JP3225599B2 - Method for developing negative photoresist film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved method for developing a negative-type photoresist film used in a resist for manufacturing a highly integrated circuit which is sensitive to various radiations.

[0002]

2. Description of the Related Art In a lithography process for fine processing represented by the manufacture of highly integrated circuit elements, a positive resist using a novolak resin and a quinonediazide compound is known as a typical resist. With the diversification of highly integrated circuits in recent years, the demand for a thick-film resist has been increasing. However, in the above-described positive resist film, the sensitivity is remarkably reduced as the thickness of the resist is increased. Is a drawback. Therefore, negative resists are attracting attention as thick-film resists. Negative resists have a larger amount of dissolution during development than positive resists. In the paddle method, that is, a method of forming a liquid pool using the surface tension of a developing solution on a photoresist film formed on a substrate and performing static development, the developability decreases as the development proceeds. However, it is difficult to efficiently dissolve and remove the components to be dissolved, and it is difficult to obtain a satisfactory resist pattern.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved developing method capable of efficiently developing a particularly thick negative resist film.

[0004]

According to the present invention, the above objects are achieved by (i) an alkali-soluble resin, and (ii) irradiation with radiation.
A negative photoresist film having a thickness of 2 to 10 μm formed by applying a negative photoresist composition containing a compound generating a phosphoric acid and (iii) a crosslinking agent on a substrate is developed. When the photoresist film is dissolved in an aqueous solution of an alkaline compound,
A substantially fresh developing solution consisting of a liquid, is used in highly integrated circuit fabrication resist characterized that you continuously fed
This is achieved by a method for developing a negative photoresist film. Hereinafter, the present invention will be described specifically,
The purpose, structure and effect of the present invention will be clear.

Negative photoresist composition A negative photoresist film developed according to the present invention is formed by coating a negative photoresist composition on a substrate. Such a negative photoresist composition contains (i) an alkali-soluble resin, (ii) a compound capable of generating an acid upon irradiation with radiation (hereinafter, referred to as “acid generator”), and (iii) a crosslinking agent. Can be listed. Hereinafter, each component constituting the negative photoresist composition will be sequentially described.

(I) Alkali-Soluble Resin The alkali-soluble resin is not particularly limited as long as it has a property of being soluble in a developer comprising an aqueous solution of an alkaline compound. Preferred examples thereof include novolak resin and poly (hydroxy) resin. (Styrene) -based resin.

The novolak resin is obtained by polycondensing phenols and aldehydes in the presence of an acid catalyst. Examples of the phenols include phenol, o
-Cresol, m-cresol, p-cresol, o-
Ethylphenol, m-ethylphenol, p-ethylphenol, o-butylphenol, m-butylphenol, p-butylphenol, 2,3-xylenol,
2,4-xylenol, 2,5-xylenol, 3,4
-Xylenol, 3,5-xylenol, 2,3,5-
Trimethylphenol, 3,4,5-trimethylphenol, p-phenylphenol, hydroquinone, catechol, resorcinol, 2-methylresorcinol,
Examples include pyrogallol, 1-naphthol, 2-naphthol, bisphenol A, dihydroxybenzoic acid ester, and gallic acid ester. These phenols are used alone or in combination of two or more.

The aldehydes include, for example, formaldehyde, acetaldehyde, propylaldehyde, benzaldehyde, phenylacetaldehyde,
α-phenylpropylaldehyde, β-phenylpropylaldehyde, o-hydroxybenzaldehyde, m-
Hydroxybenzaldehyde, p-hydroxybenzaldehyde, o-chlorobenzaldehyde, m-chlorobenzaldehyde, p-chlorobenzaldehyde, o-nitrobenzaldehyde, m-nitrobenzaldehyde,
p-Nitrobenzaldehyde, o-methylbenzaldehyde, m-methylbenzaldehyde, p-methylbenzaldehyde, p-ethylbenzaldehyde, pn-butylbenzaldehyde, furfural and the like are used.
Of these, formaldehyde is particularly preferred. These aldehydes are used alone or in combination of two or more.

When formaldehyde is used as the aldehyde, the formaldehyde generating sources include, for example, formalin, trioxane, paraformaldehyde, hemiformals (eg, methylhemiformal, ethylhemiformal, propylhemiformal, butylhemiformal, phenylhemiformal, etc.). And the like. Of these, formalin and butyl hemiformal are particularly preferred. The amount of aldehydes used is
0.7 to 3 mol is preferable for 1 mol of phenols.

The acid catalyst used for the polycondensation of phenols and aldehydes includes, for example, hydrochloric acid, nitric acid, sulfuric acid, formic acid, oxalic acid, acetic acid, p-toluenesulfonic acid and the like. The amount of these acidic catalysts used is
Usually, 1 × 10 ^{−4 to} 5 × 1 per mole of phenols
0 ^-1 mol.

In the polycondensation of a phenol and an aldehyde, water is usually used as a reaction medium. However, when the phenol used is not dissolved in an aqueous solution of the aldehyde and becomes non-uniform from the beginning of the reaction. Alternatively, a hydrophilic solvent can be used as a reaction medium. Examples of the hydrophilic solvent include methanol, ethanol, propanol, butanol, tetrahydrofuran, dioxane and the like. The amount of the reaction medium used is usually 20 to 1,000 parts by weight per 100 parts by weight of the reaction raw material.

The polycondensation method of phenols and aldehydes includes a method of charging phenols, aldehydes, and an acid catalyst at a time, a method of preparing phenols in the presence of an acid catalyst,
A method of gradually adding aldehydes or the like during the reaction can be employed. The temperature of the polycondensation of phenols and aldehydes is usually from 10 to 200 ° C. After completion of the polycondensation, for example, the temperature of the reaction system is raised to 130 to 230 ° C., and volatile components are removed under reduced pressure, and the generated novolak resin is recovered.

The poly (hydroxystyrene) resin is a polymer having a repeating unit corresponding to a structure in which the unsaturated bond of hydroxystyrene or a derivative thereof is cleaved. Examples of the hydroxystyrene or a derivative thereof include o-hydroxystyrene, m-hydroxystyrene, p-hydroxystyrene, and 3-chloro-4.
-Hydroxystyrene, 4-chloro-3-hydroxystyrene, 4-bromo-3-hydroxystyrene, 3-ethyl-4-hydroxystyrene, 3-propyl-4-hydroxystyrene, 3-t-butyl-4-hydroxystyrene , 3-phenyl-4-hydroxystyrene, 3-
Naphthyl-4-hydroxystyrene, 3-benzyl-4
-Hydroxystyrene, styryl-4-hydroxystyrene, 3-vinyl-4-hydroxystyrene, 3-propenyl-4-hydroxystyrene, 3-cumyl-4-hydroxystyrene, 2-methyl-4-hydroxystyrene, 2,6 -Dimethyl-4-hydroxystyrene and the like.

The poly (hydroxystyrene) resin may be, for example, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, glycidyl acrylate, glycidyl methacrylate,
Propyl acrylate, propyl methacrylate, methyl vinyl ether, t-butyl vinyl ether, styrene,
α-methylstyrene, p-methylstyrene, chlorostyrene, maleic anhydride, vinyl acetate, vinylpyridine,
It may contain a repeating unit in which unsaturated bonds such as vinylpyrrolidone, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, methyl vinyl ketone, ethyl vinyl ketone, vinyl dimethylamine, vinyl diethylamine, methyl vinyl thioether, and ethyl vinyl thioether are cleaved. it can.

The alkali-soluble resin can also be used as a hydrogenated product. The hydrogenation rate is usually 70% or less, preferably 50% or less, more preferably 40% or less.

The alkali-soluble resin used in the present invention has a polystyrene-equivalent weight average molecular weight (hereinafter referred to as “M”).
w ". ) Is preferably from 2,000 to 30,000. If the Mw is less than 2,000, it becomes difficult to form a resist film, and the developability, heat resistance, and the like tend to decrease. If the Mw exceeds 30,000, the filterability of the photoresist composition solution deteriorates. Along with
Developability also tends to deteriorate.

The alkali-soluble resins in the present invention can be used alone or in combination of two or more.

(Ii) Acid generator Examples of the acid generator include onium salts, halogen-containing compounds, diazoketone compounds, sulfone compounds, nitrobenzyl compounds, sulfonic acid compounds and the like. Specific examples thereof include the compounds shown below.

Onium salts: iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, ammonium salts and the like. Preferred onium salts are compounds represented by the following formulas (1) to (3).

[0020]

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[0021]

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[0022]

Embedded image

[In the formulas (1) to (3), R ^{1 to} R ³ may be the same or different, and represent a hydrogen atom, an amino group, a nitro group, a cyano group, an alkyl group (preferably having 1 to 4 carbon atoms).
Or an alkoxy group (preferably having 1 to 4 carbon atoms), and X represents SbF ₆ , AsF ₆ , PF ₆ , BF ₄ , CF ₃ CO ₂ , ClO ₄ , CF ₃ S
O ₃ ,

Embedded image Here, R ⁴ is a hydrogen atom, an amino group, an anilino group, an alkyl group (preferably having 1 to 4 carbon atoms) or an alkoxy group (preferably having 1 to 4 carbon atoms). ｝,

Embedded image ｛Where R ⁵ is an alkoxy group (preferably having 1 to carbon atoms)
4), and each R ⁵ may be the same or different. ｝,

Embedded image Here, R ⁶ is a hydrogen atom, an amino group, an anilino group, an alkyl group (preferably having 1 to 4 carbon atoms) or an alkoxy group (preferably having 1 to 4 carbon atoms). ｝ Or

Embedded image Is shown. ]

Particularly preferred onium salts are triphenylsulfonium trifluoromethanesulfonic acid, triphenylsulfonium hexafluoroantimonate, diphenyliodonium triflate, diphenyliodonium hexafluoroantimonate and the like. Halogen-containing compounds: haloalkyl group-containing hydrocarbon compounds, haloalkyl group-containing heterocyclic compounds, and the like. Preferred halogen-containing compounds are compounds represented by the following formulas (4) and (5). [In the formula (4), R ⁷ represents a trichloromethyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted naphthyl group, or a substituted or unsubstituted phenylvinyl group. ]

Halogen-containing compounds: haloalkyl group-containing hydrocarbon compounds, haloalkyl group-containing heterocyclic compounds and the like. Preferred halogen-containing compounds are represented by the following formulas (4) to (4).
It is a compound represented by (5).

Embedded image [In the formula (4), R ⁷ represents a trichloromethyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted naphthyl group, or a substituted or unsubstituted phenylvinyl group. ]

[0026]

Embedded image [In the formula (5), R ^{8 to} R ¹⁰ may be the same or different and represent a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, or a hydroxyl group. ]

Particularly preferred halogen-containing compounds are 1,1
1-bis (4-chlorophenyl) -2,2,2-trichloroethane, phenyl-bis (trichloromethyl) -s
-Triazine, methoxyphenyl-bis (trichloromethyl) -s-triazine, naphthyl-bis (trichloromethyl) -s-triazine, methoxynaphthyl-bis (trichloromethyl) -s-triazine and the like.

Diazoketone compound: 1,3-diketo-2
-Diazo compounds, diazobenzoquinone compounds, diazonaphthoquinone compounds and the like. Preferred diazoketone compounds are
It is a compound represented by the following formulas (6) to (10).

Embedded image [In the formula (6), R ¹¹ and R ¹² may be the same or different and represent an alkyl group (preferably having 1 to 4 carbon atoms) or a substituted or unsubstituted aryl group (preferably having 6 to 20 carbon atoms). . ]

[0029]

Embedded image

[0030]

Embedded image

[0031]

[0032] [In the formulas (9) and (10), R ¹³ is Are ^{shown, R 14} is _{-CH 2 -, - C (CH} 3) 2 -, -
CO- or -SO ₂ - ^{indicates, R 15} represents a hydrogen atom or a methyl group, m is an integer from 1 to 6, n represents an integer of 0 to 5, an m + n = 1-6. ]

Particularly preferred diazoketone compounds are 1,1
2-naphthoquinonediazide-4-sulfonyl chloride,
1,2-naphthoquinonediazido-4-sulfonic acid ester of 2,3,4,4'-tetrahydroxybenzophenone, 1,2-naphthoquinonediazide-4-sulfonic acid of 1,1,1-tris (4-hydroxyphenylethane) Sulfonic acid ester, 1,2-naphthoquinonediazide-4-sulfonic acid ester of 1,1-bis (3,5-dimethyl-2-hydroxyphenyl) -1- [4- (4-hydroxybenzyl) phenyl] ethane and the like It is.

Sulfone compounds: β-ketosulfone compounds, β-sulfonylsulfone compounds and the like. Preferred sulfone compounds are compounds represented by the following formula (11).

Embedded image [In the formula (11), Y represents -CO- or -SO _2- ;
R ^{16 to} R ¹⁹ may be the same or different and represent a halogen atom or an alkyl group (preferably having 1 to 4 carbon atoms);
Is an integer of 0 to 3. ]

Particularly preferred sulfone compounds are 4-trisphenacylsulfone, mesylphenacylsulfone, bis (phenylsulfonyl) methane and the like.

Nitrobenzyl compounds: nitrobenzylsulfonate compounds, dinitrobenzylsulfonate compounds and the like. A preferred nitrobenzyl compound is represented by the following formula (1)
It is a compound represented by 2).

Embedded image [In the formula (12), s is an integer of 1 to 3, and R ²⁰
Represents an alkyl group (preferably having from 1 to 4 carbon atoms), R ²¹
Represents a hydrogen atom or a methyl group, and R ²² represents

Embedded image ｛Here, R ²³ is a hydrogen atom or an alkyl group (preferably having 1 to 4 carbon atoms). ｝,

Embedded image ｛Wherein R ²⁴ is an alkoxy group (preferably having 1 to
4) and each R ²⁴ may be the same or different. ｝ Or

Embedded image Is shown. ]

Particularly preferred nitrobenzyl compounds are 2
-Nitrobenzyl tosylate, 2,4-dinitrobenzyl tosylate, 4-nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate and the like.

Sulfonic acid compounds: alkylsulfonic acid esters, haloalkylsulfonic acid esters, arylsulfonic acid esters, iminosulfonates and the like. Preferred sulfonic acid compounds are compounds represented by the following formulas (13) to (15).

Embedded image [In the formula (13), R ²⁵ and R ²⁸ may be the same or different and each represent a hydrogen atom or an alkyl group (preferably having 1 to 4 carbon atoms), and R ²⁶ and R ²⁷ may be the same or different; Hydrogen atom, alkyl group (preferably having 1 carbon atom)
To 4) or a substituted or unsubstituted aryl group (preferably having 6 to 20 carbon atoms). ]

[0039] [In the formula (14), R ²⁹ represents a hydrogen atom or an alkyl group (preferably having 1 to 4 carbon atoms); R ³⁰ and R ³¹ may be the same or different; and an alkyl group (preferably having 1 to 4 carbon atoms) ) Or a substituted or unsubstituted aryl group (preferably having 6 to 20 carbon atoms), or a ring structural unit formed by bonding to each other. ]

[0040]

Embedded image [In the formula (15), Z represents a fluorine atom or a chlorine atom. ]

Particularly preferred sulfonic acid compounds are benzoin tosylate, tris triflate of pyrogallol and the like.

These acid generators are used alone or in combination of two or more. The addition amount is usually 0.01 part with respect to 100 parts by weight of the alkali-soluble resin.
To 20 parts by weight, preferably 0.1 to 10 parts by weight.

(Iii) Crosslinking agent A crosslinking agent is a compound that crosslinks an alkali-soluble resin in the presence of an acid, for example, an acid generated by irradiation. The cross-linking agent is not particularly limited as long as it has the above-mentioned action. Preferred cross-linking agents include, for example, compounds having a substituent capable of cross-linking reaction. Examples of the substituent capable of crosslinking reaction include, for example, (Where p is 1 or 2, and Q ¹ is a single bond, —O—, —S—, —COO— or —N when p = 1.
Or showing a H-, or when p = 2, a trivalent nitrogen atom, ^{Q 2} represents -O- or -S-, i is an integer of from 0 to 3, j is an integer from 1 to 3 , I + j = 1 to 4. ) (Where Q ³ represents —O—, —COO— or —CO—, R ³² and R ³³ may be the same or different,
A hydrogen atom or an alkyl group having 1 to 4 carbon atoms;
³⁴ represents an alkyl group having 1 to 5 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 14 carbon atoms;
k is an integer of 1 or more. ) (Here, R ³⁵ , R ³⁶ and R ³⁷ may be the same or different and represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.) (Where R ³² and R ³³ may be the same or different and represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms;
R ³⁸ and R ³⁹ may be the same or different and represent an alkylol group having 1 to 5 carbon atoms, and k is an integer of 1 or more. ) (Where R ³² and R ³³ may be the same or different and represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms;
R ⁴⁰ represents a divalent organic group having a hetero atom of any one of an oxygen atom, a sulfur atom and a nitrogen atom and forming a 3- to 8-membered ring, and k is an integer of 1 or more. )

Specific examples of such a crosslinkable substituent include glycidyl ether, glycidyl ester, glycidylamino, methoxymethyl, ethoxymethyl, benzyloxymethyl, dimethylaminomethyl, and diethylaminomethyl. Groups, dimethylolaminomethyl group, diethylolaminomethyl group, morpholinomethyl group, acetoxymethyl group, benzoyloxymethyl group, formyl group, acetyl group, vinyl group, isopropenyl group and the like.

Specific examples of the compound having a substituent capable of undergoing a crosslinking reaction include bisphenol A-based epoxy compounds, bisphenol F-based epoxy compounds, bisphenol S-based epoxy compounds, novolak resin-based epoxy compounds, resol resin-based epoxy compounds, and poly ( (Hydroxystyrene) -based epoxy compound, methylol group-containing melamine compound, methylol group-containing benzoguanamine compound, methylol group-containing urea compound, methylol group-containing phenol compound, alkoxyalkyl group-containing melamine compound, alkoxyalkyl group-containing benzoguanamine compound, alkoxyalkyl group-containing urea Compound, alkoxyalkyl group-containing phenol compound, carboxymethyl group-containing melamine compound, carboxymethyl group-containing benzoguanamine compound, carboxy Methyl group-containing urea compounds, mention may be made of carboxymethyl group-containing phenol compounds and the like.

Among these aromatic compounds, methylol group-containing phenol compounds, methoxymethyl group-containing melamine compounds, methoxymethyl group-containing phenol compounds and acetoxymethyl group-containing phenol compounds are preferred.

The amount of these crosslinking agents is preferably 5 to 95 parts by weight, more preferably 15 to 85 parts by weight, and particularly preferably 20 to 75 parts by weight, based on 100 parts by weight of the alkali-soluble resin. If the amount of the crosslinking agent is less than 5 parts by weight, it is difficult to cause a sufficient crosslinking reaction, and it is easy to cause a decrease in the residual film ratio, meandering or swelling of the pattern. The amount tends to increase, and the developability tends to deteriorate.

As the cross-linking agent, those obtained by introducing a cross-linkable substituent into the alkali-soluble resin to impart cross-linkability can also be used. In this case, the introduction ratio of the substituent is usually 5 to 60%, preferably 10 to 50%, based on the total amount of the acidic functional groups of the alkali-soluble resin.
%, More preferably 15 to 40%. If the introduction ratio of the substituent is less than 5%, it is difficult to cause a sufficient crosslinking reaction, and the reduction of the residual film ratio, meandering and swelling of the pattern are likely to occur. Tends to cause a decrease in alkali solubility, resulting in deterioration of developability.

(Iv) Other additives Various additives such as a surfactant, a sensitizer, an antihalation agent, an adhesion aid, a storage stabilizer and an antifoaming agent may be added to the negative photoresist composition. Can be blended.

Of these, surfactants have the effect of improving the coating properties, striation, developability and the like of the composition. Examples of such a surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether,
Nonionic surfactants such as polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyethylene glycol dilaurate, and polyethylene glycol distearate, as commercial products,
For example, KP341 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 (trade name, manufactured by Kyoeisha Yushi Kagaku Kogyo), F-Top EF301, EF303, EF3
52 (trade name, manufactured by Shin-Akita Kasei), Mega Fak F17
1, F172, F173 (trade name, manufactured by Dainippon Ink),
Florado FC430, FC431 (trade name, manufactured by Sumitomo 3M), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-1
03, SC-104, SC-105, SC-10
6 (trade name, manufactured by Asahi Glass) and the like. The amount of these surfactants is usually 2 parts by weight or less per 100 parts by weight of the solid content of the composition.

The sensitizer absorbs radiation energy,
It transfers the energy to the acid generator to increase the amount of generated acid, thereby improving the apparent sensitivity of the negative photoresist composition. The sensitizer used is not particularly limited as long as it has the above-mentioned action, and preferred examples thereof include acetophenones, benzophenones, naphthalenes, biacetyl, eosin, rose bengal, pyrenes, anthracenes, And phenothiazines. The compounding amount of the sensitizer is usually 50 parts by weight or less based on 100 parts by weight of the alkali-soluble resin.

Dyes and pigments are examples of the antihalation agent, and have an effect of reducing the effects of halation upon irradiation.

Photoresist Solution In forming a negative photoresist film to be treated according to the present invention, a negative photoresist composition is first dissolved in a solvent such that the concentration in terms of solid content is 5 to 60% by weight. After that, a solution is prepared, for example, by filtration with a filter having a pore size of about 0.2 μm.

Examples of the solvent used for preparing the solution include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dipropyl ether, Diethylene glycol dibutyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, toluene, xylene, methyl ethyl ketone, cyclohexanone, 2-heptanone, 3-heptanone, 4 Heptanone, 2-hydroxypropionic acid methyl, ethyl 2-hydroxypropionate, 2-hydroxy-2-methylpropionic acid ethyl,
Ethyl ethoxyacetate, ethyl hydroxyacetate, 2-hydroxy-3-methoxybutyl acetate, 3-methyl-
3-methoxybutyl propionate, 3-methyl-3-
Methoxybutyl butyrate, ethyl acetate, butyl acetate,
Examples include ethyl pyruvate, methyl acetoacetate, ethyl acetoacetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide. . These solvents are used alone or in combination of two or more.

The solvent may further include benzyl ethyl ether, dihexyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, acetonylacetone, isophorone, caproic acid, caprylic acid, 1-octanol, 1-octanol,
Nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate,
γ-butyrolactone, ethylene carbonate, propylene carbonate,
A high boiling point solvent such as phenyl cellosolve acetate can also be added.

Formation and radiation of negative photoresist film
When forming a line-irradiated negative photoresist film, the photoresist solution prepared as described above, by a method such as spin coating, casting coating, roll coating, for example, a silicon wafer, a wafer coated with aluminum And so on. In the formed negative type photoresist film,
Radiation is partially irradiated through a predetermined mask pattern (hereinafter, referred to as “exposure”). There is no particular limitation on the radiation used, for example, ultraviolet rays (g-rays, i-rays, etc.), far ultraviolet rays (including excimer lasers), X-rays, gamma rays,
Various radiations such as an electron beam, a molecular beam, and a proton beam are selected depending on the type of the acid generator. Exposure conditions such as radiation dose are appropriately selected according to the composition of the composition, the type of additive, and the like. In that case, it is preferable to perform a baking treatment after exposure. This firing temperature is usually 30 to 200
° C, preferably 50 to 150 ° C. The negative photoresist film is then developed with a developer according to the method of the present invention.

Developer The developer used in the present invention can develop a negative photoresist film formed by applying a negative photoresist composition on a substrate. Preferred developers include alkaline compounds such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, inorganic alkalis such as ammonia water, or primary amines such as ethylamine and n-propylamine; Secondary amines such as diethylamine and di-n-propylamine; tertiary amines such as triethylamine and methyldiethylamine; amino alcohols such as dimethylethanolamine and triethanolamine; tetramethylammonium hydroxide; tetraethylammonium hydroxide; Quaternary ammonium hydroxides such as propylammonium hydroxide, or choline, pyrrole, piperidine, 1,8-diazabicyclo- [5,4,0] -7-undecene, 1,5-diazabicycle - can be exemplified [4,3,0] -5-aqueous-mentioned organic alkali cyclic amines, such as nonene. The concentration of the alkaline compound in this case is usually 0.1
10 to 10% by weight, preferably 0.5 to 5% by weight. Further, a proper amount of a water-soluble organic solvent, for example, alcohols such as methanol and ethanol, a surfactant and the like can be added to the developer. When development is performed using a developer composed of an aqueous solution of these alkaline compounds, it is preferable to wash with water after development.

[0058]

Developing Method In the developing method of the present invention , an aqueous solution of an alkaline compound is applied to a negative photoresist film having a thickness of 2 to 10 μm formed by coating a negative photoresist composition on a substrate.
Substantially fresh developing solution comprising, carried out by Rukoto be continuously fed.

[0060]

[0061]

The development in the present invention can be specifically carried out by the following method (A). That is,
(A) On the negative photoresist film formed on the substrate,
A method in which a substantially fresh developer is continuously supplied by a spraying method, a dropping method, a falling method, or the like to perform development.

In a preferred embodiment of the developing method (a),
(A- 1 ) A method of developing while spraying a substantially fresh developing solution on a negative photoresist film, and this method is a particularly preferable developing method in the present invention. The (i -
In the method 1 ), it is preferable that the substrate on which the negative photoresist film is formed is rotated about 0.5 to 5 rotations per second so that the negative photoresist film always comes in contact with fresh developer.

[0064]

When the development is performed by the method (a- 1 ), the substrate can be moved at an appropriate speed, whereby it is not necessary to associate the substrate with only a specific developing solution supply means. Can be sequentially passed through the developing solution supply means, so that development can be performed in a so-called flow operation, and the development work efficiency can be improved.

[0066]

[0067]

In the present invention, the negative photoresist film is developed by continuously supplying a substantially fresh developing solution to the negative photoresist film so that the negative photoresist film has a thickness of 2 to 2.
Even if the thickness is 10 μm, development can be performed efficiently without lowering the developability, and sensitivity and resolution can be excellent.

[0069]

EXAMPLES The present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. The measurement of Mw and the evaluation of the developing method were performed by the following methods. Mw: Tosoh Corporation GPC column (G2000H _xL : 2
This, G3000H _xL: 1 this, _G4000H xL: 1
Using this method, the measurement was carried out by gel permeation chromatography using monodisperse polystyrene as a standard under the analysis conditions of a flow rate of 1.0 ml / min, an elution solvent of tetrahydrofuran, and a column temperature of 40 ° C. Sensitivity: Using an NSR-1755i7A reduced projection exposure apparatus (lens aperture coefficient: 0.50) manufactured by Nikon Corporation, changing the exposure time, and exposing with i-rays having a wavelength of 365 nm, an aqueous solution of tetramethylammonium hydroxide is used. Develop with
When a resist pattern is formed on a wafer by washing with water and drying, a minimum exposure amount (hereinafter referred to as “optimum exposure”) for forming a 2.0 μm line-and-space pattern (1L1S) in a one-to-one width. Amount "). The smaller the optimum exposure amount, the better the sensitivity. Resolution: The minimum dimension of the resist pattern that is resolved when exposed at the optimum exposure amount was defined as the resolution.

Example 1 A mixture of 97.33 g (0.9 mol) of m-cresol and 10.81 g (0.1 mol) of p-cresol was added to a 37% by weight aqueous solution of formalin 77.09 g (formaldehyde: 0.95 Mol) and 10 g of a novolak resin (Mw = 8,500) obtained by polycondensation, 2.5 g of a melamine-formaldehyde resin, and 2- (4'-
Dissolve 0.2 g of methoxy-1'-naphthyl) -4,6-bis (trichloromethyl) -1,3,5-triazine in 15.9 g of methyl 3-methoxypropionate and filter with a membrane filter having a pore size of 0.2 μm. After filtration, a negative photoresist composition solution was prepared. This solution was spin-coated on a 4-inch diameter silicon wafer using a spinner and prebaked on a hot plate at 90 ° C. for 120 seconds to form a photoresist film having a thickness of 6.0 μm. Next, after exposing through a mask, 90
Baking for 120 seconds on a hot plate at ° C. Then, 2.3 rotations of the silicon wafer are performed once per second.
Development was carried out using an 8% by weight aqueous solution of tetramethylammonium hydroxide at 25 ° C. for 60 seconds while spraying a fresh developer. Observation with a scanning electron microscope after development revealed that a negative line and space pattern of 1.0 μm was obtained at an exposure of 80 mJ / cm ² .

[0071]

COMPARATIVE EXAMPLE 1 In the same manner as in Example 1, the development by the paddle method at 25 ° C. for 60 seconds was performed in place of the development by spraying and supplying the developer.
The unexposed portions could not be dissolved and removed by development. Even if the development time was extended to 10 minutes, the unexposed portions could not be sufficiently dissolved and removed by development.

[0073]

According to the developing method of the present invention, the film thickness is 2 to 10 μm.
In addition to efficiently developing the negative photoresist film of m, a resist pattern with high sensitivity and high resolution can be obtained, and the workability of development can be improved. Therefore, the present invention greatly contributes to the manufacture of various highly integrated circuits.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Takao Miura 2--11-24 Tsukiji, Chuo-ku, Tokyo Japan Synthetic Rubber Co., Ltd. (56) References JP-A-63-109442 (JP, A) JP-A Sho 64-37549 (JP, A) JP-A-1-223448 (JP, A) JP-A-3-184050 (JP, A) JP-A-2-63060 (JP, A) (58) Fields investigated (Int. Cl. ^7, DB name) G03F 7/30 G03F 7/038 H01L 21/027

Claims (2)

(57) [Claims] (1 ) an alkali-soluble resin, (ii) radiation
Including a compound that generates an acid upon irradiation and (iii) a crosslinking agent.
When developing a negative photoresist film having a film thickness of 2 to 10 μm formed by applying a negative photoresist composition having the composition on a substrate, an alkaline compound is added to the photoresist film.
A substantially fresh developer consisting of an aqueous solution of
A highly integrated circuit fabrication resist characterized that you supply
A method for developing a negative photoresist film to be used . 2. When developing a negative photoresist film.
Then, an aqueous solution of an alkaline compound is applied to the photoresist film.
Developing while spraying a substantially fresh developing solution comprising
Item 1. The resist used for the production of highly integrated circuits according to Item 1.
A method for developing a photoresist film.