resist pattern thickening material that can be applied on a resist pattern to thicken the resist pattern and form a fine resist omission pattern beyond the exposure limit in the light source of an existing exposure apparatus, and The present invention relates to a resist pattern manufacturing method and a semiconductor device manufacturing method using the same.

Currently, high integration of semiconductor integrated circuits is progressing, and LSI and VLSI have been put into practical use, and accordingly, the wiring pattern extends to an area of 0.2 μm or less and the minimum pattern reaches 0.1 μm or less. To form a fine wiring pattern, a substrate to be processed on which a thin film is formed is covered with a resist film, subjected to selective exposure and developed to form a resist pattern, and then dry etching is performed using the resist pattern as a mask. A lithography technique that obtains a desired pattern by removing the resist pattern is very important.
The formation of a fine wiring pattern requires both the shortening of the wavelength of the light source in the exposure apparatus and the development of a resist material having a high resolution according to the characteristics of the light source. However, in order to reduce the wavelength of the light source in the exposure apparatus, it is necessary to update the exposure apparatus that requires enormous costs. On the other hand, it is not easy to develop a resist material to cope with exposure using a short wavelength light source. Therefore, at present, no technology has been provided that can use light as a light source of an exposure apparatus during patterning and can form a uniform and fine resist removal pattern with high definition.

An object of the present invention is to solve the conventional problems and achieve the following objects. That is, the present invention can use a light source such as ArF excimer laser light in an existing exposure apparatus as it is when patterning a resist pattern, is excellent in mass productivity, has no dependency on the material and size of the resist pattern, and has a resist missing pattern. An object of the present invention is to provide a method for producing a resist pattern which can be produced stably in a state where the roughness of the surface is reduced finely and uniformly beyond the exposure limit of the light source.
In addition, the present invention has no dependency on the material and size of the resist pattern, and when applied to the resist pattern, the resist pattern is stably and thickened efficiently and uniformly with reduced surface roughness. An object of the present invention is to provide a resist pattern thickening material suitable for manufacturing a fine resist omission pattern that exceeds the exposure limit of a light source of an existing exposure apparatus.
Further, according to the present invention, a fine pattern can be formed on a base layer such as an oxide film by using a finely and uniformly formed resist removal pattern, and a high-performance semiconductor device having fine wiring and the like can be efficiently used. An object of the present invention is to provide a method of manufacturing a semiconductor device that can be mass-produced.

Means for solving the above-described problems are as listed in the appendix to be described later.
The resist pattern thickening material of the present invention contains a resin, a crosslinking agent, and a nitrogen-containing compound. When the resist pattern thickening material is applied onto the resist pattern, the applied resist pattern thickening material soaks in the resist pattern near the interface with the resist pattern. Crosslink with pattern material. At this time, since the affinity between the resist pattern thickening material and the resist pattern is good, the resist pattern thickening material and the resist pattern are integrated on the surface of the resist pattern as an inner layer. The resist layer is efficiently formed (the resist pattern is efficiently thickened by the resist pattern thickening material). The resist pattern thus formed (hereinafter sometimes referred to as “thickening resist pattern”) is uniformly thickened by the resist pattern thickening material. For this reason, the missing pattern formed by the thickened resist pattern has a finer structure that exceeds the exposure limit. Since the resist pattern thickening material of the present invention contains the nitrogen-containing compound, the resist pattern thickening effect exhibits a good and uniform thickening effect regardless of the type and size of the resist pattern material. There is little dependence on the material and size. Even if free acid is generated during storage of the resist pattern thickening material, the nitrogen-containing compound neutralizes the free acid, so that the resist pattern thickening material is always maintained at a constant pH. And excellent storage stability. Since the pH of the resist pattern thickening material does not drop during storage or due to temperature conditions, stable thickening is possible regardless of temperature and storage conditions during thickening. Thus, a process margin can be ensured, and the applied resist pattern thickening material is not completely crosslinked, and the roughness of the resist pattern surface can be reduced.
The resist pattern manufacturing method of the present invention is characterized in that after forming a resist pattern, the resist pattern thickening material of the present invention is applied so as to cover the surface of the resist pattern. In the method for producing a resist pattern of the present invention, after the resist pattern is formed, when the resist pattern thickening material is applied on the resist pattern, the resist pattern thickening material applied Those in the vicinity of the interface with the resist pattern soak into the resist pattern and crosslink with the material of the resist pattern. Therefore, a surface layer formed by integrating the resist pattern thickening material and the resist pattern is formed on the surface of the resist pattern as an inner layer. The thickened resist pattern thus formed is uniformly thickened by the resist pattern thickening material. For this reason, the resist omission pattern formed by the thickened resist pattern has a finer structure exceeding the exposure limit.
In the method for manufacturing a semiconductor device of the present invention, after forming a resist pattern on an underlayer, the resist pattern thickening material of the present invention is applied so as to cover the surface of the resist pattern, thereby thickening the resist pattern. A thickened resist pattern forming step for forming a thickened resist pattern, and a patterning step for patterning the underlayer by etching using the thickened resist pattern. In the method for manufacturing a semiconductor device of the present invention, after a resist pattern is formed on the underlayer, the resist pattern thickening material is applied onto the resist pattern. Then, among the applied resist pattern thickening material, the material in the vicinity of the interface with the resist pattern soaks into the resist pattern and crosslinks with the resist pattern material. Therefore, a surface layer formed by integrating the resist pattern thickening material and the resist pattern is formed on the surface of the resist pattern as an inner layer. The thickened resist pattern thus formed is uniformly thickened by the resist pattern thickening material. For this reason, the resist omission pattern formed by the thickened resist pattern has a finer structure exceeding the exposure limit. Then, since the base layer is patterned by etching using the pattern as a mask, a high-quality and high-performance semiconductor device having an extremely fine pattern is efficiently manufactured.

According to the present invention, the conventional problems can be solved in response to the demand.
Further, according to the present invention, a light source such as ArF excimer laser light in an existing exposure apparatus can be used as it is at the time of resist pattern patterning, which is excellent in mass productivity, has no dependency on the material and size of the resist pattern, and resist removal. It is possible to provide a method for producing a resist pattern which can be produced stably in a state where the pattern is finely and uniformly exceeding the exposure limit of the light source and the surface roughness is reduced.
Further, according to the present invention, there is no dependency on the material and size of the resist pattern, and when applied to the resist pattern, the resist pattern is efficiently and uniformly thickened stably with the surface roughness reduced. It is possible to provide a resist pattern thickening material suitable for manufacturing a fine resist omission pattern that exceeds the exposure limit of a light source of an existing exposure apparatus.
In addition, according to the present invention, a fine pattern can be formed in an underlayer such as an oxide film by using a finely and uniformly formed resist removal pattern as a mask pattern. A semiconductor device manufacturing method capable of efficiently mass-producing semiconductor devices can be provided.

(Resist pattern thickening material)
The resist pattern thickening material of the present invention comprises a resin, a cross-linking agent, and a nitrogen-containing compound, and further appropriately selected as necessary, a surfactant, a water-soluble aromatic compound, and an aromatic compound. Is contained in part, a resin, an organic solvent, and other components.

The resist pattern thickening material of the present invention is water-soluble or alkali-soluble.
The resist pattern thickening material of the present invention may be in the form of an aqueous solution, a colloidal liquid, an emulsion, or the like, but is preferably an aqueous solution.

-Resin-
The resin is not particularly limited and may be appropriately selected depending on the intended purpose, but is preferably water-soluble or alkali-soluble, and can cause a crosslinking reaction or does not cause a crosslinking reaction, but a water-soluble crosslinking agent. More preferably, it can be mixed with.

When the resin is a water-soluble resin, the water-soluble resin is preferably a water-soluble resin that dissolves 0.1 g or more in water at 25 ° C.
Examples of the water-soluble resin include polyvinyl alcohol, polyvinyl acetal, polyvinyl acetate, polyacrylic acid, polyvinyl pyrrolidone, polyethyleneimine, polyethylene oxide, styrene-maleic acid copolymer, polyvinylamine, polyallylamine, and an oxazoline group-containing water-soluble resin. Examples thereof include resins, water-soluble melamine resins, water-soluble urea resins, alkyd resins, and sulfonamide resins.

When the resin is alkali-soluble, the alkali-soluble resin is preferably an alkali-soluble resin that dissolves 0.1 g or more in a 2.38% tetramethylammonium hydroxide (TMAH) aqueous solution at 25 ° C.
Examples of the alkali-soluble resin include novolak resins, vinylphenol resins, polyacrylic acid, polymethacrylic acid, poly p-hydroxyphenyl acrylate, poly p-hydroxyphenyl methacrylate, and copolymers thereof.

  The said resin may be used individually by 1 type, and may use 2 or more types together. Among these, polyvinyl alcohol, polyvinyl acetal, polyvinyl acetate and the like are preferable.

  The content of the resin in the resist pattern thickening material varies depending on the type and content of the crosslinking agent, the nitrogen-containing compound, etc., and cannot be specified unconditionally, but is appropriately determined according to the purpose. Can do.

-Crosslinking agent-
There is no restriction | limiting in particular as said crosslinking agent, Although it can select suitably according to the objective, The water-soluble thing which bridge | crosslinks with a heat | fever or an acid is preferable, For example, an amino type crosslinking agent is mentioned suitably.
Suitable examples of the amino crosslinking agent include melamine derivatives, urea derivatives, uril derivatives, and the like. These may be used individually by 1 type and may use 2 or more types together.
Examples of the urea derivative include urea, alkoxymethylene urea, N-alkoxymethylene urea, ethylene urea, ethylene urea carboxylic acid, and derivatives thereof.
Examples of the melamine derivative include alkoxymethylmelamine and derivatives thereof.
Examples of the uril derivative include benzoguanamine, glycoluril, and derivatives thereof.

  The content of the cross-linking agent in the resist pattern thickening material differs depending on the resin, the type and content of the nitrogen-containing compound, and cannot be specified unconditionally, but can be appropriately determined according to the purpose. it can.

-Nitrogen compounds-
There is no restriction | limiting in particular as said nitrogen-containing compound, Although it can select suitably according to the objective, For example, an organic substance is mentioned suitably, Among these, a basic thing is preferable.
When the resist pattern thickening material contains the nitrogen-containing compound, it shows a good and uniform thickening effect regardless of the type of the resist pattern material, and the dependence on the resist pattern material is reduced, This is advantageous in that the edge roughness of the resulting thickened resist pattern is improved.

  Specific examples of the nitrogen-containing compound include amines, amides, imides, quaternary ammonium salts, and derivatives thereof. These may be used individually by 1 type and may use 2 or more types together.

  The amine is not particularly limited and may be appropriately selected depending on the intended purpose. For example, hexylamine, heptylamine, octylamine, nonylamine, decylamine, aniline, 2-, 3- or 4-methylaniline, 4-nitroaniline, 1- or 2-naphthylamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diamino-1,2-diphenylethane, 4,4'-diamino-3,3'-dimethyldiphenylmethane 4,4′-diamino-3,3′-diethyldiphenylmethane, dibutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, N-methylaniline, piperidine, diphenylamine, triethylamine, Methylamine, tripropylamine, tributylamine, tripentylamine, trihexylamine, triheptylamine, trioctylamine, trinonylamine, tridecylamine, methyldibutylamine, methyldipentylamine, methyldihexylamine, methyldicyclohexylamine, Methyldiheptylamine, methyldioctylamine, methyldinonylamine, methyldidecylamine, ethyldibutylamine, ethyldipentylamine, ethyldihexylamine, ethyldiheptylamine, ethyldioctylamine, ethyldinonylamine, ethyldidecylamine, Tris [2- (2-methoxyethoxy) ethyl] amine, triisopropanolamine, N, N-dimethylaniline, imidazole, pyridine, 4-methylpi Gin, 4-methylimidazole, bipyridine, 2,2′-dipyridylamine, di-2-pyridyl ketone, 1,2-di (2-pyridyl) ethane, 1,2-di (4-pyridyl) ethane, 1, 3-di (4-pyridyl) propane, 1,2-di (2-pyridyl) ethylene, 1,2-di (4-pyridyl) ethylene, 1,2-bis (4-pyridyloxy) ethane, 4,4 Examples thereof include linear or cyclic amines such as' -dipyridyl sulfide, 4,4'-dipyridyl disulfide, 2,2'-dipiconylamine, and 3,3'-dipiconylamine.

The amide is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include pentano-4-lactam, 5-methyl-2-pyrrolidinone, and ε-caprolactam.
The imide is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include phthalimide and cyclohex-3-ene-1,2-dicarboximide.
The quaternary ammonium salt is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include tetraisopropylammonium hydroxide and tetrabutylammonium hydroxide.

  The content of the nitrogen-containing compound in the resist pattern thickening material varies depending on the resin, the cross-linking agent, etc. and cannot be specified unconditionally, but can be appropriately selected according to the type and content. .

-Surfactant-
The surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include nonionic surfactants, cationic surfactants, anionic surfactants, and amphoteric surfactants. It is done. These may be used individually by 1 type and may use 2 or more types together. Among these, nonionic surfactants are preferable in that they do not contain metal ions.

  The nonionic surfactant is preferably selected from an alkoxylate surfactant, a fatty acid ester surfactant, an amide surfactant, an alcohol surfactant, and an ethylenediamine surfactant. Can be mentioned. Specific examples of these include polyoxyethylene-polyoxypropylene condensate compounds, polyoxyalkylene alkyl ether compounds, polyoxyethylene alkyl ether compounds, polyoxyethylene derivative compounds, sorbitan fatty acid ester compounds, glycerin fatty acid ester compounds, Primary alcohol ethoxylate compound, phenol ethoxylate compound, nonylphenol ethoxylate, octylphenol ethoxylate, lauryl alcohol ethoxylate, oleyl alcohol ethoxylate, fatty acid ester, amide, natural alcohol, ethylenediamine, Secondary alcohol ethoxylates and the like can be mentioned.

  The cationic surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include alkyl cationic surfactants, amide type quaternary cationic surfactants, and ester type quaternary cationic types. Surfactant etc. are mentioned.

  There is no restriction | limiting in particular as said amphoteric surfactant, According to the objective, it can select suitably, For example, an amine oxide type surfactant, a betaine type surfactant, etc. are mentioned.

  As the content of the above-mentioned surfactant in the resist pattern thickening material, depending on the type, content, etc. of the resin, the crosslinking agent, the nitrogen-containing compound, etc., it cannot be specified unconditionally, It can be appropriately selected according to the purpose.

-Water-soluble aromatic compounds-
It is preferable that the resist pattern thickening material contains a water-soluble aromatic compound in that the etching resistance of the resulting resist pattern can be remarkably improved.
The water-soluble aromatic compound is not particularly limited as long as it is an aromatic compound and exhibits water-solubility, and can be appropriately selected according to the purpose. However, 1 g or more is dissolved in 100 g of water at 25 ° C. Those exhibiting water solubility are preferable, those exhibiting water solubility of 3 g or more with respect to 100 g of water at 25 ° C. are more preferable, and those having water solubility of 5 g or more with respect to 100 g of water at 25 ° C. are particularly preferable.

  Examples of the water-soluble aromatic compound include polyphenol compounds, aromatic carboxylic acid compounds, naphthalene polyhydric alcohol compounds, benzophenone compounds, flavonoid compounds, porphine, water-soluble phenoxy resins, aromatic-containing water-soluble dyes, derivatives thereof, These glycosides are exemplified. These may be used alone or in combination of two or more.

  Examples of the polyphenol compound and derivatives thereof include catechin, anthocyanidin (pelargosine type (4′-hydroxy), cyanidin type (3 ′, 4′-dihydroxy), delphinidin type (3 ′, 4 ′, 5′-trihydroxy). )), Flavan-3,4-diol, proanthocyanidins, resorcin, resorcin [4] arene, pyrogallol, gallic acid, derivatives or glycosides thereof, and the like.

  Examples of the aromatic carboxylic acid compound and derivatives thereof include salicylic acid, phthalic acid, dihydroxybenzoic acid, tannin, derivatives and glycosides thereof, and the like.

  Examples of the naphthalene polyhydric alcohol compound and derivatives thereof include naphthalenediol, naphthalenetriol, derivatives or glycosides thereof, and the like.

  Examples of the benzophenone compound and derivatives thereof include alizarin yellow A, derivatives or glycosides thereof, and the like.

  Examples of the flavonoid compound and derivatives thereof include flavone, isoflavone, flavanol, flavonone, flavonol, flavan-3-ol, aurone, chalcone, dihydrochalcone, quercetin, derivatives or glycosides thereof, and the like.

Among the water-soluble aromatic compounds, those having two or more polar groups are preferable, those having three or more are more preferable, and those having four or more are particularly preferable in terms of excellent water solubility.
There is no restriction | limiting in particular as said polar group, Although it can select suitably according to the objective, For example, a hydroxyl group, a carboxyl group, a carbonyl group, a sulfonyl group etc. are mentioned.

  The content of the water-soluble aromatic compound in the resist pattern thickening material can be appropriately determined according to the type and content of the resin, the crosslinking agent, the nitrogen-containing compound, and the like.

-Resin which has aromatic compound in part-
It is preferable that the resist pattern thickening material contains a resin partly containing an aromatic compound because the etching resistance of the resulting resist pattern can be remarkably improved.
The resin partially containing the aromatic compound is not particularly limited and may be appropriately selected depending on the intended purpose. However, it is preferable that a crosslinking reaction can occur, for example, a polyvinyl aryl acetal resin. , Polyvinyl aryl ether resins, polyvinyl aryl ester resins, derivatives thereof, and the like are preferable, and at least one selected from these is preferable, and is an acetyl group in that it exhibits moderate water solubility or alkali solubility. It is more preferable to have These may be used individually by 1 type and may use 2 or more types together.

The polyvinyl aryl acetal resin is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include β-resorcin acetal.
There is no restriction | limiting in particular as said polyvinyl aryl ether resin, According to the objective, it can select suitably, For example, 4-hydroxybenzyl ether etc. are mentioned.
There is no restriction | limiting in particular as said polyvinyl aryl ester resin, According to the objective, it can select suitably, For example, benzoic acid ester etc. are mentioned.

  There is no restriction | limiting in particular as a manufacturing method of the said polyvinyl aryl acetal resin, Although it can select suitably according to the objective, For example, the manufacturing method using a well-known polyvinyl acetal reaction etc. are mentioned suitably. The production method is, for example, a method in which an acetalization reaction is performed between polyvinyl alcohol and a stoichiometrically required amount of aldehyde under an acid catalyst. Specifically, USP 5,169, Preferable examples include the methods disclosed in U.S. Patent No. 897, No. 5,262,270, and Japanese Patent Laid-Open No. 5-78414.

  The method for producing the polyvinyl aryl ether resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the copolymerization reaction of the corresponding vinyl aryl ether monomer and vinyl acetate, the presence of a basic catalyst Examples include etherification reaction between polyvinyl alcohol and an aromatic compound having a halogenated alkyl group (Williamson's ether synthesis reaction). Specific examples include JP-A-2001-40086 and JP-A-2001-181383. A method disclosed in JP-A-6-116194 is preferable.

  The method for producing the polyvinyl aryl ester resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, the copolymerization reaction of the corresponding vinyl aryl ester monomer and vinyl acetate, the presence of a basic catalyst Below, esterification reaction of polyvinyl alcohol and an aromatic carboxylic acid halide compound, etc. are mentioned.

  The aromatic compound in the resin partially containing the aromatic compound is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include monocyclic aromatic benzene derivatives and pyridine derivatives. Preferred examples include compounds in which a plurality of aromatic rings are linked (polycyclic aromatics such as naphthalene and anthracene).

  Examples of the aromatic compound in the resin partially containing the aromatic compound include a hydroxyl group, a cyano group, an alkoxyl group, a carboxyl group, an amino group, an amide group, an alkoxycarbonyl group, a hydroxyalkyl group, a sulfonyl group, and an acid. From the viewpoint of water solubility, it is preferable to have at least one functional group such as an anhydride group, a lactone group, a cyanate group, an isocyanate group, a ketone group, or a sugar derivative. A hydroxyl group, an amino group, a sulfonyl group, a carboxyl group More preferably, it has at least one functional group selected from the group and groups derived from these derivatives.

The molar content of the aromatic compound in the resin having a part of the aromatic compound is not particularly limited as long as the etching resistance is not affected, and can be appropriately selected according to the purpose. Is required, it is preferably 5 mol% or more, more preferably 10 mol% or more.
In addition, the molar content of the aromatic compound in the resin partially including the aromatic compound can be measured using, for example, NMR.

  The content of the resin having the aromatic compound in part in the resist pattern thickening material is appropriately determined according to the type and content of the resin, the crosslinking agent, the nitrogen-containing compound, and the like. can do.

-Organic solvent-
When the organic solvent is contained in the resist pattern thickening material, the solubility of the resin, the cross-linking agent, the nitrogen-containing compound, etc. in the resist pattern thickening material can be improved.

  The organic solvent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include alcohol-based organic solvents, chain ester-based organic solvents, cyclic ester-based organic solvents, ketone-based organic solvents, and chain ethers. And organic ether solvents and cyclic ether organic solvents.

Examples of the alcohol organic solvent include methanol, ethanol, propyl alcohol, isopropyl alcohol, butyl alcohol, and the like.
Examples of the chain ester organic solvent include ethyl lactate and propylene glycol methyl ether acetate (PGMEA).
Examples of the cyclic ester organic solvent include lactone organic solvents such as γ-butyrolactone.
Examples of the ketone organic solvent include ketone organic solvents such as acetone, cyclohexanone, and heptanone.
Examples of the chain ether organic solvent include ethylene glycol dimethyl ether.
Examples of the cyclic ether include tetrahydrofuran, dioxane, and the like.

  These organic solvents may be used individually by 1 type, and may use 2 or more types together. Among these, the thing which has a boiling point of about 80-200 degreeC is preferable at the point which can thicken finely.

  The content of the organic solvent in the resist pattern thickening material can be appropriately determined according to the type and content of the resin, the crosslinking agent, the nitrogen-containing compound, the surfactant, and the like.

-Other ingredients-
The other components are not particularly limited as long as they do not impair the effects of the present invention, and can be appropriately selected according to the purpose. Various known additives such as thermal acid generators, amines, amides, Quenchers such as ammonium chlorine are listed.
The content of the other components in the resist pattern thickening material can be appropriately determined according to the type and content of the resin, the crosslinking agent, the nitrogen-containing compound, and the like.

-Use etc.-
The resist pattern thickening material of the present invention can be used by coating on the resist pattern.
In addition, at the time of the application, the surfactant may not be contained in the resist pattern thickening material but may be separately applied before applying the resist pattern thickening material.

When the resist pattern thickening material is applied onto the resist pattern and crosslinked, the resist pattern is thickened, a surface layer is formed on the resist pattern, and a thickened resist pattern is formed.
At this time, since the nitrogen-containing compound is contained in the resist pattern thickening material, it depends on the temperature condition when thickening the resist pattern, the storage condition of the resist pattern thickening material, and the like. The resist pattern is stably thickened, and there is no dependency on the pattern size depending on the material of the resist pattern, and the thickened resist pattern is uniform, that is, obtained with improved edge roughness. It is done.
The diameter or width of the resist omission pattern formed by the thickened resist pattern thus obtained is smaller than the diameter or width of the resist omission pattern formed by the resist pattern. A finer resist omission pattern is formed beyond the exposure limit of the light source of the exposure apparatus used when patterning the resist pattern. For example, when ArF excimer laser light is used when patterning the resist pattern, the resist pattern obtained is thickened using the resist pattern thickening material of the present invention to form a thickened resist pattern. Then, the resist omission pattern formed by the thickened resist pattern provides a fine resist omission pattern similar to that obtained when patterning using an electron beam.
At this time, the thickness of the resist pattern can be controlled within a desired range by appropriately adjusting the viscosity, coating thickness, baking temperature, baking time, and the like of the resist pattern thickening material. .

-Resist pattern material-
The material of the resist pattern (the resist pattern to which the resist pattern thickening material of the present invention is applied) is not particularly limited and can be appropriately selected from known resist materials according to the purpose. For example, g-line resist, i-line resist, KrF resist, ArF that can be patterned with g-line, i-line, KrF excimer laser, ArF excimer laser, F2 excimer laser, electron beam, etc. A resist, an F2 resist, an electron beam resist and the like are preferable. These may be chemically amplified or non-chemically amplified. Among these, KrF resist, ArF resist, etc. are preferable, and ArF resist is more preferable.
Specific examples of the resist pattern material include novolak resist, PHS resist, acrylic resist, cycloolefin-maleic anhydride (COMA) resist, cycloolefin resist, and hybrid (alicyclic acrylic). -COMA copolymer) resist and the like. These may be modified with fluorine.

  The resist pattern forming method, size, thickness, and the like are not particularly limited and can be appropriately selected according to the purpose. In particular, the thickness is appropriately determined depending on the substrate to be processed, etching conditions, and the like. However, it is generally about 0.2 to 200 μm.

The thickening of the resist pattern using the resist pattern thickening material of the present invention will be described below with reference to the drawings.
As shown in FIG. 1A, after forming a resist pattern 3 on an underlayer (base material) 5, a resist pattern thickening material 1 is applied to the surface of the resist pattern 3 and prebaked (heated and dried). ) To form a coating film. Then, as shown in FIG. 1 (b), the resist pattern thickening material 1 is mixed (impregnated) into the resist pattern 3 at the interface between the resist pattern 3 and the resist pattern thickening material 1, and the inner layer resist pattern The mixed (impregnated) portion is cross-linked at the interface between 10b (resist pattern 3) and resist pattern thickening material 1 to form a surface layer 10a. At this time, since the nitrogen-containing compound is contained in the resist pattern thickening material 1, the temperature conditions and the resist pattern thickening material 1 when the inner resist pattern 10b (resist pattern 3) is thickened. The inner layer resist pattern 10b (resist pattern 3) is thickened stably regardless of the storage conditions.
Thereafter, as shown in FIG. 1 (c), by performing development processing, a portion of the applied resist pattern thickening material 1 that is not crosslinked with the resist pattern 3 or a portion that is weakly crosslinked (water-soluble) The thickened resist pattern 10 is formed (developed) in a state where the high portion is dissolved and removed, and the thickness is increased uniformly with improved edge roughness.
The development treatment may be water development or development with an alkaline developer.

  The thickened resist pattern 10 has a surface layer 10a formed by crosslinking the resist pattern thickening material 1 on the surface of the inner layer resist pattern 10b (resist pattern 3). Since the thickened resist pattern 10 is thicker than the resist pattern 3 by the thickness of the surface layer 10a, the width of the resist removal pattern formed by the thickened resist pattern 10 is formed by the resist pattern 3. It is smaller than the width of the resist omission pattern. For this reason, the resist omission pattern can be finely formed exceeding the exposure limit of the light source in the exposure apparatus when forming the resist pattern 3, and the resist omission pattern formed by the thickened resist pattern 10 is the resist pattern. It is finer than the resist omission pattern formed by 3b.

  The surface layer 10 a in the thickened resist pattern 10 is formed of the resist pattern thickening material 1. When the resist pattern thickening material 1 contains at least one of the aromatic compound and a resin partially containing the aromatic compound, the resist pattern 3 (inner layer resist pattern 10b) is a material having poor etching resistance. Even if it exists, since it has the surface layer 10a containing at least one of the resin which contains the said aromatic compound and the said aromatic compound in the surface on the surface, the thickening resist pattern 10 obtained is remarkably excellent in etching resistance.

-Use-
The resist pattern thickening material of the present invention can be suitably used to thicken a resist pattern and to refine a resist omission pattern beyond the exposure limit. Moreover, the resist pattern thickening material of the present invention can be used particularly preferably in the method for manufacturing a semiconductor device of the present invention.
Further, when the resist pattern thickening material of the present invention contains at least one of the aromatic compound and the resin partially containing the aromatic compound, it is exposed to plasma or the like, thereby improving the etching resistance of the surface. Resin comprising the aromatic compound and the aromatic compound in part as a material for the pattern, which can be suitably used for coating or thickening a pattern formed of a resin or the like that needs to be formed When at least one of these cannot be used, it can be used more suitably.

(Resist pattern manufacturing method)
In the method for producing a resist pattern of the present invention, after forming the resist pattern, the resist pattern thickening material of the present invention is applied so as to cover the surface of the resist pattern.

Suitable examples of the resist pattern material include those described above in the resist pattern thickening material of the present invention.
The resist pattern can be formed according to a known method.
The resist pattern can be formed on a base (base material), and the base (base material) is not particularly limited and may be appropriately selected depending on the intended purpose. In the case of being formed, the base (base material) is usually a substrate such as a silicon wafer, various oxide films or the like.

The method for applying the resist pattern thickening material is not particularly limited, and can be appropriately selected from known application methods according to the purpose. For example, a spin coating method is preferably used. In the case of the spin coating method, the conditions are, for example, a rotational speed of about 100 to 10,000 rpm, preferably 800 to 5,000 rpm, a time of about 1 second to 10 minutes, and preferably 1 to 90 seconds. .
The coating thickness at the time of the coating is usually about 100 to 10,000 mm (10 to 1,000 nm), preferably about 2,000 to 5,000 mm (200 to 500 nm).
In addition, at the time of the application, the surfactant may not be contained in the resist pattern thickening material but may be separately applied before applying the resist pattern thickening material.

Pre-baking (heating and drying) the applied resist pattern thickening material during or after the application is performed at the interface between the resist pattern and the resist pattern thickening material. This is preferable in that mixing (impregnation) of the material into the resist pattern can be efficiently generated.
The pre-baking (heating / drying) conditions and method are not particularly limited as long as the resist pattern is not softened, and can be appropriately selected according to the purpose. For example, the temperature is 40 to 120 ° C. 70 to 100 ° C is preferable, the time is about 10 seconds to 5 minutes, and 40 seconds to 100 seconds is preferable.

In addition, after the pre-baking (heating / drying), the applied resist pattern thickening material is subjected to cross-linking baking (cross-linking reaction) at the interface between the resist pattern and the resist pattern thickening material. This is preferable in that the crosslinking reaction of the mixed (impregnated) portion can be efficiently advanced.
The conditions and method for the cross-linking bake (cross-linking reaction) are not particularly limited and can be appropriately selected according to the purpose. However, the temperature condition is usually higher than that for the pre-bake (heating / drying). Adopted. The conditions for the crosslinking baking (crosslinking reaction) are, for example, a temperature of about 70 to 150 ° C., preferably 90 to 130 ° C., a time of about 10 seconds to 5 minutes, and preferably 40 seconds to 100 seconds.

Further, after the cross-linking bake (cross-linking reaction), the applied resist pattern thickening material is preferably developed. In this case, of the applied resist pattern thickening material, a portion that is not cross-linked with the resist pattern or a weakly cross-linked portion (highly water-soluble portion) is dissolved and removed, and the thickened resist pattern is developed (obtained). ) Is preferable.
The development processing is as described above.

Here, the method for producing a resist pattern of the present invention will be described below with reference to the drawings.
As shown in FIG. 2 (a), after applying a resist material 3a on the base layer (base material) 5, after patterning this to form a resist pattern 3 as shown in FIG. 2 (b), As shown in FIG. 2C, the resist pattern thickening material 1 is applied to the surface of the resist pattern 3 and prebaked (heated and dried) to form a coating film. Then, the resist pattern thickening material 1 is mixed (impregnated) into the resist pattern 3 at the interface between the resist pattern 3 and the resist pattern thickening material 1, and as shown in FIG. The mixed (impregnated) portion is cross-linked at the interface between the resist pattern thickening material 1 and the resist pattern thickening material 1. Thereafter, as shown in FIG. 2 (e), when development processing is performed, a portion of the applied resist pattern thickening material 1 that is not crosslinked with the resist pattern 3 or a portion that is weakly crosslinked (highly water-soluble). The thickened resist pattern 10 having the surface layer 10a is formed (developed) on the inner layer resist pattern 10b (resist pattern 3).
The development treatment may be water development or development with a weak alkaline aqueous solution, but water development is preferable in that the development treatment can be efficiently performed at low cost.

  The thickened resist pattern 10 has a surface layer 10a formed by crosslinking the resist pattern thickening material 1 on the surface of the inner layer resist pattern 10b (resist pattern 3). Since the resist pattern 10 is thickened by the thickness of the surface layer 10a compared to the resist pattern 3 (inner layer resist pattern 10b), the width of the resist removal pattern formed by the thickened resist pattern 10 is the resist pattern. 3 (the inner resist pattern 10b) is smaller than the width of the resist missing pattern, and the resist missing pattern formed by the thickened resist pattern 10 is fine.

  The surface layer 10a in the thickened resist pattern 10 is formed of the resist pattern thickening material 1, and the resist pattern thickening material 1 contains at least one of the aromatic compound and the resin partially containing the aromatic compound. When it contains, it is remarkably excellent in etching resistance. In this case, even if the resist pattern 3 (inner layer resist pattern 10b) is a material having poor etching resistance, the thickened resist pattern 10 having the surface layer 10a having excellent etching resistance on the surface thereof can be formed.

  The resist pattern manufactured by the method for manufacturing a resist pattern of the present invention has a surface layer formed by crosslinking the resist pattern thickening material of the present invention on the surface of the resist pattern. When the resist pattern thickening material contains at least one of the aromatic compound and a resin partially containing the aromatic compound, even if the resist pattern is a material having poor etching resistance, the resist pattern A resist pattern having a surface layer with excellent etching resistance on the surface can be efficiently produced. Further, since the thickened resist pattern manufactured by the method for manufacturing a resist pattern of the present invention is thickened by the thickness of the surface layer compared to the resist pattern, the thickened resist pattern 10 manufactured is The width of the resist omission pattern formed by the above is smaller than the width of the resist omission pattern formed by the resist pattern. Therefore, according to the method for producing a resist pattern of the present invention, a fine resist omission pattern is efficiently produced. can do.

The thickened resist pattern manufactured by the resist pattern thickening material of the present invention has a surface layer formed on the resist pattern by the resist pattern thickening material of the present invention.
The thickened resist pattern preferably has excellent etching resistance, and the etching rate (Å / s) is preferably equal to or higher than that of the resist pattern. Specifically, the ratio (resist pattern / surface layer) between the etching rate (Å / s) of the surface layer and the etching rate (Å / s) of the resist pattern when measured under the same conditions is 1.1. Preferably, it is 1.2 or more, more preferably 1.3 or more.
The etching rate (Å / s) is measured, for example, by performing a predetermined time etching process using a known etching apparatus, measuring the film thickness of the sample, and calculating the film thickness per unit time. be able to.

The surface layer can be suitably formed by using the resist pattern thickening material of the present invention, and partially includes the aromatic compound and the aromatic compound from the viewpoint of improving etching resistance. It is preferable to contain at least one of the resins.
Whether or not the surface layer contains at least one of the aromatic compound and a resin partially containing the aromatic compound can be confirmed, for example, by analyzing an IR absorption spectrum for the surface layer. it can.

  The thickened resist pattern may include at least one of the aromatic compound and a resin partially including the aromatic compound. In this case, it may be designed such that the content of at least one of the aromatic compound and the resin partially including the aromatic compound gradually decreases from the surface layer toward the inside.

The thickened resist pattern may have a structure where the boundary between the resist pattern and the surface layer is clear or an unclear structure.
The thickened resist pattern manufactured by the resist pattern manufacturing method of the present invention includes, for example, a mask pattern, a reticle pattern, a magnetic head, an LCD (liquid crystal display), a PDP (plasma display panel), a SAW filter (surface acoustic wave filter). ), Etc., optical components used for connection of optical wiring, microparts such as microactuators, and semiconductor devices, and can be suitably used for the semiconductor device manufacturing method of the present invention described later. Can be used.

(Method for manufacturing semiconductor device)
The method for manufacturing a semiconductor device of the present invention includes a thickened resist pattern forming step and a patterning step, and further includes other steps appropriately selected as necessary.

In the thickening resist pattern forming step, after forming a resist pattern on the underlayer, the resist pattern thickening material of the present invention is applied so as to cover the surface of the resist pattern, thereby thickening the resist pattern. Forming a thickened resist pattern. Details in the thickening resist pattern forming step are the same as those in the method for producing a resist pattern of the present invention.
Examples of the base layer include surface layers of various members in the semiconductor device, and preferred examples include a substrate such as a silicon wafer or a surface layer thereof, various oxide films, and the like. The resist pattern is as described above. The application method is as described above. Further, after the coating, it is preferable to perform the above-described pre-baking, cross-linking baking or the like.

The patterning step is a step of patterning the base layer by performing etching (using as a mask pattern or the like) using the thickened resist pattern formed by the thickened resist pattern forming step.
There is no restriction | limiting in particular as the said etching method, Although it can select suitably according to the objective from well-known methods, For example, dry etching is mentioned suitably. The etching conditions are not particularly limited and can be appropriately selected depending on the purpose.

  As said other process, a surfactant application | coating process, a development processing process, etc. are mentioned suitably, for example.

The surfactant applying step is a step of applying the surfactant to the surface of the resist pattern before the thickening resist pattern forming step.
The surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, those described above are preferably used, and examples include polyoxyethylene-polyoxypropylene condensate compounds, polyoxyalkylene alkyl ethers. Compounds, polyoxyethylene alkyl ether compounds, polyoxyethylene derivative compounds, sorbitan fatty acid ester compounds, glycerin fatty acid ester compounds, primary alcohol ethoxylate compounds, phenol ethoxylate compounds, nonylphenol ethoxylates, octylphenol ethoxylates, lauryl alcohol Ethoxylate, oleyl alcohol ethoxylate, fatty acid ester, amide, natural alcohol, ethylenediamine, secondary alcohol ethoxylate, alcohol Kirukachion system, amide quaternary cationic, ester quaternary cationic, amine oxide, and the like betaine.

  The development processing step is a step of developing the applied resist pattern thickening material after the thickening resist pattern forming step and before the patterning step. The development processing is as described above.

  According to the semiconductor device manufacturing method of the present invention, for example, various semiconductor devices including flash memory, DRAM, FRAM, and the like can be efficiently manufactured.

  Examples of the present invention will be specifically described below, but the present invention is not limited to these examples.

Example 1
-Preparation of resist pattern thickening material-
Resist pattern thickening materials A to F of the present invention having the compositions shown in Table 1 were prepared. In Table 1, the unit of numerical values in parentheses represents parts by mass. “KW-3” in the “resin” column represents a polyvinyl acetal resin (manufactured by Sekisui Chemical Co., Ltd.). In the “crosslinking agent” column, “uril” represents tetramethoxymethylglycoluril, and “urea” represents N, N′-dimethoxymethyldimethoxyethylene urea. “TN-80” in the “Surfactant” column represents a nonionic surfactant (Asahi Denka Co., Ltd., primary alcohol ethoxylate ). Further, as a main solvent component excluding the resin, the cross-linking agent and the nitrogen-containing compound, a mixed solution of pure water (deionized water) and isopropyl alcohol (mass ratio is pure water (deionized water): isopropyl alcohol = 82.6: 0.4) was used.

-Manufacture of resist patterns-
The resist pattern thickening materials A to F of the present invention prepared as described above were first applied by spin coating on a hole pattern (200 nm in diameter) formed by the ArF resist (manufactured by Sumitomo Chemical Co., Ltd., PAR700). After coating at 1,000 rpm / 5 s and then at 3,500 rpm / 40 s, the pre-baking is performed at 85 ° C./70 s, and the crosslinking baking is further performed at 110 ° C./70 s. The resist pattern thickening materials A to F are rinsed with pure water for 60 seconds, uncrosslinked portions are removed, and the resist pattern thickened with the resist pattern thickening materials A to F is developed to increase the thickness. A resist pattern was produced.

  The size of the resist omission pattern formed by the manufactured thickened resist pattern is shown in Table 2 together with the initial pattern size (size of the resist omission pattern formed by the resist pattern before thickening). In Table 2, “A” to “F” correspond to the resist pattern thickening materials A to F.

  A line & space pattern (line size: 1.0 μm, sparse size: 0) formed from the ArF resist (manufactured by Sumitomo Chemical Co., Ltd., PAR700) using the resist pattern thickening materials A to F of the present invention prepared as above. .15 .mu.m) by spin coating, first applied under conditions of 1,000 rpm / 5 s, then under conditions of 3,500 rpm / 40 s, and then prebaked under conditions of 85.degree. C./70 s. After performing the above-mentioned cross-linking bake under the condition of ℃ / 70 s, the resist pattern thickening materials A to F are rinsed with pure water for 60 seconds, the uncrosslinked portion is removed, and the resist pattern thickening materials A to F are thickened. A thickened resist pattern was produced by developing the thickened resist pattern.

  The size of the resist omission pattern formed by the manufactured thickened resist pattern is shown in Table 3 together with the initial pattern size (size of the resist omission pattern formed by the resist pattern before thickening). In Table 3, “A” to “F” correspond to the resist pattern thickening materials A to F.

  According to the resist pattern thickening material of the present invention, it can be applied to both hole patterns and line & space patterns, and there is no material dependency of the resist pattern, and the edge roughness is improved uniformly. It was found that it was possible to increase the wall thickness. When the resist pattern thickening material of the present invention is used for forming a hole pattern, the inner diameter of the hole pattern can be narrowed and made fine, and when used for forming a line & space pattern, It was found that the space width (interval between line patterns) can be made small and fine, and when used for forming an isolated pattern, the area of the isolated pattern can be increased.

Next, the resist layer thickening materials C, D and F of the present invention were applied to the surface of the resist formed on the silicon substrate to form a surface layer having a thickness of 0.5 μm. These surface layers, the KrF resist for comparison (manufactured by Shipley Co., Ltd., UV-6), and polymethyl methacrylate (PMMA) for comparison are etched with an etching apparatus (parallel plate type RIE apparatus, Fujitsu Limited). The product was etched for 3 minutes under the conditions of Pμ = 200 W, pressure = 0.02 Torr, CF ₄ gas = 100 sccm, the amount of film reduction of the sample was measured, the etching rate was calculated, and the KrF resist Relative evaluation was performed based on the etching rate.

  From the results shown in Table 4, it can be seen that the resist pattern thickening material of the present invention contains the nitrogen-containing compound and thus is close to the KrF resist and has etching resistance significantly superior to the PMMA.

(Example 2)
As shown in FIG. 3A, an interlayer insulating film 12 was formed on the silicon substrate 11, and as shown in FIG. 3B, a titanium film 13 was formed on the interlayer insulating film 12 by sputtering. Next, as shown in FIG. 3C, a resist pattern 14 is formed by a known photolithography technique, and this is used as a mask, and the titanium film 13 is patterned by reactive ion etching to form an opening 15a. . Subsequently, as shown in FIG. 3D, the resist pattern 14 was removed by reactive ion etching, and an opening 15b was formed in the interlayer insulating film 12 using the titanium film 13 as a mask.

Next, the titanium film 13 is removed by wet processing, and as shown in FIG. 4A, a TiN film 16 is formed on the interlayer insulating film 12 by a sputtering method. Subsequently, a Cu film 17 is formed on the TiN film 16. A film was formed by electrolytic plating. Next, as shown in FIG. 4B, planarization is performed by leaving the barrier metal and the Cu film (first metal film) only in the groove corresponding to the opening 15b (FIG. 3D) by CMP. A single layer of wiring 17a was formed.
Next, as shown in FIG. 4C, after an interlayer insulating film 18 is formed on the first layer wiring 17a, FIGS. 3B to 3D, FIGS. 4A and 4B, Similarly, as shown in FIG. 4D, a Cu plug (second metal film) 19 and a TiN film 17a for connecting the first layer wiring 17a to an upper layer wiring to be formed later were formed.

By repeating the above steps, a multilayer wiring structure including a first layer wiring 17a, a second layer wiring 20, and a third layer wiring 21 was provided on the silicon substrate 11, as shown in FIG. A semiconductor device was manufactured. In FIG. 5, the illustration of the barrier metal layer formed below the wiring of each layer is omitted.
In Example 2, the resist pattern 14 is a thickened resist pattern manufactured in the same manner as in Example 1 using the resist pattern thickening material of the present invention.

(Example 3)
-Flash memory and its manufacture-
Example 3 is an example of a semiconductor device of the present invention using the resist pattern thickening material of the present invention and a manufacturing method thereof. In this Example 3, the following resist films 26, 27, 29, 32 and 34 are thickened by the same method as in Examples 1 and 2 using the resist pattern thickening material of the present invention. It has been done.

  (A) and (b) in FIG. 6 are top views (plan views) of a FLASH EPROM called a FLOTOX type or an ETOX type, and (a) to (c) in FIG. 7 and (d) to (d) in FIG. FIGS. 9 (g) to 9 (i) are cross-sectional schematic views for explaining an example of the manufacturing method of the FLASH EPROM. FIGS. 7 to 9 show the memory cell portion (first element). FIG. 6 is a schematic cross-sectional view (A-direction cross-section) in the gate width direction (X direction in FIG. 6) of a portion where a MOS transistor having a floating gate electrode is formed. FIG. 6 is a schematic cross-sectional view (B-direction cross-section) of the memory cell portion in the gate length direction (Y direction in FIG. 6) orthogonal to the X direction, and the right figure shows the MOS in the peripheral circuit portion (second element region). Transistor shape It is the cross section (A direction cross section in FIG. 6) schematic of the part formed.

First, as shown in FIG. 7A, a field oxide film 23 made of a SiO ₂ film was selectively formed in an element isolation region on a p-type Si substrate 22. Thereafter, the first gate insulating film 24a in the MOS transistor in the memory cell portion (first element region) is formed by SiO ₂ film by thermal oxidation so that the thickness becomes 100 to 300 mm (10 to 30 nm). In the process, the second gate insulating film 24b in the MOS transistor in the peripheral circuit portion (second element region) was formed of a SiO ₂ film by thermal oxidation so as to have a thickness of 100 to 500 mm (10 to 50 nm). When the first gate insulating film 24a and the second gate insulating film 24b have the same thickness, an oxide film may be formed simultaneously in the same process.

Next, in order to form a MOS transistor having an n-type depletion type channel in the memory cell portion (left and center views in FIG. 7A), the peripheral circuit portion ( The right side of FIG. 7A was masked with the resist film 26. Then, phosphorus (P) or arsenic (As) with a dose amount of 1 × 10 ¹¹ to 1 × 10 ¹⁴ cm ⁻² is introduced as an n-type impurity into a channel region immediately below the floating gate electrode by an ion implantation method, A first threshold control layer 25a was formed. Note that the dose amount and the conductivity type of the impurity at this time can be appropriately selected depending on whether the depletion type or the accumulation type is used.

Next, in order to form a MOS transistor having an n-type depletion type channel in the peripheral circuit portion (the right diagram of FIG. 7B), a memory cell portion (FIG. The left figure and the middle figure of FIG. Then, phosphorus (P) or arsenic (As) having a dose amount of 1 × 10 ¹¹ to 1 × 10 ¹⁴ cm ⁻² is introduced as an n-type impurity into a channel region immediately below the gate electrode by an ion implantation method. Two threshold control layers 25b were formed.

  Next, as a floating gate electrode of the MOS transistor in the memory cell portion (the left diagram and the central diagram in FIG. 7C) and a gate electrode of the MOS transistor in the peripheral circuit portion (the right diagram in FIG. 7C) A first polysilicon film (first conductor film) 28 having a thickness of 500 to 2,000 mm (50 to 200 nm) was formed on the entire surface.

  Thereafter, as shown in FIG. 8D, the first polysilicon film 28 is patterned with a resist film 29 formed as a mask, and the MOS transistor of the memory cell portion (the left and center views of FIG. 8D) is formed. The floating gate electrode 28a was formed. At this time, as shown in FIG. 8D, patterning is performed so that the X dimension has a final dimension width, and the Y direction is not patterned, and the region that becomes the S / D region layer is covered with a resist film 29. I left it.

Next, as shown in the left diagram and the central diagram in FIG. 8E, after removing the resist film 29, the capacitor insulating film 30a made of SiO ₂ film is formed so as to cover the floating gate electrode 28a. It was formed by thermal oxidation so that the thickness was about 200 to 500 mm (20 to 50 nm). At this time, the capacitor insulating film 30b made of the SiO ₂ film is also formed on the first polysilicon film 28 in the peripheral circuit portion (the right diagram in FIG. 8E). Here, the capacitor insulating films 30a and 30b are formed of only the SiO ₂ film, but may be formed of a composite film in which two or _three SiO ₂ films and Si ₃ N ₄ films are laminated.

  Next, as shown in FIG. 8E, the thickness of the second polysilicon film (second conductor film) 31 to be the control gate electrode is set so as to cover the floating gate electrode 28a and the capacitor insulating film 30a. It formed so that it might become 500-2,000 mm (50-200 nm).

  Next, as shown in FIG. 8 (f), the memory cell portion (the left and center views of FIG. 8 (f)) is masked with a resist film 32, and the peripheral circuit portion (the right side of FIG. 8 (f)) is masked. The second polysilicon film 31 and the capacitor insulating film 30b in the figure were sequentially removed by etching, and the first polysilicon film 28 was exposed.

  Next, as shown in FIG. 9G, the second polysilicon film 31, the capacitor insulating film 30a, and the X direction of the memory cell portion (the left diagram and the central diagram in FIG. 9G) are patterned. Using the resist film 32 as a mask, the first polysilicon film 28a is patterned in the Y direction so as to have the final dimensions of the first gate portion 33a, and the control gate electrode 31a / capacitor having a width of about 1 μm in the Y direction. A stack of insulating film 30c / floating gate electrode 28c is formed, and a second gate portion is formed on resist film 32 as a mask with respect to first polysilicon film 28 in the peripheral circuit portion (the right diagram in FIG. 9G). Patterning was performed to obtain a final dimension of 33b to form a gate electrode 28b having a width of about 1 μm.

Next, using the stack of the control gate electrode 31a / capacitor insulating film 30c / floating gate electrode 28c in the memory cell portion (the left and center views of FIG. 9H) as a mask, the silicon substrate 22 in the element formation region is dosed. An amount of 1 × 10 ¹⁴ to 1 × 10 ¹⁶ cm ⁻² of phosphorus (P) or arsenic (As) is introduced by ion implantation to form n-type S / D region layers 35a and 35b, and the peripheral circuit Using the gate electrode 28b of the portion (right of FIG. 8H) as a mask, phosphorus (P) with a dose of 1 × 10 ¹⁴ to 1 × 10 ¹⁶ cm ⁻² as an n-type impurity in the Si substrate 22 in the element formation region Alternatively, arsenic (As) was introduced by ion implantation to form S / D region layers 36a and 36b.

Next, the first gate portion 33a of the memory cell portion (the left view and the center view of FIG. 9 (i)) and the second gate portion 33b of the peripheral circuit portion (the right view of FIG. 9 (i)) are connected to the PSG. An interlayer insulating film 37 made of a film was formed so as to have a thickness of about 5,000 mm (500 nm).
Thereafter, contact holes 38a and 38b and contact holes 39a and 39b are formed in the interlayer insulating film 37 formed on the S / D region layers 35a and 35b and the S / D region layers 36a and 36b, and then the S / D electrode 40a. And 40b and S / D electrodes 41a and 41b were formed.
As described above, as shown in FIG. 9I, a FLASH EPROM was manufactured as a semiconductor device.

In this FLASH EPROM, the second gate insulating film 24b of the peripheral circuit portion (the right diagram in FIGS. 7A to 9F) is formed from the first polysilicon film 28 or the gate electrode 28b from the beginning to the end. Since it is covered (the right figure in FIG. 8C to FIG. 9F), the second gate insulating film 24b keeps the thickness when it is first formed. Therefore, the thickness of the second gate insulating film 24b can be easily controlled, and the conductivity type impurity concentration for controlling the threshold voltage can be easily adjusted.
In the above embodiment, the first gate portion 33a is formed by first patterning with a predetermined width in the gate width direction (X direction in FIG. 6) and then patterning in the gate length direction (Y direction in FIG. 6). However, the pattern is patterned with a predetermined width in the gate length direction (Y direction in FIG. 6) and then patterned in the gate width direction (X direction in FIG. 6). It is good.

The manufacturing examples of FLASH EPROM shown in FIGS. 10A to 10C are the same as those shown in FIGS. 10A to 10C except that the steps shown in FIG. Is the same as in the above embodiment. That is, as shown in FIG. 10A, the second polysilicon film 31 and the peripheral circuit portion (the right view of FIG. 10A) of the memory cell portion (the left view and the center view in FIG. 10A). ) On the first polysilicon film 28, a refractory metal film (fourth conductor film) 42 made of a tungsten (W) film or a titanium (Ti) film is made to have a thickness of about 2,000 mm (200 nm). This embodiment differs from the above embodiment only in that a polycide film is provided. The steps after FIG. 10A, that is, the steps shown in FIGS. 10B to 10C were performed in the same manner as FIGS. 9G to 9I. The description of the same steps as those in FIGS. 9G to 9I is omitted, and in FIGS. 10A to 10C, the same steps as those in FIGS. 9G to 9I are denoted by the same symbols.
As a result, as shown in FIG. 10C, a FLASH EPROM was manufactured as a semiconductor device.

In this FLASH EPROM, since the refractory metal films (fourth conductor films) 42a and 42b are provided on the control gate electrode 31a and the gate electrode 28b, the electric resistance value can be further reduced.
Here, although the refractory metal films (fourth conductor film) 42a and 42b are used as the refractory metal film (fourth conductor film), a refractory metal silicide film such as a titanium silicide (TiSi) film is used. May be used.

The manufacturing example of the FLASH EPROM shown in FIGS. 11A to 11C is the same as that of the above-described embodiment in the second gate portion 33c of the peripheral circuit portion (second element region) (the right diagram in FIG. 11A). Similarly to the first gate portion 33a of the memory cell portion (first element region) (left and center views in FIG. 11A), the first polysilicon film 28b (first conductor film) / SiO _{2 is formed.} A structure of film 30d (capacitor insulating film) / second polysilicon film 31b (second conductor film) is formed, and as shown in FIG. 11B or 11C, the first polysilicon film 28b and the second polysilicon film are formed. This embodiment is the same as the above embodiment except that the gate electrode is formed by short-circuiting the film 31b.

Here, as shown in FIG. 11B, the first polysilicon film 28b (first conductor film) / SiO ₂ film 30d (capacitor insulating film) / second polysilicon film 31b (second conductor film). An opening 52a penetrating through the second gate portion 33c shown in FIG. 11A, for example, is formed on an insulating film 54, for example, and a third conductor film such as a W film is formed in the opening 52a. Alternatively, the first polysilicon film 28b and the second polysilicon film 31b are short-circuited by embedding a refractory metal film 53a such as a Ti film. Further, as shown in FIG. 11C, an opening 52b penetrating the first polysilicon film 28b (first conductor film) / SiO ₂ film 30d (capacitor insulating film) is formed, and the bottom of the opening 52b is formed. After exposing the first polysilicon film 28b as the lower layer, a third conductor film, for example, a refractory metal film 53b such as a W film or a Ti film is embedded in the opening 52b, thereby forming the first polysilicon film. 28b and the second polysilicon film 31b are short-circuited.

In this FLASH EPROM, since the second gate portion 33c of the peripheral circuit portion has the same structure as the first gate portion 33a of the memory cell portion, the peripheral circuit portion is simultaneously formed when the memory cell portion is formed. It can be formed, and the manufacturing process can be simplified and efficient.
Although the third conductor film 53a or 53b and the refractory metal film (fourth conductor film) 42 are separately formed here, they may be formed simultaneously as a common refractory metal film. Good.

Example 4
-Manufacture of magnetic heads-
Example 4 relates to the manufacture of a magnetic head as an application example of the resist pattern of the present invention using the resist pattern thickening material of the present invention. In Example 4, the following resist patterns 102 and 126 were thickened by the same method as in Example 1 using the resist pattern thickening material of the present invention.

12A to 12D are process diagrams for explaining the manufacture of the magnetic head.
First, as shown in FIG. 12 (A), a resist film is formed on the interlayer insulating layer 100 so as to have a thickness of 6 μm, and exposure and development are performed to form an opening pattern for forming a spiral thin film magnetic coil. A resist pattern 102 having the following was formed.
Next, as shown in FIG. 12B, a thickness of 0.01 μm is formed on the interlayer insulating layer 100 on the resist pattern 102 and the portion where the resist pattern 102 is not formed, that is, on the exposed surface of the opening 104. A plating base layer 106 formed by laminating a Ti adhesion film and a Cu adhesion film having a thickness of 0.05 μm was formed by vapor deposition.
Next, as shown in FIG. 12C, a portion of the interlayer insulating layer 100 where the resist pattern 102 is not formed, that is, the surface of the plating base layer 106 formed on the exposed surface of the opening 104 is formed. A thin film conductor 108 made of a Cu plating film having a thickness of 3 μm was formed.
Next, as shown in FIG. 12D, when the resist pattern 102 is dissolved and removed and lifted off from the interlayer insulating layer 100, a thin film magnetic coil 110 having a spiral pattern of the thin film conductor 108 is formed.
A magnetic head was manufactured as described above.

  In the magnetic head obtained here, since the spiral pattern is finely formed by the resist pattern 102 thickened using the resist pattern thickening material of the present invention, the thin film magnetic coil 110 is fine and fine. In addition, it is excellent in mass productivity.

13 to 18 are process diagrams for explaining the manufacture of another magnetic head.
As shown in FIG. 13, a gap layer 114 was formed on a nonmagnetic substrate 112 made of ceramic by a sputtering method. Although not shown, an insulating layer made of silicon oxide and a conductive underlayer made of Ni—Fe permalloy are previously formed on the nonmagnetic substrate 112 by sputtering, and the lower magnetic layer made of Ni—Fe permalloy is formed. A layer is formed. Then, a resin insulating film 116 was formed from a thermosetting resin in a predetermined region on the gap layer 114 excluding a portion that becomes a magnetic tip of the lower magnetic layer (not shown). Next, a resist material was applied onto the resin insulating film 116 to form a resist film 118.

  Next, as shown in FIG. 14, the resist film 118 was exposed and developed to form a spiral pattern. Then, as shown in FIG. 15, the resist film 118 having the spiral pattern was subjected to a thermosetting process at several hundred degrees C. for about one hour to form a first spiral pattern 120 having a protrusion shape. Further, a conductive base layer 122 made of Cu was formed on the surface.

Next, as shown in FIG. 16, a resist material is applied onto the conductive base layer 122 by spin coating to form a resist film 124, and then the resist film 124 is patterned on the first spiral pattern 120. A resist pattern 126 was formed.
Next, as shown in FIG. 17, a Cu conductor layer 128 was formed by plating on the exposed surface of the conductive base layer 122, that is, on the portion where the resist pattern 126 was not formed. Thereafter, as shown in FIG. 18, the resist pattern 126 was dissolved and removed to lift off the conductive base layer 122, and a spiral thin film magnetic coil 130 formed of the Cu conductor layer 128 was formed.
As described above, as shown in the plan view of FIG. 19, a magnetic head having the magnetic layer 132 on the resin insulating film 116 and the thin film magnetic coil 130 provided on the surface was manufactured.

  In the magnetic head obtained here, the spiral pattern is finely formed by the resist pattern 126 thickened using the resist pattern thickening material of the present invention, so that the thin film magnetic coil 130 is fine and fine. In addition, it is excellent in mass productivity.

Here, it will be as follows if the preferable aspect of this invention is appended.
(Supplementary Note 1) A resist pattern thickening material comprising a resin, a crosslinking agent, and a nitrogen-containing compound.
(Supplementary note 2) The resist pattern thickening material according to supplementary note 1, wherein the nitrogen-containing compound is a basic compound.
(Supplementary note 3) The resist pattern thickening material according to supplementary note 1 or 2, wherein the nitrogen-containing compound is selected from amines, amides, imides, quaternary ammoniums, and derivatives thereof.
(Supplementary note 4) The resist pattern thickening material according to any one of supplementary notes 1 to 3, which is water-soluble or alkali-soluble.
(Additional remark 5) The resist pattern thickening material in any one of Additional remark 1 to 4 containing surfactant.
(Additional remark 6) The resist pattern thickening material of Additional remark 5 whose surfactant is a nonionic surfactant.
(Appendix 7) Nonionic surfactant is a polyoxyethylene-polyoxypropylene condensate compound, polyoxyalkylene alkyl ether compound, polyoxyethylene alkyl ether compound, polyoxyethylene derivative compound, sorbitan fatty acid ester compound, glycerin fatty acid Select from ester compounds, primary alcohol ethoxylate compounds, phenol ethoxylate compounds, alkoxylate surfactants, fatty acid ester surfactants, amide surfactants, alcohol surfactants, and ethylenediamine surfactants The resist pattern thickening material according to appendix 6, which is at least one of the above.
(Supplementary note 8) The resist pattern thickening material according to any one of supplementary notes 1 to 7, wherein the resin is at least one selected from polyvinyl alcohol, polyvinyl acetal, and polyvinyl acetate.
(Additional remark 9) The resist pattern thickening material in any one of Additional remark 1 to 8 whose crosslinking agent is at least 1 sort (s) selected from a melamine derivative, a urea derivative, and a uril derivative.
(Additional remark 10) The resist pattern thickening material in any one of Additional remark 1 to 9 containing a water-soluble aromatic compound.
(Appendix 11) The water-soluble aromatic compound is at least one selected from a polyphenol compound, an aromatic carboxylic acid compound, a naphthalene polyhydric alcohol compound, a benzophenone compound, a flavonoid compound, a derivative thereof, and a glycoside thereof. The resist pattern thickening material according to appendix 10.
(Additional remark 12) The resist pattern thickening material in any one of Additional remark 1 to 11 containing resin which has an aromatic compound in part.
(Supplementary note 13) The resist pattern thickness according to supplementary note 12, wherein the resin partly having an aromatic compound is at least one selected from polyvinyl aryl acetal resins, polyvinyl aryl ether resins, and polyvinyl aryl ester resins. Meat material.
(Supplementary note 14) The resist pattern thickening material according to any one of supplementary notes 1 to 13, comprising an organic solvent.
(Supplementary note 15) In Supplementary note 14, the organic solvent is at least one selected from alcohol solvents, chain ester solvents, cyclic ester solvents, ketone solvents, chain ether solvents, and cyclic ether solvents. The resist pattern thickening material described.
(Additional remark 16) After forming a resist pattern, the resist pattern thickening material in any one of Additional remark 1 to 15 is apply | coated so that the surface of this resist pattern may be covered.
(Additional remark 17) After forming a resist pattern, the resist pattern thickening material in any one of additional remarks 1-15 is apply | coated so that the surface of this resist pattern may be covered, The manufacturing method of the resist pattern characterized by the above-mentioned.
(Supplementary Note 18) At least the material of the resist pattern is selected from a novolak resist, a PHS resist, an acrylic resist, a cycloolefin-maleic anhydride resist, a cycloolefin resist, and a cycloolefin-acryl hybrid resist 18. The method for producing a resist pattern according to appendix 17, which is one type.
(Additional remark 19) The manufacturing method of the resist pattern of Additional remark 17 or 18 which performs development processing of this resist pattern thickening material after application | coating of a resist pattern thickening material.
(Additional remark 20) The semiconductor device characterized by having the pattern formed using the resist pattern thickened using the resist pattern thickening material in any one of Additional remarks 1-15.
(Appendix 21) After forming a resist pattern on the underlayer, the resist pattern is thickened by applying the resist pattern thickening material according to any one of appendices 1 to 15 so as to cover the surface of the resist pattern. A thickened resist pattern forming step for forming a thickened resist pattern; and a patterning step for patterning the underlayer by etching using the thickened resist pattern. Method.

The resist pattern thickening material of the present invention thickens a resist pattern made of ArF resist or the like, and uses light at the time of patterning exposure, while exceeding the light exposure limit, a pattern such as a resist omission pattern or a wiring pattern The resist pattern thickening material of the present invention can be suitably applied to various patterning methods, semiconductor manufacturing methods, and the like. And the method for manufacturing a semiconductor device of the present invention can be used particularly preferably.
The method for producing a resist pattern of the present invention includes, for example, a mask pattern, a reticle pattern, a magnetic head, an LCD (liquid crystal display), a PDP (plasma display panel), a SAW filter (surface acoustic wave filter) and other functional parts, The present invention can be suitably applied to the manufacture of optical components used for connection, fine components such as microactuators, and semiconductor devices, and can be preferably used in the method of manufacturing a semiconductor device of the present invention.
The semiconductor device manufacturing method of the present invention can be suitably used for manufacturing various semiconductor devices including flash memory, DRAM, FRAM, and the like.

FIG. 1 is a schematic view for explaining the mechanism of thickening a resist pattern (inner layer range pattern) using the resist pattern thickening material of the present invention. FIG. 2 is a schematic view for explaining an example of a method for producing a resist pattern of the present invention. FIG. 3 is a schematic diagram for explaining an example of a process for manufacturing a semiconductor device having a multilayer wiring structure by the method for manufacturing a semiconductor device of the present invention (part 1). FIG. 4 is a schematic diagram for explaining an example of a process for manufacturing a semiconductor device having a multilayer wiring structure by the method for manufacturing a semiconductor device of the present invention (part 2). FIG. 5 is a schematic diagram for explaining an example of a process for manufacturing a semiconductor device having a multilayer wiring structure by the method for manufacturing a semiconductor device of the present invention (part 3). FIG. 6 is a top view for explaining a FLASH EPROM which is an example of the semiconductor device of the present invention. FIG. 7 is a schematic cross-sectional view (No. 1) for explaining the manufacturing method of the FLASH EPROM as an example relating to the manufacturing method of the semiconductor device of the present invention. FIG. 8 is a schematic cross-sectional view (No. 2) for explaining the manufacturing method of the FLASH EPROM which is an example relating to the manufacturing method of the semiconductor device of the present invention. FIG. 9 is a schematic cross-sectional view (No. 3) for explaining the manufacturing method of the FLASH EPROM which is an example relating to the manufacturing method of the semiconductor device of the present invention. FIG. 10 is a schematic cross-sectional view for explaining a manufacturing method of FLASH EPROM which is another example of the manufacturing method of the semiconductor device of the present invention. FIG. 11 is a schematic cross-sectional view for explaining a method for manufacturing a FLASH EPROM, which is another example of the method for manufacturing a semiconductor device of the present invention. FIG. 12 is a schematic cross-sectional view for explaining an example in which a resist pattern thickened using the resist pattern thickening material of the present invention is applied to the manufacture of a magnetic head. FIG. 13 is a schematic cross-sectional view for explaining another example process (part 1) in which a resist pattern thickened using the resist pattern thickening material of the present invention is applied to the manufacture of a magnetic head. FIG. 14 is a schematic cross-sectional view for explaining another example process (part 2) in which the resist pattern thickened using the resist pattern thickening material of the present invention is applied to the manufacture of a magnetic head. FIG. 15 is a schematic cross-sectional view for explaining another example process (No. 3) in which a resist pattern thickened using the resist pattern thickening material of the present invention is applied to the manufacture of a magnetic head. FIG. 16 is a schematic cross-sectional view for explaining another example process (part 4) in which the resist pattern thickened using the resist pattern thickening material of the present invention is applied to the manufacture of a magnetic head. FIG. 17 is a schematic cross-sectional view for explaining another example process (No. 5) in which a resist pattern thickened using the resist pattern thickening material of the present invention is applied to the manufacture of a magnetic head. FIG. 18 is a schematic cross-sectional view for explaining another example process (No. 6) in which a resist pattern thickened using the resist pattern thickening material of the present invention is applied to the manufacture of a magnetic head. FIG. 19 is a plan view showing an example of the magnetic head manufactured in the steps of FIGS.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resist pattern thickening material 3 Resist pattern 3a Resist material 5 Underlayer (base material)
DESCRIPTION OF SYMBOLS 10 Thickening resist pattern 10a Surface layer 10b Inner layer resist pattern 11 Silicon substrate 12 Interlayer insulating film 13 Titanium film 14 Resist pattern 15a Opening 15b Opening 16 TiN film 17 Cu film 17a First layer wiring 18 Interlayer insulating film 19 Cu plug 20 Second-layer wiring 21 Third-layer wiring 22 Si substrate (semiconductor substrate)
23 field oxide film 24a first gate insulating film 24b second gate insulating film 25a first threshold control layer 25b second threshold control layer 26 resist film 27 resist film 28 first polysilicon layer (first conductor film)
28a Floating gate electrode 28b Gate electrode (first polysilicon film)
28c Floating gate electrode 29 Resist film 30a Capacitor insulating film 30b Capacitor insulating film 30c Capacitor insulating film 30d SiO ₂ film 31 Second polysilicon layer (second conductor film)
31a control gate electrode 31b second polysilicon film 32 resist film 33a first gate portion 33b second gate portion 33c second gate portion 34 resist film 35a S / D (source / drain) region layer 35b S / D (source / drain) ) Region layer 36a S / D (source / drain) region layer 36b S / D (source / drain) region layer 37 interlayer insulating film 38a contact hole 38b contact hole 39a contact hole 39b contact hole 40a S / D (source / drain) Electrode 40b S / D (source / drain) electrode 41a S / D (source / drain) electrode 41b S / D (source / drain) electrode 42 refractory metal film (fourth conductor film)
42a refractory metal film (fourth conductor film)
42b refractory metal film (fourth conductor film)
44a First gate portion 44b Second gate portion 45a S / D (source / drain) region layer 45b S / D (source / drain) region layer 46a S / D (source / drain) region layer 46b S / D (source / drain) region layer Drain) region layer 47 Interlayer insulating film 48a Contact hole 48b Contact hole 49a Contact hole 49b Contact hole 50a S / D (source / drain) electrode 50b S / D (source / drain) electrode 51a S / D (source / drain) electrode 51b S / D (Source / Drain) Electrode 52a Opening 52b Opening 53a Refractory Metal Film (Third Conductor Film)
53b refractory metal film (third conductor film)
54 Insulating film 100 Interlayer insulating layer 102 Resist pattern 104 Opening 106 Plating underlayer 108 Thin film conductor (Cu plating film)
DESCRIPTION OF SYMBOLS 110 Thin film magnetic coil 112 Nonmagnetic board | substrate 114 Gap layer 116 Resin insulating layer 118 Resist film 118a Resist pattern 120 1st spiral pattern 122 Conductive underlayer 124 Resist film 126 Resist pattern 128 Cu conductor film 130 Thin film magnetic coil 132 Magnetic layer

Claims (6)

After forming a resist pattern with an ArF resist, a resist pattern thickness containing a resin, a crosslinking agent, a nitrogen-containing compound, and a primary alcohol ethoxylate so as to cover the surface of the resist pattern formed with the ArF resist A method for producing a resist pattern, which comprises applying a meatizing material. The method for producing a resist pattern according to claim 1, wherein the nitrogen-containing compound is a quaternary ammonium salt.   The method for producing a resist pattern according to claim 1, wherein after the application of the resist pattern thickening material, development processing of the resist pattern thickening material is performed. Contains a resin, a crosslinking agent, a nitrogen-containing compound, and a primary alcohol ethoxylate so as to cover the surface of the resist pattern formed with the ArF resist after forming a resist pattern with the ArF resist on the underlayer. A thickened resist pattern forming step of forming a thickened resist pattern by thickening the resist pattern by applying a resist pattern thickening material, and etching the lower resist pattern by etching using the thickened resist pattern. And a patterning step of patterning the formation. The method for manufacturing a semiconductor device according to claim 4, wherein the nitrogen-containing compound is a quaternary ammonium salt. Contains a resin, a crosslinking agent, a nitrogen-containing compound, and a primary alcohol ethoxylate so as to cover the surface of the resist pattern formed with the ArF resist after forming a resist pattern with the ArF resist on the underlayer. A thickened resist pattern forming step of forming a thickened resist pattern by thickening the resist pattern by applying a resist pattern thickening material, and etching the lower resist pattern by etching using the thickened resist pattern. And a patterning step of patterning the formation.